JP7634219B2 - Polycyclic aromatic compounds - Google Patents

Description

The present invention relates to polycyclic aromatic compounds, and organic devices using the same, such as organic electroluminescent elements, organic field-effect transistors, and organic thin-film solar cells, as well as display devices and lighting devices.

Display devices using electroluminescent light-emitting elements have been extensively studied because they can be made thin and energy-efficient. Furthermore, organic electroluminescent devices made from organic materials have been actively studied because they can be easily made large and lightweight. In particular, there has been active research into the development of organic materials that have the luminescence properties of blue, one of the three primary colors of light, and organic materials that have the ability to transport charges such as holes and electrons (potential to become semiconductors or superconductors), regardless of whether they are polymeric or low molecular weight compounds.

An organic EL element has a structure consisting of a pair of electrodes consisting of an anode and a cathode, and one or more layers containing an organic compound that are disposed between the pair of electrodes. Layers containing organic compounds include a light-emitting layer and a charge transport/injection layer that transports or injects charges such as holes and electrons, and various organic materials suitable for these layers have been developed.

There are three known types of light-emitting materials for organic EL elements: fluorescent materials, phosphorescent materials, and thermally activated delayed fluorescence (TADF) materials. The fluorescent materials that have traditionally been used have high color purity but low luminous efficiency. On the other hand, phosphorescent and TADF materials are expected to have luminous efficiency three to four times higher than fluorescent materials.

As phosphorescent materials, many studies have been reported, particularly on iridium complexes (for example, Patent Document 1).
Furthermore, in Patent Document 2, a compound in which a plurality of aromatic rings are condensed with a central atom such as boron is reported as a TADF material with high color purity.

As a material for the light-emitting layer of an organic EL element, a host material is generally used together with a light-emitting material (dopant material) to improve the light-emitting efficiency. As a host material, a molecule in which multiple existing aromatic rings such as benzene and carbazole are linked by single bonds, phosphorus atoms, or silicon atoms is generally used. This is because a large HOMO-LUMO gap (band gap Eg in a thin film) required for a host material is guaranteed by linking a large number of relatively small conjugated aromatic rings. Furthermore, a high lowest excited triplet energy level (E _T1 ) is also required for a host material of an organic EL element using a phosphorescent material or a TADF material, but by linking a donor or acceptor aromatic ring or a substituent to the molecule, SOMO1 and SOMO2 in the triplet excited state (T1) are localized, and the exchange interaction between the two orbitals is reduced, making it possible to improve E _T1 . However, small conjugated aromatic rings do not have sufficient redox stability, and an element using a molecule in which existing aromatic rings are linked as a host material does not have a sufficient life. On the other hand, polycyclic aromatic compounds having an extended π-conjugated system generally have excellent redox stability, but have been considered unsuitable as host materials due to their low HOMO-LUMO gap (band gap Eg in a thin film) and E _T1 .

International Publication No. 2001/41512 International Publication No. 2015/102118

As mentioned above, various materials have been developed for use in organic EL elements, but in order to further improve the organic EL characteristics, such as the light-emitting characteristics, and to increase the options for organic EL materials, such as materials for the light-emitting layer, there is a need to develop compounds that were not previously specifically known.

As a result of intensive research to solve the above problems, the present inventors have succeeded in improving charge transport properties and amorphous stability in a polycyclic aromatic compound in which multiple aromatic rings are linked by boron atoms and nitrogen atoms or oxygen atoms, etc., by introducing pyridinic nitrogen into the aromatic rings and further forming a structure having a specific substituent. They have also found that excellent organic EL devices can be obtained using this polycyclic aromatic compound, and have completed the present invention. In other words, the present invention provides the following polycyclic aromatic compounds, and further organic device materials containing the following polycyclic aromatic compounds.

<1> A polycyclic aromatic compound represented by the following formula (1):

In formula (1),
^X1 and ^X2 are each independently >N-R, >O, >C(-R) ₂ , >S or >Se, and ^X1 and ^X2 are not both >C(-R) ₂ ;
R in the >N-R and >C(-R) ₂ is independently hydrogen or any substituent selected from the substituent group YZ, and R in the >N-R and >C(-R) ₂ may be independently bonded to Y ¹ and/or Y ² , or Y ⁵ and/or Y ⁶ via a linking group or a single bond;
Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ each independently represent ═C(-R ^Y )- or ═N-, at least one of which is ═N-;
R and ^Y are each independently a group represented by formula (A-1) or formula (A-2), a hydrogen atom or a substituent selected from the group YZ of substituents excluding the group represented by formula (A-1), or a group represented by formula (21),
adjacent groups among R and ^Y may be bonded to each other to form a ring, and at least one hydrogen atom in the formed ring may be substituted with a group represented by formula (A-1) or formula (A-2), a substituent selected from the substituent group YZ excluding the group represented by formula (A-1), or a group represented by formula (21),
at least one of R 1 and R ² is a group represented by formula (A-1) or formula (A-2), provided that when R 1 and R ² are bonded to each other to form a ring, at least one selected from the group consisting of R 1 and R ² , which substitute a hydrogen atom in the ring, is a group represented by formula (A-1) or formula (A-2);
In formula (A-1),
W ¹ and W ² are each independently a single bond, >C(-R ^W ) ₂ , >N-R ^W , >O, >Si(-R ^W ) ₂ , >S, >SO or >SO ₂ ;
R ^W of the >N-R ^W is any substituent selected from the substituent group YZ, a group represented by formula (A-2) or a group represented by formula (21),
R ^W in the >C(-R ^W ) ₂ and >Si(-R ^W ) ₂ are each independently hydrogen, any substituent selected from the substituent group YZ, a group represented by formula (A-2) or a group represented by formula (21);
R and ^W that are bonded to the same element may be bonded to each other,
R in >N-R ^W , >C(-R ^W ) ₂ and >Si(-R ^W ) ₂ may each independently be bonded to at least one Z;
Z is -N= or -CR ^Z =, and R ^Z is each independently hydrogen, any substituent selected from the substituent group YZ, a group represented by formula (A-2), or a group represented by formula (21);
R and ^Z in adjacent Z may be bonded to each other to form an aryl ring or a heteroaryl ring, and the formed ring may have any substituent selected from the substituent group YZ, a group represented by formula (A-2), or a group represented by formula (21),
^L1 is a single bond or a linking group;
L ¹ is bonded to any C of -CR ^Z = through R ^Z as a bond, or to a ring-constituting atom of a ring formed by bonding R ^Z in Z to each other;
* indicates the bonding position of the group represented by formula (A-1),
In formula (A-2),
Ar ³ is each independently an aryl (excluding the group represented by formula (A-1)) which may be substituted with at least one substituent selected from the substituent group YZ or a group represented by formula (21), a heteroaryl (excluding the group represented by formula (A-1)) which may be substituted with at least one substituent selected from the substituent group YZ or a group represented by formula (21), or a group represented by formula (A-1),
^W3 is Si, P or S;
When W ³ is Si, m is 3 and n is 0; when W ³ is P, m is 2 and n is 0 or 1; when W ³ is S, m is 1 and n is an integer from 0 to 2;
^L2 is a single bond or a linking group;
* indicates the bonding position of the group represented by formula (A-2),
In formula (21),
X ²¹ and X ²² are each independently >N—R ^X21 , >O, >C(—R ^X21 ) ₂ , >S or >Se;
R ^X21 in >N-R ^X21 and >C(-R ^X21 ) ₂ is each independently hydrogen or any substituent selected from the substituent group YZ, and R ^X21 in >N-R ^X21 and >C(-R ^X21 ) ₂ may each independently be bonded to Y ²¹ and/or Y ²² , or Y ²⁵ and/or Y ²⁶ via a linking group or a single bond;
Y ²¹ , Y ²² , Y ²³ , Y ²⁴ , Y ²⁵ and Y ²⁶ each independently represent ═C(—R ^2Y )— or ═N—;
Each R ^2Y is independently hydrogen or any substituent selected from the substituent group YZ;
Adjacent groups among R ^2Y may be bonded to each other to form a ring, and at least one hydrogen atom in the formed ring may be substituted with a substituent selected from the substituent group YZ;
^L3 is a single bond or a linking group, and ^L3 is bonded to C via any one of ^R2Y as a bond, or is bonded to a ring-constituting atom of a ring formed by adjacent ^R2Ys being bonded to each other;
* indicates the bonding position of the group represented by formula (21),
the number of groups represented by formula (21) in the polycyclic aromatic compound is 0 to 2,
At least one hydrogen atom in the structure represented by formula (1) may be substituted with cyano, halogen or deuterium;
Substituent group YZ:
aryl optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl;
aryl, heteroaryl, heteroaryl optionally substituted with alkyl or cycloalkyl;
diarylamino optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl;
diheteroarylamino optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl;
arylheteroarylamino optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl;
diarylboryl optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl (two aryls may be bonded via a single bond or a linking group);
alkyl optionally substituted with aryl, heteroaryl, or cycloalkyl;
cycloalkyl optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl;
Alkoxy which may be substituted with aryl, heteroaryl, or cycloalkyl; and aryloxy which may be substituted with aryl, heteroaryl, alkyl, or cycloalkyl.

<2> L ¹ , L ² and L ³ are each independently a single bond or a linking group selected from the group consisting of arylene which may be substituted with aryl or heteroaryl, heteroarylene which may be substituted with aryl or heteroaryl, >N-R ^L , >O, >C(-R ^L ) ₂ , >Si(-R ^L ) ₂ , >S, >Se and a combination of two or more thereof;
The polycyclic aromatic compound according to <1>, wherein R ^L in >N-R ^L , >C(-R ^L ) ₂ and >Si(-R ^L ) ₂ in L ¹ , L ² or L ³ is each independently hydrogen, any substituent selected from the substituent group YZ, or a group represented by formula (A-2), and R ^Ls bonded to the same element may be bonded to each other.
<3> The polycyclic aromatic compound according to <1>, wherein ^L1 and ^L2 are each independently a linking group selected from the group consisting of arylene optionally substituted with aryl or heteroaryl, heteroarylene optionally substituted with aryl or heteroaryl, and a combination of two or more thereof, and ^L3 is a single bond.

<4> The polycyclic aromatic compound according to any one of <1> to <3>, wherein ^X1 and ^X2 are each independently >N—R or >O.
<5> Y ² , Y ³ , Y ⁴ and Y ⁵ each independently represent ═C(—R ^Y )—, and at least one of Y ¹ or Y ⁶ represents ═N—;
<4> The polycyclic aromatic compound according to any one of <1> to <4>.
<6> X ¹ and X ² are both >O,
Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ are each independently =C(-R ^Y )-; and Y ¹ is =N-;
The polycyclic aromatic compound according to <5>.

<7> The polycyclic aromatic compound according to any one of <1> to <6>, wherein, in formula (1), one or two of R ¹ and ^{Y 1} are groups represented by formula (A-1) or formula (A-2), and, when R ^{1 and Y} 1 are bonded to each other to form a ring, one or two selected from the group consisting of R 1 and Y 1 and a group substituting a hydrogen atom on the ring are groups represented by formula (A-1) or formula (A-2).
<8> In formula (1), at least one of R 1 and R ² is a group represented by formula (A-1), provided that when R 1 and R ² are bonded to each other to form a ring, at least one selected from the group consisting of R 1 and R ² , which replaces a hydrogen atom in the ring, is a group represented by formula (A-1);
W ¹ is >C(-R ^W ) ₂ , >O, >Si(-R ^W ) ₂ or >S, and W ² is a single bond;
<7> The polycyclic aromatic compound according to any one of <1> to <7>.
<9> In formula (1), at least one of R 1 and R ² is a group represented by formula (A-2), provided that when R 1 and R ² are bonded to each other to form a ring, at least one selected from the group consisting of R 1 and R ² , which substitute a hydrogen atom in the ring, is a group represented by formula (A-2),
^W3 is Si;
<8> The polycyclic aromatic compound according to any one of <1> to <8>.

<10> In formula (1),
When adjacent R and ^Y are not bonded to form a ring,
R ^Y other than the group represented by formula (A-1) or formula (A-2) is hydrogen, aryl which may be substituted with aryl or heteroaryl, or heteroaryl which may be substituted with aryl or heteroaryl,
When adjacent R and ^Y are bonded to form a ring,
Among the groups substituting hydrogen in the ring formed by R ^Y and adjacent R ^Ys bonding to each other, a group other than the group represented by formula (A-1) or formula (A-2) is hydrogen, an aryl which may be substituted with an aryl or a heteroaryl, or a heteroaryl which may be substituted with an aryl or a heteroaryl.
<9> The polycyclic aromatic compound according to any one of <1> to <9>.

<11> The polycyclic aromatic compound according to <1>, represented by the following formula (1-11):

<12> The polycyclic aromatic compound according to <1>, which is represented by the following formula (1-13):

<13> A reactive compound in which the polycyclic aromatic compound according to any one of <1> to <12> is substituted with a reactive substituent.
<14> A polymer compound obtained by polymerizing the reactive compound according to <13> as a monomer, or a crosslinked polymer obtained by further crosslinking the polymer compound.
<15> A pendant polymer compound in which the reactive compound according to <13> is substituted on a main chain polymer, or a pendant polymer crosslinked product in which the pendant polymer compound is further crosslinked.
<16> A material for an organic device, comprising the polycyclic aromatic compound according to any one of <1> to <12>.
<17> A material for an organic device, comprising the reactive compound according to <13>.
<18> A material for an organic device, comprising the polymer compound or crosslinked polymer according to <14>.
<19> A material for an organic device, comprising the pendant type polymer compound or the pendant type crosslinked polymer according to <15>.

<20> An organic electroluminescence device comprising a pair of electrodes consisting of an anode and a cathode, and an organic layer disposed between the pair of electrodes and containing the polycyclic aromatic compound according to any one of <1> to <12>, the reactive compound according to <13>, the polymer compound or crosslinked polymer according to <14>, or the pendant polymer compound or crosslinked polymer according to <15>.
<21> The organic electroluminescent device according to <20>, wherein the organic layer is an electron transport layer.
<22> The organic electroluminescent device according to <20>, wherein the organic layer is a light-emitting layer.
<23> The organic electroluminescent device according to <22>, wherein the light-emitting layer contains at least one selected from the group consisting of a light-emitting metal complex and a TADF material.

<24> The organic electroluminescent device according to <23>, wherein the light-emitting layer contains a polycyclic aromatic compound which is a monomer represented by formula (2) or a polymer having a plurality of structural units represented by formula (2).

ring A, ring B and ring C each independently represent an optionally substituted aryl ring or an optionally substituted heteroaryl ring, provided that in ring A, ring B and ring C in the monomer, none of the rings bonded to B and to ^X11 and/or ^X12 is a 6-membered ring containing nitrogen;
^X11 and ^X12 are each independently >O or >N-R, and R of the >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and R of the >N-R may be bonded to ring A and/or ring B or ring A and/or ring C via a linking group or a single bond;
In the structure represented by formula (2) or the structure having a plurality of structural units represented by formula (2), at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-;
At least one hydrogen atom in the structure represented by formula (2) or the structure having a plurality of structural units represented by formula (2) may be substituted with deuterium, cyano or halogen.

<25> The organic electroluminescence device according to any one of <22> to <24>, further comprising at least one of an electron transport layer and an electron injection layer disposed between the cathode and the light-emitting layer, wherein at least one of the electron transport layer and the electron injection layer contains at least one selected from the group consisting of borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, arylnitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes.
<26> The organic electroluminescent device according to <25>, wherein at least one of the electron transport layer and the electron injection layer further contains at least one selected from the group consisting of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal oxide, an alkali metal halide, an alkaline earth metal oxide, an alkaline earth metal halide, a rare earth metal oxide, a rare earth metal halide, an alkali metal organic complex, an alkaline earth metal organic complex, and a rare earth metal organic complex.

<27> The organic electroluminescence device according to any one of <22> to <25>, wherein at least one of the hole injection layer, the hole transport layer, the light-emitting layer, the electron transport layer and the electron injection layer comprises a polymer compound obtained by polymerizing a low molecular compound capable of forming each layer as a monomer, or a crosslinked polymer obtained by further crosslinking the polymer compound, or a pendant-type polymer compound obtained by reacting a low molecular compound capable of forming each layer with a main-chain polymer, or a pendant-type crosslinked polymer obtained by further crosslinking the pendant-type polymer compound.
<28> A display device or a lighting device comprising the organic electroluminescent device according to any one of <21> to <27>.

The present invention provides a novel compound that can be used as a material for organic devices such as organic EL elements. The polycyclic aromatic compound of the present invention can be used to increase the options for organic EL materials such as materials for light-emitting layers. The polycyclic aromatic compound of the present invention is expected to be used as an electron transport material, a phosphorescent material, or a host material for TADF materials.

1 is a schematic cross-sectional view showing an organic EL element according to an embodiment of the present invention. 1A to 1C are diagrams illustrating a method for producing an organic EL element on a substrate having a bank by using an inkjet method.

The present invention will be described in detail below. The following explanation of the constituent elements may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "~" means a range that includes the numerical values written before and after "~" as the lower and upper limits. In this specification, "hydrogen" in the explanation of the structural formula means "hydrogen atom (H)".

In this specification, chemical structures and substituents are sometimes expressed by the number of carbon atoms, but when a chemical structure is substituted with a substituent or when a substituent is further substituted with a substituent, the number of carbon atoms means the number of carbon atoms in each of the chemical structures and the substituents, and does not mean the total number of carbon atoms in the chemical structure and the substituents, or the total number of carbon atoms in the substituents and the substituents. For example, "substituent B of carbon number Y substituted with substituent A of carbon number X" means that "substituent B of carbon number Y" is substituted with "substituent A of carbon number X", and the carbon number Y is not the total number of carbon atoms in the substituents A and B. Also, for example, "substituent B of carbon number Y substituted with substituent A" means that "substituent B of carbon number Y" is substituted with "substituent A (with no carbon number limit)", and the carbon number Y is not the total number of carbon atoms in the substituents A and B.

1. Polycyclic aromatic compound represented by formula (1) The present invention relates to a polycyclic aromatic compound represented by formula (1). The polycyclic aromatic compound represented by formula (1) has a group represented by formula (A-1) or formula (A-2).

In the present invention, in the compound in which a plurality of aromatic rings are condensed with boron as the central atom described in International Publication No. 2015/102118, the pyridinic nitrogen of the electron-accepting element is arranged in the meta position with respect to boron (i.e., the positional relationship between the central element B and Y ¹ to Y ⁶ in the above formula (1)), thereby obtaining a stronger multiple resonance effect. In addition, by introducing pyridinic nitrogen as described above, the LUMO becomes deeper, the electron-accepting ability improves, and electron injection becomes favorable. Furthermore, when pyridinic nitrogen is included in the above specified position, both E _S1 (the lowest excited singlet energy level) and E _T1 (the lowest excited triplet energy level) become higher, and a structure having a large number of rings constituting the condensed ring as shown in formula (1) can be obtained while maintaining a wide gap. The polycyclic condensed ring increases the orbital overlap with adjacent molecules, improving carrier transportability.

Furthermore, in the present invention, a group represented by formula (A-1) or formula (A-2) is introduced as a substituent to an aromatic ring to realize a structure having excellent charge transport properties and excellent amorphous stability. The polycyclic aromatic compound represented by formula (1) has high electron transport properties and is characterized by high E _S1 and E _T1 . Therefore, the polycyclic aromatic compound represented by formula (1) is suitable as a host material and an electron transport material for a phosphorescent device, a TADF device, or a TAF device.

(1) Group represented by formula (A-1) or formula (A-2) In formula (1), at least one selected from the group consisting of R 1 ^Y and groups substituting hydrogen in a ring formed by bonding adjacent R ^{1 Ys} is a group represented by formula (A-1) or formula (A-2). In the compound of the present invention, the group represented by formula (A-1) or formula (A-2) imparts amorphous stability. In addition, the group represented by formula (A-1) or formula (A-2) can adjust carrier transportability.

When R ^{1 and R 2} are bonded to each other to form no ring, at least one of R 1 and R ² is a group represented by formula (A-1) or formula (A-2). When R 1 and R ² are bonded to each other to form a ring, at least one selected from the group consisting of groups substituting hydrogen in R ¹ and the ring formed by bonding adjacent R ¹ and R 2 is a group represented by formula (A-1) or formula (A-2).
The number of groups represented by formula (A-1) or formula (A-2) contained in formula (1) as described above (the number of groups represented by formula (A-1) or formula (A-2) directly bonded to ring a, ring b, ring c, or a fused ring containing any of these in formula (1)) is preferably 1 to 4, and more preferably 1 or 2.

In formula (A-1),
W ¹ and W ² are each independently a single bond, >C(-R ^W ) ₂ , >O, >N-R ^W , >Si(-R ^W ) ₂ , >S, >SO or >SO ₂ , R ^W of the >N-R ^W is any substituent selected from the substituent group YZ, a group represented by formula (A-2) or a group represented by formula (21), and R ^W of the >C(-R ^W ) ₂ and >Si(-R ^W ) ₂ are each independently a hydrogen atom, any substituent selected from the substituent group YZ, a group represented by formula (A-2) or a group represented by formula (21). R ^W bonded to the same element may be bonded to each other, and R ^W of >N-R ^W , >C(-R ^W ) ₂ and >Si(-R ^W ) ₂ may each independently be bonded to at least one Z.
Z is -N= or -CR ^Z =, and R ^Z is each independently hydrogen, any substituent selected from the substituent group YZ, a group represented by formula (A-2) or a group represented by formula (21). R ^Z in adjacent Z may be bonded to each other to form an aryl ring or a heteroaryl ring. In addition, the formed ring may have any substituent selected from the substituent group YZ, a group represented by formula (A-2) or a group represented by formula (21).
^L1 is a single bond or a linking group.
L ¹ is bonded to any C of -CR ^Z = via R ^Z as a bond, or to a ring-constituting atom of a ring formed by bonding R ^Z in Z to each other.
* indicates the bonding position of the group represented by formula (A-1).

In formula (A-2),
Each ^Ar3 is independently an aryl (excluding the group represented by formula (A-1)) which may be substituted with at least one substituent selected from the substituent group YZ or a group represented by formula (21), a heteroaryl (excluding the group represented by formula (A-1)) which may be substituted with at least one substituent selected from the substituent group YZ or a group represented by formula (21), or a group represented by formula (A-1).
^W3 is Si, P or S, and when ^W3 is Si, m is 3 and n is 0, when ^W3 is P, m is 2 and n is 0 or 1, and when ^W3 is S, m is 1 and n is an integer from 0 to 2.
^L2 is a single bond or a linking group.
* indicates the bonding position of the group represented by formula (A-2).

In formula (A-1) or formula (A-2), L ¹ and L ² are each preferably independently a single bond or a linking group selected from the group consisting of arylene, heteroarylene, >N-R ^L , >O, >C(-R ^L ) ₂ , >Si(-R ^L ) ₂ , >S, >Se, and a combination of any two or more of these. It is more preferable that ^{L 1} and L ² are each independently a single bond or a linking group selected from the group consisting of arylene which may be substituted with aryl or heteroaryl, heteroarylene which may be substituted with aryl or heteroaryl, >N-R ^L , >O, >C(-R ^L ) ₂ , >Si(-R ^L ) ₂ , >S, >Se, and a combination of any two or more of these.

R ^L in >N-R ^L , >C(-R ^L ) ₂ and >Si(-R ^L ) ₂ in L ¹ or L ² is each independently hydrogen, any substituent selected from the substituent group YZ (described later) or a group represented by formula (A-2), and R ^Ls bonded to the same element may be bonded to each other.

R ^L in >N-R ^L in ^L1 or ^L2 is preferably an aryl which may be substituted with an aryl or a heteroaryl, or a heteroaryl which may be substituted with an aryl or a heteroaryl. R L in >C( ^-L R) ₂ in ^L1 or ^L2 are preferably both alkyl, and two ^R which are both alkyl are preferably bonded to form a cycloalkane such as cyclohexane. R ^L in >Si(-R ^L ) ₂ in ^L1 or ^L2 are preferably both methyl.

^L1 and ^L2 are preferably a single bond, an arylene which may be substituted with an aryl or heteroaryl, a heteroarylene which may be substituted with an aryl or heteroaryl, or a linking group formed by linking two or more selected from an arylene which may be substituted with an aryl or heteroaryl and a heteroarylene which may be substituted with an aryl or heteroaryl;
More preferably, it is a linking group formed by linking two or more selected from an arylene which may be substituted with an aryl or heteroaryl, a heteroarylene which may be substituted with an aryl or heteroaryl, or an arylene which may be substituted with an aryl or heteroaryl and a heteroarylene which may be substituted with an aryl or heteroaryl.

The arylene which may be substituted with an aryl or heteroaryl and the heteroarylene which may be substituted with an aryl or heteroaryl in ^L1 or ^L2 preferably have bonding positions that are cross-conjugated. For example, phenylene is preferably 1,3-phenylene.

The arylene and heteroarylene in L ¹ and L ² include a divalent group formed by eliminating any hydrogen atom of the aryl and heteroaryl described below as the first substituent.
For the aryl and heteroaryl in L ¹ and L ² , reference can be made to the description of the aryl and heteroaryl as the first substituent given below.
Examples of the linking groups represented by ^L1 and ^L2 include linking groups represented by the following formulae: In the following formulae, * indicates a bonding position, with one * bonding to ring a, ring b or ring c and the other bonding to a partial structure other than ^L1 in formula (A-1) or a partial structure other than ^L2 in formula (A-2).

In the group represented by formula (A-1), when W ¹ or W ² is >N-R ^W , R ^W is preferably an optionally substituted aryl or an optionally substituted heteroaryl.
In the group represented by formula (A-1), when W ¹ or W ² is >C(-R ^W ) ₂ , it is preferable that both R ^W are aryl which may be substituted, or both R W are heteroaryl which may be substituted. It is also preferable that two R ^W are bonded to each other by a single bond, as this provides excellent compound stability. It is more preferable that both R ^W are phenyl, and the phenyls are bonded to each other by a single bond.
In the group represented by formula (A-1), when W ¹ or W ² is >Si(-R ^W ) ₂ , it is preferable that both R ^W are aryl which may be substituted, or both R W are heteroaryl which may be substituted. It is also preferable that two R ^W are bonded to each other by a single bond, as this provides excellent compound stability. It is more preferable that both R ^W are phenyl, and the phenyls are bonded to each other by a single bond.

In the group represented by formula (A-1), it is preferable that W ¹ is >N-R ^W , >C(-R ^W ) ₂ , >O, >Si(-R ^W ) ₂ or >S and W ² is a single bond. This is because the compound has excellent stability and carrier transport properties. It is more preferable that W ¹ is >N-R ^W , >O or >S and W ² is a single bond, and further more preferable that W ¹ is >O and W ² is a single bond.

R W in >N-R ^W which is ^W1 or ^W2 , >C(-R ^W ) ₂ and >Si(-R ^{W )} ₂ may each independently be bonded to at least one Z. Examples of the structure in which >N-R ^W which is ^W1 or ^W2 is bonded to Z include the following structures.

In the group represented by formula (A-1), it is preferable that 0 to 2 Z are -N= and the others are -CR ^Z =, it is more preferable that 0 to 1 Z are -N= and the others are -CR ^Z =, and it is even more preferable that all Z are -CR ^Z =. It is preferable that ^{R Z} is each independently hydrogen, aryl which may be substituted with aryl or heteroaryl, heteroaryl which may be substituted with aryl or heteroaryl, diheteroarylamino which may be substituted with aryl or heteroaryl, arylheteroarylamino which may be substituted with aryl or heteroaryl. This is because the carrier transportability is good. The aryl or heteroaryl which is a substituent may be further substituted with aryl or heteroaryl. In the group represented by formula (A-1), it is preferable that -CR ^Z = in which R ^Z is other than hydrogen is 0 to 3. This is because the amorphous stability is good. It is more preferable that -CR ^Z = in which R ^Z is other than hydrogen is 0 to 2, and even more preferable that it is 0 to 1.

In the group represented by formula (A-1), two R ^Z in adjacent Z groups each representing -CR ^Z = may be bonded to each other to form an aryl ring or a heteroaryl ring. Examples of the group represented by formula (A-1) thus forming an aryl ring or a heteroaryl ring include groups represented by any of the following formulas.

式中、Ｍｅはメチルであり、＊は結合位置を示す。

In the formula, Me is methyl and * indicates the position of attachment.

The ring formed may have a substituent. The number of substituents is preferably 0 to 2, and more preferably 0 to 1. The substituent is preferably an aryl which may be substituted with an aryl or heteroaryl, a heteroaryl which may be substituted with an aryl or heteroaryl, a diheteroarylamino which may be substituted with an aryl or heteroaryl, or an arylheteroarylamino which may be substituted with an aryl or heteroaryl.

^L1 is bonded to any C of -CR ^Z = through R ^Z as a bond, or is directly bonded to a ring-constituting atom of a ring formed by bonding R ^Z in Z to each other. That is, ^L1 is not bonded to ^W1 or ^W2 .
In the group represented by formula (A-1), it is preferable that Z at either para position of W ¹ that is not a single bond is bonded to L ^1. In other words, it is preferable that Z at either para position of W ¹ that is not a single bond is -CR ^Z ═, and this C is bonded to L ¹ via R ^Z as a bond.

In the group represented by formula (A-2), each Ar ³ is preferably independently an aryl which may be substituted with an aryl or a heteroaryl (excluding the group represented by formula (A-1)), a heteroaryl which may be substituted with an aryl or a heteroaryl (excluding the group represented by formula (A-1)), or a group represented by formula (A-1), and is preferably an unsubstituted aryl, an unsubstituted heteroaryl, or a group represented by formula (A-1).
In the group represented by formula (A-2), it is preferable that m is large in terms of excellent electron transport properties. In the group represented by formula (A-2), it is preferable that ^W3 is Si in terms of excellent compound stability.
In the group represented by formula (A-2), it is most preferable that ^W3 is Si, m is 3 and n is 0.

(2) ^Y1 to ^Y6
Y ¹ to Y ⁶ are each independently =C(-R ^Y )- or =N-, and at least one of them is =N-. Any of ^{Y 1} to Y ⁶ may be =N-. Preferably, ^Y1 and ^Y6 are =N- (ring a is a pyrimidine ring), ^Y1 or ^Y6 are =N- (ring a is a pyridine ring), ^Y2 and ^Y5 are =N- (ring b and ring c are pyridine rings), ^Y3 and ^Y4 are =N- (ring b and ring c are pyridine rings), ^Y2 to ^Y5 are =N- (ring b and ring c are pyrimidine rings), ^Y1 , ^Y3 , ^Y4 and ^Y6 are =N- (ring a is a pyrimidine ring, ring b and ring c are pyridine rings), ^Y1 , ^Y2 , ^Y5 and ^Y6 are =N- (ring a is a pyrimidine ring, ring b and ring c are pyridine rings), ^Y1 to ^Y6 are =N- (ring a, ring b and ring c are pyrimidine rings), and ^Y2 or ^Y5 is =N- (ring b or ring c is a pyridine ring).

At least one of ^Y1 and ^Y6 is preferably =N-- (the rest of ^Y1 to ^Y6 are =C(-R ^Y )-). When only ^Y1 is =N--, the HOMO and LUMO heights are appropriate, which is most preferable.

In addition to the above =N- configuration, ^X1 and ^X2 are preferably >O, and polycyclic aromatic compounds containing a partial structure represented by any of the following formulae are preferred.

In particular, polycyclic aromatic compounds containing a partial structure represented by formula (1-1601-R) have high E _S1 , high E _T1 , and small ΔE _S1T1 (energy difference between E _S1 and E _T1 ) compared with structures without N, and are therefore promising as blue TADF assist dopants, TADF hosts, and phosphorescent hosts. In addition, they have deep HOMO and deep LUMO, and are therefore promising as hole blocking materials and electron transporting materials.

Each of the above formulas shows a "partial structure" of a polycyclic aromatic compound. Therefore, the following are omitted: R ^Y defined in formula ( ¹ ); R ^Y of =C(-R ^Y )- as Y1, etc.; aryl rings or heteroaryl rings that may be formed by bonding adjacent groups among R Y and R ^Y of =C(-R ^Y )- as ^{Y 1} to Y ⁶ , and further substituents thereon (first and second substituents); second substituents to R of >N-R as X ¹ and X ² , and linking groups or single bonds between said R and Y ¹ and/or Y ² , or Y ⁵ and/or Y ⁶ ; and cyano, halogen, or deuterium that may further be substituted in the compound.

From a synthetic standpoint, polycyclic aromatic compounds having the partial structures represented by the above formulas (1-1601-R) and (1-841-R) are preferred. This is because the aromatic rings (rings b and c) that undergo the Friedel-Crafts reaction on boron do not contain nitrogen and are not electron deficient.

(3) R ^Y (and a group replacing a hydrogen atom in a ring formed by bonding adjacent R ^Ys together) (other than the group represented by formula (A-1) or formula (A-2))
In this specification, R 2 ^Y includes R ^{2 Y} according to formula (1) and R 2 ^Y when any one or more of Y ¹ to Y ⁶ is ═C(—R 2 ^Y )—.
R ^Y are each independently a group represented by formula (A-1) or formula (A-2), hydrogen, or any substituent selected from the substituent group YZ excluding the group represented by formula (A-1), or a group represented by formula (21). Adjacent groups among R ^Y may be bonded to each other to form a ring. At least one hydrogen atom in the formed ring may be substituted with a group represented by formula (A-1) or formula (A-2), a substituent selected from the substituent group YZ excluding the group represented by formula (A-1), or a group represented by formula (21).

