JP7795166B2 - Polycyclic aromatic compounds - Google Patents

Description

The present invention relates to a polycyclic aromatic compound. The present invention also relates to a material for an organic device, an organic electroluminescent device, a display device, and a lighting device, each containing the polycyclic aromatic compound.

Display devices using electroluminescent light-emitting elements have been the subject of extensive research due to their potential for power saving and thinning. Furthermore, organic electroluminescent elements (sometimes referred to as "organic EL elements" or simply "elements" in this specification) made from organic materials have been actively investigated due to their ease of lightweight and large size. In particular, active research has been conducted into the development of organic materials with luminescent properties such as blue, one of the three primary colors of light, and organic materials with charge transport capabilities for holes, electrons, etc. (potentially serving as semiconductors or superconductors), regardless of whether they are polymeric or low-molecular-weight compounds.

Organic EL elements have a structure consisting of a pair of electrodes consisting of an anode and a cathode, and one or more layers containing organic compounds that are placed between the pair of electrodes. Layers containing organic compounds include light-emitting layers and charge transport/injection layers that transport or inject charges such as holes and electrons, and a variety of organic materials suitable for these layers have been developed.

Among these, Patent Document 1 discloses that polycyclic aromatic compounds in which aromatic rings are linked by heteroelements such as boron, phosphorus, oxygen, nitrogen, and sulfur are useful as materials for organic electroluminescent devices, etc. It has been reported that these polycyclic aromatic compounds have a large HOMO-LUMO gap and high triplet excitation energy (E _T ) and also exhibit thermally activated delayed fluorescence, making them particularly useful as fluorescent materials for organic electroluminescent devices.

International Publication No. 2015/102118

As mentioned above, a variety of materials have been developed for use in organic EL elements, but to increase the options for materials for organic EL elements, there is a need for the development of materials made from unconventional compounds. The objective of the present invention is to provide novel materials useful as materials for organic devices such as organic EL elements.

The inventors conducted extensive research to solve the above problems and succeeded in producing a new polycyclic aromatic compound in which aromatic rings are linked by heteroelements such as boron, phosphorus, oxygen, nitrogen, and sulfur. They also discovered that an excellent organic EL device can be obtained by constructing an organic EL device by placing a layer containing this polycyclic aromatic compound between a pair of electrodes, thereby completing the present invention. Specifically, the present invention provides the following polycyclic aromatic compounds, as well as organic device materials containing the following polycyclic aromatic compounds.

<1> A polycyclic aromatic compound having a structure consisting of one or more structural units represented by the following formula (1):

In formula (1),
ring A and ring B are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted;
^Y1 is B, P, P=O or P=S;
R ^XC is optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl or optionally substituted cycloalkyl;
R ^XC may be bonded to at least one of the ring A or ring B via a linking group or a single bond shown by a dashed line,
X ¹ is >C(—R) ₂ , >N—R, >O, >Si(—R) ₂ or >S, 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 >C(—R) ₂ and >Si(—R) ₂ is hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and may be bonded to each other by a linking group, and at least one of R of the >N—R, the >C(—R) ₂ and the >Si(—R) ₂ may be bonded to at least one of the ring A or ring B by a linking group or a single bond,
In the above structure, at least one selected from the group consisting of ring A, ring B, and R ^XC contains at least one partial structure represented by formula (A),
The partial structure represented by formula (A) is bonded to two adjacent atoms on an aryl ring or heteroaryl ring at two * marks, respectively.
In formula (A),
L is >N-R, >O, >Si(-R) ₂ or >S, 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 >Si(-R) ₂ is hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and may be bonded to each other via a linking group, and at least one of the R of the >N-R and the >Si(-R) ₂ may be bonded to at least one selected from the group consisting of ring A, ring B, R ^XC and R ^A via a linking group or a single bond,
r is an integer from 1 to 4,
Each R ^A is independently hydrogen, optionally substituted alkyl, or optionally substituted cycloalkyl, and any R ^A may be bonded to any other R ^A via a linking group or a single bond;
At least one selected from the group consisting of an aryl ring and a heteroaryl ring in the structure may be fused 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— or —S—;
At least one hydrogen in the structure may be replaced with deuterium, cyano, or halogen.

<2> The polycyclic aromatic compound according to <1>, wherein when at least one hydrogen atom in the ring A, ring B, and the aryl ring or heteroaryl ring in R ^XC is replaced, the substituent is selected from the group consisting of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted alkylarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted diarylboryl (two aryls may be bonded via a single bond or a linking group), substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, and substituted silyl.
<3> The polycyclic aromatic compound according to <1> or <2>, wherein Y ¹ is B.

<4> The polycyclic aromatic compound according to any one of <1> to <3>, which contains at least one tertiary alkyl represented by the following formula (tR) in the structure:
In formula (tR), R ^a , R ^b and R ^c each independently represent alkyl having 1 to 24 carbon atoms, any —CH ₂ — in the alkyl may be replaced with —O—, and * represents the bonding position.

<5> The polycyclic aromatic compound according to any one of <1> to <4>, wherein the partial structure represented by formula (A) is bonded to an aryl ring or heteroaryl ring in ring B.
<6> The partial structure represented by formula (A) is bonded to two adjacent carbon atoms on an aryl ring or heteroaryl ring at two * marks,
r is 2,
The polycyclic aromatic compound according to any one of <1> to <5>, wherein two R 1 ^A 's bonded to adjacent carbon atoms are bonded to each other, and the other R 1 ^A 's are each independently hydrogen or optionally substituted alkyl.
<7> The polycyclic aromatic compound according to <6>, wherein two R 1 ^{A s} bonded to adjacent carbon atoms are bonded to each other to form —(CH ₂ ) ₄ —, and the remaining R 1 ^{A s} are all methyl.
<8> The polycyclic aromatic compound according to any one of <1> to <7>, wherein L is >N—R, and R of the >N—R is an optionally substituted aryl.

<9> The polycyclic aromatic compound according to any one of <1> to <5>, wherein the partial structure represented by (A) is the following structure:

In the formula, two *'s are attached to two adjacent atoms on the aryl or heteroaryl ring, respectively, and Me is methyl.
<10> R ^XC is an optionally substituted aryl or an optionally substituted heteroaryl, and is bonded to ring A via a linking group ^X2 ,
The polycyclic aromatic compound according to any one of <1> to <9>, wherein ^X2 is >C(-R) _2, >N-R, >O, >Si(-R) ₂ , or >S, 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 >C(-R) ₂ and >Si(-R) ₂ is hydrogen, an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and they may be bonded to each other via a linking group, and at least one of R of the >N-R, the >C(-R) ₂ , and the >Si(-R) ₂ may be bonded to at least one selected from the group consisting of ring A and R ^XC via a linking group or a single bond.
<11> ^X1 is >N—R, and R of >N—R which is ^X1 is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and is optionally bonded to at least one of the ring A or ring B via a linking group or a single bond,
The polycyclic aromatic compound according to <10>, wherein ^X2 is >N-R, and R of >N-R that is ^X2 is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and is optionally bonded to at least one selected from the group consisting of ring A and R ^XC via a linking group or a single bond.
<12> The polycyclic aromatic compound according to any one of <1> to <9>, wherein R ^XC is an optionally substituted aryl or an optionally substituted heteroaryl, and is bonded to ring A via a single bond.

<13> The polycyclic aromatic compound according to <1>, having a structure represented by the following formula (1-BA1) or formula (1-BA2):

In formula (1-BA1) and formula (1-BA2),
ring c is an optionally substituted benzene ring, an optionally substituted benzofuran ring, or an optionally substituted benzothiophene ring;
Each R is independently an optionally substituted phenyl;
R ² ' is hydrogen or alkyl having 1 to 6 carbon atoms;
In at least one benzene ring in the structure, hydrogen atoms bonded to adjacent carbon atoms may be substituted with a partial structure represented by formula (B):

In formula (B), Me represents methyl, and * represents the bonding position.

<14> The polycyclic aromatic compound according to <13>, having a structure represented by any one of the following formulas:
In the formula, Me represents methyl, and tBu represents t-butyl.

<15> The polycyclic aromatic compound according to <1>, having a structure represented by the following formula (1-BA3) or formula (1-BA4):
In formula (1-BA3) and formula (1-BA4),
ring c is an optionally substituted benzene ring, an optionally substituted benzofuran ring, or an optionally substituted benzothiophene ring;
Each R is independently an optionally substituted phenyl;
R ² ' is hydrogen or alkyl having 1 to 6 carbon atoms;
In at least one benzene ring in the structure, hydrogen atoms bonded to adjacent carbon atoms may be substituted with a partial structure represented by formula (B):

In formula (B), Me represents methyl, and * represents the bonding position.

<16> The polycyclic aromatic compound according to <15>, having a structure represented by any one of the following formulas:
In the formula, Me represents methyl, and tBu represents t-butyl.

<17> The polycyclic aromatic compound according to <1>, having a structure represented by the following formula (1-BA5), (1-BA6), (1-BA7), or (1-BA8):

In formulas (1-BA5), (1-BA6), (1-BA7) and (1-BA8),
Ring D is an optionally substituted benzene ring or an optionally substituted cyclohexane ring;
Each R is independently an optionally substituted phenyl;
Each ^Rd is independently hydrogen, optionally substituted alkyl, optionally substituted aryl, optionally substituted heteroaryl, or optionally substituted diarylamino;
In at least one benzene ring in the structure, hydrogen atoms bonded to adjacent carbon atoms may be substituted with a partial structure represented by formula (B):

In formula (B), Me represents methyl, and * represents the bonding position.

<18> The polycyclic aromatic compound according to <17>, having a structure represented by any one of the following formulas:
In the formula, Me represents methyl, and tBu represents t-butyl.

<19> The polycyclic aromatic compound according to <1>, having a structure represented by any one of the following formulas:

In formula (1-BA11), formula (1-BA12), formula (1-BA13) and formula (1-BA14),
Z is C(—R ^Z ) or N, and R ^Z are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl;
Each R is independently an optionally substituted phenyl;
R ² ' is hydrogen or alkyl having 1 to 6 carbon atoms;
In at least one benzene ring in the structure, hydrogen atoms bonded to adjacent carbon atoms may be substituted with a partial structure represented by formula (B):

In formula (B), Me represents methyl, and * represents the bonding position.

<20> The polycyclic aromatic compound according to <19>, having a structure represented by any one of the following formulas:

<21> A reactive compound in which the polycyclic aromatic compound according to any one of <1> to <20> is substituted with a reactive substituent.
<22> A polymer compound obtained by polymerizing the reactive compound according to <21> as a monomer, or a crosslinked polymer obtained by further crosslinking the polymer compound.
<23> A pendant polymer compound obtained by substituting the reactive compound according to <21> on a main chain polymer, or a pendant polymer crosslinked product obtained by further crosslinking the pendant polymer compound.
<24> A material for an organic device, containing the polycyclic aromatic compound according to any one of <1> to <20>.
<25> A material for an organic device, containing the reactive compound according to <21>.
<26> A material for an organic device, comprising the polymer compound or crosslinked polymer according to <22>.
<27> A material for an organic device, comprising the pendant polymer compound or the pendant polymer crosslinked product according to <23>.
<28> The material for an organic device according to any one of <24> to <27>, wherein the material for an organic device is 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.
<29> The material for an organic device according to <28>, wherein the material for an organic electroluminescent element is a material for a light-emitting layer.

<30> An ink composition comprising the polycyclic aromatic compound according to any one of <1> to <20> and an organic solvent.
<31> An ink composition comprising the reactive compound according to <21> and an organic solvent.
<32> An ink composition comprising a main chain polymer, the reactive compound according to <21>, and an organic solvent.
<33> An ink composition comprising the polymer compound or crosslinked polymer according to <22> and an organic solvent.
<34> An ink composition comprising the pendant polymer compound or the pendant polymer crosslinked product according to <23> and an organic solvent.

<35> An organic electroluminescent 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 <20>, the reactive compound according to <21>, the polymer compound or crosslinked polymer according to <22>, or the pendant polymer compound or crosslinked pendant polymer according to <23>.
<36> The organic electroluminescent device according to <35>, wherein the organic layer is a light-emitting layer.
<37> The organic electroluminescent device according to <36>, wherein the light-emitting layer contains a host and the polycyclic aromatic compound, its reactive compound, polymer compound, crosslinked polymer, pendant polymer compound, or pendant crosslinked polymer as a dopant.
<38> The organic electroluminescent device according to <37>, wherein the host is an anthracene-based compound, a fluorene-based compound, or a dibenzochrysene-based compound.
<39> The organic electroluminescent device according to any one of <35> to <38>, 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.
<40> The organic electroluminescent device according to <39>, 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, alkali metal oxides, alkali metal halides, alkaline earth metal oxides, alkaline earth metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes, and rare earth metal organic complexes.
<41> The organic electroluminescent device according to any one of <35> to <40>, wherein at least one layer selected from 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-weight 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-weight 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.
<42> A display device or a lighting device comprising the organic electroluminescent device according to any one of <35> to <41>.

The present invention provides novel polycyclic aromatic compounds. The polycyclic aromatic compounds of the present invention are useful as materials for organic devices, particularly as light-emitting layer materials for forming the light-emitting layer of organic electroluminescent devices.

FIG. 1 is a schematic cross-sectional view illustrating an example of an organic EL element. 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 is 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, numerical ranges expressed using "to" refer to ranges that include the numerical values before and after "to" as the lower and upper limits. In addition, in this specification, "hydrogen" in explanations of structural formulas refers to "hydrogen atom (H)."

In this specification, chemical structures and substituents are sometimes represented by the number of carbon atoms. However, when a chemical structure is substituted with a substituent, or when a substituent is further substituted with a substituent, the number of carbon atoms refers to the number of carbon atoms in the chemical structure or the substituent, and does not refer to the total number of carbon atoms in the chemical structure and the substituent, or the total number of carbon atoms in the substituent and the substituent. 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 carbon number Y is not the total number of carbon atoms in substituents A and B. 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 restriction)," and carbon number Y is not the total number of carbon atoms in substituents A and B.

1. Polycyclic aromatic compound The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure consisting of one or more structural units represented by the following formula (1): The polycyclic aromatic compound of the present invention has at least one partial structure represented by formula (A):

1-1. Partial Structure Represented by Formula (A): In a structure consisting of one or more structural units represented by formula (1), at least one selected from the group consisting of ring A, ring B, and R ^XC contains at least one partial structure represented by formula (A). In the above structure, it is preferable that one or two partial structures represented by formula (A) are contained. The partial structure represented by formula (A) is preferably contained in ring B or R ^XC . The partial structure represented by formula (A) has two *s, which are bonded to two adjacent atoms on the ring of an aryl ring or heteroaryl ring in ring A, ring B, or R ^XC . In this case, it is preferable that both adjacent atoms on the ring are carbon atoms. A fused ring structure is formed by bonding the partial structure represented by formula (A) to an aryl ring or heteroaryl ring. Because the polycyclic aromatic compound of the present invention has this fused ring structure, the compound has a more rigid structure. This rigidity is expected to suppress molecular vibration, improve EQE, increase molecular stability, and extend device life.

In formula (A), L is >N-R, >O, >Si(-R) ₂ , or >S. By selecting the type of L in the partial structure represented by formula (A), it is possible to control the HOMO and LUMO of the compound of the present invention. When L is >N-R, >O, or >S, the HOMO and LUMO become shallower, and when L is >Si(-R) ₂ , the HOMO and LUMO become deeper. If the HOMO and LUMO become shallower, it is expected that the TTF device using this will have a longer life, higher efficiency, and lower driving voltage. On the other hand, if the HOMO and LUMO become deeper, it is expected that the hole trapping properties of the dopant will disappear, and the driving voltage will be significantly lowered.

R in >N-R as L in formula (A) is optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl, or optionally substituted cycloalkyl. R in >Si(-R) ₂ as L in formula (A) is hydrogen, optionally substituted aryl, optionally substituted alkyl, or optionally substituted cycloalkyl, and may be bonded to each other via a linking group. Furthermore, at least one of R in >N-R as L and >Si(-R) ₂ as L may be bonded to at least one selected from the group consisting of ring A, ring B R ^XC (ring C), and R ^A via a linking group or a single bond. L is preferably >N-R, >O, or >S, more preferably >N-R or >O, and even more preferably >N-R.

When L is >N-R, R is preferably aryl optionally substituted with alkyl or cycloalkyl, heteroaryl optionally substituted with alkyl or cycloalkyl, alkyl or cycloalkyl, more preferably aryl optionally substituted with alkyl or cycloalkyl, or heteroaryl optionally substituted with alkyl or cycloalkyl, even more preferably aryl optionally substituted with alkyl or cycloalkyl, and particularly preferably phenyl optionally substituted with alkyl or cycloalkyl.

In formula (A), r is an integer of 1 to 4, preferably 2 or 3, and more preferably 2 (the structure below).

