JP7450432B2 - triazine compounds - Google Patents

Description

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

Organic electroluminescent devices have begun to be put into practical use for applications such as small mobile devices. However, performance improvement is essential for further expansion of applications, and materials with high luminous efficiency and long life characteristics are required. Furthermore, in materials used for organic electroluminescent devices, crystallization is often a problem when the materials are made into thin films, so materials with high crystallization temperatures are required from the perspective of expanding the environments in which they can be used.
Patent Document 1 discloses a triazine compound that is a material for an organic electroluminescent device that has a long life and excellent luminescent properties.

Japanese Patent Application Publication No. 2007-314503

Regarding the expansion of applications and environments in which it can be used, the development of materials with high luminous efficiency characteristics, excellent life characteristics, and high crystallization temperatures is expected, but the triazine described in Patent Document 1 Compounds cannot be said to fully satisfy these requirements, and there is a need for compounds with further improved three properties: high luminous efficiency, long life, and high crystallization temperature.

Accordingly, one aspect of the present invention provides a triazine compound having a high crystallization temperature that contributes to the formation of an organic electroluminescent device with high luminous efficiency and long life, a material for an organic electroluminescent device containing the triazine compound, and an organic electroluminescent device. The present invention is directed to providing electron transport materials for devices. Furthermore, another aspect of the present invention is directed to providing an organic electroluminescent device with high luminous efficiency and long life.

According to one aspect of the present invention, a triazine compound represented by formula (1) is provided:

During the ceremony,
Ar ¹ and Ar ² each independently represent a phenyl group, a naphthyl group, or a biphenylyl group;
Ar ³ represents an aromatic hydrocarbon group having 6 to 18 carbon atoms;
Ar ⁴ represents a phenyl group, a naphthyl group, or a biphenylyl group;
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may each be independently substituted with one or more groups selected from the group consisting of a methyl group, a phenyl group and a cyano group;
One of X ¹ and X ² represents N and the other represents CH.

According to another aspect of the present invention, there is provided a material for an organic electroluminescent device containing the above triazine compound.
According to yet another aspect of the present invention, an electron transport material for an organic electroluminescent device containing the above triazine compound is provided.
According to yet another aspect of the present invention, an organic electroluminescent device containing the above triazine compound is provided.

According to one aspect of the present invention, it is possible to provide a triazine compound having a high crystallization temperature and contributing to the formation of an organic electroluminescent device with high luminous efficiency and long life. Further, according to another aspect of the present invention, it is possible to provide a material for an organic electroluminescent device and an electron transport material for an organic electroluminescent device, which contain the above triazine compound. Furthermore, according to yet another aspect of the present invention, it is possible to provide an organic electroluminescent device with high luminous efficiency and long life.

1 is a schematic cross-sectional view showing an example of a stacked structure of an organic electroluminescent element according to one embodiment of the present disclosure. FIG. 3 is a schematic cross-sectional view showing another example of a stacked structure of an organic electroluminescent device according to one embodiment of the present disclosure (structure of device example-1).

Hereinafter, the triazine compound according to one embodiment of the present invention will be explained in detail.
<Triazine compound>
The triazine compound according to one embodiment of the present invention is a triazine compound represented by formula (1):

During the ceremony,
Ar ¹ and Ar ² each independently represent a phenyl group, a naphthyl group, or a biphenylyl group;
Ar ³ represents an aromatic hydrocarbon group having 6 to 18 carbon atoms;
Ar ⁴ represents a phenyl group, a naphthyl group, or a biphenylyl group;
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may each be independently substituted with one or more groups selected from the group consisting of a methyl group, a phenyl group and a cyano group;
One of X ¹ and X ² represents N and the other represents CH.

Hereinafter, the triazine compound represented by formula (1) may be referred to as triazine compound (1). Definitions of the substituents in the triazine compound (1) and preferred specific examples thereof are as follows.

[About Ar ¹ and Ar ² ]
Ar ¹ and Ar ² each independently represent a phenyl group, a naphthyl group, or a biphenylyl group. Ar ¹ and Ar ² may each be independently substituted with one or more groups selected from the group consisting of a methyl group, a phenyl group, and a cyano group.
Examples of Ar ¹ include phenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 3,5-dimethylphenyl group, 2-cyanophenyl group, 3-cyanophenyl group, 4- Cyanophenyl group, 3,5-dicyanophenyl group, 1-naphthyl group, 4-phenyl-1-naphthyl group, 4-methyl-1-naphthyl group, 4-cyano-1-naphthyl group, 2-naphthyl group, 5 -phenyl-2-naphthyl group, 5-cyano-2-naphthyl group, m-terphenyl-4-yl group, m-terphenyl-2'-yl group, p-terphenyl-4-yl group, biphenyl- 2-yl group, biphenyl-3-yl group, biphenyl-4-yl group, 3'-methyl-biphenyl-3-yl group, 3'-cyano-biphenyl-3-yl group, 4'-methyl-biphenyl- 3-yl group, 4'-cyano-biphenyl-3-yl group, 3'-methyl-biphenyl-4-yl group, 3'-cyano-biphenyl-4-yl group, 4'-methyl-biphenyl-4-yl group yl group, 4'-cyano-biphenyl-4-yl group, and the like.

