JP6014350B2 - Organic electroluminescent device, organic electroluminescent device material, film, light emitting layer, and organic electroluminescent device manufacturing method - Google Patents

Description

  The present invention relates to an organic electroluminescent device, a material for an organic electroluminescent device, a film, a light emitting layer, and a method for manufacturing the organic electroluminescent device.

An organic electroluminescent element is a self-luminous display device, and is used for displays and illumination. A display using an organic electroluminescent element has advantages in display performance such as high visibility and less viewing angle dependency compared to conventional CRTs and LCDs. There is also an advantage that the display can be reduced in weight and thickness.
In addition to the advantages of lighter weight and thinner layers, organic electroluminescent elements have the potential to realize illumination in a shape that could not be realized before by using a flexible substrate.

  As described above, the organic electroluminescent element has excellent characteristics including the above-mentioned matters, but generally, the refractive index of each layer constituting the organic electroluminescent element including the light emitting layer is higher than that of air. For example, in an organic electroluminescent element, the refractive index of an organic layer such as a light emitting layer is 1.6 to 1.9. For this reason, the emitted light is easily totally reflected at the interface, and its light extraction efficiency is less than 20%, and most of the light is lost. That is, there is a problem that the light emission efficiency (external quantum efficiency) is low.

  In order to solve such problems, for example, a method for improving the light extraction efficiency by controlling the shape of the luminescent compound itself and the orientation of the luminescent compound by using a liquid crystalline host material has been proposed. (Non-Patent Document 1).

  However, in this proposal, a rod-like fluorescent material is used to increase the polarization emission ratio, and since it is oriented uniaxially, the luminous efficiency is improved by Forster energy transfer (fluorescence resonance energy transfer) and light emission reabsorption. There was a problem that decreased. Moreover, since the electric exciton generation efficiency of the fluorescent material is as low as about 25%, there is a problem that the external quantum efficiency cannot be improved as a result.

  In order to solve such a problem, for example, a phosphorescent material that does not decrease in luminous efficiency due to Forster-type energy transfer is used as a light emitting material, and alignment is performed by applying a liquid crystal host material. A light emitting device has been proposed (Patent Document 1, Patent Document 2).

  However, in these proposals, since a liquid crystalline material is used for alignment, there is not sufficient film strength as an organic EL element, and there is a substituent that exhibits film quality change and liquid crystallinity during long-time light emission. There were problems such as deterioration of material stability due to influence.

  In order to solve such a problem, for example, an attempt has been made to align a non-liquid crystalline material (Patent Document 3). However, it is limited to a very limited number of materials, and the efficiency and durability required for the organic electroluminescent device are insufficient.

  As described above, there is a strong demand for prompt development of an organic electroluminescent device capable of satisfying high external quantum efficiency and high durability.

JP-A-10-321371 JP 2002-43056 A JP 2010-212112 A

Polymers For Advanced Technologies, 9, 443-460 (1998).

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, an object of the present invention is to provide an organic electroluminescent device that can satisfy high external quantum efficiency and high durability, an organic electroluminescent device material used therefor, and a method for manufacturing the organic electroluminescent device. .

  Means for solving the above-mentioned problems are as follows. That is,

[1]
An organic electroluminescent device having a pair of electrodes including an anode and a cathode on a substrate, and at least one organic layer including a light emitting layer between the electrodes,
In the light emitting layer, a planar light emitting material having an aspect ratio (molecular length / molecular thickness) of 3 or more in molecular length and molecular thickness, and an aspect ratio (molecular length / molecular thickness) of molecular length and molecular thickness of 2 or less Containing at least a host material,
An organic electroluminescence device having a size ratio of the molecular radius of the light emitting material to the molecular radius of the host material (the molecular radius of the light emitting material / the molecular radius of the host material) of 0.8 to 1.2.
[2]
The organic electroluminescent element according to [1], wherein the light emitting material is a phosphorescent compound.
[3]
The organic electroluminescent element according to [1] or [2], wherein the phosphorescent compound is a platinum complex represented by the following general formula (C-1).

(In the formula, Q ¹ , Q ² , Q ³ and Q ⁴ each independently represent a ligand coordinated to Pt. L ¹ , L ² and L ³ are each independently a single bond, double bond And represents a group consisting of a bond, a divalent linking group, or a combination thereof, and Q ³ and Q ⁴ may be linked to form a ring.)
[4]
The organic electroluminescent element according to [3], wherein the platinum complex is represented by the following general formula (C-3-1), (C-5-1), (C-6), or (C-9).

(In General Formula (C-3-1), X, Y, Z, and M each independently represent a carbon atom or a nitrogen atom, provided that either Z or Y is a nitrogen atom. When it is a nitrogen atom, X is a carbon atom, m, n, p, and q each independently represents an integer of 0 to 3. Ar represents a substituted or unsubstituted aryl group, R ₁ to. R ₃ and R ₃₀ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, wherein m, n, p, and q are 2 or more. In this case, a plurality of R ₁ , R ₂ , R ₃ and R ₃₀ may be linked to each other to form a cyclic structure, and Q is a carbon atom or a nitrogen atom.)

(In General Formula (C-5-1), X, Y, and Z each independently represent a carbon atom or a nitrogen atom, and either Z or Y is a nitrogen atom, and Y is a nitrogen atom. When X is a carbon atom, m, n, p and q each independently represents an integer of 0 to 3. Ar represents a substituted or unsubstituted aryl group, and R _{1 to} R ₄ represent Each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when m, n, p, and q are 2 or more, a plurality of R ₁ to R ₄ cyclic structure linked to each other and each next to each other may be formed.)

(In General Formula (C-6), X, Y, and Z each independently represent a carbon atom or a nitrogen atom, and one of Z and Y is a nitrogen atom. When Y is a nitrogen atom, , X is a carbon atom, r, s, t and u each independently represents an integer of 0 to 3. R _{5 to} R ₈ each independently represents an alkyl group, an aryl group, an alkoxy group, Represents an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when r, s, t, and u are 2 or more, a plurality of R _{5 to} R ₈ are connected to each other and cyclic W ₁ and W ₂ each independently represent an alkyl group, and may be bonded to each other to form a cyclic structure.

In the formula, A and B represent a cyclic structure, A represents an aromatic ring, and B represents an aromatic heterocycle. When one of A and B forms a ring, the other may not form a ring. R _{13 to} R ₁₆ each independently represent a hydrogen atom, an alkyl group, an aryl group, a silyl group, or a heterocyclic group, and R ₁₄ and R ₁₅ , R ₁₃ and R ₁₆ are bonded to each other to form a cyclic structure. It may be formed.
[5]
The organic electroluminescent element according to [1], wherein the light emitting material is a fluorescent compound.
[6]
The organic electroluminescent element according to [5], wherein the fluorescent compound is represented by the following general formula (P-1).
Formula (P-1)

(In General Formula (P-1), R _P ^{1 to} R _P ¹⁰ may each independently have a hydrogen atom, an aromatic hydrocarbon group that may have a substituent, or a substituent. An alkenyl group, an alkynyl group which may have a substituent, an alkyl group which may have a substituent, a silyl group which may have a substituent, a heterocyclic ring which may have a substituent Group, an alkylamino group which may have a substituent, and an arylamino group which may have a substituent, wherein at least one of R _P ^{1 to} R _P ¹⁰ is a substituent other than a hydrogen atom .)
[7]
The organic electroluminescent element according to [5], wherein the fluorescent compound is represented by the following general formula (PE-1).
General formula (PE-1)

(In the general formula (PE-1), R _PE ^{1 to} R _PE ⁴ are each independently an alkyl group, an aryl group, a heterocyclic group, an amino group, a silyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, or a carbamoyl group. A group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkylthio group, and an arylthio group, which may have a substituent, and may combine with each other to form a ring.
n _PE ¹ ~n _PE ⁴ each independently represents an integer of 0 to 3. When n _PE ^{1 to} n _PE ⁴ is 2 or more, the plurality of R _PE ^{1 to} R _PE ⁴ may be bonded to each other to form a ring.
Further, the hydrogen atom in the formula may be a deuterium atom. )
[8]
The organic electroluminescent element according to [5], wherein the fluorescent compound is represented by the following general formula (F-1).

(In General Formula (F-1), R _F ^{1 to} R _F ¹⁰ may each independently have a hydrogen atom, an aromatic hydrocarbon group that may have a substituent, or a substituent. An alkenyl group, an alkynyl group which may have a substituent, an alkyl group which may have a substituent, a silyl group which may have a substituent, a heterocyclic ring which may have a substituent A group, an alkylamino group which may have a substituent, and an arylamino group which may have a substituent, wherein at least one of R _F ^{1 to} R _F ¹⁰ is a substituent other than a hydrogen atom; .)
[9]
The organic electroluminescent element according to any one of [1] to [8], wherein an aspect ratio (molecular length / molecular thickness) between the molecular length and the molecular thickness of the flat luminescent material is larger than 5.
[10]
The organic electroluminescence device according to any one of [1] to [9], wherein the host material is a metal complex compound.
[11]
A flat light emitting material having an aspect ratio (molecular length / molecular thickness) of 3 or more and a host material having an aspect ratio (molecular length / molecular thickness) of 2 or less of the molecular length and molecular thickness. For an organic electroluminescence device containing at least a size ratio of the molecular radius of the light emitting material to the molecular radius of the host material (molecular radius of the light emitting material / molecular radius of the host material) of 0.8 to 1.2 material.
[12]
The manufacturing method of an organic electroluminescent element including at least the process of forming a light emitting layer by the vacuum evaporation process or wet process using the organic electroluminescent element material as described in [11].
[13]
The film | membrane containing the organic electroluminescent element material as described in [11].
[14]
The light-emitting device using the organic electroluminescent element of any one of [1]-[10].
[15]
The display apparatus using the organic electroluminescent element of any one of [1]-[10].
[16]
The illuminating device using the organic electroluminescent element of any one of [1]-[10].

  ADVANTAGE OF THE INVENTION According to this invention, the organic electroluminescent element which can satisfy high orientation degree, high external quantum efficiency, and high durability, and the organic electroluminescent element material used therefor can be provided.

It is the schematic which shows an example of the layer structure of the organic electroluminescent element which concerns on this invention. It is a schematic diagram for demonstrating the molecular length of material. It is a schematic diagram for demonstrating the molecular radius of material. It is a schematic diagram for demonstrating the molecular radius of material. It is a schematic diagram for demonstrating the molecular radius of material.

  Hereinafter, the present invention will be described in detail. In the present specification, “to” indicates a range including the numerical values described before and after the minimum and maximum values, respectively.

In the present invention, the substituent group A and the substituent group B are defined as follows.
(Substituent group A)
An alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methyl, ethyl, isopropyl, 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, for example vinyl , Allyl, 2-butenyl, 3-pentenyl, etc.), alkynyl groups (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as propargyl , 3-pentynyl, etc.), an aryl group (preferably having 6 to 30 carbon atoms, more preferably carbon 6 to 20, particularly preferably 6 to 12 carbon atoms, such as phenyl, p-methylphenyl, naphthyl, anthracenyl, etc.), amino group (preferably 0 to 30 carbon atoms, more preferably 0 carbon atoms) -20, 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 carbon atoms). More preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methoxy, ethoxy, butoxy, 2-ethylhexyloxy, etc.), an aryloxy group (preferably 6 to 6 carbon atoms). 30, more preferably 6-20 carbon atoms, particularly preferably 6-12 carbon atoms, Enyloxy, 1-naphthyloxy, 2-naphthyloxy, etc.), a heterocyclic oxy group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms). For example, pyridyloxy, pyrazyloxy, pyrimidyloxy, quinolyloxy, etc.), acyl groups (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, for example acetyl , Benzoyl, formyl, pivaloyl, etc.), an alkoxycarbonyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms such as methoxycarbonyl, ethoxy Carbonyl etc.), an aryloxycarbonyl group (preferably Has 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, and particularly preferably 7 to 12 carbon atoms, and examples thereof include phenyloxycarbonyl. ), An acyloxy group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms such as acetoxy and benzoyloxy), an acylamino group (preferably 2-30 carbon atoms, more preferably 2-20 carbon atoms, particularly preferably 2-10 carbon atoms, and examples thereof include acetylamino, benzoylamino, and the like, and an alkoxycarbonylamino group (preferably having 2-2 carbon atoms). 30, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino, etc.), aryloxycarbonylamino group (preferably 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonyl And sulfonylamino groups (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and particularly preferably 1 to 12 carbon atoms, such as 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, phenyl Sulfamoyl, etc.), a carbamoyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as carbamoyl, methylcarbamoyl, diethylcarbamoyl, Phenylcarbamoyl etc.), alkylthio group ( Preferably, it has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include methylthio, ethylthio and the like, and an arylthio group (preferably 6 to 30 carbon atoms). , More preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenylthio, etc.), a heterocyclic thio group (preferably 1 to 30 carbon atoms, more preferably 1 to carbon atoms). 20, particularly preferably 1 to 12 carbon atoms, such as pyridylthio, 2-benzimidazolylthio, 2-benzoxazolylthio, 2-benzthiazolylthio and the like, and a sulfonyl group (preferably having a carbon number). 1 to 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as mesyl and tosyl). Rufinyl 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 methanesulfinyl and benzenesulfinyl. ), A ureido 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 ureido, methylureido, phenylureido, etc.), phosphoric acid. An amide group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as diethyl phosphoric acid amide and phenylphosphoric acid amide), a hydroxy group , Mercapto group, halogen atom (eg 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 ( An aromatic heterocyclic group is also included, preferably 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, Is, for example, a nitrogen atom, oxygen atom, sulfur atom, phosphorus atom, silicon atom, selenium atom, tellurium atom, specifically pyridyl, pyrazinyl, pyrimidyl, pyridazinyl, pyrrolyl, pyrazolyl, triazolyl, imidazolyl, oxazolyl, thiazolyl, And isoxazolyl, isothiazolyl, quinolyl, furyl, thienyl, selenophenyl, tellurophenyl, piperidyl, piperidino, morpholino, pyrrolidyl, pyrrolidino, benzoxazolyl, benzoimidazolyl, benzothiazolyl, carbazolyl group, azepinyl group, silolyl group and the like. A silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, and examples thereof include trimethylsilyl and triphenylsilyl). Ryloxy group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, such as trimethylsilyloxy, triphenylsilyloxy, etc.), phosphoryl group (for example, A diphenylphosphoryl group, a dimethylphosphoryl group, etc.). These substituents may be further substituted, and examples of the further substituent include a group selected from the substituent group A described above. When there are a plurality of the further substituents, the substituents may be connected to each other to form a ring.

(Substituent group B)
An alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, such as methyl, ethyl, isopropyl, 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, for example vinyl , Allyl, 2-butenyl, 3-pentenyl, etc.), alkynyl groups (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, such as propargyl , 3-pentynyl, etc.), an aryl group (preferably having 6 to 30 carbon atoms, more preferably carbon 6 to 20, particularly preferably 6 to 12 carbon atoms, including phenyl, p-methylphenyl, naphthyl, anthracenyl, etc.), cyano group, heterocyclic group (including aromatic heterocyclic group, Has 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom, a silicon atom, a selenium atom, and a tellurium atom. Is pyridyl, pyrazinyl, pyrimidyl, pyridazinyl, pyrrolyl, pyrazolyl, triazolyl, imidazolyl, oxazolyl, thiazolyl, isoxazolyl, isothiazolyl, quinolyl, furyl, thienyl, selenophenyl, tellurophenyl, piperidyl, piperidino, morpholino, pyrrolidyl, pyrrolidino, benzoxazolid Le, benzoimida Ryl, benzothiazolyl, carbazolyl group, azepinyl group, silylyl group, etc.) These substituents may be further substituted, and examples of further substituents include groups selected from the above substituent group A. Can do. When there are a plurality of the further substituents, the substituents may be connected to each other to form a ring.

