JP7285663B2 - Triazine compound having a 2'-arylbiphenylyl group - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to triazine compounds, methods for producing the same, and materials for organic electroluminescent devices.

Organic electroluminescence devices have begun to be put into practical use, mainly for small mobile applications. However, although recent organic field effect light-emitting devices have been gradually improved, further improvement in performance is required. Here, improving the performance of an organic electroluminescent device means achieving a high level of three of the following without sacrificing any of the following: drive voltage reduction, luminous efficiency improvement, and longevity. There is a strong demand for its realization from the viewpoint of expansion of applications.
In addition, organic electroluminescence elements have begun to be put into practical use for applications other than small-sized mobile applications, and are used, for example, as in-vehicle display devices.

Here, Patent Document 1 discloses a triazine compound having a specific structure as an electron transport material.

JP 2011-063584 A

However, even the triazine compound according to Patent Document 1 is required to be further improved in driving voltage, luminous efficiency and life.
Furthermore, applications such as in-vehicle display devices are exposed to high-temperature environments, and even compact mobile applications are increasingly being used in various environments, including high-temperature environments, due to the spread of such applications. Therefore, further heat resistance is required for materials used in organic electroluminescence devices.

Therefore, one aspect of the present disclosure contributes to the production of an organic electroluminescent device that achieves high driving voltage, luminous efficiency, and longevity, and also has a high heat resistance triazine compound, a material for an organic electroluminescent device, and the It is directed to providing a method for producing triazine compounds. Another aspect of the present disclosure is directed to providing an organic electroluminescence device that achieves a high level of driving voltage, luminous efficiency and life and has excellent heat resistance.

A triazine compound according to one aspect of the present disclosure is represented by formula (1):

During the ceremony,
Ar ¹ and Ar ² each independently represent a phenyl group, a biphenylyl group or a naphthyl group;
Ar ³ consists of 3 or 4 rings,
an aromatic hydrocarbon group,
a nitrogen-containing heterocyclic group, or
represents a heterocyclic group in which the heteroatom is a Group 16 element;
Ar ⁴ represents a phenyl, biphenylyl or naphthyl group;
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may each independently be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group and a phenyl group;
each R independently represents a monocyclic, linked ring or condensed ring aromatic hydrocarbon group having 6 to 13 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms;
p represents 0 or 1;
q represents 1 or 2;

A method for producing a triazine compound represented by formula (1) according to another aspect of the present disclosure comprises coupling a compound represented by formula (2) with a compound represented by formula (3). including:

During the ceremony,
Ar ¹ and Ar ² each independently represent a phenyl group, a biphenylyl group or a naphthyl group;
Ar ³ consists of 3 or 4 rings,
an aromatic hydrocarbon group,
a nitrogen-containing heterocyclic group, or
represents a heterocyclic group in which the heteroatom is a Group 16 element;
Ar ⁴ represents a phenyl, biphenylyl or naphthyl group;
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may each independently be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group and a phenyl group;
each R independently represents a monocyclic, linked ring or condensed ring aromatic hydrocarbon group having 6 to 13 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms;
p represents 0 or 1;
q represents 1 or 2;
M ¹ represents ZnY ¹ , MgY ² , Sn(Y ³ ) ₃ , or B(OY ⁴ ) ₂ in which two (OY ⁴ ) groups together may form a ring together with a boron atom. ;
Y ¹ and Y ² each independently represent 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 independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group;
^X1 represents a chlorine atom, a bromine atom, a trifluoromethanesulfonyloxy group or an iodine atom.

A method for producing a triazine compound represented by formula (1) according to another aspect of the present disclosure comprises coupling a compound represented by formula (4) with a compound represented by formula (5). including:

During the ceremony,
Ar ¹ and Ar ² each independently represent a phenyl group, a biphenylyl group or a naphthyl group;
Ar ³ consists of 3 or 4 rings,
an aromatic hydrocarbon group,
a nitrogen-containing heterocyclic group, or
represents a heterocyclic group in which the heteroatom is a Group 16 element;
Ar ⁴ represents a phenyl, biphenylyl or naphthyl group;
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may each independently be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group and a phenyl group;
each R independently represents a monocyclic, linked ring or condensed ring aromatic hydrocarbon group having 6 to 13 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms;
p represents 0 or 1;
q represents 1 or 2;
X ² represents a chlorine atom, a bromine atom, a trifluoromethanesulfonyloxy group or an iodine atom;
M ² represents ZnY ¹ , MgY ² , Sn(Y ³ ) ₃ , or B(OY ⁴ ) ₂ in which two (OY ⁴ ) groups together may form a ring together with a boron atom. ;
Y ¹ and Y ² each independently represent 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;
Each ^Y4 independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.

A material for an organic electroluminescence device according to another aspect of the present disclosure contains the triazine compound.

An organic electroluminescent device according to another aspect of the present disclosure contains the triazine compound.

According to one aspect of the present disclosure, a triazine compound and a material for an organic electroluminescent device that contribute to the production of an organic electroluminescent device that achieves high driving voltage, luminous efficiency, and longevity and have high heat resistance, and the triazine A method for producing a compound can be provided.
According to another aspect of the present disclosure, it is possible to provide an organic electroluminescence device that achieves high levels of drive voltage, luminous efficiency, and longevity, and that is excellent in heat resistance.

1 is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescence element according to one aspect of the present disclosure; FIG. FIG. 4 is a schematic cross-sectional view showing another example of the layered structure of the organic electroluminescence element according to one aspect of the present disclosure (structure of Element Example-1).