When adjacent R ^Y's are not bonded to form a ring, at least one of the R ^Y's is a group represented by formula (A-1) or formula (A-2), and the other R ^Y 's are hydrogen or any substituent selected from the substituent group YZ, excluding the group represented by formula (A-1). When adjacent R ^Y's are bonded to form a ring, at least one of the groups substituting hydrogen in the ring formed by bonding R ^Y and adjacent R ^Y 's is a group represented by formula (A-1) or formula (A-2), and the other groups substituting hydrogen in the ring formed by bonding R ^Y and adjacent R ^Y 's is any substituent selected from the substituent group YZ, excluding the group represented by formula (A-1).

The substituent group YZ consists of the following:
aryl optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl;
aryl, heteroaryl, heteroaryl optionally substituted with alkyl or cycloalkyl;
diarylamino optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl;
diheteroarylamino optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl;
arylheteroarylamino optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl;
diarylboryl optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl (two aryls may be bonded via a single bond or a linking group);
alkyl optionally substituted with aryl, heteroaryl, or cycloalkyl;
cycloalkyl optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl;
Alkoxy which may be substituted with aryl, heteroaryl, or cycloalkyl; and aryloxy which may be substituted with aryl, heteroaryl, alkyl, or cycloalkyl.

In this specification, in the substituent group YZ, the above-mentioned aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (the two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, or aryloxy, which corresponds to the portion directly bonded to rings a to c in formula (1), may be referred to as the first substituent. The aryl, heteroaryl, alkyl, or cycloalkyl which replaces at least one hydrogen in these may be referred to as the second substituent.

The "aryl" as the first substituent is, for example, an aryl having 6 to 30 carbon atoms, preferably an aryl having 6 to 20 carbon atoms, more preferably an aryl having 6 to 16 carbon atoms, even more preferably an aryl having 6 to 12 carbon atoms, and particularly preferably an aryl having 6 to 10 carbon atoms.

Specific examples of the aryl include phenyl, which is a monocyclic ring, biphenylyl, which is a bicyclic ring, naphthyl, which is a fused bicyclic ring, terphenylyl (m-terphenylyl, o-terphenylyl, p-terphenylyl), which is a tricyclic ring, acenaphthylenyl, fluorenyl, phenalenyl, phenanthrenyl, which are fused tricyclic rings, triphenylenyl, pyrenyl, and naphthacenyl, which are fused tetracyclic rings, perylenyl, pentacenyl, etc. Examples of the aryl include a group represented by formula (A-1) in which L ¹ is a single bond and does not contain a heteroatom.

The "heteroaryl" as the first substituent is, for example, a heteroaryl having 2 to 30 carbon atoms, preferably a heteroaryl having 2 to 25 carbon atoms, more preferably a heteroaryl having 2 to 20 carbon atoms, even more preferably a heteroaryl having 2 to 15 carbon atoms, and particularly preferably a heteroaryl having 2 to 10 carbon atoms. In addition, the heteroaryl is, for example, a heterocycle containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms.

Specific examples of heteroaryl include pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, pyrazolyl, pyridinyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, and acridinyl. Examples of heteroaryl include aryl, phenoxathiinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenazasilinyl, indolizinyl, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, naphthobenzofuranyl, thiophenyl, benzothiophenyl, isobenzothiophenyl, dibenzothiophenyl, naphthobenzothiophenyl, benzophosphoryl, dibenzophosphoryl, a monovalent group of a benzophosphole oxide ring, a monovalent group of a dibenzophosphole oxide ring, furazanyl, thianthrenyl, indolocarbazolyl, benzoindolocarbazolyl, and benzobenzoindolocarbazolyl. Examples of heteroaryl include a group represented by formula (A-1) in which L ¹ is a single bond and contains a heteroatom.

As the first substituent, the "aryl" in "diarylamino", the "heteroaryl" in "diheteroarylamino" (first substituent), the "aryl" and "heteroaryl" in "arylheteroarylamino" (first substituent), and the "aryl" in "aryloxy" (first substituent) can be referenced from the above explanations of aryl and heteroaryl.

The "alkyl" as the first substituent may be either linear or branched, for example, linear alkyl having 1 to 24 carbon atoms or branched alkyl having 3 to 24 carbon atoms. An alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms) is preferred, an alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms) is more preferred, an alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms) is even more preferred, and an alkyl having 1 to 5 carbon atoms (branched alkyl having 3 to 5 carbon atoms) or an alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms) is particularly preferred.

Specific examples of alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl (t-amyl), n-hexyl, 1-methylpentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl (1,1,3,3-tetramethylbutyl), and 1-methyl. heptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl.
Further, for example, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl-1-methylhexyl, 1-ethyl-1,3-dimethylbutyl, 1,1,2,2-tetramethylpropyl, 1-butyl-1-methylpentyl, 1,1-diethylbutyl, 1-ethyl-1-methylpentyl, 1,1,3-trimethylbutyl, 1-propyl-1-methylpentyl, 1,1,2-trimethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, 1-propyl-1-methylbutyl, and 1,1-dimethylhexyl.

Examples of "cycloalkyl" as the first substituent include cycloalkyl having 3 to 24 carbon atoms, cycloalkyl having 3 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, cycloalkyl having 5 to 8 carbon atoms, cycloalkyl having 5 to 6 carbon atoms, and cycloalkyl having 5 carbon atoms.

Specific examples of cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and alkyl (especially methyl) substituted derivatives of these having 1 to 4 carbon atoms, as well as norbornenyl, bicyclo[1.0.1]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.0.1]pentyl, bicyclo[1.2.1]hexyl, bicyclo[3.0.1]hexyl, bicyclo[2.1.2]heptyl, bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, and decahydroazulenyl.

The "alkoxy" as the first substituent is, for example, a straight-chain alkoxy having 1 to 24 carbon atoms or a branched-chain alkoxy having 3 to 24 carbon atoms. An alkoxy having 1 to 18 carbon atoms (branched-chain alkoxy having 3 to 18 carbon atoms) is preferred, an alkoxy having 1 to 12 carbon atoms (branched-chain alkoxy having 3 to 12 carbon atoms) is more preferred, an alkoxy having 1 to 6 carbon atoms (branched-chain alkoxy having 3 to 6 carbon atoms) is even more preferred, and an alkoxy having 1 to 5 carbon atoms (branched-chain alkoxy having 3 to 5 carbon atoms) or an alkoxy having 1 to 4 carbon atoms (branched-chain alkoxy having 3 to 4 carbon atoms) is particularly preferred.

Specific examples of alkoxy include methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, s-butoxy, t-butoxy, t-amyloxy, n-pentyloxy, isopentyloxy, neopentyloxy, t-pentyloxy, n-hexyloxy, 1-methylpentyloxy, 3,3-dimethylbutoxy, 2-ethylbutoxy, n-heptyloxy, 1-methylhexyloxy, n-octyloxy, t-octyloxy, 1-methylheptyloxy, and 2-ethylhexyl. Examples include oxy, 2-propylpentyloxy, n-nonyloxy, 2,2-dimethylheptyloxy, 2,6-dimethyl-4-heptyloxy, 3,5,5-trimethylhexyloxy, n-decyloxy, n-undecyloxy, 1-methyldecyloxy, n-dodecyloxy, n-tridecyloxy, 1-hexylheptyloxy, n-tetradecyloxy, n-pentadecyloxy, n-hexadecyloxy, n-heptadecyloxy, n-octadecyloxy, and n-eicosyloxy.

The "aryl" in the "diarylboryl" as the first substituent can be cited from the above description of the aryl. The two aryls may be bonded via a single bond or a linking group (e.g., >C(-R) ₂ , >O, >S, or >N-R). Here, R in >C(-R) ₂ and >N-R is aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy (above, the first substituent), and the first substituent may be further substituted with aryl, heteroaryl, alkyl, or cycloalkyl (above, the second substituent), and specific examples of these groups can be cited from the above description of the aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy as the first substituent.

As for the aryl, heteroaryl, alkyl, or cycloalkyl (above, the second substituent) that substitutes the first substituent, the above description of the aryl, heteroaryl, alkyl, or cycloalkyl as the first substituent can be cited.

When adjacent R 1 ^Y 's are not bonded to form a ring, it is preferable that R 1 ^Y's other than the R 1 ^Y's group represented by formula (A-1) or formula (A-2) are hydrogen, aryl which may be substituted with aryl or heteroaryl, or heteroaryl which may be substituted with aryl or heteroaryl. It is preferable that 0 to 2 of R 1 ^Y 's other than the R 1 Y's group represented by formula (A-1) or formula (A-2) are groups other than hydrogen, and it is preferable that 0 to 1 of R ^{1 Y} 's are groups other than hydrogen.

When adjacent R ^{1 Ys} are bonded to form a ring, it is preferable that, among the groups substituting hydrogen in the ring formed by bonding between R ^{1 Y} and adjacent R ^{1 Ys} , R 1 ^Ys other than the R 1 ^Ys which are the groups represented by formula (A-1) or formula (A-2) are hydrogen, aryl which may be substituted with aryl or heteroaryl, or heteroaryl which may be substituted with aryl or heteroaryl. It is preferable that 0 to 2 of the groups other than R ^{1 Ys which are the groups represented by formula (A-1) or formula (A-2) are groups other than hydrogen, and it is preferable that 0 to 1 of the groups other than R 1 Ys} are groups other than hydrogen.

As described above as "0", it is also preferable that R ^Y other than R ^Y which is a group represented by formula (A-1) or formula (A-2) is hydrogen, and that hydrogen in a ring formed by bonding R ^Y and adjacent R ^Ys is not substituted with anything other than a group represented by formula (A-1) or formula (A-2).

Specifically, preferred groups (other than groups represented by formula (A-1) or (A-2)) as groups substituting hydrogen in R ^Y other than hydrogen and in a ring formed by bonding adjacent R ^Ys together include any of the following:

(4) Formation of a condensed ring by bonding between R ^Y In formula (1), adjacent groups among R ^Y may be bonded to each other to form a ring. It is preferable that an aryl ring or heteroaryl ring is formed together with at least one of the rings a, b, and c by the formation of the ring. In the polycyclic aromatic compound represented by formula (1), the ring structure constituting the compound changes as shown in the following formulas (1'-1) and (1'-2) depending on the mutual bonding form of the substituents in the ring a, ring b, and ring c. Note that the definitions of R ^Y , Y ¹ to Y ⁶ , a, b, c, X ¹ , and X ² in each formula are the same as those in formula (1).

The ring a', ring b' and ring c' in the above formula (1'-1) and formula (1'-2) represent aryl or heteroaryl rings formed together with the ring a, ring b and ring c by bonding adjacent groups among the R ^Y of =C(-R ^Y )- as the substituents R ^Y and Y ¹ to Y ⁶ (they may also be considered as condensed rings formed by condensing the ring a, ring b or ring c with another ring structure). Although not shown in the formula, there are also compounds in which the ring a, ring b and ring c are all changed to the ring a', ring b' and ring c'.

As can be seen from the above formulas (1'-1) and (1'-2), for example, R Y of =C(-R ^Y )- as Y ¹ in ring ^a and R Y of =C(-R ^Y )- as ^{Y 2} in ring b, R ³ in ring b and R ⁴ in ring c, R ^Y of =C(-R ^Y )- as Y ⁵ in ring ^c and R ^Y of =C(-R ^Y )- as Y 6 in ring a, do not fall under the category of "adjacent groups" and are not bonded to each other. In other words, "adjacent groups" means groups adjacent on the same ring, more specifically, groups directly bonded to two elements adjacent (directly bonded) on the same ring.

The compounds represented by the above formula (1'-1) or formula (1'-2) are compounds having a ring a' (or ring b ^' or ring c') formed by condensing a benzene ring, indole ring, ^pyrrole ring, benzofuran ring, benzothiophene ring, or the like to a 6-membered ring which is ring a (or ring ^b or ring c) (a benzene ring when Y1 and Y6 are =C(-R Y )-). The condensed ring a' (or condensed ring b' or condensed ring c') formed is a naphthalene ring, carbazole ring, indole ring, dibenzofuran ring, dibenzothiophene ring, or the like, when ring a (or ring b or ring c) is a benzene ring.
For example, when ring a (or ring b or ring c) is a pyridine ring (either ^Y1 or ^Y6 is =N-), a benzene ring, an indole ring, a pyrrole ring, a benzofuran ring, a benzothiophene ring, or the like may be condensed to it. Note that, as described later, when two Ys on one ring (for example, both ^Y1 and ^Y6 on ring a) are =N-, a condensed ring is not formed.

Only when Y ¹ to Y ⁶ are ═C(-R ^Y )- can they bond to R ^Y other than the Y ¹ to Y ⁶ moieties form a fused ring, and when Y ¹ to Y ⁶ are ═N-, a fused ring originating from this ═N- is not formed. For example, as shown in the example of the structural formula below, when Y ¹ and Y ⁶ of ring a are both ═N-, fused ring a' is not formed, and when at least one of Y ¹ and Y ⁶ is ═C(-R ^Y )-, fused ring a' is formed.

Examples of the "aryl ring" (ring a', ring b' or ring c') formed in this manner include an aryl ring having 9 to 30 carbon atoms, an aryl ring having 9 to 16 carbon atoms, an aryl ring having 9 to 12 carbon atoms or an aryl ring having 9 to 10 carbon atoms. The lower limit of the number of carbon atoms in the aryl ring, 9, corresponds to the total carbon number of 9 in the fused ring formed by fusing a 5-membered ring (having 5 carbon atoms) to a benzene ring having 6 carbon atoms (Y ¹ to Y ⁶ are =C(-R ^Y )-) in ring a, ring b or ring c.

Specific examples of "aryl rings" include a naphthalene ring, which is a fused bicyclic ring; an acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, which are fused tricyclic rings; a triphenylene ring, a pyrene ring, a naphthacene ring, which are fused tetracyclic rings; a perylene ring, a pentacene ring, which are fused pentacyclic rings, and the like.

Examples of the "heteroaryl ring" (ring a', ring b' or ring c') formed include a heteroaryl ring having 5 to 30 carbon atoms, a heteroaryl ring having 5 to 25 carbon atoms, a heteroaryl ring having 5 to 20 carbon atoms, a heteroaryl ring having 5 to 15 carbon atoms and a heteroaryl ring having 5 to 10 carbon atoms. Examples of the "heteroaryl ring" include a heterocycle containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen as ring-constituting atoms. The lower limit of the number of carbon atoms in this heteroaryl ring, 5, is the lower limit when ring a, ring b or ring c is a pyridine ring (assuming that one of Y ¹ to Y ⁶ on each ring is =N-), and corresponds to the total carbon number of 5 in the fused ring formed by condensing a 5-membered ring to a pyridine ring having 5 carbon atoms. Therefore, for example, for ring a, when both Y ¹ and Y ⁶ are =C(-R)-, the lower limit is changed to 6 (when both Y ¹ and Y ⁶ are =N-, a fused ring is not formed).

Specific examples of "heteroaryl rings" include an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a benzothiophene ring, a dibenzothiophene ring, and a thianthrene ring.

The aryl ring or heteroaryl ring thus formed may be substituted with a group represented by formula (A-1) or formula (A-2) or a substituent selected from the substituent group YZ, excluding the group represented by formula (A-1). For the substituent selected from the substituent group YZ, see the explanation of R ^Y above.

(5) A group represented by formula (21)

The polycyclic aromatic compound represented by formula (1) may have a group represented by formula (21). As described above, the group represented by formula (21) can be included in the structure of the polycyclic aromatic compound represented by formula (1) as R ^Y , a substituent of a ring formed by bonding adjacent R ^Ys together, R ^W , R ^Z , a substituent of a ring formed by bonding adjacent R ^Zs together, or a substituent of an aryl or heteroaryl in Ar ^3. The number of groups represented by formula (21) included in the polycyclic aromatic compound represented by formula (1) is 0 to 2. That is, when a group represented by formula (21) is included in the polycyclic aromatic compound represented by formula (1), the number is 1 or 2. Within this range, it can be produced in the same way as the polycyclic aromatic compound represented by formula (1) that does not contain a group represented by formula (21), and can be used in the production of an organic EL device as a host material, a hole blocking layer forming material, or the like, in the same way as the polycyclic aromatic compound represented by formula (1) that does not contain a group represented by formula (21). The number of groups represented by formula (21) contained in the polycyclic aromatic compound represented by formula (1) is preferably 0 or 1, and more preferably 0.

The position of the group represented by formula (21) in the polycyclic aromatic compound represented by formula (1) containing one group represented by formula (21) is not particularly limited, but it is preferable that either R ^{1 Y} or either R 2 ^Z is a group represented by formula (21). R 1 ^Y , which is a group represented by formula (21), is preferably at the para position of boron. R 2 ^Z , which is a group represented by formula (21), is preferably not adjacent to R 2 ^Z which is a bond to L ¹ , and is preferably bonded to a ring different from the ring to which R 2 ^Z which is a bond to L ¹ is bonded. For example, in the group represented by formula (A-1), when Z at one para position of W ¹ which is not a single bond is bonded to L ¹ , Z at the other para position of W ¹ which is not a single bond is -CR ² =, and this R 2 ^Z is preferably a group represented by formula (21). In the polycyclic aromatic compound represented by formula (1) containing two groups represented by formula (21), the positions of the groups represented by formula (21) are preferably any two positions of R ^Y , or any one position of R ^Y and any one position of R ^Z. The two R ^Ys are preferably R ^Ys bonded to different rings.

In formula (21), X ²¹ and X ²² are each independently >N-R ^X21 , >O, >C(-R ^X21 ) ₂ , >S or >Se. R ^X21 in >N-R ^X21 and >C(-R ^X21 ) ₂ is each independently hydrogen or any substituent selected from the substituent group YZ, and R ^X21 in >N-R ^X21 and >C(-R ^X21 ) ₂ may each independently be bonded to Y ²¹ and/or Y ^{22 , or Y 25 and} /or Y ²⁶ via a linking group or a single bond. For details of X ²¹ and X ²² , see the description in "(6) X ¹ and X ² " below. For the case where R ^X21 in >N-R ^X21 and >C(-R ^X21 ) ₂ is bonded to Y ²¹ and/or Y ²² , or Y ²⁵ and/or Y ²⁶ , see the description in "(7) Bonds between X ¹ and X ² and Y ¹ and/or Y ² , or Y ⁵ and/or Y ⁶ " below.

In formula (21), Y ²¹ , Y ²² , Y ²³ , Y ²⁴ , Y ²⁵ and Y ²⁶ are each independently ═C(—R ^2Y )— or ═N—. R ^2Y is each independently hydrogen or any substituent selected from the substituent group YZ, and adjacent groups among R ^2Y may be bonded to form a ring, and at least one hydrogen in the formed ring may be substituted with a substituent selected from the substituent group YZ.

For details of Y ²¹ , Y ²² , Y ²³ , Y ²⁴ , Y ²⁵ and Y ²⁶ , the description of "(2) Y ¹ to Y ⁶ " can be referred to. However, unlike Y ¹ to Y ⁶ , there is no limitation that at least one is =N-, and Y ²¹ , Y ²² , Y ²³ , Y ²⁴ , Y ²⁵ and Y ²⁶ may all be C(-R ^2Y )-. That is, in the group represented by formula (21), all three rings including any of Y ²¹ , Y ²² , Y ²³ , Y ²⁴ , Y ²⁵ and Y ²⁶ may be benzene rings. It is also preferable that the fused ring structure of the group represented by formula (21) is the same as the fused ring structure including Y ¹ to Y ⁶ of formula (1). For example, in a compound represented by formula (1) in which Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ are each independently =C(-R ^Y )- and Y ¹ is =N-, it is also preferable that Y ²² , Y ²³ , Y ²⁴ , Y ²⁵ and Y ²⁶ are each independently =C(-R ^2Y )- and Y ²¹ is =N- in the group represented by formula (21).

For the ring formed by bonding between R ^2Y and adjacent R ^2Ys , the descriptions in "(3) R ^2Y " and "(4) Formation of a fused ring by bonding between R ^2Ys " above can be referred to.

In formula (21), ^L3 is a single bond or a linking group. For details and specific examples of ^L3 , please refer to the description of ^L1 above. ^L3 is particularly preferably a single bond. ^L3 is bonded to a C (carbon atom) to which any ^R2Y is bonded, via any ^R2Y as a bond, or to any ring-constituting atom of a ring formed by bonding adjacent ^R2Ys to each other.
* indicates the bonding position of the group represented by formula (21).

(6) ^X1 and ^X2
X1 and ^X2 are each independently >N-R (amine nitrogen), >O, >C(-R) ₂ , >S or >Se, and ^X1 and ^X2 are not both >C(-R) ₂ . Among these, >N-R, >O or >C(-R) ₂ are preferred, and >N-R or >O are preferred. It is particularly preferred that ^X1 and ^X2 are both >N-R or >O, and most preferred that ^X1 and ^X2 are both >O. This is because the electron transporting property is highest when ^X1 and ^X2 are both >O.

R in >N-R and >C(-R) ₂ is hydrogen or any substituent selected from the substituent group YZ. For the substituent selected from the substituent group YZ, see the explanation for R ^Y above.

(7) Bonding of X1 and ^X2 to ^Y1 and/or Y2 ^, or Y5 ^and /or Y6 ^The provision in formula (1) that "R in ^> N-R and >C(-R) ₂ (as ^X1 and ^X2 ) is each independently bonded to ^Y1 and/or ^Y2 , or ^Y5 and/or ^Y6 via a linking group or a single bond" can also be expressed as a compound having a ring structure in which at least one of ^X1 and ^X2 is incorporated into a fused ring a', as represented by the following formula (1'-3) or formula (1'-4). That is, for example, it is a compound having an a' ring formed by condensing another ring so as to incorporate ^X1 (or ^X2 , or ^X1 and ^X2 ) into the 6-membered ring that is the a ring in formula (1). More specifically, for example, R of >N-R or >C(-R) ₂ as ^X1 and R ^Y of =C(-R ^Y )- as ^Y1 are bonded via a linking group or a single bond. The same applies to the bond between ^X2 and ^Y6 . The formed fused ring a' is, for example, a phenoxazine ring, a phenothiazine ring or an acridine ring.

The above definition can be expressed by a compound having a ring structure in which X ¹ and X ² are incorporated into fused ring b' and fused ring c', as represented by the following formula (1'-5). That is, for example, it is a compound having ring b' (or ring c', or ring b' and ring c') formed by condensing another ring so as to incorporate X ¹ (or X ² , or X ¹ and X ² ) to the 6-membered ring that is ring b (or ring c, or ring b and ring c) in formula (1). More specifically, for example, an embodiment in which R of >N-R or >C(-R) ₂ as X ¹ and R of =C(-R ^Y )- as Y ² are bonded by a linking group or a single bond can be exemplified. The same applies to the bond between ^{X 2} and Y ^5. The formed fused ring b' (or fused ring c') is, for example, a phenoxazine ring, a phenothiazine ring, or an acridine ring.
In addition, the definitions of R ^Y , Y ¹ to Y ⁶ , a, b, c, a′, b′, c′, X1 and X2 in the following formulas (1′-3), (1′- ⁴ ) and (1′- ⁵⁾ are the same as those in formula (1).

The linking group is preferably -O-, -S- or -C(-R) ₂ -. R in the above "-C(-R) ₂ -" is hydrogen, alkyl or cycloalkyl, and the details of these groups can be found in the explanation of the alkyl or cycloalkyl as the first substituent in the above-mentioned substituent group YZ. In particular, an alkyl having 1 to 4 carbon atoms (such as methyl or ethyl) is preferred.

(8) Description of other substituents All or a part of the hydrogen atoms in the chemical structure of the polycyclic aromatic compound represented by formula (1) may be substituted with cyano, halogen or deuterium. The halogen atom is fluorine, chlorine, bromine or iodine, preferably fluorine, chlorine or bromine, more preferably fluorine.

(9) Preferred Structure A preferred example of the polycyclic aromatic compound represented by formula (1) is the compound represented by the following formula (1-YZ-1).

In formula (1-YZ-1),
^XW is each independently >N-R, >O or >S, and R of the >N-R is an aryl having 6 to 12 carbon atoms or a heteroaryl having 2 to 12 carbon atoms, or is a bond to L ^YZ , with the proviso that at least one ^XW is not >N-R in which R is a bond to L ^YZ ;
Each of L, ^{Y, and Z} is independently a single bond, an arylene having 6 to 12 carbon atoms, a heteroarylene having 2 to 12 carbon atoms, or >NR, wherein R in >NR is an aryl having 6 to 12 carbon atoms or a heteroaryl having 2 to 12 carbon atoms;
R ^YZ is hydrogen, an aryl having 6 to 12 carbon atoms, or a heteroaryl having 2 to 12 carbon atoms;
i is 2 to 4;
At least one hydrogen atom in the chemical structure of the compound represented by formula (2) may be replaced with deuterium.
^XW is preferably >N--R or >O. ^{L YZ} is preferably a single bond. R ^YZ is preferably hydrogen.

More specific examples of the polycyclic aromatic compound of the present invention include compounds represented by the following structural formulas.

(10) Polymer Compound The polycyclic aromatic compound represented by the formula (1) can be used as a material for an organic device, for example, a material for an organic electroluminescent element, a material for an organic field effect transistor, or a material for an organic thin-film solar cell, in the form of a polymer compound obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer (the monomer for obtaining this polymer compound has a polymerizable substituent), or a crosslinked polymer obtained by further crosslinking the polymer compound (the polymer compound for obtaining this crosslinked polymer has a crosslinkable substituent), or a pendant polymer compound obtained by reacting a main-chain polymer with the reactive compound (the reactive compound for obtaining this pendant polymer compound has a reactive substituent), or a pendant polymer crosslinked by further crosslinking the pendant polymer compound (the pendant polymer compound for obtaining this pendant polymer crosslinked polymer has a crosslinkable substituent).

The reactive substituents described above (including the polymerizable substituents, the crosslinkable substituents, and the reactive substituents for obtaining a pendant polymer, hereinafter also referred to simply as "reactive substituents") are not particularly limited as long as they are substituents capable of increasing the molecular weight of the polycyclic aromatic compound, substituents capable of further crosslinking the polymer compound thus obtained, and substituents capable of pendant reaction with the main chain polymer, but the following structures are preferred. * in each structural formula indicates the bond position.

Each L is independently a single bond, -O-, -S-, >C=O, -O-C(=O)-, an alkylene having 1 to 12 carbon atoms, an oxyalkylene having 1 to 12 carbon atoms, or a polyoxyalkylene having 1 to 12 carbon atoms. Among the above substituents, groups represented by formula (XLS-1), (XLS-2), (XLS-3), (XLS-9), (XLS-10) or (XLS-17) are preferred, and groups represented by formula (XLS-1), (XLS-3) or (XLS-17) are more preferred.

The uses of such polymer compounds, crosslinked polymers, pendant polymer compounds, and pendant polymer crosslinked polymers (hereinafter simply referred to as "polymer compounds and crosslinked polymers") will be described in detail below.

2. Method for Producing Polycyclic Aromatic Compound The polycyclic aromatic compound of the present invention can be synthesized by applying the method disclosed in, for example, International Publication No. WO 2015/102118. That is, as shown in the following scheme, an intermediate in which rings a to c are bonded is synthesized, and the intermediate is cyclized by a tandem hetero Friedel-Crafts reaction (successive aromatic electrophilic substitution reaction) to synthesize a desired polycyclic aromatic compound. In the following scheme, the symbols of each formula are defined as above. A compound having a group represented by formula (A-1) or formula (A-2) can be produced by using a raw material having a group represented by formula (A-1) or formula (A-2) somewhere in the reaction process, or by adding a process of introducing a group represented by formula (A-1) or formula (A-2).

The intermediate before cyclization in the above scheme can also be synthesized by the method shown in WO 2015/102118 etc. In other words, by appropriately combining the Buchwald-Hartwig reaction, Suzuki coupling reaction, or etherification reaction by nucleophilic substitution reaction, Ullmann reaction etc., an intermediate having the desired substituent can be synthesized.

The cyclization by the tandem hetero Friedel-Crafts reaction shown in the above scheme is a reaction of introducing B (boron) which bonds the a ring, the b ring, and the c ring. First, the hydrogen atom (-H) on the a ring between ^X1 and ^X2 is orthometalated with n-butyllithium, sec-butyllithium, t-butyllithium, or the like. Next, boron trichloride, boron tribromide, or the like is added to carry out lithium-boron metal exchange, and then a tandem boron Friedel-Crafts reaction is carried out by adding a Bronsted base such as N,N-diisopropylethylamine to obtain the target product. Here, a Lewis acid such as aluminum trichloride may be added to promote the reaction.

In addition to the method of introducing lithium into the desired position by orthometalation, it is also possible to introduce a halogen such as a bromine atom into the desired position and then introduce lithium into the desired position by halogen-metal exchange.

3. Organic Devices The polycyclic aromatic compound according to the present invention can be used as a material for organic devices, such as organic electroluminescent devices, organic field effect transistors, and organic thin-film solar cells.

3-1. Organic Electroluminescence Device The organic EL device according to this embodiment will now be described in detail with reference to the drawings. Fig. 1 is a schematic cross-sectional view showing the organic EL device according to this embodiment.

3-1-1. Structure of Organic Electroluminescent Device The organic EL device 100 shown in FIG. 1 has a substrate 101, an anode 102 provided on the substrate 101, a hole injection layer 103 provided on the anode 102, a hole transport layer 104 provided on the hole injection layer 103, a light emitting layer 105 provided on the hole transport layer 104, an electron transport layer 106 provided on the light emitting layer 105, an electron injection layer 107 provided on the electron transport layer 106, and a cathode 108 provided on the electron injection layer 107.

The organic EL element 100 may be fabricated in the reverse order, for example, with a substrate 101, a cathode 108 provided on the substrate 101, an electron injection layer 107 provided on the cathode 108, an electron transport layer 106 provided on the electron injection layer 107, a light-emitting layer 105 provided on the electron transport layer 106, a hole transport layer 104 provided on the light-emitting layer 105, a hole injection layer 103 provided on the hole transport layer 104, and an anode 102 provided on the hole injection layer 103.

Not all of the above layers are essential, and the minimum structural unit is the anode 102, the light-emitting layer 105, and the cathode 108, with the hole injection layer 103, the hole transport layer 104, the electron transport layer 106, and the electron injection layer 107 being layers that may be provided optionally. Each of the above layers may be a single layer or multiple layers.

In addition to the above-mentioned "substrate/anode/hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode" configuration, the layers constituting the organic EL element may be "substrate/anode/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole injection layer/light-emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole injection layer/light-emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole injection layer/hole transport layer/light-emitting ... transport", The configuration may be "transport layer/cathode", "substrate/anode/light-emitting layer/electron transport layer/electron injection layer/cathode", "substrate/anode/hole transport layer/light-emitting layer/electron injection layer/cathode", "substrate/anode/hole transport layer/light-emitting layer/electron transport layer/cathode", "substrate/anode/hole transport layer/light-emitting layer/electron transport layer/cathode", "substrate/anode/hole injection layer/light-emitting layer/electron injection layer/cathode", "substrate/anode/hole injection layer/light-emitting layer/electron transport layer/cathode", "substrate/anode/light-emitting layer/electron transport layer/cathode", "substrate/anode/light-emitting layer/electron transport layer/cathode", or "substrate/anode/light-emitting layer/electron injection layer/cathode".

3-1-2. Substrate in organic electroluminescence element The substrate 101 is a support for the organic EL element 100, and is usually made of quartz, glass, metal, plastic, etc. The substrate 101 is formed into a plate, film, or sheet shape depending on the purpose, and for example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, etc. are used. Among them, a glass plate and a plate made of a transparent synthetic resin such as polyester, polymethacrylate, polycarbonate, polysulfone, etc. are preferable. For a glass substrate, soda lime glass or alkali-free glass is used, and the thickness is sufficient to maintain mechanical strength, so that it is sufficient to be, for example, 0.2 mm or more. The upper limit of the thickness is, for example, 2 mm or less, preferably 1 mm or less. As for the material of the glass, it is better to have fewer ions eluted from the glass, so alkali-free glass is preferable, but soda lime glass with a barrier coat such as SiO ₂ is also commercially available, so it can be used. In addition, in order to improve the gas barrier properties, the substrate 101 may be provided with a gas barrier film such as a dense silicon oxide film on at least one side, and it is preferable to provide a gas barrier film, especially when a synthetic resin plate, film or sheet with poor gas barrier properties is used as the substrate 101.

The anode 102 plays a role of injecting holes into the light-emitting layer 105. When the hole injection layer 103 and/or the hole transport layer 104 are provided between the anode 102 and the light-emitting layer 105, the holes are injected into the light-emitting layer 105 through these layers.

Materials for forming the anode 102 include inorganic and organic compounds. Examples of inorganic compounds include metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (ITO), indium-zinc oxide (IZO), etc.), metal halides (copper iodide, etc.), copper sulfide, carbon black, ITO glass, and Nesa glass. Examples of organic compounds include polythiophenes such as poly(3-methylthiophene), polypyrrole, polyaniline, and other conductive polymers. In addition, materials that are used as anodes in organic EL elements can be appropriately selected and used.

The resistance of the transparent electrode is not limited as long as it can supply sufficient current to light the light-emitting element, but a low resistance is desirable from the viewpoint of the power consumption of the light-emitting element. For example, an ITO substrate of 300 Ω/□ or less will function as an element electrode, but since it is now possible to supply substrates of around 10 Ω/□, it is particularly desirable to use a low resistance product of, for example, 100 to 5 Ω/□, preferably 50 to 5 Ω/□. The thickness of the ITO can be selected arbitrarily according to the resistance value, but it is usually used in the range of 50 to 300 nm.