[Materials for organic electroluminescent elements]
The material for an organic electroluminescent element of the present invention includes a flat light emitting material having an aspect ratio (molecular length / molecular thickness) of 3 or more to a molecular length and molecular thickness, and an aspect ratio (molecular length / molecular thickness / molecular thickness). And a size ratio of the molecular radius of the light emitting material to the molecular radius of the host material (the molecular radius of the light emitting material / the molecular radius of the host material) is 0. 8 to 1.2.

The organic electroluminescent element material of the present invention contains at least a flat light emitting material having an aspect ratio of 3 or more and a host material having an aspect ratio of 2 or less, and the molecular radius of the light emitting material and the molecules of the host material By setting the size ratio with respect to the radius to 0.8 to 1.2, when the organic electroluminescent element material is applied to film formation such as a light emitting layer of the organic electroluminescent element, the amorphous property of the formed film is improved. In addition, the durability of the formed film is improved.
In order to improve light extraction efficiency with luminescent materials, it is important to increase the directivity of light emission by arranging guest (luminescent material) molecules in a highly ordered manner by arranging flat host molecules with a large aspect ratio. Has been considered. However, when the host molecules are arranged in a highly ordered manner, there is a problem that the amorphous film is crystallized at the time of preparation, and device characteristics such as durability are deteriorated.
According to the study by the present inventors, it was found that when a guest molecule having high planarity is used, the guest molecule is arranged in a certain order or more even when a host molecule having a small aspect ratio is used.
In the organic electroluminescent device material of the present invention, when the light emitting material and the host material are close in size, the organic electroluminescent device material is deposited to form a light emitting layer of the organic electroluminescent device. There is nothing to do.

In the present invention, the “molecular length” of the light-emitting material and the host material means the lengths a and b of two sides in the closest rectangle when the molecules of the material are assumed to have a flat plate structure, as shown in FIG. Mean value [(a + b) / 2]. Here, the “closest quadrangle” is defined as a quadrangle in which the average value [(a + b) / 2] of a and b is the smallest among quadrilaterals (rectangles or squares) whose two sides are in contact with the molecule. . This “molecular length” is defined as follows by theoretical calculation. That is, the density functional method is used. Specifically, using Gaussian 03 (Gaussian, USA), the basis optimization function is 6-31G ^* and the exchange correlation functional is B3LYP / LANL2DZ. Do. Using the optimized structure obtained by the structure optimization calculation, the average length of two sides in the closest rectangle in the ball and stick display is defined as the molecular length.
Further, the “molecular thickness” refers to the flat plate portion of the flat plate structure as the x axis and the y axis (for example, the direction of the side of the length a in FIG. 2 is the y axis and the direction of the side of the length b is the x axis). It means the thickness of the molecule in the z-axis direction orthogonal to the x-axis and y-axis when assumed. The molecular thickness is also determined by the same method as the molecular length, and the length in the thickness direction of the molecule in ball and stick display is defined as the molecular thickness.

“Molecular radius” means the distance from the center of a molecule to an atom connected to the free rotational bond of a group in which two free rotational bonds are continuous. When there is no group in which two free rotational bonds are continuous (in the case of 0 or 1), it means the atom farthest from the molecular center.
Here, the “molecular center” means the center of the chromophore or the molecular core. For example, in the case of a metal complex having a chromophore with respect to the central metal, such as a platinum complex exemplified as a light emitting material below, the central metal of the complex is the molecular center. In the case of a material having a substituent with respect to the core of the condensed ring structure exemplified below as the host material, the condensed ring structure is the molecular center.
“Free-rotation bond” is a free-rotation bond axis. For example, a bond axis to which a methyl group is connected is a free-rotation bond, but a bond axis to which a rigid group such as a phenyl group is connected is not freely rotatable. .
Therefore, as shown in FIG. 3, when two or more methylene groups are continuously linked from the phenyl group on the molecular center side, [(molecular center) -Ph—CH ₂ —CH ₂ —CH ₂ —. Taking an example, “distance from the molecular center to two consecutive groups” (ie, “molecular radius”) means the carbon atom of the second methylene group from the molecular center to the molecular center side (in FIG. 3, This means the distance to the circled atoms. In addition, when two or more phenyl groups (Ph) are continuously connected, for example, when (four) are connected continuously as shown in FIG. 4, [(molecular center) -Ph-Ph-Ph-Ph] is an example. In this case, since there is no free rotational bond, the fourth carbon atom in the fourth phenyl group from the center of the molecule (the atom surrounded by a circle in Fig. 4) is the farthest atom from the center of the molecule. The distance to the carbon atom is the “molecular radius”. Furthermore, as shown in FIG. 5, taking the case where the phenyl group and the methylene group is linked to [(molecular _{centers) -Ph-Ph-CH 2 -CH} 2 -Ph] as an example, the second phenyl molecular center Since two methylene groups whose bond axes can freely rotate are bonded continuously between the group and the third phenyl group, the carbon atom of the second methylene group from the center of the molecule (FIG. 5). In the middle, the distance to the circled atoms) is the “distance from the molecule center to two consecutive atoms” (ie, “molecular radius”).

Examples of the group whose bond axis is a freely rotatable axis include amino group, silyl group, alkoxy group, alkylthio group and the like in addition to the above methyl group (methylene group). In addition to the phenyl group, examples of the group whose bond axis is not freely rotatable include a cyclohexane ring, a condensed aryl group, and a heterocycle.
The molecular radius is also determined by the same method as the molecular length. In the ball and stick display, the free rotational bond is connected to the free rotational bond of the group in which two free rotational bonds are continuous from the center of the molecule when viewed from the z-axis direction. It can be obtained from the length to the atom to be.

  Hereinafter, the structure of the organic electroluminescent element material of the present invention will be described.

(Luminescent material)
The light emitting material used for the organic electroluminescent element material of the present invention will be described.
The light emitting material has an aspect ratio (molecular length / molecular thickness) of 3 or more, preferably 5 or more, more preferably 5 or more and 30 or less from the viewpoint of improving the orientation of the host material without disturbing the orientation of the host material. Preferably, 5.3 to 20 is particularly preferable.
If the aspect ratio is less than 3, molecular fluctuations may increase and orientation may deteriorate.

  The molecular radius of the light emitting material is preferably 0.40 nm to 3.0 nm, more preferably 0.45 nm to 2.0 nm, and particularly preferably 0.5 nm to 1.5 nm. This range is preferable from the viewpoints of improving the orientation, ease of controlling the emission intensity and emission wavelength, and the like.

  The size ratio between the molecular radius of the luminescent material and the molecular radius of the host material (the molecular radius of the luminescent material / the molecular radius of the host material) is 0.8 to 1.2, and 0.85 to 1.15. Is preferable, and 0.9 to 1.1 is more preferable. When the size ratio is within this range, the luminance in the front direction of the organic electroluminescent element increases.

As the light emitting material, either a phosphorescent material or a fluorescent material can be used. From the viewpoint of luminous efficiency, a phosphorescent material is preferable. Examples of the phosphorescent material include a complex containing a transition metal atom. These may be used alone or in combination of two or more.
The complex may have one transition metal atom in the compound, or may be a so-called binuclear complex having two or more. Different metal atoms may be contained at the same time.

Examples of the ligand of the complex include G.I. Wilkinson et al., Comprehensive Coordination Chemistry, Pergamon Press, 1987, H.C. Listed by Yersin, “Photochemistry and Photophysics of Coordination Compounds”, published by Springer-Verlag, 1987, Akio Yamamoto, “Organic Metal Chemistry-Fundamentals and Applications,” published by Soukabo, 1982, etc. It is done.
Examples of the ligand include aromatic carbocyclic ligand, nitrogen-containing heterocyclic ligand, diketone ligand, carboxylic acid ligand, alcoholate ligand, carbon monoxide ligand, isonitrile coordination Child, cyano ligand and the like. Among these, a nitrogen-containing heterocyclic ligand is particularly preferable.
Examples of the aromatic carbocyclic ligand include a cyclopentadienyl anion, a benzene anion, and a naphthyl anion.
Examples of the nitrogen-containing heterocyclic ligand include phenylpyridine, benzoquinoline, quinolinol, bipyridyl, phenanthroline and the like.
Examples of the diketone ligand include acetylacetone.
Examples of the carboxylic acid ligand include an acetic acid ligand.
Examples of the alcoholate ligand include a phenolate ligand.

  Examples of the transition metal atom include ruthenium, rhodium, palladium, osmium, iridium, platinum and the like.

  The light emitting material is not particularly limited and may be appropriately selected depending on the intended purpose. However, a phosphorescent compound is preferable, and a tetradentate structure having a planar coordination structure is preferable in that the aspect ratio is 3 or more. Platinum (platinum complex) is preferable, and a platinum complex having a salen or porphyrin skeleton is more preferable.

  The platinum complex is preferably a platinum complex represented by the general formula (C-1).

(In the formula, Q ¹ , Q ² , Q ³ and Q ⁴ each independently represent a ligand coordinated to Pt. L ¹ , L ² and L ³ are each independently a single bond, double bond And represents a group consisting of a bond, a divalent linking group, or a combination thereof, and Q ³ and Q ⁴ may be linked to form a ring.)

General formula (C-1) is demonstrated. Q ¹ , Q ² , Q ³ and Q ⁴ each independently represent a ligand coordinated to Pt. At this time, the bond between Q ¹ , Q ² , Q ³ and Q ⁴ and Pt may be any of a covalent bond, an ionic bond, a coordinate bond, and the like. As an atom couple | bonded with Pt in Q < ¹ >, Q < ² >, Q < ³ > and Q < ⁴ >, a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, and a phosphorus atom are preferable, In Q < ¹ >, Q < ² >, Q < ³ > and Q < ⁴ > Of the atoms bonded to Pt, at least one is preferably a carbon atom, more preferably two are carbon atoms, particularly preferably two are carbon atoms and two are nitrogen atoms.
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt by a carbon atom may be an anionic ligand or a neutral ligand, and the anionic ligand is a vinyl ligand, Aromatic hydrocarbon ring ligand (eg benzene ligand, naphthalene ligand, anthracene ligand, phenanthrene ligand), heterocyclic ligand (eg furan ligand, thiophene ligand, pyridine) Ligand, pyrazine ligand, pyrimidine ligand, pyridazine ligand, triazine ligand, thiazole ligand, oxazole ligand, pyrrole ligand, imidazole ligand, pyrazole ligand, triazole A ligand, an oxadiazole ligand, a thiadiazole ligand, and a condensed ring containing them (for example, a quinoline ligand, a benzothiazole ligand, etc.). A carbene ligand is mentioned as a neutral ligand.
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt with a nitrogen atom may be neutral ligands or anionic ligands, and as neutral ligands, nitrogen-containing aromatic hetero Ring ligand (pyridine ligand, pyrazine ligand, pyrimidine ligand, pyridazine ligand, triazine ligand, imidazole ligand, pyrazole ligand, triazole ligand, oxazole ligand, Examples include thiazole ligands and condensed rings containing them (for example, quinoline ligands, benzimidazole ligands), amine ligands, nitrile ligands, and imine ligands. Examples of anionic ligands include amino ligands, imino ligands, nitrogen-containing aromatic heterocyclic ligands (pyrrole ligands, imidazole ligands, triazole ligands and condensed rings containing them) (For example, indole ligand, benzimidazole ligand, etc.)).
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt with an oxygen atom may be neutral ligands or anionic ligands, and neutral ligands are ether ligands, Examples include ketone ligands, ester ligands, amide ligands, oxygen-containing heterocyclic ligands (furan ligands, oxazole ligands and condensed rings containing them (benzoxazole ligands, etc.)). It is done. Examples of the anionic ligand include an alkoxy ligand, an aryloxy ligand, a heteroaryloxy ligand, an acyloxy ligand, a silyloxy ligand, and the like.
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt with a sulfur atom may be neutral ligands or anionic ligands, and neutral ligands include thioether ligands, Examples include thioketone ligands, thioester ligands, thioamide ligands, sulfur-containing heterocyclic ligands (thiophene ligands, thiazole ligands and condensed rings containing them (such as benzothiazole ligands)). It is done. Examples of the anionic ligand include an alkyl mercapto ligand, an aryl mercapto ligand, and a heteroaryl mercapto ligand.
Q ¹ , Q ² , Q ³ and Q ⁴ bonded to Pt with a phosphorus atom may be neutral ligands or anionic ligands, and neutral ligands include phosphine ligands, Examples include phosphate ester ligands, phosphite ester ligands, and phosphorus-containing heterocyclic ligands (phosphinin ligands, etc.). Anionic ligands include phosphino ligands and phosphinyl ligands. And phosphoryl ligands.
The ligands represented by Q ¹ , Q ² , Q ^3, and Q ⁴ may have a substituent, and those listed as the substituent group A can be appropriately applied as the substituent. Moreover, substituents may be connected to each other (when Q ³ and Q ⁴ are connected, a Pt complex of a cyclic tetradentate ligand is formed).

The ligand represented by Q ¹ , Q ² , Q ³ and Q ⁴ is preferably an aromatic hydrocarbon ring ligand bonded to Pt with a carbon atom, or an aromatic heterocyclic ring bonded to Pt with a carbon atom. Ligands, nitrogen-containing aromatic heterocyclic ligands that bind to Pt with nitrogen atoms, acyloxy ligands, alkyloxy ligands, aryloxy ligands, heteroaryloxy ligands, silyloxy ligands More preferably, an aromatic hydrocarbon ring ligand bonded to Pt by a carbon atom, an aromatic heterocyclic ligand bonded to Pt by a carbon atom, a nitrogen-containing aromatic heterocyclic ring bonded to Pt by a nitrogen atom A ligand, an acyloxy ligand, an aryloxy ligand, more preferably an aromatic hydrocarbon ring ligand bonded to Pt by a carbon atom, an aromatic heterocyclic ligand bonded to Pt by a carbon atom, Bonded to Pt by nitrogen atom That the nitrogen-containing aromatic heterocyclic ligand, an acyloxy ligand.

L ¹ , L ² and L ³ represent a group consisting of a single bond, a double bond, a divalent linking group, or a combination thereof. Examples of the divalent linking group represented by L ¹ , L ² and L ³ include alkylene groups (methylene, ethylene, propylene, etc.), arylene groups (phenylene, naphthalenediyl), heteroarylene groups (pyridinediyl, thiophenediyl, etc.) ), Imino group (—NR—) (such as phenylimino group), oxy group (—O—), thio group (—S—), phosphinidene group (—PR—) (such as phenylphosphinidene group), silylene group (-SiRR'-) (dimethylsilylene group, diphenylsilylene group, etc.), a carbonyl group, or a combination thereof. These linking groups may further have a substituent. R and R ′ each independently represents a substituent. As these substituents, those mentioned as the substituent group A can be applied. When there are a plurality of the substituents, the substituents may be connected to each other to form a ring.
From the viewpoint of the stability of the complex and the emission quantum yield, L ² and L ³ are preferably a single bond, an alkylene group, an arylene group, a heteroarylene group, an imino group, an oxy group, a thio group, or a silylene group, and more preferably. Is a single bond, an alkylene group, an arylene group or an imino group, more preferably a single bond, an alkylene group or an arylene group, still more preferably a single bond, a methylene group or a phenylene group, still more preferably a single bond, A disubstituted methylene group, more preferably a single bond, dimethylmethylene group, diethylmethylene group, diisobutylmethylene group, dibenzylmethylene group, ethylmethylmethylene group, methylpropylmethylene group, isobutylmethylmethylene group, diphenylmethylene group, Methylphenylmethylene, cyclohexanediyl, Ropentanjiiru group, fluorenediyl group, a fluoromethyl methylene group, particularly preferably a single bond, a dimethylmethylene group, a diphenylmethylene group, a cyclohexane diyl group, most preferably a single bond.