From the viewpoint of easy synthesis of the triazine compound (1), it is preferable that Ar ¹ and Ar ² are the same group.
From the viewpoint of excellent electron-transporting material properties, it is more preferable that Ar ¹ and Ar ² are the same group, and are a phenyl group or a 4-biphenylyl group.

[About Ar ³ ]
Ar ³ represents an aromatic hydrocarbon group having 6 to 18 carbon atoms. Ar ³ may be substituted with one or more groups selected from the group consisting of a methyl group, a phenyl group, and a cyano group.

Examples of Ar ³ include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-phenanthrenyl group, 2-phenanthrenyl group, 3-phenanthrenyl group, 4-phenanthrenyl group, 9-phenanthrenyl group, 1-fluorenyl group, 2-phenanthrenyl group, -Fluorenyl group, 3-fluorenyl group, 4-fluorenyl group, 9-fluorenyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 9,9-dimethylfluoren-1-yl group, 9,9- Dimethylfluoren-2-yl group, 9,9-dimethylfluoren-3-yl group, 9,9-dimethylfluoren-4-yl group, 1-triphenylenyl group, 2-triphenylenyl group, pyrenyl group, fluorenyl group, 1- Triphenylenyl group, 2-triphenylenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 3,5-dimethylphenyl group, 2-cyanophenyl group, 3-cyanophenyl group, 4-cyanophenyl group group, 3,5-dicyanophenyl group, 1-naphthyl group, 4-phenyl-1-naphthyl group, 4-methyl-1-naphthyl group, 4-cyano-1-naphthyl group, 2-naphthyl group, 5-phenyl Examples include -2-naphthyl group and 5-cyano-2-naphthyl group.
Since the triazine compound (1) has excellent electron-transporting material properties, Ar ³ is preferably a phenyl group, a naphthyl group, a phenanthryl group, an anthryl group, a pyrenyl group, a fluorenyl group, or a triphenylenyl group. Moreover, it is more preferable that Ar ³ is a phenyl group or a phenanthryl group.

[About Ar ⁴ ]
Ar ⁴ represents a phenyl group, a naphthyl group, or a biphenylyl group. Ar ⁴ may be substituted with one or more groups selected from the group consisting of a methyl group, a phenyl group, and a cyano group.

Examples of Ar ⁴ include phenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 3,5-dimethylphenyl group, 2-cyanophenyl group, 3-cyanophenyl group, 4- Cyanophenyl group, 3,5-dicyanophenyl group, 1-naphthyl group, 4-phenyl-1-naphthyl group, 4-methyl-1-naphthyl group, 4-cyano-1-naphthyl group, 2-naphthyl group, 5 -phenyl-2-naphthyl group, 5-cyano-2-naphthyl group, m-terphenyl-4-yl group, m-terphenyl-2'-yl group, p-terphenyl-4-yl group, biphenyl- 2-yl group, biphenyl-3-yl group, biphenyl-4-yl group, 3'-methyl-biphenyl-3-yl group, 3'-cyano-biphenyl-3-yl group, 4'-methyl-biphenyl- 3-yl group, 4'-cyano-biphenyl-3-yl group, 3'-methyl-biphenyl-4-yl group, 3'-cyano-biphenyl-4-yl group, 4'-methyl-biphenyl-4-yl group yl group, 4'-cyano-biphenyl-4-yl group, and the like.
A phenyl group is preferable since the triazine compound (1) has excellent electron transporting material properties.

[X ¹ and X ² ]
One of X ¹ and X ² represents N and the other represents CH.

[Specific example of triazine compound (1)]
Specific examples of the triazine compound (1) include the following (1-1) to (1-276), but the present invention is not limited thereto.

The triazine compound (1) is preferably a compound represented by 1-37, 1-67, or 1-103 in terms of its good performance as an electron transport material in an organic electroluminescent device. More preferred are compounds represented by:

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

In formulas (2) to (10),
The definitions of Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , X ¹ and X ² are the same as the definitions of Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , X ¹ and X ² in formula (1), respectively. be;
Y ¹ , Y ² , Y ³ , Y ⁴ and Y ⁵ 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 's of B(OR ¹ ) ₂ may be the same or different;
Two OR ¹ groups and a boron atom may be combined to form a ring.

Examples of the halogen atom represented by Y ¹ , Y ² , Y ³ and Y ⁴ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. , chlorine atom or bromine atom are 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 . Note that Me represents a methyl group, ⁱ Pr represents an isopropyl group, Bu represents a butyl group, and Ph represents a phenyl group.
Examples of B(OR ¹ ) ₂ in which two OR ¹ groups and a boron atom combine to form a ring include the following groups (I) to (VI). The group represented by (II) is preferable because it provides a good yield.

The coupling reaction in synthetic routes (i) to (ii) is carried out between a halogenated aryl compound represented by formula (2), (4), (7), (8), or (9) and formula (3). , (5), (6), or (10) 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 halogenated aryl compound (2), (4), (7), (8), or (9) is described, for example, in Journal of the American Chemical Society, Vol. 74, p. 6289, 1952 or Synlett, p. 808, 2002. It can be manufactured according to the following. Alternatively, commercially available products may be used. The halogenated aryl compound is preferably used in an amount of 0.5 to 3.0 molar equivalents relative to the boron compound in terms of a good reaction yield.

