JP2001247858A - Benzimidazole derivative, luminescent element material and luminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a blue-colored luminescent element (material) which may efficiently emit light with a high brightness at a low voltage drive, shows an excellent stability at repetitive use and has an excellent color purity. SOLUTION: A benzimidazole derivative of formula (I) (wherein R1, R2 and R3 are each hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group; L is a linking group; R1 and R2, R1 and L, and R2 and L may be linked to each other to form a ring if possible; R4, R5, R6 and R7 are each hydrogen atom or a substituent; and each of R3-R7 may be linked to R1-R7 or L to form a ring if possible) is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dye for a filter, a color conversion filter, a dye for a photographic material, a sensitizing dye,
The present invention relates to a compound suitable for use as a pulp dye, a laser dye, a fluorescent agent for medical diagnosis, a material for a light emitting device, and a light emitting device using the same.

[0002]

2. Description of the Related Art Organic electroluminescent (EL) devices are expected to be used as inexpensive, large-area, full-color display devices of the solid-state light emitting type, and many developments have been made. In general, a light emitting element includes a light emitting layer and a pair of opposed electrodes sandwiching the light emitting layer. When an electric field is applied between the two electrodes, electrons are injected from the cathode and holes are injected from the anode. Further, the electrons and holes recombine in the light emitting layer, and an excited state is generated. When the excited state returns to the ground state, light is emitted by emitting energy as light.

[0003] Conventional light-emitting elements have a high driving voltage and low light emission luminance and light emission efficiency. In addition, characteristic deterioration is remarkable,
It had not been put to practical use. In recent years, a light-emitting element in which a thin film containing an organic compound having high quantum efficiency and emitting light at a low voltage of 10 V or less is laminated has been reported (Applied Physics Letters, 51, 913, 1987).
Years), has attracted interest. This device uses a metal chelate complex as an electron-transporting and light-emitting material, and obtains high-luminance green light emission by laminating with a hole-transporting material (amine compound). Number 100
0 cd / m ² . However, in consideration of a practical device, development of a further higher luminance and higher efficiency light emitting device is desired. Further, in consideration of utilization as a full-color display and a light source, it is necessary to emit three primary colors or white in practical use. The above-mentioned device has a light-emitting material of 8-
It uses an A1 complex of quinolinol (Alq) and emits green light. Therefore, development of a light-emitting element having another light-emitting color is desired. Until now, various light emitting materials that emit light other than green light have been developed, but there are problems such as low light emission luminance, low light emission efficiency, and low durability.

A conventional device having good color purity and high luminous efficiency is obtained by doping a charge transporting material with a small amount of a fluorescent dye, and has a problem in reproducibility of device characteristics in manufacturing. Because of its low durability, there have been problems such as a decrease in luminance and color change when used for a long time. As a means to solve this, the development of a material having both a charge transport function and a light-emitting function is desired. However, in the materials developed so far, when a fluorescent dye is used at a high concentration, the brightness decreases due to association and the like. There was a problem.

On the other hand, organic light-emitting devices that achieve high-luminance light emission are devices in which organic substances are stacked by vacuum deposition. However, from the viewpoints of simplification of the manufacturing process, workability, and large area, etc. It is desirable to produce the element by a coating method.
However, a device manufactured by a conventional coating method is inferior to a device manufactured by a vapor deposition method in terms of luminous luminance and luminous efficiency, and high luminance and highly efficient luminescence have been major issues.

[0006] In recent years, there are various types of substances having fluorescence in dyes for filters, color conversion filters, dyes for photographic light-sensitive materials, sensitizing dyes, dyes for pulp dyeing, laser dyes, fluorescent agents for medical diagnosis, organic light emitting element materials, and the like. Although it is used and its demand is increasing, there are not many compounds having high blue color purity and strong fluorescence intensity, and thus development of a new material has been desired.

[0007]

SUMMARY OF THE INVENTION A first object of the present invention is to provide a light-emitting element material and a light-emitting element which can emit light with high luminance and high efficiency at low voltage driving and have excellent stability when used repeatedly. On offer. A second object of the present invention is to provide a light-emitting element having excellent color purity and a light-emitting element material that enables the light-emitting element. A third object of the present invention is to provide a blue light emitting material having excellent color purity.

[0008]

This object has been achieved by the following means.

[1] A light emitting device material characterized by being a compound represented by the following general formula (I).

[0010]

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(Wherein R ₁ , R ₂ and R ₃ are hydrogen atoms,
Represents an aliphatic hydrocarbon group, an aryl group or a heterocyclic group. L represents a linking group. R ₁ and R ₂ , R ₁ and L, and R ₂
And L may be combined with each other to form a ring, if possible. R ₄ , R ₅ , R ₆ and R ₇ each represent a hydrogen atom or a substituent. If possible, R _{3 to} R ₇ may be combined with R _{1 to} R ₇ or L to form a ring. )

[2] A compound represented by the following general formula (II):

[0013]

