JP2006256999A - Organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal complex compound having good light-emitting characteristics and durability; and to provide an organic electroluminescent element. <P>SOLUTION: The compound is represented by general formula (IIA) (wherein, L<SP>1</SP>is a single bond or a divalent linking group; and R<SP>21</SP>to R<SP>56</SP>are each independently a hydrogen atom or a substituent). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a platinum complex compound useful as a light emitting material and an organic electroluminescent device using the same.

  Organic electroluminescence devices have been actively researched and developed because they can emit light with high brightness 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. As luminescent materials, iridium complexes and complexes are known (see, for example, Patent Document 1 and Patent Document 2). However, an element that achieves both high efficiency and high durability has not yet been developed, and light emission that can achieve both is achieved. Development of materials (preferably phosphorescent materials) is desired.

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

  An object of the present invention is to provide a complex compound suitable as a light emitting material. Another object of the present invention is to provide an organic electroluminescent device having high luminous efficiency and high durability using the same.

As a result of investigations to solve the above problems, the present inventors have found that an organic EL device containing a complex of a tetradentate ligand having a specific structure in an organic layer solves the above problems. That is, the present invention has been achieved by the following means.
(1) A compound represented by the following general formula (IIA).
General formula (IIA)

(In the general formula (IIA), L ¹ represents a single bond or a divalent linking group. R ²¹ , R ²² , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ and R ⁵⁶ are each independently hydrogen. Represents an atom or a substituent.)
(2) The compound according to 1, wherein the general formula (IIA) is represented by the following general formula (IIB):
General formula (IIB)

(In the general formula (IIB), R ²¹ , R ²² , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁶¹ and R ⁶² each independently represents a hydrogen atom or a substituent.)
(3) The compound according to 2, wherein the general formula (IIB) is represented by the following general formula (IIC):
General formula (IIC)

(In the general formula (IIC), R ²¹ , R ²² , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ and R ⁵⁶ represent a hydrogen atom or a substituent.)
(4) The compound according to 3, wherein the general formula (IIC) is represented by the following general formula (IID).
General formula (IID)

(In the general formula (IID), R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ and R ⁵⁶ represent a hydrogen atom or a substituent. R ²¹ represents a substituent.)
(5) The compound according to 4, wherein in the general formula (IID), R ⁵¹ , R ⁵³ , R ⁵⁴ and R ⁵⁶ each represent a hydrogen atom.
(6) The compound according to any one of 1 to 4, wherein the substituent is a substituent selected from the following group.
(Group: an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a carbon number 6-20 aryloxy group, C1-C20 acyl group, C2-C20 alkoxycarbonyl group, C1-C20 alkylthio group, C1-C20 sulfonyl group, hydroxy group, halogen atom , Cyano group, nitro group, heterocyclic group having 5 to 7 ring members)

  A complex represented by general formula (I) to general formula (IV) and (IIA) to (IID) of the present invention (used in the present specification in the same meaning as the “complex of the present invention”) is contained in the organic layer. By doing so, an organic electroluminescent element (used synonymously with “the element of the present invention” in the present specification) having high luminous efficiency (for example, external quantum efficiency) and excellent durability can be provided. In addition, by using a compound (complex) having a specific structure, it is possible to provide an element that emits light with high external quantum efficiency in the blue region and has excellent durability.

  In this specification, the substituent group A is 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, iso-propyl, tert-butyl, n-octyl, n- Decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, For example, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), alkynyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, For example, propargyl, 3-pentynyl, etc.), aryl groups (preferably having 6 to 30 carbon atoms, more preferably A prime number of 6 to 20, particularly preferably a carbon number of 6 to 12, such as phenyl, p-methylphenyl, naphthyl, anthranyl, etc., an amino group (preferably a carbon number of 0 to 30, more preferably a carbon number). 0 to 20, particularly preferably 0 to 10 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino, diphenylamino, ditolylamino, etc.), an alkoxy group (preferably 1 to 1 carbon atoms). 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, and examples thereof include methoxy, ethoxy, butoxy, 2-ethylhexyloxy and the like, and aryloxy groups (preferably 6 carbon atoms). -30, more preferably 6-20 carbons, particularly preferably 6-12 carbons, Phenyloxy, 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 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as acetyl, benzoyl, formyl, pivaloyl, etc.), an alkoxycarbonyl group ( Preferably it has 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms, and examples thereof include methoxycarbonyl, ethoxycarbonyl and the like, and an aryloxycarbonyl group (preferably having a carbon number). 7 to 30, more preferably 7 to 20 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonyl, and acyloxy groups (preferably 2 to 30 carbon atoms, more preferably carbon atoms). 2 to 20, particularly preferably 2 to 10 carbon atoms, for example, acetoxy, benzoyloxy An acylamino group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include acetylamino and benzoylamino). An alkoxycarbonylamino group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, particularly preferably 2 to 12 carbon atoms such as methoxycarbonylamino), aryloxycarbonylamino group (Preferably has 7 to 30 carbon atoms, more preferably 7 to 20 carbon atoms, and particularly preferably 7 to 12 carbon atoms, and examples thereof include phenyloxycarbonylamino).

A sulfonylamino group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfonylamino and benzenesulfonylamino), a sulfamoyl group ( Preferably it is C0-30, More preferably, it is C0-20, Most preferably, it is C0-12, for example, sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl etc. are mentioned. ), 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). An alkylthio group (preferably having 1 to 30 carbon atoms) Preferably it is C1-C20, Most preferably, it is C1-C12, for example, methylthio, ethylthio etc. are mentioned, for example, An arylthio group (Preferably C6-C30, More preferably C6-C20, Particularly preferably, it has 6 to 12 carbon atoms, and examples thereof include phenylthio.), A heterocyclic thio group (preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms). For example, pyridylthio, 2-benzimidazolylthio, 2-benzoxazolylthio, 2-benzthiazolylthio and the like, and a sulfonyl group (preferably having 1 to 30 carbon atoms, more preferably 1 carbon atom). To 20, particularly preferably 1 to 12 carbon atoms, such as mesyl and tosyl).

A sulfinyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfinyl, benzenesulfinyl, etc.), ureido group (preferably carbon 1 to 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as ureido, methylureido, phenylureido, etc.), phosphoric acid amide group (preferably having 1 carbon atom) To 30, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as diethyl phosphate amide and phenyl phosphate amide), hydroxy group, mercapto group, halogen atom (for example, Fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group Hydroxamic acid group, sulfino group, hydrazino group, imino group, heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms. Examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom. Specific examples include imidazolyl, pyridyl, quinolyl, furyl, thienyl, piperidyl, morpholino, benzoxazolyl, benzimidazolyl, benzthiazolyl, carbazolyl group, azepinyl group, etc., silyl group (preferably carbon number) 3 to 40, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, such as trimethylsilyl and triphenylsilyl), silyloxy groups (preferably 3 to 40 carbon atoms, more preferably Has 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms. Trimethylsilyloxy, etc. triphenylsilyl oxy and the like.) And the like. These substituents may be further substituted.

The substituent group A or the following groups (R ²¹ , R ²² , R ³¹ , R ³² , R ³³ , R ⁴¹ , R ⁴² , R ⁵¹ ) in the general formula (I) to the general formula (IID) described below. , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ^61, and R ⁶² ) are a substituent group selected from the following group: (group: an alkyl group having 1 to 20 carbon atoms, 2 to 2 carbon atoms) 10 alkenyl groups, aryl groups having 6 to 20 carbon atoms, amino groups having 0 to 20 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, aryloxy groups having 6 to 20 carbon atoms, acyl groups having 1 to 20 carbon atoms , An alkoxycarbonyl group having 2 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, a sulfonyl group having 1 to 20 carbon atoms, a hydroxy group, a halogen atom, a cyano group, a nitro group, a heterocyclic group having 5 to 7 ring members Is particularly preferred.

  The device of the present invention will be described in detail. The element of the present invention has at least one organic layer between a pair of electrodes. The element of the present invention has a pair of electrodes (a cathode and an anode) on a substrate, and an organic layer between both electrodes. In view of the properties of the element, at least one of the anode and the cathode is preferably transparent.

  The element of the present invention is characterized by containing a complex of a tetradentate ligand having a specific structure in the organic layer of the present invention. The function of the at least one organic layer is not particularly limited, but in addition to the light emitting layer, a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a hole block layer, an electron block layer, and an exciton block It may be a layer, a protective layer, or the like. In the element of the present invention, in addition to the at least one organic layer, a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a hole block layer, an electron block layer, an exciton block layer, a protection You may have a layer. Each of these layers may also have other functions.

  As an aspect of lamination of the organic layer in the present invention, an aspect in which a hole transport layer, a light emitting layer, and an electron transport layer are laminated in this order from the anode side is preferable. Further, a charge blocking layer or the like may be provided between the hole transport layer and the light-emitting layer, or between the light-emitting layer and the electron transport layer. A hole injection layer may be provided between the anode and the hole transport layer, and an electron injection layer may be provided between the cathode and the electron transport layer. Each layer may be divided into a plurality of secondary layers.

  The complex of the present invention can be contained in any layer when the organic layer is composed of a plurality of layers. The complex of the present invention is preferably contained in the light emitting layer, more preferably contained in the light emitting layer as a light emitting material, and particularly preferably contained in the light emitting layer together with at least one kind of host material.

  The content of the complex of the present invention, when contained in the light emitting layer as a light emitting material, is preferably in the range of 0.1% by mass or more and 50% by mass or less, and 0.2% by mass or more with respect to the total mass of the layer. A range of 30% by mass or less is more preferable, a range of 0.3% by mass or more and 20% by mass or less is further preferable, and a range of 0.5% by mass or more and 15% by mass or less is most preferable.

  The host material is a compound mainly responsible for charge injection and transport in the light emitting layer, and is a compound that does not emit light substantially. In this specification, “substantially no light emission” means that the light emission amount from the substantially non-light emitting compound is preferably 5% or less, more preferably 3% or less of the total light emission amount of the entire device. More preferably, it means 1% or less.

  The concentration of the host material in the light emitting layer is not particularly limited, but is preferably the main component (the component having the largest content) in the light emitting layer, more preferably 50% by mass or more and 99.9% by mass or less, 70 mass% or more and 99.8 mass% or less are more preferable, 80 mass% or more and 99.7 mass% or less are especially preferable, and 90 mass% or more and 99.5 mass% or less are the most preferable.

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

  The fluorescence wavelength in the film state of the host material contained in the light emitting layer of the present invention is preferably in the range of 400 nm to 650 nm, more preferably in the range of 420 nm to 600 nm, and in the range of 440 nm to 550 nm. More preferably.

  As the host material used in the present invention, the compounds described in paragraphs 0113 to 0161 of JP-A No. 2002-1000047 and the compounds described in paragraphs of 0087 to 0098 of JP-A No. 2004-214179 can be suitably used. It is not limited to.

The complex represented by the general formula (I) will be described. In the general formula (I), Z ¹ and Z ² each represent a nitrogen-containing aromatic 6-membered ring coordinated to platinum with a nitrogen atom. Q represents an aromatic 5-membered ring containing 1 or 2 nitrogen atoms. L ¹ and L ² represent a single bond or a linking group. n represents 0 or 1.

Z ¹ and Z ² represent a nitrogen-containing aromatic 6-membered ring coordinated to platinum with a nitrogen atom. Examples of Z ¹ and Z ² include pyridine, pyrazine, pyrimidine, pyridazine, and triazine, preferably pyridine, pyrazine, and pyrimidine, more preferably pyridine, pyrazine, and pyrimidine, and more preferably pyridine and pyrazine. Particularly preferred is pyridine. Z ¹ and Z ² may be equal to or different from each other. Z ¹ and Z ² may have a substituent selected from the substituent group A if possible.

Z ¹ and Z ² may preferably have an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group, an alkylthio group, a sulfonyl group, a hydroxy group, A halogen atom, a cyano group, a nitro group, or a heterocyclic group.