In formula (A), each R ^A is independently hydrogen, optionally substituted alkyl, or optionally substituted cycloalkyl, and any R ^A may be linked to any other R ^A via a linking group or a single bond.

It is preferred that at least two of the R ^s in a pair are bonded to each other by a linking group or a single bond, and it is more preferred that two R ^s each bonded to adjacent carbon atoms are bonded to each other by a linking group or a single bond. Examples of the linking group include >O and >S.
An example of the divalent group formed by bonding to each other is alkylene. At least one hydrogen atom in the alkylene may be substituted with an alkyl or cycloalkyl, and at least one (preferably one) -CH ₂ - in the alkylene may be substituted with -O- and -S-. As the divalent group formed by bonding to each other, a straight-chain alkylene having 2 to 5 carbon atoms is preferred, a straight-chain alkylene having 3 or 4 carbon atoms is more preferred, and a straight-chain alkylene having 4 carbon atoms (-(CH ₂ ) ₄ -) is even more preferred. It is particularly preferred that the straight-chain alkylene having 4 carbon atoms (-(CH ₂ ) ₄ -) is unsubstituted.

When two R ^A 's each bonded to adjacent carbon atoms are bonded to each other by a linking group or a single bond, the remaining R ^A 's not involved in this bond are preferably each independently hydrogen or an optionally substituted alkyl, or bonded to R of >N-R which is L.

When two R ^A 's each bonded to adjacent carbon atoms are bonded to each other by a linking group or a single bond, the optionally substituted alkyl as the remaining R ^A not involved in this bond is more preferably an optionally substituted alkyl having 1 to 6 carbon atoms, even more preferably an unsubstituted alkyl having 1 to 6 carbon atoms, and most preferably methyl.
That is, a preferred example of the partial structure represented by formula (A) is a structure represented by formula (Aa-1).

In the formula, Me is methyl.

At least one of the Rs in >N-R and >Si(-R) ₂ which are L may be bonded to at least one selected from the group consisting of ring A, ring B, R ^XC (ring C), and R ^A via a linking group or a single bond. Examples of such a structure when L is >N-R include structures represented by any of the following formulae, and a structure represented by formula (A-b-1) is preferred.

In each formula, Me is methyl. In each formula, * binds to two or three consecutive (adjacent) atoms on ring A, ring B, and any aryl or heteroaryl ring in R ^XC .

1-2. Structural unit (skeletal structure) represented by formula (1)
In formula (1), "A" and "B" are symbols indicating ring structures.
In formula (1), ring A and ring B are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted.
R ^XC is optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkyl or optionally substituted cycloalkyl.
R ^XC may be bonded to at least one of the rings A and B via a linking group shown by a broken line or a single bond. Examples of the linking group include the linking group shown as X ² described below.
R ^XC is preferably an optionally substituted aryl or an optionally substituted heteroaryl. Furthermore, R ^XC is more preferably an optionally substituted aryl or an optionally substituted heteroaryl, and is bonded to ring A via a single bond or a linking group ^X2 . That is, formula (1) is preferably the following formula (2).

In formula (2), the same symbols as in formula (1) have the same meanings as those in formula (1). "C" is a symbol representing a ring structure and is one embodiment of R ^XC in formula (1). (X ² ) _n is one embodiment of the dashed line in formula (1), and n is 0 or 1. When n is 0, this indicates that ring A and ring C are bonded by a single bond, and when n is 1, this indicates that ring A and ring C are bonded by a linking group X ² .
(X ² ) _n is preferably bonded to an atom in ring A adjacent to the atom to which Y ¹ is bonded.

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

Here, the term "fused bicyclic structure" refers to a structure in which two rings comprising Y ¹ , X ¹ , and (X ² ) _n in the center of formula (2) are fused together. Preferably, both of the two rings in this fused bicyclic structure are six-membered rings. The term "six-membered ring sharing a bond with the fused bicyclic structure" refers to a six-membered ring (e.g., a benzene ring) fused to the fused bicyclic structure. Furthermore, the term "aryl ring or heteroaryl ring (which is ring A) has this six-membered ring" means that ring A is formed solely from this six-membered ring, or that ring A is formed by further condensing another ring to this six-membered ring so as to include this six-membered ring. In other words, the term "aryl ring or heteroaryl ring (which is ring A) having a six-membered ring" refers to the six-membered ring constituting all or part of ring A being fused to the fused bicyclic structure. The same explanation applies to "ring B,""ringC," and "five-membered ring." When n is 0, that is, when ring A and ring C are bonded via a single bond, ring C is an aryl ring or heteroaryl ring having a fused ring structure, and it is preferred that any two directly fused monocyclic rings in this fused ring structure are each fused to the fused bicyclic structure.

Examples of polycyclic aromatic compounds having a structure consisting of one of the structural units represented by formula (2) include polycyclic aromatic compounds represented by any of the following formulas (2-1) to (2-9).

In formulas (2-1) to (2-9), Z is C(-R ^Z ) or N. R ^Z is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted alkylarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted diarylboryl (two aryls may be bonded via a single bond or a linking group), substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, or substituted silyl, and R bonded to an adjacent C (carbon atom) ^Z 's 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 atom in the formed ring may be substituted with substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted diarylboryl (the two aryls may be bonded via a single bond or a linking group), substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, or substituted silyl.

In formulas (2-1) to (2-9), Y ¹ , X ¹ and X ² have the same meanings as Y ¹ , X ¹ and X ² in formula (2), respectively.
In formulas (2-2) to (2-6), (2-8), and (2-9), ^X3 and ^X4 each independently represent >C(—R) _2, >N—R, >O, >Si(—R) ₂ , or >S, and R in the >N—R represents an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, an alkyl having 1 to 6 carbon atoms, or a cycloalkyl having 3 to 14 carbon atoms, and R in the >C(—R) ₂ and >Si(—R) ₂ represents hydrogen, an aryl having 6 to 12 carbon atoms, an alkyl having 1 to 6 carbon atoms, or a cycloalkyl having 3 to 14 carbon atoms.

In each of formulas (2-1) to (2-9), the partial structure represented by formula (A) is bonded at two * positions to two adjacent carbon atoms on any one or more rings selected from the group consisting of ring a, ring b, ring c, and a ring formed by bonding R and ^Z. In each of formulas (2-1) to (2-9), the partial structure represented by formula (A) is preferably bonded at two * positions to two adjacent carbon atoms on ring b and/or ring c, and more preferably bonded at two * positions to two adjacent carbon atoms on ring b.

In formulas (2-2) to (2-6), (2-8), and (2-9), ^X3 and ^X4 each independently represent preferably >C(—R) _2, >N—R, >O, or >S, and more preferably >O or >S.

In formulas (2-1) to (2-9), Z is C(-R ^Z ) or N. In each of formulas (2-1) to (2-9), the number of rings (monocycles) containing Z that is N is preferably 0 to 4, more preferably 0 to 3, still more preferably 0 to 2, and particularly preferably 0 to 1. In each of formulas (2-1) to (2-9), it is also preferable that all of Z are C(-R ^Z ).

In formulas (2-1) to (2-9), in a ring (monocycle) containing Z where N, it is preferable that one or two of the multiple Zs are N, and when two are N, it is preferable that the two Ns are not adjacent to each other. When the six-membered ring is a ring containing Z where N, it is preferably a pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, or 1,2,3-triazine ring, and more preferably a pyridine ring or pyrimidine ring. When the five-membered ring is a ring containing Z where N, it is preferably an imidazole ring, thiazole ring, or oxazole ring.

In formulas (2-1) to (2-9), the preferred ranges of Y ¹ , X ¹ , X ² and R ^Z in C(-R ^Z ) will be described later.

In each of formulas (2-1) to (2-9), R and ^Z bonded to adjacent C (carbon atoms) may be bonded to each other to form an aryl ring or heteroaryl ring together with ring a, ring b or ring c.
Taking the compound represented by formula (2-1) as an example, 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 (2-1-1) and (2-1-2). Ring A', ring B', and ring C' in each formula correspond to ring A, ring B, and ring C in formula (2-1), respectively. In addition, the definitions of Z, a, b, c, Y ¹ , X ¹ , and X ² in each formula are the same as those in formula (2-1).

When explained in terms of formula (2-1), ring A', ring B', and ring C' in formula (2-1-1) and formula (2-1-2) represent aryl or heteroaryl rings formed together with ring a, ring b, and ring c by bonding together R and ^Z bonded to adjacent C (carbon atoms) (these may also be considered fused rings formed by fusing ring a, ring b, or ring c with another ring structure). Although not shown in the formula, there are also compounds in which ring a, ring b, and ring c are all changed to ring A', ring B', and ring C'.

For example, the fused ring A' (or fused ring B' or fused ring C') formed by fusing 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 the benzene ring, which is the a ring (or b ring or c ring), is a naphthalene ring, carbazole ring, indole ring, benzofuran ring, benzothiophene ring, dibenzofuran ring, dibenzothiophene ring, indene ring, or fluorene ring, respectively.

Similarly, in each of formulas (2-2) to (2-9), a fused ring may be formed by fusing another ring structure to ring a, ring b, or ring c. For example, the benzene ring that is ring a or ring b may be fused with another ring structure to form a fused ring, similar to the benzene ring in formula (2-1).
In formulas (2-2) to (2-6), (2-8), and (2-9), it is particularly preferred that in the 5-membered ring that is ring b or ring c, R ^{and Z} bonded to adjacent carbon atoms are bonded to each other to form a ring, thereby forming a fused ring. For example, in ring c of formulas (2-2) and (2-3), and ring b and ring c of formulas (2-4), (2-5), and (2-6), R and ^Z bonded to adjacent C atoms are bonded to each other to form a ring, thereby forming a fused ring B' or C' ring. When the ring formed is a benzene ring, examples of the fused ring include an indene ring, an indole ring, a benzofuran ring, and a benzothiophene ring.

In formulas (2-1) to (2-6), structural examples in which all Z's are C(-R ^Z ) are shown in the following formulas (3-1) to (3-11). The following formulas (3-7) to (3-11) are examples of structures in which R ^Z 's bonded to adjacent C's are bonded to each other to form a benzene ring and a fused ring is formed in a 5-membered ring that is ring b or ring c in formulas (2-2) to (2-6).

In the formulas (3-1) to (3-11), Y ¹ and X ¹ to X ⁴ have the same meanings as Y ¹ and X ¹ to X ⁴ in the formulas (2-1) to (2-6), respectively.
In formulas (3-1) to (3-11), R ¹ to R ¹¹ are hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted alkylarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted diarylboryl (the two aryls may be bonded via a single bond or a linking group), substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, or substituted silyl.

In each of formulas (3-1) to (3-11), the partial structure represented by formula (A) is bonded to two adjacent carbon atoms on one or more rings selected from the group consisting of ring a, ring b, and ring c at two * positions. It is preferable that the partial structure represented by formula (A) is bonded to two adjacent carbon atoms on ring b and/or ring c at two * positions in each of formulas (3-1) to (3-11).

In formulas (3-1) to (3-11), ^X3 and ^X4 each independently preferably represent >C(—R) _2, >N—R, >O, or >S, and more preferably represent >O or >S.
In formulas (3-1) to (3-11), the preferred ranges of Y ¹ , X ¹ , X ² and R ¹ to R ¹¹ will be described later.

Among formulas (3-1) to (3-11), formula (3-1), formula (3-2), formula (3-3), formula (3-7), or formula (3-8) is preferred, and formula (3-1) or formula (3-7) is more preferred.

Of formulas (2-7) to (2-9), formula (2-7) is preferred. Preferred examples of compounds represented by formula (2-7) include compounds represented by formula (3-21) or formula (3-22) below.

In formulas (3-21) to (3-22), Y ¹ and X ¹ have the same meanings as Y ¹ and X ¹ in formulas (2-1) to (2-9), respectively. R ¹ to R ¹² have the same meanings as R ¹ to R ¹¹ in formulas (3-1) to (3-11).

1-2. Structure consisting of two or more structural units represented by formula (1) The polycyclic aromatic compound of the present invention is a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1). Examples of polycyclic aromatic compounds having a structure consisting of one of the above structural units include polycyclic aromatic compounds represented by the formulas described above for the structural unit represented by formula (1). Examples of polycyclic aromatic compounds having a structure consisting of two or more structural units represented by formula (1) include compounds corresponding to multimers of polycyclic aromatic compounds represented by the formulas described above for the structural unit represented by formula (1). The multimer is preferably a dimer to a hexamer, more preferably a dimer to a trimer, and particularly preferably a dimer. The polymer may be in a form having a plurality of the above unit structures in one compound, and may be in a form in which any ring (ring A, ring B or ring C, ring a, ring b or ring c) contained in the above structural unit is bonded so as to be shared by a plurality of unit structures, or in which any ring (ring A, ring B or ring C, ring a, ring b or ring c) contained in the above unit structure is bonded so as to be condensed with each other. Furthermore, the above unit structures may be bonded in a form in which a plurality of unit structures are bonded via a linking group such as a single bond, alkylene having 1 to 3 carbon atoms, phenylene, naphthylene, etc.

As an example of a structure consisting of two or more structural units represented by formula (1), examples of an embodiment in which the structural unit represented by formula (1) is a structural unit represented by formula (3-1) include structures represented by the following formulas. In the following formulas, ring a, ring b, ring c, Y ¹ , X ¹ , X ² , and R ¹ to R ¹¹ are synonymous with ring a, ring b, ring c, Y ¹ , X ¹ , X ² , and R ¹ to R ¹¹ in formula (3-1), respectively. In the following formulas, at least one ring selected from the group consisting of ring a, ring b, and ring c contains at least one partial structure represented by formula (A). The partial structure represented by formula (A) may or may not be contained in each structural unit represented by formula (1), as long as at least one partial structure is contained in the overall structure of the polycyclic aromatic compound.

In formula (3-1-4), formula (3-1-4-1), formula (3-1-4-2), formula (3-1-5-1) to formula (3-1-5-5), formula (3-1-6), and formula (3-1-7), X ¹ , X ² , R ¹ to R ¹¹ , ring a, ring b, and ring c have the same meanings as those in formula (3-1). The multimeric compound represented by formula (3-1-4), when explained in terms of formula (3-1), is a multimeric compound (dimer) having a plurality of unit structures represented by formula (3-1) in one compound, so as to share a benzene ring that is an a-ring. Furthermore, the multimeric compound represented by formula (3-1-4-1), when explained in terms of formula (3-1), is a multimeric compound (dimer) having two unit structures represented by formula (3-1) in one compound, so as to share a benzene ring that is an a-ring. Furthermore, the multimeric compound represented by formula (3-1-4-2), when explained in terms of formula (3-1), is a multimeric compound (trimer) having three unit structures represented by formula (3-1) in one compound, with the benzene ring being the a-ring in common. Furthermore, the multimeric compounds represented by formulas (3-1-5-1) to (3-1-5-5), when explained in terms of formula (3-1), are multimeric compounds having a plurality of unit structures represented by formula (3-1) in one compound, with the benzene ring being the b-ring (or c-ring) in common (formula (3-1-5-4) is a trimer, and the others are dimers). Furthermore, when explained in terms of formula (3-1), the multimeric compound represented by formula (3-1-6) is a multimeric compound (dimer) having, in one compound, a plurality of unit structures represented by formula (3-1), for example, such that a benzene ring that is the b-ring (or a-ring, c-ring) of a certain unit structure is fused with a benzene ring that is the b-ring (or a-ring, c-ring) of a certain unit structure. Furthermore, when explained in terms of formula (3-1), the multimeric compound represented by formula (3-1-7) is a multimeric compound (trimer) having, in one compound, a plurality of unit structures represented by formula (3-1), such that a benzene ring that is the b-ring or c-ring is shared.

1-3. In the structural unit, the rings A and B in the partial structural formula (1) and the rings A, B, and C in the formula (2) are each independently an aryl ring or a heteroaryl ring. At least one hydrogen atom in these rings may be substituted with a substituent.

The "aryl rings" that are rings A and B in formula (1) and rings A, B, and C in formula (2) include, for example, 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.

Specific examples of "aryl rings" include a monocyclic benzene ring, a bicyclic bicyclic bicyclic naphthalene ring and an indene ring, tricyclic terphenyl rings (m-terphenyl, o-terphenyl, p-terphenyl), fused tricyclic acenaphthylene ring, fluorene ring, phenalene ring, phenanthrene ring, and anthracene ring, fused tetracyclic tricyclic triphenylene ring, pyrene ring, naphthacene ring, and chrysene ring, and fused pentacyclic perylene ring and pentacene ring. Furthermore, fluorene rings, benzofluorene rings, and indene rings also include structures in which fluorene rings, benzofluorene rings, cyclopentane rings, etc. are spiro-bonded, respectively. The fluorene ring, benzofluorene ring, and indene ring also include rings in which two of the two hydrogen atoms of the methylene are each replaced by an alkyl group such as methyl as the first substituent described below, resulting in a dimethylfluorene ring, dimethylbenzofluorene ring, and dimethylindene ring, etc.

