Triazine compounds having a dipyridylphenyl group

Abstract

To provide a triazine compound that contributes to forming an organic electroluminescent device having excellent drive voltage, luminous efficiency, and service life, and to provide an organic electroluminescent device having excellent drive voltage, luminous efficiency, and service life.SOLUTION: The present invention provides a triazine compound represented by the formula (1).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a triazine compound, a material for an organic electroluminescent device, and an organic electroluminescent device. [Background technology]

[0002] Organic electroluminescent devices have begun to be put to practical use, primarily in small mobile devices. However, further expansion of their range of applications requires improved performance, and improvements in device characteristics such as driving voltage characteristics, luminous efficiency characteristics, and lifetime characteristics are required. Patent Document 1 discloses a triazine derivative that is a material used in organic electroluminescent devices with long life and excellent luminous efficiency characteristics. Patent Document 2 discloses a triazine derivative having a pyridyl group that is a material that can contribute to improving device characteristics such as driving voltage characteristics or luminous efficiency characteristics. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-314503 [Patent Document 2] Korean Patent No. 101666751B1 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the triazine derivatives disclosed in Patent Documents 1 and 2 do not sufficiently satisfy the three characteristics of organic electroluminescent elements, i.e., driving voltage characteristics, luminous efficiency characteristics, and lifetime characteristics, which are required for expanding the range of applications, and there is a demand for materials that achieve these three characteristics at an even higher level. In particular, in order to reduce power consumption during use of organic electroluminescent elements, there is a demand for materials for organic electroluminescent elements that provide element characteristics superior to known materials in the two characteristics of luminous efficiency characteristics and lifetime characteristics.

[0005] Therefore, one aspect of the present invention is to provide a triazine compound having a partial structure that contributes to improving electron transport ability, which contributes to the formation of an organic electroluminescent device that is excellent in driving voltage characteristics, luminous efficiency characteristics, and life characteristics. Furthermore, another aspect of the present invention is to provide an organic electroluminescent device that exhibits excellent driving voltage characteristics, luminous efficiency characteristics, and life characteristics. [Means for solving the problem]

[0006] As a result of extensive research to solve the above problems, the present inventors have found that the use of a triazine compound having a partial structure containing a dipyridylphenyl group introduced via a divalent aromatic group as an electron transport layer of an organic electroluminescent element significantly improves the driving voltage characteristics, luminous efficiency characteristics, and life characteristics of the organic electroluminescent element, and have thus completed the present invention.

[0007] The gist of the present invention is as follows. That is, the present invention is (A) a triazine compound represented by the following formula (1):

[0008] [ka] (In formula (1), Ar 1 and Ar 2 each independently represents an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a heteroaromatic group having 4 to 17 carbon atoms, which contains a 6-membered ring consisting of C, H, and N, but does not contain a 5-membered ring consisting of C, H, and N. The aromatic hydrocarbon group and the heteroaromatic group each consist of a single ring or condensed ring, or a linked ring formed by linking any ring selected from these rings, and may be substituted with one or more cyano groups or methyl groups. L represents a divalent six-membered ring aromatic hydrocarbon group or a divalent six-membered ring nitrogen-containing aromatic group. n represents an integer of 1 to 4, provided that when n is 1, L does not represent paraphenylene, and when n is 2, 3, or 4, L may be different from each other. Py 1 and Py 2each independently represents a pyridyl group which may be substituted with one or two groups selected from the group consisting of a methyl group, a cyano group, a phenyl group, a biphenylyl group, a naphthyl group, a phenanthrenyl group, and a pyridyl group.

[0009] (ii) a material for organic electroluminescent devices containing the triazine compound described in (i) above; and, (c) an organic electroluminescent device containing the triazine compound described in (a) above; It is related to. [Effects of the Invention]

[0010] According to one aspect of the present invention, a triazine compound can be provided that contributes to the formation of an organic electroluminescent device that exhibits high levels of driving voltage characteristics, luminous efficiency characteristics, and lifespan characteristics. According to another aspect of the present invention, a material for an organic electroluminescent device containing the triazine compound can be provided. Furthermore, according to yet another aspect of the present invention, an organic electroluminescent device that exhibits high levels of driving voltage characteristics, luminous efficiency characteristics, and lifespan characteristics and can be used for various applications can be provided. [Brief explanation of the drawings]

[0011] [Figure 1] 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 invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing another example of a laminated structure of an organic electroluminescence element according to one embodiment of the present invention (structure of element example 1). DETAILED DESCRIPTION OF THE INVENTION

[0012] The triazine compound according to one embodiment of the present invention will be described in detail below.

[0013] <Triazine compounds> A triazine compound according to one embodiment of the present invention is a triazine compound represented by formula (1).

[0014] [ka]

[0015] In the formula, Ar 1 and Ar 2 each independently represents an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a heteroaromatic group having 4 to 17 carbon atoms, which contains a 6-membered ring consisting of C, H, and N, but does not contain a 5-membered ring consisting of C, H, and N. The aromatic hydrocarbon group and the heteroaromatic group each consist of a single ring or condensed ring, or a linked ring formed by linking any ring selected from these rings, and may be substituted with one or more cyano groups or methyl groups. L represents a divalent six-membered ring aromatic hydrocarbon group or a divalent six-membered ring nitrogen-containing aromatic group. n represents an integer of 1 to 4, provided that when n is 1, L does not represent paraphenylene, and when n is 2, 3, or 4, L may be different from each other. Py 1 and Py 2 each independently represents a pyridyl group which may be substituted with one or two groups selected from the group consisting of a methyl group, a cyano group, a phenyl group, a biphenylyl group, a naphthyl group, a phenanthrenyl group, and a pyridyl group. Hereinafter, the triazine compound according to one embodiment of the present invention represented by formula (1) may be referred to as triazine compound (1). The definition of the substituent in triazine compound (1) and preferred specific examples thereof will be described in detail below.

