JP2009227663A - Quinoline compound, material for organic electroluminescent device, composition for organic electroluminescent device, organic electroluminescent device, organic el display, and organic el illumination - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent device which is excellent in driving stability and is drivable at low voltage by using a material for an organic electroluminescent device which is soluble in various solvents, has a high charge transport property and does not easily crystallize. <P>SOLUTION: A quinoline compound represented by formula (1) (wherein Ar<SP>1</SP>is an aromatic group; R<SP>1</SP>-R<SP>4</SP>are each an organic group with 50 or less carbons; L<SP>1</SP>is an aromatic ring group with 25 or less carbons; n is an integer of 2-6; m is an integer of 0-5; and p, r and s are each an integer of 0-4) is suitably used as a host material of a luminous layer in the organic electroluminescent device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a quinoline-based organic compound that is soluble in various solvents, has a high charge transporting ability, and does not easily crystallize, an organic electroluminescent element material comprising the compound, and an organic electroluminescent element including the compound The present invention relates to an organic electroluminescent device having a composition, a layer containing the compound, having high luminous efficiency and excellent driving stability, and an organic EL display and organic EL lighting using the organic electroluminescent device.

  In recent years, electroluminescence devices using organic thin films (organic electroluminescence (EL) devices) have been developed. Examples of the method for forming the organic thin film in the organic electroluminescence device include a vacuum deposition method and a wet film formation method. Among these, the wet film-forming method does not require a vacuum process, is easy to increase in area, and a plurality of materials having various functions in a coating liquid (composition for an organic electroluminescent element) for forming one layer. There are advantages such as easy mixing and mixing.

Polymer materials such as poly (p-phenylene vinylene) derivatives and polyfluorene derivatives are mainly used as the material for the light emitting layer formed by the wet film formation method. There's a problem.
・ It is difficult to control the degree of polymerization and molecular weight distribution of polymer materials.
・ Deterioration due to terminal residues occurs during continuous driving.
・ High purity of the material itself is difficult and contains impurities.

  Due to the above-described problems, an element using a wet film formation method is inferior in driving stability as compared with an element using a vacuum deposition method, and has not reached a practical level except for a part.

  As an attempt to solve the above problems, Patent Document 1 uses an organic thin film formed by a wet film-forming method by mixing a plurality of low-molecular materials (charge transporting materials and light-emitting materials) instead of a polymer compound. Organic electroluminescent devices are described. However, since the organic electroluminescent element described in Patent Document 1 uses fluorescent light emission, the light emission efficiency and the maximum light emission luminance of the element are low, and the practical characteristics are not satisfied.

  In an organic electroluminescent device using an organic thin film made of a plurality of low-molecular materials formed by a wet film formation method, Non-Patent Document 1 describes a device using phosphorescence emission in order to increase the luminous efficiency of the device. ing. The charge transport material of the organic electroluminescence device described in Non-Patent Document 1 uses the following biphenyl derivative.

  However, the biphenyl derivative is very easy to crystallize, and it has been difficult to obtain a uniform amorphous film by the wet film formation method. Furthermore, the biphenyl derivative has low solubility in a solvent. For this reason, it is necessary to use a halogen-based solvent such as chloroform or 1,2-dichloroethane as a coating solvent, but the halogen-based solvent has a large environmental load and has a practical problem. In addition, since there is a high possibility that the material is deteriorated by impurities contained in the halogen-based solvent, it is conceivable that the driving stability of the element formed by the wet film formation method using the halogen-based solvent is not sufficient.

  Patent Document 2 describes a charge transport material containing a quinoline ring and a carbazole ring in the molecule as described below. However, the organic electroluminescent device using this charge transport material has not been sufficiently driven.

Japanese Patent Laid-Open No. 11-238359 JP 2006-199677 A

Japanese Journal of Applied Physics Vol.44, No.1B, 2005, pp.626-629

  The present invention has been made in view of the above-described conventional situation, and provides an organic electroluminescent element material that is soluble in various solvents, has high charge transportability, and does not easily crystallize. Aims to provide a composition for forming an organic electroluminescent device that has excellent driving stability and can be driven at a low voltage, and an organic electroluminescent device, an organic EL display and an organic EL illumination using the composition. .

  As a result of intensive studies by the present inventors, a quinoline compound having the following structure is excellent in solubility in a solvent and has an amorphous property, so that a thin film can be formed by a wet film formation method, and an excellent charge can be obtained. Since it has transportability, it has been found that when it is used in an organic electroluminescence device, it exhibits high driving stability and can be driven with a low driving voltage, and the present invention has been achieved.

That is, the present invention
A quinoline compound represented by the following formula (1) (claim 1),
An organic electroluminescent element material comprising the quinoline compound (claim 6);
A composition for an organic electroluminescent device containing the quinoline-based compound (claim 7);
An organic electroluminescent device having an anode, a cathode, and an organic layer provided between the anode and the cathode, wherein the organic layer contains the quinoline compound (claim 8),
An organic EL display using the organic electroluminescent element (Claim 9) and organic EL illumination (Claim 10),
Exist.

(In Formula (1), Ar ¹ represents an aromatic ring group which may have a substituent. R ^{1 to} R ⁴ each independently has an organic group having 50 or less carbon atoms which may have a substituent. L ¹ represents a single bond or an optionally substituted aromatic ring group having 25 or less carbon atoms, n represents an integer of 2 to 6, and m is an integer of 0 to 5 P, r and s each independently represents an integer of 0 or more and 4 or less.)

The quinoline compound of the present invention is excellent in solubility in various solvents and has an amorphous property, so that a thin film can be formed by a wet film-forming method and has excellent charge transport properties.
For this reason, using the quinoline compound of the present invention, it is possible to easily provide an organic electroluminescence device that is excellent in driving stability and can be driven with a low driving voltage.

It is typical sectional drawing which showed an example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention. It is typical sectional drawing which showed another example of the organic electroluminescent element of this invention.

  Embodiments of the present invention will be described in detail below. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the invention.

[Explanation of words]
In the present invention, when the term “heterocycle” or “hydrocarbon ring” is used, it includes both a ring having aromaticity and a ring having no aromaticity. In addition, when simply referred to as “aromatic ring”, it includes both a hydrocarbon aromatic ring and a heteroaromatic ring.
In the present invention, the “aromatic ring group” refers to “a group derived from a monocyclic aromatic ring”, “a group derived from a condensed ring in which two or more rings are condensed”, And / or a group in which two or more of the condensed rings are linked via a single bond.
In the present invention, “may have a substituent” means that one or more substituents may be present.
“(Hetero) aryl” means both “aryl” and “heteroaryl”.

[Quinoline compound represented by formula (1)]
The quinoline compound of the present invention is represented by the following formula (1).

(In Formula (1), Ar ¹ represents an aromatic ring group which may have a substituent. R ^{1 to} R ⁴ each independently has an organic group having 50 or less carbon atoms which may have a substituent. L ¹ represents a single bond or an optionally substituted aromatic ring group having 25 or less carbon atoms, n represents an integer of 2 to 6, and m is an integer of 0 to 5 P, r and s each independently represents an integer of 0 or more and 4 or less.)

[1] Structural Features In the quinoline compound of the present invention represented by the above formula (1), a carbazole ring is substituted via a linker L ¹ on a quinoline skeleton or an aromatic ring group Ar ¹ substituted on the quinoline skeleton. It is considered that this structure has a function to enhance the durability of the compound against positive and negative charges.
In addition, the structure in which the aromatic ring group Ar ¹ is substituted at the 4-position of the quinoline ring is considered to improve the durability of the device in order to suppress decomposition of the quinoline ring.

[2] Each component in Formula (1) Each component in the said Formula (1) is demonstrated in detail below.

<About n>
n is an integer of 2 or more and 6 or less representing the number of partial structures represented by the following formula (i). n is preferably 2 to 3, particularly preferably 2. A plurality of partial structures represented by the following formula (i) contained in one molecule may be the same or different. L ¹ is bonded to Ar ¹ substituted on the quinoline ring or quinoline ring.

<About Ar ¹ >
Ar ¹ in formula (1) represents an aromatic ring group which may have a substituent.

The aromatic ring group for Ar ¹ is preferably an aromatic ring group having 3 to 25 carbon atoms. Specific examples of the aromatic ring group include naphthyl groups such as a phenyl group, a 1-naphthyl group and a 2-naphthyl group, and 9-phenanthyl. Groups, phenanthryl groups such as 3-phenanthyl groups, 1-anthryl groups, 2-anthryl groups, 9-anthryl groups such as 9-anthryl groups, 1-naphthacenyl groups, 2-naphthacenyl groups such as naphthacenyl groups, 1-chrycenyl groups, 2 -Chrysenyl group, 3-chrycenyl group, 4-chrycenyl group, 5-chrycenyl group, 6-chrycenyl group and other chrycenyl groups, 1-pyrenyl group and other pyrenyl groups, 1-triphenylenyl group and other triphenylenyl groups, 1-coronenyl group Aromatic hydrocarbon groups such as coronenyl groups, pyridyl groups such as 2-pyridyl groups, and thienyl groups such as 2-thienyl groups Groups, benzothienyl groups such as 3-benzothienyl group, and aromatic heterocyclic groups such as quinolinyl group such as 2-quinolinyl group, and aromatic hydrocarbon groups are particularly preferable.

From the viewpoint of stability of the compound, Ar ¹ is preferably a phenyl group, a 2-naphthyl group, a 1-anthranyl group, a 9-phenanthryl group, or a 9-anthranyl group, and the phenyl group and the 2-naphthyl group are used for purification of the compound. Particularly preferred from the standpoint of ease, and a phenyl group is most preferred.

Ar ¹ may have a substituent, and specific examples of the substituent include an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 25 carbon atoms, and 3 to 20 carbon atoms. Aromatic heterocyclic group, C 1-20 alkyloxy group, C 3-20 (hetero) aryloxy group, C 1-20 alkylthio group, C 3-20 (hetero) arylthio group And a cyano group. These groups may further have a substituent, and specific examples thereof are the same as those exemplified as the substituent for Ar ¹ . As the substituent that Ar ¹ has, an alkyl group and an aromatic hydrocarbon group are preferable from the viewpoint of stability of the compound, and an aromatic hydrocarbon group is particularly preferable.

Examples of the alkyl group having 1 to 20 carbon atoms as the substituent that Ar ¹ may have include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an iso-butyl group, and a sec-butyl group. Tert-butyl group, hexyl group, octyl group, cyclohexyl group, decyl group, octadecyl group and the like. Preferably, they are a methyl group, an ethyl group, and an isopropyl group. Of these, a methyl group and an ethyl group are preferable from the viewpoint of availability of raw materials and low cost, and the iso-butyl group, sec-butyl group, and tert-butyl group have high solubility in nonpolar solvents. preferable.

Examples of the aromatic hydrocarbon group having 6 to 25 carbon atoms as the substituent that Ar ¹ may have include a naphthyl group such as a phenyl group, a 1-naphthyl group, and a 2-naphthyl group, and a 9-phenanthyl group. A phenanthryl group such as a 3-phenanthyl group, an anthryl group such as a 1-anthryl group, a 2-anthryl group, and a 9-anthryl group, a naphthacenyl group such as a 1-naphthacenyl group and a 2-naphthacenyl group, a 1-chrycenyl group, a 2- Crisenyl group, 3-chrenyl group, 4-chrenyl group, 5-chrenyl group, 6-chrenyl group and other chrysenyl groups, 1-pyrenyl group and other pyrenyl groups, 1-triphenylenyl group and other triphenylenyl groups, 1-coronenyl group and the like Coronenyl group, 4-biphenyl group, biphenyl group of 3-biphenyl group, ortho-terphenyl group, meta-terphee Examples thereof include terphenyl groups such as nyl group and para-terphenyl group. Of these, phenyl group, 2-naphthyl group, 1-anthranyl group, 9-phenanthryl group, 9-anthranyl group, 4-biphenyl group, and 3-biphenyl group are preferable from the viewpoint of stability of the compound. In view of easiness, a phenyl group, a 2-naphthyl group, and a 3-biphenyl group are particularly preferable.

Examples of the aromatic heterocyclic group having 3 to 20 carbon atoms as a substituent that Ar ¹ may have include a thienyl group such as a 2-thienyl group, a furyl group such as a 2-furyl group, and 2-imidazolyl. An imidazolyl group such as a group, a carbazolyl group such as a 9-carbazolyl group, a pyridyl group such as a 2-pyridyl group, and a triazine-yl group such as a 1,3,5-triazin-2-yl group. Of these, a 9-carbazolyl group is preferable from the viewpoint of stability of the compound.

Examples of the alkyloxy group having 1 to 20 carbon atoms as a substituent that Ar ¹ may have include a methoxy group, an ethoxy group, an isopropyloxy group, a cyclohexyloxy group, an octadecyloxy group, and the like.

Examples of the (hetero) aryloxy group having 3 to 20 carbon atoms as a substituent that Ar ¹ may have include a phenoxy group, a 1-naphthyloxy group, a 9-anthranyloxy group, and a 2-thienyloxy group. Etc.