The "heteroaryl rings" that are rings A and B in formula (1) and rings A, B, and C in formula (2) include, for example, 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, even more preferably heteroaryl rings having 2 to 15 carbon atoms, and particularly preferably heteroaryl rings having 2 to 10 carbon atoms. Furthermore, "heteroaryl rings" include, for example, heterocyclic rings containing, in addition to carbon, 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen as ring-constituting atoms.

Specific examples of "heteroaryl rings" include pyrrole rings, oxazole rings, isoxazole rings, thiazole rings, isothiazole rings, imidazole rings, oxadiazole rings, thiadiazole rings, triazole rings, tetrazole rings, pyrazole rings, pyridine rings, pyrimidine rings, pyridazine rings, pyrazine rings, triazine rings, indole rings, isoindole rings, 1H-indazole rings, benzimidazole rings, benzoxazole rings, benzothiazole rings, 1H-benzotriazole rings, quinoline rings, isoquinoline rings, cinnoline rings, quinazoline rings, quinoxaline rings, phthalazine rings, naphthyridine rings, purine rings, and pteridine rings. , a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, a phenazasiline 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, a thianthrene ring, an indolocarbazole ring, a benzoindolocarbazole ring, a benzobenzoindolocarbazole ring, a naphthobenzofuran ring, a dioxin ring, a dihydroacridine ring, a xanthene ring, a thioxanthene ring, a dibenzodioxin ring, a dibenzazepine ring, a tribenzazepine ring, an iminodibenzyl ring, etc. Furthermore, it is also preferable that two of the two hydrogen atoms of the methylene of the dihydroacridine ring, the xanthene ring, and the thioxanthene ring are each substituted with an alkyl such as methyl as the first substituent described below, to form a dimethyldihydroacridine ring, a dimethylxanthene ring, a dimethylthioxanthene ring, etc. Additionally, bicyclic rings such as bipyridine rings, phenylpyridine rings, and pyridylphenyl rings, and tricyclic rings such as terpyridyl rings, bispyridylphenyl rings, and pyridylbiphenyl rings are also included as "heteroaryl rings." Furthermore, "heteroaryl rings" also include pyran rings.

When at least one hydrogen atom in the above aryl or heteroaryl ring is replaced with a substituent, the substituent is preferably a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted diarylamino, a substituted or unsubstituted alkylarylamino, a substituted or unsubstituted diheteroarylamino, a substituted or unsubstituted arylheteroarylamino (an amino having an aryl and a heteroaryl), a substituted or unsubstituted diarylboryl (the two aryls may be bonded via a single bond or a linking group), a substituted or unsubstituted alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryloxy, or a substituted silyl. When these groups have a substituent, examples of the substituent include an aryl, heteroaryl, alkyl, cycloalkyl, or diarylamino.

At least one hydrogen atom in the above "aryl ring" or "heteroaryl ring" may be replaced by a first substituent, which is a substituted or unsubstituted "aryl," a substituted or unsubstituted "heteroaryl," a substituted or unsubstituted "diarylamino," a substituted or unsubstituted "alkylarylamino," a substituted or unsubstituted "diheteroarylamino," a substituted or unsubstituted "arylheteroarylamino," a substituted or unsubstituted "diarylboryl (the two aryls may be bonded via a single bond or a linking group)," a substituted or unsubstituted "alkyl," a substituted or unsubstituted "cycloalkyl," a substituted or unsubstituted "alkoxy," a substituted or unsubstituted "aryloxy," or a substituted "silyl." Examples of the "aryl" or "heteroaryl" as the first substituent include the aryl in "diarylamino," the aryl in "alkylarylamino," the heteroaryl in "diheteroarylamino," the aryl and heteroaryl in "arylheteroarylamino," the aryl in "diarylboryl," and the aryl in "aryloxy," as well as monovalent groups of the "aryl ring" or "heteroaryl ring" described above.

Specific examples of "aryl" include aryls having 6 to 30 carbon atoms, preferably aryls having 6 to 24 carbon atoms, more preferably aryls having 6 to 20 carbon atoms, even more preferably aryls having 6 to 16 carbon atoms, particularly preferably aryls having 6 to 12 carbon atoms, and most preferably aryls having 6 to 10 carbon atoms.

Specific examples of aryl include monocyclic aryl phenyl, bicyclic aryl (2-, 3-, 4-)biphenylyl, fused bicyclic aryl (1-, 2-)naphthyl and (2-, 3-, 4-, 5-, 6-, 7-)indenyl, and 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). acenaphthylene-(1-,3-,4-,5-)yl, fluoren-(1-,2-,3-,4-,9-)yl, phenalen-(1-,2-)yl, (1-,2-,3-,4-,9-)phenanthryl, which are fused tricyclic aryls; quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-2-yl), which are tetracyclic aryls; Examples include fused tetracyclic aryls such as triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, naphthacene-(1-, 2-, 5-)yl, and fused pentacyclic aryls such as perylene-(1-, 2-, 3-)yl and pentacene-(1-, 2-, 5-, 6-)yl.

Examples of "heteroaryl" include heteroaryls having 2 to 30 carbon atoms, preferably heteroaryls having 2 to 25 carbon atoms, more preferably heteroaryls having 2 to 20 carbon atoms, even more preferably heteroaryls having 2 to 15 carbon atoms, and particularly preferably heteroaryls having 2 to 10 carbon atoms. Examples of heteroaryls 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, dibenzofuranyl, benzo[b]thienyl, dibenzothienyl, and indyl. Examples include propyl, 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 "alkyl" as the first substituent may be either linear or branched, and examples include linear alkyls having 1 to 24 carbon atoms or branched alkyls having 3 to 24 carbon atoms. Alkyls having 1 to 18 carbon atoms (branched alkyls having 3 to 18 carbon atoms) are preferred, alkyls having 1 to 12 carbon atoms (branched alkyls having 3 to 12 carbon atoms) are more preferred, alkyls having 1 to 8 carbon atoms (branched alkyls having 3 to 8 carbon atoms) are even more preferred, alkyls having 1 to 6 carbon atoms (branched alkyls having 3 to 6 carbon atoms) are particularly preferred, and alkyls having 1 to 5 carbon atoms (branched alkyls having 3 to 5 carbon atoms) are most preferred.

Specific alkyl groups 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, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 1-methylhexyl, n-octyl, and t-octyl (1,1,3,3-tetramethylbutyl). ), 1-methylheptyl, 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.

Other examples include 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.

Among the substituents containing the above "alkyl," tertiary alkyls represented by the following formula (tR) are particularly preferred as substituents when at least one hydrogen atom in the above aryl or heteroaryl ring is substituted with a substituent. This is because such bulky substituents increase the intermolecular distance, thereby improving the luminescence quantum yield (PLQY). Substituents in which the tertiary alkyl represented by formula (tR) is substituted with another substituent as a second substituent are also preferred. Specific examples include diarylamino substituted with tertiary alkyl represented by (tR), carbazolyl (preferably N-carbazolyl) substituted with tertiary alkyl represented by (tR), or benzocarbazolyl (preferably N-benzocarbazolyl) substituted with tertiary alkyl represented by (tR). Examples of "diarylamino" include the groups described below as "first substituents." Examples of substitution of the group of formula (tR) on diarylamino, carbazolyl, and benzocarbazolyl include those 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 formula (tR).

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

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

The total number of carbon atoms of R ^a , R ^b and R ^c in formula (tR) of formula (1) 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 groups 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. Of these, t-butyl and t-amyl are preferred.

Methylphenylamino is preferred as "alkylarylamino".

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 5 carbon atoms, as well as norbornyl (bicyclo[2.2.1]heptyl), bicyclo[1.1.0]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, and decahydroazulenyl.

Also, examples of "alkoxy" as the first substituent include straight-chain alkoxy having 1 to 24 carbon atoms or branched-chain alkoxy having 3 to 24 carbon atoms. Alkoxy having 1 to 18 carbon atoms (branched-chain alkoxy having 3 to 18 carbon atoms) is preferred, alkoxy having 1 to 12 carbon atoms (branched-chain alkoxy having 3 to 12 carbon atoms) is more preferred, alkoxy having 1 to 6 carbon atoms (branched-chain alkoxy having 3 to 6 carbon atoms) is even more preferred, and alkoxy having 1 to 5 carbon atoms (branched-chain alkoxy having 3 to 5 carbon atoms) is particularly preferred.

Specific examples of alkoxy include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, s-butoxy, t-butoxy, t-amyloxy, pentyloxy, hexyloxy, heptyloxy, and octyloxy.

Furthermore, examples of "substituted silyl" as the first substituent include 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.

"Trialkylsilyl" refers to a silyl group in which three hydrogen atoms are each independently substituted with an alkyl, and the alkyl can be any of the groups described above as the "alkyl" 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 trialkylsilyl groups include trimethylsilyl, triethylsilyl, tripropylsilyl, tri-i-propylsilyl, tributylsilyl, tri-sec-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 methyldiethylsilyl, sec-butyldiethylsilyl, t-butyldiethylsilyl, t-amyldiethylsilyl, methyldipropylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, t-butyldipropylsilyl, t-amyldipropylsilyl, methyldi-i-propylsilyl, ethyldi-i-propylsilyl, butyldi-i-propylsilyl, sec-butyldi-i-propylsilyl, t-butyldi-i-propylsilyl, and t-amyldi-i-propylsilyl.

"Tricycloalkylsilyl" refers to a silyl group in which three hydrogen atoms are each independently replaced with a cycloalkyl, and examples of this cycloalkyl include the groups described above as "cycloalkyl" in the first substituent. Preferred cycloalkyl groups for substitution are those having 5 to 10 carbon atoms, such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclo[1.1.1]pentyl, bicyclo[2.1.0]pentyl, bicyclo[2.1.1]hexyl, bicyclo[3.1.0]hexyl, bicyclo[2.2.1]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 listed 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. Specific examples of triarylsilyl include triphenylsilyl.

Furthermore, the "aryl" in the "diarylboryl" of the first substituent can be referenced from the above description of the aryl. Furthermore, the two aryls may be bonded via a single bond or a linking group (for example, >C(-R) ₂ , >O, >S, or >N-R). Here, R in >C(-R) ₂ and >N-R is aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy (all of which are first substituents), and the first substituent may be further substituted with an aryl, heteroaryl, alkyl, or cycloalkyl (all of which are second substituents). Specific examples of these groups can be referenced from the above description of the aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy as the first substituent.

As described above, at least one hydrogen atom in the first substituent, substituted or unsubstituted "aryl," substituted or unsubstituted "heteroaryl," substituted or unsubstituted "diarylamino," substituted or unsubstituted "alkylarylamino," substituted or unsubstituted "diheteroarylamino," substituted or unsubstituted "arylheteroarylamino," substituted or unsubstituted "diarylboryl (the two aryls may be bonded via a single bond or a linking group)," substituted or unsubstituted "alkyl," substituted or unsubstituted "cycloalkyl," substituted or unsubstituted "alkoxy," substituted or unsubstituted "aryloxy," or substituted "silyl," may be substituted or unsubstituted by a second substituent. Examples of this second substituent include aryl, heteroaryl, alkyl, and cycloalkyl. Specific examples of these groups can be found in the descriptions of the monovalent groups in the "aryl ring" or "heteroaryl ring" and the "alkyl" or "cycloalkyl" first substituents described above. Additionally, the aryl and heteroaryl as the second substituent also include structures in which at least one hydrogen atom is substituted with an aryl such as phenyl (specific examples include the groups listed above), an alkyl such as methyl or t-butyl (specific examples include the groups listed above), or a cycloalkyl such as cyclohexyl (specific examples include the groups listed above). For example, if the second substituent is carbazolyl, then the heteroaryl as the second substituent also includes a carbazolyl in which at least one hydrogen atom at the 9-position is substituted with an aryl such as phenyl, an alkyl such as methyl, or a cycloalkyl such as cyclohexyl.

The emission wavelength can be adjusted by the steric hindrance, electron donating property, and electron withdrawing property of the structure of the first substituent. Groups represented by the following structural formulas are preferred, and more preferred are methyl, t-butyl, t-amyl, t-octyl, neopentyl, 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 (particularly N-carbazolyl), and 3,6-dimethylcarbazolyl. and more preferably methyl, t-butyl, t-amyl, t-octyl, neopentyl, 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 perspective of ease of synthesis, larger steric hindrance is preferred for selective synthesis, and specifically, t-butyl, 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 formulas, "Me" represents methyl, "tBu" represents t-butyl, "tAm" represents t-amyl, "tOct" represents t-octyl, and * represents the bonding position.

In formulas (2-1) to (2-9), when Z is C(-R ^Z ), R ^Z is hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted alkylarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted diarylboryl (the two aryls may be bonded via a single bond or a linking group), substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, or substituted silyl. In each of formulas (2-1) to (2-9), R ^Z includes a partial structure represented by formula (A) formed by bonding together atoms bonded to adjacent atoms. Furthermore, R and ^Z may bond together so that atoms bonded to adjacent atoms form a ring, and together with ring a, ring b, or ring c, form an aryl ring or a heteroaryl ring, and these rings may be substituted with a substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted alkylarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted diarylboryl (the two aryls may be bonded via a single bond or a linking group), substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, or substituted silyl.

For details and preferred ranges of these, please refer to the explanations of the first and second substituents above. Specifically, when each of the above substituents is substituted, the substituent (second substituent) may be aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (the two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, or alkyldicycloalkylsilyl, and at least one hydrogen atom in these may be substituted with an aryl, heteroaryl, alkyl, or cycloalkyl.

In formulas (2-1) to (2-9), when Z is C(-R ^Z ), R ^Z is preferably each independently hydrogen, aryl having 6 to 30 carbon atoms, heteroaryl having 2 to 30 carbon atoms, diarylamino (wherein aryl is aryl having 6 to 12 carbon atoms), diarylboryl (wherein aryl is aryl having 6 to 12 carbon atoms, and two aryls may be bonded via a single bond or a linking group), alkyl having 1 to 24 carbon atoms, cycloalkyl having 3 to 24 carbon atoms, triarylsilyl (wherein aryl is aryl having 6 to 12 carbon atoms), or trialkylsilyl (wherein alkyl is alkyl having 1 to 6 carbon atoms), provided that adjacent R ^Z 's may be bonded to each other to form, together with ring a, ring b or ring c, an aryl ring having 9 to 16 carbon atoms or a heteroaryl ring having 6 to 15 carbon atoms, and at least one hydrogen atom in the formed ring may be substituted with aryl having 6 to 10 carbon atoms, alkyl having 1 to 12 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, triarylsilyl (provided that aryl is aryl having 6 to 12 carbon atoms), or trialkylsilyl (provided that alkyl is alkyl having 1 to 5 carbon atoms);
More preferably, they are each independently hydrogen, an aryl having 6 to 16 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, a diarylamino (wherein the aryl is an aryl having 6 to 10 carbon atoms), an alkyl having 1 to 12 carbon atoms, or a cycloalkyl having 3 to 16 carbon atoms;
More preferably, they are each independently hydrogen, aryl having 6 to 16 carbon atoms, diarylamino (wherein aryl has 6 to 10 carbon atoms), alkyl having 1 to 12 carbon atoms, or cycloalkyl having 3 to 16 carbon atoms.

In the rings a, b, and c in each of formulas (2-1) to (2-9) that are bonded to the partial structure represented by formula (A), Z other than the bonding portion is preferably C-H.

In formulas (3-1) to (3-11), (3-21), and (3-22), R ¹ to R ¹² are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted alkylarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted diarylboryl (two aryls may be bonded via a single bond or a linking group), substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, or substituted silyl. For details and preferred ranges of these, please refer to the explanations of the first substituent and the second substituent above. Specifically, examples of the substituent (second substituent) when each of the above substituents is substituted include aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, diarylboryl (two aryls may be bonded via a single bond or a linking group), alkyl, cycloalkyl, alkoxy, aryloxy, triarylsilyl, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, and alkyldicycloalkylsilyl, and at least one hydrogen atom in these may be substituted with aryl, heteroaryl, alkyl, or cycloalkyl.

Specifically, in formulas (3-1) to (3-11), (3-21), and (3-22), R ¹ to R ¹² are each independently preferably hydrogen, an aryl having 6 to 30 carbon atoms, a heteroaryl having 2 to 30 carbon atoms, a diarylamino (wherein the aryl is an aryl having 6 to 12 carbon atoms), a diarylboryl (wherein the aryl is an aryl having 6 to 12 carbon atoms, and two aryls may be bonded via a single bond or a linking group), an alkyl having 1 to 24 carbon atoms, a cycloalkyl having 3 to 24 carbon atoms, a triarylsilyl (wherein the aryl is an aryl having 6 to 12 carbon atoms), or a trialkylsilyl (wherein the alkyl is an alkyl having 1 to 6 carbon atoms);
More preferably, they are each independently hydrogen, an aryl having 6 to 16 carbon atoms, a heteroaryl having 2 to 20 carbon atoms, a diarylamino (wherein the aryl is an aryl having 6 to 10 carbon atoms), an alkyl having 1 to 12 carbon atoms, or a cycloalkyl having 3 to 16 carbon atoms;
More preferably, they are each independently hydrogen, aryl having 6 to 16 carbon atoms, diarylamino (wherein aryl has 6 to 10 carbon atoms), alkyl having 1 to 12 carbon atoms, or cycloalkyl having 3 to 16 carbon atoms.