[0016] [Ar 1 , Ar 2 About Ar 1 and Ar 2each independently represents an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a heteroaromatic group having 4 to 17 carbon atoms, which contains a 6-membered ring consisting of C, H, and N, but does not contain a 5-membered ring consisting of C, H, and N. The aromatic hydrocarbon group and the heteroaromatic group each consist of a single ring or condensed ring, or a linked ring formed by linking any ring selected from these rings, and may be substituted with one or more cyano groups or methyl groups. As mentioned above, Ar 1 and Ar 2 Examples of the group that Ar may take include aromatic hydrocarbon groups having 6 to 18 carbon atoms which may be substituted with a cyano group or a methyl group. Here, the aromatic hydrocarbon group may be in the form of a single ring, a condensed ring, or a linked ring. 1 and Ar 2 Possible groups include heteroaromatic groups having 4 to 17 carbon atoms, which may be substituted with a cyano group or a methyl group. The heteroaromatic group contains a 6-membered ring consisting of C, H, and N, but does not contain a 5-membered ring consisting of C, H, and N. The heteroaromatic group may be a 6-membered ring consisting of C, H, and N, or a fused ring containing the 6-membered ring. Furthermore, the heteroaromatic group may be a linked ring formed by linking any ring selected from a 6-membered ring consisting of C, H, and N, or a fused ring containing the 6-membered ring. The linked ring of the heteroaromatic group also includes a ring formed by linking a ring of the heteroaromatic group and a ring of an aromatic hydrocarbon group.

[0017] Ar 1 and Ar 2Examples of the alkyl group include a phenyl 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 3-[1:1',4':1'']terphenyl group, a 4-[1:1',4':1'']terphenyl group, a 3'-cyanobiphenyl-2-yl group, a 3'-cyanobiphenyl-3-yl group, a 3'-cyanobiphenyl-4-yl group, a 4'-cyanobiphenyl-2-yl group, a 4'-cyanobiphenyl-3-yl group, a 4'-cyanobiphenyl-4-yl group, a -yl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 3,5-dimethylphenyl group, 2-(1-naphthyl)phenyl group, 3-(1-naphthyl)phenyl group, 4-(1-naphthyl)phenyl group, 2-(2-naphthyl)phenyl group, 3-(2-naphthyl)phenyl group, 4-(2-naphthyl)phenyl group, 2-cyanophenyl group, 3-cyanophenyl group, 4-cyanophenyl group, 3,5-dicyanophenyl group, 2-pyridyl group, 3-pyridyl group, 4-pyridyl group methylpyridinyl group, 2-pyrimidyl group, 4-pyrimidyl group, 5-pyrimidyl group, 2-pyrazyl group, 3-methylpyridin-2-yl group, 4-methylpyridin-2-yl group, 5-methylpyridin-2-yl group, 6-methylpyridin-2-yl group, 2-methylpyridin-3-yl group, 4-methylpyridin-3-yl group, 5-methylpyridin-3-yl group, 6-methylpyridin-3-yl group, 2-methylpyridin-4-yl group, 3-methylpyridin-4-yl group, 2,6-dimethylpyridin-3-yl group , a 2,4-dimethylpyridin-3-yl group, a 2,5-dimethylpyridin-3-yl group, a 3-phenylpyridin-2-yl group, a 4-phenylpyridin-2-yl group, a 5-phenylpyridin-2-yl group, a 6-phenylpyridin-2-yl group, a 2-phenylpyridin-3-yl group, a 4-phenylpyridin-3-yl group, a 5-phenylpyridin-3-yl group, a 6-phenylpyridin-3-yl group, a 2-phenylpyridin-4-yl group, a 3-phenylpyridin-4-yl group, and the like.

[0018] The triazine compound (1) has excellent properties as an electron transport material, and therefore, Ar 1 and Ar 2is preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms which may be modified with one cyano group or one methyl group, more preferably a phenyl group, naphthyl group, or biphenylyl group which may be modified with one cyano group or one methyl group, in that triazine compound (1) has excellent mobility, and even more preferably a phenyl group or a biphenylyl group in that triazine compound (1) can be easily adapted to a vapor deposition process.

[0019] Triazine compound (1) Ar 1 and Ar 2 is a heteroaromatic group having 4 to 17 carbon atoms which may be substituted with a cyano group or a methyl group, in terms of excellent properties as an electron transport material, it is preferably a pyridyl group, a methylpyridyl group, a dimethylpyridyl group, a cyanopyridyl group, a pyrazyl group, a pyrimidyl group, a methylpyrimidyl group, a dimethylpyrimidyl group, a quinolyl group, a methylquinolyl group, an isoquinolyl group, a methylisoquinolyl group, an acridyl group, a phenanthridyl group, a benzoquinolyl group, or a benzoisoquinolyl group, in terms of ease of synthesis.

[0020] [Py 1 , Py 2 About Py 1 and Py 2 each independently represents a pyridyl group which may be substituted with one or two groups selected from the group consisting of a methyl group, a cyano group, a phenyl group, a biphenylyl group, a naphthyl group, a phenanthrenyl group, and a pyridyl group.