L ¹ is preferably an alkylene group, an arylene group, a heteroarylene group, an imino group, an oxy group, a thio group, a silylene group or a carbonyl group, more preferably an alkylene group, an arylene group or an imino group, still more preferably an alkylene group Group, an imino group, more preferably a methylene group and an imino group. These may have a substituent, and as the substituent, those exemplified as the substituent group A can be applied. When there are a plurality of the substituents, the substituents may be connected to each other to form a ring.
L ¹ is more preferably a single bond, a disubstituted methylene group, or an optionally substituted arylimino group, and more preferably a dimethylmethylene group, a diethylmethylene group, a diisobutylmethylene group, a dibenzylmethylene group, or an ethylmethylmethylene group. , Methylpropylmethylene group, isobutylmethylmethylene group, diphenylmethylene group, methylphenylmethylene group, cyclohexanediyl group, cyclopentanediyl group, fluorenediyl group, fluoromethylmethylene group, phenylimino group, 4-t-butylphenylimino Particularly preferably a dimethylmethylene group, a diphenylmethylene group, a cyclohexanediyl group or a phenylimino group. If possible, these groups may be further substituted with the groups mentioned in the substituent group A.

  Of the platinum complexes represented by the general formula (C-1), a platinum complex represented by the following general formula (C-2) is more preferable.

(In the formula, L ²¹ represents a single bond or a divalent linking group. A ²¹ , A ²² , B ²¹ , and B ²² each independently represent a carbon atom or a nitrogen atom, but two or more represent a nitrogen atom. Z ²¹ , Z ²² , Z ²³ and Z ²⁴ each independently represent a benzene ring or a nitrogen-containing aromatic heterocycle.

General formula (C-2) is demonstrated. L ²¹ represents a single bond or a divalent linking group, and a preferred range is the same as L ¹ in the general formula (C-1).

A ²¹ , A ²² , B ²¹ and B ²² each independently represent a carbon atom or a nitrogen atom, but preferably two or more represent a nitrogen atom, preferably two or three represent a nitrogen atom, and two represent a nitrogen atom. Is more preferable. From the viewpoint of the stability of the complex, it is preferable that A ²¹ and A ²² represent a nitrogen atom, or that B ²¹ and B ²² represent a nitrogen atom.

Z ²¹ , Z ²² , Z ²³ and Z ²⁴ each independently represent a benzene ring or a nitrogen-containing aromatic heterocycle. Examples of the nitrogen-containing aromatic heterocycle represented by Z ²¹ , Z ²² , Z ²³ , and Z ²⁴ include a pyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, a triazine ring, an imidazole ring, a pyrazole ring, an oxazole ring, and a thiazole ring. , Triazole ring, oxadiazole ring, thiadiazole ring, and the like. From the viewpoint of the stability of the complex, emission wavelength control and emission quantum yield, the ring represented by Z ²³ or Z ²⁴ is preferably a benzene ring, a pyridine ring, a pyrazine ring, an imidazole ring or a pyrazole ring, more preferably A benzene ring, a pyridine ring, and a pyrazole ring are more preferable, and a benzene ring and a pyridine ring are more preferable.

The benzene ring and nitrogen-containing aromatic heterocycle represented by Z ²¹ , Z ²² , Z ²³ , and Z ²⁴ may have a substituent, and examples of the substituent on the carbon atom include the substituent group A. The substituent group B is applicable as a substituent on the nitrogen atom.

  The substituent on the carbon atom is preferably an alkyl group, a fluoroalkyl group, an aryl group, a heterocyclic group, a dialkylamino group, a diarylamino group, an alkoxy group, an aryloxy group, a silyl group, a cyano group, or a halogen atom. An alkyl group, a fluoroalkyl group, an aryl group, an aryloxy group, a heterocyclic group, a diarylamino group, an alkoxy group, a cyano group, or a halogen atom, more preferably an alkyl group, an alkoxy group, an aryl group, an aryloxy group, A fluorine atom or a cyano group is more preferable.

The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkyl group preferably has 1 to 12 carbon atoms, for example, methyl group, butyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, t-butyl group, t-amyl group, s-butyl. Group and the like.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The fluoroalkyl group is preferably a trifluoromethyl group.
The alkoxy group represents a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkoxy group preferably has 1 to 12 carbon atoms, and examples thereof include a methoxy group, a butyloxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, an s-octyloxy group, and a benzyloxy group.
The hetero ring group represents a substituted or unsubstituted nitrogen-containing aromatic hetero ring group having 6 to 10 carbon atoms, which may be condensed, such as a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, Examples thereof include a triazine ring and a carbazole ring, and a carbazole ring is preferable.
The diarylamino group represents a substituted or unsubstituted diarylamino group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a diphenylamino group, a ditoluylamino group, and a dinaphthylamino group.
The dialkylamino group represents a substituted or unsubstituted dialkylamino having 2 to 20 carbon atoms, and may have any of a linear, branched, or cyclic structure. The dialkylamino group preferably has 2 to 12 carbon atoms. Specifically, for example, a dimethylamino group, a diethylamino group, a dioctylamino group, a didecylamino group, a didodecylamino group, a dit-butylamino group, a dit -An amylamino group, a di s-butylamino group, etc. are mentioned.
The aryloxy group represents a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyloxy group, a toluyloxy group, and a naphthyloxy group.
The silyl group represents a silyl group substituted with a carbon atom having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. The silyl group preferably has 3 to 18 carbon atoms. Specific examples include a trimethylsilyl group, a t-butyldimethylsilyl group, a triphenylsilyl group, and a t-butyldiphenylsilyl group.
As the halogen atom, a fluorine atom is preferable.

  The substituent is appropriately selected for controlling the emission wavelength and potential, but in the case of increasing the wavelength, an electron donating group and an aromatic ring group are preferable, for example, an alkyl group, a dialkylamino group, an alkoxy group, an aryl group, An aromatic heterocyclic group or the like is selected. In order to shorten the wavelength, an electron withdrawing group is preferable, and for example, a fluorine atom, a cyano group, a trifluoroalkyl group, and the like are selected.

  The substituent on the nitrogen atom is preferably an alkyl group, an aryl group, or an aromatic heterocyclic group, and an alkyl group or an aryl group is preferable from the viewpoint of the stability of the complex.

The substituents on Z ²¹ , Z ²² , Z ²³ , and Z ²⁴ may be linked to form a condensed ring. Examples of the ring formed include a benzene ring, a pyridine ring, a pyrazine ring, a pyridazine ring, Examples include a pyrimidine ring, an imidazole ring, an oxazole ring, a thiazole ring, a pyrazole ring, a thiophene ring, and a furan ring. When the substituents of Z ²³ and Z ²⁴ are linked to each other, the platinum complex represented by the general formula (C-2) becomes a Pt complex of a cyclic tetradentate ligand.

  Of the platinum complexes represented by the general formula (C-2), one of the more preferable embodiments is a platinum complex represented by the following general formula (C-3).

(In the formula, A ^{301 to} A ³¹³ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. L ³¹ represents a single bond or a divalent linking group. Y, Z and M each independently represent a carbon atom or a nitrogen atom, and one of Z and Y is a nitrogen atom.)

General formula (C-3) is demonstrated.
L ³¹ has the same meaning as L ²¹ in formula (C-2), and the preferred range is also the same.

A ^{301 to} A ³⁰⁶ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. As the substituent represented by R, those exemplified as the substituent group A can be applied.
A ^{301 to} A ³⁰⁶ are preferably C—R, and Rs may be connected to each other to form a ring. When A ^{301 to} A ³⁰⁶ are C—R, R in A ³⁰² and A ³⁰⁵ is preferably a hydrogen atom, alkyl group, trifluoroalkyl group, aryl group, heterocyclic group, dialkylamino group, diarylamino group , An alkoxy group, an aryloxy group, a silyl group, a cyano group, or a halogen atom, a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, a heterocyclic group, a diarylamino group, an alkoxy group, a cyano group, or A halogen atom is more preferable, a hydrogen atom, an alkyl group, an alkoxy group, or a cyano group is further preferable, and a hydrogen atom is particularly preferable. The alkyl group and aryl group may further have a substituent, and examples of the substituent include an alkyl group, an aryl group, a cyano group, an amino group, a halogen atom, and a fluoroalkyl group. -6 alkyl group, cyano group, amino group, halogen atom, fluoroalkyl group (preferably trifluoromethyl group), more preferably C1-6 alkyl group, halogen atom (preferably fluorine atom). is there. In the case where A ³⁰² and A ³⁰⁵ are C—R, R in the A ³⁰² and A ³⁰⁵ is preferably an aryl group from the viewpoint of improving the durability of the device, and a hydrogen atom or an alkyl group from the viewpoint of a short emission wavelength. An amino group, an alkoxy group, a fluorine atom, and a cyano group are preferable.
R in A ³⁰¹ , A ³⁰³ , A ³⁰⁴ and A ³⁰⁶ is preferably a hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom or a cyano group, more preferably a hydrogen atom or an amino group. Group, an alkoxy group, an aryloxy group and a fluorine atom, and particularly preferably a hydrogen atom.

A ³⁰⁷ , A ³⁰⁸ , A ³⁰⁹ and A ³¹⁰ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. As the substituent represented by R, those exemplified as the substituent group A can be applied. When A ³⁰⁷ , A ³⁰⁸ , A ³⁰⁹ and A ³¹⁰ are C—R, R is preferably a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, an aromatic heterocyclic group, a dialkylamino group, a diaryl. An amino group, an alkyloxy group, a cyano group, and a halogen atom, more preferably a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, a dialkylamino group, a cyano group, a fluorine atom, still more preferably a hydrogen atom, An alkyl group, a trifluoromethyl group, and a fluorine atom; If possible, the substituents may be linked to form a condensed ring structure. When shifting the emission wavelength to the short wavelength side, A ³⁰⁸ is preferably a nitrogen atom.

In the general formula (C-3), the 6-membered ring formed from two carbon atoms and A ³⁰⁷ , A ³⁰⁸ , A ³⁰⁹ and A ³¹⁰ includes a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, and a triazine. A ring, more preferably a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring and a pyridazine ring, and particularly preferably a benzene ring and a pyridine ring. When the 6-membered ring is a pyridine ring, a pyrazine ring, a pyrimidine ring, or a pyridazine ring (particularly preferably a pyridine ring), a hydrogen atom present at a position where a metal-carbon bond is formed as compared with a benzene ring. Since acidity improves, it is advantageous at the point which becomes easier to form a metal complex.

A ³¹¹ , A ³¹² and A ³¹³ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. As the substituent represented by R, those exemplified as the substituent group A can be applied. When A ³¹¹ , A ³¹² and A ³¹³ are C—R, R is preferably a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, a heterocyclic group, a dialkylamino group, a diarylamino group, an alkoxy group. , Aryloxy group, cyano group, halogen atom, more preferably hydrogen atom, alkyl group, trifluoroalkyl group, aryl group, dialkylamino group, cyano group, fluorine atom, more preferably hydrogen atom, alkyl group , A trifluoromethyl group and a fluorine atom. If possible, the substituents may be linked to form a condensed ring structure.
At least one of A ³¹¹ , A ³¹² and A ³¹³ is preferably a nitrogen atom, and particularly preferably A ³¹¹ is a nitrogen atom.

  Of the platinum complexes represented by the general formula (C-3), one of more preferable embodiments is a platinum complex represented by the following general formula (C-3-1).

(In General Formula (C-3-1), X, Y, Z, and M each independently represent a carbon atom or a nitrogen atom, provided that either Z or Y is a nitrogen atom. When it is a nitrogen atom, X is a carbon atom, m, n, p, and q each independently represents an integer of 0 to 3. Ar represents a substituted or unsubstituted aryl group, R ₁ to. R ₃ and R ₃₀ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, wherein m, n, p, and q are 2 or more. In this case, a plurality of R ₁ , R ₂ , R ₃ and R ₃₀ may be linked to each other to form a cyclic structure, and Q is a carbon atom or a nitrogen atom.)

In general formula (C-3-1), X, Y, and Z represent a carbon atom or a nitrogen atom, and when either Z or Y is a nitrogen atom and Y is a nitrogen atom, X is It is a carbon atom. Preferably, Z is a carbon atom, Y is a nitrogen atom, and X is a carbon atom.
m, n and p each independently represents an integer of 0 to 3. Among these, m is preferably 0 to 2, and more preferably 0 to 1. n is preferably 0 to 2, and more preferably 0 to 1. p is preferably 0 to 2, and more preferably 0 to 1.

R _{1 to} R ₃ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group.
The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkyl group preferably has 1 to 12 carbon atoms. Specifically, for example, methyl group, butyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, n-butyl group, t-butyl Group, t-amyl group, s-butyl group and the like.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The alkoxy group represents a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkoxy group preferably has 1 to 12 carbon atoms, and specific examples include a methoxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, an s-octyloxy group, and a benzyloxy group.
The aryloxy group represents a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyloxy group, a toluyloxy group, and a naphthyloxy group.
The silyl group represents a silyl group substituted with a hydrocarbon group having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. . The silyl group preferably has 3 to 18 carbon atoms. Specific examples include a trimethylsilyl group, a t-butyldimethylsilyl group, a triphenylsilyl group, and a t-butyldiphenylsilyl group.
Examples of the heterocyclic group include pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, thiophene ring, furan A ring etc. are mentioned.
R ₁ and R ₂ are preferably an alkyl group, an aryl group, a fluorine atom, a cyano group or a silyl group, more preferably an alkyl group or an aryl group, and a phenyl group.
R ₃ is preferably an alkyl group or an aryl group, more preferably a methyl group, a trifluoromethyl group, or a phenyl group, and even more preferably a methyl group or a trifluoromethyl group.

Examples of the aryl group represented by Ar include a phenyl group and a naphthyl group, and a phenyl group is preferable. The aryl group represented by Ar may further have a substituent, and examples of the substituent include an alkyl group, an aryl group, a cyano group, an amino group, a fluorine atom, and a fluoroalkyl group, preferably 1 to 6 carbon atoms. Alkyl group, cyano group, amino group, fluorine atom and fluoroalkyl group (preferably trifluoromethyl group), more preferably an alkyl group having 1 to 6 carbon atoms and a fluorine atom. Ar is more preferably a phenyl group having a substituent, and the substituent is preferably a methyl group, a t-butyl group, a 4-pentyl-cyclohexyl group, a 4-pentyl-cyclohexylmethoxy group, or the like.
When m, n, and p are 2 or more, a plurality of R _{1 to} R ₃ may be connected to each other next to each other to form a cyclic structure.
M and Q are each independently a carbon atom or a nitrogen atom.
q represents an integer of 0 to 3, and an integer of 0 to 2 is preferable.

R ₃₀ represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group.
The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkyl group preferably has 1 to 12 carbon atoms. Specifically, for example, methyl group, octyl group, decyl group, dodecyl group, n-butyl group, t-butyl group, t-amyl group, s- A butyl group etc. are mentioned.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The alkoxy group represents a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkoxy group preferably has 1 to 12 carbon atoms, and specific examples include a methoxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, an s-octyloxy group, and a benzyloxy group.
The aryloxy group represents a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms, and may be condensed, and specifically includes a phenyloxy group, a toluyloxy group, a naphthyloxy group, and the like. Can be mentioned.
The silyl group represents a silyl group substituted with a carbon atom having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. The silyl group preferably has 3 to 18 carbon atoms. Specific examples include a trimethylsilyl group, a t-butyldimethylsilyl group, a triphenylsilyl group, and a t-butyldiphenylsilyl group.
Examples of the heterocyclic group include pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, thiophene ring, furan A ring etc. are mentioned.
R ₃₀ is preferably a fluorine atom.

  Among the platinum complexes represented by the general formula (C-2), one of more preferable embodiments is a platinum complex represented by the following general formula (C-4).

(In General Formula (C-4), A ^{401 to} A ⁴¹⁴ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. L ⁴¹ represents a single bond or a divalent linking group. Represents.)

