JP2011049563A - Light-emitting element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting element having high light emission luminance, high light emission efficiency and high durability, and also to provide a metal complex composition suitable to obtain the light-emitting element. <P>SOLUTION: The organic electroluminescent element has at least an organic layer including a light-emitting layer between a pair of electrodes, wherein the organic layer contains at least one kind of platinum complex compound of quadridentate ligand including a partial structure expressed by a general formula (I). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an organic electroluminescent element (hereinafter also referred to as “organic EL element”, “light emitting element”, or “element”), and particularly relates to an organic electroluminescent element that is excellent in light emission characteristics and durability.

  Organic electroluminescent elements (organic EL elements) have been actively researched and developed in recent years because they can emit light with high brightness when driven at a low voltage. In general, an organic EL element is composed of an organic layer including a light emitting layer and a pair of electrodes sandwiching the layer, and the electrons injected from the cathode and the holes injected from the anode are recombined in the light emitting layer. The energy of the excitons is used for light emission.

  In recent years, the use of phosphorescent light emitting materials has led to higher efficiency of devices. As phosphorescent materials, iridium complexes and platinum complexes are known (see, for example, Patent Document 1 and Patent Document 2), but no device has been developed that achieves both high efficiency and high durability. At present, the development of phosphorescent materials that can be used is eagerly desired.

US Pat. No. 6,303,238 International Publication No. 00/57676

  An object of the present invention is to provide a light-emitting element having high light emission luminance, high light emission efficiency, and high durability. Another object is to provide a metal complex compound suitable for providing the light emitting element.

As a result of studying to solve the above-mentioned problems, the present inventors have developed a platinum complex of a cyclic or non-cyclic tetradentate ligand having a substituent at the para position of the phenyl group bonded to platinum as an organic layer. It was found that the organic EL element contained in the solution solves the above problems. That is, the present invention has been achieved by the following means.
[1]
An organic electroluminescent element having at least one organic layer including a light emitting layer between a pair of electrodes, and comprising at least one tetradentate platinum complex compound containing a partial structure represented by the following general formula (I) An organic electroluminescent element characterized by containing an organic layer in an organic layer.

(In general formula (I), Z ¹ represents a nitrogen-containing heterocycle that coordinates to platinum with a nitrogen atom. L ¹ represents a single bond or a linking group. R ¹ , R ³ , and R ⁴ are each hydrogen. Represents an atom or a substituent, and R ² represents a substituent.)

[2]
The platinum complex compound of the tetradentate ligand containing the partial structure represented by the general formula (I) is a platinum complex compound represented by the following general formula (II), according to [1] Organic electroluminescent device.

(In General Formula (II), Z ¹ and Z ² each represent a nitrogen-containing heterocycle that coordinates to platinum with a nitrogen atom. Q ² represents a carbon atom, an oxygen atom, a sulfur atom, a nitrogen atom, or a phosphorus atom. Represents a group bonded to platinum, L ¹ , L ² and L ³ each represent a single bond or a linking group, R ¹ , R ³ and R ⁴ each represents a hydrogen atom or a substituent, and R ² Represents a substituent.)

[3]
[2] The organic electroluminescent element as described in [2], wherein the platinum complex compound represented by the general formula (II) is a platinum complex compound represented by the following general formula (III).

(In General Formula (III), Q ² represents a group bonded to platinum by a carbon atom, an oxygen atom, a sulfur atom, a nitrogen atom, or a phosphorus atom. L ¹ , L ^2, and L ³ are each a single bond or a bond. R ¹ , R ³ and R ⁴ each represent a hydrogen atom or a substituent, R ² represents ^a substituent, R ^a and R ^b each represent a substituent, and n and m are And each represents an integer of 0 to 3.)

[4]
The organic electroluminescent element according to [3], wherein the platinum complex compound represented by the general formula (III) is a platinum complex compound represented by the following general formula (IV).

(In the general formula (IV), Q ⁴ represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group bonded to platinum by a carbon atom or a nitrogen atom. L ¹ , L ² and L ³ are a single bond or a linking group. R ¹ , R ³ and R ⁴ each represent a hydrogen atom or a substituent, R ² represents ^a substituent, R ^a and R ^b each represent a substituent, and n and m are Each represents an integer of 0 to 3.)

[5]
The organic electric field according to [1], wherein the platinum complex compound of the tetradentate ligand containing the partial structure represented by the general formula (I) is a compound represented by the following general formula (V): Light emitting element.

(In the general formula (V), L ¹ , L ² and L ³ represent a single bond or a linking group. R ¹ , R ³ , R ⁴ , R ⁵ , R ⁷ and R ⁸ are each a hydrogen atom or a substituent. R ² and R ⁶ each represent ^a substituent, R ^a and R ^b each represent a substituent, and n and m each represent an integer of 0 to 3.)

[6]
The light-emitting layer contains at least one of the tetradentate platinum complex compound having the partial structure represented by the general formula (I) and the compounds represented by the general formula (II) to the general formula (V). The organic electroluminescent element according to any one of [1] to [5], wherein
[7]
A platinum complex compound of a tetradentate ligand having a partial structure represented by the general formula (I) and at least one compound represented by the general formulas (II) to (V) and at least one host material; The organic electroluminescent element according to any one of [1] to [6], which is contained in the light emitting layer.
[8] A compound represented by the general formula (V).

(In the general formula (V), L ¹ , L ² and L ³ each represent a single bond or a linking group. R ¹ , R ³ , R ⁴ , R ⁵ , R ⁷ and R ⁸ are each hydrogen. R ² and R ⁶ each represent ^a substituent, R ^a and R ^b each represent a substituent, and n and m each represent an integer of 0 to 3. )

  The light emitting device of the present invention has high emission luminance, high external quantum efficiency, and excellent durability. Moreover, the platinum complex compound of the present invention is suitable for providing an excellent light-emitting device as described above.

