JP6922734B2 - Iridium complex compound, organic electroluminescent device containing the compound, display device and lighting device - Google Patents

Description

The present invention relates to an iridium complex compound, in particular, an iridium complex compound useful as a material for a light emitting layer of an organic electroluminescent element, a composition containing the compound and a solvent, an organic electroluminescent element containing the compound, and the organic electroluminescent element. The present invention relates to a display device including an element and lighting.

In recent years, various electronic devices using an organic electroluminescent element (hereinafter referred to as "organic EL element") such as an organic EL lighting and an organic EL display are being put into practical use. Since the organic EL element has a low applied voltage, low power consumption, and is capable of emitting three primary colors, its application to lighting and displays is being studied. In order to realize these, not only the adjustment of the emission wavelength but also the improvement of the luminous efficiency and the drive life of the light emitting element are being actively studied for the light emitting material.

For the purpose of improving the luminous efficiency, it has been proposed to use a phosphorescent material for the light emitting layer of the organic EL element. Examples of the phosphorescent material include bis (2-phenylpyridinato-N, C2') iridium acetylacetonate (Ir (ppy) ₂ (acac)) and tris (2-phenylpyridinato-N, C2). ') (Ir (ppy) ₃ ) Orthometallated iridium complexes such as iridium are widely known.

As a method of forming an organic EL element using a phosphorescent material, a vacuum vapor deposition method is mainly used. However, usually, an element is manufactured by laminating a plurality of layers such as a light emitting layer, a charge injection layer, and a charge transport layer. Therefore, the vacuum vapor deposition method has a problem that the vapor deposition process becomes complicated, the productivity is inferior, and it is extremely difficult to increase the size of the lighting or display panel composed of these elements.

On the other hand, the organic EL element can be formed into a film by a coating method to form a layer. Since the coating method can easily form a stable layer as compared with the vacuum vapor deposition method, it is expected to be mass-produced for displays and lighting devices and to be applied to large devices.
For film formation by the coating method, it is necessary that the organic material contained in the layer is easily dissolved in the organic solvent. Usually, a solvent having a low boiling point and a low viscosity such as toluene is used. An ink prepared with such a solvent can be easily formed into a film by a spin coating method or the like.

Regarding the production of organic EL devices by the coating method, it is mainly necessary to improve the solubility of the orthometalated iridium complex. Generally, a specific functional group such as an alkyl group or an aralkyl group is introduced into the molecular structure as a solubilizing group (Patent Documents 1 and 2). In addition, there is an example in which the solubility is improved by devising the structure of the ligand without introducing a solubilizing group (Patent Document 3).

International Publication No. 2004/026886 International Publication No. 2013/105615 Japanese Patent Application Laid-Open No. 2014-74000

However, in these patent documents, regarding the ease of dissolving the phosphorescent material in an organic solvent, only the solubility of the phosphorescent material alone has been focused on. When a phosphorescent material is actually used as the light emitting layer of the organic EL element, it is generally used as a composition in which a charge transporting material is mixed, but the solubility of such a composition in an organic solvent Was not paid attention to. That is, even if the phosphorescent material alone dissolves in an organic solvent, does not precipitate as crystals even when stored for a long period of time, and has good storage stability, the phosphorescent material is in a state of a composition mixed with a charge transport material. It has been found that the above-mentioned storage stability may be a problem.
In addition, since the iridium complex, which is a phosphorescent material, is vulnerable to reduction, when it receives an electron and becomes an anionic state, the iridium complex itself deteriorates, or the charge transport material existing around the iridium complex in the light emitting layer deteriorates. Therefore, there is a problem that the light emission efficiency and the drive life of the element are lowered.
Further, as one of further methods for improving the luminous efficiency and the driving life, so-called heavy doping, in which the concentration of the iridium complex in the light emitting layer is increased, may be performed. However, when a heavy-doped device was examined in addition to a device having a normal doping concentration using the iridium complex specifically described in the above patent, the efficiency was not increased even by heavy doping because the original luminous efficiency was low. Or, the problem that the drive life is shortened on the contrary was found.

The present invention has been made in view of the above problems, has good storage stability even in the state of a composition mixed with a charge transport material, and has a light emitting layer formed by using the composition. An object of the present invention is to provide an iridium complex compound having improved element characteristics of an organic electroluminescent device.
Another object of the present invention is to provide an organic electroluminescent device having an improved device life, and a display device and a lighting device using the organic electroluminescent device.

As a result of diligent studies by the present inventors to solve the above problems, the iridium complex compound having a specific chemical structure has good storage stability even in the state of a composition mixed with a charge transport material, and The present invention has been completed by finding that the light emitting efficiency of an organic electroluminescent element having a light emitting layer formed by using the composition can be improved and the driving life can be extended.
That is, the gist of the present invention lies in the following [1] to [9].
[1] An iridium complex compound represented by the following formula (1).

In formula (1), Ir represents an iridium atom.
Ring Cy ¹ represents an aromatic ring or a heteroaromatic ring containing carbon atoms C ¹ and C ^2.
Ring Cy ² represents a 6-membered heteroaromatic ring containing a carbon atom C ³ and a nitrogen atom N ^1.
Ring Cy ³ represents an aromatic or heteroaromatic ring containing carbon atoms C ⁴ and C ^5.
Ring Cy ⁴ represents a 6-membered heteroaromatic ring containing a carbon atom C ⁶ and a nitrogen atom N ^2.
m = 1 or 2
m + n = 3.
a and c independently represent an integer of 1 to 2, and b and d independently represent an integer of 0 to 2.
One of a R ¹ and b R ² is represented by the following formula (2), one of c R ³ and d R ⁴ is represented by the following formula (3), and the other R ¹ and R ³ are independently hydrogen atom, fluorine atom, chlorine atom, bromine atom, amino group, hydroxy group, mercapto group, alkyl group having 1 to 30 carbon atoms, alkoxy group having 1 to 30 carbon atoms, and carbon. An alkenyl group having 2 to 30 carbon atoms, an alkylamino group having 1 to 30 carbon atoms, an aryloxy group having 3 to 30 carbon atoms, an aryl group having 3 to 30 carbon atoms, a heteroaryl group having 3 to 30 carbon atoms, and 3 carbon atoms. 30 arylamino group, or a selected aralkyl group or these having 7 to 40 carbon atoms, each other ^{R 2} and ^{R 4} are independently a fluorine atom, a chlorine atom, a bromine atom, an amino group, hydroxy group, a mercapto group , An alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkylamino group having 1 to 30 carbon atoms, an aryloxy group having 3 to 30 carbon atoms, and an aryloxy group having 3 to 30 carbon atoms. 3-30 aryl group, a heteroaryl group having 3 to 30 carbon atoms, Ru chosen arylamino group having 3 to 30 carbon atoms or an aralkyl group having 7 to 40 carbon atoms.

In equation (2), x represents an integer from 0 to 10.
h represents an integer of 1 to 3.
* Represents a bond.
R may be the same or different for each appearance, and may be independently further substituted with a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a cyano group, or a fluorine atom. It is selected from an alkyl group of ~ 20, an alkoxy group having 1 to 20 carbon atoms, an amino group which may be further substituted with an aryl group having 5 to 30 carbon atoms, or an acyl group having 1 to 20 carbon atoms.
R'may be the same or different for each appearance, and each is independently further substituted with an alkyl group having 1 to 20 carbon atoms or a fluorine atom which may be further substituted with a fluorine atom. It is selected from good aralkyl groups having 1 to 40 carbon atoms.

In equation (3), k represents an integer from 0 to 5.
y represents an integer of 1-10.
* Represents a bond.
R is synonymous with equation (2) and
R'' may be the same or different for each appearance, and may be independently further substituted with a fluorine atom or a fluorine atom. Alkyl group having 1 to 20 carbon atoms, carbon number 1 to 1 It is selected from a naphthyl group optionally substituted with 20 alkyl or aryl groups, or a heteroaryl group having 1 to 20 carbon atoms.
The hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, and a group of the R ¹ to R ⁴ excluding group, represented by the formula (2) and the formula (3) further, fluorine An alkyl group having 1 to 30 carbon atoms which may be further substituted with an atom, a chlorine atom, a bromine atom or a fluorine atom, and an aryl having 3 to 30 carbon atoms which may be further substituted with an alkyl group having 1 to 30 carbon atoms. It may be substituted with a group or an arylamino group having 3 to 30 carbon atoms.
When ^{there are a plurality of R 1 to} R ⁴ , they may be the same or different.
When a plurality of R ^{1 to} R ⁴ are adjacent to each other on the same ring ^{, the adjacent R 1 to} R ⁴ are directly bonded or have an alkylene group having 3 to 12 carbon atoms and an alkaneylene having 3 to 12 carbon atoms. Rings may be formed by bonding via a group or an arylene group having 6 to 12 carbon atoms, and these rings may be further substituted with a fluorine atom, a chlorine atom, a bromine atom, or a fluorine atom. Alkyl groups having 1 to 30 carbon atoms, alkoxy groups having 1 to 30 carbon atoms, aryloxy groups having 3 to 30 carbon atoms, and alkyl groups having 1 to 30 carbon atoms may be further substituted with 3 to 30 carbon atoms. It may be substituted with an aryl group or an arylamino group having 3 to 30 carbon atoms.
Further, R ¹ and R ² or R ³ and R ⁴ are directly bonded or bonded via an alkylene group having 3 to 12 carbon atoms, an alkaneylene group having 3 to 12 carbon atoms, or an arylene group having 6 to 12 carbon atoms. These rings may be further substituted with a fluorine atom, a chlorine atom, a bromine atom, or a fluorine atom, and have an alkyl group having 1 to 30 carbon atoms and 1 to 30 carbon atoms. It is further substituted with an alkoxy group, an aryloxy group having 3 to 30 carbon atoms, an alkyl group having 1 to 30 carbon atoms, an aryl group having 3 to 30 carbon atoms or an arylamino group having 3 to 30 carbon atoms. May be.
[2] The iridium complex compound according to [1], wherein the formula (2) is represented by the following formula (4), and the formula (3) is represented by the following formula (5).

ｐは０から２の整数を表し、
ｑは０から１０の整数を表し、
ｒは０から２の整数を表し、
ｐ＋ｑ＋ｒは０から１０の整数である。
＊は結合手を表す。
Ｒ、Ｒ’およびｈは式（２）と同義である。

p represents an integer from 0 to 2
q represents an integer from 0 to 10
r represents an integer from 0 to 2
p + q + r is an integer from 0 to 10.
* Represents a bond.
R, R'and h are synonymous with equation (2).

s represents an integer from 0 to 2
t represents an integer from 1 to 10
u represents an integer from 0 to 2
w represents an integer from 0 to 4
s + t + u + w is an integer from 1 to 10.
* Represents a bond.
R, R'' and k are synonymous with equation (3).
[3] At ^{least one of R 1} is represented by the formula (2) or the formula (4), and ^{at least one of R 3} is represented by the formula (3) or the formula (5) [1]. Alternatively, the iridium complex compound according to [2].
[4] The iridium complex compound according to any one of [1] to [3], wherein R'is selected from an aralkyl group having 4 to 40 carbon atoms which may be further substituted with a fluorine atom.
[5] The iridium complex compound according to any one of [1] to [4], wherein ^{Cy 1} and Cy ^{3 are benzene rings.}
[6] A composition containing the iridium complex compound according to any one of [1] to [5] and an organic solvent.
[7] An organic electroluminescent device containing the iridium complex compound according to any one of [1] to [5].
[8] A display device having the organic electroluminescent element according to [7].
[9] A lighting device having the organic electroluminescent element according to [7].