[0021] Py 1 and Py 2Examples of the methylpyridin-4-yl group include a 2-pyridyl group, a 3-pyridyl group, a 4-pyridyl group, a 3-methylpyridin-2-yl group, a 4-methylpyridin-2-yl group, a 5-methylpyridin-2-yl group, a 6-methylpyridin-2-yl group, a 2-methylpyridin-3-yl group, a 4-methylpyridin-3-yl group, a 5-methylpyridin-3-yl group, a 6-methylpyridin-3-yl group, a 2-methylpyridin-4-yl group, a 3-methylpyridin-4-yl group, a 2,6-dimethylpyridin-3-yl group, a 2,4-dimethylpyridin-3-yl group, and a 2,5-dimethylpyridin-3-yl group. group, 3-cyanopyridin-2-yl group, 4-cyanopyridin-2-yl group, 5-cyanopyridin-2-yl group, 6-cyanopyridin-2-yl group, 2-cyanopyridin-3-yl group, 4-cyanopyridin-3-yl group, 5-cyanopyridin-3-yl group, 6-cyanopyridin-3-yl group, 2-cyanopyridin-4-yl group, 3-cyanopyridin-4-yl group, 2,6-dicyanopyridin-3-yl group, 2,4-dicyanopyridin-3-yl group, 2,5-dicyanopyridin-3-yl group, 3-phenylpyridin-2-yl group, 4-phenylpyridine -2-yl group, 5-phenylpyridin-2-yl group, 6-phenylpyridin-2-yl group, 2-phenylpyridin-3-yl group, 4-phenylpyridin-3-yl group, 5-phenylpyridin-3-yl group, 6-phenylpyridin-3-yl group, 2-phenylpyridin-4-yl group, 3-phenylpyridin-4-yl group, 3-(biphenyl-2-yl)pyridin-2-yl group, 4-(biphenyl-2-yl)pyridin-2-yl group, 5-(biphenyl-2-yl)pyridin-2-yl group, 6-(biphenyl-2-yl)pyridin-2-yl group, 2-( (biphenyl-2-yl)pyridin-3-yl group, 4-(biphenyl-2-yl)pyridin-3-yl group, 5-(biphenyl-2-yl)pyridin-3-yl group, 6-(biphenyl-2-yl)pyridin-3-yl group, 2-(biphenyl-2-yl)pyridin-4-yl group, 3-(biphenyl-2-yl)pyridin-4-yl group, 3-(biphenyl-3-yl)pyridin-2-yl group, 4-(biphenyl-3-yl)pyridin-2-yl group, 5-(biphenyl-3-yl)pyridin-2-yl group, 6-(biphenyl-3-yl)pyridin-2-yl group,2-(biphenyl-3-yl)pyridin-3-yl group, 4-(biphenyl-3-yl)pyridin-3-yl group, 5-(biphenyl-3-yl)pyridin-3-yl group, 6-(biphenyl-3-yl)pyridin-3-yl group, 2-(biphenyl-3-yl)pyridin-4-yl group, 3-(biphenyl-3-yl)pyridin-4-yl group, 3-(1-naphthyl)pyridin-2-yl group, 4-(1-naphthyl)pyridin-2-yl group, 5-(1-naphthyl)pyridin-2 -yl group, 6-(1-naphthyl)pyridin-2-yl group, 2-(1-naphthyl)pyridin-3-yl group, 4-(1-naphthyl)pyridin-3-yl group, 5-(1-naphthyl)pyridin-3-yl group, 6-(1-naphthyl)pyridin-3-yl group, 2-(1-naphthyl)pyridin-4-yl group, 3-(1-naphthyl)pyridin-4-yl group, 3-(2-naphthyl)pyridin-2-yl group, 4-(2-naphthyl)pyridin-2-yl group, 5-(2-naphthyl)pyridin -2-yl group, 6-(2-naphthyl)pyridin-2-yl group, 2-(2-naphthyl)pyridin-3-yl group, 4-(2-naphthyl)pyridin-3-yl group, 5-(2-naphthyl)pyridin-3-yl group, 6-(2-naphthyl)pyridin-3-yl group, 2-(2-naphthyl)pyridin-4-yl group, 3-(2-naphthyl)pyridin-4-yl group, 3-phenyl-4-methylpyridin-2-yl group, 4-phenyl-3-methylpyridin-2-yl group, 5-phenyl-4 3-methylpyridin-2-yl group, 5-phenyl-6-methylpyridin-2-yl group, 5-phenyl-6-methylpyridin-2-yl group, 3-(2-pyridyl)pyridin-2-yl group, 4-(2-pyridyl)pyridin-2-yl group, 5-(2-pyridyl)pyridin-2-yl group, 6-(2-pyridyl)pyridin-2-yl group, 4-phenyl-6-(2-pyridyl)pyridin-2-yl group, 6-phenyl-4-(2-pyridyl)pyridin-2-yl group, etc.

[0022] Py 1 and Py 2 may be different from each other, but Py is preferred in terms of ease of synthesis of the triazine compound (1). 1 and Py 2It is preferable that Py be the same as Py. 1 and Py 2 is preferably a pyridyl group optionally substituted with one methyl group, one cyano group, or one phenyl group, and is preferred in that it is easily applicable to the vapor deposition process. 1 and Py 2 is more preferably a 2-pyridyl group.

[0023] [About L] L represents a divalent 6-membered ring aromatic hydrocarbon group or a divalent 6-membered ring nitrogen-containing aromatic group, and n represents an integer of 1 to 4. However, when n is 1, L does not become paraphenylene.

[0024] Examples of L include an ortho-phenylene group, a meta-phenylene group, a para-phenylene group, a 2,3-pyridylene group, a 2,4-pyridylene group, a 2,5-pyridylene group, a 2,6-pyridylene group, a 3,4-pyridylene group, a 3,5-pyridylene group, a 2,3-pyrazylene group, a 2,5-pyrazylene group, a 2,6-pyrazylene group, a 2,4-pyrimidylene group, a 2,5-pyrimidylene group, a 4,5-pyrimidylene group, and a 4,6-pyrimidylene group. When n is 2, 3, or 4, L may be different from each other.

[0025] In terms of contributing to improving the properties of the triazine compound (1) as an electron transport material, L is preferably a phenylene group or a pyridylene group, and in terms of facilitating the synthesis of the triazine compound (1), L is more preferably a phenylene group.

[0026] n is preferably 1 or 2 in that the triazine compound (1) has a high glass transition temperature. When n is 1 and L is a phenylene group, L is not a paraphenylene group but a metaphenylene group or an orthophenylene group. Thus, when n is 1 and L is a phenylene group, by excluding the paraphenylene group and limiting it to a metaphenylene group or an orthophenylene group, it is possible to provide a triazine compound that contributes to the formation of an organic electroluminescent device that can achieve higher levels of the three properties of driving voltage characteristics, luminous efficiency characteristics, and life characteristics. When L is a metaphenylene group or an orthophenylene group, better results are obtained than with a paraphenylene group. It is believed that this is because metaphenylene and orthophenylene have a higher LUMO level than paraphenylene, thereby reducing the energy barrier to the light-emitting layer.

[0027] [Specific examples of triazine compound (1)] Specific examples of the triazine compound (1) include the following (A-1) to (A-144), but the present invention is not limited to these.

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031] [ka]

[0032] [ka]

[0033] [ka]

[0034] [ka]

[0035] [ka]

[0036] [ka]

[0037] [ka]

[0038] [ka]

[0039] As the triazine compound, the compounds represented by A-37, A-58, A-73, or A-133 are preferred because they have good performance as an electron transport material in an organic electroluminescent device.

[0040] <Method for producing triazine compounds> Next, a method for producing a triazine compound (1) according to another embodiment of the present invention (hereinafter referred to as a method for producing a triazine compound (1)) will be described.