In the boronation reaction in synthetic routes (i) to (ii), the halogenated aryl compound represented by formula (4) is reacted with a boron reagent (such as pinacolatoborane, bispinacolatodiboron, etc.) in the presence of a palladium catalyst and a base. ) is reacted to produce a boron compound represented by formula (6). 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 the palladium catalyst used in the above-mentioned coupling reaction and boronation reaction include palladium salts such as palladium chloride, palladium acetate, palladium trifluoroacetate, and palladium nitrate. Furthermore, complex compounds such as π-allylpalladium chloride dimer, palladium acetylacetonate, tris(dibenzylideneacetone)dipalladium, bis(dibenzylideneacetone)palladium, dichlorobis(acetonitrile)palladium, dichlorobis(benzonitrile)palladium; and Dichlorobis(triphenylphosphine)palladium, tetrakis(triphenylphosphine)palladium, dichloro(1,1'-bis(diphenylphosphino)ferrocene)palladium, bis(tri-tert-butylphosphine)palladium, bis(tricyclohexylphosphine) Palladium complexes having a tertiary phosphine such as palladium and dichlorobis(tricyclohexylphosphine)palladium as a ligand can be mentioned. These can also be prepared in a reaction system by adding a tertiary phosphine to a palladium salt or complex compound.

Examples of tertiary phosphine 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 (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.
Among these, palladium complexes having tertiary phosphine as a ligand are preferable from the viewpoint of high yield. More preferred are palladium complexes having the following.

The molar ratio of tertiary phosphine and 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. preferable. 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 in the range of 0.005 to 0.5 molar equivalent relative to the boron compound. It is preferable that the

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

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

The above-mentioned coupling reaction and boronation reaction can be carried out at a temperature appropriately selected from 0°C to 200°C, and may be carried out at a temperature suitably selected from 60°C to 160°C in terms of a good reaction yield. It is preferable to implement it.

In the above-mentioned coupling reaction and boronation reaction, the desired product can be obtained by appropriately combining general purification processes such as recrystallization, column chromatography, sublimation purification, and preparative HPLC after the completion of the reaction. I can do it.
The coupling reaction and boronation reaction represented by synthetic route (i) involve reacting a compound represented by formula (2) with a compound represented by formula (5) and a compound represented by formula (7). After that, the desired product can also be obtained by reacting the compound represented by formula (3).

In addition, in the coupling reaction and boronation reaction represented by synthetic route (ii), a compound represented by formula (2), a compound represented by formula (5), a compound represented by formula (8), a compound represented by formula The target product can also be obtained by reacting the compound represented by formula (10) and then reacting the compound represented by formula (3).

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

<Materials for organic electroluminescent devices>
The organic electroluminescent element material according to one embodiment of the present invention contains a triazine compound (1).
The triazine compound (1) can be used, for example, as an electron transport material for organic electroluminescent devices. Materials for organic electroluminescent devices containing triazine compounds (1) exhibit high luminous efficiency and low voltage characteristics, have a long life, and can be used in the production of organic electroluminescent devices that can be used for various purposes or under various environments. It contributes to

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

An organic electroluminescent device according to one embodiment of the present invention contains a triazine compound (1).
The structure of the organic electroluminescent device is not particularly limited, but examples include the following structures (i) to (v).
(i): Anode/Emissive layer/Cathode (ii): Anode/Hole transport layer/Emissive layer/Cathode (iii): Anode/Emissive 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) is contained in any of the above layers. However, in view of the excellent light-emitting properties of the organic electroluminescent device, it is preferably included in one or more layers selected from the group consisting of a light-emitting layer and a layer between the light-emitting layer and the cathode. Therefore, in the case of the configurations shown in (i) to (v) above, the triazine compound (1) may be 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. preferable.

Hereinafter, the organic electroluminescent device according to one embodiment of the present invention will be described in more detail with reference to FIG. 1, taking the configuration (v) above as an example.
Note that although the organic electroluminescent device shown in FIG. 1 is an example of a device having a so-called bottom emission type device configuration, the organic electroluminescent device according to one embodiment of the present invention is limited to a bottom emission type device configuration. isn't it. That is, the organic electroluminescent device according to one embodiment of the present invention may have other known device configurations such as a top emission type.

FIG. 1 is a schematic cross-sectional view showing an example of a stacked structure of an organic electroluminescent element 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 conversely, 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. Good too. Furthermore, a single layer that has the functions of multiple layers, such as an electron injection/transport layer that combines the functions of an electron injection layer and an electron transport layer in a single layer, may be used as a layer that combines the functions of multiple layers. A configuration may be provided instead of. Furthermore, for example, the single-layer hole transport layer 4 and the single-layer electron transport layer 6 may each be composed of a plurality of layers.

<<Layer containing triazine compound (1)>>
In the configuration example shown in FIG. 1, the organic electroluminescent device 100 contains the 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). Note that the triazine compound (1) may be included in a plurality of layers included in the organic electroluminescent device.
In addition, below, the organic electroluminescent element 100 in which the electron transport layer 6 contains a triazine compound (1) is demonstrated.