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(Wherein, R ₃ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group; L represents a linking group; and Q represents a group necessary for forming a 5- to 7-membered ring with N). R ₄ , R ₅ , R _6, and R ₇ each represent a hydrogen atom or a substituent, R ₄ , R ₅ , R _6, and R ₇ represent, if possible, R _{4 to} R ₇ , a linking group; L may be combined with L and the atom group Q to form a ring.) [3] At least one light-emitting element in which a light-emitting layer or a plurality of organic compound thin layers including a light-emitting layer is formed between a pair of electrodes. A light-emitting element comprising a layer containing at least one of the compounds represented by the general formulas (I) and (II) according to [1] and [2]. [4] In a light-emitting element in which a light-emitting layer or a plurality of organic compound thin layers including a light-emitting layer is formed between a pair of electrodes, at least one of the general formulas (I) and (2) described in [1] and [2] A light emitting device comprising a layer in which at least one of the compounds represented by II) is dispersed in a polymer.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. First, the compound represented by formula (I) of the present invention will be described. R ₁ and R ₂ may be the same or different and represent a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group. If possible, R ₁ and R ₂ ,
R ₁ and L and R ₂ and L may be connected to each other to form a ring.

The aliphatic hydrocarbon group represented by R ₁ and R ₂ is a linear, branched or cyclic alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and still more preferably The number is 1 to 12, and examples thereof include methyl, ethyl, iso-propyl, n-butyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, and cyclohexyl. An alkenyl group (preferably having 2 to 2 carbon atoms)
30, more preferably 2 to 20 carbon atoms, still more preferably 2 to 12 carbon atoms, for example, vinyl, allyl, 2-
Butenyl, 3-pentenyl and the like. ), An alkynyl group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 20 carbon atoms, still more preferably having 2 to 12 carbon atoms,
For example, propargyl, 3-pentynyl and the like can be mentioned. ), And it is preferably an alkyl group, an alkenyl group, more preferably a methyl group, an ethyl group, a propyl group, a butyl group, an allyl group, R _1, R ₂ is attached to L condensed rings (e.g. Yurorijin ring, ) Is formed.

The aryl group represented by R ₁ and R ₂ is preferably a monocyclic or bicyclic aryl group having 6 to 30 carbon atoms (for example, phenyl, naphthyl, etc.), and more preferably carbon atom. A phenyl group having 6 to 20 carbon atoms or a naphthyl group having 10 to 24 carbon atoms, and more preferably a phenyl group having 6 to 12 carbon atoms or 10 to 16 carbon atoms.
Is a naphthyl group.

The heterocyclic group represented by R ₁ and R ₂ is
A 3- to 10-membered saturated or unsaturated heterocyclic group containing at least one N, O or S atom, which may be a single ring or may form a condensed ring with another ring. May be. The heterocyclic group is preferably a 5- to 10-membered aromatic heterocyclic group containing at least one nitrogen atom, oxygen atom, sulfur atom or selenium atom, more preferably a 5- to 6-membered aromatic ring. And a 5- to 6-membered aromatic heterocyclic group containing an N atom or an S atom. Specific examples of the heterocycle include, for example, pyrrolidine, piperidine, piperazine, morpholine, thiophene, selenophene, furan, pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyridazine,
Pyrimidine, triazole, triazine, indole,
Indazole, purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine,
Examples thereof include tetrazole, benzimidazole, benzoxazole, benzothiazole, benzotriazole, and tetrazaindene. Preferably as a heterocycle,
Thiophene, triazole, oxazole, pyridine,
Triazine and quinoline are more preferable, and thiophene, pyridine, triazine and quinoline are more preferable. More preferably, it is thiophene.