In formula (1), Y ¹ is B, P, P═O or P═S, preferably B or P═O, and more preferably B. This explanation also applies to Y 1 in formula (2), formulas (2-1) to (2-9), formulas (3-1) to (3-11), formula (3-21 ⁾ , and formula (3-22).

X ¹ in formula (1) and X ¹ and X ² in formula (2) are each independently >C(—R) _2, >N—R, >O, >Si(—R) ₂ or >S, 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 >C(—R) ₂ and >Si(—R) ₂ is hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, two R are preferably the same and may be bonded to each other via a linking group, and at least one of R of the >N—R, the >C(—R) ₂ and the >Si(—R) ₂ may be bonded to at least one selected from the group consisting of ring A, ring B and R ^XC via a linking group or a single bond. This explanation also applies to ^X1 and ^X2 in formula (2), formulas (2-1) to (2-9), formulas (3-1) to (3-11), formula (3-21), and formula (3-22). Note that "at least one selected from the group consisting of ring A, ring B, and R ^XC " is to be read as "at least one selected from the group consisting of ring A, ring B, and ring C" in formula (2), and as "at least one selected from the group consisting of ring a, ring b, and ring c" in formulas (2-1) to (2-9), formulas (3-1) to (3-11), formula (3-21), and formula (3-22).

In formula (1), formulas (2-7) to (2-9), formula (3-21), and formula (3-22), ^X1 is preferably each independently >O or >N—R, more preferably >N—R. In formula (2), formulas (2-1) to (2-6), and formulas (3-1) to (3-11), at least one of ^X1 and ^X2 is preferably >N—R, more preferably both are >N—R.

For the aryl, heteroaryl, alkyl, and cycloalkyl in R of >N-R in ^X1 and ^X2 , the description thereof as the first substituent can be referred to above. R of >N-R in ^X1 and ^X2 is preferably an optionally substituted aryl, an optionally substituted heteroaryl, or an optionally substituted cycloalkyl, and more preferably an optionally substituted aryl. Here, as the aryl, phenyl, biphenylyl (particularly 2-biphenylyl), and terphenylyl (particularly terphenyl-2'-yl) are preferred, and phenyl and biphenylyl are more preferred. When the aryl is substituted, preferred substituents are tertiary alkyl (particularly t-butyl) and methyl represented by formula (tR) described below. The number of substituents in the aryl is preferably 0 to 3, and more preferably 1 to 3.
It is also preferred that the aryl ring in the above aryl is condensed with a cycloalkane as described below.

Particularly preferred R of >N—R in ^X1 and ^X2 is unsubstituted phenyl, phenyl having t-butyl bonded to the para position, phenyl having t-butyl bonded to the para position and methyl bonded to one or two ortho positions, and 2-(5,4′-ditertiarybutyl)biphenylyl.

R in at least one of >N-R, >Si(-R) ₂ , and >C(-R) ₂ in ^X1 and ^X2 may be bonded to at least one of the rings A, B, and C via a linking group or a single bond. The linking group is preferably -O-, -S-, or -C(-R) _2- . R in the "-C(-R) _2- " is hydrogen, alkyl, or cycloalkyl. Examples of such a structure include a compound represented by the following formula (1-3-1) having a ring structure in which ^X1 is incorporated into the fused ring B', a compound represented by the following formula (1-3-2) having a ring structure in which ^X1 is incorporated into the fused ring A', a compound represented by the following formula (2-3-1) having a ring structure in which ^X2 in formula (2) is incorporated into the fused ring C', and a compound represented by the following formula (2-3-2) having a ring structure in which ^X2 in formula (2) is incorporated into the fused ring A'. The fused ring A' (fused ring B' or fused ring C') thus formed is, for example, a carbazole ring, a phenoxazine ring, a phenothiazine ring or an acridine ring.

When R in >N-R in ^X1 and ^X2 is bonded to at least one of ring A, ring B, and ring C via a linking group or a single bond, ^X1 or ^X2 may form the following partial structure (A10):

In formula (A10), R 1 ^B each independently represents hydrogen, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and any two to four R 1 ^B may be bonded to each other via a linking group or a single bond, and are bonded to ring A at the two * positions and ring B or ring C at the ** position, or are bonded to ring B or ring C at the two * positions and ring A at the ** position. That is, N in formula (A10) is N of >N-R where ^X1 or ^X2 . The atoms on the ring bonded at the two * positions may be adjacent atoms (preferably carbon atoms).
Although the partial structure represented by formula (A10) contains an N-C bond with a weak bond dissociation energy (BDE), the presence of another bond that forms a ring promotes a reverse reaction (recombination reaction) even when the N-C bond is broken, and therefore, a polycyclic aromatic compound having a partial structure represented by formula (A10) has a more stable structure. Therefore, an organic EL device manufactured using a polycyclic aromatic compound having a partial structure represented by formula (A10) is expected to have a longer device life.
The number of partial structures represented by formula (A10) formed by the above-described linkage contained in the polycyclic aromatic compound is preferably one or two.

In formula (A10), R 1 ^B is hydrogen, optionally substituted alkyl or optionally substituted cycloalkyl, and any R 1 ^B may be linked to another R 1 ^B via a linking group or a single bond.
It is preferable that any two R ^{A1 and R A4} are bonded to each other via a linking group or a single bond, and it is more preferable that R ^A1 and R ^A4 are bonded to each other via a linking group or a single bond. An example of the divalent group formed by bonding to each other is alkylene. At least one hydrogen atom in the alkylene may be substituted with an alkyl or cycloalkyl, and at least one (preferably one) -CH ₂ - in the alkylene may be substituted with -O- and -S-. The linking group is preferably a straight-chain alkylene having 2 to 5 carbon atoms, more preferably a straight-chain alkylene having 3 or 4 carbon atoms, and even more preferably a straight-chain alkylene having 4 carbon atoms (-(CH ₂ ) ₄ -). It is particularly preferable that the straight-chain alkylene having 4 carbon atoms (-(CH ₂ ) ₄ -) is unsubstituted.

The remaining R 1 and R ² that are not involved in the linking via the linking group are each preferably independently hydrogen or an alkyl which may be substituted, more preferably an alkyl having 1 to 6 carbon atoms which may be substituted, further preferably an unsubstituted alkyl having 1 to 6 carbon atoms, and most preferably methyl.
That is, the partial structure represented by formula (A10) is preferably a structure represented by the following formula (A11).

In formula (A11), Me is methyl and is bonded to ring A at the two * positions and to ring B or C at the ** position, or is bonded to ring B or C at the two * positions and to ring A at the ** position.

Furthermore, a compound represented by formula (2-3-1) having a ring structure in which ^X2 in formula (2) is incorporated into fused ring C', and a compound represented by the following formula (2-3-2) having a ring structure in which ^X2 in formula (2) is incorporated into fused ring A' can also be considered to be a compound in which n is 0 in formula (2).
Examples of the structure of the fused ring C′ in formula (2-3-1) include structures represented by any of the following formulas (each structure may have a substituent).

In each formula, * binds to ^Y1 and # binds to ring A (preferably to the carbon atom adjacent to the carbon atom to which ^Y1 is bonded).
Examples of the structure of the fused ring A' in formula (2-3-1) include structures represented by any of the following formulas (each structure may have a substituent).

In each formula, * is attached to Y ¹ , ** is attached to X ¹ , and # is attached to ring C.

The polycyclic aromatic compound of the present invention can be used as a material for organic devices. Examples of organic devices include organic electroluminescent devices, organic field-effect transistors, and organic thin-film solar cells. In particular, in organic electroluminescent devices, as a dopant material for the light-emitting layer, compounds represented by formula (2) in which ^Y1 is B, and ^X1 and ^X2 are all >N-R, compounds in which ^Y1 is B, ^X1 is >O, and ^X2 is >N-R, compounds in which ^Y1 is B, ^X1 and ^X2 are all >O, and compounds in which ^Y1 is B, ^X1 and ^X2 are all >C(-R) ₂ are preferred, compounds in which ^Y1 is B, ^X1 and ^X2 are all >N-R, compounds in which ^Y1 is B, ^X1 and ^X2 are all >C(-R) ₂ are more preferred, and compounds in which ^Y1 is B, ^X1 and ^X2 are all >N-R are most preferred. As the host material of the light-emitting layer, a compound in which ^Y1 is B, ^X1 is >O, and ^X2 are both >N—R, or a compound in which ^Y1 is B, and ^X1 and ^X2 are both >O, is preferred. As the electron-transporting material, a compound in which ^Y1 is B, ^X1 and ^X2 are both >O, or a compound in which ^Y1 is P═O, and ^X1 and ^X2 are both >O is preferred.

R of >Si(-R) ₂ in ^X1 of formula (1) and ^X1 and ^X2 of formula (2), and R of >Si(-R) ₂ as a linking group connecting ring B and ring C are aryl, heteroaryl, alkyl, or cycloalkyl, each optionally substituted with the second substituent described above. Examples of the aryl, heteroaryl, alkyl, or 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 R of >Si(-R) ₂ as ^X1 and ^X2 in formulas (2-1) to (2-9), formulas (3-1) to (3-11), formula (3-21), and formula (3-22).

R of >C(-R) ₂ in ^X1 of formula (1) and ^X1 and ^X2 of formula (2), and R of >C(-R) ₂ as a linking group connecting ring B and ring C, are hydrogen, aryl, heteroaryl, alkyl, or cycloalkyl optionally substituted with the second substituent described above. Examples of the aryl, heteroaryl, alkyl, or 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 R of >C(-R) ₂ as ^X1 and ^X2 in formulas (2-1) to (2-9), formulas (3-1) to (3-11), formula (3-21), and formula (3-22).

In the case where R in at least one of >N-R, >Si(-R) ₂ , and >C(-R) ₂ in ^X1 in formula (1) and ^X1 and ^X2 in formula (2) is bonded to at least one of rings A, B, and C via a linking group or a single bond, examples of the linking group include -O-, -S-, -C(-R) _2- , or a single bond, and among these, R in "-C(-R) _2- " is hydrogen, alkyl, or cycloalkyl, and examples of this alkyl or 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) are preferred. This explanation also applies to the linking group "-C(-R) 2 -" in the formulas (2-1) to (2-9), (3-1) to (3-11), (3-21), and (3-22) when X ¹ and _X ² are bonded to at least one of the ring a, ring b, and ring c.

At least one selected from the group consisting of aryl rings and heteroaryl rings in the structure consisting of one or more structural units represented by formula (1) 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— or —S—. The same applies to formulas (2), (2-1) to (2-9), (3-1) to (3-11), (3-21), and (3-22).

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

Specific cycloalkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, norbornane (bicyclo[2.2.1]heptane), bicyclo[1.1.0]butane, bicyclo[1.1.1]pentane, bicyclo[2.1.0]pentane, bicyclo[2.1.1]hexane, bicyclo[3.1.0]hexane, bicyclo[2.2.2]octane, adamantane, diamantane, decahydronaphthalene, and decahydroazulene, as well as alkyl (especially methyl), halogen (especially fluorine), and deuterium-substituted derivatives of these having 1 to 5 carbon atoms.

Among these, preferred are structures in which at least one hydrogen atom is substituted on the α-carbon atom of the cycloalkane (the carbon atom adjacent to the fused carbon atom in a cycloalkyl fused to an aryl or heteroaryl ring), more preferred are structures in which two hydrogen atoms are substituted on the α-carbon atom, and even more preferred are structures in which a total of four hydrogen atoms are substituted on the two α-carbon atoms. Examples of such substituents include alkyl (especially methyl) substituents having 1 to 5 carbon atoms, halogen (especially fluorine) substituents, and deuterium substituents. In particular, preferred are structures in which a partial structure represented by formula (B) below is bonded to adjacent carbon atoms in an aryl or heteroaryl ring.

In formula (B), Me represents methyl, and * represents the bonding position.

[0023] All or a portion of the hydrogen atoms in the chemical structure of a polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) or formula (2) may be substituted with deuterium, cyano, or halogen. For example, in formula (1) or formula (2), hydrogen atoms in rings A, B, and C (rings A to C are aryl or heteroaryl rings), substituents on rings A to C, and R (= alkyl, cycloalkyl, aryl) when ^X1 and ^X2 are >N-R, >C(-R) ₂ , or >Si(-R) ₂ may be substituted with deuterium, cyano, or halogen. Among these, embodiments in which all or a portion of the hydrogen atoms in the aryl or heteroaryl are substituted with deuterium, cyano, or halogen are exemplified. The halogen atom is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, more preferably fluorine or chlorine, and even more preferably fluorine. From the viewpoint of durability, it is also preferable that all or a part of the hydrogen atoms in the chemical structure of the polycyclic aromatic compound having a structure consisting of one or more structural units represented by formula (1) or formula (2) are deuterated. This explanation also applies to compounds in which formula (1) is formulas (2-1) to (2-9), formulas (3-1) to (3-11), formula (3-21), or formula (3-22).

1-4. Preferred structural examples When n is 1 in formula (2), preferred examples of the polycyclic aromatic compound of the present invention include compounds having a structure represented by formula (1-BA1), formula (1-BA2), formula (1-BA3), formula (1-BA4), formula (1-BA5), formula (1-BA6), formula (1-BA7), or formula (1-BA8).

In formulas (1-BA1), (1-BA2), (1-BA3) and (1-BA4),
ring c is an optionally substituted benzene ring, an optionally substituted benzofuran ring, or an optionally substituted benzothiophene ring;
Each R is independently an optionally substituted phenyl;
R ² ' is hydrogen or alkyl having 1 to 6 carbon atoms;
In at least one benzene ring in the above structure, hydrogen atoms bonded to adjacent carbon atoms may be substituted with a partial structure represented by formula (B).
In formula (1-BA1), formula (1-BA2), formula (1-BA3), and formula (1-BA4), the benzofuran ring and the benzothiophene ring in ring c may be bonded to B and ^X2 via a six-membered ring (benzene ring), or may be bonded to B and ^X2 via a five-membered ring (furan ring or thiophene ring).

In formulas (1-BA5), (1-BA6), (1-BA7) and (1-BA8),
Ring D is an optionally substituted benzene ring or an optionally substituted cyclohexane ring;
Each R is independently an optionally substituted phenyl;
Each ^Rd is independently hydrogen, optionally substituted alkyl, optionally substituted aryl, optionally substituted heteroaryl, or optionally substituted diarylamino;
In at least one benzene ring in the above structure, hydrogen atoms bonded to adjacent carbon atoms may be substituted with a partial structure represented by formula (B).

In formulae (1-BA5), (1-BA6), (1-BA7), and (1-BA8), ring D is preferably an unsubstituted benzene ring (bonded as 1,2-phenylene) or a 1,2-dimethylcyclohexane ring (bonded as a group resulting from the elimination of hydrogen atoms at positions 1 and 2; forming a structure represented by formula (A11)). Each ^Rd is preferably independently hydrogen or an unsubstituted alkyl having 1 to 6 carbon atoms.

From another perspective, preferred examples include compounds having the following structures:

In each of the structural formulas above, the hydrogen atoms bonded to the benzene ring may be replaced by methyl, t-butyl, diphenylamino, or phenyl, and the hydrogen atoms bonded to adjacent carbon atoms on the benzene ring may be replaced by the partial structure represented by formula (B). Furthermore, the hydrogen atoms of the diphenylamino and phenyl may be replaced by methyl or t-butyl, and the two hydrogen atoms bonded to two adjacent carbon atoms may each be replaced by the partial structure represented by formula (B).

As the polycyclic aromatic compound of the present invention, when n is 0 in formula (2), preferred examples include formula (1-BA11), formula (1-BA12), formula (1-BA13), and formula (1-BA14).

In formula (1-BA11), formula (1-BA12), formula (1-BA13) and formula (1-BA14), Z is C(-R ^Z ) or N, R ^Z is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl, R is each independently an optionally substituted phenyl, R ² ' is hydrogen or alkyl having 1 to 6 carbon atoms,
In at least one benzene ring in the above structure, hydrogen atoms bonded to adjacent carbon atoms may be substituted with a partial structure represented by formula (B).

More specific examples of the polycyclic aromatic compounds of the present invention include compounds represented by the following structural formulas. In the structural formulas below, "D" represents deuterium, "Me" represents methyl, "tBu" represents t-butyl, "Ad" represents adamantyl, and "TMS" represents trimethylsilyl.

