JP7547728B2 - Triazine compound and material for organic electroluminescent device - Google Patents

Description

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

In recent years, organic electroluminescent devices have started to be put to practical use, mainly for small mobile applications. However, to further expand their applications, performance improvement is essential, and materials with high luminous efficiency and long life characteristics are required.
Patent Document 1 discloses a triazine compound that is a material for an organic electroluminescent device that is highly efficient and can reduce the driving voltage.

Korean Patent No. 1566584

However, there is a strong demand from the market for an expansion of applications and environments in which they can be used, and the triazine compound in Patent Document 1 does not fully satisfy the characteristics of low voltage, high luminous efficiency, and long life, so there is a demand for compounds that achieve these three characteristics at an even higher level.

Therefore, one aspect of the present invention is directed to providing a triazine compound that contributes to the formation of an organic electroluminescent device exhibiting low voltage, high luminous efficiency and long life characteristics.
Another aspect of the present invention is directed to providing a material for an organic electroluminescent device, which contains the above triazine compound.

The triazine compound according to one embodiment of the present invention is a triazine compound represented by formula (1):

In the formula,
Ar ¹ and Ar ² each independently represent a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, a dibenzofuranyl group, or a dibenzothienyl group;
^Ar3 is
a monocyclic, linked or fused ring aromatic hydrocarbon group having 6 to 60 carbon atoms,
a nitrogen-containing monocyclic, linked or fused ring-containing aromatic group having 6 to 60 carbon atoms and consisting of only 6-membered rings, or
represents a monocyclic, linked or fused ring heteroaromatic group having 6 to 60 carbon atoms, in which the heteroatom is a Group 16 element;
L ¹ , L ² , L ³ and L ⁴ each independently represent a phenylene group, a naphthylene group, a pyridylene group, a diazaphenylene group, a dibenzofuranyl group, a dibenzothienyl group, or a fluorenyl group;
a, b and c each independently represent 0 or 1;
R represents a hydrogen atom, a methyl group, a phenyl group, or a pyridyl group;
Ar ¹ to Ar ³ , L ¹ to L ⁴ and R may each independently be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, a tertiary butyl group, a methoxy group, a phenyl group, a naphthyl group and a pyridyl group.

A material for an organic electroluminescent device according to yet another aspect of the present invention contains the above-mentioned triazine compound.

According to one aspect of the present invention, it is possible to provide a triazine compound that contributes to the formation of an organic electroluminescent device that exhibits low voltage, high luminous efficiency, and long life characteristics. According to another aspect of the present invention, it is possible to provide a material for an organic electroluminescent device that contains the above-mentioned triazine compound.

FIG. 1 is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescence element according to one embodiment of the present disclosure. FIG. 2 is a schematic cross-sectional view showing another example of a laminate structure of an organic electroluminescence element according to one embodiment of the present disclosure (structure of element example 1).

The triazine compound according to one embodiment of the present invention is described in detail below.

<Triazine Compound>
A triazine compound according to one embodiment of the present invention is a triazine compound represented by formula (1) (hereinafter, also referred to as triazine compound (1)).

In the formula,
Ar ¹ and Ar ² each independently represent a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, a dibenzofuranyl group, or a dibenzothienyl group;
^Ar3 is
a monocyclic, linked or fused ring aromatic hydrocarbon group having 6 to 60 carbon atoms,
a nitrogen-containing monocyclic, linked or fused ring-containing aromatic group having 6 to 60 carbon atoms and consisting of only 6-membered rings, or
represents a monocyclic, linked or fused ring heteroaromatic group having 6 to 60 carbon atoms, in which the heteroatom is a Group 16 element;
L ¹ , L ² , L ³ and L ⁴ each independently represent a phenylene group, a naphthylene group, a pyridylene group, a diazaphenylene group, a dibenzofuranyl group, a dibenzothienyl group, or a fluorenyl group;
a, b and c each independently represent 0 or 1;
R represents a hydrogen atom, a methyl group, a phenyl group, or a pyridyl group;
Ar ¹ to Ar ³ , L ¹ to L ⁴ and R may each independently be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, a tertiary butyl group, a methoxy group, a phenyl group, a naphthyl group and a pyridyl group.

In the triazine compound (1), ^Ar1 and ^Ar2 each independently represent a phenyl group, a biphenylyl group ^, a ^terphenylyl group, a naphthyl group, a dibenzofuranyl group, or a dibenzothienyl group, and each independently may be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, a tertiary butyl group, a methoxy group, a phenyl group, a naphthyl group, and a pyridyl group.

<<Ar ¹ , Ar ² >>
Ar ¹ and Ar ² are not particularly limited, and examples thereof include a phenyl group, a p-tolyl group, a m-tolyl group, an o-tolyl group, a p-tertiary butylphenyl group, an m-tertiary butylphenyl group, and an aryl group. Phenyl group, o-tertiary butylphenyl group, p-fluorophenyl group, m-fluorophenyl group, o-fluorophenyl group, 3,5-difluorophenyl group, 2,4,6-trifluorophenyl group, pentafluoro Phenyl group, 2,4-dimethylphenyl group, 3,5-dimethylphenyl group, 3,5-ditertiarybutyl group phenyl group, mesityl group, 1-naphthyl group, 2-naphthyl group, biphenyl-2-yl group, biphenyl-3-yl group, biphenyl-4-yl group, 3-methylbiphenyl-4-yl group, 2'- Methylbiphenyl-4-yl group, 4'-methylbiphenyl-4-yl group, 4'-tertiarybutylbiphenyl-4-yl group, 3',5'-dimethylbiphenyl-4-yl group, 3',5 2,2'-Ditertiary butyl biphenyl-4-yl group, 2,2'-Dimethyl biphenyl-4-yl group, 2',4',6'-Trimethyl biphenyl 4-methyl-4-yl group, 6-methylbiphenyl-3-yl group, 5-methylbiphenyl-3-yl group, 2'-methylbiphenyl-3-yl group, 4'-methylbiphenyl-3-yl group, 6'-methylbiphenyl-3-yl group, , 2'-dimethylbiphenyl-3-yl group, 5-methylbiphenyl-2-yl group, 6-methylbiphenyl-2-yl group, 2'-methylbiphenyl-2-yl group, 4'-methylbiphenyl-2 -yl group, 6,2'-dimethylbiphenyl-2-yl group, 2-(2-pyridyl)phenyl group, 3-(2-pyridyl)phenyl group, 4-(2-pyridyl)phenyl group, lysyl)phenyl group, 2-(3-pyridyl)phenyl group, 3-(3-pyridyl)phenyl group, 4-(3-pyridyl)phenyl group, 2-(4-pyridyl)phenyl group, 3-(4- pyridyl)phenyl group, 4-(4-pyridyl)phenyl group, 2-(3-methylpyridin-2-yl)phenyl group, 3-(3-methylpyridin-2-yl)phenyl group, 4-(3- 2-(4-methylpyridin-2-yl)phenyl group, 3-(4-methylpyridin-2-yl)phenyl group, 4-( 4-methylpyridin-2-yl)phenyl group, 2-(5-methylpyridin-2-yl)phenyl group, 3-(5-methylpyridin-2-yl)phenyl group, 4-(5-methylpyridin- 2-yl)phenyl group, 2-(6-methylpyridin-2-yl)phenyl group, 3-(6-methylpyridin-2-yl)phenyl group, 4-(6-methylpyridin-2-yl)phenyl group, 2-(2-methylpyridin-3-yl)phenyl group, 3-(2-methylpyridin-3-yl)phenyl group, 4-(2-methylpyridin-3-yl)phenyl group, phenyl group, 2-(4-methylpyridin-3-yl)phenyl group, 3-(4-methylpyridin-3-yl)phenyl group, 4-(4-methylpyridin-3-yl)phenyl group, 2-(5-methylpyridin-3-yl)phenyl group, 3-(5-methylpyridin-3-yl)phenyl group, 4-(5-methylpyridin-3-yl)phenyl group, 2-(6- 3-(6-methylpyridin-3-yl)phenyl group, 4-(6-methylpyridin-3-yl)phenyl group, 2-(2 3-(2-methylpyridin-4-yl)phenyl group, 4-(2-methylpyridin-4-yl)phenyl group, 2-(3-methylpyridin-4 -(3-methylpyridin-4-yl)phenyl group, 3-(3-methylpyridin-4-yl)phenyl group, 4-(3-methylpyridin-4-yl)phenyl group, p-terphenyl group, m-terphenyl group, o- Terphenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylnaphthalene-1-yl group, 4-methylnaphthalene-1-yl group, 6-methylnaphthalene phenyl group, 4-(1-naphthyl)phenyl group, 4-(2-naphthyl)phenyl group, 3-(1-naphthyl)phenyl group, 3-(2-naphthyl)phenyl group, 1-dibenzo Thienyl group, 2-dibenzothienyl group, 2-(8-phenyl)-dibenzothienyl group, 3-dibenzothienyl group, 4-dibenzothienyl group, 1-dibenzofuranyl group, 2-dibenzofuranyl group, 2-( 8-phenyl)-dibenzofuranyl group, 3-dibenzofuranyl group, 4-dibenzofuranyl group, 4-dibenzofuranyl group, and the like.

