JP2014208602A - New imidazole compound, material for electronic device, light emitting element, electronic device and method for producing thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new imidazole compound which can reduce the number of layers of a light-emitting element structure and is excellent in stability of a thin film.SOLUTION: There is used an imidazole compound represented by the general formula (1): (where, Rand Reach independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, a polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms and a biphenyl group; Rand Reach independently represents a carbazole group, which is directly bonded or bonded via a bonding chain having a conjugated structure, a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, a polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms and a biphenyl group; and at least one of Rand Ris a carbazole group, which is directly bonded or bonded via a bonding chain having a conjugated structure.)

Description

  The present invention relates to a novel imidazole compound, a material for an electronic device, a light emitting element, an electronic device, and a method for producing the same, and particularly as a light emitting material constituting a light emitting layer of a light emitting element such as an organic electroluminescence (EL) element. The present invention relates to a novel imidazole compound useful as a host material constituting a light emitting layer, an electronic device material containing the compound, a light emitting element containing the electronic device material, an electronic device including the light emitting element, and a method for manufacturing the electronic device.

Various studies have been conducted so far as materials for electronic devices, particularly light emitting materials and host materials constituting light emitting layers of light emitting elements such as organic EL elements.
For example, Patent Document 1 describes the use of a 2,4,5-triaryl-substituted imidazole compound and a 1,2,4,5-tetraaryl-substituted imidazole compound as a blue fluorescent material.
Patent Document 2 describes that a phenylpyridine derivative is used as a light-emitting material, and that a 2,4,5-tris (6-pyridylbiphenyl) imidazole derivative is used as a phosphorescent host material.
Further, in Non-Patent Document 1, CBP (4,4′-N, N′-dicarbazole-biphenyl) or mCP (1,3-di (carbazoyl-9-yl) benzene) is used as a host material. Have been described.
Non-Patent Document 2 describes the use of a benzodifuran derivative as a bipolar host material.

  A host material in a light-emitting element using a phosphorescent light-emitting material as a light-emitting material (dopant) needs to have a sufficient ability to transport electrons and holes, and have a high glass transition point (Tg) and a film-forming property.

  However, CBP, which is a well-known host compound, has insufficient thin film stability. Further, since mCP has a low glass transition point (Tg), there is a problem that thermal stability is low when an element is formed.

  In recent years, in order to obtain high luminous efficiency, the element structure has become a multi-layered structure composed of an extremely large number of layers. Therefore, it is required to simplify the manufacturing process and reduce the cost by lowering the element structure. . For example, in a light-emitting element using a benzodifuran derivative described in Non-Patent Document 2, it is possible to realize a single layer or a low layer of an organic layer, but the element structure is special and manufacturing is difficult. In addition, since the film forming process is limited to the vacuum deposition method, there is a problem that the manufacturing process is complicated. That is, the present condition is that the material for electronic devices which can simplify both an element structure and a manufacturing process has not been found until now.

  On the other hand, organic EL displays and organic EL lighting have been put into practical use in recent years. From the viewpoint of improving display color reproducibility and illumination color rendering, a light emitting material having a shorter emission wavelength, that is, emitting deep blue light. Is desired. For example, Non-Patent Document 3 describes using BDAVBi, which is a styryl derivative, in addition to the imidazole compound described in Patent Document 1 as a blue fluorescent material.

  However, the conventional imidazole derivatives described in Patent Document 1 have a low fluorescence intensity, and BDAVBi has a fluorescence emission wavelength of 476 nm (in THF), and has a problem of emitting light blue having a long emission wavelength.

International Publication No. 2005/085208 JP 2003-282270 A

Appl. Phys. Lett. 2003, 82, 2422 Adv. Mater. 2009, 21, 3776 Org. Electr. 2008, 9, 692

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a novel imidazole compound that can reduce the layer structure of a light emitting device, has excellent thin film stability, and has strong blue fluorescence. That is. Moreover, it is providing the electronic device material containing this novel imidazole compound, the light emitting element containing this electronic device material, the electronic device containing the light emitting element, and the manufacturing method of the electronic device.

As a result of intensive investigations to solve the above-mentioned problems, the present inventors have a carbazole group linked to the 4-position and / or 5-position of the imidazole ring, directly or via a bond chain having a conjugated structure. It has been found that an imidazole compound can solve the above problems.
It has also been found that a light emitting device containing the imidazole compound, for example, a light emitting device containing the imidazole compound as a light emitting material or a host material in the light emitting layer is suitable.
Furthermore, since the said imidazole compound has a high glass transition point (Tg), when the thin film was formed into a film using the said imidazole compound, it discovered also that the stability of a thin film was high.

  That is, this invention provides the imidazole compound shown by General formula (1).

（式中、Ｒ^１、及びＲ^２は、それぞれ独立して、水素原子、炭素数１〜１０のアルキル基、フェニル基、炭素数１０〜１６の多環芳香族炭化水素基、ビフェニル基を表し、Ｒ^３、及びＲ^４は、それぞれ独立して、直接又は共役構造を有する結合鎖を介して連結したカルバゾール基、水素原子、炭素数１〜１０のアルキル基、フェニル基、炭素数１０〜１６の多環芳香族炭化水素基、ビフェニル基を表し、Ｒ^３、及びＲ^４のうち少なくとも１つは、直接又は共役構造を有する結合鎖を介して連結したカルバゾール基である。）

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, a polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms, or a biphenyl group. , R ³ , and R ⁴ are each independently a carbazole group, a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, or a carbon group having 10 to 16 carbon atoms linked directly or via a bond chain having a conjugated structure. And at least one of R ³ and R ⁴ is a carbazole group linked directly or via a bond chain having a conjugated structure.)

Furthermore, this invention provides the material for electronic devices containing the imidazole compound of this invention.
Moreover, the light emitting element containing the electronic device material of this invention, the light emitting element which has the layer containing the electronic device material of this invention between a cathode and an anode, and contains the electronic device material of this invention as a light emitting material Provided are a light emitting element, a light emitting element containing the electronic device material of the present invention as a host material, and an electronic device including the light emitting element of the present invention.
Also, there is provided a method for manufacturing an electronic device comprising a step of applying a solution of the electronic device material of the present invention onto a substrate and forming a film, and a step of depositing the film of the electronic device material of the present invention on the substrate to form a film. An electronic device manufacturing method and an electronic device manufacturing method including a step of melt-coating a material for an electronic device of the present invention on a substrate and forming a film are provided.

Since the novel imidazole compound of the present invention has a high glass transition point (Tg), the stability of the thin film is high when a thin film is formed using the imidazole compound. Therefore, when the electronic device material containing the novel imidazole compound of the present invention is used, for example, when applied to a light emitting device, the light emitting efficiency is improved, the life of the light emitting device is extended, and the display device includes such a light emitting device. This also has the effect of extending the life of the electronic device.
By using the imidazole compound of the present invention as a host material, it is possible to obtain a light-emitting element having excellent low-voltage driving characteristics, stable and high quantum efficiency. In addition, when used as a light-emitting material, a light-emitting element that emits deep blue light can be obtained.
Moreover, since the material for electronic devices containing the imidazole compound of the present invention has excellent film forming properties, film formation by solution coating, vapor deposition, and melt coating methods is possible. In particular, as a host material and further as a phosphorescent dopant host material, it is possible to form a light-emitting layer by a solution coating, vapor deposition, or melt coating method, which has been difficult in the past.

It is a graph which shows the relationship between the rotation speed at the time of spin coating, and a film thickness in each density | concentration of the imidazole compound solution synthesize | combined in Example 8. FIG. 22 is a graph showing voltage-luminance characteristics of the light-emitting element created in Example 16. 22 is a graph showing voltage-current efficiency of the light-emitting element created in Example 16. 18 is a graph showing voltage-luminance characteristics of the light-emitting element created in Example 17. 14 is a graph showing voltage-current efficiency of a light-emitting element created in Example 17. 42 is a graph showing voltage-luminance characteristics of the light-emitting elements created in Example 18. 22 is a graph showing voltage-current efficiency of the light-emitting element created in Example 18. 10 is a graph showing voltage-luminance characteristics of a light emitting device created in Comparative Example 4. 6 is a graph showing voltage-current efficiency of a light emitting device created in Comparative Example 4. 42 is a graph showing voltage-luminance characteristics of the light-emitting elements created in Example 19. 22 is a graph showing voltage-current efficiency of a light-emitting element created in Example 19. 42 is a graph showing voltage-luminance characteristics of the light-emitting elements created in Example 20. It is a graph which shows the voltage-current efficiency of the light emitting element created in Example 20. FIG. 22 is a graph showing voltage-luminance characteristics of the light-emitting element created in Example 21. 22 is a graph showing voltage-current efficiency of a light emitting device created in Example 21. 10 is a graph showing voltage-luminance characteristics of a light emitting device created in Comparative Example 5. 10 is a graph showing voltage-current efficiency of a light emitting device created in Comparative Example 5. 22 is a graph illustrating voltage-luminance characteristics of the light-emitting element created in Example 22. 22 is a graph showing voltage-current efficiency of a light-emitting element created in Example 22. 22 is a graph showing an emission spectrum of the light-emitting element created in Example 22.