The iridium complex compound of the present invention is soluble in an organic solvent, and an organic electroluminescent device can be produced by a coating method. The iridium complex compound is useful as a material for an organic electroluminescent element because the luminous efficiency of the organic electroluminescent element containing the iridium complex compound is high and the drive life is long. Further, the organic electroluminescent device obtained by using the iridium complex compound is useful for a display device and a lighting device.

FIG. 1 is a cross-sectional view schematically showing an example of the structure of the organic electroluminescent device of the present invention.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.
Here, in the present specification, "% by mass" and "% by weight" and "parts by mass" and "parts by weight" are synonymous with each other.

<Iridium complex compound>
The iridium complex compound of the present invention is a compound represented by the following formula (1).

Hereinafter, each configuration of the formula (1) will be described in detail.

<Ring Cy ¹ and Ring Cy ³ >
Ring Cy ¹ represents an aromatic ring or a heteroaromatic ring containing carbon atoms C ¹ and C ^{2 coordinated to an iridium atom, and ring Cy 3} represents an aromatic ring or an aromatic ring containing ^{carbon atoms C 4} and C ⁵ coordinated to an iridium atom. Represents a heteroaromatic ring. Specifically, benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysen ring, triphenylene ring, fluorantene ring, furan ring, benzofuran ring, dibenzofuran ring, thiophene ring, Benzothiophene ring, dibenzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroylmidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, flopyrol ring, Flofuran ring, thienoflan ring, benzoisoxazole ring, benzoisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, synolin ring, quinoxalin ring, benzimidazole ring , Perimidine ring, quinazoline ring, quinazolinone ring are preferable. Among these, in order to improve the emission wavelength and solubility, or to control the wavelength of the device and improve the durability, an appropriate substituent is often introduced on these rings, and a method for introducing such a substituent is used. It is preferably a well-known ring. Rings Cy ¹ and Cy ³ are more preferably hydrocarbon aromatic rings, more preferably benzene rings or naphthalene rings, and particularly preferably benzene rings.

<Ring Cy ² and Ring Cy ⁴ >
Ring Cy ² represents a 6-membered ring heteroaromatic ring containing a carbon atom C ^{3 and a nitrogen atom N 1} coordinated with an iridium atom, ^{and ring Cy 4} represents a carbon atom C ^{6 and a nitrogen atom N 2} coordinated with an iridium atom. Represents a 6-membered heteroaromatic ring containing. Specifically, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, shea Norin ring. Among these, pyridine is preferable because it is easy to introduce a substituent and it is easy to adjust the emission wavelength and solubility, and many methods that can be synthesized in good yield when complexing with iridium are known. ring, pyrazine ring, pin Rimijin ring, a triazine ring, more preferably a pyridine ring, a pyrimidine ring.

<R ¹ , R ² , R ³ , R ⁴ >
R ¹ , R ² , R ³ , and R ⁴ represent groups attached to ring Cy ¹ , ring Cy ² , ring Cy ³ , and ring Cy ^{4, respectively.} When ^{there are a plurality of them, R 1} , R ² , R ³ , and R ⁴ may be the same or different from each other. R ¹ and R ³ are independently hydrogen atom, fluorine atom, chlorine atom, bromine atom, amino group, hydroxy group, mercapto group, alkyl group having 1 to 30 carbon atoms, alkoxy group having 1 to 30 carbon atoms, and carbon. Alkoxy group having 2 to 30 carbon atoms, alkylamino group having 1 to 30 carbon atoms, aryloxy group having 3 to 30 carbon atoms, aryl group having 3 to 30 carbon atoms, heteroaryl group having 3 to 30 carbon atoms, 3 carbon atoms. It is selected from an arylamino group of ~ 30 and an alkoxy group having 7 to 40 carbon atoms, formula (2) or formula (3). R ² and R ⁴ independently have a fluorine atom, a chlorine atom, a bromine atom, an amino group, a hydroxy group, a mercapto group, an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, and 2 to 2 carbon atoms. 30 alkoxy groups, 1 to 30 carbon atoms alkylamino groups, 3 to 30 carbon atoms aryloxy groups, 3 to 30 carbon atoms aryl groups, 3 to 30 carbon atoms heteroaryl groups, 3 to 30 carbon atoms It is selected from an arylamino group, an alkoxy group having 7 to 40 carbon atoms, the formula (2) or the formula (3).
a and c independently represent an integer of 1 to 2, and b and d independently represent an integer of 0 to 2.
From the viewpoint of sufficiently retaining the solubility of the complex and having good hole transportability, a is preferably 1 to 2, and most preferably 1.
b is preferably 0 to 2, more preferably 0 to 1, and most preferably 0, from the viewpoint of sufficiently maintaining the solubility of the complex and adjusting the durability and emission color.
c is preferably 1 to 2 and most preferably 1 from the viewpoint of sufficiently retaining the solubility of the complex and having good hole transportability.
From the viewpoint of sufficiently maintaining the solubility of the complex and adjusting the durability and emission color, d is preferably 0 to 2, more preferably 0 to 1, and most preferably 0.
However, ^{at least one of R 1 and} R ² is a group represented by the following formula (2). Light emitting materials can transport charges inside the device, but are thought to play a role in transporting holes, especially in heavy-doped devices. If holes are difficult to transport, the position is limited to charge recombination in the light emitting layer, which reduces the luminous efficiency and thus the drive life. Since the transport of holes largely ^{depends on the ring Cy 1 and its substituents, it is preferable that at least one R 1} is a group represented by the formula (2) from the viewpoint of facilitating the transport of holes.

x represents an integer of 0 to 10, and is preferably 0 or more, more preferably 1 or more, still more preferably 1 or more, from the viewpoint of sufficiently maintaining the solubility of the complex and having good hole transportability. 2 or more. Further, it is preferably 10 or less, more preferably 8 or less, and further preferably 6 or less.
h represents an integer of 1 to 3, and is preferably 1 from the viewpoint of sufficiently maintaining the solubility of the complex.
* Represents a bond.
R may be the same or different for each appearance, and may be independently further substituted with a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a cyano group, or a fluorine atom. It is selected from an amino group which may be further substituted with an alkyl group of ~ 20, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 5 to 30 carbon atoms, or an acyl group having 1 to 20 carbon atoms, preferably a hydrogen atom. , A fluorine atom, a cyano group, or an alkyl group having 1 to 20 carbon atoms which may be further substituted with a fluorine atom. From the viewpoint of enhancing hole transportability, it is more preferable that R is a hydrogen atom, and it is particularly preferable that all R are hydrogen atoms. From the viewpoint of shortening the emission wavelength, it is preferable that at least one R is an alkyl group having 1 to 20 carbon atoms which may be further substituted with a fluorine atom, a cyano group, or a fluorine atom. Of the Rs contained in one ligand, only one or two Rs are more preferably alkyl groups having 1 to 20 carbon atoms which may be further substituted with a fluorine atom, a cyano group, or a fluorine atom. Of the Rs contained in one ligand, it is most preferable that only one R is an alkyl group having 1 to 20 carbon atoms which may be further substituted with a cyano group or a fluorine atom.
Each occurrence of R'may be the same or different, and each independently is further substituted with an alkyl group having 4 to 20 carbon atoms or a fluorine atom, which may be further substituted with a fluorine atom. It is preferably selected from a good aralkyl group having 4 to 40 carbon atoms, preferably a linear alkyl group having 5 to 12 carbon atoms or an aralkyl group having 4 to 40 carbon atoms, and more preferably an aralkyl group having 4 to 40 carbon atoms. be.

Examples of alkyl groups having 4 to 20 carbon atoms include linear alkyl groups, branched alkyl groups, cyclic alkyl groups, and more specifically, n-butyl groups, n-pentyl groups, and n-. Examples thereof include a hexyl group, an n-octyl group, an isopropyl group, an isobutyl group and a cyclohexyl group. From the viewpoint of solubility and durability, a linear alkyl group is preferable, and a linear alkyl group having 5 to 12 carbon atoms is more preferable.
Examples of aralkyl groups having 4 to 40 carbon atoms are phenylmethyl group, phenylethyl group, 1,1-dimethyl-1-phenylmethyl group, 3-phenyl-1-propyl group, 4-phenyl-1-n-. Butyl group, 1-methyl-1-phenylethyl group, 5-phenyl-1-n-propyl group, 6-phenyl-1-n-hexyl group, 7-phenyl-1-n-heptyl group, 8-phenyl- Examples thereof include 1-n-octyl group and 4-phenylcyclohexyl group.

If the solubility of the iridium complex can be maintained, the affinity with the charge transport material in the light emitting layer can be enhanced, the dispersibility can be improved, and aggregation can be suppressed, the luminous efficiency and drive life of the device will not be impaired. .. From this point of view, a preferable group as R'is an aralkyl group having 4 to 40 carbon atoms which simultaneously has an alkylene moiety for ensuring solubility and an aromatic group having an affinity for a charge transport material, and a more preferable group is carbon. It is an aralkyl group having a number of 4 to 30, and is particularly preferably a 1,1-dimethyl-1-phenylmethyl group or a 5-phenyl-1-n-propyl group from the viewpoint of solubility in a solvent and ease of synthesis. , 6-Phenyl-1-n-hexyl group, 7-phenyl-1-n-heptyl group and 8-phenyl-1-n-octyl group.

Further, ^{at least one of R 3} or R ⁴ is a group represented by the following formula (3). Light emitting materials can transport charges inside the device, but are thought to play a role in transporting holes, especially in heavy-doped devices. If holes are difficult to transport, the position is limited to charge recombination in the light emitting layer, which reduces the luminous efficiency and thus the drive life. Since the transport of holes largely ^{depends on the ring Cy 3 and its substituents, it is preferable that at least one R 3} is a group represented by the formula (3) from the viewpoint of facilitating the transport of holes.

y represents an integer of 1 to 10, and is preferably 2 or more from the viewpoint of sufficiently maintaining the solubility of the complex and having good hole transportability. Further, k is preferably 8 or less, more preferably 6 or less, and represents an integer of 0 to 5, and 0 or 1 is preferable from the viewpoint of sufficiently maintaining the solubility of the complex and having good hole transportability. , 0 is more preferable from the viewpoint of better hole transportability.
* Represents a bond.
R in equation (3) is synonymous with equation (2).
R'' may be the same or different for each appearance, and may be independently further substituted with a fluorine atom or a fluorine atom. Alkyl group having 1 to 20 carbon atoms and 1 to 20 carbon atoms. It is selected from a naphthyl group optionally substituted with 20 alkyl or aryl groups, or a heteroaryl group optionally substituted with an aryl group having 1 to 20 carbon atoms. From the viewpoint of promoting hole transportability, an alkyl group or a naphthyl group having 1 to 20 carbon atoms is preferable, and an alkyl group or a naphthyl group having 1 to 3 carbon atoms is more preferable.