[0041] The triazine compound (1) can be produced by the methods shown in the following synthetic routes (I) to (VI). [Synthetic Route (I)]

[0042] [ka] [Synthetic Route (II)]

[0043] [ka] [Synthetic Route (III)]

[0044] [ka] [Synthetic Route (IV)]

[0045] [ka] [Synthetic Route (V)]

[0046] [ka] [Synthetic Route (VI)]

[0047] [ka]

[0048] In the formulas (1) to (13), the meanings of the symbols are as follows: Ar 1 , Ar 2 ,L,n,Py 1 , and Py 2 The definition of Ar in formula (1) 1 , Ar 2 ,L,n,Py 1 , and Py 2 is the same as the definition of X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , and X 7 represents a chlorine atom, a bromine atom, a trifluoromethanesulfonyloxy group, or an iodine atom. M 1 , M 2 , M 3 , M4 , M 5 , M 6 , and M 7 ZnY 1 , MgY 2 , Sn(Y 3 )3 or 2 (OY 4 ) groups may together form a ring with the boron atom; 4 )2. Y 1 and Y 2 each independently represents a chlorine atom, a bromine atom, or an iodine atom. Y 3 each independently represents an alkyl group having 1 to 4 carbon atoms or a phenyl group. Y 4 Each of (OY) independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group. 4 ) groups may be taken together to form a ring with the boron atom.

[0049] The coupling reactions in synthetic pathways (I) to (VI) are methods in which an aryl halide compound represented by formula (2), (5), (6), (9), (10), or (13) is reacted with a boron compound or organometallic compound represented by formula (3), (4), (7), (8), (11), or (12) in the presence of a palladium catalyst, and reaction conditions for general cross-coupling reactions such as the Suzuki-Miyaura reaction, Negishi reaction, Tamao-Kumada reaction, and Stille reaction can be applied.

[0050] The boron compound can be produced according to the method disclosed in, for example, JP 2011-063584 A, The Journal of Organic Chemistry, Vol. 60, p. 7508, 1995, or The Journal of Organic Chemistry, Vol. 65, p. 164, 2000. The organometallic compounds can be prepared, for example, according to the methods disclosed in Chemical Reviews, Vol. 93, p. 2117, 1993 or Angewante Chemie International Edition, Vol. 46, p. 5359, 2007.

[0051] The halogenated aryl compound can be produced, for example, according to the production method shown in Synthesis Reference Example 1 or 2, Patent Document 1 or 2, Journal of the American Chemical Society, Vol. 74, p. 6289, 1952, or Synlett, p. 808, 2002. Commercially available products may also be used. In terms of good reaction yield, the halogenated aryl compound is preferably used in an amount of 0.5 to 3.0 molar equivalents relative to the organometallic compound or boron compound.

[0052] Examples of palladium catalysts used in the coupling 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.

[0053] 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, and the like.

[0054] Among these, palladium complexes having a tertiary phosphine as a ligand are preferred in terms of good yield, and palladium complexes having 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl or tricyclohexylphosphine as a ligand are more preferred.

[0055] 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 limitation on the amount of the palladium catalyst used in the above-mentioned coupling 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 aryl halide compound.

[0056] The aforementioned coupling reaction can be carried out in a solvent.

[0057] 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-lanthate. Examples of suitable solvents include esters such as methacrylate; amides such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and N-methylpyrrolidone (NMP); ureas such as N,N,N',N'-tetramethylurea (TMU) and N,N'-dimethylpropyleneurea (DMPU); and alcohols such as dimethyl sulfoxide (DMSO), methanol, ethanol, isopropyl alcohol, butanol, octanol, benzyl alcohol, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, and 2,2,2-trifluoroethanol. These may be used alone or in any combination. There are no particular limitations on the amount of solvent used. Among these, water, ethers, amides, alcohols, and mixed solvents thereof are preferred due to their high reaction yield, and mixed solvents of THF and water or toluene and water are even more preferred.

[0058] The above-mentioned coupling 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.

[0059] After the completion of the above-mentioned coupling reaction, the target product can be obtained by appropriately combining, as necessary, common purification treatments such as recrystallization, column chromatography, sublimation purification, and preparative HPLC.

[0060] <Materials for organic electroluminescent devices> The material for organic electroluminescent devices according to one aspect of the present invention contains the triazine compound (1) described above. The triazine compound (1) can be used, for example, as a material for organic electroluminescent devices, particularly as an electron transport material for organic electroluminescent devices. The material for organic electroluminescent devices containing the triazine compound (1) contributes to the production of organic electroluminescent devices that can achieve high levels of luminous efficiency and lifespan.

[0061] <Organic electroluminescent device> The organic electroluminescent device according to one aspect of the present invention contains the triazine compound (1) described above. For example, an organic electroluminescent device can be formed using a material for organic electroluminescent devices containing the triazine compound (1). The material for organic electroluminescent devices containing the triazine compound (1) exhibits high luminous efficiency and low voltage characteristics, has a long life, and contributes to the fabrication of organic electroluminescent devices that can be used for various purposes or in various environments.

[0062] An organic electroluminescent device containing the triazine compound (1) (hereinafter, sometimes 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 / Emitting layer / Cathode (ii): Anode / hole transport layer / light-emitting layer / cathode (iii): Anode / 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

[0063] The triazine compound (1) may be contained in any of the above layers, but is preferably 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, in order to provide excellent light-emitting properties to the organic electroluminescent device. Therefore, in the case of the structures (i) to (v) above, the triazine compound (1) is preferably contained in one or more layers selected from the group consisting of the light-emitting layer, the electron-transporting layer, and the electron-injecting layer. At least one of the light-emitting layer, the electron-transporting layer and the electron-injecting layer is preferably formed using a material for organic electroluminescent devices containing the triazine compound (1).

[0064] 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 electroluminescent element according to one embodiment of the present invention is not limited to the bottom-emission type element configuration. That is, the organic electroluminescent element according to one embodiment of the present invention may have another known element configuration, such as a top-emission type.

[0065] FIG. 1 is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescent device according to one embodiment of the present invention.

[0066] The organic electroluminescent device 100 comprises, in this order, a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, an emitting layer 5, an electron transport layer 6, an electron injection layer 7, and a cathode 8. However, some of these layers may be omitted, or other layers may be added. For example, a hole blocking layer 9 may be provided between the 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. Alternatively, a single layer having the functions of multiple layers, such as an electron injection / transport layer that combines the functions of both an electron injection layer and an electron transport 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 composed of multiple layers.

[0067] <<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 the light-emitting layer 5, the electron transport layer 6, and the 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 multiple layers of 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.

[0068] [Board 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, and a plastic film. Among these, a glass plate, a quartz plate, and a light-transmitting plastic film are preferred. 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), etc. 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.