The present invention is described in detail below.
The imidazole compound of the present invention is an imidazole compound represented by the following general formula (1).

In general formula (1), R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, a polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms, or biphenyl. Represents a group.
R ³ and R ⁴ are each independently a carbazole group, a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, or a carbon number of 10 to 10 linked directly or via a bond chain having a conjugated structure. 16 polycyclic aromatic hydrocarbon groups and a biphenyl group are represented.
In general formula (1), at least one of R ³ and R ⁴ is a carbazole group linked directly or via a bond chain having a conjugated structure.
Therefore, the imidazole compound of the present invention represented by the general formula (1) includes the following imidazole compounds.

（式中、Ｒ^１、及びＲ^２は、それぞれ独立して、水素原子、炭素数１〜１０のアルキル基、フェニル基、炭素数１０〜１６の多環芳香族炭化水素基、ビフェニル基を表し、Ｒ^３、及びＲ^４は、共役構造を有する結合鎖を介して連結したカルバゾール基である。） An imidazole compound represented by the general formula (1).

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, a polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms, or a biphenyl group. , R ³ , and R ⁴ are carbazole groups linked via a bond chain having a conjugated structure.)

（式中、Ｒ^１、Ｒ^２、及びＲ^３は、それぞれ独立して、水素原子、炭素数１〜１０のアルキル基、フェニル基、炭素数１０〜１６の多環芳香族炭化水素基、ビフェニル基を表し、Ｒ^４は、共役構造を有する結合鎖を介して連結したカルバゾール基である。） An imidazole compound represented by the following general formula (1).

(In the formula, R ¹ , R ² , and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, a polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms, or biphenyl. And R ⁴ is a carbazole group linked via a bond chain having a conjugated structure.

（式中、Ｒ^１、Ｒ^２、及びＲ^４は、それぞれ独立して、水素原子、炭素数１〜１０のアルキル基、フェニル基、炭素数１０〜１６の多環芳香族炭化水素基、ビフェニル基を表し、Ｒ^３は、共役構造を有する結合鎖を介して連結したカルバゾール基である。 An imidazole compound represented by the following general formula (1).

(Wherein R ¹ , R ² , and R ⁴ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, a polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms, or biphenyl. R ³ represents a carbazole group linked via a bond chain having a conjugated structure.

（式中、Ｘは不飽和炭化水素鎖、芳香族鎖、又は複素芳香族鎖を表し、Ｒ^１、及びＲ^２は、それぞれ独立して、水素原子、炭素数１〜１０のアルキル基、フェニル基、多環芳香族炭化水素基、ビフェニル基を表し、Ｒ^５、Ｒ^６、Ｒ^７、Ｒ^８、Ｒ^９、Ｒ^１０、Ｒ^１１及びＲ^１２は、それぞれ独立して、水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、フェニル基、多環芳香族炭化水素基を有するアミノ基、フッ化アルキル基、ハロゲン原子、ニトロ基、シアノ基、カルバゾール基を表し、又は、それぞれ縮環して５員環もしくは６員環を形成していても良い。 An imidazole compound represented by the following general formula (2).

(In the formula, X represents an unsaturated hydrocarbon chain, an aromatic chain, or a heteroaromatic chain, and R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, phenyl, Group, polycyclic aromatic hydrocarbon group, biphenyl group, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently a hydrogen atom, carbon number An alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenyl group, an amino group having a polycyclic aromatic hydrocarbon group, a fluorinated alkyl group, a halogen atom, a nitro group, a cyano group, and a carbazole group; Alternatively, each may be condensed to form a 5-membered ring or a 6-membered ring.

（式中、Ｘは不飽和炭化水素鎖、芳香族鎖、又は複素芳香族鎖を表し、Ｒ^１、Ｒ^２及びＲ^４は、それぞれ独立して、水素原子、炭素数１〜１０のアルキル基、フェニル基、多環芳香族炭化水素基、ビフェニル基を表し、Ｒ^５、Ｒ^６、Ｒ^７、Ｒ^８、Ｒ^９、Ｒ^１０、Ｒ^１１及びＲ^１２は、それぞれ独立して、水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、フェニル基、多環芳香族炭化水素基を有するアミノ基、フッ化アルキル基、ハロゲン原子、ニトロ基、シアノ基、カルバゾール基を表し、又は、それぞれ縮環して５員環もしくは６員環を形成していても良い。） An imidazole compound represented by the following general formula (3).

(In the formula, X represents an unsaturated hydrocarbon chain, an aromatic chain, or a heteroaromatic chain, and R ¹ , R ^2, and R ⁴ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. , Phenyl group, polycyclic aromatic hydrocarbon group, biphenyl group, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently a hydrogen atom, An alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenyl group, an amino group having a polycyclic aromatic hydrocarbon group, a fluorinated alkyl group, a halogen atom, a nitro group, a cyano group, and a carbazole group. Or may be condensed to form a 5-membered ring or a 6-membered ring.

（式中、Ｘは不飽和炭化水素鎖、芳香族鎖、又は複素芳香族鎖を表し、Ｒ^１、Ｒ^２及びＲ^３は、それぞれ独立して、水素原子、炭素数１〜１０のアルキル基、フェニル基、多環芳香族炭化水素基、ビフェニル基を表し、Ｒ^５、Ｒ^６、Ｒ^７、Ｒ^８、Ｒ^９、Ｒ^１０、Ｒ^１１及びＲ^１２は、それぞれ独立して、水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、フェニル基、多環芳香族炭化水素基を有するアミノ基、フッ化アルキル基、ハロゲン原子、ニトロ基、シアノ基、カルバゾール基を表し、又は、それぞれ縮環して５員環もしくは６員環を形成していても良い。） An imidazole compound represented by the following general formula (4).

(In the formula, X represents an unsaturated hydrocarbon chain, an aromatic chain, or a heteroaromatic chain, and R ¹ , R ^2, and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. , Phenyl group, polycyclic aromatic hydrocarbon group, biphenyl group, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently a hydrogen atom, An alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenyl group, an amino group having a polycyclic aromatic hydrocarbon group, a fluorinated alkyl group, a halogen atom, a nitro group, a cyano group, and a carbazole group. Or may be condensed to form a 5-membered ring or a 6-membered ring.

Each substituent in the imidazole compound represented by the general formulas (1) to (4) will be specifically described.
Examples of the alkyl group having 1 to 10 carbon atoms represented by R ¹ , R ² , R ³ , and R ⁴ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and sec-butyl. Group, tert-butyl group, n-pentyl group, amyl group, isoamyl group, tert-amyl group, neopentyl group, n-hexyl group and the like, preferably 1 to 8 carbon atoms, particularly preferably 1 to carbon atoms. 6, More preferably, it is a C1-C4 alkyl group.
The alkyl group may have a substituent. Examples of the substituent include an amino group, an amino group having an aromatic hydrocarbon group (for example, a diphenylamino group, a dinaphthylamino group, etc.), a halogen atom, and the like. (For example, fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), nitro group, cyano group, alkoxy group having 1 to 6 carbon atoms (for example, methoxy group, ethoxy group, propyloxy group, isopropyloxy group, butyloxy group) Pentyloxy group, hexyloxy group, etc.), phenyl group, polycyclic aromatic hydrocarbon group and the like. The above aromatic hydrocarbon group, phenyl group, and polycyclic aromatic hydrocarbon group are an amino group, a halogen atom, a nitro group, a cyano group, an alkoxy group having 1 to 6 carbon atoms, and an alkyl group having 1 to 6 carbon atoms. May have a fluorinated alkyl group having 1 to 6 carbon atoms.