Examples of the alkylthio group having 1 to 20 carbon atoms as a substituent that Ar ¹ may have include a methylthio group, an ethylthio group, an isopropylthio group, a cyclohexylthio group, and the like.

Examples of the (hetero) arylthio group having 3 to 20 carbon atoms as a substituent that Ar ¹ may have include a phenylthio group, a 1-naphthylthio group, a 9-anthranylthio group, and a 2-thienylthio group. It is done.

When Ar ¹ has these substituents, the substitution position is not particularly limited. For example, when Ar ¹ is a phenyl group, it is preferably a para position or a meta position with respect to the substitution position on the quinoline skeleton. .

<About R ^{1 to} R ⁴ , m, r, s, p>
R ¹ in the formula (1) is a substituent bonded to the quinoline ring, and m represents the number of R ¹ substituted on the quinoline ring. m is an integer of 0 or more and 5 or less, preferably 0 or more and 2 or less, and particularly preferably 0 or more and 1 or less, and m = 0 means that R ¹ is not substituted on the quinoline ring. When m is 2 or more, the plurality of R ¹ substituted on the quinoline ring may be the same or different.

R ² in the formula (1) is a substituent bonded to the carbazole ring (one benzene ring constituting the carbazole ring), and r represents the number of R ² substituted on the carbazole ring. r is an integer of 0 or more and 4 or less, preferably 0 or more and 1 or less, and r is 0 means that R ² is not substituted on the carbazole ring. When r is 2 or more, the plurality of R ² substituted on the carbazole ring may be the same or different.

R ³ in Formula (1) is a substituent bonded to the carbazole ring (the other benzene ring constituting the carbazole ring), and s represents the number of R ³ substituted on the carbazole ring. s is an integer of 0 or more and 4 or less, preferably 0 or more and 1 or less, and s of 0 means that R ³ is not substituted on the carbazole ring. When s is 2 or more, the plurality of R ³ substituted on the carbazole ring may be the same or different.

R ⁴ in formula (1) is a substituent bonded to the benzene ring substituted by the carbazole ring, and p represents the number of R ⁴ substituted on the benzene ring. p is an integer of 0 or more and 4 or less, preferably 0 or more and 2 or less, particularly preferably 0 or more and 1 or less, and p of 0 means that R ⁴ is not substituted with a benzene ring. When p is 2 or more, the plurality of R ⁴ substituted on the benzene ring may be the same or different.

R ^{1 to} R ⁴ in the formula (1) each independently represent an organic group having 50 or less carbon atoms, and these may have a substituent. The carbon number of the organic group R ¹ to R ^4, when having a substituent is usually 50 or less including their substituents, preferably 30 or less.

Specific examples of the organic group represented by R ^{1 to} R ⁴ include an alkyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 25 carbon atoms, an aromatic heterocyclic group having 3 to 20 carbon atoms, and 1 carbon atom. -20 alkyloxy group, C3-C20 (hetero) aryloxy group, C1-C20 alkylthio group, C3-C20 (hetero) arylthio group, and cyano group. As R ^{1 to} R ⁴ , an alkyl group, an aromatic hydrocarbon group, and an aromatic heterocyclic group are preferable from the viewpoint of stability of the compound, and an aromatic hydrocarbon group is particularly preferable.

Examples of the alkyl group having 1 to 20 carbon atoms as the organic group for R ^{1 to} R ⁴ include methyl group, ethyl group, propyl group, isopropyl group, butyl group, iso-butyl group, sec-butyl group, tert- Examples thereof include a butyl group, a hexyl group, an octyl group, a cyclohexyl group, a decyl group, and an octadecyl group. Preferably, they are a methyl group, an ethyl group, and an isopropyl group. Among these, a methyl group and an ethyl group are preferable because of availability of raw materials and low cost, and an iso-butyl group, a sec-butyl group, and a tert-butyl group are preferable because they have high solubility in nonpolar solvents. .

Examples of the aromatic hydrocarbon group having 6 to 25 carbon atoms as the organic group for R ^{1 to} R ⁴ include a naphthyl group such as a phenyl group, a 1-naphthyl group, and a 2-naphthyl group, a 9-phenanthyl group, a 3- Phenanthyl group such as phenanthyl group, 1-anthryl group, 2-anthryl group, anthryl group such as 9-anthryl group, 1-naphthacenyl group, 2-naphthacenyl group such as naphthacenyl group, 1-chrycenyl group, 2-chrycenyl group, Coronenyl groups such as 3-chrysenyl group, 4-chrysenyl group, 5-chrycenyl group, 6-chrycenyl group, etc., pyrenyl group such as 1-pyrenyl group, 1-triphenylenyl group such as 1-corenylenyl group, etc. Etc. Of these, phenyl group, 2-naphthyl group, 1-anthryl group, 9-anthryl group, and 9-phenanthryl group are preferable from the viewpoint of stability of the compound, and phenyl group, 2-naphthyl group are preferable from the viewpoint of easy purification of the compound. The group is particularly preferred.

Examples of the aromatic heterocyclic group having 3 to 20 carbon atoms as the organic group of R ^{1 to} R ⁴ include a thienyl group such as a 2-thienyl group, a furyl group such as a 2-furyl group, and a 2-imidazolyl group. Examples thereof include carbazolyl groups such as imidazolyl group and 9-carbazolyl group, pyridyl groups such as 2-pyridyl group, and triazine-yl groups such as 1,3,5-triazin-2-yl group. Of these, a 9-carbazolyl group is preferable from the viewpoint of stability of the compound.

Examples of the alkyl group having 1 to 20 carbon atoms as an organic group R ¹ to R ⁴ include a methoxy group, an ethoxy group, an isopropyloxy group, a cyclohexyl group, octadecyl group and the like. Of these, a methoxy group and an ethoxy group are preferable from the viewpoint of improving solubility in a solvent and high glass transition temperature.

Examples of the (hetero) aryloxy group having 3 to 20 carbon atoms as the organic group for R ^{1 to} R ⁴ include phenoxy group, 3-phenoxyphenoxy group, 2-naphthyloxy group, 9-anthranyloxy group, 2- Examples include thienyloxy group. Among these, a phenoxy group, a 3-phenoxyphenoxy group, and a 2-naphthyloxy group are preferable from the viewpoint of improving solubility in a solvent, and a 3-phenoxyphenoxy group is particularly preferable.

Examples of the alkylthio group having 1 to 20 carbon atoms as the organic group of R ^{1 to} R ⁴ include a methylthio group, an ethylthio group, an isopropylthio group, a cyclohexylthio group, and the like. Among these, a methylthio group and an ethylthio group are preferable from the viewpoint of improving solubility in a solvent and a high glass transition temperature.

Examples of the (hetero) arylthio group having 3 to 20 carbon atoms as the organic group for R ^{1 to} R ⁴ include a phenylthio group, a 1-naphthylthio group, a 9-anthranylthio group, and a 2-thienylthio group. Among these, a phenylthio group is preferable from the viewpoint of improving solubility in a solvent.

These organic groups may further have a substituent, and examples of the substituent include those exemplified as the substituent for Ar ¹ described above.

<For ^{L 1>}
L ¹ in Formula (1) represents a single bond or an aromatic ring group having 25 or less carbon atoms which may have a substituent. Specific examples of the aromatic ring group having 25 or less carbon atoms include an aromatic hydrocarbon group having 6 to 25 carbon atoms and an aromatic heterocyclic group having 3 to 25 carbon atoms. In particular, the aromatic hydrocarbon group is a compound. From the standpoint of stability.

Examples of the aromatic hydrocarbon group having 6 to 25 carbon atoms of L ¹ include phenylene groups such as 1,4-phenylene group and 1,3-phenylene group, naphthylene groups such as 1,6-naphthylene group, 3, Phenanthylene groups such as 9-phenanthylene groups, 2,6-anthranylene groups, anthranylene groups such as 9,10-anthranylene groups, pyrenylene groups such as 1,6-pyrenylene groups, and triphenylenylene groups such as 2,7-triphenylenylene groups. And a biphenylene group such as a len group, a 4,4′-biphenylene group, a 3,3′-biphenylene group, a 4,3′-biphenylene group, and the like. , 3-phenylene group, 3,3′-biphenylene group, 4,3′-biphenylene group and 1,6-naphthylene group are preferred, and 1,3-phenylene group is preferred from the viewpoint of solubility of the compound in a solvent. - phenylene group, 3,3'-biphenylene, 1,6-naphthylene group is particularly preferred.
Examples of the aromatic heterocyclic group having 3 to 25 carbon atoms of L ¹ include a thienylene group such as a 2,5-thienylene group, a furylene group such as a 2,5-furylene group, and a pyridylene such as a 2,6-pyridylene group. Group, a quinolylene group such as a 2,6-quinolylene group, and the like. Among these, 2,6-pyridylene group and 2,6-quinolylene group are preferable from the viewpoint of stability of the compound.

[3] Quinoline compound represented by the formula (2) Among the quinoline compounds represented by the formula (1), the quinoline compound represented by the following formula (2) has a solubility in various solvents. It is preferable because it improves. This is presumed that the solubility in an organic solvent is improved by designing the quinoline ring substituent to be asymmetric.

(In Formula (2), Ar ¹¹ is synonymous with Ar ¹ in Formula (1). R ^{12 to} R ¹⁴ and R ^{22 to} R ²⁴ each independently have 50 carbon atoms. L ¹¹ and L ¹² each independently represent a single bond or an aromatic ring group having 25 or less carbon atoms which may have a substituent p ₁ , r ₁ , s ₁ , p ₂ , r ₂ and s ₂ each independently represents an integer of 0 or more and 4 or less.

<Regarding ^R 12 ^{to R 14} and ^R 22 ^{to R 24>}
R ^{12 to} R ¹⁴ and R ^{22 to} R ²⁴ in the formula (2) each independently represent an organic group having 50 or less carbon atoms, which may have a substituent. Specific examples, preferred examples and preferred substituents of R ^{12 to} R ¹⁴ and R ^{22 to} R ²⁴ are the same as the specific examples, preferred examples and preferred substituents of R ^{1 to} R ⁴ .

<About ^{L 11} and ^{L 12>}
L ¹¹ and L ¹² in the formula (2) each independently represent a single bond or an aromatic ring group having 25 or less carbon atoms which may have a substituent. Specific examples, preferred examples and preferred substituents of L ¹¹ and L ¹² are the same as the specific examples, preferred examples and preferred substituents of L ¹ described above.

L ¹¹ and L ¹² may be the same or different, but different ones are preferable in terms of increasing the solubility of the compound in the solvent.

[4] Quinoline-based compound represented by the formula (3) In the quinoline-based compound represented by the formula (2), a quinoline-based compound in which L ¹¹ and L ¹² are different is particularly preferable as the following formula ( The quinoline compound represented by 3) is preferred.

(In the formula (3), Ar ¹¹ , L ¹¹ , R ^{12 to} R ¹⁴ , R ^{22 to} R ²⁴ , p ₁ , r ₁ , s ₁ , p ₂ , r ₂ and s ₂ are respectively in the formula (2). L′-ring B corresponds to L ¹² in formula (2), ring B represents a benzene ring which may have a substituent, and L ′ has a single bond or a substituent. Represents an optionally substituted aromatic ring group having 19 or less carbon atoms.)

In the combination of L ′ with the benzene ring of ring B, L ¹² in the above formula (2) and its specific examples, preferred examples, and the substituents that it may have are the same.

L ′ is particularly preferably a phenylene group such as a 1,3-phenylene group or a 1,4-phenylene group and a single bond, and more preferably a single bond. In this case, L ¹¹ is preferably a phenylene group such as a 1,3-phenylene group or a 1,4-phenylene group and a single bond, and more preferably a single bond.

In the formula (3), the substitution position of L ^{11 on} the benzene ring substituted on the nitrogen atom of the carbazole ring is preferably the 3rd and 4th positions from the substitution position on the carbazole ring of the benzene ring.
Further, the substitution position of L ′ on ring B is preferably the 3rd and 4th positions from the substitution position of ring B on the quinoline ring.
Moreover, it is preferable that the substitution position of L 'to the benzene ring substituted by the nitrogen atom of a carbazole ring is the 3rd position and the 4th position from the substitution position to the carbazole ring of the said benzene ring.

[5] About molecular weight The upper limit of the molecular weight of the quinoline compound of the present invention is usually 7000 or less, preferably 5,000 or less in view of the ease of purification of the compound, especially when considering solubility in a solvent. Preferably, it is 3000 or less, and most preferably 1500 or less when considering high purification by sublimation purification.
Further, the lower limit of the molecular weight of the quinoline compound of the present invention is usually 100 or more, and preferably 500 or more in consideration of the thermal stability of the compound.

[6] Glass Transition Temperature The quinoline compound of the present invention usually has a glass transition temperature of 100 ° C. or higher, but is preferably 120 ° C. or higher from the viewpoint of heat resistance.

[7] Illustrative compounds Specific examples of the quinoline compounds of the present invention will be given, but the quinoline compounds of the present invention are not limited to the following exemplary compounds.