Z ¹ and Z ² may form a condensed ring with other rings if possible. Examples of condensed rings include benzene ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, thiophene ring, furan ring, pyrrole ring, imidazole ring, pyrazole ring, triazole ring, oxazole ring, thiazole ring, oxadiazole. Ring, thiadiazole ring and the like.

Z ¹ and Z ² are preferably substituted and unsubstituted pyridine rings, pyrazine rings and pyrimidine rings, more preferably unsubstituted pyridine and pyrazine rings, and still more preferably unsubstituted pyridine rings.

Q represents a nitrogen-containing aromatic 5-membered ring containing one or two nitrogen atoms. That is, Q forms a nitrogen-containing aromatic five-membered ring having one or two nitrogen atoms together with the carbon atom and nitrogen atom represented by Z ¹ —NC—Pt (or Z ² —NC—Pt). Represents a group. Examples of Q include (un) substituted pyrrole, pyrazole, and imidazole, preferably (unsubstituted) pyrrole and pyrazole, more preferably (unsubstituted) substituted pyrazole, and further preferably 3-position. A pyrazole having a substituent at the 3-position, more preferably a pyrazole having an alkyl group and a cyano group at the 3-position, and particularly preferably a pyrazole having a trifluoromethyl group, a t-butyl group and a cyano group at the 3-position. is there.

  Q may have a substituent if possible, and the substituent is synonymous with the substituent group A. The substituent for Q is preferably an alkyl group, an aryl group, a heterocyclic group, or a cyano group, more preferably an alkyl group or a cyano group, and still more preferably a trifluoromethyl group, a t-butyl group, or a cyano group. It is.

  Q may form a condensed ring with other rings if possible. Examples of condensed rings include benzene ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, thiophene ring, furan ring, pyrrole ring, imidazole ring, pyrazole ring, triazole ring, oxazole ring, thiazole ring, oxadiazole. Ring, thiadiazole ring and the like.

L ¹ and L ² represent a single bond or a divalent linking group, and n represents 0 or 1. n is preferably 0. That is, when n = 0, two Q's are not connected to form a ring. Although it does not specifically limit as a bivalent coupling group, The coupling group which consists of a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, and a silicon atom is preferable. Specific examples of the divalent linking group are shown below, but the present invention is not limited thereto.

These linking groups may further have a substituent if possible, and examples of the substituent that can be introduced include those listed as the substituents for Z ¹ and Z ² .

L ¹ is preferably a dialkylmethylene group, a diarylmethylene group or a diheteroarylmethylene group, more preferably a dimethylmethylene group or a diphenylmethylene group, still more preferably a dimethylmethylene group.

Among the complexes represented by the general formula (I), one of preferred forms is a complex represented by the general formula (II). In the general formula (II), Z ¹ and Z ² represent nitrogen-containing aromatic 6-membered rings coordinated to platinum with nitrogen atoms. L ¹ represents a single bond or a divalent linking group. L ¹ has the same meaning as that in formula (I), and the preferred range is also the same. R ²¹ and R ²² each independently represent a hydrogen atom or a substituent, and the substituent has the same meaning as the substituent group A. R ²¹ and R ²² substituted on the same pyrazole ring may be linked to form a condensed ring. R ²² may combine with R ²² substituted with another pyrazole to form a ring.

R ²¹ is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, a t-butyl group or a cyano group, more preferably a methyl group, a trifluoromethyl group, a t-butyl group or a cyano group, A trifluoromethyl group, a t-butyl group, and a cyano group are preferable.

R ²² is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, a t-butyl group, a cyano group, or a group in which R ²² are linked to each other to form a substituted or unsubstituted methylene or ethylene, more preferably , A hydrogen atom, a cyano group, and a group in which R ²² are linked to form a substituted or unsubstituted ethylene, and more preferably a hydrogen atom, R ²² are linked to each other to form a tetramethylethylene. Particularly preferred is a hydrogen atom.

Of the complexes represented by the general formula (I), one of other preferred forms is a complex represented by the general formula (III). In general formula (III), Z < ¹ >, Z < ² > represents the nitrogen-containing aromatic 6-membered ring coordinated to platinum with a nitrogen atom. L ¹ represents a single bond or a divalent linking group. L ¹ has the same meaning as that in formula (I), and the preferred range is also the same. R ³¹ , R ³² , and R ³³ each independently represent a hydrogen atom or a substituent, and the substituent is as defined in Substituent Group A. R ³¹ and R ³² , and R ³² and R ³³ may be linked to each other to form a condensed ring.

The condensed ring formed by linking R ³¹ and R ³² and R ³² and R ³³ includes a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, a pyrrole ring, a pyrazole ring, an imidazole ring, and an oxazole ring. , Thiazole ring, isothiazole ring, isoxazole ring and the like, and preferred are a benzene ring, a pyridine ring, a pyrimidine ring and a pyrazine ring. These rings may be further condensed with other rings.

R ³¹ is preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, or a group that forms a condensed ring with R ³² , and more preferably a hydrogen atom, a methyl group, a t-butyl group, a phenyl group, or a cyano group. , A trifluoromethyl group, and a group that forms a condensed ring with R ³² , more preferably a methyl group, a t-butyl group, and a group that forms a condensed ring with R ³² .

R ³² is preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, a group that forms a condensed ring with R ³¹ , or a group that forms a condensed ring with R ³³ , more preferably a hydrogen atom, a methyl group, a t-butyl group, a phenyl group, a cyano group, a trifluoromethyl group, a group that forms a condensed ring with R ³¹ , a group that forms a condensed ring with R ³³ , and more preferably a t-butyl group, a cyano group, It is a group that forms a condensed ring together with the trifluoromethyl group and R ³¹ .

R ³³ is preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, or a group that forms a condensed ring with R ³² , and more preferably a hydrogen atom, a methyl group, or a group that forms a condensed ring with R ^32. And more preferably a hydrogen atom or a group which forms a condensed ring together with R ³² .