Polycyclic aromatic compounds having a structure consisting of one or more structural units represented by formula (1) can be used as materials for organic devices, such as materials for organic electroluminescent elements, organic field-effect transistors, and organic thin-film solar cells, in the form of polymer compounds obtained by polymerizing reactive compounds substituted with reactive substituents as monomers (the monomers used to obtain these polymer compounds have polymerizable substituents), or crosslinked polymers obtained by further crosslinking these polymer compounds (the polymer compounds used to obtain these crosslinked polymers have crosslinkable substituents), or pendant polymer compounds obtained by reacting a main-chain polymer with the reactive compound (the reactive compound used to obtain this pendant polymer compound has reactive substituents), or pendant crosslinked polymers obtained by further crosslinking these pendant polymer compounds (the pendant polymer compounds used to obtain this pendant crosslinked polymers have crosslinkable substituents).

The reactive substituents mentioned above (including the polymerizable substituents, the crosslinkable substituents, and 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 pendantly reacting with the main-chain polymer, but examples include unsaturated alkenyl, alkynyl, and cycloalkyl (e.g., cyclobutenyl), groups in which at least one -CH ₂ - in cycloalkyl is replaced with -O- (e.g., epoxy), and unsaturated condensed cycloalkanes (e.g., condensed cyclobutene), and substituents having the following structures are preferred: * in each structural formula indicates a bonding position.

Each L is independently a single bond, -O-, -S-, >C=O, -O-C(=O)-, alkylene having 1 to 12 carbon atoms, oxyalkylene having 1 to 12 carbon atoms, or 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 Compounds Polycyclic aromatic compounds having a structure consisting of one or more structural units represented by formula (1) are basically produced by first bonding ring A (ring a), ring B (ring b), and R ^XC (ring C, ring c) with a bonding group (a group containing ^X1 or ^X2 ) to produce an intermediate (first reaction), and then bonding ring A (ring a), ring B (ring b), and ring C (ring c) with a bonding group (a group containing ^Y1 ) to produce a final product (second reaction). In the first reaction, for example, a common reaction such as a nucleophilic substitution reaction or an Ullmann reaction can be used for an etherification reaction, and a common reaction such as a Buchwald-Hartwig reaction can be used for an amination reaction. Furthermore, in the second reaction, a tandem hetero-Friedel-Crafts reaction (sequential aromatic electrophilic substitution reaction, the same applies hereinafter) can be used. For these production methods, reference can be made to methods described in prior art documents such as International Publication No. WO 2015/102118. A compound having a partial structure represented by formula (A) can be produced by using a raw material having a partial structure represented by formula (A) somewhere in the reaction process or by adding a step of introducing a partial structure represented by formula (A).

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 Electroluminescent Device The organic EL device according to this embodiment will now be described in detail with reference to the drawings. Figure 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, to have 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, an emissive layer 105 provided on the electron transport layer 106, a hole transport layer 104 provided on the emissive 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; the minimum structural unit is the anode 102, light-emitting layer 105, and cathode 108, with the hole injection layer 103, hole transport layer 104, electron transport layer 106, and electron injection layer 107 being optional layers. Each of the above layers may consist of a single layer or multiple layers. In this specification, the layers that make up an organic EL element, such as the light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer, may be referred to as organic layers.

The layers constituting an organic EL element may be configured in the above-mentioned "substrate/anode/hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode" configuration, as well as "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/hole transport layer/light-emitting layer/electron injection layer/cathode," "substrate/anode/hole injection layer/hole transport layer/light-emitting layer/electron injection layer/cathode," or "substrate/anode/hole injection layer/hole transport layer/light-emitting layer/electron transport" configuration. The configurations 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 injection layer/light-emitting layer/electron injection 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", or "substrate/anode/light-emitting layer/electron injection layer/cathode".

3-1-2. Substrate in Organic Electroluminescent Devices The substrate 101 is a support for the organic EL element 100 and is typically made of quartz, glass, metal, plastic, or the like. The substrate 101 is formed into a plate, film, or sheet shape depending on the purpose, and examples include glass plates, metal plates, metal foils, plastic films, and plastic sheets. Glass plates and plates made of transparent synthetic resins such as polyester, polymethacrylate, polycarbonate, and polysulfone are preferred. For glass substrates, soda-lime glass or alkali-free glass is used, and the thickness should be sufficient to maintain mechanical strength, e.g., 0.2 mm or more. The upper limit of the thickness is, for example, 2 mm or less, preferably 1 mm or less. Regarding the glass material, alkali-free glass is preferred because fewer ions are eluted from the glass. However, commercially available soda-lime glass coated with a barrier coating such as _SiO2 can also be used. Furthermore, in order to improve the gas barrier properties of the substrate 101, a gas barrier film such as a dense silicon oxide film may be provided on at least one side thereof, and it is particularly preferable to provide a gas barrier film when a synthetic resin plate, film or sheet with poor gas barrier properties is used as the substrate 101.

The anode 102 serves to inject holes into the light-emitting layer 105. If a hole injection layer 103 and/or a hole transport layer 104 is provided between the anode 102 and the light-emitting layer 105, holes are injected into the light-emitting layer 105 via these layers.

Materials for forming the anode 102 include inorganic and organic compounds. Inorganic compounds include, for example, 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. Organic compounds include, for example, polythiophenes such as poly(3-methylthiophene), and conductive polymers such as polypyrrole and polyaniline. Other materials that can be appropriately selected from those used as anodes in organic EL elements can also be used.

The resistance of the transparent electrode is not limited as long as it can supply enough current to light the light-emitting element, but low resistance is desirable from the perspective 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 substrates of around 10 Ω/□ are now available, 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 depending on the resistance value, but it is usually between 50 and 300 nm.

3-1-4. Hole Injection Layer and Hole Transport Layer in Organic Electroluminescent Device The hole injection layer 103 serves to efficiently inject holes migrating from the anode 102 into the light-emitting layer 105 or the hole transport layer 104. The hole transport layer 104 serves to efficiently transport holes injected from the anode 102 or holes injected from the anode 102 via 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 or mixing one or more hole injection/transport materials, or by a mixture of a hole injection/transport material and a polymer binder. Alternatively, an inorganic salt such as iron (III) chloride may be added to the hole injection/transport material to form a layer.

A 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. It is desirable for the material to have high hole injection efficiency and efficiently transport the injected holes. To achieve this, it is preferable for the material to have a low ionization potential, high hole mobility, excellent stability, and a low tendency for impurities that can become traps to be generated during manufacturing and use.

As materials 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 thereof 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 group 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 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]- Examples of suitable polymers include triphenylamine derivatives such as 4-amine, starburst amine derivatives, 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), heterocyclic compounds such as porphyrin derivatives, and polysilanes. Among polymers, polycarbonates and styrene derivatives having the above-mentioned monomers in their side chains, polyvinylcarbazole, and polysilanes are preferred, but any compound is usable as long as it can form a thin film necessary for fabricating a light-emitting device, can inject holes from the anode, and can transport holes.

It is also known that the conductivity of organic semiconductors is strongly affected by doping. Organic semiconductor matrix materials consist of compounds with good electron-donating or electron-accepting properties. Strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are known for doping with electron-donating substances (see, for example, M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(22), 3202-3204 (1998) and J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73(6), 729-731 (1998)). These generate so-called holes through an electron transfer process in an electron-donating base material (hole-transporting material). The conductivity of the base material varies significantly depending on the number and mobility of the holes. Known examples of matrix materials with hole-transporting properties include benzidine derivatives (such as TPD) or starburst amine derivatives (such as TDATA), as well as certain metal phthalocyanines (e.g., 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 polymer compounds 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. Regarding the reactive substituent in this case, the same explanation as for the polycyclic aromatic compound represented by formula (1) can be cited.
The uses of such polymer compounds and crosslinked polymers will be described in detail below.

3-1-5. Light-Emitting Layer in Organic Electroluminescent Device The light-emitting layer 105 is a layer that 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 that forms the light-emitting layer 105 may be a compound that emits light upon excitation by the recombination of holes and electrons (light-emitting compound), and is preferably a compound that can be formed into a stable thin film and exhibits strong light-emitting (fluorescence) efficiency in the solid state. In the present invention, the material for the light-emitting layer can be a host material and, for example, a polycyclic aromatic compound represented by formula (1) as a dopant material.

The light-emitting layer may consist of a single layer or multiple layers, each formed from light-emitting layer materials (host material, dopant material). The host material and dopant material may each be one type, or a combination of multiple types. The dopant material may be contained entirely or partially in the host material. As a doping method, the dopant material can be formed by co-evaporation with the host material, but it can also be mixed with the host material in advance and then vapor-deposited simultaneously.

The amount of host material used varies depending on the type of host material and can be determined based on the characteristics of the host material. The recommended amount of 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 materials.

The amount of dopant material used varies depending on the type of dopant material and can be determined based on the properties of the dopant material. The recommended 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, for example, because they can prevent concentration quenching. Furthermore, from the perspective of durability, it is also preferable that some or all of the hydrogen atoms in the dopant material are deuterated.

Examples of host materials include fused ring derivatives such as anthracene, pyrene, dibenzochrysene, and fluorene, which have long been known as light emitters; bisstyryl derivatives such as bisstyryl anthracene derivatives and distyrylbenzene derivatives; tetraphenylbutadiene derivatives; cyclopentadiene derivatives; and carbazole compounds such as 3,3'-di(9H-carbazol-9-yl)-1,1'-biphenyl. Anthracene-based compounds, fluorene-based compounds, dibenzochrysene-based compounds, and carbazole compounds are preferred, with anthracene-based compounds and carbazole compounds being more preferred. Furthermore, from the perspective of durability, it is also preferable for some or all of the hydrogen atoms in the host material to be deuterated. Furthermore, it is also preferable to form an emitting layer by combining a host compound in which some or all of the hydrogen atoms have been deuterated with a dopant compound in which some or all of the hydrogen atoms have been deuterated.

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 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 the injection and transport of electrons from the cathode. It is desirable for the electron injection/transport layer to have high electron injection efficiency and efficiently transport the injected electrons. To achieve this, it is preferable for the material to have high electron affinity, high electron mobility, and excellent stability, and to be less likely to generate impurities that act as traps during manufacture and use. However, when considering the balance between hole and electron transport, if a material's primary function is to efficiently block holes from the anode from flowing toward the cathode without recombining, then even if its electron transport capacity is not that high, it can still have the same effect of improving luminous efficiency as a material with high electron transport capacity. Therefore, the electron injection/transport layer in this embodiment may also function as a layer that can efficiently block the movement of holes.

The material (electron transport material) forming the electron transport layer 106 or the electron injection layer 107 can be selected from compounds conventionally used as electron transport compounds in photoconductive materials and known compounds used in the electron injection layers and electron transport layers of organic EL devices.

Materials used in the electron transport layer or electron injection layer preferably contain at least one selected from compounds consisting of aromatic or heteroaromatic rings composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus; pyrrole derivatives and their fused ring derivatives; and metal complexes having electron-accepting nitrogen. Specific examples include fused ring aromatic derivatives such as naphthalene and anthracene; styryl aromatic 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. Metal complexes having electron-accepting nitrogen include, for example, 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 other materials.

Specific examples of other electron transfer 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, and 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 atom 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 materials mentioned above, 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.

<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, and 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 fewer carbon atoms, substituted boryl, or optionally substituted carbazolyl, and each n represents independently an integer of 0 to 3. In addition, 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 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 an optionally substituted alkyl, optionally substituted cycloalkyl, or optionally substituted aryl, R ²¹ and R ²² each independently represent 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 independently an integer of 0 to 3, and m is independently an integer of 0 to 4. In addition, examples of the substituent in the case of being "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, and 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.

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 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).

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 of the following formulas (Py-1) to (Py-15) (in the formulas, * represents the bonding position), and each pyridine-based substituent may be independently substituted with alkyl having 1 to 4 carbon atoms or 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. Furthermore, the pyridine-based substituent may be bonded to the φ, anthracene ring, or fluorene ring in each formula via a phenylene group or naphthylene group.

The pyridine-based substituent is any one of formulas (Py-1) to (Py-15) (in the formulas, * represents a bonding position), and among these, any one of formulas (Py-21) to (Py-44) below is preferred.

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

The "alkyl" in R ¹¹ to R ¹⁸ may be either a straight chain or a branched chain, and examples thereof include a straight chain alkyl having 1 to 24 carbon atoms or a branched chain alkyl having 3 to 24 carbon atoms. A preferred "alkyl" is an alkyl having 1 to 18 carbon atoms (a branched chain alkyl having 3 to 18 carbon atoms). A more preferred "alkyl" is an alkyl having 1 to 12 carbon atoms (a branched chain alkyl having 3 to 12 carbon atoms). An even more preferred "alkyl" is an alkyl having 1 to 6 carbon atoms (a branched chain alkyl having 3 to 6 carbon atoms). A particularly preferred "alkyl" is an alkyl having 1 to 4 carbon atoms (a branched chain 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 may be substituted on the pyridine-based substituent.

The "cycloalkyl" in R ¹¹ to R ¹⁸ 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 for the "aryl" in R ¹¹ to R ¹⁸ , the aryl is preferably an aryl having 6 to 30 carbon atoms, more preferably an aryl having 6 to 18 carbon atoms, still more preferably an aryl having 6 to 14 carbon atoms, and particularly preferably 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 "aryl having 6 to 30 carbon atoms" include phenyl, naphthyl, phenanthryl, chrysenyl, and triphenylenyl, with phenyl, 1-naphthyl, 2-naphthyl, and phenanthryl being more preferred, and phenyl, 1-naphthyl, and 2-naphthyl being particularly preferred.

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 represent hydrogen, halogen, linear, branched, or cyclic alkyl, linear, branched, or cyclic alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl. In the case of substitution, examples of the substituent include aryl, heteroaryl, alkyl, and cycloalkyl.

Specific examples of the fluoranthene derivative include the following compounds:

<BO-based derivatives>
The BO derivative is, for example, a polycyclic aromatic compound represented by the following formula (ETM-4), or a multimer 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, and at least one hydrogen atom in these may be substituted with 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 ring a, ring b, or ring c, and at least one hydrogen atom in the formed ring may be substituted with aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy, and at least one hydrogen atom in these rings may be substituted with aryl, heteroaryl, alkyl, or cycloalkyl.

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

For an explanation of the substituents and ring formation form in formula (ETM-4), the explanation of polycyclic aromatic compounds represented by formula (1) etc. 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, a divalent benzene, a divalent naphthalene, anthracene, a divalent fluorene, or a divalent 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), and (o-, m-, p-)cumenyl, bicyclic aryls such as (2-, 3-, 4-)biphenylyl, fused bicyclic aryls such as (1-, 2-)naphthyl, and 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'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4'-yl, p-terphenyl-2-yl, m-terphenyl-2'-yl, m-terphenyl-3-yl, m-terphenyl-4'-yl, p-terphenyl-2'-yl, m-terphenyl-3'-yl, m-terphenyl-4'-yl, p-terphenyl-2'-yl, m ... 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 such as 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 such as triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, tetracene-(1-, 2-, 5-)yl, and fused pentacyclic aryls such as perylene-(1-, 2-, 3-)yl. Specific examples of "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 linear or branched. That is, it is a linear alkyl having 1 to 6 carbon atoms or a branched alkyl having 3 to 6 carbon atoms. It is more preferably an alkyl having 1 to 4 carbon atoms (branched 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. 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.

With regard to the aryl having 6 to 20 carbon atoms in R ¹ to R ⁴ , 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 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 preferred, an aryl having 6 to 12 carbon atoms is more preferred, and an aryl having 6 to 10 carbon atoms is particularly preferred. Specific examples include phenyl, biphenylyl, naphthyl, terphenylyl, anthracenyl, acenaphthylenyl, fluorenyl, phenalenyl, phenanthryl, triphenylenyl, pyrenyl, tetracenyl, and perylenyl.

Each ^Ar2 is 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), and two ^Ar2s 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). A particularly 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, and 1-methylhexyl.

Examples of the "cycloalkyl" in ^Ar2 include 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 , preferred aryl is aryl having 6 to 30 carbon atoms, more preferred aryl is aryl having 6 to 18 carbon atoms, still more preferred aryl is aryl having 6 to 14 carbon atoms, and particularly preferred aryl is 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 ^Ar2s 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 having 1 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, aryl having 6 to 20 carbon atoms, or heteroaryl having 5 to 20 carbon atoms;
^R6 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 fused 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, there is no R ¹ .

Of these substituents, alkyl refers to saturated aliphatic hydrocarbon groups such as methyl, ethyl, propyl, and butyl, which may be substituted or unsubstituted. If substituted, there are no particular restrictions on the substituents, and examples include alkyl, aryl, and heterocyclic groups, as will be described below. Furthermore, the number of carbon atoms in the alkyl is not particularly limited, but is typically in the range of 1 to 20 due to availability and cost considerations.

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

Also, aralkyl refers to an aromatic hydrocarbon group connected via an aliphatic hydrocarbon such as benzyl or phenylethyl, and both the aliphatic hydrocarbon and the aromatic hydrocarbon may be substituted or unsubstituted. There are no particular restrictions on the number of carbon atoms in the aliphatic portion, but it 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 typically 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 substituted or unsubstituted.