General formula (C-4) is demonstrated.
A ^{401 to} A ⁴¹⁴ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent.
Or as a substituent represented by R, what was mentioned as the said substituent group A is applicable.
A ^{401 to} A ⁴⁰⁶ are preferably C—R, and Rs may be connected to each other to form a ring. When A ^{401 to} A ⁴⁰⁶ are C—R, R in A ⁴⁰² and A ⁴⁰⁵ is preferably a hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom, or a cyano group. More preferably a hydrogen atom, an amino group, an alkoxy group, an aryloxy group or a fluorine atom, and particularly preferably a hydrogen atom, a fluorine atom or an alkyl group. R in A ⁴⁰¹ , A ⁴⁰³ , A ⁴⁰⁴ and A ⁴⁰⁶ is preferably a hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom or a cyano group, more preferably a hydrogen atom or an amino group. Group, an alkoxy group, an aryloxy group and a fluorine atom, and particularly preferably a hydrogen atom.
L ⁴¹ has the same meaning as L ²¹ in formula (C-2), and the preferred range is also the same.

As A ^{407 to} A ⁴¹⁴ , in each of A ^{407 to} A ⁴¹⁰ and A ^{411 to} A ⁴¹⁴ , the number of N (nitrogen atoms) is preferably 0 to 2, and more preferably 0 to 1. When shifting the emission wavelength to the short wavelength side, either A ⁴⁰⁸ or A ⁴¹² is preferably a nitrogen atom, and both A ⁴⁰⁸ and A ⁴¹² are more preferably nitrogen atoms.
When A ^{407 to} A ⁴¹⁴ represent C—R, R in A ⁴⁰⁸ and A ⁴¹² is preferably a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom. A cyano group, more preferably a hydrogen atom, a trifluoroalkyl group, an alkyl group, an aryl group, a fluorine atom or a cyano group, and particularly preferably a hydrogen atom, a phenyl group, a trifluoroalkyl group or a cyano group. . R in A ⁴⁰⁷ , A ⁴⁰⁹ , A ⁴¹¹ and A ⁴¹³ is preferably a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, a fluorine atom or a cyano group, more preferably Is a hydrogen atom, a trifluoroalkyl group, a fluorine atom or a cyano group, particularly preferably a hydrogen atom, a phenyl group or a fluorine atom. R in A ⁴¹⁰ and A ⁴¹⁴ is preferably a hydrogen atom or a fluorine atom, and more preferably a hydrogen atom. When any of A ^{407 to} A ⁴⁰⁹ and A ^{411 to} A ⁴¹³ represents C—R, Rs may be connected to each other to form a ring, and examples of the ring formed include a benzene ring. It is done.

  Of the platinum complexes represented by the general formula (C-2), one of more preferable embodiments is a platinum complex represented by the following general formula (C-5).

(In General Formula (C-5), A ^{501 to} A ⁵¹² each independently represents C—R or a nitrogen atom, R represents a hydrogen atom or a substituent, and L ⁵¹ represents a single bond or a divalent linkage. Y and Z each independently represent a carbon atom or a nitrogen atom, at least one of which is a nitrogen atom.)

General formula (C-5) is demonstrated. A ^{501 to} A ⁵⁰⁶ and L ⁵¹ have the same meanings as A ^{401 to} A ⁴⁰⁶ and L ⁴¹ in the general formula (C-4), and preferred ranges thereof are also the same.

A ⁵⁰⁷ , A ⁵⁰⁸ , A ⁵⁰⁹ , A ⁵¹⁰ , A ⁵¹¹ and A ⁵¹² each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. As the substituent represented by R, those exemplified as the substituent group A can be applied. When A ⁵⁰⁷ , A ⁵⁰⁸ , A ⁵⁰⁹ , A ⁵¹⁰ , A ⁵¹¹ and A ⁵¹² are C—R, R is preferably a hydrogen atom, an alkyl group, a trifluoroalkyl group, an aryl group, an aromatic heterocyclic group. , Dialkylamino group, diarylamino group, alkyloxy group, cyano group, halogen atom, more preferably hydrogen atom, alkyl group, trifluoroalkyl group, aryl group, dialkylamino group, cyano group, fluorine atom, Preferably, they are a hydrogen atom, an alkyl group, a trifluoromethyl group, or a fluorine atom. If possible, the substituents may be linked to form a condensed ring structure. An embodiment in which at least one of A ⁵⁰⁷ , A ⁵⁰⁸ , and A ⁵⁰⁹ , and at least one of A ⁵¹⁰ , A ^511, and A ⁵¹² is a nitrogen atom is also preferable. In this embodiment, A ⁵¹⁰ or A ⁵⁰⁷ is A nitrogen atom is preferred.

  Of the platinum complexes represented by the general formula (C-5), one of more preferable embodiments is a platinum complex represented by the following general formula (C-5-1).

(In General Formula (C-5-1), X, Y, and Z each independently represent a carbon atom or a nitrogen atom, and either Z or Y is a nitrogen atom, and Y is a nitrogen atom. When X is a carbon atom, m, n, p and q each independently represents an integer of 0 to 3. Ar represents a substituted or unsubstituted aryl group, and R _{1 to} R ₄ represent Each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when m, n, p, and q are 2 or more, a plurality of R ₁ to R ₄ cyclic structure linked to each other and each next to each other may be formed.)

In general formula (C-5-1), X, Y, and Z represent a carbon atom or a nitrogen atom, and when one of Z and Y is a nitrogen atom and Y is a nitrogen atom, X is It is a carbon atom. Preferably, Z is a carbon atom, Y is a nitrogen atom, and X is a carbon atom.
m, n, p, and q each independently represents an integer of 0 to 3. Among these, m is preferably 0 to 2, and more preferably 0 to 1. n is preferably 0 to 2, and more preferably 0 to 1. p is preferably 0 to 2, and more preferably 0 to 1. q is preferably 0 to 2, and more preferably 0 to 1.

R _{1 to} R ₄ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group.
The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkyl group preferably has 1 to 12 carbon atoms. Specifically, for example, methyl group, butyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, n-butyl group, t-butyl Group, t-amyl group, s-butyl group and the like.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The alkoxy group represents a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The alkoxy group preferably has 1 to 12 carbon atoms, and specific examples include a methoxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, an s-octyloxy group, and a benzyloxy group.
The aryloxy group represents a substituted or unsubstituted aryloxy group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyloxy group, a toluyloxy group, and a naphthyloxy group.
The silyl group represents a silyl group substituted with a hydrocarbon group having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. . The silyl group preferably has 3 to 18 carbon atoms. Specific examples include a trimethylsilyl group, a t-butyldimethylsilyl group, a triphenylsilyl group, and a t-butyldiphenylsilyl group.
Examples of the heterocyclic group include pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, thiophene ring, furan A ring etc. are mentioned.
R ₁ and R ₂ are preferably an alkyl group, an aryl group, a fluorine atom, a cyano group or a silyl group, more preferably an alkyl group or an aryl group, and a phenyl group.
R ₃ and R ₄ are preferably an alkyl group or an aryl group, more preferably a methyl group, a trifluoromethyl group, or a phenyl group, and even more preferably a methyl group or a trifluoromethyl group.

Examples of the aryl group represented by Ar include a phenyl group and a naphthyl group, and a phenyl group is preferable. The aryl group represented by Ar may further have a substituent, and examples of the substituent include an alkyl group, an aryl group, a cyano group, an amino group, a fluorine atom, and a fluoroalkyl group, preferably 1 to 6 carbon atoms. Are an alkyl group, a cyano group, an amino group, a fluorine atom, and a fluoroalkyl group (preferably a trifluoromethyl group), and more preferably an alkyl group having 1 to 6 carbon atoms and a fluorine atom. Ar is more preferably a phenyl group having a substituent, and the substituent is preferably a methyl group, a t-butyl group, a 4-pentyl-cyclohexyl group, a 4-pentyl-cyclohexylmethoxy group, or the like.
When m, n, p, q is 2 or more, a plurality of R _{1 to} R ₄ may be connected to each other adjacent to each other to form a cyclic structure.

  Of the platinum complexes represented by the general formula (C-2), one of more preferable embodiments is a platinum complex represented by the following general formula (C-6).

(In general formula (C-6), X, Y, and Z represent a carbon atom or a nitrogen atom, and any one of Z and Y is a nitrogen atom. When Y is a nitrogen atom, X is a carbon atom. R, s, t and u each independently represents an integer of 0 to 3. R _{5 to} R ₈ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, A cyano group, a silyl group, or a heterocyclic group is represented, and when r, s, t, and u are 2 or more, a plurality of R _{5 to} R ₈ may be connected to each other to form a cyclic structure. W ₁ and W ₂ each independently represent an alkyl group, and may be bonded to each other to form a cyclic structure.)

  In general formula (C-6), X, Y, and Z are synonymous with X, Y, and Z of general formula (C-5-1), and their preferable ranges are also the same.

R < ₅ > -R < ₈ > is synonymous with R < ₁ > -R < ₄ > of general formula (C-5-1).
R ₅ and R ₆ are preferably an alkyl group, an alkoxy group, an aryl group, a fluorine atom, or a cyano group.
As the alkyl group represented by R ₅ and R ₆ , an optionally substituted methyl group, butyl group, octyl group, decyl group, dodecyl group and the like are preferable, and a butyl group, a trifluoromethyl group, an octyl group, A decyl group is more preferred.
The alkoxy group represented by R ₅ and R ₆ is preferably a decyloxy group.
The aryl group represented by R ₅ and R ₆ is preferably a phenyl group which may have a substituent, and the substituent is preferably an alkyl group, more preferably a propyl group or a butyl group.
R ₇ and R ₈ are preferably an alkyl group or an aryl group.

r, s, t, and u each independently represent an integer of 0 to 3. Among these, r is preferably 0 to 2, and more preferably 0 or 1. s is preferably 0 to 2, more preferably 0 or 1. t is preferably 0 or 1, and u is preferably 0 or 1.
When r, s, t, u is 2 or more, the plurality of R _{5 to} R ₈ may be connected to each other adjacent to each other to form a cyclic structure. Examples of the cyclic structure include a structure that forms a fluorene ring together with a benzene ring, a benzofuran ring, and a 6-membered ring having Z.

W ₁ and W ₂ represent an alkyl group having 1 to 10 carbon atoms and may be bonded to each other to form a cyclic structure.
Examples of the alkyl group represented by W ₁ and W ₂ include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and a pentyl group.
Examples of the cyclic structure formed by combining W ₁ and W ₂ include a cyclohexyl cyclic structure.
W ₁ and W ₂ are preferably a methyl group from the viewpoint of a high aspect ratio or are bonded to each other to form a cyclohexyl ring structure.

  Among the platinum complexes represented by the general formula (C-1), another more preferable embodiment is a platinum complex represented by the following general formula (C-7).

(In the formula, L ⁶¹ represents a single bond or a divalent linking group. A ⁶¹ represents a carbon atom or a nitrogen atom. Z ⁶¹ and Z ⁶² each independently represent a nitrogen-containing aromatic heterocycle. Z ⁶³ represents a benzene ring or an aromatic heterocycle, and Q represents an anionic acyclic ligand bonded to Pt.)

General formula (C-7) is demonstrated. L ⁶¹ represents a single bond or a divalent linking group, and a preferred range is the same as L ¹ in the general formula (C-1).

A ⁶¹ represents a carbon atom or a nitrogen atom. In view of the stability of the complex and the light emission quantum yield of the complex, A ⁶¹ is preferably a carbon atom.

Z ⁶¹ and Z ⁶² are synonymous with Z ²¹ and Z ²² in the general formula (C-2), respectively, and preferred ranges thereof are also the same. Z ⁶³ has the same meaning as Z ²³ in formula (C-2), and the preferred range is also the same.

Q is an anionic acyclic ligand that binds to Pt. An acyclic ligand is one in which atoms bonded to Pt do not form a ring in the form of a ligand. As an atom couple | bonded with Pt in Q, a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom are preferable, a nitrogen atom and an oxygen atom are more preferable, and an oxygen atom is the most preferable.
Examples of Q bonded to Pt by a carbon atom include a vinyl ligand. Examples of Q bonded to Pt with a nitrogen atom include an amino ligand and an imino ligand. Q bonded to Pt with an oxygen atom includes an alkoxy ligand, an aryloxy ligand, a heteroaryloxy ligand, an acyloxy ligand, a silyloxy ligand, a carboxyl ligand, a phosphate ligand, Examples thereof include sulfonic acid ligands. Examples of Q bonded to Pt with a sulfur atom include alkyl mercapto ligands, aryl mercapto ligands, heteroaryl mercapto ligands, and thiocarboxylic acid ligands.
The ligand represented by Q may have a substituent, and those listed as the substituent group A can be appropriately applied as the substituent. Moreover, substituents may be connected to each other.

  The ligand represented by Q is preferably a ligand bonded to Pt with an oxygen atom, and more preferably an acyloxy ligand, an alkyloxy ligand, an aryloxy ligand, a heteroaryloxy ligand A silyloxy ligand, more preferably an acyloxy ligand.

  Of the platinum complexes represented by the general formula (C-7), one of more preferred embodiments is a platinum complex represented by the following general formula (C-8).

(In the general formula (C-8), A ^{701 to} A ⁷¹⁰ each independently represents C—R or a nitrogen atom, R represents a hydrogen atom or a substituent, and L ⁷¹ represents a single bond or a divalent linkage. Q represents an anionic acyclic ligand that binds to Pt.)

General formula (C-8) is demonstrated. L ⁷¹ has the same meaning as L ^{61 in} formula (C-6), and the preferred range is also the same. A ^{701 to} A ⁷¹⁰ have the same meanings as A ^{401 to} A ⁴¹⁰ in formula (C-4), and preferred ranges thereof are also the same. Q has the same meaning as that in formula (C-6), and the preferred range is also the same.

  Among the platinum complexes represented by the general formula (C-1), one of other preferable embodiments is a platinum complex represented by the following general formula (C-9).

In the formula, A and B represent a cyclic structure, A represents an aromatic ring, and B represents an aromatic heterocycle. When one of A and B forms a ring, the other may not form a ring. R _{13 to} R ₁₆ each independently represent a hydrogen atom, an alkyl group, an aryl group, a silyl group, or a heterocyclic group, and R ₁₄ and R ₁₅ , R ₁₃ and R ₁₆ are bonded to each other to form a cyclic structure. It may be formed.

General formula (C-9) is demonstrated.
A represents an aromatic ring. Examples of the aromatic ring include an aromatic hydrocarbon ring and an aromatic heterocycle, and an aromatic hydrocarbon ring is preferable. As the aromatic hydrocarbon ring represented by A, a benzene ring and a naphthalene ring are preferable. As the aromatic heterocycle represented by A, a pyridine ring, a pyrazine ring, a pyrimidine ring and a quinoline ring are preferable.
B represents an aromatic heterocycle. As the aromatic heterocycle represented by B, a pyridine ring and a pyrimidine ring are preferable.
As a combination of A and B, it is preferable that A is a benzene ring and B is a non-ring (does not form a ring), A is a naphthalene ring and B is a non-ring, and A is a benzene ring and B is a pyridine ring, or More preferably, A is a non-ring and B is a pyridine ring.
R _{13 to} R ₁₆ represent a hydrogen atom, an alkyl group, an aryl group, a silyl group, or a heterocyclic group, and R ₁₄ and R ₁₅ , or R ₁₃ and R ₁₆ may be bonded to each other to form a cyclic structure. .
The alkyl group represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. As said alkyl group, C1-C12 is preferable, for example, a methyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group etc. are mentioned.
The aryl group represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms and may be condensed, and examples thereof include a phenyl group, a toluyl group, and a naphthyl group.
The silyl group represents a silyl group substituted with a carbon atom having 3 to 24 carbon atoms, and may be any of a trialkylsilyl group, an aryldialkylsilyl group, an alkyldiarylsilyl group, and a triarylsilyl group. As said silyl group, C3-C18 is preferable and a trimethylsilyl group, t-butyldimethylsilyl group, a triphenylsilyl group, t-butyldiphenylsilyl group, etc. are mentioned.
Examples of the heterocyclic group include pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring, thiophene ring, furan A ring etc. are mentioned.

