JP7635928B2 - Polycyclic aromatic compounds - Google Patents

Description

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

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

An organic EL element has a structure consisting of a pair of electrodes consisting of an anode and a cathode, and one or more layers containing an organic compound disposed between the pair of electrodes. The layers containing the organic compound include a light-emitting layer and a charge transport/injection layer that transports or injects charges such as holes and electrons, and various organic materials suitable for these layers have been developed.
Among them, in recent years, polycyclic aromatic compounds containing boron have been developed as materials for the light-emitting layer, and organic EL devices using them have been reported (Patent Documents 1 and 2).

International Publication No. 2015/102118 JP 2018-43984 A

As described above, various materials have been developed for use in organic EL elements, but in order to increase the options for materials for organic EL elements, it is desirable to develop materials made of compounds different from conventional ones. The objective of the present invention is to provide a new material that is useful as a material for organic devices such as organic EL elements.

The present inventors conducted extensive research to solve the above problems, and succeeded in producing a novel polycyclic aromatic compound having a structure in which multiple aromatic rings are linked by boron atoms, nitrogen atoms, etc., similar to the compounds described in Patent Documents 1 and 2. They also discovered that an excellent organic EL device can be obtained by constructing an organic EL device by disposing a layer containing this polycyclic aromatic compound between a pair of electrodes, and completed the present invention. In other words, the present invention provides the following polycyclic aromatic compound or a multimer thereof, and further provides a material for an organic EL device containing the following polycyclic aromatic compound or a multimer thereof.

<1> A polycyclic aromatic compound represented by formula (1), or a multimer of a polycyclic aromatic compound having a plurality of structures represented by formula (1).

(In formula (1),
ring A, ring B and ring C each independently represent an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings may be substituted;
provided that at least one ring selected from the group consisting of ring A, ring B, and ring C is a fused ring composed of two or more rings selected from the group consisting of a monocyclic aryl ring, a monocyclic heteroaryl ring, and a cyclopentadiene ring, and at least one hydrogen atom in this fused ring is optionally substituted;
^Y1 is B, P, P=O, P=S, Al, Ga, As, Si-R, or Ge-R, wherein R in the Si-R and Ge-R is aryl, alkyl, or cycloalkyl;
X ¹ , X ² , and X ³ are each independently >O, >N—R, >C(—R) ₂ , >S, >Si(—R) ₂ , >S(═O) ₂ , or >Se;
R in the >N-R is each independently an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl;
R in the >C(-R) ₂ and >Si(-R) ₂ is each independently hydrogen, an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl;
R in the >N-R, >C(-R) ₂ and >Si(-R) ₂ may be bonded to at least one ring selected from the group consisting of ring A, ring B and ring C via a linking group or a single bond;
In the compound or structure represented by formula (1), at least one of the aryl ring and the heteroaryl ring may be condensed with at least one cycloalkane, at least one hydrogen in the cycloalkane may be substituted, and at least one -CH ₂ - in the cycloalkane may be substituted with -O-;
At least one hydrogen atom in the compound represented by formula (1) or a multimer thereof may be substituted with deuterium, cyano, or halogen.

<2> The polycyclic aromatic compound or a multimer thereof according to <1>, wherein the fused ring contains a heteroaryl ring containing a sulfur atom or an oxygen atom, or the fused ring is naphthalene.
<3> The polycyclic aromatic compound or a multimer thereof according to <1>, wherein the fused ring is a ring represented by formula (1a) or formula (1b).

(In formula (1a),
^X4 and ^X5 are each independently >O, >N-R, >C(-R) ₂ , >S, >Si(-R) ₂ , >S(=O) ₂ , or >Se;
R in the >N-R is each independently an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl;
R in the above >C(-R) ₂ and >Si(-R) ₂ is each independently hydrogen, an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl;
R ^a1 to R ^a8 are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, 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, substituted or unsubstituted arylsulfonyl, substituted or unsubstituted diarylphosphine, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted diarylphosphine sulfide, or substituted silyl, with the proviso that adjacent three of R ^a1 to R ^a8 are bonds to Y ¹ , X ¹ , X ² , or X ³ in formula (1), and adjacent two of any of R ^a1 to R ^a8 other than the above three may be bonded to each other to form a benzene ring which may have a substituent;
n1 and n2 each independently represent 0 or 1, and are not both 0;
In formula (1b),
R ^a9 to R ^a16 are each independently hydrogen, 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 (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, a substituted or unsubstituted arylsulfonyl, a substituted or unsubstituted diarylphosphine, a substituted or unsubstituted diarylphosphine oxide, a substituted or unsubstituted diarylphosphine sulfide, or a substituted silyl, with the proviso that at least one pair of adjacent three R ^a9 to R ^a16 is a bond to Y ¹ , X ¹ , X ² , or X ³ in formula (1).

<4> The polycyclic aromatic compound or a multimer thereof according to <3>, wherein the ring represented by formula (1a) is any one of rings represented by formulas (1a-1) to (1a-14).

In formula (1a-3), formula (1a-9), formula (1a-13), and formula (1a-14), R in N-R is each independently an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl;
In formulas (1a-4), (1a-5), and (1a-11) to (1a-13), _R in >C(-R) and >Si(-R) is _each independently hydrogen, an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl;
In formulas (1a-1) to (1a-14),
R ^a1 to R ^a8 and R ^aa1 to R ^a4 are each independently hydrogen, 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, substituted or unsubstituted arylsulfonyl, substituted or unsubstituted diarylphosphine, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted diarylphosphine sulfide, or substituted silyl, with the proviso that adjacent three of R ^a1 to R ^a8 and R ^aa1 to R ^a4 are bonds to Y ¹ , X ¹ , X ² , or X ³ in formula (1).

<5> The polycyclic aromatic compound or a multimer thereof according to <4>, wherein the ring represented by formula (1a) is a ring represented by formula (1a-1) or formula (1a-2).
<6> A polycyclic aromatic compound represented by any one selected from the group consisting of formula (3), formula (4), formula (5), formula (6), formula (7), formula (8), formula (9), formula (10), formula (11), formula (12), formula (13), formula (14), and formula (15); or a polycyclic aromatic compound or a multimer thereof according to <1>, having a plurality of structures represented by any one selected from the group consisting of formula (3), formula (4), formula (5), formula (6), formula (7), formula (8), formula (9), formula (10), formula (11), formula (12), formula (13), formula (14), and formula (15).

(In formulas (3), (4), (5), (6), (7), (8), (9), (10), (11), (12), (13), (14), and (15),
^Y1 is B, P, P=O, P=S, Al, Ga, As, Si-R, or Ge-R, wherein R in the Si-R and Ge-R is aryl, alkyl, or cycloalkyl;
X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , and X ⁷ are each independently >O, >N—R, >C(—R) ₂ , >S, >Si(—R) ₂ , >S(═O) ₂ , or >Se;
R in the >N-R is each independently an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl;
R in the >C(-R) ₂ and >Si(-R) ₂ is each independently hydrogen, an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl;
R in the >N-R, >C(-R) ₂ and >Si(-R) ₂ may be bonded to the ring via a linking group or a single bond;
At least one of the rings may be fused with at least one cycloalkane, at least one hydrogen in the cycloalkane may be replaced, and at least one -CH ₂ - in the cycloalkane may be replaced with -O-;
R ^b1 to R ^b13 are each hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, 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, substituted or unsubstituted arylsulfonyl, substituted or unsubstituted diarylphosphine, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted diarylphosphine sulfide, or substituted silyl;
At least one hydrogen atom in the compounds represented by formula (3), formula (4), formula (5), formula (6), formula (7), formula (8), formula (9), formula (10), formula (11), formula (12), formula (13), formula (14), and formula (15) or a multimer thereof may be substituted with deuterium, cyano, or halogen.

<7> The polycyclic aromatic compound or a multimer thereof according to any one of <1> to <6>, wherein Y ¹ is B, and X ² and X ³ are both C(—R) ₂ .
<8> The polycyclic aromatic compound or a multimer thereof according to any one of <1> to <6>, wherein Y ¹ is B, X ² is C(—R) ₂ , and X ³ is >N—R.

<9> The polycyclic aromatic compound according to <1>, which is represented by any one of the following structural formulas:

<10> A reactive compound in which the polycyclic aromatic compound or a multimer thereof according to any one of <1> to <9> is substituted with a reactive substituent.
<11> A polymer compound obtained by polymerizing the reactive compound according to <10> as a monomer, or a polymer crosslinked product obtained by further crosslinking the polymer compound.
<12> A pendant polymer compound in which the reactive compound according to <10> is substituted on a main chain polymer, or a pendant polymer crosslinked product in which the pendant polymer compound is further crosslinked.
<13> A material for an organic device, comprising the polycyclic aromatic compound or a multimer thereof according to any one of <1> to <9>.
<14> A material for an organic device, comprising the reactive compound according to <10>.
<15> A material for an organic device, comprising the polymer compound or crosslinked polymer according to <11>.
<16> A material for an organic device, comprising the pendant type polymer compound or the pendant type crosslinked polymer according to <12>.
<17> The material for an organic device according to any one of <13> to <16>, 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.
<18> The material for an organic device according to <17>, wherein the material for an organic electroluminescent element is a material for a light-emitting layer.

<19> A composition comprising the polycyclic aromatic compound or a multimer thereof according to any one of <1> to <9> and an organic solvent.
<20> A composition comprising the reactive compound according to <10> and an organic solvent.
<21> A composition comprising a main chain polymer, the reactive compound according to <10>, and an organic solvent.
<22> A composition comprising the polymer compound or crosslinked polymer according to <11> and an organic solvent.
<23> A composition comprising the pendant type polymer compound or the pendant type crosslinked polymer according to <12> and an organic solvent.

<24> An organic electroluminescence device comprising a pair of electrodes consisting of an anode and a cathode, and an organic layer disposed between the pair of electrodes and containing the polycyclic aromatic compound or a multimer thereof according to any one of <1> to <9>, the reactive compound according to <10>, the polymer compound or crosslinked polymer according to <11>, or the pendant polymer compound or crosslinked polymer according to <12>.
<25> An organic electroluminescence device comprising a pair of electrodes consisting of an anode and a cathode, and a light-emitting layer disposed between the pair of electrodes and containing the polycyclic aromatic compound or a multimer thereof according to any one of <1> to <9>, the reactive compound according to <10>, the polymer compound or crosslinked polymer according to <11>, or the pendant polymer compound or crosslinked polymer according to <12>.
<26> The organic electroluminescent device according to <25>, wherein the light-emitting layer contains a host and the polycyclic aromatic compound, or a multimer, reactive compound, polymer compound, crosslinked polymer, pendant polymer compound, or pendant crosslinked polymer as a dopant.
<27> The organic electroluminescent device according to <26>, wherein the host is an anthracene-based compound, a fluorene-based compound or a dibenzochrysene-based compound.

<28> The organic electroluminescence device according to any one of <24> to <27>, which has an electron transport layer and/or an electron injection layer disposed between the cathode and the light-emitting layer, and at least one of the electron transport layer and the electron injection layer contains at least one selected from the group consisting of borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, arylnitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, quinolinol-based metal complexes, thiazole derivatives, benzothiazole derivatives, silole derivatives, and azoline derivatives.

<29> The organic electroluminescent device according to <28>, wherein the electron transport layer and/or the electron injection layer further contains at least one selected from the group consisting of an alkali metal, an alkaline earth metal, a rare earth metal, an oxide of an alkali metal, a halide of an alkali metal, an oxide of an alkaline earth metal, a halide of an alkaline earth metal, an oxide of a rare earth metal, a halide of a rare earth metal, an organic complex of an alkali metal, an organic complex of an alkaline earth metal, and an organic complex of a rare earth metal.
<30> The organic electroluminescence device according to any one of <24> to <29>, wherein at least one of the hole injection layer, the hole transport layer, the light-emitting layer, the electron transport layer and the electron injection layer comprises a polymer compound obtained by polymerizing a low molecular compound capable of forming each layer as a monomer, or a crosslinked polymer obtained by further crosslinking the polymer compound, or a pendant-type polymer compound obtained by reacting a low molecular compound capable of forming each layer with a main-chain polymer, or a pendant-type crosslinked polymer obtained by further crosslinking the pendant-type polymer compound.
<31> A display device or a lighting device comprising the organic electroluminescent device according to any one of <24> to <29>.

According to a preferred embodiment of the present invention, it is possible to provide a novel polycyclic aromatic compound that can be used, for example, as a material for an organic EL device, and by using this polycyclic aromatic compound, it is possible to provide an excellent organic EL device.

FIG. 1 is a schematic cross-sectional view showing an organic EL element.

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

In this specification, the chemical structure or the substituent may be expressed by the number of carbon atoms, but in the case where a substituent is substituted on the chemical structure or where a substituent is further substituted on the substituent, the number of carbon atoms means the number of carbon atoms in each of the chemical structure and the substituent, and does not mean 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 the carbon number Y is not the total number of carbon atoms in the substituents A and B. Also, for example, "substituent B of carbon number Y substituted with substituent A" means that "substituent B of carbon number Y" is substituted with "substituent A (with no carbon number limit)", and the carbon number Y is not the total number of carbon atoms in the substituents A and B.

1. Polycyclic aromatic compounds and multimers thereof The present inventors have found that polycyclic aromatic compounds represented by formula (1) in which aromatic rings are linked by hetero elements such as boron, nitrogen, phosphorus, oxygen, and sulfur, or multimers of polycyclic aromatic compounds having a plurality of structures represented by formula (1), have a large HOMO-LUMO gap (band gap Eg in a thin film) and high triplet excitation energy (E _T ). This is believed to be because the six-membered ring containing a hetero element has low aromaticity, which suppresses the decrease in the HOMO-LUMO gap associated with the expansion of the conjugated system, and because electronic perturbation of the hetero element causes localization of SOMO1 and SOMO2 in the triplet excited state (T1). In addition, the hetero element-containing polycyclic aromatic compound according to the present invention is useful as a fluorescent material for an organic EL device because the exchange interaction between the two orbitals is reduced due to the localization of SOMO1 and SOMO2 in the triplet excited state (T1), the energy difference between the triplet excited state (T1) and the singlet excited state (S1) is small, and the compound exhibits thermally activated delayed fluorescence. In addition, materials having high triplet excitation energy (E _T ) are also useful as electron transport layers and hole transport layers for phosphorescent organic EL devices and organic EL devices using thermally activated delayed fluorescence. Furthermore, these polycyclic aromatic compounds can arbitrarily move the energy of HOMO and LUMO by introducing a substituent, so that the ionization potential and electron affinity can be optimized according to the surrounding materials.

The polycyclic aromatic compound represented by formula (1) or a multimer thereof is preferably a polycyclic aromatic compound represented by the following formula (2) or a multimer of a polycyclic aromatic compound having a plurality of structures represented by the following formula (2).

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 replaced by a substituent, provided that at least one ring selected from the group consisting of ring A, ring B, and ring C is a fused ring composed of two or more rings selected from the group consisting of a monocyclic aryl ring, a monocyclic heteroaryl ring, and a cyclopentadiene ring, and at least one hydrogen atom in this fused ring may be replaced. The substituent is preferably 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 (an amino group 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, a substituted or unsubstituted arylsulfonyl, a substituted or unsubstituted diarylphosphine, a substituted or unsubstituted diarylphosphine oxide, a substituted or unsubstituted diarylphosphine sulfide, or a substituted silyl. When these groups have a substituent, examples of the substituent include aryl, heteroaryl, alkyl, cycloalkyl, or diarylamino.

In addition, the aryl ring or heteroaryl ring preferably has a 5- or 6-membered ring that shares a bond with the central fused three-ring structure of formula (1) composed of Y ¹ , X ¹ , X ² and X ³ (hereinafter, this structure is also referred to as the "D structure").

Here, the term "condensed three-ring structure (D structure)" means a structure in which three saturated hydrocarbon rings including Y ¹ , X ¹ , X ² and X ³ are condensed, as shown in the center of formula (1). The term "six-membered ring sharing a bond with the condensed three-ring structure" means, for example, a ring (benzene ring (six-membered ring)) condensed to the D structure, as shown in formula (2). The term "aryl ring or heteroaryl ring (A ring) has this six-membered ring" means that the A ring is formed only by this six-membered ring, or that the A ring is formed by further condensing other rings to this six-membered ring so as to include this six-membered ring. In other words, the term "aryl ring or heteroaryl ring (A ring) having a six-membered ring" means that the six-membered ring constituting all or a part of the A ring is condensed to the D structure. The same explanation applies to "B ring (b ring)", "C ring (c ring)" and "five-membered ring".

In formula (1), at least one ring selected from the group consisting of ring A, ring B, and ring C is a fused ring composed of two or more rings selected from the group consisting of monocyclic aryl rings, monocyclic heteroaryl rings, and cyclopentadiene rings. The present inventors have found that by constructing an organic EL device using a polycyclic aromatic compound having such a fused ring as a material for the light-emitting layer, it is possible to improve the luminous efficiency and device life.

The number of rings constituting the fused ring is not particularly limited, but is preferably 2 to 5, more preferably 2 or 1 to 4, even more preferably 3 or 4, and particularly preferably 3. Examples of fused rings include a fused ring of two monocyclic aryl rings and one monocyclic heteroaryl ring, a fused ring of two monocyclic aryl rings and one cyclopentadiene ring, a fused ring of two monocyclic aryl rings and one monocyclic heteroaryl ring, and a fused ring of two monocyclic aryl rings and one cyclopentadiene ring. In this case, the monocyclic aryl ring is preferably a benzene ring. Examples of monocyclic heteroaryl rings include a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, a thiadiazole ring, a pyridine ring, and a pyrimidine ring. In addition, the central ring of a thianthrene ring and a phenoxathiin ring are also examples of monocyclic heteroaryl rings.

