JP5973692B2 - Organic electroluminescence device - Google Patents

Description

  The present invention relates to an organic electroluminescent device.

  Organic electroluminescent elements (hereinafter also referred to as “elements” and “organic EL elements”) are actively researched and developed because they emit light with high luminance when driven at a low voltage. An organic electroluminescent element has an organic layer between a pair of electrodes, and electrons injected from the cathode and holes injected from the anode recombine in the organic layer, and the generated exciton energy is used for light emission. To do.

In recent years, the use of phosphorescent light emitting materials has led to higher efficiency of devices. In addition, a doped element using a light emitting layer in which a light emitting material is doped in a host material is widely used.
For example, Patent Document 1 proposes an organic electroluminescent element that has improved luminous efficiency and durability by using a platinum complex having a specific structure as a phosphorescent material. Further, Patent Document 2 proposes an organic light emitting layer using an iridium complex as a phosphorescent material and using a triphenylene compound as a host material.

  Regarding conventional organic electroluminescent elements, it has been found that when a plurality of elements having the same configuration are continuously manufactured, the element performance varies within a certain performance difference range among the plurality of elements. However, these patent documents do not describe the suppression of variations in element performance among a plurality of elements.

Patent No. 4399429 Special table 2008-543086 gazette

When a plurality of elements having the same configuration are continuously manufactured with respect to a conventional organic electroluminescence element, the element performance varies within a certain range of performance difference between the plurality of elements. Here, “manufacturing a plurality of elements having the same configuration in succession” means that a plurality of elements having the same material and configuration are manufactured using the same lot of material.
From the viewpoint of mass production of elements and stable supply of elements having uniform element performance, even in the case where a plurality of elements having the same configuration are continuously manufactured, the element performance is not improved between the plurality of elements. There is a need to suppress variation.

An object of the present invention is to provide an organic electroluminescence device in which variation in device performance is suppressed among a plurality of devices when a plurality of devices having the same configuration are continuously manufactured.
Another object of the present invention is to provide a light emitting device, a display device and a lighting device including the organic electroluminescent element.

As a result of intensive studies to solve the above problems, the present inventors have obtained the following knowledge. That is, an organic electroluminescent element having a platinum complex having a specific structure and a host material in a light emitting layer, wherein the emission maximum wavelength λ1 when the element is energized and the platinum complex having the specific structure in dichloromethane at a concentration of 5 mg / L It has been found that the above-mentioned problems can be solved by selecting a platinum complex and a host material so that the difference from the maximum emission wavelength λ2 when dissolved and photoexcited is 3 nm or less.
Patent Documents 1 and 2 do not disclose that variation in element performance can be suppressed by setting the difference between the light emission maximum wavelength λ1 and the light emission maximum wavelength λ2 to 3 nm or less.

That is, the present invention has been achieved by the following means.
[1]
An organic electroluminescent element having a pair of electrodes consisting of an anode and a cathode and an organic layer including a light emitting layer between the electrodes on a substrate, and represented by the following general formula (C-1) in the light emitting layer A compound having a light emitting maximum wavelength λ1 when the device is energized and the compound represented by the general formula (C-1) dissolved in dichloromethane at a concentration of 5 mg / L and photoexcited. An organic electroluminescent device having a difference from the light emission maximum wavelength λ2 of 3 nm or less.

(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 or a divalent linking group. Represents.)
[2]
The organic electroluminescent element according to [1], wherein the host material is a compound having a shape with an aspect ratio of 3 or more.
[3]
The organic electroluminescent element according to [1] or [2], wherein the host material is a triphenylene derivative.
[4]
The organic electroluminescent element according to any one of [1] to [3], wherein the light emission maximum wavelength λ1 and the light emission maximum wavelength λ2 have a relationship of λ1> λ2.
[5]
The compound represented by the general formula (C-1) is represented by any one of the following general formulas (C-3-1), (C-5-1) and (C-6), [1] -The organic electroluminescent element as described in any one of [4].

(In general formula (C-3-1), X, Y, Z and M 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. In this case, 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, and when m, n, p and q are 2 or more, each is adjacent to each other. And may be connected to each other to form a cyclic structure, 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 one of Z and Y is a nitrogen atom, and Y is a nitrogen atom. X represents 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 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, they are linked to each other To form a ring structure.)

(In General Formula (C-6), X, Y, and Z each independently 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 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 or an aryloxy group. , a fluorine atom, a cyano group, a silyl group, or a heterocyclic group, r, s, t and when u is 2 or more, may be formed a cyclic structure via connection to each other at each next to each other .W ₁ and W ₂ each independently represents an alkyl group, which may be bonded to each other to form a cyclic structure.)
[6]
The organic electroluminescent element according to any one of [1] to [5], wherein at least one of the organic layers is formed by a solution coating process.
[7]
A light emitting device using the organic electroluminescent element according to any one of [1] to [6].
[8]
The display apparatus using the organic electroluminescent element as described in any one of [1]-[6].
[9]
The illuminating device using the organic electroluminescent element as described in any one of [1]-[6].

  ADVANTAGE OF THE INVENTION According to this invention, when the element which consists of several same structure is produced continuously, the organic electroluminescent light emitting element by which the dispersion | variation in element performance was suppressed among this several element can be provided. Furthermore, a light emitting device, a display device, and a lighting device including the organic electroluminescent element can be provided.

It is the schematic which shows an example of a structure of the organic electroluminescent element which concerns on this invention. It is the schematic which shows an example of the light-emitting device which concerns on this invention. It is the schematic which shows an example of the illuminating device which concerns on this invention.

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, anthranyl, 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 and more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms. Nyloxy, 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.), an acyl group (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 It has 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, 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.
(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, for example, phenyl, p-methylphenyl, naphthyl, anthranyl, 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, benzimidazo , 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.

In the following description of the general formula (TI), a hydrogen atom includes an isotope (deuterium atom and the like), and an atom constituting a substituent further includes the isotope.
In the present invention, when referred to as “substituent”, the substituent may be substituted. For example, the term “alkyl group” in the present invention includes an alkyl group substituted with a fluorine atom (for example, trifluoromethyl group) and an alkyl group substituted with an aryl group (for example, triphenylmethyl group). When the term “alkyl group having 1 to 6 carbon atoms” is used, it means that the number of carbon atoms is 1 to 6 as all groups including those substituted.

  The organic electroluminescent element of the present invention is an organic electroluminescent element having a pair of electrodes consisting of an anode and a cathode and an organic layer including a light emitting layer between the electrodes on the substrate, and the light emitting layer is described later. A compound having a compound represented by the general formula (C-1) and a host material, and a concentration of the compound represented by the general formula (C-1) in dichloromethane at a light emission maximum wavelength λ1 when the element is energized The difference from the emission maximum wavelength λ2 when dissolved and photoexcited at 5 mg / L is 3 nm or less.