The polycyclic aromatic hydrocarbon group represented by R ¹ , R ² , R ³ , and R ⁴ has 10 to 16 carbon atoms, preferably 10 to 15 carbon atoms, more preferably 10 to 13 carbon atoms. A ring aromatic hydrocarbon group is mentioned.
For example, carbon condensed bicyclic systems such as azulenyl group and naphthyl group, carbon condensed tricyclic systems such as indacenyl group, biphenylenyl group, acenaphthylenyl group, fluorenyl group, phenalenyl group, phenanthryl group and anthracenyl group, and carbon condensed tetracyclic groups such as pyrenyl group Examples include ring systems. Preferred are carbon-fused bi- to tetra-ring systems, and particularly preferred are carbon-fused bi- to tri-ring systems.
Preferred is a C10-16 carbon condensed bicyclic to tetracyclic system, particularly preferred is a C10-13 carbon condensed bicyclic to tricyclic system, and particularly preferred is an unsubstituted carbon number 10 ~ 13 carbon fused bicyclic ring systems.

The alkyl group having 1 to 10 carbon atoms, the phenyl group, and the biphenyl group represented by R ¹ , R ² , R ³ , and R ⁴ may have a substituent. Examples of the substituent include amino Group, an amino group having an aromatic hydrocarbon group (for example, a diphenylamino group, a dinaphthylamino group, etc., and the aromatic hydrocarbon group is an amino group, a halogen atom, a nitro group, a cyano group, or a carbon number of 1 to 6). An alkoxy group having 1 to 6 carbon atoms, a fluorinated alkyl group having 1 to 6 carbon atoms, or a fluorinated alkyl group (for example, a fluorinated alkyl group having 1 to 6 carbon atoms). ), Halogen atoms (for example, fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), nitro group, cyano group, alkyl group having 1 to 6 carbon atoms (for example, methyl group, ethyl group, propyl group, isopropyl group, n -Butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, amyl group, isoamyl group, tert-amyl group, neopentyl group, n-hexyl group, etc.), alkoxy having 1 to 6 carbon atoms Group (for example, methoxy group, ethoxy group, propyloxy group, isopropyloxy group, butyloxy group, pentyloxy group, hexyloxy group, etc.) and the like.

R ¹ , R ² , R ³ other than the carbazole group, and R ⁴ other than the carbazole group are preferably a phenyl group or a polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms, and more preferably a phenyl group. As the substituent when the phenyl group or the polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms has a substituent, a cyano group, an alkoxy group having 1 to 4 carbon atoms, and a diphenylamino group are preferable.
That is, a phenyl group; a phenyl group having at least one substituent selected from a cyano group, an alkoxy group having 1 to 4 carbon atoms, and a diphenylamino group; a polycyclic aromatic hydrocarbon group (for example, a naphthyl group, a pyrenyl group, etc. ); A polycyclic aromatic hydrocarbon group having at least one substituent selected from a cyano group, an alkoxy group having 1 to 4 carbon atoms, and a diphenylamino group (for example, a naphthyl group, a pyrenyl group, etc.) is particularly preferable. A phenyl group having at least one substituent selected from a cyano group, an alkoxy group having 1 to 4 carbon atoms, and a diphenylamino group is preferable.

In the general formula (1), examples of the bonding chain having a conjugated structure represented by R ³ and R ⁴ include a linking structure that has a conjugated structure and can maintain molecular conjugation. X in 2) to (4) can be mentioned.

X in the general formulas (2) to (4) is a bond chain that has a conjugated structure and can maintain the conjugation of the molecule, and examples thereof include unsaturated hydrocarbon chains, aromatic chains, and heteroaromatic chains. It is done.
Examples of the unsaturated hydrocarbon chain include an unsaturated hydrocarbon chain in which a conjugated system is extended by a double bond or a triple bond. Specifically, for example, vinylene, propenylene, tetramethylene, 1,2-dimethylethylene, Examples include ethynylene and 1,3-butadienylene.
The aromatic chain is derived from phenylene (for example, 1,4-phenylene), a divalent chain derived from a polycyclic aromatic hydrocarbon, biphenylylene (for example, 4,4′-biphenylylene), or azulene. Bivalent chains are mentioned.
Examples of the heteroaromatic chain include a divalent chain derived from a heteroaromatic hydrocarbon such as imidazole, furan, thiophene, and pyrrole.
X may be a linking chain linked by combining two or more types of linking chains selected from these linking chains.

  The unsaturated hydrocarbon chain, aromatic chain, and heteroaromatic chain represented by X may have a substituent. Examples of such substituent include an amino group and an amino group having an aromatic hydrocarbon group. (For example, a diphenylamino group, a dinaphthylamino group, and the aromatic hydrocarbon group includes an amino group, a halogen atom, a nitro group, a cyano group, an alkoxy group having 1 to 6 carbon atoms, and an alkyl group having 1 to 6 carbon atoms. Group, may have a fluorinated alkyl group having 1 to 6 carbon atoms.), Fluorinated alkyl group (for example, fluorinated alkyl group having 1 to 6 carbon atoms), halogen atom (for example, fluorine atom, chlorine) Atom, bromine atom, iodine atom, etc.), nitro group, cyano group, alkyl group having 1 to 6 carbon atoms (for example, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl) , Tert-butyl group, n-pentyl group, amyl group, isoamyl group, tert-amyl group, neopentyl group, n-hexyl group, etc.), alkoxy group having 1 to 6 carbon atoms (for example, methoxy group, ethoxy group, propyl group) Oxy group, isopropyloxy group, butyloxy group, pentyloxy group, hexyloxy group, etc.).

  X in the general formulas (2) to (4) is preferably a divalent chain derived from an aromatic hydrocarbon which may have a substituent, for example, phenylene which may have a substituent, A divalent chain derived from an optionally substituted polycyclic aromatic hydrocarbon, an optionally substituted biphenylylene is preferred, an optionally substituted phenylene, and a substituent Biphenylylene, which may have, is particularly preferred.

In general formula (1), the carbazole group represented by R ³ and R ⁴ may have a substituent. Examples of the substituent include groups represented by R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² in the general formulas (2) to (4).
R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ^11, and R ¹² in the general formulas (2) to (4) represent substituents that the carbazole group has, and each independently , Hydrogen atom, alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, phenyl group, amino group having a polycyclic aromatic hydrocarbon group, fluorinated alkyl group, halogen atom, nitro group, cyano group Represents a carbazole group.

Examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, and amyl group. , Isoamyl group, tert-amyl group, neopentyl group, n-hexyl group and the like.
Examples of the alkoxy group having 1 to 6 carbon atoms include methoxy group, ethoxy group, propyloxy group, isopropyloxy group, butyloxy group, pentyloxy group, hexyloxy group and the like.
Examples of the amino group having a polycyclic aromatic hydrocarbon group include a dinaphthylamino group and a dianthracenyl group, and the polycyclic aromatic hydrocarbon group may have a substituent. Examples thereof include an amino group, a halogen atom, a nitro group, a cyano group, an alkoxy group having 1 to 6 carbon atoms, and an alkyl group having 1 to 6 carbon atoms. In addition, the above-mentioned thing is mentioned as a halogen atom, a C1-C6 alkoxy group, and a C1-C6 alkyl group.
When the carbazole group has two or more substituents, the substituents may be condensed to form a 5-membered ring or a 6-membered ring.

Since the imidazole compounds represented by the general formulas (1) to (4) have a high glass transition point, they can be suitably used as a light-emitting element having excellent thermal stability and further as an electronic device.
The glass transition point (Tg) of such a compound is usually 100 ° C. or higher. Since it is preferable that the light emitting layer of the light emitting element is in an amorphous state particularly when used as a host material, the glass transition point is preferably high or has no peak. The glass transition point (Tg) is preferably 130 ° C. or higher, particularly preferably 150 ° C. or higher, in that various manufacturing methods described later can be employed. Moreover, melting | fusing point (Tm) is 150 to 400 degreeC normally, Preferably it is 180 to 380 degreeC, Most preferably, it is 200 to 350 degreeC.

  The imidazole compounds represented by the general formulas (1) to (4) can be produced by a known method.

  The imidazole compounds represented by the general formulas (1) to (4) of the present invention can be suitably used as light-emitting elements, organic thin-film solar cells, and the like as electronic device materials. Specifically, for example, it can be suitably used as a host material or a light emitting material contained in a light emitting layer of a light emitting element such as an organic EL display or organic EL illumination. When used as a light-emitting material, deep blue light emission that has not been obtained conventionally can be obtained.

  The electronic device material of the present invention contains the novel imidazole compound of the present invention usually in an amount of 1 to 100% by weight. Depending on the intended use, it may contain 0 to 99% by weight of known solvents, other light emitting materials, other host materials, additives and the like.