The fused ring is preferably a combination of a 6-membered ring and a 5-membered ring, or a combination of a plurality of 6-membered rings. In this case, the 6-membered ring may share a bond with the fused 3-ring structure, or the 5-membered ring may share a bond with the fused 3-ring structure, but it is preferable that the 6-membered ring share a bond with the fused 3-ring structure. The fused ring is not composed of only cyclopentadiene rings. The cyclopentadiene ring is preferably a 1,1-dimethyl-2,4-cyclopentadiene ring.
In formula (1), among rings A, B and C, those which are not fused rings are preferably monocyclic aryl rings or monocyclic heteroaryl rings, more preferably benzene rings.

Ring A (or ring B, ring C) in formula (1) corresponds to ring a and its substituents R ¹ to R ³ (or ring b and its substituents R ⁴ to R ⁶ , ring c and its substituents R ⁷ to R ⁹ ) in formula (2). That is, formula (2) corresponds to a formula in which "rings A to C having 6 members" are selected as rings A to C of formula (1). In that sense, each ring in formula (2) is represented by lower case letters a to c.

In formula (2), adjacent groups among the substituents R ¹ to R ⁹ of the ring a, ring b, and ring c may be bonded together to form an aryl ring or a heteroaryl ring together with the ring a, ring b, or ring c, and at least one hydrogen atom in the formed ring may be substituted with an aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, alkoxy, or aryloxy, and at least one hydrogen atom in these may be substituted with an aryl, heteroaryl, or alkyl, provided that adjacent groups among the substituents R ¹ to R ⁹ are bonded together in at least one ring selected from the group consisting of the ring a, ring b, and ring c to form a condensed ring composed of two or more rings selected from the group consisting of a monocyclic aryl ring, a monocyclic heteroaryl ring, and a cyclopentadiene ring, and at least one hydrogen atom in this condensed ring may be substituted. Thus, the ring structure constituting the polycyclic aromatic compound represented by formula (2) changes depending on the mutual bonding form of the substituents in the ring a, ring b, and ring c, as shown in the following formulas (2-1) and (2-2). The rings A', B' and C' in each formula correspond to the rings A, B and C in formula (1), respectively.

In formula (2-1) and formula (2-2), the ring A', ring B' and ring C' are condensed rings formed by bonding adjacent groups among the substituents R ¹ to R ⁹ together with the ring a, ring b and ring c, respectively, as explained in formula (2). As can be seen from the above formula (2-1) and formula (2-2), for example, R ³ of ring a and R ⁴ of ring b, R ⁶ of ring b and R ⁷ of ring c, R ⁹ of ring c and R ¹ of ring a are not "adjacent groups" and are not bonded to each other. In other words, "adjacent groups" means groups adjacent on the same ring.

Although not shown in the formula, the structure may be such that only one of the ring a and the ring b is a fused ring (ring A' and ring B', respectively), or the structure may be such that the ring a, ring b, and ring c are all fused rings (ring A', ring B', and ring C', respectively).
Among these structures, a structure having at least one fused ring selected from ring B' and ring C' is preferred, and a structure represented by formula (2-1) is more preferred.

In formula 1, the "fused ring composed of two or more rings selected from the group consisting of a monocyclic aryl ring, a monocyclic heteroaryl ring, and a cyclopentadiene ring," or the fused rings A', B', and C' mentioned above, include fused rings represented by formula (1a) and formula (1b).

In formula (1a), ^X4 and ^X5 are each independently >O, >N-R, >C(-R) ₂ , >S, >Si(-R) ₂ , >S(=O) ₂ , or >Se, R in the >N-R is each independently an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, R in the >C(-R) ₂ and >Si(-R) ₂ is each independently a hydrogen atom, an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, R ^a1 to R ^a8 are each independently hydrogen, 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 (an amino group having an aryl and a heteroaryl), a substituted or unsubstituted diarylboryl (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, a substituted or unsubstituted arylsulfonyl, a substituted or unsubstituted diarylphosphine, a substituted or unsubstituted diarylphosphine oxide, a substituted or unsubstituted diarylphosphine sulfide, or a substituted silyl, provided that at least one pair of adjacent three R ^a1 to R ^a8 are bonds to Y ¹ , X ¹ , X ² , or X ³ in formula (1), formula (2-1), or formula (2-2), and R ^a1 to R other than the three Any two adjacent ⁿ⁸ 's may be bonded to each other to form a benzene ring which may have a substituent (see R ^aa1 to R ^aa4 in formula (1a-8)), and n1 and n2 are each independently 0 or 1 and cannot both be 0.

In formula (1b), R ^a9 to R ^a16 are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino (an amino group having an aryl and a heteroaryl), 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, substituted or unsubstituted arylsulfonyl, substituted or unsubstituted diarylphosphine, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted diarylphosphine sulfide, or substituted silyl, with the proviso that at least one pair of adjacent three R ^a9 to R ^a16 is a bond to Y ¹ , X ¹ , X ² , or X ³ in formula (1).
Specific examples of R ^a1 to R ^a8 in formula (1a) and R ^a9 to R ^a16 in formula (1b) can be found in the description of the first and second substituents in formula (1) given below.

Specific examples of the structure represented by formula (1a) are shown below, but the structure is not limited to these.

In formula (1a-3), formula (1a-9), formula (1a-13), and formula (1a-14), R in N-R is each independently an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl;
In formula (1a-4), formula (1a-5), and (1a-11) to ( _1a -13), R in >C(-R) and >Si(-R) is _each independently an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl;
In formulas (1a-1) to (1a-14),
R ^a1 to R ^a8 and R ^aa1 to R ^aa4 are each independently hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino (an amino group having an aryl and a heteroaryl), 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, substituted or unsubstituted arylsulfonyl, substituted or unsubstituted diarylphosphine, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted diarylphosphine sulfide, or substituted silyl, with the proviso that at least one pair of adjacent three R ^a1 to R ^a8 and R ^aa1 to R ^a4 are bonds to Y ¹ , X ¹ , X ² , or X ³ in formula (1). For each of the substituents represented by R ^a1 to R ^a8 and R ^aa1 to R ^aa4 in formulas (1a-1) to (1a-14), reference can be made to the description of the first and second substituents in formula (1) given below.

For a skeleton structure in which R ^a1 to R ^a8 (and R ^aa1 to R ^aa4 ) are all hydrogen, examples include structures in which any of R ^a1 to R ^a8 (and R ^aa1 to R ^aa4 ) is a substituent (a group other than hydrogen) as follows. From the viewpoint of stability during device operation, when the emitter in the light-emitting layer undergoes hole-trapping recombination, it is preferable that it is stable against radical cations (holes), and when X ⁴ and/or X ⁵ are >O, >N-R, >S, or >Se, the substituents in R ^a1 to R ^a8 (and R ^aa1 to R ^aa4 ) are preferably in the o-position or p-position relative to X ⁴ or X ⁵ , and similarly, when X ⁴ and/or X ⁵ are >C(-R) ₂ or >Si(-R) ₂ , it is preferable that the substituents in R ^a1 to R ^a8 (and R ^aa1 to R ^aa4 ) are in the m-position relative to X ⁴ or X ⁵ .

From a synthesis standpoint, high symmetry and/or low molecular weight during synthesis are preferred because they result in higher reaction selectivity or lower sublimation temperatures. High symmetry is preferred not only for the final step in the synthesis but also for the synthesis of partial structures, allowing the selection of a synthetic route with high symmetry.

From the viewpoint of reducing intermolecular interactions, a large steric hindrance is preferred, and the substituent which is any one of R ^a1 to R ^a8 (and R ^aa1 to R ^aa4 ) is preferably methyl, t-butyl, t-amyl, t-octyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-t-butylcarbazolyl, phenoxy, cyclohexyl, and alkyl (particularly methyl)-substituted cyclohexyl having 1 to 5 carbon atoms, norbornenyl, and adamantyl, and more preferably methyl, t-butyl, t-amyl, o-tolyl, 2,6-xylyl, or 2,4,6-mesityl.

Of the formulas (1a-1) to (1a-14), when used as element materials described below, formulas (1a-1) and (1a-2) are preferred from the viewpoint of improving the efficiency and life span.

Examples of polycyclic aromatic compounds represented by formula (1) and polycyclic aromatic compounds represented by formula (2) containing fused ring structures represented by formula (1a) and formula (1b) include polycyclic aromatic compounds represented by formula (3), formula (4), formula (5), formula (6), formula (7), formula (8), formula (9), formula (10), formula (11), formula (12), formula (13), formula (14), and formula (15).

In formula (3), formula (4), formula (5), formula (6), formula (7), formula (8), formula (9), formula (10), formula (11), formula (12), formula (13), formula (14), and formula (15), X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , and X ⁷ are each independently >O, >N-R, >C(-R) ₂ , >S, >Si(-R) ₂ , >S(=O) ₂ , or >Se, and R in the >N-R is each independently an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and R in the >C(-R) ₂ and >Si(-R) ₂ is each independently hydrogen, an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and the >N-R and >C(-R) ₂ and R in >Si(-R) ₂ may be bonded to the ring via a linking group or a single bond. ^X1 , ^X2 , ^X3 , and ^X4 will be described in more detail below. ^X4 , ^X5 , ^X6 , and ^X7 are preferably each independently >O, >N-R, >C(-R) ₂ , or >S, and ^X4 and ^X6 are more preferably each independently >O or >S.

In formulae (3), (4), (5), (6), (7), (8), (9), (10), (11), (12), (13), (14), and (15), R ^b1 to R ^b13 are hydrogen, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted diarylamino, substituted or unsubstituted diheteroarylamino, substituted or unsubstituted arylheteroarylamino (an amino group having an aryl and a heteroaryl), 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, substituted or unsubstituted arylsulfonyl, substituted or unsubstituted diarylphosphine, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted diarylphosphine sulfide, substituted silyl, or cyano. For each of the substituents represented by R ^b1 to R ^b13 , the description of the first and second substituents in formula (1) given below can be referred to.

For a skeleton structure in which R ^a1 to R ^a8 (and R ^aa1 to R ^aa4 ) are all hydrogen, examples include structures in which any of R ^a1 to R ^a8 (and R ^aa1 to R ^aa4 ) is a substituent (a group other than hydrogen) as follows. From the viewpoint of stability when the device is operated, when the emitter in the light-emitting layer undergoes hole-trapping recombination, it is preferable that it is stable against radical cations (holes), and when X ⁴ and/or X ⁵ are O, N-R, S or Se, the substituents in R ^a1 to R ^a8 (and R ^aa1 to R ^aa4 ) are preferably in the o-position or p-position with respect to X ⁴ or X ⁵ , and similarly, when X ⁴ and/or X ⁵ are C(-R) ₂ or Si(-R) ₂ , it is preferable that the substituents in R ^a1 to R ^a8 (and R ^aa1 to R ^aa4 ) are in the m-position with respect to X ⁴ or X ⁵ . Similarly, it is also preferred that the group has a substituent at the p-position relative to ^Y1 .

From the viewpoint of synthesis, a high symmetry and/or a low molecular weight during synthesis is preferable because it results in a high reaction selectivity or a low sublimation temperature. High symmetry is preferable not only for the final step in the synthesis but also for the synthesis of partial structures, and a synthetic route with high symmetry can be selected. In other words, from the viewpoint of the above-mentioned symmetry, formula (3), formula (4), formula (7), formula (8), formula (12), formula (13) or formula (15) is preferable, and formula (3), formula (4), formula (7), formula (12) or formula (13) is more preferable. Furthermore, the structure of these compounds can be adjusted according to the emission wavelength, and when the emission wavelength is shortened, it is preferable that X is in the m position, and when the emission wavelength is shortened, it is preferable that X is in the o position or p position.

From the viewpoint of reducing intermolecular interactions, a large steric hindrance is preferred, and the substituent which is any one of R ^a1 to R ^a8 (and R ^aa1 to R ^aa4 ) is methyl, t-butyl, t-amyl, t-octyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-t-butylcarbazolyl, phenoxy, cyclohexyl, and alkyl (particularly methyl)-substituted cyclohexyl having 1 to 5 carbon atoms, norbornenyl, and adamantyl, and more preferably methyl, t-butyl, t-amyl, o-tolyl, 2,6-xylyl, or 2,4,6-mesityl.

In formula (1), formula (2), formula (3), formula (4), formula (5), formula (6), formula (7), formula (8), formula (9), formula (10), formula (11), formula (12), formula (13), formula (14), and formula (15), Y ¹ is B, P, P═O, P═S, Al, Ga, As, Si-R, or Ge-R, and R in the Si-R and Ge-R is aryl, alkyl, or cycloalkyl. When ^{Y 1} is P═O, P═S, Si-R, or Ge-R, the atom bonded to ring A, ring B, or ring C is P, Si, or Ge.

From the viewpoint of emitting light at a short wavelength, ^Y1 is preferably P, P=O, or P=S, and from the viewpoint of emitting light at a long wavelength, ^Y1 is preferably B. From the viewpoint of use as a light-emitting material, depending on the combination with ^X1 to ^{X3, Y1} is preferably B. From the viewpoint of charge transport, ^Y1 is preferably B, P, P=O, or P=S, and for use as a light-emitting layer or adjacent to a light-emitting layer, ^Y1 is preferably B from the viewpoint of stability and energy gap.

In formula (1), formula (2), formula (3), formula (4), formula (5), formula (6), formula (7), formula (8), formula (9), formula (10), formula (11), formula (12), formula (13), formula (14), and formula (15), X ¹ , X ² , and X ³ are each independently >O, >N-R, >C(-R) ₂ , >S, >Si(-R) ₂ , >S(═O) ₂ , or >Se, R in the >N-R is each independently an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, R in the >C(-R) ₂ and >Si(-R) ₂ is each independently a hydrogen atom, an optionally substituted aryl, an optionally substituted alkyl, or an optionally substituted cycloalkyl, and the >N-R, >C(-R) ₂ , and >Si(-R) R in ₂ may be bonded to the ring via a linking group or a single bond.

The linking group is preferably -O-, -S-, -C(-R) ₂ -, >N-R, or an arylene having 6 to 30 carbon atoms. In addition, R in the "-C(-R) ₂ -" is hydrogen, alkyl, or aryl. In addition, R in the ">N-R" is alkyl or aryl which may be substituted with alkyl.

From the viewpoint of emitting light at a short wavelength, X ¹ , X ² , and X ³ are each independently preferably >O, >N-R, >C(-R) ₂ , or >S, and more preferably >O or >C(-R) _2. Similarly, from the viewpoint of emitting light at a short wavelength, X ¹ , X ² , and X ³ are preferably all the same. From the viewpoint of high luminous efficiency, X ¹ , X ² , and X ³ are preferably at least two of >O, >N-R, >C(-R) ₂ , or >S, and more preferably at least two of >O, >N-R, or >C(-R) ₂ . From the viewpoint of the narrowness of the emission spectrum (narrowness of the half-width), it is preferable to strengthen the multiple resonance effect, and X ¹ , X ² , and X ³ are preferably >O, >N-R, >C(-R) ₂ , or >S, more preferably >O, >N-R, or >C(-R) ₂ , even more preferably >O or >N-R, and even more preferably >N-R. From the viewpoint of high triplet energy, X ¹ , X ² , and X ³ are preferably >N-R, and from the same viewpoint, it is preferable that X ¹ , X ² , and X ³ are all the same. On the other hand, from the viewpoint of low triplet energy, it is preferable that >O, >C(-R) ₂ , or >S, and from the same viewpoint, it is preferable that X ¹ , X ² , and X ³ are at least two kinds.

Moreover, it is preferable that X ¹ , X ² , and X ³ are each independently >O, >N-R, or >C(-R) _2. In particular, it is preferable that one of X ¹ , X ² , and X ³ is >C(-R) _2. It is more preferable that one of X ¹ and X ² is >C(-R) ₂ , and it is even more preferable that both X ¹ and X ² are >C(-R) _2. It is also preferable that one of X ¹ and X ² is >C(-R) ₂ , and X ³ is >N-R.

Here, the ring in the definition of "R of N-R is bonded to the ring by a linking group or a single bond" in formula (1) is ring A, ring B, and/or ring C in formula (1), and ring a, ring b, and/or ring c in formula (2).

This definition can be expressed by a compound having a ring structure in which ^X2 and ^X1 are incorporated into fused ring B' and fused ring C', as represented by the following formula (2-3-1). That is, for example, it is a compound having ring B' (or ring C'') formed by condensing another ring to ring b (or ring c) of formula (2) so as to incorporate ^X2 (or ^X1 ). The fused ring B'' (or fused ring C'') thus formed is, for example, a phenoxazine ring, a phenothiazine ring, an acridine ring or a phenophosphazine ring.

The above definition can also be expressed by a compound having a ring structure in which ^X1 and/or ^X2 are incorporated into a fused ring A', as represented by the following formula (2-3-2) or formula ( ^2-3-3 ). That is, for example, it is a compound having a ring A' formed by condensing another ring to the benzene ring, which is the ring a in formula (2), so as to incorporate ^X1 (and/or X2). The fused ring A'' thus formed is, for example, a phenoxazine ring, a phenothiazine ring, an acridine ring, or a phenophosphazine ring.