  The difference between the light emission maximum wavelength λ1 and the light emission maximum wavelength λ2 of 3 nm or less means that a compound represented by the following general formula (C-1) (hereinafter also referred to as “specific platinum complex”). It is considered that this means that the light emitting layer is arranged in a highly ordered state while it exists in a free state in the solution. It is presumed that the platinum complex having a specific structure having a planar shape contributes to the arrangement in a highly regular state. In a light emitting layer using a platinum complex having a specific structure having such a planar shape, the regularity of the arrangement when the platinum complex and the host material are mixed is high, and the platinum complex is removed from the mixed initial state. It is presumed that the intermolecular distance between the host and the host material is close. For this reason, even when a plurality of elements having the same configuration are continuously manufactured, the arrangement state in the light-emitting layer formed in each element is not easily changed between elements, so that a uniform light-emitting layer can be obtained between elements. Therefore, it is considered that an organic electroluminescence device in which variation in device performance is suppressed can be obtained.

The light emission maximum wavelength can be determined, for example, by using a source measure unit 2400 manufactured by Toyo Technica to emit light by applying a DC voltage to each element and measuring the light emission spectrum using a spectrum analyzer PMA-11 manufactured by Hamamatsu Photonics. it can.
Note that the energization when observing the light emission maximum wavelength λ1 generally refers to a state in which a current having a current density of 0.1 to 1 mA / cm 2 is passed.
For example, it can also be determined by measuring the emission spectrum obtained by irradiating the solution of the light emitting material with light using RF-5300 manufactured by Shimadzu Corporation and exciting it.
Photoexcitation when observing the above-mentioned maximum emission wavelength λ2 refers to a spectrum obtained by measuring an excitation spectrum for an approximate emission wavelength and exciting at the maximum wavelength. For example, Ir (ppy) ₃ , which is known to emit green light, has an excitation maximum wavelength of 380 nm when 510 nm in dichloromethane is used as a detection wavelength. Therefore, by measuring the emission spectrum with excitation light of 380 nm, It can be seen that the emission maximum wavelength is 521 nm.

The difference between the light emission maximum wavelength λ1 and the light emission maximum wavelength λ2 is preferably 3 nm or less, more preferably 0.5 nm or more and 2 nm or less.
It is preferable that the light emission maximum wavelength λ1 and the light emission maximum wavelength λ2 have a relationship of λ1> λ2.

  Hereinafter, the compound represented by formula (C-1) and the host material used in the light emitting layer according to the present invention will be described.

[Compound represented by formula (C-1)]
Hereinafter, the compound represented by formula (C-1) will be described.

(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 or a divalent linking group. Represents.)

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 And a condensed ring containing them (for example, quinoline ligand, 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 groups 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 group 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, and an aromatic heterocyclic ligand bonded to Pt with a carbon atom. A nitrogen-containing aromatic heterocyclic ligand that binds to Pt with a nitrogen atom, an acyloxy ligand, an alkyloxy ligand, an aryloxy ligand, a heteroaryloxy ligand, a silyloxy ligand, and 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 ligand bonded to Pt by a nitrogen atom , An acyloxy ligand, an aryloxy ligand, more preferably an aromatic hydrocarbon ring ligand bonded to Pt with a carbon atom, an aromatic heterocyclic ligand bonded to Pt with a carbon atom, a nitrogen atom Containing Pt Containing aromatic heterocyclic ligand, an acyloxy ligand.

L ¹ , L ² and L ³ represent a single bond or a divalent linking group. 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.), or a combination of these. These linking groups may further have a substituent. Here, R and R ′ each independently represent a substituent. As the substituent, those exemplified as the substituent group A can be appropriately applied.
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, more preferably a single bond, a methylene group or a phenylene group, still more preferably a single bond, Di-substituted methylene group, more preferably a single bond, dimethylmethylene group, diethylmethylene group, diisobutylmethylene group, dibenzylmethylene group, ethylmethylmethylene group, methylpropylmethylene group, isobutylmethylmethylene group, diphenylmethylene group, Methylphenylmethylene group, cyclohexanediyl group, cyclopen Njiiru 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 or a silylene group, more preferably an alkylene group, an arylene group or an imino group, still more preferably an alkylene group or an imino group. More preferably a methylene group or an imino group. These may have a substituent, and as the substituent, those exemplified as the substituent group A can be applied.
L ¹ is more preferably a single bond, a disubstituted methylene group, or an arylimino group, and more preferably a dimethylmethylene group, a diethylmethylene group, a diisobutylmethylene group, a dibenzylmethylene group, an ethylmethylmethylene group, or a methylpropylmethylene group. , Isobutylmethylmethylene group, diphenylmethylene group, methylphenylmethylene group, cyclohexanediyl group, cyclopentanediyl group, fluorenediyl group, fluoromethylmethylene group, phenylimino group, 4-t-butylphenylimino group, 3,5 -Di-t-butylphenylimino group, particularly preferably dimethylmethylene group, diphenylmethylene group, cyclohexanediyl group, and 3,5-di-t-butylphenylimino group.

  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 and Z ²² each independently represent a benzene ring or a nitrogen-containing aromatic heterocycle, and 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 has the same meaning as L ^{1 in} formula (C-1), and the preferred range is also the same.

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 to represent A ²¹ and A ²² nitrogen atoms, or that B ²¹ and B ²² are nitrogen atoms.

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 stability of the complex, emission wavelength control and emission quantum yield, the ring represented by Z ²³ and Z ²⁴ is preferably a benzene ring, a pyridine ring, a pyrazine ring, an imidazole ring, a pyrazole ring, or a thiophene ring, More preferred are a benzene ring, a pyridine ring and a pyrazole ring, and still more preferred are a benzene ring and a pyridine ring.

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 carbon is preferably an alkyl group, trifluoroalkyl group, aryl group, heterocyclic group, dialkylamino group, diarylamino group, alkoxy group, aryloxy group, silyl group, cyano group, or halogen 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, and an alkyl group, an alkoxy group, a fluorine atom, or a cyano group is still 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. As said alkyl group, C1-C12 is preferable, For example, a methyl group, an octyl group, a decyl group, a dodecyl group, t-butyl group, t-amyl group, s-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 trifluoroalkyl 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 alkyl group having 1 to 20 carbon atoms, and may have a linear, branched, or cyclic structure. The dialkylamino group preferably has 1 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.