Most preferably, at least one of R ¹ is represented by the formula (2) and ^{at least one of R 3} is represented by the formula (3). Iridium complexes of the present invention this time, at least one alkyl group or an aralkyl group as R ^1, preferably having an aralkyl group, and has at least one, two or more linked group a phenylene group as R ³ Then, as will be described later, the effect of the present invention can be easily obtained.
^{The groups of R 1 to} R ⁴ excluding the groups represented by the formulas (2) and (3) may be further substituted with a fluorine atom, a chlorine atom, a bromine atom, or a fluorine atom. It may be further substituted with an alkyl group having ~ 30 and an alkyl group having 1 to 30 carbon atoms. It may be further substituted with an aryl group having 3 to 30 carbon atoms or an arylamino group having 3 to 30 carbon atoms.
Further, when a plurality of R ^{1 to} R ⁴ are adjacent to each other, the adjacent R ^{1 to} R ⁴ are directly bonded or have an alkylene group having 3 to 12 carbon atoms, an alkaneylene group having 3 to 12 carbon atoms, or an alkaneylene group having 3 to 12 carbon atoms. Rings may be formed by bonding via an arylene group of 6 to 12, and these rings may be further substituted with a fluorine atom, a chlorine atom, a bromine atom, or a fluorine atom. It may be further substituted with an alkyl group of 30 and an alkyl group having 1 to 30 carbon atoms, and may be further substituted with an aryl group having 3 to 30 carbon atoms or an arylamino group having 3 to 30 carbon atoms.
Further, R ¹ and R ² or R ³ and R ⁴ are directly bonded or bonded via an alkylene group having 3 to 12 carbon atoms, an alkaneylene group having 3 to 12 carbon atoms, or an arylene group having 6 to 12 carbon atoms. These rings may be further substituted with a fluorine atom, a chlorine atom, a bromine atom, or a fluorine atom, and have an alkyl group having 1 to 30 carbon atoms and 1 to 30 carbon atoms. It may be further substituted with an alkyl group or an aryl group having 3 to 30 carbon atoms or an arylamino group having 3 to 30 carbon atoms.

Specific examples of the above rings include a fluorene ring, a carbazole ring, a carboline ring, a diazacarbazole ring, a naphthalene ring, a phenanthrene ring, an anthracene ring, a chrysene ring, a triphenylene ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, and a benzoquinoline ring. Examples thereof include an azaphenanthrene ring, an azaanthracene ring, and an azatriphenylene ring. If the condensed ring structure to which the π electron is conjugated is too large, the emission wavelength will be extended to the infrared region and the solubility will be reduced. Therefore, a fluorene ring, a carbazole ring, a quinoline ring, an isoquinoline ring, and a quinazoline ring are preferable. , Selected from the azatriphenylene ring.
Examples of the alkyl group having 1 to 30 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a hexyl group, an octyl group, an isobutyl group and the like, and a methyl group is preferable.

Examples of the alkoxy group having 1 to 30 carbon atoms include a methoxy group, an ethoxy group, a propyloxy group, an octyloxy group and the like, and among them, the methoxy group is preferable.
Examples of the alkenyl group having 2 to 30 carbon atoms include a vinyl group, an allyl group, a 3-buteno group, a 2-buteno group, a 1,3-butadienyl group and the like, and a vinyl group is preferable.
Examples of the alkylamino group having 1 to 30 carbon atoms include a methylamino group, a dimethylamino group, a diethylamino group, a dibutylamino group, an octylamino group, a dioctylamino group and the like, and a methylamino group or a dimethylamino group is preferable.

Examples of the aryloxy group having 3 to 30 carbon atoms include an aryloxy group, a phenoxy group, a methylphenyloxy group and the like, and a phenoxy group is preferable.
Examples of the aryl group having 3 to 30 carbon atoms include a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a naphthylphenyl group and a naphthylbiphenyl group, and among them, a phenyl group, a biphenyl group and a terphenyl group are preferable.

Examples of the heteroaryl group having 3 to 30 carbon atoms include a pyridyl group, a pyrimidyl group, a triazine group, a phenylpyridyl group, a phenylpyrimidyl group, a diphenylpyrimidyl group and the like.
Examples of the arylamino group having 3 to 30 carbon atoms include a phenylamino group, a diphenylamino group, a ditrilamino group, and a di (2,6-dimethylphenyl) amino group.

The aralkyl groups having 7 to 40 carbon atoms are 1,1-dimethyl-1-phenylmethyl group, 1,1-di (n-butyl) -1-phenylmethyl group, and 1,1-di (n-hexyl)-. 1,1-dialkyl-1-phenylmethyl group, phenylmethyl group, phenylethyl group, 3-phenyl-, which are exemplified by 1-phenylmethyl group and 1,1-di (n-octyl) -1-phenylmethyl group. 1-propyl group, 4-phenyl-1-n-butyl group, 1-methyl-1-phenylethyl group, 5-phenyl-1-n-propyl group, 6-phenyl-1-n-hexyl group, 7- Examples thereof include a phenyl-1-n-heptyl group, an 8-phenyl-1-n-octyl group, and a 4-phenylcyclohexyl group.

<M, n>
Although m is 1 or 2, it is more preferable that m = 1 from the viewpoint of sufficiently maintaining the solubility of the complex and improving the hole transportability. Further, m + n = 3.

<Preferable embodiments of the formula (2) and the formula (3)>
The formula (2) is preferably represented by the following formula (4).

In equation (4), p represents an integer from 0 to 2, q represents an integer from 0 to 10, r represents an integer from 0 to 2, and p + q + r is an integer from 0 to 10. * Represents a bond. Note that R, R'and h are synonymous with equation (2).
From the viewpoint of maintaining high solubility, p is more preferably 0 or 1, and r is more preferably 0 or 1.
From the viewpoint of maintaining high hole transportability, p + q + r is more preferably an integer of 0 to 5.

Further, the above formula (3) is preferably represented by the following formula (5).

In equation (5), s represents an integer from 0 to 2, t represents an integer from 1 to 10, u represents an integer from 0 to 2, w represents an integer from 0 to 4, and s + t + u + w represents from 1. It is an integer of 10. * Represents a bond. Note that R, R'' and k are synonymous with equation (3).
From the viewpoint of maintaining high solubility, s is more preferably 0 or 1, and u is more preferably 0 or 1.
From the viewpoint of maintaining high hole transportability, s + t + u + w is more preferably an integer from 0 to 5.

The reason why the formula (4) and the formula (5) are more preferable will be described. The formula (2) and the formula (3) are linked by a phenylene ring. This combination mode includes ortho, meta, and para positions. Of these, when they are bonded at the ortho position, adjacent phenylene rings become steric hindrance to each other, causing a large twist. Although the solubility of the complex is improved by this twist, the conjugate of the π electron of the phenylene ring becomes small, which does not necessarily have a good effect on the hole transport property. Therefore, the preferred binding mode is the meta or para position. In particular, ^{when the phenylene ring directly bonded to Cy 1} or Cy ³ has a para-position bonding mode, the conjugation of a large π electron extends from the iridium atom to the adjacent phenylene ring, which has a favorable effect on hole transportability.
Further, in the iridium complex in the present invention, it is more preferable that the formula (2) is the formula (4) and the formula (3) is the formula (5).
Further, at least one of R ¹ is represented by the formula (2) or formula (4), and at least one of R ³ is preferably represented by the formula (3) or formula (5) ..
Further, it is more preferable that at least one of R ¹ is represented by the formula (4) and ^{at least one of R 3} is represented by the formula (5).

<Specific example>
Hereinafter, preferred specific examples of the iridium complex compound of the present invention will be shown, but the present invention is not limited thereto.

<Structural features>
The coating liquid for forming a light emitting layer using the iridium complex compound of the present invention, that is, the storage stability of maintaining a uniform state without precipitation in the state of a solution coexisting with a charge transport material is improved, and light emission of the device. The reason why the element characteristics such as efficiency and drive life are improved is estimated as follows.
In order to improve the solubility in an organic solvent, a group having a flexible structure containing an aliphatic hydrocarbon group such as an alkyl group or an aralkyl group is usually introduced into the ligand of the iridium complex compound. Since these groups can take many conformations, the energy for rearrangement increases during crystallization. Therefore, the iridium complex compound is expected to have the effect of making it difficult to crystallize and improving the solubility.

However, when these flexible structures with respect to the iridium complex compound are introduced with good symmetry, that is, when a homoreptic complex is formed, the rearrangement energy for crystallization is lowered and crystallization is facilitated, so that the solubility is sufficient. The improvement effect cannot be obtained.
Further, the charge transport material coexisting with the coating liquid for forming a light emitting layer usually does not have a group having these flexible structures, but has a rigid structure in which benzene rings are connected. It is generally known that substances with similar chemical structures dissolve well in each other, but the structural similarity between the iridium complex compound and the charge transport material, which should have been improved in solubility by the above method, is Since it is not necessarily high, the coexistence of these compounds significantly reduces the solubility of any compound, particularly the charge transport material, in an organic solvent, and makes it easy to precipitate as a solid.
In addition, these flexible structural groups are essentially insulators, thus inhibiting charge injection into the iridium complex and charge transport between the iridium complexes or between the iridium complex and the host. In addition, since the motility of the group is high, there is a drawback that it provides a path for non-radiative deactivation from the excited state, and as a result, the luminous efficiency is deteriorated.

On the other hand, when a substituent in which an arylene group is linked, such as an m-phenylene group, is introduced into the ligand, many conformations can be obtained, though not as much as the alkyl group, which is sufficient for the coating method. It can be made to have a good solubility. Further, although the light emitting material can transport electric charges inside the device, the orbitals or empty orbitals of π electrons are spatially expanded by connecting the phenylene groups for a long time, and the electric charges are easily transported. In particular, an iridium complex having a group in which a phenylene group is long-linked is likely to receive holes. By using such an iridium complex as a light emitting material in the light emitting layer, the hole transport property in the light emitting layer can be improved. Further, it is considered that the light emitting position in the light emitting layer can be adjusted by adjusting the doping concentration of such an iridium complex. The fact that charges are easily transported is expected to improve the luminous efficiency and drive life because the position of charge recombination in the light emitting layer in the device is widened. However, at the same time, excellent electrical conductivity means that the interaction between iridium complexes is not hindered in the light emitting layer, and exciton quenching, that is, concentration due to the interaction between excitons or excitons and charges, especially during heavy doping. Since quenching occurs at the same time, the range of improvement in luminous efficiency is small or rather reduced.