The aliphatic hydrocarbon group, aryl group and heterocyclic group represented by R ₁ and R ₂ may have a substituent. Examples of the substituent include an alkyl group (preferably having 1 to 1 carbon atoms). 20, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, for example, methyl, ethyl,
iso-propyl, tert-butyl, n-octyl,
n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl and the like. ), An alkenyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms, particularly preferably having 2 to 8 carbon atoms,
For example, vinyl, allyl, 2-butenyl, 3-pentenyl and the like can be mentioned. ), An alkynyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms, particularly preferably having 2 to 8 carbon atoms, and examples thereof include propargyl and 3-pentynyl), and an aryl group (preferably). Has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, for example, phenyl, p
-Methylphenyl, naphthyl and the like. ), An amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 12 carbon atoms, particularly preferably 0 to 6 carbon atoms, for example, amino, methylamino, dimethylamino, diethylamino, diphenylamino, dibenzylamino) Etc.), an alkoxy group (preferably having 1 to 20 carbon atoms,
More preferably, it has 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, for example, methoxy, ethoxy, butoxy and the like. ), An aryloxy group (preferably having 6 to 20 carbon atoms, more preferably having 6 to 16 carbon atoms, particularly preferably having 6 to 12 carbon atoms, for example, phenyloxy,
2-naphthyloxy and the like. ), An acyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 1 carbon atoms)
6, particularly preferably 1 to 12 carbon atoms, for example, acetyl, benzoyl, formyl, pivaloyl and the like. ), An alkoxycarbonyl group (preferably having 2 carbon atoms)
-20, more preferably 2-16 carbon atoms, particularly preferably 2-12 carbon atoms, for example, methoxycarbonyl,
Ethoxycarbonyl and the like. ), An aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, and particularly preferably having 7 to 10 carbon atoms.
And, for example, phenyloxycarbonyl and the like. ), An acyloxy group (preferably having 2 to 2 carbon atoms)
It has 0, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 10 carbon atoms, and examples thereof include acetoxy and benzoyloxy. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably having 2 to 10 carbon atoms, for example, acetylamino, benzoylamino, etc.), an alkoxycarbonylamino group (Preferably has 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 2 carbon atoms.
12, for example, methoxycarbonylamino and the like. ), An aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 1 carbon atoms)
6, particularly preferably having 7 to 12 carbon atoms, such as phenyloxycarbonylamino. ), A sulfonylamino group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms)
And examples thereof include methanesulfonylamino, benzenesulfonylamino and the like. ), A sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably having 0 carbon atoms)
To 16, particularly preferably 0 to 12 carbon atoms, for example, sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl and the like. ), A carbamoyl group (preferably having 1 to 20 carbon atoms,
More preferably, it has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include carbamoyl, methylcarbamoyl, diethylcarbamoyl, and phenylcarbamoyl. ), An alkylthio group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, particularly preferably having 1 to 12 carbon atoms, for example, methylthio, ethylthio, etc.), and an arylthio group (preferably having carbon thiol). A number of from 6 to 20, more preferably from 6 to 16 carbon atoms, particularly preferably from 6 to 12 carbon atoms, such as phenylthio and the like, a sulfonyl group (preferably from 1 to 20 carbon atoms, more preferably from 1 to 20 carbon atoms) 1 to 16, particularly preferably 1 to 12 carbon atoms, for example, mesyl, tosyl and the like.), A sulfinyl group (preferably 1 carbon atom)
-20, more preferably 1-16 carbon atoms, particularly preferably 1-12 carbon atoms, such as methanesulfinyl,
Benzenesulfinyl and the like. ), A ureido group (preferably having 1 to 20 carbon atoms, more preferably 1 carbon atom)
To 16, particularly preferably 1 to 12 carbon atoms, for example, ureide, methylureide, phenylureide and the like. ), A phosphoric amide group (preferably having 1 to 2 carbon atoms)
It has 0, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include diethylphosphoramide, phenylphosphoramide and the like. ), A hydroxy group, a mercapto group, a halogen atom (for example, a fluorine atom,
Chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 1 carbon atoms
And the hetero atom includes, for example, a nitrogen atom, an oxygen atom, and a sulfur atom, and specifically includes, for example, imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzothiazolyl And the like. ), A silyl group (preferably having 3 to 40 carbon atoms, more preferably having 3 to 30 carbon atoms, particularly preferably having 3 to 24 carbon atoms,
For example, trimethylsilyl, triphenylsilyl and the like can be mentioned. ) And the like. These substituents may be further substituted. When there are two or more substituents, they may be the same or different. When possible, they may be connected to each other to form a ring.

R ₁ and R ₂ are preferably a hydrogen atom, an alkyl group, an aryl group, or an aromatic heterocyclic group. When used as a charge transport material and a luminescent material (undoped type), R
₁ and R ₂ are preferably an aryl group or an aromatic heterocyclic group, more preferably an aryl group (preferably a monocyclic or bicyclic aryl group having 6 to 30 carbon atoms, more preferably 6 carbon atoms). -20, more preferably a phenyl group having 6 to 12 carbon atoms or a naphthyl group). When used as a doped luminescent material, R
₁ and R ₂ are preferably a hydrogen atom, an alkyl group, an alkylene group linked to L to form a ring, more preferably an alkyl group, an alkylene group linked to L to form a ring, even more preferably An alkyl group having 1 to 8 carbon atoms, L
And an alkylene group which forms a 6-membered ring by linking with, particularly preferably a methyl group, an ethyl group, or an alkylene group which forms a 6-membered ring by linking to L (trimethylene group, 3,3-dimethyltrimethylene group) It is.

R ₃ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group. As the aliphatic hydrocarbon group represented by R ₃ , an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, for example, methyl, ethyl , Iso-propyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl,
Cyclopentyl, cyclohexyl and the like can be mentioned. ),
An alkenyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms, particularly preferably having 2 to 8 carbon atoms, and examples thereof include vinyl, allyl, 2-butenyl, and 3-pentenyl); An alkynyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms, particularly preferably having 2 to 8 carbon atoms, for example, propargyl, 3
-Pentynyl and the like. ), And more preferably an alkyl group.

The aryl group represented by R ₃ preferably has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms.
p-methylphenyl, m-methylphenyl, o-methylphenyl, p-phenylphenyl, m-phenylphenyl, o-phenylphenyl, p-methoxyphenyl, m
-Methoxyphenyl, o-methoxyphenyl, 2,6-
Dimethylphenyl, 2,6-diphenylphenyl, 2,
4,6-trimethylphenyl, m-trifluoromethylphenyl, pentafluorophenyl, 1-naphthyl, 2
-Naphthyl and the like. The heterocyclic group represented by R ₃ is a monocyclic or condensed heterocyclic group (preferably having 1 carbon atom).
To 20, more preferably a heterocyclic group having 1 to 12 carbon atoms, still more preferably a heterocyclic group having 2 to 10 carbon atoms), and preferably an aromatic ring containing at least one of a nitrogen atom, an oxygen atom, a sulfur atom and a selenium atom. It is a terrorist ring group. Specific examples of the heterocyclic group represented by R ₃ include, for example, pyrrolidine, piperidine, piperazine, morpholine, thiophene, selenophene, furan, pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyridazine, pyrimidine, triazole, triazine, indole , Indazole,
Purine, thiazoline, thiazole, thiadiazole, oxazoline, oxazole, oxadiazole, quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole,
Benzimidazole, benzoxazole, benzothiazole, benzotriazole, tetrazaindene and the like, preferably, furan, thiophene, pyridine,
Pyrazine, pyrimidine, pyridazine, triazine, quinoline, phthalazine, naphthyridine, quinoxaline and quinazoline, more preferably furan, thiophene, pyridine and quinoline.