Among the complexes represented by the general formula (I), one of other preferred forms is a complex represented by the general formula (IV). The general formula (IV) will be described. In the general formula (IV), Z ¹ and Z ² represent a nitrogen-containing aromatic 6-membered ring coordinated to platinum with a nitrogen atom. L ¹ represents a single bond or a divalent linking group. L ¹ has the same meaning as that in formula (I), and the preferred range is also the same. R ⁴¹ and R ⁴² each independently represent a hydrogen atom or a substituent, and as the substituent, a substituent selected from the substituent group A can be applied. R ⁴¹ and R ⁴² may be connected to each other to form a condensed ring. The condensed ring formed by linking R ⁴¹ and R ⁴² includes a benzene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxazole ring, a thiazole ring, and an isothiazole ring. , An isoxazole ring, and the like, preferably a benzene ring, a pyridine ring, a pyrimidine ring, and a pyrazine ring. These rings may be further condensed with other rings.

R ⁴¹ is preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, or a group that forms a condensed ring together with R ⁴² , and more preferably a hydrogen atom, a methyl group, a t-butyl group, a phenyl group, or a cyano group. , trifluoromethyl group, a group forming a condensed ring together with R ^42, more preferably, a methyl group, a cyano group, a group forming a condensed ring together with R ^42.

R ⁴² is preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, or a group that forms a condensed ring together with R ⁴¹ , and more preferably a hydrogen atom, a methyl group, a t-butyl group, a phenyl group, or a cyano group. , A trifluoromethyl group, and a group that forms a condensed ring with R ⁴¹ , and more preferably a group that forms a condensed ring with a methyl group, a cyano group, and R ⁴¹ .

The complex represented by the general formula (II) is more preferably a complex represented by the general formula (IIA). The general formula (IIA) will be described. In General Formula (IIA), L ¹ represents a single bond or a divalent linking group. L ¹ has the same meaning as that in formula (I), and the preferred range is also the same. R ²¹ , R ²² , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ and R ⁵⁶ represent a hydrogen atom or a substituent. R ²¹ and R ²² have the same meanings as those in formula (II), and preferred ranges are also the same. R ^{51 to} R ⁵⁶ represent a hydrogen atom or a substituent. The substituents represented by R ^{51 to} R ⁵⁶ have the same meaning as the substituent group A. R ^{51 to} R ⁵⁶ may be bonded to each other to form a ring, if possible.

R ⁵¹ and R ⁵⁴ are preferably hydrogen atoms, alkyl groups, aryl groups, amino groups, alkoxy groups, aryloxy groups, acyl groups, alkoxycarbonyl groups, alkylthio groups, sulfonyl groups, hydroxy groups, halogen atoms, cyano groups. , A nitro group, a heterocyclic group, more preferably a hydrogen atom, an alkyl group, an aryl group, a halogen atom, a cyano group, or a heterocyclic group, still more preferably a hydrogen atom, a methyl group, a t-butyl group, A trifluoromethyl group, a phenyl group, a fluorine atom, a cyano group, and a pyridyl group are more preferable, and a hydrogen atom, a methyl group, and a fluorine atom are more preferable, and a hydrogen atom is particularly preferable.

R ⁵³ and R ⁵⁶ are preferably synonymous with the preferred ranges of R ⁵¹ and R ⁵⁴ .

R ⁵² and R ⁵⁵ are preferably a hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a halogen atom, a cyano group, or a heterocyclic group, more preferably A hydrogen atom, an alkyl group, an aryl group, an amino group, an alkoxy group, an aryloxy group and a heterocyclic group, more preferably a hydrogen atom, an alkyl group, an amino group, an alkoxy group and a heterocyclic group, and more preferably Is a hydrogen atom, a methyl group, a t-butyl group, a dimethylamino group, a diphenylamino group, a methoxy group or a carbazolyl group, particularly preferably a hydrogen atom.

The complex represented by the general formula (IIA) is more preferably a complex represented by the general formula (IIB). General formula (IIB) is demonstrated. In the general formula (IIB), R ²¹ , R ²² , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁶¹ and R ⁶² represent a hydrogen atom or a substituent. R ²¹ and R ²² have the same meanings as those in formula (II), and preferred ranges are also the same. R ^{51 to} R ⁵⁶ have the same meanings as those in formula (IIA), and preferred ranges are also the same. R ⁶¹ and R ⁶² represent a hydrogen atom or a substituent. The substituent represented by R ⁶¹ and R ⁶² has the same meaning as the substituent group A. R ⁶¹ and R ⁶² are preferably a hydrogen atom, an alkyl group, an aryl group, a halogen atom, a cyano group, or a heterocyclic group, more preferably a hydrogen atom, a methyl group, a trifluoromethyl group, a phenyl group, or a fluorine atom. , A cyano group and a pyridyl group, more preferably a methyl group, a phenyl group and a pyridyl group, and still more preferably a methyl group.

The complex represented by the general formula (IIB) is more preferably a complex represented by the general formula (IIC). The general formula (IIC) will be described. In the general formula (IIC), R ²¹ , R ²² , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ and R ⁵⁶ represent a hydrogen atom or a substituent. R ²¹ and R ²² have the same meanings as those in formula (II), and preferred ranges are also the same. R ^{51 to} R ⁵⁶ have the same definitions as those in formula (IIA), and preferred ranges are also the same.

The complex represented by the general formula (IIC) is more preferably a complex represented by the general formula (IID). The general formula (IID) will be described. In the general formula (IID), R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ and R ⁵⁶ represent a hydrogen atom or a substituent. R ²¹ represents a substituent. R ^{51 to} R ⁵⁶ have the same definitions as those in formula (IIA), and preferred ranges are also the same. R ²¹ represents a substituent. The substituent represented by R ²³ has the same meaning as the substituent group A. R ²¹ is preferably an alkyl group, aryl group, amino group, alkoxy group, aryloxy group, acyl group, alkoxycarbonyl group, alkylthio group, sulfonyl group, hydroxy group, halogen atom, cyano group, nitro group, heterocyclic group More preferably an alkyl group, an aryl group, a sulfonyl group, a halogen atom, a cyano group, or a heterocyclic group, and still more preferably an alkyl group, a perfluoroalkyl group, an aryl group, a perfluoroaryl group, a sulfonyl group, a halogen group. Atom, cyano group, heterocyclic group, more preferably methyl group, t-butyl group, trifluoromethyl group, phenyl group, tolyl group, pentafluorophenyl group, mesyl group, tosyl group, fluorine atom, cyano group A pyridyl group, more preferably a methyl group or a t-butyl group A trifluoromethyl group, a cyano group, especially preferably, t- butyl group, a trifluoromethyl group, a cyano group.