Although not specifically described, the above definition also includes a form in which R of N-R of ^X3 is bonded to ring B and/or ring C (ring b and/or ring c) via a linking group or a single bond. For example, it is a compound having ring B'' (or ring C'') formed by condensing another ring to ring ^b (or ring c) of the benzene ring in formula (2) so as to incorporate X3. For example, it corresponds to a compound represented by formula (1-70) or formula (1-71) listed as specific compounds to be described later, and the condensed ring B' (or condensed ring C'') formed is, for example, a phenoxazine ring, a phenothiazine ring, an acridine ring or a phenophosphazine ring.

The above definition also includes a combination of X ¹ , X ² or X ³ incorporated into any of the fused rings.

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

Specific examples of "aryl rings" include a monocyclic benzene ring, a bicyclic ...

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

Specific examples of the "heteroaryl ring" include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring (unsubstituted, substituted with an alkyl group such as methyl, or substituted with an aryl group such as phenyl), an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzoxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnamoyl ring, a quinol ... Examples include a phosphorus ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a naphthobenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a naphthobenzothiophene ring, a benzophosphole ring, a dibenzophosphole ring, a benzophosphole oxide ring, a dibenzophosphole oxide ring, a furazan ring, an oxadiazole ring, and a thianthrene ring.

At least one hydrogen atom in each of the above "aryl ring", "heteroaryl ring", and "fused ring composed of two or more rings selected from the group consisting of a monocyclic aryl ring, a monocyclic heteroaryl ring, and a cyclopentadiene ring" is a first substituent, which is 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", a substituted or unsubstituted "alkyl", a substituted or unsubstituted "cycloalkyl", a substituted or unsubstituted "alkoxy", a substituted or unsubstituted "aryloxy", a substituted or unsubstituted "arylsulfonyl ... It may be substituted with a substituted "diarylphosphine", a substituted or unsubstituted "diarylphosphine oxide", a substituted or unsubstituted "diarylphosphine sulfide" or a substituted silyl, but examples of the first substituent, the "aryl" or "heteroaryl", the aryl of the "diarylamino", the heteroaryl of the "diheteroarylamino", the aryl and heteroaryl of the "arylheteroarylamino", the "aryl" of the "diarylboryl", the aryl of the "aryloxy", the aryl of the "arylsulfonyl", the aryl of the "diarylphosphine", the aryl of the "diarylphosphine", the aryl of the "diarylphosphine oxide", and the aryl of the "diarylphosphine sulfide", include the monovalent groups of the "aryl ring" or "heteroaryl ring" described above.

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

Specific alkyl groups 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, 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, n-eicosyl, etc.

The "cycloalkyl" as the first substituent is, for example, a cycloalkyl having 3 to 12 carbon atoms. A preferred cycloalkyl is a cycloalkyl having 3 to 10 carbon atoms. A more preferred cycloalkyl is a cycloalkyl having 3 to 8 carbon atoms. An even more preferred cycloalkyl is a cycloalkyl having 3 to 6 carbon atoms. This explanation can also be cited as an explanation of a cycloalkyl that can be fused to at least one of the A ring, the B ring, and the C ring.

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 norbornenyl, bicyclo[1.0.1]butyl, bicyclo[1.1.1]pentyl, bicyclo[2.0.1]pentyl, bicyclo[1.2.1]hexyl, bicyclo[3.0.1]hexyl, bicyclo[2.1.2]heptyl, bicyclo[2.2.2]octyl, adamantyl, diamantyl, decahydronaphthalenyl, and decahydroazulenyl.

Also, examples of the "alkoxy" as the first substituent include linear alkoxy having 1 to 24 carbon atoms or branched alkoxy having 3 to 24 carbon atoms. An alkoxy having 1 to 18 carbon atoms (branched alkoxy having 3 to 18 carbon atoms) is preferred, an alkoxy having 1 to 12 carbon atoms (branched alkoxy having 3 to 12 carbon atoms) is more preferred, an alkoxy having 1 to 6 carbon atoms (branched alkoxy having 3 to 6 carbon atoms) is even more preferred, and an alkoxy having 1 to 4 carbon atoms (branched alkoxy having 3 to 4 carbon atoms) is particularly preferred.

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

The "substituted silyl" as the first substituent is, for example, a 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 replaced with an alkyl, and the alkyl can be any of the groups described above as "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 examples of trialkylsilyl include trimethylsilyl, triethylsilyl, tripropylsilyl, tri-i-propylsilyl, tributylsilyl, trisec-butylsilyl, tri-t-butylsilyl, tri-t-amylsilyl, ethyldimethylsilyl, propyldimethylsilyl, i-propyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, t-amyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, i-propyldiethylsilyl, and butyl. Examples include ethyl diethylsilyl, sec-butyl diethylsilyl, t-butyl diethylsilyl, t-amyl diethylsilyl, methyl dipropylsilyl, ethyl dipropylsilyl, butyl dipropylsilyl, sec-butyl dipropylsilyl, t-butyl dipropylsilyl, t-amyl dipropylsilyl, methyl di-i-propylsilyl, ethyl di-i-propylsilyl, butyl di-i-propylsilyl, sec-butyl di-i-propylsilyl, t-butyl di-i-propylsilyl, and t-amyl di-i-propylsilyl.

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

Specific examples of tricycloalkylsilyl include tricyclopentylsilyl and tricyclohexylsilyl.

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

Specific examples of dialkylarylsilyl substituted with two alkyls and one aryl, alkyldiarylsilyl substituted with one alkyl and two aryls, and triarylsilyl substituted with three aryls include silyl substituted with groups selected from the specific alkyls and aryls listed above.

As explained as being substituted or unsubstituted, at least one hydrogen atom in the first substituents, substituted or unsubstituted "aryl", substituted or unsubstituted "heteroaryl", substituted or unsubstituted "diarylamino", substituted or unsubstituted "diheteroarylamino", substituted or unsubstituted "arylheteroarylamino", substituted or unsubstituted "diarylboryl", substituted or unsubstituted "alkyl", substituted or unsubstituted "cycloalkyl", substituted or unsubstituted "alkoxy", substituted or unsubstituted "aryloxy", substituted or unsubstituted "arylsulfonyl", substituted or unsubstituted "diarylphosphine", substituted or unsubstituted "diarylphosphine oxide", and substituted or unsubstituted "diarylphosphine sulfide", may be substituted with a second substituent. Examples of the second substituent include aryl, heteroaryl, and alkyl, and specific examples thereof can be found in the explanation of the monovalent group of the "aryl ring" or "heteroaryl ring" described above, and the "alkyl" as the first substituent. The aryl and heteroaryl as the second substituent also include groups in which at least one hydrogen atom is replaced by an aryl such as phenyl (specific examples are the groups described above) or an alkyl such as methyl (specific examples are the groups described above). For example, when the second substituent is carbazolyl, the heteroaryl as the second substituent also includes carbazolyl in which at least one hydrogen atom at the 9-position is replaced by an aryl such as phenyl or an alkyl such as methyl.

The emission wavelength can be adjusted by the steric hindrance, electron donating and electron withdrawing properties of the structure of the substituents (first substituent, second substituent and combination of first and second substituents). Preferred are groups represented by the following structural formulas, more preferably methyl, t-butyl, t-amyl, t-octyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-t-butylcarbazolyl, and phenoxy, and even more preferably methyl, t-butyl, t-amyl, t-octyl, 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.

In the following structural formula, "Me" represents methyl, "tBu" represents t-butyl, "tAm" represents t-amyl, and "tOct" represents t-octyl.

Examples of the aryl, heteroaryl, aryl of diarylamino, heteroaryl of diheteroarylamino, aryl and heteroaryl of arylheteroarylamino, and aryl of aryloxy in R ¹ to R ⁹ in formula (2), R, R ^a1 to R ^a8 , R ^aa1 to R ^aa4 in formulas (1a), (1a- ¹ ) to (1a-15), and R, R a9 to R a16 in formula (1b) ^, and R ^b1 to R ^b13 in formulas (3), (4), (5), (6), (7), (8), (9), (10), (11), (12), (13), (14), and (15) include monovalent groups of "aryl ring" or "heteroaryl ring" explained in formula (1). In addition, for the alkyl or alkoxy in R ¹ to R ⁹ in formula (2), R, R ^a1 to R ^a8 in formula (1a), formula (1a-1) to formula (1a-15), and R, R ^a9 to R ^a16 in formula (1b), and R b1 to R b13 in formula (3), formula (4), formula (5), formula (6), formula (7), formula (8), formula (9), formula (10), formula (11), formula ( ¹² ), formula (13), formula ( ¹⁴ ), and formula (15), reference can be made to the explanation of "alkyl" or "alkoxy" as the first substituent in the explanation of formula (1) above. Furthermore, the same applies to aryl, heteroaryl, or alkyl as a substituent to these groups.

R of Si-R and Ge-R in Y ¹ of formula (1) is aryl, alkyl, or cycloalkyl, and specific examples of this aryl, alkyl, and cycloalkyl include the groups described above. In particular, aryls having 6 to 12 carbon atoms, aryls having 6 to 10 carbon atoms (e.g., phenyl, naphthyl, etc.), alkyls having 1 to 6 carbon atoms, and alkyls having 1 to 4 carbon atoms (e.g., methyl, ethyl, etc.) are preferred. This explanation also applies to Y 1 in formulas (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12), (13), (14), and ( ¹⁵ ).

R in >C(-R) ₂ and >Si(-R) ₂ in X ¹ , X ² , and X ³ in formula (1) is hydrogen, aryl which may be substituted with the above-mentioned second substituent, alkyl which may be substituted with the second substituent, or cycloalkyl which may be substituted with the second substituent. Specific 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.) and alkyl having 1 to 4 carbon atoms (e.g., methyl, ethyl, etc.) are preferred. R in >C(-R) ₂ in X ¹ , X ² , and X ³ in formula (1) is preferably methyl. This explanation also applies to X1, X2, and X3 in formulas (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12), ( ¹³ ), ( ¹⁴ ), and ( ¹⁵ ).

R of N-R in X ¹ , X ² , and X ³ of formula (1) is aryl which may be substituted with the second substituent, heteroaryl which may be substituted with the second substituent, alkyl which may be substituted with the second substituent, or cycloalkyl which may be substituted with the second substituent. Specific 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.), and alkyl having 1 to 4 carbon atoms (e.g., methyl, ethyl, etc.) are preferred. As R of N-R in ^{X 1} , X ² , and X ³ , methyl, t-butyl, t-amyl, t-octyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, or 2,4,6-mesityl are particularly preferred. This explanation also applies to X1, X2, and X3 in formulas (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12), ( ¹³ ), ( ¹⁴ ), and ( ¹⁵ ).

In formula (1), R in "-C(-R) ₂ -" which is a linking group is hydrogen, alkyl or aryl, and R in ">N-R" is alkyl or aryl which may be substituted with alkyl, and specific examples of the alkyl or aryl include the groups described above. In particular, alkyl having 1 to 6 carbon atoms, alkyl having 1 to 4 carbon atoms (e.g., methyl, ethyl, etc.), and aryl having 6 to 12 carbon atoms (e.g., phenyl, naphthyl, etc.) which may be substituted with alkyl having 1 to 6 carbon atoms or alkyl having 1 to 4 carbon atoms (e.g., methyl, ethyl, etc.) are preferred. This explanation also applies to the linking groups "-C(-R) 2 -" and ">N-R" in formulas (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12), (13), ( ₁₄ ), and (15).

The linking group "arylene" and "arylene having 6 to 30 carbon atoms" in formula (1) can be a divalent group having the same structure as the aryl described above. This explanation also applies to the linking group "arylene having 6 to 12 carbon atoms" in formulas (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12), (13), (14), and (15).

The multimer of the polycyclic aromatic compound having two unit structures represented by formula (1) is preferably a dimer. The dimer is preferably a dimer of a polycyclic aromatic compound having two unit structures represented by any one of formulas (3) to (15). The dimer may be in a form having two of the above unit structures in one compound, and may be in a form in which the above unit structures are bonded together by a linking group such as a single bond, an alkylene having 1 to 3 carbon atoms, phenylene, or naphthylene, or in which any ring (ring A, ring B, or ring C, etc.) contained in the above unit structure is shared by two unit structures, or in which any ring (ring A, ring B, or ring C) contained in the above unit structure is bonded together so as to be condensed.

Examples of such dimers include dimers represented by the following formula (2-4), formula (2-5), or formula (2-6). That is, when explained using formula (2), it is a dimer having two unit structures represented by formula (2) in one compound, with the benzene ring being the a-ring being shared. Also, when explained using formula (2-5), it is a dimer having two unit structures represented by formula (2) in one compound, with the benzene ring being the a-ring being shared with X ^2. Also, when explained using formula (2-6), it is a dimer having two unit structures represented by formula (2) in one compound, with the benzene ring being the a-ring (or b-ring, c-ring) of a certain unit structure being condensed with the benzene ring being the a-ring (or b-ring, c-ring) of a certain unit structure. In the following formula, the definitions of Y ¹ , X ¹ , X ² , X ³ , R ¹ and R ³ to R ⁹ are the same as those in formula (2).

In addition, all or a part of hydrogen in the chemical structure of the polycyclic aromatic compound and its multimer represented by any one of formulas (1) and (2) to (15) may be cyano, halogen, or deuterium. For example, in formula (1), hydrogen in ring A, ring B, ring C (rings A to C are aryl rings or heteroaryl rings), substituents on rings A to C, R when Y ¹ is Si-R or Ge-R, and R when X ¹ , X ² and X ³ are >C(-R) ₂ or N-R may be replaced with cyano, halogen, or deuterium, and among these, there is an embodiment in which all or a part of hydrogen in aryl or heteroaryl is replaced with cyano, halogen, or deuterium. The halogen is fluorine, chlorine, bromine, or iodine, preferably fluorine, chlorine, or bromine, and more preferably chlorine.

At least one selected from the group consisting of aryl rings and heteroaryl rings in the chemical structures of the polycyclic aromatic compounds represented by formulas (1) to (15) and their multimers may be condensed with at least one cycloalkane.

For example, at least one of the A ring, B ring, C ring, a ring, b ring, c ring, aryl ring and heteroaryl ring in the fused ring, aryl (aryl moiety in aryl, diarylamino, arylheteroarylamino, diarylboryl or aryloxy) and heteroaryl (heteroaryl moiety in heteroaryl, diheteroarylamino or arylheteroarylamino) as the first and second substituents, aryl (similar ^{to above} ) as R in Si-R and Ge- ^R which are ^Y1 , and aryl (similar to above) and heteroaryl (similar to ^above ) as R in >N-R, >Si(-R) ₂ and >C(-R) ₂ which are X1, X2 and X3 may be fused with at least one cycloalkane.

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

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

Among these, for example, a structure in which at least one hydrogen atom is substituted on the α-position carbon of a cycloalkane (the carbon atom adjacent to the carbon atom at the condensation site in a cycloalkyl fused to an aromatic ring or heteroaromatic ring) is preferred, a structure in which two hydrogen atoms are substituted on the α-position carbon is more preferred, and a structure in which a total of four hydrogen atoms are substituted on the two α-position carbons is even more preferred. Examples of such a substituent include an alkyl (particularly methyl) substituent having 1 to 5 carbon atoms, a halogen (particularly fluorine) substituent, and a deuterium substituent.

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

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

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

Other forms of cycloalkane condensation include polycyclic aromatic compounds and multimers thereof represented by formulas (1) to (15), such as >N-R, where R is an aryl condensed with a cycloalkane, diarylamino condensed with a cycloalkane (condensed to the aryl portion), carbazolyl condensed with a cycloalkane (condensed to the benzene ring portion), or benzocarbazolyl condensed with a cycloalkane (condensed to the benzene ring portion). Examples of "diarylamino" include the groups described above as the "first substituent."

Further, as a more specific example, there can be mentioned an example in which ^R2 in the polycyclic aromatic compound represented by formula (2) and its multimer is a diarylamino condensed with a cycloalkane (condensed to the aryl portion) or a carbazolyl condensed with a cycloalkane (condensed to the benzene ring portion).

The polycyclic aromatic compound and its multimer of 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. In particular, in the organic electroluminescent device, the dopant material of the emitting layer is preferably a compound in which Y ¹ is B and X ¹ , X ² and X ³ are N-R, a compound in which Y ¹ is B and one of X ¹ , X ² and X ³ is O and the others are N-R, a compound in which Y ¹ is B and two of X ¹ , X ² and X ³ are O and the others are N-R, a compound in which Y ¹ is B and two of X ¹ , X ² and X ³ are >C(-R) ₂ and the others are N-R, a compound in which Y ¹ is B and two of X 1 , X ² and X ³ are >C(-R) 2 and the others are O, and a compound in which Y ¹ is B and two of X 1 , X 2 and X ³ are >C(-R) ₂ and the others are O. As the host material of the emitting layer, a compound in which Y 1 is B or P=O and X ¹ , X ² and X ³ are N-R, A compound in which ^Y1 is B or P=O, one of ^X1 , ^X2 , and ^X3 is O, and the others are N-R, and a compound in which ^Y1 is B or P=O, two of ^X1 , ^X2 , and ^X3 are O, and the others are N-R are preferred, and as an electron transporting material, a compound in which ^Y1 is B or P=O, and ^X1 , ^X2 , and ^X3 are O, a compound in which ^Y1 is B or P=O, and ^X1 , ^X2 , and ^X3 are S, a compound in which ^Y1 is B or P=O, and ^X1 , ^X2 , and ^X3 are >C(-R) ₂ , and a compound in which ^Y1 is B or P=O, two of ^X1 , ^X2 , and ^X3 are O, and the others are N-R are preferably used.