In view of the excellent electron transporting material properties of the triazine compound (1), ^Ar1 and ^Ar2 are preferably each independently a phenyl group, a biphenylyl group, or a naphthyl group which may be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, and a tertiary butyl group, and more preferably each independently an unsubstituted phenyl group, a biphenylyl group, or a naphthyl group.

In addition, Ar ¹ and Ar ² are preferably the same group in terms of easiness of synthesis of triazine compound (1). That is, it is preferable that Ar ¹ and Ar ² are a phenyl group, a biphenylyl group, or a naphthyl group which may be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, and a tertiary butyl group, and are the same, and it is more preferable that Ar 1 and Ar 2 are an unsubstituted phenyl group, a biphenylyl group, or a naphthyl group, and are the same.

<^<Ar3>>
^Ar3 is
a monocyclic, linked or fused ring aromatic hydrocarbon group having 6 to 60 carbon atoms,
a nitrogen-containing monocyclic, linked or fused ring-containing aromatic group having 6 to 60 carbon atoms and consisting of only 6-membered rings, or
It represents a monocyclic, linked or condensed ring heteroaromatic group having 6 to 60 carbon atoms in which the heteroatom is a Group 16 element.
^Ar3 may be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, a tertiary butyl group, a methoxy group, a phenyl group, a naphthyl group, and a pyridyl group.

The monocyclic, linked, or fused aromatic hydrocarbon group having 6 to 60 carbon atoms for ^Ar3 is not particularly limited, and examples thereof include a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a phenanthryl group, a fluorenyl group, a spirobifluorenyl group, a chrysenyl group, a benzofluorenyl group, an anthryl group, a pyrenyl group, a benzofluorenyl group, a triphenylenyl group, and a fluoranthenyl group; and groups in which these groups are substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, a tertiary butyl group, a methoxy group, a phenyl group, a naphthyl group, and a pyridyl group.

The nitrogen-containing aromatic group in ^Ar3 which is a monocyclic, linked or fused ring and which consists of only a 6-membered ring and has 6 to 60 carbon atoms is not particularly limited, and examples thereof include a pyridyl group, a diazaphenyl group, a benzo[b]quinolyl group, a benzo[c]quinolyl group, a benzo[f]quinolyl group, a benzo[g]quinolyl group, a benzo[h]quinolyl group, a phenazinyl group, an azapyrenyl group, a diazapyrenyl group, an azatriphenylenyl group, a diazatriphenylenyl group; and groups in which these groups are substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, a tertiary butyl group, a methoxy group, a phenyl group, a naphthyl group, and a pyridyl group.

The monocyclic, linked, or fused heteroaromatic group having 6 to 60 carbon atoms and in which the heteroatom in ^Ar3 is a Group 16 element is not particularly limited, and examples thereof include a benzofuranyl group, a benzothiophenyl group, a dibenzothiophenyl group, a dibenzofuranyl group, a benzonaphthofuranyl group, a benzonaphthothiophenyl group; and groups in which these groups are substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, a tertiary butyl group, a methoxy group, a phenyl group, a naphthyl group, and a pyridyl group.

Specific examples of ^Ar3 include, but are not limited to, a phenyl group, a p-tolyl group, a m-tolyl group, an o-tolyl group, a p-tertiary butylphenyl group, a m-tertiary butylphenyl group, an o-tertiary butylphenyl group, a 2,4-dimethylphenyl group, a 3,5-dimethylphenyl group, a 3,5-ditertiary butylphenyl group, a mesityl group, a 1-naphthyl group, a 2-naphthyl group, a biphenyl-2-yl group, a biphenyl-3-yl group, a biphenyl-4-yl group, a p-methoxyphenyl group, a m-methoxyphenyl group, an o-methoxyphenyl group, a 2-methyl-4-methoxyphenyl group, a 2-methyl-5-methoxyphenyl group, a 2,4-dimethoxyphenyl group, a 2,5-dimethoxyphenyl group, a 2,6-dimethoxyphenyl group, a 3,4-dimethoxyphenyl group, a 3,5-dimethoxyphenyl group, a p-fluorophenyl group, a m-fluorophenyl group, an o-fluorophenyl group, a 2, 3-difluorophenyl group, 2,4-difluorophenyl group, 2,5-difluorophenyl group, 2,6-difluorophenyl group, 3,4-difluorophenyl group, 3,5-difluorophenyl group, 2,4,6-trifluorophenyl group, pentafluorophenyl group, biphenyl-2-yl group, biphenyl-3-yl group, biphenyl-4-yl group, 3-methylbiphenyl-4-yl group, 2'-methylbiphenyl-4-yl group, 4'-methylbiphenyl nyl-4-yl group, 4'-tert-butylbiphenyl-4-yl group, 3',5'-dimethylbiphenyl-4-yl group, 3',5'-di-tert-butylbiphenyl-4-yl group, 2,2'-dimethylbiphenyl-4-yl group, 2',4',6'-trimethylbiphenyl-4-yl group, 6-methylbiphenyl-3-yl group, 5-methylbiphenyl-3-yl group, 2'-methylbiphenyl-3-yl group, 4'-methylbiphenyl-3-yl group, 6,2'-dimethylbiphenyl-3-yl group, 5-methylbiphenyl-2-yl group, 6-methylbiphenyl-2-yl group, 2'-methylbiphenyl-2-yl group, 4'-methylbiphenyl-2-yl group, 6,2'-dimethylbiphenyl-2-yl group, p-terphenyl group, m-terphenyl group, o-terphenyl group, quaterphenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylnaphthalene-1-yl group, 4-methylnaphthalene-1-yl group, yl group, 6-methylnaphthalen-2-yl group, 4-(1-naphthyl)phenyl group, 4-(2-naphthyl)phenyl group, 3-(1-naphthyl)phenyl group, 3-(2-naphthyl)phenyl group, 2-fluorenyl group, 9,9-dimethyl-2-fluorenyl group, 9,9-diethyl-2-fluorenyl group, 9,9-di-n-propyl-2-fluorenyl group, 9,9-di-n-octyl-2-fluorenyl group, 9,9-diphenyl-2-fluorenyl group, 9 , 9'-spirobifluorenyl group, 9-phenanthryl group, 2-phenanthryl group, 11,11'-dimethylbenzo[a]fluoren-9-yl group, 11,11'-dimethylbenzo[a]fluoren-3-yl group, 11,11'-dimethylbenzo[b]fluoren-9-yl group, 11,11'-dimethylbenzo[b]fluoren-3-yl group, 11,11'-dimethylbenzo[c]fluoren-9-yl group, 11,11'-dimethylbenzo[c ... ]fluoren-2-yl group, 3-fluoranthenyl group, 8-fluoranthenyl group, 1-pyrenyl group, 2-pyrenyl group, 9-anthryl group, 2-anthryl group, 2-triphenylene group, 3-chrysenyl group, 6-chrysenyl group, 3-perylenyl group, 2-pyridyl group, 3-methyl-2-pyridyl group, 4-methyl-2-pyridyl group, 5-methyl-2-pyridyl group, 6-methyl-2-pyridyl group, 6-phenyl-2-pyridyl group, 6-(1-naphthyl)-2-pyridyl group, -pyridyl group, 6-(2-naphthyl)-2-pyridyl group, 3-pyridyl group, 4-methyl-3-pyridyl group, 2-methyl-3-pyridyl group, 2-phenyl-3-pyridyl group, 2-(1-naphthyl)-3-pyridyl group, 2-(2-naphthyl)-3-pyridyl group, 6-methyl-3-pyridyl group, 6-phenyl-3-pyridyl group, 6-(1-naphthyl)-3-pyridyl group, 6-(2-naphthyl)-3-pyridyl group, 2,6-dimethyl-3-pyridyl group, 2,6-diphenyl-3-pyridyl group, 4-pyridyl group, 2-methyl-4-pyridyl group, 2-phenyl-4-pyridyl group, 2-(1-naphthyl)-4-pyridyl group, 2-(2-naphthyl)-4-pyridyl group, 2,6-dimethyl-4-pyridyl group, 2,6-diphenyl-4-pyridyl group, 2-pyrimidyl group, 2,2'-bipyridin-3-yl group, 2,2'-bipyridin-4-yl group, 2,2'-bipyridin-5-yl group, 2,3'-bipyridin- 3-yl group, 2,3'-bipyridin-4-yl group, 2,3'-bipyridin-5-yl group, 5-pyrimidyl group, pyrazyl group, 2-quinolyl group, 3-quinolyl group, 5-quinolyl group, 6-quinolyl group, 1-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 2-quinoxalyl group, 3-phenyl-2-quinoxalyl group, 6-quinoxalyl group, 2,3-dimethyl-6-quinoxalyl group, 2,3-diphenyl-6-quinoxalyl group, 2-quinazolyl a quinazolyl group, a 4-quinazolyl group, a 2-acridinyl group, a 9-acridinyl group, a 1,10-phenanthrolin-3-yl group, a 1,10-phenanthrolin-5-yl group, a 2-thienyl group, a 3-thienyl group, a 2-benzothienyl group, a 2-(3-phenyl)benzothienyl group, a 3-benzothienyl group, a 3-(2-phenyl)benzothienyl group, a 1-dibenzothienyl group, a 2-dibenzothienyl group, a 3-dibenzothienyl group, a 4-dibenzothienyl group, a 2-furanyl group, nyl group, 3-furanyl group, 2-benzofuranyl group, 2-(3-phenyl)benzofuranyl group, 3-benzofuranyl group, 3-(2-phenyl)benzofuranyl group, 4-benzofuranyl group, 1-dibenzofuranyl group, 2-dibenzofuranyl group, 3-dibenzofuranyl group, 4-dibenzofuranyl group, 2-thianthryl group, 10-phenylphenothiazin-3-yl group, 10-phenylphenothiazin-2-yl group, 10-phenylphenoxazine-3 -yl group, 10-phenylphenoxazin-2-yl group, 4-(2-pyridyl)phenyl group, 4-(3-pyridyl)phenyl group, 4-(4-pyridyl)phenyl group, 3-(2-pyridyl)phenyl group, 3-(3-pyridyl)phenyl group, 3-(4-pyridyl)phenyl group, 4-(2-thienyl)phenyl group, 4-(2-furanyl)phenyl group, 5-phenylthiophen-2-yl group, 5-phenylfuran-2-yl group, 4-(5-phenylthiophen-2-yl group, ... [0036] Examples of such aryl groups include a 3-(2-dibenzothienyl)phenyl group, a 3-(4-dibenzothienyl)phenyl group, a 4-(2-dibenzofuranyl)phenyl group, a 4-(4-dibenzofuranyl)phenyl group, a 3-(2-dibenzofuranyl)phenyl group, a 3-(4-dibenzofuranyl)phenyl group, a 5-phenylpyridin-2-yl group, a 4-phenylpyridin-2-yl group, a 5-phenylpyridin-3-yl group, and a 5-phenylpyridin-3-yl group.