[Substrate 1]
The substrate 1 is not particularly limited, and examples thereof include a glass plate, a quartz plate, a plastic plate, and the like. Examples of the substrate 1 include a glass plate, a quartz plate, a plastic plate, and a plastic film. Among these, glass plates, quartz plates, and light-transmitting plastic films are preferred. Examples of light-transmissive plastic films include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, and polycarbonate (PC). ), cellulose triacetate (TAC), cellulose acetate propionate (CAP), and the like. Note that in the case of a configuration in which light emission 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 hole injection layer 3 side).
Examples of the material for the anode include metals with a large work function (for example, 4 eV or more), alloys, electrically conductive compounds, and mixtures thereof. Specific examples of the material for the anode include metals such as Au; conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO.
For organic electroluminescent devices in which the emitted light is extracted through an anode, the anode is formed of an electrically conductive transparent material that is transparent or substantially transparent to the emitted light.

[Hole injection layer 3, hole transport layer 4]
Between the anode 2 and a light emitting layer 5, which will be described later, 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 a function of transmitting holes injected from the anode to the light emitting layer, and the hole injection layer and the hole transport layer are interposed between the anode and the light emitting layer. As a result, many holes are injected into the light emitting layer at a lower electric field.
Further, the hole injection layer and the hole transport layer also function as electron barrier layers. In other words, electrons injected from the cathode and transported from the electron injection layer and/or the electron transport layer to the light emitting layer are blocked by the electron barrier existing at the interface between the light emitting layer and the hole injection layer and/or the hole transport layer. , leakage to the hole injection layer and/or hole transport layer is suppressed. As a result, the electrons are accumulated 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.

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

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, and amino-substituted chalcone. Derivatives, oxazole derivatives, styryl anthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, conductive polymer oligomers (especially thiophene oligomers), porphyrin compounds, aromatic tertiary amine compounds, styryl Examples include amine compounds. Among these, porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred, since they provide good performance for organic electroluminescent devices.

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-tolylamino phenyl)-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] Examples include biphenyl (NPD), 4,4',4''-tris[N-(m-tolyl)-N-phenylamino]triphenylamine (MTDATA), and the like.

Further, inorganic compounds such as p-type Si and p-type SiC can also be cited as examples of materials for the hole injection layer and hole transport layer.

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

[Light-emitting layer 5]
A light emitting layer 5 is provided between the hole transport layer 4 and an electron transport layer 6, which will be described later.
Examples of 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.
The emissive layer may consist of a single small molecule material or a single polymeric material, but may also consist of a host material doped with a guest compound. Luminescence arises primarily from the dopant and can have any color.

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 specifically, DPVBi (4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl), BCzVBi (4,4'-bis(9-ethyl-3-carbazovinylene)-1 , 1'-biphenyl), TBADN (2-tert-butyl-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 compound, thiopyran compound, polymethine compound, pyrylium, thiapyrylium compound, fluorene derivative, periflanthene derivative, and indenoperylene. Examples include derivatives, bis(azinyl)amine boron compounds, bis(azinyl)methane compounds, carbostyryl compounds, boron compounds, and cyclic amine compounds. The fluorescent dopant may be a combination of two or more selected from these.

Examples of the phosphorescent dopant include metal complexes such as iridium, platinum, palladium, and osmium.

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

Furthermore, the luminescent material is not limited to being contained only in the luminescent layer. For example, the luminescent material may be contained in a layer adjacent to the luminescent layer (hole transport layer 4 or electron transport layer 6). This further increases the luminous efficiency of the organic electroluminescent device.
The light-emitting layer may have a single layer structure made of one or more kinds of materials, or may have a laminated structure made of multiple layers having the same composition 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, which will be described later.
The electron transport layer has a function of transmitting electrons injected from the cathode to the light emitting layer. By interposing the electron transport layer between the cathode and the emissive layer, electrons are injected into the emissive layer at a lower electric field.
It is preferable that the electron transport layer contains the triazine compound (1). Moreover, 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.

Note that if the triazine compound (1) is not included in the electron transport layer but is included in another layer, one or more types selected from conventionally known electron transport materials may be used as the electron transport material constituting the electron transport layer. I can do it.
Conventionally known electron transporting materials include typical metal complexes, transition metal complexes, and the like. Examples of typical metal complexes and transition metal complexes include lithium 8-hydroxyquinolinate (Liq), zinc bis(8-hydroxyquinolinate), copper bis(8-hydroxyquinolinate), and copper bis(8-hydroxyquinolinate). quinolinate) manganese, tris(8-hydroxyquinolinate) aluminum, tris(2-methyl-8-hydroxyquinolinate) aluminum, tris(8-hydroxyquinolinate) gallium, bis(10-hydroxybenzo[h ] Quinolinate) beryllium, bis(10-hydroxybenzo[h]quinolinate) zinc, bis(2-methyl-8-quinolinate) chlorogallium, bis(2-methyl-8-quinolinate) (o-cresolate) gallium, bis( Examples thereof include aluminum 2-methyl-8-quinolinate)-1-naphtholate, gallium bis(2-methyl-8-quinolinate)-2-naphthlate, and the like.