To make up for these drawbacks, it is effective to have the above two types of ligands simultaneously present on one iridium complex in an appropriate state as in the present invention. The symmetry of the iridium complex compound is lowered by making it a heteroreptic type complex, and the similarity with the charge transport material is made by the presence of a ligand having a group in which a phenylene group having no flexible structure is linked. By increasing the concentration, the storage stability of the coating liquid for forming a light emitting layer can be improved.

Further, in the organic EL device in which the iridium complex in the present invention is used as a light emitting material in the light emitting layer, the effect of improving the drive life is expected. The mechanism of action is considered as follows. Since the iridium complex having a group in which a phenylene group is long-linked is likely to receive holes, it is considered that most of the iridium complexes in the light emitting layer of the device being driven by energization are in a state of receiving holes. Further, the iridium complex in the present invention also has an insulating aralkyl group. The aralkyl group appropriately suppresses the hole transport property of the iridium complex of the present invention as an insulating spacer. Therefore, there is a high probability that the holes will exist in the cation state, which is the state in which the holes have been received. Since the iridium complex in the cationic state emits light immediately after receiving an electron, it is considered that the luminous efficiency is high. Moreover, since the iridium complex in the cationic state is stable, it is considered that the drive life is also improved.

In the present invention, by arranging an appropriate substituent portion and a solubilized portion mainly composed of a phenylene bond in the ligand, the above-mentioned drawbacks are eliminated, the luminous efficiency of the device is improved, and the drive life is improved. It can be compatible.

<Organic solvent>
In the wet film formation method, the organic material of the light emitting layer is once dissolved in an organic solvent, then applied by a spin coating method or an inkjet method, and then the organic solvent is evaporated and vaporized by heating, reducing the pressure, or spraying an inert gas. It is a method of forming a film by means of. If necessary, in order to make the formed organic material solvent-insoluble, for example, by allowing a cross-linking group such as C = C group, C≡C group or benzocyclobutene group to be present in the molecule of the organic material. It can also be crosslinked and insolubilized by a known method such as heating or light irradiation.

The types of organic solvents preferably used in such a wet film forming method are optionally substituted aliphatic hydrocarbons such as hexane, heptane, methyl ethyl ketone, ethyl acetate and butyl acetate, toluene, xylene, phenylcyclohexanone and benzo. Examples thereof include aromatic hydrocarbons which may be substituted such as ethyl acid, cyclohexane, cyclohexanone, methylcyclohexanone, and alicyclic hydrocarbons which may be substituted such as 3,3,5-trimethylcyclohexanone. .. These may be used alone or may be used as a composition by mixing a plurality of kinds of solvents in order to prepare a coating liquid suitable for the coating process. The type of organic solvent mainly used is preferably an aromatic hydrocarbon or an alicyclic hydrocarbon, and more preferably an aromatic hydrocarbon. In particular, phenylcyclohexane is said to have a favorable viscosity and boiling point in the wet film formation process. Therefore, the solubility of the iridium complex compound preferably used in the wet film forming method is usually 0.5% by mass or more, preferably 1.0% by mass or more, more preferably 1.0% by mass or more, based on phenylcyclohexane at 25 ° C. under atmospheric pressure. Is 1.5% by mass or more.

<Method for synthesizing iridium complex compound>
The iridium complex compound of the present invention can be synthesized by a combination of known methods and the like. Ligsands can be synthesized by combining known organic synthesis reactions such as the so-called Suzuki-Miyaura coupling reaction. The iridium complex compound can be synthesized by this ligand and the iridium compound.

Regarding the method for synthesizing the iridium complex compound, for example, a method via a chlorine-bridged iridium binuclear complex as shown in the following formula (A) (MG Colombo, TC Brund, T. Riedener, HU). Gudel, Inorgan. Chem., 1994, 33, 545-550), a method of further exchanging a chlorine bridge with an acetylacetonate from a dinuclear complex of the following formula (B) to convert it into a mononuclear complex (S). Lamansky, P. Djurovich, D. Murphy, F. Abdel-Razzaq, R. Kwong, ITSyba, M. Borz, B. Mui, R. Bau, M. Acetylacetone, Inorgan. Chem., 2001, 40. 1704-1711) and the like can be exemplified, but the present invention is not limited thereto. In addition, in formulas (A) and (B), R represents hydrogen or an arbitrary substituent, and a plurality of Rs existing may be the same or different.

For example, the typical reaction conditions represented by the following formula (A) are as follows. As a first step, a chlorine-crosslinked iridium binuclear complex is synthesized by a reaction of 2 equivalents of the first ligand and 1 equivalent of iridium chloride n hydrate. As the solvent, a mixed solvent of 2-ethoxyethanol and water is usually used, but a solvent-free solvent or another solvent may be used. The reaction can be promoted by using an excessive amount of the ligand or by using an additive such as a base. Other crosslinkable anionic ligands such as bromine can be used instead of chlorine. The reaction temperature is not particularly limited, but is usually in the range of 0 ° C. to 250 ° C., preferably 50 ° C. to 150 ° C.

In the second step, a halogen ion scavenger such as silver trifluoromethanesulfonate is added and brought into contact with the second ligand to obtain the desired complex. As the solvent, ethoxyethanol or diclim is usually used, but no solvent or other solvent can be used depending on the type of ligand, and a plurality of solvents can be mixed and used. It is not always necessary because the reaction may proceed without the addition of a halogen ion scavenger, but the scavenger is used to increase the reaction yield and selectively synthesize facial isomers having a higher quantum yield. Is advantageous. The reaction temperature is not particularly limited, but is usually carried out in the range of 0 ° C. to 250 ° C.

Moreover, the typical reaction conditions represented by the formula (B) will be described. The first-stage dikaryon complex can be synthesized in the same manner as in the formula (A). In the second step, one equivalent or more of a 1,3-dione compound such as acetylacetone and a basic compound capable of extracting active hydrogen of the 1,3-dione compound such as sodium carbonate are added to the dinuclear complex. By reacting in an equivalent amount or more, it is converted into a mononuclear complex in which the 1,3-dionat ligand is coordinated. Usually, a solvent such as ethoxyethanol or dichloromethane that can dissolve the dinuclear complex of the raw material is used, but if the ligand is liquid, it can be carried out without a solvent. The reaction temperature is not particularly limited, but is usually carried out in the range of 0 ° C. to 200 ° C.

The third step is to react one or more equivalents of the second ligand. The type and amount of the solvent are not particularly limited, and may be solvent-free as long as the second ligand is liquid at the reaction temperature. The reaction temperature is also not particularly limited, but since the reactivity is slightly poor, the reaction is often carried out at a relatively high temperature of 100 ° C. to 300 ° C. Therefore, a solvent having a high boiling point such as glycerin is preferably used.
After the final reaction, purification is performed to remove unreacted raw materials, reaction by-products and solvents. Purification operations in ordinary synthetic organic chemistry can be applied, but purification is mainly performed by normal phase silica gel column chromatography as described in the above non-patent documents. A single or mixed solution of hexane, heptane, dichloromethane, chloroform, ethyl acetate, toluene, methyl ethyl ketone, and methanol can be used as the developing solution. Purification may be performed multiple times under different conditions. Other chromatography techniques (reverse phase silica gel chromatography, size exclusion chromatography, paper chromatography) and purification operations such as liquid separation washing, reprecipitation, recrystallization, powder suspension washing, and vacuum drying are required as required. Can be applied.

<Use of iridium complex compound>
The iridium complex compound of the present invention can be suitably used as a material used for an organic electroluminescent device, that is, an organic electroluminescent device material, and can also be suitably used as a light emitting material for an organic electroluminescent device or other light emitting device. Is.

<Iridium complex compound-containing composition>
Since the iridium complex compound of the present invention has excellent solubility, it is preferably used together with a solvent. Hereinafter, a composition containing the iridium complex compound of the present invention and a solvent (iridium complex compound-containing composition) will be described.

The iridium complex compound-containing composition of the present invention contains the above-mentioned iridium complex compound and solvent of the present invention. The iridium complex compound-containing composition of the present invention is usually used for forming a layer or a film by a wet film forming method, and is particularly preferably used for forming an organic layer of an organic electroluminescent device. The organic layer is particularly preferably a light emitting layer. That is, the iridium complex compound-containing composition is preferably a composition for an organic electroluminescent device, and is particularly preferably used as a composition for forming a light emitting layer. ..

The content of the iridium complex compound of the present invention in the iridium complex compound-containing composition is usually 0.001% by mass or more, preferably 0.01% by mass or more, usually 99.9% by mass or less, preferably 99% by mass or less. Is. By setting the content of the iridium complex compound in the composition within this range, holes and electrons are efficiently injected from adjacent layers (for example, hole transport layer and hole blocking layer) into the light emitting layer. The drive voltage can be reduced. The iridium complex compound of the present invention may be contained in the iridium complex compound-containing composition in combination of only one type or a combination of two or more types.

When the iridium complex compound-containing composition of the present invention is used, for example, for an organic electroluminescent element, it contains the above-mentioned iridium complex compound and solvent, as well as an organic electroluminescent element, particularly a charge-transporting compound used for a light emitting layer. be able to.
When the light emitting layer of the organic electroluminescent element is formed by using the iridium complex compound-containing composition of the present invention, the iridium complex compound of the present invention is used as a light emitting material, and another charge transporting compound is contained as a charge transporting material. Is preferable.

The solvent contained in the iridium complex compound-containing composition of the present invention is a volatile liquid component used for forming a layer containing the iridium complex compound by wet film formation.
Since the iridium complex compound of the present invention, which is a solute, has high solubility, the solvent is not particularly limited as long as it is a solvent in which the charge transporting compound described later dissolves well. Preferred solvents include, for example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, bicyclohexane; aromatic hydrocarbons such as toluene, xylene, methicylene, phenylcyclohexane, tetralin; chlorobenzene, dichlorobenzene, trichlorobenzene and the like. Halogenized aromatic hydrocarbons such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, etc. Aromatic ethers such as 2,4-dimethylanisole and diphenyl ether; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate, cyclohexanone, cycloocta Aromatic ketones such as non- and fencon; Aromatic alcohols such as cyclohexanol and cyclooctanol; Aromatic ketones such as methyl ethyl ketone and dibutyl ketone; Aromatic alcohols such as butanol and hexanol; Ethylene glycol dimethyl ether and ethylene Examples thereof include aliphatic ethers such as glycol diethyl ether and propylene glycol-1-monomethyl ether acetate (PGMEA).

Of these, alkanes and aromatic hydrocarbons are preferable, and phenylcyclohexane in particular has a preferable viscosity and boiling point in the wet film forming process.
One of these solvents may be used alone, or two or more of these solvents may be used in any combination and ratio.
The boiling point of the solvent is usually 80 ° C. or higher, preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and usually 270 ° C. or lower, preferably 250 ° C. or lower, more preferably 230 ° C. or lower. If it falls below this range, the film formation stability may decrease due to solvent evaporation from the composition during wet film formation.