[0069] [Anode 2] An anode 2 is provided on the substrate 1 (on the hole injection layer 3 side). Examples of anode materials include metals, alloys, electrically conductive compounds, and mixtures thereof, each having a large work function (e.g., 4 eV or more). Specific examples of anode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO2, and ZnO. In the case of an organic electroluminescent device configured so that light is extracted through the anode, the anode is formed from a conductive transparent material that is transparent or substantially transparent to the light emitted.

[0070] [Hole injection layer 3, hole transport layer 4] Between the anode 2 and the 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.

[0071] 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 these 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.

[0072] The hole injection layer and the hole transport layer also function as electron barrier layers. That is, 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 electron barrier 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 accumulate at the interface within the light-emitting layer, resulting in effects such as improved light-emitting efficiency, and an organic electroluminescent device with excellent light-emitting performance can be obtained.

[0073] 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, and may be either organic or inorganic.

[0074] Specific examples of materials for the hole injection layer and the 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, styrylamine compounds, etc. Among these, porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred, in terms of good performance of organic electroluminescent devices.

[0075] Specific examples of aromatic tertiary amine compounds and styrylamine compounds include N,N,N',N'-tetraphenyl-4,4'-diaminobiphenyl, 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-diphenylaminostilbenzene, N-phenylcarbazole, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPD), 4,4',4''-tris[N-(m-tolyl)-N-phenylamino]triphenylamine (MTDATA), and the like.

[0076] Furthermore, inorganic compounds such as p-type Si and p-type SiC can also be given as examples of materials for the hole injection layer and the hole transport layer.

[0077] The hole injection layer and the hole transport layer may have a single structure made of one or more materials, or may have a laminate structure made of multiple layers of the same or different compositions.

[0078] [Emitting layer 5] The light-emitting layer 5 is provided between the hole transport layer 4 and the electron transport layer 6 described below. Materials for the light-emitting layer include phosphorescent materials, fluorescent materials, and thermally activated delayed fluorescent materials. In the light-emitting layer, electron-hole pairs recombine, resulting in light emission.

[0079] The light-emitting layer may consist of a single small molecule or polymer 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.

[0080] Examples of the host material include compounds having a biphenylyl group, a fluorenyl group, a triphenylsilyl group, a carbazole group, a pyrenyl group, and an anthryl group. More specific examples 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.

[0081] 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, etc. The fluorescent dopant may be a combination of two or more selected from these.

[0082] Examples of phosphorescent dopants include organometallic complexes of transition metals such as iridium, platinum, palladium, and osmium.

[0083] Specific examples of fluorescent dopants 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))).

[0084] Furthermore, 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.

[0085] The light-emitting layer may have a single layer structure made of one or more materials, or may have a laminate structure made of multiple layers of the same or different compositions.

[0086] [Electron transport layer 6] An electron transport layer 6 is provided between the light emitting layer 5 and the 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.

[0087] As described above, the electron transport layer preferably contains the triazine compound (1). In addition to the triazine compound (1), the electron transport layer may further contain one or more types selected from conventionally known electron transport materials. When the triazine compound (1) is not contained in the electron transport layer but is contained in another layer, one or more electron transport materials selected from conventionally known electron transport materials can be used as the electron transport material constituting the electron transport layer.

[0088] Conventionally known electron transporting materials include alkali metal complexes, alkaline earth metal complexes, earth metal complexes, etc. Examples of alkali metal complexes, alkaline earth metal complexes, and earth metal complexes include 8-hydroxyquinolinatolithium (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). Examples of suitable gallium compounds include 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-naphtholatealuminum, and bis(2-methyl-8-quinolinato)-2-naphtholategallium.

[0089] A preferred embodiment of the electron transport material for organic electroluminescent devices is a mixture of the triazine compound (1) and one or more electron transport materials selected from conventionally known electron transport materials. Among these, a more preferred embodiment is an electron transport material for organic electroluminescent devices, which is a mixture of triazine compound (1) and 8-hydroxyquinolinatolithium (Liq). When the electron transport material for organic electroluminescent elements is prepared by mixing the triazine compound (1) with a conventionally known electron transport material, the mixing ratio of the triazine compound (1) is, for example, 5 to 70 mass %, preferably 30 to 60 mass %, based on the electron transport material for organic electroluminescent elements.

[0090] The electron transport layer may have a single layer structure made of one or more materials, or may have a laminate structure made of multiple layers of the same or different compositions.

[0091] In the organic electroluminescent device according to this embodiment, an electron injection layer may be provided for the purpose of improving electron injection properties and improving device characteristics (for example, luminous efficiency, constant voltage driving, or high durability).

[0092] [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 the 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.

[0093] 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, fluorenylidenemethane, anthrone, etc. Examples of materials for the electron injection layer also include various oxides such as SiO2, AlO, SiON, AlON, GeO, LiO, LiON, TiO, TiON, TaO, TaON, etc., various fluorides such as LiF, nitrides and oxynitrides such as SiN and TaN, and inorganic compounds such as Yb.

[0094] [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, a metal with a low work function is, for example, a metal 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 (Al2O3) mixtures, indium, lithium / aluminum mixtures, and rare earth metals. Among these, from the viewpoints of electron injection properties and durability against oxidation, etc., mixtures of an electron-injecting metal and a second metal that has a larger and more stable work function than the electron-injecting metal, such as magnesium / silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al2O3) mixtures, and lithium / aluminum mixtures, are preferred.

[0095] [Hole-blocking layer 9] As described above, the organic electroluminescent device 100 may further be provided with a hole blocking layer 9 . Although not shown in FIG. 1, for example, a hole blocking layer 9 can be provided between the light emitting layer 5 and the electron transporting layer 6. The hole blocking layer has the role of suppressing leakage of holes from the light emitting layer and improving the recombination probability of electrons and holes, thereby improving the luminous efficiency. Specific examples of materials for the hole blocking layer include triazine derivatives, pyrimidine derivatives, fluoranthene derivatives, polycyclic aromatic hydrocarbon compounds, carbazole derivatives, fluorene derivatives, and spirofluorene derivatives.

[0096] [How each layer is formed] Each layer except for the electrodes (anode and cathode) described above can be formed into 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 are no particular limitations on the thickness of each layer thus formed, and it can be selected appropriately depending on the situation, but it is usually in the range of 5 nm to 5 μm.

[0097] The anode and 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 of a desired shape during vapor deposition or sputtering, or a pattern of a desired shape may be formed by photolithography after forming a thin film by vapor deposition, sputtering, etc.

[0098] 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.

[0099] In addition, to form a layer containing triazine compound (1), the triazine compound (1) may be used in combination with the above-mentioned conventionally known electron transporting material. 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).