The electron transport layer may have a single layer structure made of one or more kinds of materials, or may have a laminated structure made of multiple layers having 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 electron injection properties and improving device characteristics (for example, luminous efficiency, low voltage drive, 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 transmitting electrons injected from the cathode to the light emitting layer. By interposing the electron injection layer between the cathode and the emissive layer, electrons are injected into the emissive layer at a lower electric field.
Examples of materials for the electron injection layer include fluorenone, anthraquinodimethane, diphenoquinone, thiopyrane dioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, fluorenylidenemethane, anthraquinodimethane, anthrone, etc. Examples include organic compounds. In addition, materials for the electron injection layer include various oxides and fluorides such as SiO ₂ , AlO, SiN, SiON, AlON, GeO, LiO, LiON, TiO, TiON, TaO, TaON, TaN, LiF, C, and Yb. , nitrides, oxynitrides, and other inorganic compounds.

[Cathode 8]
A cathode 8 is provided on the electron injection layer 7.
In the case of an organic electroluminescent device configured such that only light emitted from the anode is extracted, the cathode can be formed from any conductive material.

Examples of the material for the cathode include metals with a small work function (hereinafter also referred to as electron-injecting metals), alloys, electrically conductive compounds, and mixtures thereof. Here, the metal with a small 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 alloy, magnesium, lithium, magnesium/copper mixture, magnesium/silver mixture, magnesium/aluminum mixture, magnesium/indium mixture, aluminum/aluminum oxide (Al ₂ O ₃ ). Mixtures, indium, lithium/aluminum mixtures, rare earth metals, and the like.
Among these, from the viewpoint of electron injection properties and durability against oxidation, mixtures of electron injection metals and second metals that are stable metals with a larger work function value, such as magnesium/silver mixtures, magnesium /aluminum mixture, magnesium/indium mixture, aluminum/aluminum oxide (Al ₂ O ₃ ) mixture, lithium/aluminum mixture, etc. are preferred.

[Formation method of each layer]
Each layer other than the electrodes (anode, cathode) described above is formed by forming a thin film by a known method such as a vacuum evaporation method, a spin coating method, a casting method, or an LB (Langmuir-Blodgett method) method. be able to. The materials for each layer may be used alone, or may be used together with materials such as a binder resin and a solvent, if necessary. The thickness of each layer formed in this way is not particularly limited and can be appropriately selected depending on the situation, but is usually in the range of 5 nm to 5 μm.
The anode and the cathode can be formed by forming electrode materials into thin films by methods such as vapor deposition and sputtering. A pattern may be formed through a mask having a desired shape during vapor deposition or sputtering, or a thin film may be formed by vapor deposition or sputtering, and then a pattern having a desired shape may be formed by photolithography.
The film thickness of the anode and cathode is preferably 1 μm or less, more preferably 10 nm or more and 200 nm or less.

Note that when forming a layer containing the triazine compound (1), it may be used in combination with the above-mentioned conventionally known electron transporting materials. Therefore, for example, the 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 the layer of the triazine compound (1).

Organic electroluminescent elements may be used as a type of lamp for illumination or as an exposure light source, or as a type of projection device that projects images onto a screen, or as a type of display that allows direct viewing of still or moving images. It may also be used as a device (display). When using an organic electroluminescent element as a display device for video playback, 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 that emit light of different colors, it is possible to produce a full-color display device.

The triazine compound (1), when used as an electron transport layer, can provide an organic electroluminescent device with significantly superior luminous efficiency compared to conventionally known triazine compounds. Further, the triazine compound (1) has high amorphous property due to its moderately sterically hindered molecular structure, and has high film quality stability. Therefore, effects such as improvement in driving stability of the organic electroluminescent device and improvement in luminous efficiency are expected. Furthermore, the triazine compound (1) has high chemical stability due to its characteristic molecular structure, and can contribute to extending the life of the organic electroluminescent device.

When the triazine compound (1) is used as an electron transport layer of an organic electroluminescent device, it is possible to provide a triazine compound that can achieve both high efficiency and long life of the device. Furthermore, it is possible to provide an organic electroluminescent device using the triazine compound (1) that can exhibit high efficiency and long life.

EXAMPLES Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention should not be interpreted as being limited by these Examples.

[ ¹ H-NMR measurement]
For ¹ H-NMR measurement, Bruker ASCEND HD (400 MHz; manufactured by BRUKER) was used. ¹ H-NMR was measured using deuterated chloroform (CDCl ₃ ) as a measurement solvent and tetramethylsilane (TMS) as an internal standard substance. In addition, commercially available reagents were used.

[DSC measurement (glass transition temperature, crystallization temperature)]
The glass transition temperature, crystallization temperature, and melting point were measured using a DSC (differential scanning calorimetry) device DSC7020 (manufactured by Hitachi High-Tech Science). Aluminum oxide (Al ₂ O ₃ ) was used as a reference in the DSC measurement, and the measurement was performed using 10 mg of the sample.
As a pretreatment for measurement, the temperature was raised from 30° C. to a temperature above the melting point at a rate of 10° C./min to melt the sample, and then the sample was brought into contact with dry ice to perform rapid cooling. Subsequently, the temperature of the pretreated sample was raised from 30° C. at a rate of 10° C./min, and the glass transition temperature and crystallization temperature were measured.