Specific examples of the polycyclic aromatic compounds of the present invention include compounds represented by the following chemical structural formulas. In the chemical structural formulas, Me is methyl, tBu is tert-butyl, and tAm is t-amyl.

The polycyclic aromatic compound represented by formula (1) according to the present invention and its multimer can also be used as a polymer compound obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer (the monomer for obtaining this polymer compound has a polymerizable substituent), or as a crosslinked polymer obtained by further crosslinking the polymer compound (the polymer compound for obtaining this crosslinked polymer has a crosslinkable substituent), or as a pendant polymer compound obtained by reacting a main chain polymer with the reactive compound (the reactive compound for obtaining this pendant polymer compound has a reactive substituent), or as a pendant polymer crosslinked polymer obtained by further crosslinking the pendant polymer compound (the pendant polymer compound for obtaining this pendant polymer crosslinked polymer has a crosslinkable substituent), for example, as a material for an organic device, for example, a material for an organic electroluminescent element, a material for an organic field effect transistor, or a material for an organic thin-film solar cell.

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

L ^X are each independently a single bond, -O-, -S-, >C=O, -O-C(=O)-, an alkylene having 1 to 12 carbon atoms, an oxyalkylene having 1 to 12 carbon atoms, and a polyoxyalkylene having 1 to 12 carbon atoms. Among the above substituents, a group represented by formula (XLS-1), formula (XLS-2), formula (XLS-3), formula (XLS-9), formula (XLS-10) or formula (XLS-17) is preferred, and a group represented by formula (XLS-1), formula (XLS-3) or formula (XLS-17) is 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 and their multimers Basically, polycyclic aromatic compounds and their dimers represented by formula (1) or (2) are produced by first bonding ring A (ring a), ring B (ring b) and ring C (ring c) with a bonding group (group containing X ¹ , X ² , X ³ ) 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 (group containing Y ¹ ) to produce a final product (second reaction). In the first reaction, for example, if it is an etherification reaction, a general reaction such as a nucleophilic substitution reaction or an Ullmann reaction can be used, and if it is an amination reaction, a general reaction such as a Buchwald-Hartwig reaction can be used. In addition, in the second reaction, a tandem hetero Friedel-Crafts reaction (successive aromatic electrophilic substitution reaction, the same applies below) can be used. In the following schemes, the definitions of Y ¹ , X ¹ , X ² , X ³ , R ¹ to R ⁹ and R are the same as those in formula (1) or formula (2).

The second reaction is a reaction for introducing Y ¹ which bonds the A ring (a ring), the B ring (b ring) and the C ring (c ring) as shown in the following schemes (1) and (2). An example in which Y ¹ is a boron atom and X ¹ , X ² and X ³ are >N-R is shown below. First, the hydrogen atoms between X ¹ , X ² and X ³ are orthometalated with n-butyllithium, sec-butyllithium or t-butyllithium. Next, boron trichloride, boron tribromide or the like is added to carry out lithium-boron metal exchange, and then a tandem boron-Friedel-Crafts reaction is carried out by adding a Bronsted base such as N,N-diisopropylethylamine to obtain the target product. In the second reaction, a Lewis acid such as aluminum trichloride may be added to promote the reaction.

The above schemes (1) and (2) mainly show the method for producing the polycyclic aromatic compounds represented by formulas (1) and (2), but the dimers can be produced by using intermediates having multiple A rings (a rings), B rings (b rings) and C rings (c rings). Details are explained in the following schemes (3) and (4). In this case, the target product can be obtained by doubling the amount of the reagent such as butyllithium used.

In the above scheme, lithium was introduced at the desired position by orthometalation, but as in schemes (5) and (6) below, lithium can also be introduced at the desired position by introducing a halogen atom (Hal) at the desired position and then performing halogen-metal exchange.

In addition, for the methods for producing dimers described in schemes (3) and (4), lithium can also be introduced to the desired position by introducing a halogen such as a bromine atom or a chlorine atom into the position where lithium is to be introduced, as in schemes (5) and (6) above, and then by halogen-metal exchange (schemes (7) and (8) below).

This method is useful because it allows the synthesis of the desired product even in cases where ortho-metallation is not possible due to the influence of substituents.

By appropriately selecting the above-mentioned synthesis method and the raw materials to be used, it is possible to synthesize a polycyclic aromatic compound and a dimer thereof having substituents at desired positions, in which Y ¹ is a boron atom, and X ¹ , X ² and X ³ are nitrogen atoms.

Next, as an example, the case where Y ¹ is a boron atom, X ¹ and X ² are nitrogen atoms, and X ³ is an oxygen atom is shown in the following schemes (9) and (10). As in the case where X ¹ , X ² , and X ³ are all nitrogen atoms, a halogen such as a bromine atom or a chlorine atom is introduced at the position where lithium is to be introduced, and n-butyllithium or the like is allowed to act to metalize by halogen-metal exchange. Next, boron tribromide or the like is added to perform lithium-boron metal exchange, and then a Bronsted base such as N,N-diisopropylethylamine is added to perform a tandem boron-Friedel-Crafts reaction to obtain the target product. Here, a Lewis acid such as aluminum trichloride may be added to promote the reaction.

In addition, in the case of a dimer in which ^Y1 is a boron atom, ^X1 and ^X2 are nitrogen atoms, and ^X3 is an oxygen atom, lithium can also be introduced into the desired position by introducing a halogen such as a bromine atom or a chlorine atom into the position where lithium is to be introduced as in the above schemes (7) and (8) and then subjecting the halogen to halogen-metal exchange (the following schemes (11) and (12)).

Next, as an example, the case where Y ¹ is phosphorus sulfide, phosphorus oxide or phosphorus atom, and X ¹ , X ² , and X ³ are all nitrogen atoms is shown in the following schemes (13) to (16). As in the above, first, a halogen such as a bromine atom or a chlorine atom is introduced at the position where lithium is to be introduced, and metalization is performed by halogen-metal exchange. Next, phosphorus trichloride and sulfur are added in this order, and finally, a Lewis acid such as aluminum trichloride and a Bronsted base such as N,N-diisopropylethylamine are added to perform a tandem phospha Friedel-Crafts reaction, thereby obtaining a compound in which Y ¹ is phosphorus sulfide. In addition, a compound in which Y ¹ is phosphorus oxide can be obtained by treating the obtained phosphorus sulfide compound with m-chloroperbenzoic acid (m-CPBA), and a compound in which Y ¹ is a phosphorus atom can be obtained by treating the obtained phosphorus oxide compound with triethylphosphine.

In addition, for a dimer in which Y ¹ is phosphorus sulfide and X ¹ , X ² , and X ³ are all nitrogen atoms, a halogen such as a bromine atom or a chlorine atom can be introduced into the desired position as in the above schemes (7) and (8), and lithium can be introduced into the desired position by halogen-metal exchange (the following schemes (17) and (18)). In addition, for a dimer in which Y ¹ is phosphorus sulfide and X ¹ , X ² , and X ³ are all nitrogen atoms, a compound in which Y ¹ is phosphorus oxide can be obtained by treating the phosphorus sulfide compound with m-chloroperbenzoic acid (m-CPBA) as in the above schemes (15) and (16), and a compound in which Y ¹ is a phosphorus atom can be obtained by treating the obtained phosphorus oxide compound with triethylphosphine.

Here, an example is described in which Y ¹ is B, P, P=O or P=S, and X ¹ , X ² and X ³ are N-R or O, but by appropriately changing the raw material, it is also possible to synthesize a compound in which Y ¹ is P(-R) ₂ , Al, Ga, As, Si-R, Ge-R, Sn-R, Sb, Sb=O, Sb=S, Sb(-R) ₂ , Sb bonded with orthochloranil, Bi, Bi=O, Bi=S, Bi(-R) ₂ or Bi bonded with orthochloranil, or X ¹ , X ² and X ³ are S. It is also possible to convert Sn from a compound in which Y ¹ is Sn-R to another transition metal.

Specific examples of solvents used in the above reactions include t-butylbenzene and xylene.

In addition, in formula (2), adjacent groups among the substituents R ¹ to R ⁹ of the ring a, ring b, and ring c may be bonded to each other to form an aryl ring or a heteroaryl ring together with the ring a, ring b, or ring c, and at least one hydrogen atom in the formed ring may be substituted with an aryl or a heteroaryl. Therefore, the ring structure constituting the polycyclic aromatic compound represented by formula (2) changes as shown in formulas (2-1) and (2-2) in the following schemes (19) and (20) depending on the mutual bonding form of the substituents in the ring a, ring b, and ring c. These compounds can be synthesized by applying the synthetic methods shown in the above schemes (1) to (18) to the intermediates shown in the following schemes (19) and (20).

The rings A', B' and C' in the above formula (2-1) and formula (2-2) represent aryl or heteroaryl rings formed by bonding adjacent groups among the substituents R ¹ to R ⁹ together with the rings a, b and c, respectively (they may also be considered as condensed rings formed by condensing other ring structures to the rings a, b or c). Although not shown in the formula, there are also compounds in which the rings a, b and c are all changed to the rings A', B' and C'.

The provision in formula (2) that "R of N-R is bonded to the ring a, ring b and/or ring c by -O-, -S-, -C(-R) _2- , >N-R, arylene, a single bond or condensation" can be expressed by a compound having a ring structure in which ^X1 or ^X2 is incorporated into fused ring B' or fused ring C', as represented by formula (2-3-1) in the following scheme (21), or a compound having a ring structure in which ^X1 or ^X2 is incorporated into fused ring A', as represented by formula (2-3-2) or formula (2-3-3). These compounds can be synthesized by applying the synthetic methods shown in the above schemes (1) to (18) to the intermediates shown in the following scheme (21).

In the above synthesis schemes (1) to (14) and (17) to (21), examples have been shown in which a tandem hetero Friedel-Crafts reaction was carried out by ortho-metalating the hydrogen atoms (or halogen atoms) between X ¹ , X ² , and X ³ with butyllithium or the like before adding boron trichloride, boron tribromide, or the like. However, the reaction can also be carried out by adding boron trichloride, boron tribromide, or the like without carrying out ortho-metalating using butyllithium or the like.

When ^Y1 is a phosphorus-based compound, as shown in the following schemes (22) and (23), the hydrogen atom (or halogen atom) between ^X1 and ^X2 and ^X3 (>NR in the following formula) can be orthometalated with n-butyllithium, sec-butyllithium, t-butyllithium, or the like, and then bisdiethylaminochlorophosphine is added to carry out lithium-phosphorus metal exchange, followed by adding a Lewis acid such as aluminum trichloride to carry out a tandem phospha Friedel-Crafts reaction to obtain the target compound. This reaction method is also described in WO 2010/104047 (e.g., page 27).

In the above schemes (22) and (23), a dimer can be synthesized by using an orthometalation reagent such as butyllithium in a molar amount twice that of intermediate 1. Also, a halogen such as a bromine atom or a chlorine atom can be introduced in advance to the position where a metal such as lithium is to be introduced, and then the metal can be introduced to the desired position by halogen-metal exchange.

The orthometalation reagents used in the above schemes (1) to (23) include alkyllithiums such as methyllithium, n-butyllithium, sec-butyllithium, and t-butyllithium, and organic alkali compounds such as lithium diisopropylamide, lithium tetramethylpiperidide, lithium hexamethyldisilazide, and potassium hexamethyldisilazide.

Examples of the metal exchange reagent for metal- ^Y1 used in the above schemes (1) to (23) include halides of Y1 such as trifluoride of ^Y1 , trichloride of ^Y1 , tribromide of ^Y1 , and triiodide of ^Y1 , amidohalides of ^Y1 such as CIPN( _NEt2 ) ₂ , alkoxylates of ^Y1 , and aryloxylates of ^{Y1 .}

Examples of Bronsted bases used in the above schemes (1) to (23) include N,N-diisopropylethylamine, triethylamine, 2,2,6,6-tetramethylpiperidine, 1,2,2,6,6-pentamethylpiperidine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2,6-lutidine, sodium tetraphenylborate, potassium tetraphenylborate, triphenylborane, tetraphenylsilane, Ar ₄ BNa, Ar ₄ BK, Ar ₃ B, and Ar ₄ Si (Ar is an aryl such as phenyl).

Examples of Lewis acids used in the above schemes (1) to (23) include _AlCl3 , AlBr3, _AlF3 , _BF3.OEt2 , _BCl3 , _BBr3 , _GaCl3 , _GaBr3 , _InCl3 , _InBr3 , In(OTf) ₃ , _SnCl4 , _SnBr4 , AgOTf, _ScCl3 , Sc ₍ OTf) ₃ , ZnCl2, _ZnBr2 , Zn(OTf) ₂ , _MgCl2 , _MgBr2 , Mg(OTf) ₂ , LiOTf, NaOTf, KOTf, Me3SiOTf, Cu(OTf) _{2 , CuCl2 , YCl3} , and Y(OTf) _{3 .} , _TiCl4 , _TiBr4 , _ZrCl4 , _ZrBr4 , _FeCl3 , _FeBr3 , _CoCl3 , _CoBr3 , etc.

In the above schemes (1) to (23), a Bronsted base or Lewis acid may be used to promote the tandem hetero Friedel-Crafts reaction. However, when a halide of Y 1 such as trifluoride of Y ¹ , trichloride of Y ¹ , tribromide of Y ¹ , or triiodide of Y ¹ is used, acids such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide are generated as the aromatic electrophilic substitution reaction proceeds, so ^it is effective to use a Bronsted base to capture the acid. On the other hand, when an amino halide of Y ¹ or an alkoxylated product of Y ¹ is used, amines and alcohols are generated as the aromatic electrophilic substitution reaction proceeds, so in many cases it is not necessary to use a Bronsted base, but since the amino group and alkoxy group have low elimination ability, it is effective to use a Lewis acid to promote their elimination.

In the above, the case where X ¹ , X ² , and X ³ are >N-R has been mainly shown, but for compounds where X ¹ , X ² , and X ³ are >C(-R) ₂ , the raw material compound is changed and the compound can be synthesized by the method described in Organic & Biomolecular Chemistry, 2019, 17, 5500-5504 by Yamaguchi et al.

The polycyclic aromatic compounds and their multimers of the present invention also include compounds in which at least some of the hydrogen atoms are replaced by cyano, deuterium, or halogens such as fluorine or chlorine. Such compounds can be synthesized in the same manner as above by using raw materials in which the desired sites are cyanated, deuterized, fluorinated, or chlorinated.

3. Organic Devices The compound of the present invention (polycyclic aromatic compound represented by formula (1) and its multimer, reactive compound in which any of the above is substituted with a reactive substituent, polymer compound obtained by polymerizing any of the above, crosslinked polymer, pendant polymer compound, or pendant crosslinked polymer) 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.

3-1. Organic electroluminescence element The compound of the present invention can be used, for example, as a material for an organic electroluminescence element. The organic EL element according to this embodiment will be described in detail below with reference to the drawings. Figure 1 is a schematic cross-sectional view showing an organic EL element according to this embodiment.

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

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

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

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

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

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

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

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

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

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

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

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

The above-mentioned hole injection layer material and hole transport layer material can also be used as a hole layer material in the form of a polymer compound obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer, or a crosslinked polymer thereof, or a pendant polymer compound obtained by reacting a main chain polymer with the reactive compound, or a crosslinked pendant polymer thereof. In this case, the explanation of the polycyclic aromatic compound represented by formula (1) can be cited as the reactive substituent.
The applications 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 for the light-emitting layer 105 may be a compound that is excited and emits light by the recombination of holes and electrons (light-emitting compound), and is preferably a compound that can be formed into a stable thin film shape and shows strong light-emitting (fluorescence) efficiency in a solid state.

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

The compound of the present invention is preferably used as a material for the light-emitting layer, and is particularly preferably used as a dopant material.

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

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

Examples of host materials include condensed ring derivatives such as anthracene, pyrene, dibenzochrysene, and fluorene, which have long been known as light emitters, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, and cyclopentadiene derivatives. In particular, anthracene-based compounds, fluorene-based compounds, and dibenzochrysene-based compounds are preferred.

<<Host Material>>
<Anthracene-based compounds>
The anthracene-based compound as the host is, for example, a compound represented by the following formula (H3).

In formula (H3),
X and Ar ⁴ are each independently hydrogen, an optionally substituted aryl, an optionally substituted heteroaryl, an optionally substituted diarylamino, an optionally substituted diheteroarylamino, an optionally substituted arylheteroarylamino, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted alkenyl, an optionally substituted alkoxy, an optionally substituted aryloxy, an optionally substituted arylthio or an optionally substituted silyl, and all of X and Ar ⁴ are not hydrogen at the same time;
At least one hydrogen in the compound represented by formula (H3) may be substituted with halogen, cyano, deuterium or an optionally substituted heteroaryl.

A polymer (preferably a dimer) may be formed using the structure represented by formula (H3) as a unit structure. In this case, for example, the unit structures represented by formula (H3) may be bonded to each other via X, where X may be a single bond, an arylene (phenylene, biphenylene, naphthylene, etc.), or a heteroarylene (a pyridine ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a benzocarbazole ring, a phenyl-substituted carbazole ring, etc., having a divalent bond).

