JP7551273B2 - Compound, material for organic electroluminescence device, composition for organic electroluminescence device, and organic electroluminescence device - Google Patents

Description

The present invention relates to a compound, a material for an organic electroluminescent device, a composition for an organic electroluminescent device, and an organic electroluminescent device.

In recent years, there has been active development of display devices and lighting equipment using organic electroluminescence devices, which are self-luminous light-emitting elements. Organic electroluminescence devices (hereinafter sometimes referred to as organic electroluminescence devices or organic EL devices) have an organic layer containing a light-emitting material. In the organic layer of an organic EL device, the light-emitting material is excited by the recombination of electrons and holes, and light is emitted when the light-emitting material returns to the ground state.

In such organic EL elements, various materials have been developed to form the organic layer in order to improve element characteristics such as current efficiency and luminescence life. For example, Patent Documents 1 to 5 disclose organic electroluminescence elements using carbazole compounds.

In addition, in the manufacture of organic EL elements, the organic films that constitute the organic EL elements are generally formed by a dry film formation method such as a vapor deposition method. However, film formation by a dry film formation method such as a vapor deposition method is time-consuming and costly, so instead of such dry film formation methods, the use of wet film formation methods such as a solution coating method (hereinafter referred to as a coating method) that can reduce time and costs is being considered.

International Publication No. 2014/094963 International Publication No. 2013/122402 International Publication No. 2003/078541 International Publication No. 2006/067976 International Publication No. 2006/062062

However, when forming an organic EL element using a wet film formation method such as a solution coating method, the organic EL material used in the deposition is often difficult to dissolve in the coating solvent, and even if there is no problem with solubility, organic molecules are more likely to aggregate in a thin film formed by a wet method than in a thin film formed by a deposition method. When multiple organic molecules aggregate, the molecular orbital is expanded more than in a single molecule state, and there is a possibility that energy levels such as HOMO, LUMO, S1, and T1 that are different from those in a single molecule state are formed. These are likely to have adverse effects such as carrier trapping and deactivation of luminescent excitons. As a result, organic EL elements formed by a coating method do not achieve sufficient current efficiency and luminescence life.

The object of the present invention is to provide a compound that can be used to fabricate an organic electroluminescence device having excellent current efficiency and luminescence life by a coating method.

In order to solve the above problems, one aspect of the present invention provides a compound represented by the following general formula (1):

_L1 and _L2 each independently represent a single bond, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms;
m and n are each independently an integer of 0 or 1;
_A1 is a substituent selected from the following general formulae (A1-1) to (A1-6),

上記一般式（Ａ１－１）～（Ａ１－６）において、
Ｘ_１１～Ｘ_１８は、それぞれ独立して、Ｃ（Ｒ_１）または窒素原子であり、
Ｙ_１１～Ｙ_１５は、それぞれ独立して、Ｃ（Ｒ_１）または窒素原子であり、
Ｚ_１１～Ｚ_１５は、それぞれ独立して、Ｃ（Ｒ_１）または窒素原子であり、
Ｅ_１は、Ｃ（Ｒ_１１）（Ｒ_１２）、Ｓｉ（Ｒ_１３）（Ｒ_１４）、Ｎ（Ｒ_１５）、酸素原子または硫黄原子であり、
Ｘ_１１～Ｘ_１８、Ｙ_１１～Ｙ_１５、及びＺ_１１～Ｚ_１５中のＲ_１は、それぞれ独立して、水素原子、重水素原子、置換されたもしくは無置換の炭素数１～３０のアルキル基、置換されたもしくは無置換の炭素数１～３０のアルコキシ基、置換されたもしくは無置換の炭素数６～３０のアリールオキシ基、置換されたもしくは無置換の炭素数１～３０のアミノ基、シアノ基、置換されたもしくは無置換の炭素数６～３０の芳香族炭化水素環基、または置換されたもしくは無置換の環形成原子数３～３０の芳香族複素環基であり、
Ｅ_１中のＲ_１１～Ｒ_１４は、それぞれ独立して、水素原子、重水素原子、置換されたもしくは無置換の炭素数１～３０のアルキル基、置換されたもしくは無置換の炭素数１～３０のアルコキシ基、置換されたもしくは無置換の炭素数６～３０のアリールオキシ基、置換されたもしくは無置換の炭素数１～３０のアミノ基、シアノ基、置換されたもしくは無置換の炭素数６～３０の芳香族炭化水素環基、または置換されたもしくは無置換の環形成原子数３～３０の芳香族複素環基であり、
Ｅ_１中のＲ_１５は、置換されたもしくは無置換の炭素数１～３０のアルキル基、置換されたもしくは無置換の炭素数１～３０のアルコキシ基、置換されたもしくは無置換の炭素数６～３０のアリールオキシ基、置換されたもしくは無置換の炭素数１～３０のアミノ基、シアノ基、置換されたもしくは無置換の炭素数６～３０の芳香族炭化水素環基、または置換されたもしくは無置換の環形成原子数３～３０の芳香族複素環基であり、
Ｑ_１は、置換されたもしくは無置換の炭素数６～３０の芳香族炭化水素環基、または置換されたもしくは無置換の環形成原子数３～３０の芳香族複素環基であり、
Ｎ_１１は、Ｌ_１と結合する窒素原子であり、
Ｘ_１１～Ｘ_１８、Ｙ_１１～Ｙ_１５、Ｚ_１１～Ｚ_１５のいずれか１つは、Ｌ_１と結合する炭素原子であり、
ただし、Ａ_１が上記一般式（Ａ１－１）で表される置換基のとき、Ｌ_１はＸ_１４と結合し、
Ａ_１が上記一般式（Ａ１－２）で表される置換基のとき、Ｌ_１はＸ_１４、Ｙ_１１～Ｙ_１４、Ｚ_１１～Ｚ_１５のいずれか１つと結合し、
Ａ_１が上記一般式（Ａ１－３）で表される置換基のとき、Ｌ_１はＸ_１４と結合し、
Ａ_１が上記一般式（Ａ１－４）で表される置換基のとき、Ｌ_１はＺ_１１～Ｚ_１５のいずれか１つと結合し、
Ａ_１が上記一般式（Ａ１－５）で表される置換基のとき、Ｌ_１はＸ_１４、Ｘ_１５、Ｑが有する水素原子以外の原子のいずれか１つと結合し、または、
Ａ_１が上記一般式（Ａ１－６）で表される置換基のとき、Ｌ_１はＸ_１４、Ｘ_１５、Ｙ_１１～Ｙ_１５、Ｑ_１が有する水素原子以外の原子のいずれか１つと結合し、
Ａ_２は、下記一般式（Ａ２－１）～（Ａ２－６）から選ばれる置換基であり、

In the above general formulae (A1-1) to (A1-6),
X ₁₁ to X ₁₈ each independently represent C(R ₁ ) or a nitrogen atom;
Y ₁₁ to Y ₁₅ each independently represent C(R ₁ ) or a nitrogen atom;
Z ₁₁ to Z ₁₅ each independently represent C(R ₁ ) or a nitrogen atom;
_E1 is C( _R11 )( _R12 ), Si( _R13 )( _R14 ), N( _R15 ), an oxygen atom or a sulfur atom;
R ₁ in X ₁₁ to X ₁₈ , Y ₁₁ to Y ₁₅ , and Z ₁₁ to Z ₁₅ is each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms;
R ₁₁ to R ₁₄ in E ₁ are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms;
R ₁₅ in E ₁ is a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms;
_Q1 is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms;
_N11 is a nitrogen atom bonded to _L1 ;
any one of X ₁₁ to X ₁₈ , Y ₁₁ to Y ₁₅ and Z ₁₁ to Z ₁₅ is a carbon atom bonded to L ₁ ;
provided that when A ₁ is a substituent represented by the above general formula (A1-1), L ₁ is bonded to X ₁₄ ;
When A ₁ is a substituent represented by the above general formula (A1-2), L ₁ is bonded to any one of X ₁₄ , Y ₁₁ to Y ₁₄ , and Z ₁₁ to Z ₁₅ ;
When A ₁ is a substituent represented by the above general formula (A1-3), L ₁ is bonded to X ₁₄ ;
When A ₁ is a substituent represented by the above general formula (A1-4), L ₁ is bonded to any one of Z ₁₁ to Z ₁₅ ;
When A ₁ is a substituent represented by the above general formula (A1-5), L ₁ is bonded to any one of atoms other than hydrogen atoms contained in X ₁₄ , X ₁₅ and Q, or
When A ₁ is a substituent represented by the above general formula (A1-6), L ₁ is bonded to any one of atoms other than a hydrogen atom possessed by X ₁₄ , X ₁₅ , Y ₁₁ to Y ₁₅ , and Q ₁ ;
_A2 is a substituent selected from the following general formulae (A2-1) to (A2-6),

上記一般式（Ａ２－１）～（Ａ２－６）において、
Ｘ_２１～Ｘ_２８は、それぞれ独立して、Ｃ（Ｒ_２）または窒素原子であり、
Ｙ_２１～Ｙ_２５は、それぞれ独立して、Ｃ（Ｒ_２）または窒素原子であり、
Ｚ_２１～Ｚ_２５は、それぞれ独立して、Ｃ（Ｒ_２）または窒素原子であり、
Ｅ_２は、Ｃ（Ｒ_２１）（Ｒ_２２）、Ｓｉ（Ｒ_２３）（Ｒ_２４）、Ｎ（Ｒ_２５）、酸素原子または硫黄原子であり、
Ｘ_２１～Ｘ_２８、Ｙ_２１～Ｙ_２５、及びＺ_２１～Ｚ_２５中のＲ_２は、それぞれ独立して、水素原子、重水素原子、置換されたもしくは無置換の炭素数１～３０のアルキル基、置換されたもしくは無置換の炭素数１～３０のアルコキシ基、置換されたもしくは無置換の炭素数６～３０のアリールオキシ基、置換されたもしくは無置換の炭素数１～３０のアミノ基、シアノ基、置換されたもしくは無置換の炭素数６～３０の芳香族炭化水素環基、または置換されたもしくは無置換の環形成原子数３～３０の芳香族複素環基であり、
Ｅ_２中のＲ_２１～Ｒ_２４は、それぞれ独立して、水素原子、重水素原子、置換されたもしくは無置換の炭素数１～３０のアルキル基、置換されたもしくは無置換の炭素数１～３０のアルコキシ基、置換されたもしくは無置換の炭素数６～３０のアリールオキシ基、置換されたもしくは無置換の炭素数１～３０のアミノ基、シアノ基、置換されたもしくは無置換の炭素数６～３０の芳香族炭化水素環基、または置換されたもしくは無置換の環形成原子数３～３０の芳香族複素環基であり、
Ｅ_２中のＲ_２５は、置換されたもしくは無置換の炭素数６～３０の芳香族炭化水素環基、または置換されたもしくは無置換の環形成原子数３～３０の芳香族複素環基であり、
Ｑ_２は、置換されたもしくは無置換の炭素数６～３０の芳香族炭化水素環基、または置換されたもしくは無置換の環形成原子数３～３０の芳香族複素環基であり、
Ｎ_２１は、Ｌ_２と結合する窒素原子であり、
Ｘ_２１～Ｘ_２８、Ｙ_２１～Ｙ_２５、Ｚ_２１～Ｚ_２５のいずれか１つは、Ｌ_２と結合する炭素原子であり、
ただし、Ａ_２が上記一般式（Ａ２－１）で表される置換基のとき、Ｌ_２はＸ_２４、Ｙ_２１～Ｙ_２５のいずれか１つと結合し、
Ａ_２が上記一般式（Ａ２－２）で表される置換基のとき、Ｌ_２はＸ_２４、Ｙ_２１～Ｙ_２４、Ｚ_２１～Ｚ_２５のいずれか１つと結合し、
Ａ_２が上記一般式（Ａ２－３）で表される置換基のとき、Ｌ_２はＸ_２４と結合し、
Ａ_２が上記一般式（Ａ２－４）で表される置換基のとき、Ｌ_２はＺ_２１～Ｚ_２５のいずれか１つと結合し、
Ａ_２が上記一般式（Ａ２－５）で表される置換基のとき、Ｌ_２はＮ_２１、Ｘ_２４、Ｘ_２５、Ｑ_２が有する水素原子以外の原子のいずれか１つと結合し、または、
Ａ_２が上記一般式（Ａ２－６）で表される置換基のとき、Ｌ_２はＮ_２１、Ｘ_２４、Ｘ_２５、Ｙ_２１～Ｙ_２５、Ｑ_２が有する水素原子以外の原子のいずれか１つと結合し、
Ａ_３は、置換されたもしくは無置換の炭素数６～３０の芳香族炭化水素環基、または置換されたもしくは無置換の環形成原子数３～３０の芳香族複素環基であり、
上記一般式（１）の化合物は、１分子内に含む飽和型窒素原子が３個以下である。