R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are each preferably a substituted or unsubstituted aryl group, or an aromatic ring in which R ₁₃ and R ₁₆ , and R ₁₄ and R ₁₅ are bonded to each other. Examples of the aromatic ring include a benzene ring. The aromatic ring may further have a substituent, for example, an alkyl group (methyl group, butyl group, pentyl group, hexyl group, octyl group, decyl group), alkoxy group (methoxy group, ethoxy group, butoxy group). Etc.).
Among these, an aromatic ring in which R ₁₃ and R ₁₆ , R ₁₄ and R ₁₅ are bonded to each other is preferable from the viewpoint of aspect ratio and molecular size.

  As a more preferable aspect of the compound represented by general formula (C-9), the compound of the following general formula (C-9-1) is mentioned.

In the formula, B may form an aromatic 6-membered heterocycle.
R _{17 to} R ₂₆ each independently represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and R ₁₇ and R ₁₈ , R ₁₈ and R ₁₉ , R ₁₉ and R ₂₀ , R ₂₁ and R ₂₂ , R ₂₂ and R ₂₃ , R ₂₃ and R ₂₄ , and R ₂₅ and R ₂₆ may be bonded to each other to form a cyclic structure. Preferred examples of the alkyl group, aryl group, alkoxy group, aryloxy group, cyano group, silyl group, and heterocyclic group represented by R _{17 to} R ₂₆ are the same as the examples of each group represented by R _{13 to} R _26. .
R ₁₇ , R ₂₀ , R ₂₁ and R ₂₄ are preferably a hydrogen atom or an alkyl group.
R ₁₈ , R ₁₉ , R ₂₂ and R ₂₃ are preferably an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a fluorine atom, a cyano group or a silyl group, more preferably an alkyl group or an alkoxy group, a decyloxy group or a dodecyl group. An oxy group is more preferable.
R _{25 to} R ₂₆ are preferably a hydrogen atom, an alkyl group, a fluorine atom, or an aromatic ring in which R ₂₅ and R ₂₆ are bonded.
The aromatic 6-membered heterocycle represented by B is preferably a pyridine ring or a pyrimidine ring, and more preferably a pyridine ring. The ring may have a substituent, and examples of the substituent include an alkyl group (methyl group and butyl group) and an aryl group (phenyl group).

  The platinum complex is preferably a platinum complex represented by the general formula (C-1) from the viewpoint of planarity, and is represented by any one of the general formulas (C-2), (C-7), and (C-9). The platinum complex is more preferably a platinum complex represented by the general formula (C-2) or (C-9). The platinum complex represented by the general formula (C-2) is a platinum complex represented by any one of the general formulas (C-3), (C-4), (C-5), and (C-6). The platinum complex is more preferably a platinum complex represented by any one of the general formulas (C-3-1), (C-5-1), and (C-6). A platinum complex represented by -5-1) or (C-6) is particularly preferable.

Specific examples of the platinum complex represented by the general formula (C-1) include [0143] to [0152], [0157] to [0158], and [0162] to [0168] of JP-A-2005-310733. The compounds described in JP-A-2006-256999, [0065] to [0083], the compounds described in JP-A-2006-93542, [0065] to [0090], JP-A-2007-73891 Nos. [0063] to [0071], No. 2007-324309, No. 0079 to [0083], No. 2006-93542 No. [0065] to [0090] The compounds described in JP-A-2007-96255, [0055] to [0071], JP-A-2006-313796 0043] include - [0046], platinum complexes exemplified other following can be mentioned.
Examples of the platinum complex represented by the general formula (C-1) and other platinum complexes having an aspect ratio of 3 or more are given below. In addition, the alkyl group and the alkyl group in the exemplary compound include a linear alkyl group, a branched alkyl group, and a cycloalkyl group, and preferably a linear alkyl group.

Examples of the platinum complex compound represented by the general formula (C-1) include Journal of Organic Chemistry 53,786, (1988), G.S. R. Newkome et al. ), Page 789, method described in left line 53 to right line 7, line 790, method described in left line 18 to line 38, method 790, method described in right line 19 line to line 30 and The combination, Chemische Berichte 113, 2749 (1980), H.C. Lexy et al.), Page 2752, lines 26-35, and the like.
For example, a ligand or a dissociated product thereof and a metal compound are mixed with a solvent (for example, a halogen solvent, an alcohol solvent, an ether solvent, an ester solvent, a ketone solvent, a nitrile solvent, an amide solvent, a sulfone solvent, In the presence of a sulfoxide solvent, water, etc., or in the absence of a solvent, in the presence of a base (inorganic or organic bases such as sodium methoxide, t-butoxypotassium, triethylamine, potassium carbonate, etc.) Or in the absence of a base, at room temperature or below, or by heating (in addition to normal heating, a method of heating with a microwave is also effective).

(Fluorescent material)
Examples of the fluorescent light-emitting material include pyrene derivatives, perylene derivatives, fluoranthene derivatives, chrysene derivatives, and coumarin derivatives. Of these, pyrene derivatives, perylene derivatives, fluoranthene derivatives, and chrysene derivatives are preferable from the viewpoint of material stability.

[Pyrene derivatives]
A conventionally known pyrene derivative can be used as the pyrene derivative, but a compound represented by the following general formula (P-1) is preferably used.
Formula (P-1)

(Wherein R _P ^{1 to} R _P ¹⁰ each independently represents a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, an alkenyl group which may have a substituent, or a substituent. An alkynyl group which may have a substituent, an alkyl group which may have a substituent, a silyl group which may have a substituent, a heterocyclic group which may have a substituent, and a substituent. An alkylamino group which may have a substituent and an arylamino group which may have a substituent, and at least one of R _P ^{1 to} R _P ¹⁰ is a substituent other than a hydrogen atom.)

_<R ^P 1 ~R ^{P 10>}
(Types of substituents R _P ^{1 to} R _P ¹⁰ )
R _P ^{1 to} R _P ¹⁰ may each independently have a hydrogen atom, an aromatic hydrocarbon group that may have a substituent, an alkyl group that may have a substituent, or a substituent. A good silyl group, a heterocyclic group which may have a substituent, an alkylamino group which may have a substituent, and an arylamino group which may have a substituent are represented. These may be bonded to each other and condensed.
At least one of R _P ^{1 to} R _P ¹⁰ is a substituent other than a hydrogen atom.

When two or more of R _P ^{1 to} R _P ¹⁰ are substituents other than hydrogen atoms, the substituents other than a plurality of hydrogen atoms may be the same or different. It is preferable that they are the same in terms of ease of synthesis, and are preferably different in that the emission wavelength can be tuned.

Further, in terms of obtaining high luminous efficiency, the substituents other than the hydrogen atoms of R _P ^{1 to} R _P ¹⁰ may have an aromatic hydrocarbon group which may have a substituent, or a substituent. A good silyl group is preferable, and an aromatic hydrocarbon group which may have a substituent is particularly preferable. In terms of obtaining light emission with a narrow half-value width, the substituents other than the hydrogen atoms of R _P ^{1 to} R _P ¹⁰ are an alkyl group which may have a substituent and an aryl which may have a substituent. An amino group and a heterocyclic group which may have a substituent are preferable, and R _P ¹ , R _P ^{3 to} R _P ⁶ and R _P ^{8 to} R _P ¹⁰ are hydrogen in terms of obtaining a long emission wavelength. An aromatic hydrocarbon which may have a substituent as a substituent other than an atom, an alkenyl group which may have a substituent, and a heterocyclic group which may have a substituent are preferable.

As the aromatic hydrocarbon group of R _P ^{1 to} R _P ¹⁰ , those having 6 to 16 carbon atoms are preferable, and specific examples include phenyl group, biphenyl group, phenanthryl group, naphthyl group, anthryl group, fluorenyl group and the like. It is done.
As the alkyl group represented by R _P ^{1 to} R _P ¹⁰ , an alkyl group having 1 to 10 carbon atoms is preferable, and specific examples include i-propyl group, t-butyl group, cyclohexyl group and the like.
The silyl group represented by R _P ^{1 to} R _P ¹⁰ is preferably one having 3 to 20 carbon atoms, and specific examples include trimethylsilyl group, dimethylphenylsilyl group, dimethylbutylsilyl group, triisopropylsilyl group, methyldibutylsilyl group. Etc.
As the heterocyclic group represented by R _P ^{1 to} R _P ¹⁰ , those having 3 to 10 carbon atoms are preferable, and specific examples include pyridyl group, thienyl group, oxazole group, oxadiazole group, benzothienyl group, dibenzofuryl group. , Dibenzothienyl group, pyrazyl group, pyrimidyl group, pyrazoyl group, imidazolyl group, phenylcarbazoyl group and the like.
The alkylamino group represented by R _P ^{1 to} R _P ¹⁰ is preferably an alkylamino group having 1 to 10 carbon atoms, and specific examples include a dimethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, and the like.
The arylamino group represented by R _P ^{1 to} R _P ¹⁰ is preferably an arylamino group having 6 to 30 carbon atoms, and specific examples thereof include a diphenylamino group, a carbazoyl group, and a phenylnaphthylamino group.

  These substituents may further have a substituent. Further, the substituents that may be included are aryl group, arylamino group, alkyl group, perfluoroalkyl group, halide group, carboxyl group, cyano group, alkoxyl group, aryloxy group, carbonyl group, oxycarbonyl group, carboxyl group An acid group, a heterocyclic group, etc. are mentioned. Preferably, an aryl group having 6 to 16 carbon atoms, an arylamino group having 12 to 30 carbon atoms, an alkyl group having 1 to 12 carbon atoms, a perfluoroalkyl group having 1 to 12 carbon atoms, a fluoride group, and 1 to 10 carbon atoms. Oxycarbonyl groups, cyano groups, alkoxy groups having 1 to 10 carbon atoms, aryloxy groups having 6 to 16 carbon atoms, carbonyl groups having 2 to 16 carbon atoms, heterocyclic groups having 5 to 20 carbon atoms, and the like.

Further, among the substituents that may be included, examples of the aryl group having 6 to 16 carbon atoms include a phenyl group, a naphthyl group, and a phenanthryl group.
Examples of the arylamino group having 12 to 30 carbon atoms include a diphenylamino group, a carbazoyl group, and a phenylcarbazoyl group.
Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a butyl group, an i-propyl group, a neopentthiol group, and a t-butyl group.
A trifluoromethyl group etc. are mentioned as an example of a C1-C12 perfluoroalkyl group.
Examples of the oxycarbonyl group having 1 to 10 carbon atoms include a methoxycarbonyl group and an ethoxycarbonyl group.
Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group and an ethoxy group.
Examples of the aryloxy group having 6 to 16 carbon atoms include a phenyloxy group.
Examples of the carbonyl group having 2 to 16 carbon atoms include an acetyl group and a phenylcarbonyl group.
Examples of the heterocyclic group having 5 to 20 carbon atoms include pyridyl group, thienyl group, oxazole group, oxadiazole group, benzothienyl group, dibenzofuryl group, dibenzothienyl group, pyrazyl group, pyrimidyl group, pyrazoyl group, and imidazoyl. Group and the like.
Among the substituents that R _P ^{1 to} R _P ¹⁰ and R _P ^{1 to} R _P ^{10 described above} may have, an electron donating group such as an arylamino group and an alkoxy group, a thienyl group, and a benzothienyl group And the like contribute to the increase in the emission wavelength of the compound (P-1). Thus the substituent that may be _R ^P 1 _~R ^{P 10} and _R ^P 1 _~R ^{P 10} has, by selecting these substituents, can be obtained that exhibit a green light emission.

Of the compounds (P-1), particularly preferred are the following general formulas (P-1a), (P-1b), (P-1c), (P-1d), or (P-1e). In the following general formulas (P-1a), (P-1b), (P-1c), (P-1d), and (P-1e), R _P ^{1 to} R _P ¹⁰ are It is synonymous with R _P ^{1 to} R _P ¹⁰ in General Formula (P-1), and R _P ¹ and R _P ² , R _P ⁶ and R _P ⁷ in General Formula (P-1c), and General Formula (P _R ^{P 1} and _R ^P _{10, R} ^{P 5} and _R ^{P 6} in -1d), the general formula _(R ^{P 9} and _R ^P 10 in the _{^P-1e), R} P ⁴ and _R ^{P 5} is bonded to each other to form a ring The ring formed here is preferably a 5- or 6-membered ring, more preferably a 6-membered ring.

  Specific examples of pyrene derivatives that can be used in the present invention are shown below, but the present invention is not limited thereto.

  The pyrene derivatives represented by the general formulas (P-1a) to (P-1e) can be synthesized according to the following scheme.

[Perylene derivatives]
As the perylene derivative, a conventionally known perylene derivative can be used, but a compound represented by the following general formula (PE-1) is preferably used.
General formula (PE-1)

In the formula, R _PE ^{1 to} R _PE ⁴ are each independently an alkyl group, an aryl group, a heterocyclic group, an amino group, a silyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an alkoxy group, or an aryloxy group. Represents a group, a heteroaryloxy group, an alkylthio group, or an arylthio group, which may have a substituent. These may be bonded to each other to form a ring.
n _PE ¹ ~n _PE ⁴ each independently represents an integer of 0 to 3. When n _PE ^{1 to} n _PE ⁴ is 2 or more, the plurality of R _PE ^{1 to} R _PE ⁴ may be bonded to each other to form a ring.
Further, the hydrogen atom in the formula may be a deuterium atom.

R _PE ^{1 to} R _PE ⁴ are preferably an alkyl group, an aryl group, a heterocyclic group, an amino group, a silyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkylthio group or an arylthio group, and an alkyl group or an aryl group , A heterocyclic group, an amino group, and a silyl group are more preferable. These groups may have a substituent, and examples of the substituent include the groups mentioned in the above-mentioned substituent group A. In the case of having a plurality of substituents, the substituents may be linked to form a ring.
n _PE ¹ ~n _PE ⁴ is preferably 0-2, 0-1 is more preferable.

As the compound represented by the general formula (PE-1), a compound represented by any one of the following general formulas (PE-1a) to (PE-1f) is preferable.
In the general formulas (PE-1a) to (PE-1f), R _pe is each independently an alkyl group, aryl group, heterocyclic group, amino group, silyl group, alkyloxycarbonyl group, aryloxycarbonyl group, carbamoyl. A group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkylthio group, and an arylthio group; These may further have a substituent. Furthermore, R _pe in the general formulas (PE-1d) to (PE-1f) independently form a 5-membered or 6-membered ring, and the ring may further have a substituent.
Further, the hydrogen atoms in the general formulas (PE-1a) to (PE-1f) may be deuterium atoms.

_Rpe is preferably an alkyl group (such as a methyl group, a propyl group, or a butyl group), an aryl group (such as a phenyl group or a naphthyl group), a heterocyclic group (such as a pyridyl group), an amino group, a silyl group, or an amide group. It is.
_Examples of the substituent that the ring formed by R _pe and R _pe may have include an alkyl group (such as a methyl group and a butyl group) and an aryl group (such as a phenyl group).

  Specific examples of perylene derivatives that can be used in the present invention are shown below, but the present invention is not limited thereto.

  The perylene derivative represented by the general formula (PE-1) can be synthesized according to the following scheme.

In the above scheme, R _pe has the same _{meaning as} R _PE ^{1 to} R _PE ⁴ in formula (PE-1). X represents a halogen atom.