Alkynyl refers to an unsaturated aliphatic hydrocarbon group containing a triple bond, such as acetylenyl, which may be substituted or unsubstituted. The number of carbon atoms in an alkynyl is not particularly limited, but is typically 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 typically in the range of 1 to 20.

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

Also, cycloalkylthio is a group in which the oxygen atom in the ether bond of 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 typically in the range of 6 to 40.

Also, an aryl thioether is a group in which the oxygen atom in 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, or pyrenyl. Aryl may be unsubstituted or substituted. The number of carbon atoms in aryl is not particularly limited, but is typically in the range of 6 to 40.

Heterocyclic groups refer to cyclic structural groups containing 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 a heterocyclic group is not particularly limited, but is typically 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.

Furthermore, 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 substituted or unsubstituted. The number of carbon atoms in the silyl is not particularly limited, but is typically in the range of 3 to 20. The number of silicon atoms is typically 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 together. These fused rings may contain a nitrogen, oxygen or sulfur atom in the ring structure, and may further 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 phenyl, which is a monocyclic aryl; (2-, 3-, 4-)biphenylyl, which is a bicyclic aryl; (1-, 2-)naphthyl, which is a fused bicyclic aryl; terphenylyl, which is a tricyclic aryl (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); and fused tricyclic aryl. Examples of aryls include acenaphthylene-(1-, 3-, 4-, 5-)yl, fluoren-(1-, 2-, 3-, 4-, 9-)yl, phenalene-(1-, 2-)yl, and (1-, 2-, 3-, 4-, 9-)phenanthryl; tetracyclic aryls include quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, and m-quaterphenylyl); fused tetracyclic aryls include triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, and naphthacene-(1-, 2-, 5-)yl; and fused pentacyclic aryls include perylene-(1-, 2-, 3-)yl and pentacene-(1-, 2-, 5-, 6-)yl.

Examples of the "heteroaryl" in "optionally substituted heteroaryl" include heteroaryls having 2 to 30 carbon atoms, preferably heteroaryls having 2 to 25 carbon atoms, more preferably heteroaryls having 2 to 20 carbon atoms, even more preferably heteroaryls having 2 to 15 carbon atoms, and particularly preferably heteroaryls having 2 to 10 carbon atoms. Furthermore, examples of heteroaryls 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 also 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.

<Arylnitrile 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 via single bonds, etc. Details are described in the specification of U.S. Application Publication No. 2014/0197386.

Ar _ni preferably has a large number of carbon atoms from the viewpoint of fast electron transport properties, and preferably has a small number of carbon atoms from the viewpoint of a high T1. Specifically, Ar _ni preferably has a high 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 a high T1, and is preferably small from the viewpoint of a high 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 or 2, and even more preferably 1.

Each Ar is independently an optionally substituted aryl or an optionally substituted heteroaryl. From the viewpoint of high S1 and high T1, donor heteroaryls are preferred, and since the compound is used as an electron transport layer, it is preferable to have fewer donor heteroaryls. From the viewpoint of charge transport properties, aryls or heteroaryls with a large number of carbon atoms are preferred, and it is preferable to have many substituents. The number of substitutions m on Ar is specifically an integer from 1 to 4, preferably an integer from 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 phenyl, which is a monocyclic aryl; (2-, 3-, 4-)biphenylyl, which is a bicyclic aryl; (1-, 2-)naphthyl, which is a fused bicyclic aryl; terphenylyl, which is a tricyclic aryl (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); and fused tricyclic aryl. Examples of aryls include acenaphthylene-(1-, 3-, 4-, 5-)yl, fluoren-(1-, 2-, 3-, 4-, 9-)yl, phenalene-(1-, 2-)yl, and (1-, 2-, 3-, 4-, 9-)phenanthryl; tetracyclic aryls include quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, and m-quaterphenylyl); fused tetracyclic aryls include triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, and naphthacene-(1-, 2-, 5-)yl; and fused pentacyclic aryls include perylene-(1-, 2-, 3-)yl and pentacene-(1-, 2-, 5-, 6-)yl.

Examples of the "heteroaryl" in "optionally substituted heteroaryl" include heteroaryls having 2 to 30 carbon atoms, preferably heteroaryls having 2 to 25 carbon atoms, more preferably heteroaryls having 2 to 20 carbon atoms, even more preferably heteroaryls having 2 to 15 carbon atoms, and particularly preferably heteroaryls having 2 to 10 carbon atoms. Furthermore, examples of heteroaryls 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 also be substituted, for example, by the above aryl or heteroaryl, respectively.

The aryl nitrile derivative may be a polymer in which multiple compounds represented by formula (ETM-9) are bonded together via single bonds or the like. In this case, in addition to single bonds, they may be bonded together via 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 phenyl, which is a monocyclic aryl; (2-, 3-, 4-)biphenylyl, which is a bicyclic aryl; (1-, 2-)naphthyl, which is a fused bicyclic aryl; terphenylyl, which is a tricyclic aryl (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); and fused tricyclic aryl. Examples of aryls include acenaphthylene-(1-, 3-, 4-, 5-)yl, fluoren-(1-, 2-, 3-, 4-, 9-)yl, phenalene-(1-, 2-)yl, and (1-, 2-, 3-, 4-, 9-)phenanthryl; tetracyclic aryls include quaterphenylyl (5'-phenyl-m-terphenyl-2-yl, 5'-phenyl-m-terphenyl-3-yl, 5'-phenyl-m-terphenyl-4-yl, and m-quaterphenylyl); fused tetracyclic aryls include triphenylene-(1-, 2-)yl, pyrene-(1-, 2-, 4-)yl, and naphthacene-(1-, 2-, 5-)yl; and fused pentacyclic aryls include perylene-(1-, 2-, 3-)yl and pentacene-(1-, 2-, 5-, 6-)yl.

Examples of the "heteroaryl" in "optionally substituted heteroaryl" include heteroaryls having 2 to 30 carbon atoms, preferably heteroaryls having 2 to 25 carbon atoms, more preferably heteroaryls having 2 to 20 carbon atoms, even more preferably heteroaryls having 2 to 15 carbon atoms, and particularly preferably heteroaryls having 2 to 10 carbon atoms. Furthermore, examples of heteroaryls 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 also 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 "benzimidazole-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 benzimidazolyl, 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 description of R ¹¹ in formulae (ETM-2-1) and (ETM-2-2) can be cited.

It is further preferable that φ is an anthracene ring or a fluorene ring, and in this case, the structure can be explained with reference to the explanation for formula (ETM-2-1) or formula (ETM-2-2), and R ¹¹ to R ¹⁸ in each formula can be explained with reference to the explanation for formula (ETM-2-1) or formula (ETM-2-2). Furthermore, in formula (ETM-2-1) or formula (ETM-2-2), two pyridine-based substituents are explained as being bonded together, 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-(naphthalen-2-yl)anthracen-9-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 2-(4-(9,10-di(naphthalen-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole, 1-(4-(9,10-di(naphthalen-2-yl)anthracen-2-yl)phenyl)-2-phenyl-1H-benzo[d]imidazole, 5-(9,10-di(naphthalen-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 atom in each phenanthroline derivative may be replaced with deuterium.

The alkyl, cycloalkyl, and aryl in R ¹¹ to R ¹⁸ can be determined from the explanations of R ¹¹ to R ¹⁸ in formula (ETM-2). In addition to the examples given above, φ can also have the following structural formula: In the structural formula below, 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 phenanthroline derivatives include 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 9,10-di(1,10-phenanthrolin-2-yl)anthracene, 2,6-di(1,10-phenanthrolin-5-yl)pyridine, 1,3,5-tri(1,10-phenanthrolin-5-yl)benzene, 9,9'-difluoro-bi(1,10-phenanthrolin-5-yl), bathocuproine, 1,3-bis(2-phenyl-1,10-phenanthrolin-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.

<Quinolinol-based 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 of 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)(2-phenylphenolate)aluminum linolinolate)(3-phenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(4-phenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,3-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,6-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(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 hydroxybenzoate) 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) 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 Examples include bis(2-methyl-5-cyano-8-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, and bis(10-hydroxybenzo[h]quinoline)beryllium.

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

<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 represents 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. A "thiazole-based substituent" or "benzothiazole-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 the thiazolyl or benzothiazolyl shown below, and at least one hydrogen atom in the thiazole derivative or benzothiazole derivative may be replaced with deuterium.

It is further preferable that φ is an anthracene ring or a fluorene ring, and in this case, the structure can be explained with reference to the explanation for formula (ETM-2-1) or formula (ETM-2-2), and for R ¹¹ to R ¹⁸ in each formula, the explanation for formula (ETM-2-1) or formula (ETM-2-2) can be explained with reference to the explanation for formula (ETM-2-1) or formula (ETM-2-2). Furthermore, in formula (ETM-2-1) or formula (ETM-2-2), two pyridine-based substituents are explained as being bonded together, 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), and the "pyridine-based substituent" may be replaced 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 alkyl, cycloalkyl, alkenyl, alkynyl, alkoxy, alkenyloxy, alkynyloxy, aryl, or heteroaryl, which may be substituted. For details of these groups, the explanations for formula (1) and formula (2) and the explanation for formula (ETM-7-2) can be cited. Furthermore, alkenyloxy and alkynyloxy are groups in which the alkyl moiety in alkoxy is replaced with alkenyl or alkynyl, respectively, and for details of these alkenyls and alkynyls, the explanation for 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 explanations in formula (1) and formula (2) can be cited.

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 (1) and formula (2) can be cited.

Examples of silyl include silyl groups and groups in which at least one of the three hydrogen atoms of a 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 about the aryl, alkyl, and cycloalkyl groups, see the explanations for formulas (1) and (2).

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, or may be fused with another ring.

However, preferably, when ^R1 and ^R4 are phenyl, X and Y are not alkyl or phenyl. Also, preferably, when ^R1 and ^R4 are thienyl, X and Y are alkyl, and ^R2 and ^R3 are not alkyl, aryl, alkenyl, or cycloalkyl where ^R2 and ^R3 are bonded to form a ring. Also, preferably, when ^R1 and ^R4 are silyl groups, ^R2 , ^R3 , X, and Y are not each independently hydrogen or alkyl having 1 to 6 carbon atoms. Also, preferably, when a benzene ring is fused with ^R1 and ^R2 , 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 with alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, aryl having 6 to 18 carbon atoms, or 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 atom 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 bonding to L,
L's are each 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 each independently represent ═CR ⁶ — or ═N—, at least two of X ¹ to X ⁶ represent ═CR ⁶ —, R 6 in two of X ¹ to X ⁶ representing ═CR ⁶ — represents φ or a bonding site to an azoline ring, ^{and R 6 in} the remaining ═CR ⁶ — represents hydrogen;
In formula (L-2), X ⁷ to X ¹⁴ each independently represent ═CR ⁶ — or ═N—, at least two of X ⁷ to X ¹⁴ represent ═CR ⁶ —, R ⁶ in two of X ⁷ to X ¹⁴ represent φ or a bonding site to an azoline ring, ^{and R 6 in the remaining ═CR 6 —} represents hydrogen;
At least one hydrogen atom in L may be substituted with 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 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 with alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, aryl having 6 to 18 carbon atoms, or 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 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;
In formula (ETM-16-1), R ¹ to R ⁴ 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-16-2), 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),
L's are each 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 each independently represent ═CR ⁶ — or ═N—, at least two of X ¹ to X ⁶ represent ═CR ⁶ —, R 6 in two of X ¹ to X ⁶ representing ═CR ⁶ — represents φ or a bonding site to an azoline ring, ^{and R 6 in} the remaining ═CR ⁶ — represents hydrogen;
In formula (L-2), X ⁷ to X ¹⁴ each independently represent ═CR ⁶ — or ═N—, at least two of X ⁷ to X ¹⁴ represent ═CR ⁶ —, R ⁶ in two of X ⁷ to X ¹⁴ represent φ or a bonding site to an azoline ring, ^{and R 6 in the remaining ═CR 6 —} represents hydrogen;
At least one hydrogen atom in L may be substituted with 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 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 atom in φ may be substituted with alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, aryl having 6 to 18 carbon atoms, or 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 alkyl having 1 to 4 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, aryl having 6 to 12 carbon atoms or 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 aryl having 6 to 12 carbon atoms or 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 atom in L may be substituted with an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a heteroaryl group 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 atom in 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, provided that R ¹ and R ² are the same, R ³ and R ⁴ are the same, 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 atom in 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 atom of L is optionally substituted with 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 atom of 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 azoline derivatives include the following compounds: In the structural formula, "Me" represents methyl.

For details about the alkyl, cycloalkyl, aryl, or heteroaryl in the above formulas defining this azoline derivative, please refer to the explanations for formulas (1) and (2).

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

<Reducing Substances>
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. Various substances can be used as this reducing substance as long as they have a certain level of reducing ability. For example, at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, alkali metal oxides, alkali metal halides, alkaline earth metal oxides, alkaline earth metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes, and rare earth metal organic complexes 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). Substances with a work function of 2.9 eV or less are particularly preferred. Among these, alkali metals K, Rb, or Cs are more preferred, with Rb or Cs being even more preferred, and Cs being the most preferred. These alkali metals have particularly high reducing power, and adding relatively small amounts to the materials forming the electron transport layer or electron injection layer can improve the luminance and extend the life of organic EL devices. Combinations of two or more of these alkali metals are also preferred as reducing substances with a work function of 2.9 eV or less, and combinations containing Cs, such as Cs and Na, Cs and K, Cs and Rb, or Cs, Na and K, are particularly preferred. By including Cs, the reducing ability can be efficiently exerted, and adding it to the material that forms the electron transport layer or electron injection layer can improve the luminance and extend the life of the organic EL element.

The above-mentioned electron injection layer material and electron transport layer material can also be used as electron layer materials in the form of polymer compounds 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. Regarding the reactive substituent in this case, the same explanation as for the polycyclic aromatic compound represented by formula (1) can be cited.
The uses of such polymer compounds and crosslinked polymers will be described in detail below.

3-1-7. Cathode in Organic Electroluminescent Device The cathode 108 serves to inject electrons into the light-emitting layer 105 via the electron injection layer 107 and the electron transport layer 106 .

The material for the cathode 108 is not particularly limited as long as it can efficiently inject electrons into the organic layer, but the same materials as those for the anode 102 can be used. Among these, metals such as tin, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium, and magnesium, or alloys thereof (e.g., magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys such as lithium fluoride/aluminum alloys), are preferred. To increase electron injection efficiency and improve device performance, 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 address this issue, a known method is to dope the organic layer with trace amounts of lithium, cesium, or magnesium to create a highly stable electrode. Other dopants that can be used include, but are not limited to, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide.

Furthermore, for electrode protection, 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. There are no particular restrictions on the method for producing these electrodes, as long as electrical conductivity can be achieved, and methods such as resistance heating, electron beam evaporation, sputtering, ion plating, and coating can be used.

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 be used alone to form each layer, but they can also be used as a polymer binder by being dispersed in a solvent-soluble resin such as polyvinyl chloride, polycarbonate, polystyrene, poly(N-vinylcarbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate resin, ABS resin, or polyurethane resin, or a curable resin such as phenol resin, xylene resin, petroleum resin, urea resin, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, or silicone resin.

3-1-9. Method for Fabricating Organic Electroluminescent Devices Each layer constituting an organic EL device can be formed by forming the materials constituting each layer into a thin film using methods such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination, printing, spin coating, casting, and coating. The thickness of each layer thus formed is not particularly limited and can be set appropriately depending on the properties of the material, but is typically in the range of 2 nm to 5,000 nm. The film thickness can typically be measured using a quartz crystal oscillator film thickness measuring device. When forming a thin film using a vapor deposition method, the vapor deposition conditions vary depending on the type of material, the desired crystal structure and association structure of the film, and other factors. The vapor deposition conditions are generally preferably set appropriately within the following range: boat heating temperature +50 to +400°C, vacuum level 10 ⁻⁶ to 10 ⁻³ Pa, vapor deposition rate 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 + polarity and the cathode to - polarity. When a voltage of approximately 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 pulse current or AC current is applied. The AC waveform applied can be any waveform.

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

<Vapor deposition method>
A thin film of an anode material is formed on a suitable substrate by vapor deposition or the like to form an anode, and then thin films of a hole injection layer and a hole transport layer are formed on the anode. A host material and a dopant material are co-deposited on the anode to form a thin film to form an emissive layer. An electron transport layer and an electron injection layer are formed on the emissive layer, and a thin film of a cathode material is further formed by vapor deposition or the like to form a cathode, thereby obtaining the desired organic EL device. It is also possible to reverse the order of fabrication of the above-described organic EL device, forming the layers in the order of cathode, electron injection layer, electron transport layer, emissive layer, hole transport layer, hole injection layer, and anode.