In the above general formulae (A2-1) to (A2-6),
X ₂₁ to X ₂₈ each independently represent C(R ₂ ) or a nitrogen atom;
Y ₂₁ to Y ₂₅ each independently represent C(R ₂ ) or a nitrogen atom;
Z ₂₁ to Z ₂₅ each independently represent C(R ₂ ) or a nitrogen atom;
_E2 is C( _R21 )( _R22 ), Si( _R23 )( _R24 ), N( _R25 ), an oxygen atom or a sulfur atom;
R ₂ in X ₂₁ to X ₂₈ , Y ₂₁ to Y ₂₅ , and Z ₂₁ to Z ₂₅ is each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms;
R ₂₁ to R ₂₄ in E ₂ are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms;
R ₂₅ in E ₂ is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms;
_Q2 is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms;
_N21 is a nitrogen atom bonded to _L2 ;
any one of X ₂₁ to X ₂₈ , Y ₂₁ to Y ₂₅ and Z ₂₁ to Z ₂₅ is a carbon atom bonded to L ₂ ;
provided that when _A2 is a substituent represented by the above general formula (A2-1), _L2 is bonded to any one of _X24 and _Y21 to _Y25 ;
When _A2 is a substituent represented by the above general formula (A2-2), _L2 is bonded to any one of _X24 , _Y21 to _Y24 , and _Z21 to _Z25 ;
When _A2 is a substituent represented by the above general formula (A2-3), _L2 is bonded to _X24 ,
When _A2 is a substituent represented by the above general formula (A2-4), _L2 is bonded to any one of _Z21 to _Z25 ;
When _A2 is a substituent represented by the above general formula (A2-5), _L2 is bonded to any one of atoms other than a hydrogen atom possessed by _N21 , _X24 , _X25 , and _Q2 , or
When _A2 is a substituent represented by the above general formula (A2-6), _L2 is bonded to any one of atoms other than hydrogen atoms possessed by _N21 , _X24 , _X25 , _Y21 to _Y25 , and _Q2 ,
_A3 is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms;
The compound of the above general formula (1) contains three or less saturated nitrogen atoms in one molecule.

According to one aspect of the present invention, a compound is provided that can be used to fabricate an organic electroluminescence device having excellent current efficiency and luminescence life by a coating method.

1 is a schematic diagram showing an organic electroluminescence element according to an embodiment of the present invention.

The following describes in detail the embodiments of the present invention. Note that the present invention is not limited to the following embodiments.

<Compound>
The compound according to this embodiment is a compound represented by the following general formula (1).

In the above general formula (1), _A1 is a substituent selected from the following general formulae (A1-1) to (A1-6).

In the above general formulae (A1-1) to (A1-6), X ₁₁ to X ₁₈ are each independently C(R ₁ ) or a nitrogen atom. Y ₁₁ to Y ₁₅ are each independently C(R ₁ ) or a nitrogen atom. Z ₁₁ to Z ₁₅ are each independently C(R ₁ ) or a nitrogen atom. E ₁ is C(R ₁₁ )(R ₁₂ ), Si(R ₁₃ )(R ₁₄ ), N(R ₁₅ ), an oxygen atom or a sulfur atom.

Here, "independently" means that each selection of R ₁₁ to R ₁₄ etc. may be the same or different.

R ₁ in X ₁₁ to X ₁₈ , Y ₁₁ to Y ₁₅ , and Z ₁₁ to Z ₁₅ is each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms.

In this specification, "substituted or unsubstituted" means that the substituents, etc. may further have substituents other than hydrogen atoms and deuterium atoms. In addition, these substituents may be bonded to each other to form a ring.

In addition, in this specification, "A-B" means the range from A to B, including A and B.

The alkyl group having 1 to 30 carbon atoms that may constitute _R1 is not particularly limited, and may be, for example, a linear or branched alkyl group having 1 to 30 carbon atoms. Specific examples of such alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl, 1,2-dimethylpropyl, n-hexyl, isohexyl, 1,3-dimethylbutyl, 1-isopropylpropyl, 1,2-dimethylbutyl, n-heptyl, 1,4-dimethylpentyl, 3-ethylpentyl, 2-methyl-1-isopropylpropyl, 1-ethyl-3-methylbutyl, n-octyl, 2-ethyl-1-isopropylpropyl, 1-ethyl-3-methylbutyl, n-octyl, 2-ethyl-1-isopropylpropyl, 1-ethyl-2-ethyl-1-isopropylpropyl, ... Examples of such alkyl groups include butylhexyl group, 3-methyl-1-isopropylbutyl group, 2-methyl-1-isopropyl group, 1-tert-butyl-2-methylpropyl group, n-nonyl group, 3,5,5-trimethylhexyl group, n-decyl group, isodecyl group, n-undecyl group, 1-methyldecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, n-heneicosyl group, n-docosyl group, n-tricosyl group, and n-tetracosyl group. Among these, linear or branched alkyl groups having 1 to 8 carbon atoms are preferred.

The alkoxy group having 1 to 30 carbon atoms that can constitute _R1 is not particularly limited, and is, for example, a linear or branched alkoxy group having 1 to 30 carbon atoms. Specific examples include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, a dodecyloxy group, a tridecyloxy group, a tetradecyloxy group, a pentadecyloxy group, a hexadecyloxy group, a heptadecyloxy group, an octadecyloxy group, a 2-ethylhexyloxy group, and a 3-ethylpentyloxy group. Of these, a linear or branched alkoxy group having 1 to 8 carbon atoms is preferred.

The aryloxy group having 6 to 30 carbon atoms which may constitute _R1 is not particularly limited, but is, for example, a monocyclic or condensed polycyclic aryloxy group having 6 to 30 carbon atoms which may contain a heteroatom. Specific examples include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 2-azulenyloxy group, a 2-furanyloxy group, a 2-thienyloxy group, a 2-indolyloxy group, a 3-indolyloxy group, a 2-benzofuryloxy group, and a 2-benzothienyloxy group.

The amino group having 1 to 30 carbon atoms that may constitute R ₁ is not particularly limited, and may be, for example, a linear or branched alkylamino group having 1 to 30 carbon atoms. Specific examples include N-alkylamino groups such as N-methylamino group, N-ethylamino group, N-propylamino group, N-isopropylamino group, N-butylamino group, N-isobutylamino group, N-sec-butylamino group, N-tert-butylamino group, N-pentylamino group, and N-hexylamino group, and N,N,N-dialkylamino groups such as N,N,N-dimethylamino group, N-methyl-N-ethylamino group, N,N-diethylamino group, N,N-dipropylamino group, N,N-diisopropylamino group, N,N-dibutylamino group, N,N-diisobutylamino group, N,N-dipentylamino group, and N,N-dihexylamino group.

The aromatic hydrocarbon ring group having 6 to 30 carbon atoms that may constitute _R1 is a group derived from a hydrocarbon ring (aromatic hydrocarbon ring) having a carbon ring containing one or more aromatic rings having 6 to 30 carbon atoms. When the aromatic hydrocarbon ring group contains two or more rings, the two or more rings may be condensed with each other. Furthermore, one or more hydrogen atoms present in these aromatic hydrocarbon ring groups may be substituted with a substituent.

The aromatic hydrocarbons constituting the aromatic hydrocarbon ring group are not particularly limited, but specific examples include benzene, pentalene, indene, naphthalene, anthracene, azulene, heptalene, acenaphthalene, phenalene, fluorene, phenanthrene, biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, triphenylene, pyrene, chrysene, picene, perylene, pentaphene, pentacene, tetraphene, hexaphene, hexacene, rubicene, trinaphthylene, heptaphene, pyranthrene, etc.

The aromatic heterocyclic group having 3 to 30 ring atoms which may constitute _R1 is a group derived from a ring (aromatic heterocycle) having 3 to 30 ring atoms and containing one or more aromatic rings having one or more heteroatoms (e.g., nitrogen atom (N), oxygen atom (O), phosphorus atom (P), sulfur atom (S)) and the remaining ring atoms being carbon atoms (C). When the aromatic heterocyclic group contains two or more rings, the two or more rings may be condensed with each other. Furthermore, one or more hydrogen atoms present in these aromatic heterocyclic groups may be substituted with a substituent.

Here, the number of ring atoms refers to the number of atoms that make up the ring itself in a compound having a structure in which atoms are bonded in a ring (e.g., a single ring, a condensed ring, a ring assembly). Atoms that do not make up the ring (e.g., hydrogen atoms terminating the bonds of atoms that make up the ring) and atoms contained in the substituent when the ring is substituted with a substituent are not included in the number of ring atoms. For example, a carbazolyl group has 13 ring atoms.

The aromatic heterocycle constituting the aromatic heterocyclic group is not particularly limited, but examples thereof include π-electron-deficient aromatic heterocycles, π-electron-rich aromatic heterocycles, and mixed π-electron-deficient-π-electron-rich aromatic heterocycles that are a mixture of a π-electron-deficient aromatic heterocycle and a π-electron-rich aromatic heterocycle.

Specific examples of π-electron deficient aromatic heterocycles include pyridine, pyrazine, pyridazine, pyrimidine, triazine, quinoline, isoquinoline, quinoxaline, quinazoline, naphthyridine, acridine, phenazine, benzoquinoline, benzoisoquinoline, phenanthridine, phenanthroline, benzoquinone, coumarin, anthraquinone, and fluorenone.

Specific examples of π-electron-rich aromatic heterocycles include furan, thiophene, benzofuran, benzothiophene, dibenzofuran, dibenzothiophene, pyrrole, indole, and carbazole.

Specific examples of π-electron deficient-π-electron rich mixed aromatic heterocycles include imidazole, benzimidazole, pyrazole, indazole, oxazole, isoxazole, benzoxazole, benzisoxazole, thiazole, isothiazole, benzothiazole, benzisothiazole, imidazolinone, benzimidazolinone, imidazopyridine, imidazopyrimidine, imidazophenanthridine, benzimidazophenanthridine, azadibenzofuran, azacarbazole, azadibenzothiophene, diazadibenzofuran, diazacarbazole, diazadibenzothiophene, xanthone, thioxanthone, etc.

R ₁₁ to R ₁₄ which can constitute E ₁ in the above general formula (A1-3) or (A1-4) are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms.

Here, "independently" means that the substituents R ₁₁ to R ₁₄ may be the same or different. In addition, the hydrogen atom, deuterium atom, alkyl group, alkoxy group, aryloxy group, amino group, cyano group, aromatic hydrocarbon ring group, and aromatic heterocyclic group which can constitute R ₁₁ to R ₁₄ have the same definition as the hydrogen atom, deuterium atom, alkyl group, alkoxy group, aryloxy group, amino group, cyano group, aromatic hydrocarbon ring group, and aromatic heterocyclic group which can constitute R ₁ , and therefore the explanation thereof will be omitted here.

R ₁₅ which can constitute E ₁ in the above general formula (A1-3) or (A1-4) is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms.

Here, the alkyl group, alkoxy group, aryloxy group, amino group, cyano group, aromatic hydrocarbon ring group, and aromatic heterocyclic group which can constitute _R15 have the same definitions as the alkyl group, alkoxy group, aryloxy group, amino group, cyano group, aromatic hydrocarbon ring group, and aromatic heterocyclic group which can constitute _R1 , and therefore the explanation thereof will be omitted.

In general formula (1), _L1 and _L2 each independently represent a single bond, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms.

Here, when _L1 and _L2 are single bonds, this indicates that _A1 and _A2 are directly bonded to the triazine ring in general formula (1). The aromatic hydrocarbon ring group and aromatic heterocyclic group which can constitute _L1 and _L2 have the same definition as the aromatic hydrocarbon ring group and aromatic heterocyclic group which can constitute _R1 described above.