[Fluoranthene derivative]
As the fluoranthene derivative, a conventionally known fluoranthene derivative can be used, but a compound represented by the following general formula (F-1) is preferably used.
Formula (F-1)

(In the formula, R _F ^{1 to} R _F ¹⁰ each independently represent a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, an alkenyl group which may have a substituent, or a substituent. An alkynyl group which may have a substituent, an alkyl group which may have a substituent, a silyl group which may have a substituent, a heterocyclic group which may have a substituent, and a substituent. An alkylamino group which may have a substituent and an arylamino group which may have a substituent, at least one of R _F ^{1 to} R _F ¹⁰ is a substituent other than a hydrogen atom.)

<R _F ^{1 to} R _F ¹⁰ >
(Types of substituents R _F ^{1 to} R _F ¹⁰ )
R _F ^{1 to} R _F ¹⁰ may each independently have a hydrogen atom, an aromatic hydrocarbon group that may have a substituent, an alkyl group that may have a substituent, or a substituent. A good silyl group, a heterocyclic group which may have a substituent, an alkylamino group which may have a substituent, and an arylamino group which may have a substituent are represented. These may be bonded to each other and condensed.
At least one of R _F ^{1 to} R _F ¹⁰ is a substituent other than a hydrogen atom.

When two or more of R _F ^{1 to} R _F ¹⁰ are substituents other than hydrogen atoms, the substituents other than a plurality of hydrogen atoms may be the same or different. It is preferable that they are the same in terms of ease of synthesis, and are preferably different in that the emission wavelength can be tuned.

The aromatic hydrocarbon group of R _F ^{1 to} R _F ¹⁰ is preferably one having 6 to 16 carbon atoms, and specific examples include phenyl group, biphenyl group, phenanthryl group, naphthyl group, anthryl group, fluorenyl group and the like. It is done.
The alkyl group represented by R _F ¹ ~R _F ^10, preferably has 1 to 10 carbon atoms, specific examples are i- propyl, t- butyl group, a cyclohexyl group.
The silyl group represented by R _F ^{1 to} R _F ¹⁰ is preferably one having 3 to 20 carbon atoms, and specific examples include trimethylsilyl group, dimethylphenylsilyl group, dimethylbutylsilyl group, triisopropylsilyl group, and methyldibutylsilyl group. Etc.
The heterocyclic group represented by R _F ^{1 to} R _F ¹⁰ is preferably one having 3 to 10 carbon atoms, and specific examples include pyridyl group, thienyl group, oxazole group, oxadiazole group, benzothienyl group, dibenzofuryl group. , Dibenzothienyl group, pyrazyl group, pyrimidyl group, pyrazoyl group, imidazolyl group, phenylcarbazoyl group and the like.
The alkylamino group represented by R _F ^{1 to} R _F ¹⁰ is preferably an alkylamino group having 1 to 10 carbon atoms, and specific examples include a dimethylamino group, a diethylamino group, a dipropylamino group, and a dibutylamino group.
The arylamino group represented by R _F ^{1 to} R _F ¹⁰ is preferably an arylamino group having 6 to 30 carbon atoms, and specific examples thereof include a diphenylamino group, a carbazoyl group, and a phenylnaphthylamino group.

  These substituents may further have a substituent. Further, the substituents that may be included are aryl group, arylamino group, alkyl group, perfluoroalkyl group, halide group, carboxyl group, cyano group, alkoxyl group, aryloxy group, carbonyl group, oxycarbonyl group, carboxyl group An acid group, a heterocyclic group, etc. are mentioned. Preferably, an aryl group having 6 to 16 carbon atoms, an arylamino group having 12 to 30 carbon atoms, an alkyl group having 1 to 12 carbon atoms, a perfluoroalkyl group having 1 to 12 carbon atoms, a fluoride group, and 1 to 10 carbon atoms. Oxycarbonyl groups, cyano groups, alkoxy groups having 1 to 10 carbon atoms, aryloxy groups having 6 to 16 carbon atoms, carbonyl groups having 2 to 16 carbon atoms, heterocyclic groups having 5 to 20 carbon atoms, and the like.

Further, among the substituents that may be included, examples of the aryl group having 6 to 16 carbon atoms include a phenyl group, a naphthyl group, and a phenanthryl group.
Examples of the arylamino group having 12 to 30 carbon atoms include a diphenylamino group, a carbazoyl group, and a phenylcarbazoyl group.
Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a butyl group, an i-propyl group, a neopentthiol group, and a t-butyl group.
A trifluoromethyl group etc. are mentioned as an example of a C1-C12 perfluoroalkyl group.
Examples of the oxycarbonyl group having 1 to 10 carbon atoms include a methoxycarbonyl group and an ethoxycarbonyl group.
Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group and an ethoxy group.
Examples of the aryloxy group having 6 to 16 carbon atoms include a phenyloxy group.
Examples of the carbonyl group having 2 to 16 carbon atoms include an acetyl group and a phenylcarbonyl group.
Examples of the heterocyclic group having 5 to 20 carbon atoms include pyridyl group, thienyl group, oxazole group, oxadiazole group, benzothienyl group, dibenzofuryl group, dibenzothienyl group, pyrazyl group, pyrimidyl group, pyrazoyl group, and imidazoyl. Group and the like.
Among the substituents that R _F ^{1 to} R _F ¹⁰ and R _F ^{1 to} R _F ^{10 described above} may have, an electron donating group such as an arylamino group and an alkoxy group, a thienyl group, and a benzothienyl group And the like contribute to the increase in the emission wavelength of the compound represented by formula (F-1). Thus the substituent that may be _R ^F 1 _~R ^{F 10} and _R ^F 1 _~R ^{F 10} has, by selecting these substituents, can be obtained that exhibit a green light emission.

  Specific examples of the fluoranthene derivative that can be used in the present invention are shown below, but the present invention is not limited thereto.

  The content of the light emitting material in the organic electroluminescent element material is preferably 0.1% by mass to 30% by mass, more preferably 1% by mass to 25% by mass, and particularly preferably 5% by mass to 20% by mass.

In the organic electroluminescent element, it is preferable to orient the transition dipole moment of the luminescent material horizontally with respect to the anode. Since the transition dipole moment of the luminescent material is oriented horizontally with respect to the anode, the luminous component in the vertical direction with respect to the anode is increased, which is advantageous in that the light extraction efficiency is improved and the luminous efficiency is improved. is there. For this reason, the ratio of the horizontal alignment component of the transition dipole moment of the light emitting material in the light emitting layer is preferably greater than 85%, and more preferably 90% or greater.
The direction of the transition dipole moment is defined as follows by theoretical calculation. The theoretical calculation here is performed using Gaussian 03 (Gaussian, USA). As the molecular structure used for the calculation, the direction of the transition dipole moment can be obtained by performing the structure optimization calculation and using the structure having the minimum generation energy.
Or after forming a light emitting layer, it can also measure by an ATR-IR measuring method or a grazing incidence UV measuring method.

(Host material)
The host material used in the present invention has an aspect ratio (molecular length / molecular thickness) of 2 or less, preferably 1 to 1.9, and preferably 1.3 to 1.9 from the viewpoint of suppressing crystallization in the light emitting layer. Is more preferable.
When the aspect ratio of the host material is larger than 2, the host material is likely to be regularly arranged, so that the crystallinity of the film formed using the host material is increased and the durability is deteriorated.

  The molecular radius of the host material is preferably 0.40 nm to 3.0 nm, more preferably 0.45 nm to 2.0 nm, and particularly preferably 0.5 nm to 1.5 nm. This range is preferable from the viewpoints of improving the orientation, ease of controlling the emission intensity and emission wavelength, and the like.

  The host material used in the present invention is not particularly limited as long as the aspect ratio is 2 or less and the size ratio with the light emitting material satisfies a relationship of 0.8 to 1.2. Preferably there is.

  Examples of structures having an aspect ratio of 2 or less include those having quaternary carbon, quaternary silicon, ortho-linking, meta-linking, and metal elements in the center, and preferably having a molecular structure twisted by a substituent. Can be mentioned. Preferably, it is a compound represented by any one of the following general formulas (H-1) to (H-4).

In formula ^{(H-1), Z 100} ~Z 103 each independently represent an alkyl group, an aromatic ring comprising a 5-membered or 6-membered ring substituted or unsubstituted, is it are further condensed with an aromatic ring Good. Z ^{100 to} Z ¹⁰³ may be bonded to each other via a single bond or a divalent to tetravalent linking group to form a condensed ring. A ′ represents a carbon atom or a silicon atom.
In the general formula (H-2), Z ¹⁰⁴ and Z ¹⁰⁵ each independently represents an alkyl group, a substituted or unsubstituted 5-membered or 6-membered aromatic ring, and these may be further condensed with an aromatic ring. Good. Z ¹⁰⁴ and Z ¹⁰⁵ , Z ¹⁰⁴ and B ′, and Z ¹⁰⁵ and B ′ may be bonded via a single bond or a divalent to tetravalent linking group to form a condensed ring. B ′ represents a carbon atom or a nitrogen atom which may have a substituent, and a plurality of B ′ may be the same or different.
In the general formula (H-3), Z ¹⁰⁶ and Z ¹⁰⁷ each independently represent an alkyl group, a substituted or unsubstituted 5-membered or 6-membered aromatic ring, and these may be further condensed with an aromatic ring. Good. Z ¹⁰⁶ and Z ¹⁰⁷ , Z ¹⁰⁶ and B ′, and Z ¹⁰⁷ and B ′ may be bonded to each other via a single bond or a divalent to tetravalent linking group to form a condensed ring. B ′ represents a carbon atom or a nitrogen atom which may have a substituent, and a plurality of B ′ may be the same or different.
In the general formula (H-4), Z ¹⁰⁸ and Z ¹⁰⁹ each independently represent an alkyl group, a substituted or unsubstituted 5-membered or 6-membered aromatic ring, and these may be further condensed with an aromatic ring. Good. M ′ represents a divalent to tetravalent metal atom, and L represents a coordination bond, a single bond, or a divalent linking group. n ′ represents an integer of 2 or 3, and a plurality of Z ¹⁰⁸ , Z ¹⁰⁹ , and L may be the same or different.

When Z ^{100 to} Z ¹⁰⁹ represent an alkyl group, the alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a neopentyl group, an isobutyl group, or a cyclohexyl group. Groups and the like.

When Z ^{100 to} Z ¹⁰⁹ represent an aromatic ring composed of a 5-membered or 6-membered ring, examples of the aromatic ring include a benzene ring, a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, a pyrazole ring, an oxazole ring, Examples include a thiazole ring, a triazole ring, an oxadiazole ring, a thiadiazole ring, a furan ring, and a thiophene ring. These may be further condensed with an aromatic ring, such as benzene ring, pyridine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, pyrazole ring, oxazole ring, thiazole ring, triazole ring, oxadiazole ring, thiadiazole ring. , A furan ring, a thiophene ring or the like. Examples of the structure formed by the condensed ring include a carbazole structure, a dibenzofuran structure, a dibenzothiophene structure, and a fluorene structure.

When Z ^{100 to} Z ¹⁰⁹ represent an aromatic ring composed of a 5-membered or 6-membered ring, the aromatic ring may have a substituent. The substituent is not particularly limited, and examples thereof include an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a heteroaryl group, an amino group, an alkylthio group, an arylthio group, and a silyl group. As an alkyl group, a C1-C10 alkyl group is preferable, and a methyl group, isopropyl, t-butyl, isobutyl, neopentyl, and cyclohexyl are specifically preferable. Examples of the aryl group include phenyl group, biphenyl group, naphthyl group, fluorene, dibenzothiophene, dibenzofuran, phenanthrene, anthracene and the like. As an alkoxy group, a C1-C6 alkoxy group is preferable, and a methoxy group, an ethoxy group, etc. are mentioned specifically ,. As the aryloxy group, an aryloxy group having 6 to 12 carbon atoms is preferable, and specific examples include a phenoxy group and a naphthyloxy group. The heteroaryl group is preferably a heteroaryl group having 2 to 10 carbon atoms, specifically, thiophene, thiazole, thiadiazole, furan, oxazole, oxadiazole, pyridine, pyrimidine, triazine, benzothiol, benzothiazole, benzofuran. Benzoxazole, quinoline, pyrrole, pyrazole, imidazole, triazole, benzopyrrole, benzopyrazole, benzimidazole and the like. Specific examples of the amino group include a diarylamino group, an N-aryl-N-alkylamino group, and a dialkylamino group. As an alkylthio group, a C1-C6 alkylthio group is preferable, and a methylthio group, an ethylthio group, etc. are mentioned specifically ,. As the arylthio group, an arylthio group having 6 to 12 carbon atoms is preferable, and specific examples include a phenylthio group and a naphthylthio group. As the silyl group, a silyl group having 3 to 18 carbon atoms is preferable, and specific examples include a trimethylsilyl group and a dimethylphenylsilyl group.
These substituents may further have a substituent. Examples of the further substituent include an alkyl group (for example, a methyl group, an isopropyl group, a t-butyl group, a neopentyl group, and an isobutyl group), an aryl group (for example, , Phenyl group, tolyl group, naphthyl group), silyl group (trimethylsilyl group) and the like. When the cyclic structure has a plurality of substituents, the plurality of substituents may be the same or different.

Examples of the substituent for B ′ include a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a heteroaryl group, an amino group, an alkylthio group, an arylthio group, and a silyl group. The preferred range is the same as the substituent that the aromatic ring may have when Z ^{100 to} Z ¹⁰⁹ represent an aromatic ring composed of a 5-membered or 6-membered ring.

  Examples of the metal atom represented by M ′ include aluminum, gallium, indium, beryllium, magnesium, titanium, zirconium, zinc, copper, and the like, and aluminum, beryllium, and zinc are preferable from the viewpoint of the stability of the complex.

  L represents a coordination bond, a single bond, or a divalent linking group, and examples of the divalent linking group include a nitrogen atom, an oxygen atom, and a sulfur atom.

Z ^{100 to} Z ¹⁰³ , Z ¹⁰⁴ and Z ¹⁰⁵ , Z ¹⁰⁴ and B ′, Z ¹⁰⁵ and B ′, Z ¹⁰⁶ and Z ¹⁰⁷ , Z ¹⁰⁶ and B ′, Z ¹⁰⁷ and B ′ are each a single bond or 2- to 4-valent. And a condensed ring may be formed. As the divalent to tetravalent linking group, an oxygen atom, a sulfur atom, an optionally substituted carbon atom, a nitrogen atom, or a silicon atom may be used. Can be mentioned. Examples of the substituent include an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a heteroaryl group, an amino group, an alkylthio group, an arylthio group, and a silyl group. The preferred range is the same as the substituent that the aromatic ring may have when Z ^{100 to} Z ¹⁰⁹ represent an aromatic ring composed of a 5-membered or 6-membered ring.

  A compound represented by the following general formula (H-5) is also preferred as a structure having an aspect ratio of 2 or less.

In general formula (H-5), Z ¹¹⁰ and Z ¹¹¹ each independently represent an alkyl group, a substituted or unsubstituted aromatic ring composed of 6 or 6 members, and these may be further condensed with an aromatic ring. Good. Z ¹¹⁰ and Z ¹¹¹ may be bonded to each other via a single bond or a divalent to tetravalent linking group to form a condensed ring. X ′ represents a carbon atom, an oxygen atom, a nitrogen atom, or a sulfur atom, and the carbon atom or the nitrogen atom may have a substituent.

Z ¹¹⁰ and Z ¹¹¹ have the same meanings as Z ^{100 to} Z ¹⁰⁹ , and preferred ranges thereof are also the same, but a carbazole ring, a dibenzofuran ring, and a dibenzothiophene ring are particularly preferred, and these may further have a substituent.
X ′ preferably represents an oxygen atom, a nitrogen atom, or a sulfur atom, and the nitrogen atom may have a substituent (preferably an aryl group).

  Specific examples of the host material having an aspect ratio of 2 or less are shown below, but the present invention is not limited to these compounds.