The triazine compound according to one aspect of the present disclosure will be described in detail below.
A triazine compound according to one aspect of the present disclosure is represented by formula (1):

During the ceremony,
Ar ¹ and Ar ² each independently represent a phenyl group, a biphenylyl group or a naphthyl group;
Ar ³ consists of 3 or 4 rings,
an aromatic hydrocarbon group,
a nitrogen-containing heterocyclic group, or
represents a heterocyclic group in which the heteroatom is a Group 16 element;
Ar ⁴ represents a phenyl, biphenylyl or naphthyl group;
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may each independently be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group and a phenyl group;
each R independently represents a monocyclic, linked ring or condensed ring aromatic hydrocarbon group having 6 to 13 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms;
p represents 0 or 1;
q represents 1 or 2;

The present inventors have found that the triazine compound having the structure represented by formula (1) is given a twisted molecular structure by introducing a 1,2-phenylene moiety at an appropriate position in the molecule. I'm assuming it can be resolved.

The triazine compound according to one aspect of the present disclosure (hereinafter also simply referred to as triazine compound (1)) will be described in more detail below.
Definitions of Ar ¹ , Ar ² , Ar ³ , Ar ⁴ , R, p and q in triazine compound (1) are explained.

[Regarding Ar ¹ and Ar ² ]
Ar ¹ and Ar ² each independently represent a phenyl group, a biphenylyl group or a naphthyl group. Ar ¹ and Ar ² may each independently be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group and a phenyl group.
Ar ¹ and Ar ² are preferably the same group for easy synthesis of the triazine compound (1).
Moreover, it is preferable that Ar ¹ and Ar ² are each independently a phenyl group or a biphenylyl group, because the triazine compound (1) has excellent properties as an electron-transporting material.

[About Ar ³ ]
Ar ³ consists of 3 or 4 rings,
(i) an aromatic hydrocarbon group,
(ii) a nitrogen-containing heterocyclic group, or
(iii) represents a heterocyclic group in which the heteroatom is a Group 16 element;

(i) Aromatic Hydrocarbon Group Examples of the aromatic hydrocarbon group include phenanthryl group, anthryl group, pyrenyl group, fluorenyl group, benzofluorenyl group, triphenylenyl group and fluoranthenyl group. These groups may be substituted with one or more groups selected from the group consisting of fluorine atoms, methyl groups and phenyl groups. Ar ³ is an unsubstituted 3- or 4-ring aromatic hydrocarbon group or a 3- or 4-ring aromatic hydrocarbon group substituted with a methyl group, for ease of synthesis of the triazine compound (1). A phenanthrenyl group, a dimethylfluorenyl group, and a triphenylenyl group are particularly preferred.

(ii) Nitrogen-Containing Heterocyclic Group Examples of the nitrogen-containing heterocyclic ring include a benzo[b]quinolyl group, a benzo[c]quinolyl group, a benzo[f]quinolyl group, a benzo[g]quinolyl group, and a benzo[h] group. quinolyl group, phenazinyl group, azapyrenyl group, diazapyrenyl group, azatriphenylenyl group, diazatriphenylenyl group and the like. These groups may be substituted with one or more groups selected from the group consisting of fluorine atoms, methyl groups and phenyl groups. Ar ³ is an unsubstituted benzo[c]quinolyl group, benzo[h]quinolyl group, azapyrenyl group, or azatriphenyl group in that the triazine compound (1) contributes to the formation of a higher-performance organic electroluminescent device. A nilenyl group and a diazatriphenylenyl group are preferred.

(iii) Heterocyclic Group Examples of the heterocyclic group include a dibenzothiophenyl group, a dibenzofuranyl group, a benzonaphthofuranyl group and a benzonaphthothiophenyl group. These groups may be substituted with one or more groups selected from the group consisting of fluorine atoms, methyl groups and phenyl groups. Ar ³ is preferably a dibenzofuranyl group or a dibenzothiophenyl group in that the triazine compound (1) contributes to the formation of an organic electroluminescent device with higher performance.

[About ^Ar4 ]
Ar ⁴ represents a phenyl group, a biphenylyl group or a naphthyl group. These groups may be substituted with one or more groups selected from the group consisting of fluorine atoms, methyl groups and phenyl groups. Ar ⁴ is preferably a phenyl group or a biphenylyl group in terms of easy synthesis of the triazine compound (1).

[About R]
Each R independently represents a monocyclic, connected ring or condensed ring aromatic hydrocarbon group having 6 to 13 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms. The aromatic hydrocarbon group represented by R includes a phenyl group, a naphthyl group, a biphenylyl group and a fluorenyl group.
The aromatic hydrocarbon group represented by R may be substituted with an alkyl group having 1 to 4 carbon atoms. The alkyl group having 1 to 4 carbon atoms may be a linear, branched or cyclic alkyl group, and specifically includes a methyl group, ethyl group, propyl group, 2-methylpropyl group, isopropyl group, cyclo Examples include propyl group, butyl group, 2-butyl group, tert-butyl group and cyclobutyl group.
R is preferably a phenyl group or a biphenylyl group in terms of easy synthesis of the triazine compound (1).

[About p]
p represents 0 or 1; It is preferable that p is 0 in terms of easy synthesis of the triazine compound (1).

[About q]
q represents 1 or 2; q is preferably 1 from the viewpoint of easy synthesis of the triazine compound (1).

[Specific examples of triazine compound (1)]
Specific examples of the triazine compound (1) are not particularly limited, but specific examples include compounds having structures shown in 1-1 to 1-78 below. A compound represented by 1-1 or 1-2 is preferable as the triazine compound (1) in terms of good performance as an electron transport material in an organic electroluminescent device.

Next, a method for producing a triazine compound (hereinafter referred to as a method for producing triazine compound (1)) according to another aspect of the present disclosure will be described.
Triazine compound (1) can be produced by Step 1 or 2 shown in the following reaction scheme.
That is, the method for producing the triazine compound (1) is
or
It includes performing a coupling reaction between the compound represented by formula (4) and the compound represented by formula (5).