From the viewpoint of improving the current efficiency and luminous life of an organic electroluminescence device, the aromatic hydrocarbon ring group and aromatic heterocyclic group which may constitute L ₁ and L ₂ are preferably substituted or unsubstituted aromatic hydrocarbon ring groups having 6 to 18 carbon atoms, or substituted or unsubstituted aromatic heterocyclic groups having 3 to 18 ring atoms, more preferably substituted or unsubstituted aromatic hydrocarbon ring groups having 6 to 13 carbon atoms (e.g., fluorene, etc.), or substituted or unsubstituted aromatic heterocyclic groups having 3 to 13 ring atoms (e.g., dibenzofuran, etc.), and even more preferably substituted or unsubstituted aromatic hydrocarbon ring groups having 6 to 10 carbon atoms (e.g., benzene ring, naphthalene ring), or substituted or unsubstituted pyridine ring, pyrazine ring, pyrimidine ring, triazine ring, quinoline ring, quinoxaline ring, quinazoline ring, dibenzofuran ring, or dibenzothiophene ring.

m and n are each independently an integer of 0 or 1. "Independently" means that m and n may be the same or different. When m and n are 0, this indicates that A ₁ and A ₂ are directly bonded to the triazine ring in general formula (1).

_Q1 in the above general formulae (A1-5) and (A1-6) is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms. The aromatic hydrocarbon ring group and aromatic heterocyclic group that can constitute _Q1 have the same definition as the aromatic hydrocarbon ring group and aromatic heterocyclic group that can constitute _R1 in the above-mentioned _A1 , and therefore description thereof will be omitted.

In addition, in _A1 , any one of X ₁₁ to X ₁₈ , Y ₁₁ to Y ₁₅ , and Z ₁₁ to Z ₁₅ is a carbon atom bonded to L _1. That is, _A1 is bonded to L ₁ via any one of carbon atoms of X ₁₁ to X ₁₈ , Y ₁₁ to Y ₁₅ , and Z ₁₁ to Z ₁₅ .

However, when A ₁ is a substituent represented by the above general formula (A1-1), L ₁ is bonded to X _14. That is, in the above general formula (1), the substituent represented by the above general formula (A1-1) is bonded to L ₁ via X ₁₄ .

Furthermore, when A ₁ is a substituent represented by the above general formula (A1-2), L ₁ is bonded to any one of X ₁₄ , Y ₁₁ to Y ₁₄ , and Z ₁₁ to Z _15. That is, in the above general formula (1), the substituent represented by the above general formula (A1-2) is bonded to L ₁ via any one of X ₁₄ , Y ₁₁ to Y ₁₄ , and Z ₁₁ to Z ₁₅ .

When A ₁ is a substituent represented by the above general formula (A1-3), L ₁ is bonded to X _14. That is, in the above general formula (1), the substituent represented by the above general formula (A1-3) is bonded to L ₁ via X ₁₄ .

When A ₁ is a substituent represented by the above general formula (A1-4), L ₁ is bonded to any one of Z ₁₁ to Z _15. That is, in the above general formula (1), the substituent represented by the above general formula (A1-4) is bonded to L ₁ via any one of Z ₁₁ to Z ₁₅ .

Furthermore, when A ₁ is a substituent represented by the above general formula (A1-5), L ₁ bonds to any one of the atoms other than hydrogen atoms contained in X ₁₄ , X ₁₅ , and Q _1. That is, in the above general formula (1), the substituent represented by the above general formula (A1-5) bonds to L ₁ via any one of the atoms other than hydrogen atoms contained in X ₁₄ , X ₁₅ , and Q ₁ .

Furthermore, when A ₁ is a substituent represented by the above general formula (A1-6), L ₁ bonds to any one of the atoms other than hydrogen atoms contained in X ₁₄ , X ₁₅ , Y ₁₁ to Y ₁₅ , and Q _1. That is, in the above general formula (1), the substituent represented by the above general formula (A1-6) bonds to L ₁ via any one of the atoms other than hydrogen atoms contained in X ₁₄ , X ₁₅ , Y ₁₁ to Y ₁₅ , and Q ₁ .

By limiting the bonding position of _A1 in this manner, it is possible to make the dihedral angle of a plane including _A1 ( _A1 plane described below) with respect to a LUMO region, which will be described later, large.

From the viewpoint of improving the photochemical stability of the compound according to this embodiment, when A ₁ is a substituent represented by the above general formula (A1-1), (A1-2) or (A1-6), it is preferable that L ₁ is bonded to Y ₁₂ or Y _13. When L ₁ is bonded to a group other than Y ₁₂ or Y ₁₃ , it is preferable that either one of Y ₁₂ and Y ₁₃ is C(R ₁ ), and R ₁ is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms.

In addition, in the above general formula (1), _A2 is a substituent selected from the following general formulae (A2-1) to (A2-6).

In the above general formulae (A2-1) to (A2-6), X ₂₁ to X ₂₈ are each independently C(R ₂ ) or a nitrogen atom. Y ₂₁ to Y ₂₅ are each independently C(R ₂ ) or a nitrogen atom. Z ₂₁ to Z ₂₅ are each independently C(R ₂ ) or a nitrogen atom. E ₂ is C(R ₂₁ )(R ₂₂ ), Si(R ₂₃ )(R ₂₄ ), N(R ₂₅ ), an oxygen atom or a sulfur atom.

R ₂ in X ₂₁ to X ₂₈ , Y ₂₁ to Y ₂₅ and Z ₂₁ to Z ₂₅ is each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms.

Here, the hydrogen atom, deuterium atom, alkyl group, alkoxy group, aryloxy group, amino group, cyano group, aromatic hydrocarbon ring group, and aromatic heterocyclic group which can constitute _R2 have the _same definitions as the hydrogen atom, deuterium atom, alkyl group, alkoxy group, aryloxy group, amino group, cyano group, aromatic hydrocarbon ring group, and aromatic heterocyclic group which can constitute R1 in _A1 described above, and therefore their explanation will be omitted here.

R ₂₁ to R ₂₄ which can constitute E ₂ in the above general formulae (A2-3) and (A2-4) are each independently a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms.

Here, the hydrogen atom, deuterium atom, alkyl group, alkoxy group, aryloxy group, amino group, cyano group, aromatic hydrocarbon ring group, and aromatic heterocyclic group which can constitute R ₂₁ to R ₂₄ have the same definitions as the hydrogen atom, deuterium atom, alkyl group, alkoxy group, aryloxy group, amino group, cyano group, aromatic hydrocarbon ring group, and aromatic heterocyclic group which can constitute R ₁ in A ₁ described above, and therefore further explanation is omitted here.

R ₂₅ which can constitute E ₂ in the above general formulae (A2-3) and (A2-4) is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms. The aromatic hydrocarbon ring group and aromatic heterocyclic group which can constitute R ₂₅ have the same definition as the aromatic hydrocarbon ring group and aromatic heterocyclic group which can constitute R ₁ in A ₁ described above, and therefore description thereof will be omitted.

_Q2 in the above general formulae (A2-5) and (A2-6) is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms. The aromatic hydrocarbon ring group and aromatic heterocyclic group that can constitute _Q2 have the same definition as the aromatic hydrocarbon ring group and aromatic heterocyclic group that can constitute _R1 in _A1 described above, and therefore description thereof will be omitted.

_N21 in the above general formula (A2-5) is a nitrogen atom that bonds to _L2 .
-5) is bonded to _L2 via the nitrogen atom constituting _N21 .

In addition, any one of X ₂₁ to X ₂₈ , Y ₂₁ to Y ₂₅ , and Z ₂₁ to Z ₂₅ in the above general formulae (A2-1) to (A2-4) and (A2-6) is a carbon atom bonded to L _2. That is, (A2-1) to (A2-4) and (A2-6) are bonded to L ₂ via any one of carbon atoms of X ₂₁ to X ₂₈ , Y ₂₁ to Y ₂₅ , and Z ₂₁ to Z ₂₅ .

However, when _A2 is a substituent represented by the above general formula (A2-1), _L2 is bonded to any one of _X24 and _Y21 to _Y25 . That is, in the above general formula (1), the substituent represented by the above general formula (A2-1) is bonded to _L2 via any one of _X24 and _Y21 to _Y25 .

Furthermore, when A ₂ is a substituent represented by the above general formula (A2-2), L ₂ is bonded to any one of X ₂₄ , Y ₂₁ to Y ₂₄ , and Z ₂₁ to Z _25. That is, in the above general formula (1), the substituent represented by the above general formula (A2-2) is bonded to L ₂ via any one of X ₂₄ , Y ₂₁ to Y ₂₄ , and Z ₂₁ to Z ₂₅ .

When _A2 is a substituent represented by the above general formula (A2-3), _L2 is bonded to _X24 . That is, in the above general formula (1), the substituent represented by the above general formula (A2-3) is bonded to _L2 via _X24 .

Furthermore, when _A2 is a substituent represented by the above general formula (A2-4), _L2 is bonded to any one of _Z21 to _Z25 . That is, in the above general formula (1), the substituent represented by the above general formula (A2-4) is bonded to _L2 via any one of _Z21 to _Z25 .

Furthermore, when A ₂ is a substituent represented by the above general formula (A2-6), L ₂ bonds to any one of the atoms other than hydrogen atoms contained in X ₂₄ , X ₂₅ , Y ₂₁ to Y ₂₅ , and Q _2. That is, in the above general formula (1), the substituent represented by the above general formula (A2-6) bonds to L ₂ via any one of the atoms other than hydrogen atoms contained in X ₂₄ , X ₂₅ , Y ₂₁ to Y ₂₅ , and Q ₂ .

By limiting the bonding position of _A2 in this manner, it is possible to make the dihedral angle of a plane including _A2 ( _A2 plane described below) with respect to a LUMO region, which will be described later, large.

From the viewpoint of improving the photochemical stability of the compound according to this embodiment, when A ₂ is a substituent represented by the above general formula (A2-1), (A2-2) or (A2-6), it is preferable that L ₂ is bonded to Y ₂₂ or Y _23. When L ₂ is bonded to a group other than Y ₂₂ or Y ₂₃ , it is preferable that either one of Y ₂₂ and Y ₂₃ is C(R ₂ ), and R ₂ is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms.

_A3 in the above general formula (1) is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms. In the above general formula (1), _A3 is directly bonded to the triazine ring. Note that the aromatic hydrocarbon ring group and aromatic heterocyclic group that can constitute _A3 have the same definition as the aromatic hydrocarbon ring group and aromatic heterocyclic group that can constitute _R1 in the above-mentioned _A1 , and therefore description thereof will be omitted.

The compound of general formula (1) contains three or less saturated nitrogen atoms in one molecule. Here, "containing three or less saturated nitrogen atoms in one molecule" means that the compound of general formula (1) does not contain four or more saturated nitrogen atoms, including the substituents bonded to A ₁ , L ₁ , A ₂ , L ₂ , and A _3. In this embodiment, the compound of general formula (1) does not contain four or more saturated nitrogen atoms, including the general formulas (A1-1) to (A1-6), L ₁ , (A2-1) to (A2-6), L ₂ , A ₃ , and the substituents bonded thereto. This makes it possible to reduce the molecular weight ratio of the HOMO distributed on the A ₁ plane to the total molecular weight (hereinafter, sometimes referred to as the HOMO molecular weight ratio), and thus it is possible to suppress the hole transport property and relatively emphasize the electron transport property derived from the LUMO region.

In the above general formulae (A1-1), (A1-2) and (A1-6), it is preferred that Y ₁₃ is C(R ₁ ) and R ₁ does not contain a saturated nitrogen atom, and/or in the above general formulae (A2-1), (A2-2) and (A2-6), Y ₂₃ is C(R ₂ ) and R ₂ does not contain a saturated nitrogen atom. This is because Y ₁₃ and Y ₂₃ are at para positions having a high π-conjugation effect with respect to the N atoms in the above general formulae (A1-1), (A1-2), (A1-6), (A2-1), (A2-2) and (A2-6), and therefore by making the R ₁ or the R ₂ not contain a saturated nitrogen atom, it is possible to suppress the formation of a HOMO partial structure having high hole transportability due to the conjugation effect, and to enhance the electron transportability.

In the compound represented by the above general formula (1), LUMO (Lowest Unoccupied Molecular Orbital) is distributed in a region including the triazine ring and its peripheral portion (vicinity portion). In this specification, the region in which such LUMO is distributed is hereinafter referred to as a "LUMO region including a triazine ring" or "LUMO region". In addition, the peripheral portion (vicinity portion) of the triazine ring constituting a part of the LUMO region includes all or a part of the planes including L ₁ and L ₂ (hereinafter referred to as L ₁ and L ₂ planes, respectively) that are bonded to the plane including the triazine ring (hereinafter referred to as the triazine ring plane). Note that the peripheral portion (vicinity portion) of the triazine ring may be on the same plane as the triazine ring plane or may be twisted relative to the triazine ring plane.