  70 mass%-99.9 mass% are preferable, as for content of the host material in an organic electroluminescent element material, 75 mass%-99 mass% are more preferable, and 80 mass%-95 mass% are especially preferable.

〔film〕
With the organic electroluminescent element material of the present invention, it is possible to obtain a film in which the orientation of the host material and the light emitting material is high and the amorphous property is good. The film is preferably formed by a vacuum deposition process from the viewpoint of orientation, but a film having both good orientation and amorphous properties can be obtained by a coating process (wet process). The film can be used as a light-emitting layer of an organic electroluminescence device, and has a high orientation, so that the light extraction efficiency is excellent, and since the amorphous property is good, a highly durable light-emitting layer can be obtained.

[Organic electroluminescence device]
The organic electroluminescent element in the present invention will be described in detail.
The organic electroluminescent element in the present invention is an organic electroluminescent element having a pair of electrodes including an anode and a cathode and at least one organic layer including a light emitting layer between the electrodes on a substrate, A planar light emitting material having an aspect ratio (molecular length / molecular thickness) of 3 or more and a host material having an aspect ratio (molecular length / molecular thickness) of 2 or less of the molecular length and molecular thickness; The size ratio of the molecular radius of the light emitting material to the molecular radius of the host material (molecular radius of the light emitting material / molecular radius of the host material) is 0.8 to 1.2.

In the organic electroluminescent element of the present invention, the light emitting layer is an organic layer, and further includes at least one organic layer between the light emitting layer and the anode, but may further have an organic layer in addition to these.
In view of the properties of the light-emitting element, at least one of the anode and the cathode is preferably transparent or translucent.
FIG. 1 shows an example of the configuration of an organic electroluminescent device according to the present invention.
In the organic electroluminescent element 10 according to the present invention shown in FIG. 1, a light emitting layer 6 is sandwiched between an anode 3 and a cathode 9 on a support substrate 2. Specifically, a hole injection layer 4, a hole transport layer 5, a light emitting layer 6, a hole block layer 7, and an electron transport layer 8 are laminated in this order between the anode 3 and the cathode 9.

<Structure of organic layer>
There is no restriction | limiting in particular as a layer structure of the said organic layer, Although it can select suitably according to the use and objective of an organic electroluminescent element, It is preferable to form on an anode or a cathode. In this case, the organic layer is formed on the front surface or one surface on the anode or the cathode.
There is no restriction | limiting in particular about the shape of a organic layer, a magnitude | size, thickness, etc., According to the objective, it can select suitably.

Specific examples of the layer configuration include the following, but the present invention is not limited to these configurations.
Anode / hole transport layer / light emitting layer / electron transport layer / cathode,
Anode / hole transport layer / light emitting layer / block layer / electron transport layer / cathode,
Anode / hole transport layer / light emitting layer / block layer / electron transport layer / electron injection layer / cathode,
Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode,
Anode / hole injection layer / hole transport layer / light emitting layer / block layer / electron transport layer / cathode,
Anode / hole injection layer / hole transport layer / light emitting layer / block layer / electron transport layer / electron injection layer / cathode.
The element configuration, the substrate, the cathode, and the anode of the organic electroluminescence element are described in detail in, for example, Japanese Patent Application Laid-Open No. 2008-270736, and the matters described in the publication can be applied to the present invention.

<Board>
The substrate used in the present invention is preferably a substrate that does not scatter or attenuate light emitted from the organic layer. In the case of an organic material, it is preferable that it is excellent in heat resistance, dimensional stability, solvent resistance, electrical insulation, and workability.

<Anode>
The anode usually only needs to have a function as an electrode for supplying holes to the organic layer, and there is no particular limitation on the shape, structure, size, etc., depending on the use and purpose of the light-emitting element, It can select suitably from well-known electrode materials. As described above, the anode is usually provided as a transparent anode.

<Cathode>
The cathode usually has a function as an electrode for injecting electrons into the organic layer, and there is no particular limitation on the shape, structure, size, etc., and it is known depending on the use and purpose of the light-emitting element. The electrode material can be selected as appropriate.

  Regarding the substrate, anode, and cathode, the matters described in paragraphs [0070] to [0089] of JP-A-2008-270736 can be applied to the present invention.

<Organic layer>
The organic layer in the present invention will be described.

[Formation of organic layer]
In the organic electroluminescence device of the present invention, each organic layer is preferably formed by any of dry processes such as vacuum deposition and sputtering, and wet processes such as transfer, printing, spin coating, and bar coating. Can be formed. As a dry method, a vacuum deposition method, a sputtering method, etc. can be used. As a wet method (wet film forming method), a dipping method, a spin coating method, a dip coating method, a casting method, a die coating method, a roll coating method, a bar coating method, A gravure coating method, a spray coating method, an ink jet method, or the like can be used.
These film forming methods can be appropriately selected according to the material of the organic layer.
When the film is formed by a wet method, it may be dried after the film is formed. Drying is performed by selecting conditions such as temperature and pressure so that the coating layer is not damaged.

The coating solution used in the wet film-forming method (coating process) usually comprises an organic layer material and a solvent for dissolving or dispersing it. A solvent is not specifically limited, What is necessary is just to select according to the material used for an organic layer. Specific examples of the solvent include halogen solvents (chloroform, carbon tetrachloride, dichloromethane, 1,2-dichloroethane, chlorobenzene, etc.), ketone solvents (acetone, methyl ethyl ketone, diethyl ketone, n-propyl methyl ketone, cyclohexanone, etc.), Aromatic solvents (benzene, toluene, xylene, etc.), ester solvents (ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, diethyl carbonate, etc.), ether solvents (Tetrahydrofuran, dioxane, etc.), amide solvents (dimethylformamide, dimethylacetamide, etc.), dimethyl sulfoxide, alcohol solvents (methanol, propanol, butanol, etc.), water and the like.
The solid content with respect to the solvent in the coating solution is not particularly limited, and the viscosity of the coating solution can be arbitrarily selected according to the film forming method.

[Light emitting layer]
In the organic electroluminescent element of the present invention, the light emitting layer contains the aforementioned organic electroluminescent element material of the present invention.
As the light emitting material, from the viewpoint of orientation, the light emitting material having high planarity described above is preferable, a phosphorescent light emitting material is preferable, and a platinum complex is more preferable. A luminescent material may be used independently or may use 2 or more types together.
The light emitting layer can be formed by a vacuum deposition process or a wet process. From the viewpoint of orientation, the light emitting layer is preferably formed by a vacuum deposition process.

  Although content in particular of the luminescent material in a light emitting layer is not restrict | limited, For example, it is preferable that it is 0.1-30 mass%, it is more preferable that it is 1-25 mass%, and it is 5-20 mass%. Particularly preferred.

The host compound is a compound that causes energy transfer from the excited state to the light-emitting material, and as a result, emits the emitted light.
In the organic electroluminescent element of the present invention, the light emitting layer contains the host material described above. 70 mass%-99.9 mass% are preferable, as for content in the light emitting layer of this host material, 75 mass%-99 mass% are more preferable, and 80 mass%-95 mass% are especially preferable.

  As the host material, materials other than the above-described host materials may be included. Specific examples thereof include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, Pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidene compounds, porphyrins Compounds, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives Bodies, distyrylpyrazine derivatives, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, phthalocyanine derivatives, metal complexes of 8-quinolinol derivatives, metal complexes having metal phthalocyanine, benzoxazole, benzothiazole, etc. as ligands, polysilane compounds , Conductive polymers such as poly (N-vinylcarbazole) derivatives, aniline copolymers, thiophene oligomers, polythiophenes, polythiophene derivatives, polyphenylene derivatives, polyphenylene vinylene derivatives, polyfluorene derivatives, and the like. A host compound may be used individually by 1 type, or may use 2 or more types together.

  The thickness of the light emitting layer is preferably 10 to 200 nm, more preferably 20 to 80 nm, from the viewpoint of suppressing an increase in driving voltage and preventing a short circuit.

(Hole injection layer, hole transport layer)
The organic electroluminescent element of the present invention may have a hole injection layer and a hole transport layer. The hole injection layer and the hole transport layer are layers having a function of receiving holes from the anode or the anode side and transporting them to the cathode side.
The hole injection layer and the hole transport layer are described in detail, for example, in JP-A-2008-270736 and JP-A-2007-266458, and the matters described in these publications can be applied to the present invention.

(Electron injection layer, electron transport layer)
The organic electroluminescent element of the present invention may have an electron injection layer and an electron transport layer. The electron injection layer and the electron transport layer are layers having a function of receiving electrons from the cathode or the cathode side and transporting them to the anode side. The electron injection material and the electron transport material used for these layers may be a low molecular compound or a high molecular compound.
The electron injection layer and the electron transport layer are described in detail, for example, in JP-A-2008-270736 and JP-A-2007-266458, and the matters described in these publications can be applied to the present invention.

(Hole blocking layer)
The hole blocking layer is a layer having a function of preventing holes transported from the anode side to the light emitting layer from passing through to the cathode side. In the present invention, a hole blocking layer can be provided as an organic layer adjacent to the light emitting layer on the cathode side.
As an example of the organic compound constituting the hole blocking layer, aluminum (III) bis (2-methyl-8-quinolinato) 4-phenylphenolate (Aluminum (III) bis (2-methyl-8-quinolinato) 4- aluminum complexes such as phenylphenolate (abbreviated as BAlq), triazole derivatives, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (2,9-Dimethyl-4,7-diphenyl-1,10-) phenanthroline derivatives such as phenanthroline (abbreviated as BCP), triphenylene derivatives, carbazole derivatives, and the like.
The thickness of the hole blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and still more preferably 10 nm to 100 nm.
The hole blocking layer may have a single layer structure made of one or more of the materials described above, or may have a multilayer structure made of a plurality of layers having the same composition or different compositions.

(Electronic block layer)
The electron blocking layer is a layer having a function of preventing electrons transported from the cathode side to the light emitting layer from passing through to the anode side. In the present invention, an electron blocking layer can be provided as an organic layer adjacent to the light emitting layer on the anode side.
As an example of the organic compound constituting the electron blocking layer, for example, those mentioned as the hole transport material described above can be applied.
The thickness of the electron blocking layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and even more preferably 10 nm to 100 nm.
The electron blocking 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.

[Other organic layers]
The organic electroluminescent device of the present invention has a protective layer described in JP-A-7-85974, 7-192866, 8-22891, 10-275682, 10-106746, etc. Also good. The protective layer is formed on the uppermost surface of the light emitting element. Here, when the base material, the transparent electrode, the organic layer, and the back electrode are laminated in this order, the top surface refers to the outer surface of the back electrode, and the base material, the back electrode, the organic layer, and the transparent electrode are laminated in this order. In some cases, it refers to the outer surface of the transparent electrode. The shape, size, thickness and the like of the protective layer are not particularly limited. The material for forming the protective layer is not particularly limited as long as it has a function of suppressing intrusion or permeation of a light-emitting element such as moisture or oxygen into the element. Silicon, germanium oxide, germanium dioxide or the like can be used.

  The method for forming the protective layer is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular sensing epitaxy, cluster ion beam, ion plating, plasma polymerization, plasma CVD, laser CVD Thermal CVD method, coating method, etc. can be applied.

[Sealing]
The organic electroluminescent element is preferably provided with a sealing layer for preventing moisture and oxygen from entering. As a material for forming the sealing layer, a copolymer of tetrafluoroethylene and at least one comonomer, a fluorinated copolymer having a cyclic structure in the copolymer main chain, polyethylene, polypropylene, polymethyl methacrylate, polyimide, Polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, chlorotrifluoroethylene or a copolymer of dichlorodifluoroethylene and another comonomer, a water-absorbing substance having a water absorption of 1% or more, a water absorption of 0. 1% or less moisture-proof material, metal (In, Sn, Pb, Au, Cu, Ag, Al, Tl, Ni, etc.), metal oxide (MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, _{CaO, BaO, Fe 2 O 3} , Y 2 O 3, TiO 2 , etc.), metal fluorides (M _{F 2, LiF, AlF 3,} CaF 2 , etc.), liquid fluorinated carbon (perfluoroalkane, perfluoro amines, perfluoroether, etc.), the liquid fluorinated carbon as dispersed adsorbent moisture or oxygen, etc. Can be used.

  The organic electroluminescence device of the present invention emits light by applying a direct current (which may include an alternating current component as necessary) voltage (usually 2 to 15 volts) or a direct current between the anode and the cathode. Can be obtained.

The driving method of the organic electroluminescence device of the present invention is described in JP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558, JP-A-8-234658, and JP-A-8-2441047. The driving method described in each publication, Japanese Patent No. 2784615, US Pat. Nos. 5,828,429, 6023308, and the like can be applied.
The organic electroluminescent element of the present invention can be suitably used for a display element, a display, a backlight, an electrophotography, an illumination light source, a recording light source, an exposure light source, a reading light source, a sign, a signboard, an interior, or optical communication. In particular, it is preferably used for a device that is driven in a region where light emission luminance is high, such as a light emitting device, a lighting device, and a display device.

The present invention will be described more specifically with reference to the following examples. The materials, reagents, substance amounts and ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.
Hereinafter, the mixing ratio of the solvent represents a volume ratio.

[Synthesis of Luminescent Material (Guest)]
The platinum complex in the present invention is described in, for example, Journal of Organic Chemistry 53,786, (1988), G.A. R. Newkome et al. ), Page 789, method described in left line 53 to right line 7, line 790, method described in left line 18 to line 38, method 790, method described in right line 19 line to line 30 and The combination, Chemische Berichte 113, 2749 (1980), H.C. Lexy et al.), Page 2752, lines 26-35, and the like.
For example, a ligand or a dissociated product thereof and a metal compound are mixed with a solvent (for example, a halogen solvent, an alcohol solvent, an ether solvent, an ester solvent, a ketone solvent, a nitrile solvent, an amide solvent, a sulfone solvent, In the presence of a sulfoxide solvent, water, etc., or in the absence of a solvent, in the presence of a base (inorganic or organic bases such as sodium methoxide, t-butoxypotassium, triethylamine, potassium carbonate, etc.) Or in the absence of a base, at room temperature or below, or by heating (in addition to normal heating, a method of heating with a microwave is also effective).

<Synthesis of D-1>

(Synthesis of Compound 1a)
5 drops of acetic acid was added dropwise to an ethanol solution (30 ml) of 2-hydroxy-4-methoxybenzaldehyde (1.6 g) and 4,5-dimethyl-1,2-phenylenediamine (0.73 g) with a 1 ml Komagome pipette. The reaction was carried out at 6 ° C. for 6 hours. The precipitated solid was collected by filtration and recrystallized with ethanol to obtain Compound 1a (2.0 g).
(Synthesis of D-1)
To a solution of compound 1a (0.9 g) and sodium acetate (0.19 g) in acetonitrile (30 ml), a solution of PtCl ₂ (0.61 g) in DMSO (dimethyl sulfoxide) (15 ml) was added dropwise at 80 ° C. for 7 hours. Reacted. The reaction solution was filtered and recrystallized with THF (tetrahydrofuran) to obtain D-1 (1.04 g). The compound was identified by elemental analysis, NMR and MASS spectrum.

<Synthesis of D-3>

  Under a nitrogen atmosphere, a 100 mL three-necked flask was charged with 10 g (78 mmol) of 3,3-dimethyl-2,4-pentanedione (A), 27.6 mL of dimethylformamide-dimethylacetal, and 60 mL of dimethylformamide for 18 hours at 150 ° C. It was made to react with. After the reaction solution was concentrated under reduced pressure, the residue was purified by silica gel chromatography (developing solution: ethyl acetate / methanol = 9/1) to obtain 4.83 g of Compound (B) (yield 26%).

  Under a nitrogen atmosphere, a 300 mL three-necked flask was charged with 2.70 g (21.0 mmol) of Compound (B), 1.19 g (23.8 mmol) of hydrazine monohydrate, and 200 mL of ethanol, and heated to reflux for 7 hours. The reaction solution was concentrated, and the residue was purified by silica gel chromatography (developing solution: ethyl acetate / ethanol = 8/2) to obtain 1.77 g of compound (C) (yield 89%).