During the ceremony,
Ar ¹ and Ar ² each independently represent a phenyl group, a biphenylyl group or a naphthyl group;
Ar ³ consists of 3 or 4 rings,
an aromatic hydrocarbon group,
a nitrogen-containing heterocyclic group, or
represents a heterocyclic group in which the heteroatom is a Group 16 element;
Ar ⁴ represents a phenyl, biphenylyl or naphthyl group;
Ar ¹ , Ar ² , Ar ³ and Ar ⁴ may each independently be substituted with one or more groups selected from the group consisting of a fluorine atom, a methyl group and a phenyl group;
each R independently represents a monocyclic, linked ring or condensed ring aromatic hydrocarbon group having 6 to 13 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms;
p represents 0 or 1;
q represents 1 or 2;
M ¹ represents ZnY ¹ , MgY ² , Sn(Y ³ ) ₃ , or B(OY ⁴ ) ₂ in which two (OY ⁴ ) groups together may form a ring together with a boron atom. ;
M ² represents ZnY ¹ , MgY ² , Sn(Y ³ ) ₃ , or B(OY ⁴ ) ₂ in which two (OY ⁴ ) groups together may form a ring together with a boron atom. ;
Y ¹ and Y ² each independently represent 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 independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group;
X ¹ represents a chlorine atom, a bromine atom, a trifluoromethanesulfonyloxy group or an iodine atom;
^X2 represents a chlorine atom, a bromine atom, a trifluoromethanesulfonyloxy group or an iodine atom.

Step 1 is a step of reacting triazine compound (2) and compound (3) in the presence of a catalyst to produce triazine compound (1). In step 1, by applying reaction conditions for general coupling reactions such as Suzuki-Miyaura reaction, Negishi reaction, Tamao-Kumada reaction, and Stille reaction, the desired product can be obtained in good yield. When the reaction conditions for the Suzuki-Miyaura reaction are applied to step 1, it is preferably carried out in the presence of a base. Moreover, a palladium catalyst is preferable as the catalyst.

The compound represented by formula (2) used in step 1 can be obtained, for example, by the method disclosed in Japanese Patent No. 6326930, or by synthesizing a general organometallic compound from the compound represented by formula (4). It can be synthesized using a reaction (see, for example, Angew. Chem. Int. Ed. 2007, 46, 5359-5363).
As the compound represented by formula (2), compounds having structures shown in 2-1 to 2-36 below can be exemplified, but the present invention is not limited thereto. In formulas (2-1) to (2-36), ^M1 has the same definition as in formula (2).

_The ^group represented by ^{M 1} is not ^particularly limited ^. B(OY ⁴ ) ₂ and the like, which may form Among these, B(OY ⁴ ) ₂ is preferred.

Examples of ZnY ¹ and MgY ² include, but are not limited to, ZnCl, ZnBr, ZnI, MgCl, MgBr, and MgI.
Examples of Sn(Y ³ ) ₃ include, but are not limited to, Sn(Me) ₃ and Sn(Bu) ₃ .
Examples of B(OY ⁴ ) ₂ include, but are not limited to, B(OH) ₂ , B(OMe) ₂ , B(O ⁱ Pr) ₂ , B(OBu) ₂ , B(OPh) ₂ etc. can be exemplified. Me is a methyl group, ⁱ Pr is an isopropyl group, Bu is a butyl group, and Ph is a phenyl group. Further, examples of B(OY ⁴ ) ₂ when two (OY ⁴ ) groups are united to form a ring together with a boron atom are not particularly limited, but for example, the following ( The groups represented by I) to (VI) can be exemplified, and the group represented by (II) is preferable in that the yield is good.

Compound (3) used in step 1 can be produced, for example, according to International Publication 2017/209297. Moreover, you may use a commercial item.
Examples of compound (3) include the following 3-1 to 3-6, but the present invention is not limited to these. In formulas (3-1) to (3-6), ^X1 has the same definition as in formula (3).

The leaving group represented by X ¹ is not particularly limited, but can be exemplified by a chlorine atom, a bromine atom, a trifluoromethanesulfonyloxy group and an iodine atom. A chlorine atom or a bromine atom is preferable because However, in some cases, it is preferable to use a trifluoromethanesulfonyloxy group from the availability of raw materials.

The palladium catalyst that can be used in step 1 is not particularly limited, but specifically,
palladium salts such as palladium chloride, palladium acetate, palladium trifluoroacetate, palladium nitrate;
complex compounds such as π-allylpalladium chloride dimer, palladium acetylacetonato, 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 tertiary phosphines as ligands such as palladium and dichlorobis(tricyclohexylphosphine)palladium;
can be exemplified.

A palladium complex having a tertiary phosphine as a ligand can also be prepared in a reaction system by adding a tertiary phosphine to a palladium salt or complex compound. Tertiary phosphines that can be used in this case 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, a palladium complex having a tertiary phosphine as a ligand is preferable in that the yield is good, and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl or triphenylphosphine is coordinated. Further preferred are palladium complexes having as child.

The molar ratio of the tertiary phosphine and the palladium salt or complex compound is preferably in the range of 1:10 to 10:1, more preferably in the range of 1:2 to 3:1 in terms of good yield. preferable. Although the amount of the palladium catalyst used in step 1 is not limited, it is preferable that the molar equivalent of the palladium catalyst is in the range of 0.005 to 0.5 molar equivalents relative to the boron compound in terms of good yield.