The electronic device of the present invention includes a light emitting element, for example, a light emitting element having a cathode and an anode, and a light emitting layer interposed between these electrodes. Examples of such light emitting elements include organic EL elements. In the organic EL element, holes from the anode and electrons from the cathode are injected into the light emitting layer, and they recombine in the light emitting layer to generate excitons, which emit light when they are deactivated. This organic EL element can be applied to electronic devices such as a light emitting light source, a lighting device, and a display device.
In addition, the cathode, anode, and other materials constituting the light emitting layer of the organic EL element can be appropriately selected from known materials. The element may include an electron transport layer including an electron transport material between the cathode and the light emitting layer, and a hole transport layer including a hole transport material between the anode and the organic thin film layer. It may be. Furthermore, the device includes a carrier injection layer containing a carrier injection material between the cathode or the anode and the carrier transport layer or the light emitting layer for the purpose of electron injection from the cathode or hole injection from the anode. Also good. As these electron transport material, hole transport material and carrier injection material, known materials can be appropriately used.

The imidazole compound of the present invention can be suitably used as a light emitting material (dopant material) or a host material contained in the light emitting layer as a material for electronic devices.
In the light emitting layer composed of two or more compounds, the compound having the lowest mixing ratio (mass ratio) is the light emitting material, and the compound having the highest mixing ratio (mass ratio) is the host material. For example, when the light emitting layer is composed of two types of compound A and compound B and the mixing ratio is A: B = 10: 90, compound A is a light emitting material compound and compound B is a host compound. Further, when the light emitting layer is composed of three types of compound A, compound B, and compound C and the mixing ratio is A: B: C = 5: 10: 85, compound A is a light emitting material compound, and compound C Is a host compound.

  Note that, when a light emitting element using the electronic device material of the present invention as a light emitting material is produced, if a method of doping the light emitting layer of a conventional light emitting element with the electronic device material of the present invention is adopted, the luminous efficiency is improved. This is preferable in terms of extending the life of the light emitting element. For example, a host compound represented by CBP or the like may be used by doping.

In addition, since the electronic device material contains the novel imidazole compound of the present invention, a light-emitting element can be produced by forming a thin film on a substrate by a solution coating method, a vapor deposition method, or a melt coating method.
For example, as a method of forming a light-emitting layer of a light-emitting element using the electronic device material of the present invention, a method of applying a solution of the electronic device material on a substrate, and depositing the electronic device material on the substrate And a method in which the electronic device material is melted and applied onto a substrate.

Examples of such a substrate include known substrates generally used for electronic devices, such as glass, quartz, sapphire, silicon, silicon carbide, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyimide, polyaramid, and cycloolefin polymers. And polycarbonate.
Such a substrate may have a transparent conductive layer such as ITO.

Examples of the method for applying the solution of the electronic device material of the present invention on the substrate include a spin coating method, a casting method, an ink jet method, and a printing method. Examples of the solvent used in the solution of the electronic device material include aromatic compounds such as toluene and xylene, halogen-containing solvents such as 1,2-dichloroethane and chlorobenzene, ether solvents such as ethylene glycol dimethyl ether, and ethyl acetate. Examples include aliphatic esters, ketone solvents such as acetone and methyl ethyl ketone, amide solvents such as N, N-dimethylformamide, and dimethyl sulfoxide. These may be used alone or in combination of two or more.
After the solution of the electronic device material is applied on the substrate or other layers, the light emitting layer is formed by removing the solvent by performing drying by heating or drying under reduced pressure as necessary.

As a method for vapor-depositing the electronic device material of the present invention on a substrate, a known vapor deposition method can be applied.
Moreover, as a method of melt-coating the electronic device material of the present invention on a substrate, a known melt coating method can be applied.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded.
The compounds obtained in the examples have melting point (mp), infrared spectroscopy (IR), nuclear magnetic resonance ( ¹ H NMR, ¹³ C NMR), matrix-assisted laser desorption / ionization (MALDI) and time of flight, respectively. Identified using a mold (TOF) mass spectrometer (MS). Analysis conditions and the like employed in the examples are described in the examples.

[Reference Example 1]
Synthesis of 9- (4-bromophenyl) carbazole Under an argon stream, carbazole (3.34 g), potassium carbonate (2.76 g), and copper sulfate (0.255 g) were converted to 1,4-dibromobenzene (14.16 g). Heated at reflux for 7 hours. The obtained brown suspension was cooled to room temperature, water (200 ml) was added, and the mixture was extracted 3 times with benzene (50 ml). The benzene layer was concentrated under reduced pressure, and the resulting brown solid was subjected to silica gel column chromatography to obtain a white solid (4.40 g) from the fraction eluted with cyclohexane. The obtained white solid was recrystallized from hexane to obtain 9- (4-bromophenyl) carbazole (3.75 g, yield 58%).

[Reference Example 2]
Synthesis of 4- (9-carbazolyl) phenylboronic acid In a suspension of 9- (4-bromophenyl) carbazole (4.83 g) in dry THF (tetrahydrofuran, 24 ml) under a stream of argon, 1.6 M butyllithium in hexane The solution (10.6 ml) was added dropwise at −60 ° C. over 50 minutes and stirred at the same temperature for 1 hour. Next, a dry THF (6 ml) solution of trimethylborate ester (2.34 g) was added dropwise at −60 ° C. over 30 minutes, and the mixture was stirred at the same temperature for 1 hour. Then, it heated up to 27 degreeC and stirred for 3 hours. After adding 3.0 M hydrochloric acid (20 ml) to the mixture, the mixture was stirred for 15 minutes. After completion of the reaction, the reaction mixture was extracted 3 times with diethyl ether (20 ml), and the extract was washed 3 times with saturated brine (20 ml). The organic layer was dried over anhydrous magnesium sulfate and then concentrated under reduced pressure to obtain a yellow viscous liquid. Benzene (100 ml) was added thereto, and the precipitated crystals were filtered and dried to obtain 4- (9-carbazolyl) phenylboronic acid (3.23 g) as a pale yellow powder.

[Reference Example 3]
Synthesis of 5,5-dimethyl-2-[(9-carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane Under argon stream, boronic acid (3.16 g) and neopentyl were added to benzene (45 ml). Glycol (1.49 g) was added and stirred at room temperature for 1 hour, then anhydrous magnesium sulfate (7 g) was added, and then stirred overnight. After completion of the reaction, the reaction mixture was filtered, and the obtained filtrate was concentrated under reduced pressure to obtain a white solid. The obtained solid was subjected to silica gel column chromatography, and a white solid was obtained from the fraction eluted with cyclohexane. This was recrystallized from cyclohexane to obtain 5,5-dimethyl-2-[(9-carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane (3.01 g) as colorless needles.

[Reference Example 4]
Synthesis of 4,5-bis (4-bromophenyl) -2-phenyl-1H-imidazole Acetic acid (40 ml), ammonium acetate (1.27 g), benzaldehyde (0.41 g), and 4,4′-dibromobenzyl (1.10 g) was added and heated to reflux for 24 hours. After completion of the reaction, water (60 ml) was added to the reaction mixture, the deposited precipitate was collected by filtration, and washed with water (150 ml) three times. The obtained solid was dissolved in THF, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The obtained solid was washed with benzene (80 ml) to obtain a white solid. This was recrystallized with a mixed solvent of THF-benzene (1: 1) to give 4,5-bis (4-bromophenyl) -2-phenyl-1H-imidazole (1.09 g, yield 80%) as colorless needles. )

[Reference Example 5]
Synthesis of 4,5-bis (4-bromophenyl) -2- (4-cyanophenyl) -1H-imidazole The same procedure as in Reference Example 4 was performed, except that benzaldehyde was changed to 4-cyanobenzaldehyde. 5-bis (4-bromophenyl) -2- (4-cyanophenyl) -1H-imidazole (yield 77%) was obtained.

[Reference Example 6]
Synthesis of 4,5-bis (4-bromophenyl) -2- (4-methoxyphenyl) -1H-imidazole The same procedure as in Reference Example 4 was performed, except that benzaldehyde was replaced with p-anisaldehyde. 5-bis (4-bromophenyl) -2- (4-methoxyphenyl) -1H-imidazole (yield 70%) was obtained.

[Reference Example 7]
Synthesis of 4,5-bis (4-bromophenyl) -2- [4- (N, N-diphenylamino) phenyl] -1H-imidazole Except for replacing benzaldehyde with 4- (N, N-diphenylamino) benzaldehyde The same operation as in Reference Example 4 was performed to obtain 4,5-bis (4-bromophenyl) -2- [4- (N, N-diphenylamino) phenyl] -1H-imidazole (yield 77%). It was.