3-1-4. Hole injection layer and hole transport layer in organic electroluminescence element The hole injection layer 103 plays a role of efficiently injecting holes moving from the anode 102 into the light emitting layer 105 or the hole transport layer 104. The hole transport layer 104 plays a role of efficiently transporting holes injected from the anode 102 or holes injected from the anode 102 through the hole injection layer 103 to the light emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are each formed by laminating and mixing one or more types of hole injection/transport materials, or by a mixture of a hole injection/transport material and a polymer binder. Alternatively, a layer may be formed by adding an inorganic salt such as iron (III) chloride to the hole injection/transport material.

The hole injection/transport material must be able to efficiently inject and transport holes from the positive electrode between electrodes to which an electric field is applied, and it is desirable for the hole injection efficiency to be high and for the injected holes to be efficiently transported. To achieve this, it is preferable for the material to have a small ionization potential, a large hole mobility, excellent stability, and a low probability of generating impurities that act as traps during manufacture and use.

As the material for forming the hole injection layer 103 and the hole transport layer 104, any compound can be selected from compounds conventionally used as charge transport materials for holes in photoconductive materials, p-type semiconductors, and known compounds used in hole injection layers and hole transport layers of organic EL elements. Specific examples of such compounds include carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis(N-arylcarbazole) or bis(N-alkylcarbazole), triarylamine derivatives (polymers having an aromatic tertiary amino in the main chain or side chain, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine, N,N'-dinaphthyl-N,N'-diphenyl-4,4'-diphenyl-1,1'-diamine, N ⁴ ,N ^{4 '} -diphenyl-N ⁴ ,N ⁴ '-Bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4,4'-diamine, N ⁴ ,N ⁴ ,N ⁴ ',N ⁴ '-tetra[1,1'-biphenyl]-4-yl)-[1,1'-biphenyl]-4,4'-diamine, 4,4',4"-tris(3-methylphenyl(phenyl)amino)triphenylamine, N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1':4',1"-terphenyl]- triphenylamine derivatives such as 4-amine, starburst amine derivatives, etc.), stilbene derivatives, phthalocyanine derivatives (metal-free, copper phthalocyanine, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, quinoxaline derivatives (for example, 1,4,5,8,9,12-hexaazatriphenylene-2,3,6,7,10,11-hexacarbonitrile, etc.), heterocyclic compounds such as porphyrin derivatives, polysilanes, etc. As for polymers, polycarbonates and styrene derivatives having the above-mentioned monomers in the side chains, polyvinylcarbazole, polysilanes, etc. are preferred, but there is no particular limitation as long as the compound can form a thin film necessary for the production of a light-emitting element, can inject holes from the anode, and can transport holes.

It is also known that the electrical conductivity of organic semiconductors is strongly influenced by doping. Organic semiconductor matrix substances consist of compounds with good electron donating or accepting properties. For doping with electron donating substances, strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are known (see, for example, the literature "M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202-3204 (1998)" and the literature "J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731 (1998)"). These generate so-called holes by an electron transfer process in an electron-donating base material (hole transport material). The conductivity of the base material varies considerably depending on the number and mobility of the holes. Matrix materials with hole transport properties are known, for example, benzidine derivatives (such as TPD) or starburst amine derivatives (such as TDATA), or certain metal phthalocyanines (especially zinc phthalocyanine (ZnPc)) (JP 2005-167175 A).

The hole injection layer material and the hole transport layer material described above can also be used as hole layer materials in the form of a polymer compound obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer, or a crosslinked polymer thereof, or a pendant polymer compound obtained by reacting a main chain polymer with the reactive compound, or a crosslinked pendant polymer thereof. In this case, the reactive substituent can be quoted from the description of the polycyclic aromatic compound consisting of a partial structure represented by formula (1A) and at least two partial structures represented by formula (1B).
The applications of such polymer compounds and crosslinked polymers will be described in detail below.

3-1-5. Light-emitting layer in organic electroluminescent element The light-emitting layer 105 emits light by recombining holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material for forming the light-emitting layer 105 may be a compound (light-emitting compound) that is excited by the recombination of holes and electrons to emit light, and is preferably a compound that can form a stable thin film shape and shows strong light-emitting (fluorescence) efficiency in a solid state. The light-emitting layer may be a single layer or multiple layers, each of which is formed from a material for the light-emitting layer (host material, dopant material). The host material and the dopant material may each be one type or a combination of multiple types. For example, an emitting dopant and an assisting dopant may be used as the dopant material. The dopant material may be contained in the entire host material or may be contained partially in the host material. As a doping method, the light-emitting layer may be formed by co-evaporation with the host material, but it may also be mixed with the host material in advance and then evaporated at the same time. The light-emitting layer can also be formed by a wet film-forming method using a composition for forming a light-emitting layer prepared by dissolving materials in an organic solvent.

The polycyclic aromatic compound of the present invention can be preferably used as a material for forming the light-emitting layer of an organic electroluminescent device.

The light-emitting layer containing the polycyclic aromatic compound of the present invention may contain a host compound. The polycyclic aromatic compound of the present invention is preferably used as a host compound in the light-emitting layer. Here, the host compound may be one type or two or more types.
The light-emitting layer may be a single layer or multiple layers. The host compound, the emitting dopant material, and the assisting dopant material may be contained in the same layer, or at least one component may be contained in each of the multiple layers. The host compound and the dopant material (emitting dopant or assisting dopant) contained in the light-emitting layer may each be one type or a combination of multiple types. The assisting dopant and the emitting dopant may be entirely or partially contained in the host compound as a matrix.

The amount of the host material used varies depending on the type of host material, and may be determined according to the characteristics of the host material. The amount of the host material used is preferably 50 to 99.999% by mass, more preferably 80 to 99.95% by mass, and even more preferably 90 to 99.9% by mass, of the total light-emitting layer material.

The amount of dopant material used varies depending on the type of dopant material, and may be determined according to the characteristics of the dopant material. The amount of dopant used is preferably 0.001 to 50% by mass of the total light-emitting layer material, more preferably 0.05 to 20% by mass, and even more preferably 0.1 to 10% by mass. The above ranges are preferable in that, for example, concentration quenching can be prevented.

On the other hand, in an organic electroluminescent device using a TADF material as a dopant material, a low concentration of the dopant material is preferable in terms of preventing concentration quenching, but a high concentration of the dopant material is preferable in terms of the efficiency of the thermally activated delayed fluorescence mechanism. Furthermore, in an organic electroluminescent device using a TADF material as an assisting dopant, a low concentration of the emitting dopant is preferable compared to the amount of the assisting dopant in terms of the efficiency of the thermally activated delayed fluorescence mechanism of the assisting dopant.

When an assisting dopant material is used, the approximate amounts of the host material, assisting dopant, and emitting dopant used are 40 to 99% by weight, 59 to 1% by weight, and 20 to 0.001% by weight, respectively, of the total light-emitting layer material, preferably 60 to 95% by weight, 39 to 5% by weight, and 10 to 0.01% by weight, respectively, and more preferably 70 to 90% by weight, 29 to 10% by weight, and 5 to 0.05% by weight.

3-1-5-1. Host Compound The polycyclic aromatic compound of the present invention is preferably used as a host compound in the light-emitting layer.

From the viewpoint of promoting rather than inhibiting the generation of TADF in the light-emitting layer, the _ET1 of the host material is preferably higher than the ET1 of the dopant having the highest _ET1 in the light-emitting layer or the _ET1 of the assisting dopant. Specifically, the _ET1 of the host is preferably 0.01 eV or more, more preferably 0.03 eV or more, and even more preferably 0.1 eV or more.
In addition, a compound having TADF activity may be used as the host material.

In addition to the polycyclic aromatic compound of the present invention, examples of the host material include condensed ring derivatives such as anthracene and pyrene, which have long been known as light emitters, bisstyryl derivatives such as bisstyryl anthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, fluorene derivatives, and benzofluorene derivatives. Further examples of the host material include a compound represented by the following formula (H1), a compound represented by the following formula (H2), a compound represented by the following formula (H3), a compound containing a structure represented by the following formula (H4), a compound represented by the following formula (H5), and a compound represented by the following formula (H6). Any one or more of these compounds may be used in combination with the polycyclic aromatic compound of the present invention.

3-1-5-1-1. Compound represented by formula (H1)

In formula (H1), L ¹ is an arylene having 6 to 24 carbon atoms, preferably an arylene having 6 to 16 carbon atoms, more preferably an arylene having 6 to 12 carbon atoms, and particularly preferably an arylene having 6 to 10 carbon atoms. Specific examples thereof include divalent groups such as a benzene ring, a biphenyl ring, a naphthalene ring, a terphenyl ring, an acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, a triphenylene ring, a pyrene ring, a naphthacene ring, a perylene ring, and a pentacene ring.
At least one hydrogen atom in the compound represented by formula (H1) may be substituted with alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cyano, halogen or deuterium.

3-1-5-1-2. Compound represented by formula (H2)

In formula (H2), ^L2 and ^L3 are each independently an aryl having 6 to 30 carbon atoms or a heteroaryl having 2 to 30 carbon atoms. The aryl is preferably an aryl having 6 to 24 carbon atoms, more preferably an aryl having 6 to 16 carbon atoms, still more preferably an aryl having 6 to 12 carbon atoms, and particularly preferably an aryl having 6 to 10 carbon atoms. Specific examples of the aryl include monovalent groups such as a benzene ring, a biphenyl ring, a naphthalene ring, a terphenyl ring, an acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, a triphenylene ring, a pyrene ring, a naphthacene ring, a perylene ring, and a pentacene ring. The heteroaryl is preferably a heteroaryl having 2 to 25 carbon atoms, more preferably a heteroaryl having 2 to 20 carbon atoms, still more preferably a heteroaryl having 2 to 15 carbon atoms, and particularly preferably a heteroaryl having 2 to 10 carbon atoms. Specific examples thereof include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, an isoindole ring, a 1H-indazole ring, a benzo Examples of monovalent groups include an imidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a furazan ring, an oxadiazole ring, and a thianthrene ring.
At least one hydrogen atom in the compound represented by formula (H2) may be substituted with alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cyano, halogen or deuterium.

3-1-5-1-3. Compound represented by formula (H3)

In formula (H3),
Each MU is independently a divalent aromatic group, each EC is independently a monovalent aromatic group, and k is an integer of 2 to 50,000.

More specifically,
Each MU is independently arylene, heteroarylene, diarylenarylamino, diarylenarylboryl, oxaborine-diyl, or azaborine-diyl;
each E C is independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy;
At least one hydrogen in MU and EC may be further substituted with aryl, heteroaryl, diarylamino, alkyl, and cycloalkyl;
k is an integer from 2 to 50,000.
k is preferably an integer from 20 to 50,000, and more preferably an integer from 100 to 50,000.

At least one hydrogen atom in MU and EC in formula (H3) may be substituted with alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 24 carbon atoms, halogen or deuterium; further, any -CH ₂ - in the alkyl may be substituted with -O- or -Si(CH ₃ ) ₂ -; any -CH ₂ - in the alkyl except for the -CH ₂ - directly bonded to EC in formula (H3) may be substituted with arylene having 6 to 24 carbon atoms; and any hydrogen atom in the alkyl may be substituted with fluorine.

Examples of MU include divalent derivatives of the following structures (e.g., a divalent group represented by removing any two hydrogen atoms from any of the compounds of the following structures, a divalent group composed of a combination of two or more divalent groups represented by removing any two hydrogen atoms from any of the compounds of the following structures, and a divalent group in which at least one hydrogen in such a group has been substituted with an alkyl or the like).

More specifically, examples include divalent groups having any of the following structures. In these, MU bonds to another MU or EC at the *.

Examples of EC include groups represented by the following formulas. In these, EC bonds to MU at *.

From the viewpoints of solubility and coating film-forming properties, the compound represented by formula (H3) is preferably such that 10 to 100% of the total number of MUs (k) in the molecule have an alkyl having 1 to 24 carbon atoms, more preferably 30 to 100% of the total number of MUs (k) in the molecule have an alkyl having 1 to 18 carbon atoms (branched chain alkyl having 3 to 18 carbon atoms), and even more preferably 50 to 100% of the total number of MUs (k) in the molecule have an alkyl having 1 to 12 carbon atoms (branched chain alkyl having 3 to 12 carbon atoms). On the other hand, from the viewpoints of in-plane alignment and charge transport, it is preferable that 10 to 100% of the total number of MUs (k) in the molecule have an alkyl having 7 to 24 carbon atoms, and more preferably 30 to 100% of the total number of MUs (k) in the molecule have an alkyl having 7 to 24 carbon atoms (branched chain alkyl having 7 to 24 carbon atoms).

Compound containing a structure represented by formula (H4) The compound containing a structure represented by formula (H4) contains a plurality of structures represented by formula (H4), preferably 1 to 5 structures, more preferably 1 to 3 structures, even more preferably 1 to 2 structures, and most preferably 1 structure. When a plurality of structures are contained, the structures are directly bonded to each other via a single bond or a specific linking group.

In formula (H4), G is "=C(-H)-" or "=N-", and the H in the "=C(-H)-" may be substituted with a substituent or another structure represented by formula (H4).

Compounds containing the structure represented by formula (H4) can be, for example, compounds described in WO 2012/153780 and WO 2013/038650, and can be produced according to the methods described in the above documents.

When the H in "=C(-H)-" which is G is substituted, examples of the substituent include aryl, heteroaryl, substituted silyl, substituted phosphine oxide group, and substituted carboxy.

Specific examples of the "aryl" substituent include phenyl, tolyl, xylyl, naphthyl, phenanthryl, pyrenyl, chrysenyl, benzo[c]phenanthryl, benzo[g]chrysenyl, benzanthryl, triphenylenyl, fluorenyl, 9,9-dimethylfluorenyl, benzofluorenyl, dibenzofluorenyl, biphenylyl, terphenylyl, quaterphenylyl, fluoranthenyl, etc., and preferably phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, triphenylenyl, and fluorenyl. Examples of aryl having a substituent include tolyl, xylyl, and 9,9-dimethylfluorenyl. As shown in the specific examples, aryl includes both fused and non-fused aryl.

Specific examples of the substituent "heteroaryl" include pyrrolyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyridyl, triazinyl, indolyl, isoindolyl, imidazolyl, benzimidazolyl, indazolyl, imidazo[1,2-a]pyridinyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, azadibenzofuranyl, thienyl, benzothienyl, dibenzothienyl, azadibenzothienyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolinyl, and naphthyridinyl. Examples of the aryl include carbazolyl, azacarbazolyl, phenanthridinyl, acridinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, phenoxazinyl, oxazolyl, oxadiazolyl, furazanyl, benzoxazolyl, thiazolyl, thiadiazolyl, benzothiazolyl, triazolyl, and tetrazolyl. Preferred examples include dibenzofuranyl, dibenzothienyl, carbazolyl, pyridyl, pyrimidinyl, triazinyl, azadibenzofuranyl, and azadibenzothienyl. Dibenzofuranyl, dibenzothienyl, azadibenzofuranyl, and azadibenzothienyl are more preferred.

It is also preferred that the substituent "substituted silyl" is a group selected from the group consisting of substituted or unsubstituted trialkylsilyl, substituted or unsubstituted arylalkylsilyl, and substituted or unsubstituted triarylsilyl.

Specific examples of substituted or unsubstituted trialkylsilyl include trimethylsilyl and triethylsilyl. Specific examples of substituted or unsubstituted arylalkylsilyl include diphenylmethylsilyl, ditolylmethylsilyl, and phenyldimethylsilyl. Specific examples of substituted or unsubstituted triarylsilyl include triphenylsilyl and tritolylsilyl.

The "substituted phosphine oxide group" which is a substituent is also preferably a substituted or unsubstituted diarylphosphine oxide group. Specific examples of substituted or unsubstituted diarylphosphine oxide groups include diphenylphosphine oxide and ditolylphosphine oxide.

Examples of the "substituted carboxy" substituent include benzoyloxy.

Examples of linking groups that bond multiple structures represented by formula (H4) include divalent to tetravalent, divalent to trivalent, or divalent derivatives of the above-mentioned aryl or heteroaryl.

Specific examples of the compound containing the structure represented by formula (H4) are shown below.

3-1-5-1-5. Compound represented by formula (H5) and compound represented by formula (H6)
3-1-5-1-5-1. Compound represented by formula (H5)

In formula (H5), R ¹ to R ¹¹ each independently represent a hydrogen atom, an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, or an aryloxy group, in which at least one hydrogen atom may be further substituted with an aryl group, a heteroaryl group, or a diarylamino group;
Adjacent groups among R ¹ to R ¹¹ may be bonded to each other to form an aryl ring or a heteroaryl ring together with the ring a, ring b, or ring c, and at least one hydrogen atom in the formed ring may be substituted with an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy, and at least one hydrogen atom in these rings may be further substituted with an aryl, heteroaryl, or diarylamino.
In addition, at least one (preferably 1 to 3) arbitrary —C(R ⁿ )= (n is 1 to 11) in formula (H5) may be substituted with —N=.
Furthermore, at least one hydrogen atom in the compound represented by formula (H5) may be substituted with a group represented by formula (FG-1), a group represented by formula (FG-2), or an alkyl having 1 to 24 carbon atoms, and further, any -CH ₂ - in the alkyl may be substituted with -O- or -Si(CH ₃ ) ₂ -, any -CH ₂ - in the alkyl except for the -CH ₂ - directly bonded to the compound represented by formula (H5) may be substituted with an arylene having 6 to 24 carbon atoms, and any hydrogen atom in the alkyl may be substituted with fluorine.
In addition, at least one hydrogen in the compound represented by formula (H5) may be substituted with a halogen or deuterium.

In formula (H5), adjacent groups among the substituents R ¹ to R ¹¹ of ring a, ring b, and ring c may be bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, ring b, or ring c, and at least one hydrogen in the formed ring may be substituted with an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy, and at least one hydrogen in these may be further substituted with an aryl, heteroaryl, or diarylamino. However, here, "adjacent groups" refers to groups adjacent to each other on the same ring, and a compound in which "adjacent groups are bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, ring b, or ring c" corresponds to, for example, compounds represented by formulae (H5-2) to (H5-17) listed below as specific compounds. That is, for example, it is a compound formed by condensing a benzene ring, an indole ring, a pyrrole ring, a benzofuran ring, or a benzothiophene ring to ring a (or ring b or ring c), and the condensed ring formed is a naphthalene ring, a carbazole ring, an indole ring, a dibenzofuran ring, or a dibenzothiophene ring, respectively.

3-1-5-1-5-2. Compound represented by formula (H6)

In formula (H6), R ¹ to R ¹⁶ each independently represent a hydrogen atom, an aryl group, a heteroaryl group, a diarylamino group, a diheteroarylamino group, an arylheteroarylamino group, or an aryloxy group, in which at least one hydrogen atom may be further substituted with an aryl group, a heteroaryl group, or a diarylamino group;
Adjacent groups among R ¹ to R ¹⁶ may be bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, ring b, ring c or ring d, and at least one hydrogen atom in the formed ring may be substituted with aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino or aryloxy, and at least one hydrogen atom in these rings may be further substituted with aryl, heteroaryl or diarylamino.
Furthermore, at least one hydrogen atom in the compound represented by formula (H-6) may be substituted with an alkyl group having 1 to 24 carbon atoms, and further, any -CH ₂ - in the alkyl group may be substituted with -O- or -Si(CH ₃ ) ₂ -, any -CH ₂ - in the alkyl group except for the -CH ₂ - directly bonded to the compound represented by formula (H6) may be substituted with an arylene group having 6 to 24 carbon atoms, and any hydrogen atom in the alkyl group may be substituted with fluorine.
In addition, at least one hydrogen in the compound represented by formula (H6) may be substituted with a halogen or deuterium.

In formula (H6), adjacent groups among the substituents R ¹ to R ¹⁶ of ring a, ring b, ring c, and ring d may be bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, ring b, ring c, or ring c, and at least one hydrogen in the formed ring may be substituted with an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy, and at least one hydrogen in these may be further substituted with an aryl, heteroaryl, or diarylamino. However, here, "adjacent groups" refers to groups adjacent to each other on the same ring, and a compound in which "adjacent groups are bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, ring b, ring c, or ring d" can be explained with reference to, for example, compounds represented by formulas (H6-2) to (H6-5) listed below as specific compounds of formula (H6). That is, for example, it is a compound formed by condensing a benzene ring, an indole ring, a pyrrole ring, a benzofuran ring, or a benzothiophene ring to ring a (or ring b, ring c, or ring d), and the condensed ring formed is a naphthalene ring, a carbazole ring, an indole ring, a dibenzofuran ring, or a dibenzothiophene ring, respectively.

3-1-5-1-5-3. "R ¹ to R ¹¹ in formula (H5) " and "R ¹ to R ¹⁶ in formula (H6) "
"R ¹ to R ¹¹ in formula (H5)" and "R ¹ to R ¹⁶ in formula (H6)" are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino or aryloxy, and preferably an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, diarylamino (amino having two aryls having 6 to 30 carbon atoms), diheteroarylamino (amino having two heteroaryls having 2 to 30 carbon atoms), arylheteroarylamino (amino having an aryl having 6 to 30 carbon atoms and a heteroaryl having 2 to 30 carbon atoms) or an aryloxy having 6 to 30 carbon atoms.

Examples of the aryl in "aryl" and "diarylamino", the aryl in "arylheteroarylamino", and the aryl in "aryloxy" include a monocyclic benzene ring, a bicyclic ...

Examples of the heteroaryl in "heteroaryl" and "diheteroarylamino" and the heteroaryl in "arylheteroarylamino" include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H -benzotriazole ring, quinoline ring, isoquinoline ring, cinnoline ring, quinazoline ring, quinoxaline ring, phthalazine ring, naphthyridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathiin ring, phenoxazine ring, phenothiazine ring, phenazine ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, furazan ring, oxadiazole ring, thianthrene ring, and monovalent groups such as the above heteroaryl substituted with N-aryl. Furthermore, as described below, those heteroaryls substituted with the aryls defined above are also defined as heteroaryls in formula (H5) and formula (H6).

In addition, at least one hydrogen atom in the aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, or aryloxy groups described as R ¹ to R ¹¹ in formula (H5) and R ¹ to R ¹⁶ in formula (H6) may be further substituted with an aryl, heteroaryl, or diarylamino group. Examples of the aryl, heteroaryl, or diarylamino group to be substituted in this manner include the same groups as those described in the sections for R ¹ to R ¹¹ and R ¹ to R ¹⁶ .

Specific examples of R ¹ to R ¹¹ and R ¹ to R ¹⁶ include groups represented by the following formulae (RG-1) to (RG-10). The groups represented by the following formulae (RG-1) to (RG-10) are bonded to formula (H5) or formula (H6) at *.

With reference to the specific groups mentioned above, the definitions of "aryl" and "heteroaryl" in formulae (H5) and (H6) are as follows: Formulae (RG-1), (RG-4) and (RG-7) are aryl, Formulae (RG-2), (RG-3) and (RG-6) are heteroaryl, Formula (RG-9) is heteroaryl substituted with heteroaryl, and Formula (RG-10) is aryl substituted with heteroaryl. Formula (RG-5) is aryl (phenyl) substituted with diarylamino (diphenylamino), and Formula (RG-8) is diarylamino (diphenylamino).

3-1-5-1-5-4. In formula (H5), the ring formed by bonding adjacent groups of ring a, ring b, or ring c, and in formula (H6), the ring formed by bonding adjacent groups of ring a, ring b, ring c, or ring d, "the aryl ring formed together with ring a, ring b, or ring c by bonding adjacent groups among R ¹ to R ¹¹ " in formula (H5), and "the aryl ring formed together with ring a, ring b, ring c, or ring d by bonding adjacent groups among R ¹ to R ¹⁶ " in formula (H6) include, for example, an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms, and particularly preferably an aryl ring having 6 to 10 carbon atoms. However, the number of carbon atoms of the formed aryl ring includes the 6 carbon atoms of ring a, ring b, ring c, or ring d.

Specific examples of the aryl rings formed include a naphthalene ring, which is a fused bicyclic ring; an acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, which are fused tricyclic rings; a triphenylene ring, a pyrene ring, a naphthacene ring, which are fused tetracyclic rings; a perylene ring, a pentacene ring, which are fused pentacyclic rings, and the like.

Examples of the "heteroaryl ring formed together with the ring a, ring b, or ring c by bonding adjacent groups among R ¹ to R ¹¹ " in formula (H5), and the "aryl ring formed together with the ring a, ring b, ring c, or ring d by bonding adjacent groups among R ¹ to R ¹⁶ " in formula (H6) include heteroaryl rings having 6 to 30 carbon atoms, preferably heteroaryl rings having 6 to 25 carbon atoms, more preferably heteroaryl rings having 6 to 20 carbon atoms, even more preferably heteroaryl rings having 6 to 15 carbon atoms, and particularly preferably heteroaryls having 6 to 10 carbon atoms. Examples of the "heteroaryl ring" include heterocycles containing, as ring-constituting atoms, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon. However, the number of carbon atoms in the formed heteroaryl ring includes the 6 carbon atoms in the ring a, ring b, ring c, or ring d.

Specific examples of the heteroaryl ring formed include an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a benzothiophene ring, a dibenzothiophene ring, and a thianthrene ring.

At least one hydrogen atom in the formed ring may be replaced by an aryl, a heteroaryl, a diarylamino, a diheteroarylamino, an arylheteroarylamino, or an aryloxy, and at least one hydrogen atom in these may be further replaced by an aryl, a heteroaryl, or a diarylamino. For this explanation, reference may be made to the explanations of R ¹ to R ¹¹ in formula (H5) and R ¹ to R ¹⁶ in formula (H6).

3-1-5-1-5-5. Specific examples of compounds More specific structures of the compounds represented by formula (H5) or formula (H6) are shown below.
The specific structure of the compound represented by the following formula (H5) or formula (H6) may be substituted with an alkyl group having 1 to 24 carbon atoms.

3-1-5-1-5-6. Method for producing a compound represented by formula (H5) or formula (H6) For the compound represented by formula (H5), first, rings a to c are bonded with a bonding group (-O-) to produce an intermediate (first reaction), and then rings a to c are bonded with a bonding group (group containing B) to produce a final product (second reaction). For the compound represented by formula (H6), first, rings a to d are bonded with a bonding group (>NH or single bond) to produce an intermediate (first reaction), and then rings a to d are bonded with a bonding group (group containing B) to produce a final product (second reaction). For the first reaction, for example, if it is an etherification reaction, a general reaction such as a nucleophilic substitution reaction or an Ullmann reaction can be used, and if it is an amination reaction, a general reaction such as a Buchwald-Hartwig reaction can be used. For the second reaction, a tandem hetero Friedel-Crafts reaction (successive aromatic electrophilic substitution reaction, the same applies below) can be used.

<Production Method: Example of the Second Reaction of the Compound Represented by Formula (H5)>
The second reaction is a reaction to introduce B (boron) that bonds the a ring, the b ring, and the c ring, as shown in the following scheme (1). As an example, the case of a compound represented by formula (H5) is shown below. First, the hydrogen atom between two Os is orthometalated with n-butyllithium, sec-butyllithium, t-butyllithium, or the like. Next, boron trichloride, boron tribromide, or the like is added to perform lithium-boron metal exchange, and then a tandem boron-Friedel-Crafts reaction is carried out by adding a Bronsted base such as N,N-diisopropylethylamine, thereby obtaining the target product. In the second reaction, a Lewis acid such as aluminum trichloride may be added to promote the reaction.

In the above scheme, lithium was introduced at the desired position by orthometalation, but it is also possible to introduce lithium at the desired position by introducing a bromine atom or the like at the desired position and then performing halogen-metal exchange, as in scheme (2) below.

By appropriately selecting the above synthesis method and the raw materials to be used, it is possible to synthesize a compound represented by formula (H-5) having a substituent at the desired position.

<Production method: Example of the production method for the compound represented by formula (H6)>
The first and second reactions in the method for producing the compound represented by formula (H5) described above can also be applied to the method for producing the compound represented by formula (H6). That is, the second reaction is a reaction for introducing B (boron) which bonds NH to the c-ring and d-ring, and the hydrogen atom of NH is orthometalated with n-butyllithium, sec-butyllithium, t-butyllithium, or the like, and then boron trichloride, boron tribromide, or the like is added to carry out lithium-boron metal exchange, and further, a tandem boron-Friedel-Crafts reaction can be carried out by adding a Bronsted base such as N,N-diisopropylethylamine, to obtain the target product. Here again, in the second reaction, a Lewis acid such as aluminum trichloride may be added to promote the reaction.

3-1-5-2. Dopant material The dopant material is not particularly limited, and any known compound can be used, and can be selected from various materials depending on the desired emission color. The polycyclic aromatic compound of the present invention may be used as the dopant material.
Specific examples of such compounds include condensed ring derivatives of phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, rubrene, and chrysene, benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, benzotriazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazoline derivatives, stilbene derivatives, thiophene derivatives, and tetraphenylbutadiene. derivatives, cyclopentadiene derivatives, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives (JP Patent Publication No. 1-245087), bisstyrylarylene derivatives (JP Patent Publication No. 2-247278), diazaindacene derivatives, furan derivatives, benzofuran derivatives, isobenzofuran derivatives such as phenylisobenzofuran, dimesitylisobenzofuran, di(2-methylphenyl)isobenzofuran, di(2-trifluoromethylphenyl)isobenzofuran, and phenylisobenzofuran coumarin derivatives such as dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinocoumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzothiazolylcoumarin derivatives, 3-benzimidazolylcoumarin derivatives, and 3-benzoxazolylcoumarin derivatives, dicyanomethylenepyran derivatives, dicyanomethylenethiopyran derivatives, polymethine derivatives, cyanine derivatives, oxobenzoanthracene derivatives, xanthene derivatives, rhodamine derivatives, conductors, fluorescein derivatives, pyrylium derivatives, carbostyril derivatives, acridine derivatives, oxazine derivatives, phenylene oxide derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furopyridine derivatives, 1,2,5-thiadiazolopyrene derivatives, pyrromethene derivatives, perinone derivatives, pyrrolopyrrole derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, acridone derivatives, deazaflavin derivatives, fluorene derivatives and benzofluorene derivatives.

As examples of dopant materials for each color of light emitted, blue to blue-green dopant materials include aromatic hydrocarbon compounds such as naphthalene, anthracene, phenanthrene, pyrene, triphenylene, perylene, fluorene, indene, and chrysene, and their derivatives, as well as furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, and pyrrolopyridine. Examples include aromatic heterocyclic compounds such as lysine and thioxanthene and their derivatives, distyrylbenzene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, coumarin derivatives, azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, and triazole, and metal complexes thereof, and aromatic amine derivatives such as N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine.

In addition, examples of green to yellow dopant materials include coumarin derivatives, phthalimide derivatives, naphthalimide derivatives, perinone derivatives, pyrrolopyrrole derivatives, cyclopentadiene derivatives, acridone derivatives, quinacridone derivatives, and naphthacene derivatives such as rubrene. Further, suitable examples include compounds in which a substituent that enables longer wavelengths, such as aryl, heteroaryl, arylvinyl, amino, or cyano, has been introduced into the compounds exemplified as the blue to blue-green dopant materials above.

Further, examples of orange to red dopant materials include naphthalimide derivatives such as bis(diisopropylphenyl)perylenetetracarboxylic acid imide, perinone derivatives, rare earth complexes such as Eu complexes with ligands such as acetylacetone, benzoylacetone and phenanthroline, 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran and its analogues, metal phthalocyanine derivatives such as magnesium phthalocyanine and aluminum chlorophthalocyanine, rhodamine compounds, deazaflavin derivatives, coumarin derivatives, quinacridone derivatives, phenoxazine derivatives, oxazine derivatives, quinazoline derivatives, pyrrolopyridine derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, phenoxazone derivatives and thiadiazolopyrene derivatives. Further examples of suitable compounds include those obtained by introducing substituents such as aryl, heteroaryl, arylvinyl, amino and cyano that enable longer wavelengths into the compounds exemplified above as blue to blue-green and green to yellow dopant materials.

As other dopants, compounds described in Chemical Industry, June 2004, p. 13 and references cited therein can be appropriately selected and used.

Among the dopant materials described above, amines having a stilbene structure, perylene derivatives, borane derivatives, aromatic amine derivatives, coumarin derivatives, pyran derivatives, or pyrene derivatives are particularly preferred.

当該式中、Ａｒ^１は炭素数６～３０のアリールに由来するｍ価の基であり、Ａｒ^２およびＡｒ^３は、それぞれ独立して炭素数６～３０のアリールであるが、Ａｒ^１～Ａｒ^３の少なくとも１つはスチルベン構造を有し、Ａｒ^１～Ａｒ^３は、アリール、ヘテロアリール、アルキル、シクロアルキル、トリ置換シリル（アリール、アルキルおよび／またはシクロアルキルでトリ置換されたシリル）またはシアノで置換されていてもよく、そして、ｍは１～４の整数である。 The amine having a stilbene structure is represented, for example, by the following formula.

In the formula, Ar ¹ is an m-valent group derived from an aryl having 6 to 30 carbon atoms, Ar ² and Ar ³ are each independently an aryl having 6 to 30 carbon atoms, at least one of Ar ¹ to Ar ³ has a stilbene structure, Ar ¹ to Ar ³ may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, tri-substituted silyl (silyl tri-substituted with aryl, alkyl and/or cycloalkyl) or cyano, and m is an integer of 1 to 4.