^Ar3 is preferably any one of the following (A) to (D), more preferably any one of the following (E), and further preferably any one of the following (F), in that the triazine compound (1) contributes to the formation of an organic electroluminescent device with higher performance.
(A) a monocyclic, linked or fused aromatic hydrocarbon group having 6 to 20 carbon atoms; (B) a monocyclic, linked or fused nitrogen-containing aromatic group having 6 to 20 carbon atoms consisting only of a 6-membered ring; (C) a monocyclic, linked or fused heteroaromatic group having 6 to 20 carbon atoms in which the heteroatom is a Group 16 element; (D) a group in which the above groups (A) to (C) are substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, a tertiary butyl group, a methoxy group, a phenyl group, a naphthyl group, and a pyridyl group; (E) a phenyl group, a biphenyl group, a pyridyl group, a naphthyl group, a phenanthryl group, a fluorenyl group, a benzofluorenyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzothienyl group, or a dibenzofuranyl group, which may be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, a tertiary butyl group, a methoxy group, a phenyl group, a naphthyl group, and a pyridyl group; or (F) a phenyl group, a methylphenyl group, a dimethylphenyl group, a trimethylphenyl group, a tertiary butylphenyl group, a ditertiary butylphenyl group, a pyridyl group, a methylpyridyl group, a dimethylpyridyl group, a phenylpyridyl group, a diphenylpyridyl group, a naphthyl group, a phenanthryl group, a fluorenyl group, a benzofluorenyl group, a dibenzothienyl group, or a dibenzofuranyl group.

The above-mentioned monocyclic, linked, or condensed aromatic hydrocarbon group having 6 to 20 carbon atoms is not particularly limited, but examples thereof include a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a phenanthryl group, a fluorenyl group, a chrysenyl group, a benzofluorenyl group, an anthryl group, a pyrenyl group, a benzofluorenyl group, a triphenylenyl group, and a fluoranthenyl group.

Examples of nitrogen-containing aromatic groups that are monocyclic, linked, or fused and have 6 to 20 carbon atoms and are composed only of 6-membered rings include, but are not limited to, pyridyl, diazaphenyl, benzo[b]quinolyl, benzo[c]quinolyl, benzo[f]quinolyl, benzo[g]quinolyl, benzo[h]quinolyl, phenazinyl, azapyrenyl, diazapyrenyl, azatriphenylenyl, and diazatriphenylenyl.

Examples of the monocyclic, linked, or fused heteroaromatic group having 6 to 20 carbon atoms and a heteroatom of a Group 16 element include, but are not limited to, a benzofuranyl group, a benzothiophenyl group, a dibenzothiophenyl group, a dibenzofuranyl group, a benzonaphthofuranyl group, and a benzonaphthothiophenyl group.

<<L ¹ , L ² , L ³ , L ⁴ >>
L ¹ , L ² , L ³ and L ⁴ each independently represent a phenylene group, a naphthylene group, a pyridylene group, a diazaphenylene group, a dibenzofuranylene group, ^a dibenzothionylene group, or a fluorenylene group. L ² , L ³ and L ⁴ each independently may be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group and a tertiary butyl group.

Specific examples of L ¹ , L ² , L ³ , and L ⁴ are not particularly limited, but include, for example, a 1,4-phenylene group, a 2-methyl-1,4-phenylene group, a 1,3-phenylene group, a 5-methyl-1,3-phenylene group, a 1,2-phenylene group, a 4-methyl-1,2-phenylene group, a 3-methyl-1,2-phenylene group, a 3,6-dimethyl-1,4-phenylene group, a 2,3-dimethyl-1,4-phenylene group, a 2-fluoro-1,4-phenylene group, a 5-fluoro-1,3-phenylene group, a 2-fluoro fluoro-1,3-phenylene group, 4-fluoro-1,3-phenylene group, 4-fluoro-1,2-phenylene group, 3-fluoro-1,2-phenylene group, 3,6-difluoro-1,4-phenylene group, 2,3-difluoro-1,4-phenylene group, 2,5-difluoro-1,3-phenylene group, 2,4-difluoro-1,3-phenylene group, 4,5-difluoro-1,3-phenylene group, 3,4-difluoro-1,2-phenylene group, 4,5-difluoro-1,2-phenylene group, fluorene group, 1,4-naphthylene group, 1,5-naphthylene group, 2,6-naphthylene group, 2,7-naphthylene group, 1-phenylnaphthalene-2,6-diyl group, 2-phenylnaphthalene-1,4-diyl group, 9,9-dimethylfluorene-2,7-diyl group, 9,9-dioctylfluorene-2,7-diyl group, 9,9-diphenylfluorene-2,7-diyl group, 9,9'-spirobifluorene-2,7-diyl group, 11,11'-dimethylbenzo[a]fluorene-3, 9-diyl group, 11,11'-dimethylbenzo[a]fluorene-2,9-diyl group, 11,11'-dimethylbenzo[b]fluorene-3,9-diyl group, 11,11'-dimethylbenzo[c]fluorene-2,9-diyl group, 2,3-pyridylene group, 2,4-pyridylene group, 2,5-pyridylene group, 2,6-pyridylene group, 3,6-pyridylene group, 3,4-pyridylene group, dibenzothiophene-2,8-diyl group, dibenzofuran-2,8-diyl group, and the like.