In the compound of this embodiment, the dihedral angle of the plane including _A1 (hereinafter referred to as the _A1 plane) and the dihedral angle of the plane including _A2 (hereinafter referred to as the _A2 plane) can both have a large angle with respect to this LUMO region. Note that the dihedral angle is the angle between the plane including the vicinity of the LUMO region where _A1 and _A2 are bonded, and a partial plane of the vicinity of the _A1 plane and the _A2 plane that are bonded to the LUMO region.

Specifically, in the compound of the present embodiment represented by general formula (1), the substituent A ₁ bonded to the LUMO region has a partial structure in which the dihedral angle in the most stable structure in a simulation using a method for measuring rotational barrier energy described later is large (e.g., 50° or more) and the minimum dihedral angle that can be reached with 25 meV, which is the thermal energy at room temperature (298 K), is large (e.g., 40° or more). The substituent A ₂ bonded to the LUMO region has a partial structure in which the dihedral angle in the most stable structure in the same simulation described above is large (e.g., 30° or more) and the minimum dihedral angle that can be reached with 25 meV, which is the thermal energy at room temperature (298 K), is large (e.g., 20° or more).

This makes it possible to suppress the interaction of the same or different molecules with the LUMO region containing the triazine ring. This makes it possible to improve the performance (e.g., electron transport properties) of the organic electroluminescence element produced by the coating method. As a result, it is possible to provide an organic electroluminescence element with excellent current efficiency and luminescence life.

In the compound of this embodiment, it is preferable that at least two of _A1 or _L1 , _A2 or _L2 , and _A3 bonded to the triazine ring in general formula (1) are groups having a ring structure in which the two atoms adjacent to the carbon atom bonded to the triazine ring are carbon atoms or nitrogen atoms having no substituents other than hydrogen atoms or deuterium atoms.

That is, among _A1 or _L1 , _A2 or _L2 , and _A3 , two or more of the substituents are not bonded to the ortho position of the triazine ring to which they are directly bonded, which is a substituent that is a steric hindrance to the triazine ring. As a result, two or more of the substituents that are directly bonded to the triazine ring are bonded at a small dihedral angle of 15° or less, and the LUMO is expanded and distributed in two or more directions from the triazine ring to the substituents. Therefore, the electron transport property and stability of the compound can be further improved.

In the compounds according to this embodiment, in the above general formulae (A1-1), (A1-2) and (A1-6), it is preferable that one of Y ₁₂ and Y ₁₃ is C(R ₁ ), and the R ₁ is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms. Here, when the R ₁ is an aromatic heterocyclic group, the aromatic heterocyclic group is more preferably a π-electron deficient aromatic heterocyclic group.

The π-electron-deficient aromatic heterocyclic group is a group derived from an aromatic heterocycle having an unsaturated heteroatom as shown in the following general formula (3-1), (3-2), or (3-3). Examples of the π-electron-deficient aromatic heterocycle constituting the π-electron-deficient aromatic heterocyclic group include pyridine, pyrimidine, pyrazine, triazine, quinoline, quinoxaline, quinazoline, naphthyridine, phenanthridine, acridine, quinone, anthraquinone, xanthone, thioxanthone, coumarin, 6H-benzo[c]chromen-6-one, fluorenone, imidazole, benzimidazole, pyrazole, indazole, oxazole, isoxazole, benzoxazole, benzisoxazole, thiazole, isothiazole, benzothiazole, benzisothiazole, phosphole, dibenzophosphole, and dibenzothiophene 5,5-dioxide.

（式中のＲ'は炭素原子、窒素原子、酸素原子、硫黄原子またはリン原子を表す。）

(In the formula, R' represents a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, or a phosphorus atom.)

（式中のＲ'は炭素原子、窒素原子、酸素原子、硫黄原子またはリン原子を表す。）

(In the formula, R' represents a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, or a phosphorus atom.)

In addition, examples of the π-electron-rich aromatic heterocycles constituting the aromatic heterocycles having saturated heteroatoms (π-electron-rich aromatics) shown in the above general formulas (2-3), (3-2), and (4) include pyrrole, indole, carbazole, furan, benzofuran, dibenzofuran, thiophene, benzothiophene, and dibenzothiophene.

In the compound represented by the above general formula (1), the HOMO (Highest Occupied Molecular Orbital) is distributed in the A1 plane having the carbazole ring, relative to the LUMO region containing the triazine ring. On the other hand, in the compounds having the substituents represented by the above general formulae (A1-1), (A1-2) and (A1-6), it is preferable that either one of Y ₁₂ and Y ₁₃ is C(R ₁ ), and the R ₁ is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted π-electron deficient aromatic heterocyclic group having 3 to 30 ring atoms.

By adopting such an embodiment, the photochemical stability of the compound can be improved. Furthermore, by adopting such an embodiment, in the compound of the above general formula (1), the molecular weight ratio of the HOMO distributed in the A1 plane to the total molecular weight (hereinafter sometimes referred to as the HOMO molecular weight ratio) can be reduced. Therefore, the hole transport property can be suppressed and the electron transport property derived from the LUMO region can be emphasized.

In addition, in the substituents represented by general formulae (A1-1), (A1-2), and (A1-6), when either one of Y ₁₂ and Y ₁₃ is C(R ₁ ) and R ₁ is a π-electron-deficient aromatic heterocyclic group, the molecular weight ratio occupied by the LUMO region can be reliably increased, and the electron transport property of the compound can be improved.

In the compounds according to this embodiment, in the above general formulae (A2-1), (A2-2) and (A2-6), it is preferable that one of Y ₂₂ and Y ₂₃ is C(R ₂ ), and the R ₂ is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 3 to 30 ring atoms. Here, when the R ₂ is an aromatic heterocyclic group, the aromatic heterocyclic group is more preferably a π-electron deficient aromatic heterocyclic group.

In the compound represented by the above general formula (1), the HOMO is distributed in the A2 plane having the carbazole ring with respect to the LUMO region containing the triazine ring.On the other hand, in the compound represented by the above general formula (1), in the compound having the substituent represented by the above general formula (A2-1), general formula (A2-2) and general formula (A2-6), it is preferable that one of Y ₂₂ and Y ₂₃ is C(R ₂ ), and the R ₂ is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted π-electron deficient aromatic heterocyclic group having 3 to 30 ring atoms.

By adopting such an embodiment, the photochemical stability of the compound can be improved. Furthermore, by adopting such an embodiment, in the compound of the above general formula (1), the molecular weight ratio of the HOMO distributed in the _A2 plane to the total molecular weight (hereinafter, sometimes referred to as the HOMO molecular weight ratio) can be reduced, and the hole transport property can be suppressed and the electron transport property derived from the LUMO region can be relatively emphasized.

In addition, in the substituents represented by general formulae (A2-1), (A2-2), and (A2-6), when either one of Y ₂₂ and Y ₂₃ is C(R ₂ ) and R ₂ is a π-electron-deficient aromatic heterocyclic group, the molecular weight ratio occupied by the LUMO region can be reliably increased, and the electron transport property of the compound can be improved.

In addition, in the compound represented by the above general formula (1), it is more preferable that the three substituents bonded to the triazine ring each have a structure different from each other. By adopting such an embodiment, it is possible to reduce the crystallinity and increase the solubility of the compound.

Specific examples of the compounds of the general formula (1) of the present invention are shown below, but the present invention is not limited to these examples. In the following exemplary compound diagrams, the left-side substituent for triazine corresponds to the substitution containing _A1 and _L1 , the right-side substituent corresponds to the substitution containing _A2 and _L2 , and the upper-side substituent corresponds to _A3 .

上記一般式（１－１）～（１－６３）に例示される本実施形態の化合物によれば、有機エレクトロルミネッセンス素子を塗布法により作製した場合でも、電子輸送性を高めて、電流効率および発光寿命を向上させることができる。

According to the compounds of the present embodiment exemplified by the above general formulas (1-1) to (1-63), even when an organic electroluminescence device is produced by a coating method, the electron transport property can be improved, and the current efficiency and luminescence life can be improved.

<Materials for organic electroluminescence devices>
The organic electroluminescence device material (hereinafter referred to as the organic EL device material) according to this embodiment contains the compound represented by the above general formula (1). As described above, the compound represented by the general formula (1) can be easily formed into a film (thin film) by a wet coating method because the molecular aggregation is suppressed (high solubility in a solvent). In addition, the compound has high electron transport properties. Therefore, the organic EL device material containing the compound can be used as a material for, for example, an electron transport layer, an electron injection layer, and an emission layer.

As a result, an organic electroluminescence element using a compound represented by general formula (1) can improve current efficiency and luminescence life even when produced by a wet coating method. Therefore, the compound represented by general formula (1) can be used as a material for an organic EL element.

That is, this embodiment can provide a material for an organic EL device that contains a compound represented by general formula (1). Therefore, an organic electroluminescence device that is excellent in current efficiency and luminescence life can be produced by a coating method using the material for an organic EL device that contains a compound represented by general formula (1). The organic electroluminescence device material of this embodiment is an example of a material for an electroluminescence device according to the present invention.

<Composition for organic electroluminescence device>
The composition for an organic electroluminescence device according to this embodiment (hereinafter referred to as a composition for an organic EL device) is used, for example, to form each layer of an organic EL device by a solution coating method.

The composition for an organic EL device according to this embodiment contains a compound represented by general formula (1) and a solvent. Such a composition for an organic EL device can be composed of the above-mentioned material for an organic EL device and a solvent.

The solvent is not particularly limited, but is preferably capable of dissolving the above-mentioned organic EL element material. In other words, the composition for an organic EL element is preferably a solution composition. The composition for an organic electroluminescence element of this embodiment is an example of the composition for an electroluminescence element according to the present invention.

The solvent contained in the composition for organic EL elements is not particularly limited, but examples thereof include toluene, xylene, ethylbenzene, diethylbenzene, methylene, propylbenzene, cyclohexylbenzene, dimethoxybenzene, anisole, ethoxytoluene, phenoxytoluene, isopropylbiphenyl, dimethylanisole, phenyl acetate, and phenyl propionic acid. acid), methyl benzoate, ethyl benzoate, etc.

The concentration of the material for an organic EL device in the composition for an organic EL device is not particularly limited and can be adjusted appropriately depending on the application. However, from the viewpoint of ease of application, the concentration of the material for an organic EL device is adjusted so that the concentration of the compound represented by general formula (1) is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.5% by mass to 5% by mass.

<Organic electroluminescence element>
Hereinafter, the organic electroluminescence element according to the present embodiment will be described in detail with reference to Fig. 1. Fig. 1 is a schematic diagram showing the organic electroluminescence element according to the present embodiment. In this specification, the "organic electroluminescence element" may be abbreviated to "organic EL element".

As shown in FIG. 1, the organic electroluminescence element (organic EL element) 100 according to this embodiment includes a substrate 110, a first electrode 120 disposed on the substrate 110, a hole injection layer 130 disposed on the first electrode 120, a hole transport layer 140 disposed on the hole injection layer 130, a light emitting layer 150 disposed on the hole transport layer 140, an electron transport layer 160 disposed on the light emitting layer 150, an electron injection layer 170 disposed on the electron transport layer 160, and a second electrode 180 disposed on the electron injection layer 170.

Here, the compound represented by the general formula (1) of this embodiment is, for example, contained in any of the organic layers arranged between the first electrode 120 and the second electrode 180. Specifically, the compound represented by the general formula (1) is preferably contained in the light-emitting layer 150 as a light-emitting layer material (host), in the electron transport layer 160 as an electron transport material, or in the electron injection layer 170 as an electron injection layer, more preferably contained in the light-emitting layer 150 as a light-emitting layer material (host) or in the electron transport layer 160 as an electron transport material, and particularly preferably contained in the light-emitting layer 150 as a light-emitting layer material (host).

In addition, the organic layer containing the compound represented by general formula (1) in this embodiment is formed by a coating method. Specifically, the organic layer containing the compound represented by general formula (1) can be formed by a solution coating method such as a spin coat method, a casting method, a microgravure coat method, a gravure coat method, a bar coat method, a roll coat method, a wire bar coat method, a dip coat method, a spray coat method, a screen printing method, a flexographic printing method, an offset printing method, or an ink jet printing method.

The solvent used in the solution coating method can be any solvent that can dissolve the compound represented by general formula (1). Examples of such solvents include toluene, xylene, ethylbenzene, diethylbenzene, methylene, propylbenzene, cyclohexylbenzene, dimethoxybenzene, anisole, ethoxytoluene, phenoxytoluene, isopropylbiphenyl, dimethylanisole, phenyl acetate, phenyl propionate, methyl benzoate, and ethyl benzoate. The amount of the solvent used is not particularly limited, but from the viewpoint of ease of coating, the concentration of the compound represented by general formula (1) is preferably 0.1% by mass to 10% by mass, and more preferably 0.5% by mass to 5% by mass.