In the general formula (IID), R ⁵¹ , R ⁵³ , R ⁵⁴ and R ⁵⁶ preferably all represent a hydrogen atom.

  Specific examples of the complex represented by the general formula (I) in the present invention are illustrated below, but the present invention is not limited to these (Ph represents a phenyl group).

  Each element constituting the element of the present invention will be described in detail.

<Board>
The substrate used in the present invention is preferably a substrate that does not scatter or attenuate light emitted from the organic layer. Specific examples thereof include zirconia stabilized yttrium (YSZ), inorganic materials such as glass, polyesters such as polyethylene terephthalate, polybutylene phthalate, and polyethylene naphthalate, polystyrene, polycarbonate, polyethersulfone, polyarylate, polyimide, and polycycloolefin. , Organic materials such as norbornene resin and poly (chlorotrifluoroethylene).
For example, when glass is used as the substrate, alkali-free glass is preferably used as the material in order to reduce ions eluted from the glass. Moreover, when using soda-lime glass, it is preferable to use what gave barrier coatings, such as a silica. 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.

  There is no restriction | limiting in particular about the shape of a board | substrate, a structure, a magnitude | size, It can select suitably according to the use, purpose, etc. of a light emitting element. In general, the shape of the substrate is preferably a plate shape. The structure of the substrate may be a single layer structure, a laminated structure, may be formed of a single member, or may be formed of two or more members.

  The substrate may be colorless and transparent or colored and transparent, but is preferably colorless and transparent in that it does not scatter or attenuate light emitted from the organic light emitting layer.

The substrate can be provided with a moisture permeation preventing layer (gas barrier layer) on the front surface or the back surface.
As a material for the moisture permeation preventive layer (gas barrier layer), inorganic materials such as silicon nitride and silicon oxide are preferably used. The moisture permeation preventing layer (gas barrier layer) can be formed by, for example, a high frequency sputtering method. When a thermoplastic substrate is used, a hard coat layer, an undercoat layer, or the like may be further provided as necessary.

<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.

  Suitable examples of the material for the anode include metals, alloys, metal oxides, conductive compounds, and mixtures thereof. Specific examples of the anode material include conductive metals such as tin oxide (ATO, FTO) doped with antimony or fluorine, tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), etc. Metals such as oxides, gold, silver, chromium, nickel, and mixtures or laminates of these metals and conductive metal oxides, inorganic conductive materials such as copper iodide and copper sulfide, polyaniline, polythiophene, polypyrrole, etc. Organic conductive materials, and a laminate of these and ITO. Among these, conductive metal oxides are preferable, and ITO is particularly preferable from the viewpoints of productivity, high conductivity, transparency, and the like.

  The anode is composed of, for example, a wet method such as a printing method and a coating method, a physical method such as a vacuum deposition method, a sputtering method, and an ion plating method, and a chemical method such as a CVD and a plasma CVD method. It can be formed on the substrate according to a method appropriately selected in consideration of suitability with the material to be processed. For example, when ITO is selected as the anode material, the anode can be formed according to a direct current or high frequency sputtering method, a vacuum deposition method, an ion plating method, or the like.

  In the organic electroluminescent element of the present invention, the formation position of the anode is not particularly limited and can be appropriately selected according to the use and purpose of the light emitting element. Is preferably formed on the substrate. In this case, the anode may be formed on the entire one surface of the substrate, or may be formed on a part thereof.

  The patterning for forming the anode may be performed by chemical etching such as photolithography, or may be performed by physical etching such as laser, or vacuum deposition or sputtering with a mask overlapped. It may be performed by a lift-off method or a printing method.

  The thickness of the anode can be appropriately selected depending on the material constituting the anode and cannot be generally defined, but is usually about 10 nm to 50 μm, and preferably 50 nm to 20 μm.

The resistance value of the anode is preferably 10 ³ Ω / □ or less, and more preferably 10 ² Ω / □ or less. When the anode is transparent, it may be colorless and transparent or colored and transparent. In order to take out light emission from the transparent anode side, the transmittance is preferably 60% or more, and more preferably 70% or more.

  The transparent anode is described in detail in the book “New Development of Transparent Electrode Films” published by CMC (1999), supervised by Yutaka Sawada, and the matters described here can be applied to the present invention. In the case of using a plastic substrate having low heat resistance, a transparent anode formed using ITO or IZO at a low temperature of 150 ° C. or lower is preferable.

<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.

  Examples of the material constituting the cathode include metals, alloys, metal oxides, electrically conductive compounds, and mixtures thereof. Specific examples include alkali metals (eg, Li, Na, K, Cs, etc.), alkaline earth metals (eg, Mg, Ca, etc.), gold, silver, lead, aluminum, sodium-potassium alloys, lithium-aluminum alloys, magnesium. -Rare earth metals such as silver alloys, indium, ytterbium, and the like. These may be used alone, but two or more can be suitably used in combination from the viewpoint of achieving both stability and electron injection.

Among these, as a material constituting the cathode, an alkali metal or an alkaline earth metal is preferable from the viewpoint of electron injecting property, and a material mainly composed of aluminum is preferable from the viewpoint of excellent storage stability.
The material mainly composed of aluminum is aluminum alone, an alloy of aluminum and 0.01 to 10% by mass of alkali metal or alkaline earth metal, or a mixture thereof (for example, lithium-aluminum alloy, magnesium-aluminum alloy, etc.) Say.

  The materials for the cathode are described in detail in JP-A-2-15595 and JP-A-5-121172, and the materials described in these public relations can also be applied in the present invention.