Among these, from the viewpoint of aspect ratio, the above-mentioned substituent having a linear alkyl group and a linear alkyl group as a substituent 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 group, 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 may be linked to each other to form a condensed ring. Examples of the ring formed include a benzene ring, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, an imidazole ring, an oxazole ring, a thiazole ring, and a pyrazole. Ring, thiophene ring, furan ring and the like.

  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 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 group and a cyano group are preferred.
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 group or a cyano group, more preferably a hydrogen atom or an amino group. Group, alkoxy group, aryloxy group and fluorine group, 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, and either Z or Y is a nitrogen atom, and Y is a nitrogen atom. In this case, 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 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, or q is 2 or more, And may be connected to each other to form a cyclic structure, Q is a carbon atom or a nitrogen atom.)

General formula (C-3-1) is demonstrated.
m, n, p, and q each independently represents an integer of 0 to 3. Among these, m is preferably 0 to 2, more preferably 0 to 1, and still more preferably 0. n is preferably 0 to 2, more preferably 0 to 1, and still more preferably 0. p is preferably 0-2, more preferably 1-2. q is preferably 0 to 2, and more preferably 0 to 1.
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 halogen atom, and a fluoroalkyl group, preferably 1 to 6 carbon atoms. An alkyl group, a cyano group, an amino group, a halogen atom and a fluoroalkyl group (preferably a trifluoromethyl group), more preferably an alkyl group having 1 to 6 carbon atoms and a halogen atom (preferably a fluorine atom). Among these, from the viewpoint of aspect ratio, the above-mentioned substituent having a linear alkyl group and an alkyl group as a substituent is preferable.
More preferable examples of Ar include a phenyl group, a 4-t-butylphenyl group, and a 3,5-di-t-butylphenyl group.
R _{1 to} R ₃ and R ₃₀ are preferably the same as R in the general formula (C-3), and preferably R _{1 to} R ₂ are an alkyl group, an aryl group, a fluorine atom, Represents a cyano group and a silyl group. R ₃ is preferably a trifluoroalkyl group, a cyano group, or a halogen atom, and more preferably a trifluoroalkyl group. R ₃₀ is preferably a trifluoroalkyl group, a cyano group, or a halogen atom, more preferably a halogen atom, and particularly preferably a fluorine atom.
When m, n, p, q is 2 or more, they may be linked to each other to form a cyclic structure.

  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 represents C—R or N. R represents a hydrogen atom or a substituent. L ⁴¹ represents a single bond or a divalent linking group. .)

General formula (C-4) is demonstrated.
A ^{401 to} A ⁴¹⁴ each independently represent C—R or N. 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 group, or a cyano group. More preferably a hydrogen atom, an amino group, an alkoxy group, an aryloxy group or a fluorine group, and particularly preferably a hydrogen atom or a fluorine 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 group or a cyano group, more preferably a hydrogen atom or an amino group. Group, alkoxy group, aryloxy group and fluorine group, particularly preferably a hydrogen atom.
L ⁴¹ has the same meaning as L ^{1 in} formula (C-1), 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 an N atom, and both A ⁴⁰⁸ and A ⁴¹² are more preferably N atoms.
In the case where 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 group. A cyano group, more preferably a hydrogen atom, a trifluoroalkyl group, an alkyl group, an aryl group, a fluorine group 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 group or a cyano group, more preferably Is a hydrogen atom, a trifluoroalkyl group, a fluorine group or a cyano group, particularly preferably a hydrogen atom, a phenyl group or a fluorine group. R in A ⁴¹⁰ and A ⁴¹⁴ is preferably a hydrogen atom or a fluorine group, and more preferably a hydrogen atom. When any of A ^{407 to} A ⁴⁰⁹ and A ^{411 to} A ⁴¹³ represents CR, Rs may be connected to each other to form a ring.

  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 represent C—R or N. R represents a hydrogen atom or a substituent. L ⁵¹ represents a single bond or a divalent linking group. Y and Z each independently represent a carbon atom or a nitrogen atom, and Z or Y 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 N. 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. At least one of A ⁵⁰⁷ , A ⁵⁰⁸ , A ⁵⁰⁹ , A ⁵¹⁰ , A ⁵¹¹ and A ⁵¹² is preferably N, and particularly preferably A ⁵¹⁰ or A ⁵⁰⁷ is N.

  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, They may be linked together to form a ring structure.)

R ₁ and R ₂ 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.
R ₃ and R ₄ are preferably an alkyl group, a trifluoroalkyl group, an aryl group, an aromatic heterocyclic group, a dialkylamino group, a diarylamino group, an alkyloxy group, a cyano group, or a halogen atom, more preferably , An alkyl group, a trifluoroalkyl group, an aryl group, a dialkylamino group, a cyano group, and a fluorine atom, and more preferably an alkyl group, a trifluoromethyl group, and a fluorine atom. If possible, the substituents may be linked to form a condensed ring structure.
Ar is synonymous with Ar in formula (C-3-1), and preferred ones are also the same.
m, n, p, and q each independently represents an integer of 0 to 3. Among these, m is preferably 0 to 2, more preferably 0 to 1, and still more preferably 0. n is preferably 0 to 2, more preferably 0 to 1, and still more preferably 0. p is preferably 0 to 2, and more preferably 1. q is preferably 0 to 2, and more preferably 1.

  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 each independently 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 a carbon atom, r, s, t, and u each independently represent an integer of 0 to 3. R _{5 to} R ₈ are each independently an alkyl group, aryl group, alkoxy group, aryl It represents an oxy 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, they may be linked to each other to form a cyclic structure. ₁ and W ₂ each independently represents an alkyl group, and may combine with each other to form a cyclic structure.)

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.
R ₅ and R ₆ are preferably an alkyl group, an alkoxy group, an aryl group, a trifluoroalkyl group, or a halogen atom, and the aryl group may have an alkyl group as a substituent.
R ₇ and R ₈ are preferably an alkyl group, a trifluoroalkyl group, an aryl group, an aromatic heterocyclic group, a dialkylamino group, a diarylamino group, an alkyloxy group, a cyano group, or a halogen atom, and the aryl group is Preferably, the aryl group may have an alkyl group as a substituent. .
W ₁ and W ₂ are preferably alkyl groups having 1 to 6 carbon atoms, and examples thereof include a methyl group, an ethyl group, an isopropyl group, an n-propyl group, a t-butyl group, and the like. preferable. The alkyl groups may be linked to each other to form a cyclic structure (eg, cyclopentane, cyclohexane, cycloheptane, preferably cyclopropane).

  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 C—R or N. R represents a hydrogen atom or a substituent. Z ⁶¹ and Z ⁶² each independently contain nitrogen. .Z represents an aromatic heterocycle ⁶³ .Y in which represents a benzene ring or an aromatic heterocyclic ring is an anionic non-cyclic ligand that binds to Pt.)