The base used in step 1 is not particularly limited, but for example, metal hydroxide salts such as sodium hydroxide, potassium hydroxide, calcium hydroxide; sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate metal carbonates 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 metal alkoxides such as methoxide, potassium methoxide, sodium ethoxide, potassium isopropyl oxide, potassium tert-butoxide; Among them, metal carbonates and metal phosphates are preferable, and potassium carbonate or potassium phosphate is more preferable, because of good reaction yield. Although the amount of the base is not particularly limited, the molar ratio between the base and the boron compound is preferably in the range of 1:2 to 10:1, more preferably 1:1 to 4:1, from the viewpoint of good reaction yield. is more preferably in the range of

Step 1 can be carried out in a solvent such as water; diisopropyl ether, dibutyl ether, cyclopentyl methyl ether (CPME), tetrahydrofuran (THF), 2-methyltetrahydrofuran, 1,4-dioxane, dimethoxyethane. ethers such as; benzene, toluene, xylene, mesitylene, tetralin and other aromatic hydrocarbons; ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate, 4-fluoroethylene carbonate and other carbonate esters; ethyl acetate, acetic acid esters such as butyl, methyl propionate, ethyl propionate, methyl butyrate, γ-lactone; amides such as N,N-dimethylformamide (DMF), dimethylacetamide (DMAc), N-methylpyrrolidone (NMP); N,N , N′,N′-tetramethylurea (TMU), N,N′-dimethylpropyleneurea (DMPU); and dimethylsulfoxide (DMSO), methanol, ethanol, isopropyl alcohol, butanol, octanol, benzyl alcohol. , ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 2,2,2-trifluoroethanol and the like; and the like, and these may be used by mixing them at any ratio. There are no particular restrictions on the amount of solvent used. Among these, water, ether, amide, alcohol, or a mixed solvent thereof is preferable in that the reaction yield is good, and a mixed solvent of THF and water or a mixed solvent of toluene and butanol is more preferable.

Step 1 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 100° C. to 160° C. in terms of good reaction yield.
Step 1 is obtained by normal treatment after completion of the reaction. If necessary, it may be purified by recrystallization, column chromatography, sublimation, preparative HPLC, or the like.

Next, step 2 will be described.
Step 2 is a step of reacting the compound represented by formula (4) with compound (5) represented by formula (5) in the presence of a catalyst to produce triazine compound (1). . In step 2, the desired product can be obtained in good yield by applying general coupling reaction conditions such as Suzuki-Miyaura reaction, Negishi reaction, Tamao-Kumada reaction, and Stille reaction. When the reaction conditions for the Suzuki-Miyaura reaction are applied to step 2, it is preferably carried out in the presence of a base. Moreover, a palladium catalyst is preferable as the catalyst.

The triazine compound represented by formula (4) used in step 2 can be produced, for example, according to the method disclosed in Japanese Patent No. 5812583.
The triazine compound represented by formula (4) is a compound in which M ¹ in formulas (2-1) to (2-36), which are specific examples of the compound represented by formula (2), is replaced with X ² . can be exemplified. Here, ^X2 has the same definition as in formula (4).

The leaving group represented by ^X2 is not particularly limited, but can be exemplified by a chlorine atom, a bromine atom, a trifluoromethanesulfonyloxy group or an iodine atom. , a chlorine atom or a bromine atom is preferred.

The compound represented by formula (5) used in step 2 can be produced, for example, according to Journal of American Chemical Society, 134, 18932, 2012. Further, it can be synthesized from the compound represented by formula (3) using a reaction for synthesizing a general organometallic compound (for example, Angew.Chem.Int.Ed.2007, 46, 5359-5363), You may use a commercial item.

The compound represented by formula (5) can be exemplified by a skeleton obtained by replacing X ¹ in the compounds represented by formulas (3-1) to (3-6) with M ² . ^M2 has the same definition as in formula (5).

The palladium catalyst, base, solvent, reaction temperature, and post-treatment (purification) that can be used in step 2 are the same as those exemplified in step 1, and the preferred configurations are the same. be.

The triazine compound (1) can be used, for example, for organic electronic devices such as organic electroluminescence devices and photoelectric devices. Among these, the triazine compound (1) is preferably used as a material for organic electroluminescence devices.

<Materials for Organic Electroluminescent Devices>
A material for an organic electroluminescence device according to one aspect of the present disclosure contains the triazine compound (1) described above.
Triazine compound (1) can be used, for example, as an electron transport material for organic electroluminescence devices. A material for an organic electroluminescence device containing the triazine compound (1) achieves a high level of driving voltage, luminous efficiency and life, and contributes to the production of an organic electroluminescence device that can be used in various applications and under various environments. is.

<Organic electroluminescent device>
A material for an organic electroluminescence device according to one aspect of the present disclosure contains the triazine compound (1) described above.

<Organic electroluminescent element>
An organic electroluminescence device containing the triazine compound (1) (hereinafter sometimes simply referred to as an organic electroluminescence device) will be described below.
An organic electroluminescence device according to one aspect of the present disclosure contains a triazine compound (1).
The configuration of the organic electroluminescent device is not particularly limited, but includes, for example, configurations (i) to (v) shown below.
(i): anode/light emitting layer/cathode (ii): anode/hole transport layer/light emitting layer/cathode (iii): anode/light emitting layer/electron transport layer/cathode (iv): anode/hole transport layer/ Light emitting layer/electron transport layer/cathode (v): anode/hole injection layer/hole transport layer/light emitting layer/electron transport layer/electron injection layer/cathode

The triazine compound (1) may be contained in any of the above layers, but from the viewpoint of excellent light emitting properties of the organic electroluminescent device, It is preferably contained in one or more selected layers. Therefore, in the case of the structures shown in (i) to (v) above, the triazine compound (1) is preferably contained in one or more layers selected from the group consisting of a light-emitting layer, an electron-transporting layer and an electron-injecting layer. .

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

FIG. 1 is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescent device containing a triazine compound according to one aspect of the present disclosure.