当該式中、Ａｒ^２およびＡｒ^３は、それぞれ独立して炭素数６～３０のアリールであり、Ａｒ^２およびＡｒ^３は、アリール、ヘテロアリール、アルキル、シクロアルキル、トリ置換シリル（アリール、アルキルおよび／またはシクロアルキルでトリ置換されたシリル）またはシアノで置換されていてもよい。 The amine having a stilbene structure is more preferably a diaminostilbene represented by the following formula.

In the formula, Ar ² and Ar ³ are each independently an aryl having 6 to 30 carbon atoms, and Ar ² and Ar ³ may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, tri-substituted silyl (silyl tri-substituted with aryl, alkyl and/or cycloalkyl) or cyano.

Specific examples of aryls having 6 to 30 carbon atoms include phenyl, naphthyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthrenyl, anthryl, fluoranthenyl, triphenylenyl, pyrenyl, chrysenyl, naphthacenyl, perylenyl, stilbenyl, distyrylphenyl, distyrylbiphenylyl, and distyrylfluorenyl.

Specific examples of the amine having a stilbene structure include N,N,N',N'-tetra(4-biphenylyl)-4,4'-diaminostilbene, N,N,N',N'-tetra(1-naphthyl)-4,4'-diaminostilbene, N,N,N',N'-tetra(2-naphthyl)-4,4'-diaminostilbene, N,N'-di(2-naphthyl)-N,N'-diphenyl-4,4'-diaminostilbene, and N,N'-di(9-phenanthryl)-N,N'-diphenyl-4,4'-diaminostilbene. 4,4'-bis(9-ethyl-3-carbazovinylene)-biphenyl, 4,4'-bis(9-phenyl-3-carbazovinylene)-biphenyl, and the like.
Furthermore, amines having a stilbene structure as described in JP-A Nos. 2003-347056 and 2001-307884 may also be used.

Examples of perylene derivatives include 3,10-bis(2,6-dimethylphenyl)perylene, 3,10-bis(2,4,6-trimethylphenyl)perylene, 3,10-diphenylperylene, 3,4-diphenylperylene, 2,5,8,11-tetra-t-butylperylene, 3,4,9,10-tetraphenylperylene, 3-(1'-pyrenyl)-8,11-di(t-butyl)perylene, 3-(9'-anthryl)-8,11-di(t-butyl)perylene, and 3,3'-bis(8,11-di(t-butyl)perylenyl).
Also usable are perylene derivatives described in JP-A-11-97178, JP-A-2000-133457, JP-A-2000-26324, JP-A-2001-267079, JP-A-2001-267078, JP-A-2001-267076, JP-A-2000-34234, JP-A-2001-267075, and JP-A-2001-217077.

Examples of the borane derivatives include 1,8-diphenyl-10-(dimesitylboryl)anthracene, 9-phenyl-10-(dimesitylboryl)anthracene, 4-(9'-anthryl)dimesitylborylnaphthalene, 4-(10'-phenyl-9'-anthryl)dimesitylborylnaphthalene, 9-(dimesitylboryl)anthracene, 9-(4'-biphenylyl)-10-(dimesitylboryl)anthracene, and 9-(4'-(N-carbazolyl)phenyl)-10-(dimesitylboryl)anthracene.
Furthermore, borane derivatives described in International Publication No. 2000/40586 and the like may also be used.

当該式中、Ａｒ^４は炭素数６～３０のアリールに由来するｎ価の基であり、Ａｒ^５およびＡｒ^６はそれぞれ独立して炭素数６～３０のアリールであり、Ａｒ^４～Ａｒ^６は、アリール、ヘテロアリール、アルキル、シクロアルキル、トリ置換シリル（アリール、アルキルおよび／またはシクロアルキルでトリ置換されたシリル）またはシアノで置換されていてもよく、そして、ｎは１～４の整数である。 The aromatic amine derivative is represented, for example, by the following formula:

In the formula, Ar ⁴ is an n-valent group derived from an aryl having 6 to 30 carbon atoms, Ar ⁵ and Ar ⁶ are each independently an aryl having 6 to 30 carbon atoms, Ar ⁴ to Ar ⁶ may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, tri-substituted silyl (silyl tri-substituted with aryl, alkyl and/or cycloalkyl) or cyano, and n is an integer from 1 to 4.

In particular, an aromatic amine derivative in which Ar ⁴ is a divalent group derived from anthracene, chrysene, fluorene, benzofluorene or pyrene, Ar ⁵ and Ar ⁶ are each independently an aryl having 6 to 30 carbon atoms, Ar ⁴ to Ar ⁶ may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, tri-substituted silyl (silyl tri-substituted with an aryl, alkyl and/or cycloalkyl) or cyano, and n is 2 is more preferred.

Specific examples of aryls having 6 to 30 carbon atoms include phenyl, naphthyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthrenyl, anthryl, fluoranthenyl, triphenylenyl, pyrenyl, chrysenyl, naphthacenyl, perylenyl, and pentacenyl.

As aromatic amine derivatives, examples of chrysene derivatives include N,N,N',N'-tetraphenylchrysene-6,12-diamine, N,N,N',N'-tetra(p-tolyl)chrysene-6,12-diamine, N,N,N',N'-tetra(m-tolyl)chrysene-6,12-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl)chrysene-6,12-diamine, N,N,N',N'-tetra(naphthalene-2-yl)chrysene-6,12-diamine, N,N'-diphenyl Examples include -N,N'-di(p-tolyl)chrysene-6,12-diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl)chrysene-6,12-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)chrysene-6,12-diamine, N,N'-diphenyl-N,N'-bis(4-t-butylphenyl)chrysene-6,12-diamine, and N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)chrysene-6,12-diamine.

Examples of pyrene-based compounds include N,N,N',N'-tetraphenylpyrene-1,6-diamine, N,N,N',N'-tetra(p-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetra(m-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(3,4-dimethylphenyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-di(p-tolyl)pyrene-1,6-diamine, and N,N'-diphenyl-N,N'-bis(4-ethylphenyl)pyrene-1, 6-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)pyrene-1,6-diamine, N,N'-diphenyl-N,N'-bis(4-t-butylphenyl)pyrene-1,6-diamine, N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)pyrene-1,6-diamine, N,N,N',N'-tetrakis(3,4-dimethylphenyl)-3,8-diphenylpyrene-1,6-diamine, N,N,N,N-tetraphenylpyrene-1,8-diamine, N,N'-bis(biphenyl-4-yl)-N,N'-diphenylpyrene-1,8-diamine, N ¹ ,N ⁶ -diphenyl- ^{N 1} ,N ⁶ -bis-(4-trimethylsilanyl-phenyl)-1H,8H-pyrene-1,6-diamine and the like.

Examples of anthracene-based compounds include N,N,N,N-tetraphenylanthracene-9,10-diamine, N,N,N',N'-tetra(p-tolyl)anthracene-9,10-diamine, N,N,N',N'-tetra(m-tolyl)anthracene-9,10-diamine, N,N,N',N'-tetrakis(4-isopropylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-di(p-tolyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-di(m-tolyl)anthracene-9,10 -diamine, N,N'-diphenyl-N,N'-bis(4-ethylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)anthracene-9,10-diamine, N,N'-diphenyl-N,N'-bis(4-t-butylphenyl)anthracene-9,10-diamine, N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-di-t-butyl-N,N,N',N'-tetra(p-tolyl)anthracene-9,10-diamine 2,6-di-t-butyl-N,N'-diphenyl-N,N'-bis(4-isopropylphenyl)anthracene-9,10-diamine, 2,6-di-t-butyl-N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-dicyclohexyl-N,N'-bis(4-isopropylphenyl)-N,N'-di(p-tolyl)anthracene-9,10-diamine, 2,6-dicyclohexyl-N,N'-bis(4-isopropylphenyl)-N,N'-bis(4-t-butylphenyl) Examples include anthracene-9,10-diamine, 9,10-bis(4-diphenylamino-phenyl)anthracene, 9,10-bis(4-di(1-naphthylamino)phenyl)anthracene, 9,10-bis(4-di(2-naphthylamino)phenyl)anthracene, 10-di-p-tolylamino-9-(4-di-p-tolylamino-1-naphthyl)anthracene, 10-diphenylamino-9-(4-diphenylamino-1-naphthyl)anthracene, and 10-diphenylamino-9-(6-diphenylamino-2-naphthyl)anthracene.

Other examples include [4-(4-diphenylamino-phenyl)naphthalene-1-yl]-diphenylamine, [6-(4-diphenylamino-phenyl)naphthalene-2-yl]-diphenylamine, 4,4'-bis[4-diphenylaminonaphthalene-1-yl]biphenyl, 4,4'-bis[6-diphenylaminonaphthalene-2-yl]biphenyl, 4,4"-bis[4-diphenylaminonaphthalene-1-yl]-p-terphenyl, and 4,4"-bis[6-diphenylaminonaphthalene-2-yl]-p-terphenyl.
Furthermore, aromatic amine derivatives described in JP-A-2006-156888 and the like may also be used.

Examples of the coumarin derivatives include coumarin-6 and coumarin-334.
Furthermore, coumarin derivatives described in JP-A-2004-43646, JP-A-2001-76876, JP-A-6-298758, and the like may also be used.

Examples of the pyran derivative include the following DCM and DCJTB.

In addition, pyran derivatives described in JP-A-2005-126399, JP-A-2005-097283, JP-A-2002-234892, JP-A-2001-220577, JP-A-2001-081090, and JP-A-2001-052869 may also be used.

In particular, in the light-emitting layer, it is preferable to use the polycyclic aromatic compound of the present invention as a host material and a phosphorescent material or a TADF material (thermally activated delayed fluorescent material) as a dopant material.

3-1-5-2-1. Phosphorescent materials Phosphorescent materials utilize the intramolecular spin-orbit interaction (heavy atom effect) of metal atoms to obtain light emission from triplets. For example, a luminescent metal complex can be used as such a phosphorescent material. For example, a compound represented by the following formula (B-1) can be used as the luminescent metal complex.

In formula (B-1), M is at least one selected from the group consisting of Ir, Pt, Au, Eu, Ru, Re, Ag, and Cu, n is an integer of 1 to 3, and each "X-Y" is independently a bidentate monoanionic ligand.
Examples of the compound represented by formula (B-1) include compounds represented by the following formula (B-10) or formula (B-15).

In formula (B-10) and formula (B-15), X' is an aromatic ring containing a carbon (C) bonded to M, and Y' is a heterocycle containing a nitrogen (N) that is coordinately bonded to M. X' and Y' are bonded, and X' and Y' may form a new ring. In addition, in formula (B-15), Z is a bidentate ligand having two oxygen atoms. In formula (B-10) and formula (B-15), M is preferably Ir from the viewpoint of high efficiency and long life.

Examples of the compound represented by formula (B-10) include Ir(ppy) ₃ , Ir(ppy) ₂ (acac), Ir(mppy) ₃ , Ir(PPy) ₂ (m-bppy), BtpIr(acac), Ir(btp) ₂ (acac), Ir(2-phq) ₃ , Hex-Ir(phq) ₃ , Ir(fbi) ₂ (acac), fac-Tris(2-(3-p-xylyl)phenyl)pyridine iridium(III), Eu(dbm) ₃ (Phen), Ir(piq) ₃ , Ir(piq) ₂ (acac), and Ir(Fliq) ₂ (acac), Ir(Flq) ₂ (acac), Ru(dtb-bpy) _3.2 (PF ₆ ), Ir(2-phq) ₃ , Ir(BT) ₂ (acac), Ir(DMP) ₃ , Ir(Mphq) ₃ IR(phq) ₂ tpy, fac-Ir(ppy) ₂ Pc, Ir(dp)PQ ₂ , Ir(Dpm)(Piq) ₂ , Hex-Ir(piq) ₂ (acac), Hex-Ir(piq) ₃ , Ir(dmpq) ₃ , Ir(dmpq) ₂ (acac), FPQIrpic, etc.

Other examples of the compound represented by formula (B-10) include compounds represented by the following formulas (B-10-1) to (B-10-31).

Other examples of the compound represented by formula (B-15) include compounds represented by the following formulas (B-15-1) to (B-15-6).

In addition, iridium complexes described in JP 2006-089398 A, JP 2006-080419 A, JP 2005-298483 A, JP 2005-097263 A, and JP 2004-111379 A, U.S. Patent Application Publication No. 2019/0051845, and the like, may also be used.

3-1-5-2-2. TADF material In this specification, the TADF material means a material that is a "thermally activated delayed fluorescent material". In the "thermally activated delayed fluorescent material", the energy difference between the excited singlet state and the excited triplet state is reduced, and the reverse energy transfer from the excited triplet state, which usually has a low transition probability, to the excited singlet state occurs with high efficiency, and light emission from the singlet state (thermally activated delayed fluorescence, TADF) occurs. In normal fluorescent emission, 75% of the triplet excitons generated by current excitation pass through a thermal deactivation path and cannot be extracted as fluorescence. On the other hand, in TADF, all excitons can be used for fluorescent emission, and a highly efficient organic EL element can be realized.

The TADF material is preferably a donor-acceptor type TADF compound (D-A type TADF compound) designed to localize the HOMO and LUMO within the molecule using electron-donating substituents called donors and electron-accepting substituents called acceptors, thereby allowing efficient reverse intersystem crossing to occur.

Here, in this specification, "electron-donating substituent" (donor) means a substituent or partial structure in which the HOMO orbital is localized in the TADF compound molecule, and "electron-accepting substituent" (acceptor) means a substituent or partial structure in which the LUMO orbital is localized in the TADF compound molecule.

As the TADF material, for example, a polycyclic aromatic compound that is a monomer represented by the following formula (2) or a polymer having multiple structural units represented by formula (2) (hereinafter, sometimes referred to as a "polycyclic aromatic compound of formula (2)"), or a combination of a polycyclic aromatic compound of formula (2) with another TADF material can be used.

<Polycyclic aromatic compound of formula (2)>
A polycyclic aromatic compound which is a monomer represented by the following formula (2) or a polymer having a plurality of structural units represented by formula (2) can provide high color purity as a TADF material (see WO 2015/102118, WO 2020/162600, etc.).

ring A, ring B and ring C are each independently an optionally substituted aryl ring or an optionally substituted heteroaryl ring, provided that in ring A, ring B and ring C in the polycyclic aromatic compound represented by formula (2), none of the rings bonded to B and ^X11 and/or ^X12 is a 6-membered ring containing nitrogen;
^X11 and ^X12 are each independently >O or >N-R, and R of the >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and R of the >N-R may be bonded to ring A and/or ring B or ring A and/or ring C via a linking group or a single bond;
In the structure represented by formula (2) or the structure having a plurality of structural units represented by formula (2), at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-,
At least one hydrogen atom in the structure represented by formula (2) or in the structure having a plurality of structural units represented by formula (2) may be substituted with deuterium, cyano or halogen.

The polycyclic aromatic compound of formula (2) is preferably a polycyclic aromatic compound which is a monomer represented by the following formula (2-a), (2-b), (2-c), (2-d), (2-e), or (2-f), or a polycyclic aromatic compound which is a polymer having a plurality of structural units represented by the following formula (2-a), (2-b), (2-c), (2-d), (2-e), or (2-f).

In each structural formula, "A" to "C" and "a" to "c" are symbols that indicate a ring, a benzene ring, or a ring structure represented by a five-membered ring, and the other symbols are defined as above.

The A ring, B ring and C ring in formula (2) are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted with a substituent.The substituent is preferably a substituent selected from the above-mentioned substituent group YZ, or a substituted silyl.In the A ring, B ring and C ring in the polycyclic aromatic compound which is a monomer represented by formula (2), none of the rings bonded to B (boron) and ^X11 and/or ^X12 are 6-membered rings containing nitrogen.That is, the polycyclic aromatic compound of formula (2) which is not a polymer does not have a 6-membered ring containing nitrogen as a ring that shares a bond with the condensed two-ring structure described later in the A ring, B ring and C ring.

It is preferable that at least one of the rings A, B, and C is an aryl ring having at least one substituent or a heteroaryl ring having at least one substituent, it is more preferable that the rings A, B, and C are all aryl rings having at least one substituent or heteroaryl rings having at least one substituent, and it is even more preferable that the rings A, B, and C are each an aryl ring having one substituent or a heteroaryl ring having one substituent.

In particular, the substituent is preferably a substituted or unsubstituted alkyl (especially neopentyl) or a cycloalkyl such as adamantyl. Also preferred is a tertiary alkyl (tR). This is because such bulky substituents prevent inactivation due to aggregation of molecules, improving the luminescence quantum yield (PLQY). Also preferred as the substituent is a substituted or unsubstituted diarylamino.

The tertiary alkyl is represented by the following formula (tR).

In formula (tR), R ^a , R ^b , and R ^c each independently represent an alkyl group having 1 to 24 carbon atoms, any —CH ₂ — in the alkyl group may be replaced with —O—, and the group represented by formula (tR) replaces at least one hydrogen atom in the polycyclic aromatic compound of formula (2) at *.

The "alkyl having 1 to 24 carbon atoms" of R ^a , R ^b , and R ^c may be either linear or branched, and examples thereof include linear alkyl having 1 to 24 carbon atoms or branched alkyl having 3 to 24 carbon atoms, alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms), alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms), alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms), and alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms).

The total number of carbon atoms of R ^a , R ^b and R ^c in formula (tR) in formula (2) is preferably 3 to 20, and particularly preferably 3 to 10.

Specific examples of alkyl for R ^a , R ^b , and R ^c include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, Examples include 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl.

Examples of the group represented by formula (tR) include t-butyl, t-amyl, 1-ethyl-1-methylpropyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-ethyl-1-methylbutyl, 1,1,3,3-tetramethylbutyl, 1,1,4-trimethylpentyl, 1,1,2-trimethylpropyl, 1,1-dimethyloctyl, 1,1-dimethylpentyl, 1,1-dimethylheptyl, 1,1,5-trimethylhexyl, 1-ethyl- Examples include 1-methylhexyl, 1-ethyl-1,3-dimethylbutyl, 1,1,2,2-tetramethylpropyl, 1-butyl-1-methylpentyl, 1,1-diethylbutyl, 1-ethyl-1-methylpentyl, 1,1,3-trimethylbutyl, 1-propyl-1-methylpentyl, 1,1,2-trimethylpropyl, 1-ethyl-1,2,2-trimethylpropyl, 1-propyl-1-methylbutyl, and 1,1-dimethylhexyl groups. Of these, t-butyl and t-amyl are preferred.

Other preferred examples of the substituents in the A ring, the B ring, and the C ring include, for example, diarylamino substituted with a group of the formula (tR), carbazolyl substituted with a group of the formula (tR), or benzocarbazolyl substituted with a group of the formula (tR). For "diarylamino", the group described below as the "first substituent" is included. Examples of the substitution form of the group of the formula (tR) on diarylamino, carbazolyl, and benzocarbazolyl include examples in which some or all of the hydrogen atoms on the aryl ring or benzene ring in these groups are substituted with a group of the formula (tR).

The aryl or heteroaryl rings in rings A, B and C preferably have a 5- or 6-membered ring that shares a bond with the central fused two-ring structure of formula (2) composed of "B", "X ¹ " and "X ² ".

Here, the term "fused bicyclic structure" refers to a structure in which two saturated hydrocarbon rings, each of which includes "B", "X ¹¹ " and "X ¹² " as shown in the center of formula (2), are fused together. The term "six-membered ring sharing a bond with the fused bicyclic structure" refers to a ring (a benzene ring (six-membered ring)) fused to the fused bicyclic structure, as shown in formulas (2-a), (2-b), (2-c), (2-d), (2-e) and (2-f). The term "an aryl ring or heteroaryl ring (which is the A ring) has this six-membered ring" refers to the A ring being formed solely from this six-membered ring, or the A ring being formed by further condensing another ring to this six-membered ring so as to include this six-membered ring. In other words, the term "an aryl ring or heteroaryl ring (which is the A ring) having a six-membered ring" refers to the six-membered ring constituting all or a part of the A ring being fused to the fused bicyclic structure. The same explanation applies to the "five-membered ring". The same explanation applies to "B ring (b ring)" and "C ring (c ring)".

The A ring in formula (2) corresponds to the a ring and its substituents R 1 to R 3 in formulas (2-a), (2-b), (2-c), (2-d), (2-e), and (2-f). The B ring in formula (2) corresponds to the b ring and its substituents R ⁸ to R ¹¹ in formulas (2-a), (2-b), and ( ² -c), the b ring and its substituents R ¹⁰ and ^{R 11 in} formula (2-d), and the b ring and its substituents R ⁸ and R ⁹ in formulas (2-e) and (2-f). The C ring in formula (2) corresponds to the c ring and its substituents R ⁴ to R ⁷ in formula (2-a), the c ring and its substituents R ⁴ and R ⁵ in formulas (2-b), (2-d), and (2-f), and the c ring and its substituents R ⁶ and R ⁷ in formulas (2-c) and (2-e). That is, formula (2-a) corresponds to a structure in which rings having at least a 6-membered ring structure are selected as rings A to C of formula (2), and formulas (2-b), (2-c), (2-d), (2-e), and (2-f) correspond to structures in which a ring having at least a 6-membered ring structure and a ring having at least a 5-membered ring structure are selected as rings A to C of formula (2), respectively. In this sense, each ring in formula (2-a) etc. is represented by lowercase letters a to c.

X _{1 X} in formulae (2-b), (2-c), (2-d), (2-e), and (2-f) are each independently >O, >S, >N-R, or >C(-R) _2. Here, R in the >N-R is an aryl which may be substituted, a heteroaryl which may be substituted, an alkyl which may be substituted, or a cycloalkyl which may be substituted, preferably an aryl which may be substituted, and more preferably an unsubstituted aryl. Also, R in the >C(-R) ₂ are each independently hydrogen, an aryl which may be substituted with an alkyl or cycloalkyl, a heteroaryl which may be substituted with an alkyl or cycloalkyl, an alkyl, or a cycloalkyl, preferably an alkyl, and more preferably a methyl. It is preferable that the two R in >C(-R) ₂ are the same. It is also preferable that the two R in >C(-R) ₂ form a ring together. _{X 1 X} is each independently preferably >O, >S, or >N-R, more preferably >O or >S, and even more preferably >S.

In formulas (2-a), (2-b), (2-c), (2-d), (2-e), and (2-f), R ¹ to R ¹¹ each independently represent a substituent selected from the substituent group YZ, or a substituted silyl.

In each of formulas (2-a), (2-b), (2-c), (2-d), (2-e), and (2-f), it is preferred that 0 to 1 of R ¹ to R ³ are substituents other than hydrogen and the rest are hydrogen, 0 to 1 of R ⁴ to R ⁷ are substituents other than hydrogen and the rest are hydrogen, and 0 to 1 of R ⁸ to R ¹¹ are substituents other than hydrogen and the rest are hydrogen;
It is more preferred that one of R ¹ to R ³ is a substituent other than hydrogen and the others are hydrogen, one of R ⁴ to R ⁷ is a substituent other than hydrogen and the others are hydrogen, and one of R ⁸ to R ¹¹ is a substituent other than hydrogen and the others are hydrogen. For a preferred range of the substituent other than hydrogen, reference can be made to the description of the substituent below as the first substituent (which may have a second substituent). Particularly preferred substituents other than hydrogen are alkyl (particularly the above tertiary alkyl (tR), neopentyl, etc.), cycloalkyl (for example, adamantyl, etc.), or substituted or unsubstituted diarylamino.

In formula (2-a), formula (2-b), formula (2-c), formula (2-d), formula (2-e), and formula (2-f), adjacent groups among the substituents R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ of the ring a, ring b, and ring c may be bonded to each other to form an aryl ring or a heteroaryl ring together with the ring a, ring b, or ring c, and at least one hydrogen atom in the formed ring may be substituted with an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, or substituted silyl, and at least one hydrogen atom in these may be substituted with an aryl, heteroaryl, alkyl, cycloalkyl, or substituted silyl.

For example, in the compound represented by formula (2-a), the ring structure constituting the compound changes depending on the mutual bonding form of the substituents in ring a, ring b, and ring c, as shown in the following formulas (2-a-1) and (2-a-2). Ring A', ring B', and ring C' in each formula correspond to ring A, ring B, and ring C in formula (2), respectively. In addition, the definitions of R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , a, b, c, X ¹¹ , and X ¹² in each formula are the same as those in formula (2-a).

In formula (2-a-1) and formula (2-a-2), the ring A', ring B' and ring C' are, when explained in formula (2-a), aryl or heteroaryl rings formed by bonding adjacent groups among ^the substituents R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R 9 , R ¹⁰ and R ¹¹ together with the ring a, ring b and ring c, respectively (they may also be considered as condensed rings formed by condensing other ring structures to the ring a, ring b or ring c). Although not shown in the formula, there are also compounds in which all of the ring a, ring b and ring c are changed to ring A', ring B' and ring C'. As can be seen from formula (2-a-1) and formula (2-a-2), for example, R ⁸ of ring b and R ⁷ of ring c, R ¹¹ of ring b and R ¹ of ring a, R ⁴ of ring c and R ³ of ring a, etc. do not fall under the category of "adjacent groups" and are not bonded to each other. In other words, "adjacent groups" means groups adjacent on the same ring.

The compounds represented by formula (2-a-1) and formula (2-a-2) correspond to, for example, compounds represented by formulas (2-67) to (2-74), (2-76) to (2-83), (2-273) to (2-276), (2-290) to (2-295), and (2-350) to (2-355), which are listed as specific compounds described below. That is, for example, it is a compound having ring A' (or ring B' or ring C') formed by condensing a benzene ring, an indole ring, a pyrrole ring, a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, a cyclopentadiene ring, or an indene ring to a benzene ring, which is ring a (or ring b or ring c), and the condensed ring A' (or condensed ring B' or condensed ring C') formed is a naphthalene ring, a carbazole ring, an indole ring, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, a dibenzothiophene ring, an indene ring, or a fluorene ring, respectively.

Similarly, in formula (2-b), formula (2-c), formula (2-d), formula (2-e), and formula (2-f), a fused ring may be formed by condensing another ring structure to ring a, ring b, or ring c. For example, the benzene ring which is ring a or ring b may be condensed with another ring structure to form a fused ring, similar to the benzene ring in formula (2-a).
In formula (2-b), formula (2-c), formula (2-d), formula (2-e), and formula (2-f), it is particularly preferred that adjacent groups among R ⁴ to R ¹¹ are bonded to each other to form a ring and a fused ring is formed in the 5-membered ring which is the b-ring or the c-ring in formula (2-b) and formula (2-c), and in the b-ring and the c-ring in formula (2-d), formula (2-e), and formula (2-f), adjacent groups among R ³ to R ¹¹ are bonded to each other to form a ring, thereby forming a fused ring B' ring or C' ring. Examples of the fused ring when the ring formed is a benzene ring include an indole ring, a benzofuran ring, and a benzothiophene ring.

As an example, in the five-membered ring that is ring c in formula (2-b), R ⁴ and R ⁵ are bonded to each other to form a benzene ring, forming a fused ring, as shown below.

In formula (2-b-1), R ¹ , R ² , R ³ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , X ₂ X 3 , X ¹¹ and X ¹² are the same as those in formula (2-b), and the preferred ranges are also the same. R ^4b , R ^5b , R ^6b and R ^7b are hydrogen, a substituent selected from the substituent group YZ, or a substituted silyl. Of R ^4b , R ^5b , R ^6b and R ^7b , it is preferable that 0 to 2 are substituents other than hydrogen and the others are hydrogen, and it is more preferable that one is a substituent other than hydrogen and the others are hydrogen. For the preferred range of the substituent other than hydrogen, the description of the substituent described below can be referred to. As the substituent other than hydrogen, it is particularly preferable that it is alkyl (particularly the above tertiary alkyl (tR), neopentyl, etc.), cycloalkyl (for example, adamantyl, etc.), or substituted or unsubstituted diarylamino.

For example, in (2-b), formula (2-c), formula (2-d), formula (2-e), and formula (2-f), when X _X is >O, ring b and/or ring c is a furan ring, and the rings corresponding to ring B' and/or ring C' in formula (2-a-1) formed by condensing a benzene ring to this furan ring are benzofuran rings.
In addition, for example, in (2-b), formula (2-c), formula (2-d), formula (2-e), and formula (2-f), when X _X is >S, ring b and/or ring c is a thiophene ring, and the ring corresponding to ring B' and/or ring C' in formula (2-a-1) formed by condensing a benzene ring to this thiophene ring is a benzothiophene ring.
Examples of such structures include compounds represented by any one of formulas (2-572) to (1-588) described below.

X ¹¹ and X ¹² in formula (2) are each independently >O or >N-R, and R in the >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and R in the >N-R may be bonded to the B ring and/or the C ring via a linking group or a single bond, and the linking group is preferably -O-, -S-, or -C(-R) ₂ -. In addition, R in the "-C(-R) ₂ -" is hydrogen, an alkyl, or a cycloalkyl. This explanation is also true for X 11 and X 12 in formulas (2-a), (2-b), (2-c), (2-d), ( ² -e), and ( ² -f).

In formula (2) and formulas (2-a), (2-b), (2-c), (2-d), (2-e), and (2-f), X ¹¹ and X ¹² are more preferably >N-R in which R is an optionally substituted phenyl, further preferably >N-R in which at least one R is a phenyl substituted with one or two t-butyl, t-amyl, methyl, or phenyl, and particularly preferably >N-R in which at least one R is a phenyl substituted with one t-butyl or t-amyl. X ¹² and X ¹² may be the same group or different groups.

Here, the provision in formula (2) that "R of >N-R is bonded to ring A and/or ring B, or ring A and/or ring C via a linking group or a single bond" corresponds to the provision in formulas (2-a), (2-b), (2-c), (2-d), (2-e), and (2-f) that "R of R of >N-R is bonded to ring a and/or ring b, or ring a and/or ring c via -O-, -S-, -C(-R) ₂ -, or a single bond."

This definition can be expressed by a compound having a ring structure in which ^X11 and ^X12 are incorporated into fused ring B' and fused ring C', as represented by the following formula (2-a- ^3-1 ). That is, for example, it is a compound having ring B' (or ring C') formed by condensing another ring to ring b (or ring c) of formula (2-a) so as to incorporate ^X11 (or X12) into the benzene ring. The fused ring B' (or fused ring C') thus formed is, for example, a phenoxazine ring, a phenothiazine ring or an acridine ring.

The above definition can also be expressed by a compound having a ring structure in which ^X11 and/or ^X12 are incorporated into a fused ring A', as represented by the following formula (2-a-3-2) or formula (2-a-3-3). That is, for example, it is a compound having a ring A' formed by condensing another ring to the benzene ring, which is the ring a in formula (2-a), so as to incorporate ^X11 (and/or ^X12 ). The fused ring A' thus formed is, for example, a phenoxazine ring, a phenothiazine ring, or an acridine ring.

Examples of the "aryl ring" which is ring A, ring B and ring C in formula (2) include aryl rings having 6 to 30 carbon atoms, preferably aryl rings having 6 to 16 carbon atoms, more preferably aryl rings having 6 to 12 carbon atoms, and particularly preferably aryl rings having 6 to 10 carbon atoms. Note that this "aryl ring" corresponds to "an aryl ring formed together with ring a, ring b or ring c by bonding adjacent groups among R ¹ to R ¹¹ " defined in formula (2), and since ring a (or ring b or ring c) is already composed of a benzene ring having 6 carbon atoms, the lower limit of the carbon number is 9, which is the total carbon number of the fused rings fused with a 5-membered ring.

Specific examples of "aryl rings" include a monocyclic benzene ring, a bicyclic bicyclic bicyclic naphthalene ring, an indene ring, and a tetralin ring, a tricyclic terphenyl ring (m-terphenyl, o-terphenyl, and p-terphenyl), a fused tricyclic acenaphthylene ring, a fluorene ring, a phenalene ring, a phenanthrene ring, and an anthracene ring, a fused tetracyclic triphenylene ring, a pyrene ring, a naphthacene ring, and a chrysene ring, and a fused pentacyclic perylene ring and a pentacene ring.

Examples of the "heteroaryl ring" which is ring A, ring B, and ring C in formula (2) include heteroaryl rings having 2 to 30 carbon atoms, preferably heteroaryl rings having 2 to 25 carbon atoms, more preferably heteroaryl rings having 2 to 20 carbon atoms, still more preferably heteroaryl rings having 2 to 15 carbon atoms, and particularly preferably heteroaryl rings having 2 to 10 carbon atoms. In addition, examples of the "heteroaryl ring" include heterocycles containing, as ring-constituting atoms other than carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen. Note that this "heteroaryl ring" corresponds to "a heteroaryl ring formed together with ring a, ring b or ring c by bonding adjacent groups among R ¹ , R ² , R 3 , R ⁴ , R 5 , R 6 , R 7 , R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ " defined in formulae (2 ^- a), ( ^2- b), (2-c), (2- ^d) , (2-e) and (2-f ⁾ . In addition, since ring a (or ring b or ring c) is already composed of a benzene ring having 6 carbon atoms, the lower limit of the carbon number is the total carbon number of the fused rings formed by condensing a 5-membered ring to this benzene ring, which is 6.

Specific examples of "heteroaryl rings" include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, and a phthalazine ring. , naphthyridine ring, purine ring, pteridine ring, carbazole ring, acridine ring, phenoxathiin ring, phenoxazine ring, phenothiazine ring, phenazine ring, indolizine ring, furan ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, thiophene ring, benzothiophene ring, dibenzothiophene ring, furazan ring, thianthrene ring, indolocarbazole ring, benzoindolocarbazole ring, benzobenzoindolocarbazole ring, naphthobenzofuran ring, dioxin ring, dihydroacridine ring, xanthene ring, thioxanthene ring, dibenzodioxin ring, etc.