Hereinafter, the organic EL device of the present invention will be described in detail. The organic EL device of the present invention has at least one organic layer including a light emitting layer between a pair of electrodes. The organic EL device of the present invention is a platinum complex of a tetradentate ligand in an organic layer, and contains a substituent at the para position of a phenyl group bonded to platinum. The above-described bond between the carbon atom of the phenyl group and platinum is usually a covalent bond, and the bond between the other atom and platinum is a coordination bond or a covalent bond.
In the organic EL device of the present invention, in addition to the light emitting layer, a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a hole block layer, an electron block layer, an exciton block layer, a protective layer and the like are appropriately provided. It may be arranged. Each of these layers may have other functions.

The functions of the tetradentate platinum complex compound having the partial structure represented by the general formula (I) and the compounds represented by the general formula (II) to the general formula (V) used in the present invention are limited. When the organic layer is composed of a plurality of layers, it can be contained in any layer, but is preferably contained in the light emitting layer, more preferably contained in the light emitting layer as a light emitting material, Particularly preferably, it is contained in the light emitting layer together with at least one kind of host material.
The content of the platinum complex used in the present invention is preferably 0.1% by mass or more and 50% by mass or less, and preferably 0.2% by mass or more and 30% by mass when the platinum complex used in the present invention is contained in the light emitting layer as a light emitting material. % Or less is more preferable, 0.3 mass% or more and 20 mass% or less is still more preferable, and 0.5 mass% or more and 10 mass% or less is the most preferable.

The host material is a compound mainly responsible for charge injection and transport in the light emitting layer, and itself is a compound that does not substantially emit light. In this specification, “substantially no light emission” means that the light emission amount from the substantially non-light emitting compound is preferably 5% or less, more preferably 3% or less of the total light emission amount of the entire device. More preferably, it means 1% or less.
The concentration of the host material in the light emitting layer is not particularly limited, but is preferably the main component (the component having the largest content) in the light emitting layer, more preferably 50% by mass or more and 99.9% by mass or less, 70 mass% or more and 99.8 mass% or less are still more preferable, 80 mass% or more and 99.7 mass% or less are especially preferable, and 90 mass% or more and 99.5 mass% or less are the most preferable.

  The glass transition point of the host material is preferably 100 ° C. or higher and 500 ° C. or lower, more preferably 110 ° C. or higher and 300 ° C. or lower, and still more preferably 120 ° C. or higher and 250 ° C. or lower.

The fluorescence wavelength in the film state of the host material contained in the light emitting layer of the present invention is preferably 400 nm or more and 650 nm or less, more preferably 420 nm or more and 600 nm or less, and further preferably 440 nm or more and 550 nm or less.
As the host material used in the present invention, the compounds described in paragraphs [0113] to [0161] of JP-A No. 2002-1000047 and the compounds described in paragraphs [0087] to [0098] of JP-A No. 2004-214179 are suitable. However, the present invention is not limited to these.

  The platinum complex of the present invention is preferably a phosphorescent material.

  The phosphorescence lifetime (room temperature) of the platinum complex of the present invention is not particularly limited, but is preferably 1 ms or less, more preferably 100 μs or less, and even more preferably 10 μs. The phosphorescence quantum yield at room temperature is preferably 70% or more, more preferably 80% or more, and still more preferably 90% or more.

In the organic EL device of the present invention, the host material and the light-emitting material have a T ₁ value (lowest triplet excited state energy value) of 60 kcal / mol (251 kJ / mol) or more and are obtained from a phosphorescent compound. It is preferable that the light has a λmax (emission maximum wavelength) of 550 nm or less, the T ₁ value of the host material and the light-emitting material is 62 kcal / mol (259 kJ / mol) or more, and the phosphorescence λmax obtained from the light-emitting material The (emission maximum wavelength) is more preferably 500 nm or less, the T ₁ value of the host material and the light emitting material is 65 kcal / mol (272 kJ / mol) or more, and λmax of phosphorescence obtained from the light emitting material It is more preferable that (the maximum wavelength of light emission) is 480 nm or less.

In the organic EL device of the present invention, the T ₁ value of the organic layer adjacent to the light emitting layer is preferably 60 kcal / mol or more, more preferably 63 kcal / mol or more, and further 65 kcal / mol or more. preferable.

  In the organic EL device of the present invention, the organic compound layer is composed of at least three layers of a hole transport layer, a light emitting layer, and an electron transport layer, and the Ip value of the electron transport layer is preferably 5.9 eV or more, and 6.0 eV or more. It is more preferable that it is 6.1 eV or more.

  The platinum complex compound of a tetradentate ligand containing the partial structure represented by the general formula (I) will be described.

(In general formula (I), Z ¹ represents a nitrogen-containing heterocycle that coordinates to platinum with a nitrogen atom. L ¹ represents a single bond or a linking group. R ¹ , R ³ , and R ⁴ represent a hydrogen atom or a substituent. And R ² represents a substituent.)

Z ¹ represents a nitrogen-containing heterocycle that coordinates to platinum with a nitrogen atom. Examples of Z ¹ include pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, pyrazole ring, imidazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring and benzo condensed ring thereof. And a pyrido condensed ring, and the like, preferably a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyrazole ring and a triazole ring, more preferably a pyridine ring, a pyrazine ring and a pyrimidine ring, particularly preferably a pyridine ring. . These may have a substituent, and as the substituent, those exemplified as the substituent of L ¹ described later can be applied.