In terms of ease of synthesis of the triazine compound (1), L ¹ , L ² , and L ³ are each independently preferably the following (G), more preferably the following (H), and further preferably the following (I):
(G) An unsubstituted phenylene group, naphthylene group, pyridylene group, diazaphenylene group, dibenzofuranyl group, dibenzothienyl group, or fluorenyl group; (H) An unsubstituted phenylene group, naphthylene group, pyridylene group, diazaphenylene group, or fluorenyl group; unsubstituted 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, 1,4-naphthylene group, 1,5-naphthylene group, 2,6-naphthylene group, 2,7-naphthylene group, 9,9-dimethylfluorene-2,7-diyl group, 9,9-dioctylfluorene-2,7-diyl group, 9,9-diphenylfluorene-2,7-diyl group, 9,9'-spirobifluorene-2,7-diyl group, 2,3-pyridylene group, 2,4-pyridylene group, 2,5-pyridylene group, 2,6-pyridylene group, 3,6-pyridylene group, or 3,4-pyridylene group

In terms of ease of synthesis of the triazine compound (1), ^L4 is preferably the following (J), more preferably the following (K), and further preferably the following (L).
(J) an unsubstituted phenylene group, naphthylene group, pyridylene group, diazaphenylene group, fluorenyl group, dibenzofuranyl group, or dibenzothienyl group; (K) an unsubstituted phenylene group, naphthylene group, pyridylene group, dibenzofuranyl group, or dibenzothienyl group; (L) unsubstituted 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, 1,4-naphthylene group, 1,5-naphthylene group, 2,6-naphthylene group, 2,7-naphthylene group, 9,9-dimethylfluorene-2,7-diyl group, 9,9-dioctylfluorene-2,7-diyl group, 9,9-diphenylfluorene-2,7-diyl group, 9,9'-spirobifluorene-2,7-diyl group, 2,3-pyridylene group, 2,4-pyridylene group, 2,5-pyridylene group, 2,6-pyridylene group, 3,6-pyridylene group, 3,4-pyridylene group, 3,6-dibenzofuranyl group, 2,8-dibenzofuranyl group, 3,6-dibenzothienyl group, or 2,8-dibenzothienyl group;

<<a, b, c>>
a, b and c each represent 0 or 1.

<<R>>
R represents a hydrogen atom, a methyl group, a phenyl group, or a pyridyl group. R may be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, a tertiary butyl group, a methoxy group, a phenyl group, a naphthyl group, and a pyridyl group. However, when R is substituted, R represents a methyl group, a phenyl group, or a pyridyl group.

Specific examples of R include, but are not limited to, a phenyl group, a p-tolyl group, a m-tolyl group, an o-tolyl group, a p-tertiary butylphenyl group, a m-tertiary butylphenyl group, an o-tertiary butylphenyl group, a 2,4-dimethylphenyl group, a 3,5-dimethylphenyl group, a 3,5-ditertiary butylphenyl group, a mesityl group, a p-fluorophenyl group, a m-fluorophenyl group, an o-fluorophenyl group, a 2,3-difluorophenyl group, a 2,4-difluorophenyl group, a 2,5-difluorophenyl group, a 2,6-difluorophenyl group, a 3,4-difluorophenyl group, a 3,5-difluorophenyl group, a 2,4,6-trifluorophenyl group, Examples of such groups include fluorophenyl, pentafluorophenyl, 2-pyridyl, 3-methyl-2-pyridyl, 4-methyl-2-pyridyl, 5-methyl-2-pyridyl, 6-methyl-2-pyridyl, 6-phenyl-2-pyridyl, 3-pyridyl, 4-methyl-3-pyridyl, 2-methyl-3-pyridyl, 2-phenyl-3-pyridyl, 6-methyl-3-pyridyl, 6-phenyl-3-pyridyl, 2,6-dimethyl-3-pyridyl, 2,6-diphenyl-3-pyridyl, 4-pyridyl, 2-methyl-4-pyridyl, 2-phenyl-4-pyridyl, 2,6-dimethyl-4-pyridyl, and 2,6-diphenyl-4-pyridyl.

R is preferably a hydrogen atom, a methyl group, an unsubstituted phenyl group, or an unsubstituted pyridyl group, and more preferably a hydrogen atom, in that triazine compound (1) has excellent electron transport material properties.

[Specific examples of triazine compound (1)]
Specific examples of the triazine compound (1) include the following (A-1) to (C-177), but the present invention is not limited thereto. As the triazine compound (1), the compounds represented by (A-3), (A-39), (A-98), (A-106), (A-122) and (A-254) are preferred in terms of their excellent performance as an electron transport material in an organic electroluminescent device.

Next, a method for producing the triazine compound (1) will be described.
The triazine compound (1) can be produced by the methods shown in the following synthetic routes (i) to (vi).

Synthetic Route (i)

Synthetic route (ii)

Synthetic route (iii)

Synthetic route (iv)

Synthetic Route (v)

In formulas (2) to (16),
Ar ¹ , Ar ² , Ar ³ , L ¹ , L ² , L ³ , L ⁴ , R, a, b, and c are defined as Ar ¹ , Ar ² , Ar ³ , L 4 , R, a, b, and c in formula (1), respectively. ¹ , ^L2 , ^L3 , ^L4 , R, a, b, and c are the same as defined above;
Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ , and Y ⁶ each independently represent a halogen atom;
R ¹ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group;
The two R ¹ in B(OR ¹ ) ₂ may be the same or different;
Two R ¹ s, an oxygen atom, and a boron atom may form a ring.

Examples of the halogen atom represented by ^Y1 , ^Y2 , ^Y3 , ^Y4 , ^Y5 , and ^Y6 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. In terms of the good yield of the triazine compound (1), a chlorine atom, a bromine atom, or an iodine atom is preferred.

Examples of B(OR ¹ ) ₂ include B(OH) ₂ , B(OMe) ₂ , B(O ⁱ Pr) ₂ , B(OBu) ₂ , and B(OPh) ₂ , where Me is a methyl group, ⁱ Pr is an isopropyl group, Bu is a butyl group, and Ph is a phenyl group.

Examples of B(OR ¹ ) ₂ in which two R ¹ s, an oxygen atom, and a boron atom form a ring include the following groups (I) to (VI), of which the group (II) is preferred in terms of good yield.

The coupling reactions in synthetic pathways (i) to (v) are methods in which an aryl halide compound represented by formula (2), (4), (6), (8), (9), or (12) is reacted with a boron compound represented by formula (3), (5), (7), (10), or (11) in the presence of a palladium catalyst and a base, and general Suzuki-Miyaura reaction conditions can be applied.

The boron compound can be produced, for example, according to the method disclosed in The Journal of Organic Chemistry, Vol. 60, p. 7508, 1995, or The Journal of Organic Chemistry, Vol. 65, p. 164, 2000.

The aryl halide can be produced, for example, according to Journal of the American Chemical Society, Vol. 74, p. 6289, 1952, or Synlett, p. 808, 2002. Commercially available products may also be used. It is preferable to use 0.5 to 3.0 molar equivalents of the aryl halide relative to the boron compound, as this provides a good reaction yield.

The boronation reaction in the synthetic routes (i), (iii), (iv), and (v) is a method of producing a boron compound represented by formula (5), (11), or (15) by reacting a halogenated aryl compound represented by formula (4), (9), or (14) with a boron source (e.g., pinacolatoborane, bispinacolatodiboron, etc.) in the presence of a palladium catalyst and a base. These boron compounds can be produced, for example, according to the method disclosed in The Journal of Organic Chemistry, Vol. 60, p. 7508, 1995, or Tetrahedron Letters, Vol. 38, p. 3447, 1997.

Examples of palladium catalysts used in the above-mentioned coupling reaction and boronization reaction include palladium salts such as palladium chloride, palladium acetate, palladium trifluoroacetate, and palladium nitrate. Further examples include complex compounds such as π-allylpalladium chloride dimer, palladium acetylacetonate, tris(dibenzylideneacetone)dipalladium, bis(dibenzylideneacetone)palladium, dichlorobis(acetonitrile)palladium, and dichlorobis(benzonitrile)palladium; and palladium complexes having tertiary phosphines as ligands such as dichlorobis(triphenylphosphine)palladium, tetrakis(triphenylphosphine)palladium, dichloro(1,1'-bis(diphenylphosphino)ferrocene)palladium, bis(tri-tert-butylphosphine)palladium, bis(tricyclohexylphosphine)palladium, and dichlorobis(tricyclohexylphosphine)palladium. These can also be prepared in the reaction system by adding a tertiary phosphine to a palladium salt or complex compound.