  There is no restriction | limiting in particular about the formation method of a cathode, According to a well-known method, it can carry out. For example, the cathode described above is configured from a wet method such as a printing method or a coating method, a physical method such as a vacuum deposition method, a sputtering method, or an ion plating method, or a chemical method such as CVD or plasma CVD method. It can be formed according to a method appropriately selected in consideration of suitability with the material. For example, when a metal or the like is selected as the cathode material, one or more of them can be simultaneously or sequentially performed according to a sputtering method or the like.

  Patterning when forming the cathode may be performed by chemical etching such as photolithography, physical etching by laser, or the like, or by vacuum deposition or sputtering with the mask overlaid. It may be performed by a lift-off method or a printing method.

In the present invention, the cathode forming position is not particularly limited, and may be formed on the entire organic layer or a part thereof.
Further, a dielectric layer made of an alkali metal or alkaline earth metal fluoride or oxide may be inserted between the cathode and the organic layer with a thickness of 0.1 to 5 nm. This dielectric layer can also be regarded as a kind of electron injection layer. The dielectric layer can be formed by, for example, a vacuum deposition method, a sputtering method, an ion plating method, or the like.

The thickness of the cathode can be appropriately selected depending on the material constituting the cathode and cannot be generally defined, but is usually about 10 nm to 5 μm, and preferably 50 nm to 1 μm.
Further, the cathode may be transparent or opaque. The transparent cathode can be formed by depositing a thin cathode material to a thickness of 1 to 10 nm and further laminating a transparent conductive material such as ITO or IZO.

<Organic layer>
The organic layer in the present invention will be described. The element of the present invention has at least one organic layer including a light emitting layer, and the organic layer other than the organic light emitting layer includes a hole transport layer, an electron transport layer, and a hole block layer as described above. , Electron blocking layer, hole injection layer, electron injection layer and the like.

-Formation of organic layer-
In the organic electroluminescent element of the present invention, each layer constituting the organic layer can be suitably formed by any of a dry film forming method such as a vapor deposition method and a sputtering method, a transfer method, and a printing method.

-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 and to emit light.
The light emitting layer in the present invention may be composed of only a light emitting material, or may be a mixed layer of a host material and a light emitting material. The light emitting material 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. Further, the light emitting layer may include a material that does not have charge transporting properties and does not emit light. The light emitting layer is preferably one using the complex of the present invention as a light emitting material, and more preferably composed of at least one kind of host material and the complex of the present invention.
In addition, the light emitting layer may be a single layer or two or more layers, and each layer may emit light in different emission colors.

  Examples of fluorescent materials that can be used in the present invention include, for example, benzoxazole derivatives, benzimidazole derivatives, benzothiazole derivatives, styrylbenzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalimide derivatives, coumarin derivatives. , Condensed aromatic compounds, perinone derivatives, oxadiazole derivatives, oxazine derivatives, aldazine derivatives, pyralidine derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazolopyridine derivatives, cyclopentadiene derivatives, styryl Complexes of amine derivatives, diketopyrrolopyrrole derivatives, aromatic dimethylidin compounds, 8-quinolinol derivatives and pyromethene derivatives Various complexes represented, polythiophene, polyphenylene, polyphenylene vinylene polymer compounds include compounds such as organic silane derivatives.

Examples of the phosphorescent material that can be used in the present invention include, in addition to the complex of the present invention, a complex containing a transition metal atom or a lanthanoid atom.
Although it does not specifically limit as a transition metal atom, Preferably, ruthenium, rhodium, palladium, tungsten, rhenium, osmium, iridium, and platinum are mentioned, More preferably, they are rhenium, iridium, and platinum.
Examples of lanthanoid atoms include lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium. Among these lanthanoid atoms, neodymium, europium, and gadolinium are preferable.

Examples of the ligand of the complex include G. Wilkinson et al., Comprehensive Coordination Chemistry, Pergamon Press, 1987, H. Yersin, “Photochemistry and Photophysics of Coordination Compounds,” Springer-Verlag, 1987, Akio Yamamoto. Examples of the ligands described in the book “Organic Metal Chemistry-Fundamentals and Applications-” published in 1982 by Hankabosha.
Specific ligands are preferably halogen ligands (preferably chlorine ligands), nitrogen-containing heterocyclic ligands (eg, phenylpyridine, benzoquinoline, quinolinol, bipyridyl, phenanthroline, etc.), diketones Ligand (for example, acetylacetone), carboxylic acid ligand (for example, acetic acid ligand), carbon monoxide ligand, isonitrile ligand, cyano ligand, more preferably nitrogen-containing Heterocyclic ligand. The complex may have one transition metal atom in the compound, or may be a so-called binuclear complex having two or more. Different metal atoms may be contained at the same time.

  The phosphorescent material is preferably contained in the light emitting layer in an amount of 0.1 to 40% by mass, and more preferably 0.5 to 20% by mass.

  Examples of the host material contained in the light emitting layer in the present invention include those having a carbazole skeleton, those having a diarylamine skeleton, those having a pyridine skeleton, those having a pyrazine skeleton, those having a triazine skeleton, and aryl. Examples thereof include materials having a silane skeleton and materials exemplified in the sections of a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer described later.

  Although the thickness of a light emitting layer is not specifically limited, Usually, it is preferable that they are 1 nm-500 nm, it is more preferable that they are 5 nm-200 nm, and it is still more preferable that they are 10 nm-100 nm.

-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. Specifically, the hole injection layer and the hole transport layer are carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamines. Derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, porphyrin compounds, organosilane derivatives, carbon And the like.

The thicknesses of the hole injection layer and the hole transport layer are each preferably 500 nm or less from the viewpoint of lowering the driving voltage.
The thickness of the hole transport layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and still more preferably 10 nm to 100 nm. In addition, the thickness of the hole injection layer is preferably 0.1 nm to 200 nm, more preferably 0.5 nm to 100 nm, and still more preferably 1 nm to 100 nm.
The hole injection layer and the hole transport layer may have a single layer structure composed of one or more of the above-described materials, or may have a multilayer structure composed of a plurality of layers having the same composition or different compositions.