General formula (C-7) is demonstrated. L ⁶¹ has the same meaning as L ^{1 in} formula (C-1), and the preferred range is also the same.

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.

Y 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 Y, 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.
A vinyl ligand is mentioned as Y couple | bonded with Pt by a carbon atom. Examples of Y bonded to Pt with a nitrogen atom include an amino ligand and an imino ligand. Examples of Y bonded to Pt with an oxygen atom include 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 Y bonded to Pt with a sulfur atom include alkyl mercapto ligands, aryl mercapto ligands, heteroaryl mercapto ligands, thiocarboxylic acid ligands, and the like.
The ligand represented by Y may have a substituent, and those exemplified as the substituent group A can be appropriately applied as the substituent. Moreover, substituents may be connected to each other.

  The ligand represented by Y is preferably a ligand bonded to Pt with an oxygen atom, more preferably an acyloxy ligand, an alkyloxy ligand, an aryloxy ligand, a heteroaryloxy ligand. , A silyloxy ligand, and 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 N. R represents a hydrogen atom or a substituent. L ⁷¹ represents a single bond or a divalent linking group. Y is 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. Y 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 General Formula (C-9), R _{9 to} R ₁₆ each independently represent a hydrogen atom, an alkyl group, an aryl group, a silyl group, or a heterocyclic group, and R ₉ and R ₁₁ , R ₁₁ and R ₁₂ , R ₁₂ and R ₁₀ , R ₁₄ and R ₁₅ , R ₁₃ and R ₁₆ may be independently bonded to each other to form a cyclic structure.)

R ₉ and R ₁₁ , R ₁₁ and R ₁₂ , R ₁₂ and R ₁₀ , R ₁₄ and R ₁₅ , and R ₁₃ and R ₁₆ are preferably bonded to each other to form a cyclic structure. More preferably, R ₉ and R ₁₁ , R ₁₂ and R ₁₀ , R ₁₄ and R ₁₅ , and R ₁₃ and R ₁₆ are independently bonded to each other to form a cyclic structure.
The cyclic structures formed by combining R ₉ and R ₁₁ , R ₁₁ and R ₁₂ , R ₁₂ and R ₁₀ , R ₁₄ and R ₁₅ , R ₁₃ and R ₁₆ include benzene ring, naphthalene ring, pyridine ring , A pyrazine ring, a pyrimidine ring, a pyridazine ring, and a triazine ring, and more preferably a benzene ring or a naphthalene ring.
R ₁₄ and R ₁₅ , R ₁₁ and R ₁₂ , R ₁₃ and R ₁₆ are preferably bonded to each other to form a cyclic structure.
The cyclic structure may further have a substituent, and as the further substituent, those exemplified as the substituent group A can be applied, and an alkyl group and an alkoxy group are preferable, and an alkyl having 1 to 20 carbon atoms is preferable. Group, a C1-C20 alkoxy group is more preferable, a C5-C15 alkyl group and a C5-C15 alkoxy group are still more 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. 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 and 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).

The content of the compound represented by the general formula (C-1) in the light emitting layer of the present invention is preferably 2 to 30% by mass, more preferably 5 to 20% by mass in the light emitting layer, and 7 to More preferably, it is 15 mass%.
The molecular weight of the compound represented by the general formula (C-1) in the light emitting layer of the present invention is preferably 300 to 2000, more preferably 400 to 1200, and still more preferably 450 to 900. . Moreover, it is preferable that the molecular weight of a host is 250-2000, It is more preferable that it is 300-1500, It is still more preferable that it is 400-1200. If the molecular weight is 400 or more, a high-quality amorphous thin film can be formed, and if the molecular weight is 1200 or less, it is preferable in terms of solubility in a solvent, sublimation, and deposition suitability.

[Host material]
The host material of the present invention will be described in detail.
As the host material used in the present invention, a conventionally known material can be used as long as the above-mentioned conditions relating to the maximum emission wavelength are satisfied, but when mixed with a platinum complex having the above specific structure, It is preferable that the host material has high planarity (hereinafter also referred to as “flat plate host compound”), and specifically, a compound having a shape with an aspect ratio of 3 or more is preferable. More preferred.

The aspect ratio is the ratio (molecular diameter / molecular thickness) between the molecular diameter and the molecular thickness of the compound.
From the viewpoint of orientation, the host material used in the present invention preferably has an aspect ratio of 3 or more, and more preferably has an aspect ratio of 3.5 or more.
Here, the molecular diameter means the longest molecular length, and is defined as follows by theoretical calculation. The theoretical calculation here is performed using a density functional method. Specifically, using Gaussian 03 (US Gaussian), basis function: 6-31G ^* , exchange correlation functional: B3LYP / LANL2DZ, Perform structural optimization calculations. Using the optimized structure obtained by the structure optimization calculation, the length in the ball and stick display of the longest molecular length is defined as the molecular diameter of the host material.
In addition, the molecular thickness is assumed to be the above-mentioned molecular diameter as the x-axis, the y-axis is taken so that the molecular length in the y-axis direction becomes the maximum in this state, and the direction perpendicular to the x and y axes is taken as the z-axis. Means the thickness of the molecule in the z-axis direction. The molecular thickness is also obtained by the same method as the molecular diameter, and the length in the thickness direction of the molecule in the ball and stick display is defined as the molecular thickness.
Furthermore, the host material used in the light emitting layer of the present invention is preferably a discotic compound among the flat host compounds, and more preferably a discotic liquid crystalline host compound corresponding to the following.

[Discotic liquid crystalline host compound]
The discotic liquid crystalline host compound forms a liquid crystal phase composed of highly planar disk-like molecules.

The discotic liquid crystalline host compound also includes a compound having a structure in which a linear alkyl group, an alkoxy group, and a substituted benzoyloxy group are radially substituted as a side chain of the mother nucleus with respect to the mother nucleus at the center of the molecule. The molecule or the assembly of molecules is preferably a compound having rotational symmetry and imparting a certain orientation.
The discotic liquid crystalline host compound is preferably selected from any of triphenylene derivatives, pyrene derivatives, triazine derivatives, and carbazole derivatives, and may be selected from any of triphenylene derivatives, pyrene derivatives, and triazine derivatives. More preferred is a triphenylene derivative, most preferred.

[Discotic liquid crystalline triphenylene derivatives]
As a triphenylene derivative exhibiting liquid crystallinity, any conventionally known discotic liquid crystalline triphenylene derivative can be used, and examples thereof include a triphenylene derivative represented by the following general formula (TI).