Examples of tertiary phosphines include triphenylphosphine, trimethylphosphine, tributylphosphine, tri(tert-butyl)phosphine, tricyclohexylphosphine, tert-butyldiphenylphosphine, 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene, 2-(diphenylphosphino)-2'-(N,N-dimethylamino)biphenyl, 2-(di-tert-butylphosphino)biphenyl, 2-(dicyclohexylphosphino)biphenyl, bis(diphenylphosphine), bis(diphenylphosphino)methane, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,1'-bis(diphenylphosphino)ferrocene, tri(2-furyl)phosphine, tri(o-tolyl)phosphine, tris(2,5-xylyl)phosphine, (±)-2,2'-bis(diphenylphosphino)-1,1'-binaphthyl, 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl, etc.

Among these, palladium complexes having a tertiary phosphine as a ligand are preferred because of their good yield, and palladium complexes having 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl or tricyclohexylphosphine as a ligand are even more preferred.

The molar ratio of the tertiary phosphine to the palladium salt or complex compound is preferably in the range of 1:10 to 10:1, and more preferably in the range of 1:2 to 3:1 in terms of good yield. There is no limit to the amount of palladium catalyst used in the above-mentioned coupling reaction and boronation reaction, but in terms of good yield, the molar equivalent of the palladium catalyst is preferably in the range of 0.005 to 0.5 molar equivalents relative to the boron compound.

Examples of bases used in the above-mentioned coupling reaction and boronization reaction include metal hydroxide salts such as sodium hydroxide, potassium hydroxide, calcium hydroxide, etc.; metal carbonate salts such as sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate, etc.; metal acetate salts such as potassium acetate, sodium acetate, etc.; metal phosphate salts such as potassium phosphate, sodium phosphate, etc.; metal fluoride salts such as sodium fluoride, potassium fluoride, cesium fluoride, etc.; and metal alkoxides such as sodium methoxide, potassium methoxide, sodium ethoxide, potassium isopropyl oxide, potassium tert-butoxide, etc., in terms of good reaction yield. Among these, metal carbonates or metal phosphates are preferred, and potassium carbonate or potassium phosphate is more preferred. There are no particular limitations on the amount of base used. In terms of good reaction yield, the molar ratio of the base to the boron compound is preferably in the range of 1:2 to 10:1, and more preferably in the range of 1:1 to 4:1.

The above-mentioned coupling reaction and boronation reaction can be carried out in a solvent.
Examples of the solvent include ethers such as water, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether (CPME), tetrahydrofuran (THF), 2-methyltetrahydrofuran, 1,4-dioxane, and dimethoxyethane; aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, and tetralin; carbonates such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and 4-fluoroethylene carbonate; ethyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, and γ-butyl acetate. esters such as .-lactones; amides such as N,N-dimethylformamide (DMF), dimethylacetamide (DMAc), and N-methylpyrrolidone (NMP); ureas such as N,N,N',N'-tetramethylurea (TMU) and N,N'-dimethylpropyleneurea (DMPU); alcohols such as dimethylsulfoxide (DMSO), methanol, ethanol, isopropyl alcohol, butanol, octanol, benzyl alcohol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, and 2,2,2-trifluoroethanol; and the like. These may be used alone or in any ratio. There is no particular limit to the amount of solvent used. Among these, water, ethers, amides, alcohols, and mixed solvents thereof are preferred in terms of good reaction yield, and a mixed solvent of THF and water, or a mixed solvent of toluene and 1-butanol is more preferred.

The above-mentioned coupling reaction and boronization reaction can be carried out at a temperature appropriately selected from 0°C to 200°C, and is preferably carried out at a temperature appropriately selected from 60°C to 160°C in terms of good reaction yield.

After the above-mentioned coupling reaction and boronization reaction are completed, the desired product can be obtained by appropriately combining common purification processes such as recrystallization, column chromatography, sublimation purification, and preparative HPLC as necessary.

Triazine compound (1) can be used, for example, in organic electronic devices such as organic electroluminescent devices and photoelectric devices.

<Materials for organic electroluminescence devices>
The material for an organic electroluminescent device according to one aspect of the present invention contains the above-mentioned triazine compound (1).
The triazine compound (1) can be used, for example, as an electron transport material for organic electroluminescence devices. The material for organic electroluminescence devices containing the triazine compound (1) exhibits high luminous efficiency and long life characteristics, and contributes to the production of organic electroluminescence devices that can be used for various purposes or under various environments.

<Organic electroluminescent device>
An organic electroluminescent device containing a triazine compound (1) (hereinafter, may be simply referred to as an organic electroluminescent device) will be described below.

The organic electroluminescent device according to one aspect of the present invention contains a triazine compound (1).
The configuration of the organic electroluminescent device is not particularly limited, but examples thereof include the following configurations (i) to (v).

(i): anode/light-emitting layer/cathode (ii): anode/hole-transport layer/light-emitting layer/cathode (iii): anode/light-emitting layer/electron-transport layer/cathode (iv): anode/hole-transport layer/light-emitting layer/electron-transport layer/cathode (v): anode/hole-injection layer/hole-transport layer/light-emitting layer/electron-transport layer/electron-injection layer/cathode

The triazine compound (1) may be contained in any of the above layers, but in terms of excellent light-emitting properties of the organic electroluminescent device, it is preferable that it is contained in one or more layers selected from the group consisting of the light-emitting layer and the layer between the light-emitting layer and the cathode. Therefore, in the case of the configurations shown in (i) to (v) above, it is preferable that the triazine compound (1) is contained in one or more layers selected from the group consisting of the light-emitting layer, the electron transport layer, and the electron injection layer.

Hereinafter, an organic electroluminescent device according to one embodiment of the present invention will be described in more detail with reference to FIG. 1, taking the above configuration (v) as an example.
1 has a so-called bottom emission type element configuration, the organic electroluminescence element according to one embodiment of the present invention is not limited to the bottom emission type element configuration. That is, the organic electroluminescence element according to one embodiment of the present invention may have another known element configuration, such as a top emission type.

FIG. 1 is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescent device containing a triazine compound according to one embodiment of the present invention.
The organic electroluminescent device 100 includes a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, a light emitting layer 5, an electron transport layer 6, an electron injection layer 7, and a cathode 8 in this order. However, some of these layers may be omitted, or other layers may be added. For example, a hole blocking layer may be provided between the light emitting layer 5 and the electron transport layer 6, or the hole injection layer 3 may be omitted and the hole transport layer 4 may be provided directly on the anode 2. In addition, a single layer having the functions of multiple layers, such as an electron injection/transport layer having the functions of an electron injection layer and an electron transport layer in a single layer, may be provided instead of the multiple layers. Furthermore, for example, the single-layer hole transport layer 4 and the single-layer electron transport layer 6 may each be made up of multiple layers.

<<Layer Containing Triazine Compound (1)>>
1, the organic electroluminescent device 100 contains a triazine compound (1) in one or more layers selected from the group consisting of a light-emitting layer 5, an electron transport layer 6, and an electron injection layer 7. In particular, it is preferable that the electron transport layer 6 contains the triazine compound (1). The triazine compound (1) may be contained in a plurality of layers provided in the organic electroluminescent device.
In the following, an organic electroluminescent device 100 in which the electron transport layer 6 contains the triazine compound (1) will be described.

[Substrate 1]
The substrate 1 is not particularly limited, and examples thereof include a glass plate, a quartz plate, and a plastic plate.
Examples of the substrate 1 include a glass plate, a quartz plate, a plastic plate, a plastic film, etc. Among these, a glass plate, a quartz plate, and a light-transmitting plastic film are preferable.
Examples of light-transmitting plastic films include films made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propionate (CAP), and the like.
In the case of a configuration in which light is extracted from the substrate 1 side, the substrate 1 is transparent to the wavelength of light.

[Anode 2]
An anode 2 is provided on the substrate 1 (on the side of the hole injection layer 3).
Examples of the anode material include metals, alloys, electrically conductive compounds, and mixtures thereof, each having a large work function (e.g., 4 eV or more). Specific examples of the anode material include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO.
In the case of an organic electroluminescent device in which light is extracted through the anode, the anode is formed of a conductive transparent material that is transparent or substantially transparent to the light emitted.

[Hole injection layer 3, hole transport layer 4]
Between the anode 2 and a light-emitting layer 5 described below, a hole injection layer 3 and a hole transport layer 4 are provided in this order from the anode 2 side.
The hole injection layer and the hole transport layer have the function of transporting holes injected from the anode to the light-emitting layer. By interposing this hole injection layer and hole transport layer between the anode and the light-emitting layer, a large number of holes can be injected into the light-emitting layer with a lower electric field.

The hole injection layer and the hole transport layer also function as electron barrier layers. That is, the electrons injected from the cathode and transported from the electron injection layer and/or the electron transport layer to the light emitting layer are prevented from leaking to the hole injection layer and/or the hole transport layer due to the barrier of electrons present at the interface between the light emitting layer and the hole injection layer and/or the hole transport layer. As a result, the electrons are accumulated at the interface in the light emitting layer, which brings about effects such as improved light emitting efficiency, and an organic electroluminescent device with excellent light emitting performance is obtained.