Details of the above aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, aryloxy, arylthio, or silyl are described in the preferred embodiments section below. In addition, examples of substituents for these include aryl, heteroaryl, diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy, aryloxy, arylthio, or silyl, and details of these are also described in the preferred embodiments section below.

Preferred embodiments of the above anthracene-based compounds are described below. The symbols in the structures below are defined as above.

In formula (H3), X is each independently a group represented by formula (3-X1), formula (3-X2) or formula (3-X3) above, and the group represented by formula (3-X1), formula (3-X2) or formula (3-X3) is bonded to the anthracene ring of formula (H3) at *. Preferably, two Xs are not simultaneously a group represented by formula (3-X3). More preferably, two Xs are not simultaneously a group represented by formula (3-X2).

A polymer (preferably a dimer) may be formed using the structure represented by formula (H3) as a unit structure. In this case, for example, the unit structures represented by formula (H3) may be bonded to each other via X, where X may be a single bond, an arylene (phenylene, biphenylene, naphthylene, etc.), or a heteroarylene (a pyridine ring, a dibenzofuran ring, a dibenzothiophene ring, a carbazole ring, a benzocarbazole ring, a phenyl-substituted carbazole ring, etc., having a divalent bond).

The naphthylene moieties in formula (3-X1) and formula (3-X2) may be condensed with one benzene ring. The condensed structures are as follows:

Ar ¹ and Ar ² are each independently hydrogen, phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenylyl, or a group represented by the above formula (A) (including carbazolyl, benzocarbazolyl, and phenyl-substituted carbazolyl). When Ar ¹ or Ar ² is a group represented by formula (A), the group represented by formula (A) is bonded to the naphthalene ring in formula (3-X1) or formula (3-X2) at the *.

Ar ³ is phenyl, biphenylyl, terphenylyl, quaterphenylyl, naphthyl, phenanthryl, fluorenyl, benzofluorenyl, chrysenyl, triphenylenyl, pyrenylyl, or a group represented by the above formula (A) (including carbazolyl, benzocarbazolyl, and phenyl-substituted carbazolyl). When Ar ³ is a group represented by formula (A), the group represented by formula (A) is bonded to the single bond represented by a straight line in formula (3-X3) at the *. That is, the anthracene ring of formula (H3) and the group represented by formula (A) are directly bonded.

In addition, Ar ³ may have a substituent, and at least one hydrogen atom in Ar ³ may be further substituted with an alkyl having 1 to 4 carbon atoms, a cycloalkyl having 5 to 10 carbon atoms, phenyl, biphenylyl, terphenylyl, naphthyl, phenanthryl, fluorenyl, chrysenyl, triphenylenyl, pyrenylyl, or a group represented by the above formula (A) (including carbazolyl and phenyl-substituted carbazolyl). When the substituent in Ar ³ is a group represented by formula (A), the group represented by formula (A) bonds to Ar ³ in formula (3-X3) at the *.

Each Ar ⁴ is independently hydrogen, phenyl, biphenylyl, terphenylyl, naphthyl, or silyl substituted with alkyl having 1 to 4 carbon atoms (eg, methyl, ethyl, t-butyl) and/or cycloalkyl having 5 to 10 carbon atoms.

Examples of alkyl groups with 1 to 4 carbon atoms that substitute for silyl include methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, and cyclobutyl, and each of the three hydrogen atoms in the silyl is independently replaced by one of these alkyl groups.

Specific examples of "silyl substituted with alkyl having 1 to 4 carbon atoms" include trimethylsilyl, triethylsilyl, tripropylsilyl, tri-i-propylsilyl, tributylsilyl, trisec-butylsilyl, tri-t-butylsilyl, ethyldimethylsilyl, propyldimethylsilyl, i-propyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, i-propyldiethylsilyl, butyldiethylsilyl, sec-butyldiethylsilyl, t-butyldiethylsilyl, methyldipropylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, t-butyldipropylsilyl, methyldi-i-propylsilyl, ethyldi-i-propylsilyl, butyldi-i-propylsilyl, sec-butyldi-i-propylsilyl, and t-butyldi-i-propylsilyl.

Examples of cycloalkyls having 5 to 10 carbon atoms that substitute for silyl include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, norbornenyl, bicyclo[1.1.1]pentyl, bicyclo[2.0.1]pentyl, bicyclo[1.2.1]hexyl, bicyclo[3.0.1]hexyl, bicyclo[2.1.2]heptyl, bicyclo[2.2.2]octyl, adamantyl, decahydronaphthalenyl, and decahydroazulenyl, and each of the three hydrogens in the silyl is independently replaced by one of these cycloalkyls.

Specific examples of "silyl substituted with cycloalkyl having 5 to 10 carbon atoms" include tricyclopentylsilyl and tricyclohexylsilyl.

Substituted silyls include dialkylcycloalkylsilyls, which are substituted with two alkyls and one cycloalkyl, and alkyldicycloalkylsilyls, which are substituted with one alkyl and two cycloalkyls. Specific examples of the alkyl and cycloalkyl substituents are the groups mentioned above.

In addition, hydrogen in the chemical structure of the anthracene compound represented by formula (H3) may be substituted with a group represented by formula (A) above. When substituted with a group represented by formula (A), the group represented by formula (A) replaces at least one hydrogen in the compound represented by formula (H3) at the *.

The group represented by formula (A) is one of the substituents that the anthracene compound represented by formula (H3) may have.

In the above formula (A), Y is -O-, -S- or >N-R ²⁹ , R ²¹ to R ²⁸ are each independently hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted alkoxy, optionally substituted aryloxy, optionally substituted arylthio, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, optionally substituted amino, halogen, hydroxy or cyano, adjacent groups among R ²¹ to R ²⁸ may be bonded to each other to form a hydrocarbon ring, an aryl ring or a heteroaryl ring, and R ²⁹ is hydrogen or optionally substituted aryl.

The "alkyl" in the "optionally substituted alkyl" in R ^{to R} 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. An alkyl having 1 to 18 carbon atoms (branched alkyl having 3 to 18 carbon atoms) is preferred, an alkyl having 1 to 12 carbon atoms (branched alkyl having 3 to 12 carbon atoms) is more preferred, an alkyl having 1 to 6 carbon atoms (branched alkyl having 3 to 6 carbon atoms) is even more preferred, and an alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms) is particularly preferred.

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

Examples of the "cycloalkyl" in the "optionally substituted cycloalkyl" in R ^{to R} include cycloalkyl having 3 to 24 carbon atoms, cycloalkyl having 3 to 20 carbon atoms, cycloalkyl having 3 to 16 carbon atoms, cycloalkyl having 3 to 14 carbon atoms, cycloalkyl having 5 to 10 carbon atoms, cycloalkyl having 5 to 8 carbon atoms, cycloalkyl having 5 to 6 carbon atoms, and cycloalkyl having 5 carbon atoms.

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

The "aryl" in the "optionally substituted aryl" in R ^{to R} is, for example, an aryl having 6 to 30 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 "aryl" include monocyclic phenyl, bicyclic ...

Examples of the "heteroaryl" in the "optionally substituted heteroaryl" in R ^{to R} include heteroaryl having 2 to 30 carbon atoms, preferably heteroaryl having 2 to 25 carbon atoms, more preferably heteroaryl having 2 to 20 carbon atoms, still more preferably heteroaryl having 2 to 15 carbon atoms, and particularly preferably heteroaryl having 2 to 10 carbon atoms. Examples of the heteroaryl include heterocycles containing, as ring-constituting atoms other than carbon, 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen.

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

Examples of the "alkoxy" in the "optionally substituted alkoxy" in R to ^R include linear alkoxy having 1 to 24 carbon atoms or branched alkoxy having 3 to 24 carbon atoms. An alkoxy having ¹ to 18 carbon atoms (branched alkoxy having 3 to 18 carbon atoms) is preferred, an alkoxy having 1 to 12 carbon atoms (branched alkoxy having 3 to 12 carbon atoms) is more preferred, an alkoxy having 1 to 6 carbon atoms (branched alkoxy having 3 to 6 carbon atoms) is even more preferred, and an alkoxy having 1 to 4 carbon atoms (branched alkoxy having 3 to 4 carbon atoms) is particularly preferred.

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

The "aryloxy" in the "optionally substituted aryloxy" in R ^{to R} is a group in which the hydrogen of the -OH group is substituted with an aryl, and the aryl can be any of the groups explained above as the "aryl" in R ^{to R.}

The "arylthio" in the "optionally substituted arylthio" in R ^{to R} is a group in which the hydrogen of the -SH group is replaced by an aryl, and the aryl can be any of the groups explained as the "aryl" in R ^{to R} above.

The "trialkylsilyl" in R ²¹ to R ²⁸ includes a group in which three hydrogen atoms in a silyl group are each independently substituted with an alkyl, and this alkyl can be cited from the groups explained above as the "alkyl" in R ²¹ to R ^28. The alkyl to be substituted is preferably an alkyl having 1 to 4 carbon atoms, and specific examples thereof include methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, t-butyl, cyclobutyl, and the like.

Specific examples of "trialkylsilyl" include trimethylsilyl, triethylsilyl, tripropylsilyl, tri-i-propylsilyl, tributylsilyl, trisec-butylsilyl, tri-t-butylsilyl, ethyldimethylsilyl, propyldimethylsilyl, i-propyldimethylsilyl, butyldimethylsilyl, sec-butyldimethylsilyl, t-butyldimethylsilyl, methyldiethylsilyl, propyldiethylsilyl, i-propyldiethylsilyl, butyldiethylsilyl, sec-butyldiethylsilyl, t-butyldiethylsilyl, methyldipropylsilyl, ethyldipropylsilyl, butyldipropylsilyl, sec-butyldipropylsilyl, t-butyldipropylsilyl, methyldi-i-propylsilyl, ethyldi-i-propylsilyl, butyldi-i-propylsilyl, sec-butyldi-i-propylsilyl, and t-butyldi-i-propylsilyl.

The "tricycloalkylsilyl" in R ²¹ to R ²⁸ includes a group in which three hydrogen atoms in a silyl group are each independently replaced with a cycloalkyl, and this cycloalkyl can be cited from the groups explained above as the "cycloalkyl" in R ²¹ to R ^28. Preferred cycloalkyl for substitution is a cycloalkyl having 5 to 10 carbon atoms, and specific examples thereof include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclo[1.1.1]pentyl, bicyclo[2.0.1]pentyl, bicyclo[1.2.1]hexyl, bicyclo[3.0.1]hexyl, bicyclo[2.1.2]heptyl, bicyclo[2.2.2]octyl, adamantyl, decahydronaphthalenyl, and decahydroazulenyl.

Specific examples of "tricycloalkylsilyl" include tricyclopentylsilyl and tricyclohexylsilyl.

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

The "substituted amino" in the "optionally substituted amino" in R ²¹ to R ²⁸ includes, for example, an amino group in which two hydrogen atoms are substituted with aryl or heteroaryl. An amino group in which two hydrogen atoms are substituted with aryl atoms is a diaryl-substituted amino, an amino group in which two hydrogen atoms are substituted with heteroaryl atoms is a diheteroaryl-substituted amino, and an amino group in which two hydrogen atoms are substituted with an aryl and a heteroaryl atom is an arylheteroaryl-substituted amino. The aryl and heteroaryl groups can be cited from the groups explained as "aryl" and "heteroaryl" in R ²¹ to R ²⁸ above.

Specific examples of "substituted amino" include diphenylamino, dinaphthylamino, phenylnaphthylamino, dipyridylamino, phenylpyridylamino, and naphthylpyridylamino.

The "halogen" in R ²¹ to R ²⁸ includes fluorine, chlorine, bromine and iodine.

Some of the groups described as R ²¹ to R ²⁸ may be substituted as described above, and in this case, the substituents include alkyl, cycloalkyl, aryl, or heteroaryl. The alkyl, cycloalkyl, aryl, or heteroaryl may refer to the groups described as "alkyl", "cycloalkyl", "aryl", or "heteroaryl" in R ²¹ to R ²⁸ above.

R ²⁹ in ">N-R ²⁹ " as Y is hydrogen or an optionally substituted aryl, and examples of this aryl include the groups described above as "aryl" in R ²¹ to R ²⁸ , and examples of the substituents include the groups described above as the substituents for R ²¹ to R ²⁸ .

Adjacent groups among R ²¹ to R ²⁸ may be bonded to each other to form a hydrocarbon ring, an aryl ring, or a heteroaryl ring. The group represented by the following formula (A-1) does not form a ring, and examples of the group represented by the following formulas (A-2) to (A-14) include groups represented by the following formulas. At least one hydrogen atom in the group represented by any of formulas (A-1) to (A-14) may be substituted with alkyl, cycloalkyl, aryl, heteroaryl, alkoxy, aryloxy, arylthio, trialkylsilyl, tricycloalkylsilyl, dialkylcycloalkylsilyl, alkyldicycloalkylsilyl, diaryl-substituted amino, diheteroaryl-substituted amino, arylheteroaryl-substituted amino, halogen, hydroxy, or cyano.

Examples of rings formed by bonding adjacent groups to each other include hydrocarbon rings such as cyclohexane rings, and examples of aryl rings and heteroaryl rings include the ring structures explained in relation to "aryl" and "heteroaryl" in R ^to R ^above . These rings are formed so as to be condensed with one or two benzene rings in the above formula (A-1).

Examples of the group represented by formula (A) include groups represented by any of the above formulas (A-1) to (A-14), with groups represented by any of the above formulas (A-1) to (A-5) and (A-12) to (A-14) being preferred, groups represented by any of the above formulas (A-1) to (A-4) being more preferred, groups represented by any of the above formulas (A-1), (A-3) and (A-4) being even more preferred, and groups represented by the above formula (A-1) being particularly preferred.

As described above, the group represented by formula (A) is bonded to the naphthalene ring in formula (3-X1) or formula (3-X2), the single bond in formula (3-X3), or Ar ³ in formula (3-X3) at * in formula (A), and is also substituted for at least one hydrogen in the compound represented by formula (H3). Among these bonding forms, the bonding form to the naphthalene ring in formula (3-X1) or formula (3-X2), the single bond in formula (3-X3), and/or Ar ³ in formula (3-X3) is preferred.

In addition, in the structure of the group represented by formula (A), the naphthalene ring in formula (3-X1) or formula (3-X2), the single bond in formula (3-X3), and the position at which Ar ³ in formula (3-X3) is bonded, and in the structure of the group represented by formula (A), the position at which at least one hydrogen in the compound represented by formula (H3) is substituted, may be any position in the structure of formula (A), and can be bonded, for example, to any of the two benzene rings in the structure of formula (A), to any ring formed by bonding adjacent groups among R ²¹ to R ²⁸ in the structure of formula (A), or to any position in R ²⁹ in “>N-R ²⁹ ” as Y in the structure of formula (A).

Examples of the group represented by formula (A) include the following groups: In the formula, Y and * are defined as above.

In addition, all or some of the hydrogen atoms in the chemical structure of the anthracene compound represented by formula (H3) may be deuterium.

Specific examples of anthracene compounds include compounds represented by the following formulas (H3-1) to (H3-72). In the structural formulas below, "Me" stands for methyl, "D" stands for deuterium, and "tBu" stands for t-butyl.

The anthracene compound represented by formula (H3) can be produced by applying Suzuki coupling, Negishi ^{coupling, or other known coupling reactions using a compound having a reactive group at a desired position of the anthracene skeleton and a compound having a reactive group in a partial structure such as X, Ar 4} , and the structure of formula (A) as starting materials. Examples of reactive groups in these reactive compounds include halogens and boronic acids. As a specific production method, for example, the synthesis method in paragraphs [0089] to [0175] of WO 2014/141725 can be referred to.

<Fluorene-based compounds>
The compound represented by formula (H4) basically functions as a host.

In the above formula (H4),
R ¹ to R ¹⁰ are each independently hydrogen, aryl, heteroaryl (the heteroaryl may be bonded to the fluorene skeleton in the above formula (H4) via a linking group), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy or aryloxy, in which at least one hydrogen may be substituted with an aryl, heteroaryl, alkyl or cycloalkyl;
In addition, ^R1 and ^R2 , ^R2 and ^R3 , ^R3 and ^R4 , ^R5 and ^R6 , ^R6 and ^R7 , ^R7 and ^R8 , or ^R9 and ^R10 may each independently bond to form a fused ring or a spiro ring, and at least one hydrogen atom in the formed ring may be substituted with an aryl, a heteroaryl (the heteroaryl may be bonded to the formed ring via a linking group), a diarylamino, a diheteroarylamino, an arylheteroarylamino, an alkyl, a cycloalkyl, an alkenyl, an alkoxy, or an aryloxy, and at least one hydrogen atom in these rings may be substituted with an aryl, a heteroaryl, an alkyl, or a cycloalkyl, and
At least one hydrogen in the compound represented by formula (H4) may be substituted with halogen, cyano or deuterium.

For details of each group in the definition of the above formula (H4), the explanation for the polycyclic aromatic compound of formula (1) can be cited.

Examples of the alkenyl in R ¹ to R ¹⁰ include alkenyl having 2 to 30 carbon atoms, preferably alkenyl having 2 to 20 carbon atoms, more preferably alkenyl having 2 to 10 carbon atoms, further preferably alkenyl having 2 to 6 carbon atoms, and particularly preferably alkenyl having 2 to 4 carbon atoms. Preferred alkenyls are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl.