[Reference Example 8]
Synthesis of 4,5-bis (4-bromophenyl) -2- (1-naphthyl) -1H-imidazole Similar to Reference Example 4 except that benzaldehyde was replaced with 1-naphthaldehyde and 4,4′-dibromobenzyl. Thus, 4,5-bis (4-bromophenyl) -2- (1-naphthyl) -1H-imidazole (yield 65%) was obtained.

[Reference Example 9]
Synthesis of 4,5-bis (4-bromophenyl) -2- (2-naphthyl) -1H-imidazole The same procedure as in Reference Example 4 was performed, except that benzaldehyde was replaced with 2-naphthaldehyde. Bis (4-bromophenyl) -2- (2-naphthyl) -1H-imidazole (yield 71%) was obtained.

[Reference Example 10]
Synthesis of 4,5-bis (4-bromophenyl) -2- (1-pyrenyl) -1H-imidazole The same operation as in Reference Example 4 was performed except that benzaldehyde was replaced with pyrene-1-carbaldehyde. 5-bis (4-bromophenyl) -2- (1-pyrenyl) -1H-imidazole (61% yield) was obtained.

[Reference Example 11]
Synthesis of 4,5-bis (4-bromophenyl) -1-methyl-2-phenylimidazole Under a stream of argon, potassium carbonate (1.659 g), 4,5-bis (4-bromo) were added to a solution of DMF (6 ml). Phenyl) -2-phenyl-1H-imidazole (1.362 g) was added and stirred at room temperature for 30 minutes, methyl iodide (0.852 g) was added and stirred at the same temperature for 30 minutes. After completion of the reaction, water (120 ml) was added, and the deposited precipitate was collected by filtration to obtain a white solid. This was recrystallized from acetonitrile to obtain 4,5-bis (4-bromophenyl) -1-methyl-2-phenylimidazole (1.175 g, yield 84%).

[Reference Example 12]
Synthesis of 4,5-bis (4-bromophenyl) -2- (4-cyanophenyl) -1-methylimidazole 4,5-bis (4-bromophenyl) -2-phenyl-1H-imidazole was converted to 4,5 The same operation as in Reference Example 11 was performed except that -bis (4-bromophenyl) -2- (4-cyanophenyl) -1H-imidazole was used, and 4,5-bis (4-bromophenyl) -2- (4-Cyanophenyl) -1-methylimidazole (yield 80%) was obtained.

[Reference Example 13]
Synthesis of 4,5-bis (4-bromophenyl) -2- (4-methoxyphenyl) -1-methylimidazole 4,5-bis (4-bromophenyl) -2-phenyl-1H-imidazole was converted to 4,5 The same operation as in Reference Example 11 was performed except that -bis (4-bromophenyl) -2- (4-methoxyphenyl) -1H-imidazole was used, and 4,5-bis (4-bromophenyl) -2- (4-Methoxyphenyl) -1-methylimidazole (yield 80%) was obtained.

[Reference Example 14]
Synthesis of 4,5-bis (4-bromophenyl) -2- [4- (N, N-diphenylamino) phenyl] -1-methylimidazole 4,5-bis (4-bromophenyl) -2-phenyl- The same operation as in Reference Example 11 was performed except that 1H-imidazole was replaced with 4,5-bis (4-bromophenyl) -2- [4- (N, N-diphenylamino) phenyl] -1H-imidazole, 4,5-bis (4-bromophenyl) -2- [4- (N, N-diphenylamino) phenyl] -1-methylimidazole (yield 79%) was obtained.

[Reference Example 15]
Synthesis of 4,5-bis (4-bromophenyl) -1- (2-ethylhexyl) -2-phenylimidazole To a solution of dry DMF (5 ml) in a stream of argon, potassium carbonate (0.553 g), 4,5- Bis (4-bromophenyl) -2-phenyl-1H-imidazole (0.454 g) and 1-bromo-2-ethylhexane (0.290 g) were sequentially added, and the mixture was stirred at 80 ° C. for 24 hours. After completion of the reaction, water (50 ml) was added, extracted three times with hexane (20 ml), the hexane layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a white solid. The obtained white solid was subjected to column chromatography, and 4,5-bis (4-bromophenyl) -1- (2-ethylhexyl) -2-phenylimidazole (from the fraction eluted with hexane-ethyl acetate (5: 1) ( 0.558 g, 99% yield).

[Reference Example 16]
Synthesis of N-phenylacetamidine hydrochloride To a solution of ethylacetimidate hydrochloride (10.0 g) in methanol (80 ml), aniline (15.1 g) was added dropwise at room temperature over 15 minutes. After completion of dropping, the temperature was raised to 45 ° C. and reacted for 9 hours. After completion of the reaction, the reaction mixture was cooled and concentrated under reduced pressure to obtain N-phenylacetamidine hydrochloride (28.9 g) as a yellow oil. The product was used in the next reaction as it was without purification.

[Reference Example 17]
Synthesis of 2-methyl-1,5-diphenylimidazole N-phenylacetamidine hydrochloride (28.9 g) and potassium carbonate (25.6 g) were added to DMF (80 ml) and heated to an internal temperature of 56 ° C. A solution of phenacyl bromide (15.2 g) in DMF (30 ml) was added dropwise thereto over 45 minutes, and the mixture was further stirred at that temperature for 2 hours. After cooling to room temperature, water (250 ml) and toluene (160 ml) were added and the layers were separated. The aqueous layer was further extracted twice with toluene (100 ml) and mixed with the previously separated organic layer. The obtained organic layer was washed with water (100 ml) three times and then with saturated brine (100 ml). The organic layer was partially concentrated under reduced pressure (about 40 ml), succinic acid (6.8 g) was added thereto, and the mixture was stirred at room temperature for 1 hour. The precipitated crystals were filtered and washed 4 times with acetone (30 ml). The obtained crystals were dried to obtain a pale yellow solid (16.7 g). This was suspended in methanol (80 ml), and 5 M sodium methoxide in methanol (24.4 g) was added for neutralization. The precipitated crystals were filtered and washed with a small amount of methanol. The obtained filtrate was concentrated, toluene (100 ml) was added to the residue, washed with water (50 ml) three times, and then with saturated brine (50 ml). After drying with anhydrous magnesium sulfate, it was concentrated to dryness under reduced pressure to obtain 2-methyl-1,5-diphenylimidazole (9.9 g, yield 52.4%).

[Reference Example 17]
Synthesis of 4-bromo-2-methyl-1,5-diphenylimidazole To a solution of 2-methyl-1,5-diphenylimidazole (2.1 g) in acetonitrile (40 ml) under light shielding, N-bromosuccinimide (1. 6 g) was added and allowed to react for 24 hours at room temperature. After completion of the reaction, 0.1 M aqueous sodium thiosulfate solution (10 ml) was added and stirred for 1 hour. To this, methylene chloride (25 ml) and water (10 ml) were added and separated. The obtained organic layer was washed 3 times with water (10 ml) and concentrated under reduced pressure. The obtained residue was recrystallized from THF-hexane to obtain 4-bromo-2-methyl-1,5-diphenylimidazole (1.9 g, yield 66%).

[Example 1]
Synthesis of 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2-phenyl-1H-imidazole 4,5-bis (4-bromophenyl) in benzene (15 ml) under an argon stream -2-phenyl-1H-imidazole (114 mg), tetrakis (triphenylphosphine) palladium (0) (18 mg), 2M aqueous sodium carbonate (10 ml), 5,5-dimethyl-2-[(9-carbazolyl) phenyl- 4-yl] -1,3,2-dioxaborinane (206 mg) was added, and the mixture was heated to reflux for 24 hours. After completion of the reaction, water (20 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted three times with benzene (20 ml), and then the benzene layer was combined with the organic layer described above to separate insoluble matters. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give a yellow solid. This was subjected to silica gel column chromatography to obtain a pale yellow solid from the fraction eluted with hexane-ethyl acetate (3: 1). This was recrystallized from THF-methanol (1: 9) and 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2-phenyl-1H-imidazole (154 mg, as a pale yellow powder) Yield 79%).

[Example 2]
Synthesis of 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (4-cyanophenyl) -1H-imidazole Under a stream of argon, benzene (15 ml) was charged with 4,5-bis ( 4-bromophenyl) -2- (4-cyanophenyl) -1H-imidazole (120 mg), tetrakis (triphenylphosphine) palladium (0) (18 mg), 2M aqueous sodium carbonate solution (10 ml), 5,5-dimethyl- 2-[(9-carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane (206 mg) was added, and the mixture was heated to reflux for 24 hours. After completion of the reaction, water (20 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted three times with benzene (20 ml), and then the benzene layer was combined with the organic layer described above to separate insoluble matters. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give a yellow solid. This was subjected to silica gel column chromatography to obtain a yellow solid from the fraction eluted with dichloromethane. This was recrystallized from THF-cyclohexane (1: 9) and 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (4-cyanophenyl) -1H— as a yellow powder. Imidazole (47 mg, 35% yield) was obtained.