[8] Synthesis method The quinoline compound of the present invention represented by the formula (1) can be synthesized by using a substituted aminobenzophenone as a starting material, forming a quinoline ring, and then performing a coupling reaction using a metal catalyst. it can.

  For example, in the case of a compound in which the carbazolylphenyl group is substituted at the 2-position of the quinoline ring via a linker L and the carbazolylphenyl group is substituted at the 5- to 8-position, it can be synthesized according to the following scheme. is there.

(In the above reaction formula, Ar is an aromatic ring group, .L corresponding to Ar ¹ in the formula (1) is a linker, .X corresponding to L ¹ in Formula (1) is a halogen atom or trifluoromethanesulfonate Represents an acid ester group.)

  The elementary reactions shown in the above scheme will be described below.

<Quinoline ring formation reaction>
In an inert gas atmosphere, 1 mol of an aminobenzophenone derivative and 0.75 to 10 mol of a compound having an acetyl group are dissolved or suspended in a polar or nonpolar solvent, and 0 to 150 with stirring using an acid or basic catalyst. By adding a temperature of 0 ° C., a mixture of substrates containing a quinoline ring is obtained. Purification of the substrate from this mixture can be performed by a combination of distillation, filtration, extraction, recrystallization, reprecipitation, suspension washing, and chromatographic operations.
The solvent is not particularly limited as long as it can dissolve the substrate. Non-benzene nonpolar solvents such as hexane and cyclohexane, amide solvents such as N, N-dimethylformamide and N, N-dimethylacetamide, diethyl The reaction is preferably carried out using an ether solvent such as ether, tetrahydrofuran, dioxane or diethylene glycol dimethyl ether, an alcohol solvent such as methanol or ethanol, an acidic solvent such as acetic acid, butyric acid or polyphosphoric acid, and an acidic solvent such as acetic acid. Is particularly preferred.

<Coupling reaction>
Reaction of 1 mol of phenylcarbazole boron reagent and 0.75-5 mol of halide or trifluoromethanesulfonate ester reagent with quinoline substrate in the presence of a base in a nonpolar or polar solvent using a transition metal element catalyst By doing so, a substrate-coupled mixture can be obtained. Purification of the target product from this mixture can be performed by a combination of operations of distillation, filtration, extraction, recrystallization, reprecipitation, suspension washing, and chromatography.
Examples of the transition metal element catalyst include an organic palladium catalyst, an organic nickel catalyst, an organic copper catalyst, an organic platinum catalyst, an organic rhodium catalyst, an organic ruthenium catalyst, and an organic iridium catalyst. Organic palladium catalysts are preferred.
The base is not particularly limited, but metal hydroxides, metal salts, organic alkali metal reagents and the like are preferable.
The solvent to be used is not particularly limited as long as it is a solvent that is active with respect to the reaction substrate, but non-aromatic hydrocarbon solvents such as hexane, heptane, and cyclohexane, and aromatic carbonization such as benzene, toluene, and xylene. A hydrogen solvent, an ether solvent such as dimethoxyethane, tetrahydrofuran and dioxane, an alcohol solvent such as ethanol and propanol, water and the like can be used singly or in combination.
Further, if necessary, a surfactant can be added to the reaction system in an amount of 1 to 100 mol% based on the reaction substrate.

[9] Use of quinoline-based compound The quinoline-based compound of the present invention has high charge transportability, and therefore, as a charge transport material, an electrophotographic photosensitive member, an organic electroluminescent device, a photoelectric conversion device, an organic solar cell, an organic rectifying device, etc. Can be suitably used. For example, the quinoline compound of the present invention is useful as a dopant material, particularly as a host material for a red phosphorescent material, in a light emitting layer of an organic electroluminescent device.
In particular, the quinoline compound of the present invention is excellent in solubility in various solvents and has an amorphous property, so that it can be formed into a thin film by a wet film formation method, and thus is applied to a wet film formation method. Suitable as a material for an organic electroluminescent element, a wet film-forming method using an organic electroluminescent element material comprising the quinoline compound of the present invention or an organic electroluminescent element composition comprising the quinoline compound of the present invention As a result, an organic electroluminescence device that is excellent in driving stability and can be driven at a low driving voltage can be manufactured.

[Materials for organic electroluminescent elements]
The organic electroluminescent element material of the present invention is composed of the quinoline compound of the present invention, and preferably dissolves in an amount of 2% by weight or more, more preferably 5% by weight or more based on toluene.

As will be described later, an aromatic hydrocarbon is preferable as the solvent contained in the composition for organic electroluminescent elements. Toluene is listed as a representative example of aromatic hydrocarbons and is used as an indicator of solubility.
When the organic electroluminescent element material of the present invention has a solubility in toluene of 2% by weight or more, it is preferable that a layer constituting the organic electroluminescent element can be easily formed by a wet film forming method. The upper limit of the solubility is not particularly limited, but is usually about 50% by weight.

[Composition for organic electroluminescence device]
The composition for an organic electroluminescent element of the present invention contains the above-described quinoline compound of the present invention, usually contains the quinoline compound of the present invention and a solvent, and more preferably contains a phosphorescent material. Yes, it is used for organic electroluminescent devices.

[1] Solvent The solvent contained in the composition for organic electroluminescent elements of the present invention is not particularly limited as long as it is a solvent in which the quinoline compound of the present invention as a solute dissolves satisfactorily.

  Since the quinoline compound of the present invention has high solubility, various solvents can be applied. For example, aromatic hydrocarbons such as toluene, xylene, methicylene, cyclohexylbenzene and tetralin; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene and trichlorobenzene; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene and anisole , Phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole and other aromatic ethers; phenyl acetate, phenyl propionate, methyl benzoate, benzoic acid Aromatic esters such as ethyl, propyl benzoate and n-butyl benzoate; Ketones having an alicyclic ring such as cyclohexanone and cyclooctanone; Aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; Methyl ethyl ketone and cyclohexano Alcohol having an alicyclic ring such as ruthenium or cyclooctanol; Aliphatic alcohol such as butanol or hexanol; Aliphatic ether such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether or propylene glycol-1-monomethyl ether acetate (PGMEA); Ethyl acetate In addition, aliphatic esters such as n-butyl acetate, ethyl lactate, and n-butyl lactate can be used. Of these, aromatic hydrocarbons such as toluene, xylene, methicylene, cyclohexylbenzene, tetralin and the like are preferable in that they have low water solubility and are not easily altered.

  Since organic electroluminescent devices use many materials such as cathodes that deteriorate significantly due to moisture, the presence of moisture in the composition causes moisture to remain in the dried film, degrading the device characteristics. The possibility is considered and it is not preferable.

  Examples of the method for reducing the amount of water in the composition include nitrogen gas sealing, use of a desiccant, dehydration of the solvent in advance, use of a solvent having low water solubility, and the like. In particular, it is preferable to use a solvent having low water solubility because the solution film can prevent whitening by absorbing moisture in the atmosphere during the wet film forming process. From such a viewpoint, the composition for organic electroluminescent elements to which the present embodiment is applied includes, for example, a solvent having a water solubility at 25 ° C. of 1% by weight or less, preferably 0.1% by weight or less. It is preferable to contain 10% by weight or more in the composition.

  Further, in order to reduce a decrease in film formation stability due to evaporation of the solvent from the composition during wet film formation, the solvent of the composition for organic electroluminescent elements has a boiling point of 100 ° C. or higher, preferably a boiling point of 150. It is effective to use a solvent having a boiling point of 200 ° C. or higher, more preferably 200 ° C. or higher. Further, in order to obtain a more uniform film, it is necessary that the solvent evaporates from the liquid film immediately after the film formation at an appropriate rate. For this purpose, the boiling point is usually 80 ° C. or higher, preferably the boiling point is 100 ° C. or higher. It is more effective to use a solvent having a boiling point of 120 ° C. or higher, usually a boiling point of less than 270 ° C., preferably a boiling point of less than 250 ° C., more preferably a boiling point of less than 230 ° C.

  A solvent that satisfies the above-described conditions, that is, the conditions of solute solubility, evaporation rate, and water solubility may be used alone, or two or more kinds of solvents may be mixed and used.

[2] Luminescent Material The composition for organic electroluminescent elements of the present invention preferably contains a luminescent material.

A luminescent material refers to the component which mainly light-emits in the composition for organic electroluminescent elements of this invention, and corresponds to the dopant component in an organic electroluminescent device. That is, the amount of light emitted from the composition for organic electroluminescent elements (unit: cd / m ² ) is usually 10 to 100%, preferably 20 to 100%, more preferably 50 to 100%, most preferably 80 to 80%. If 100% is identified as luminescence from a component material, it is defined as the luminescent material.

As the light-emitting material, known materials can be applied, and a fluorescent light-emitting material or a phosphorescent light-emitting material can be used alone or in combination, and a phosphorescent light-emitting material is preferable from the viewpoint of internal quantum efficiency.
When used in the composition for organic electroluminescent elements of the present invention, the maximum emission peak wavelength of the luminescent material is preferably in the range of 390 to 490 nm.

  For the purpose of improving the solubility in a solvent, it is also important to reduce the symmetry and rigidity of the light emitting material molecule or introduce a lipophilic substituent such as an alkyl group.

  Examples of fluorescent dyes that emit blue light include perylene, pyrene, anthracene, coumarin, p-bis (2-phenylethenyl) benzene, and derivatives thereof. Examples of the green fluorescent dye include quinacridone derivatives and coumarin derivatives. Examples of yellow fluorescent dyes include rubrene and perimidone derivatives. Examples of red fluorescent dyes include DCM compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene and the like.

  Examples of the phosphorescent material include organometallic complexes containing a metal selected from Groups 7 to 11 of the periodic table.

Preferred examples of the metal in the phosphorescent organometallic complex containing a metal selected from Groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold. Preferred examples of these organometallic complexes include compounds represented by the following general formula (V) or formula (VI).
MQ _{(qj) Q'j} (V)
(In general formula (V), M represents a metal, q represents the valence of the metal, Q and Q ′ represent a bidentate ligand, and j represents 0, 1 or 2.)

（一般式（VI）中、Ｍ^ｄは金属を表し、Ｔは炭素または窒素を表す。Ｒ^９２〜Ｒ^９５は、それぞれ独立に、置換基を表す。ただし、Ｔが窒素の場合は、Ｒ^９４およびＲ^９５は無い。）

(In the general formula (VI), ^{M d} represents a metal, ^.R 92 ^{to R 95} T is representative of the carbon or nitrogen independently represents a substituent. However, when T is ^{nitrogen, R 94} And there is no R ^95. )

Hereinafter, the compound represented by the general formula (V) will be described first.
In the general formula (V), M represents an arbitrary metal, and specific examples of preferable ones include the metals described above as the metal selected from Groups 7 to 11 of the periodic table.
Further, the bidentate ligands Q and Q ′ in the general formula (V) each represent a ligand having the following partial structure.

As Q ′, from the viewpoint of the stability of the complex, the following are particularly preferable.

  In the partial structures of Q and Q ′, the ring A1 represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and these may have a substituent. Ring A2 represents a nitrogen-containing aromatic heterocyclic group, and these may have a substituent.

  When the rings A1 and A2 have a substituent, preferred substituents include halogen atoms such as fluorine atoms; alkyl groups such as methyl groups and ethyl groups; alkenyl groups such as vinyl groups; methoxycarbonyl groups and ethoxycarbonyl groups. Alkoxycarbonyl groups; alkoxy groups such as methoxy groups and ethoxy groups; aryloxy groups such as phenoxy groups and benzyloxy groups; dialkylamino groups such as dimethylamino groups and diethylamino groups; diarylamino groups such as diphenylamino groups; carbazolyl groups; An acyl group such as an acetyl group; a haloalkyl group such as a trifluoromethyl group; a cyano group; an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, and a phenanthyl group.

  More preferable examples of the compound represented by the general formula (V) include compounds represented by the following general formulas (Va), (Vb), and (Vc).

（一般式（Ｖａ）中、Ｍ^ａはＭと同様の金属を表し、ｗは上記金属の価数を表す。また、環Ａ１は置換基を有していてもよい芳香族炭化水素基を表し、環Ａ２は置換基を有していてもよい含窒素芳香族複素環基を表す。）

(In general formula (Va), M ^a represents the same metal as M, w represents the valence of the metal, and ring A1 represents an aromatic hydrocarbon group which may have a substituent. Ring A2 represents a nitrogen-containing aromatic heterocyclic group which may have a substituent.

（一般式（Ｖｂ）中、Ｍ^ｂはＭと同様の金属を表し、ｗは上記金属の価数を表す。また、環Ａ１は置換基を有していてもよい芳香族炭化水素基または置換基を有していてもよい芳香族複素環基を表し、環Ａ２は置換基を有していてもよい含窒素芳香族複素環基を表す。）

(In the general formula (Vb), M ^b represents the same metal as M, w represents the valence of the metal. Further, the ring A1 is an aromatic optionally substituted hydrocarbon group or a substituted Represents an aromatic heterocyclic group which may have a group, and ring A2 represents a nitrogen-containing aromatic heterocyclic group which may have a substituent.)