The content of the solvent in the iridium complex compound-containing composition is preferably 1% by mass or more, more preferably 10% by mass or more, particularly preferably 50% by mass or more, and preferably 99.99% by mass or less, more preferably 99.99% by mass or less. It is 99.9% by mass or less, particularly preferably 99% by mass or less. Normally, the thickness of the light emitting layer is about 3 to 200 nm, but if the solvent content is less than this lower limit, the viscosity of the composition becomes too high, and the film forming workability may decrease. On the other hand, if this upper limit is exceeded, the thickness of the film obtained by removing the solvent after the film formation cannot be increased, so that the film formation tends to be difficult.

As the other charge-transporting compound that can be contained in the iridium complex compound-containing composition of the present invention, those conventionally used as materials for an organic electroluminescent device can be used. For example, pyridine, carbazole, naphthalene, perylene, pyrene, anthracene, chrysen, naphthalene, phenanthrene, coronen, fluorantene, benzophenanthrene, fluorene, acetnaphthofluoranthene, coumarin, p-bis (2-phenylethenyl) benzene and theirs. Derivatives, quinacridone derivatives, DCM (4- (dicyanomethyrene) -2-methyl-6- (p-dimethylaminostyly) -4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene, aryl Examples thereof include a fused aromatic ring compound in which an amino group is substituted, a styryl derivative in which an arylamino group is substituted, and the like.

One of these may be used alone, or two or more of them may be used in any combination and ratio.
The content of the other charge-transporting compound in the iridium complex compound-containing composition is usually 1000 parts by mass or less, preferably 1000 parts by mass or less, based on 1 part by mass of the iridium complex compound of the present invention in the iridium complex compound-containing composition. It is 100 parts by mass or less, more preferably 50 parts by mass or less, usually 0.01 parts by mass or more, preferably 0.1 parts by mass or more, still more preferably 1 part by mass or more.

The iridium complex compound-containing composition of the present invention may contain other compounds in addition to the above compounds, if necessary. For example, in addition to the above solvent, another solvent may be contained. Examples of such a solvent include amides such as N, N-dimethylformamide and N, N-dimethylacetamide, dimethyl sulfoxide and the like. One of these may be used alone, or two or more of them may be used in any combination and ratio.

<Organic electroluminescent device>
Hereinafter, embodiments of the organic electroluminescent device, the organic electroluminescent illuminator, and the organic electroluminescent display device of the present invention will be described in detail, but the present invention is limited by these contents as long as the gist of the present invention is not exceeded. is not it.

(substrate)
The substrate serves as a support for the organic electroluminescent element, and usually a quartz or glass plate, a metal plate, a metal foil, a plastic film, a sheet, or the like is used. Of these, a glass plate or a transparent synthetic resin plate such as polyester, polymethacrylate, polycarbonate, or polysulfone is preferable. The substrate is preferably made of a material having a high gas barrier property because the organic electroluminescent element is unlikely to be deteriorated by the outside air. Therefore, particularly when a material having a low gas barrier property such as a synthetic resin substrate is used, it is preferable to provide a dense silicon oxide film or the like on at least one surface of the substrate to improve the gas barrier property.

(anode)
The anode has the function of injecting holes into the layer on the light emitting layer side. The anode is usually a metal such as aluminum, gold, silver, nickel, palladium, platinum; a metal oxide such as an oxide of indium and / or tin; a metal halide such as copper iodide; carbon black and poly (3-). It is composed of conductive polymers such as methylthiophene), polypyrrole, and polyaniline. The anode is usually formed by a dry method such as a sputtering method or a vacuum vapor deposition method. When forming an anode using metal fine particles such as silver, fine particles such as copper iodide, carbon black, conductive metal oxide fine particles, conductive polymer fine powder, etc., use an appropriate binder resin solution. It can also be formed by dispersing and applying it on a substrate. Further, in the case of a conductive polymer, a thin film can be formed directly on the substrate by electrolytic polymerization, or an anode can be formed by applying the conductive polymer on the substrate (Appl. Phys. Lett., 60). Vol. 2711, 1992).

The anode usually has a single-layer structure, but may have a laminated structure as appropriate. When the anode has a laminated structure, different conductive materials may be laminated on the first-layer anode. The thickness of the anode may be determined according to the required transparency, material, and the like. When particularly high transparency is required, a thickness having a visible light transmittance of 60% or more is preferable, and a thickness having a visible light transmittance of 80% or more is more preferable. The thickness of the anode is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. On the other hand, when transparency is not required, the thickness of the anode may be arbitrarily set according to the required strength and the like. In this case, the anode may have the same thickness as the substrate.
When forming a film on the surface of the anode, the impurities on the anode are removed by treating the surface of the anode with ultraviolet rays + ozone, oxygen plasma, argon plasma, etc., and the ionization potential is adjusted to be positive. It is preferable to improve the pore injection property.

(Hole injection layer)
The layer having a function of transporting holes from the anode side to the light emitting layer side is usually called a hole injection transport layer or a hole transport layer. When there are two or more layers having a function of transporting holes from the anode side to the light emitting layer side, the layer closer to the anode side may be called a hole injection layer. The hole injection layer is preferably used because it enhances the function of transporting holes from the anode to the light emitting layer side. When a hole injection layer is used, the hole injection layer is usually formed on the anode.

The film thickness of the hole injection layer is usually 1 nm or more, preferably 5 nm or more, and usually 1000 nm or less, preferably 500 nm or less.
The hole injection layer may be formed by either a vacuum vapor deposition method or a wet film deposition method. In terms of excellent film forming property, it is preferably formed by a wet film forming method.
The hole injection layer preferably contains a hole transporting compound, and more preferably contains a hole transporting compound and an electron accepting compound. Further, it is preferable to contain a cationic radical compound in the hole injection layer, and it is particularly preferable to contain a cationic radical compound and a hole transporting compound.

(Hole transporting compound)
The composition for forming a hole injection layer usually contains a hole transporting compound that serves as a hole injection layer. Further, in the case of the wet film forming method, a solvent is usually further contained. It is preferable that the composition for forming a hole injection layer has high hole transportability and can efficiently transport the injected holes. Therefore, it is preferable that the hole mobility is high and impurities that serve as traps are unlikely to be generated during production or use. Further, it is preferable that the stability is excellent, the ionization potential is small, and the transparency to visible light is high. In particular, when the hole injection layer is in contact with the light emitting layer, those that do not quench the light emitted from the light emitting layer or those that form an exciplex with the light emitting layer and do not reduce the luminous efficiency are preferable.

As the hole transporting compound, a compound having an ionization potential of 4.5 eV to 6.0 eV is preferable from the viewpoint of a charge injection barrier from the anode to the hole injection layer. Examples of hole-transporting compounds include aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds in which a tertiary amine is linked with a fluorene group, and hydrazone. Examples thereof include system compounds, silazane compounds, and quinacridone compounds.

Among the above-mentioned exemplified compounds, aromatic amine compounds are preferable, and aromatic tertiary amine compounds are particularly preferable, from the viewpoint of amorphousness and visible light transmission. Here, the aromatic tertiary amine compound is a compound having an aromatic tertiary amine structure, and also includes a compound having a group derived from the aromatic tertiary amine.
The type of the aromatic tertiary amine compound is not particularly limited, but is a polymer compound having a weight average molecular weight of 1,000 or more and 1,000,000 or less (polymerized compound in which repeating units are continuous) from the viewpoint that uniform light emission can be easily obtained due to the surface smoothing effect. Is preferably used. Preferred examples of the aromatic tertiary amine polymer compound include a polymer compound having a repeating unit represented by the following formula (I).

(In formula (I), Ar ¹ and Ar ² each independently represent an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. . Ar ^{3 to} Ar ⁵ each independently represent an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Y represents the following. It represents a linking group selected from the linking group group. Further, two groups of Ar ^{1 to} Ar ⁵ that are bonded to the same N atom may be bonded to each other to form a ring.
The linking groups are shown below.

(In each of the above formulas, Ar ^{6 to} Ar ¹⁶ each independently represent an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. R ¹ and R ² independently represent a hydrogen atom or an arbitrary substituent.) As the aromatic hydrocarbon group and aromatic heterocyclic group of ^{Ar 1 to} Ar ^{16, the solubility of a high molecular compound,} From the viewpoint of heat resistance and hole injection transportability, groups derived from benzene ring, naphthalene ring, phenanthrene ring, thiophene ring and pyridine ring are preferable, and groups derived from benzene ring and naphthalene ring are more preferable.
Specific examples of the aromatic tertiary amine polymer compound having a repeating unit represented by the formula (I) include those described in International Publication No. 2005/089024.

(Electron accepting compound)
Since the hole injecting layer can improve the conductivity of the hole injecting layer by oxidizing the hole transporting compound, it is preferable that the hole injecting layer contains an electron accepting compound.
As the electron-accepting compound, a compound having an oxidizing power and having an ability to accept one electron from the above-mentioned hole-transporting compound is preferable, and specifically, a compound having an electron affinity of 4 eV or more is preferable, and an electron affinity is preferable. A compound having a value of 5 eV or more is more preferable.

Such an electron-accepting compound includes, for example, a triarylboron compound, a metal halide, a Lewis acid, an organic acid, an onium salt, a salt of an arylamine and a metal halide, and a salt of an arylamine and a Lewis acid. One or more compounds selected from the group may be mentioned. Specifically, an onium salt substituted with an organic group such as 4-isopropyl-4'-methyldiphenyliodonium tetrakis (pendafluorophenyl) borate, triphenylsulfonium tetrafluoroborate (International Publication No. 2005/089024); chloride. High valence inorganic compounds such as iron (III) (Japanese Patent Laid-Open No. 11-251067), ammonium peroxodisulfate; cyano compounds such as tetracyanoethylene; tris (pendafluorophenyl) borane (Japanese Patent Laid-Open No. 2003-) Aromatic boron compounds such as 31365); fullerene derivatives, iodine and the like can be mentioned.

(Cation radical compound)
As the cation radical compound, an ionic compound composed of a cation radical, which is a chemical species obtained by removing one electron from a hole transporting compound, and a counter anion is preferable. However, when the cation radical is derived from a hole-transporting polymer compound, the cation radical has a structure in which one electron is removed from the repeating unit of the polymer compound.

The cation radical is preferably a chemical species obtained by removing one electron from the above-mentioned compound as a hole transporting compound. A chemical species obtained by removing one electron from a preferable compound as a hole transporting compound is preferable from the viewpoints of amorphousness, visible light transmittance, heat resistance, solubility and the like.
Here, the cationic radical compound can be produced by mixing the hole transporting compound and the electron accepting compound described above. That is, by mixing the above-mentioned hole transporting compound and the electron accepting compound, electron transfer occurs from the hole transporting compound to the electron accepting compound, and the cation radical and the counter anion of the hole transporting compound become A cationic ion compound consisting of is produced.