The material for the hole injection layer and the hole transport layer has at least one of hole injection property, hole transport property, and electron barrier property. The material for the hole injection layer and the hole transport layer may be either an organic material or an inorganic material.

Specific examples of materials for the hole injection layer and hole transport layer include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, conductive polymer oligomers (particularly thiophene oligomers), porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds. Among these, porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds are preferred in terms of the good performance of the organic electroluminescent device, and aromatic tertiary amine compounds are particularly preferred.

Specific examples of aromatic tertiary amine compounds and styrylamine compounds include N,N,N',N'-tetraphenyl-4,4'-diaminophenyl, N,N'-diphenyl-N,N'-bis(m-tolyl)-[1,1'-biphenyl]-4,4'-diamine (TPD), 2,2-bis(4-di-p-tolylaminophenyl)propane, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N,N',N'-tetra-p-tolyl-4,4'-diaminobiphenyl, 1,1-bis(4-di-p-tolylaminophenyl)-4-phenylcyclohexane, bis(4-dimethylamino-2-methylphenyl)phenylmethane, bis(4-di-p-tolylaminophenyl)phenylmethane, N,N'-diphenyl-N,N'-di (4-methoxyphenyl)-4,4'-diaminobiphenyl, N,N,N',N'-tetraphenyl-4,4'-diaminodiphenyl ether, 4,4'-bis(diphenylamino)quadriphenyl, N,N,N-tri(p-tolyl)amine, 4-(di-p-tolylamino)-4'-[4-(di-p-tolylamino)styryl]stilbene, 4-N,N-diphenylamino-(2-diphenylvinyl)benzene, 3-methoxy-4'-N,N-diphenylaminostilbene, N-phenylcarbazole, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPD), 4,4',4''-tris[N-(m-tolyl)-N-phenylamino]triphenylamine (MTDATA), etc.

Inorganic compounds such as p-type Si and p-type SiC can also be used as examples of materials for the hole injection layer and hole transport layer.

The hole injection layer and the hole transport layer may be a single structure made of one or more materials, or may be a laminate structure made of multiple layers of the same or different compositions.

[Light-emitting layer 5]
The light-emitting layer 5 is provided between the hole transport layer 4 and the electron transport layer 6 described below.
The material of the light-emitting layer includes a phosphorescent material, a fluorescent material, and a thermally activated delayed fluorescent material. In the light-emitting layer, electron-hole pairs are recombined, resulting in light emission.

The light-emitting layer may consist of a single small molecule material or a single polymeric material, but more commonly consists of a host material doped with a guest compound. Emission comes primarily from the dopant and can be of any color.

Examples of host materials include compounds having a biphenylyl group, a fluorenyl group, a triphenylsilyl group, a carbazole group, a pyrenyl group, and an anthryl group. More specifically, examples of the compound include DPVBi (4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl), BCzVBi (4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl), TBADN (2-tertiarybutyl-9,10-di(2-naphthyl)anthracene), ADN (9,10-di(2-naphthyl)anthracene), CBP (4,4'-bis(carbazol-9-yl)biphenyl), CDBP (4,4'-bis(carbazol-9-yl)-2,2'-dimethylbiphenyl), 2-(9-phenylcarbazol-3-yl)-9-[4-(4-phenylphenylquinazolin-2-yl)carbazole, 9,10-bis(biphenyl)anthracene, and the like.

Examples of fluorescent dopants include anthracene, pyrene, tetracene, xanthene, perylene, rubrene, coumarin, rhodamine, quinacridone, dicyanomethylenepyran compounds, thiopyran compounds, polymethine compounds, pyrylium, thiapyrylium compounds, fluorene derivatives, periflanthene derivatives, indenoperylene derivatives, bis(azinyl)amine boron compounds, bis(azinyl)methane compounds, carbostyril compounds, and the like. The fluorescent dopant may be a combination of two or more selected from these.

Examples of phosphorescent dopants include organometallic complexes of transition metals such as iridium, platinum, palladium, and osmium.

Specific examples of fluorescent and phosphorescent dopants include Alq3 (tris(8-hydroxyquinoline)aluminum), DPAVBi (4,4'-bis[4-(di-p-tolylamino)styryl]biphenyl), perylene, bis[2-(4-n-hexylphenyl)quinoline](acetylacetonate)iridium(III), Ir(PPy)3 (tris(2-phenylpyridine)iridium(III)), and FIrPic (bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III))).

The light-emitting material is not limited to being contained only in the light-emitting layer. For example, the light-emitting material may be contained in a layer adjacent to the light-emitting layer (hole transport layer 4 or electron transport layer 6). This can further increase the current efficiency of the organic electroluminescent device.

The light-emitting layer may be a single layer structure made of one or more materials, or a laminate structure made of multiple layers of the same or different compositions.

[Electron transport layer 6]
An electron transport layer 6 is provided between the light emitting layer 5 and an electron injection layer 7 described below.
The electron transport layer has a function of transporting electrons injected from the cathode to the light emitting layer. By interposing the electron transport layer between the cathode and the light emitting layer, electrons are injected into the light emitting layer at a lower electric field.

As described above, the electron transport layer preferably contains the triazine compound (1). The electron transport layer may further contain, in addition to the triazine compound (1), one or more types selected from conventionally known electron transport materials.
In addition, when the triazine compound (1) is not contained in the electron transport layer but is contained in another layer, one or more types selected from conventionally known electron transport materials can be used as the electron transport material constituting the electron transport layer.

Conventionally known electron transport materials include alkali metal complexes, alkaline earth metal complexes, and earth metal complexes. Examples of alkali metal complexes, alkaline earth metal complexes, and earth metal complexes include 8-hydroxyquinolinato lithium (Liq), bis(8-hydroxyquinolinato) zinc, bis(8-hydroxyquinolinato) copper, bis(8-hydroxyquinolinato) manganese, tris(8-hydroxyquinolinato) aluminum, tris(2-methyl-8-hydroxyquinolinato) aluminum, and tris(8-hydroxyquinolinato) gallium. bis(10-hydroxybenzo[h]quinolinato) beryllium, bis(10-hydroxybenzo[h]quinolinato) zinc, bis(2-methyl-8-quinolinato) chlorogallium, bis(2-methyl-8-quinolinato) (o-cresolate) gallium, bis(2-methyl-8-quinolinato)-1-naphtholate aluminum, bis(2-methyl-8-quinolinato)-2-naphtholate gallium, etc.

The electron transport layer may have a single layer structure made of one or more materials, or a laminate structure made of multiple layers of the same composition or different compositions.
In the organic electroluminescent device according to this embodiment, an electron injection layer may be provided for the purpose of improving the electron injection property and improving the device characteristics (for example, luminous efficiency, constant voltage driving, or high durability).

[Electron injection layer 7]
An electron injection layer 7 is provided between the electron transport layer 6 and a cathode 8 which will be described later.
The electron injection layer has a function of transferring electrons injected from the cathode to the light-emitting layer. By interposing the electron injection layer between the cathode and the light-emitting layer, electrons are injected into the light-emitting layer at a lower electric field.

Examples of materials for the electron injection layer include organic compounds such as fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenylidene methane, anthraquinodimethane, anthrone, etc. Examples of materials for the electron injection layer include inorganic compounds such as various oxides, nitrides, and oxynitrides, such as _SiO2 , AlO, SiN, SiON, AlON, GeO, LiO, LiON, TiO, TiON, TaO, TaON, TaN, and C.

[Cathode 8]
A cathode 8 is provided on the electron injection layer 7 .
In the case of an organic electroluminescence element having a configuration in which only light emitted through the anode is extracted, the cathode can be formed from any conductive material.

Examples of materials for the cathode include metals with a low work function (hereinafter also referred to as electron injecting metals), alloys, electrically conductive compounds, and mixtures thereof. Here, the metals with a low work function are, for example, metals with a work function of 4 eV or less.
Specific examples of cathode materials include sodium, sodium-potassium alloys, magnesium, lithium, magnesium/copper mixtures, magnesium/silver mixtures, magnesium/aluminum mixtures, magnesium/indium mixtures, aluminum/aluminum oxide (Al ₂ O ₃ ) mixtures, indium, lithium/aluminum mixtures, rare earth metals, and the like.
Among these, from the viewpoints of electron injectability and durability against oxidation, etc., preferred are mixtures of an electron injecting metal and a second metal which has a larger and more stable work function than the electron injecting metal, such as a magnesium/silver mixture, a magnesium/aluminum mixture, _a magnesium/indium mixture, an aluminum/aluminum oxide ( _Al2O3 ) mixture, and a lithium/aluminum mixture.