（一般式（Ｖｃ）中、Ｍ^ｃはＭと同様の金属を表し、ｗは上記金属の価数を表す。また、ｊは０、１または２を表す。さらに、環Ａ１および環Ａ１’は、それぞれ独立に、置換基を有していてもよい芳香族炭化水素基または置換基を有していてもよい芳香族複素環基を表す。また、環Ａ２および環Ａ２’は、それぞれ独立に、置換基を有していてもよい含窒素芳香族複素環基を表す。）

(In the general formula (Vc), M ^c represents the same metal as M, w represents the valence of the metal, and j represents 0, 1 or 2. Further, ring A1 and ring A1 ′ represent Each independently represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group, and ring A2 and ring A2 ′ are each independently Represents a nitrogen-containing aromatic heterocyclic group which may have a substituent.

  In the above general formulas (Va), (Vb), and (Vc), the group of ring A1 and ring A1 ′ is preferably, for example, phenyl group, biphenyl group, naphthyl group, anthryl group, thienyl group, furyl group, benzo Examples include thienyl group, benzofuryl group, pyridyl group, quinolyl group, isoquinolyl group, carbazolyl group and the like.

  In addition, the group of ring A2 and ring A2 ′ is preferably a pyridyl group, pyrimidyl group, pyrazyl group, triazyl group, benzothiazole group, benzoxazole group, benzimidazole group, quinolyl group, isoquinolyl group, quinoxalyl group, A phenanthridyl group and the like can be mentioned.

  Furthermore, the substituents that the compounds represented by the general formulas (Va), (Vb), and (Vc) may have include halogen atoms such as fluorine atoms; alkyl groups such as methyl groups and ethyl groups; vinyls Alkenyl groups such as methoxy groups; alkoxycarbonyl groups such as methoxycarbonyl groups and ethoxycarbonyl groups; alkoxy groups such as methoxy groups and ethoxy groups; aryloxy groups such as phenoxy groups and benzyloxy groups; dialkyls such as dimethylamino groups and diethylamino groups An amino group; a diarylamino group such as a diphenylamino group; a carbazolyl group; an acyl group such as an acetyl group; a haloalkyl group such as a trifluoromethyl group; a cyano group;

  When the said substituent is an alkyl group, the carbon number is 1 or more and 6 or less normally. Furthermore, when the substituent is an alkenyl group, the carbon number is usually 2 or more and 6 or less. When the substituent is an alkoxycarbonyl group, the carbon number is usually 2 or more and 6 or less. Further, when the substituent is an alkoxy group, the carbon number is usually 1 or more and 6 or less. Moreover, when a substituent is an aryloxy group, the carbon number is 6 or more and 14 or less normally. Furthermore, when the substituent is a dialkylamino group, the carbon number is usually 2 or more and 24 or less. Further, when the substituent is a diarylamino group, the carbon number is usually 12 or more and 28 or less. Furthermore, when the substituent is an acyl group, the carbon number is usually 1 or more and 14 or less. Moreover, when a substituent is a haloalkyl group, the carbon number is 1 or more and 12 or less normally.

  These substituents may be linked to each other to form a ring. As a specific example, a substituent of the ring A1 and a substituent of the ring A2 are bonded, or a substituent of the ring A1 ′ and a substituent of the ring A2 ′ are bonded. Two fused rings may be formed. Examples of such a condensed ring group include a 7,8-benzoquinoline group.

  Among them, as a substituent of ring A1, ring A1 ′, ring A2 and ring A2 ′, more preferably an alkyl group, an alkoxy group, an aromatic hydrocarbon group, a cyano group, a halogen atom, a haloalkyl group, a diarylamino group, a carbazolyl group Is mentioned.

In general formula (Va), (Vb), preferably as ^{M a, M b, M c} in (Vc), ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum or gold.

  Specific examples of the organometallic complex represented by the general formula (V), (Va), (Vb) or (Vc) are shown below, but are not limited to the following compounds (in the following, Ph is phenyl Represents a group).

Among the organometallic complexes represented by the general formulas (V), (Va), (Vb), and (Vc), in particular, as the ligand Q and / or Q ′, a 2-arylpyridine-based ligand, , 2-arylpyridine, a compound having an arbitrary substituent bonded thereto, and a compound having an arbitrary group condensed thereto are preferable.
In addition, compounds described in WO2005 / 019373 can also be used.

Next, the compound represented by the general formula (VI) will be described.
In the general formula (VI), M ^d represents a metal, and specific examples thereof include the metals described above as the metal selected from Groups 7 to 11 of the periodic table. Among these, ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum or gold is preferable, and divalent metals such as platinum and palladium are particularly preferable.

In the general formula (VI), R ⁹² and R ⁹³ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an amino group, an acyl group, an alkoxycarbonyl group, or a carboxyl group. Represents an alkoxy group, an alkylamino group, an aralkylamino group, a haloalkyl group, a hydroxyl group, an aryloxy group, an aromatic hydrocarbon group or an aromatic heterocyclic group.

Further, when T is carbon, R ⁹⁴ and R ⁹⁵ each independently represent a substituent represented by the same examples as R ⁹² and R ⁹³ . Further, as described above, when T is nitrogen, there is no R ⁹⁴ or R ⁹⁵ .

R ^{92 to} R ⁹⁵ may further have a substituent. In this case, the substituent which may further be present is not particularly limited, and any group can be used as the substituent.
Furthermore, R ^{92 to} R ⁹⁵ may be linked to each other to form a ring, and this ring may further have an arbitrary substituent.

  Specific examples (T-1, T-10 to T-15) of the organometallic complex represented by the general formula (VI) are shown below, but are not limited to the following exemplified compounds. In the following, Me represents a methyl group, and Et represents an ethyl group.

[3] Other components In the composition for organic electroluminescent elements of the present invention, various other solvents may be contained as necessary in addition to the solvent and the light emitting material described above. Examples of such other solvents include amides such as N, N-dimethylformamide and N, N-dimethylacetamide, and dimethyl sulfoxide.
Moreover, various additives, such as a leveling agent and an antifoamer, may be included.

  In addition, when two or more layers are laminated by a wet film formation method, in order to prevent these layers from being compatible with each other, a photocurable resin or a thermosetting resin is used for the purpose of curing and insolubilizing after film formation. Can also be contained.

[4] Material concentration and blending ratio in the composition for organic electroluminescence devices The quinoline compound of the present invention, the luminescent material and components (leveling agents, etc.) that can be added as necessary in the composition for organic electroluminescence devices, etc. The solid content concentration is usually 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.1% by weight or more, still more preferably 0.5% by weight or more, and most preferably 1% by weight or more. It is usually 80% by weight or less, preferably 50% by weight or less, more preferably 40% by weight or less, still more preferably 30% by weight or less, and most preferably 20% by weight or less. If this concentration is below the lower limit, it is difficult to form a thick film when forming a thin film, and if it exceeds the upper limit, it may be difficult to form a thin film.

  In the composition for organic electroluminescent elements of the present invention, the weight mixing ratio of the light emitting material / quinoline compound is usually 0.1 / 99.9 or more, more preferably 0.5 / 99.5 or more. More preferably, it is 1/99 or more, most preferably 2/98 or more, usually 50/50 or less, more preferably 40/60 or less, and further preferably 30/70 or less. Most preferably, it is 20/80 or less. If this ratio falls below the lower limit or exceeds the upper limit, the luminous efficiency may be significantly reduced.

[5] Preparation method of composition for organic electroluminescence device The composition for organic electroluminescence device of the present invention includes the quinoline compound of the present invention, a luminescent material, and a leveling agent and an antifoaming agent that can be added as necessary. It is prepared by dissolving a solute composed of various additives in an appropriate solvent. In order to shorten the time required for the dissolution step and to keep the solute concentration in the composition uniform, the solute is usually dissolved while stirring the liquid. The dissolution step may be performed at room temperature, but when the dissolution rate is slow, it can be heated and dissolved. After completion of the dissolution step, a filtration step such as filtering may be performed as necessary.

[6] Properties, physical properties, etc. (moisture concentration) of the composition for organic electroluminescent elements
When an organic electroluminescence device is produced by forming a layer by a wet film forming method using the composition for organic electroluminescence device of the present invention, a film formed when water is present in the composition for organic electroluminescence device to be used. Since moisture is mixed into the film and the uniformity of the film is impaired, the water content in the composition for organic electroluminescent elements of the present invention is preferably as low as possible. In general, since organic electroluminescent devices use many materials such as cathodes that deteriorate significantly due to moisture, when moisture is present in the composition for organic electroluminescent devices, moisture remains in the dried film. However, there is a possibility of deteriorating the characteristics of the element, which is not preferable.

  Specifically, the amount of water contained in the composition for organic electroluminescent elements of the present invention is usually 1% by weight or less, preferably 0.1% by weight or less, more preferably 0.01% by weight or less.

  As a method for measuring the moisture concentration in the composition for organic electroluminescent elements, the method described in Japanese Industrial Standard “Method for Measuring Moisture of Chemical Products” (JIS K0068: 2001) is preferable. For example, the Karl Fischer reagent method (JIS K0211). -1348) and the like.

(Uniformity)
The composition for organic electroluminescent elements of the present invention is preferably in a uniform liquid state at room temperature in order to enhance stability in a wet film forming process, for example, ejection stability from a nozzle in an ink jet film forming method. . The uniform liquid at normal temperature means that the composition is a liquid composed of a uniform phase and does not contain a particle component having a particle size of 0.1 μm or more in the composition.

(Physical properties)
Regarding the viscosity of the composition for organic electroluminescent elements of the present invention, when the viscosity is extremely low, for example, coating surface non-uniformity due to excessive liquid film flow in the film forming process, nozzle ejection failure in ink jet film formation, etc. are likely to occur. In the case of extremely high viscosity, nozzle clogging or the like in ink jet film formation is likely to occur. For this reason, the viscosity at 25 ° C. of the composition of the present invention is usually 2 mPa · s or more, preferably 3 mPa · s or more, more preferably 5 mPa · s or more, and usually 1000 mPa · s or less, preferably 100 mPa · s or less. More preferably, it is 50 mPa · s or less.

  Further, when the surface tension of the composition for organic electroluminescent elements of the present invention is high, the wettability of the film forming liquid to the substrate is lowered, the leveling property of the liquid film is poor, and the film formation surface is disturbed during drying. Since problems such as being easy to occur may occur, the surface tension of the composition of the present invention at 20 ° C. is usually less than 50 mN / m, preferably less than 40 mN / m.

  Furthermore, when the vapor pressure of the composition for organic electroluminescent elements of the present invention is high, problems such as changes in solute concentration due to evaporation of the solvent may easily occur. For this reason, the vapor pressure at 25 ° C. of the composition of the present invention is usually 50 mmHg or less, preferably 10 mmHg or less, more preferably 1 mmHg or less.

[7] Method for Preserving Composition for Organic Electroluminescence Device The composition for organic electroluminescence device of the present invention is filled in a container capable of preventing the transmission of ultraviolet rays, for example, a brown glass bottle, and sealed and stored. Is preferred. The storage temperature is usually −30 ° C. or higher, preferably 0 ° C. or higher, and usually 35 ° C. or lower, preferably 25 ° C. or lower.

[Organic electroluminescence device]
The organic electroluminescent element of the present invention has an anode, a cathode, and an organic layer provided between both electrodes on a substrate, and the organic layer contains the quinoline compound of the present invention. To do. The layer containing the quinoline compound is preferably formed using the organic electroluminescent element material or the organic electroluminescent element composition of the present invention. The organic layer containing the quinoline compound of the present invention is preferably a light emitting layer. The layer containing the quinoline compound is preferably doped with an organometallic complex. As this organometallic complex, those exemplified as the light emitting material can be used.

  1 to 7 are schematic cross-sectional views showing structural examples suitable for the organic electroluminescence device of the present invention. In FIG. 1, 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a light emitting layer, 5 represents an electron injection layer, and 6 represents a cathode.

[1] Substrate The substrate 1 serves as a support for the organic electroluminescent element, and quartz or glass plates, metal plates, metal foils, plastic films, sheets, and the like are used. In particular, a glass plate or a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, or polysulfone is preferable. When using a synthetic resin substrate, it is necessary to pay attention to gas barrier properties. If the gas barrier property of the substrate is too small, the organic electroluminescent element may be deteriorated by the outside air that has passed through the substrate, which is not preferable. For this reason, a method of providing a gas barrier property by providing a dense silicon oxide film or the like on at least one surface of the synthetic resin substrate is also a preferable method.

[2] Anode An anode 2 is provided on the substrate 1. The anode 2 plays a role of hole injection into a layer on the light emitting layer side (such as the hole injection layer 3 or the light emitting layer 4).

  This anode 2 is usually a metal such as aluminum, gold, silver, nickel, palladium, platinum, a metal oxide such as an oxide of indium and / or tin, a metal halide such as copper iodide, carbon black, or A conductive polymer such as poly (3-methylthiophene), polypyrrole, or polyaniline is used.