Cationic radical compounds derived from polymer compounds such as PEDOT / PSS (Adv. Mater., 2000, Vol. 12, p. 481) and emeraldine hydrochloride (J. Phys. Chem., 1990, Vol. 94, p. 7716) It is also produced by oxidative polymerization (dehydrogenation polymerization).
The oxidative polymerization referred to here is to chemically or electrochemically oxidize a monomer in an acidic solution using peroxodisulfate or the like. In the case of this oxidative polymerization (dehydropolymerization), a cation radical obtained by removing one electron from a repeating unit of a polymer, which is polymerized by oxidizing a monomer and has an anion derived from an acidic solution as a counter anion, is generated. Generate.

<Formation of hole injection layer by wet film formation method>
When the hole injection layer is formed by the wet film formation method, the material to be the hole injection layer is usually mixed with a soluble solvent (solvent for the hole injection layer) to form a composition for film formation (hole injection). A composition for forming a layer) is prepared, and the composition for forming a hole injection layer is applied onto a layer (usually an anode) corresponding to the lower layer of the hole injection layer to form a film, which is formed by drying. Let me.

The concentration of the hole transporting compound in the composition for forming a hole injection layer is arbitrary as long as the effect of the present invention is not significantly impaired, but it is preferable that the concentration is low in terms of film thickness uniformity. , A higher value is preferable in that defects are less likely to occur in the hole injection layer. Specifically, it is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and on the other hand, 70% by mass. It is preferably less than or equal to, more preferably 60% by mass or less, and particularly preferably 50% by mass or less.

Examples of the solvent include ether solvents, ester solvents, aromatic hydrocarbon solvents, amide solvents and the like.
Examples of the ether-based solvent include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA), 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, and anisole. , Fenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole and other aromatic ethers.

Examples of the ester-based solvent include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.
Examples of the aromatic hydrocarbon solvent include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, methylnaphthalene and the like. Be done. Examples of the amide-based solvent include N, N-dimethylformamide, N, N-dimethylacetamide and the like.

In addition to these, dimethyl sulfoxide and the like can also be used.
The formation of the hole injection layer 3 by the wet film formation method is usually performed on the layer corresponding to the lower layer of the hole injection layer 3 (usually, the anode 2) after preparing the composition for forming the hole injection layer. It is carried out by applying a film to the film and drying it. In the hole injection layer 3, the coating film is usually dried by heating, vacuum drying, or the like after the film formation.

<Formation of hole injection layer by vacuum deposition method>
When the hole injection layer 3 is formed by the vacuum deposition method, usually one or more of the constituent materials of the hole injection layer 3 (the above-mentioned hole transporting compound, electron accepting compound, etc.) are vacuumed. Place in a crucible installed inside the container (when using two or more materials, usually put each in a separate crucible), ^{exhaust the inside of the vacuum container to about 10-4} Pa with a vacuum pump, and then heat the crucible. (When two or more types of materials are used, each crucible is usually heated), and the material in the crucible is evaporated while controlling the amount of evaporation (when two or more types of materials are used, each is usually independent). Evaporate while controlling the amount of evaporation) to form a hole injection layer on the anode on the substrate placed facing the crucible. When two or more kinds of materials are used, a mixture thereof can be put in a crucible and heated and evaporated to form a hole injection layer.

The degree of vacuum during vapor deposition is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.1 × 10 ^-6 Torr (0.13 × 10 ^-4 Pa) or more, 9.0 × 10 ^-6 Torr ( It is 12.0 × 10 ^-4 Pa) or less. The vapor deposition rate is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.1 Å / sec or more and 5.0 Å / sec or less. The film formation temperature at the time of vapor deposition is not limited as long as the effect of the present invention is not significantly impaired, but is preferably 10 ° C. or higher and 50 ° C. or lower.

(Hole transport layer)
The hole transport layer is a layer that has a function of transporting holes from the anode side to the light emitting layer side. The hole transport layer is not an essential layer in the organic electroluminescent device of the present invention, but it is preferable to use this layer from the viewpoint of enhancing the function of transporting holes from the anode to the light emitting layer. When a hole transport layer is used, the hole transport layer is usually formed between the anode and the light emitting layer. Further, when the hole injection layer described above is present, it is formed between the hole injection layer and the light emitting layer.

The film thickness of the hole transport layer is usually 5 nm or more, preferably 10 nm or more, and on the other hand, usually 300 nm or less, preferably 100 nm or less.
The hole transport layer may be formed by either a vacuum vapor deposition method or a wet film deposition method. In terms of excellent film forming property, it is preferably formed by a wet film forming method.
The hole transport layer usually contains a hole transporting compound that serves as a hole transport layer. Examples of the hole-transporting compound contained in the hole-transporting layer include two or more tertiary amines represented by 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl. Aromatic amine in which two or more fused aromatic rings are substituted with nitrogen atoms (Japanese Patent Laid-Open No. 5-234681), 4,4', 4''-tris (1-naphthylphenylamino) triphenyl Aromatic amine compounds having a starburst structure such as amines (J. Lumin., 72-74, pp. 985, 1997), aromatic amine compounds consisting of triphenylamine tetramers (Chem. Commun., 2175). P. 1996), Spiro compounds such as 2,2', 7,7'-tetrax- (diphenylamino) -9,9'-spirobifluorene (Synth. Metals, Vol. 91, p. 209, 1997), Examples thereof include carbazole derivatives such as 4,4'-N and N'-dicarbazolebiphenyl. In addition, for example, polyvinylcarbazole, polyvinyltriphenylamine (Japanese Patent Laid-Open No. 7-53953), and polyarylene ether sulfone containing tetraphenylbenzidine (Polym. Adv. Tech., Vol. 7, p. 33, 1996). Etc. can also be preferably used.

<Formation of hole transport layer by wet film formation method>
When the hole transport layer is formed by the wet film forming method, holes are usually formed instead of the hole injection layer forming composition in the same manner as when the hole injection layer is formed by the wet film forming method. It is formed using a composition for forming a transport layer.
When the hole transport layer is formed by the wet film formation method, the hole transport layer forming composition usually further contains a solvent. As the solvent used in the hole transport layer forming composition, the same solvent as the solvent used in the hole injection layer forming composition described above can be used.

The concentration of the hole-transporting compound in the composition for forming the hole-transporting layer can be in the same range as the concentration of the hole-transporting compound in the composition for forming the hole-injecting layer.
The hole transport layer can be formed by the wet film formation method in the same manner as the hole injection layer film formation method described above.

<Formation of hole transport layer by vacuum deposition method>
When the hole transport layer is formed by the vacuum vapor deposition method, the hole transport is usually performed instead of the hole injection layer forming composition in the same manner as in the case where the hole injection layer is formed by the vacuum vapor deposition method. It can be formed using a layer-forming composition. The film formation conditions such as the degree of vacuum, the vapor deposition rate, and the temperature at the time of vapor deposition can be the same as those at the time of vacuum deposition of the hole injection layer.

(Light emitting layer)
The light emitting layer is a layer that is excited by recombination of holes injected from the anode and electrons injected from the cathode when an electric field is applied between the pair of electrodes, and has a function of emitting light. The light emitting layer is a layer formed between the anode and the cathode, and the light emitting layer is formed between the hole injection layer and the cathode when there is a hole injection layer on the anode, and is on the anode. If there is a hole transport layer, it is formed between the hole transport layer and the cathode.

The film thickness of the light emitting layer is arbitrary as long as the effect of the present invention is not significantly impaired, but a thicker one is preferable in that defects are less likely to occur in the film, and on the other hand, a thinner film is preferable in that a low drive voltage is likely to be obtained. Therefore, it is preferably 3 nm or more, more preferably 5 nm or more, and on the other hand, usually 200 nm or less, further preferably 100 nm or less.
The light emitting layer contains at least a material having a light emitting property (light emitting material) and preferably a material having a charge transporting property (charge transporting material).

(Luminescent material)
The light emitting material is not particularly limited as long as it emits light at a desired light emitting wavelength and the effect of the present invention is not impaired, and a known light emitting material can be applied. The light emitting material may be either a fluorescent light emitting material or a phosphorescent light emitting material, but a material having good luminous efficiency is preferable, and a phosphorescent light emitting material is preferable from the viewpoint of internal quantum efficiency. As the phosphorescent material, it is preferable to use the iridium complex compound of the present invention.

Examples of the fluorescent light emitting material include the following materials.
Examples of the fluorescent light emitting material (blue fluorescent light emitting material) that gives blue light emission include naphthalene, perylene, pyrene, anthracene, coumarin, chrysene, p-bis (2-phenylethenyl) benzene, and derivatives thereof.
The fluorescent light-emitting material giving green luminescence (green fluorescent material), for example, quinacridone derivatives, coumarin _derivatives, aluminum complexes such as _{Al (C 9 H 6 NO)} 3 and the like. Examples of the fluorescent light emitting material (yellow fluorescent light emitting material) that gives yellow light emission include rubrene, a perimidone derivative, and the like.

Examples of the fluorescent light emitting material (red fluorescent light emitting material) that gives red light emission include DCM (4- (dicyanomethyrene) -2-methyl-6- (p-dimethylaminostylyl) -4H-pyran) compounds, benzopyran derivatives, and rhodamine derivatives. , Benzothioxanthene derivatives, azabenzothioxanthene and the like.

Further, as the phosphorescent material, for example, the 7th to 11th of the long periodic table (hereinafter, unless otherwise specified, the term "periodic table" refers to the long periodic table). Examples thereof include an organic metal complex containing a metal selected from the group. Preferred metals selected from Groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, renium, osmium, iridium, platinum, gold and the like.

As the ligand of the organic metal complex, a ligand in which a (hetero) aryl group such as a (hetero) arylpyridine ligand or a (hetero) arylpyrazole ligand is linked to a pyridine, pyrazole, phenanthroline or the like is preferable. In particular, a phenylpyridine ligand and a phenylpyrazole ligand are preferable. Here, the (hetero) aryl represents an aryl group or a heteroaryl group.

Specific preferred phosphorescent materials include, for example, tris (2-phenylpyridine) iridium, tris (2-phenylpyridine) ruthenium, tris (2-phenylpyridine) palladium, bis (2-phenylpyridine) platinum, and tris. Examples thereof include phenylpyridine complexes such as (2-phenylpyridine) osmium and tris (2-phenylpyridine) renium, and porphyrin complexes such as octaethyl platinum porphyrin, octaphenyl platinum porphyrin, octaethyl palladium porphyrin, and octaphenyl palladium porphyrin.

Polymer-based luminescent materials include poly (9,9-dioctylfluorene-2,7-diyl) and poly [(9,9-dioctylfluorene-2,7-diyl) -co- (4,4'-). (N- (4-sec-Butylphenyl)) diphenylamine)], poly [(9,9-dioctylfluorene-2,7-diyl) -co- (1,4-benzo-2 {2,1'-3) } -Triazole)] and other polyfluorene-based materials, and poly-phenylene vinylene-based materials such as poly [2-methoxy-5- (2-hepylhexyloxy) -1,4-phenylene vinylene] can be mentioned.