[0100] Organic electroluminescent elements may be used as a type of lamp for illumination or exposure light sources, or as a projection device that projects images onto a screen or the like, or as a display device (display) that directly recognizes still images or moving images. When organic electroluminescent elements are used as a display device for playing moving images, the driving method may be a simple matrix (passive matrix) method or an active matrix method. Furthermore, by using two or more types of organic electroluminescent elements having different emission colors, it is possible to produce a full-color display device.

[0101] When used as an electron transport layer, triazine compound (1) can provide organic electroluminescent devices with significantly superior luminous efficiency and long life characteristics compared to conventionally known triazine compounds. Furthermore, triazine compound (1) has a highly amorphous structure due to its sterically hindered skeleton, resulting in high film stability. This contributes to improved driving stability and luminous efficiency of organic electroluminescent devices. Furthermore, triazine compound (1) has a characteristic skeleton that provides high chemical stability, contributing to the long life of organic electroluminescent devices.

[0102] 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 at a high level.Furthermore, an organic electroluminescent device that can achieve low-voltage operation, high efficiency, and long life using the triazine compound (1) can be provided. [Example]

[0103] The present invention will be described in more detail below based on examples, but the present invention should not be construed as being limited to these examples.

[0104] [ 1 H-NMR measurement] 1 For the H-NMR measurement, a Bruker ASCEND HD (400 MHz; manufactured by BRUKER) was used. 1 H-NMR was measured using deuterated chloroform (CDCl3) as the measurement solvent and tetramethylsilane (TMS) as the internal standard. Commercially available reagents were used.

[0105] [Emission characteristics measurement] 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 (manufactured by Topcon Technohouse Corporation).

[0106] [Compound synthesis] Synthesis reference example-1 5-chloro-1,3-bis(2-pyridyl)benzene

[0107] [ka]

[0108] Under an argon atmosphere, 5-chloro-1,3-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzene (10.0 g, 27.3 mmol), 2-bromopyridine (11.9 g, 71.1 mmol), and tetrakis(triphenylphosphine)palladium (1.12 g, 1.00 mmol) were suspended in THF (120 mL). 2M aqueous sodium carbonate (60 mL) was added to the suspension, followed by heating to reflux for 24 hours. After cooling, water and methanol were added to the reaction mixture. The precipitated solid was collected by filtration and purified by silica gel column chromatography (hexane / ethyl acetate) to yield the desired 5-chloro-1,3-bis(2-pyridyl)benzene (6.21 g, 23.1 mmol, 85%). 1 H-NMR(CDCl3)δ7.29(td,J=4.9,1.4Hz,2H),7.76-7.85(m,4H),8.07(d,J=1.6Hz,2H),8.51(t,J=1.7Hz,1H),8.72(dt,J=4.9,0.8Hz,2H).

[0109] Synthesis reference example-2 2,4-Bis(2-pyridyl)-1-trifluoromethanesulfonyloxybenzene

[0110] [ka] 2,4-Bis(2-pyridyl)phenol (2.45 g, 9.87 mmol) was suspended in dichloromethane (50 mL) under atmospheric pressure. Trifluoromethanesulfonic anhydride (5.02 mL, 29.6 mmol) and pyridine (1.59 mL, 19.7 mmol) were added to the suspension, which was then stirred for 3 hours. Saturated brine and ethyl acetate were added to the reaction mixture, and the organic layer was separated. The organic layer was dried over sodium sulfate, and the filtrate was concentrated under reduced pressure to obtain the desired product, 2,4-bis(2-pyridyl)-1-trifluoromethanesulfonyloxybenzene (2.91 g, 2.26 mmol, 78%). 1 H-NMR(CDCl3)δ7.38-7.44(m,2H),7.55(d,J=8.6Hz,1H),7.75(dt,J=7.9,0.9Hz,1H),7 .86-7.96(m,3H),8.15(dd,J=8.6,2.4Hz,1H),8.39(d,J=2.4Hz,1H),8.76-8.83(m,2H).

[0111] Synthesis Example 1 2,4-bis(4-biphenyl)-6-[3',5'-bis(2-pyridyl)biphenyl-3-yl]-1,3,5-triazine

[0112] [ka]

[0113] Under an argon atmosphere, 4,6-bis(4-biphenyl)-2-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-1,3,5-triazine (4.89 g, 8.28 mmol), 5-chloro-1,3-bis(2-pyridyl)benzene (2.52 g, 9.31 mmol), palladium acetate (60 mg, 0.29 mmol), and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (254 mg, 0.58 mmol) were suspended in THF (80 mL). 2M aqueous potassium carbonate (13 mL) was added to the suspension, followed by heating under reflux for 24 hours. After cooling, water and methanol were added to the reaction mixture. The precipitated solid was collected by filtration and recrystallized from toluene to obtain the desired 2,4-bis(4-biphenyl)-6-[3',5'-bis(2-pyridyl)biphenyl-3-yl]-1,3,5-triazine (Compound A-37) (5.00 g, 7.17 mmol, 87%). 1 H-NMR(CDCl3)δ7.31(td,J=4.9,1.1Hz,2H),7.50(t,J=7.4Hz,4H),7.60-7.74(m ,7H),7.80-7.86(m,6H),7.97(dt,J=8.0,1.0Hz,2H),8.01(dd,J=8.2,1.6Hz,1H) ,8.43(d,J=1.7Hz,2H),8.70(t,J=1.7Hz,1H),8.78(ddd,J=4.8,1.7,0.9Hz,2H) ,8.85(dt,J=7.9,1.4Hz,1H),8.89(dd,J=8.5,1.8Hz,4H),9.12(t,J=1.7Hz,1H).