<Wet film formation method>
The wet film formation method is carried out by preparing a liquid organic layer-forming composition from a low molecular weight compound capable of forming each organic layer of an organic EL element, and using this. If there is no suitable organic solvent that can dissolve this low molecular weight compound, the organic layer-forming composition may be prepared from a reactive compound obtained by substituting a reactive substituent on the low molecular weight compound, such as another monomer having a solubility function as a reactive compound or a polymer compound polymerized together with a main-chain polymer.

Wet film formation methods generally form a coating film through a coating step in which an organic layer-forming composition is applied to a substrate, followed by a drying step in which the solvent is removed from the applied organic layer-forming composition. If the polymer compound has a crosslinkable substituent (also known as a crosslinkable polymer compound), the drying step causes further crosslinking to form a crosslinked polymer. Depending on the coating process, methods using a spin coater are called spin coating methods; methods using a slit coater are called slit coating methods; methods using a plate are called gravure, offset, reverse offset, or flexographic printing methods; methods using an inkjet printer are called inkjet methods; and methods spraying in a mist are called spray methods.

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

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

Wet film formation methods are film formation methods that use solutions, and include some printing methods (inkjet methods), spin coating 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.

However, compared to vacuum deposition, wet deposition can be difficult to use for layering. When using wet deposition to create layered films, it is necessary to prevent the dissolution of the lower layer by the composition of the upper layer, and this requires the use of compositions with controlled solubility, crosslinking of the lower layer, and orthogonal solvents (solvents that are not soluble in each other). However, even with these techniques, it can be difficult to use wet deposition for applying all films.

Therefore, a common method for producing organic EL elements is to use wet film formation 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-forming 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 composed of a host material and a dopant material/electron transport layer/electron injection layer/cathode is obtained.
Of course, if there is a means for preventing dissolution of the underlying light-emitting layer, or if a means for forming a film from the cathode side in the reverse of the above procedure is used, a layer-forming composition containing a material for the electron transport layer and a material for the electron injection layer can be prepared, and the layer can be formed by a wet film-forming method.

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

<Optional step>
Before and after each film-forming step, appropriate treatment steps, cleaning steps, and drying steps may be added as appropriate. 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 create banks. Positive and negative resist materials can be used as bank materials for photolithography. Patternable printing methods such as inkjet printing, gravure offset printing, reverse offset printing, and screen printing can also be used. In these cases, permanent resist materials can also be used.

Materials that can be used for banks 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, polyacetate, polynorbornene, synthetic rubbers, fluorinated polymers such as polyfluorovinylidene, polytetrafluoroethylene, and polyhexafluoropropylene, fluoroolefin-hydrocarbonolefin copolymers, and fluorocarbon polymers.

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

<Organic solvent>
The organic layer-forming composition 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 film-forming properties, the presence or absence of defects in the coating film, surface roughness, and smoothness. Furthermore, during film formation using an inkjet method, it is possible to control meniscus stability at the pinhole of the inkjet head, thereby controlling and improving 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 lifespan of an organic EL device having an organic layer obtained from the organic layer-forming composition.

(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. A boiling point higher than 130°C is preferred from the viewpoint of inkjet ejection properties. Furthermore, a boiling point lower than 300°C is preferred from the viewpoints of coating film defects, surface roughness, residual solvent, and smoothness. From the viewpoints of good inkjet ejection properties, film-forming properties, smoothness, and low residual solvent, it is more preferred that the organic solvent contains two or more organic solvents. Meanwhile, in some cases, taking into consideration transportability, etc., the composition may be a solid composition obtained by removing the solvent from the organic layer-forming composition.

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 high-boiling poor solvent, the low-boiling good solvent evaporates first during film formation, increasing the concentration of the ingredients in the composition and the concentration of the poor solvent, facilitating rapid film formation. This results in a coating with few defects, minimal 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 film formation, the organic solvent is removed from the coating film through a drying process using vacuum, reduced pressure, heating, or other methods. When heating, from the perspective of improving coating film formation, it is preferable to perform the heating at a temperature below the glass transition temperature (Tg) of at least one of the solutes +30°C. Furthermore, from the perspective of reducing residual solvent, it is preferable to heat at a temperature above the glass transition temperature (Tg) of at least one of the solutes -30°C. Even if the heating temperature is lower than the boiling point of the organic solvent, the film is thin enough that the organic solvent is sufficiently removed. Furthermore, drying may be performed multiple times at different temperatures, or 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, propylene ... 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. The solvents may be used alone or in combination.

<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 organic layer-forming composition 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 organic layer-forming composition.

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 a single type or a mixture of multiple types.

(2) Surfactants 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 their hydrophilic group, and further classified into alkyl, silicone, and fluorine-based based on the structure of their hydrophobic group. Furthermore, based on their molecular structure, they are classified into monomolecular systems with relatively small and simple molecular weights and polymer systems with large molecular weights and side chains or branches. Based on their composition, they are classified into single systems and mixed systems containing two or more surfactants and base materials. All types of surfactants 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, and B YK344, BYK346 (trade names, manufactured by BYK Japan Co., Ltd.), KP-341, KP-358, KP-368, KF-96-50CS, KF-50-100CS (trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), Surflon SC-101, Surflon KH-40 (trade names, manufactured by Seimi Chemical Co., Ltd.), Ftergent 222F, Ftergent 251, FTX-218 (trade names, manufactured by Neos Co., Ltd.), EFTOP EF-351, EFTOP EF-352, EFTOP EF-601, EFTOP EF-801, EFTOP EF-802 (trade 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 (trade name, manufactured by DIC Corporation), fluoroalkylbenzene sulfonate, fluoroalkyl carboxylate, fluoroalkyl polyoxyethylene ether, fluoroalkyl ammonium iodide, fluoroalkyl betaine, fluoroalkyl sulfonate, diglycerin tetrakis (fluoroalkyl polyoxyethylene ether), fluoroalkyl trimethyl ammonium salt, fluoroalkyl amino sulfonate, polyoxyethylene nonyl Examples of such alkyl ethers include phenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene laurate, polyoxyethylene oleate, polyoxyethylene stearate, polyoxyethylene laurylamine, sorbitan laurate, sorbitan palmitate, sorbitan stearate, sorbitan oleate, sorbitan fatty acid esters, polyoxyethylene sorbitan laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan oleate, polyoxyethylene naphthyl ether, alkyl benzene sulfonates, and alkyl diphenyl ether disulfonates.

Furthermore, surfactants may be used alone or in combination of 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 taking into consideration the good solubility, storage stability, and film-forming ability of each component in the composition for forming an organic layer, the good film quality of a coating film obtained from the composition for forming an organic layer, the good dischargeability when using an inkjet method, and the good electrical properties, light-emitting properties, efficiency, and life of an organic EL device 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 be 0.0001% by mass to 2.0% by mass, the second component be 0.0999% by mass to 8.0% by mass, and the third component be 90.0% by mass to 99.9% by mass, relative to the total mass of the composition for forming an emitting layer.

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

The organic layer-forming composition can be produced by appropriately selecting and performing known processes such as stirring, mixing, heating, cooling, dissolving, and dispersing the above-mentioned components. After preparation, the composition may also be subjected to appropriately selected processes such as filtration, degassing, ion exchange, and inert gas replacement/filling.

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

The lower the surface tension of the organic layer-forming composition, 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 inkjet ejection properties. For this reason, the surface tension of the organic layer-forming composition at 25°C is preferably 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), each MUx independently represents a divalent group obtained by removing two hydrogen atoms from any aromatic compound, each ECx independently represents a monovalent group obtained by removing one hydrogen atom from any aromatic compound, and k is an integer from 2 to 50,000. For details about MUx, ECx, and k, please refer to the descriptions of MU, EC, and k in formula (SPH-1) in paragraphs 0269 to 0285 of WO 2020/162600. However, 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% by mass in the molecule.

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

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 bonding position.

Each L is independently a single bond, -O-, -S-, >C=O, -O-C(=O)-, alkylene having 1 to 12 carbon atoms, oxyalkylene having 1 to 12 carbon atoms, or 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:

<Methods of producing polymer compounds and crosslinkable polymer compounds>
The methods for producing the polymer compound and the crosslinkable polymer compound will be described below using the compound represented by the formula (XLP-1) as an example. 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 (XLP-1) may be produced in a single step or multiple steps. Furthermore, it may be produced by a bulk polymerization method in which all raw materials are placed in a reaction vessel and the reaction is initiated; a dropwise polymerization method in which raw materials are added dropwise to a reaction vessel; or a precipitation polymerization method in which the product precipitates as the reaction progresses. These methods can be combined as appropriate. For example, when synthesizing a compound of formula (XLP-1) in a single step, the target product is obtained by adding a monomer having a polymerizable group bonded to the monomer unit (MUx) and a monomer having a polymerizable group bonded to the end-capping unit (ECx) to a reaction vessel and then reacting them. Furthermore, when synthesizing a compound of formula (XLP-1) in multiple steps, the target product is obtained by polymerizing a monomer having a polymerizable group bonded to the monomer unit (MUx) to the target molecular weight, and then adding a monomer having a polymerizable group bonded to the end-capping unit (ECx) and reacting them. By adding monomers with polymerizable groups bonded to different types of monomer units (MUx) in multiple stages and carrying out the reaction, it is possible to create polymers with a concentration gradient in the monomer unit structure. Furthermore, after preparing the 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 polymers with random primary structures (Synthetic Scheme 1) and polymers with regular primary structures (Synthetic Schemes 2 and 3), and these can be combined appropriately depending on the intended purpose. Furthermore, by using a monomer with three or more polymerizable groups, it is possible to synthesize hyperbranched polymers and dendrimers.

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 Japanese Patent Application Laid-Open No. 2002/045184, Japanese Patent Application Laid-Open No. 2010-215886, Japanese Patent Application Laid-Open No. 2008-106241, Japanese Patent Application Laid-Open No. 2010-215886, International Publication No. 2016/031639, Japanese Patent Application Laid-Open No. 2011-174062, International Publication No. 2016/031639, Japanese Patent Application Laid-Open No. 2016/031639, and Japanese Patent Application Laid-Open No. 2002/045184.

For specific polymer synthesis procedures, see 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 Nos. 031639, 2016/125560, 2016/031639, 2016/031639, 2016/125560, 2015/145871, 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 equipped with organic EL devices or lighting devices equipped with 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 10-335066 A, JP 2003-321546 A, and JP 2004-281086 A). Display methods include, for example, matrix and/or segment methods. Note that matrix display and segment display may coexist on the same panel.

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

In the segment type, 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 and backlights for liquid crystal display devices (see, for example, JP 2003-257621 A, JP 2003-277741 A, and JP 2004-119211 A). Backlights are primarily used to improve the visibility of non-self-luminous display devices, and are used in liquid crystal display devices, clocks, audio equipment, automotive panels, display boards, signs, and the like. In particular, backlights for liquid crystal display devices, particularly those used in personal computers where thinning is an issue, are difficult to achieve because conventional systems use fluorescent lamps and light guide plates. Therefore, backlights using the light-emitting elements of 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 to produce 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 using an electric field generated by voltage input. In addition to source and drain electrodes, it has a gate 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 and drain electrodes can be blocked at will, allowing current to be controlled. Field-effect transistors are easier to miniaturize than simple transistors (bipolar transistors), and are often used as elements in integrated circuits.

The organic field-effect transistor generally has a structure in which 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 device structure include the following structures.
(1) Substrate/gate electrode/insulating layer/source electrode/drain electrode/organic semiconductor active layer (2) Substrate/gate electrode/insulating layer/organic semiconductor active layer/source electrode/drain electrode (3) Substrate/organic semiconductor active layer/source electrode/drain electrode/insulating layer/gate electrode (4) Substrate/source electrode/drain electrode/organic semiconductor active layer/insulating layer/gate electrode An organic field effect transistor configured in this manner can be used as a pixel driving switching element for active matrix driven 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 layered 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 of the present invention can be used as a material for the hole transport layer, p-type semiconductor layer, n-type semiconductor layer, or electron transport layer, depending on its physical properties. The polycyclic aromatic compound of the present invention can function as a hole transport material or electron transport material in an organic thin-film solar cell. In addition to the above, the organic thin-film solar cell may also include a hole blocking layer, electron blocking layer, electron injection layer, hole injection layer, smoothing layer, etc. as appropriate. Known materials used in organic thin-film solar cells can be selected and combined as appropriate for use in the organic thin-film solar cell.

The present invention will be explained in more detail below using examples, but the present invention is not limited to these. First, an example of the synthesis of a polycyclic aromatic compound will be described below.

Synthesis Example (1)
Synthesis Example (1): Synthesis of Compound (1-363)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-1) (10.2 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) (manufactured by Nippon Alcohol Sales Co., Ltd.) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-363) (3.0 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₆₄ H ₇₈ BN ₃ : 899.629

Synthesis Example (2): Synthesis of Compound (1-370)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-2) (12.4 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-370) (3.4 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₇₈ H ₉₅ BN ₄ : 1098.765

Synthesis Example (3): Synthesis of Compound (1-383)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-3) (10.8 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-383) (2.6 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₆₆ H ₇₈ BN ₃ S: 955.601

Synthesis Example (4): Synthesis of Compound (1-517)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-4) (9.3 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-517) (2.6 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₅₈ H ₇₂ BN ₃ : 821.582

Synthesis Example (5): Synthesis of Compound (1-532)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-5) (10.1 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-532) (1.2 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₆₃ H ₇₃ BN ₄ : 896.593

Synthesis Example (6): Synthesis of Compound (1-544)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-6) (9.3 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-544) (0.9 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₅₇ H ₆₇ BN ₄ : 818.546

Synthesis Example (7): Synthesis of Compound (1-551)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-7) (10.2 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-551) (2.3 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₆₄ H ₈₀ BN ₃ : 901.645

Synthesis Example (8): Synthesis of Compound (1-555)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-8) (9.3 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-555) (2.1 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₅₈ H ₇₄ BN ₃ : 823.598

Synthesis Example (9): Synthesis of Compound (1-221)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-9) (9.3 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-221) (2.0 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₅₈ H ₇₀ BN ₃ : 819.566

Synthesis Example (10): Synthesis of Compound (1-222)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-10) (9.3 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and an aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-222) (2.2 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₅₈ H ₇₀ BN ₃ : 819.566

Synthesis Example (11): Synthesis of Compound (1-241)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-11) (9.5 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-241) (2.1 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₆₀ H ₆₈ BN ₃ : 841.551

Synthesis Example (12): Synthesis of Compound (1-402)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-12) (9.6 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-402) (2.4 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₆₁ H ₇₀ BN ₃ : 855.566

Synthesis Example (13): Synthesis of Compound (1-518)

A 1.53 M tert-butyllithium pentane solution (15.2 ml) was added to a flask containing intermediate (I-13) (9.9 g) and tert-butylbenzene (80 ml) under a nitrogen atmosphere at 0°C. After the dropwise addition was complete, the temperature was raised to 60°C and stirred for 0.5 hours, after which components with a boiling point lower than that of tert-butylbenzene were distilled off under reduced pressure. The mixture was cooled to -50°C, boron tribromide (5.8 g) was added, and the mixture was heated to room temperature and stirred for 0.5 hours. The mixture was then cooled again to 0°C, N,N-diisopropylethylamine (2.6 g) was added, and the mixture was stirred at room temperature until the heat generation subsided, after which the mixture was heated to 100°C and stirred for 1 hour. The reaction mixture was cooled to room temperature, and aqueous sodium acetate solution cooled in an ice bath, followed by ethyl acetate, was added and stirred for 1 hour. The yellow suspension was filtered, and the precipitate was washed with methanol. The yellow crystals were dissolved in toluene by heating and then purified using a silica gel short column (eluent: toluene). Toluene was added to the resulting crude product, which was then concentrated, and Solmix (A-11) was added. The precipitated crystals were filtered and washed with methanol to obtain compound (1-518) (2.5 g).

It was confirmed by MS measurement that the compound was obtained. MS: C ₆₀ H ₇₇₂ BN ₃ S: 877.554

By appropriately changing the raw material compounds, other polycyclic aromatic compounds of the present invention can be synthesized using methods similar to the synthesis examples described above.

In order to explain the present invention in more detail, examples of organic EL devices using the compounds of the present invention are shown below, but the present invention is not limited to these.

The organic EL devices of Examples 1 to 3 and Comparative Example 1 were fabricated, and the maximum wavelength (EL wavelength) (nm) and full width at half maximum (FWHM) (nm) of the emission spectrum at 1000 cd/ ^m² emission, the driving voltage (V), and the external quantum efficiency (EQE) (%) were measured.

The quantum efficiency of light-emitting elements can be divided into internal quantum efficiency and external quantum efficiency. Internal quantum efficiency indicates the rate at which external energy injected as electrons (or holes) into the light-emitting layer of the light-emitting element is converted purely into photons. On the other hand, external quantum efficiency is calculated based on the amount of these photons that are emitted to the outside of the light-emitting element. Since some of the photons generated in the light-emitting layer are absorbed or continue to be reflected within the light-emitting element and are not emitted to the outside of the light-emitting element, the external quantum efficiency is lower than the internal quantum efficiency.