L ¹ represents a single bond or a linking group. Although it does not specifically limit as a coupling group, The coupling group which consists of a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, and a silicon atom is preferable, Although a specific example is shown below, it is not limited to these.

  These linking groups may further have a substituent if possible, and examples of the substituent that can be introduced include an alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 30 carbon atoms). 20, particularly preferably 1 to 10 carbon atoms, such as methyl, ethyl, iso-propyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.) An alkenyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include vinyl, allyl, 2-butenyl, and 3-pentenyl.) An alkynyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, Rugyl, 3-pentynyl, etc.), aryl groups (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyl, p-methylphenyl) , Naphthyl, anthranyl, etc.), amino group (preferably having 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, particularly preferably 0 to 10 carbon atoms, such as amino, methylamino, dimethylamino , Diethylamino, dibenzylamino, diphenylamino, ditolylamino, etc.), an alkoxy group (preferably having 1 to 30 carbons, more preferably 1 to 20 carbons, particularly preferably 1 to 10 carbons, Methoxy, ethoxy, butoxy, 2-ethylhexyloxy, etc.), aryloxy group Preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyloxy, 1-naphthyloxy, 2-naphthyloxy.),

Heterocyclic oxy group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy, etc.), acyl A group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as acetyl, benzoyl, formyl, pivaloyl), an alkoxycarbonyl group (preferably Has 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, and examples thereof include methoxycarbonyl, ethoxycarbonyl and the like, and an aryloxycarbonyl group (preferably 7 carbon atoms). To 30, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 1 carbon atoms. Such as phenyloxycarbonyl), acyloxy groups (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as acetoxy, benzoyloxy An acylamino group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino). An alkoxycarbonylamino group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms such as methoxycarbonylamino), aryloxycarbonylamino group (Preferably 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferred. Or a sulfonylamino group (preferably having a carbon number of 1-30, more preferably having a carbon number of 1-20, and particularly preferably having a carbon number of 1-. 12 and examples thereof include methanesulfonylamino and benzenesulfonylamino).

A sulfamoyl group (preferably having 0 to 30 carbon atoms, more preferably 0 to 20 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl, etc. ), A carbamoyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms, such as carbamoyl, methylcarbamoyl, diethylcarbamoyl, phenylcarbamoyl, etc. ), An alkylthio group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylthio and ethylthio), an arylthio group (preferably). Has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, Preferably it is C6-C12, for example, phenylthio etc. are mentioned), heterocyclic thio group (preferably C1-C30, more preferably C1-C20, especially preferably C1-C12. Yes, for example, pyridylthio, 2-benzimidazolylthio, 2-benzoxazolylthio, 2-benzthiazolylthio, etc.), a sulfonyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 1 carbon atoms). 20, particularly preferably 1 to 12 carbon atoms, such as mesyl and tosyl), sulfinyl group (preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 carbon atom). -12, and examples thereof include methanesulfinyl and benzenesulfinyl).

Ureido group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include ureido, methylureido, phenylureido), phosphoric acid amide group (Preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms, such as diethyl phosphoric acid amide and phenyl phosphoric acid amide), hydroxy group, mercapto Group, halogen atom (for example, 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 It has 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms. Examples of the hetero atom include a nitrogen atom and an oxygen atom. A sulfur atom, specifically, imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, carbazolyl group, azepinyl group, etc.), silyl group (preferably 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, such as trimethylsilyl, triphenylsilyl, etc.), silyloxy groups (preferably 3 to 40 carbon atoms, More preferably, it has 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, and examples thereof include trimethylsilyloxy, triphenylsilyloxy and the like. These substituents may be further substituted. The substituent is preferably an alkyl group, an aryl group, a heterocyclic group, a halogen atom or a silyl group, more preferably an alkyl group, an aryl group, a heterocyclic group or a halogen atom, still more preferably an alkyl group or an aryl group. An aromatic heterocyclic group or a fluorine atom.

L ¹ is preferably a single bond, a methylene group, a dimethylmethylene group, or a diphenylmethylene group.

R ¹ , R ³ and R ⁴ represent a hydrogen atom or a substituent. When R ¹ , R ³ , and R ⁴ represent a substituent, those exemplified as the substituent for the linking group L ¹ can be applied as the substituent. R ¹ , R ³ and R ⁴ are preferably a hydrogen atom, alkyl group, aryl group, amino group, alkoxy group, aryloxy group, heterocyclic oxy group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylthio group , Arylthio group, heterocyclic thio group, sulfonyl group, halogen atom, cyano group, heterocyclic group, silyl group, silyloxy group, more preferably hydrogen atom, alkyl group, aryl group, amino group, alkoxy group, acyl Group, alkylthio group, sulfonyl group, halogen atom, cyano group, heterocyclic group, silyl group, more preferably hydrogen atom, alkyl group, aryl group, alkoxy group, acyl group, sulfonyl group, fluorine atom, cyano group , A heterocyclic group, and a silyl group, more preferably a hydrogen atom, an alkyl group, an Lumpur group, a sulfonyl group, a fluorine atom, a cyano group, a heterocyclic group, particularly preferably a hydrogen atom, an alkyl group, an aryl group, a fluorine atom, a cyano group, a heterocyclic group. Most preferably, they are a hydrogen atom, an alkyl group, a fluorine atom, a fluoroalkyl group, and a cyano group. These substituents may be further substituted with another group.