[0114] Synthesis Example 2 2,4-Bis(4-biphenyl)-6-[3'',5''-bis(2-pyridyl)-1,1':3',1''-terphenyl-3-yl]-1,3,5-triazine

[0115] [ka]

[0116] Under an argon atmosphere, 4,6-bis(4-biphenyl)-2-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)biphenyl-3'-yl]-1,3,5-triazine (100 mg, 0.15 mmol), 5-chloro-1,3-bis(2-pyridyl)benzene (48 mg, 0.18 mmol), palladium acetate (2 mg, 0.01 mmol), and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (8 mg, 0.02 mmol) were suspended in THF (1 mL). 2M aqueous potassium carbonate (0.3 mL) was added to the suspension, and the mixture was heated to reflux for 24 hours. After cooling, water and methanol were added to the reaction mixture. The precipitated solid was collected by filtration and recrystallized from toluene to obtain the desired 2,4-bis(4-biphenyl)-6-[3'',5''-bis(2-pyridyl)-1,1':3',1''-terphenyl-3-yl]-1,3,5-triazine (Compound A-58) (101 mg, 0.14 mmol, 95%). 1 H-NMR(CDCl3)δ7.24(td,J=6.7,0.9Hz,2H),7.42(tt,J=7.4,1.2Hz,2H),7.50(t,J= 7.7Hz,4H),7.64-7.73(m,6H),7.75-7.85(m,7H),7.92-7.96(m,3H),8.13(t,J=1.8 Hz,1H),8.42(d,J=1.4Hz,2H),8.64(t,J=1.7Hz,2H),8.73(ddd,J=4.9,1.9,1.4Hz, 2H),8.83(dt,J=8.8,1.7Hz,1H),8.87(dd,J=8.6,1.6Hz,4H),9.10(t,J=1.4Hz,1H).

[0117] Synthesis Example 3 2,4-diphenyl-6-[3',5'-bis(2-pyridyl)biphenyl-3-yl]-1,3,5-triazine

[0118] [ka]

[0119] Under an argon atmosphere, 4,6-diphenyl-2-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-1,3,5-triazine (100 mg, 0.23 mmol), 5-chloro-1,3-bis(2-pyridyl)benzene (67 mg, 0.27 mmol), palladium acetate (2 mg, 0.01 mmol), and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (8 mg, 0.02 mmol) were suspended in THF (2 mL). 2M aqueous potassium carbonate solution (0.4 mL) was added to the suspension, and the mixture was heated to reflux for 24 hours. After cooling, water and methanol were added to the reaction mixture. The precipitated solid was collected by filtration and washed with toluene to obtain the desired 2,4-diphenyl-6-[3',5'-bis(2-pyridyl)biphenyl-3-yl]-1,3,5-triazine (Compound A-1) (111 mg, 0.22 mmol, 93%). 1 H-NMR(CDCl3)δ7.31(ddd,J=7.5,4.6,1.1Hz,2H),7.56-7.64(m,6H),7.70(t,J=7.7Hz,1H),7.83(td,J=7.7,1.8Hz,2H),7.96(d, J=8.0Hz,2H),8.00(dt,J=7.7,1.3Hz,1H),8.42(d,J=1.1Hz,2H),8.69(t,J=2.0Hz,1H),8.76-8.83(m,7H),9.12(t,J=1.7Hz,1H).

[0120] Synthesis Example 4 2,4-diphenyl-6-[3'',5''-bis(2-pyridyl)-1,1':3',1''-terphenyl-3-yl]-1,3,5-triazine

[0121] [ka]

[0122] Under an argon atmosphere, 4,6-diphenyl-2-[3'-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)biphenyl-3-yl]-1,3,5-triazine (100 mg, 0.20 mmol), 5-chloro-1,3-bis(2-pyridyl)benzene (57 mg, 0.25 mmol), palladium acetate (2 mg, 0.01 mmol), and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (8 mg, 0.02 mmol) were suspended in THF (2 mL). 2M aqueous potassium carbonate (0.4 mL) was added to the suspension, and the mixture was heated to reflux for 24 hours. After cooling, water and methanol were added to the reaction mixture. The precipitated solid was collected by filtration and washed with toluene to obtain the desired 2,4-diphenyl-6-[3'',5''-bis(2-pyridyl)-1,1':3',1''-terphenyl-3-yl]-1,3,5-triazine (Compound A-7) (106 mg, 0.19 mmol, 90%). 1 H-NMR(CDCl3)δ7.29(ddd,J=7.7,4.1,1.2Hz,2H),7.54-7.71(m,8H),7.75-7.85(m,4H),7.93(d,J=8.2Hz,3H) ,8.10(t,J=1.7Hz,1H),8.41(d,J=1.6Hz,2H)8.64(t,J=1.7Hz,1H),8.73-8.81(m,7H),9.06(t,J=1.7Hz,1H).

[0123] Synthesis Example 5 4,6-Bis(4-biphenylyl)-2-[2',4'-bis(2-pyridyl)biphenyl-3-yl]-1,3,5-triazine

[0124] [ka]

[0125] Under an argon atmosphere, 4,6-bis(4-biphenylyl)-2-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-1,3,5-triazine (3.88 g, 6.60 mmol), 2,4-bis(2-pyridyl)-1-trifluoromethanesulfonyloxybenzene (2.76 g, 7.26 mmol), palladium acetate (74 mg, 0.33 mmol), and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (315 mg, 0.66 mmol) were suspended in THF (66 mL). A 2.0 M aqueous solution of potassium carbonate was added to the suspension, followed by heating under reflux for 24 hours. After cooling, water and methanol were added to the reaction mixture. The resulting solid was collected by filtration and purified by silica gel column chromatography (ethyl acetate / chloroform) to obtain the desired 4,6-bis(4-biphenylyl)-2-[2',4'-bis(2-pyridyl)biphenyl-3-yl]-1,3,5-triazine (Compound A-133) (2.23 g, 3.23 mmol, 49%). 1 H-NMR(CDCl3)δ7.08-7.12(m,2H),7.27-7.29(m,1H),7.39-7.46(m,3H),7.47-7.55(m,6H),7.70-7.84(m,10H), 7.92(d,J=8.0Hz,1H),8.25(dd,J=8.0,1.9Hz,1H),8.39(d,J=1.9Hz,1H),8.68-8.76(m,4H),8.79-8.84(m,4H).

[0126] Synthesis reference example-3 2,4-bis(4-biphenylyl)-6-[4'-(4-pyridyl)biphenyl-4-yl]-1,3,5-triazine

[0127] [ka]

[0128] As a reference example, 2,4-bis(4-biphenylyl)-6-[4'-(4-pyridyl)biphenyl-4-yl]-1,3,5-triazine (compound ETL-1) was synthesized by the same method as described in Example 22 of Japanese Patent No. 2007-314503.

[0129] Next, the obtained compound was used to carry out device evaluation.

[0130] Element Example 1 (see Figure 2)

[0131] (Prepare substrate 1 and anode 2) A glass substrate with an indium tin oxide (ITO) transparent electrode, on which a 2 mm wide striped pattern of an ITO film (thickness: 110 nm), was prepared as a 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.