The "aryl ring" and "heteroaryl ring" of the A ring, B ring, and C ring may be bonded to B (boron) and ^X11 or ^X12 at any position. That is, the "aryl ring" and "heteroaryl ring" of the A ring, B ring, and C ring may share a bond with the central fused bicyclic structure of formula (2) at any position. For example, when the "aryl ring" and "heteroaryl ring" are fused rings of two or more rings, any ring may share a bond with the central fused bicyclic structure of formula (2). Of these, as described above, it is preferable that the A ring, B ring, and C ring have a 5-membered or 6-membered ring that shares a bond with the central fused bicyclic structure of formula (2) composed of B (boron), ^X11 , and ^X12 . That is, for example, in formula (2-a), when adjacent groups among R ¹ to R ³ are bonded to each other to form an aryl ring or a heteroaryl ring together with ring a, adjacent groups among R ⁴ to R ⁷ are bonded to each other to form an aryl ring or a heteroaryl ring together with ring c, and adjacent groups among R ⁸ to R ¹¹ are bonded to each other to form an aryl ring or a heteroaryl ring together with ring b, the benzene ring, which is a 6-membered ring, shares a bond with the central fused two-ring structure of formula (2), which is preferable. In addition, when R ⁴ and R ⁵ of formula (2-b) form an aryl ring or a heteroaryl ring together with the ring c, when R ⁶ and R ⁷ of formula (2-c) form an aryl ring or a heteroaryl ring together with the ring c, when R ⁴ and R ⁵ of formula (2-d) form an aryl ring or a heteroaryl ring together with the ring c or when R ¹⁰ and R ¹¹ of formula (2-d) form an aryl ring or a heteroaryl ring together with the ring b, when R ⁶ and R ⁷ of formula (2-e) form an aryl ring or a heteroaryl ring together with the ring c or when R ⁸ and R ⁹ of formula (2-f) form an aryl ring or a heteroaryl ring together with the ring c or when R ⁸ and R ⁹ of formula ( ² -f) form an aryl ring or a heteroaryl ring together with the ring ^b , it is a 5-membered ring that shares a bond with the fused 2-ring structure in the center of formula (2), and is preferable. Examples of the 5-membered ring in this case include a pyrrole ring, a furan ring, and a thiophene ring.

For the substituents selected from the substituent group YZ, the description of the substituents selected from the substituent group YZ in the polycyclic aromatic compound represented by formula (1) can be referred to.

"Substituted silyl" includes, for example, silyl substituted with three substituents selected from the group consisting of alkyl, cycloalkyl, and aryl. Examples include trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, triarylsilyl, dialkylarylsilyl, and alkyldiarylsilyl.

An example of a "trialkylsilyl" is a group in which the three hydrogen atoms in a silyl group are each independently replaced with an alkyl group, and the alkyl group can be any of the groups described above as the "alkyl" group in the first substituent. Preferred alkyl groups for substitution are those having 1 to 5 carbon atoms, and specific examples include methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, and t-amyl.

Specific examples of trialkylsilyl include trimethylsilyl, triethylsilyl, tripropylsilyl, tri-i-propylsilyl, tributylsilyl, trisec-butylsilyl, tri-t-butylsilyl, tri-t-amylsilyl, ethyldimethylsilyl, propyldimethylsilyl, i-propyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, t-amyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, i-propyldiethylsilyl, and butyl. Examples include ethyl diethylsilyl, sec-butyl diethylsilyl, t-butyl diethylsilyl, t-amyl diethylsilyl, methyl dipropylsilyl, ethyl dipropylsilyl, butyl dipropylsilyl, sec-butyl dipropylsilyl, t-butyl dipropylsilyl, t-amyl dipropylsilyl, methyl di-i-propylsilyl, ethyl di-i-propylsilyl, butyl di-i-propylsilyl, sec-butyl di-i-propylsilyl, t-butyl di-i-propylsilyl, and t-amyl di-i-propylsilyl.

"Tricycloalkylsilyl" refers to a group in which three hydrogen atoms in silyl are each independently replaced with a cycloalkyl, and the cycloalkyl can be cited from the groups described as "cycloalkyl" in the first substituent above. Preferred cycloalkyl groups for substitution are cycloalkyl groups having 5 to 10 carbon atoms, and specific examples include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclo[1.1.1]pentyl, bicyclo[2.0.1]pentyl, bicyclo[1.2.1]hexyl, bicyclo[3.0.1]hexyl, bicyclo[2.1.2]heptyl, bicyclo[2.2.2]octyl, adamantyl, decahydronaphthalenyl, and decahydroazulenyl.

Specific examples of tricycloalkylsilyl include tricyclopentylsilyl and tricyclohexylsilyl.

Specific examples of dialkylcycloalkylsilyl substituted with two alkyls and one cycloalkyl, and alkyldicycloalkylsilyl substituted with one alkyl and two cycloalkyls include silyl substituted with a group selected from the specific alkyls and cycloalkyls mentioned above.

Specific examples of dialkylarylsilyl substituted with two alkyls and one aryl, alkyldiarylsilyl substituted with one alkyl and two aryls, and triarylsilyl substituted with three aryls include silyl substituted with a group selected from the specific alkyls and aryls listed above. A specific example of triarylsilyl is triphenylsilyl.

In the polycyclic aromatic compound of formula (2), the emission wavelength can be adjusted by the steric hindrance, electron donating property and electron withdrawing property of the structure of the first substituent. The first substituent is preferably a group represented by the following structural formula, and more preferably methyl, t-butyl, t-pentyl (t-amyl), t-octyl, neopentyl, cyclohexyl, adamantyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethyl carbazolyl, 3,6-di-t-butylcarbazolyl and phenoxy, and more preferably methyl, t-butyl, t-octyl, neopentyl, cyclohexyl, adamantyl, phenyl, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl and 3,6-di-t-butylcarbazolyl. From the viewpoint of ease of synthesis, a larger steric hindrance is preferred for selective synthesis, and specifically, t-butyl, t-pentyl (t-amyl), t-octyl, adamantyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, 3,6-dimethylcarbazolyl, and 3,6-di-t-butylcarbazolyl are preferred.

In the following structural formula, "Me" is methyl, "tBu" is t-butyl, "tAm" is t-amyl, "tOct" is t-octyl, and * indicates a bonding position.

In formula (2-a), formula (2-b), formula (2-c), formula (2-d), formula (2-e), and formula (2-f), the ^aryl , ^heteroaryl , aryl of diarylamino, heteroaryl of diheteroarylamino, ^aryl and heteroaryl of arylheteroarylamino, aryl of diarylboryl, or aryl of aryloxy in R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , ^R 8 , R 9 , R 10 , and R 11 include the monovalent group of "aryl ring" or "heteroaryl ring" explained in formula (2). In addition, for the alkyl, cycloalkyl, or alkoxy in R ¹ to R ¹¹ , the explanation of "alkyl", "cycloalkyl" or "alkoxy" as the first substituent in the explanation of formula (2) above can be referred to. Furthermore, the same applies to the aryl, heteroaryl, alkyl, or cycloalkyl as a substituent to these groups. In addition, when adjacent groups among R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ are bonded to each other to form an aryl ring or heteroaryl ring together with ring a, ring b, or ring c, the same applies to the heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl, alkyl, cycloalkyl, alkoxy, or aryloxy as substituents on these rings, and the aryl, heteroaryl, alkyl, or cycloalkyl as further substituents.

R of >N-R in X ¹¹ and X ¹² of formula (2) is aryl, heteroaryl, alkyl, or cycloalkyl, and at least one hydrogen in the aryl or heteroaryl may be substituted with, for example, alkyl, cycloalkyl, or substituted silyl. Examples of the aryl, heteroaryl, alkyl, and cycloalkyl include the groups described above. In particular, aryl having 6 to 10 carbon atoms (e.g., phenyl, naphthyl, etc.), heteroaryl having 2 to 15 carbon atoms (e.g., carbazolyl, etc.), alkyl having 1 to 5 carbon atoms (e.g., methyl, ethyl, etc.), or cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) are preferred. This explanation also applies to X ¹ and X ² in formulas (2-a), (2-b), (2-c), (2-d), (2-e), and (2-f). R of >N-R in ^X1 and ^X2 of formula (2-a), formula (2-b), formula (2-c), formula (2-d), formula (2-e), and formula (2-f) is an aryl having 6 to 12 carbon atoms which may be substituted with an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms, a heteroaryl having 2 to 15 carbon atoms which may be substituted with an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms, an alkyl having 1 to 6 carbon atoms, or a cycloalkyl having 3 to 14 carbon atoms, and is preferably an aryl having 6 to 10 carbon atoms which may be substituted with an alkyl having 1 to 4 carbon atoms or a cycloalkyl having 5 to 10 carbon atoms, an alkyl having 1 to 4 carbon atoms, or a cycloalkyl having 5 to 10 carbon atoms.

R in the linking group "-C(-R) ₂ -" in formula (2) is hydrogen, alkyl, or cycloalkyl, and examples of the alkyl and cycloalkyl include the groups described above. In particular, alkyl having 1 to 5 carbon atoms (e.g., methyl, ethyl, etc.) or cycloalkyl having 5 to 10 carbon atoms (preferably cyclohexyl or adamantyl) is preferred. This explanation also applies to the linking group "-C(-R) ₂ -" in formulas (2-a), (2-b), (2-c), (2-d), (2-e), and (2-f).

The dopant material may be a polycyclic aromatic compound that is a polymer having a plurality of structural units represented by formula (2). The polymer is preferably a polycyclic aromatic compound that is a polymer having a plurality of structural units represented by formula (2-a), formula (2-b), formula (2-c), formula (2-d), formula (2-e), and formula (2-f). The polymer is preferably a dimer to a hexamer, more preferably a dimer to a trimer, and particularly preferably a dimer. The multimer may have a plurality of the above structural units in one compound. For example, the above structural units may be bonded together with a linking group such as a single bond, an alkylene having 1 to 3 carbon atoms, phenylene, or naphthylene. In addition, the multimer may be bonded so that any ring (ring A, ring B or ring C, ring a, ring b or ring c) contained in the above structural unit is shared by multiple structural units, or any ring (ring A, ring B or ring C, ring a, ring b or ring c) contained in the above structural unit is bonded together so as to be condensed.

Examples of such multimers include multimer compounds represented by the following formula (2-4), formula (2-4-1), formula (2-4-2), formula (2-5-1) to formula (2-5-4), formula (2-6) or formula (2-7). The multimer compound represented by the following formula (2-4) is a multimer compound having a plurality of structural units represented by formula (2-a) in one compound, with the benzene ring being the a-ring shared, as explained by formula (2-a). The multimer compound represented by the following formula (2-4-1) is a multimer compound having two structural units represented by formula (2-a) in one compound, with the benzene ring being the a-ring shared, as explained by formula (2-a). The multimer compound represented by the following formula (2-4-2) is a multimer compound having three structural units represented by formula (2-a) in one compound, with the benzene ring being the a-ring shared, as explained by formula (2-a). Furthermore, the multimeric compounds represented by the following formulae (2-5-1) to (2-5-4) are multimeric compounds having a plurality of structural units represented by formula (2-a) in one compound, in such a way that the benzene ring which is the b-ring (or the c-ring) is shared when explained by formula (2-a). Furthermore, the multimeric compound represented by the following formula (2-6) is a multimeric compound having a plurality of structural units represented by formula (2-a) in one compound, in such a way that the benzene ring which is the b-ring (or the a-ring, the c-ring) of a certain structural unit is condensed with the benzene ring which is the b-ring (or the a-ring, the c-ring) of a certain structural unit. Furthermore, the multimeric compound represented by the following formula (2-7), when explained using formula (2-a), is a multimeric compound having three structural units represented by formula (2-a) in one compound, for example, in such a manner that the benzene rings which are the b ring and the c ring of a certain structural unit are condensed with the benzene rings which are the b ring and the c ring of another structural unit, respectively.
In the following formulas (2-4), (2-4-1), (2-4-2), (2-5-1) to (2-5-4), (2-6) and (2-7), R ¹ to R ¹¹ , and X ¹¹ and X ¹² have the same meanings as R ¹ to R ¹¹ , and X ¹¹ and X ¹² in formula (2-a), respectively.

The multimeric compound may be a multimer in which a multimerization form represented by formula (2-4), formula (2-4-1) or formula (2-4-2) is combined with a multimerization form represented by any one of formulas (2-5-1) to (2-5-4) or formula (2-6), a multimer in which a multimerization form represented by any one of formulas (2-5-1) to (2-5-4) is combined with a multimerization form represented by formula (2-6), or a multimer in which a multimerization form represented by formula (2-4), formula (2-4-1) or formula (2-4-2), a multimerization form represented by any one of formulas (2-5-1) to (2-5-4) and a multimerization form represented by formula (2-6).

As a polycyclic aromatic compound that is a polymer having a plurality of structural units represented by formula (2), a compound represented by the following formula (D2) or formula (D3), which includes the compounds represented by formula (2-5-3) and formula (2-7), respectively, as described in formula (2-a), is preferred.

In formula (D2) or formula (D3), A to C, ^X11 and ^X12 have the same meanings as A to C, R ¹ to R ¹¹ , and ^X11 and ^X12 in formula (2-a), respectively. In the polycyclic aromatic compound represented by formula (D2) or formula (D3), unlike the polycyclic aromatic compound (monomer) represented by formula (2), the rings bonded to B (boron) and ^X11 and/or ^X12 in ring A, ring B and ring C may be six-membered rings containing nitrogen.

At least one selected from the group consisting of aryl rings and heteroaryl rings in the chemical structure of a polycyclic aromatic compound that is a monomer represented by formula (2), formula (2-a), formula (2-b), formula (2-c), formula (2-d), formula (2-e), or formula (2-f), or a polymer having a plurality of structural units represented by any of these, may be condensed with at least one cycloalkane.

For example, at least one of the aryl rings and heteroaryl rings in the aryl rings and heteroaryl rings which are ring A, ring B, ring C, ring a, ring b and ring c, the aryl (aryl moiety in aryl, diarylamino, arylheteroarylamino, diarylboryl or aryloxy) and heteroaryl (heteroaryl moiety in heteroaryl, diheteroarylamino or arylheteroarylamino) as the first and second substituents in ring A to ring C, the aryl (similar to above) and heteroaryl (similar to above) as the first and second substituents on ring a, ring b and ring c, and the aryl (similar to above) and heteroaryl (similar to above) as >N-R which is X ¹¹ and X ¹² may be fused with at least one cycloalkane.

Preferably, at least one of the aryl and heteroaryl rings which are ring A, ring B, ring C, ring a, ring b and ring c, the aryl (aryl moiety in aryl, diarylamino, diarylboryl or aryloxy) and heteroaryl (heteroaryl moiety in heteroaryl or diheteroarylamino) as the first substituents in rings A to C, the aryl (similar to above) and heteroaryl (similar to above) as the first substituents on rings a to c, and the aryl (similar to above) and heteroaryl (similar to above) as >N-R which is X ¹ and X ² may be fused with at least one cycloalkane.

More preferably, at least one of the aryl rings which are ring A, ring B, ring C, ring a, ring b and ring c, the aryl (aryl moiety in aryl or diarylamino) and heteroaryl (heteroaryl moiety in heteroaryl) as the first substituents in rings A to C, the aryl (similar to above) and heteroaryl (similar to above) as the first substituents on ring a, ring b and ring c, and the aryl (similar to above) as R of >N-R which is X ¹¹ and X ² may be fused with at least one cycloalkane.

More preferably, at least one of the aryl rings which are ring A, ring B, ring C, ring a, ring b, and ring c, the aryl as the first substituent in ring A to ring C (aryl or aryl moiety in diarylamino), the aryl as the first substituent on ring a, ring b, and ring c (similar to above), and the aryl as R in >N-R which are X ¹¹ and X ¹² (similar to above) may be condensed with at least one cycloalkane.

Examples of "cycloalkanes" include cycloalkanes with 3 to 24 carbon atoms, cycloalkanes with 3 to 20 carbon atoms, cycloalkanes with 3 to 16 carbon atoms, cycloalkanes with 3 to 14 carbon atoms, cycloalkanes with 5 to 10 carbon atoms, cycloalkanes with 5 to 8 carbon atoms, cycloalkanes with 5 to 6 carbon atoms, and cycloalkanes with 5 carbon atoms.

Specific examples of cycloalkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, norbornene, bicyclo[1.0.1]butane, bicyclo[1.1.1]pentane, bicyclo[2.0.1]pentane, bicyclo[1.2.1]hexane, bicyclo[3.0.1]hexane, bicyclo[2.1.2]heptane, bicyclo[2.2.2]octane, adamantane, diamantane, decahydronaphthalene, and decahydroazulene, as well as alkyl (especially methyl) substituted, halogen (especially fluorine) substituted, and deuterium substituted derivatives of these having 1 to 5 carbon atoms.

Among these, for example, as shown in the structural formula below, a structure in which at least one hydrogen atom is substituted on the carbon atom at the α-position of a cycloalkane (the carbon atom at the position adjacent to the carbon atom at the condensation site in a cycloalkane fused to an aryl ring or heteroaryl ring) is preferred, a structure in which two hydrogen atoms are substituted on the carbon atom at the α-position is more preferred, and a structure in which a total of four hydrogen atoms are substituted on the two α-position carbons is even more preferred. Examples of this substituent include alkyl (particularly methyl) substituents having 1 to 5 carbon atoms, halogen (particularly fluorine) substituents, and deuterium substituents. In particular, a structure in which a partial structure represented by the following formula (B) is bonded to adjacent carbon atoms in an aryl ring or heteroaryl ring is preferred.

In formula (B), Me represents methyl, * represents a bonding position, and each bond is bonded to two adjacent elements on the aryl ring or heteroaryl ring to which the group represented by formula (B) is bonded.
Examples of such structures include the structures of compounds represented by any one of formulas (2-559) to (2-563) and (2-580) described below.

The number of cycloalkanes fused to one aromatic ring or heteroaromatic ring is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. For example, an example in which one or more cycloalkanes are fused to one benzene ring (phenyl) is shown below. Cycloalkanes fused as in formula (Cy-1-4) and formula (Cy-2-4) may be fused together. The same applies even when the fused ring (group) is an aromatic ring or heteroaromatic ring other than a benzene ring (phenyl), or when the fused cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

At least one -CH ₂ - in a cycloalkane may be replaced with -O-. For example, examples in which one or more -CH ₂ - in a cycloalkane fused to a benzene ring (phenyl) are replaced with -O- are shown below. The same applies even when the fused ring (group) is an aromatic ring or heteroaromatic ring other than a benzene ring (phenyl) or when the fused cycloalkane is a cycloalkane other than cyclopentane or cyclohexane.

At least one hydrogen atom in the cycloalkane may be substituted. Examples of the substituent include aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (the two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, substituted silyl, deuterium, cyano, and halogen. For details of these, see the explanation of the first substituent above. Among these substituents, alkyl (e.g., alkyl having 1 to 6 carbon atoms), cycloalkyl (e.g., cycloalkyl having 3 to 14 carbon atoms), halogen (e.g., fluorine), and deuterium are preferred. In addition, when cycloalkyl is substituted, it may be substituted in a form that forms a spiro structure, an example of which is shown below.

Other forms of cycloalkane condensation include polycyclic aromatic compounds represented by formula (2), (2-a), (2-b), (2-c), (2-d), (2-e), or (2-f), or polymers having multiple structural units represented by any of these, such as >N-R, where R is an aryl condensed with a cycloalkane, diarylamino condensed with a cycloalkane (condensed to the aryl portion), carbazolyl condensed with a cycloalkane (condensed to the benzene ring portion), or benzocarbazolyl condensed with a cycloalkane (condensed to the benzene ring portion). Examples of "diarylamino" include the groups described above as the "first substituent."

Further, as a more specific example, there can be mentioned an example in which R 2 in a polycyclic aromatic compound which is represented by formula (2-a), formula (2-b), formula (2-c ⁾ , formula (2-d), formula (2-e), or formula (2-f), or which is a polymer having a plurality of structural units represented by any of these, is a diarylamino condensed with a cycloalkane (condensed to the aryl portion) or a carbazolyl condensed with a cycloalkane (condensed to the benzene ring portion).

In addition, all or a part of hydrogen in the chemical structure of the polycyclic aromatic compound which is represented by formula (2), formula (2-a), formula (2-b), formula (2-c), formula (2-d), formula (2-e), or formula (2-f), or which is a polymer having a plurality of structural units represented by any of these, may be deuterium, cyano, or halogen. For example, in formula (2), hydrogen in ring A, ring B, ring C (rings A to C are aryl rings or heteroaryl rings), substituents on rings A to C, and R (= alkyl, cycloalkyl, aryl) when X ¹¹ and X ¹² are >N-R may be substituted with deuterium, cyano, or halogen, and among these, there is an embodiment in which all or a part of hydrogen in aryl or heteroaryl is substituted with deuterium, cyano, or halogen. The halogen is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, and more preferably fluorine or chlorine.

More specific examples of the polycyclic aromatic compound of formula (2) include compounds represented by the following formula. In the formula, "Me" is methyl, "tBu" is tertiary butyl, "iPr" is isopropyl, "Ph" is phenyl, "tAm" is tertiary amyl (tertiary pentyl), and "D" is deuterium.

The polycyclic aromatic compound of formula (2) can be synthesized, for example, by the method disclosed in WO 2019/009052 as "Method for producing a polycyclic aromatic compound represented by formula (2) and a multimer thereof."

<Other TADF materials: Compound of formula (H7)>
The polycyclic aromatic compound of formula (2) above is preferably used in combination with a TADF material whose emission spectrum at least partially overlaps with the absorption spectrum of the polycyclic aromatic compound of formula (2) used. Examples of such TADF materials include a compound represented by the following formula (H7) or a compound having the following formula (H7) as a partial structure (hereinafter, sometimes referred to as "a compound of formula (H7)"). By using the polycyclic aromatic compound of formula (2) and the compound of formula (H7) simultaneously, the polycyclic aromatic compound of formula (2) functions as an emitting dopant, and the compound of formula (H7) functions as an assisting dopant, thereby providing high color purity. The polycyclic aromatic compound of formula (2) and the compound of formula (H7) may be contained in the same layer or in adjacent layers. When the polycyclic aromatic compound of formula (1), the compound of formula (H7), and the polycyclic aromatic compound of formula (2) are contained in the same light-emitting layer, their contents are preferably 60 to 95 mass%, 39 to 5 mass%, and 10 to 0.01 mass%, respectively, and more preferably 70 to 90 mass%, 29 to 10 mass%, and 5 to 0.05 mass%, respectively.

In formula (H7), ED is an electron donating group, Ln is a linking group, EA is an electron accepting group, and the energy difference (ΔE S1 _T1 ) between the lowest excited singlet energy level (E _S1 ) and the lowest excited triplet energy level (E _T1 ) of the compound represented by formula (H7) is 0.2 eV or less (Hiroki Uoyama, Kenichi Goushi, Katsuyuki Shizu, Hiroko Nomura, Chihaya Adachi, Nature, 492, 234-238 (2012)). The energy difference (ΔE _{S1 T1} ) is preferably 0.15 eV or less, more preferably 0.10 eV or less, and even more preferably 0.08 eV or less.

As the electron donating group (donor structure) and the electron accepting group (acceptor structure) used in the TADF material, for example, the structures described in Chemistry of Materials, 2017, 29, 1946-1963 can be used. Examples of ED include functional groups containing sp ³ nitrogen, and more specifically, groups derived from carbazole, dimethylcarbazole, di-tert-butylcarbazole, dimethoxycarbazole, tetramethylcarbazole, benzofluorocarbazole, benzothienocarbazole, phenyldihydroindolocarbazole, phenylbicarbazole, bicarbazole, tercarbazole, diphenylcarbazolylamine, tetraphenylcarbazolyldiamine, phenoxazine, dihydrophenazine, phenothiazine, dimethyldihydroacridine, diphenylamine, bis(tert-butyl)phenyl)amine, (diphenylamino)phenyl)diphenylbenzenediamine, dimethyltetraphenyldihydroacridinediamine, tetramethyl-dihydro-indenoacridine, and diphenyl-dihydrodibenzoazasiline. Examples of EA include groups derived from sp ² Nitrogen-containing aromatic rings, CN-substituted aromatic rings, rings having ketones and cyano, more specifically sulfonyldibenzene, benzophenone, phenylenebis(phenylmethanone), benzonitrile, isonicotinonitrile, phthalonitrile, isophthalonitrile, paraphthalonitrile, triazole, oxazole, thiadiazole, benzothiazole, benzobis(thiazole), benzoxazole, benzobis(oxazole), quinoline, benzimidazole, dibenzoquinoxaline, heptaazaphenalene, thioxanthone dioxane, Examples of the group derived from cyclohexyl ether, dimethylanthracenone, anthracenedione, pyridine, cycloheptabipyridine, benzenetricarbonitrile, fluorene dicarbonitrile, pyrazine dicarbonitrile, pyridine dicarbonitrile, dibenzoquinoxaline dicarbonitrile, pyrimidine, phenylpyrimidine, methylpyrimidine, triazine, triphenyltriazine, bis(phenylsulfonyl)benzene, dimethylthioxanthene dioxide, thianthrene tetraoxide, and tris(dimethylphenyl)borane. Examples of Ln include single bonds and arylenes, more specifically, phenylene, biphenylene, naphthylene, and the like. In addition, in any of the structures, hydrogen may be substituted with alkyl, cycloalkyl, and aryl. In particular, it is preferable that the compound has at least one partial structure selected from carbazole, phenoxazine, acridine, triazine, pyrimidine, pyrazine, thioxanthene, benzonitrile, phthalonitrile, isophthalonitrile, diphenylsulfone, triazole, oxadiazole, thiadiazole, and benzophenone.
In formula (H7), the linking group Ln functions as a spacer structure that separates the donor partial structure and the acceptor partial structure.

More specifically, the compound represented by formula (H7) may be any of the compounds represented by formulas (H7-1), (H7-2) and (H7-3).

In formulas (H7-1), (H7-2) and (H7-3),
M is each independently a single bond, -O-, >N-Ar or >C(-Ar) ₂ , and is preferably a single bond, -O- or >N-Ar from the viewpoint of the HOMO depth and the height of the excited singlet energy level and the excited triplet energy level of the partial structure to be formed;
J is a linking group corresponding to Ln in formula (H7), and each J is independently an arylene having 6 to 18 carbon atoms. From the viewpoint of the magnitude of conjugation exuded from the donor partial structure and the acceptor partial structure, an arylene having 6 to 12 carbon atoms is preferable, and more specific examples thereof include phenylene, methylphenylene, and dimethylphenylene.
Q is each independently ═C(—H)— or ═N—, and is preferably ═N— from the viewpoint of the shallowness of the LUMO and the height of the excited singlet energy level and the excited triplet energy level of the partial structure to be formed,
Ar are each independently hydrogen, an aryl having 6 to 24 carbon atoms, a heteroaryl having 2 to 24 carbon atoms, an alkyl having 1 to 12 carbon atoms, or a cycloalkyl having 3 to 18 carbon atoms; from the viewpoint of the HOMO depth and the height of the excited singlet energy level and the excited triplet energy level of the partial structure to be formed, preferably hydrogen, an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 14 carbon atoms, an alkyl having 1 to 4 carbon atoms, or a cycloalkyl having 6 to 10 carbon atoms, more preferably hydrogen, phenyl, tolyl, xylyl, mesityl, biphenyl, pyridyl, bipyridyl, triazyl, carbazolyl, dimethylcarbazolyl, di-tert-butylcarbazolyl, benzimidazole, or phenylbenzimidazole, and further preferably hydrogen, phenyl, or carbazolyl;
m is 1 or 2;
n is an integer of 2 to (6-m), and from the viewpoint of steric hindrance, is preferably an integer of 4 to (6-m).
Furthermore, at least one hydrogen atom in the compounds represented by the above formulas may be substituted with a halogen or deuterium.

Examples of compounds represented by formula (H7) include compounds represented by the following structures. In the structural formula, * indicates the bond position, "Me" indicates methyl, and "tBu" indicates t-butyl.

Among the specific compounds represented by formula (H7), PIC-TRZ, TXO-TPA, TXO-PhCz, PXZD SO2, ACRD SO2, DTC-DBT, DTAO, 4CzBN, 4CzBN-Ph, 5CzBN, 3Cz2DPhCzBN, 4CzIPN, 2PXZ-TAZ, Cz-TRZ3, BDPCC-TPTA, MA-TA, PA-TA, FA-TA, PXZ-TRZ, DMAC-TRZ, BCzT, DCzTrz, DDCzTrz, spiroAC-TRZ, Ac-HPM, Ac-PPM, Ac-MPM, TCzTrz, TmCzTrz and DCzmCzTrz are preferred.

3-1-6. Electron Injection Layer and Electron Transport Layer in Organic Electroluminescent Device The electron injection layer 107 plays a role of efficiently injecting electrons moving from the cathode 108 into the light emitting layer 105 or the electron transport layer 106. The electron transport layer 106 plays a role of efficiently transporting electrons injected from the cathode 108 or electrons injected from the cathode 108 via the electron injection layer 107 to the light emitting layer 105. The electron transport layer 106 and the electron injection layer 107 are each formed by laminating or mixing one or more types of electron transport/injection materials, or by a mixture of an electron transport/injection material and a polymer binder.

The electron injection/transport layer is a layer that is responsible for injecting electrons from the cathode and transporting the electrons. It is desirable for the electron injection layer to have a high electron injection efficiency and efficiently transport the injected electrons. For this purpose, it is preferable for the material to have a large electron affinity, a large electron mobility, excellent stability, and a low probability of generating impurities that become traps during manufacture and use. However, when considering the balance between the transport of holes and electrons, if the material mainly plays a role in efficiently blocking holes from the anode from flowing to the cathode without recombining, it has the same effect of improving the luminous efficiency as a material with a high electron transport ability, even if the electron transport ability is not that high. Therefore, the electron injection/transport layer in this embodiment may also include the function of a layer that can efficiently block the movement of holes (hole blocking layer).

The material (electron transport material) forming the electron transport layer 106 or the electron injection layer 107 can be arbitrarily selected from compounds conventionally used as electron transport compounds in photoconductive materials and known compounds used in the electron injection layer and electron transport layer of organic EL elements. Since the polycyclic aromatic compound of the present invention has a deep HOMO and deep LUMO, it is also preferable to use it as an electron transport material or a hole blocking material (hole blocking material) in the electron injection/transport layer.

In addition to the polycyclic aromatic compound of the present invention, materials used in the electron transport layer or electron injection layer preferably contain at least one selected from compounds consisting of aromatic rings or heteroaromatic rings composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus, pyrrole derivatives and their condensed ring derivatives, and metal complexes having electron-accepting nitrogen. Specific examples include condensed ring aromatic ring derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives such as 4,4'-bis(diphenylethenyl)biphenyl, perinone derivatives, coumarin derivatives, naphthalimide derivatives, quinone derivatives such as anthraquinone and diphenoquinone, phosphorus oxide derivatives, arylnitrile derivatives, and indole derivatives. Examples of metal complexes having electron-accepting nitrogen include hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. These materials can be used alone or in combination with different materials.

Specific examples of other electron transport compounds include pyridine derivatives, naphthalene derivatives, anthracene derivatives, benzofluorene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives (such as 1,3-bis[(4-t-butylphenyl)1,3,4-oxadiazolyl]phenylene), thiophene derivatives, triazole derivatives (such as N-naphthyl-2,5-diphenyl-1,3,4-triazole), thiadiazole derivatives, metal complexes of oxine derivatives, quinolinol-based metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazole compounds, gallium complexes, pyrazole derivatives, perfluorinated phenylene derivatives, triazine derivatives pyrazine derivatives, benzoquinoline derivatives (such as 2,2'-bis(benzo[h]quinolin-2-yl)-9,9'-spirobifluorene), imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (such as tris(N-phenylbenzimidazol-2-yl)benzene), benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives, oligopyridine derivatives such as terpyridine, bipyridine derivatives, terpyridine derivatives (such as 1,3-bis(4'-(2,2':6'2"-terpyridinyl))benzene), naphthyridine derivatives (such as bis(1-naphthyl)-4-(1,8-naphthyridin-2-yl)phenylphosphine oxide), aldazine derivatives, arylnitrile derivatives, indole derivatives, phosphine oxide derivatives, and bisstyryl derivatives.

Metal complexes having an electron-accepting nitrogen can also be used, such as quinolinol metal complexes, hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes.

The above materials can be used alone or in combination with other materials.

Among the above-mentioned materials, borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, arylnitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes are preferred.

式（ＥＴＭ－１）中、Ｒ^１１およびＲ^１２は、それぞれ独立して、水素、アルキル、シクロアルキル、置換されていてもよいアリール、置換されているシリル、置換されていてもよい窒素含有複素環、またはシアノの少なくとも１つであり、Ｒ^１３～Ｒ^１６は、それぞれ独立して、置換されていてもよいアルキル、置換されていてもよいシクロアルキル、または置換されていてもよいアリールであり、Ｘは、置換されていてもよいアリーレンであり、Ｙは、置換されていてもよい炭素数１６以下のアリール、置換されているボリル、または置換されていてもよいカルバゾリルであり、そして、ｎはそれぞれ独立して０～３の整数である。また、「置換されていてもよい」または「置換されている」場合の置換基としては、アリール、ヘテロアリール、アルキルまたはシクロアルキルなどがあげられる。 <Borane derivatives>
The borane derivative is, for example, a compound represented by the following formula (ETM-1), and is disclosed in detail in JP-A-2007-27587.