[Method of forming each layer]
Each layer except for the electrodes (anode, cathode) described above can be formed by forming a thin film by a known method such as vacuum deposition, spin coating, casting, LB (Langmuir-Blodgett) method, etc. The material for each layer may be used alone or, if necessary, together with a material such as a binder resin or a solvent.
There is no particular limitation on the thickness of each layer thus formed, and it can be appropriately selected depending on the circumstances, but it is usually in the range of 5 nm to 5 μm.

The anode and the cathode can be formed by forming a thin film of an electrode material by a method such as vapor deposition, sputtering, etc. A pattern may be formed through a mask having a desired shape during vapor deposition or sputtering, or a pattern having a desired shape may be formed by photolithography after forming a thin film by vapor deposition, sputtering, etc.
The thickness of the anode and cathode is preferably 1 μm or less, and more preferably 10 nm or more and 200 nm or less.

The layer containing triazine compound (1) may be used in combination with the above-mentioned conventionally known electron transporting material. Thus, for example, triazine compound (1) and a conventionally known electron transporting material may be co-deposited, or a layer of a conventionally known electron transporting material may be laminated on a layer of triazine compound (1).

Organic electroluminescent elements may be used as a type of lamp for illumination or exposure light sources, as a projection device that projects images onto a screen, or as a display device that directly views still or moving images. When using organic electroluminescent elements as a display device for playing moving images, the driving method may be a simple matrix (passive matrix) method or an active matrix method. In addition, a full-color display device can be produced by using two or more types of organic electroluminescent elements that emit different light colors.

When used as an electron transport layer, triazine compound (1) can provide an organic electroluminescent device that is significantly superior in luminous efficiency and long life characteristics compared to conventionally known triazine compounds. Furthermore, triazine compound (1) has high amorphousness and high film quality stability due to its steric hindrance skeleton. Therefore, effects such as improved driving stability and improved luminous efficiency of organic electroluminescent devices are expected. Furthermore, triazine compound (1) has high chemical stability due to its characteristic skeleton, and can contribute to the long life of organic electroluminescent devices.

The triazine compound (1) can be used as an electron transport layer in an organic electroluminescent device to provide a triazine compound that can achieve low-voltage operation, high efficiency, and long life of the device to a high degree. Furthermore, it is possible to provide an organic electroluminescent device that can achieve low-voltage operation, high efficiency, and long life by using the triazine compound (1).

The present invention will be described in more detail below with reference to examples, but the present invention should not be construed as being limited in any way by these examples.

[ ¹ H-NMR measurement]
For ¹ H-NMR measurements, a Bruker ASCEND 400 (400 MHz; manufactured by BRUKER) was used. ¹ H-NMR was performed using deuterated chloroform (CDCl ₃ ) as the measurement solvent and tetramethylsilane (TMS) as the internal standard. The measurements were performed using commercially available reagents.

[Measurement of luminescence characteristics]
The light emitting characteristics of the organic electroluminescent device were evaluated by applying a direct current to the device prepared in each Example (described later) in a 25° C. environment using a luminance meter BM-9 (product name, manufactured by Topcon Technohouse).

Synthesis Example-A

Under a nitrogen atmosphere, 6-chloro-2-(4-tert-butylphenyl)quinoline (4.43 g, 15.0 mmol), bis(pinacolato)diboron (4.57 g, 18.0 mmol), palladium acetate (33.68 mg, 0.15 mmol), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (143.02 mg, 0.30 mmol), and potassium acetate (4.42 g, 45.0 mmol) were suspended in tetrahydrofuran (50 mL) and stirred for 2 hours at 70° C. After cooling to room temperature, the solid content was removed by filtration through Celite, and the solvent was distilled off. This crude product was further suspended in hexane and collected by filtration to obtain a white solid, 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane)-2-(4-tertiarybutylphenyl)quinoline (5.03 g, 86.5%).
The compounds were identified by FDMS measurement.
FDMS: 387

Synthesis Example 1

Under a nitrogen atmosphere, 2,4-diphenyl-6-(4'-bromobiphenyl-4-yl)-1,3,5-triazine (2.1 g, 4.6 mmol), 2-phenyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)quinoline (1.6 g, 5.1 mmol), tetrakis(triphenylphosphine)palladium(0) (53.8 g, 0.05 mmol), and 1M potassium phosphate aqueous solution (14 mL) were suspended in tetrahydrofuran (100 mL) and stirred at 70°C for 16 hours. After cooling to room temperature, the reaction mixture was filtered and washed with water and methanol. The obtained solid was suspended in toluene (250 mL) and stirred at 100° C. for a while, and then the obtained solution was allowed to cool to room temperature. The precipitated solid was collected by filtration to obtain the target product, 6-[4'-(2-phenyl-6-quinolyl)biphenyl-4-yl]-2,4-diphenyl-1,3,5-triazine, as a white solid (yield: 2.36 g, 87.1%).
The compounds were identified by FDMS measurement.
FDMS: 588

Synthesis Example 2

Under a nitrogen atmosphere, 2,4-diphenyl-6-(4'-bromobiphenyl-4-yl)-1,3,5-triazine (4.64 g, 10.0 mmol), 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane)-2-(4-tertiarybutylphenyl)quinoline (4.26 g, 11.0 mmol), tetrakis(triphenylphosphine)palladium(0) (115.6 g, 0.1 mmol), and 1M potassium phosphate aqueous solution (30 mL) were suspended in tetrahydrofuran (200 mL) and stirred at 70°C for 16 hours. After cooling to room temperature, the reaction mixture was filtered and washed with water and methanol. The obtained solid was suspended in toluene (1600 mL) and stirred at 100° C. for a while, and then the obtained solution was allowed to cool to room temperature. The precipitated solid was collected by filtration to obtain the target product, -6-[4'-(2-phenyl-6-quinolyl)biphenyl-4-yl]-2,4-diphenyl-1,3,5-triazine, as a white solid (yield: 4.92 g, 76.3%).
The compounds were identified by FDMS measurement.
FDMS: 644

Synthesis Example 3

Under a nitrogen atmosphere, 2,4-bis(4-biphenylyl)-6-(3'-chlorobiphenyl-3-yl)-1,3,5-triazine (3.43 g, 6.0 mmol), 2-phenyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)quinoline (3.00 g, 9.0 mmol), palladium acetate (13.5 mg, 0.06 mmol), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (57.2 mg, 0.12 mmol), and 1M potassium phosphate aqueous solution (18 mL) were suspended in tetrahydrofuran (120 mL) and stirred at 70° C. for 16 hours. After cooling to room temperature, the reaction mixture was filtered and washed with water and methanol. The obtained solid was suspended in toluene (1000 mL) and stirred at 100° C. for a while, and then the obtained solution was allowed to cool to room temperature, and the precipitated solid was collected by filtration to obtain the target product, 2,4-bis(4-biphenylyl)-6-[3'-(2-phenyl-6-quinolyl)biphenyl-3-yl]-1,3,5-triazine as a white solid (yield: 4.05 g, yield: 91.0%).
The compounds were identified by FDMS measurement.
FDMS: 740

Reference Example 1

The compound described in Synthesis Example 5 of Korean Patent Registration No. 1566584, 2-(2,4-diphenylquinolin-6-yl)-4,6-di-1-naphthalenyl-1,3,5-triazine (ETL-1), was synthesized.
The compounds were identified by FDMS measurement.
FDMS: 612

Next, the obtained compound was used to carry out element evaluation.
Element Example 1 (see FIG. 2)
(Preparation of Substrate 1 and Anode 2)
A glass substrate with an indium tin oxide (ITO) transparent electrode, on which a 2 mm wide ITO film (thickness: 110 nm) was patterned in a stripe shape, was prepared as the substrate 1 having an anode 2 on its surface. Next, this substrate was washed with isopropyl alcohol, and then subjected to surface treatment by ozone ultraviolet cleaning.

(Preparation for vacuum deposition)
After cleaning and surface treatment, each layer was deposited by vacuum deposition on the substrate by vacuum deposition, so that each layer was laminated.
First, the glass substrate was placed in a vacuum deposition chamber, and the pressure was reduced to 1.0×10 ⁻⁴ Pa. Then, each layer was produced according to the film-forming conditions in the following order. Each organic material was formed by a resistance heating method.