式（４－Ａｒ１）から式（４－Ａｒ５）中、Ｙ¹は、それぞれ独立して、Ｏ、ＳまたはＮ－Ｒであり、Ｒはフェニル、ビフェニリル、ナフチル、アントラセニルまたは水素であり、
上記式（４－Ａｒ１）から式（４－Ａｒ５）の構造における少なくとも１つの水素はフェニル、ビフェニリル、ナフチル、アントラセニル、フェナントレニル、メチル、エチル、プロピル、または、ブチルで置換されていてもよい。 Specific examples of heteroaryl include monovalent groups represented by removing any one hydrogen atom from a compound of the following formula (4-Ar1), formula (4-Ar2), formula (4-Ar3), formula (4-Ar4), or formula (4-Ar5).

In formula (4-Ar1) to formula (4-Ar5), each Y ¹ is independently O, S or N—R, and R is phenyl, biphenylyl, naphthyl, anthracenyl or hydrogen;
At least one hydrogen atom in the structures of the above formulae (4-Ar1) to (4-Ar5) may be substituted with phenyl, biphenylyl, naphthyl, anthracenyl, phenanthrenyl, methyl, ethyl, propyl, or butyl.

These heteroaryls may be bonded to the fluorene skeleton in formula (H4) via a linking group. That is, the fluorene skeleton in formula (H4) and the heteroaryl may be bonded directly, or may be bonded to each other via a linking group. _Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, _ethylene , _-OCH2CH2- , _{-CH2CH2O- ,} and _-OCH2CH2O- .

In addition, R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R 6 and R ⁷ or R ⁷ and R ⁸ in formula (H4 ⁾ may be bonded independently to form a fused ring, and R ⁹ and R ¹⁰ may be bonded to form a spiro ring. The fused ring formed by R ¹ to R ⁸ is a ring fused to the benzene ring in formula (H4), and is an aliphatic ring or an aromatic ring. It is preferably an aromatic ring, and examples of the structure including the benzene ring in formula (H4) include a naphthalene ring and a phenanthrene ring. The spiro ring formed by R ⁹ and R ¹⁰ is a ring spiro-bonded to the 5-membered ring in formula (H4), and is an aliphatic ring or an aromatic ring. It is preferably an aromatic ring, and examples of the structure including the benzene ring in formula (H4) include a fluorene ring.

The compound represented by formula (H4) is preferably a compound represented by the following formula (4-1), formula (4-2) or formula (4-3), which is a compound in which a benzene ring formed by bonding R ¹ and R ² in formula (H4) is condensed, a compound in which a benzene ring formed by bonding R ³ and R ⁴ in formula (H4) is condensed, or a compound in which none of R ¹ to R ⁸ is bonded in formula (H4), respectively.

The definitions of R ¹ to R ¹⁰ in formulas (4-1), (4-2) and (4-3) are the same as the corresponding R ¹ to R ¹⁰ in formula (H4), and the definitions of R ¹¹ to R ¹⁴ in formulas (4-1) and (4-2) are the same as the corresponding R ¹ to R ¹⁰ in formula (H4).

The compound represented by formula (H4) is more preferably a compound represented by the following formula (4-1A), formula (4-2A) or formula (4-3A), which is a compound in which R ⁹ and R ¹⁰ are bonded to form a spiro-fluorene ring in formula (4-1), formula (4-1) or formula (4-3), respectively.

The definitions of R ² to R ⁷ in formulae (4-1A), (4-2A) and (4-3A) are the same as the corresponding R ² to R ⁷ in formulae (4-1), (4-2) and (4-3), and the definitions of R ¹¹ to R ¹⁴ in formulae (4-1A) and (4-2A) are the same as the corresponding R ¹¹ to R ¹⁴ in formulae (4-1) and (4-2).

In addition, all or some of the hydrogen atoms in the compound represented by formula (H4) may be replaced with halogen, cyano, or deuterium.

<Dibenzochrysene compounds>
The dibenzochrysene compound as the host is, for example, a compound represented by the following formula (H5).

In the above formula (H5),
R ¹ to R ¹⁶ are each independently hydrogen, aryl, heteroaryl (the heteroaryl may be bonded to the dibenzochrysene skeleton in the above formula (H5) via a linking group), diarylamino, diheteroarylamino, arylheteroarylamino, alkyl, cycloalkyl, alkenyl, alkoxy or aryloxy, in which at least one hydrogen may be substituted with an aryl, heteroaryl, alkyl or cycloalkyl;
In addition, adjacent groups among R ¹ to R ¹⁶ may be bonded to each other to form a condensed ring, and at least one hydrogen atom in the formed ring may be substituted with an aryl, a heteroaryl (the heteroaryl may be bonded to the formed ring via a linking group), a diarylamino, a diheteroarylamino, an arylheteroarylamino, an alkyl, a cycloalkyl, an alkenyl, an alkoxy, or an aryloxy, and at least one hydrogen atom in these may be substituted with an aryl, a heteroaryl, an alkyl, or a cycloalkyl, and
At least one hydrogen in the compound represented by formula (H5) may be substituted with halogen, cyano or deuterium.

For details of each group in the definition of the above formula (5), the explanation for the polycyclic aromatic compound of formula (1) can be cited.

The alkenyl in the definition of the above formula (H5) is, for example, an alkenyl having 2 to 30 carbon atoms, preferably an alkenyl having 2 to 20 carbon atoms, more preferably an alkenyl having 2 to 10 carbon atoms, even more preferably an alkenyl having 2 to 6 carbon atoms, and particularly preferably an alkenyl having 2 to 4 carbon atoms. Preferred alkenyls are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl.

Specific examples of heteroaryl include monovalent groups represented by removing any one hydrogen atom from the compounds of the following formula (5-Ar1), (5-Ar2), (5-Ar3), (5-Ar4), or (5-Ar5).

In formula (5-Ar1) to formula (5-Ar5), each Y ¹ is independently O, S or N—R, and R is phenyl, biphenylyl, naphthyl, anthracenyl or hydrogen;
At least one hydrogen atom in the structures of the above formulae (5-Ar1) to (5-Ar5) may be substituted with phenyl, biphenylyl, naphthyl, anthracenyl, phenanthrenyl, methyl, ethyl, propyl, or butyl.

These heteroaryls may be bonded to the dibenzochrysene skeleton in formula (H5) via a linking group. That is, the dibenzochrysene skeleton in formula (H5) and the heteroaryl may be bonded directly or via a linking group. Examples of the linking group include phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, _{-OCH2CH2- , -CH2CH2O- ,} and _{-OCH2CH2O- .}

In the compound represented by formula (H5), R ¹ , R ⁴ , R ⁵ , R ⁸ , R ⁹ , R ¹² , R ¹³ and R ¹⁶ are preferably hydrogen. In this case, it is preferable that R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ and R ¹⁵ in formula (H5) are each independently hydrogen, phenyl, biphenylyl, naphthyl, anthracenyl, phenanthrenyl, a monovalent group having the structure of the above formula (5-Ar1), (5-Ar2), (5-Ar3), (5-Ar4) or (5-Ar5) (the monovalent group having the structure may be bonded to the dibenzochrysene skeleton in formula (H5)) via phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH ₂ CH ₂ -, -CH ₂ CH ₂ O- or -OCH ₂ CH ₂ O-), methyl, ethyl, propyl or butyl.

In the compound represented by formula (H5), R ¹ , R ² , R ⁴ , R ⁵ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹² , R ¹³ , R ¹⁵ and R ¹⁶ are more preferably hydrogen. In this case, at least one (preferably one or two, more preferably one) of R ³ , R ⁶ , R ¹¹ and R ¹⁴ in formula (H5) is a single bond, phenylene, biphenylene, naphthylene, anthracenylene, methylene, ethylene, -OCH ₂ CH ₂ -, -CH ₂ CH ₂ O-, or a monovalent group having the structure of formula (5-Ar1), formula (5-Ar2), formula (5-Ar3), formula (5-Ar4) or formula (5-Ar5) via -OCH ₂ CH ₂ O-,
The other than the at least one (i.e., other than the position substituted with the monovalent group having the structure) is hydrogen, phenyl, biphenylyl, naphthyl, anthracenyl, methyl, ethyl, propyl, or butyl, and at least one hydrogen in these may be substituted with phenyl, biphenylyl, naphthyl, anthracenyl, methyl, ethyl, propyl, or butyl.

In addition, when a monovalent group having a structure represented by formula (5-Ar1) to formula (5-Ar5) is selected as R ² , R ³ , R ⁶ , R ⁷ , R ¹⁰ , R ¹¹ , R ¹⁴ and R ¹⁵ in formula (H5), at least one hydrogen atom in the structure may be bonded to any one of R ¹ to R ¹⁶ in formula (H5) to form a single bond.

The above-mentioned light-emitting layer materials (host material and dopant material) can be used as light-emitting layer materials in the form of polymer compounds obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer, or crosslinked polymers thereof, or pendant-type polymer compounds obtained by reacting a main-chain polymer with the reactive compound, or crosslinked pendant polymers thereof. In this case, the explanation of the polycyclic aromatic compound represented by formula (1) can be cited as the reactive substituent.
The applications of such polymer compounds and crosslinked polymers will be described in detail below.

<Examples of polymer host materials>

In formula (SPH-1),
Each MU is independently a divalent aromatic compound, each EC is independently a monovalent aromatic compound, two hydrogens in MU are replaced by EC or MU, and k is an integer of 2 to 50,000.

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

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

Examples of MU include a divalent group represented by removing any two hydrogen atoms from any of the following compounds:

More specifically, it is a divalent group represented by any of the following structures. In these, MU is bonded to another MU or EC at *.

EC can be, for example, a monovalent group represented by any of the following structures. In these, EC bonds to MU at *.

From the viewpoint of solubility and coating film-forming properties, the compound represented by formula (SPH-1) is preferably such that 10 to 100% of the total number of MUs (k) in the molecule have an alkyl having 1 to 24 carbon atoms, more preferably 30 to 100% of the total number of MUs (k) in the molecule have an alkyl having 1 to 18 carbon atoms (branched chain alkyl having 3 to 18 carbon atoms), and even more preferably 50 to 100% of the total number of MUs (k) in the molecule have an alkyl having 1 to 12 carbon atoms (branched chain alkyl having 3 to 12 carbon atoms). On the other hand, from the viewpoint of in-plane orientation and charge transport, it is preferable that 10 to 100% of the total number of MUs (k) in the molecule have an alkyl having 7 to 24 carbon atoms, and more preferably 30 to 100% of the total number of MUs (k) in the molecule have an alkyl having 7 to 24 carbon atoms (branched chain alkyl having 7 to 24 carbon atoms).
The applications of such polymer compounds and crosslinked polymers will be described in detail below.

<<Assisting dopant>>
The light-emitting layer may further contain an assisting dopant. In this case, the compound of the present invention functions as the emitting dopant. Examples of the assisting dopant include the following compounds. In the following formula, Me represents methyl, tBu represents t-butyl, Ph represents phenyl, and the wavy line represents a bonding position.

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

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

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

Materials used in the electron transport layer or electron injection layer preferably contain at least one selected from compounds consisting of aromatic rings or heteroaromatic rings composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus, pyrrole derivatives and their condensed ring derivatives, and metal complexes having electron-accepting nitrogen. Specific examples include condensed ring aromatic ring derivatives such as naphthalene and anthracene, styryl aromatic ring derivatives such as 4,4'-bis(diphenylethenyl)biphenyl, perinone derivatives, coumarin derivatives, naphthalimide derivatives, quinone derivatives such as anthraquinone and diphenoquinone, phosphorus oxide derivatives, arylnitrile derivatives, and indole derivatives. 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 different materials.

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

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

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

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

<Borane derivatives>
The borane derivative is, for example, a compound represented by the following formula (ETM-1), and is disclosed in detail in JP-A-2007-27587.

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

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

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

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

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

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

Specific examples of the borane derivative include the following compounds:

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

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

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

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

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

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

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

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

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

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

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

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

As the "aryl" in R ¹¹ to R ¹⁸ , the preferred aryl is an aryl having 6 to 30 carbon atoms, more preferably an aryl having 6 to 18 carbon atoms, even 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 examples of "aryl having 6 to 30 carbon atoms" include phenyl, naphthyl, phenanthryl, chrysenyl, and triphenylenyl, more preferably phenyl, 1-naphthyl, 2-naphthyl, and phenanthryl, and particularly preferably phenyl, 1-naphthyl, and 2-naphthyl.

In formula (ETM-2-2), R ¹¹ and R ¹² may be bonded to form a ring. 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 ^to X ^each represent a hydrogen atom, a halogen atom, a linear, branched or cyclic alkyl group, a linear, branched or cyclic alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, where examples of the substituent in the case of a substitution include an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, and the like.

Specific examples of the fluoranthene derivative include the following compounds:

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

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

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

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

For an explanation of the substituents and ring formation form in formula (ETM-4), the explanation of the polycyclic aromatic compound represented by formula (1) or formula (1-a), etc. may 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 example of the anthracene derivative is a compound represented by the following formula (ETM-5).

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

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

R ¹ to R ⁴ are each independently hydrogen, alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 6 carbon atoms, or aryl having 6 to 20 carbon atoms.
The alkyl having 1 to 6 carbon atoms in R ¹ to R ⁴ may be either 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, and methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, or t-butyl is preferred, and methyl, ethyl, or t-butyl is more preferred.

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

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

Specific examples of these anthracene derivatives include the following compounds.

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

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

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

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

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

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

As the "aryl" in ^Ar2 , the preferred aryl is an aryl having 6 to 30 carbon atoms, the more preferred aryl is an aryl having 6 to 18 carbon atoms, the further more preferred aryl is an aryl having 6 to 14 carbon atoms, and the particularly preferred aryl is an aryl having 6 to 12 carbon atoms.

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

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

Specific examples of the benzofluorene derivative include the following compounds:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The fused ring formed between adjacent substituents is, for example, a conjugated or non ^{-conjugated fused ring formed between Ar1 and R2 , Ar1} and ^R3 , ^Ar2 and ^R2 , ^Ar2 and ^R3 , ^R2 and ^R3 , Ar1 and ^{Ar2 ,} etc. Here, when n is 1, two ^R1s may form a conjugated or non-conjugated fused ring. These fused rings may contain a nitrogen, oxygen, or sulfur atom in the ring structure, or may be fused with another ring.

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

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

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

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

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

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

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

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

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

Specific examples of the pyrimidine derivative include the following compounds:

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

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

From the viewpoint of fast electron transportability, Ar _ni preferably has a large number of carbon atoms, and from the viewpoint of high T1, Ar ni preferably has a small number of carbon atoms. 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. In addition, the number of nitrile group substitutions n is preferably large from the viewpoint of high T1, and is preferably small from the viewpoint of 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 to 2, and even more preferably 1.

Each Ar is independently an aryl which may be substituted, or a heteroaryl which may be substituted. From the viewpoint of high S1 and high T1, it is preferable that the heteroaryl has donor properties, and since it is used as an electron transport layer, it is preferable that there are few heteroaryl donors. From the viewpoint of charge transport, it is preferable that the aryl or heteroaryl has a large number of carbon atoms, and it is preferable that it has many substituents. The number of substitutions m of Ar is specifically an integer of 1 to 4, preferably an integer of 1 to 3, and more preferably 1 to 2.

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

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

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

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

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

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

Specific examples of the arylnitrile derivative include the following compounds:

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

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

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

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

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

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

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

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

Specific examples of the triazine derivative include the following compounds:

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

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

φ is an n-valent aryl ring (preferably an n-valent benzene ring, naphthalene ring, anthracene ring, fluorene ring, benzofluorene ring, phenalene ring, phenanthrene ring, or triphenylene ring), n is an integer from 1 to 4, and the "benzoimidazole-based substituent" is a substituent in which the pyridyl in the "pyridine-based substituent" in the formulae (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 explanation of R ¹¹ in formulae (ETM-2-1) and (ETM-2-2) can be cited.

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

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

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 bonded to φ which is an aryl ring.

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

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

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

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

式中、Ｒ¹～Ｒ⁶は、それぞれ独立して、水素、フッ素、アルキル、シクロアルキル、アラルキル、アルケニル、シアノ、アルコキシまたはアリールであり、ＭはＬｉ、Ａｌ、Ｇａ、ＢｅまたはＺｎであり、ｎは１～３の整数である。 <Quinolinol metal complexes>
The quinolinol metal complex is, for example, a compound represented by the following formula (ETM-13).

In the formula, R ¹ to R ⁶ are each independently hydrogen, fluorine, alkyl, cycloalkyl, aralkyl, alkenyl, cyano, alkoxy or aryl; M is Li, Al, Ga, Be or Zn; and n is an integer 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)(phenolate)aluminum linolinate)(3-phenylphenolate)aluminum, bis(2-methyl-8-quinolinate)(4-phenylphenolate)aluminum, bis(2-methyl-8-quinolinate)(2,3-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinate)(2,6-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinate)(3,4-dimethylphenolate)aluminum, bis(2-methyl bis(2-methyl-8-quinolinolate)(3,5-dimethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(3,5-di-t-butylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,6-diphenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,4,6-triphenylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(2,4,6-trimethylphenolate)aluminum bis(2-methyl-8-quinolinolate)(2,4,5,6-tetramethylphenolate)aluminum, bis(2-methyl-8-quinolinolate)(1-naphtholate)aluminum, bis(2-methyl-8-quinolinolate)(2-naphtholate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(2-phenylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(3-phenylphenolate)aluminum bis(2,4-dimethyl-8-quinolinolate)(4-phenylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(3,5-dimethylphenolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)(3,5-di-t-butylphenolate)aluminum, bis(2-methyl-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-8-quinolinolate)aluminum quinolinolate)aluminum, bis(2,4-dimethyl-8-quinolinolate)aluminum-μ-oxo-bis(2,4-dimethyl-8-quinolinolate)aluminum, bis(2-methyl-4-ethyl-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-4-ethyl-8-quinolinolate)aluminum, bis(2-methyl-4-methoxy-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-4-methoxy-8-quinolinolate)aluminum quinolinolate)aluminum, bis(2-methyl-5-cyano-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-5-cyano-8-quinolinolate)aluminum, bis(2-methyl-5-trifluoromethyl-8-quinolinolate)aluminum-μ-oxo-bis(2-methyl-5-trifluoromethyl-8-quinolinolate)aluminum, bis(10-hydroxybenzo[h]quinoline)beryllium, etc.