[Emission characteristics measurement]
The luminescence properties of the organic electroluminescent device were evaluated using a luminance meter BM-9 (manufactured by Topcon Technohouse) by applying a direct current to the device produced in each example (described later) in a 25° C. environment.

Synthesis Example-1

Under a nitrogen atmosphere, 2-phenyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (7.59 g, 27 mmol), 4-bromochlorobenzene (5. 32g, 28mmol), tetrakis(triphenylphosphine)palladium (470mg, 0.41mmol), and 2M aqueous potassium phosphate solution (41mL) were suspended in THF (54mL) and stirred at 70°C for 24 hours. After cooling to room temperature, the reaction mixture was extracted with toluene. After drying with magnesium sulfate, vacuum distillation was performed. The obtained oily solid was purified by silica gel chromatography to obtain the target product 2-phenyl-3-(4-chlorophenyl)pyridine as a white solid (yield: 7.00 g, yield: 98%).
¹ H-NMR (400 MHz, CDCl ₃ ) δ (ppm): 8.70 (dd, J = 4.7, 1.7 Hz, 1H), 7.69 (dd, J = 7.7, 1.7 Hz, 1H), 7.32-7.35 (m, 3H), 7.29-7.27 (m, 3H), 7.25 (ddd, J = 8.6, 2.4, 2.1Hz, 2H ), 7.11 (ddd, J=8.6, 2.4, 2.1Hz, 2H).

Under nitrogen atmosphere, 2,4-bis(4-biphenylyl)-6-(5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)biphenyl-3-yl) -1,3,5-triazine (7.30 g, 11 mmol), 2-phenyl-3-(4-chlorophenyl)pyridine (3.36 g, 13 mmol), palladium acetate (49.0 mg, 0.22 mmol), 2- Dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (210 mg, 0.44 mmol) and 2M aqueous potassium phosphate solution (17 mL) were suspended in THF (110 mL) and stirred at 70°C for 18 hours. Stirred. After cooling to room temperature, the precipitated solid was collected by filtration and washed with water and methanol. The obtained solid was dissolved in toluene (500 mL), activated carbon was added thereto, the mixture was stirred for a while at 100°C, and then filtered through Celite. The solvent was distilled off from the obtained solution and recrystallized with toluene (300 mL) to obtain the target product 2,4-bis(4-biphenylyl)-6-[4-(2-phenylpyridine) as a white solid. -3-yl)-m-terphenyl-5-yl]-1,3,5-triazine (Compound 1-103) was obtained (6.60 g, yield 78%).
¹ H-NMR (400 MHz, CDCl ₃ ) δ (ppm): 8.97 (d, J = 1.7 Hz, 2H), 8.85 (dd, J = 8.6, 1.8 Hz, 4H), 8 .75 (dd, J=4.8, 1.7Hz, 1H), 8.02 (dd, J=1.8, 1.8Hz, 1H), 7.84-7.80 (m, 7H), 7.75-7.71 (m, 6H), 7.57-7.26 (m, 17H).
The glass transition temperature (Tg) of the obtained compound 1-103 was 129°C, and the crystallization temperature (Tc) was not detected in the range of 30 to 350°C.

Synthesis Example-2

Under nitrogen atmosphere, 2-(3-(9-phenanthrenyl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl-4,6-diphenyl-1 , 3,5-triazine (6.73 g, 11 mmol), 2-phenyl-3-(4-chlorophenyl)pyridine (3.36 g, 13 mmol), palladium acetate (49.0 mg, 0.22 mmol), to 2-dicyclo Xylphosphino-2',4',6'-triisopropylbiphenyl (210 mg, 0.44 mmol) and 2M aqueous potassium phosphate solution (17 mL) were suspended in THF (110 mL) and stirred at 70°C for 18 hours. After cooling to room temperature, the precipitated solid was collected by filtration and washed with water and methanol.The obtained solid was dissolved in toluene (500 mL), activated carbon was added, and the mixture was stirred at 100°C for a while, then filtered through Celite. The solvent was distilled off from the resulting solution and recrystallized with toluene (200 mL) to obtain the target product 2-[5-(9-phenanthrenyl)-4'-(2-phenyl) as a white solid. Pyridin-3-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (Compound 1-37) was obtained (yield: 5.40 g, yield: 69%).
¹ H-NMR (400 MHz, CDCl ₃ ) δ (ppm): 9.11 (d, J = 1.6 Hz, 1H), 8.91 (d, J = 1.6 Hz, 1H), 8.84 (d , J=8.3Hz, 1H), 8.78 (d, J=8.1Hz, 5H), 8.73 (d, J=4.8Hz, 1H), 8.02-7.96 (m, 3H), 7.86 (s, 1H), 7.82 (d, J=7.7Hz, 1H), 7.78-7.71 (m, 4H), 7.69-7.65 (m, 1H), 7.61-7.54 (m, 7H), 7.45-44 (m, 2H), 7.38-7.35 (m, 3H), 7.29-25 (m, 3H) ．．
FDMS:714
The glass transition temperature of the obtained compound 1-37 was 144°C, and the crystallization temperature was not detected in the range of 30 to 350°C.