  In general, the anode 2 is often formed by sputtering, vacuum deposition, or the like. In addition, when forming an anode using fine metal particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, or conductive polymer fine powder, an appropriate binder resin solution is used. The anode 2 can also be formed by dispersing and coating the substrate 1. Further, in the case of a conductive polymer, a thin film can be directly formed on the substrate 1 by electrolytic polymerization, or the anode 2 can be formed by applying a conductive polymer on the substrate 1 (Appl. Phys. Lett. 60, 2711, 1992).

The anode 2 usually has a single-layer structure, but it can also have a laminated structure made of a plurality of materials if desired.

  The thickness of the anode 2 varies depending on the required transparency. When transparency is required, the visible light transmittance is usually 60% or more, preferably 80% or more. In this case, the thickness of the anode is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably about 500 nm or less. When it may be opaque, the thickness of the anode 2 is arbitrary, and the anode 2 may be the same as the substrate 1. Furthermore, it is also possible to laminate different conductive materials on the anode 2 described above.

  The surface of the anode is treated with ultraviolet (UV) / ozone, oxygen plasma, or argon plasma for the purpose of removing impurities adhering to the anode and adjusting the ionization potential to improve hole injection. Is preferred.

[3] Hole Injection Layer Since the hole injection layer 3 is a layer that transports holes from the anode 2 to the light emitting layer 4, the hole injection layer 3 preferably contains a hole transporting compound.

  In the hole injection layer 3, a cation radical obtained by removing one electron from an electrically neutral compound accepts one electron from a nearby electrically neutral compound, whereby holes move. When the cation radical compound is not included in the hole injection layer 3 when the element is not energized, the cation radical of the hole transport compound is generated when the hole transport compound gives electrons to the anode 2 during energization, Holes are transported by transferring electrons between the cation radical and an electrically neutral hole transporting compound.

  When the hole injection layer 3 contains a cation radical compound, cation radicals necessary for hole transport are present at a concentration higher than that generated by oxidation by the anode 2, and the hole transport performance is improved. It is preferable that the hole injection layer 3 contains a cation radical compound. When an electrically neutral hole transporting compound is present in the vicinity of the cation radical compound, electrons are transferred smoothly, so that the hole injection layer 3 contains a cation radical compound and a hole transporting compound. Is more preferable.

  Here, the cation radical compound is a cation radical that is a chemical species obtained by removing one electron from a hole transporting compound, and an ionic compound composed of a counter anion, and already has holes (free carriers) that are easy to move. Yes.

  Further, by mixing an electron-accepting compound with the hole-transporting compound, one-electron transfer from the hole-transporting compound to the electron-accepting compound occurs, and the above-described cation radical compound is generated. For this reason, it is preferable that the hole injection layer 3 contains a hole transporting compound and an electron accepting compound.

  Summarizing the above preferred materials, the hole injection layer 3 preferably contains a hole transporting compound, and more preferably contains a hole transporting compound and an electron accepting compound. The hole injection layer 3 preferably contains a cation radical compound, and more preferably contains a cation radical compound and a hole transporting compound.

  Furthermore, the hole injection layer 3 may contain a binder resin that does not easily trap charges and a coating property improving agent as necessary.

  However, as the hole injection layer 3, a film is formed on the anode 2 by a wet film formation method using only the electron-accepting compound or the electron-accepting compound and the hole-transporting compound. It is also possible to laminate | stack the composition for organic electroluminescent elements by application | coating or vapor deposition. In this case, a part or all of the composition for organic electroluminescent elements of the present invention interacts with the electron-accepting compound, so that the hole transport layer 10 having excellent hole injecting property as shown in FIGS. Is formed.

(Hole transporting compound)
As the hole transporting compound, a compound having an ionization potential of 4.5 eV to 6.0 eV is preferable.

  Examples of the hole transporting compound include aromatic amine compounds, phthalocyanine derivatives, porphyrin derivatives, oligothiophene derivatives, polythiophene derivatives, etc., in addition to the quinoline compounds of the present invention. Of these, aromatic amine compounds are preferred from the viewpoints of amorphousness and visible light transmittance.

  Of the aromatic amine compounds, aromatic tertiary amine compounds are particularly preferable. Here, the aromatic tertiary amine compound is a compound having an aromatic tertiary amine structure, and includes a compound having a group derived from an aromatic tertiary amine.

  The type of the aromatic tertiary amine compound is not particularly limited, but a polymer compound having a weight average molecular weight of 1,000 or more and 1,000,000 or less (a polymerization organic compound in which repeating units are linked) is more preferable from the viewpoint of the surface smoothing effect.

  Preferable examples of the aromatic tertiary amine polymer compound include a polymer compound having a repeating unit represented by the following general formula (VII).

（一般式（VII）中、Ａｒ^２１，Ａｒ^２２は各々独立して、置換基を有していてもよい芳香族炭化水素基、または置換基を有していてもよい芳香族複素環基を表す。Ａｒ^２３〜Ａｒ^２５は、各々独立して、置換基を有していてもよい２価の芳香族炭化水素基、または置換基を有していてもよい２価の芳香族複素環基を表す。Ｙは、下記の連結基群の中から選ばれる連結基を表す。また、Ａｒ^２１〜Ａｒ^２５のうち、同一のＮ原子に結合する二つの基は互いに結合して環を形成してもよい。）

(In the general formula (VII), Ar ²¹ and Ar ²² each independently represents an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent. Ar ^{23 to} Ar ²⁵ each independently represents a divalent aromatic hydrocarbon group which may have a substituent, or a divalent aromatic heterocyclic group which may have a substituent. Y represents a linking group selected from the following group of linking groups, and among Ar ^{21 to} Ar ²⁵ , two groups bonded to the same N atom are bonded to each other to form a ring. May be.)

（上記各式中、Ａｒ^３１〜Ａｒ^４１は、各々独立して、置換基を有していてもよい芳香族炭化水素環、または置換基を有していてもよい芳香族複素環由来の１価または２価の基を表す。Ｒ^１０１およびＲ^１０２は、各々独立して、水素原子または任意の置換基を表す。））

(In the above formulas, Ar ^{31 to} Ar ⁴¹ are each independently 1 derived from an aromatic hydrocarbon ring which may have a substituent, or an aromatic heterocyclic ring which may have a substituent. And R ¹⁰¹ and R ¹⁰² each independently represents a hydrogen atom or an optional substituent.)

As Ar ^{21 to} Ar ²⁵ and Ar ^{31 to} Ar ⁴¹ , any monovalent or divalent group derived from any aromatic hydrocarbon ring or aromatic heterocyclic ring is applicable. These may be the same or different from each other. Moreover, you may have arbitrary substituents.

  Examples of the aromatic hydrocarbon ring include a 5- or 6-membered monocyclic ring or a 2-5 condensed ring. Specific examples include a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluoranthene ring, fluorene ring and the like.

  The aromatic heterocycle includes a 5- or 6-membered monocyclic ring or a 2-4 condensed ring. Specific examples include furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, Thienopyrrole ring, thienothiophene ring, furopyrrole ring, furofuran ring, thienofuran ring, benzoisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring , Synoline ring, quinoxaline ring, phenanthridine ring, benzimidazole ring, perimidine ring, quinazoline ring, quinazolinone ring, azulene ring and the like.

Moreover, as Ar < ²³ > -Ar < ²⁵ >, Ar < ³¹ > -Ar < ³⁵ >, Ar < ³⁷ > -Ar < ⁴⁰ >, the bivalent origin derived from the 1 type or 2 types or more of aromatic hydrocarbon ring and / or aromatic heterocycle which were illustrated above is shown. Two or more groups may be linked and used.

The group derived from the aromatic hydrocarbon ring and / or aromatic heterocycle of Ar ^{21 to} Ar ⁴¹ may further have a substituent. The molecular weight of the substituent is usually 400 or less, preferably about 250 or less. The type of the substituent is not particularly limited, and examples thereof include one or more selected from the following substituent group D.

[Substituent group D]
An alkyl group having usually 1 or more, usually 10 or less, preferably 8 or less, such as a methyl group or an ethyl group; an alkenyl group having 2 or more, usually 11 or less, preferably 5 or less carbon atoms, such as a vinyl group. An alkynyl group having usually 2 or more, usually 11 or less, preferably 5 or less, such as an ethynyl group; an alkoxy having a carbon number of usually 1 or more, usually 10 or less, preferably 6 or less, such as a methoxy group or an ethoxy group; A group; an aryloxy group such as a phenoxy group, a naphthoxy group, a pyridyloxy group, etc., usually 4 or more, preferably 5 or more, usually 25 or less, preferably 14 or less; a carbon such as a methoxycarbonyl group or an ethoxycarbonyl group An alkoxycarbonyl group having a number of usually 2 or more, usually 11 or less, preferably 7 or less; a dimethylamino group, a diethylamino group or the like, and usually having 2 or more carbon atoms Usually 20 or less, preferably 12 or less dialkylamino group; diphenylamino group, ditolylamino group, N-carbazolyl group, etc., and usually diarylamino having 10 or more carbon atoms, preferably 12 or more, usually 30 or less, preferably 22 or less Group: an arylalkylamino group having 6 or more carbon atoms, preferably 7 or more, usually 25 or less, preferably 17 or less, such as a phenylmethylamino group; an acetyl group, a benzoyl group or the like, and usually having 2 or more carbon atoms, Usually an acyl group of 10 or less, preferably 7 or less; a halogen atom such as a fluorine atom or a chlorine atom; a haloalkyl group having a carbon number of usually 1 or more, usually 8 or less, preferably 4 or less, such as a trifluoromethyl group; An alkylthio group having 1 to 10 carbon atoms, preferably 6 or less, preferably 6 or less; An arylthio group having usually 4 or more, preferably 5 or more, usually 25 or less, preferably 14 or less, such as a ruthio group, a naphthylthio group, or a pyridylthio group; Or more, preferably 3 or more, usually 33 or less, preferably 26 or less silyl group; trimethylsiloxy group, triphenylsiloxy group, etc., the carbon number is usually 2 or more, preferably 3 or more, usually 33 or less, preferably 26 or less. A siloxy group; a cyano group; an aromatic hydrocarbon ring group having usually 6 or more, usually 30 or less, preferably 18 or less, such as a phenyl group or a naphthyl group; a carbon number such as a thienyl group or a pyridyl group. An aromatic heterocyclic group of 3 or more, preferably 4 or more, usually 28 or less, preferably 17 or less.

Ar ²¹ and Ar ²² are preferably monovalent groups derived from a benzene ring, a naphthalene ring, a phenanthrene ring, a thiophene ring, or a pyridine ring from the viewpoint of the solubility, heat resistance, and hole injection / transport properties of the polymer compound. More preferred are a phenyl group and a naphthyl group.

Ar ^{23 to} Ar ²⁵ are preferably divalent groups derived from a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring from the viewpoint of heat resistance and hole injection / transport properties including redox potential. More preferably a group, a biphenylene group, or a naphthylene group.

As R ¹⁰¹ and R ¹⁰² , a hydrogen atom or an arbitrary substituent is applicable. These may be the same or different from each other. The type of the substituent is not particularly limited, and examples of applicable substituents include alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, silyl groups, siloxy groups, aromatic hydrocarbon groups, aromatic heterocyclic rings. Group and halogen atom. Specific examples thereof include the groups exemplified in the above substituent group D.

  Preferable examples of the other aromatic tertiary amine polymer compounds include polymer compounds containing a repeating unit represented by the following general formula (VIII) and / or general formula (IX).

（一般式（VIII）、（IX）中、Ａｒ^４５，Ａｒ^４７およびＡｒ^４８は各々独立して、置換基を有していてもよい芳香族炭化水素基、または置換基を有していてもよい芳香族複素環基を表す。Ａｒ^４４およびＡｒ^４６は各々独立して、置換基を有していてもよい２価の芳香族炭化水素基、または置換基を有していてもよい２価の芳香族複素環基を表す。また、Ａｒ^４５〜Ａｒ^４８のうち、同一のＮ原子に結合する２つの基は互いに結合して環を形成してもよい。Ｒ^１１１〜Ｒ^１１３は各々独立して、水素原子または任意の置換基を表す。）

(In the general formulas (VIII) and (IX), Ar ⁴⁵ , Ar ⁴⁷ and Ar ⁴⁸ may each independently have an aromatic hydrocarbon group which may have a substituent, or a substituent. And each of Ar ⁴⁴ and Ar ⁴⁶ independently represents a divalent aromatic hydrocarbon group which may have a substituent, or a divalent which may have a substituent. In addition, two groups bonded to the same N atom among Ar ^{45 to} Ar ⁴⁸ may be bonded to each other to form a ring, and R ^{111 to} R ¹¹³ are each independently And represents a hydrogen atom or an arbitrary substituent.)