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

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

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

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

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

It is further preferred that φ is an anthracene ring or a fluorene ring, and in this case, the structure can be referred to in the explanation of formula (ETM-2-1) or formula (ETM-2-2), and for R ¹¹ to R ¹⁸ in each formula, the explanation of formula (ETM-2-1) or formula (ETM-2-2) can be referred to. In addition, in formula (ETM-2-1) or formula (ETM-2-2), two pyridine-based substituents are 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) to replace the "pyridine-based substituent" with R ¹¹ to R ¹⁸ .

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

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

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

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, isocyanate, thiocyanate, isothiocyanate, 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 (1-a) 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 (1-a) can be cited.

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

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

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

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

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

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

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

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

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

式（Ｌ－１）中、Ｘ¹～Ｘ⁶はそれぞれ独立して＝ＣＲ⁶－または＝Ｎ－であり、Ｘ¹～Ｘ⁶のうちの少なくとも２つは＝ＣＲ⁶－であり、Ｘ¹～Ｘ⁶のうちの２つの＝ＣＲ⁶－におけるＲ⁶はφまたはアゾリン環と結合する部位であり、それ以外の＝ＣＲ⁶－におけるＲ⁶は水素であり、
式（Ｌ－２）中、Ｘ⁷～Ｘ¹⁴はそれぞれ独立して＝ＣＲ⁶－または＝Ｎ－であり、Ｘ⁷～Ｘ¹⁴のうちの少なくとも２つは＝ＣＲ⁶－であり、Ｘ⁷～Ｘ¹⁴のうちの２つの＝ＣＲ⁶－におけるＲ⁶はφまたはアゾリン環と結合する部位であり、それ以外の＝ＣＲ⁶－におけるＲ⁶は水素であり、
Ｌの少なくとも１つの水素は炭素数１～４のアルキル、炭素数５～１０のシクロアルキル、炭素数６～１０のアリールまたは炭素数２～１０のヘテロアリールで置換されていてもよく、
ｍは１～４の整数であり、ｍが２～４であるとき、アゾリン環とＬとで形成される基は同一であっても異なっていてもよく、そして、
式（ＥＴＭ－１６－１）または式（ＥＴＭ－１６－２）で表される化合物中の少なくとも１つの水素は重水素で置換されていてもよい。

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

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

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

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

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

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

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

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

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

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

For details on the alkyl, cycloalkyl, aryl, or heteroaryl in the above formulas that define this azoline derivative, the explanations in formula (1) and formula (1-a) can be cited.

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

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

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

＜Other＞
The above-mentioned electron injection layer material and electron transport layer material can be used as a polymer compound obtained by polymerizing a reactive compound substituted with a reactive substituent as a monomer, or a crosslinked polymer thereof, or a pendant polymer compound obtained by reacting a main chain polymer with the reactive compound, or a crosslinked pendant polymer thereof, for the electron layer material. In this case, the explanation of the polycyclic aromatic compound represented by formula (1) can be cited as the reactive substituent.
The applications of such polymer compounds and crosslinked polymers will be described in detail below.

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

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

Furthermore, preferred examples of the electrode protection include lamination of 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 limitations on the method of producing these electrodes, as long as electrical conductivity can be achieved, and they can be produced by resistance heating, electron beam deposition, sputtering, ion plating, and coating.

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

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

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

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

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

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

In the wet film formation method, a coating film is generally formed through a coating process in which an organic layer forming composition is applied to a substrate and a drying process in which the solvent is removed from the applied organic layer forming composition. When the polymer compound has a crosslinkable substituent (also called a crosslinkable polymer compound), the polymer is further crosslinked by the drying process to form a crosslinked polymer. Depending on the difference in the coating process, the method using a spin coater is called the spin coat method, the method using a slit coater is called the slit coat method, the method using a plate is called the gravure, offset, reverse offset, or flexographic printing method, the method using an inkjet printer is called the inkjet method, and the method spraying in a mist form is called the spray method. The drying process includes air drying, heating, and drying under reduced pressure. The drying process may be performed only once, or may be performed multiple times using different methods and conditions. In addition, different methods may be used in combination, such as baking under reduced pressure.

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

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

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

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

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

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

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

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

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

<Organic solvent>
The 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 the film formability, the presence or absence of defects in the coating film, the surface roughness, and the smoothness. In addition, during film formation using the inkjet method, it is possible to control the meniscus stability at the pinhole of the inkjet head, and control and improve the ejection properties. In addition, by controlling the drying rate of the film and the orientation of the derivative molecules, it is possible to improve the electrical properties, light emitting properties, efficiency, and life of an organic EL element having an organic layer obtained from the 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. When the boiling point is higher than 130°C, it is preferable from the viewpoint of inkjet dischargeability. Also, when the boiling point is lower than 300°C, it is preferable from the viewpoint of coating film defects, surface roughness, residual solvent, and smoothness. From the viewpoint of good inkjet dischargeability, film-forming property, smoothness, and low residual solvent, it is more preferable that the organic solvent contains two or more organic solvents. On the other hand, in some cases, the composition may be a solid state composition obtained by removing the solvent from the composition for forming the organic layer, taking into consideration transportability, etc.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

式（ＸＬＰ－１）において、
ＭＵｘ、ＥＣｘおよびｋは上記式（ＳＰＨ－１）におけるＭＵ、ＥＣおよびｋと同定義であり、ただし、式（ＸＬＰ－１）で表される化合物は少なくとも１つの架橋性置換基（ＸＬＳ）を有し、好ましくは架橋性置換基を有する１価または２価の芳香族化合物の含有量は、分子中０．１～８０質量％である。 <Crosslinkable polymer compound: compound represented by formula (XLP-1)>
Next, the case where the above-mentioned polymer compound has a crosslinkable substituent will be described. Such a crosslinkable polymer compound is, for example, a compound represented by the following formula (XLP-1).

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

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

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

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

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

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

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

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

The compound of formula (SPH-1) and the compound of formula (XLP-1) may be produced in one step or in multiple steps. In addition, the reaction may be started after all the raw materials are placed in a reaction vessel by a batch polymerization method, or may be performed by a dropwise polymerization method in which the raw materials are added dropwise to a reaction vessel, or may be performed by a precipitation polymerization method in which the product precipitates as the reaction proceeds, and these methods can be combined appropriately to synthesize the compound. For example, when synthesizing the compound represented by formula (SPH-1) in one step, the target product is obtained by carrying out a reaction in a state in which the monomer unit (MU) and the end cap unit (EC) are added to a reaction vessel. In addition, when synthesizing the compound represented by formula (SPH-1) in multiple steps, the monomer unit (MU) is polymerized to the target molecular weight, and then the end cap unit (EC) is added and reacted to obtain the target product. If different types of monomer units (MU) are added and reacted in multiple steps, a polymer having a concentration gradient in the structure of the monomer unit can be produced. In addition, after preparing a precursor polymer, the target polymer can be obtained by a subsequent reaction.

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

The monomer units 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, WO 2015/14 It can be synthesized in accordance with the methods described in JP 2010-215886, JP 2008-106241, JP 2010-215886, WO 2016/031639, JP 2011-174062, WO 2016/031639, WO 2016/031639, and WO 2002/045184.

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

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

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

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

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

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

3-2. Other Organic Devices The compound of the present invention can be used for producing an organic field effect transistor or an organic thin-film solar cell, in addition to the organic electroluminescent device described above.

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

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

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

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

Synthesis example (1): Compound (4-37)

[First paragraph]
3-Bromodibenzo[b,d]furan[r-1] (24.7 g, 100 mmol), 2,6-dimethylaniline[r-2] (29.6 g, 308 mmol), cesium carbonate (65.1 g), copper(I) chloride (0.99 g) and xylene (200 ml) were placed in a flask and refluxed for 24 hours. After the reaction, water and toluene were added to the reaction solution and stirred, and then the organic layer was separated and washed with water. The organic layer was then concentrated to obtain a crude product. The crude product was purified using a silica gel column (eluent: ethyl acetate/toluene = 1/5 (volume ratio)), and the fraction containing the target product was concentrated to obtain oily N-(dibenzo[b,d]furan-3-yl)-N-(2,6-dimethylphenyl)dibenzo[b,d]furan-3-amine[r-3] (19.2 g).

[2nd to 3rd paragraphs]
The compound [r-3] (19.2 g, 42.3 mmol) obtained in the first step was dissolved in chlorobenzene (50 mL), and boron tribromide (31.8 g, 127 mmol) was added and stirred at room temperature for 8 hours. The temperature was raised to 100°C and the pressure was reduced to remove volatiles. The reaction mixture containing the target product [r-4] was not purified and was advanced to the next step. The reaction mixture was added with chlorobenzene (100 mL) in which 2,6-di(propen-2-yl)phenyllithium (6.3 g, 38 mmol) and N-butyllithium (30 mL, 1.1 mmol) were dissolved, and the mixture was stirred at 100°C for 24 hours. A saturated aqueous solution of ammonium chloride was added to the reaction liquid, and the mixture was stirred and extracted with toluene. The reaction solution was subjected to silica gel column chromatography (eluent: toluene) to recover only the fraction containing the target product, thereby obtaining 15-(2,6-di(propan-1-en-2-yl)phenyl)-7-(2,6-dimethylphenyl)-7,15-dihydrobenzo[2,3]benzofuro[6,5-b]benzo[2,3]benzofuro[5,6-e][1,4]azaborinine[r-5] (10.7 g).

[4th paragraph]
15-(2,6-di(propan-1-en-2-yl)phenyl)-7-(2,6-dimethylphenyl)-7,15-dihydrobenzo[2,3]benzofuro[6,5-b]benzo[2,3]benzofuro[5,6-e][1,4]azaborinine[r-5] (10.7 g, 17.3 mmol) and scandium triflate (8.5 g, 17.3 mmol) synthesized in the third step were dissolved in chlorobenzene (200 ml) and heated and stirred at 100° C. for 7 hours. Saturated sodium bicarbonate was added, and the mixture was extracted with toluene. After concentration under reduced pressure, the obtained crude product was purified by silica gel column chromatography (eluent: toluene/hexane=1/4 (volume ratio)) to obtain 11-(2,6-dimethylphenyl)-4,4,18,18-tetramethyl-11,18-dihydro-4H-9,13-dioxa-11-aza-3a2-borabenzo[jk]fluoreno[2,3,4-fg]indeno[1,2-a]pyrene [compound (4-37)] (6.4 g, yield 60%).

The structure of the compound obtained was confirmed by NMR spectroscopy.
¹ H-NMR (400 MHz, CDCl ₃ ): δ = 1.70 (s, 12H), 2.11 (s, 6H), 6.68-6.74 (m, 6H), 6.82 (dd, 2H), 7.04 (m, 2H), 7.27 (m, 2H), 7.81 (m, 2H).

By appropriately changing the raw material compounds, other compounds of the present invention can be synthesized according to the methods of the above synthesis examples and by referring to Yamaguchi et al., Organic & Biomolecular Chemistry, 2019, 17, 5500-5504.

Next, we will describe the evaluation of the basic physical properties of the compound of the present invention and the fabrication and evaluation of an organic EL device using the compound of the present invention.

(1) Preparation and evaluation of deposition type organic EL element Organic EL elements according to the examples and comparative examples are prepared, and voltage is applied to measure current density, luminance, chromaticity, and external quantum efficiency. The following four configurations, Configuration A (Table 1), Configuration B (Table 2), Configuration C (Table 3), and Configuration D (Table 4), are selected as the configurations of the prepared organic EL elements and evaluated. Configurations A, C, and D are configurations suitable for thermally activated delayed fluorescence materials, and Configuration B is a general configuration using TTF. Configuration A is an element configuration that can be expected to have high efficiency as shown in the literature (Adv. Mater. 2016, 28, 2777-2781). Configuration C is an element configuration that can be expected to have relatively high efficiency and long-term driving stability as shown in the literature (Scientific Reports, 6, 2016, 22463). Configuration D is an element that uses thermally activated delayed fluorescence as an assisting dopant. However, application of the compound of the present invention is not limited to these structures, and the film thickness and constituent materials of each layer can be appropriately changed depending on the basic physical properties of the compound of the present invention.

Example 1

In Table 1, "NPD" is N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl, "TcTa" is 4,4',4"-tris(N-carbazolyl)triphenylamine, "mCP" is 1,3-bis(N-carbazolyl)benzene, "mCBP" is 3,3'-bis(N-carbazolyl)-1,1'-biphenyl, and "TSPO1" is diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide. The chemical structures are shown below.

<Configuration A: Element Using Compound (4-37) 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 200 nm was formed by sputtering and polished to 50 nm was used as a transparent support substrate. This transparent support substrate was fixed to a substrate holder of a commercially available deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum deposition boat containing NPD, TcTa, mCP, mCBP, compound (4-37), and TSPO1, and a tungsten deposition boat containing LiF and aluminum were attached.

The following layers are sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber is depressurized to 5×10 ⁻⁴ Pa, and NPD is heated and evaporated to a thickness of 40 nm to form a hole injection layer. Next, TcTa is heated and evaporated to a thickness of 15 nm to form a hole transport layer. Next, mCP is heated and evaporated to a thickness of 15 nm to form an electron blocking layer. Next, mCBP and compound (4-37) are heated simultaneously and evaporated to a thickness of 20 nm to form a light emitting layer. The evaporation rate is adjusted so that the mass ratio of mCBP to compound (4-37) is approximately 99:1. Next, TSPO1 is heated and evaporated to a thickness of 40 nm to form an electron transport layer. The evaporation rate of each layer is 0.01 to 1 nm/sec. Thereafter, LiF is heated and evaporated at a evaporation rate of 0.01 to 0.1 nm/sec to a thickness of 1 nm, and then aluminum is heated and evaporated to a thickness of 100 nm to form a cathode, thereby obtaining an organic EL device. At this time, the deposition rate of aluminum is adjusted to 1 to 10 nm/sec.

The ITO electrode serves as the anode and the aluminum electrode serves as the cathode, and a DC voltage is applied to measure the luminance, chromaticity, and external quantum efficiency.

Example 2

In Table 2, "HI-1" 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" is 1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile, "HT-1" 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" is N,N-bis(4-(dibenzo[b,d]furan-4-yl) phenyl)-[1,1':4',1"-terphenyl]-4-amine, "EMH2" is 9-phenyl-10-(4-phenylnaphthalen-1-yl)anthracene, "ET-1" is 4,6,8,10-tetraphenyl[1,4]benzoxaborinino[2,3,4-kl]phenoxaborinine, and "ET-2" is 3,3'-((2-phenylanthracene-9,10-diyl)bis(4,1-phenylene))bis(4-methylpyridine), the chemical structures of which are shown below along with "Liq."

<Configuration B: Element Using Compound (4-37) as a Dopant>
An EL element of structure B is obtained according to the constituent materials and film thicknesses in Table 2 by the same procedure as in structure A. However, the deposition rate is adjusted so that the mass ratio of EMH2 to compound (4-37) in the emitting layer is about 99:1, and the mass ratio of ET-2 to Liq in the electron transport layer 2 is about 1:1. In addition, the deposition rate is adjusted so that the mass ratio of silver to magnesium is 1:9.
The ITO electrode is used as the anode and the silver-magnesium alloy electrode is used as the cathode, and a direct current voltage is applied to the electrode, allowing the luminance, chromaticity, and external quantum efficiency to be measured.

Example 3

In Table 3, "Tris-PCz" is 9,9',9"-triphenyl-9H,9H',9H"-3,3',6',3"-tert-carbazole, "T2T" is 2,4,6-tri[[1,1'-biphenyl]-3-yl]-1,3,5-triazine, and "BPy-TP2" is 2,7-di([2,2'-bipyridine]-5-yl)triphenylene. The chemical structures are shown below.

<Configuration C: Device using compound (4-37) as dopant>
A 26 mm × 28 mm × 0.7 mm glass substrate (Optoscience Co., Ltd.) on which an ITO film formed by sputtering was polished to 50 nm was used as a transparent support substrate. This transparent support substrate was fixed to a substrate holder of a commercially available deposition device (Choshu Sangyo Co., Ltd.), and tantalum deposition crucibles containing HAT-CN, Tris-PCz, mCBP, compound (4-37), T2T, and BPy-TP2, and aluminum nitride deposition crucibles containing LiF and aluminum were attached.