R ² represents a substituent. As the substituent represented by R ² , those exemplified as the substituent represented by R ¹ , R ³ and R ⁴ can be applied. The substituent represented by R ² is preferably an alkyl group, aryl group, amino group, alkoxy group, aryloxy group, heterocyclic oxy group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylthio group, arylthio group. , Heterocyclic thio group, sulfonyl group, halogen atom, cyano group, heterocyclic group, silyl group, silyloxy group, more preferably alkyl group, aryl group, amino group, alkoxy group, acyl group, alkylthio group, sulfonyl Group, halogen atom, cyano group, heterocyclic group and silyl group, more preferably alkyl group, aryl group, alkoxy group, acyl group, sulfonyl group, fluorine atom, cyano group, heterocyclic group and silyl group. More preferably, alkyl group, aryl group, sulfonyl group, fluorine atom, cyano , A heterocyclic group, particularly preferably an alkyl group, an aryl group, a fluorine atom, a cyano group, a heterocyclic group. Most preferably, they are an alkyl group, a fluorine atom, a fluoroalkyl group, and a cyano group. These substituents may be further substituted with another group.

  The platinum complex compound of the tetradentate ligand containing the partial structure represented by the general formula (I) is preferably a platinum complex represented by the general formula (II).

(In the general formula (II), Z ¹ and Z ² represent nitrogen-containing heterocycles coordinated to platinum with nitrogen atoms. Q ² is bonded to platinum with carbon atoms, oxygen atoms, sulfur atoms, nitrogen atoms or phosphorus atoms. L ¹ , L ² and L ³ each represents a single bond or a linking group, R ¹ , R ³ and R ⁴ each represent a hydrogen atom or a substituent, and R ² represents a substituent.

General formula (II) is demonstrated. Z ¹ and Z ² have the same meaning as Z ¹ in formula (I), and the preferred ranges are also the same. Z ¹ and Z ² may be the same or different. L ¹ , L ² and L ³ have the same meaning as L ¹ in formula (I), and preferred ranges are also the same. L ¹ , L ² and L ³ may be the same or different. Q ² represents a group bonded to platinum by a carbon atom, an oxygen atom, a sulfur atom, a nitrogen atom or a phosphorus atom.
Examples of Q ² bonded to platinum by a carbon atom include an imino group, an aromatic hydrocarbon group (phenyl group, naphthyl group, etc.), and an aromatic heterocyclic group (pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring). , Triazole ring, imidazole ring, pyrazole ring, thiophene ring, furan ring and the like) and condensed rings containing these. These groups may be further substituted.
Examples of Q ² bonded to platinum with a nitrogen atom include a nitrogen-containing heterocyclic group (pyrrole ring, pyrazole ring, imidazole ring, triazole ring, etc.), amino group (alkylamino group, arylamino group, acylamino group, alkoxycarbonylamino). Group, aryloxycarbonylamino group, sulfonylamino group, etc. These groups may be further substituted.
Examples of Q ² bonded to platinum with an oxygen atom include an oxy group, a carbonyloxy group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an acyloxy group, and a silyloxy group.
Examples of Q ² bonded to platinum with a sulfur atom include a thio group, an alkylthio group, an arylthio group, a heterocyclic thio group, and a carbonylthio group.
Examples of Q ² bonded to platinum with a phosphorus atom include a diarylphosphine group.

The group represented by Q ² is preferably an aromatic hydrocarbon group bonded to platinum by carbon, an aromatic heterocyclic group bonded to platinum by carbon, a nitrogen-containing heterocyclic group bonded to platinum by nitrogen, or an aryloxy group A carbonyloxy group, more preferably an aromatic hydrocarbon group bonded to platinum with carbon, an aromatic heterocyclic group bonded to platinum with carbon, an aryloxy group, or a carbonyloxy group, and more preferably platinum with carbon. An aromatic hydrocarbon group bonded to, an aromatic heterocyclic group bonded to platinum with carbon, and a carbonyloxy group. Q ² may have a substituent if possible. As the substituent, those exemplified as the substituent of the linking group L ¹ in formula (I) can be applied.
R ¹ , R ² , R ₃ and R ⁴ have the same meanings as those in formula (I), and preferred ranges are also the same.

  The platinum complex represented by the general formula (II) is preferably a platinum complex represented by the general formula (III).

(In the general formula (III), Q ² represents a group bonded to platinum by a carbon atom, an oxygen atom, a sulfur atom, a nitrogen atom or a phosphorus atom. L ¹ , L ² and L ³ represent a single bond or a linking group. R ¹ , R ³ and R ⁴ represent a hydrogen atom or a substituent, R ² represents a substituent, R ^a and R ^b represent ^a substituent, and n and m represent an integer of 0 to ^3. )

General formula (III) is demonstrated. Q ² , L ¹ , L ² , L ³ , R ¹ , R ² , R ³ , R ⁴ have the same meanings as those in formula (II), and preferred ranges are also the same. R ^a and R ^b represent a hydrogen atom or a substituent. As the substituent, those exemplified as the substituent for L ¹ can be applied. R ^a and R ^b are preferably a hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, or a fluorine atom, more preferably an alkyl group or an aryl group, and still more preferably an alkyl group. n and m represent an integer of 0 to 3.

  The platinum complex represented by the general formula (III) is preferably a platinum complex represented by the general formula (IV).

(In the general formula (IV), Q ⁴ represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group bonded to platinum by a carbon atom or a nitrogen atom. L ¹ , L ² and L ^{3 are a} single bond or a bond. R ¹ , R ³ and R ⁴ represent a hydrogen atom or a substituent, R ² represents ^a substituent, R ^a and R ^b represent ^a substituent, and n and m represent an integer of 0 to 3. To express.)