The method for forming the layer other than the organic layer containing the compound represented by general formula (1) is not particularly limited. Such a layer other than the organic layer may be formed, for example, by a vacuum deposition method or a solution coating method.

The substrate 110 may be a substrate used in a typical organic EL element. For example, the substrate 110 may be a glass substrate, a semiconductor substrate such as a silicon substrate, or a plastic substrate.

A first electrode 120 is formed on the substrate 110. The first electrode 120 is specifically an anode, and is formed of a metal, an alloy, a conductive compound, or the like having a large work function (the minimum energy required to remove one electron from within a substance). For example, the first electrode 120 may be formed as a transmissive electrode using indium tin oxide (In ₂ O ₃ -SnO ₂ :ITO), indium zinc oxide (In ₂ O ₃ -ZnO), tin oxide (SnO ₂ ), zinc oxide (ZnO), or the like, which are excellent in transparency and conductivity. The first electrode 120 may also be formed as a reflective electrode by laminating magnesium (Mg), aluminum (Al), or the like on the transparent conductive film.

A hole injection layer 130 is formed on the first electrode 120. The hole injection layer 130 is a layer that facilitates the injection of holes from the first electrode 120, and may be formed to a thickness of, specifically, about 10 nm to about 1000 nm, more specifically, about 10 nm to about 100 nm.

The hole injection layer 130 can be formed of a known hole injection material. Known hole injection materials for forming the hole injection layer 130 include, for example, triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate (4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate (PPBI), N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine (DNTPD), copper phthalocyanine (copper phthalocyanine), 4,4',4"-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB), 4,4',4"-tris(diphenylamino ) triphenylamine (4,4',4"-tris(diphenylamino)triphenylamine: TDATA), 4,4',4"-tris(N,N-2-naphthylphenylamino)triphenylamine (2-TNATA), polyaniline/dodecylbenzenesulphonic acid acid), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), and polyaniline/10-camphorsulfonic acid (polyaniline/10-camphorsulfonic acid).

A hole transport layer 140 is formed on the hole injection layer 130. The hole transport layer 140 is a layer that has the function of transporting holes, and may be formed with a thickness of, for example, about 10 nm to 150 nm. The hole transport layer 140 may also be formed of a known hole transport material.

Examples of known hole transport materials include carbazole derivatives such as 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), N-phenylcarbazole, and polyvinylcarbazole, and N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (N, Examples include N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD), 4,4',4"-tris(N-carbazolyl)triphenylamine (TCTA), and N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB).

The light-emitting layer 150 is formed on the hole transport layer 140. The light-emitting layer 150 is a layer that emits light by fluorescence, phosphorescence, or the like. The light-emitting layer 150 may be formed to a thickness of, for example, about 10 nm to about 60 nm. A known light-emitting material can be used as the light-emitting material of the light-emitting layer 150. However, it is preferable that the light-emitting material contained in the light-emitting layer 150 is a light-emitting material that can emit light from triplet excitons (i.e., phosphorescence emission). In such a case, the current efficiency and light-emitting life of the organic EL element 100 can be further improved.

The light-emitting layer 150 can be formed by a solution coating method using the organic EL element material according to this embodiment. In this embodiment, the light-emitting layer 150 containing the compound represented by general formula (1), which can improve the current efficiency and luminescence life of the organic EL element 100, can be efficiently formed over a large area by such a solution coating method.

However, when any other organic layer of the organic EL element 100 contains the compound represented by the general formula (1) according to this embodiment, the light-emitting layer 150 may be composed of a known material.

The light-emitting layer 150 contains, as a host material, for example, tris(8-quinolinato)aluminum (Alq3), 4,4'-bis(carbazol-9-yl)biphenyl (CBP), poly(n-vinylcarbazole) (poly(n-vinyl carbazole: PVK), 9,10-di(naphthalene)anthracene (ADN), 4,4',4"-tris(N-carbazolyl)triphenylamine (TCTA), 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (1,3,5-tris(N-phenyl-benzimidazol-2-yl)benzene (1,3,5-tris(N-phenyl-benzimidazol-2-yl)benzene) l)benzene (TPBI), 3-tert-butyl-9,10-di(naphth-2-yl)anthracene (TBADN), distyrylarylene (DSA), 4,4'-bis(9-carbazole)-2,2'-dimethyl-biphenyl (dmCBP), etc. may also be included.

In addition, the light-emitting layer 150 may contain, as a dopant material, for example, perylene and its derivatives, rubrene and its derivatives, coumarin and its derivatives, 4-dicyanomethylene-2-(p-dimethylaminostyryl)-6-methyl-4H-pyran (DCM) and its derivatives, bis[2-(4,6-difluorophenyl)pyridinate]picolinate iridium(III) and its derivatives, iridium(III):FIrpic), bis(1-phenylisoquinoline)(acetylacetonate)iridium(III):Ir(piq)2(acac), tris(2-phenylpyridine)iridium(III):Ir(ppy)3, tris(2-(3-p-oxyl)phenyl)pyridine iridium(III), and other iridium (Ir) complexes, osmium (Os) complexes, platinum complexes, and the like may also be included.

The light emitting layer 150 may also include nanoparticles such as quantum dots as a light emitting material. Quantum dots are nanoparticles made of a semiconductor of the I-VI series, the III-V series, or the IV-IV series. Examples of the semiconductor include, but are not limited to, CdS, CdSe, CdTe, ZnSe, ZnS, PbS, PbSe, HgS, HgSe, HgTe, CdHgTe, CdSe _x Te _1-x , GaAs, InAs, and InP.

The diameter of the nanoparticles is not particularly limited, but can be, for example, 1 to 20 nm. Nanoparticles such as quantum dots may have a single core structure, or may have a so-called core/shell structure in which the surface of the core is covered with a shell.

The electron transport layer 160 is formed on the light-emitting layer 150. The electron transport layer 160 is a layer that has the function of transporting electrons. The electron transport layer 160 may be formed to a thickness of, for example, about 15 nm to about 50 nm.

The electron transport layer 160 may be formed of a known electron transport material. Examples of known electron transport materials include tris(8-quinolinato)aluminum (Alq3) and compounds having a nitrogen-containing aromatic ring. Specific examples of compounds having a nitrogen-containing aromatic ring include compounds containing a pyridine ring such as 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, and the like. Examples of such compounds include compounds containing a triazine ring such as 2-(4-(N-phenylbenzimidazolyl-1-yl-phenyl)-9,10-dinaphthylanthracene, and compounds containing an imidazole ring such as 2-(4-(N-phenylbenzimidazolyl-1-yl-phenyl)-9,10-dinaphthylanthracene.

An electron injection layer 170 is formed on the electron transport layer 160. The electron injection layer 170 is a layer having a function of facilitating the injection of electrons from the second electrode 180. The electron injection layer 170 may be formed to a thickness of 0.3 nm to 20 nm. The electron injection layer 170 is not particularly limited, and a material known as a material for forming the electron injection layer 170 can be used. For example, the electron injection layer 170 may be formed of a lithium compound such as (8-quinolinato)lithium (Liq) and lithium fluoride (LiF), sodium chloride (NaCl), cesium fluoride (CsF), lithium oxide (Li ₂ O), barium oxide (BaO), or the like.

A second electrode 180 is formed on the electron injection layer 170. The second electrode 180 is specifically a cathode, and is formed of a metal, an alloy, or a conductive compound having a small work function. For example, the second electrode 180 may be formed as a reflective electrode using a metal such as lithium (Li), magnesium (Mg), aluminum (Al), or calcium (Ca), or an alloy such as aluminum-lithium (Al-Li), magnesium-indium (Mg-In), or magnesium-silver (Mg-Ag). The second electrode 180 may also be formed as a transmissive electrode using a thin film of the above metal material having a thickness of 20 nm or less, or a transparent conductive film such as indium tin oxide (In ₂ O ₃ -SnO ₂ ) or indium zinc oxide (In ₂ O ₃ -ZnO).

The organic EL element 100 according to this embodiment has an organic layer containing the compound represented by general formula (1), and thus an organic electroluminescence element having excellent current efficiency and luminescence life can be produced by a coating method. The organic EL element 100 according to this embodiment is an example of an electroluminescence element according to the present invention.

The layered structure of the organic EL element 100 according to this embodiment is not limited to the above example. The organic EL element 100 according to this embodiment may be formed with other known layered structures. For example, the organic EL element 100 may omit one or more of the hole injection layer 130, the hole transport layer 140, the electron transport layer 160, and the electron injection layer 170, or may include other layers in addition. Each layer of the organic EL element 100 may be formed as a single layer or as multiple layers.

For example, the organic EL element 100 may further include a hole blocking layer between the light emitting layer 150 and the electron transport layer 160 to prevent excitons or holes from diffusing into the electron transport layer 160. The hole blocking layer may be formed of, for example, an oxadiazole derivative, a triazole derivative, or a phenanthroline derivative.

The present invention will be described below in more detail with reference to examples. Note that the present invention is not limited to these examples. In the following, "%" is based on weight unless otherwise specified. In addition, tests and evaluations were performed according to the following.

<Analysis of dihedral angles>
The dihedral angle of the compound is analyzed. First, in the following general formula (5), a single bond is represented by A-B, and a partial structure in which LUMO is distributed is bonded to form a plane including the point X-A-B. On the other hand, the substituent forms a plane including the point A-B-Y. The angle between these two planes (the plane including the point X-A-B and the plane including the point A-B-Y) is defined as a dihedral angle. In this embodiment, the angle between the triazine ring plane and the A1 plane in formula (1) is defined as dihedral angle I, and the angle between the triazine ring and the A2 plane is defined as dihedral angle II. Note that the actual compound can be confirmed by a known method (for example, solid-state NMR analysis using a compound in which the element in the dihedral angle portion is labeled with an isotope element, etc.).

The above dihedral angles were calculated using quantum computing software (Gaussian 09, Revision D.01). Specifically, in the first step, a molecular structure was drawn using molecular drawing software (Marvin sketch 17.5.0, manufactured by ChemAxon) and conformation calculations were performed, and the conformation structure with the minimum energy value was used as the initial structure.

In the second stage, the dihedral angles are calculated from the initial structure obtained in the first stage using a quantum chemistry calculation program (Gaussian 09, Revision D.01, Gaussian). At this time, the molecular structure is optimized to improve the accuracy of the simulation for the actual molecular structure. Specifically, the dihedral angles of W-X-A-B and A-B-Y-Z in general formula (5) are restricted so that they do not change from the initial structure, and the other parts are set as movable, and the molecular structure is optimized using the keyword B3LYP/6-31G*.

Then, in the third stage, the optimized molecular structure was used to calculate the energy (total energy value of the molecule, molecular orbital energy level, etc.) and the molecular orbital distribution using the keyword B3LYP/6-31+G**. From the calculation results, the LUMO distribution can be known, and the site corresponding to X-A-B-Y for each compound was selected, and the absolute value of the dihedral angle on the narrow angle side was read. The dihedral angle in this optimized structure is represented as DA ₀ , and the results are shown in Table X.

<Calculation of rotational barrier energy>
The optimized structure obtained in the second stage of the method used in the above-mentioned dihedral angle analysis was used as the initial structure to calculate the rotational barrier energy of the dihedral angle. In the calculation of the rotational barrier energy, first, the dihedral angles W-X-A-B and A-B-Y-Z in the general formula (5) were restricted so as not to change from the initial structure, and the other parts were set as movable, and the dihedral angles of the target parts were changed by 5° per step. In this case, the molecular structure was also optimized to improve the simulation accuracy for the actual molecular structure. In the optimization of the molecular structure, B3LYP/6-31G* was used as the keyword.

Next, energy calculations (total energy value possessed by the molecule, molecular orbital energy levels, etc.) are performed using B3LYP/6-31+G** as the keyword. This step is performed for dihedral angles of 0° to 360°. The rotational barrier energy of the target dihedral angle was obtained by setting the dihedral angle as the x-axis and the total energy value possessed by the molecule obtained at this time as the y-axis. From this result, the minimum value of the dihedral angle that can be reached with thermal energy at room temperature (298 K = 25 meV (millielectron volts) = 2.5 kJ/mol) was obtained. The dihedral angle in this calculation is represented as DA _rt , and the results are shown in Table 1.