The following layers are formed in sequence on the ITO film of the transparent support substrate. The vacuum chamber is depressurized to 2.0×10 ⁻⁴ Pa, and first, HAT-CN is heated and evaporated to a thickness of 10 nm, and then Tris-PCz is heated and evaporated to a thickness of 30 nm to form a hole layer consisting of two layers. Next, mCBP and compound (4-37) are heated simultaneously and evaporated to a thickness of 30 nm to form a light-emitting layer. The evaporation rate is adjusted so that the mass ratio of mCBP to compound (4-37) is approximately 90:10. Next, T2T is heated and evaporated to a thickness of 10 nm, and BPy-TP2 is evaporated to a thickness of 30 nm to form an electron transport layer consisting of two layers. The evaporation rate of each layer is 0.01 to 1 nm/sec. Thereafter, LiF is heated and evaporated at a deposition rate of 0.01 to 0.1 nm/sec to a thickness of 1 nm, and then aluminum is heated and evaporated at a deposition rate of 0.1 to 2 nm/sec to a thickness of 100 nm to form a cathode, thereby obtaining an organic EL element.

The ITO electrode serves as the anode and the aluminum electrode serves as the cathode, and a DC voltage is applied to measure the luminance, chromaticity, and external quantum efficiency.

Example 4

In Table 4, "3Cz2DPhCzBN" is 2,4,6-tri(9H-carbazol-9-yl)-3,5-bis(3,6-diphenyl-9H-carbazol-9-yl)benzonitrile. The chemical structure is shown below.

<Configuration D: Element using 3Cz2DPhCzBN as an assisting dopant and compound (4-37) as an emitting 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 200 nm was formed by sputtering and polished to 50 nm was used as a transparent support substrate. This transparent support substrate was fixed to a substrate holder of a commercially available deposition apparatus (manufactured by Choshu Sangyo Co., Ltd.), and a tantalum deposition boat containing HAT-CN, Tris-PCz, mCBP, 3Cz2DPhCzBN, compound (4-37), T2T, and BPy-TP2, and an aluminum nitride deposition boat containing Liq, LiF, and aluminum, were attached.

The following layers are formed in sequence on the ITO film of the transparent support substrate. The vacuum chamber is depressurized to 5×10 ⁻⁴ Pa, and first, HAT-CN is heated and evaporated to a thickness of 10 nm, and then, Tris-PCz is heated and evaporated to a thickness of 30 nm to form a hole layer consisting of two layers. Next, mCBP as a host, 3Cz2DPhCzBN as an assisting dopant, and compound (4-37) as an emitting dopant are simultaneously heated and co-evaporated to a thickness of 30 nm to form a light-emitting layer. The evaporation rate is adjusted so that the mass ratio of the host, the assisting dopant, and the emitting dopant is approximately 80:19:1. Next, T2T is heated and evaporated to a thickness of 10 nm, and then, BPy-TP2 and Liq are heated and evaporated to a thickness of 30 nm to form electron transport layers 1 and 2. The evaporation rate of each of the above layers is 0.01 to 1 nm/sec. Thereafter, LiF is heated and evaporated at a deposition rate of 0.01 to 0.1 nm/sec to a thickness of 1 nm, and then aluminum is heated and evaporated to a thickness of 100 nm to form a cathode, thereby obtaining an organic EL element. At this time, the evaporation rate of aluminum is adjusted to 1 to 10 nm/sec.

The ITO electrode serves as the anode and the aluminum electrode serves as the cathode, and a DC voltage is applied to measure the luminance, chromaticity, and external quantum efficiency.

<Example 5, Comparative Example 1>
(Structure B1 of Organic EL Element)
The organic EL element having the structure B1 has a structure in which the materials of the host and the cathode in the organic EL element having the structure B described above are changed.

In Table 5, "EMH3" is 2-(10-phenylanthracen-9-yl)dibenzo[b,d]furan, and "BD1" is 4,8,12-triphenyl-8,12-dihydro-4H-4,8,12-triaza-3a2-boradibenzo[cd,mn]pyrene. The chemical structures are shown below.

<Structure B1: Element using compound (4-37) as a dopant (Example 5)>
A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) on which an ITO film formed to a thickness of 200 nm by sputtering was polished to 50 nm was used as a transparent support substrate. This transparent support substrate was fixed to a substrate holder of a commercially available deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum deposition boat containing HI-1, HAT-CN, HT-1, HT-2, EMH3, compound (4-37), ET-1, ET-2, and Liq, and a tungsten deposition boat containing LiF and aluminum were attached.

The following layers were formed in sequence on the ITO film of the transparent support substrate. The vacuum chamber was depressurized to 5×10 ⁻⁴ Pa, and first, HI-1 was heated and evaporated to a thickness of 40 nm, and HAT-CN was further heated and evaporated to a thickness of 5 nm to form a two-layer hole injection layer. Next, HT-1 was heated and evaporated to a thickness of 15 nm, and HT-2 was further heated and evaporated to a thickness of 10 nm to form a two-layer hole transport layer. Next, EMH3 and compound (4-37) were simultaneously heated and evaporated to a thickness of 25 nm to form a light-emitting layer. The evaporation rate was adjusted so that the mass ratio of EMH3 to compound (4-37) was approximately 99:1. Next, ET-1 was heated and evaporated to a thickness of 5 nm, and further, ET-2 and Liq were heated and evaporated to a thickness of 25 nm to form a two-layer electron transport layer. The deposition rate was adjusted so that the mass ratio of ET-2 and Liq was approximately 1:1. The deposition rate of each layer was 0.01 to 1 nm/sec. Thereafter, LiF was heated and deposited at a deposition rate of 0.01 to 0.1 nm/sec so as to have a film thickness of 1 nm, and then aluminum was heated and deposited to have a film thickness of 100 nm to form a cathode, thereby obtaining an organic EL device. At this time, the deposition rate of aluminum was adjusted to be 1 to 10 nm/sec.

When a direct current voltage was applied to the ITO electrode as the anode and the aluminum electrode as the ^cathode , the emission peak wavelength was 450 nm, the emission half-width was 30 nm, and the external quantum efficiency was 5.5% when the luminance was 1000 cd/ ^m2 . In addition, the LT90 (the time until the luminance reached 900 cd/ ^m2 ) when continuously driven at an initial luminance of 1000 cd/m2 was 32 hours.

<Configuration B1: Element using compound (BD1) as a dopant (Comparative Example 1)>
An organic EL device was obtained in the same manner as in Example 5, except that compound (BD1) was used as the dopant instead of compound (4-37). When a direct current voltage was applied between an ITO electrode as the anode and an aluminum electrode as the cathode, the emission peak wavelength was 405 nm, the emission half-width was 24 nm, and the external quantum efficiency was 1.5% at a luminance of 1000 cd/ ^m2 . In addition, the LT90 when continuously driven at an initial luminance of 1000 cd/ ^m2 was 1 hour or less.

The characteristics of Example 5 and Comparative Example 1 are summarized below. The organic EL device using the compound of the present invention was superior to the comparative examples in external quantum efficiency and device life.

(2) Preparation and Evaluation of Composition for Forming Light-Emitting Layer <Examples S-1 to S-3 and Comparative Example S-1>
As shown in Table 7, 0.99% by mass of the host as the first component, 0.01% by mass of the dopant as the second component, and 99% by mass of the solvent as the third component were mixed to prepare compositions for forming an emission layer with a solid content of 1% by mass.

In Table 7 above, "EMH4" is 9-(7-([1,1':3',1":3",1'"-quatrophenyl]-3-yl)naphthalen-2-yl)-10-phenylanthracene. The chemical structure is shown below.

The solvents used in preparing the composition for forming the light-emitting layer are as follows.
"Tol / DHNp (9/1)"
Mixture of toluene and decahydronaphthalene = 9/1 (volume ratio) "3PxT / c6B (7/3)"
Mixture of 3-phenoxytoluene and cyclohexylbenzene = 7/3 (volume ratio)

The following evaluations were carried out on the prepared light-emitting layer-forming composition. The results are shown in Table 8.

<Evaluation of Solubility>
The solubility was evaluated by checking the presence or absence of turbidity and precipitation in the prepared compositions for forming a light-emitting layer. Compositions without turbidity and precipitation were rated as "A," and compositions with turbidity or precipitation were rated as "F."

<Evaluation of film-forming properties>
For compositions for forming an emitting layer that were rated "A" for solubility, the films obtained after spin-coating or inkjet printing were observed according to the procedure described below. Films having pinholes, compound precipitation, or unevenness were rated "C." Films free of pinholes, compound precipitation, and unevenness were rated "B." Films that were rated "B" and also had high smoothness (Ra<5 nm) were rated "A."

(Film formation method by spin coating)
A clean glass substrate with a thickness of 0.5 mm and a size of 28 x 26 mm was irradiated with an irradiation energy of 1000 mJ/ ^cm2 (low pressure mercury lamp (254 nanometers)) to perform UV- _O3 treatment. Next, 0.3 to 0.6 ml of the composition for forming an emitting layer was dropped onto the glass, and spin coating (slope (increase to a specified rotation speed in 5 seconds) → coating at 500 to 5000 rpm (maintain at a specified rotation speed for 10 seconds) → slope (decrease the rotation speed in 5 seconds, and set the rotation speed to 0 rpm)) was performed. Furthermore, the substrate was dried on a hot plate at 120°C for 10 minutes to form a film.

(Inkjet film formation method)
The composition for forming a light-emitting layer was discharged into a pixel of 100 ppi using an inkjet printer, and dried at 120° C. to form a film.

<Evaluation of Inkjet Ejection Stability>
For the compositions for forming light-emitting layers that were rated "A" for solubility, the compositions for forming light-emitting layers were discharged into a pixel of 100 ppi using an inkjet, and the discharge stability of each inkjet was evaluated immediately after the start of discharge and after 24 hours of continuous operation. In the evaluation, the composition was rated "C" when it could be discharged from less than 50% of the discharge holes (including cases where it could not be discharged), "B" when it could be discharged from 50% to less than 90% of the discharge holes, and "A" when it could be discharged from 90% or more of the discharge holes.

(3) Preparation and Evaluation of Coating-Type Organic EL Device Next, an organic EL device obtained by coating an organic layer will be described.

<Synthesis of polymer hole transport compound: XLP-101>
XLP-101 was synthesized according to the method described in JP 2018-61028 A. A copolymer in which M5 or M6 was bonded next to M4 was obtained, and it is estimated from the charge ratio that each unit is 40:10:50 (molar ratio). In the following formula, Bpin is pinacolatoboryl.

<Preparation of Polymer Hole Transport Compound: XLP-101 Solution>
XLP-101 synthesized according to the method described in JP 2018-61028 A was dissolved in a mixed solution of 3-phenoxytoluene/cyclohexylbenzene = 7/3 (volume ratio) to a concentration of 0.7 mass%.

<Preparation of Organic EL Devices of Example SD-1 and Comparative Example SD-1>
Table 9 shows the material composition of each layer in the organic EL element.

In Table 9 above, a commercially available PEDOT:PSS solution (Clevios(TM) P VP AI4083, an aqueous dispersion of PEDOT:PSS represented by the following formula, manufactured by Heraeus Holdings) was used as the "PEDOT:PSS" material for forming the hole injection layer.

<Example SD-1>
On a glass substrate on which ITO was evaporated to a thickness of 50 nm, a PEDOT:PSS solution was spin-coated and baked on a hot plate at 200°C for 1 hour to form a hole injection layer with a thickness of 40 nm. Next, an XLP-101 solution was spin-coated, dried on a hot plate at 80°C for 10 minutes, and then baked on a hot plate at 200°C for 1 hour to form a hole transport layer with a thickness of 30 nm that is insoluble in the composition for forming an emitting layer. Next, the composition for forming an emitting layer prepared in Example S-3 was spin-coated and baked on a hot plate at 120°C for 1 hour to form a emitting layer with a thickness of 20 nm.

The prepared multilayer film was fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Showa Vacuum Co., Ltd.), and a molybdenum vapor deposition boat containing ET-1, ET-2, Liq, and LiF, and a tungsten vapor deposition boat containing aluminum were attached. After the vacuum chamber was reduced in pressure to 5×10 ⁻⁴ Pa, ET-1 was heated and vapor-deposited to a thickness of 10 nm to form an electron transport layer 1. Next, ET-2 and Liq were heated and vapor-deposited to a thickness of 20 nm to form an electron transport layer 2. The vapor deposition rate was adjusted so that the mass ratio of ET-2 and Liq was approximately 1:1. The vapor deposition rate when forming the electron transport layer was 1 nm/sec. Thereafter, LiF was heated and vapor-deposited at a vapor deposition rate of 0.01 to 0.1 nm/sec to a thickness of 1 nm. Next, aluminum was heated and vapor-deposited to a thickness of 100 nm to form a cathode. In this manner, an organic EL device was obtained.

When a direct current voltage was applied to the ITO electrode as the anode and the aluminum electrode as the cathode, the characteristics at 1000 cd/ ^m2 emission were measured, and the emission surface was uniform, the emission spectrum had a peak wavelength of 452 nm, a half-width of 38 nm, and the external quantum efficiency at 1000 cd/ ^m2 emission was 2.1%.

<Comparative Example SD-1>
An organic EL element was obtained in the same procedure and configuration as in Example SD-1, except that Comparative Example S-1 was formed instead of Example S-2. A direct current voltage was applied to the ITO electrode as the anode and the aluminum electrode as the cathode, and the characteristics at 1000 cd/ ^m2 emission were measured. Bright spots were observed on the emission surface, suggesting that crystallization of the compound had occurred. The emission spectrum had a peak wavelength of 425 nm and a half-width of 67 nm. The external quantum efficiency at 1000 cd/ ^m2 emission was 0.2%.

The results of Example SD-1 and Comparative Example SD-1 are summarized in Table 10. Higher efficiency was obtained in Example SD-1, which used the compound of the present invention.

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

REFERENCE SIGNS LIST 100 Organic electroluminescent element 101 Substrate 102 Anode 103 Hole injection layer 104 Hole transport layer 105 Light-emitting layer 106 Electron transport layer 107 Electron injection layer 108 Cathode

Claims (15)

A polycyclic aromatic compound represented by formula (4) or formula (12) :
( In formula (4) and formula (12),
Y1 is B ^,
X1 is >O, >N-R, or >C(-R) ₂ ^;
X2 is >O, >C(-R) ₂ , or >S;
X3 ^is >O, >N--R, >C(--R) ₂ , or >S;
X4 and X6 ^{are each} independently >O, >N-R, or >S;
R in the >N-R is each independently phenyl (which may be substituted with alkyl having 1 to 6 carbon atoms or phenyl which may be substituted with alkyl having 1 to 6 carbon atoms);
R in the >C(-R) ₂ is methyl;
R ^b1 to R ^b13 each represent a hydrogen atom or any substituent selected from methyl, t-butyl, t-amyl, t-octyl, phenyl, o-tolyl, p-tolyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 2,4,6-mesityl, diphenylamino, di-p-tolylamino, bis(p-(t-butyl)phenyl)amino, carbazolyl, 3,6-dimethylcarbazolyl, 3,6-di-t-butylcarbazolyl, and phenoxy;
At least one hydrogen atom in each of the compounds represented by formula (4) and formula (12) may be replaced with deuterium . X ¹ The polycyclic aromatic compound according to claim 1, wherein >N-R. X ² and X ³ All of them are >C(-R) ₂ The polycyclic aromatic compound according to claim 1 or 2, The polycyclic aromatic compound according to claim 1 , which is represented by any one of the following structural formulas:
A material for an organic device, comprising the polycyclic aromatic compound according to any one of claims 1 to 4 . The material for an organic device according to claim 5 , 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 6 , wherein the material for an organic electroluminescent element is a material for a light-emitting layer. A composition comprising the polycyclic aromatic compound according to any one of claims 1 to 4 and an organic solvent. 5. An organic electroluminescence device comprising a pair of electrodes consisting of an anode and a cathode, and an organic layer disposed between the pair of electrodes and containing the polycyclic aromatic compound according to claim 1. 5. An organic electroluminescence device comprising a pair of electrodes consisting of an anode and a cathode, and a light-emitting layer disposed between the pair of electrodes and containing the polycyclic aromatic compound according to claim 1. The organic electroluminescent device according to claim 10 , wherein the light-emitting layer comprises a host and the polycyclic aromatic compound as a dopant. The organic electroluminescent device according to claim 11 , wherein the host is an anthracene-based compound, a fluorene-based compound, or a dibenzochrysene-based compound. The organic electroluminescence device according to any one of claims 10 to 12, further comprising an electron transport layer and/or an electron injection layer disposed between the cathode and the light emitting layer, and at least one of the electron transport layer and the electron injection layer contains at least one selected from the group consisting of borane derivatives, pyridine derivatives, fluoranthene derivatives, BO-based derivatives, anthracene derivatives, benzofluorene derivatives, phosphine oxide derivatives, pyrimidine derivatives, arylnitrile derivatives, triazine derivatives, benzimidazole derivatives, phenanthroline derivatives, quinolinol-based metal complexes, thiazole derivatives, benzothiazole derivatives, silole derivatives, and azoline derivatives. 14. The organic electroluminescent device according to claim 13, wherein the electron transport layer and/or the electron injection layer further contains at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, oxides of alkali metals, halides of alkali metals, oxides of alkaline earth metals, halides of alkaline earth metals, oxides of rare earth metals, halides of rare earth metals, organic complexes of alkali metals, organic complexes of alkaline earth metals, and organic complexes of rare earth metals. A display device or a lighting device comprising the organic electroluminescent device according to any one of claims 9 to 14 .