The aliphatic hydrocarbon group, aryl group and heterocyclic group represented by R ₃ may have a substituent, and the substituent may be a substituent of the group represented by R ₁ or R _2. The above-mentioned ones can be applied, and preferred substituents are also the same. R ₃
Are preferably an alkyl group, an aryl group and an aromatic heterocyclic group, more preferably an aryl group and an aromatic heterocyclic group, and still more preferably an aryl group and an aromatic azole group.

R ₄ , R ₅ , R ₆ and R ₇ represent a hydrogen atom or a substituent. As the substituent, in the general formula (I),
R _1, those exemplified as the substituents of R ₂ are applicable, R _4,
R ₅ , R ₆ and R ₇ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, a halogen atom, a cyano group, a heterocyclic group, a silyl group. Yes, more preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, a halogen atom, a cyano group, an aromatic heterocyclic group, and still more preferably a hydrogen atom, an alkyl Group, aryl group and aromatic heterocyclic group, particularly preferably a hydrogen atom. If possible, the substituents may be linked to each other and the substituent and the linking group L may be linked to form a ring.

L represents a linking group. The linking group represented by L is preferably a single bond, C, N, O, S, Se, T
e, Si, a linking group formed of Si, Ge, etc., more preferably a single bond, alkylene, alkenylene, alkynylene, arylene, divalent heterocycle (preferably aromatic heterocycle, more preferably azole, Thiophene, an aromatic hetero ring formed from a furan ring, etc.) and N and a combination thereof, more preferably an arylene, a divalent aromatic hetero ring and N and a combination thereof. And more preferably a phenylene, thienylene group or a group composed of N and a combination thereof, and particularly preferably a phenylene group. If possible, L may be linked to R _{1 to} R ₇ to form a ring.

Specific examples of the linking group represented by L include the following, in addition to a single bond.

[0027]

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[0028]

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[0029]

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[0030]

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The linking group represented by L may have a substituent. As the substituent, for example, those mentioned as the substituents of the groups represented by R ₁ and R ₂ can be applied. The substituent of L is preferably an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, a halogen atom, a cyano group, a heterocyclic group, a silyl group, more preferably an alkyl group, Alkenyl group,
Preferred are an alkynyl group, an aryl group, an alkoxy group, an aryloxy group, a halogen atom, a cyano group, and an aromatic heterocyclic group, and more preferred are an alkyl group, an aryl group, and an aromatic heterocyclic group.

Among the compounds represented by the general formula (I), a compound represented by the following general formula (II) is preferred.

[0033]

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R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and L have the same meanings as those in formula (I), and their preferred ranges are also the same. Q represents an atomic group necessary for bonding to N to form a 5- to 7-membered nitrogen-containing heterocyclic ring. Q and N
As the 5- to 7-membered nitrogen-containing heterocyclic ring formed by, a pyrrole ring, an azepine ring, a piperidine ring, a pyrrolidine ring,
Piperazine ring, morpholine ring, thiomorpholine ring,
Hexamethyleneimine ring and the like are preferable, and a pyrrole ring and an azepine ring are preferable. 5 formed by Q and N
The 7-membered nitrogen-containing hetero ring may further form a condensed ring with another ring, and may have a substituent. Examples of the condensed ring include a benzene ring, a thiophene ring, a pyrrole ring,
Furan ring, selenophene ring, pyridine ring, pyrazine ring,
Pyrimidine ring, pyridazine ring, imidazole ring, oxazole ring, thiazole ring and the like, preferably,
A benzene ring, a thiophene ring, a pyridine ring, and a pyrazine ring are preferred, a benzene ring and a thiophene ring are more preferred, and a benzene ring is particularly preferred. As the substituent, for example, those exemplified as the substituents of the groups represented by R ₁ and R ₂ can be applied. As the substituent of Q, preferably an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, an acylamino group, an alkoxycarbonylamino Group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, alkylthio group, arylthio group, sulfonyl group, halogen atom, cyano group, heterocyclic group, more preferably alkyl group, alkenyl group, aryl group , An alkoxy group, an aryloxy group, a halogen atom, a cyano group, and a heterocyclic group, more preferably an alkyl group, an aryl group, an alkoxy group, an aryloxy group, and an aromatic heterocyclic group, and particularly preferably an alkyl group. , Aryl group, an alkoxy group, an aromatic heterocyclic group. Specific examples of the 5- to 7-membered ring formed by Q and N include the following.