From Table 1, it can be seen that in the compound represented by general formula (1) of the present invention, the substituent A1 bonding to the LUMO region has a large DA ₀ of 50° or more and a large DA _rt of 40° or more, and further, the substituent A2 bonding to the LUMO region has a large DA ₀ of 30° or more and a large DA _rt of 20° or more.

<Molecular weight and molecular weight ratio>
The molecular weight of each compound was calculated using molecular structure drawing software (ChemBioDraw Ultra, manufactured by CambridgeSoft). The HOMO distribution was determined by molecular orbital calculation using the quantum chemical calculation program described above, and the molecular structure unit in which the HOMO was distributed was identified by visualizing the HOMO (grayscale part in Table 2). The molecular weight ratio was determined based on the molecular weight of the unit on the molecular structure drawing software described above. The results are shown in Table 2.

From Table 1 (dihedral angle) and Table 2 (HOMO/LUMO diagram), it can be seen that in the compound represented by general formula (1) of the present invention, at least two of the substituents that are directly bonded to the triazine ring are bonded at a small dihedral angle of 15° or less, and as a result, the LUMO is distributed by extending from the triazine ring in two or more directions of the substituents.

<Solubility Measurement>
50 mg of the sample solid was placed in a colorless transparent sample bottle, 500 mg of solvent was added, and ultrasonic irradiation was performed at room temperature for 5 minutes, and the presence or absence of remaining sample solids was confirmed visually. If the sample solids were dissolved without remaining at this point, the solubility was 10 wt% or more. If the sample solids remained, the addition of solvent and ultrasonic irradiation were repeated in small amounts, and the solubility was calculated from the amount of solvent at the time when the sample solids were completely dissolved. The results are shown in Table 3.

<Evaluation of photochemical stability>
The photochemical stability was evaluated under the following conditions.

[Creating a measurement sample]
In a nitrogen atmosphere glove box with a water concentration of 1 ppm or less and an oxygen concentration of 1 ppm or less, a thin film layer with a thickness of 50 nm is formed on a quartz substrate by coating method from a methyl benzoate solution with a solid content ratio of TEG=100% by weight:5% by weight and a solid content ink concentration of 4% by weight, and treated at a vacuum degree of 1E ^-3 Pa and 120°C for 15 minutes. The film is transported to a vacuum deposition machine, and a circular aluminum thin film with a thickness of 100 nm and a diameter of 2 mm is formed on the film by vacuum deposition using a metal mask. This is sealed using a glass sealing tube with a desiccant and an ultraviolet-curing resin to prepare a measurement sample.

[Measurement system]
The measurement system mainly consists of the following two components:
1. Photoluminescence (PL) intensity measurement system 2. UV irradiation deterioration system

1. Photoluminescence (PL) intensity measurement system A high-power UV-Vis fiber light source unit (L10290, manufactured by Hamamatsu Photonics) and an ultraviolet transmission visible absorption filter (S76-U340, manufactured by Suruga Seiki) were used as the excitation light source, with light with wavelengths of 250 nm or less and 400 nm or more removed. A compact fiber optic spectrometer (USB2000+UV-VIS, manufactured by Ocean Photonics) was used as the light receiver. During measurement, the sample substrate is installed so that the excitation light is accurately incident on the aluminum-coated sample film measurement site described above from an angle tilted by 20° or more from the front of the quartz substrate side. The excitation light causes the sample film measurement site to emit light in the hemispherical direction in front of the quartz substrate. The light receiver is installed within a distance that can capture this emission and at a position that avoids regular reflection of the excitation light by the quartz substrate. In order to keep the intensity of the excitation light irradiated on the sample constant for each measurement, the intensity of the excitation light source and the geometric arrangement of the optical system are kept constant.

2. UV irradiation deterioration system A UV-LED (manufactured by CCS) with a maximum emission wavelength of 365 nm was used as the light source, and the light with uniform intensity in the irradiation port plane was used as the excitation light for deterioration through a synthetic quartz light pipe (manufactured by Edmund Optics, #65-829) with a diameter of 2 mm and a length of 75 mm. The total luminous flux intensity of the excitation light was controlled using a digital power supply (manufactured by CCS, PD3-10024-8-PI) and an optical power meter (manufactured by ADCMT, 8230E). The excitation light irradiation port and the quartz substrate side of the sample film were aligned and then brought into close contact. The sample film was optically loaded and deteriorated by irradiating the sample film with excitation light from the quartz substrate side for a certain period of time.

[Photochemical Deterioration Test at Excitation Light Total Luminous Flux Intensity of 10 mW]
In the first step, the photoluminescence (PL) intensity of the sample thin film before degradation is measured using the photoluminescence (PL) intensity measurement system described in 1. In the second step, the UV irradiation degradation system described in 2. is used to irradiate the sample thin film with excitation light for degradation for 5 minutes at a total luminous flux intensity of 10 mW, and then the photoluminescence (PL) intensity of the sample thin film subjected to a load for 5 minutes is measured using the photoluminescence (PL) intensity measurement system described in 1. Thereafter, the same operation as in the second step is repeated to measure the photoluminescence (PL) intensity of the sample thin film versus the time during which the excitation light load is applied.

[Photochemical Degradation Test at Excitation Light Total Luminous Intensity of 20 mW]
Except for changing the total luminous flux intensity of the excitation light to 20 mW, the measurement was carried out in the same manner as in the deterioration test at 10 mW.

[Photochemical Degradation Test at Excitation Light Total Luminous Intensity of 50 mW]
Except for changing the total luminous flux intensity of the excitation light to 50 mW, the measurement was carried out in the same manner as in the deterioration test at 10 mW.

[Analysis of photochemical degradation tests]
First, based on the emission intensity decay data obtained from the photochemical deterioration test in which the total luminous flux intensity of the excitation light was changed in various ways, the following correspondence relationship was applied and the acceleration coefficient a was adjusted to obtain a decay curve that is independent of the total luminous flux intensity of the excitation light.
Vertical axis: R _{I (t)} = I _(t) / I ₀
Horizontal axis: _Xc = ^Ea x t
R _{I (t)} : photoluminescence intensity ratio of the sample film to the initial luminance at excitation light irradiation time t t: excitation light irradiation time I _(t) : photoluminescence intensity of the sample film at excitation light irradiation time t I ₀ : photoluminescence intensity of the sample film before excitation light irradiation X _c : corrected excitation light integrated intensity E: total excitation light luminous flux intensity a: acceleration coefficient

From the "decay curve independent of the total excitation light intensity" obtained by this analysis, the corrected excitation light integrated intensity Xc90 required for _RI(t) to reach 0.9 (luminescence intensity decreases by 10%) is used as an index of photochemical stability in this embodiment. The larger the value of Xc90, the more energy is required to deteriorate the luminescence intensity, and the more difficult it is to deteriorate. Table 4 shows the results of Xc90 as relative values.

<Evaluation method of organic EL element>
[Evaluation of current efficiency and durability (luminescence lifetime)]
The current efficiency and durability (luminescence lifetime) of the examples and comparative examples were evaluated under the following conditions: First, the voltage and current applied to the organic EL element were measured using a DC constant voltage power supply (Keyence, source meter), and the luminance of the organic EL element was measured using a luminance measuring device (Topcon, SR-3).

The current value per unit area (current density) was calculated from the area and current value of the organic EL element, and the current efficiency (cd/A) was calculated by dividing the luminance (cd/m2) by the current density (A/m2). Note that the current efficiency indicates the efficiency of converting current into luminous energy (conversion efficiency), and the higher the current efficiency, the higher the performance of the organic EL element.

Durability (light emission life) was evaluated by continuously driving each organic EL element at a current value that gave an initial brightness of 6000 cd/m2, and the time (hours) until the light emission brightness, which decays over time, reached 80% of the initial brightness was defined as "LT80 (h)."

<Synthesis of Compounds>
[Synthesis Example 1]
First, compound 1-1 was synthesized according to the following reaction scheme (6).

Specifically, 1-bromocarbazole (307 mmol, 75.6 g), phenylboronic acid (338 mmol, 41.2 g), potassium carbonate (461 mmol, 63.7 g), 2M aqueous solution (230 ml), and 1,4-dioxane (614 ml) were placed in a three-neck flask, the atmosphere in the reaction system was replaced with nitrogen, palladium acetate (II) (9.2 mmol, 2.07 g), tri(o-tolyl)phosphine [P(o-tolyl) ₃ ] (13.8 mmol, 4.20 g) were added, and the mixture was heated and stirred at 80° C. for 8 hours. After cooling to room temperature, the mixture was diluted with toluene (1 L), filtered using Celite, and washed twice with water using a separatory funnel. After drying with anhydrous magnesium sulfate, the mixture was filtered through a silica gel pad and concentrated. A solid precipitated, which was dispersed in hexane (300 ml) and refluxed in a nitrogen atmosphere for 2 hours. After cooling to room temperature, the solid was collected by filtration to obtain compound 1-1. The yield of compound 1-1 was 58.9 g, and the yield was 79%.

Compound 1-2 was then synthesized according to the following reaction scheme (7).

Specifically, compound 1-1 (224.4 mmol, 54.5 g) and dimethylformamide (440 ml) were placed in a three-neck flask, the reaction system was replaced with nitrogen, and cooled to 0°C. Sodium hydride (62% paraffin dispersion) (235.6 mmol, 9.12 g) was added stepwise while paying attention to the amount of hydrogen gas generated, and the mixture was heated and stirred at 0°C for 1 hour. 2-Phenyl-4,6-dichlorotriazine (246.8 mmol, 55.8 g) was added and stirred at 0°C for 30 minutes, and then stirred at room temperature for 1 hour. The mixture was then stirred at 80°C for 4 hours. After cooling to room temperature, the mixture was diluted with toluene (500 ml) and the reaction was inactivated with a small amount of water. The mixture was filtered using Celite and washed three times with water using a separatory funnel. After drying over anhydrous magnesium sulfate, the mixture was filtered through a silica gel pad and concentrated. This was purified by silica gel column chromatography (eluent: hexane:ethyl acetate = 7:3) to obtain compound 1-2. The yield of compound 1-2 was 56.2 g, and the yield was 58%.

Next, compound 1-3 was synthesized according to the following reaction scheme (8).

Specifically, carbazole (800 mmol) was placed in a three-neck flask.
133.8 g), 2-bromo-4-chloro-1-fluorobenzene (840 mmol, 175.9 g), and dimethylformamide (160 ml) were added, and the reaction system was replaced with nitrogen. Sodium hydride (62% paraffin dispersion) (800 mmol, 31.0 g) was added stepwise in five or more portions while paying attention to the amount of hydrogen gas generated, and then the mixture was heated slowly while paying attention to the amount of hydrogen gas generated, and heated and stirred at 150° C. for 20 hours. After cooling to room temperature, the mixture was diluted with toluene (1 L) and inactivated with a small amount of water under a nitrogen atmosphere. The mixture was filtered using Celite and washed with water three times using a separatory funnel. After drying with anhydrous magnesium sulfate, the mixture was filtered through a silica gel pad and concentrated. This was recrystallized from a mixed solvent of ethanol:methanol=1:1 to obtain compound 1-3. The amount of compound 1-3 obtained was 156.1 g, and the yield was 55%.

Next, compound 1-4 was synthesized according to the following reaction scheme (9).

Specifically, compound 1-3 (435 mmol, 155.1 g), phenylboronic acid (478.5 mmol, 58.3 g), potassium carbonate (652.5 mmol, 90.2 g) 2M aqueous solution (435 ml), toluene (870 ml), and ethanol (218 ml) were placed in a three-neck flask, the inside of the reaction system was replaced with nitrogen, tetrakis(triphenylphosphine)palladium(0) (Pd(PPh ₃ ) ₄ ) (21.8 mmol, 25.1 g) was added, and the mixture was heated and stirred at 80° C. for 8 hours. After cooling to room temperature, the mixture was diluted with toluene (1 L), filtered using Celite, and washed twice with water using a separatory funnel. After drying with anhydrous magnesium sulfate, the mixture was filtered through a silica gel pad and concentrated. A solid precipitated, which was purified by silica gel column chromatography (developing solvent hexane:toluene=7:3) and further recrystallized from ethanol to obtain compound 1-4. The amount of compound 1-4 obtained was 109.3 g, and the yield was 71%.

Compound 1-5 was then synthesized according to the following reaction scheme (10).