[0132] (Preparation for vacuum deposition) After cleaning, each layer was deposited on the surface-treated substrate by vacuum deposition using a vacuum deposition method, and each layer was laminated. First, the glass substrate was placed in a vacuum deposition chamber. -4 The pressure was reduced to 100 Pa. Then, each layer was formed in the following order according to the film formation conditions. Each organic material was formed by resistance heating.

[0133] (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 mass ratio of 99:1 to form a 10 nm film, thereby producing hole injection layer 3. The film formation rate was 0.1 nm / sec.

[0134] (Fabrication 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 deposited at a rate of 0.2 nm / sec to form a 85 nm film, thereby forming a first hole transport layer 41.

[0135] (Fabrication of the second hole transport layer 42) Sublimation-purified N-phenyl-N-(9,9-diphenylfluoren-2-yl)-N-(1,1′-biphenyl-4-yl)amine was deposited at a rate of 0.15 nm / sec to form a film of 5 nm, thereby forming second hole transport layer 42 .

[0136] (Fabrication 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 mass ratio of 95:5 to form a 20 nm film, thereby producing the light-emitting layer 5. The film formation rate was 0.1 nm / sec.

[0137] (Fabrication 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 deposited at a rate of 0.05 nm / sec to form a 6 nm film as a hole-blocking layer 9 .

[0138] (Fabrication of Electron Transport Layer 6) 2,4-bis(4-biphenyl)-6-[3',5'-bis(2-pyridyl)biphenyl-3-yl]-1,3,5-triazine (Compound A-37) synthesized in Synthesis Example 2 and 8-hydroxyquinolinolatolithium (hereinafter referred to as Liq) were mixed in a mass ratio of 50:50 to form a 25 nm film, thereby producing an electron transport layer 6. The film formation rate was 0.15 nm / sec.

[0139] (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 .

[0140] (Fabrication of cathode 8) Finally, a metal mask was placed perpendicular to the ITO stripes (anode 2) on the substrate 1, and a cathode 8 was formed. The cathode had a two-layer structure, with silver / magnesium (mass ratio 1 / 10) and silver deposited in that order to thicknesses of 80 nm and 20 nm, respectively. The silver / magnesium deposition rate was 0.5 nm / sec, and the silver deposition rate was 0.2 nm / sec.

[0141] As a result, the light-emitting area of ​​4mm as shown in Figure 2 2 An organic electroluminescent device 100 was produced. The thickness of each film was measured using a stylus film thickness measuring instrument (DEKTAK, manufactured by Bruker). The device was then sealed in a nitrogen atmosphere glove box with an oxygen and moisture concentration of 1 ppm or less by sealing the glass sealing cap and the film-formed substrate (device) with bisphenol F epoxy resin (manufactured by Nagase ChemteX Corporation).

[0142] Element reference example 1 An organic electroluminescent device was produced in the same manner as in Device Example 1, except that, instead of forming a 25 nm film (film formation rate: 0.15 nm / sec) of 2,4-bis(4-biphenyl)-6-[3′,5′-bis(2-pyridyl)biphenyl-3-yl]-1,3,5-triazine (Compound A-37) and Liq in a mass ratio of 50:50 as the electron transport layer 6, a 25 nm film (film formation rate: 0.15 nm / sec) of ETL-1 synthesized in Synthesis Reference Example 3 and Liq in a mass ratio of 50:50 was formed.

[0143] A direct current was applied to the produced organic electroluminescent device, and the light-emitting characteristics were evaluated according to the method described above for measuring light-emitting characteristics.

[0144] The light-emitting characteristics are as follows: current density 10mA / cm 2 The voltage (V) and current efficiency (cd / A) were measured when current was applied, and the device lifespan during continuous lighting was measured. The device lifespan was measured when the initial luminance was 1000 cd / m 2 The luminance decay time was measured during continuous lighting when driven at 1000 Hz, and the luminance (cd / m2 The time required for the electrical conductivity (V) to decrease by 5% was measured. The voltage (V), current efficiency (cd / A) and lifespan values ​​were expressed as relative values ​​with the value of Reference Example Element-1 taken as 100. The results are shown in Table 1.

[0145] [Table 1]

[0146] Element Examples 2 to 5 Organic electroluminescent devices of Element Example-2 to Element Example-5 were prepared in the same manner as Element Example-1, except that in Element Example-1, the triazine compound (1) synthesized in Synthesis Example-1, Synthesis Example-3, Synthesis Example-4, and Synthesis Example-5 was used in the electron transport layer 6 instead of 2,4-bis(4-biphenyl)-6-[3′,5′-bis(2-pyridyl)biphenyl-3-yl]-1,3,5-triazine (Compound A-37) synthesized in Synthesis Example-2. The light-emitting characteristics of the organic electroluminescent devices of Element Example-2 to Element Example-5 thus fabricated were evaluated in the same manner as in Element Example-1. As a result, Element Example-2 to Element Example-5 also exhibited superior driving voltage characteristics, light-emitting efficiency characteristics, and element life characteristics compared to Element Reference Example-1, just like Element Example-1.

[0147] From the results of the Examples compared with the Reference Examples, it was found that the organic electroluminescent device using the triazine compound (1) can achieve high levels of driving voltage characteristics, luminous efficiency characteristics, and device life characteristics. [Explanation of symbols]

[0148] 1. Substrate 2.Anode 3. Hole injection layer 4. Hole transport layer 5. Emitting layer 6.Electron transport layer 7.Electron injection layer 8.Cathode 9. Hole-blocking layer 41. First hole transport layer 42. Second hole transport layer 100. Organic electroluminescent device

Claims

1. A triazine compound represented by the following formula (1): 【Chemistry 1】 (In formula (1), Ar １ and Ar ２ each independently represents a phenyl group, a biphenyl-2-yl group, a biphenyl-3-yl group, or a biphenyl-4-yl group; L represents a metaphenylene group or an orthophenylene group. n represents an integer of 1 or 2; Py １ and Py ２ each independently represents a 2-pyridyl group, a 3-pyridyl group, or a 4-pyridyl group.

2. Py １ and Py ２ The triazine compound according to claim 1, wherein is a 2-pyridyl group.

3. A material for an organic electroluminescent device, comprising the triazine compound according to claim 1 or 2.

4. The material for organic electroluminescent devices according to claim 3 , wherein the material for organic electroluminescent devices is an electron transport material for organic electroluminescent devices.

5. An organic electroluminescent device comprising the triazine compound according to claim 1 or 2.

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