In the above general formula (T-I), R _T represents R _T ¹ —, R _T ¹ —O—, R _T ¹ —CO—O—, or R _T ¹ —O—CO—. Although all the compounds having these groups are not discotic liquid crystalline, an appropriate group that exhibits discotic liquid crystallinity can be selected and used based on known techniques. As R _T ^1, there are an alkyl group, an aryl group, an alkyl group in which a ring such as a phenylene group or a cyclohexylene group is combined, an oxygen group in which an oxygen atom is arranged between carbon and carbon of the alkyl group, and the like.

As R _T , specifically, R _T ² —, R _T ² —O—, R _T ² —O—R _T ³ —, R _T ² —O—R _T ³ —O—, R _T ² — O—Ph—COO—, R _T ² — (O—R _T ³ ) _nT —O—Ph—COO—, R _T ² —O—Ph—CH═CH—COO—, CH ₂ = CH—COO—R _T ³ —O—Ph—COO— may be mentioned. Here, R _T ² represents an alkyl group which may have a polymerizable group, R _T ³ represents an alkylene group, Ph represents a phenylene group which may have a substituent, n _T , Is a repeating number _of- (O-R _T ³ )-and represents an integer of 1 or more.

R _T ² represents an alkyl group which may have a polymerizable group, when having a polymerizable group, it is preferable from the viewpoint of the expression of the N _D phase having a polymerizable group at the top end of the alkyl group. Examples of the polymerizable group include an acrylic acid ester group, a methacrylic acid ester group, a crotonic acid ester group, an epoxy group, and the like. Groups are preferred, and acrylate groups are more preferred.
Carbon number of the alkyl group part in the alkyl group which may have a polymerizable group represented by R _T ² is preferably in the range of 1-20, more preferably in the range of 1-15, and further Preferably it is the range of 3-10.
The number of carbon atoms of the alkylene group represented by R _T ³ is preferably in the range of 1 to 20, more preferably in the range of 1 to 15, and still more preferably in the range of 3 to 10.
Ph represents a phenylene group which may have a substituent group, includes as the substituent also be a halogen atom such as fluorine atom, an alkyl group, an alkoxy group, and the expression of the N _D phase From the viewpoint, an alkyl group is preferable. The number of carbon atoms of the alkyl group or alkoxy group as a substituent is preferably in the range of 1 to 20, more preferably in the range of 1 to 10, and still more preferably in the range of 1 to 6.
n _{T ^{is, - (O-R T 3}} ) - number of repetitions of the represents an integer of 1 or more. n _T is preferably an integer of 1 to 10, more preferably an integer from 1 to 6, more preferably an integer of 1 to 3.

The R _T, in terms of expression of the _{N D ^{phase, R T 2 -O-Ph-}} COO-, R T 2 - (O-R T 3) n T -O-Ph-COO-, R T 2 -O-Ph-CH = CH- COO- is ^{_{preferred, R T 2 -O-Ph-}} COO- are more preferred.

Triphenylene derivative represented by the above general formula (T-I) in that they express the N _D phase, it is preferably a triphenylene derivative represented by the following general formula (T-II).

In the general formula (T-II), R _T ′ represents R _T ² —O—Ph—CO—, R _T ² — (O—R _T ³ ) n _T— O—Ph—CO—, or R _T ^{It represents 2-} O-Ph-CH = CH-CO-. The definitions of R _T ² , Ph, R _T ³ , and n _T are synonymous with R _T ² , Ph, R _T ³ , and n _{T in} the general formula (TI). Specific examples and preferred ranges of R _T ² , Ph, R _T ³ , and n _{T in} the general formula (T-II) are the same as those in the general formula (T-I).

R _T ', since the expression of _{N D} phase is good, the following general formula (T-II-1) ~ It is more preferably represented by any one of (T-II-5).

In the general formulas (T-II-1) to (T-II-5), n and n ′ each independently represent an integer of 1 or more.
X _T represents a polymerizable group.

n represents an integer of 1 or more. n is preferably an integer of 1 to 20, more preferably an integer of 1 to 15, and still more preferably an integer of 3 to 10.
n ′ represents an integer of 1 or more. n ′ is preferably an integer of 1 to 10, more preferably an integer of 1 to 6, and still more preferably an integer of 1 to 3.
X _T represents a polymerizable group, and specific examples and preferred ranges are specific examples of the general formula (T-I) in which may have an alkyl group represented by R _T ² polymerizable groups and This is the same as the preferred range.

  The triphenylene derivative represented by the above general formula (TI) is also preferably a triphenylene derivative represented by the following general formula (T-III) in that it is resistant to electrical oxidation.

In the general formula (T-III), R _T represents R _T ¹ —, R _T ¹ —O—, R _T ¹ —CO—O—, or R _T ¹ —O—CO—. As R _T ^1, there are an alkyl group, an aryl group, an alkyl group in which a ring such as a phenylene group or a cyclohexylene group is combined, an oxygen group in which an oxygen atom is arranged between carbon and carbon of the alkyl group, and the like. The definitions of R _T ² , Ph, R _T ³ , and n _T are synonymous with R _T ² , Ph, R _T ³ , and n _{T in} the general formula (TI). Specific examples and preferred ranges of R _T ² , Ph, R _T ³ , and n _{T in} the general formula (T-III) are the same as those in the general formula (T-I).

  Among the triphenylene derivatives exhibiting liquid crystallinity in the present invention, those that cause the liquid crystal phase to be expressed in the range of 20 ° C to 300 ° C are preferable. More preferably, it is 40 degreeC-280 degreeC, More preferably, it is 60 degreeC-250 degreeC. Here, the expression of the liquid crystal phase at 20 ° C. to 300 ° C. also means that the liquid crystal temperature range extends over 20 ° C. (for example, 10 ° C. to 22 ° C.) or 300 ° C. (for example, 298 ° C. to 310 ° C.). Including. The same applies to 40 ° C to 280 ° C and 60 ° C to 250 ° C.

  The content of the host material in the light emitting layer of the present invention is preferably 15 to 97% by mass in the light emitting layer, more preferably 30 to 95% by mass, and still more preferably 50 to 90% by mass. .

  Specific examples of the triphenylene derivative exhibiting liquid crystallinity are shown below, but the present invention is not limited thereto.

[Location and concentration of host material]
In the present invention, the triphenylene derivative represented by the above general formula (TI) is contained in the light emitting layer, but its use is not limited and is further contained in any layer in the organic layer. Also good. Examples of the introduction layer of the triphenylene derivative represented by the general formula (TI) include any of a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, an exciton block layer, and a charge block layer. be able to.
When the triphenylene derivative represented by the general formula (TI) is further contained in a layer other than the light emitting layer, it is preferably contained in an amount of 70 to 100% by mass, more preferably 85 to 100% by mass.