Synthesis Example-3

Under argon atmosphere, 2,4-diphenyl-6-[5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-o-terphenyl-3-yl]- 1,3,5-triazine (8.53g, 15mmol), 2-phenyl-3-(4-chlorophenyl)pyridine (5.01g, 19mmol), tris(dibenzylideneacetone)dipalladium (218mg, 0.24mmol) , 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (417 mg, 0.87 mmol), and 2M aqueous potassium phosphate solution (22 mL) were suspended in THF (190 mL) and heated at 80°C. The mixture was stirred for 23 hours. After adding chloroform and water to the reaction mixture, the organic layer was extracted and further washed with saturated brine. After adding sodium sulfate and activated carbon to the organic layer and stirring, the organic layer was filtered through Celite, and the low boiling point fraction was removed under reduced pressure. The obtained solid was washed with methanol (400 mL) and suspended in toluene (1000 mL) at 110°C. After cooling to room temperature, insoluble components were removed by filtration, the filtrate was removed under reduced pressure, and 4,6-diphenyl- [4-(2-phenylpyridin-3-yl)-1,1':3',1'':2'', 1'''-quarterphenyl-5'-yl]-1,3,5-triazine ( Compound 1-67) was obtained (4.13 g, yield 41%).
¹ H-NMR (400 MHz, CDCl ₃ ) δ (ppm): 8.81 (dd, J = 1.64, 1.60 Hz, 1H), 8.74 (brd, J = 8.0 Hz, 4H)), 8.72 (dd, J=5.9, 1.64Hz, 1H), 8.65 (dd, J=1.60, 1.56Hz, 1H), 7.79 (dd, J=7.7, 1.7Hz, 1H), 7.68-7.51 (m, 11H), 7.43-7.42 (m, 2H), 7.38-7.35 (m, 3H), 7.32- 7.25 (m, 9H), 7.22-7.18 (m, 1H).

Reference example-1

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. Incidentally, ETL-1 was synthesized by a method similar to that described in Example 22 of JP-A No. 2007-314503.
The resulting compound ETL-1 had a glass transition temperature of 125°C and a crystallinity of 174°C. Incidentally, the DSC measurement was performed under the same conditions as in Synthesis Example-1.

From the above results, it was found that Compound 1-37 and Compound 1-103 obtained in this example had a higher crystallization temperature than the conventionally known triazine compound obtained in Reference Example-1.

Next, device evaluation was performed using the obtained compound.
Element example-1 (see Figure 2)

(Preparation of substrate 1 and anode 2)
A glass substrate with an ITO transparent electrode on which a 2 mm wide indium-tin oxide (ITO) film (film thickness: 110 nm) was patterned in stripes was prepared as a substrate 1 having an anode 2 on its surface. Next, this substrate was cleaned with isopropyl alcohol, and then surface-treated by ozone ultraviolet cleaning.

(Preparation for vacuum deposition)
Each layer was vacuum-deposited using a vacuum evaporation method on the surface-treated substrate after cleaning, and each layer was laminated.
First, the glass substrate was introduced into a vacuum deposition tank, and the pressure was reduced to 1.0×10 ⁻⁴ Pa.
Then, each layer was manufactured according to the film forming conditions in the following order. Note that each organic material was formed into a film by a resistance heating method.

(Preparation 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-fluorene-2 - A 10 nm film was formed of amine and 1,2,3-tris[(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane at a ratio of 99:1 (mass ratio), and positive A hole injection layer 3 was produced. The film deposition 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-fluorene-2 -Amine was deposited to a thickness of 85 nm at a rate of 0.2 nm/sec to produce the first hole transport layer 41.

(Preparation of second hole transport layer 42)
A 5 nm film of N-phenyl-N-(9,9-diphenylfluoren-2-yl)-N-(1,1'-biphenyl-4-yl)amine purified by sublimation was formed at a speed of 0.15 nm/sec. , the second hole transport layer 42 was produced.

(Preparation of light emitting layer 5)
Sublimation-purified 3-(10-phenyl-9-anthryl)-dibenzofuran and 2,7-bis[N,N-di-(4-tert-butylphenyl)]amino-bisbenzofurano-9,9'-spiro A light emitting layer 5 was prepared by forming a 20 nm film of fluorene and fluorene at a ratio of 95:5 (mass ratio). The film deposition rate was 0.1 nm/sec.

(Preparation of hole blocking layer 9)
2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)(1,1'-biphenyl)-3-yl]-4,6-diphenyl-1,3,5- purified by sublimation Triazine was deposited to a thickness of 6 nm at a rate of 0.05 nm/sec to produce a hole blocking layer 9.

(Preparation of electron transport layer 6)
2-[5-(9-phenanthrenyl)-4'-(2-phenylpyridin-3-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5 synthesized in Synthesis Example-2 - Triazine (compound 1-37) and Liq were formed into a 25 nm film at a ratio of 50:50 (mass ratio) to prepare an electron transport layer 6. The film deposition rate was 0.15 nm/sec.