General formula (IV) is demonstrated. L ¹ , L ² , L ³ , R ¹ , R ² , R ³ , R ⁴ , R ^a , R ^b , n and m have the same meanings as those in formula (III), and preferred ranges are also the same. . Q ⁴ represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group bonded to platinum with a carbon atom or a nitrogen atom. Q ⁴ bonded to platinum by a carbon atom includes benzene ring, pyridine ring, pyrimidine ring, pyridazine ring, pyrazine ring, triazole ring, pyrazole ring, imidazole ring, thiophene ring, furan ring or their benzo condensed ring, pyrido Examples include condensed rings. Examples of Q ⁴ bonded to platinum with a nitrogen atom include a pyrrole ring, an imidazole ring, a pyrazole ring, a triazole ring, or a benzo condensed ring or a pyrido condensed ring thereof. Q ⁴ may have a substituent if possible. As the substituent, those exemplified as the substituent of the linking group L ¹ in formula (I) can be applied.

  Of the platinum complexes represented by the general formula (IV), one of the preferred forms is a platinum complex represented by the general formula (V).

(In General Formula (V), L ¹ , L ² and L ³ represent a single bond or a linking group. R ¹ , R ³ , R ⁴ , R ⁵ , R ⁷ and R ⁸ represent a hydrogen atom or a substituent. , R ² and R ⁶ each represent ^a substituent, R ^a and R ^b each represent a substituent, and n and m each represent an integer of 0 to 3).

The general formula (V) will be described. L ¹ , L ² , L ³ , R ¹ , R ² , R ³ , R ⁴ , R ^a , R ^b , n and m have the same meanings as those in formula (IV), and preferred ranges are also the same. . R ⁵ , R ⁶ , R ⁷ and R ⁸ have the same meanings as R ¹ , R ² , R ³ and R ^4, and preferred ranges are also the same, but may be the same or different.

  Specific examples of the compounds represented by the general formulas (I) to (V) are listed below, but the present invention is not limited to these compounds.

Next, the organic EL element containing the metal complex of the present invention will be described. The light emitting device of the present invention can use a normal light emitting system, a driving method, a usage form, and the like except that it is a device using the platinum complex of the present invention.
The platinum complex of the present invention can be used for any of a hole injection material, a hole transport material, a light emitting material, an electron injection material, an electron transport material, a hole block material, an electron block material, and an exciton block material. Is preferably a luminescent material. When used as a light emitting material, it may be ultraviolet light emission, visible light light emission, or infrared light emission, and may be fluorescent light emission or phosphorescence light emission, but it is visible light emission, and is phosphorescence light emission.

  The method for forming the organic compound layer of the present invention is not particularly limited, but resistance heating evaporation, electrophotography, electron beam, sputtering, molecular lamination, coating (spray coating, dip coating, impregnation, roll Coating method, gravure coating method, reverse coating method, roll brush method, air knife coating method, curtain coating method, spin coating method, flow coating method, bar coating method, micro gravure coating method, air doctor coating, blade coating method, squeeze Coating methods, transfer roll coating methods, kiss coating methods, cast coating methods, extrusion coating methods, wire bar coating methods, screen coating methods, etc.), ink jet methods, printing methods, transfer methods and the like are possible. Among these, the resistance heating vapor deposition method, the coating method, and the transfer method are preferable in consideration of the characteristics of the element, the ease of manufacture, the cost, and the like. When the light-emitting element has a stacked structure of two or more layers, it can be manufactured by combining the above methods.

  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, and 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, silicon resin and the like.

  The light-emitting device of the present invention includes at least a light-emitting layer, but may additionally have a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a protective layer, etc. as these organic layers. Each layer may be provided with other functions. Details of each layer will be described below.

  The material of the hole injection layer and the hole transport layer has any one of the function of injecting holes from the anode, the function of transporting holes, and the function of blocking electrons injected from the cathode. As specific examples, in addition to the platinum complex of the present invention, carbazole, imidazole, triazole, oxazole, oxadiazole, polyarylalkane, pyrazoline, pyrazolone, phenylenediamine, arylamine, amino-substituted chalcone, styrylanthracene, fluorenone, Hydrazone, stilbene, silazane, aromatic tertiary amine compound, styrylamine, aromatic dimethylidin compound, porphyrin compound, polysilane compound, poly (N-vinylcarbazole), aniline copolymer, thiophene oligomer, polythiophene, etc. Conductive polymer oligomer, Machine metal complexes, transition metal complexes, or derivatives of the above compounds.

  The film thicknesses of the hole injection layer and the hole transport layer are not particularly limited, but are 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 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.

  The material for the electron injection layer and the electron transport layer may be any material that has any one of the function of injecting electrons from the cathode, the function of transporting electrons, and the function of blocking holes injected from the anode. . Specific examples thereof include, in addition to the platinum complex of the present invention, for example, triazole, triazine, oxazole, oxadiazole, fluorenone, anthraquinodimethane, anthrone, diphenylquinone, thiopyran dioxide, carbodiimide, fluorenylidenemethane, di- Aromatic ring tetracarboxylic anhydrides such as styrylpyrazine, silole, naphthaleneperylene, various metal complexes represented by metal complexes of silole, phthalocyanine, 8-quinolinol derivatives, metal phthalocyanine, benzoxazole and benzothiazole Examples thereof include metal complexes and derivatives of the above compounds.

  Although the film thickness of an electron injection layer and an electron carrying layer is not specifically limited, The thing of the range of 1 nm-5 micrometers is preferable normally, More preferably, it is 5 nm-1 micrometer, More preferably, it is 10 nm-500 nm. The electron injection layer and the electron transport layer may have a single layer structure made of one or more of the above-described materials, or may have a multilayer structure made of a plurality of layers having the same composition or different compositions.