Example 3
Synthesis of 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (4-methoxyphenyl) -1H-imidazole Under a stream of argon, benzene (15 ml) was charged with 4,5-bis ( 4-Bromophenyl) -2- (4-methoxyphenyl) -1H-imidazole (122 mg), tetrakis (triphenylphosphine) palladium (0) (18 mg), 2M aqueous sodium carbonate solution (10 ml), 5,5-dimethyl- 2-[(9-carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane (206 mg) was added, and the mixture was heated to reflux for 24 hours. After completion of the reaction, water (20 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted three times with benzene (20 ml), and then the benzene layer was combined with the organic layer described above to separate insoluble matters. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a reddish brown solid. This was subjected to silica gel column chromatography to obtain a yellow solid from the fraction eluted with ethyl acetate. This was recrystallized from THF-methanol (1: 9) and 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (4-methoxyphenyl) -1H as a pale yellow powder. -Imidazole (127 mg, 63% yield) was obtained.

Example 4
Synthesis of 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- [4- (N, N-diphenylamino) phenyl] -1H-imidazole Benzene (15 ml) under a stream of argon 4,5-bis (4-bromophenyl) -2- [4- (N, N-diphenylamino) phenyl] -1H-imidazole (156 mg), tetrakis (triphenylphosphine) palladium (0) (18 mg), 2M aqueous sodium carbonate solution (10 ml) and 5,5-dimethyl-2-[(9-carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane (206 mg) were added, and the mixture was heated to reflux for 24 hours. After completion of the reaction, water (20 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted three times with benzene (20 ml), and then the benzene layer was combined with the organic layer described above to separate insoluble matters. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a dark green solid. This was subjected to silica gel column chromatography to obtain a yellow solid from the fraction eluted with benzene. This was recrystallized from THF-methanol (1: 9), and 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- [4- (N, N) as yellow needles. -Diphenylamino) phenyl] -1H-imidazole (126 mg, 53% yield) was obtained.

Example 5
Synthesis of 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (1-naphthyl) -1H-imidazole Under argon flow, 4,5-bis (4 -Bromophenyl) -2- (1-naphthyl) -1H-imidazole (126 mg), tetrakis (triphenylphosphine) palladium (0) (18 mg), 2M aqueous sodium carbonate solution (10 ml), 5,5-dimethyl-2- [(9-Carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane (206 mg) was added, and the mixture was heated to reflux for 24 hours. After completion of the reaction, water (20 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted three times with benzene (20 ml), and then the benzene layer was combined with the organic layer described above to separate insoluble matters. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a dark green solid. This was subjected to silica gel column chromatography to obtain a yellow solid from the fraction eluted with benzene. This was recrystallized with THF-cyclohexane (1: 9) and 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (1-naphthyl) -1H— as a pale yellow powder. Imidazole (182 mg, 88% yield) was obtained.

Example 6
Synthesis of 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (2-naphthyl) -1H-imidazole Under argon flow, 4,5-bis (4 -Bromophenyl) -2- (2-naphthyl) -1H-imidazole (126 mg), tetrakis (triphenylphosphine) palladium (0) (18 mg), 2M aqueous sodium carbonate (10 ml), 5,5-dimethyl-2- [(9-Carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane (206 mg) was added, and the mixture was heated to reflux for 24 hours. After completion of the reaction, water (20 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted three times with benzene (20 ml), and then the benzene layer was combined with the organic layer described above to separate insoluble matters. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a dark green solid. This was subjected to silica gel column chromatography to obtain a yellow solid from the fraction eluted with benzene. This was recrystallized from THF-cyclohexane (1: 9) and 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (2-naphthyl)-as pale yellow needles. 1H-imidazole (178 mg, 86% yield) was obtained.

Example 7
Synthesis of 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (1-pyrenyl) -1H-imidazole Into benzene (15 ml), 4,5-bis (4 -Bromophenyl) -2- (1-pyrenyl) -1H-imidazole (145 mg), tetrakis (triphenylphosphine) palladium (0) (18 mg), 2M aqueous sodium carbonate (10 ml), 5,5-dimethyl-2- [(9-Carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane (266 mg) was added, and the mixture was heated to reflux for 54 hours. After completion of the reaction, water (20 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted three times with benzene (20 ml), and then the benzene layer was combined with the organic layer described above to separate insoluble matters. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give a green solid. This was subjected to silica gel column chromatography to obtain a yellow solid from the fraction eluted with benzene. This was recrystallized from THF-cyclohexane (1: 9) and 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (1-pyrenyl)-as pale yellow needles. 1H-imidazole (188 mg, 83% yield) was obtained.

Example 8
Synthesis of 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -1-methyl-2-phenylimidazole 4,5-bis (4-bromophenyl) was added to benzene (30 ml) under an argon stream. ) -1-methyl-2-phenylimidazole (234 mg), tetrakis (triphenylphosphine) palladium (0) (35 mg), 2M aqueous sodium carbonate solution (20 ml), 5,5-dimethyl-2-[(9-carbazolyl) Phenyl-4-yl] -1,3,2-dioxaborinane (409 mg) was added, and the mixture was heated to reflux for 24 hours. After completion of the reaction, water (40 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted with benzene (40 ml) three times, and the benzene layer was combined with the organic layer described above to separate insolubles. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a gray solid. This was subjected to silica gel column chromatography to obtain a pale yellow solid from the fraction eluted with hexane-ethyl acetate (2: 1). This was recrystallized from ethyl acetate and 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -1-methyl-2-phenylimidazole (279 mg, yield 70%) as a pale white powder. Got.

Example 9
Synthesis of 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (4-cyanophenyl) -1-methylimidazole 4,5-Bis in toluene (30 ml) under an argon stream. (4-Bromophenyl) -2- (4-cyanophenyl) -1-methylimidazole (247 mg), tetrakis (triphenylphosphine) palladium (0) (35 mg), 2M aqueous sodium carbonate solution (20 ml), 5,5- Dimethyl-2-[(9-carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane (409 mg) was added and heated to reflux for 24 hours. After completion of the reaction, water (40 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted three times with toluene (40 ml), and then the toluene layer was combined with the organic layer described above to separate insoluble matters. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a gray solid. This was subjected to silica gel column chromatography to obtain a pale yellow solid from the fraction eluted with hexane-ethyl acetate (3: 1). This was recrystallized from THF-ethanol (1: 6), and 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (4-cyanophenyl) -1-methylimidazole ( 191 mg, 47% yield).

Example 10
Synthesis of 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (4-methoxyphenyl) -1-methylimidazole Into benzene (30 ml) under argon flow, 4,5-bis (4-Bromophenyl) -2- (4-methoxyphenyl) -1-methylimidazole (249 mg), tetrakis (triphenylphosphine) palladium (0) (35 mg), 2M aqueous sodium carbonate solution (20 ml), 5,5- Dimethyl-2-[(9-carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane (409 mg) was added and heated to reflux for 24 hours. After completion of the reaction, water (40 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted with benzene (40 ml) three times, and the benzene layer was combined with the organic layer described above to separate insolubles. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a gray solid. This was subjected to silica gel column chromatography to obtain a pale yellow solid from the fraction eluted with hexane-ethyl acetate (2: 1). This was recrystallized from THF-ethanol (1: 6), and 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- (4-methoxyphenyl) -1-methylimidazole ( 259 mg, yield 63%).

Example 11
Synthesis of 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- [4- (N, N-diphenylamino) phenyl] -1-methylimidazole Under a stream of argon, benzene (30 ml) ), 4,5-bis (4-bromophenyl) -2- [4- (N, N-diphenylamino) phenyl] -1-methylimidazole (318 mg), tetrakis (triphenylphosphine) palladium (0) (35 mg) ) 2M aqueous sodium carbonate solution (20 ml) and 5,5-dimethyl-2-[(9-carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane (409 mg) were added, and the mixture was heated to reflux for 24 hours. After completion of the reaction, water (40 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted with benzene (40 ml) three times, and the benzene layer was combined with the organic layer described above to separate insolubles. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a gray solid. This was subjected to silica gel column chromatography to obtain a pale yellow solid from the fraction eluted with hexane-ethyl acetate (2: 1). This was recrystallized from THF-ethanol (1: 6) to give 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -2- [4- (N, N-diphenylamino) phenyl. ] -1-methylimidazole (259 mg, yield 63%) was obtained.