(Preparation of electron injection layer 7)
Liq was deposited to a thickness of 1 nm at a rate of 0.02 nm/sec to produce an electron injection layer 7.

(Preparation of cathode 8)
Finally, a metal mask was placed so as to be perpendicular to the ITO stripe (anode 2) on the substrate 1, and the cathode 8 was formed. The cathode had a two-layer structure by forming films of silver/magnesium (mass ratio 1/10) and silver to have a thickness of 80 nm and 20 nm, respectively, in this order. The deposition rate of silver/magnesium was 0.5 nm/sec, and the deposition rate of silver was 0.2 nm/sec.

As described above, an organic electroluminescent device 100 having a light emitting area of 4 mm ² as shown in FIG. 2 was manufactured.
The thickness of each film was measured using a stylus-type film thickness meter (DEKTAK, manufactured by Bruker).

Furthermore, this device was sealed in a nitrogen atmosphere glove box with an oxygen and moisture concentration of 1 ppm or less. Sealing was performed using a glass sealing cap and a film-forming substrate (device) using bisphenol F type epoxy resin (manufactured by Nagase ChemteX).

Element example-2
In device example 1, 2-[5-(9-phenanthrenyl)-4'-(2-phenylpyridin-3-yl)biphenyl-3-yl]-4,6-bisphenyl was added to the electron transport layer 6. -1,3,5-triazine (compound 1-37) and Liq were used in Synthesis Example-4 instead of forming a 25 nm film (film forming rate 0.15 nm/sec) at a ratio of 50:50 (mass ratio). Synthesized 2,4-bis(4-biphenylyl)-6-[4-(2-phenylpyridin-3-yl)-m-terphenyl-5-yl]-1,3,5-triazine (compound A- An organic electroluminescent device was fabricated in the same manner as Device Example 1, except that 25 nm of 103) and Liq were formed at a ratio of 50:50 (mass ratio) at a film forming rate of 0.15 nm/sec.

Element reference example-1
In device example 1, 2-[5-(9-phenanthrenyl)-4'-(2-phenylpyridin-3-yl)biphenyl-3-yl]-4,6-bisphenyl was added to the electron transport layer 6. - Instead of forming a 25 nm film (film formation rate 0.15 nm/sec) of 1,3,5-triazine (compound 1-37) and Liq at a ratio of 50:50 (mass ratio), synthesis was performed using Reference Example-1. An organic electroluminescent device was produced in the same manner as Device Example 1, except that ETL-1 and Liq were formed into a 25 nm film (film formation rate 0.15 nm/sec) at a ratio of 50:50 (mass ratio). .

A direct current was applied to the produced organic electroluminescent device, and the luminescent properties were evaluated according to the method described in the measurement of luminescent properties above.

As for the luminescence characteristics, the voltage (V) and power efficiency (lm/A) when a current density of 10 mA/cm ² was applied were measured, and the element life during continuous lighting was measured. The device life was determined by measuring the brightness decay time during continuous lighting when the device was driven at an initial brightness of 1000 cd/m ² and the time required for the brightness (cd/m ² ) to decrease by 3%. Note that the values of voltage (V), power efficiency (lm/A), and lifespan are expressed as relative values when Element Reference Example-1 is taken as 100. The results are shown in Table 1.

In Table 1, Tg represents glass transition temperature (°C), Tc represents crystallization temperature (°C), and mp represents melting point (°C).
From Table 1, it was found that the organic electroluminescent device using the triazine compound (1) is highly superior in power efficiency and device life while maintaining the voltage, as 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 (10)

Triazine compound represented by formula (1):

During the ceremony,
Ar ¹ and Ar ² each independently represent a phenyl group, a naphthyl group, or a biphenylyl group;
Ar ³ represents an aromatic hydrocarbon group having 6 to 18 carbon atoms;
Ar ⁴ represents a phenyl group, a naphthyl group, or a biphenylyl group;
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may each be independently substituted with one or more groups selected from the group consisting of a methyl group, a phenyl group and a cyano group;
One of X ¹ and X ² represents N and the other represents CH. The triazine compound according to claim 1, wherein Ar ¹ and Ar ² are the same group. The triazine compound according to claim 2, wherein Ar ¹ and Ar ² are phenyl groups or 4-biphenylyl groups. The triazine compound according to any one of claims 1 to 3, wherein Ar ⁴ is a phenyl group. The triazine compound according to any one of claims 1 to 4, wherein ^Ar3 is a phenyl group, a naphthyl group, a phenanthryl group, an anthryl group, a pyrenyl group, a fluorenyl group, or a triphenylenyl group. The triazine compound according to any one of claims 1 to 5, wherein Ar ³ is a phenyl group or a phenanthryl group. A triazine compound represented by formula (1-103) or (1-37).

An organic electroluminescent device material containing the triazine compound according to any one of claims 1 to 7. An electron transport material for an organic electroluminescent device, comprising the triazine compound according to any one of claims 1 to 7. An organic electroluminescent device containing the triazine compound according to any one of claims 1 to 7.

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