[Organic electroluminescence device]
The device of the present invention will be described in detail.
The organic electroluminescent element of the present invention is an organic electroluminescent element having a pair of electrodes consisting of an anode and a cathode and an organic layer including a light emitting layer between the electrodes on a substrate, It contains a compound represented by the formula (C-1) and a host material.

In the organic electroluminescent element of the present invention, the light emitting layer is an organic layer, and includes at least one organic layer between the light emitting layer and the cathode, and has an organic layer adjacent to the light emitting layer between the light emitting layer and the cathode, Furthermore, you may have a some organic layer.
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 the said transparent electrode or the said back electrode. . In this case, the organic layer is formed on the front surface or one surface of the transparent electrode or the back electrode.
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 / block layer / electron transport 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 / 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 deposition methods such as vapor deposition and sputtering, and solution coating processes such as transfer, printing, spin coating, and bar coating. Can be formed. It is preferable that at least one of the organic layers is formed by a solution coating process.

[Light emitting layer]
The light-emitting layer receives holes from the anode, the hole injection layer, or the hole transport layer when an electric field is applied, receives electrons from the cathode, the electron injection layer, or the electron transport layer, and recombines holes and electrons. It is a layer which has the function to provide light emission.
The light emitting layer of the present invention may further contain at least one kind of host material different from the above-described ones in addition to the platinum complex having the specific structure and the host material. The host material may be a hole transporting host material or an electron transporting host material, but a both-charge transporting host material is preferred.

  The substrate, anode, cathode, organic layer, and light emitting layer are described in detail in, for example, Japanese Patent Application Laid-Open No. 2008-270736 and Japanese Patent Application Laid-Open No. 2007-266458, and the matters described in these documents can be applied to the present invention. . Furthermore, the light emitting layer may include a material that does not have charge transporting properties and does not emit light.

(Luminescent material)
As the light emitting material in the present invention, a phosphorescent light emitting material, a fluorescent light emitting material, or the like can be further used in addition to the platinum complex having the specific structure.
The light emitting layer in the present invention can contain two or more kinds of light emitting materials in order to improve the color purity and widen the light emission wavelength region. The element of the present invention may further contain at least one phosphorescent metal complex in the light emitting layer in addition to the platinum complex having the specific structure.
The light emitting material in the present invention further satisfies the relationship of 1.2 eV>ΔIp> 0.2 eV and / or 1.2 eV>ΔEa> 0.2 eV with the host material. It is preferable from the viewpoint. Here, ΔIp means the difference in Ip value between the host material and the light emitting material, and ΔEa means the difference in Ea value between the host material and the light emitting material.
The fluorescent light-emitting material and the phosphorescent light-emitting material are described in detail, for example, in paragraph numbers [0100] to [0164] of JP-A-2008-270736 and paragraph numbers [0088] to [0090] of JP-A-2007-266458, The matters described in these publications can be applied to the present invention.

  The compound represented by general formula (C-1) is contained at least in the light emitting layer.

  The total amount of the light emitting material in the light emitting layer is generally 0.1% by mass to 50% by mass with respect to the total compound mass forming the light emitting layer in the light emitting layer. From the viewpoint, the content is preferably 1% by mass to 50% by mass, and more preferably 2% by mass to 40% by mass.

  Although the thickness of the light emitting layer is not particularly limited, it is usually preferably 2 nm to 500 nm, more preferably 3 nm to 200 nm, and more preferably 5 nm to 100 nm from the viewpoint of external quantum efficiency. More preferably.

The light emitting layer in the device of the present invention is a mixed layer of at least a host material and a platinum complex having a specific structure. The light emitting material that may be further contained in the light emitting layer may be a fluorescent light emitting material or a phosphorescent light emitting material, and the dopant may be one kind or two or more kinds. The host material is preferably a charge transport material. The host material may be one kind or two or more kinds, and examples thereof include a configuration in which an electron transporting host material and a hole transporting host material are mixed.
Furthermore, the light emitting layer may include a material that does not have charge transporting properties and does not emit light.
The light emitting layer may be a single layer or a multilayer of two or more layers. In addition, each light emitting layer may emit light with different emission colors.

<Host material>
The host material used in the present invention is preferably a triphenylene derivative represented by the above general formula (TI).

The host material used in the present invention may contain the following compounds in addition to the triphenylene derivative represented by the general formula (TI).
Examples of the host material include an electron transport material and a hole transport material, and a charge transport material is preferable. The host material may be one type or two or more types, and examples thereof include a configuration in which an electron transporting host material and a hole transporting host material are mixed.
For example, pyrrole, indole, carbazole (eg, CBP (4,4′-di (9-carbazoyl) biphenyl)), azaindole, azacarbazole, triazole, oxazole, oxadiazole, pyrazole, imidazole, thiophene, polyarylalkane, Pyrazoline, pyrazolone, phenylenediamine, arylamine, amino-substituted chalcone, styrylanthracene, fluorenone, hydrazone, stilbene, silazane, aromatic tertiary amine compound, styrylamine compound, porphyrin compound, polysilane compound, poly (N-vinyl) Carbazole), aniline copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, organic silane, carbon film, pyridine, pyrimidine, triazine, imidazo , Pyrazole, triazole, oxazole, oxadiazol, fluorenone, triphenylene, etc., condensed hydrocarbon aromatic compounds, anthraquinodimethane, anthrone, diphenylquinone, thiopyran dioxide, carbodiimide, fluorenylidene Ligands such as methane, distyrylpyrazine, fluorine-substituted aromatic compounds, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, metal complexes of phthalocyanine and 8-quinolinol derivatives, metal phthalocyanine, benzoxazole and benzothiazol And various metal complexes typified by metal complexes and derivatives thereof (which may have a substituent or a condensed ring).

In the light emitting layer of the present invention, the host material triplet lowest excitation energy (T ₁ energy) is preferably higher than the T ₁ energy of the phosphorescent light emitting material in terms of color purity, light emission efficiency, and driving durability.

  Further, the total content of the host compound in the present invention is not particularly limited, but from the viewpoint of light emission efficiency and driving voltage, it is 15% by mass to 97% by mass with respect to the total compound mass forming the light emitting layer. It is preferable that

(Charge transport layer)
The charge transport layer refers to a layer in which charge transfer occurs when a voltage is applied to the organic electroluminescent element.
Specific examples include a hole injection layer, a hole transport layer, an electron block layer, a light emitting layer, a hole block layer, an electron transport layer, and an electron injection layer. A hole injection layer, a hole transport layer, an electron blocking layer, or a light emitting layer is preferable. If the charge transport layer formed by the coating method is a hole injection layer, a hole transport layer, an electron block layer, or a light emitting layer, it is possible to produce an organic electroluminescent element with low cost and high efficiency. The charge transport layer is more preferably a hole injection layer, a hole transport layer, or an electron block layer.