[0035]

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[0036]

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The compounds represented by the general formulas (I) and (II) may be low molecular weight compounds or high molecular weight compounds having residues connected to the polymer main chain (preferably a weight average molecular weight of 1000). ~ 5,000,000, more preferably 5
000-2,000,000, more preferably 10,000-
1,000,000) or a high molecular weight compound having a compound of the present invention in its main chain (preferably a weight average molecular weight of 1,000).
５5,000,000, more preferably 5,000 to 2,000
000, more preferably 10,000 to 1,000,000)
It may be. In the case of a high molecular weight compound, it may be a homopolymer, or may be a copolymer with another polymer.If it is a copolymer, it may be a random copolymer or a block copolymer. There may be. The compound used in the present invention is preferably a low molecular weight compound.

Specific examples of the compound represented by formula (I) of the present invention are shown below, but the present invention is not limited to these.

[0039]

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[0040]

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[0041]

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[0042]

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[0043]

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[0044]

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[0045]

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[0046]

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[0047]

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[0048]

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[0049]

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The above compound may be a tautomer thereof.

Next, the method for synthesizing the compound represented by formula (I) of the present invention will be described with reference to specific examples. Synthesis Example 1 Synthesis of Exemplified Compound 1

[0052]

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1-1. Synthesis of Compound a 75.1 g (0.371 mol) of o-bromo-nitrobenzene, 205 g (1.48 mol) of potassium carbonate, 10.6 g (0.0557 mol) of copper (I) iodide, toluene 4
While stirring 50 ml at room temperature under a nitrogen atmosphere, 86.4 g (0.928 mol) of aniline was added. After heating under reflux for 5 hours, the reaction solution was filtered, and the filtrate was concentrated under reduced pressure. Silica gel column chromatography (Developing solvent: chloroform: hexane = 1: 1vol / vo)
After purifying in l), recrystallization from chloroform / hexane yielded 35.8 g (0.17 mol) of compound a. Yield 45%. 1-2. Synthesis of Compound b 24.0 g (0.112 mol) of Compound a was dissolved in 200 mL of tetrahydrofuran, and the mixture was dissolved in a nitrogen atmosphere.
While stirring at room temperature, a solution of 100 g (0.560 mol) of sodium hydrosulfite / 280 ml of water was added dropwise. Further, 20 ml of methanol was added, and the mixture was stirred for 1 hour. Next, ethyl acetate 20
Add 0ml and add 20g of sodium bicarbonate
A solution of (0.224 mol) / 160 ml of water was added. Further, 24.6 g of 4-bromobenzoyl chloride.
A solution of (0.112 mol) / 70 ml of ethyl acetate was added dropwise, and the mixture was stirred at room temperature for 3 hours. The mixture was extracted with ethyl acetate, washed sequentially with water and saturated saline, dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. After purification by silica gel column chromatography (developing solvent: chloroform), recrystallization from chloroform / hexane gave 34.0 g (0.092 mol) of compound b. Yield 83%.

1-3. Synthesis of Compound c 34 g (0.092 mol) of Compound b was dissolved in 500 ml of xylene, and 5 g (0.03 mol) of p-toluenesulfonic acid monohydrate was added. Boiling dehydration was performed. After cooling the reaction solution to room temperature, the precipitated solid was collected by filtration and recrystallized from ethanol / chloroform to give Compound c with 27.8.
g (0.080 mol). 86% yield.

1-4. Synthesis of Exemplified Compound 1 0.48 g (0.0029 mol) of diphenylamine was dissolved in 20 ml of xylene, 0.33 g (0.0034 mol) of sodium methoxide, and a catalytic amount of palladium (II) acetate (0.025 mol%) And tri-t-butylphosphine (0.1 mol%) were added and stirred. Next, 1.0 g (0.0029 mol) of compound c was added, and the mixture was heated under reflux for 3 hours. After the reaction solution was cooled to room temperature, insolubles were removed by filtration, and the filtrate was extracted from ethyl acetate. The organic phase was washed sequentially with water and saturated saline, dried over anhydrous magnesium sulfate, and then the solvent was distilled off under reduced pressure. After purification by silica gel column chromatography (developing solvent: chloroform), recrystallization from chloroform / hexane gave 0.63 g (0.0014 mol) of Exemplified Compound 1. Yield 48%.

Next, a light emitting device containing the compound of the present invention will be described. The method for forming the organic layer of the light-emitting element containing the compound of the present invention is not particularly limited, but includes methods such as resistance heating evaporation, electron beam, sputtering, molecular lamination, coating, inkjet, and printing. Is used, and resistance heating evaporation and a coating method are preferable in consideration of characteristics and production.

When the compound of the present invention is used as a material for a light emitting device, it may be used in any of a hole injection / transport layer, an electron injection / transport layer, and a light emitting layer, but is preferably used as a light emitting layer.

The light-emitting device of the present invention is a device in which a light-emitting layer or a plurality of organic compound thin films including the light-emitting layer is formed between a pair of anode and cathode electrodes. It may have a transport layer, an electron injection layer, an electron transport layer, a protective layer, and the like, and each of these layers may have another function. Various materials can be used for forming each layer.

The anode supplies holes to the hole injection layer, the hole transport layer, the light emitting layer, etc., and may be made of a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof. It is possible to use a material having a work function of 4 eV or more. Specific examples thereof include conductive metal oxides such as tin oxide, zinc oxide, indium oxide, and indium tin oxide (ITO), and metals such as gold, silver, chromium, and nickel, and furthermore, these metals and conductive metal oxides. Or a laminate, an inorganic conductive substance such as copper iodide, copper sulfide, an organic conductive material such as polyaniline, polythiophene, and polypyrrole; and a laminate of these with ITO, and the like. A metal oxide, and particularly from the viewpoints of productivity, high conductivity, transparency, etc.
TO is preferred. The thickness of the anode can be appropriately selected depending on the material, but is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, and still more preferably 100 nm to 500 nm.