Specific examples of Ar ⁴⁵ , Ar ⁴⁷ , Ar ⁴⁸ and Ar ⁴⁴ , Ar ⁴⁶ , preferred examples, examples of substituents that may be included and examples of preferred substituents are Ar ²¹ , Ar ^22, and Ar ²³ ˜ Same as Ar ²⁵ . R ^{111 to} R ¹¹³ are preferably a hydrogen atom or a substituent described in [Substituent group D], more preferably a hydrogen atom, an alkyl group, an alkoxy group, an amino group, an aromatic hydrocarbon group, It is an aromatic hydrocarbon group.

  Specific examples of the aromatic tertiary amine polymer compound containing a repeating unit represented by the general formula (VIII) and / or (IX) include those described in WO2005 / 089024, and preferred examples thereof are also included. Although it is the same, it is not limited to them at all.

  Moreover, when forming a positive hole injection layer with a wet film-forming method, the positive hole transport compound which is easy to melt | dissolve in a various solvent is preferable. As the aromatic tertiary amine compound, for example, a binaphthyl compound (Japanese Patent Laid-Open No. 2004-014187) and an asymmetric 1,4-phenylenediamine compound (Japanese Patent Laid-Open No. 2004-026732) are preferable.

  In addition, compounds that are easily soluble in various solvents may be appropriately selected from aromatic amine compounds that have been conventionally used as a hole injection / transport thin film purification material in organic electroluminescent devices. Examples of the aromatic amine compound applicable to the hole-transporting compound of the hole-injecting layer include conventionally known compounds that have been utilized as a hole-injecting / transporting layer-forming material in organic electroluminescence devices. It is done. For example, an aromatic diamine compound in which a tertiary aromatic amine unit such as 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane is linked (JP 59-194393 A); 4,4′- An aromatic amine compound containing two or more tertiary amines represented by bis [N- (1-naphthyl) -N-phenylamino] biphenyl and having two or more condensed aromatic rings substituted with nitrogen atoms No. 5-23481); an aromatic triamine compound having a starburst structure as a derivative of triphenylbenzene (US Pat. No. 4,923,774); N, N′-diphenyl-N, N′-bis (3- Aromatic diamine compounds such as methylphenyl) biphenyl-4,4′-diamine (US Pat. No. 4,764,625); α, α, α ′, α′-tetramethyl-α, α′- (4-di (p-tolyl) aminophenyl) -p-xylene (Japanese Patent Laid-Open No. 3-269084); sterically asymmetric triphenylamine derivative as a whole molecule (Japanese Patent Laid-Open No. 4-129271); pyrenyl A compound in which a plurality of aromatic diamino groups are substituted on the group (Japanese Patent Laid-Open No. 4-175395); an aromatic diamine compound in which a tertiary aromatic amine unit is linked with an ethylene group (Japanese Patent Laid-Open No. 4-264189); a styryl structure An aromatic diamine having a thiophene group (JP-A-4-290851); a compound in which an aromatic tertiary amine unit is linked by a thiophene group (JP-A-4-304466); a starburst type aromatic triamine compound (JP-A-4-30481) 308688); benzylphenyl compound (Japanese Patent Laid-Open No. 4-364153); Compounds in which thiones are linked (JP-A-5-25473); triamine compounds (JP-A-5-239455); bisdipyridylaminobiphenyl (JP-A-5-320634); N, N, N-triphenylamine Derivatives (JP-A-6-1972); Aromatic diamines having a phenoxazine structure (JP-A-7-138562); Diaminophenylphenanthridine derivatives (JP-A-7-252474); 2-311591); silazane compounds (US Pat. No. 4,950,950); silanamine derivatives (JP-A-6-49079); phosphamine derivatives (JP-A-6-25659); quinacridone compounds, etc. Can be mentioned. These aromatic amine compounds may be used in combination of two or more as required.

  Preferred specific examples of the phthalocyanine derivative or porphyrin derivative applicable to the hole transporting compound of the hole injection layer include porphyrin, 5,10,15,20-tetraphenyl-21H, 23H-porphyrin, 5,10 , 15,20-tetraphenyl-21H, 23H-porphyrin cobalt (II), 5,10,15,20-tetraphenyl-21H, 23H-porphyrin copper (II), 5,10,15,20-tetraphenyl- 21H, 23H-porphyrin zinc (II), 5,10,15,20-tetraphenyl-21H, 23H-porphyrin vanadium (IV) oxide, 5,10,15,20-tetra (4-pyridyl) -21H, 23H -Porphyrin, 29H, 31H-phthalocyanine copper (II), phthalocyanine zinc (II), Russia Nin titanium, phthalocyanine oxide magnesium, phthalocyanine lead, phthalocyanine copper (II), 4,4 ', 4 ", 4' '' - tetraaza-29H, 31H-phthalocyanine, and the like.

  Further, preferred specific examples of the oligothiophene derivative applicable as a hole transporting compound of the hole injection layer include α-terthiophene and its derivative, α-sexithiophene and its derivative, and oligothiophene containing a naphthalene ring. Derivatives (JP-A-6-256341) and the like.

  Further, preferred specific examples of the polythiophene derivative applicable as the hole transporting compound in the present invention include poly (3,4-ethylenedioxythiophene) (PEDOT), poly (3-hexylthiophene) and the like.

  The molecular weight of these hole transporting compounds is usually 9000 or less, preferably 5000 or less, and usually 200 or more, preferably 400 or more, except in the case of a polymer compound (a polymerizable compound in which repeating units are continuous). Range. If the molecular weight of the hole transporting compound is too high, synthesis and purification are difficult, which is not preferable. On the other hand, if the molecular weight is too low, the heat resistance may be lowered, which is also not preferable.

  The hole transporting compound used as the material for the hole injection layer may contain any one of these compounds alone, or may contain two or more. When two or more hole transporting compounds are contained, the combination thereof is arbitrary, but one or more aromatic tertiary amine polymer compounds and one or two other hole transporting compounds are used. It is preferable to use the above together.

(Electron-accepting compound)
The electron-accepting compound is preferably a compound having an oxidizing power and the ability to accept one electron from the above-described hole transporting compound, specifically, a compound having an electron affinity of 4 eV or more is preferable, and 5 eV or more. The compound which is the compound of these is further more preferable.

  Examples include onium salts substituted with an organic group such as 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, iron (III) chloride (JP-A-11-251067), ammonium peroxodisulfate and the like. Examples thereof include valent inorganic compounds, cyano compounds such as tetracyanoethylene, aromatic boron compounds such as tris (pentafluorophenyl) borane (Japanese Patent Laid-Open No. 2003-31365), fullerene derivatives, iodine and the like.

  Of the above compounds, onium salts substituted with organic groups and high valent inorganic compounds are preferred because of their strong oxidizing power, and organic groups are substituted because they are soluble in various solvents and applicable to wet coating. Preferred are onium salts, cyano compounds, and aromatic boron compounds.

  Specific examples of an onium salt substituted with an organic group, a cyano compound, and an aromatic boron compound suitable as an electron-accepting compound include those described in WO 2005/089024, and suitable examples thereof are also the same. Although the compound (A-2) represented by the following structural formula is mentioned, it is not limited to them at all.

(Cation radical compound)
The cation radical compound is an ionic compound composed of a cation radical which is a chemical species obtained by removing one electron from a hole transporting compound and a counter anion. However, when the cation radical is derived from a hole transporting polymer compound, the cation radical has a structure in which one electron is removed from the repeating unit of the polymer compound.

  The cation radical is preferably a chemical species obtained by removing one electron from the aforementioned compound in the hole transporting compound, and is preferably a chemical species obtained by removing one electron from a compound more preferable as the hole transporting compound. From the viewpoints of visible light transmittance, heat resistance, solubility, and the like.

  The cation radical compound can be generated by mixing the hole transporting compound and the electron accepting compound. That is, by mixing the hole transporting compound and the electron accepting compound, electron transfer occurs from the hole transporting compound to the electron accepting compound, and the cation radical and the counter anion of the hole transporting compound are included. A cation ion compound is formed.

  Cationic radical compounds derived from polymer compounds such as PEDOT / PSS (Adv. Mater., 2000, 12, 481) and emeraldine hydrochloride (J. Phys. Chem., 1990, 94, 7716) It is also generated by oxidative polymerization (dehydrogenation polymerization), that is, by oxidizing a monomer chemically or electrochemically with peroxodisulfate in an acidic solution. In the case of this oxidative polymerization (dehydrogenation polymerization), the monomer is oxidized to be polymerized, and the cation radical is formed by removing one electron from the repeating unit of the polymer with an anion derived from an acidic solution as a counter anion. Produces.

  The hole injection layer 3 is formed on the anode 2 by a wet film formation method or a vacuum deposition method.

  ITO (indium tin oxide), which is generally used as the anode 2, has a surface roughness of about 10 nm (Ra) and, in addition, often has protrusions locally, resulting in short-circuit defects. There was a problem that it was easy to produce. When the hole injection layer 3 formed on the anode 2 is formed by the wet film forming method, the defect of the element is generated due to the unevenness of the surface of the anode as compared with the case of forming by the vacuum deposition method. Has the advantage of reducing.

  In the case of layer formation by a wet film formation method, one or more predetermined amounts of each of the above-described materials (hole transporting compound, electron accepting compound, cation radical compound) do not become a charge trap if necessary. Add binder resin and coatability improver, dissolve in solvent, prepare coating solution, by wet film forming method such as spin coating, spray coating, dip coating, die coating, flexographic printing, screen printing, inkjet method etc. It is applied on the anode and dried to form the hole injection layer 3.

  As the solvent used for the layer formation by the wet film forming method, any solvent can be used as long as it can dissolve the above-mentioned materials (hole transporting compound, electron accepting compound, cation radical compound). Is not particularly limited, but generates a deactivated substance or deactivated substance that may deactivate each material (hole transporting compound, electron accepting compound, cation radical compound) used in the hole injection layer The thing which does not contain is preferable.

  Preferred solvents that satisfy these conditions include, for example, ether solvents and ester solvents. Specifically, examples of the ether solvent include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1, 3 -Aromatic ethers such as dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole and the like. Examples of the ester solvent include aliphatic esters such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and benzoic acid. Examples include aromatic esters such as n-butyl. Any one of these may be used alone, or two or more thereof may be used in any combination and ratio.

  Examples of solvents that can be used in addition to the ether solvents and ester solvents described above include aromatic hydrocarbon solvents such as benzene, toluene, and xylene, and amides such as N, N-dimethylformamide and N, N-dimethylacetamide. System solvents, dimethyl sulfoxide and the like. Any one of these may be used alone, or two or more thereof may be used in any combination and ratio. Moreover, you may use 1 type (s) or 2 or more types among these solvents in combination with 1 type (s) or 2 or more types among the above-mentioned ether solvent and ester solvent. In particular, aromatic hydrocarbon solvents such as benzene, toluene, and xylene have a low ability to dissolve electron accepting compounds and cation radical compounds, and therefore are preferably mixed with ether solvents and ester solvents.

  The concentration of the solvent in the coating solution is usually 10% by weight or more, preferably 30% by weight or more, more preferably 50% by weight or more, and usually 99.999% by weight or less, preferably 99.99% by weight or less. Preferably it is the range of 99.9 weight% or less. When two or more kinds of solvents are mixed and used, the total of these solvents is set to satisfy this range.

In the case of forming a layer by vacuum deposition, one or more of the aforementioned materials (hole transporting compound, electron accepting compound, cation radical compound) are put in a crucible installed in a vacuum vessel ( When two or more materials are used, put them in each crucible), and after evacuating the inside of the vacuum vessel to about 10 ⁻⁴ Pa with an appropriate vacuum pump, heat the crucible (if using two or more materials, each Heat the crucible) and evaporate by controlling the amount of evaporation (if more than one material is used, evaporate by independently controlling the amount of evaporation) and place it on the anode of the substrate placed facing the crucible. A hole injection layer is formed. In addition, when using 2 or more types of materials, they can also be put into a crucible, can be heated and evaporated, and can be used for hole injection layer formation.

The film thickness of the hole injection layer 3 that may be formed in this manner is usually in the range of 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less.
The hole injection layer 3 may be omitted as shown in FIG.

[4] Light-Emitting Layer A normal light-emitting layer 4 is provided on the hole injection layer 3. The light emitting layer 4 is a layer containing a light emitting material, and between the electrodes to which an electric field is applied, holes injected from the anode 2 through the hole injection layer 3 and electrons injected from the cathode 6 through the electron injection layer 5 It is a layer that is excited by recombination and becomes a main light emitting source. The light emitting layer 4 preferably contains a light emitting material (dopant) and one or more host materials, and the light emitting layer 4 more preferably contains the quinoline compound of the present invention as a host material, and is formed by a vacuum deposition method. However, it is particularly preferable that the layer be prepared by a wet film-forming method using the composition for organic electroluminescent elements of the present invention.

  Here, the wet film-forming method is a method in which the composition for organic electroluminescent elements of the present invention containing the above-mentioned solvent is applied by spin coating, spray coating, dip coating, die coating, flexographic printing, screen printing, or inkjet method. It is a film.