In formula (ETM-1), R ¹¹ and R ¹² each independently represent at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, R ¹³ to R ¹⁶ each independently represent optionally substituted alkyl, optionally substituted cycloalkyl, or optionally substituted aryl, X represents optionally substituted arylene, Y represents optionally substituted aryl having 16 or less carbon atoms, substituted boryl, or optionally substituted carbazolyl, and n represents each independently an integer of 0 to 3. Examples of the substituent in the case of being "optionally substituted" or "substituted" include aryl, heteroaryl, alkyl, and cycloalkyl.

Among the compounds represented by formula (ETM-1), compounds represented by the following formula (ETM-1-1) and compounds represented by the following formula (ETM-1-2) are preferred.

In formula (ETM-1-1), R ¹¹ and R ¹² are each independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, R ¹³ to R ¹⁶ are each independently at least one of optionally substituted alkyl, optionally substituted cycloalkyl, or optionally substituted aryl, R ²¹ and R ²² are each independently at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, X ¹ is an optionally substituted arylene having 20 or less carbon atoms, n is each independently an integer of 0 to 3, and m is each independently an integer of 0 to 4. In addition, examples of the substituent in the case of "optionally substituted" or "substituted" include aryl, heteroaryl, alkyl, and cycloalkyl.

In formula (ETM-1-2), R ¹¹ and R ¹² each independently represent at least one of hydrogen, alkyl, cycloalkyl, optionally substituted aryl, substituted silyl, optionally substituted nitrogen-containing heterocycle, or cyano, R ¹³ to R ¹⁶ each independently represent optionally substituted alkyl, optionally substituted cycloalkyl, or optionally substituted aryl, X ¹ represents an optionally substituted arylene having 20 or less carbon atoms, and each n represents independently an integer of 0 to 3. In addition, examples of the substituent in the case of "optionally substituted" or "substituted" include aryl, heteroaryl, alkyl, and cycloalkyl.

（各式中、Ｒ^ａは、それぞれ独立してアルキル、シクロアルキルまたは置換されていてもよいフェニルであり、＊は結合位置を表す。） Specific examples of ^X1 include divalent groups represented by any one of the following formulae (X-1) to (X-9).

(In each formula, each R ^a is independently alkyl, cycloalkyl, or optionally substituted phenyl, and * represents the bonding position.)

Specific examples of the borane derivative include the following compounds:

This borane derivative can be produced using known raw materials and known synthesis methods.

<Pyridine derivatives>
The pyridine derivative is, for example, a compound represented by the following formula (ETM-2), and is preferably a compound represented by formula (ETM-2-1) or (ETM-2-2).

φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), and n is an integer from 1 to 4.

In formula (ETM-2-1), R ¹¹ to R ¹⁸ are each independently hydrogen, alkyl (preferably alkyl having 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl having 3 to 12 carbon atoms) or aryl (preferably aryl having 6 to 30 carbon atoms).

In formula (ETM-2-2), R ¹¹ and R ¹² each independently represent hydrogen, alkyl (preferably alkyl having 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl having 3 to 12 carbon atoms) or aryl (preferably aryl having 6 to 30 carbon atoms), and R ¹¹ and R ¹² may be bonded to form a ring.

In each formula, the "pyridine-based substituent" is any one of the following formulae (Py-1) to (Py-15) (in the formulae, * indicates a bonding position), and each pyridine-based substituent may be independently substituted with an alkyl having 1 to 4 carbon atoms or a cycloalkyl having 5 to 10 carbon atoms. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, and t-butyl, with methyl being preferred. In addition, the pyridine-based substituent may be bonded to the φ, anthracene ring, or fluorene ring in each formula via phenylene or naphthylene.

The pyridine-based substituent is any one of the formulae (Py-1) to (Py-15) (wherein * represents a bonding position), and among these, any one of the following formulae (Py-21) to (Py-44) is preferable.

At least one hydrogen in each pyridine derivative may be replaced with deuterium, and one of the two "pyridine-based substituents" in formula (ETM-2-1) and formula (ETM-2-2) may be replaced with an aryl.

The "alkyl" in R ¹¹ to R ¹⁸ may be either linear or branched, and examples thereof include linear alkyl having 1 to 24 carbon atoms or branched alkyl having 3 to 24 carbon atoms. A preferred "alkyl" is an alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms). A more preferred "alkyl" is an alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms). An even more preferred "alkyl" is an alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms). An especially preferred "alkyl" is an alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms).

Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, t-octyl, 1-methylheptyl, Examples include 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 2,6-dimethyl-4-heptyl, 3,5,5-trimethylhexyl, n-decyl, n-undecyl, 1-methyldecyl, n-dodecyl, n-tridecyl, 1-hexylheptyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, and n-eicosyl.

The above description of alkyl can be used for the alkyl having 1 to 4 carbon atoms that substitutes the pyridine-based substituent.

The "cycloalkyl" in R ¹¹ to R ¹⁸ is, for example, a cycloalkyl having 3 to 12 carbon atoms. A preferred "cycloalkyl" is a cycloalkyl having 3 to 10 carbon atoms. A more preferred "cycloalkyl" is a cycloalkyl having 3 to 8 carbon atoms. An even more preferred "cycloalkyl" is a cycloalkyl having 3 to 6 carbon atoms.
Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, and dimethylcyclohexyl.

As the "aryl" in R ¹¹ to R ¹⁸ , the preferred aryl is an aryl having 6 to 30 carbon atoms, the more preferred aryl is an aryl having 6 to 18 carbon atoms, the further more preferred aryl is an aryl having 6 to 14 carbon atoms, and the most preferred aryl is an aryl having 6 to 12 carbon atoms.

Specific examples of "aryls having 6 to 30 carbon atoms" include monocyclic aryls such as phenyl, fused bicyclic aryls such as (1-, 2-)naphthyl, fused tricyclic aryls such as acenaphthylene-(1-, 3-, 4-, 5-)yl, fluorene-(1-, 2-, 3-, 4-, 9-)yl, phenalene-(1-, 2-)yl, and (1-, 2-, 3-, 4-, 9-)phenanthryl, fused tetracyclic aryls such as triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, and naphthacene-(1-, 2-, 5-)yl, and fused pentacyclic aryls such as perylene-(1-, 2-, 3-)yl and pentacene-(1-, 2-, 5-, 6-)yl.

Preferred examples of "aryl having 6 to 30 carbon atoms" include phenyl, naphthyl, phenanthryl, chrysenyl, and triphenylenyl, more preferably phenyl, 1-naphthyl, 2-naphthyl, and phenanthryl, and particularly preferably phenyl, 1-naphthyl, and 2-naphthyl.

In formula (ETM-2-2), R ¹¹ and R ¹² may be bonded to form a ring, and as a result, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, fluorene, indene, or the like may be spiro-bonded to the five-membered ring of the fluorene skeleton.

Specific examples of the pyridine derivative include the following compounds:

This pyridine derivative can be produced using known raw materials and known synthesis methods.

<Fluoranthene Derivatives>
The fluoranthene derivative is, for example, a compound represented by the following formula (ETM-3), and is disclosed in detail in WO 2010/134352.

In formula (ETM-3), X ¹² to X ²¹ each represent hydrogen, halogen, linear, branched or cyclic alkyl, linear, branched or cyclic alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, where examples of the substituent in the case of substitution include aryl, heteroaryl, alkyl, and cycloalkyl.

Specific examples of the fluoranthene derivative include the following compounds:

<BO derivatives>
The BO derivative is, for example, a polycyclic aromatic compound represented by the following formula (ETM-4) or a polymer of a polycyclic aromatic compound having a plurality of structures represented by the following formula (ETM-4).

R ¹ to R ¹¹ are each independently hydrogen, aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy, in which at least one hydrogen may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl.

Adjacent groups among R ¹ to R ¹¹ may be bonded to each other to form an aryl ring or a heteroaryl ring together with the ring a, ring b, or ring c, and at least one hydrogen atom in the formed ring may be substituted with an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen atom in these rings may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl.

In addition, at least one hydrogen atom in the compound or structure represented by formula (ETM-4) may be replaced with a halogen or deuterium.

For an explanation of the substituents and ring formation form in formula (ETM-4), the explanation of the polycyclic aromatic compounds represented by formulas (1A) and (1B) can be cited.

Specific examples of the BO derivative include the following compounds:

This BO derivative can be produced using known raw materials and known synthesis methods.

<Anthracene derivatives>
One of the anthracene derivatives is, for example, a compound represented by the following formula (ETM-5).

Each Ar ¹ is independently a single bond, or a divalent benzene, naphthalene, anthracene, fluorene, or phenalene.

Each ^Ar2 is independently an aryl having 6 to 20 carbon atoms, preferably an aryl having 6 to 16 carbon atoms, more preferably an aryl having 6 to 12 carbon atoms, and particularly preferably an aryl having 6 to 10 carbon atoms. Specific examples of the "aryl having 6 to 20 carbon atoms" include monocyclic aryls such as phenyl, (o-, m-, p-) tolyl, (2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5-) xylyl, mesityl (2,4,6-trimethylphenyl), (o-, m-, p-) cumenyl, bicyclic aryls such as (2-, 3-, 4-) biphenylyl, condensed bicyclic aryls such as (1-, 2-) naphthyl, tricyclic aryls such as terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4'-yl, p-terphenyl-2 ...4'-yl, p-terphenyl-2-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4'-yl, p-terphenyl-2-yl, m-terphenyl-4'-yl, p-terphenyl-2-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m aryl, o-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl; fused tricyclic aryls, anthracene-(1-,2-,9-)yl, acenaphthylene-(1-,3-,4-,5-)yl, fluorene-(1-,2-,3-,4-,9-)yl, phenalene-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl; fused tetracyclic aryls, triphenylene-(1-,2-)yl, pyrene-(1-,2-,4-)yl, tetracene-(1-,2-,5-)yl; fused pentacyclic aryls, perylene-(1-,2-,3-)yl, and the like. Specific examples of the "aryl having 6 to 10 carbon atoms" include phenyl, biphenylyl, naphthyl, terphenylyl, anthracenyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, tetracenyl, and perylenyl.

R ¹ to R ⁴ are each independently hydrogen, alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 6 carbon atoms, or aryl having 6 to 20 carbon atoms.
The alkyl having 1 to 6 carbon atoms in R ¹ to R ⁴ may be either a straight chain or a branched chain. That is, it is a straight chain alkyl having 1 to 6 carbon atoms or a branched chain alkyl having 3 to 6 carbon atoms. It is more preferably an alkyl having 1 to 4 carbon atoms (branched chain alkyl having 3 to 4 carbon atoms). Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, and 2-ethylbutyl, and methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, or t-butyl is preferred, and methyl, ethyl, or t-butyl is more preferred.

Specific examples of the cycloalkyl having 3 to 6 carbon atoms for R ¹ to R ⁴ include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, and dimethylcyclohexyl.

The aryl having 6 to 20 carbon atoms in R ¹ to R ⁴ is preferably an aryl having 6 to 16 carbon atoms, more preferably an aryl having 6 to 12 carbon atoms, and particularly preferably an aryl having 6 to 10 carbon atoms. Specific examples of the "aryl having 6 to 20 carbon atoms" include the specific examples of the "aryl having 6 to 20 carbon atoms" in Ar ^2. Preferred examples of the "aryl having 6 to 20 carbon atoms" include phenyl, biphenylyl, terphenylyl, or naphthyl, more preferably phenyl, biphenylyl, 1-naphthyl, 2-naphthyl, or m-terphenyl-5'-yl, even more preferably phenyl, biphenylyl, 1-naphthyl, or 2-naphthyl, and most preferably phenyl.

Specific examples of these anthracene derivatives include the following compounds.

These anthracene derivatives can be produced using known raw materials and known synthesis methods.

<Benzofluorene derivatives>
The benzofluorene derivative is, for example, a compound represented by the following formula (ETM-6).

Each Ar ¹ is independently an aryl having 6 to 20 carbon atoms, and the same explanation as for "aryl having 6 to 20 carbon atoms" in Ar ² of formula (ETM-5) can be cited. An aryl having 6 to 16 carbon atoms is preferable, an aryl having 6 to 12 carbon atoms is more preferable, and an aryl having 6 to 10 carbon atoms is particularly preferable. Specific examples include phenyl, biphenylyl, naphthyl, terphenylyl, anthracenyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, etc.

Each Ar ² is independently hydrogen, an alkyl (preferably an alkyl having 1 to 24 carbon atoms), a cycloalkyl (preferably a cycloalkyl having 3 to 12 carbon atoms) or an aryl (preferably an aryl having 6 to 30 carbon atoms), and two Ar ² may be bonded to form a ring.

The "alkyl" in ^Ar2 may be either linear or branched, and examples thereof include linear alkyl having 1 to 24 carbon atoms or branched alkyl having 3 to 24 carbon atoms. A preferred "alkyl" is an alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms). A more preferred "alkyl" is an alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms). An even more preferred "alkyl" is an alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms). An especially preferred "alkyl" is an alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms). Specific examples of "alkyl" include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, and the like.

The "cycloalkyl" in ^Ar2 includes, for example, cycloalkyl having 3 to 12 carbon atoms. A preferred "cycloalkyl" is cycloalkyl having 3 to 10 carbon atoms. A more preferred "cycloalkyl" is cycloalkyl having 3 to 8 carbon atoms. An even more preferred "cycloalkyl" is cycloalkyl having 3 to 6 carbon atoms. Specific examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclopentyl, cycloheptyl, methylcyclohexyl, cyclooctyl, and dimethylcyclohexyl.

As the "aryl" in ^Ar2 , a preferable aryl is an aryl having 6 to 30 carbon atoms, a more preferable aryl is an aryl having 6 to 18 carbon atoms, an even more preferable aryl is an aryl having 6 to 14 carbon atoms, and an especially preferable aryl is an aryl having 6 to 12 carbon atoms.

Specific examples of "aryl having 6 to 30 carbon atoms" include phenyl, naphthyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, naphthacenyl, perylenyl, and pentacenyl.

Two ^Ar2 may be bonded to form a ring, and as a result, cyclobutane, cyclopentane, cyclopentene, cyclopentadiene, cyclohexane, fluorene, indene, or the like may be spiro-bonded to the five-membered ring of the fluorene skeleton.

Specific examples of the benzofluorene derivative include the following compounds:

This benzofluorene derivative can be produced using known raw materials and known synthesis methods.

<Phosphine oxide derivatives>
The phosphine oxide derivative is, for example, a compound represented by the following formula (ETM-7-1). Details are also described in WO 2013/079217 and WO 2013/079678.

^R5 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 16 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a heteroaryl group having 5 to 20 carbon atoms;
R ⁶ is CN, a substituted or unsubstituted alkyl having 1 to 20 carbon atoms, a cycloalkyl having 3 to 16 carbon atoms, a heteroalkyl having 1 to 20 carbon atoms, an aryl having 6 to 20 carbon atoms, a heteroaryl having 5 to 20 carbon atoms, an alkoxy having 1 to 20 carbon atoms, or an aryloxy having 6 to 20 carbon atoms;
R ⁷ and R ⁸ are each independently a substituted or unsubstituted aryl having 6 to 20 carbon atoms or a heteroaryl having 5 to 20 carbon atoms;
^R9 is oxygen or sulfur;
j is 0 or 1, k is 0 or 1, r is an integer of 0 to 4, and q is an integer of 1 to 3.
When substituted, the substituent may be an aryl, heteroaryl, alkyl or cycloalkyl.

The phosphine oxide derivative may be, for example, a compound represented by the following formula (ETM-7-2).

R ¹ to R ³ may be the same or different and are selected from hydrogen, alkyl, cycloalkyl, aralkyl, alkenyl, cycloalkenyl, alkynyl, alkoxy, alkylthio, cycloalkylthio, aryl ether (aryl ether group), aryl thioether (aryl thioether group), aryl, heterocyclic group, halogen, cyano, formyl, carbonyl, carboxyl, amino, nitro, silyl, and a fused ring formed between adjacent substituents.

Ar ¹ may be the same or different and is arylene or heteroarylene. Ar ² may be the same or different and is aryl or heteroaryl. However, at least one of Ar ¹ and Ar ² has a substituent or forms a condensed ring with the adjacent substituent. n is an integer of 0 to 3, when n is 0, there is no unsaturated structural portion, and when n is 3, R ¹ does not exist.

Among these substituents, alkyl refers to saturated aliphatic hydrocarbon groups such as methyl, ethyl, propyl, and butyl, which may be unsubstituted or substituted. If substituted, there is no particular limit to the substituent, and examples include alkyl, aryl, and heterocyclic groups, which is also the case in the following descriptions. In addition, the number of carbon atoms in the alkyl is not particularly limited, but is usually in the range of 1 to 20 from the standpoint of ease of availability and cost.

Cycloalkyl refers to a saturated alicyclic hydrocarbon group, such as cyclopropyl, cyclohexyl, norbornyl, or adamantyl, which may be unsubstituted or substituted. The number of carbon atoms in the alkyl portion is not particularly limited, but is usually in the range of 3 to 20.

Also, aralkyl refers to an aromatic hydrocarbon group via an aliphatic hydrocarbon such as benzyl or phenylethyl, and both the aliphatic and aromatic hydrocarbons may be unsubstituted or substituted. The number of carbon atoms in the aliphatic portion is not particularly limited, but is usually in the range of 1 to 20.

Alkenyl refers to an unsaturated aliphatic hydrocarbon group containing a double bond, such as vinyl, allyl, or butadienyl, which may be unsubstituted or substituted. The number of carbon atoms in an alkenyl is not particularly limited, but is usually in the range of 2 to 20.

Cycloalkenyl refers to an unsaturated alicyclic hydrocarbon group containing a double bond, such as cyclopentenyl, cyclopentadienyl, or cyclohexenyl, which may be unsubstituted or substituted.

Alkynyl refers to an unsaturated aliphatic hydrocarbon group containing a triple bond, such as acetylenyl, which may be unsubstituted or substituted. The number of carbon atoms in alkynyl is not particularly limited, but is usually in the range of 2 to 20.

Alkoxy refers to an aliphatic hydrocarbon group, such as methoxy, that is bonded via an ether bond, and the aliphatic hydrocarbon group may be unsubstituted or substituted. The number of carbon atoms in the alkoxy is not particularly limited, but is usually in the range of 1 to 20.

Alkylthio is a group in which the oxygen atom of the ether bond of an alkoxy is replaced with a sulfur atom.

Cycloalkylthio is a group in which the oxygen atom of the ether bond of a cycloalkoxy is replaced with a sulfur atom.

Also, aryl ether refers to an aromatic hydrocarbon group, such as phenoxy, that is bonded via an ether bond, and the aromatic hydrocarbon group may be unsubstituted or substituted. The number of carbon atoms in the aryl ether is not particularly limited, but is usually in the range of 6 to 40.

An aryl thioether is a group in which the oxygen atom of the ether bond of an aryl ether is replaced with a sulfur atom.

Also, aryl refers to an aromatic hydrocarbon group such as phenyl, naphthyl, biphenylyl, phenanthryl, terphenylyl, pyrenyl, etc. The aryl may be unsubstituted or substituted. The number of carbon atoms in the aryl is not particularly limited, but is usually in the range of 6 to 40.

Heterocyclic groups refer to cyclic structural groups having atoms other than carbon, such as furanyl, thienyl, oxazolyl, pyridyl, quinolinyl, and carbazolyl, which may be unsubstituted or substituted. The number of carbon atoms in the heterocyclic group is not particularly limited, but is usually in the range of 2 to 30.

Halogen refers to fluorine, chlorine, bromine, and iodine.

Formyl, carbonyl, and amino can also include groups substituted with aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, heterocycles, etc.

In addition, the aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and heterocycles may be unsubstituted or substituted.

Silyl refers to a silicon compound group such as trimethylsilyl, which may be unsubstituted or substituted. The number of carbon atoms in silyl is not particularly limited, but is usually in the range of 3 to 20. The number of silicon atoms is usually 1 to 6.

The fused ring formed between adjacent substituents is, for example, a conjugated or non-conjugated fused ring formed between Ar ¹ and R ² , Ar ¹ and R ³ , Ar ² and R ² , Ar ² and R ³ , R ² and R ³ , Ar ¹ and Ar ^2, etc. Here, when n is 1, two R ^1s may form a conjugated or non-conjugated fused ring. These fused rings may contain a nitrogen, oxygen, or sulfur atom in the ring structure, or may be fused with another ring.

Specific examples of the phosphine oxide derivative include the following compounds:

This phosphine oxide derivative can be produced using known raw materials and known synthesis methods.

<Pyrimidine derivatives>
The pyrimidine derivative is, for example, a compound represented by the following formula (ETM-8), preferably a compound represented by the following formula (ETM-8-1). Details are also described in WO 2011/021689.

Each Ar is independently an optionally substituted aryl or an optionally substituted heteroaryl. n is an integer from 1 to 4, preferably an integer from 1 to 3, and more preferably 2 or 3.

The "aryl" in "optionally substituted aryl" includes, for example, aryl having 6 to 30 carbon atoms, preferably aryl having 6 to 24 carbon atoms, more preferably aryl having 6 to 20 carbon atoms, and even more preferably aryl having 6 to 12 carbon atoms.

Specific examples of "aryl" include monocyclic aryl phenyl, bicyclic aryl (2-, 3-, 4-) biphenylyl, condensed bicyclic aryl (1-, 2-) naphthyl, tricyclic aryl terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl), condensed tricyclic aryl Examples of the aryl include acenaphthylene-(1-,3-,4-,5-)yl, fluorene-(1-,2-,3-,4-,9-)yl, phenalene-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl, tetracyclic aryl quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl), condensed tetracyclic aryl triphenylene-(1-,2-)yl, pyrene-(1-,2-,4-)yl, naphthacene-(1-,2-,5-)yl, condensed pentacyclic aryl perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl, etc.

The "heteroaryl" in "optionally substituted heteroaryl" includes, for example, heteroaryl having 2 to 30 carbon atoms, preferably heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, even more preferably heteroaryl having 2 to 15 carbon atoms, and particularly preferably heteroaryl having 2 to 10 carbon atoms. In addition, examples of heteroaryl include heterocycles containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms.

Specific examples of heteroaryl include furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, and indolizinyl.

The above aryl and heteroaryl may be substituted, for example, by the above aryl or heteroaryl, respectively.

Specific examples of the pyrimidine derivative include the following compounds:

This pyrimidine derivative can be produced using known raw materials and known synthesis methods.

<Aryl nitrile derivatives>
The arylnitrile derivative is, for example, a compound represented by the following formula (ETM-9), or a multimer in which a plurality of such compounds are bonded together via single bonds, etc. Details are described in the specification of U.S. Patent Application Publication No. 2014/0197386.

From the viewpoint of fast electron transport properties, Ar _ni preferably has a large number of carbon atoms, and from the viewpoint of high E _T1 , Ar ni preferably has a small number of carbon atoms. Specifically, Ar _ni preferably has a high E _T1 when used in a layer adjacent to the light-emitting layer, and is an aryl having 6 to 20 carbon atoms, preferably an aryl having 6 to 14 carbon atoms, and more preferably an aryl having 6 to 10 carbon atoms. Furthermore, the number of nitrile group substitutions n is preferably large from the viewpoint of high E _T1 , and is preferably small from the viewpoint of high E _S1 . Specifically, the number of nitrile group substitutions n is an integer of 1 to 4, preferably an integer of 1 to 3, more preferably an integer of 1 to 2, and even more preferably 1.

Each Ar is independently an aryl which may be substituted, or a heteroaryl which may be substituted. From the viewpoint of high E _S1 and high E _T1 , it is preferable that the heteroaryl has donor properties, and it is preferable that the number of donor heteroaryls is small because it is used as an electron transport layer. From the viewpoint of charge transportability, it is preferable that the aryl or heteroaryl has a large number of carbon atoms, and it is preferable that the aryl or heteroaryl has many substituents. The number of substitutions m of Ar is specifically an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 1 to 2.

The "aryl" in "optionally substituted aryl" includes, for example, aryl having 6 to 30 carbon atoms, preferably aryl having 6 to 24 carbon atoms, more preferably aryl having 6 to 20 carbon atoms, and even more preferably aryl having 6 to 12 carbon atoms.

Specific examples of "aryl" include monocyclic aryl phenyl, bicyclic aryl (2-, 3-, 4-) biphenylyl, condensed bicyclic aryl (1-, 2-) naphthyl, tricyclic aryl terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl), condensed tricyclic aryl Examples of the aryl include acenaphthylene-(1-,3-,4-,5-)yl, fluorene-(1-,2-,3-,4-,9-)yl, phenalene-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl, tetracyclic aryl quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl), condensed tetracyclic aryl triphenylene-(1-,2-)yl, pyrene-(1-,2-,4-)yl, naphthacene-(1-,2-,5-)yl, condensed pentacyclic aryl perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl, etc.

The "heteroaryl" in "optionally substituted heteroaryl" includes, for example, heteroaryl having 2 to 30 carbon atoms, preferably heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, even more preferably heteroaryl having 2 to 15 carbon atoms, and particularly preferably heteroaryl having 2 to 10 carbon atoms. In addition, examples of heteroaryl include heterocycles containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms.

Specific examples of heteroaryl include furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, and indolizinyl.

The above aryl and heteroaryl may be substituted, for example, by the above aryl or heteroaryl, respectively.

The arylnitrile derivative may be a polymer in which a plurality of compounds represented by formula (ETM-9) are bonded together by single bonds or the like. In this case, in addition to single bonds, the compounds may be bonded together by aryl rings (preferably polyvalent benzene rings, naphthalene rings, anthracene rings, fluorene rings, benzofluorene rings, phenalene rings, phenanthrene rings, or triphenylene rings).

Specific examples of the arylnitrile derivative include the following compounds:

This arylnitrile derivative can be produced using known raw materials and known synthesis methods.

<Triazine derivatives>
The triazine derivative is, for example, a compound represented by the following formula (ETM-10), preferably a compound represented by the following formula (ETM-10-1), the details of which are described in U.S. Patent Application Publication No. 2011/0156013.

Each Ar is independently an optionally substituted aryl or an optionally substituted heteroaryl. n is an integer from 1 to 3, preferably 2 or 3.

The "aryl" in "optionally substituted aryl" includes, for example, aryl having 6 to 30 carbon atoms, preferably aryl having 6 to 24 carbon atoms, more preferably aryl having 6 to 20 carbon atoms, and even more preferably aryl having 6 to 12 carbon atoms.

Specific examples of "aryl" include monocyclic aryl phenyl, bicyclic aryl (2-, 3-, 4-) biphenylyl, condensed bicyclic aryl (1-, 2-) naphthyl, tricyclic aryl terphenylyl (m-terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl-3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3-yl, p-terphenyl-4-yl), condensed tricyclic aryl Examples of the aryl include acenaphthylene-(1-,3-,4-,5-)yl, fluorene-(1-,2-,3-,4-,9-)yl, phenalene-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl, tetracyclic aryl quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, m-quaterphenylyl), condensed tetracyclic aryl triphenylene-(1-,2-)yl, pyrene-(1-,2-,4-)yl, naphthacene-(1-,2-,5-)yl, condensed pentacyclic aryl perylene-(1-,2-,3-)yl, pentacene-(1-,2-,5-,6-)yl, etc.

The "heteroaryl" in "optionally substituted heteroaryl" includes, for example, heteroaryl having 2 to 30 carbon atoms, preferably heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, even more preferably heteroaryl having 2 to 15 carbon atoms, and particularly preferably heteroaryl having 2 to 10 carbon atoms. In addition, examples of heteroaryl include heterocycles containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms.

Specific examples of heteroaryl include furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo[b]thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathiinyl, thianthrenyl, and indolizinyl.

The above aryl and heteroaryl may be substituted, for example, by the above aryl or heteroaryl, respectively.

Specific examples of the triazine derivative include the following compounds:

This triazine derivative can be produced using known raw materials and known synthesis methods.

<Benzimidazole Derivatives>
The benzimidazole derivative is, for example, a compound represented by the following formula (ETM-11).

φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), n is an integer from 1 to 4, and the "benzoimidazole-based substituent" is a substituent in which the pyridyl in the "pyridine-based substituent" in formulas (ETM-2), (ETM-2-1), and (ETM-2-2) is replaced with benzoimidazolyl, and at least one hydrogen in the benzimidazole derivative may be replaced with deuterium.

R ¹¹ in the benzimidazolyl is hydrogen, alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 12 carbon atoms, or aryl having 6 to 30 carbon atoms, and the explanation of R ¹¹ in formulae (ETM-2-1) and (ETM-2-2) can be cited.

It is further preferred that φ is an anthracene ring or a fluorene ring, and in this case, the structure can be referred to in the explanation of formula (ETM-2-1) or formula (ETM-2-2), and for R ¹¹ to R ¹⁸ in each formula, the explanation of formula (ETM-2-1) or formula (ETM-2-2) can be referred to. In addition, in formula (ETM-2-1) or formula (ETM-2-2), two pyridine-based substituents are described as being bonded, but when these are replaced with benzimidazole-based substituents, both pyridine-based substituents may be replaced with benzimidazole-based substituents (i.e., n=2), or one of the pyridine-based substituents may be replaced with a benzimidazole-based substituent and the other pyridine-based substituent may be replaced with R ¹¹ to R ¹⁸ (i.e., n=1). Furthermore, for example, at least one of R ¹¹ to R ¹⁸ in formula (ETM-2-1) may be replaced with a benzimidazole-based substituent, and the “pyridine-based substituent” may be replaced with R ¹¹ to R ¹⁸ .

Specific examples of this benzimidazole derivative include 1-phenyl-2-(4-(10-phenylanthracen-9-yl)phenyl)-1H-benzo[d]imidazole, 2-(4-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 2-(3-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, and 5-(10-(naphthalen-2-yl)anthracen-9-yl)-1,2-diphenyl-1H-benzo[d]imidazole. , 1-(4-(10-(naphthalene-2-yl)anthracen-9-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 2-(4-(9,10-di(naphthalene-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 1-(4-(9,10-di(naphthalene-2-yl)anthracen-2-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 5-(9,10-di(naphthalene-2-yl)anthracen-2-yl)-1,2-diphenyl-1H-benzo[d]imidazole, etc.

This benzimidazole derivative can be produced using known raw materials and known synthesis methods.

<Phenanthroline derivatives>
The phenanthroline derivative is, for example, a compound represented by the following formula (ETM-12) or formula (ETM-12-1), the details of which are described in WO 2006/021982.

φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), and n is an integer from 1 to 4.

R ¹¹ to R ¹⁸ in each formula are each independently hydrogen, alkyl (preferably alkyl having 1 to 24 carbon atoms), cycloalkyl (preferably cycloalkyl having 3 to 12 carbon atoms), or aryl (preferably aryl having 6 to 30 carbon atoms). In addition, in formula (ETM-12-1), any of R ¹¹ to R ¹⁸ is a bond to φ which is an aryl ring.

At least one hydrogen in each phenanthroline derivative may be replaced with deuterium.

The alkyl, cycloalkyl and aryl in R ¹¹ to R ¹⁸ can be the same as those described for R ¹¹ to R ¹⁸ in formula (ETM-2). In addition to the above examples, φ can have the following structural formula: In the structural formula, each R is independently hydrogen, methyl, ethyl, isopropyl, cyclohexyl, phenyl, 1-naphthyl, 2-naphthyl, biphenylyl or terphenylyl, and * indicates the bonding position.

Specific examples of the phenanthroline derivative include 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 9,10-di(1,10-phenanthroline-2-yl)anthracene, 2,6-di(1,10-phenanthroline-5-yl)pyridine, 1,3,5-tri(1,10-phenanthroline-5-yl)benzene, 9,9'-difluoro-bi(1,10-phenanthroline-5-yl), bathocuproine, 1,3-bis(2-phenyl-1,10-phenanthroline-9-yl)benzene, and compounds represented by the following structural formula.

This phenanthroline derivative can be produced using known raw materials and known synthesis methods.

式中、Ｒ^１～Ｒ^６は、それぞれ独立して、水素、フッ素、アルキル、シクロアルキル、アラルキル、アルケニル、シアノ、アルコキシ、またはアリールであり、ＭはＬｉ、Ａｌ、Ｇａ、Ｂｅ、またはＺｎであり、ｎは１～３の整数である。 <Quinolinol metal complexes>
The quinolinol metal complex is, for example, a compound represented by the following formula (ETM-13).

In the formula, R ¹ to R ⁶ are each independently hydrogen, fluorine, alkyl, cycloalkyl, aralkyl, alkenyl, cyano, alkoxy, or aryl; M is Li, Al, Ga, Be, or Zn; and n is an integer from 1 to 3.