As the anode, a layer formed on a soda lime glass, an alkali-free glass, a transparent resin substrate or the like is usually used. When glass is used, it is preferable to use non-alkali glass in order to reduce ions eluted from the glass. Further, when soda lime glass is used, it is preferable to use a glass coated with a barrier coat such as silica. The thickness of the substrate is not particularly limited as long as the thickness is sufficient to maintain the mechanical strength. When glass is used, the thickness is usually 0.2 mm or more, preferably 0.7 mm or more. Various methods are used to produce the anode depending on the material.
In the case of O, a film is formed by a method such as an electron beam method, a sputtering method, a resistance heating evaporation method, a chemical reaction method (such as a sol-gel method), and the application of an ITO dispersion. The anode can be washed or otherwise treated to lower the driving voltage of the device or increase the luminous efficiency. For example, in the case of ITO, UV
-Ozone treatment, plasma treatment, etc. are effective.

The cathode supplies electrons to the electron injection layer, the electron transport layer, the light-emitting layer, and the like. The cathode has good adhesion, ionization potential, and the like between the adjacent layers such as the electron injection layer, the electron transport layer, and the light-emitting layer. It is selected in consideration of stability and the like. As a material of the cathode, a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. Specific examples thereof include alkali metals (eg, Li, Na, K, Cs
Or a fluoride thereof, an alkaline earth metal (eg, Mg, Ca, etc.) or a fluoride thereof, gold, silver, lead, aluminum, a sodium-potassium alloy, or a mixed metal thereof, a lithium-aluminum alloy, or a mixture thereof. Mixed metals, magnesium-silver alloys, or mixed metals thereof, indium, rare earth metals such as ytterbium, and the like, preferably a material having a work function of 4 eV or less, more preferably aluminum, a lithium-aluminum alloy, or a mixture thereof It is a mixed metal, a magnesium-silver alloy, or a mixed metal thereof. The thickness of the cathode can be appropriately selected depending on the material, but is usually 10 nm.
-5 μm is preferable, and more preferably 50 μm.
nm to 1 μm, and more preferably 100 nm to 1 μm.
m. A method such as an electron beam method, a sputtering method, a resistance heating evaporation method, or a coating method is used for manufacturing the cathode, and a metal can be evaporated alone or two or more components can be simultaneously evaporated. Furthermore, it is possible to form an alloy electrode by depositing a plurality of metals at the same time, or an alloy prepared in advance may be deposited. The sheet resistance of the anode and the cathode is preferably low, and is preferably several hundred Ω / □ or less.

The material of the light emitting layer is capable of injecting holes from an anode or a hole injection layer or a hole transport layer and applying electrons from a cathode or an electron injection layer or an electron transport layer when an electric field is applied. Any material can be used as long as it can form a layer having a function, a function of transferring injected charges, and a function of providing a field of recombination of holes and electrons and emitting light. As the compound used for the light emitting layer, in addition to the compound of the present invention, for example, benzoxazole derivative, benzimidazole derivative, benzothiazole derivative, styrylbenzene derivative, polyphenyl derivative, diphenylbutadiene derivative, tetraphenylbutadiene derivative, naphthalimide derivative, coumarin derivative , Perylene derivatives, perinone derivatives, oxadiazole derivatives, aldazine derivatives, pyrazine derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazolopyridine derivatives, styrylamine derivatives, aromatic dimethylidyne compounds, 8 -Polythiophene, polyphenylene, such as metal complexes of quinolinol derivatives, orthometalated complexes and various metal complexes represented by rare earth complexes Polymeric compounds such as polyphenylene vinylene, and the like. Although the thickness of the light emitting layer is not particularly limited, it is usually 1 nm.
~ 5 μm, more preferably 5n
m to 1 μm, more preferably 10 nm to 500 n
m.

The method for forming the light emitting layer is not particularly limited, but includes resistance heating evaporation, electron beam, sputtering, molecular lamination, coating (spin coating, casting, dipping, etc.), LB, and ink jet. A method such as a printing method or a printing method is used, and a resistance heating evaporation method and a coating method are preferable.

The material of the hole injection layer and the hole transport layer has one of a function of injecting holes from the anode, a function of transporting holes, and a function of blocking electrons injected from the cathode. Anything is fine. Specific examples thereof include carbazole derivatives, imidazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styryl anthracene derivatives , Fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine derivatives, aromatic dimethylidin compounds, porphyrin compounds, polysilane compounds, poly (N-vinylcarbazole) derivatives, aniline compounds Examples thereof include polymers, thiophene oligomers, and conductive polymer oligomers such as polythiophene. Hole injection layer,
The thickness of the hole transport layer is not particularly limited by the material, but is preferably in the range of 1 nm to 5 μm.
It is more preferably 5 nm to 1 μm, and still more preferably 10 nm to 500 nm. The hole injection layer and the hole transport layer may have a single-layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions. As a method for forming the hole injection layer and the hole transport layer, a vacuum deposition method, an LB method, an ink jet method, a printing method, a method in which the hole injection material and the hole transport material are dissolved or dispersed in a solvent, and coated. (A spin coating method, a casting method, a dip coating method, etc.) are used. In the case of the coating method, it can be dissolved or dispersed together with the resin component.Examples of the resin component include polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene,
Poly (N-vinylcarbazole), hydrocarbon resin, ketone resin, phenoxy resin, polyamide, ethyl cellulose, vinyl acetate, ABS resin, polyurethane, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, silicone resin, etc. .