  In addition, the light emitting layer 4 may contain other materials and components as long as the performance of the present invention is not impaired.

  In general, when the same material is used in the organic electroluminescent element, the thinner the film thickness between the electrodes, the larger the effective electric field, so that the injected current increases, so the driving voltage decreases. For this reason, the driving voltage of the organic electroluminescence device decreases when the total film thickness between the electrodes is thin, but if it is too thin, a short circuit occurs due to the protrusion caused by the electrode such as ITO. Necessary.

  In the present invention, in addition to the light emitting layer 4, when the organic layer such as the hole injection layer 3 and the electron transport layer 7 described later is provided, the light emitting layer 4 and other organic materials such as the hole injection layer 3 and the electron transport layer 7 are used. The total film thickness combined with the layer is usually 30 nm or more, preferably 50 nm or more, more preferably 100 nm or more, usually 1000 nm or less, preferably 500 nm or less, more preferably 300 nm or less. In addition, when the conductivity of the hole injection layer 3 other than the light emitting layer 4 and the electron injection layer 5 described later is high, the amount of charge injected into the light emitting layer 4 increases. It is also possible to reduce the drive voltage while increasing the thickness to reduce the thickness of the light emitting layer 4 and maintaining the total thickness to some extent.

  Therefore, the thickness of the light emitting layer 4 is usually 10 nm or more, preferably 20 nm or more, and usually 300 nm or less, preferably 200 nm or less. When the element of the present invention has only the light emitting layer 4 between the anode and the cathode, the thickness of the light emitting layer 4 is usually 30 nm or more, preferably 50 nm or more, usually 500 nm or less, preferably 300 nm or less. is there.

[5] Electron Injection Layer The electron injection layer 5 plays a role of efficiently injecting electrons injected from the cathode 6 into the light emitting layer 4. In order to perform electron injection efficiently, the material for forming the electron injection layer 5 is preferably a metal having a low work function, and alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium are used.
The film thickness of the electron injection layer 5 is preferably 0.1 to 5 nm.

Further, it is also possible to insert an ultrathin insulating film (0.1 to 5 nm) such as LiF, MgF ₂ , Li ₂ O, CsCO _{3 at} the interface between the cathode 6 and the light emitting layer 4 or the electron transport layer 7 described later. (Appl. Phys. Lett., 70, 152, 1997; JP-A-10-74586; IEEE Trans. Electron. Devices, 44, 1245, 1997); SID 04 Digest, page 154).

  Furthermore, organic metal transport materials represented by metal complexes such as nitrogen-containing heterocyclic compounds such as bathophenanthroline and aluminum complexes of 8-hydroxyquinoline described later are doped with alkali metals such as sodium, potassium, cesium, lithium and rubidium. (Described in JP-A-10-270171, JP-A 2002-1000047, JP-A 2002-1000048, and the like) makes it possible to improve electron injection / transport properties and achieve excellent film quality. Therefore, it is preferable. The film thickness in this case is usually 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.

The electron injection layer 5 is formed by laminating on the light emitting layer 4 by a wet film forming method or a vacuum deposition method in the same manner as the light emitting layer 4. In the case of the vacuum evaporation method, the evaporation source is put into a crucible or metal boat installed in a vacuum vessel, and the inside of the vacuum vessel is evacuated to about 10 ⁻⁴ Pa with an appropriate vacuum pump, and then the crucible or metal boat is Heat and evaporate to form an electron injection layer on the substrate placed facing the crucible or metal boat.

The alkali metal is deposited using an alkali metal dispenser in which nichrome is filled with an alkali metal chromate and a reducing agent. By heating the dispenser in a vacuum container, the alkali metal chromate is reduced and the alkali metal is evaporated. In the case of co-evaporating the organic electron transport material and the alkali metal, the organic electron transport material is put in a crucible installed in a vacuum vessel, and the inside of the vacuum vessel is evacuated to about 10 ⁻⁴ Pa with a suitable vacuum pump. Each crucible and dispenser are heated simultaneously to evaporate to form an electron injection layer on the substrate placed facing the crucible and dispenser.

At this time, co-evaporation is uniformly performed in the film thickness direction of the electron injection layer 5, but there may be a concentration distribution in the film thickness direction.
The electron injection layer 5 may be omitted as shown in FIGS.

[6] Cathode The cathode 6 plays a role of injecting electrons into a layer on the light emitting layer side (such as the electron injection layer 5 or the light emitting layer 4). The material used for the cathode 6 can be the material used for the anode 2, but a metal having a low work function is preferable for efficient electron injection, such as tin, magnesium, indium, calcium, A suitable metal such as aluminum or silver or an alloy thereof is used. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.

  The film thickness of the cathode 6 is usually the same as that of the anode 2. For the purpose of protecting the cathode made of a low work function metal, further laminating a metal layer having a high work function and stable to the atmosphere on the cathode increases the stability of the device. For this purpose, metals such as aluminum, silver, copper, nickel, chromium, gold, platinum are used.

[7] Other Constituent Layers While the description has been given centering on the element having the layer constitution shown in FIG. 1, the performance between the anode 2 and the cathode 6 and the light emitting layer 4 in the organic electroluminescent element of the present invention is described. In addition to the layers described above, any layer may be included, and any layer other than the light emitting layer 4 may be omitted.

  Examples of the layer that may be included include the electron transport layer 7. The electron transport layer 7 is provided between the light emitting layer 4 and the electron injection layer 5 as shown in FIG. 2 for the purpose of further improving the light emission efficiency of the device.

The electron transport layer 7 is formed of a compound capable of efficiently transporting electrons injected from the cathode 6 between electrodes to which an electric field is applied in the direction of the light emitting layer 4. As the electron transporting compound used for the electron transport layer 7, the electron injection efficiency from the cathode 6 or the electron injection layer 5 is high, and the injected electrons can be efficiently transported with high electron mobility. It must be a compound.
Materials satisfying such conditions include metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Laid-Open No. 59-194393), metal complexes of 10-hydroxybenzo [h] quinoline, oxadiazole derivatives, Styryl biphenyl derivative, silole derivative, 3- or 5-hydroxyflavone metal complex, benzoxazole metal complex, benzothiazole metal complex, trisbenzimidazolylbenzene (US Pat. No. 5,645,948), quinoxaline compound No. 207169), phenanthroline derivatives (Japanese Patent Laid-Open No. 5-331459), 2-t-butyl-9,10-N, N′-dicyanoanthraquinonediimine, n-type hydrogenated amorphous silicon carbide, n-type sulfide Examples thereof include zinc and n-type zinc selenide.

  The lower limit of the thickness of the electron transport layer 7 is usually 1 nm, preferably about 5 nm, and the upper limit is usually about 300 nm, preferably about 100 nm.

  The electron transport layer 7 is formed by laminating on the light emitting layer 4 by the wet film formation method or the vacuum deposition method in the same manner as the hole injection layer 3. Usually, a vacuum deposition method is used.

  Moreover, it is preferable in this invention to have the positive hole transport layer 10, and the compound illustrated as a positive hole transport compound of the said positive hole injection layer can also be used for the positive hole transport layer 10. FIG. Alternatively, a polymer material such as polyarylene ether sulfone containing polyvinyl carbazole, polyvinyl triphenylamine, or tetraphenylbenzidine may be used. The hole transport layer 10 is formed by laminating these materials on the hole injection layer by a wet film formation method or a vacuum deposition method. The film thickness of the hole transport layer 10 thus formed is usually 10 nm or more, preferably 30 nm or more. However, it is usually 300 nm or less, preferably 100 nm or less.

  In particular, when a phosphorescent material or a blue light emitting material is used as the light emitting substance, it is also effective to provide the hole blocking layer 8 as shown in FIG. The hole blocking layer 8 has a function of confining holes and electrons in the light emitting layer 4 and improving luminous efficiency. That is, the hole blocking layer 8 is generated by blocking the holes moving from the light emitting layer 4 from reaching the electron transport layer 7, thereby increasing the recombination probability with electrons in the light emitting layer 4. There is a role of confining excitons in the light emitting layer 4 and a role of efficiently transporting electrons injected from the electron transport layer 7 in the direction of the light emitting layer 4.

  The hole blocking layer 8 prevents the holes moving from the anode 2 from reaching the cathode 6 and can efficiently transport the electrons injected from the cathode 6 toward the light emitting layer 4. The compound is laminated on the light emitting layer 4 so as to be in contact with the interface of the light emitting layer 4 on the cathode 6 side.

  The physical properties required for the material constituting the hole blocking layer 8 include high electron mobility, low hole mobility, a large energy gap (difference between HOMO and LUMO), and excited triplet level (T1). Is high.

  Examples of the hole blocking layer material satisfying such conditions include mixed arrangements of bis (2-methyl-8-quinolinolato) (phenolato) aluminum, bis (2-methyl-8-quinolinolato) (triphenylsilanolato) aluminum, and the like. Ligand complexes, metal complexes such as bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolinato) aluminum binuclear metal complexes, styryl compounds such as distyrylbiphenyl derivatives ( JP-A-11-242996), triazole derivatives such as 3- (4-biphenylyl) -4-phenyl-5 (4-tert-butylphenyl) -1,2,4-triazole (JP-A-7-41759) And phenanthroline derivatives such as bathocuproine (Japanese Patent Laid-Open No. 10-79297).

  Furthermore, a compound having at least one pyridine ring substituted at the 2,4,6-positions described in WO2005 / 022962 is also preferable as the hole blocking material.

  The film thickness of the hole blocking layer 8 is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less.

  The hole blocking layer 8 can also be formed by the same method as the hole injection layer 3, but a vacuum deposition method is usually used.

  The electron transport layer 7 and the hole blocking layer 8 may be appropriately provided as necessary. 1) Only the electron transport layer, 2) Only the hole blocking layer, 3) Lamination of the hole blocking layer / electron transport layer, 4) There are usages such as not using. Further, as shown in FIG. 5, the electron injection layer 5 may be omitted and the hole blocking layer 8 and the electron transport layer 7 may be laminated, or only the electron transport layer 7 may be used as shown in FIG.

  For the same purpose as the hole blocking layer 8, it is also effective to provide an electron blocking layer 9 between the hole injection layer 3 and the light emitting layer 4 as shown in FIG. The electron blocking layer 9 increases the probability of recombination with holes in the light emitting layer 4 by blocking the electrons moving from the light emitting layer 4 from reaching the hole injection layer 3, thereby generating excitons generated. Has a role of confining the light in the light emitting layer 4 and a role of efficiently transporting holes injected from the hole injection layer 3 in the direction of the light emitting layer 4.

  The characteristics required for the electron blocking layer 9 include high hole transportability, a large energy gap (difference between HOMO and LUMO), and a high excited triplet level (T1). Further, when the light emitting layer 4 is formed by a wet film forming method, it is preferable that the electron blocking layer 9 is also formed by a wet film forming method because the device manufacturing becomes easy.

  For this reason, it is preferable that the electron blocking layer 9 also has wet film formation compatibility. As a material used for such an electron blocking layer 9, a copolymer of dioctylfluorene and triphenylamine typified by F8-TFB is used. (Described in WO 2004/084260).

  The structure opposite to that shown in FIG. 1, that is, the cathode 6, the electron injection layer 5, the light emitting layer 4, the hole injection layer 3, and the anode 2 can be laminated on the substrate 1 in this order. It is also possible to provide the organic electroluminescent element of the present invention between two substrates, at least one of which is highly transparent. Similarly, it is also possible to laminate | stack to the structure opposite to the said each layer structure shown in FIGS.

Further, a structure in which a plurality of layers shown in FIG. 1 are stacked (a structure in which a plurality of light emitting units are stacked) may be employed. In that case, instead of the interfacial layer (between the light emitting units) (when the anode is ITO and the cathode is Al, the two layers), for example, V ₂ O ₅ is used as the charge generation layer (CGL). This is more preferable from the viewpoint of luminous efficiency and driving voltage.

  The present invention can be applied to any of an organic electroluminescent element having a single element, an element having a structure arranged in an array, and a structure having an anode and a cathode arranged in an XY matrix.

[Organic EL display]
The organic EL display of the present invention uses the organic electroluminescent element of the present invention as described above. There is no restriction | limiting in particular about the model and structure of the organic electroluminescent display of this invention, It can assemble in accordance with a conventional method using the organic electroluminescent element of this invention.
For example, the organic EL display of the present invention is formed by a method as described in “Organic EL Display” (Ohm, published on August 20, 2004, Shizushi Tokito, Chiba Adachi, Hideyuki Murata). can do.

[Organic EL lighting]
The organic EL illumination of the present invention uses the above-described organic electroluminescent element of the present invention. There is no restriction | limiting in particular about the model and structure of the organic EL illumination of this invention, It can assemble in accordance with a conventional method using the organic electroluminescent element of this invention.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example, unless the summary is exceeded.