(Fabrication of Hole Injection Layer 3)
Sublimation purified N-[1,1'-biphenyl]-4-yl-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluoren-2-amine and 1,2,3-tris[(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane were mixed in a ratio of 99:1 (mass ratio) to form a 10 nm film, to produce hole injection 3. The film formation rate was 0.1 nm/sec.

(Preparation of First Hole Transport Layer 41)
Sublimation purified N-[1,1′-biphenyl]-4-yl-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluoren-2-amine was formed into a film of 85 nm at a rate of 0.2 nm/sec to prepare a first hole transport layer 41 .

(Preparation of second hole transport layer 42)
Sublimation-purified N-phenyl-N-(9,9-diphenylfluoren-2-yl)-N-(1,1′-biphenyl-4-yl)amine was formed into a film having a thickness of 5 nm at a rate of 0.15 nm/sec to prepare a second hole transport layer 42 .

(Preparation of Light-Emitting Layer 5)
Sublimation-purified 3-(10-phenyl-9-anthryl)-dibenzofuran and 2,7-bis[N,N-di-(4-tertbutylphenyl)]amino-bisbenzofurano-9,9′-spirofluorene were mixed in a ratio of 95:5 (mass ratio) to form a film of 20 nm, thereby producing the light-emitting layer 5. The film formation rate was 0.1 nm/sec.

(Preparation of Hole Blocking Layer 9)
Sublimation-purified 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)[1,1'-biphenyl]-3-yl]-4,6-diphenyl-1,3,5-triazine was formed into a film having a thickness of 6 nm at a rate of 0.05 nm/sec to prepare a hole blocking layer 9 .

(Preparation of Electron Transport Layer 6)
A film of 25 nm was formed using 6-[4'-(2-phenyl-6-quinolyl)biphenyl-4-yl]-2,4-diphenyl-1,3,5-triazine (compound A-81) synthesized in Synthesis Example 1 and lithium 8-hydroxyquinolinolato (hereinafter, Liq) in a ratio of 50:50 (mass ratio) to prepare an electron transport layer 6. The film formation rate was 0.15 nm/sec.

(Fabrication of Electron Injection Layer 7)
Liq was deposited at a rate of 0.02 nm/sec to a thickness of 1 nm to form an electron injection layer 7 .

(Preparation of Cathode 8)
Finally, a metal mask was placed so as to be perpendicular to the ITO stripes (anode 2) on the substrate 1, and a cathode 8 was formed. The cathode had a two-layer structure in which silver/magnesium (mass ratio 1/10) and silver were formed in this order to thicknesses of 80 nm and 20 nm, respectively. The film formation rate of silver/magnesium was 0.5 nm/sec, and the film formation rate of silver was 0.2 nm/sec.

In this manner, an organic electroluminescent device 100 having a light-emitting area of 4 ^mm2 was produced as shown in Fig. 2. The thickness of each film was measured using a stylus film thickness gauge (DEKTAK, manufactured by Bruker).

The device was then sealed in a nitrogen atmosphere glove box with oxygen and moisture concentrations of 1 ppm or less. The glass sealing cap and the film-formed substrate (device) were sealed using bisphenol F epoxy resin (manufactured by Nagase ChemteX Corporation).

Element Example 2
An organic electroluminescent device was produced in the same manner as in Element Example-1, except that in Element Example-1, 2,4-bis(4-biphenylyl)-6-[3'-(2-phenyl-6-quinolyl)biphenyl-3-yl]-1,3,5-triazine (compound B-51) synthesized in Synthesis Example-3 and Liq were used in place of the compound A-81 and Liq in a ratio of 50:50 (mass ratio) used in the electron transport layer 6.

Element Reference Example 1
An organic electroluminescent device was produced in the same manner as in Element Example-1, except that in Element Example-1, ETL-1 synthesized in Reference Example-1 and Liq were used in a ratio of 50:50 (mass ratio) in the electron transport layer 6 instead of Compound A-81 and Liq in a ratio of 50:50 (mass ratio).

A direct current was applied to the produced organic electroluminescent device, and the light-emitting characteristics were evaluated according to the method described in the above-mentioned measurement of light-emitting characteristics.
As the luminous characteristics, the voltage (V) and power efficiency (lm/A) when a current density of 10 mA/ ^cm2 was applied were measured, and the element life during continuous lighting was measured. The element life was measured by measuring the luminance decay time during continuous lighting when driven at an initial luminance of 1000 cd/ ^m2 , and measuring the time required for the luminance (cd/ ^m2 ) to decrease by 10%. The values of voltage (V), current efficiency (lm/A; luminous efficiency) and element life were expressed as relative values when the element reference example-1 was set to 100. The results are shown in Table 1.

From Table 1, it was found that the organic electroluminescent device using triazine compound (1) is highly superior in terms of voltage, luminous efficiency, and device life, compared to the reference example.

1. Substrate 2. Anode 3. Hole injection layer 4. Hole transport layer 5. Light emitting layer 6. Electron transport layer 7. Electron injection layer 8. Cathode 9. Hole blocking layer 51. First hole transport layer 52. Second hole transport layer 100. Organic electroluminescent device

Claims (11)

Triazine compound represented by formula (1):
In the formula,
Ar ¹ and Ar ² each independently represent a phenyl group, a biphenylyl group, a terphenylyl group, a naphthyl group, a dibenzofuranyl group, or a dibenzothienyl group;
^Ar3 is
a monocyclic, linked or fused ring aromatic hydrocarbon group having 6 to 60 carbon atoms,
A pyridyl group, a diazaphenyl group, a benzo[b]quinolyl group, a benzo[c]quinolyl group, a benzo[f]quinolyl group, a benzo[g]quinolyl group, a benzo[h]quinolyl group, a phenazinyl group, an azapyrenyl group, a diazapyrenyl group, an azatriphenylenyl group, a diazatriphenylenyl group,
Or,
represents a monocyclic, linked or fused ring heteroaromatic group having 6 to 60 carbon atoms, in which the heteroatom is a Group 16 element;
L ¹ , L ² , L ³ and L ⁴ each independently represent a phenylene group, a naphthylene group, a pyridylene group, a diazaphenylene group, a dibenzofuranyl group, a dibenzothienyl group, or a fluorenyl group;
a, b and c each independently represent 0 or 1;
R represents a hydrogen atom, a methyl group, a phenyl group, or a pyridyl group;
Ar ¹ to Ar ³ , L ¹ to L ⁴ and R may each independently be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, a tertiary butyl group, a methoxy group, a phenyl group, a naphthyl group and a pyridyl group. The triazine compound according to claim 1, wherein R is a hydrogen atom. 3. The triazine compound according to claim 1, wherein Ar ¹ and Ar ² each independently represent an unsubstituted phenyl group, biphenylyl group, or naphthyl group. The triazine compound according to any one of claims 1 to 3, wherein Ar ¹ and Ar ² are the same group. The triazine compound according to any one of claims 1 to 4, wherein ^Ar3 is a phenyl group, a biphenyl group, a pyridyl group, a naphthyl group, a phenanthryl group, a fluorenyl group, a benzofluorenyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzothienyl group, or a dibenzofuranyl group, which may be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group, a tertiary butyl group, a methoxy group, a phenyl group, a naphthyl group, and a pyridyl group. The triazine compound according to any one of claims 1 to 5, wherein ^Ar3 is a phenyl group, a methylphenyl group, a dimethylphenyl group, a trimethylphenyl group, a tertiary butylphenyl group, a ditertiary butylphenyl group, a pyridyl group, a methylpyridyl group, a dimethylpyridyl group, a phenylpyridyl group, a diphenylpyridyl group, a naphthyl group, a phenanthryl group, a fluorenyl group, a benzofluorenyl group, a dibenzothienyl group, or a dibenzofuranyl group. The triazine compound according to any one of claims 1 to 6, wherein ^L1 , ^L2 and ^L3 each independently represent an unsubstituted phenylene group, naphthylene group, pyridylene group, diazaphenylene group, dibenzofuranyl group, dibenzothienyl group or fluorenyl group. 8. The triazine compound according to claim 1, wherein ^L1 , ^L2 and ^L3 each independently represent an unsubstituted phenylene group, naphthylene group, pyridylene group, diazaphenylene group or fluorenyl group. The triazine compound according to any one of claims 1 to 8, wherein ^L4 is an unsubstituted phenylene group, naphthylene group, pyridylene group, diazaphenylene group, fluorenyl group, dibenzofuranyl group, or dibenzothienyl group. The triazine compound according to any one of claims 1 to 9, wherein ^L4 is an unsubstituted phenylene group, naphthylene group, pyridylene group, dibenzofuranyl group, or dibenzothienyl group. A material for an organic electroluminescent device, comprising the triazine compound according to any one of claims 1 to 10.

Images