The material of the electron injection layer and the electron transport layer has one of a function of injecting electrons from the cathode, a function of transporting electrons, and a function of blocking holes injected from the anode. I just want it. Specific examples thereof include a triazole derivative, a triazole derivative, an oxazole derivative,
Aromatic tetracarboxylic acids such as oxadiazole derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, and naphthalene perylene Anhydride, phthalocyanine derivative, 8-
Examples include metal complexes of quinolinol derivatives, various metal complexes represented by metal phthalocyanines, metal complexes having benzoxazole or benzothiazole as ligands, and the like. The thickness of the electron injecting layer and the electron transporting layer is not particularly limited, but is usually preferably in the range of 1 nm to 5 μm, more preferably 5 nm to 1 μm, and still more preferably 10 nm to 500 nm. The electron injection layer and the electron transport layer may have a single-layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions. Examples of the method for forming the electron injection layer and the electron transport layer include a vacuum deposition method, an LB method, an inkjet method, a printing method, and a method in which the electron injection material and the electron transport material are dissolved or dispersed in a solvent and coated (spin coating method). , A casting method, a dip coating method, etc.). In the case of the coating method, it can be dissolved or dispersed together with the resin component. As the resin component, for example, those exemplified for the hole injection / transport layer can be applied.

As the material of the protective layer, any material may be used as long as it has a function of preventing a substance that promotes element deterioration such as moisture or oxygen from entering the element. As a specific example,
In, Sn, Pb, Au, Cu, Ag, Al, Ti, N
metal such as i, MgO, SiO, SiO ₂ , Al ₂ O ₃ ,
GeO, NiO, CaO, BaO, Fe 2 O 3, Y 2 O 3,
Metal oxides such as TiO ₂ , MgF ₂ , LiF, Al
F ₃ , metal fluoride such as CaF ₂ , polyethylene, polypropylene, polymethyl methacrylate, polyimide,
Obtained by copolymerizing polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, and a monomer mixture containing tetrafluoroethylene and at least one comonomer. Copolymer, a fluorine-containing copolymer having a cyclic structure in the main chain of the copolymer, a water-absorbing substance having a water absorption of 1% or more, and a moisture-proof substance having a water absorption of 0.1% or less. There is no particular limitation on the method for forming the protective layer. For example, a vacuum evaporation method, a sputtering method, a reactive sputtering method, MB
E (molecular beam epitaxy) method, cluster ion beam method, ion plating method, plasma polymerization method (high frequency excitation ion plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, An inkjet method can be applied.

Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

[0068]

EXAMPLES Comparative Example 1.25 mm x 25 mm x 0.7 mm
A film of ITO having a thickness of 150 nm (manufactured by Tokyo Sanyo Vacuum Co., Ltd.) was used as a transparent support substrate.
After etching and cleaning this transparent support substrate, NPD (N,
N'-bis (1-naphthyl) -N, N'-diphenylbenzidine) is about 40 nm in thickness, blue light emitting material B1 is about 20 nm in thickness, and electron transporting material ETM1 is about 40 n in thickness.
m, in this order, in a vacuum of 10 ^-3 to 10 ^-4 Pa, about 0.
Deposition was performed at a substrate temperature of room temperature at a deposition rate of 4 nm / sec. Next, a mask (a mask having a light emitting area of 5 mm × 5 mm) patterned on the organic thin film is provided, and magnesium: silver = 10: 1 is co-evaporated at 250 nm in an evaporation apparatus, and then silver is evaporated to a thickness of 300 nm. The element was created. Using a source measure unit 2400 manufactured by Toyo Technica, a DC constant voltage is applied to the EL element to emit light, and the luminance is measured by the luminance meter BM-8 of Topcon, emission wavelength and CIE.
The chromaticity coordinates were measured using a spectrum analyzer PMA-11 manufactured by Hamamatsu Photonics. As a result, blue-green light with CIE chromaticity coordinates of (0.19, 0.30) is obtained,
At 13 V, a luminance of 2520 cd / m ² was obtained.

[0069]

Embedded image

[0070]

Embedded image

Embodiment 1 In the same manner as in Comparative Example 1, NPD was deposited on the ITO substrate to a thickness of about 40 nm, Exemplified Compound 3 to a thickness of about 20 nm, and Electron Transporting Material ETM1 to a thickness of about 40 nm, and a cathode was deposited to produce a device. As a result of performing device evaluation in the same manner as in Comparative Example 1, the maximum emission wavelength was 432 nm,
Blue light emission having a CIE chromaticity coordinate of (0.16, 0.10) was obtained, and a luminance of 2640 cd / m ² was obtained at 14 V.

Embodiment 2 FIG. When the luminance and chromaticity of the device manufactured in Example 1 were measured at driving voltages of 8 V and 15 V, (0.16, 0.10) when driving at 8 V and (0.16, 0.10) when driving at 15 V. 11), and there was almost no change in chromaticity.