The organic electroluminescent device 100 comprises 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-transporting layer 6, the hole-injecting layer 3 may be omitted, and the hole-transporting layer 4 may be provided directly on the anode 2. good too. Further, a single layer having the functions of a plurality of layers, such as an electron injection/transport layer having both the function of an electron injection layer and the function of an electron transport layer in a single layer. It may be a configuration provided instead of. Furthermore, for example, the single-layer hole transport layer 4 and the single-layer electron transport layer 6 may each consist of a plurality of layers.

<<Layer containing triazine compound (1)>>
In the structural example shown in FIG. 1, the organic electroluminescence 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 . In particular, it is preferred that the electron transport layer 6 contains the triazine compound (1). In addition, the triazine compound (1) may be contained in a plurality of layers provided in the organic electroluminescence device.
In addition, the organic electroluminescence device 100 in which the electron transport layer 6 contains the triazine compound (1) will be described below.

[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, a glass plate, a quartz plate, and a transparent plastic film are preferable.
Examples of light-transmitting plastic films include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC ), cellulose triacetate (TAC), cellulose acetate propionate (CAP), and the like.
In addition, in the case of the 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).
Materials for the anode include metals, alloys, electrically conductive compounds, and mixtures thereof having a large work function (for example, 4 eV or more). Specific examples of materials 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 emitted light is extracted through the anode, the anode is formed of a conductive transparent material that passes or substantially passes the emitted light.

[Hole injection layer 3, hole transport layer 4]
A hole injection layer 3 and a hole transport layer 4 are provided in this order from the anode 2 side between the anode 2 and a light emitting layer 5 to be described later.

The hole-injecting layer and the hole-transporting layer have a function of transferring holes injected from the anode to the light-emitting layer, and the hole-injecting layer and the hole-transporting layer are interposed between the anode and the light-emitting layer. causes more holes to be injected into the light-emitting layer at lower electric fields.

Moreover, the hole injection layer and the hole transport layer also function as electron blocking 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 blocked by the electron barrier present at the interface between the light-emitting layer and the hole injection layer and/or the hole transport layer. , leakage into the hole injection layer and/or the hole transport layer is suppressed. As a result, the electrons are accumulated at the interface in the light-emitting layer, resulting in an effect such as an improvement in light-emitting efficiency, and an organic electroluminescence device having excellent light-emitting performance can be obtained.

Materials for the hole injection layer and the hole transport layer have at least one of hole injection, hole transport, and electron barrier properties. Materials 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, styrylanthracene 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, from the viewpoint of good performance of the organic electroluminescent device.

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] biphenyl (NPD), 4,4′,4″-tris[N-(m-tolyl)-N-phenylamino]triphenylamine (MTDATA) and the like.

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

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

[Light emitting layer 5]
A light-emitting layer 5 is provided between the hole-transporting layer 4 and an electron-transporting layer 6, which will be described later.
Materials for the light-emitting layer include phosphorescent light-emitting materials, fluorescent light-emitting materials, and thermally activated delayed fluorescent light-emitting 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 more commonly consists of a host material doped with a guest compound. Emission comes primarily from dopants and can have any color.

Host materials include, for example, 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 can be mentioned.

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, and indenoperylenes. derivatives, bis(azinyl)amine boron compounds, bis(azinyl)methane compounds, carbostyril compounds, and the like. The fluorescent dopant may be a combination of two or more selected from these.

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

Specific examples of fluorescent 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](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.

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

The light-emitting layer may have a single-layer structure composed of one or more materials, or may have a laminated structure composed of a plurality of 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 an electron-transporting layer between the cathode and the light-emitting layer, electrons are injected into the light-emitting layer at a lower electric field.

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

Conventionally known electron-transporting materials include alkali metal complexes, alkaline earth metal complexes, earth metal complexes, and the like. Alkali metal complexes, alkaline earth metal complexes, and earth metal complexes include, for example, 8-hydroxyquinolinatolithium (Liq), bis(8-hydroxyquinolinato)zinc, and bis(8-hydroxyquinolinato)copper. , bis(8-hydroxyquinolinato)manganese, tris(8-hydroxyquinolinato)aluminum, tris(2-methyl-8-hydroxyquinolinato)aluminum, tris(8-hydroxyquinolinato)gallium, bis (10-hydroxybenzo[h]quinolinate) beryllium, bis(10-hydroxybenzo[h]quinolinate)zinc, bis(2-methyl-8-quinolinato)chlorogallium, bis(2-methyl-8-quinolinate)(o -cresolato)gallium, bis(2-methyl-8-quinolinato)-1-naphtholatoaluminum, bis(2-methyl-8-quinolinato)-2-naphtholatogallium, and the like.

The electron-transporting layer may have a single-layer structure composed of one or more materials, or may have a laminated structure composed of multiple layers having the same composition or different compositions.

In the organic electroluminescent device according to this aspect, an electron injection layer may be provided for the purpose of improving electron injection properties and improving device characteristics (e.g., luminous efficiency, constant 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 transferring electrons injected from the cathode to the light emitting layer. By interposing an electron injection layer between the cathode and the light emitting layer, electrons are injected into the light emitting layer at a lower electric field.