Example 12
Synthesis of 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -1- (2-ethylhexyl) -2-phenylimidazole Into benzene (15 ml), 4,5-bis ( 4-Bromophenyl) -1- (2-ethylhexyl) -2-phenylimidazole (142 mg), tetrakis (triphenylphosphine) palladium (0) (17 mg), 2M aqueous sodium carbonate solution (10 ml), 5,5-dimethyl- 2-[(9-carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane (205 mg) was added, and the mixture was heated to reflux for 24 hours. After completion of the reaction, water (20 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted three times with benzene (20 ml), and then the benzene layer was combined with the organic layer described above to separate insoluble matters. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a gray solid. This was subjected to silica gel column chromatography, and a pale yellow oil was obtained from the fraction eluted with hexane-ethyl acetate (4: 1). This was recrystallized from THF-ethanol (1: 5) to give 4,5-bis [4 ′-(9-carbazolyl) biphenyl-4-yl] -1- (2-ethylhexyl) -2-phenylimidazole (155 mg). Yield 70%).

Example 13
Synthesis of 4,5-bis [4- (9-carbazolyl) phenyl] -1-methyl-2-phenylimidazole A solution of carbazole (1.7 g) in N, N-dimethylacetamide (27 ml) was added under nitrogen atmosphere to 4 , 5-bis (4-bromophenyl) -1-methyl-2-phenylimidazole (2.0 g) and copper (I) iodide (2.0 g) were added and heated to reflux for 50.5 hours. After completion of the reaction, the reaction mixture was allowed to cool to room temperature, methylene chloride (30 ml) was added, the precipitate was filtered, and the obtained organic layer was washed 3 times with water (40 ml). After evaporating the solvent under reduced pressure, the resulting residue was subjected to silica gel column chromatography to obtain a brown oil from the fraction eluted with methylene chloride. This was recrystallized from acetone-methanol (2: 1) to give 4,5-bis [4- (9-carbazolyl) phenyl] -1-methyl-2-phenylimidazole (990 mg, 36% yield). Obtained.

Example 14
Synthesis of 4- [4- (9-carbazolyl) phenyl] -2-methyl-1,5-diphenylimidazole Under a stream of argon, 4-bromo-2-methyl-1,5-diphenylimidazole (1.5 g), tetrakis (Triphenylphosphine) palladium (0) (260 mg), 5,5-dimethyl-2-[(9-carbazolyl) phenyl-4-yl] -1,3,2-dioxaborinane (2.0 g) and toluene (18 ml) ), Ethanol (6 ml), and 2M aqueous sodium carbonate solution (12 ml) were added, and the mixture was heated to reflux for 7 hours. After completion of the reaction, methylene chloride (35 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The organic layer was washed 3 times with water (20 ml) and concentrated under reduced pressure to give a gray solid. Methanol (20 ml) was added to this, stirred and then filtered. The obtained solid was subjected to silica gel column chromatography, and a beige solid was obtained from the fraction eluted with acetone. This was recrystallized from acetone to obtain 4- [4- (9-carbazolyl) phenyl] -2-methyl-1,5-diphenylimidazole (1.3 g, yield 71%).

[Comparative Example 1]
Synthesis of 4,5-bis [4 ′-(N, N-diphenylamino) biphenyl-4-yl] -1-methyl-2-phenylimidazole Under nitrogen flow, 4,5-bis (4 -Bromophenyl) -1-methyl-2-phenylimidazole (234 mg), tetrakis (triphenylphosphine) palladium (0) (35 mg), 2M aqueous sodium carbonate (20 ml), 5,5-dimethyl-2- [4- (N, N-diphenylamino) phenyl-4-yl] -1,3,2-dioxaborinane (412 mg) was added, and the mixture was heated to reflux for 24 hours. After completion of the reaction, water (60 ml) was added to the reaction mixture, and the organic layer and the aqueous layer were separated. The aqueous layer was extracted with benzene (60 ml) three times, and then the benzene layer was combined with the organic layer described above to separate insolubles. The filtrate was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a light brown solid. This was subjected to silica gel column chromatography, and a pale yellowish white solid was obtained from the fraction eluted with toluene-ethyl acetate (15: 1). This was recrystallized from THF-cyclohexane (1: 1) to give 4,5-bis [4 ′-(N, N-diphenylamino) biphenyl-4-yl] -1-methyl-2-phenylimidazole (261 mg, Yield 65%).

〔Evaluation item〕
1. Measurement of Thermal Properties Melting point (Tm) and glass transition temperature (Tg) were measured by DSC measurement of the compounds of Examples. First, the sample was heated at 10 ° C./min, and the temperature at which a peak showing endothermic melting was obtained was defined as Tm. This was cooled and solidified to be in an amorphous state, and then heated again, and the temperature at which an endothermic peak was observed was defined as Tg. As Comparative Example 2, CBP (4,4′-N, N′-dicarbazolebiphenyl) was also measured for melting point (Tm) and glass transition temperature (Tg).
The results are shown in Table 1.

  From Table 1, since all the imidazole compounds of this invention have high Tg and have high Tm, when manufacturing light emitting elements, such as an organic EL element, using the imidazole compound of this invention. It can be seen that the thermal stability is high and the device life can be expected to be extended.

Example 15
Washed ITO (indium tin oxide) glass of 2.5 cm × 2.5 cm using 0.01 g / mL, 0.02 g / mL, and 0.03 g / mL chlorobenzene solution of the imidazole compound synthesized in Example 8 The substrate was spin-coated at a rotational speed range of 1000 to 6000 rpm and annealed at 130 ° C. for 10 minutes. About the obtained thin film of the imidazole compound, the film thickness was measured with Veeco Dektak150. The film thickness at six locations was measured for each substrate, and the average value was plotted by the concentration and the number of rotations. As a result, it was found that the film thickness can be controlled in the range of 10 to 150 nm as shown in FIG.

Example 16
<Creation and evaluation of light-emitting element of single-layer light-emitting layer by coating method>
The imidazole compound synthesized in Example 8 was used as the host material. A coating solution was prepared by adding 5 wt% Ir (ppy) ₃ to a 0.03 g / mL chlorobenzene solution of the imidazole compound. Using this coating solution, spin-coating was performed on a cleaned ITO glass substrate at 1500 rpm for 20 seconds, and annealing was performed at 130 ° C. for 10 minutes to form a light emitting layer (100 nm). Next, lithium fluoride (1 nm) and aluminum (100 nm) were formed by vacuum deposition to form a cathode, and sealed with a cap glass to produce a light-emitting element. Green light emission was confirmed by applying a voltage to the light emitting element. The element characteristics of the obtained light-emitting element are shown in FIGS.

Example 17
A coating solution was prepared by adding ₃ % by weight of Ir (piq) ₃ to a 0.015 g / mL chloroform solution of the imidazole compound synthesized in Example 8. Using this coating solution, spin-coating was performed on a cleaned ITO glass substrate at 1500 rpm for 30 seconds, and annealing was performed at 100 ° C. for 10 minutes to form a light emitting layer (100 nm). Next, lithium fluoride (1 nm) and aluminum (100 nm) were formed by vacuum deposition to form a cathode, and sealed with a cap glass to produce a light-emitting element. Red light emission was confirmed by applying a voltage to the light emitting element. The element characteristics of the obtained light-emitting element are shown in FIGS.

[Comparative Example 3]
The imidazole compound of Example 8 used in Example 15 was replaced with CBP, which is a general host material, and film formation was examined by spin coating. However, at any concentration, the CBP thin film was crystallized on the ITO glass substrate, and an amorphous film necessary for the organic EL element could not be obtained. Therefore, a light-emitting element similar to that using the imidazole compound of Example 8 in Example 13 could not be produced by a coating method.

Example 18
4,4 ′, 4 ″ -tris [2-naphthyl (phenyl) amino] triphenylamine (10 nm) is deposited on a cleaned ITO substrate (film thickness 155 nm) by vacuum deposition to form a hole injection layer; N, N′-di (1-naphthyl) -N, N′-diphenylbenzidine (30 nm) was formed into a hole transport layer, and Ir (piq) ₃ and the compound of Example 8 were formed into a film thickness. A light-emitting layer (20 nm) was formed by co-evaporation so that the ratio was 20: 1, and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (10 nm) was further formed. A hole blocking layer was formed, and then an electron transport layer was formed by depositing tris (8-hydroxyquinolinato) aluminum (40 nm), followed by lithium fluoride (0.5 nm) and aluminum (100 nm). A cathode was formed to form a film and sealed with a cap glass to produce a light-emitting element, and red light emission was confirmed by applying a voltage to the light-emitting element. 6 and FIG.