The spectral radiance (emission spectrum) and external quantum efficiency were measured as follows. Using an Advantest voltage/current generator R6144, a voltage was applied to the device to achieve a luminance of 1000 cd/ ^m² , causing the device to emit light. Using a TOPCON SR-3AR spectroradiometer, the spectral radiance in the visible light region was measured from a direction perpendicular to the light-emitting surface. Assuming that the light-emitting surface is a perfectly diffusing 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 device. The applied current value was divided by the elementary charge to obtain the number of carriers injected into the device, and the total number of photons emitted from the device divided by the number of carriers injected into the device was obtained to obtain the external quantum efficiency. The half-width of the emission spectrum was calculated as the width between the wavelengths above and below which the intensity was 50%, centered on the maximum emission wavelength.

The materials of each layer in the fabricated organic EL device are shown below. "HI" (hole injection layer 1 material) is N ⁴ ,N ⁴ '-diphenyl-N ⁴ ,N ⁴ '-bis(9-phenyl-9H-carbazol-3-yl)-[1,1'-biphenyl]-4,4'-diamine, "HAT-CN" (hole injection layer 2 material) is 1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile, "HT-1" (hole transport layer 1 material) is N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine, and "HT-2" (hole transport layer 2 material) is N,N-di([1,1'-biphenyl]-4-yl)-3'-(9H-carbazol- "Host-1" is 2-(10-phenylanthracen-9-yl)dibenzo[b,d]furan, "ET-1" (electron transport layer 1 material) is 2-(3'-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1'-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine, and "ET-2" (electron transport layer 2 material) is 4'-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1'-biphenyl]-4-carbonitrile. Their chemical structures are shown below along with those of compounds "0-1" and "Liq," which are dopants in Comparative Example 1.

Example 1
<Device using compound (1-363) as a dopant>
A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) on which an ITO film having a thickness of 180 nm was formed by sputtering and polished to 120 nm was used as a transparent support substrate. This transparent support substrate was fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Nagasu Sangyo Co., Ltd.), and tantalum vapor deposition boats containing HI, HAT-CN, HT-1, HT-2, compound (Host-1), compound (1-363), ET-1, and ET-2, and aluminum nitride vapor deposition boats containing Liq, magnesium, and silver, respectively, were attached.

The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was depressurized to 5 × 10 ⁻⁴ Pa, and first, HI was heated and vapor-deposited to a thickness of 40 nm to form hole injection layer 1. Next, HAT-CN was heated and vapor-deposited to a thickness of 5 nm to form hole injection layer 2. Next, HT-1 was heated and vapor-deposited to a thickness of 45 nm to form hole transport layer 1. Next, HT-2 was heated and vapor-deposited to a thickness of 10 nm to form hole transport layer 2. Next, compound (Host-1) and compound (1-363) were simultaneously heated and vapor-deposited to a thickness of 20 nm to form an emitting layer. The vapor deposition rate was adjusted so that the mass ratio of compound (Host-1) as the host material to compound (1-363) as the dopant material was approximately 98:2. Next, ET-1 was heated and vapor-deposited to a thickness of 5 nm to form electron transport layer 1. Next, ET-2 and Liq were simultaneously heated and evaporated to a thickness of 25 nm to form an electron transport layer 2. The evaporation rate was adjusted so that the mass ratio of ET-2 to Liq was approximately 50:50. The evaporation rate for each layer was 0.01 to 1 nm/sec. Liq was then heated and evaporated at an evaporation rate of 0.01 to 0.1 nm/sec to a thickness of 1 nm. Next, magnesium and silver were simultaneously heated and evaporated to a thickness of 100 nm to form a cathode, thereby obtaining an organic EL device. At this time, the evaporation rate was adjusted between 0.1 nm and 10 nm/sec so that the atomic ratio of magnesium to silver was 10:1.

<Examples 2 to 13 and Comparative Example 1>
Organic EL devices were fabricated in the same manner as in Example 1, except that the dopant material was changed to the compounds shown in Table 1.

A direct current voltage was applied between the ITO electrode as the anode and the magnesium/silver electrode as the cathode, and the characteristics at 1000 cd/m ² light emission were measured, with the results shown in Table 1.

The polycyclic aromatic compounds of the present invention are useful as materials for organic devices, particularly as light-emitting layer materials for forming the light-emitting layer of organic electroluminescent devices.

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 (29)

A polycyclic aromatic compound having a structure consisting of one or more structural units represented by the following formula (1):
In formula (1),
ring A, ring B, and ring C are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted;
^Y1 is B, P, P=O or P=S;
The aryl or heteroaryl rings in ring A, ring B, and ring C each have a 6-membered ring that shares a bond with the central fused bicyclic structure of formula (1) composed of Y ¹ , X ¹ , and X ² ;
X ² is >C(-R) _2, >N-R, >O, >Si(-R) ₂ or >S, 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 >C(-R) ₂ and >Si(-R) ₂ is hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl , at least one of R of the >N-R, the >C(-R) ₂ and the >Si(-R) ₂ may be bonded to the C ring by -O-, -S-, -C(-R) ₂ - or a single bond , and R of the -C(-R) ₂ - is hydrogen, an alkyl or a cycloalkyl,
X ¹ is >C(-R) ₂ , >N-R, >O, >Si(-R) ₂ or >S, 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 >C(-R) ₂ and >Si(-R) ₂ is hydrogen, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl , at least one of R of the >N-R, the >C(-R) ₂ and the >Si(-R) ₂ may be bonded to at least one of the A ring or the B ring by -O-, -S-, -C(-R) ₂ - or a single bond, and R of the -C(-R) ₂ - is hydrogen, an alkyl or a cycloalkyl,
In the above structure, at least one selected from the group consisting of ring A, ring B , and ring C contains at least one partial structure represented by formula (A),
The partial structure represented by formula (A) is bonded to two adjacent atoms on an aryl ring or heteroaryl ring at two * marks, respectively.
In formula (A),
L is >N-R, >O, >Si(-R) ₂ or >S, 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 >Si(-R) ₂ is a hydrogen atom, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl , and at least one of the >N-R and R of the >Si(-R) ₂ may be bonded to at least one selected from the group consisting of ring A, ring B , ring C and R ^A via a single bond ;
r is an integer from 1 to 4,
Each R ^A is independently hydrogen, optionally substituted alkyl, or optionally substituted cycloalkyl, and any R ^A may be bonded to any other R ^A via a single bond ;
At least one selected from the group consisting of an aryl ring and a heteroaryl ring in the structure may be fused 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— or —S—;
At least one hydrogen in the structure may be replaced with deuterium, cyano, or halogen. 2. The polycyclic aromatic compound according to claim 1, wherein when at least one hydrogen atom in an aryl ring or heteroaryl ring in rings A, B, and C is replaced with a substituent selected from the group consisting of substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted alkylarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted diarylboryl (two aryls may be bonded via a single bond , >C(-R) ₂ , >O, >S, or >N-R, and R in >C(-R) ₂ and >N-R is aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy, which may be further substituted with an aryl, heteroaryl, alkyl, or cycloalkyl ), substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, and substituted silyl. The polycyclic aromatic compound according to claim 1 or 2, wherein Y ¹ is B. The polycyclic aromatic compound according to any one of claims 1 to 3, which contains at least one tertiary alkyl represented by the following formula (tR) in the structure:
In formula (tR), R ^a , R ^b and R ^c each independently represent alkyl having 1 to 24 carbon atoms, any —CH ₂ — in the alkyl may be replaced with —O—, and * represents the bonding position. The polycyclic aromatic compound according to any one of claims 1 to 4, wherein the partial structure represented by formula (A) is bonded to an aryl ring or heteroaryl ring in ring B. The partial structure represented by formula (A) is bonded to two adjacent carbon atoms on an aryl ring or heteroaryl ring at two * marks,
r is 2,
The polycyclic aromatic compound according to any one of claims 1 to 5, wherein two R ^As bonded to adjacent carbon atoms are bonded to each other, and the remaining R ^As are each independently hydrogen or optionally substituted alkyl. 7. The polycyclic aromatic compound according to claim 6, wherein two R 1 ^{A s} bonded to adjacent carbon atoms are bonded to each other to form —(CH ₂ ) ₄ —, and the remaining R 1 ^{A s} are all methyl. The polycyclic aromatic compound according to any one of claims 1 to 7, wherein L is >N-R, and R in the >N-R is an optionally substituted aryl. The polycyclic aromatic compound according to any one of claims 1 to 5, wherein the partial structure represented by (A) is the following structure:
In the formula, two *'s are attached to two adjacent atoms on the aryl or heteroaryl ring, respectively, and Me is methyl. X ¹ is >N—R, and R of >N—R that is X ¹ is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, and is optionally bonded to at least one of the ring A or ring B by —O—, —S—, —C(—R) ₂ — or a single bond;
The polycyclic aromatic compound according to any one of claims 1 to 9, wherein ^X2 is >N-R, and R of ^X2 > N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and is optionally bonded to at least one selected from the group consisting of ring A and ring C via -O-, -S-, -C(-R) ₂ -, or a single bond. A polycyclic aromatic compound represented by any one of the following formulas (2-7) to (2-9):
^Y1 is B, P, P=O or P=S;
X ¹ is >C(-R) ₂ , >N-R, >O, >Si(-R) ₂ or >S, R of said >N-R is an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl or an optionally substituted cycloalkyl, R of said >C(-R) ₂ and >Si(-R) ₂ is hydrogen, an optionally substituted aryl , an optionally substituted alkyl or an optionally substituted cycloalkyl, at least one of R of said >N-R, said >C(-R) ₂ and said >Si(-R) ₂ may be bonded to at least one of ring a or ring b by -O-, -S-, -C(-R) ₂ - or a single bond, R of said -C(-R) ₂ - is hydrogen, alkyl or cycloalkyl,
Z is C(-R ^Z ) or N, and R ^Z is each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted alkylarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino, substituted or unsubstituted diarylboryl (two aryls may be bonded via a single bond , >C(-R) ₂ , >O, >S, or >N-R, and R in >C(-R) ₂ and >N-R is aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy, which may be further substituted with aryl, heteroaryl, alkyl, or cycloalkyl ), substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryloxy, or substituted silyl, and R bonded to adjacent C ^Z 's 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 atom in the formed ring may be substituted by a substituted or unsubstituted aryl, a substituted or unsubstituted heteroaryl, a substituted or unsubstituted diarylamino, a substituted or unsubstituted diheteroarylamino, a substituted or unsubstituted arylheteroarylamino, a substituted or unsubstituted diarylboryl (the two aryls may be bonded via a single bond , >C(-R) ₂ , >O, >S, or >N-R , and R in >C(-R) ₂ and >N-R is an aryl, heteroaryl, diarylamino, alkyl, cycloalkyl, alkoxy, or aryloxy, which may be further substituted by an aryl, heteroaryl, alkyl, or cycloalkyl ), a substituted or unsubstituted alkyl, a substituted or unsubstituted cycloalkyl, a substituted or unsubstituted alkoxy, a substituted or unsubstituted aryloxy, or a substituted silyl;
^X3 each independently represents >C(-R) ₂ , >N-R, >O, >Si(-R) ₂ or >S, and R of the >N-R represents an aryl having 6 to 12 carbon atoms, a heteroaryl having 2 to 15 carbon atoms, an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms, and R of the >C(-R) ₂ and >Si(-R) ₂ represents hydrogen, an aryl having 6 to 12 carbon atoms, an alkyl having 1 to 6 carbon atoms or a cycloalkyl having 3 to 14 carbon atoms,
In each of formulas (2-7) to (2-9), the partial structure represented by formula (A) is bonded at two * positions to two adjacent carbon atoms on any one or more rings selected from the group consisting of ring a, ring b, ring c, and a ring formed by bonding R and ^Z together,
In formula (A),
L is >N-R, >O, >Si(-R) ₂ or >S, 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 >Si(-R) ₂ is a hydrogen atom, an optionally substituted aryl, an optionally substituted alkyl or an optionally substituted cycloalkyl , and at least one of the R of the >N-R and the >Si(-R) ₂ is optionally bonded to at least one selected from the group consisting of Z, ^X3 and R ^A via a single bond ;
r is an integer from 1 to 4,
Each R ^A is independently hydrogen, optionally substituted alkyl, or optionally substituted cycloalkyl, and any R ^A may be bonded to any other R ^A via a single bond ;
At least one selected from the group consisting of aryl rings and heteroaryl rings in each of formulas (2-7) to (2-9) may be fused 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— or —S—;
At least one hydrogen atom in each of formulas (2-7) to (2-9) may be substituted with deuterium, cyano or halogen. A polycyclic aromatic compound having a structure represented by the following formula (1-BA1) or formula (1-BA2):
In formula (1-BA1) and formula (1-BA2),
ring c is an optionally substituted benzene ring, an optionally substituted benzofuran ring, or an optionally substituted benzothiophene ring;
Each R is independently an optionally substituted phenyl;
R ² ' is hydrogen or alkyl having 1 to 6 carbon atoms;
Me represents methyl;
In at least one benzene ring in the structure, hydrogen atoms bonded to adjacent carbon atoms may be substituted with a partial structure represented by formula (B):
In formula (B), Me represents methyl, and * represents the bonding position. The polycyclic aromatic compound according to claim 12, having a structure represented by any one of the following formulas:
In the formula, Me represents methyl, and tBu represents t-butyl. A polycyclic aromatic compound having a structure represented by the following formula (1-BA3) or formula (1-BA4):
In formula (1-BA3) and formula (1-BA4),
ring c is an optionally substituted benzene ring, an optionally substituted benzofuran ring, or an optionally substituted benzothiophene ring;
Each R is independently an optionally substituted phenyl;
R ² ' is hydrogen or alkyl having 1 to 6 carbon atoms;
Me represents methyl;
In at least one benzene ring in the structure, hydrogen atoms bonded to adjacent carbon atoms may be substituted with a partial structure represented by formula (B):
In formula (B), Me represents methyl, and * represents the bonding position. The polycyclic aromatic compound according to claim 14, having a structure represented by any one of the following formulas:
In the formula, Me represents methyl, and tBu represents t-butyl. A polycyclic aromatic compound having a structure represented by the following formula (1-BA5), (1-BA6), (1-BA7) or (1-BA8):
In formulas (1-BA5), (1-BA6), (1-BA7) and (1-BA8),
Ring D is an optionally substituted benzene ring or an optionally substituted cyclohexane ring;
Each R is independently an optionally substituted phenyl;
Each ^Rd is independently hydrogen, optionally substituted alkyl, optionally substituted aryl, optionally substituted heteroaryl, or optionally substituted diarylamino;
Me represents methyl;
In at least one benzene ring in the structure, hydrogen atoms bonded to adjacent carbon atoms may be substituted with a partial structure represented by formula (B):
In formula (B), Me represents methyl, and * represents the bonding position. The polycyclic aromatic compound according to claim 16, having a structure represented by any one of the following formulas:
In the formula, Me represents methyl, and tBu represents t-butyl. A polycyclic aromatic compound having a structure represented by any one of the following formulas:
In formula (1-BA11), formula (1-BA12), formula (1-BA13) and formula (1-BA14),
Z is C(—R ^Z ) or N, and R ^Z are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted alkyl, or substituted or unsubstituted cycloalkyl;
Each R is independently an optionally substituted phenyl;
R ² ' is hydrogen or alkyl having 1 to 6 carbon atoms;
Me represents methyl;
In at least one benzene ring in the structure, hydrogen atoms bonded to adjacent carbon atoms may be substituted with a partial structure represented by formula (B):
In formula (B), Me represents methyl, and * represents the bonding position. The polycyclic aromatic compound according to claim 18, having a structure represented by any one of the following formulas:
In the formula, Me represents methyl, and tBu represents t-butyl. A material for organic devices containing the polycyclic aromatic compound described in any one of claims 1 to 19. The material for an organic device according to claim 20 , which is 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. The material for an organic device according to claim 21 , wherein the material for an organic electroluminescent element is a material for a light-emitting layer. An ink composition comprising the polycyclic aromatic compound according to any one of claims 1 to 19 and an organic solvent. An organic electroluminescent 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 claims 1 to 19 . 25. The organic electroluminescent device according to claim 24 , wherein the organic layer is a light-emitting layer. 26. The organic electroluminescent device according to claim 25 , wherein the light-emitting layer comprises a host and the polycyclic aromatic compound as a dopant. 27. The organic electroluminescent device according to claim 26 , wherein the host is an anthracene-based compound, a fluorene-based compound, or a dibenzochrysene-based compound. The organic electroluminescent device according to any one of claims 25 to 27, 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 a compound represented by formula (ETM-10) .
In formula (ETM-10), each Ar is independently an optionally substituted aryl or an optionally substituted heteroaryl, and n is an integer of 1 to 3. A display device or a lighting device comprising the organic electroluminescent device according to any one of claims 24 to 28 .