  The material of the light-emitting layer can receive holes from the anode, the hole injection layer, the hole transport layer, etc. when a voltage is applied, and can receive electrons from the cathode, the electron injection layer, the electron transport layer, etc. One of the function to move the injected charge, to provide a recombination field of holes and electrons, to generate excitons, to move excitation energy, and to emit light from excitons The material used for the light emitting layer is not limited to the platinum complex of the present invention, for example, benzoxazole, benzimidazole, benzothiazole, styrylbenzene, polyphenyl, diphenylbutadiene, tetraphenylbutadiene, naphthalimide, Coumarin, perylene, perinone, oxadiazole, aldazine, pyraridine, cyclopentadiene, bis Polymer compounds such as tyrylanthracene, quinacridone, pyrrolopyridine, thiadiazolopyridine, styrylamine, aromatic dimethylidin compounds, polythiophene, polyphenylene, polyphenylene vinylene, carbazole, imidazole, triazole, oxazole, oxadiazole, polyarylalkane, pyrazoline , Pyrazolone, phenylenediamine, arylamine, amino-substituted chalcone, styrylanthracene, fluorenone, hydrazone, stilbene, silazane, aromatic tertiary amine compound, styrylamine, aromatic dimethylidin compound, porphyrin compound, polysilane compound, poly ( N-vinylcarbazole), aniline copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, Metal complex, transition metal complex, triazole, triazine, oxazole, oxadiazole, fluorenone, anthraquinodimethane, anthrone, diphenylquinone, thiopyran dioxide, carbodiimide, fluorenylidenemethane, distyrylpyrazine, silole, naphthaleneperylene Aromatic metal tetracarboxylic anhydrides, phthalocyanines, metal complexes of 8-quinolinol derivatives, metal phthalocyanines, various metal complexes represented by metal complexes having benzoxazole or benzothiazole as a ligand, or derivatives of the above compounds Is mentioned.

  The light emitting layer may be a single layer or a multilayer of two or more layers. When there are a plurality of light emitting layers, each layer may emit different light emission colors. Even when there are a plurality of light emitting layers, each light emitting layer is preferably composed only of a phosphorescent material and a metal complex. Although the film thickness of a light emitting layer is not specifically limited, Usually, the thing of the range of 1 nm-5 micrometers is preferable, More preferably, it is 5 nm-1 micrometer, More preferably, it is 10 nm-500 nm.

As the material for the protective layer, any material may be used as long as it has a function of preventing the material that promotes device deterioration such as moisture and oxygen from entering the device. Specific examples thereof include metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti, and Ni, MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, CaO, BaO, and Fe ₂ O. ₃ , metal oxides such as Y ₂ O ₃ and TiO ₂ , metal fluorides such as MgF ₂ , LiF, AlF ₃ and CaF ₂ , polyethylene, polypropylene, polymethyl methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychloro Trifluoroethylene, polydichlorodifluoroethylene, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, a copolymer obtained by copolymerizing a monomer mixture containing tetrafluoroethylene and at least one comonomer, and a copolymer main chain A fluorine-containing copolymer having a cyclic structure, a water-absorbing substance having a water absorption rate of 1% or more, Examples include moisture-proof substances having a water content of 0.1% or less. There is no particular limitation on the method for forming the protective layer. For example, vacuum deposition, sputtering, reactive sputtering, MBE (molecular beam epitaxy), cluster ion beam, ion plating, plasma polymerization (high frequency excitation ions) Plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, ink jet method, printing method, transfer method, and electrophotographic method can be applied.

  The anode supplies holes to a hole injection layer, a hole transport layer, a light emitting layer, and the like, and a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof can be used, preferably Is a material having a work function of 4 eV or more. Specific examples include conductive metal oxides such as tin oxide, zinc oxide, indium oxide, and indium tin oxide (ITO), or metals such as gold, silver, chromium, and nickel, and these metals and conductive metal oxides. Inorganic conductive materials such as laminates, copper iodide and copper sulfide, organic conductive materials such as polyaniline, polythiophene and polypyrrole, and mixtures and laminates of these with ITO, It is a conductive metal oxide, and ITO is particularly preferable from the viewpoints of productivity, high conductivity, transparency, and the like. Although the film thickness of the anode can be appropriately selected depending on the material, it is usually preferably in the range of 10 nm to 5 μm, more preferably 50 nm to 1 μm, still more preferably 100 nm to 500 nm.