Materials for the electron injection layer include fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, frelenylidenemethane, anthraquinodimethane, anthrone, and the like. Examples include organic compounds. Materials for the electron injection layer include SiO ₂ , AlO, SiN, SiON, AlON, GeO, LiO, LiON, TiO, TiON, TaO, TaON, TaN, various oxides such as C, nitrides, and oxynitrides. Inorganic compounds such as

[Cathode 8]
A cathode 8 is provided on the electron injection layer 7 .
In the case of an organic electroluminescence device configured so that only light emitted through the anode is taken out, the cathode can be made of any conductive material.
Materials for the cathode include, for example, metals with a small work function (hereinafter also referred to as electron-injecting metals), alloys, electrically conductive compounds, and mixtures thereof. Here, a metal with a small work function is, for example, a metal of 4 eV or less.
Specific examples of cathode materials include sodium, sodium-potassium alloys, magnesium, lithium, magnesium/copper mixtures, magnesium/silver mixtures, magnesium/aluminum mixtures, magnesium/indium mixtures, aluminum/aluminum oxide (Al ₂ O ₃ ). mixtures, indium, lithium/aluminum mixtures, rare earth metals, and the like.
Among them, from the viewpoint of electron injection properties and durability against oxidation, etc., a mixture of an electron injection metal and a second metal that has a higher work function and is more stable, such as a magnesium/silver mixture, magnesium /aluminum mixtures, magnesium/ _indium mixtures, aluminum/aluminum oxide ( _Al2O3 ) mixtures, lithium/aluminum mixtures, etc. are preferred.

[Method of Forming Each Layer]
Each layer except for the electrodes (anode, cathode) described above is formed by thinning by a known method such as a vacuum deposition method, a spin coating method, a casting method, or a LB (Langmuir-Blodgett method) method. be able to. The material for each layer may be used alone, or if necessary, it may be used together with a material such as a binder resin and a solvent.
The thickness of each layer thus formed 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 cathode can be formed by thinning an electrode material by a method such as vapor deposition or sputtering. 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, or the like.

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.

Incidentally, the layer containing the triazine compound (1) may be formed in combination with the conventionally known electron-transporting material. 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).

The organic electroluminescence element may be used as a kind of lamp for illumination or as a light source for exposure, a projection device for projecting an image onto a screen or the like, or a display for directly viewing a still image or a moving image. You may use it as a device (display). When the organic electroluminescence element is used as a display device for reproducing moving images, the drive system may be a simple matrix (passive matrix) system or an active matrix system. Further, by using two or more kinds of organic electroluminescent elements having different emission colors, it is possible to produce a full-color display device.

The triazine compound (1) can provide an organic electroluminescence device which, when used as an electron-transporting layer, is remarkably superior in luminous efficiency and long-life characteristics compared to conventionally known triazine compounds. Furthermore, the triazine compound (1) is highly amorphous due to its sterically hindered skeleton and has high film quality stability. Therefore, effects such as improvement in drive stability of the organic electroluminescence device and improvement in luminous efficiency can be obtained. Furthermore, the triazine compound (1) has high chemical stability due to its characteristic skeleton, and can contribute to extending the life of the organic electroluminescent device.

By using the triazine compound (1) as an electron transport layer of an organic electroluminescent device, it is possible to provide a triazine compound capable of achieving high levels of low-voltage drive, high efficiency, and long life of the device. Further, it is possible to provide an organic electroluminescence device using the triazine compound (1), which can be driven at a low voltage, has a high efficiency, and has a long life.

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

[ ¹ H-NMR measurement]
Bruker ASCEND 400 (400 MHz; manufactured by BRUKER) was used for ¹ H-NMR measurement. ¹ H-NMR was measured using deuterated chloroform (CDCl ₃ ) as a measurement solvent and tetramethylsilane (TMS) as an internal standard substance.

[DSC measurement (glass transition temperature, crystallization temperature, melting point)]
The glass transition temperature, crystallization temperature, and melting point of compounds 1-1 and 1-2 (obtained in Synthesis Examples 1 and 2 described later) were measured using a DSC (Differential scanning calorimetry) device DSC6220 (product name, Hitachi manufactured by Hi-tech Science Co., Ltd.) under a nitrogen atmosphere (flow rate: 50 ml/min). Aluminum oxide (Al ₂ O ₃ ) was used as a reference in the DSC measurement, and the sample was 10 mg.
As a pretreatment for the measurement, the sample was melted by raising the temperature from 50° C. to the melting point or higher at a rate of 10° C./min, and then rapidly cooled with liquid nitrogen. Subsequently, the temperature of the pretreated sample was increased from 50° C. at a rate of 10° C./min, and the glass transition temperature, crystallization temperature and melting point were measured.

The glass transition temperature, crystallization temperature and melting point of ETL-2 (details will be described later) were measured using a DSC (Differential scanning calorimetry) device DSC7020 (product name, manufactured by Hitachi High-Tech Science) under a nitrogen atmosphere (flow rate 50 ml/ min). Aluminum oxide (Al ₂ O ₃ ) was used as a reference in the DSC measurement, and the sample was 10 mg.
As a pretreatment for the measurement, the sample was melted by increasing the temperature from 30°C to the melting point or higher at a rate of 15°C/min, and then rapidly cooled with liquid nitrogen. Subsequently, the temperature of the pretreated sample was increased from 30° C. at a rate of 5° C./min, and the glass transition temperature, crystallization temperature and melting point were measured.

[Emission characteristic measurement]
The luminous properties of the organic electroluminescence device were evaluated using a luminance meter BM-9 (product name, manufactured by Topcon Technohouse Co., Ltd.) by applying a direct current to the device prepared in each example (described later) in an environment of 25°C. bottom.
Commercially available reagents were used.

Synthetic Example-1

4,6-diphenyl-2-[3-(phenanthren-9-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) under argon atmosphere Phenyl]-1,3,5-triazine (7.83 g, 13 mmol), palladium acetate (144 mg, 0.64 mmol), 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (XPhos, 544 mg , 1.3 mmol) and cesium carbonate (12.5 g, 38 mmol) with 2′-chloro-1,1′:4′,1″-terphenyl (4.40 g, 17 mmol) dissolved in THF (128 mL). The mixture was added dropwise and stirred for 17 hours at 80° C. After allowing to cool to room temperature, water and methanol were added to the reaction mixture, and the precipitated solid was filtered off and washed with water and methanol. ° C, 470 mL), added activated carbon and stirred for a while.The liquid after stirring was filtered through celite, and the low-boiling components were distilled off.This crude product was repeatedly recrystallized from toluene to obtain the desired product. 4,6-diphenyl-2-[3″-(phenanthren-9-yl)-4′-phenyl-1,1′:2′,1″-terphenyl-5″-yl]-1,3 ,5-triazine (compound 1-1) was obtained (3.94 g, 43%).