(Charge transport material)
The charge transporting material is a material having a positive charge (hole) or negative charge (electron) transporting property, and is not particularly limited as long as the effect of the present invention is not impaired, and a known light emitting material can be applied.
As the charge transporting material, a compound or the like conventionally used for the light emitting layer of the organic electroluminescent device can be used, and in particular, a compound used as a host material for the light emitting layer is preferable.

Specific examples of the charge transporting material include aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, and compounds in which a tertiary amine is linked with a fluorene group. , Hydrazone-based compounds, silazane-based compounds, silanamin-based compounds, phosphamine-based compounds, quinacridone-based compounds, and other compounds exemplified as hole-transporting compounds in the hole injection layer, as well as anthracene-based compounds and pyrene-based compounds. Examples thereof include electron-transporting compounds such as carbazole-based compounds, pyridine-based compounds, phenanthroline-based compounds, oxadiazole-based compounds, and silol-based compounds.

Further, for example, two or more fused aromatic rings containing two or more tertiary amines represented by 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl are converted into nitrogen atoms. Aromatic amine compounds (J) having a starburst structure such as substituted aromatic diamine (Japanese Patent Laid-Open No. 5-234681), 4,4', 4 "-tris (1-naphthylphenylamino) triphenylamine and the like. Lumin., 72-74, 985, 1997), aromatic amine compounds consisting of triphenylamine tetramers (Chem. Commun., 2175, 1996), 2, 2', 7, Fluorone compounds such as 7'-tetrakis- (diphenylamino) -9,9'-spirobifluorene (Synth. Metals, Vol. 91, p. 209, 1997), 4,4'-N, N'-dicarbazole. Compounds exemplified as hole-transporting compounds in the hole-transporting layer such as carbazole-based compounds such as biphenyl can also be preferably used. In addition, 2- (4-biphenylyl) -5- (p-talsal) can be used. Oxaziazole compounds such as butylphenyl) -1,3,4-oxadiazole (tBu-PBD), 2,5-bis (1-naphthyl) -1,3,4-oxadiazole (BND), Cyrol compounds such as 2,5-bis (6'-(2', 2 "-bipyridyl))-1,1-dimethyl-3,4-diphenylsilol (PyPySPyPy), vasophenantroline (BPhen), 2,9 Examples thereof include phenanthroline compounds such as −dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP, bassokproin).

<Formation of light emitting layer by wet film formation method>
The light emitting layer may be formed by either a vacuum vapor deposition method or a wet film forming method, but the wet film forming method is preferable because of its excellent film forming property. In the present invention, the wet film forming method is a film forming method, that is, as a coating method, for example, a spin coating method, a dip coating method, a die coating method, a bar coating method, a blade coating method, a roll coating method, a spray coating method, and a capillary. A method of forming a film by adopting a wet film forming method such as a coating method, an inkjet method, a nozzle printing method, a screen printing method, a gravure printing method, and a flexographic printing method, and drying the coating film. When the light emitting layer is formed by the wet film forming method, usually, in the same manner as when the hole injection layer is formed by the wet film forming method, a light emitting layer is used instead of the composition for forming the hole injection layer. The material is formed by using a composition for forming a light emitting layer prepared by mixing a soluble solvent (solvent for a light emitting layer).
Examples of the solvent include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents mentioned for the formation of the hole injection layer, as well as alcan-based solvents, halogenated aromatic hydrocarbon-based solvents, and aliphatic solvents. Examples thereof include alcohol solvents, alicyclic alcohol solvents, aliphatic ketone solvents and alicyclic ketone solvents. Specific examples of the solvent are given below, but the present invention is not limited thereto as long as the effect of the present invention is not impaired.

For example, aliphatic ether solvents such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetol, 2 Aromatic ether solvents such as −methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, diphenyl ether; phenyl acetate, phenyl propionate, methyl benzoate, benzoic acid Aromatic ester solvents such as ethyl, ethyl benzoate, propyl benzoate, n-butyl benzoate; toluene, xylene, methicylene, cyclohexylbenzene, tetraline, 3-iropropylbiphenyl, 1,2,3,4-tetramethyl Aromatic hydrocarbon solvents such as benzene, 1,4-diisopropylbenzene, cyclohexylbenzene, methylnaphthalene; amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide; n-decane, cyclohexane, ethylcyclohexane Alcan solvents such as decalin and bicyclohexane; halogenated aromatic hydrocarbon solvents such as chlorobenzene, dichlorobenzene and trichlorobenzene; aliphatic alcohol solvents such as butanol and hexanol; alicyclic solvents such as cyclohexanol and cyclooctanol. Alcohol-based solvents; aliphatic ketone-based solvents such as methyl ethyl ketone and dibutyl ketone; alicyclic ketone-based solvents such as cyclohexanone, cyclooctanone, and fencon can be mentioned. Of these, alkane-based solvents and aromatic hydrocarbon-based solvents are particularly preferable.

Further, in order to obtain a more uniform film, it is preferable that the solvent evaporates at an appropriate rate from the liquid film immediately after the film formation. Therefore, the boiling point of the solvent is usually 80 ° C. or higher, preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and usually 270 ° C. or lower, preferably 250 ° C. or lower, more preferably 230 ° C. or lower.
The amount of the solvent used is arbitrary as long as the effect of the present invention is not significantly impaired, but it is preferable that the total content in the light emitting layer forming composition is large in that the film formation work is easy because of its low viscosity. On the other hand, a thick film is preferable because it is easy to form a film. The content of the solvent in the iridium complex compound-containing composition is preferably 1% by mass or more, more preferably 10% by mass or more, particularly preferably 50% by mass or more, and preferably 99.99% by mass or less, more preferably 99.99% by mass or less. It is 99.9% by mass or less, particularly preferably 99% by mass or less.

As the solvent removing method, heating or depressurization can be used. As the heating means used in the heating method, a clean oven and a hot plate are preferable because heat is evenly applied to the entire film.
The heating temperature in the heating step is arbitrary as long as the effect of the present invention is not significantly impaired, but a high temperature is preferable in terms of shortening the drying time, and a low temperature is preferable in terms of less damage to the material. The upper limit is usually 250 ° C. or lower, preferably 200 ° C. or lower, and more preferably 150 ° C. or lower. The lower limit is usually 30 ° C. or higher, preferably 50 ° C. or higher, and more preferably 80 ° C. or higher. A temperature above the upper limit is higher than the heat resistance of a commonly used charge transport material or phosphorescent material, and may decompose or crystallize, which is not preferable. Below the lower limit, it takes a long time to remove the solvent, which is not preferable. The heating time in the heating step is appropriately determined by the boiling point and vapor pressure of the solvent in the composition for forming the light emitting layer, the heat resistance of the material, and the heating conditions.

<Formation of light emitting layer by vacuum deposition method>
When forming a light emitting layer by a vacuum vapor deposition method, usually one or more of the constituent materials of the light emitting layer (the above-mentioned light emitting material, charge transporting compound, etc.) are placed in a crucible installed in a vacuum vessel. (When using two or more types of materials, usually put each in a separate crucible), evacuate the inside of the vacuum vessel to ^{about 10-4} Pa with a vacuum pump, and then heat the crucible (two or more types of materials). When used, each crucible is usually heated) and the material in the crucible is evaporated while controlling the amount of evaporation (when two or more kinds of materials are used, each is usually evaporated while controlling the amount of evaporation independently). ), A light emitting layer is formed on the hole injection transport layer placed facing the crucible. When two or more kinds of materials are used, a mixture thereof can be put in a crucible and heated and evaporated to form a light emitting layer.

The degree of vacuum during vapor deposition is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.1 × 10 ^-6 Torr (0.13 × 10 ^-4 Pa) or more, 9.0 × 10 ^-6 Torr ( It is 12.0 × 10 ^-4 Pa) or less. The vapor deposition rate is not limited as long as the effect of the present invention is not significantly impaired, but is usually 0.1 Å / sec or more and 5.0 Å / sec or less. The film formation temperature at the time of vapor deposition is not limited as long as the effect of the present invention is not significantly impaired, but is preferably 10 ° C. or higher and 50 ° C. or lower.

(Heavy dope)
The usual doping concentration of the iridium complex compound in the light emitting layer of the phosphorescent organic electroluminescent element is a concentration of 0.1 mmol / g or less of the iridium complex compound per unit weight of the light emitting layer. In the present invention, the doping concentration exceeding this concentration is referred to as a heavy doping concentration. In general, heavy dope has various effects on organic electroluminescent devices, and while it is expected that the drive life of the device will be extended, it is well known that the luminous efficiency will also decrease due to the pair annihilation of excitons between the light emitting materials. ing.

(Hole blocking layer)
A hole blocking layer may be provided between the light emitting layer and the electron injection layer described later. The hole blocking layer is a layer that is laminated on the light emitting layer so as to be in contact with the interface on the cathode side of the light emitting layer.
The hole blocking layer has a role of blocking holes moving from the anode from reaching the cathode and a role of efficiently transporting electrons injected from the cathode toward the light emitting layer. The physical properties required for the material constituting the hole blocking layer 6 are high electron mobility and low hole mobility, a large energy gap (difference between HOMO and LUMO), and an excited triplet level (T1). Is high.

Examples of the material of the hole blocking layer satisfying such conditions include bis (2-methyl-8-quinolinolato) (phenolato) aluminum, bis (2-methyl-8-quinolinolato) (triphenylsilanorat) aluminum and the like. Mixed ligand complexes, bis (2-methyl-8-quinolato) aluminum-μ-oxo-bis- (2-methyl-8-quinolilato) aluminum dinuclear metal complexes and other metal complexes, distyrylbiphenyl derivatives and the like Triazole derivatives such as styryl compounds (Japanese Patent Laid-Open No. 11-2429996), 3- (4-biphenylyl) -4-phenyl-5 (4-tert-butylphenyl) -1,2,4-triazole (Japan) Japanese Patent Application Laid-Open No. 7-41759), phenanthroline derivatives such as bathocuproine (Japanese Patent Application Laid-Open No. 10-79297), and the like can be mentioned. Further, a compound having at least one pyridine ring in which the 2, 4 and 6 positions are substituted as described in WO 2005/022962 is also preferable as a material for the hole blocking layer.

The method for forming the hole blocking layer 6 is not limited, and the hole blocking layer 6 can be formed in the same manner as the above-mentioned method for forming the light emitting layer.
The film thickness of the hole blocking layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less. ..

(Electronic transport layer)
The electron transport layer is provided between the light emitting layer and the electron injection layer for the purpose of further improving the current efficiency of the device.
The electron transport layer is formed of a compound capable of efficiently transporting electrons injected from the cathode between electrodes to which an electric field is applied in the direction of the light emitting layer. The electron-transporting compound used in the electron-transporting layer is a compound having high electron-injection efficiency from the cathode or the electron-injecting layer and having high electron mobility and capable of efficiently transporting the injected electrons. It is necessary.