  As the anode, a layer formed on a soda-lime glass, non-alkali glass, a transparent resin substrate or the like is usually used. When glass is used, it is preferable to use non-alkali glass as the material in order to reduce ions eluted from the glass. Moreover, when using soda-lime glass, it is preferable to use what gave barrier coatings, such as a silica. The thickness of the substrate is not particularly limited as long as it is sufficient to maintain the mechanical strength. However, when glass is used, the thickness is usually 0.2 mm or more, preferably 0.7 mm or more. Various methods are used for producing the anode depending on the material. For example, in the case of ITO, an electron beam method, a sputtering method, a resistance heating vapor deposition method, an ion plating method, a chemical reaction method (sol-gel method, etc.), a spray method, etc. A film is formed by a method such as dipping, thermal CVD, plasma CVD, or ITO dispersion coating. The anode can be subjected to cleaning and other treatments to lower the drive voltage of the element and increase the light emission 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, etc., and the adhesion, ionization potential, stability, etc. between the cathode and the adjacent layer such as the electron injection layer, electron transport layer, light emitting layer, etc. Selected in consideration of As a material for the cathode, a metal, an alloy, a metal oxide, an electrically conductive compound, or a mixture thereof can be used. Specific examples include alkali metals (for example, Li, Na, K, Cs, etc.) or fluorides thereof, Alkaline earth metal (eg, Mg, Ca, etc.) or fluorides thereof, gold, silver, lead, aluminum, sodium-potassium alloy, or a mixed metal thereof, lithium-aluminum alloy, or a mixed metal thereof, magnesium-silver alloy Or a mixed metal thereof, or a rare earth metal such as indium or ytterbium, preferably a material having a work function of 4 eV or less, more preferably aluminum, a lithium-aluminum alloy, or a mixed metal thereof, a magnesium-silver alloy Or a mixed metal thereof. The film thickness of the cathode 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, still more preferably 100 nm to 1 μm. A method such as an electron beam method, a sputtering method, a resistance heating vapor deposition method, or a coating method is used for producing the cathode, and a metal can be vapor-deposited alone or two or more components can be vapor-deposited simultaneously. Further, a plurality of metals can be vapor deposited at the same time to form an alloy electrode, or an alloy prepared in advance may be vapor deposited. The sheet resistance of the anode and the cathode is preferably low, and is preferably several hundred Ω / □ or less.

  The light-emitting element of the present invention can improve the light extraction efficiency by various known devices. For example, by processing the substrate surface shape (for example, forming a fine concavo-convex pattern), controlling the refractive index of the substrate / ITO layer / organic layer, controlling the film thickness of the substrate / ITO layer / organic layer, etc. It is possible to improve light extraction efficiency and external quantum efficiency.

The external quantum efficiency of the light emitting device of the present invention is preferably 5% or more, more preferably 10% or more, and further preferably 15% or more. The value of the external quantum efficiency should be the maximum value of the external quantum efficiency when the device is driven at 25 ° C., or the value of the external quantum efficiency near 100 to 2000 cd / m ² when the device is driven at 25 ° C. Can do. The light-emitting element of the present invention may be a so-called top emission type in which light emission is extracted from the anode side.

  The substrate used in the light-emitting device of the present invention is not particularly limited, but inorganic materials such as zirconia-stabilized yttrium and glass, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene, polycarbonate, and polyethersulfone. High molecular weight materials such as polyarylate, allyl diglycol carbonate, polyimide, polycycloolefin, norbornene resin, poly (chlorotrifluoroethylene), Teflon (registered trademark), polytetrafluoroethylene-polyethylene copolymer good.

  The light emitting layer of the organic electroluminescent element of the present invention may have at least one laminated structure. The number of laminated layers is preferably 2 or more and 50 or less, more preferably 4 or more and 30 or less, and still more preferably 6 or more and 20 or less.

  The thickness of each layer constituting the stack is not particularly limited, but is preferably 0.2 nm or more and 20 nm or less, more preferably 0.4 nm or more and 15 nm or less, further preferably 0.5 nm or more and 10 nm or less, and more preferably 1 nm or more and 5 nm or less. Particularly preferred.

  The light emitting layer of the organic electroluminescent element of the present invention may have a plurality of domain structures. The light emitting layer may have another domain structure. The diameter of each domain is preferably 0.2 nm to 10 nm, more preferably 0.3 nm to 5 nm, still more preferably 0.5 nm to 3 nm, and particularly preferably 0.7 nm to 2 nm.

  The organic EL element of the present invention can be suitably used for display elements, displays, backlights, electrophotography, illumination light sources, recording light sources, exposure light sources, reading light sources, signs, signboards, interiors, optical communications, and the like.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these. <Synthesis Example> Synthesis of Exemplified Compound 24 The ligand 24 can be synthesized by known methods described in the literature, and SM is used as a starting material (see Journal of Organic Chemistry, 53, 786-790 (1988)). Synthesized using known organic synthesis techniques.

  Under a nitrogen stream, 235 mg of ligand 24 and 156 mg of platinum platinum were suspended in 10 mL of benzonitrile. The temperature was raised to 200 ° C. and heated for 2 hours. Upon cooling to room temperature, a precipitate was deposited. The precipitate was collected by filtration and purified with a silica gel column (developing solvent: chloroform) to obtain 189 mg of Exemplified Compound 24. Yield 54%.

Synthesis of Illustrative Compound 25 Ligand 25 can be synthesized by a known method described in literature, and synthesized using SM as a starting material and a known organic synthesis method.

  Under a nitrogen stream, 175 mg of ligand 25 and 105 mg of platinum platinum were suspended in 10 mL of benzonitrile. The temperature was raised to 200 ° C. and heated for 2 hours. When cooled to room temperature and a small amount of hexane was added, a precipitate was deposited. The precipitate was collected by filtration and purified with a silica gel column (developing solvent: chloroform) to obtain 155 mg of Exemplified Compound 25. Yield 61%.

Synthesis of Exemplified Compound 26 Ligand 26 can be synthesized by a known method described in the literature, and synthesized using SM as a starting material and a known organic synthesis method.

  Under a nitrogen stream, 800 mg of the ligand 26 and 437 mg of platinum platinum were suspended in 20 mL of benzonitrile. The temperature was raised to 200 ° C. and heated for 2 hours. When cooled to room temperature and a small amount of hexane was added, a precipitate was deposited. The precipitate was collected by filtration and purified with a silica gel column (developing solvent: chloroform) to obtain 501 mg of Exemplified Compound 26. Yield 45%.

Synthesis of Exemplified Compound 34 The ligand 34 can be synthesized by a known method described in literature, and synthesized using SM as a starting material and a known organic synthesis method.