(Hole injection layer, 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.
In the present invention, the organic layer preferably includes a hole injection layer or a hole transport layer containing an electron-accepting dopant.

(Electron injection layer, 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 hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer are described in detail in, for example, Japanese Patent Application Laid-Open No. 2008-270736 and Japanese Patent Application Laid-Open No. 2007-266458. Can be applied to.
The hole injection layer, the hole transport layer, the electron injection layer, and the electron transport layer are described in detail in paragraphs [0165] to [0167] of Japanese Patent Application Laid-Open No. 2008-270736. The matter 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.
Examples of the organic compound constituting the hole blocking layer include a triphenylene derivative represented by the general formula (TI) in the present invention and aluminum (III) bis (2-methyl-8-quinolinato) 4-phenyl. Aluminum complexes such as phenolate (Aluminum (III) bis (2-methyl-8-quinolinato) 4-phenylphenolate (abbreviated as BAlq)), triazole derivatives, 2,9-dimethyl-4,7-diphenyl-1,10 -Phenanthroline derivatives such as phenanthroline (2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline (abbreviated as BCP)) 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.

(Protective layer)
In the present invention, the entire organic EL element may be protected by a protective layer.
As a material contained in the protective layer, any material may be used as long as it has a function of preventing materials that promote device deterioration such as moisture and oxygen from entering the device.
Regarding the protective layer, the matters described in paragraph numbers [0169] to [0170] of JP-A-2008-270736 can be applied to the present invention.

(Sealing container)
The element of this invention may seal the whole element using a sealing container.
Regarding the sealing container, the matters described in paragraph No. [0171] of JP-A-2008-270736 can be applied to the present invention.
Further, a moisture absorbent or an inert liquid may be sealed in a space between the sealing container and the light emitting element.
Although it does not specifically limit as a moisture absorber, For example, barium oxide, sodium oxide, potassium oxide, calcium oxide, sodium sulfate, calcium sulfate, magnesium sulfate, phosphorus pentoxide, calcium chloride, magnesium chloride, copper chloride Cesium fluoride, niobium fluoride, calcium bromide, vanadium bromide, molecular sieve, zeolite, magnesium oxide and the like. The inert liquid is not particularly limited, and examples thereof include paraffins, liquid paraffins, fluorinated solvents such as perfluoroalkane, perfluoroamine, and perfluoroether, chlorinated solvents, and silicone oils. It is done.

(Drive)
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 methods described in each publication, Japanese Patent No. 2,784,615, US Pat. Nos. 5,828,429 and 6,023,308 can be applied.

The external quantum efficiency of the organic electroluminescent element of the present invention is preferably 5% or more, more preferably 7% or more. The value of the external quantum efficiency should be the maximum value of the external quantum efficiency when the device is driven at 20 ° C., or the value of the external quantum efficiency near 100 to 300 cd / m ² when the device is driven at 20 ° C. Can do.

  The internal quantum efficiency of the organic electroluminescence device of the present invention is preferably 30% or more, more preferably 50% or more, and further preferably 70% or more. The internal quantum efficiency of the device is calculated by dividing the external quantum efficiency by the light extraction efficiency. In a normal organic EL element, the light extraction efficiency is about 20%. However, the substrate shape, electrode shape, organic layer thickness, inorganic layer thickness, organic layer refractive index, inorganic layer refractive index, etc. By devising it, it is possible to increase the light extraction efficiency to 20% or more.

The organic electroluminescent element of the present invention preferably has a maximum emission wavelength (maximum intensity wavelength of emission spectrum) of 350 nm to 700 nm, more preferably 450 nm to 600 nm, still more preferably 470 nm to 580 nm, particularly preferably. It is 490 nm or more and 550 nm or less _.

(Use of light emitting device of the present invention)
The light-emitting element of the present invention can be suitably used for light-emitting devices, pixels, display elements, displays, backlights, electrophotography, illumination light sources, recording light sources, exposure light sources, reading light sources, signs, signboards, interiors, optical communications, and the like. . In particular, it is preferably used for a device driven in a region having a high light emission luminance, such as a lighting device and a display device.

(Light emitting device)
Next, the light emitting device of the present invention will be described with reference to FIG.
The light emitting device of the present invention uses the organic electroluminescent element of the present invention.
FIG. 2 is a cross-sectional view schematically showing an example of the light emitting device of the present invention.
The light emitting device 20 in FIG. 2 includes a transparent substrate (supporting substrate) 2, an organic electroluminescent element 10, a sealing container 11, and the like.

The organic electroluminescent device 10 is configured by sequentially laminating an anode (first electrode) 3, an organic layer 11, and a cathode (second electrode) 9 on a substrate 2. A protective layer 12 is laminated on the cathode 9, and a sealing container 16 is provided on the protective layer 12 with an adhesive layer 14 interposed therebetween. In addition, a part of each electrode 3 and 9, a partition, an insulating layer, etc. are abbreviate | omitted.
Here, as the adhesive layer 14, a photocurable adhesive such as an epoxy resin or a thermosetting adhesive can be used, and for example, a thermosetting adhesive sheet can also be used.

  The use of the light-emitting device of the present invention is not particularly limited, and for example, in addition to a lighting device, a display device such as a television, a personal computer, a mobile phone, and electronic paper can be used.

(Lighting device)
Next, an illumination device according to an embodiment of the present invention will be described with reference to FIG.
The lighting device of the present invention uses the organic electroluminescent element of the present invention.
FIG. 3 is a cross-sectional view schematically showing an example of a lighting device according to an embodiment of the present invention.
As shown in FIG. 3, the illumination device 40 according to the embodiment of the present invention includes the organic EL element 10 and the light scattering member 30 described above. More specifically, the lighting device 40 is configured such that the substrate 2 of the organic EL element 10 and the light scattering member 30 are in contact with each other.
The light scattering member 30 is not particularly limited as long as it can scatter light. In FIG. 3, the light scattering member 30 is a member in which fine particles 32 are dispersed on a transparent substrate 31. As the transparent substrate 31, for example, a glass substrate can be preferably cited. As the fine particles 32, transparent resin fine particles can be preferably exemplified. As the glass substrate and the transparent resin fine particles, known ones can be used. In such an illuminating device 40, when light emitted from the organic electroluminescent element 10 is incident on the light incident surface 30A of the scattering member 30, the incident light is scattered by the light scattering member 30, and the scattered light is emitted from the light emitting surface 30B. It is emitted as illumination light.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these. In particular, the presence or absence of a substituent hardly affects the effect of the present invention, and the same effect can be obtained even if the compound used in the following examples has a substituent. In addition, Example A-1, A-2, A-3, A-4 shall be read as reference example A-1, A-2, A-3, A-4, respectively.