  In a 200 mL three-necked flask under a nitrogen atmosphere, 1.00 g (4.20 mmol) of compound (C), 4.94 g (16.8 mmol) of 4-iododibenzofuran, 81.1 mg (0.567 mmol) of copper oxide, salicylaldoxime 311 mg (2.27 mmol), 7.39 g (38.3 mmol) of cesium carbonate and 100 mL of butyronitrile were charged and reacted at 140 ° C. for 16 hours. The reaction was filtered and concentrated. The obtained residue was purified by silica gel chromatography (developing solution: hexane / ethyl acetate = 10/1) to obtain 1.18 g of compound (D) (yield 55%). The compound was identified by elemental analysis, NMR and MASS spectrum.

  Under a nitrogen atmosphere, a 50 mL eggplant flask was charged with 0.51 g (1 mmol) of compound (D), 0.26 g (1 mmol) of platinum chloride and 30 mL of benzonitrile, and heated at 200 ° C. for 5 hours. After cooling to room temperature, 40 mL of hexane was added to the reaction solution, and the precipitated brown solid was purified by silica gel chromatography (developing solution: chloroform) to obtain 0.13 g of D-3. Yield 18%.

Example 1
The order parameter and crystallinity of the light emitting layer were evaluated as follows.
The cleaned quartz substrate is put in a vapor deposition apparatus, a film is formed by co-depositing the host material and the light emitting material shown in Table 1 below in a ratio (mass ratio) of 85:15, and the light emitting material is measured by ATR-IR deflection measurement. The order parameters were calculated. Moreover, the presence or absence of the crystal | crystallization in a film | membrane was confirmed with the polarizing microscope what passed for one week in a 40 degreeC thermostat after film preparation. The results are shown in Table 1.
In the table, “crystallinity” means “◯” when no crystal was observed with a polarizing microscope, and “X” when crystal was observed. It is preferable that no crystals are observed.

  As can be seen from the results in Table 1, a light emitting material having an aspect ratio of 3 or more and a host material having an aspect ratio of 2 or less were used, and the ratio of (light emitting material molecular radius / host material molecular radius) was 0.8 to 1. It can be seen that the examples of the present invention in the range of 2 give a high degree of horizontal orientation order S and no crystallinity is seen.

(Example 2)
<Element creation example 1>
A glass substrate having a thickness of 0.5 mm and a 2.5 cm square ITO film (manufactured by Geomat Co., Ltd., surface resistance 10 Ω / □) is placed in a cleaning container, subjected to ultrasonic cleaning in 2-propanol, and then subjected to UV-ozone treatment for 30 minutes. Went. The following organic compound layers were sequentially deposited on the transparent anode (ITO film) by vacuum deposition. The “Ω / □” has the same meaning as “Ω / sq.”.
First layer: HIL-1: film thickness 10 nm
Second layer: NPD: film thickness 30 nm
Third layer: H-1 and D-1 (mass ratio 95: 5): film thickness 30 nm
Fourth layer: ETL-1: film thickness 50 nm
On this, 1 nm of lithium fluoride and 70 nm of metal aluminum were vapor-deposited in this order, and it was set as the cathode.
This laminated body is put in a glove box substituted with nitrogen gas without being exposed to the atmosphere, and sealed with a glass sealing can and an ultraviolet curable adhesive (XNR5516HV, manufactured by Nagase Ciba Co., Ltd.). The device of the present invention 11 was obtained.
Similarly, each element was obtained using the material shown in Table 2 as the material of the third layer.

The performance of the device was evaluated as follows.
(A) External quantum efficiency Using a source measure unit 2400 manufactured by Toyo Technica, a direct current voltage was applied to each element to emit light, and the luminance was measured using a luminance meter BM-8 manufactured by Topcon Corporation. The emission spectrum and emission wavelength were measured using a spectrum analyzer PMA-11 manufactured by Hamamatsu Photonics. Based on these, the external quantum efficiency at a luminance of around 1000 cd / m ² was calculated by the luminance conversion method. The higher the number, the better the efficiency.

(B) Device durability Using a source measure unit 2400 manufactured by KEITHLEY, applying a constant current ( ^2.5 mA / cm ² ) at room temperature so that the initial light emission luminance is 1,000 cd / m ^2. The time until the light emission luminance decreased by 10% was measured. The emission luminance was measured with a luminance meter SR-3 manufactured by Topcon Corporation. The durability shown in Table 2 is shown as a relative value where the element of the eleventh aspect of the present invention is 1. The larger the number, the better the durability.

(Example 3)
Table 3 shows the results of fabricating an element in the same manner as in Example 2 except that the layer configuration was changed to the following, and performing the same evaluation as in Example 2. The durability shown in Table 3 was expressed as a relative value with 1.0 of the element of the present invention 15.
First layer: HIL-1: film thickness 10 nm
Second layer: HTL-2: film thickness 20 nm
Third layer: host materials and light emitting materials described in Table 3 (mass ratio = 93: 7): film thickness 30 nm
Fourth layer: ETL-2: film thickness 30 nm

Example 4
(Evaluation of organic electroluminescence device (coating))
-Preparation of coating solution for forming light emitting layer-
MEK (methyl ethyl ketone) (99.0% by mass) is mixed with the light emitting material (0.1% by mass) and the host material (0.9% by mass) shown in Table 4, and each coating solution for forming a light emitting layer is prepared. Got.

(Element fabrication procedure)
-Fabrication of organic electroluminescence device-
A transparent support substrate was formed by depositing ITO to a thickness of 150 nm on a 25 mm × 25 mm × 0.7 mm glass substrate. This transparent support substrate was etched and washed.
On this ITO glass substrate, 2 parts by mass of PTPDES-2 (manufactured by Chemipro Kasei, Tg = 205 ° C.) represented by the following structural formula was dissolved in 98 parts by mass of cyclohexanone for electronics industry (manufactured by Kanto Chemical), and the thickness was about After spin coating (2,000 rpm, 20 seconds) to 40 nm, a hole injection layer was formed by drying at 120 ° C. for 30 minutes and annealing at 160 ° C. for 10 minutes.

The light emitting layer forming coating solution was spin-coated (1,300 rpm, 30 seconds) to a thickness of about 40 nm on the hole injection layer to form a light emitting layer.
Next, BAlq was formed as an electron transport layer on the light emitting layer by a vacuum deposition method so as to have a thickness of 40 nm.

On the electron transport layer, lithium fluoride (LiF) was formed as an electron injection layer by a vacuum deposition method so as to have a thickness of 1 nm. Furthermore, 70 nm of metal aluminum was vapor-deposited to make a cathode.
The laminate produced as described above is placed in a glove box substituted with argon gas, and sealed using a stainless steel sealing can and an ultraviolet curable adhesive (XNR5516HV, manufactured by Nagase Ciba Co., Ltd.). Thereby, each organic electroluminescent element was produced.
Table 4 shows the result of evaluation similar to that of Example 2 for the obtained element. The durability shown in Table 4 is shown as a relative value where the element of the present invention 16 is 1.

  As can be seen from the results in Tables 2 to 4, a light emitting material having an aspect ratio of 3 or more and a host material having an aspect ratio of 2 or less were used, and the ratio of (light emitting material molecular radius / host material molecular radius) was 0.8. It turns out that the Example of this invention made into the range of 1.2 is excellent in efficiency and durability.

DESCRIPTION OF SYMBOLS 2 ... Substrate 3 ... Anode 4 ... Hole injection layer 5 ... Hole transport layer 6 ... Light emitting layer 7 ... Hole block layer 8 ... Electron transport layer 9 ...・ Cathode 10: Organic electroluminescent device

Claims (13)

An organic electroluminescent device having a pair of electrodes including an anode and a cathode on a substrate, and at least one organic layer including a light emitting layer between the electrodes,
The light emitting layer has a planar light emitting material having an aspect ratio (molecular length / molecular thickness) of molecular length to molecular thickness of 3 to 30 and an aspect ratio (molecular length / molecular thickness) of molecular length to molecular thickness. Containing at least 1 or more and 2 or less host material,
And molecular radius of the light emitting material, the size ratio of the molecular radius of the host material (molecular radius of molecular radius / host material of a light-emitting material), Ri 0.8-1.2 der,
The flat luminescent material is a fluorescent compound, or the following general formulas (C-3), (C-4), (C-5-1), (C-6), (C-7), An organic electroluminescent element, which is a platinum complex of a phosphorescent compound represented by any one of (C-8) and (C-9-1) .
(In General Formula (C-3), A ^{301 to} A ³¹³ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. L ³¹ represents a single bond or a divalent linkage. Y, Z, and M each independently represent a carbon atom or a nitrogen atom, and one of Z and Y is a nitrogen atom.)
(In General Formula (C-4), A ^{401 to} A ⁴¹⁴ each independently represent C—R or a nitrogen atom. R represents a hydrogen atom or a substituent. L ⁴¹ represents a single bond or a divalent linking group. Represents.)
(In General Formula (C-5-1), X, Y, and Z each independently represent a carbon atom or a nitrogen atom, and either Z or Y is a nitrogen atom, and Y is a nitrogen atom. When X is a carbon atom, m, n, p and q each independently represents an integer of 0 to 3. Ar represents a substituted or unsubstituted aryl group, and R _{1 to} R ₄ represent Each independently represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, and when m, n, p, and q are 2 or more, a plurality R _{1 to} R ₄ may be adjacent to each other to form a cyclic structure.)
(In General Formula (C-6), X, Y, and Z each independently represent a carbon atom or a nitrogen atom, and one of Z and Y is a nitrogen atom. When Y is a nitrogen atom, , X is a carbon atom, r, s, t and u each independently represents an integer of 0 to 3. R _{5 to} R ₈ each independently represents a hydrogen atom, an alkyl group, an aryl group, Represents an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, a heterocyclic group, and when r, s, t, and u are 2 or more, a plurality of R _{5 to} R ₈ are connected to each other adjacent to each other. And W ₁ and W ₂ each independently represent an alkyl group, and may be bonded to each other to form a cyclic structure.)
(In General Formula (C-7), L ⁶¹ represents a single bond or a divalent linking group. A ⁶¹ represents a carbon atom or a nitrogen atom. Z ⁶¹ and Z ⁶² are each independently a nitrogen-containing aromatic. Z ⁶³ represents a benzene ring or an aromatic heterocyclic ring, and Q represents an anionic acyclic ligand bonded to Pt.)
(In the general formula (C-8), A ^{701 to} A ⁷¹⁰ each independently represents C—R or a nitrogen atom, R represents a hydrogen atom or a substituent, and L ⁷¹ represents a single bond or a divalent linkage. Q represents an anionic acyclic ligand that binds to Pt.)
(In General Formula (C-9-1), B may form an aromatic 6-membered heterocycle. R _{17 to} R ₂₄ each independently represent a hydrogen atom, an alkyl group, an aryl group, or an alkoxy group. Group, aryloxy group, fluorine atom, cyano group, silyl group, heterocyclic group, R ₁₇ and R ₁₈ , R ₁₈ and R ₁₉ , R ₁₉ and R ₂₀ , R ₂₁ and R ₂₂ , R ₂₂ and R ₂₃ , R ₂₃ and R ₂₄ may combine with each other to form a cyclic structure, and R ₂₅ and R ₂₆ each independently represents an alkyl group, a fluorine atom, an aryl group, an alkoxy group, an aryloxy group, a cyano group, Represents a silyl group or a heterocyclic group, and R ₂₅ and R ₂₆ may combine to form an aromatic ring.) The platinum complex is represented by the following general formula (C-3-1) or any one of the general formulas (C-5-1), (C-6), and (C-9-1). Item 2. The organic electroluminescent device according to Item 1.
(In General Formula (C-3-1), X, Y, Z, and M each independently represent a carbon atom or a nitrogen atom, provided that either Z or Y is a nitrogen atom. When it is a nitrogen atom, X is a carbon atom, m, n, p, and q each independently represents an integer of 0 to 3. Ar represents a substituted or unsubstituted aryl group. ₁ ~ R ₃ And R ₃₀ Each independently represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a fluorine atom, a cyano group, a silyl group, or a heterocyclic group. When m, n, p, q is 2 or more, a plurality of R ₁ , R ₂ , R ₃ And R ₃₀ May be adjacent to each other to form a ring structure. Q is a carbon atom or a nitrogen atom. ) The organic electroluminescent element according to claim 1, wherein the fluorescent compound is represented by the following general formula (P-1).
Formula (P-1)
(In general formula (P-1), R _P ¹ ~ R _P ¹⁰ Each independently represents a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, or a substituent. An alkyl group which may have a substituent, a silyl group which may have a substituent, a heterocyclic group which may have a substituent, an alkylamino group which may have a substituent, a substituent Represents an arylamino group optionally having R _P ¹ ~ R _P ¹⁰ At least one of is a substituent other than a hydrogen atom. ) The organic electroluminescent element according to claim 1, wherein the fluorescent compound is represented by the following general formula (PE-1).
General formula (PE-1)
(In the general formula (PE-1), R _PE ¹ ~ R _PE ⁴ Are each independently a hydrogen atom, alkyl group, aryl group, heterocyclic group, amino group, silyl group, alkyloxycarbonyl group, aryloxycarbonyl group, carbamoyl group, alkoxy group, aryloxy group, heteroaryloxy group, An alkylthio group and an arylthio group are represented, and these may have a substituent. These may be bonded to each other to form a ring.
n _PE ¹ ~ N _PE ⁴ Each independently represents an integer of 0 to 3. n _PE ¹ ~ N _PE ⁴ When R is 2 or more, multiple R _PE ¹ ~ R _PE ⁴ May be bonded to each other to form a ring.
Further, the hydrogen atom in the formula may be a deuterium atom. ) The organic electroluminescent element according to claim 1, wherein the fluorescent compound is represented by the following general formula (F-1).
(In general formula (F-1), R _F ¹ ~ R _F ¹⁰ Each independently represents a hydrogen atom, an aromatic hydrocarbon group which may have a substituent, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, or a substituent. An alkyl group which may have a substituent, a silyl group which may have a substituent, a heterocyclic group which may have a substituent, an alkylamino group which may have a substituent, a substituent Represents an arylamino group optionally having R _F ¹ ~ R _F ¹⁰ At least one of is a substituent other than a hydrogen atom. ) The organic electroluminescent element according to any one of claims 1 to 5, wherein an aspect ratio (molecular length / molecular thickness) between a molecular length and a molecular thickness of the flat luminescent material is larger than 5. The organic electroluminescent element according to claim 1, wherein the host material is a metal complex compound. A flat luminescent material having an aspect ratio (molecular length / molecular thickness) of 3 to 30 and an aspect ratio (molecular length / molecular thickness) of molecular length to molecular thickness and an aspect ratio (molecular length / molecular thickness) of molecular length to molecular thickness of 1 to 2 And a size ratio of the molecular radius of the light emitting material to the molecular radius of the host material (molecular radius of the light emitting material / molecular radius of the host material) is 0.8 to 1.2. ,
The flat light-emitting material is a fluorescent compound, or the general formulas (C-3), (C-4), (C-5-1), (C-6), (C -7) A material for an organic electroluminescent element, which is a platinum complex of a phosphorescent compound represented by any one of (C-8) and (C-9-1). The manufacturing method of an organic electroluminescent element at least including the process of forming a light emitting layer by the vacuum evaporation process using the organic electroluminescent element material of Claim 8, or a wet process. The film | membrane containing the organic electroluminescent element material of Claim 8. The light-emitting device using the organic electroluminescent element of any one of Claims 1-7. The display apparatus using the organic electroluminescent element of any one of Claims 1-7. The illuminating device using the organic electroluminescent element of any one of Claims 1-7.