¹ H-NMR (CDCl ₃ ): δ 8.93 (dd, J = 1.6 Hz, 1.6 Hz, 1 H), 8.82 (dd, J = 1.6 Hz, 1.6 Hz, 1 H), 8.77 (d, J=9.0 Hz, 1 H), 8.74 (ddd, J=6.7 Hz, 3.2 Hz, 1.4 Hz, 4 H), 8.72-8.74 (m, 1 H), 7. 92 (d, J = 1.9Hz, 1H), 7.89 (dd, J = 7.6Hz, 1.4Hz, 1H), 7.73-7.77 (m, 3H), 7.63-7 .71 (m, 3H), 7.59-7.62 (m, 2H), 7.54-7.58 (m, 5H), 7.44-7.53 (m, 6H), 7.36 -7.41 (m, 6H).

The obtained compound 1-1 had a glass transition temperature of 138° C., a melting point of 277° C., and no crystallization temperature was observed.

Synthesis example-2

4,6-diphenyl-2-[3-(phenanthren-9-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl under argon atmosphere ]-1,3,5-triazine (5.00 g, 8.2 mmol), 2′-iodo-1,1′:3′,1″-terphenyl (3.20 g, 9.0 mmol), tetrakis (tri Phenylphosphine)palladium (472 mg, 0.41 mmol) and cesium carbonate (7.99 g, 25 mmol) were suspended in toluene (82 mL), and the suspension was heated under reflux for 24 hours. Water and methanol were added, and the resulting solid was separated by filtration.The resulting solid was dissolved in toluene (115° C., 120 ml), activated carbon was added, and the mixture was stirred for a while.After stirring, the liquid was filtered through celite, and cooled to room temperature. The target product, 4,6-diphenyl-2-[3″-(phenanthren-9-yl)-3′-phenyl-1,1′:2′, was obtained by filtering off the precipitated solid after standing to cool. ,1″-terphenyl-5″-yl]-1,3,5-triazine (compound 1-2) was obtained (4.10 g, 70%).

¹ H NMR (CDCl ₃ ) δ 8.75 (d, J = 8.2 Hz, 1 H), 8.71 (d, J = 8.0, Hz, 1 H), 8.66 (dd, J = 8.0, 1.6Hz, 4H), 8.56 (dd, J = 1.6, 1.6Hz, 1H), 8.43 (dd, J = 1.6, 1.6Hz, 1H), 7.87 (dd , J = 7.7, 1.5Hz, 1H), 7.50-7.69 (m, 13H), 7.42 (ddd, J = 7.0, 7.0, 1.0Hz, 1H), 7.24-7.39 (m, 12H).

The obtained compound 1-2 had a melting point of 290° C., a crystallization temperature of 213° C., and no glass transition temperature.

Reference example-1

Under a nitrogen atmosphere, 2-[3-chloro-5-(phenanthren-9-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (1.00 g, 1.9 mmol), phenylboronic acid ( 282 mg, 2.3 mmol), palladium acetate (13.0 mg, 0.06 mmol), 2-dicyclohexylphosphino-2′,4′,6′-triisopropylbiphenyl (XPhos, 55.0 mg, 0.12 mmol), 1 , 4-dioxane (50 mL) and 2M tripotassium phosphate aqueous solution (2.9 mL, 5.8 mmol) were added to a 300 mL four-necked flask and stirred at 95° C. for 6 hours. After allowing the obtained reaction solution to cool to room temperature, water (100 mL) was added to the reaction mixture, the precipitate was collected by filtration and washed with water, methanol and then hexane to obtain a gray powder. The resulting gray powder was purified by recrystallization from toluene to give the desired product, 4,6-diphenyl-2-[5-(phenanthren-9-yl)-biphenyl-3-yl]-1,3, A gray powder of 5-triazine (compound ETL-1) was obtained (yield 700 mg, yield 65%).

¹ H-NMR (CDCl ₃ ): δ 7.45 (t, J = 7.3 Hz, 1 H), 7.52-7.63 (m, 9 H), 7.67 (t, J = 7.2 Hz, 1 H ), 7.73 (t, J = 7.8Hz, 1.3Hz, 2H), 7.84 (dd, J = 8.1Hz, 1.0Hz, 2H), 7.88 (s, 1H), 7 .98 (dd, J=7.8Hz, 1.4Hz, 1H), 8.01-8.04 (m, 2H), 8.77-8.80 (m, 5H), 8.85 (d, J=8.3 Hz, 1 H), 8.93 (t, J=1.7 Hz, 1 H), 9.12 (t, J=1.7 Hz, 1 H).

The obtained compound ETL-1 had a glass transition temperature of 108°C, a crystallization temperature of 207°C, and a melting point of 260°C.

From the above results, Compound 1-1, which is a triazine compound according to one embodiment of the present disclosure, has a higher glass transition temperature than the conventionally known triazine compound (Compound ETL-1) obtained in Reference Example-1. I understand. Furthermore, it was found that the triazine compound according to one embodiment of the present disclosure has low crystallinity due to its skeleton characteristics, and the crystallization temperature is not detected or the crystallization temperature is high. Therefore, triazine compound (1) can be expected to have high amorphous properties when formed into a thin film, and it is believed that high driving stability and high luminous efficiency are exhibited when an organic electroluminescence device using triazine compound (1) is produced. guessed.