[Comparative Example 4]
The imidazole compound of Example 8 used in Example 18 was formed by vacuum deposition in place of CBP, which is a general host material, to produce a light emitting device. The element characteristics of the obtained light-emitting element are shown in FIGS.

Example 19
1,1-bis [(N, N-di-p-tolylamino) phenyl] cyclohexane (40 nm) was formed on a cleaned ITO substrate (film thickness: 155 nm) by vacuum deposition to form a hole transport layer. Ir (piq) ₃ and the compound of Example 8 were co-evaporated into a film thickness ratio of 20: 1 to form a light emitting layer (20 nm). Next, 1,3,5-tri (p-pyrid-3-yl-phenyl) benzene (50 nm) was formed to form an electron transport layer, and then lithium fluoride (0.5 nm) and aluminum (100 nm) were formed. Was formed to form a cathode and sealed with a cap glass to prepare a light emitting device. Red light emission was confirmed by applying a voltage to the light emitting element. The element characteristics of the obtained light-emitting element are shown in FIGS.

Example 20
The imidazole compound of Example 8 used in Example 19 was formed by vacuum deposition in place of the imidazole compound of Example 13, and a light emitting device was produced. Element characteristics of the obtained light-emitting element are shown in FIGS.

Example 21
The imidazole compound of Example 8 used in Example 19 was formed by vacuum deposition in place of the imidazole compound of Example 14, and a light emitting device was produced. The element characteristics of the obtained light emitting element are shown in FIGS.

[Comparative Example 5]
The imidazole compound of Example 8 used in Example 19 was formed by vacuum deposition in place of CBP, which is a general host material, to produce a light emitting device. Element characteristics of the obtained light-emitting element are shown in FIGS.

  Table 2 shows the light emission luminance at 5 V for each of the light-emitting elements of Examples 18 to 21 and Comparative Examples 4 and 5 prepared by vacuum deposition.

From the above results, since the imidazole compound of the present invention has excellent film-forming properties, it is possible to form a light-emitting layer by a coating method, which has heretofore been difficult as a light-emitting material or a host material, particularly as a host material for a phosphorescent dopant. It turns out that is possible.
In addition, when a multi-layered light emitting device is formed using the imidazole compound of the present invention, it has a current efficiency equal to or higher than that of a device using CBP as a comparative material and is driven at a low voltage. It can be seen that the characteristics are superior to those of the device using CBP.
Furthermore, since the imidazole compound of the present invention has a high glass transition point (Tg) and a high melting point (Tm), it can be seen that the stability of the thin film is high when the thin film is formed.
Therefore, when the material for an electronic device containing the imidazole compound of the present invention is applied to, for example, a light emitting element, the light emission efficiency is improved, and the effect that the life of the light emitting element and thus the electronic device is extended is obtained.

2. Measurement of fluorescence spectrum The fluorescence spectrum of the synthesized imidazole compound solution and thin film was measured.
For measurement in solution, (A) a 1.0 × 10 ⁻⁶ M THF solution is prepared and measured with a Hitachi F-4500 spectrofluorometer, or (B) 1.0 × 10 ^−6. A THF solution of M was prepared and measured with a Perkin Elmer LS55 Fluorescence Spectrometer, or (C) a 1.0 × 10 ⁻⁸ M THF solution was prepared and measured with a Perkin Elmer LS55 Fluorescence Spectrometer.
For measurement with a thin film, (D) a thin film prepared by spin coating at 1000 rpm for 20 seconds using a THF solution adjusted to 8.3 mM on quartz glass, or (E) vacuum deposition on quartz glass. The thin film thus prepared was measured with JASCO FP-6500-A-ST FL.
Table 2 shows the measured maximum fluorescence wavelength (λEm (nm)) together with the measurement methods (A) to (E).
The absolute quantum yield (Φ) was measured using a C9920-02 Hamamatsu Photonics integrating sphere, and the results are also shown in Table 3.

  From Table 3, it can be seen that the imidazole compounds of Examples 1 to 12 all have a strong blue fluorescence compared to the imidazole compound of Comparative Example 1.

[Example 22]
<Creation and evaluation of light emitting element>
The imidazole compound of Example 8 was used as the light emitting material.
0.2 mL of PEDOT / PSS (Heraeus Clious PVP CH4083) was dropped on the cleaned ITO glass substrate, spin-coated at 2000 rpm for 90 seconds, and annealed at 200 ° C. for 10 minutes to form a 20 nm hole injection layer.
The imidazole compound of Example 8 was used as the light emitting material, and the compound represented by the following chemical formula was used as the host material. The imidazole compound of Example 8 was blended so as to be 10% by weight with respect to the compound represented by the following chemical formula, and dissolved in chlorobenzene so as to be 30 mg / mL to prepare a solution. On the ITO glass substrate on which the hole injection layer was formed, 0.2 mL of the chlorobenzene solution was dropped and spin-coated at 1000 rpm for 30 seconds, and then annealed at 130 ° C. for 10 minutes to form a 100 nm light emitting layer.

  Lithium fluoride (1 nm) and aluminum (100 nm) were formed by vacuum deposition to form a cathode and sealed with an aluminum cap to produce a light emitting device. Blue light emission was confirmed by applying a voltage to the light emitting element. The element characteristics of the obtained light-emitting element are shown in FIGS.

  The electronic device material containing the novel imidazole compound of the present invention can be used in various electronic devices such as light-emitting elements and organic thin-film solar cells. For example, various electronic devices including light-emitting elements such as organic EL elements, more specifically, flat panel displays (for example, computer displays and wall-mounted televisions) and surface-emitting body light sources (for example, lighting, light sources for copying machines) , Liquid crystal display backlight light source, instrument backlight light source), display boards, beacon lamps and other electronic devices.

Claims (13)

An imidazole compound represented by the general formula (1).

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, a polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms, or a biphenyl group. , R ³ , and R ⁴ are each independently a carbazole group, a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, or a carbon group having 10 to 16 carbon atoms linked directly or via a bond chain having a conjugated structure. And at least one of R ³ and R ⁴ is a carbazole group linked directly or via a bond chain having a conjugated structure.) An imidazole compound represented by the general formula (2).

(In the formula, X represents an unsaturated hydrocarbon chain, an aromatic chain, or a heteroaromatic chain, and R ¹ and R ² are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, phenyl, group, polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms, represents a biphenyl ^{radical, R 5, R 6, R} 7, R 8, R 9, R 10, R 11 and ^{R 12} are each independently , Hydrogen atom, alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, phenyl group, amino group having a polycyclic aromatic hydrocarbon group, fluorinated alkyl group, halogen atom, nitro group, cyano group Represents a carbazole group, or each may be condensed to form a 5-membered or 6-membered ring.) An imidazole compound represented by the general formula (3).

(In the formula, X represents an unsaturated hydrocarbon chain, an aromatic chain, or a heteroaromatic chain, and R ¹ , R ^2, and R ⁴ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Represents a phenyl group, a polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms, and a biphenyl group, and R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently A hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenyl group, an amino group having a polycyclic aromatic hydrocarbon group, a fluorinated alkyl group, a halogen atom, a nitro group, A cyano group or a carbazole group, or each may be condensed to form a 5-membered or 6-membered ring.) An imidazole compound represented by the general formula (4).

(In the formula, X represents an unsaturated hydrocarbon chain, an aromatic chain, or a heteroaromatic chain, and R ¹ , R ^2, and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. Represents a phenyl group, a polycyclic aromatic hydrocarbon group having 10 to 16 carbon atoms, and a biphenyl group, and R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are each independently A hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenyl group, an amino group having a polycyclic aromatic hydrocarbon group, a fluorinated alkyl group, a halogen atom, a nitro group, A cyano group or a carbazole group, or each may be condensed to form a 5-membered or 6-membered ring.)   The material for electronic devices containing the imidazole compound in any one of Claims 1-4.   The light emitting element containing the material for electronic devices of Claim 5.   A light-emitting element having a layer containing the electronic device material according to claim 5 between a cathode and an anode.   A light emitting device comprising the electronic device material according to claim 5 as a light emitting material.   A light emitting device comprising the electronic device material according to claim 5 as a host material.   The electronic device containing the light emitting element in any one of Claims 6-9.   An electronic device manufacturing method comprising a step of applying a film of the electronic device material according to claim 5 on a substrate and forming a film.   An electronic device manufacturing method comprising a step of depositing a film for an electronic device according to claim 5 on a substrate to form a film. An electronic device manufacturing method comprising a step of melt-coating a material for an electronic device according to claim 5 on a substrate and forming a film.

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