Specifically, compound 1-4 (305 mmol, 107.9 g), bis(pinacolato)diboron (335.5 mmol, 85.2 g), potassium acetate (610 mmol, 59.9 g), and 1,4-dioxane (610 ml) were placed in a three-neck flask, the reaction system was replaced with nitrogen, and bis(dibenzylideneacetone)palladium(0) (15.25 mmol, 8.76 g), tricyclohexylphosphonium tetrafluoroborate (1,4-dioxane) (1,5-dichlorophenyl) tetrafluoroborate (1,5-dichlorophenyl) tetrafluoroborate (1,4 ... Tetrafluoroborate (12.2 mmol, 4.49 g) was added and the mixture was heated and stirred at 80°C for 8 hours. After cooling to room temperature, it was diluted with toluene (1 L), filtered using Celite, and washed twice with water using a separatory funnel. After drying with anhydrous magnesium sulfate, it was filtered through a silica gel pad and concentrated. This was dispersed in hexane (300 ml) and subjected to ultrasonic treatment for 30 minutes, filtered, and vacuum dried (50°C, 6 hours) to obtain compound 1-5. The yield of compound 1-5 was 112.7 g, and the yield was 83%.

Compound 1 was then synthesized according to the following reaction scheme (11).

Specifically, compound 1-2 (10 mmol, 4.33 g), compound 1-5 (11 mmol, 4.90 g), potassium carbonate (15 mmol, 2.07 g) 1M aqueous solution (15 ml), toluene (100 ml), and ethanol (20 ml) were placed in a three-neck flask, the inside of the reaction system was replaced with nitrogen, tetrakis(triphenylphosphine)palladium(0) (Pd(PPh ₃ ) ₄ ) (0.5 mmol, 0.58 g) was added, and the mixture was heated and stirred at 80° C. for 8 hours. After cooling to room temperature, the mixture was diluted with toluene (200 ml), filtered using Celite, and washed twice with water using a separatory funnel. After drying with anhydrous magnesium sulfate, the mixture was filtered through a silica gel pad and concentrated. The mixture was purified by silica gel column chromatography (developing solvent hexane:toluene=6:4), and further recrystallized from a mixed solvent of ethyl acetate:ethanol=2:8 to obtain compound 1. The yield of compound 1 was 5.30 g, and the yield was 74%.

[Synthesis Example 2]
Compound 3-1 was synthesized according to the following reaction scheme (12).

Specifically, 4-bromo-2-chloro-1-fluorobenzene (720 mmol, 150.8 g), phenylboronic acid (792 mmol, 96.6 g), potassium carbonate (1080 mmol, 149.3 g) 2M aqueous solution (360 ml), toluene (720 ml), and ethanol (144 ml) were placed in a three-neck flask, the reaction system was replaced with nitrogen, tetrakis(triphenylphosphine)palladium(0) (Pd(PPh ₃ ) ₄ ) (21.6 mmol, 21.6 g) was added, and the mixture was heated and stirred at 80° C. for 8 hours. After cooling to room temperature, the mixture was diluted with toluene (1 L), filtered using Celite, and washed twice with water using a separatory funnel. After drying with anhydrous magnesium sulfate, the mixture was filtered through a silica gel pad and concentrated. A solid precipitated, which was purified by silica gel column chromatography (eluent: hexane:toluene=7:3) and further recrystallized from methanol to obtain Compound 3-1. The yield of Compound 3-1 was 101.2 g, and the yield was 68%.

Next, compound 3-2 was synthesized according to the following reaction scheme (13).

Specifically, compound 3-1 (488 mmol, 100.8 g), bis(pinacolato)diboron (536.8 mmol, 136.3 g), potassium acetate (976 mmol, 95.8 g), and 1,4-dioxane (976 ml) were placed in a three-neck flask, the reaction system was replaced with nitrogen, and bis(dibenzylideneacetone)palladium(0) (24.4 mmol, 14.0 g), tricyclohexylphosphonium tetrafluoroborate (24.4 mmol, 14.0 g), and 1,4-dioxane (24.4 ml) were added to the flask. Tetrafluoroborate (19.5 mmol, 7.2 g) was added and heated and stirred at 80°C for 8 hours. After cooling to room temperature, it was diluted with toluene (1 L), filtered using Celite, and washed twice with water using a separatory funnel. After drying with anhydrous magnesium sulfate, it was filtered through a silica gel pad and concentrated. This was dispersed in hexane (300 ml) and subjected to ultrasonic treatment for 30 minutes, filtered, and vacuum dried (50°C, 6 hours) to obtain compound 3-2. The yield of compound 3-2 was 116.4 g, and the yield was 80%.

Compound 3-3 was synthesized according to the following reaction scheme (14).

Specifically, compound 3-2 (388 mmol, 115.7 g), 1-bromo-4-iodobenzene (426.8 mmol, 120.7 g), potassium carbonate (582 mmol, 80.4 g) 2M aqueous solution (291 ml), toluene (776 ml), and ethanol (194 ml) were placed in a three-neck flask, the inside of the reaction system was replaced with nitrogen, tetrakis(triphenylphosphine)palladium(0) (Pd(PPh ₃ ) ₄ ) (19.4 mmol, 22.4 g) was added, and the mixture was heated and stirred at 70° C. for 8 hours. After cooling to room temperature, the mixture was diluted with toluene (1 L), filtered using Celite, and washed twice with water using a separatory funnel. After drying with anhydrous magnesium sulfate, the mixture was filtered through a silica gel pad and concentrated. A solid precipitated, which was purified by silica gel column chromatography (developing solvent hexane:toluene=7:3) and further recrystallized from methanol to obtain compound 3-3. The amount of compound 3-3 was 90.1 g, and the yield was 71%.

Compound 3-4 was synthesized according to the following reaction scheme (15).

Specifically, carbazole (409.5 mmol, 68.5 g), compound 3-3 (273 mmol, 89.3 g), and dimethylformamide (137 ml) were placed in a three-neck flask, the reaction system was replaced with nitrogen, and sodium hydride (62% paraffin dispersion) (327.6 mmol, 12.7 g) was added stepwise in five or more portions while paying attention to the amount of hydrogen gas generated, and then the mixture was heated slowly while paying attention to the amount of hydrogen gas generated, and heated and stirred at 150°C for 20 hours. After cooling to room temperature, it was diluted with toluene (1 L) and inactivated with a small amount of water under a nitrogen atmosphere. It was filtered using Celite and washed with water three times using a separatory funnel. After drying with anhydrous magnesium sulfate, it was filtered through a silica gel pad and concentrated. This was recrystallized from a mixed solvent of ethanol:methanol = 1:1 to obtain compound 3-4. The yield of compound 3-4 was 110.1 g, and the yield was 85%.

Compound 3-5 was synthesized according to the following reaction scheme (16).

Specifically, compound 3-4 (230 mmol, 109.1 g), bis(pinacolato)diboron (253 mmol, 64.2 g), potassium acetate (460 mmol, 45.1 g), and 1,4-dioxane (460 ml) were placed in a three-neck flask, the reaction system was replaced with nitrogen, and bis(dibenzylideneacetone)palladium(0) (11.5 mmol, 6.61 g), tricyclohexylphosphonium tetrafluoroborate (11.5 mmol, 6.61 g), and 1,4-dioxane (11.5 mmol, 6.61 g) were added. Tetrafluoroborate (9.2 mmol, 9.6 g) was added and the mixture was heated and stirred at 80°C for 8 hours. After cooling to room temperature, it was diluted with toluene (1 L), filtered using Celite, and washed twice with water using a separatory funnel. After drying with anhydrous magnesium sulfate, it was filtered through a silica gel pad and concentrated. This was dispersed in hexane (300 ml) and subjected to ultrasonic treatment for 30 minutes, filtered, and vacuum dried (50°C, 6 hours) to obtain compound 3-5. The yield of compound 3-5 was 100.7 g, and the yield was 84%.

Compound 3-6 was synthesized according to the following reaction scheme (17).

Specifically, compound 3-5 (190 mmol, 99.1 g), 2,4-dichloro-6-phenyl-1,3,5-triazine (380 mmol, 85.9 g), potassium carbonate (380 mmol, 52.5 g) 2M aqueous solution (190 ml), and tetrahydrofuran (950 ml) were placed in a three-neck flask, the atmosphere in the reaction system was replaced with nitrogen, and the sample was dissolved by heating and stirring at 70°C for 30 minutes, and then cooled to room temperature. To this, potassium carbonate (380 mmol, 52.5 g) 2M aqueous solution (190 ml), tri(o-tolyl)phosphine (15.2 mmol, 4.6 g), and palladium acetate (9.5 mmol, 2.1 g) were added, and the mixture was heated and stirred at 50°C for 2 hours. After cooling to room temperature, the mixture was diluted with toluene (1.5 L), filtered using Celite, and washed twice with water using a separatory funnel. After drying with anhydrous magnesium sulfate, the mixture was filtered through a silica gel pad and concentrated. This was recrystallized twice with ethyl acetate:hexane = 3:7 to obtain compound 3-6. The yield of compound 3-6 was 72.3 g, and the yield was 65%.

Compound 3 was synthesized according to the following reaction scheme (18).

Specifically, compound 3-6 (15 mmol, 8.78 g), 1-phenylcarbazole (22.5 mmol, 5.47 g), and dimethylformamide (30 ml) were placed in a three-neck flask, the reaction system was replaced with nitrogen, sodium hydride (62% paraffin dispersion) (22.5 mmol, 0.87 g) was added stepwise while paying attention to the amount of hydrogen gas generated, and then the mixture was heated slowly while paying attention to the amount of hydrogen gas generated, and heated and stirred at 120°C for 8 hours. After cooling to room temperature, the mixture was diluted with methanol (200 ml) under a nitrogen atmosphere and inactivated. The precipitated solid was ultrasonicated for 10 minutes and filtered. After vacuum drying (50°C, 6 hours), it was heated and dissolved in toluene (200 ml), filtered through a silica gel pad, and concentrated. This was recrystallized twice from ethyl acetate to obtain compound 3. The yield of compound 3 was 8.32 g, and the yield was 70%.

[Synthesis Example 3]
Compound 5-1 was synthesized according to the following reaction scheme (19).

Specifically, compound 5-1 was synthesized in the same manner as in reaction scheme (8) (synthesis of compound 1-3) above, except that the reagents were changed to those shown in reaction scheme (12) above. The yield of compound 5-1 was 214.0 g, and the yield was 75%.

Next, compound 5-2 was synthesized according to the following reaction scheme (20).

Specifically, compound 5-2 was synthesized in the same manner as in reaction scheme (9) (synthesis of compound 1-4) above, except that phenylboronic acid was replaced with 3-biphenylboronic acid (660 mmol, 130.7 g). The yield of compound 5-2 was 221.9 g, and the yield was 86%.

Next, compound 5-3 was synthesized according to the following reaction scheme (21).

Specifically, compound 5-3 was synthesized in the same manner as in reaction scheme (10) (synthesis of compound 1-5) above, except that compound 1-4 was changed to compound 5-2. The yield of compound 5-3 was 126.7 g, and the yield was 81%.

Compound 5 was then synthesized according to the following reaction scheme (22).

Specifically, compound 5 was synthesized in the same manner as in reaction scheme (11) (synthesis of compound 1) above, except that compound 1-5 was changed to compound 5-3. The yield of compound 5 was 6.57 g, and the yield was 83%.

Compounds other than compounds 1, 3, and 5 obtained above were also synthesized by the same method or by combining methods known to those skilled in the art to give the compounds shown in Table 5.

<Examples and Comparative Examples>
[Example 1]
First, a glass substrate with stripes of indium tin oxide (ITO) formed to a thickness of 150 nm was prepared as a first electrode (anode). Poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate): PEDOT/PSS (Sigma-Aldrich) was applied to the glass substrate by spin coating to a dry thickness of 30 nm to form a hole injection layer.

Next, commercially available TFB was dissolved in xylene at 1% by mass to prepare a hole transport layer coating solution. The hole transport layer coating solution was applied onto the hole injection layer by spin coating to a dry thickness of 30 nm, and heated at 230°C for 1 hour to form a hole transport layer.

Next, a toluene solution was prepared using compound H-1, whose molecular structure is shown below, as a hole-transporting host material, compound 1 synthesized in Synthesis Example 1 above as an electron-transporting host material, and tris(2-(3-p-oxyl)phenyl)pyridine iridium (hereinafter referred to as TEG), whose molecular structure is shown below, as an emitting dopant material. This was applied to the hole-transporting layer by spin coating to a film thickness of 50 nm, and heated at 120°C for 1 hour to form an emitting layer. The content ratio of H-1 as a hole-transporting host material, compound 1 as an electron-transporting host material, and TEG as an emitting dopant material in the emitting layer was 25:70:5% by mass, respectively, relative to the total mass of the emitting layer.