Then, element evaluation was carried out using the obtained compound.

Device example-1 (see Fig. 2)

(Preparation of substrate 1 and anode 2)
As a substrate 1 having an anode 2 on its surface, a glass substrate with an ITO transparent electrode, in which an indium-tin oxide (ITO) film (thickness: 110 nm) with a width of 2 mm was patterned in stripes, was prepared. Then, after washing the substrate with isopropyl alcohol, the surface was treated by ozone ultraviolet washing.

(Preparation for vacuum deposition)
Each layer was vacuum-deposited on the surface-treated substrate after cleaning by a vacuum deposition method to laminate each layer.
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 produced in the following order according to the film forming conditions of each layer. In addition, 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 -Amine and 1,2,3-tris[(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane were deposited at a ratio of 99:1 (mass ratio) to form a 10 nm film, A hole injection layer 3 was produced. The 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 at a rate of 0.2 nm/sec to a thickness of 85 nm to form the first hole transport layer 41 .

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

(Preparation of light-emitting layer 5)
3-(10-phenyl-9-anthryl)-dibenzofuran and 2,7-bis[N,N-di-(4-tertbutylphenyl)]amino-bisbenzofurano-9,9′-spirofluorene purified by sublimation and were deposited at a ratio of 95:5 (mass ratio) to a thickness of 20 nm to prepare a light-emitting layer 5 . The deposition rate was 0.1 nm/sec.

(Preparation of hole blocking layer 9)
4,6-diphenyl-2-[3″-(phenanthren-9-yl)-4′-phenyl-1,1′:2′,1″terphenyl-5″-yl synthesized in Synthesis Example-1 ]-1,3,5-triazine was deposited at a rate of 0.05 nm/sec to form a film having a thickness of 6 nm, thereby forming a hole blocking layer 9 .

(Preparation of electron transport layer 6)
Sublimation purified 4,6-diphenyl-2-[5-(phenanthren-9-yl)-3-(dimethylpyridin-3-yl)phenyl]-1,3,5-triazine and 8-hydroxyquinolinolatolithium (hereinafter referred to as Liq) was deposited at a ratio of 50:50 (mass ratio) to a thickness of 25 nm to prepare an electron transport layer 6 . The deposition rate was 0.15 nm/sec.

(Preparation of electron injection layer 7)
An electron injection layer 7 was produced by depositing Liq to a thickness of 1 nm at a rate of 0.02 nm/sec.

(Preparation 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 was formed by depositing silver/magnesium (mass ratio 1/10) and silver in this order to 80 nm and 20 nm, respectively, to form a two-layer structure. The deposition rate of silver/magnesium was 0.5 nm/second, and the deposition rate of silver was 0.2 nm/second.

As described above, an organic electroluminescence device 100 having a light emitting area of 4 mm ² as shown in FIG. 2 was produced. Each film thickness was measured with a stylus film thickness meter (DEKTAK, manufactured by Bruker).
Furthermore, this device was sealed in a nitrogen atmosphere glove box with an oxygen and water concentration of 1 ppm or less. Sealing was performed by using a bisphenol F type epoxy resin (manufactured by Nagase ChemteX Corporation) between the glass sealing cap and the film formation substrate (element).

Element reference example-1
In Device Example-1, 4,6-diphenyl-2-[5-(phenanthren-9-yl)-biphenyl-3-yl]-1,3,5-triazine (ETL- 1) Instead of depositing 25 nm of ETL-1 and Liq at a ratio of 50:50 (mass ratio) (deposition rate: 0.15 nm/sec), ETL-1 and Liq were deposited at a ratio of 50:50 (mass ratio) to 25 nm. An organic electroluminescence device was produced in the same manner as in Device Example-1, except that the film was formed at a film formation rate of 0.15 nm/sec.

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

As light emission characteristics, the voltage (V) and current efficiency (cd/A) when a current density of 10 mA/cm ² was applied were measured, and the life of the element during continuous lighting was measured. The device life was measured by measuring the luminance decay time during continuous lighting when the device was driven at an initial luminance of 1000 cd/m ² , and measuring the time required for the luminance (cd/m ² ) to decrease by 3%. The values of voltage (V), current efficiency (cd/A), and lifetime are expressed as relative values when the element reference example-1 is set to 100. Table 1 shows the results.

From Table 1, it can be seen that the organic electroluminescence device using the triazine compound (1) has a higher glass transition temperature and excellent heat resistance than the reference example, and is superior in terms of voltage, luminous efficiency, and device life. It has been found that higher dimensions can be achieved.

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 element

Claims (6)

Triazine compound represented by formula (1):

During the ceremony,
Ar ¹ and Ar ² each independently represent a phenyl group, a biphenylyl group or a naphthyl group;
Ar ³ represents a phenanthrenyl, dimethylfluorenyl or triphenylenyl group ;
Ar ⁴ represents a phenyl, biphenylyl or naphthyl group;
each R independently represents a monocyclic, linked or condensed ring aromatic hydrocarbon group having 6 to 13 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms;
p represents 0 ;
q represents 1 or 2; The triazine compound according to Claim 1, wherein Ar ¹ and Ar ² are the same group. 3. The triazine compound according to claim 1 or ² , wherein Ar ¹ and Ar 2 are each independently a phenyl group or a biphenylyl group. ^4. The triazine compound according to any one of claims 1 to 3 , wherein Ar4 is a phenyl group or a biphenylyl group. 5. The triazine compound according to any one of claims 1 to 4 , wherein R is a phenyl group or a biphenylyl group. A material for an organic electroluminescence device, comprising the triazine compound according to any one of claims 1 to 5 .

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