-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. Specifically, the electron injection layer and the electron transport layer are triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, Carbodiimide derivatives, fluorenylidenemethane derivatives, distyrylpyrazine derivatives, aromatic tetracarboxylic anhydrides such as naphthalene and perylene, phthalocyanine derivatives, 8-quinolinol derivative complexes, metal phthalocyanines, benzoxazoles and benzothiazoles as ligands It is preferably a layer containing various complexes typified by the complex to be prepared, an organosilane derivative, and the like.

The thicknesses of the electron injection layer and the electron transport layer are each preferably 50 nm or less from the viewpoint of lowering the driving voltage.
The thickness of the electron transport layer is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm, and still more preferably 10 nm to 100 nm. In addition, the thickness of the electron injection layer is preferably 0.1 nm to 200 nm, more preferably 0.2 nm to 100 nm, and still more preferably 0.5 nm to 50 nm.
The electron injection layer and the electron transport layer may have a single-layer structure made of one or more of the materials described above, or may have a multilayer structure made up of a plurality of layers having the same composition or different compositions.

-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 aluminum complexes such as BAlq, triazole derivatives, phenanthroline derivatives such 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.

<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.
Specific examples thereof include metals such as In, Sn, Pb, Au, Cu, Ag, Al, Ti, and Ni, MgO, SiO, SiO ₂ , Al ₂ O ₃ , GeO, NiO, CaO, BaO, and Fe ₂ O. ₃ , metal oxides such as Y ₂ O ₃ and TiO ₂ , metal nitrides such as SiN _x and SiN _x O _y , metal fluorides such as MgF ₂ , LiF, AlF ₃ and CaF ₂ , polyethylene, polypropylene, polymethyl Monomer mixture containing methacrylate, polyimide, polyurea, polytetrafluoroethylene, polychlorotrifluoroethylene, polydichlorodifluoroethylene, copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, tetrafluoroethylene and at least one comonomer A copolymer obtained by copolymerization of a copolymer having a cyclic structure in the copolymer main chain. Copolymer, 1% by weight of the water absorbing water absorption material, water absorption of 0.1% or less of moisture-proof material, and the like.

  The method for forming the protective layer is not particularly limited, and for example, vacuum deposition, sputtering, reactive sputtering, MBE (molecular beam epitaxy), cluster ion beam, ion plating, plasma polymerization (high frequency) Excited ion plating method), plasma CVD method, laser CVD method, thermal CVD method, gas source CVD method, coating method, printing method, transfer method can be applied.

<Sealing>
The element of this invention may seal the whole element using a sealing container. You may enclose a water | moisture-content absorber or an inert liquid in the space between a sealing container and an 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 fluorinated solvents such as paraffins, liquid paraffins, perfluoroalkanes, perfluoroamines, perfluoroethers, chlorinated solvents, and silicone oils. It is done.

  The element of the present invention can obtain light emission by applying a direct current (which may include an alternating current component if necessary) voltage (usually 2 to 15 volts) or a direct current between the anode and the cathode. it can.

  Regarding the driving method of the element of the present invention, JP-A-2-148687, JP-A-6-301355, JP-A-5-29080, JP-A-7-134558, JP-A-8-234665, and JP-A-8-214447, The driving methods described in Japanese Patent No. 2784615, US Pat. Nos. 5,828,429 and 6023308, etc. can be applied.

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

  The complex of the present invention can be produced, for example, by the steps shown below. The production method of the compound represented by the general formula (IIC) will be specifically described.

In the above formula, R ²¹ , R ²² , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ and R ⁵⁶ each independently represent a hydrogen atom or a substituent. The complex of the present invention is described in Journal of Organic Chemistry 53, 786, (1988), GR Newkome et al.), Page 789, left line 53 to right line 7, line 790, left line 18 line- It can be obtained by the method described in line 38, the method described in page 790, right line, lines 19-30, and combinations thereof. 1 to 1.2 equivalents of a base such as lithium diisopropylamide, potassium t-butoxide, sodium hydride at 0 ° C. to room temperature with respect to a solution of (A) in N, N-dimethylformamide, starting from compound (A) In addition, the mixture was reacted at 0 ° C. to room temperature for about 30 minutes, 1.5 to 4 equivalents of methyl iodide was added thereto, reacted at room temperature for about 30 minutes to monomethylate, and again under the same conditions, 1 to 1.2 equivalents of the above and an excess of methyl iodide can be reacted to obtain a dimethyl-substituted product (B) in a yield of 70 to 99%.

  The process of obtaining (C) from (B) is synthesized by following the method described in Chemische Berichte 113, 2749 (1980), H. Lexy et al., Page 2752, lines 26-35. be able to.

  In the step of obtaining the compound (D) of the present invention from (C), the compound (C) and 1 to 1.5 equivalents of platinum chloride are dissolved in benzonitrile. (Boiling point: 191 ° C.) and stirring for 30 minutes to 4 hours. Compound (D) can be purified by recrystallization using chloroform or ethyl acetate, silica gel column chromatography, sublimation purification or the like.

  In the production methods shown above, when the defined substituents change under the conditions of a certain synthesis method or are inappropriate for carrying out the method, the functional groups are protected and deprotected (for example, , Protective Groups in Organic Synthesis, TW Greene, John Wiley & Sons Inc. (1981), etc.) It can be easily manufactured by such means. Moreover, it is also possible to change the order of reaction steps such as introduction of substituents as necessary.

<Synthesis example>
(1) Synthesis of exemplary compound 2

Synthesis of Compound B1 Under a nitrogen stream, Compound A1 (18.6 g) was dissolved in 90 mL of N, N-dimethylformamide, cooled to 0 ° C., potassium t-butoxide (6.8 g, 1.05 eq) was added, The mixture was warmed to room temperature and stirred for 30 minutes. The mixture was cooled again to 0 ° C., methyl iodide (7.2 mL, 1.82 equivalents) was added, and the mixture was warmed to room temperature and stirred for 30 minutes for monomethylation. This operation was repeated again to carry out dimethylation. After extraction with ethyl acetate and washing with water and saturated brine, the organic layer was dried over magnesium sulfate, and ethyl acetate was distilled off. The obtained crude product was purified by silica gel column chromatography (hexane: ethyl acetate = 20: 1) to obtain 18.6 g (yield 92.1%) of Compound B1 as colorless crystals.