Next, (8-quinolinolato)lithium (Liq) with the molecular structure shown below and KLET-03 (manufactured by Chemipro Chemicals) were co-evaporated on the light-emitting layer in a vacuum evaporation apparatus to form an electron transport layer with a thickness of 30 nm. In addition, lithium fluoride (LiF) was evaporated on the electron transport layer in a vacuum evaporation apparatus to form an electron injection layer with a thickness of 1 nm. Furthermore, aluminum (Al) was evaporated on the electron injection layer in a vacuum evaporation apparatus to form a second electrode (cathode) with a thickness of 100 nm. Thereafter, in a nitrogen atmosphere glove box with a moisture concentration of 1 ppm or less and an oxygen concentration of 1 ppm or less, the sample was sealed using a glass sealing tube with a desiccant and an ultraviolet-curing resin and used as an organic EL element sample for evaluation. In this manner, an organic EL element was manufactured. The results are shown in Table 6.

[Example 2]
An organic EL device was produced in the same manner as in Example 1, except that Compound 3 was used as the electron transporting host material instead of Compound 1. The results are shown in Table 6.

[Example 3]
An organic EL device was produced in the same manner as in Example 1, except that Compound 4 was used as the electron transporting host material instead of Compound 1. The results are shown in Table 6.

[Example 4]
An organic EL device was produced in the same manner as in Example 1, except that Compound 5 was used as the electron transporting host material instead of Compound 1. The results are shown in Table 6.

[Example 5]
An organic EL device was produced in the same manner as in Example 1, except that Compound 6 was used as the electron transporting host material instead of Compound 1. The results are shown in Table 6.

[Example 6]
An organic EL device was produced in the same manner as in Example 1, except that Compound 8 was used as the electron transporting host material instead of Compound 1. The results are shown in Table 6.

[Example 7]
An organic EL device was produced in the same manner as in Example 1, except that Compound 9 was used as the electron transporting host material instead of Compound 1. The results are shown in Table 6.

[Comparative Example 1]
An organic EL device was produced in the same manner as in Example 1, except that Comparative Example Compound 1, the molecular structure of which is shown below, was used as the electron transporting host material instead of Compound 1. The results are shown in Table 6.

[Comparative Example 2]
An organic EL device was produced in the same manner as in Example 1, except that Comparative Example Compound 2, the molecular structure of which is shown below, was used as the electron transporting host material instead of Compound 1. The results are shown in Table 6.

[Comparative Example 3]
An organic EL device was produced in the same manner as in Example 1, except that Comparative Example Compound 3, the molecular structure of which is shown below, was used as the electron transporting host material instead of Compound 1. The results are shown in Table 6.

From Table 1, it was found that the compound of this embodiment has a large dihedral angle DA ₀ in the most stable structure of the A1 plane and A2 plane with respect to the LUMO region and a large minimum dihedral angle DA _rt that can be reached with thermal energy at room temperature, compared to the comparative compound. Therefore, it is shown that the compound of this embodiment can sterically suppress the interaction of the same or different molecules present around the triazine ring plane where the LUMO is distributed. Therefore, even when an organic electroluminescence element is produced by a coating method, it is expected to suppress the deterioration of film quality due to aggregation.

As can be seen from Table 2, the compound of this embodiment has a smaller molecular weight ratio of the HOMO portion than the comparative compound. In other words, the compound of this embodiment has a low HOMO molecular weight ratio, which suppresses hole transport properties and emphasizes electron transport properties derived from the LUMO region. Therefore, it is expected that the compound can be used in the light-emitting layer, electron transport layer, electron injection layer, hole blocking layer, etc. of an organic EL device.

From Table 3, it can be seen that the comparative example compounds 1, 4, 5, and 6, which do not satisfy the above-mentioned dihedral angle condition or the condition that there are three or less saturated nitrogen atoms, which are characteristics of the present invention, have low solubility, while the compounds of this embodiment, which satisfy all of the above-mentioned conditions, have high solubility. Furthermore, from Tables 2 and 3, it can be seen that compounds in which the three substituents bonded to the triazine ring are each different in structure have higher solubility than compounds in which two or more of the substituents bonded to the triazine ring have the same structure. Therefore, it can be seen that compounds in which the three substituents bonded to the triazine ring are each different in structure are particularly suitable for producing organic EL elements by coating method, even among the compounds of this embodiment.

Furthermore, Table 4 shows that, in the compounds in which A1 corresponds to formula A1-1 or formula A1-2, the compounds in which Y3 is a phenyl group have a larger _Xc90 and higher photochemical stability. Therefore, in this embodiment, the compounds in which Y2 or Y3 is C(R) and the R is an aromatic hydrocarbon ring group or an aromatic heterocyclic group in general formulas (A1-1), (A1-2), (A1-6), (A2-1), (A2-2), and (A2-6) can be expected to have a particularly long life when applied to an organic electroluminescence device (particularly a light-emitting layer).

From Table 6, it can be seen that Examples 1 to 7, which used the compound according to this embodiment as a host material, showed current efficiency almost equal to or higher than Comparative Examples 1 to 3, and also showed a significantly improved luminescence life. Furthermore, in Examples 1 to 7, the films were uniform and free of defects even after heating at 125°C, and showed good film-forming properties. Therefore, it was found that the compound according to the present invention is useful as a material for organic EL elements for coating methods.

In addition, the compounds used in Examples 1 to 7 are preferable from the viewpoint of mass production because they can be used to form the light-emitting layer of an organic electroluminescence element by a coating method.

The present invention has been described above with reference to embodiments and examples, but the present invention is not limited to specific embodiments and examples, and various modifications and variations are possible within the scope of the invention described in the claims.

100 Organic electroluminescence element (organic EL element)
REFERENCE SIGNS LIST 110 Substrate 120 First electrode 130 Hole injection layer 140 Hole transport layer 150 Light emitting layer 160 Electron transport layer 170 Electron injection layer 180 Second electrode

Claims (12)

The following general formula (1):

(Wherein,
_L1 and _L2 each independently represent a single bond, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 6 to 30 ring atoms;
m and n are each independently an integer of 0 or 1;
_A1 is represented by the following general formulae (A1-1), (A1-2), (A1-4), and (A1-6):

(Wherein,
X ₁₁ to X ₁₈ each independently represent C(R ₁ ) or a nitrogen atom;
Y ₁₁ to Y ₁₅ each independently represent C(R ₁ ) or a nitrogen atom;
Z ₁₁ to Z ₁₅ each independently represent C(R ₁ ) or a nitrogen atom;
_E1 is N( _R15 ),
R ₁ in X ₁₁ to X ₁₈ , Y ₁₁ to Y ₁₅ , and Z ₁₁ to Z ₁₅ is each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, or a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms;
R ₁₅ in E ₁ is a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 6 to 30 ring atoms;
_Q1 is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms;
Any one of X ₁₁ to X ₁₈ , Y ₁₁ to Y ₁₅ , and Z ₁₁ to Z ₁₅ is a carbon atom bonded to L ₁ .
is a substituent selected from
provided that when A ₁ is a substituent represented by formula (A1-1), L ₁ is bonded to X ₁₄ ;
when A ₁ is a substituent represented by formula (A1-2), L ₁ is bonded to any one of X ₁₄ , Y ₁₁ to Y ₁₄ , and Z ₁₁ to Z ₁₅ ;
When A ₁ is a substituent represented by formula (A1-4), L ₁ is bonded to any one of Z ₁₁ to Z ₁₅ ;
When A ₁ is a substituent represented by formula (A1-6), L ₁ is bonded to any one of atoms X ₁₄ , X ₁₅ , and Y ₁₁ to Y ₁₅ ;
_A2 is a substituent selected from the following general formulae (A2-1), (A2-2) and (A2-5),

(Wherein,
X ₂₁ to X ₂₈ each independently represent C(R ₂ ) or a nitrogen atom;
Y ₂₁ to Y ₂₅ each independently represent C(R ₂ ) or a nitrogen atom;
Z ₂₁ to Z ₂₅ each independently represent C(R ₂ ) or a nitrogen atom;
R ₂ in X ₂₁ to X ₂₈ , Y ₂₁ to Y ₂₅ , and Z ₂₁ to Z ₂₅ is each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a cyano group, a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 6 to 30 ring atoms;
_Q2 is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms or a substituted or unsubstituted aromatic heterocyclic group having 6 to 30 ring atoms;
_N21 is a nitrogen atom bonded to _L2 ;
In the general formulae (A2-1) and (A2-2), any one of X ₂₁ to X ₂₈ , Y ₂₁ to Y ₂₅ , and Z ₂₁ to Z ₂₅ is a carbon atom bonded to L ₂ .
is a substituent selected from
provided that when _A2 is a substituent represented by formula (A2-1), _L2 is bonded to any one of _X24 and _Y21 to _Y25 ;
when _A2 is a substituent represented by formula (A2-2), _L2 is bonded to any one of _X24 , _Y21 to _Y24 , and _Z21 to _Z25 ;
When _A2 is a substituent represented by the general formula (A2-5), _L2 is bonded to _N21 ,
_A3 is benzene, pentalene, indene, naphthalene, anthracene, azulene, heptalene, acenaphthalene, phenalene, phenanthrene, biphenyl, terphenyl, triphenylene, pyrene, chrysene, picene, perylene, pentaphene, pentacene, tetraphene, hexaphene, hexacene, rubicene, trinaphthylene, heptaphene, pyranthrene, or a substituted or unsubstituted aromatic heterocyclic group having 6 to 30 ring atoms;
The compound of the general formula (1) contains 3 or less saturated nitrogen atoms in one molecule.
A compound represented by the formula: The compound according to claim 1, wherein at least two of _A1 or _L1 , _A2 or _L2 , and _A3 bonded to the triazine ring in the general formula (1) are groups having a ring structure in which two atoms adjacent to the carbon atom bonded to the triazine ring are carbon atoms or nitrogen atoms having no substituents other than hydrogen atoms or deuterium atoms. The compound according to claim 1 or 2, wherein in the general formulae (A1-2) and (A1-6), L ₁ is bonded to Y ₁₂ or Y ₁₃ , and/or, in the general formula (A2-2), L ₂ is bonded to Y ₂₂ or Y ₂₃ . The compound according to claim 1 or 2, wherein in said general formulae (A1-1), (A1-2) and (A1-6), any one of Y ₁₂ and Y ₁₃ is C(R ₁ ) and R ₁ is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, and/or, in said general formulae (A2-1) and (A2-2), any one of Y ₂₂ and Y ₂₃ is C(R ₂ ) and R ₂ is a substituted or unsubstituted aromatic hydrocarbon ring group having 6 to 30 carbon atoms, or a substituted or unsubstituted aromatic heterocyclic group having 6 to 30 ring atoms. The compound according to claim 1 or 4, wherein the aromatic heterocyclic group is pyridine, pyrimidine, pyrazine, triazine, quinoline, quinoxaline, quinazoline, naphthyridine, phenanthridine, acridine, quinone, anthraquinone, xanthone, thioxanthone, coumarin, 6H-benzo[c]chromen-6-one, fluorenone, imidazole, benzimidazole, pyrazole, indazole, oxazole, isoxazole, benzoxazole, benzisoxazole, thiazole, isothiazole, benzothiazole, benzisothiazole, phosphole, dibenzophosphole, or dibenzothiophene 5,5-dioxide. The compound according to any one of claims 1 to 5, wherein in said general formulae (A1-1), (A1-2) and (A1-6), Y ₁₃ is C(R ₁ ) and said R ₁ does not contain a saturated nitrogen atom, and/or, in said general formulae (A2-1) and (A2-2), Y ₂₃ is C(R ₂ ) and said R ₂ does not contain a saturated nitrogen atom. The compound according to any one of claims 1 to 6, wherein the three substituents bonded to the triazine ring in the general formula (1) have mutually different structures. A material for an organic electroluminescence device comprising the compound according to any one of claims 1 to 7. A composition for an organic electroluminescence device comprising the compound according to any one of claims 1 to 7 and a solvent. A pair of electrodes;
and one or more organic layers disposed between the pair of electrodes,
At least one of the organic layers comprises a compound according to any one of claims 1 to 7.
Organic electroluminescent element. A pair of electrodes;
and one or more organic layers disposed between the pair of electrodes,
An organic electroluminescence device, wherein at least one of the organic layers comprises a light-emitting material and the compound according to claim 1 . The organic electroluminescence device according to claim 10 , wherein the organic layer containing the compound is formed by a coating method.

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