[Example 1: Synthesis of Compound 1]

<Synthesis of Intermediate 1>
A solution of 2-aminobenzophenone (10.0 g, 50.7 mmol) in methylene chloride (100 mL) was cooled to −5 ° C., and a solution of N-bromosuccinimide (9.0 g, 50.6 mmol) in methylene chloride (60 mL) was added to 0 mL. It was dripped gently within a range not exceeding ℃. After completion of the dropping, the reaction mixture was raised to room temperature and stirred at room temperature for 6 hours for reaction. After completion of the reaction, the reaction mixture was poured into purified water and extracted with methylene chloride. The organic layer was washed with purified water and dried over magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was recrystallized from hexane-ethanol to obtain Intermediate 1 (12 g).

<Synthesis of Intermediate 2>
Concentrated sulfuric acid (0.2 mL) was added to a solution of Intermediate 1 (7.0 g, 25.3 mmol), m-bromoacetophenone (5.05 g, 25.3 mmol) in acetic acid (30 mL) and refluxed for 6 hours. Stir. After cooling to room temperature, the reaction mixture was poured into water and extracted with methylene chloride. The organic layer was washed with a saturated aqueous sodium hydrogen carbonate solution and dried over magnesium sulfate. The solvent was distilled off under reduced pressure, and the residue was recrystallized from ethanol to obtain Intermediate 2 (4.23 g).

<Synthesis of Compound 1>
Under a nitrogen atmosphere, Intermediate 2 (2.0 g, 4.55 mmol), 3- (9-carbazolyl) phenylboronic acid (2.88 g, 10 mmol) in dimethoxyethane (20 mL) was added to a 2 M aqueous sodium carbonate solution (10 mL). ) And degassed with nitrogen for 10 minutes. Tetrakis (triphenylphosphine) palladium (0) (262 mg, 0.228 mmol) was added to the mixture, and the mixture was stirred for 8 hours while refluxing. After completion of the reaction, the mixture was poured into water and extracted with toluene. The organic layer was washed with purified water and dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography to obtain compound 1 (1.39 g).
The mass spectral value of this product was 763 (M ⁺ ), and the glass transition temperature was 137 ° C.

[Example 2: Synthesis of Compound 2]
<Synthesis of Intermediate 3>

  In a 500 mL four-necked flask through which nitrogen was passed, magnesium hydroxide (1.3 g, 55 mmol) and 50 mL of tetrahydrofuran were added, and a tetrahydrofuran solution (100 mL) of 4-bromobiphenyl (11.6 g, 50 mmol) was added dropwise at 90 ° C. Stir for 1 hour while heating. The solution was added dropwise to a tetrahydrofuran solution (100 mL) of 2-amino-5-bromobenzonitrile (10.8 g, 55 mmol), stirred at room temperature for 1 hour, and then added with 1N hydrochloric acid while cooling in an ice bath. The reaction was stopped. Water was added to the reaction solution, and the precipitated solid was collected by filtration to obtain Intermediate 3 (13.4 g) as a yellow solid.

<Synthesis of Intermediate 4>

  Under a nitrogen stream, a solution of intermediate 3 (5.0 g, 14 mmol) and 3-bromoacetophenone (2.8 g, 14 mmol) in acetic acid (50 mL) was stirred at room temperature for 5 minutes, and concentrated sulfuric acid (0.5 mL) was added dropwise. . The reaction mixture was stirred for 4 hours while heating at 140 ° C., allowed to cool to room temperature, poured into water, and the precipitated solid was collected by filtration. The obtained solid was recrystallized from chloroform-ethanol to obtain Intermediate 4 (4.83 g) as yellow needle crystals.

<Synthesis of Compound 2>

Into a 200 mL four-necked flask through nitrogen was placed Intermediate 4 (5.0 g, 9.7 mmol), 3- (9-carbazolyl) phenylboronic acid (5.6 g, 23 mmol), 34 mL toluene, 17 mL ethanol, and Nitrogen bubbling was performed for 10 minutes after putting 17 mL of 2M sodium carbonate aqueous solution. Thereafter, tetrakis (triphenylphosphine) palladium (0) (672 mg, 582 μmol) was added, and the mixture was stirred at 140 ° C. for 3 hours. Thereafter, the mixture was allowed to cool, and 50 mL of water was added, followed by extraction with toluene (50 mL × 3 times), and the resulting toluene layer was washed with saturated brine (100 mL). The toluene layer was dried over magnesium sulfate and concentrated to give a yellow solid. The obtained yellow solid was purified by silica gel column chromatography (silica gel 120 mL, hexane / dichloromethane = 5/1) and further purified by sublimation to obtain compound 2 (5.0 g) as a pale yellow solid.
The mass spectrum of this product was 839 (M ⁺ ) (theoretical value C ₆₃ H ₄₁ N ₃ = 839.33).

[Example 3: Synthesis of Compound 3]
<Synthesis of Intermediate 5>

  Into a 100 mL four-necked flask through which nitrogen was passed, put shaped magnesium (2.39 g, 98.3 mmol) and 40 mL of tetrahydrofuran, dropwise added a tetrahydrofuran solution of bromobenzene (2.6 M, 131 mmol) and heated at 90 ° C. Stir for 1 hour. Then, a tetrahydrofuran solution (1.6 M, 65.5 mmol) of 2-amino-4-chlorobenzonitrile was added dropwise, and after stirring for 1 hour, the reaction was stopped by adding 50 mL of 1N hydrochloric acid while cooling in an ice bath. It was. 50 mL of water was added to the reaction solution, and the precipitated solid was collected by filtration to obtain Intermediate 5 (6.85 g) as a yellow solid.

<Synthesis of Intermediate 6>

  Intermediate 5 (6.84 g, 29.5 mmol) was added to a 100 mL four-necked flask through which nitrogen was passed, and 30 mL of acetic acid was added, followed by dropwise addition of 3-bromoacetophenone (4.71 mL, 35.4 mmol) at 140 ° C. The mixture was stirred for 4 hours with heating. Then, it stood to cool, 50 mL of water was added to the reaction liquid, and solid was deposited. The obtained yellow solid was dissolved in chloroform and recrystallized by adding hexane to obtain Intermediate 6 (2.59 g) as yellow needle crystals.

<Synthesis of Compound 3>

Intermediate 6 (500 mg, 1.26 mmol), 3- (9-carbazolyl) phenylboronic acid (900 mg, 3.16 mmol) was placed in a 50 mL two-necked flask through which nitrogen was introduced, and 10 mL of toluene, 5 mL of ethanol, and 2M carbonic acid were added. Nitrogen bubbling was performed for 10 minutes after putting 5 mL of sodium aqueous solution. Then, tetrakis (triphenylphosphine) palladium (0) (51 mg, 63 μmol) was added, and the mixture was stirred at 140 ° C. for 3 hours. Thereafter, the mixture was allowed to cool, and 15 mL of water was added, followed by extraction with toluene (20 mL × 3 times), and the resulting toluene layer was washed with saturated brine (50 mL). The toluene layer was dried over magnesium sulfate and concentrated to give a yellow solid. The resulting yellow solid was purified by silica gel column chromatography (silica gel 100 mL, hexane / dichloromethane = 5/1) and further purified by sublimation to obtain compound 3 (5.0 g) as a pale yellow solid.
The mass spectrometric value of this product was 763 (M ⁺ ) (theoretical value C ₅₇ H ₃₇ N ₃ = 763.92).

[Example 4: Fabrication of device]
An organic electroluminescent element having the structure shown in FIG. 7 was produced by the following method.
An indium tin oxide (ITO) transparent conductive film 2 deposited on a glass substrate 1 with a thickness of 150 nm (sputtered film; sheet resistance 15 Ω) is formed into a 2 mm wide stripe using a normal photolithography technique and hydrochloric acid etching. The anode 2 was formed by patterning. The patterned ITO substrate was cleaned in the order of ultrasonic cleaning with acetone, water with pure water, and ultrasonic cleaning with isopropyl alcohol, dried with nitrogen blow, and finally subjected to ultraviolet ozone cleaning.

Next, as a hole injection layer 3, after applying a polymer hole injection material HI-I02A (an aromatic amine polymer having a triphenylamine structure and a boron electron accepting compound) at a film thickness of 30 nm by a spin coating method, It was dried at 230 ° C. in an oven.
Next, the substrate on which this hole injection layer 3 was formed was placed in a vacuum deposition apparatus, and the inside of the vacuum apparatus was depressurized to a vacuum degree of 1.0 × 10 ⁻³ Pa or less, and then the holes were deposited under the following deposition conditions. On the injection layer 3, a hole transport layer 10 (compound HTR-1 below, vapor deposition rate 0.1 nm / second, film thickness 40 nm), light emitting layer 4 (host material: compound 1 synthesized in Example 1, dopant material: Compound D1, weight percentage of host and dopant: host 94%, dopant 6%, vapor deposition rate 0.1 nm / second, film thickness 30 nm, electron transport layer 7 (compound ET-1, vapor deposition rate 0.1 nm / second) , Film thickness 30 nm), electron injection layer 5 (lithium fluoride, vapor deposition rate 0.01 nm / second, film thickness 0.5 nm), cathode 6 (aluminum, vapor deposition rate 0.1 nm / second, film thickness 80 nm) are sequentially laminated. did.

The efficiency of this element was 5.5 lm / W, and the half life of the element when driven at 1000 cd / m ² was 8000 hr.

  With respect to this device, the lifetime at which the luminance was 80% was measured, and the relative ratio (CBP ratio at 80% luminance) when the lifetime of the device of Comparative Example 1 was 1 was calculated to be 7. The results are shown in Table 1.

[Example 5: Fabrication of device]
An organic electroluminescent device was produced in the same manner as in Example 4 except that, in the light emitting layer 4, instead of the compound 1 used as the host material, the compound 2 synthesized in Example 2 was used.
With respect to this device, the lifetime at which the luminance was 80% was measured, and the relative ratio (CBP ratio at 80% luminance) when the lifetime of the device of Comparative Example 1 was 1 was calculated to be 12. The results are shown in Table 1.

[Comparative Example 1: Fabrication of device]
An organic electroluminescent device was produced in the same manner as in Example 4 except that, in the light-emitting layer 4, instead of the compound 1 used as the host material, a compound (CBP) represented by the following structural formula was used.

  With respect to this element, the lifetime when the luminance was 80% was measured, and this was set to 1. The results are shown in Table 1.

[Comparative Example 2: Fabrication of device]
An organic electroluminescent device was produced in the same manner as in Example 4 except that the compound (CPMQ) represented by the following structural formula was used in place of the compound 1 used as the host material in the light emitting layer 4.

  Since the compound (CPMQ) was gradually crystallized on the device, the lifetime when the luminance was 80% could not be measured.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Hole injection layer 4 Light emitting layer 5 Electron injection layer 6 Cathode 7 Electron transport layer 8 Hole blocking layer 9 Electron blocking layer 10 Hole transport layer

Claims (10)

A quinoline compound represented by the following formula (1).

(In Formula (1), Ar ¹ represents an aromatic ring group which may have a substituent. R ^{1 to} R ⁴ each independently has an organic group having 50 or less carbon atoms which may have a substituent. L ¹ represents a single bond or an optionally substituted aromatic ring group having 25 or less carbon atoms, n represents an integer of 2 to 6, and m is an integer of 0 to 5 P, r and s each independently represents an integer of 0 or more and 4 or less.) The quinoline compound according to claim 1, wherein Ar ¹ is an aromatic hydrocarbon group. The quinoline-type compound of Claim 1 or 2 represented by following formula (2).

(In Formula (2), Ar ¹¹ is synonymous with Ar ¹ in Formula (1). R ^{12 to} R ¹⁴ and R ^{22 to} R ²⁴ each independently have 50 carbon atoms. L ¹¹ and L ¹² each independently represent a single bond or an aromatic ring group having 25 or less carbon atoms which may have a substituent p ₁ , r ₁ , s ₁ , p ₂ , r ₂ and s ₂ each independently represents an integer of 0 or more and 4 or less. The quinoline compound according to claim 3, wherein L ¹¹ and L ¹² are different from each other in the formula (2). The quinoline compound according to claim 4, which is represented by the following formula (3).

(In the formula (3), Ar ¹¹ , L ¹¹ , R ^{12 to} R ¹⁴ , R ^{22 to} R ²⁴ , p ₁ , r ₁ , s ₁ , p ₂ , r ₂ and s ₂ are respectively in the formula (2). L′-ring B corresponds to L ¹² in formula (2), ring B represents a benzene ring which may have a substituent, and L ′ has a single bond or a substituent. Represents an optionally substituted aromatic ring group having 19 or less carbon atoms.)   The organic electroluminescent element material which consists of a quinoline type compound as described in any one of Claims 1 thru | or 5.   The composition for organic electroluminescent elements containing the quinoline type compound as described in any one of Claims 1 thru | or 5.   An organic electroluminescent device comprising an anode, a cathode, and an organic layer provided between the anode and the cathode, wherein the organic layer comprises the quinoline compound according to any one of claims 1 to 5. An organic electroluminescent element containing.   The organic electroluminescent display using the organic electroluminescent element of Claim 8.   The organic electroluminescent illumination using the organic electroluminescent element of Claim 8.

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