[A. Examples A-1 to A-6 and Comparative Examples A-1 to A-4 (Production of Light-Emitting Element)]
(Example A-1)
<Preparation of Coating Solution A for Hole Transport Layer Formation>
Compound A1 was dissolved in xylene for electronic industry to give a total solid concentration of 0.4% by mass, and this was filtered through a PTFE filter having a pore size of 0.22 μm to prepare a coating liquid A for forming a hole transport layer. .

<Preparation of light emitting layer forming coating solution A>
95% by mass of the host compound H-1 and 5% by mass of the luminescent material Pt-1 are dissolved in methyl ethyl ketone (MEK) to a solid content concentration of 1.0% by mass, which has a pore size of 0.22 μm. It filtered with the PTFE filter and the coating liquid A for light emitting layer formation was prepared.

<Element fabrication>
A transparent support substrate was obtained by depositing ITO with a thickness of 150 nm on a glass substrate of 25 mm × 25 mm × 0.7 mm. This transparent support substrate was put in a cleaning container and subjected to ultrasonic cleaning in 2-propanol, and then subjected to UV-ozone treatment for 30 minutes.
On this ITO-attached glass substrate, 0.5 part by mass of Compound A (described in US2008 / 0220265) represented by the following structural formula is dissolved in 99.5 parts by mass of cyclohexanone, and spin-coated so that the thickness becomes about 5 nm ( (4000 rpm, 30 seconds), and then dried at 200 ° C. for 30 minutes to form a hole injection layer.

  On the hole injection layer, the hole transport layer forming coating liquid A prepared as described above is spin-coated (1500 rpm, 20 seconds) so as to have a thickness of about 10 nm, and then dried at 120 ° C. for 30 minutes. As a result, a hole transport layer was formed.

On the hole transport layer, spin coating (1500 rpm, 20 seconds) with the light emitting layer forming coating solution A prepared as described above in a glove box (dew point -68 degrees, oxygen concentration 10 ppm) to a thickness of about 30 nm. And a light emitting layer.
Next, BAlq (bis- (2-methyl-8-quinolinolato) -4- (phenyl-phenolato) -aluminum (III)) represented by the following structural formula is formed on the light emitting layer as an electron transporting layer. It formed by the vacuum evaporation method so that it might become 40 nm.

Lithium fluoride (LiF) was formed as an electron injection layer on the electron transport 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.). Thus, an organic electroluminescent element of Comparative Example A-1 was produced.

(Examples A-2 to A-6 and Comparative Examples A-1 to A-4)
In the preparation of the light emitting layer forming coating liquid A in Example A-1, the light emitting material and the host material described in Table 1 below were used instead of the light emitting material Pt-1 and the host compound H-1, Organic electroluminescent elements of Examples A-2 to A-6 and Comparative Examples A-1 to A-4 were obtained in the same manner as Example A-1.

(Measuring method)
A direct voltage was applied to each element to emit light using an organic electroluminescence display device (source measure unit type 2400 manufactured by KEITHLEY). The brightness 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. The results are shown in Table 1 below.
(A) Element variation The luminance at the time of DC current density of ^2.5 mA / cm ^{2 of} each element was used as an evaluation index, and the standard deviation σ of luminance when 20 elements were produced from the same material lot was shown in a table. The standard deviation σ is preferably closer to 1.
(B) Maximum emission wavelength λ1
Using a source measure unit 2400 made by Toyo Technica, a direct current voltage is applied to each element to emit light, and the emission maximum wavelength λ1 (nm) when the emission spectrum and emission wavelength are measured using a spectrum analyzer PMA-11 made by Hamamatsu Photonics. ) Is shown in Table 2.
(C) Difference Δλ (= λ1−λ2) between the emission maximum wavelength λ1 (nm) measured in (b) and the emission maximum wavelength λ2 (nm) when the luminescent material is dissolved in dichloromethane at a concentration of 5 mg / L and photoexcited. ) (Nm) is shown in Table 1.

  The structures of the compounds other than the above used in the examples and the emission maximum wavelength in the solution state of the luminescent material (dissolved in dichloromethane at a concentration of 5 mg / L) are described below.

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 element 11 ... Organic layer 12 ... Protective layer 14 ... Adhesive layer 16 ... Sealing container 20 ... Light emitting device 30 ... Light scattering member 30A ..Light incident surface 30B ... Light exit surface
31 ... Transparent substrate 32 ... Fine particles 40 ... Illumination device

Claims (9)

An organic electroluminescent element having a pair of electrodes consisting of an anode and a cathode and an organic layer including a light emitting layer between the electrodes on a substrate, the organic light emitting element represented by the following general formula (C-5) in the light emitting layer And a compound having the maximum emission wavelength λ1 when the device is energized and the compound represented by the general formula (C-5) dissolved in dichloromethane at a concentration of 5 mg / L and photoexcited. An organic electroluminescent device having a difference from the light emission maximum wavelength λ2 of 3 nm or less.
(In General Formula (C-5), A ^{501 to} A ⁵¹² each independently represents C—R or N. R represents a hydrogen atom or a substituent. L ⁵¹ represents a single bond or a divalent linking group. Y represents a nitrogen atom and Z represents a carbon atom.) The organic electroluminescent element according to claim 1, wherein the host material is a compound having a shape with an aspect ratio of 3 or more. The organic electroluminescent element according to claim 1, wherein the host material is a triphenylene derivative. The organic electroluminescent element according to any one of claims 1 to 3, wherein the light emission maximum wavelength λ1 and the light emission maximum wavelength λ2 have a relationship of λ1> λ2. The organic electroluminescent element according to claim 1, wherein the compound represented by the general formula (C-5) is represented by the following general formula (C-5-1 ) .
(In General Formula (C-5-1), X represents a carbon atom, Y represents a nitrogen atom, and Z represents 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 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; , n, if p and q is 2 or more, it may form a cyclic structure linked to each other in each next to each other.) The organic electroluminescent element according to claim 1, wherein at least one of the organic layers is formed by a solution coating process. The light-emitting device using the organic electroluminescent element as described in any one of Claims 1-6. The display apparatus using the organic electroluminescent element as described in any one of Claims 1-6. The illuminating device using the organic electroluminescent element as described in any one of Claims 1-6.