Under a nitrogen stream, 340 mg of the ligand 34 and 234 mg of platinum platinum were suspended in 15 mL of benzonitrile. The temperature was raised to 200 ° C. and heated for 2 hours. When cooled to room temperature and a small amount of hexane was added, a precipitate was deposited. The precipitate was collected by filtration and purified with a silica gel column (developing solvent: chloroform) to obtain 25 mg of Exemplified Compound 34. Yield 5%.
<Organic EL device>
(Comparative Example 1)
The cleaned ITO substrate is put into a vapor deposition apparatus, NPD is vapor-deposited by 50 nm, CBP and Ir (ppy) ₃ are vapor-deposited by 40 nm at a mass ratio of 10: 1, and BAlq is further deposited by 10 nm thereon. Alq was deposited to 30 nm. A patterned mask (with a light emission area of 4 mm × 5 mm) was placed on the obtained organic thin film, and after 3 nm of lithium fluoride was deposited, 60 nm of aluminum was deposited to prepare an organic EL device of Comparative Example 1. When a DC constant voltage was applied to the obtained organic EL device, green light emission with an emission λmax = 514 nm was observed, and the external quantum efficiency was 6.4%.

Example 1
An organic EL device of Example 1 was produced in the same manner as Comparative Example 1 except that Exemplified Compound 24 was used instead of Ir (ppy) ₃ . When a constant DC voltage was applied to the obtained organic EL device, blue-green light emission with an emission λmax = 500 nm was observed, and the external quantum efficiency was 13.0%.

(Example 2)
When the devices of Comparative Example 1 and Example 1 were continuously driven at an initial luminance of 500 cd / m ² , the luminance half time of the device of Comparative Example 1 was 85 hours, whereas the luminance half time of the device of Example 1 was 85 hours. Was 800 hours.

  From the above examples, it became clear that a highly efficient and highly durable organic EL device can be obtained by using the compound of the present invention.

Claims (8)

An organic electroluminescent element having at least one organic layer including a light emitting layer between a pair of electrodes, and comprising at least one tetradentate platinum complex compound including a partial structure represented by the following general formula (I) An organic electroluminescent element characterized by containing an organic layer in an organic layer.

(In general formula (I), Z ¹ represents a nitrogen-containing heterocycle that coordinates to platinum with a nitrogen atom. L ¹ represents a single bond or a linking group. R ¹ , R ³ , and R ⁴ are each hydrogen. Represents an atom or a substituent, and R ² represents a substituent.) The platinum complex compound of the tetradentate ligand containing the partial structure represented by the general formula (I) is a platinum complex compound represented by the following general formula (II), Organic electroluminescent device.

(In General Formula (II), Z ¹ and Z ² each represent a nitrogen-containing heterocycle that coordinates to platinum with a nitrogen atom. Q ² represents a carbon atom, an oxygen atom, a sulfur atom, a nitrogen atom, or a phosphorus atom. Represents a group bonded to platinum, L ¹ , L ² and L ³ each represent a single bond or a linking group, R ¹ , R ³ and R ⁴ each represents a hydrogen atom or a substituent, and R ² Represents a substituent.) The organic electroluminescent element according to claim 2, wherein the platinum complex compound represented by the general formula (II) is a platinum complex compound represented by the following general formula (III).

(In the general formula (III), Q ² represents a group bonded to platinum by a carbon atom, an oxygen atom, a sulfur atom, a nitrogen atom or a phosphorus atom. L ¹ , L ² and L ³ are each a single bond or a bond. R ¹ , R ³ and R ⁴ each represent a hydrogen atom or a substituent, R ² represents ^a substituent, R ^a and R ^b each represent a substituent, and n and m are And each represents an integer of 0 to 3.) The organic electroluminescent element according to claim 3, wherein the platinum complex compound represented by the general formula (III) is a platinum complex compound represented by the following general formula (IV).

(In the general formula (IV), Q ⁴ represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group bonded to platinum by a carbon atom or a nitrogen atom. L ¹ , L ² and L ³ are a single bond or a linking group. R ¹ , R ³ and R ⁴ each represent a hydrogen atom or a substituent, R ² represents ^a substituent, R ^a and R ^b each represent a substituent, and n and m are Each represents an integer of 0 to 3.) The organic electric field according to claim 1, wherein the platinum complex compound of the tetradentate ligand containing the partial structure represented by the general formula (I) is a compound represented by the following general formula (V). Light emitting element.

(In the general formula (V), L ¹ , L ² and L ³ represent a single bond or a linking group. R ¹ , R ³ , R ⁴ , R ⁵ , R ⁷ and R ⁸ are each a hydrogen atom or a substituent. R ² and R ⁶ each represent ^a substituent, R ^a and R ^b each represent a substituent, and n and m each represent an integer of 0 to 3.)   The light-emitting layer contains at least one of the tetradentate platinum complex compound having the partial structure represented by the general formula (I) and the compounds represented by the general formula (II) to the general formula (V). The organic electroluminescent element according to claim 1, wherein the organic electroluminescent element is characterized in that   A platinum complex compound of a tetradentate ligand having a partial structure represented by the general formula (I) and at least one compound represented by the general formulas (II) to (V) and at least one host material; The organic electroluminescent element according to claim 1, wherein the organic electroluminescent element is contained in a light emitting layer. A compound represented by formula (V).

(In the general formula (V), L ¹ , L ² and L ³ each represent a single bond or a linking group. R ¹ , R ³ , R ⁴ , R ⁵ , R ⁷ and R ⁸ are each hydrogen. An atom or a substituent is represented, R ² and R ⁶ represent ^a substituent, R ^a and R ^b each represent a substituent, and n and m each represents an integer of 0 to 3.)