Synthesis of Compound C1 Under a nitrogen stream, compound B1 (3 g, 8.43 mmol), 3-trifluoromethylpyrazole (3.44 g, 25.28 mmol), potassium carbonate (7 g, 50.58 mmol), copper iodide (322 mg, 1.69 mmol) was suspended in 50 mL of nitrobenzene, and the temperature of the hot water bath was raised to 200 ° C. while stirring. The mixture was stirred for 2 hours under heating, and then cooled to room temperature. The insoluble part was removed by celite filtration, and the solvent of the filtrate was distilled off under reduced pressure. Purification by a silica gel column (hexane: ethyl acetate = 9: 1) gave 2.57 g (yield 65.4%) of compound C1 as a colorless liquid.

Synthesis of Exemplified Compound 2 Under a nitrogen stream, Compound C1 (2.57 g, 5.51 mmol) and platinum platinum (1.46 g, 5.51 mmol) were suspended in 20 mL of benzonitrile. When the temperature of the stirring bath was raised to 200 ° C., an orange solution was obtained. When heated and stirred for 3 hours and then cooled to room temperature, a yellow precipitate was obtained. The resulting precipitate was collected by filtration and washed with a small amount of ethanol to obtain a crude product. Purification by silica gel column chromatography (chloroform) yielded 1.5 g (yield 41.3%) of exemplary compound 2 as pale yellow crystals.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.

<Organic electroluminescent device>
1. Preparation of organic electroluminescence device (1) Preparation of organic electroluminescence device (TC-21) of the present invention Glass substrate having 0.5 mm thickness and 2.5 cm square ITO film (manufactured by Geomat Corp., surface resistance 10Ω / □) Was put into a washing container and subjected to ultrasonic cleaning in 2-propanol, followed by UV-ozone treatment for 30 minutes. The following organic compound layers were sequentially deposited on the transparent anode (ITO film) by vacuum deposition.
The vapor deposition rate in the examples of the present invention is 0.2 nm / second unless otherwise specified. The deposition rate was measured using a quartz resonator. The film thicknesses described below were also measured using a crystal resonator.

(First hole transport layer)
Copper phthalocyanine (CuPc): film thickness 10nm
(Second hole transport layer)
NPD: film thickness 40nm
(Light emitting layer)
Mixed layer of MCP = 92 mass%, exemplary compound 2 = 8 mass%: film thickness 30 nm
(First electron transport layer)
1,3,5-TTB: film thickness 10 nm
(Second electron transport layer)
1,3,5-TPB: film thickness 10 nm
(Third electron transport layer)
Alq: film thickness 10 nm

  Finally, 0.1 nm of lithium fluoride and 100 nm of metal aluminum were deposited in this order to form a cathode. Without exposing it to the atmosphere, put it in a glove box substituted with argon gas, and seal it with a stainless steel sealing can and an ultraviolet curable adhesive (XNR5516HV, manufactured by Nagase Ciba). The organic electroluminescent element (TC-21) of the comparative example was obtained.

(2) Production of Organic Electroluminescent Device (TC-22) of Comparative Example Organic Electroluminescent Device of Example in the same manner as TC-21) except that the luminescent material is changed from the pyrazole compound of the present invention to Firpic. (TC-22) was produced.

2. Evaluation of organic electroluminescent element The organic electroluminescent elements (TC-21 to 22) obtained above were evaluated by the following methods.
(1) Measurement of emission spectrum When a voltage of 11 V was applied to the organic electroluminescent elements (TC-21 to 22), all emitted blue light derived from the phosphorescent material. These were set in an emission spectrum measurement system (ELS 1500) manufactured by Shimadzu Corporation, and an emission spectrum at a luminance of 100 Cd / m ² was measured to obtain a peak wavelength of emission.

(2) Evaluation of driving durability The obtained organic electroluminescent elements (TC-21 to 22) were replaced with OL manufactured by Tokyo System Development Co., Ltd.
Set to ED test system ST-D type, drive in constant current mode under the condition of positive constant current 0.4mA, luminance half time (time until luminance decreases to 50% of initial luminance) t0.5 Asked. The results are shown in Table 1.

  According to the above examples, an organic electroluminescence device having high efficiency and high durability can be obtained by using the compound of the present invention.

Claims (6)

The compound represented by the following general formula (IIA).
General formula (IIA)

(In the general formula (IIA), L ¹ represents a single bond or a divalent linking group. R ²¹ , R ²² , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ and R ⁵⁶ are each independently hydrogen. Represents an atom or a substituent.) The compound according to claim 1, wherein the general formula (IIA) is represented by the following general formula (IIB).
General formula (IIB)

(In the general formula (IIB), R ²¹ , R ²² , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁶¹ and R ⁶² each independently represents a hydrogen atom or a substituent.) The compound according to claim 2, wherein the general formula (IIB) is represented by the following general formula (IIC).
General formula (IIC)

(In the general formula (IIC), R ²¹ , R ²² , R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ and R ⁵⁶ represent a hydrogen atom or a substituent.) The compound according to claim 3, wherein the general formula (IIC) is represented by the following general formula (IID).
General formula (IID)

(In the general formula (IID), R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ and R ⁵⁶ represent a hydrogen atom or a substituent. R ²¹ represents a substituent.) 5. The compound according to claim 4, wherein in the general formula (IID), R ⁵¹ , R ⁵³ , R ⁵⁴ , and R ⁵⁶ each represent a hydrogen atom. The said substituent is a substituent chosen from the following group, The compound as described in any one of Claims 1-4 characterized by the above-mentioned.
(Group: an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a carbon number 6-20 aryloxy group, C1-C20 acyl group, C2-C20 alkoxycarbonyl group, C1-C20 alkylthio group, C1-C20 sulfonyl group, hydroxy group, halogen atom , Cyano group, nitro group, heterocyclic group having 5 to 7 ring members)