Specific examples of quinolinol-based metal complexes include 8-quinolinol lithium, tris(8-quinolinolato)aluminum, tris(4-methyl-8-quinolinolato)aluminum, tris(5-methyl-8-quinolinolato)aluminum, tris(3,4-dimethyl-8-quinolinolato)aluminum, tris(4,5-dimethyl-8-quinolinolato)aluminum, tris(4,6-dimethyl-8-quinolinolato)aluminum, and bis( 2-methyl-8-quinolinolate)(phenolate)aluminum, bis(2-methyl-8-quinolinolate)(2-methylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(3-methylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(4-methylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2-phenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(phenolate)aluminum linolinate)(3-phenylphenolate)aluminum, bis(2-methyl-8-quinolinate)(4-phenylphenolate)aluminum, bis(2-methyl-8-quinolinate)(2,3-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinate)(2,6-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinate)(3,4-dimethylphenolate)aluminum, bis(2-methyl bis(2-methyl-8-quinolinolate)(3,5-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(3,5-di-t-butylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,6-diphenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,4,6-triphenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,4,6-trimethylphenolate)aluminum bis(2-methyl-8-quinolinolate)(2,4,5,6-tetramethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(1-naphtholate)aluminum, bis(2-methyl-8-quinolinolate)(2-naphtholate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(2-phenylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(3-phenylphenolate)aluminum bis(2,4-dimethyl-8-quinolinolate)(4-phenylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(3,5-dimethylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(3,5-di-t-butylphenolate)aluminum, bis(2-methyl-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-8-quinolinolate)aluminum quinolinolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)aluminum-μ-oxo-bis(2,4-dimethyl-8-quinolinolate)aluminum, bis(2-methyl-4-ethyl-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-4-ethyl-8-quinolinolate)aluminum, bis(2-methyl-4-methoxy-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-4-methoxy-8-quinolinolate)aluminum quinolinolate)aluminum, bis(2-methyl-5-cyano-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-5-cyano-8-quinolinolate)aluminum, bis(2-methyl-5-trifluoromethyl-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-5-trifluoromethyl-8-quinolinolate)aluminum, bis(10-hydroxybenzo[h]quinoline)beryllium, etc.

This quinolinol metal complex can be produced using known raw materials and known synthesis methods.

ベンゾチアゾール誘導体は、例えば下記式（ＥＴＭ－１４－２）で表される化合物である。

<Thiazole Derivatives and Benzothiazole Derivatives>
The thiazole derivative is, for example, a compound represented by the following formula (ETM-14-1).

The benzothiazole derivative is, for example, a compound represented by the following formula (ETM-14-2).

In each formula, φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), and n is an integer from 1 to 4. The "thiazole-based substituent" and "benzothiazole-based substituent" are substituents in which the pyridyl in the "pyridine-based substituent" in formulae (ETM-2), (ETM-2-1), and (ETM-2-2) is replaced with the following thiazolyl or benzothiazolyl, and at least one hydrogen in the thiazole derivative and benzothiazole derivative may be replaced with deuterium.

It is further preferred that φ is an anthracene ring or a fluorene ring, and in this case, the structure can be explained with reference to formula (ETM-2-1) or formula (ETM-2-2), and R ¹¹ to R ¹⁸ in each formula can be explained with reference to formula (ETM-2-1) or formula (ETM-2-2). In addition, in formula (ETM-2-1) or formula (ETM-2-2), two pyridine-based substituents are explained in a form in which they are bonded, but when these are replaced with a thiazole-based substituent (or a benzothiazole-based substituent), both pyridine-based substituents may be replaced with a thiazole-based substituent (or a benzothiazole-based substituent) (i.e., n=2), or one of the pyridine-based substituents may be replaced with a thiazole-based substituent (or a benzothiazole-based substituent) and the other pyridine-based substituent may be replaced with R ¹¹ to R ¹⁸ (i.e., n=1). Furthermore, for example, at least one of R ¹¹ to R ¹⁸ in formula (ETM-2-1) may be replaced with a thiazole-based substituent (or a benzothiazole-based substituent) to replace the “pyridine-based substituent” with R ¹¹ to R ¹⁸ .

These thiazole or benzothiazole derivatives can be produced using known raw materials and known synthesis methods.

<Silole derivatives>
The silole derivative is, for example, a compound represented by the following formula (ETM-15), the details of which are described in JP-A-9-194487.

X and Y are each independently an alkyl, cycloalkyl, alkenyl, alkynyl, alkoxy, alkenyloxy, alkynyloxy, aryl, or heteroaryl, which may be substituted. For details of these groups, the explanations in formula (1A) and formula (1B) and further the explanation in formula (ETM-7-2) can be cited. In addition, alkenyloxy and alkynyloxy are groups in which the alkyl portion of alkoxy is replaced with alkenyl or alkynyl, respectively, and for details of these alkenyls and alkynyls, the explanation in formula (ETM-7-2) can be cited.
Furthermore, X and Y, both of which are alkyl, may be bonded to form a ring.

R ¹ to R ⁴ are each independently hydrogen, halogen, alkyl, cycloalkyl, alkoxy, aryloxy, amino, alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, azo group, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, sulfinyl, sulfonyl, sulfanyl, silyl, carbamoyl, aryl, heteroaryl, alkenyl, alkynyl, nitro, formyl, nitroso, formyloxy, isocyano, cyanate group, isocyanate group, thiocyanate group, isothiocyanate group, or cyano, which may be substituted with alkyl, cycloalkyl, aryl or halogen, and may form a condensed ring with an adjacent substituent.

For details of halogen, alkyl, cycloalkyl, alkoxy, aryloxy, amino, aryl, heteroaryl, alkenyl and alkynyl in R ¹ to R ⁴ , the descriptions in formula (1A) and formula (1B) can be referred to.

For details of the alkyl, aryl and alkoxy in the alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aryloxycarbonyl, alkylcarbonyloxy, arylcarbonyloxy, alkoxycarbonyloxy and aryloxycarbonyloxy in R ¹ to R ⁴ , the explanations in formula (1A) and formula (1B) can be cited.

Examples of silyl include a silyl group and a group in which at least one of the three hydrogen atoms of the silyl group is independently substituted with an aryl, alkyl, or cycloalkyl. Tri-substituted silyl is preferred, and examples include triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, and alkyldicycloalkylsilyl. For details of the aryl, alkyl, and cycloalkyl, see the explanations in formula (1A) and formula (1B).

The fused ring formed between adjacent substituents is, for example, a conjugated or non-conjugated fused ring formed between ^R1 and ^R2 , ^R2 and ^R3 , ^R3 and ^R4 , etc. These fused rings may contain a nitrogen, oxygen or sulfur atom in the ring structure, and may be further fused with another ring.

However, preferably, when R ¹ and R ⁴ are phenyl, X and Y are not alkyl or phenyl. Also, preferably, when R ¹ and R ⁴ are thienyl, X and Y are not alkyl, and R ² and R ³ are not alkyl, aryl, alkenyl, or cycloalkyl in which R ² and R ³ are bonded to form a ring. Also, preferably, when R ¹ and R ⁴ are silyl groups, R ² , R ³ , X and Y are not each independently hydrogen or an alkyl having 1 to 6 carbon atoms. Also, preferably, when R ¹ and R ² are condensed with a benzene ring, X and Y are not alkyl or phenyl.

These silole derivatives can be produced using known raw materials and known synthesis methods.

<Azoline derivatives>
The azoline derivative is, for example, a compound represented by the following formula (ETM-16). Details are described in WO 2017/014226.

In formula (ETM-16),
φ is an m-valent group derived from an aromatic hydrocarbon having 6 to 40 carbon atoms or an m-valent group derived from an aromatic heterocycle having 2 to 40 carbon atoms, and at least one hydrogen atom of φ is optionally substituted by an alkyl having 1 to 6 carbon atoms, a cycloalkyl having 3 to 14 carbon atoms, an aryl having 6 to 18 carbon atoms, or a heteroaryl having 2 to 18 carbon atoms;
Y's are each independently -O-, -S- or >N-Ar, Ar is an aryl having 6 to 12 carbon atoms or a heteroaryl having 2 to 12 carbon atoms, at least one hydrogen of Ar may be substituted with an alkyl having 1 to 4 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, an aryl having 6 to 12 carbon atoms or a heteroaryl having 2 to 12 carbon atoms, R ¹ to R ⁵ are each independently hydrogen, an alkyl having 1 to 4 carbon atoms or a cycloalkyl having 5 to 10 carbon atoms, with the proviso that any one of Ar and R ¹ to R ⁵ in >N-Ar is a site bonded to L,
Each L is independently selected from the group consisting of a divalent group represented by the following formula (L-1) and a divalent group represented by the following formula (L-2):

In formula (L-1), X ¹ to X ⁶ are each independently =CR ⁶ - or =N-, at least two of X ¹ to X ⁶ are =CR ⁶ -, R 6 in two of =CR ⁶ - among X ¹ to ^{X 6} is φ or a bonding site to an azoline ring, and R ⁶ in the remaining =CR ⁶ - is hydrogen;
In formula (L-2), X ⁷ to X ¹⁴ are each independently =CR ⁶ - or =N-, at least two of X ⁷ to X ¹⁴ are =CR ⁶ -, R 6 in two of =CR ⁶ - among X ⁷ to X ¹⁴ is φ or a bonding site to an azoline ring, and ^{R 6 in} the remaining =CR ⁶ - is hydrogen;
At least one hydrogen atom of L may be substituted by alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, aryl having 6 to 10 carbon atoms, or heteroaryl having 2 to 10 carbon atoms;
m is an integer of 1 to 4, and when m is an integer of 2 to 4, the groups formed by the azoline ring and L may be the same or different, and
At least one hydrogen atom in the compound represented by formula (ETM-16) may be substituted with deuterium.

Specific azoline derivatives are compounds represented by the following formula (ETM-16-1) or (ETM-16-2).

In formula (ETM-16-1) and formula (ETM-16-2),
φ is an m-valent group derived from an aromatic hydrocarbon having 6 to 40 carbon atoms or an m-valent group derived from an aromatic heterocycle having 2 to 40 carbon atoms, and at least one hydrogen atom of φ is optionally substituted by an alkyl having 1 to 6 carbon atoms, a cycloalkyl having 3 to 14 carbon atoms, an aryl having 6 to 18 carbon atoms, or a heteroaryl having 2 to 18 carbon atoms;
In formula (ETM-16-1), each Y is independently -O-, -S-, or >N-Ar, Ar is an aryl having 6 to 12 carbon atoms or a heteroaryl having 2 to 12 carbon atoms, and at least one hydrogen atom of Ar is optionally substituted by an alkyl having 1 to 4 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, an aryl having 6 to 12 carbon atoms, or a heteroaryl having 2 to 12 carbon atoms,
In formula (ETM-16-1), R ¹ to R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group having 5 to 10 carbon atoms, provided that R ¹ and R ² are the same, and R ³ and R ⁴ are the same;
In formula (ETM-16-2), R ¹ to R ⁵ each independently represent hydrogen, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, provided that R ¹ and R ² are the same, and R ³ and R ⁴ are the same;
In formula (ETM-16-1) and formula (ETM-16-2),
Each L is independently selected from the group consisting of a divalent group represented by the following formula (L-1) and a divalent group represented by the following formula (L-2):

式（Ｌ－１）中、Ｘ^１～Ｘ^６はそれぞれ独立して＝ＣＲ^６－または＝Ｎ－であり、Ｘ^１～Ｘ^６のうちの少なくとも２つは＝ＣＲ^６－であり、Ｘ^１～Ｘ^６のうちの２つの＝ＣＲ^６－におけるＲ^６はφまたはアゾリン環と結合する部位であり、それ以外の＝ＣＲ^６－におけるＲ^６は水素であり、
式（Ｌ－２）中、Ｘ^７～Ｘ^１４はそれぞれ独立して＝ＣＲ^６－または＝Ｎ－であり、Ｘ^７～Ｘ^１４のうちの少なくとも２つは＝ＣＲ^６－であり、Ｘ^７～Ｘ^１４のうちの２つの＝ＣＲ^６－におけるＲ^６はφまたはアゾリン環と結合する部位であり、それ以外の＝ＣＲ^６－におけるＲ^６は水素であり、
Ｌの少なくとも１つの水素は炭素数１～４のアルキル、炭素数５～１０のシクロアルキル、炭素数６～１０のアリールまたは炭素数２～１０のヘテロアリールで置換されていてもよく、
ｍは１～４の整数であり、ｍが２～４であるとき、アゾリン環とＬとで形成される基は同一であっても異なっていてもよく、そして、
式（ＥＴＭ－１６－１）または式（ＥＴＭ－１６－２）で表される化合物中の少なくとも１つの水素は重水素で置換されていてもよい。

In formula (L-1), X ¹ to X ⁶ are each independently =CR ⁶ - or =N-, at least two of X ¹ to X ⁶ are =CR ⁶ -, R 6 in two of =CR ⁶ - among X ¹ to ^{X 6} is φ or a bonding site to an azoline ring, and R ⁶ in the remaining =CR ⁶ - is hydrogen;
In formula (L-2), X ⁷ to X ¹⁴ are each independently =CR ⁶ - or =N-, at least two of X ⁷ to X ¹⁴ are =CR ⁶ -, R 6 in two of =CR ⁶ - among X ⁷ to X ¹⁴ is φ or a bonding site to an azoline ring, and ^{R 6 in} the remaining =CR ⁶ - is hydrogen;
At least one hydrogen atom of L may be substituted by alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, aryl having 6 to 10 carbon atoms, or heteroaryl having 2 to 10 carbon atoms;
m is an integer of 1 to 4, and when m is an integer of 2 to 4, the groups formed by the azoline ring and L may be the same or different, and
At least one hydrogen atom in the compound represented by formula (ETM-16-1) or formula (ETM-16-2) may be substituted with deuterium.

Preferably, φ is selected from the group consisting of monovalent groups represented by the following formulas (φ1-1) to (φ1-18), divalent groups represented by the following formulas (φ2-1) to (φ2-34), trivalent groups represented by the following formulas (φ3-1) to (φ3-3), and tetravalent groups represented by the following formulas (φ4-1) to (φ4-2), and at least one hydrogen of φ may be substituted with an alkyl having 1 to 6 carbon atoms, a cycloalkyl having 3 to 14 carbon atoms, an aryl having 6 to 18 carbon atoms, or a heteroaryl having 2 to 18 carbon atoms.

In the formula, Z is >CR ₂ , >N-Ar, >N-L, -O- or -S-, each R in >CR ₂ is independently an alkyl having 1 to 4 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, an aryl having 6 to 12 carbon atoms or a heteroaryl having 2 to 12 carbon atoms, and the Rs may be bonded to each other to form a ring, Ar in >N-Ar is an aryl having 6 to 12 carbon atoms or a heteroaryl having 2 to 12 carbon atoms, and L in >N-L is L in formula (ETM-16), formula (ETM-16-1) or formula (ETM-16-2). * in the formula represents a bonding position.

Preferably, L is a divalent ring group selected from the group consisting of benzene, naphthalene, pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, isoquinoline, naphthyridine, phthalazine, quinoxaline, quinazoline, cinnoline, and pteridine, and at least one hydrogen of L may be substituted with an alkyl having 1 to 4 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, an aryl having 6 to 10 carbon atoms, or a heteroaryl having 2 to 10 carbon atoms.

Preferably, Ar in >N-Ar as Y or Z is selected from the group consisting of phenyl, naphthyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, quinolinyl, isoquinolinyl, naphthyridinyl, phthalazinyl, quinoxalinyl, quinazolinyl, cinnolinyl, and pteridinyl, and at least one hydrogen of Ar in >N-Ar as Y may be substituted with alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, or aryl having 6 to 10 carbon atoms.

Preferably, R ¹ to R ⁴ are each independently hydrogen, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, with the proviso that R ¹ and R ² are the same, R ³ and R ⁴ are the same, and R ¹ to R ⁴ are not all hydrogen at the same time, and m is 1 or 2, and when m is 2, the groups formed by the azoline ring and L are the same.

Specific examples of azoline derivatives include the following compounds: In the structural formula, "Me" represents methyl.

More preferably, φ is selected from the group consisting of divalent groups represented by the following formulas (φ2-1), (φ2-31), (φ2-32), (φ2-33) and (φ2-34), and at least one hydrogen of φ may be substituted with an aryl having 6 to 18 carbon atoms.

L is a divalent ring group selected from the group consisting of benzene, pyridine, pyrazine, pyrimidine, pyridazine, and triazine, and at least one hydrogen of L is optionally substituted by alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, aryl having 6 to 10 carbon atoms, or heteroaryl having 2 to 14 carbon atoms;
Ar in >N-Ar as Y is selected from the group consisting of phenyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, and triazinyl, and at least one hydrogen of the Ar may be substituted with alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, or aryl having 6 to 10 carbon atoms;
R ¹ to R ⁴ are each independently hydrogen, alkyl having 1 to 4 carbon atoms, or cycloalkyl having 5 to 10 carbon atoms, provided that R ¹ and R ² are the same, R ³ and R ⁴ are the same, and R ¹ to R ⁴ are not all hydrogen at the same time, and
m is 2, and the groups formed by the azoline ring and L are the same.

Other specific examples of the azoline derivative include the following compounds: In the structural formula, "Me" represents methyl.

For details of the alkyl, cycloalkyl, aryl, or heteroaryl in the above formulas defining this azoline derivative, the explanations in formula (1A) and formula (1B) can be cited.

This azoline derivative can be produced using known raw materials and known synthesis methods.

<Reducing Substance>
The electron transport layer or the electron injection layer may further contain a substance capable of reducing the material forming the electron transport layer or the electron injection layer. As the reducing substance, various substances can be used as long as they have a certain degree of reducing ability, and for example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, halides of alkali metals, oxides of alkaline earth metals, halides of alkaline earth metals, oxides of rare earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals can be suitably used.

Preferred reducing substances include alkali metals such as Na (work function 2.36 eV), K (2.28 eV), Rb (2.16 eV), or Cs (1.95 eV), and alkaline earth metals such as Ca (2.9 eV), Sr (2.0-2.5 eV), or Ba (2.52 eV), with substances with a work function of 2.9 eV or less being particularly preferred. Of these, more preferred reducing substances are alkali metals such as K, Rb, or Cs, even more preferred are Rb or Cs, and most preferred is Cs. These alkali metals have particularly high reducing ability, and by adding a relatively small amount to the material forming the electron transport layer or electron injection layer, the luminance of the organic EL element can be improved and the lifespan can be extended. In addition, as a reducing substance having a work function of 2.9 eV or less, a combination of two or more of these alkali metals is also preferred, and in particular, a combination containing Cs, such as a combination of Cs and Na, Cs and K, Cs and Rb, or Cs, Na and K, is preferred. By containing Cs, the reducing ability can be efficiently exerted, and by adding it to the material forming the electron transport layer or electron injection layer, the luminance of the organic EL element can be improved and the life can be extended.

The above-mentioned electron injection layer material and electron transport layer material can be used as an electron layer material in the form of a polymer compound obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer, or a crosslinked polymer thereof, or a pendant polymer compound obtained by reacting a main chain polymer with the reactive compound, or a crosslinked pendant polymer thereof. In this case, the reactive substituent can be quoted from the description of the polycyclic aromatic compound consisting of a partial structure represented by formula (1A) and at least two partial structures represented by formula (1B).
The applications of such polymer compounds and crosslinked polymers will be described in detail below.

3-1-7. Cathode in Organic Electroluminescent Device The cathode 108 plays a role in injecting electrons into the light-emitting layer 105 via the electron injection layer 107 and the electron transport layer 106 .

The material for forming the cathode 108 is not particularly limited as long as it is a material that can efficiently inject electrons into the organic layer, but the same material as the material for forming the anode 102 can be used. Among them, metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium, and magnesium, or alloys thereof (magnesium-silver alloy, magnesium-indium alloy, aluminum-lithium alloy such as lithium fluoride/aluminum, etc.), etc. are preferable. In order to increase the electron injection efficiency and improve the device characteristics, lithium, sodium, potassium, cesium, calcium, magnesium, or alloys containing these low work function metals are effective. However, these low work function metals are generally unstable in air. To improve this point, for example, a method is known in which a trace amount of lithium, cesium, or magnesium is doped into the organic layer to use a highly stable electrode. Other dopants that can be used include inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide. However, they are not limited to these.

Furthermore, preferred examples include laminating metals such as platinum, gold, silver, copper, iron, tin, aluminum, and indium, or alloys using these metals, as well as inorganic materials such as silica, titania, and silicon nitride, polyvinyl alcohol, vinyl chloride, and hydrocarbon polymer compounds, in order to protect the electrodes. There are no particular limitations on the method of producing these electrodes, and they can be produced by resistance heating, electron beam deposition, sputtering, ion plating, coating, or the like, as long as electrical conductivity can be obtained.

3-1-8. Binders that may be used in each layer The materials used in the hole injection layer, hole transport layer, light emitting layer, electron transport layer and electron injection layer described above can form each layer alone, but they can also be used as polymer binders by dispersing them in solvent-soluble resins such as polyvinyl chloride, polycarbonate, polystyrene, poly(N-vinylcarbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resins, ketone resins, phenoxy resins, polyamide, ethyl cellulose, vinyl acetate resins, ABS resins and polyurethane resins, and curable resins such as phenol resins, xylene resins, petroleum resins, urea resins, melamine resins, unsaturated polyester resins, alkyd resins, epoxy resins and silicone resins.

3-1-9. Method for Producing Organic Electroluminescent Device Each layer constituting an organic EL device can be formed by forming the material to be formed into a thin film by a method such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination, printing, spin coating or casting, coating, etc. The thickness of each layer thus formed is not particularly limited and can be set appropriately according to the properties of the material, but is usually in the range of 2 nm to 5000 nm. The thickness can usually be measured with a quartz crystal oscillation type film thickness measuring device, etc. When forming a thin film by vapor deposition, the vapor deposition conditions vary depending on the type of material, the intended crystal structure and association structure of the film, etc. The vapor deposition conditions are generally preferably set appropriately within the range of boat heating temperature +50 to +400°C, vacuum degree 10 ^-6 to 10 ^-3 Pa, vapor deposition speed 0.01 to 50 nm/sec, substrate temperature -150 to +300°C, and film thickness 2 nm to 5 μm.

When applying a DC voltage to the organic EL element obtained in this way, the anode should be set to + and the cathode to -. When a voltage of about 2 to 40 V is applied, light emission can be observed from the transparent or semi-transparent electrode side (anode or cathode, or both). This organic EL element also emits light when a pulsed current or AC current is applied. The waveform of the AC current applied can be any waveform.

Next, as an example of a method for producing an organic EL element, we will explain a method for producing an organic EL element consisting of an anode, a hole injection layer, a hole transport layer, a light emitting layer made of a host material and a dopant material, an electron transport layer, an electron injection layer, and a cathode.

<Vapor deposition method>
A thin film of an anode material is formed on a suitable substrate by vapor deposition or the like to prepare an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. A host material and a dopant material are co-deposited on the anode to form a thin film as a light-emitting layer, an electron transport layer and an electron injection layer are formed on the light-emitting layer, and a thin film of a cathode material is further formed by vapor deposition or the like to prepare a cathode, thereby obtaining a desired organic EL element. Note that in the preparation of the above-mentioned organic EL element, the order of preparation can be reversed, and the elements can be prepared in the order of cathode, electron injection layer, electron transport layer, light-emitting layer, hole transport layer, hole injection layer, and anode.

<Wet film formation method>
The wet film formation method is carried out by preparing a low molecular weight compound capable of forming each organic layer of an organic EL element as a liquid composition for forming an organic layer, and using this. If there is no suitable organic solvent for dissolving this low molecular weight compound, the composition for forming an organic layer may be prepared from a polymer compound polymerized together with other monomers having a solubility function as a reactive compound in which the low molecular weight compound is substituted with a reactive substituent, or a main chain polymer.

In wet film formation, a coating film is generally formed through a coating step in which an organic layer-forming composition is applied to a substrate and a drying step in which the solvent is removed from the applied organic layer-forming composition. When the polymer compound has a crosslinkable substituent (also called a crosslinkable polymer compound), the polymer is further crosslinked by the drying step to form a crosslinked polymer. Depending on the coating step, a method using a spin coater is called a spin coat method, a method using a slit coater is called a slit coat method, a method using a plate is called a gravure, offset, reverse offset, or flexographic printing method, a method using an inkjet printer is called an inkjet method, and a method spraying in a mist is called a spray method.

As an example, referring to FIG. 2, a method of forming a coating film on a substrate having a bank using an inkjet method will be described. First, the bank (200) is provided on the electrode (120) on the substrate (110). In this case, ink droplets (310) are dropped between the banks (200) from the inkjet head (300) and dried to produce the coating film (130). This process is repeated to produce the next coating film (140) and then the light-emitting layer (150), and an electron transport layer, an electron injection layer, and electrodes are formed using a vacuum deposition method, making it possible to produce an organic EL element in which the light-emitting region is separated by the bank material.

The drying process can be carried out by air drying, heating, drying under reduced pressure, etc. The drying process can be carried out once, or multiple times using different methods and conditions. Also, different methods can be used in combination, such as baking under reduced pressure.

A wet film formation method is a film formation method that uses a solution, and examples of this include some printing methods (inkjet methods), spin coating methods or casting methods, and coating methods. Unlike vacuum deposition methods, wet film formation methods do not require expensive vacuum deposition equipment, and can form films under atmospheric pressure. In addition, wet film formation methods allow for large area production and continuous production, which leads to reduced manufacturing costs.

On the other hand, compared to the vacuum deposition method, wet deposition methods can be difficult to layer. When using wet deposition methods to create layered films, it is necessary to prevent the lower layer from being dissolved by the composition of the upper layer, and therefore compositions with controlled solubility, crosslinking of the lower layer, and orthogonal solvents (solvents that are not mutually soluble) are used. However, even with these techniques, it can be difficult to use wet deposition methods to apply all films.

Therefore, a common method for producing organic EL elements is to use wet deposition methods for only a few layers and vacuum deposition for the rest.

For example, the procedure for producing an organic EL element by partially applying a wet film formation method will be described below.
(Step 1) Formation of an anode by vacuum deposition (Step 2) Formation of a hole injection layer-forming composition containing a hole injection layer material by wet deposition (Step 3) Formation of a hole transport layer-forming composition containing a hole transport layer material by wet deposition (Step 4) Formation of an emitting layer-forming composition containing a host material and a dopant material by wet deposition (Step 5) Formation of an electron transport layer by vacuum deposition (Step 6) Formation of an electron injection layer by vacuum deposition (Step 7) Formation of a cathode by vacuum deposition By going through these steps, an organic EL element consisting of an anode/hole injection layer/hole transport layer/emitting layer consisting of a host material and a dopant material/electron transport layer/electron injection layer/cathode is obtained.
Of course, the electron transport layer and the electron injection layer may also be formed by a wet film formation method using a layer-forming composition containing the material for the electron transport layer and the material for the electron injection layer, respectively. In this case, it is preferable to use a means for preventing dissolution of the lower light-emitting layer, or a means for forming the film from the cathode side in the reverse order to the above procedure.

<Other film formation methods>
The composition for forming an organic layer can be formed into a film by laser thermal imaging (LITI). LITI is a method in which a compound attached to a substrate is heated and vapor-deposited by a laser, and the composition for forming an organic layer can be used as a material to be applied to the substrate.

<Optional Step>
Before and after each film-forming step, appropriate treatment steps, cleaning steps, and drying steps may be appropriately inserted. Examples of treatment steps include exposure treatment, plasma surface treatment, ultrasonic treatment, ozone treatment, cleaning treatment using an appropriate solvent, and heat treatment. Furthermore, a series of steps for preparing a bank may also be included.

Photolithography techniques can be used to fabricate the bank. Positive resist materials and negative resist materials can be used as bank materials that can be used with photolithography. In addition, patternable printing methods such as inkjet printing, gravure offset printing, reverse offset printing, and screen printing can also be used. In this case, permanent resist materials can also be used.

Materials that can be used for the bank include, but are not limited to, polysaccharides and their derivatives, homopolymers and copolymers of hydroxyl-containing ethylenic monomers, biopolymers, polyacryloyl compounds, polyesters, polystyrenes, polyimides, polyamideimides, polyetherimides, polysulfides, polysulfones, polyphenylenes, polyphenyl ethers, polyurethanes, epoxy (meth)acrylates, melamine (meth)acrylates, polyolefins, cyclic polyolefins, acrylonitrile-butadiene-styrene copolymers (ABS), silicone resins, polyvinyl chloride, chlorinated polyethylene, chlorinated polypropylene, polyacetates, polynorbornenes, synthetic rubbers, fluorinated polymers such as polyfluorovinylidene, polytetrafluoroethylene, and polyhexafluoropropylene, copolymers of fluoroolefins and hydrocarbon olefins, and fluorocarbon polymers.

<Organic layer forming composition used in wet film formation method>
The composition for forming an organic layer is obtained by dissolving a low molecular weight compound capable of forming each organic layer of an organic EL element, or a polymer compound obtained by polymerizing the low molecular weight compound, in an organic solvent. For example, the composition for forming an emitting layer contains at least one polycyclic aromatic compound (or a polymer compound thereof) as a first component, which is a dopant material, at least one host material as a second component, and at least one organic solvent as a third component. The first component functions as a dopant component of the emitting layer obtained from the composition, and the second component functions as a host component of the emitting layer. The third component functions as a solvent that dissolves the first and second components in the composition, and gives a smooth and uniform surface shape due to the controlled evaporation rate of the third component itself during application.

<Organic solvent>
The composition for forming an organic layer contains at least one organic solvent. By controlling the evaporation rate of the organic solvent during film formation, it is possible to control and improve the film formability, the presence or absence of defects in the coating film, the surface roughness, and the smoothness. In addition, during film formation using the inkjet method, it is possible to control the meniscus stability at the pinhole of the inkjet head, and to control and improve the ejection properties. In addition, by controlling the drying rate of the film and the orientation of the derivative molecules, it is possible to improve the electrical properties, light emitting properties, efficiency, and life of an organic EL element having an organic layer obtained from the composition for forming an organic layer.

(1) Physical properties of organic solvent The boiling point of at least one organic solvent is 130°C to 300°C, more preferably 140°C to 270°C, and even more preferably 150°C to 250°C. When the boiling point is higher than 130°C, it is preferable from the viewpoint of inkjet dischargeability. Also, when the boiling point is lower than 300°C, it is preferable from the viewpoint of defects, surface roughness, residual solvent, and smoothness of the coating film. From the viewpoint of good inkjet dischargeability, film-forming property, smoothness, and low residual solvent, it is more preferable that the organic solvent contains two or more organic solvents. On the other hand, in some cases, the composition may be a solid state composition obtained by removing the solvent from the composition for forming the organic layer, taking into consideration transportability and the like.

Furthermore, it is particularly preferable that the organic solvent contains a good solvent (GS) and a poor solvent (PS) for at least one type of solute, and the boiling point (BP _GS ) of the good solvent (GS) is lower than the boiling point (BP _PS ) of the poor solvent (PS).
By adding a poor solvent with a high boiling point, the good solvent with a low boiling point volatilizes first during film formation, increasing the concentration of the components in the composition and the concentration of the poor solvent, promoting rapid film formation. This results in a coating film with few defects, small surface roughness, and high smoothness.

The difference in solubility (S _GS -S _PS ) is preferably 1% or more, more preferably 3% or more, and even more preferably 5% or more. The difference in boiling point (BP _PS -BP _GS ) is preferably 10°C or more, more preferably 30°C or more, and even more preferably 50°C or more.

After the film is formed, the organic solvent is removed from the coating film by a drying process such as vacuum, reduced pressure, or heating. When heating is performed, from the viewpoint of improving the coating film-forming properties, it is preferable to perform the heating at a temperature of at least one of the solutes' glass transition temperature (Tg) +30°C or lower. From the viewpoint of reducing residual solvent, it is preferable to heat at at least one of the solutes' glass transition temperature (Tg) -30°C or higher. Even if the heating temperature is lower than the boiling point of the organic solvent, the organic solvent is sufficiently removed because the film is thin. Also, drying may be performed multiple times at different temperatures, and multiple drying methods may be used in combination.

(2) Specific Examples of Organic Solvents Examples of organic solvents used in the composition for forming an organic layer include alkylbenzene solvents, phenyl ether solvents, alkyl ether solvents, cyclic ketone solvents, aliphatic ketone solvents, monocyclic ketone solvents, solvents having a diester skeleton, and fluorine-containing solvents. Specific examples include pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tetradecanol, hexane-2-ol, heptan-2-ol, octan-2-ol, decan-2-ol, dodecan-2-ol, cyclohexanol, α-terpineol, β-terpineol, γ-terpineol, δ-terpineol, terpineol (mixture), ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, ethylene glycol ethyl ... ether, diethylene glycol isopropyl methyl ether, dipropylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, ethylene glycol monophenyl ether, triethylene glycol monomethyl ether, diethylene glycol dibutyl ether, triethylene glycol butyl methyl ether, polyethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, p-xylene, m-xylene, o-xylene, 2,6-lutidine, 2-fluoro-m-xylene, 3-fluoro-o-xylene, 2-chlorobenzotrifluoride, cumene, toluene, 2-chloro-6-fluorotoluene, 2-fluoroanisole, anisole, 2,3-Dimethylpyrazine, Bromobenzene, 4-Fluoroanisole, 3-Fluoroanisole, 3-Trifluoromethylanisole, Mesitylene, 1,2,4-Trimethylbenzene, t-Butylbenzene, 2-Methylanisole, Phenetole, Benzodioxole, 4-Methylanisole, s-Butylbenzene, 3-Methylanisole, 4-Fluoro-3-methylanisole, Cymene, 1,2,3-Trimethylbenzene, 1,2-Dichlorobenzene, 2-Fluorobenzonitrile, 4-Fluoroveratrol, 2,6-Dimethylanisole, n-Butylbenzene, 3-Fluorobenzonitrile, Decalin (Decahydronaphthalene), Neopentylbenzene, 2,5-Dimethylanisole, 2,4-Dimethylanisole, Benzonitrile, 3,5-Dimethylanisole, Diphenyl ether, 1-Fluoro-3,5-dimethoxybenzene, Methyl benzoate, Isopentylbenzene, 3,4-Dimethylanisole , o-tolunitrile, n-amylbenzene, veratrole, 1,2,3,4-tetrahydronaphthalene, ethyl benzoate, n-hexylbenzene, propyl benzoate, cyclohexylbenzene, 1-methylnaphthalene, butyl benzoate, 2-methylbiphenyl, 3-phenoxytoluene, 2,2'-bitolyl, dodecylbenzene, dipentylbenzene, tetramethylbenzene, trimethoxybenzene, trimethoxytoluene, 2,3-dihydrobenzofuran, 1-methyl-4-(propoxymethyl)benzene, 1-methyl-4-(butyloxymethyl)benzene, 1-methyl-4-(pentyloxymethyl)benzene, 1-methyl-4-(hexyloxymethyl)benzene, 1-methyl-4-(heptyloxymethyl)benzene, benzyl butyl ether, benzyl pentyl ether, benzyl hexyl ether, benzyl heptyl ether, benzyl octyl ether, etc., but are not limited thereto. In addition, the solvent may be used alone or may be mixed.