As is apparent from the results, the device containing the compound of the present invention exhibited blue light emission with extremely excellent color purity as compared with the prior art, and the deterioration of the blue purity with an increase in driving voltage. Almost no blue light was observed, indicating that blue light emission with high color purity was possible in a wide driving voltage range.

From these results, it was found that in the device using the compound of the present invention as a light emitting material, high-luminance blue light emission was obtained even in an undoped device. In particular, it was found that a light-emitting element having extremely excellent color purity was obtained. In addition, it was found that a device using the compound of the present invention can emit blue light with high color purity over a wide driving voltage range.

Embodiment 3 FIG. Poly (N-vinylcarbazole) was added on an ITO substrate which had been subjected to the same cleaning treatment as in Comparative Example 1.
0 mg, PBD (2- (4-biphenylyl) -5- (4
-Tert-butylphenyl) -1,3,4-oxadiazole), 12 mg, Exemplified Compound 1 0.5 mg,
It was dissolved in 1,2-dichloroethane (3 ml) and applied by spin coating. The thickness of the formed organic thin film is about 120
nm. A mask (a mask having a light emitting area of 5 mm × 5 mm) patterned on the organic thin film is installed,
250 nm of magnesium: silver = 10: 1 in a vapor deposition apparatus
After co-evaporation, 300 nm of silver was evaporated to produce a light-emitting element. As a result of element evaluation in the same manner as in Comparative Example 1, the maximum emission wavelength was 448 nm, and the CIE chromaticity coordinates were (0.16,
0.12) blue light emission and 1222 cd at 14V
/ M ² .

As a result, it was found that, in the device using the compound of the present invention, high-intensity light emission was possible even with a coating type device having low light emission luminance, and a blue light-emitting device having extremely high color purity was obtained.

Embodiment 4 FIG. On an ITO substrate cleaned in the same manner as in Comparative Example 1, NPD was formed to a thickness of 40 nm, and then Exemplified Compound 40 and NPD were formed in a thickness of about 2 at a ratio of 1: 100, respectively.
It vapor-deposited so that it might be set to 0 nm. Next, the electron transport material ET
M1 was deposited to a thickness of about 40 nm, and a cathode was deposited to produce an element. As a result of performing element evaluation in the same manner as in Comparative Example 1, the maximum emission wavelength was 436 nm, and the CIE chromaticity coordinates were (0.15,
0.12) blue light emission and 3130 cd at 12 V
/ M ² .

As a result, it was found that, in the device using the compound of the present invention, high-luminance light emission was possible even in a doped device, and a blue light-emitting device having extremely high color purity was obtained.

[0079]

According to the present invention, an undoped blue light-emitting device and a doped blue light-emitting device having particularly excellent color purity as compared with the prior art and exhibiting high luminance can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) C07D 409/04 C07D 409/04 5F041 413/10 413/10 417/14 417/14 471/06 471/06 495/04 101 495/04 101 103 103 103 519/00 301 519/00 301 H01L 33/00 H01L 33/00 A H05B 33/14 H05B 33/14 B F term (reference) 3K007 AB04 CA01 CB03 DA02 DA06 DB03 4C063 AA01 AA03 BB02 CC26 CC29 CC59 CC64 CC92 DD08 DD14 DD19 DD26 EE10 4C065 AA07 AA18 BB09 CC01 DD01 EE02 HH02 JJ01 KK02 LL01 PP05 4C071 AA01 AA07 BB01 BB02 BB06 CC01 CC22 DD04 EE13 A05 A01 FF03 FF03 GG01 CA45 FF16

Claims (4)

[Claims] 1. A light emitting device material, which is a compound represented by the following general formula (I). Embedded image (Wherein R ₁ , R ₂ and R ₃ represent a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group. L represents a linking group. R ₁ and R ₂ , R ₁ and L, and R ₂ and L be formed are joined respectively if possible ring good .R _4, R _5,
R ₆ and R ₇ each represent a hydrogen atom or a substituent. If possible, R _{3 to} R ₇ may be combined with R _{1 to} R ₇ or L to form a ring. ) 2. A compound represented by the following general formula (II). Embedded image (Wherein, R ₃ represents a hydrogen atom, an aliphatic hydrocarbon group, an aryl group, or a heterocyclic group; L represents a linking group; and Q represents N
And a group of atoms necessary to form a 5- to 7-membered ring. R ₄ ,
R ₅ , R ₆ and R ₇ each represent a hydrogen atom or a substituent. R ₃ to R ₇ may form a ring respectively and if R ₃ to R _7, the linking group L and atomic group Q. ) 3. A light-emitting element in which a light-emitting layer or a plurality of organic compound thin layers including a light-emitting layer is formed between a pair of electrodes, at least one of which has the general formula (I) or (II) according to claim 1 or 2. A light-emitting element comprising a layer containing at least one compound represented by the formula: 4. A light-emitting element having a light-emitting layer or a plurality of organic compound thin layers including a light-emitting layer formed between a pair of electrodes, wherein at least one of the light-emitting elements has the general formula (I) or (II) according to claim 1 or 2. A light-emitting device comprising a layer in which at least one of the compounds represented by the formula (1) is dispersed in a polymer.