<Optional ingredients>
The composition for forming the organic layer may contain optional components, such as a binder and a surfactant, to the extent that the properties of the composition are not impaired.

(1) Binder The composition for forming an organic layer may contain a binder. The binder forms a film during film formation and bonds the resulting film to a substrate. The binder also plays a role in dissolving, dispersing, and binding other components in the composition for forming an organic layer.

Examples of binders used in the organic layer forming composition include, but are not limited to, acrylic resins, polyethylene terephthalate, ethylene-vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, acrylonitrile-ethylene-styrene copolymer (AES) resins, ionomers, chlorinated polyethers, diallyl phthalate resins, unsaturated polyester resins, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, Teflon, acrylonitrile-butadiene-styrene copolymer (ABS) resins, acrylonitrile-styrene copolymer (AS) resins, phenolic resins, epoxy resins, melamine resins, urea resins, alkyd resins, polyurethanes, and copolymers of the above resins and polymers.

The binder used in the composition for forming the organic layer may be of one type or a mixture of multiple types.

(2) Surfactant The organic layer forming composition may contain a surfactant, for example, to control the film surface uniformity, solvent affinity and liquid repellency of the organic layer forming composition. Surfactants are classified into ionic and nonionic based on the structure of the hydrophilic group, and further classified into alkyl, silicon and fluorine based based on the structure of the hydrophobic group. In addition, based on the molecular structure, they are classified into monomolecular systems with relatively small molecular weight and simple structure, and polymer systems with large molecular weight and side chains or branches. In addition, based on the composition, they are classified into single systems and mixed systems in which two or more types of surfactants and base materials are mixed. All types of surfactants can be used as surfactants that can be used in the organic layer forming composition.

Examples of surfactants include Polyflow No. 45, Polyflow KL-245, Polyflow No. 75, Polyflow No. 90, Polyflow No. 95 (trade names, manufactured by Kyoeisha Chemical Industry Co., Ltd.), Disperbake 161, Disperbake 162, Disperbake 163, Disperbake 164, Disperbake 166, Disperbake 170, Disperbake 180, Disperbake 181, Disperbake 182, BYK300, BYK306, BYK310, BYK320, BYK330, BYK342, B YK344, BYK346 (product names, manufactured by BYK Japan Co., Ltd.), KP-341, KP-358, KP-368, KF-96-50CS, KF-50-100CS (product names, manufactured by Shin-Etsu Chemical Co., Ltd.), Surflon SC-101, Surflon KH-40 (product names, manufactured by Seimi Chemical Co., Ltd.), Ftergent 222F, Ftergent 251, FTX-218 (product names, manufactured by Neos Co., Ltd.), EFTOP EF-351, EFTOP EF-352, EFTOP EF-601, EFTOP EF-801, EFTOP EF-802 (product name, manufactured by Mitsubishi Materials Corporation), Megafac F-470, Megafac F-471, Megafac F-475, Megafac R-08, Megafac F-477, Megafac F-479, Megafac F-553, Megafac F-554 (product name, manufactured by DIC Corporation), fluoroalkylbenzenesulfonate, fluoroalkylcarboxylate, fluoroalkylpolyoxyethyleneether, fluoroalkylammonium iodide, fluoroalkylbetaine, fluoroalkylsulfonate, diglycerol tetrakis (fluoroalkylpolyoxyethyleneether), fluoroalkyltrimethylammonium salt, fluoroalkylaminosulfonate, polyoxyethylenenonyl Examples of such sorbitan fatty acid esters include sorbitan laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan oleate, sorbitan fatty acid esters, polyoxyethylene sorbitan laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan oleate, polyoxyethylene naphthyl ether, alkylbenzene sulfonate, and alkyldiphenyl ether disulfonate.

The surfactant may be used alone or in combination with two or more types.

<Composition and Properties of Organic Layer-Forming Composition>
The content of each component in the composition for forming an organic layer is determined in consideration of the good solubility, storage stability and film-forming property of each component in the composition for forming an organic layer, the good film quality of the coating film obtained from the composition for forming an organic layer, the good discharge property when using an ink jet method, and the good electrical properties, light-emitting properties, efficiency and life of an organic EL element having an organic layer produced using the composition. For example, in the case of a composition for forming an emitting layer, it is preferable that the first component is 0.0001% by mass to 2.0% by mass with respect to the total mass of the composition for forming an emitting layer, the second component is 0.0999% by mass to 8.0% by mass with respect to the total mass of the composition for forming an emitting layer, and the third component is 90.0% by mass to 99.9% by mass with respect to the total mass of the composition for forming an emitting layer.

More preferably, the first component is 0.005% to 1.0% by mass relative to the total mass of the composition for forming the light-emitting layer, the second component is 0.095% to 4.0% by mass relative to the total mass of the composition for forming the light-emitting layer, and the third component is 95.0% to 99.9% by mass relative to the total mass of the composition for forming the light-emitting layer. Even more preferably, the first component is 0.05% to 0.5% by mass relative to the total mass of the composition for forming the light-emitting layer, the second component is 0.25% to 2.5% by mass relative to the total mass of the composition for forming the light-emitting layer, and the third component is 97.0% to 99.7% by mass relative to the total mass of the composition for forming the light-emitting layer.

The composition for forming the organic layer can be produced by appropriately selecting and carrying out stirring, mixing, heating, cooling, dissolving, dispersing, etc. of the above-mentioned components using a known method. In addition, after preparation, filtration, degassing (also called degassing), ion exchange treatment, and inert gas replacement/filling treatment, etc. may be appropriately selected and carried out.

The higher the viscosity of the composition for forming the organic layer, the better the film-forming properties and the better the ejection properties when using the inkjet method. On the other hand, the lower the viscosity, the easier it is to form a thin film. For this reason, the viscosity of the composition for forming the organic layer at 25°C is preferably 0.3 to 3 mPa·s, and more preferably 1 to 3 mPa·s. In the present invention, the viscosity is a value measured using a cone-plate type rotational viscometer (cone-plate type).

The lower the surface tension of the composition for forming the organic layer, the better the film-forming properties and the more defect-free the coating film will be. On the other hand, the higher the surface tension, the better the ink-jet ejection properties will be. For this reason, the viscosity of the composition for forming the organic layer is preferably such that the surface tension at 25°C is 20 to 40 mN/m, and more preferably 20 to 30 mN/m. In the present invention, the surface tension is a value measured using the hanging drop method.

<Crosslinkable polymer compound: compound represented by formula (XLP-1)>
Next, the case where the above-mentioned polymer compound has a crosslinkable substituent will be described. Such a crosslinkable polymer compound is, for example, a compound represented by the following formula (XLP-1).

In formula (XLP-1),
MUx, ECx, and k are defined the same as MU, EC, and k in formula (H3), with the proviso that the compound represented by formula (XLP-1) has at least one crosslinkable substituent (XLS), and preferably the content of the monovalent or divalent aromatic group having a crosslinkable substituent is 0.1 to 80 mass% in the molecule.

The content of the monovalent or divalent aromatic compound having a crosslinkable substituent is preferably 0.5 to 50 mass%, more preferably 1 to 20 mass%.

The crosslinkable substituent (XLS) is not particularly limited as long as it is a group that can further crosslink the above-mentioned polymer compound, but substituents having the following structures are preferred: In each structural formula, * indicates a bond position.

Each L is independently a single bond, -O-, -S-, >C=O, -O-C(=O)-, an alkylene having 1 to 12 carbon atoms, an oxyalkylene having 1 to 12 carbon atoms, or a polyoxyalkylene having 1 to 12 carbon atoms. Among the above substituents, groups represented by formula (XLS-1), (XLS-2), (XLS-3), (XLS-9), (XLS-10) or (XLS-17) are preferred, and groups represented by formula (XLS-1), (XLS-3) or (XLS-17) are more preferred.

Examples of the divalent aromatic compound having a crosslinkable substituent include compounds having the following partial structures:

<Method of producing polymer compound and crosslinkable polymer compound>
The methods for producing the polymer compound and the crosslinkable polymer compound will be described below with reference to the compound represented by the above formula (H3) and the compound represented by the above formula (XLP-1). These compounds can be synthesized by appropriately combining known production methods.

Solvents used in the reaction include aromatic solvents, saturated/unsaturated hydrocarbon solvents, alcohol solvents, and ether solvents, such as dimethoxyethane, 2-(2-methoxyethoxy)ethane, and 2-(2-ethoxyethoxy)ethane.

The reaction may also be carried out in a two-phase system. When carrying out the reaction in a two-phase system, a phase transfer catalyst such as a quaternary ammonium salt may be added as necessary.

The compound of formula (H3) and the compound of formula (XLP-1) may be produced in one step or in multiple steps. The compound may be produced by a batch polymerization method in which all the raw materials are put into a reaction vessel and then the reaction is started, a dropwise polymerization method in which the raw materials are added dropwise to a reaction vessel, or a precipitation polymerization method in which the product precipitates as the reaction proceeds. These methods can be combined appropriately to synthesize the compound. For example, when the compound represented by formula (SPH-1) is synthesized in one step, the target product is obtained by adding a monomer having a polymerizable group bonded to the monomer unit (MU) and a monomer having a polymerizable group bonded to the end cap unit (EC) to a reaction vessel and then reacting the monomer. When the compound represented by formula (SPH-1) is synthesized in multiple steps, the target product is obtained by polymerizing the monomer having a polymerizable group bonded to the monomer unit (MU) to the target molecular weight, and then adding a monomer having a polymerizable group bonded to the end cap unit (EC) and reacting the monomer. By adding monomers with polymerizable groups bonded to different types of monomer units (MU) in multiple stages and carrying out a reaction, it is possible to create a polymer with a concentration gradient in the monomer unit structure. In addition, after preparing a precursor polymer, the target polymer can be obtained by further reaction.

In addition, the primary structure of the polymer can be controlled by selecting the polymerizable group of the monomer. For example, as shown in synthesis schemes 1 to 3, it is possible to synthesize a polymer with a random primary structure (synthetic scheme 1) or a polymer with a regular primary structure (synthetic schemes 2 and 3), and these can be used in appropriate combinations depending on the intended purpose. Furthermore, if a monomer with three or more polymerizable groups is used, a hyperbranched polymer or dendrimer can be synthesized.

Monomers that can be used in the present invention include those described in JP 2010-189630 A, WO 2012/086671 A, WO 2013/191088 A, WO 2002/045184 A, WO 2011/049241 A, WO 2013/146806 A, WO 2005/049546 A, and WO 2015/1458 A. It can be synthesized in accordance with the methods described in JP-A-2002/045184, JP-A-2010-215886, JP-A-2008-106241, JP-A-2010-215886, WO 2016/031639, JP-A-2011-174062, WO 2016/031639, WO 2016/031639, and WO 2002/045184.

Specific polymer synthesis procedures are described in JP 2012-036388 A, WO 2015/008851 A, JP 2012-36381 A, JP 2012-144722 A, WO 2015/194448 A, WO 2013/146806 A, WO 2015/145871 A, WO 2016/ It can be synthesized in accordance with the methods described in International Publication No. 2016/125560, International Publication No. 2016/031639, International Publication No. 2016/031639, International Publication No. 2016/125560, International Publication No. 2015/145871, International Publication No. 2011/049241, and JP 2012-144722 A.

3-1-10. Application Examples of Organic Electroluminescent Devices The present invention can also be applied to display devices including organic EL devices or lighting devices including organic EL devices.
A display device or lighting device including an organic EL element can be manufactured by a known method, for example by connecting the organic EL element according to this embodiment to a known driving device, and can be driven appropriately using a known driving method such as DC driving, pulse driving, or AC driving.

Examples of display devices include panel displays such as color flat panel displays, and flexible displays such as flexible color organic electroluminescent (EL) displays (see, for example, JP-A-10-335066, JP-A-2003-321546, JP-A-2004-281086, etc.). Display methods include, for example, matrix and/or segment methods. Note that matrix display and segment display may coexist in the same panel.

In a matrix, the pixels for display are arranged two-dimensionally, such as in a grid or mosaic pattern, and a collection of pixels displays characters and images. The shape and size of the pixels are determined by the application. For example, square pixels with sides of 300 μm or less are usually used to display images and characters on computers, monitors, and televisions, and pixels with sides on the order of mm are used for large displays such as display panels. For monochrome display, pixels of the same color can be arranged, but for color display, red, green, and blue pixels are displayed side by side. In this case, there are typically delta types and stripe types. The driving method for this matrix can be either line sequential driving method or active matrix. Line sequential driving has the advantage of being simpler in structure, but when considering operating characteristics, active matrix may be superior, so it is necessary to use it according to the application.

In the segment method, a pattern is formed to display predetermined information, and a specific area is illuminated. Examples include the time and temperature displays on digital clocks and thermometers, the operating status displays on audio equipment and induction cookers, and panel displays on automobiles.

Examples of lighting devices include lighting devices for indoor lighting, backlights for liquid crystal display devices, etc. (see, for example, JP-A-2003-257621, JP-A-2003-277741, JP-A-2004-119211, etc.). Backlights are mainly used for the purpose of improving the visibility of non-self-luminous display devices, and are used in liquid crystal display devices, clocks, audio devices, automobile panels, display boards, signs, etc. In particular, for liquid crystal display devices, and especially for backlights for personal computers, where thinning is an issue, it is difficult to make them thin because conventional methods use fluorescent lamps and light guide plates, so the backlights using the light-emitting elements according to this embodiment are characterized by their thinness and light weight.

3-2. Other Organic Devices The polycyclic aromatic compound according to the present invention can be used for producing organic field effect transistors or organic thin-film solar cells, in addition to the organic electroluminescent devices described above.

An organic field-effect transistor is a transistor that controls current by generating an electric field through voltage input, and has a gate electrode in addition to a source electrode and a drain electrode. When a voltage is applied to the gate electrode, an electric field is generated, and the flow of electrons (or holes) between the source electrode and drain electrode can be arbitrarily blocked to control the current. Field-effect transistors are easier to miniaturize than simple transistors (bipolar transistors), and are often used as elements in integrated circuits.

The structure of an organic field effect transistor may be such that a source electrode and a drain electrode are provided in contact with an organic semiconductor active layer formed using the polycyclic aromatic compound according to the present invention, and a gate electrode is provided sandwiching an insulating layer (dielectric layer) in contact with the organic semiconductor active layer. Examples of the element structure include the following structure.
(1) Substrate/gate electrode/insulator layer/source electrode/drain electrode/organic semiconductor active layer (2) Substrate/gate electrode/insulator layer/organic semiconductor active layer/source electrode/drain electrode (3) Substrate/organic semiconductor active layer/source electrode/drain electrode/insulator layer/gate electrode (4) Substrate/source electrode/drain electrode/organic semiconductor active layer/insulator layer/gate electrode An organic field effect transistor configured in this manner can be used as a pixel driving switching element for active matrix driving liquid crystal displays and organic electroluminescence displays.

An organic thin-film solar cell has a structure in which an anode such as ITO, a hole transport layer, a photoelectric conversion layer, an electron transport layer, and a cathode are laminated on a transparent substrate such as glass. The photoelectric conversion layer has a p-type semiconductor layer on the anode side and an n-type semiconductor layer on the cathode side. The polycyclic aromatic compound according to the present invention can be used as a material for a hole transport layer, a p-type semiconductor layer, an n-type semiconductor layer, and an electron transport layer depending on its physical properties. The polycyclic aromatic compound according to the present invention can function as a hole transport material or an electron transport material in an organic thin-film solar cell. In addition to the above, the organic thin-film solar cell may appropriately include a hole blocking layer, an electron blocking layer, an electron injection layer, a hole injection layer, a smoothing layer, and the like. For the organic thin-film solar cell, known materials used in organic thin-film solar cells can be appropriately selected and combined for use.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

<Synthesis examples of compounds>
First, synthesis examples of the compounds of the present invention will be described below.

Synthesis Example (1): Synthesis of Compound (1-11)

Under a nitrogen atmosphere, a flask containing compound (I-1) (91.7 mg, 0.30 mmol), compound (I-2) (110 mg, 0.33 mmol), bis(di-tert-butyl(3-methylbut-2-en-1-yl)phosphine)dichloropalladium(II) (5.5 mg, 0.009 mmol), sodium-tert-butoxide (31.7 mg, 0.33 mmol), and mesitylene (1.5 mL) was heated to 140°C and stirred for 6 hours. The reaction solution was allowed to cool to room temperature, then poured into water, and the aqueous layer was extracted with dichloromethane. The resulting organic layer was washed with saturated saline and dried over anhydrous magnesium sulfate. This solution was concentrated under reduced pressure, and the residue was washed with acetonitrile and purified with a silica gel short pass (developing solvent: dichloromethane: ethyl acetate = 1:1). Further purification by hot washing with ethyl acetate and hot washing with dichloroethane yielded compound (1-11) (88.6 mg; 49%) as a white solid.

The structure of the obtained compound was confirmed by NMR measurement.
¹ H-NMR (500 MHz, CDCl ₃ ): δ = 7.19 (dt, 1H), 7.29-7.38 (m, 3H), 7.48 (dt, 1H), 7.56-7.65 (m, 3H), 7.75-8.05 (m, 11H), 8.21 (d, 1H), 8.75 (d, 1H), 8.94-8.96 (m, 2H).

Synthesis Example (2): Synthesis of Compound (1-13)

In a nitrogen atmosphere, a flask containing compound (I-1) (61.1 mg, 0.20 mmol), compound (I-3) (256 mg, 0.48 mmol), bis(di-tert-butyl(4-dimethylaminophenyl)phosphine)dichloropalladium(II) ((AMPhos) ₂ PdCl ₂ ) (8.5 mg, 0.012 mmol), tripotassium phosphate (204 mg, 0.96 mmol), and 1,4-dioxane (2.0 mL) was stirred under heating and reflux for 4 hours. The reaction solution was cooled to room temperature and then poured into water, and the aqueous layer was extracted with dichloromethane. The resulting organic layer was washed with saturated saline and dried over anhydrous magnesium sulfate. The solution was concentrated under reduced pressure, and the residue was purified with a silica gel short pass (developing solvent: dichloromethane:ethyl acetate=1:1). Compound (1-13) (114 mg; 75%) was obtained as a white solid by further purifying with acetonitrile heating and washing.

The structure of the obtained compound was confirmed by NMR measurement.
¹ H-NMR (500 MHz, CDCl ₃ ): δ = 7.31 (d, 1H), 7.40-7.45 (m, 15H), 7.57-7.66 (m, 8H), 7.72-7.73 (m, 2H), 7.8 0-7.86 (m, 3H), 7.92-7.95 (m, 3H), 8.04 (dd, 1H), 8.75 (d, 1H), 8.94-8.99 (m, 2H).

<Basic physical property evaluation>
The basic physical properties of the synthesized compound (1-11) and compound (1-13) as well as ref_BO2 shown below were evaluated.
On a glass substrate and a glass substrate on which an ITO film was formed to a thickness of 150 nm, each material was deposited by vacuum deposition at a vacuum degree of 1.0×10 ⁻⁴ Pa to form a film having a thickness of 60 nm. The absorption spectrum of the thin film formed on the glass substrate without ITO was measured, and the fluorescence and phosphorescence spectra were measured using a wavelength shorter than the absorption peak as excitation light. The absorption spectrum of the sample was measured using an ultraviolet-visible-near infrared spectrophotometer (Shimadzu Corporation, UV-2600). The fluorescence spectrum or phosphorescence spectrum of the sample was measured using a spectrofluorophotometer (Hitachi High-Tech Corporation, F-7000). The long wavelength end of the absorption spectrum was Eg (energy gap), the short wavelength end of the fluorescence spectrum was E _S1 , and the short wavelength end of the phosphorescence spectrum was E _T1 . Furthermore, a sample single film was prepared using a glass substrate with an ITO film, and Ip (ionization potential) was measured using a photoelectron spectrometer (Sumitomo Heavy Industries, Ltd. PYS-201). Ea (electron affinity) was calculated according to the following formula.
Ea=Ip-Eg
The results are shown in Table 1.

ref_BO2 was synthesized by the method described in Synthesis Example (54) in WO 2015/102118.

<Example of using phosphorescent material as dopant>
On a glass substrate on which an anode made of indium tin oxide (ITO) with a film thickness of 150 nm was formed, each thin film was laminated by vacuum deposition at a vacuum degree of 1.0×10 ⁻⁴ Pa. First, copper phthalocyanine (CuPc) was formed to a thickness of 20 nm as a hole injection layer on ITO. Next, NPD was formed to a thickness of 40 nm as a hole transport layer. Next, a host compound (material and mass ratio shown in Table 2) and Ir(ppy) ₃ were co-deposited from different deposition sources as a light emitting layer on the hole transport layer to form a light emitting layer with a thickness of 35 nm. The concentration of Ir(ppy) ₃ was 7%. Next, Alq3 was formed to a thickness of 40 nm as an electron transport layer. Furthermore, lithium fluoride (LiF) was formed to a thickness of 0.5 nm as an electron injection layer on the electron transport layer. Finally, an aluminum (Al) electrode was formed to a thickness of 170 nm on the electron injection layer to complete an organic EL element.

For the fabricated element, a direct current voltage was applied between the ITO electrode as the anode and the aluminum electrode as the cathode, and the driving voltage and luminance were measured at a current density of 10 mA/cm ^2. The evaluation results are shown in Table 2.

<Example of using TADF material as dopant (TAF element)>
On a glass substrate on which an anode made of indium tin oxide (ITO) with a film thickness of 100 nm was formed, each thin film was laminated by vacuum deposition at a vacuum degree of 1×10 ⁻⁴ Pa. First, HATCN was formed on ITO to a thickness of 10 nm, Tris-PCz was formed thereon to a thickness of 25 nm, and mCBP was formed thereon to a thickness of 5 nm. Next, the host material, 4CzBN, and ν-DABNA or compound (2-560) were co-deposited from different deposition sources with the materials and concentrations shown in Tables 3 and 4 below, respectively, to form a layer with a thickness of 30 nm to serve as an emitting layer. Next, SF3TRZ was formed as a hole blocking layer with a thickness of 10 nm. Subsequently, SF3TRZ and Liq were co-deposited from different deposition sources to form an electron transport layer with a thickness of 40 nm. At this time, the SF3TRZ:Liq (mass ratio) was 7:3. Further, Liq was formed to a thickness of 2 nm, and then aluminum (Al) was evaporated to a thickness of 100 nm to form a cathode. By the above-mentioned procedure, organic electroluminescence elements of Comparative Examples 2 to 5 and Examples 9 to 16 were produced.

For the fabricated element, a DC voltage was applied between the ITO electrode as the anode and the aluminum electrode as the cathode, and the driving voltage and external quantum efficiency (EQE) at a luminance of 1000 cd/ ^m2 were measured. The evaluation results are shown in Tables 3 and 4.

In the examples, the external quantum efficiency was measured as follows. The element was made to emit light by applying a voltage using an Advantest voltage/current generator R6144. The spectral radiance in the visible light region was measured from a direction perpendicular to the light-emitting surface using a TOPCON SR-3AR spectroradiometer. Assuming that the light-emitting surface is a perfect diffusion surface, the measured spectral radiance value of each wavelength component was divided by the wavelength energy and multiplied by π to obtain the number of photons at each wavelength. The number of photons was then integrated over the entire observed wavelength range to obtain the total number of photons emitted from the element. The applied current value was divided by the elementary charge to obtain the number of carriers injected into the element, and the total number of photons emitted from the element was divided by the number of carriers injected into the element to obtain the external quantum efficiency.

Compound (2-560) was synthesized using the method described in WO 2020/162600.

On a glass substrate on which an anode made of indium tin oxide (ITO) with a thickness of 50 nm was formed, each thin film was laminated by vacuum deposition at a vacuum degree of 1×10 ⁻⁴ Pa. First, NPD was formed on ITO to a thickness of 40 nm, TcTa was formed thereon to a thickness of 15 nm, and mCP was further formed thereon to a thickness of 15 nm. Next, DOBNA-Tol and ν-DABNA were co-deposited from different deposition sources at a concentration of 99:1 to form a layer with a thickness of 20 nm as an emitting layer. Next, 3,4-2CzBN, compound (1-11), or compound (1-13) was formed as a hole blocking layer with a thickness of 10 nm. Subsequently, BPy-TP2 was formed as an electron transport layer with a thickness of 20 nm. Furthermore, LiF was formed to a thickness of 1 nm, and then aluminum (Al) was evaporated to a thickness of 100 nm to form a cathode. By the above-mentioned procedures, organic electroluminescence elements of Comparative Example 6 and Examples 17 and 18 were prepared.

The fabricated element was subjected to DC voltage application using the ITO electrode as the anode and the aluminum electrode as the cathode, and the external quantum efficiency (EQE) at a luminance of 1000 cd/ ^m2 and LT50 (the time to reach 500 cd/ ^m2 when continuously driven at a current density at an initial luminance of 1000 cd/ ^m2 ) were measured. The evaluation results are shown in Table 5.

On a glass substrate on which an anode made of indium tin oxide (ITO) having a thickness of 120 nm was formed, each thin film was laminated by vacuum deposition at a vacuum degree of 1×10 ⁻⁴ Pa. First, HATCN was formed on ITO to a thickness of 5 nm, HT1 was formed thereon to a thickness of 90 nm, and HT2 was formed thereon to a thickness of 10 nm. Next, Host1 and BD1 were co-deposited from different deposition sources at a concentration of 97:3 to form a layer having a thickness of 20 nm to serve as a light-emitting layer. Next, ET1, compound (1-11), or compound (1-13) was formed as a hole blocking layer having a thickness of 20 nm. Subsequently, ET2 was formed as an electron transport layer having a thickness of 10 nm. Furthermore, LiF was formed to a thickness of 1 nm, and then aluminum (Al) was evaporated to a thickness of 100 nm to form a cathode. By the above-mentioned procedures, organic electroluminescence elements of Comparative Example 7 and Examples 19 and 20 were prepared.

For the fabricated element, a DC voltage was applied to the ITO electrode as the anode and the aluminum electrode as the cathode, and the external quantum efficiency (EQE) at a luminance of 500 cd/ ^m2 and LT97 (the time until the luminance reaches 95% of the initial luminance when continuously driven at a current density of 22.5 mA/ ^cm2 ) were measured. The evaluation results are shown in Table 6.

In the present invention, by providing a novel polycyclic aromatic compound, it is possible to increase the options for materials for organic EL elements. In addition, by using a novel polycyclic aromatic compound as a material for an organic electroluminescent device, it is possible to provide an excellent organic EL element, a display device including the same, and a lighting device including the same.

REFERENCE SIGNS LIST 100 Organic electroluminescent element 101 Substrate 102 Anode 103 Hole injection layer 104 Hole transport layer 105 Light-emitting layer 106 Electron transport layer 107 Electron injection layer 108 Cathode 110 Substrate 120 Electrode 130 Coating film 140 Coating film 150 Light-emitting layer 200 Bank 300 Inkjet head 310 Ink droplet

Claims (20)

A polycyclic aromatic compound represented by the following formula (1):
In formula (1),
X ¹ and X ² are each >O;
Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ each independently represent ═C(—R ^Y )— or ═N—, at least one of which is ═N—;
at least one R ^Y is a group represented by formula (A-1) or formula (A-2), and the other R ^Y is hydrogen or any substituent selected from the substituent group YZ excluding the group represented by formula (A-1) ;
In formula (A-1),
W ¹ and W ² are each independently a single bond, >C(-R ^w ) ₂ , >N-R ^w , >O, >Si(-R ^w ) ₂ , or >S ;
R ^W in the >N-R ^W is any substituent selected from the substituent group YZ or a group represented by formula (A-2) ,
R ^W in >C(—R ^W ) ₂ and >Si(—R ^W ) ₂ each independently represents a hydrogen atom, a substituent selected from the substituent group YZ, or a group represented by formula (A-2) ,
R ^W bonded to the same element may be bonded to each other,
Each R ^W in the >N-R ^W may be independently bonded to at least one Z;
Z is -N= or -CR ^Z =, and R ^Z is each independently hydrogen, any substituent selected from the substituent group YZ, or a group represented by formula (A-2) .
^L1 is a single bond or any linking group selected from the group L of linking groups ;
L ¹ is bonded to a C of any one of -CR ^Z = through R ^Z ;
* indicates the bonding position of the group represented by formula (A-1),
In formula (A-2),
Ar ³ is each independently an aryl (excluding the group represented by formula (A-1)) which may be substituted with at least one substituent selected from the substituent group YZ, a heteroaryl (excluding the group represented by formula (A-1)) which may be substituted with at least one substituent selected from the substituent group YZ, or a group represented by formula (A-1),
^W3 is Si;
m is 3 and n is 0;
^L2 is a single bond or any linking group selected from the group L of linking groups ;
* indicates the bonding position of the group represented by formula (A-2),
At least one hydrogen atom in the structure represented by formula (1) may be substituted with cyano, halogen or deuterium;
Substituent group YZ:
aryl optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl;
Heteroaryl optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl; and
Diarylamino optionally substituted with aryl, heteroaryl, alkyl or cycloalkyl.
Linking group L:
2. The polycyclic aromatic compound according to claim 1, wherein L ¹ and L ² are each independently a single bond or a linking group represented by any one of the following formulas :
2. The polycyclic aromatic compound according to claim 1, wherein L ¹ and L ² are each independently a linking group represented by any one of the following formulas :
The polycyclic aromatic compound according to any one of claims 1 to 3, wherein ^Y2 , ^Y3 , ^Y4 and ^Y5 are each independently =C(-R ^Y )-, and at least one of ^Y1 or ^Y6 is =N-. 5. The polycyclic aromatic compound according to claim 4 , wherein Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ are each independently =C(-R ^Y )-, and Y ¹ is =N-. The polycyclic aromatic compound according to any one of claims 1 to 5, wherein in formula (1), one or two of R ^Y are a group represented by formula (A-1) or formula (A-2). In formula (1), at least one R ^Y is a group represented by formula (A-1),
The polycyclic aromatic compound according to any one of claims 1 to 6 , wherein W ¹ is >C(-R ^W ) ₂ , >O, >Si(-R ^W ) ₂ or >S, and W ² is a single bond. The polycyclic aromatic compound according to any one of claims 1 to 7, wherein in formula (1), at least one R ^Y is a group represented by formula (A-2). In formula (1),
The polycyclic aromatic compound according to any one of claims 1 to 8, wherein R ^Y other than the group represented by formula (A -1) or formula (A-2) is hydrogen, an aryl which may be substituted with an aryl or a heteroaryl, or a heteroaryl which may be substituted with an aryl or a heteroaryl. The polycyclic aromatic compound according to claim 1, represented by the following formula (1-11):
The polycyclic aromatic compound according to claim 1, represented by the following formula (1-13):
A material for an organic device, comprising the polycyclic aromatic compound according to any one of claims 1 to 11 . 12. An organic electroluminescence device comprising a pair of electrodes consisting of an anode and a cathode, and an organic layer disposed between the pair of electrodes and containing the polycyclic aromatic compound according to claim 1. The organic electroluminescent device according to claim 13 , wherein the organic layer is an electron transport layer. The organic electroluminescent device according to claim 13 , wherein the organic layer is a light-emitting layer. The organic electroluminescent device according to claim 15 , wherein the light-emitting layer contains at least one selected from the group consisting of a light-emitting metal complex and a TADF material. The organic electroluminescent device according to claim 16 , wherein the light-emitting layer contains a polycyclic aromatic compound which is a monomer represented by formula (2) or a polymer having a plurality of structural units represented by formula (2).
ring A, ring B and ring C each independently represent an optionally substituted aryl ring or an optionally substituted heteroaryl ring, provided that in ring A, ring B and ring C in the monomer, none of the rings bonded to B and to ^X11 and/or ^X12 is a 6-membered ring containing nitrogen;
X ¹¹ and X ¹² are each independently >O or >N-R, R of the >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, R of the >N-R may be bonded to ring A and/or ring B or ring A and/or ring C by -O-, -S-, -C(-R) ₂ - or a single bond, R of the -C(-R) ₂ - is hydrogen, alkyl, or cycloalkyl,
In the structure represented by formula (2) or the structure having a plurality of structural units represented by formula (2), at least one selected from the group consisting of an aryl ring and a heteroaryl ring may be condensed with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-,
At least one hydrogen atom in the structure represented by formula (2) or the structure having a plurality of structural units represented by formula (2) may be substituted with deuterium, cyano or halogen. The organic electroluminescence device according to any one of claims 15 to 17, comprising at least one of an electron transport layer and an electron injection layer disposed between the cathode and the light emitting layer, and at least one of the electron transport layer and the electron injection layer contains at least one selected from the group consisting of borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, arylnitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, and quinolinol-based metal complexes. 19. The organic electroluminescent device according to claim 18, wherein at least one of the electron transport layer and the electron injection layer further contains at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, halides of alkali metals, oxides of alkaline earth metals, halides of alkaline earth metals, oxides of rare earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals. A display device or a lighting device comprising the organic electroluminescent device according to any one of claims 13 to 19 .