The electron-transporting compound used in the electron-transporting layer is usually preferably a compound having high electron-injecting efficiency from the cathode or the electron-injecting layer and capable of efficiently transporting the injected electrons. Specific examples of the electron-transporting compound include a metal complex such as an aluminum complex of 8-hydroxyquinoline (Japanese Patent Laid-Open No. 59-194393), a metal complex of 10-hydroxybenzo [h] quinoline. Oxaziazole derivative, distyrylbiphenyl derivative, silol derivative, 3-hydroxyflavon metal complex, 5-hydroxyflavon metal complex, benzoxazole metal complex, benzothiazole metal complex, trisbenzimidazolylbenzene (US Pat. No. 5,645,948) , Kinoxalin compound (Japanese Patent Laid-Open No. 6-207169), phenanthroline derivative (Japanese Patent Application Laid-Open No. 5-331459), 2-t-butyl-9,10-N, N'-dicyanoanthraquinonediimine, n Examples thereof include type hydride amorphous silicon carbide, type n-type zinc sulfide, and type n-type zinc selenium.

The film thickness of the electron transport layer is usually 1 nm or more, preferably 5 nm or more, and on the other hand, it is usually 300 nm or less, preferably 100 nm or less.
The electron transport layer is formed by laminating on the hole blocking layer by a wet film deposition method or a vacuum vapor deposition method in the same manner as described above. Usually, the vacuum deposition method is used.

(Electron injection layer)
The electron injection layer plays a role of efficiently injecting electrons injected from the cathode into the electron transport layer or the light emitting layer.
In order to efficiently perform electron injection, the material forming the electron injection layer is preferably a metal having a low work function. As an example, alkali metals such as sodium and cesium, alkaline earth metals such as barium and calcium, and the like are used. The film thickness is usually preferably 0.1 nm or more and 5 nm or less.

Further, an organic electron transport material represented by a nitrogen-containing heterocyclic compound such as basophenanthroline or a metal complex such as an aluminum complex of 8-hydroxyquinoline is doped with an alkali metal such as sodium, potassium, cesium, lithium, or rubidium (). (Described in Japanese Patent Application Laid-Open No. 10-270171, Japanese Patent Application Laid-Open No. 2002-100478, Japanese Patent Application Laid-Open No. 2002-1000482, etc.) also improves electron injection and transportability and achieves both excellent film quality. It is preferable because it enables this.

The film thickness is usually in the range of 5 nm or more, preferably 10 nm or more, and usually 200 nm or less, preferably 100 nm or less.
The electron injection layer is formed by laminating on the light emitting layer or the hole blocking layer above it by a wet film forming method or a vacuum vapor deposition method.
The details in the case of the wet film forming method are the same as in the case of the light emitting layer described above.

(cathode)
The cathode plays a role of injecting electrons into a layer on the light emitting layer side (electron injection layer, light emitting layer, etc.). As the material of the cathode, the material used for the anode can be used, but in order to efficiently inject electrons, it is preferable to use a metal having a low work function, for example, tin, magnesium, and indium. , Calcium, aluminum, metals such as silver or alloys thereof are used. Specific examples include alloy electrodes having a low work function such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.

From the viewpoint of device stability, it is preferable to laminate a metal layer having a high work function and stable to the atmosphere on the cathode to protect the cathode made of a metal having a low work function. Examples of the metal to be laminated include metals such as aluminum, silver, copper, nickel, chromium, gold, and platinum.
The film thickness of the cathode is usually the same as that of the anode.

(Other layers)
The organic electroluminescent device of the present invention may further have another layer as long as the effect of the present invention is not significantly impaired. That is, any of the above-mentioned other layers may be provided between the anode and the cathode.

<Other element configurations>
It should be noted that the structure opposite to the above description, that is, the cathode, the electron injection layer, the light emitting layer, the hole injection layer, and the anode can be laminated in this order on the substrate.

<Others>
When the organic electroluminescent device of the present invention is applied to an organic electroluminescent device, it may be used as a single organic electroluminescent device or may be used in a configuration in which a plurality of organic electroluminescent devices are arranged in an array. The anode and cathode may be arranged in an XY matrix.

<Display device and lighting device>
The display device and the lighting device of the present invention use the organic electroluminescent element of the present invention as described above. The type and structure of the display device and the lighting device of the present invention are not particularly limited, and can be assembled according to a conventional method using the organic electroluminescent element of the present invention.
For example, the display device and the lighting device of the present invention by the method described in "Organic EL Display" (Ohmsha, published on August 20, 2004, by Shizushi Tokito, Chihaya Adachi, Hideyuki Murata). Can be formed.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to the following examples, and the present invention can be arbitrarily modified and implemented without departing from the gist thereof.
<Synthesis example of compound (D-1)>

2- (3-Pinacolat borylphenyl) pyridine (17.4 g), intermediate 1 (19.2 g), 2M tripotassium phosphate aqueous solution (77 mL), toluene (120 mL) and ethanol ( 60 mL) was added and nitrogen was bubbled for 30 minutes. Then, while stirring, [Pd (PPh ₃ )] ₄ (1.21 g) was further added, and the mixture was stirred at 105 ° C. for 1.5 hours and refluxed. Then, the mixture was cooled to room temperature, water was added, and the mixture was separated and washed, and then the organic layer was dried over magnesium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (dichloromethane / hexane = 1/1 to dichloromethane / hexane / ethyl acetate = 50/45/5) to make Intermediate 2 (23.6 g) a yellow oil. Obtained as a substance.

Intermediate 2 (18.0 g), iridium chloride n hydrate (8.0 g), 2-ethoxyethanol (200 mL) and distilled water (28 mL) were added to the reaction vessel under a nitrogen stream, and the temperature of the oil bath was 135. The temperature was gradually increased from ° C. to 150 ° C., and the mixture was stirred for a total of 10 hours. During that time, the refluxed liquid was removed from the side tube. The amount of liquid removed at the end of the reaction was 46 mL. Then, the mixture was cooled to room temperature, methanol (100 mL) was added, the mixture was filtered, washed with methanol (400 mL), and dried. Intermediate 3 (21.0 g) was obtained as a yellow solid.

Intermediate 3 (17.6 g), 1,2-dimethoxyethane (300 mL) and ethanol (50 mL) are added to the reaction vessel under a nitrogen stream, the oil bath is heated to 120 ° C., and then 3,5-heptane dione. (14 g) and sodium carbonate (11.3 g) were added, and the mixture was continuously heated under reflux for about 2 hours. After cooling and removing the solvent under reduced pressure, dichloromethane (200 mL) was added, the mixture was filtered through silica gel, and the filtrate was concentrated under reduced pressure. Ethanol (150 mL) was added to the residue to precipitate a powder, which was then filtered.

Intermediate 4 (17.9 g) was obtained as a yellow solid.

Intermediate 4 (11.6 g), Intermediate 5 (synthesized by the method described in Patent Document 2) (4.5 g) and glycerin (87 g) were placed in a reaction vessel under a nitrogen stream, and the internal temperature was adjusted from 218 ° C to 227. The mixture was stirred for 5.5 hours while warming to ° C. The by-product 3,5-heptane dione was distilled off while reacting. After cooling, water was added, the solvent was removed by decantation, and the residue was purified by silica gel column chromatography (dichloromethane / hexane = 1/1) to obtain Compound D-1 (0.70 g) as a yellow solid.

<Synthesis example of compound (D-2)>

Copper (I) bromide (54.5 g) and anhydrous lithium bromide (65.9 g) were placed in a 2 L eggplant flask at room temperature, dried at 60 ° C. for 2 hours, replaced with argon, cooled to room temperature, and dried THF ( 0.9 L) was added and stirred for 2 hours to prepare a catalytic solution.
Activated in a 10 L reactor with nitrogen undercut magnesium (190 g), dry THF (0.3 L), and trace amounts of iodine fragments, and added dropwise to a solution of bromobenzene (1192 g) in dry THF (3.5 L) over 2 hours. Then, the mixture was further refluxed and stirred for 1.5 hours to prepare a Grignard reagent solution. Put 1,5-dibromopentane (4365 g) dried THF (5.2 L) under nitrogen in a 20 L reactor, add the catalyst solution prepared above, cool to an internal temperature of 10 ° C., and then prepare the Grignard reagent prepared earlier. The solution was added dropwise over 1 hour to an internal temperature of 10 to 45 ° C., and then stirred overnight at room temperature. 3M Hydrochloric acid (3.5L) was added, the oil layer was separated, and the aqueous layer was further extracted with ethyl acetate (3.5 × 2 times). The oil layer was dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated to obtain a brown oily crude (4.9 kg). This crude material was distilled under reduced pressure to obtain Intermediate 6 (0.94 kg) as a slightly yellow transparent oil.

Put nitrogen undercut magnesium (107 g) and dry THF (0.5 L) in a 10 L reactor, activate with iodine pieces (several tens of mg), and dry THF (2.5 L) of intermediate 6 (0.91 kg). ) The solution was added dropwise over 2 hours, and the mixture was further heated and stirred at an internal temperature of 55 ° C. for 1 hour to prepare a Grignard reagent solution. After cooling 3-bromobenzonitrile and dry THF (4.5 L) to 10 ° C., the Grignard reagent solution prepared above is added dropwise at an internal temperature of 10 to 35 ° C. over 45 minutes to an internal temperature of 45 to 58 ° C. The mixture was heated and stirred for 3 hours. The above reaction solution was added dropwise to 3M hydrochloric acid (4.3L), cooled to room temperature to separate the oil layer, and the aqueous layer was further extracted with ethyl acetate (6L). The oil layers were combined, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated to obtain a brown oily crude (2.0 kg). This crude product was purified by silica gel column chromatography (ethyl acetate / hexane = 1 / 9-1 / 4) to obtain a pale yellow transparent oil (0.74 kg). Subsequently, the mixture was transferred to a 20 L reactor, charged with diglyme (5.1 L), and sodium hydroxide (0.19 kg) was added. Next, hydrazine monohydrate (0.24 kg) was added dropwise over 30 minutes, the temperature was raised to an internal temperature of 80 ° C. over 1 hour, and the mixture was stirred at an internal temperature of 123 ° C. for 4 hours. After cooling, 2M hydrochloric acid (3.6L) was added, and then hexane (3.5L) was added to separate the oil layer. The aqueous layer is extracted with hexane (2.5 L x 2 times), the oil layers are combined, washed with saturated brine (2.5 L), dried over anhydrous magnesium sulfate, filtered, the filtrate is concentrated, and brown oily. A crude body (0.92 kg) was obtained. This crude product was purified by silica gel column chromatography (hexane) to obtain Intermediate 7 (0.45 kg) as a yellow transparent oil.

To a 20 L reactor, intermediate nitrogen 7 (0.45 kg) and dry THF (4.5 L) were added, cooled to an internal temperature of −77 ° C., and a 1.65 M n-butyllithium / n-hexane solution (1). .0 L) was added dropwise at an internal temperature of −68 ° C. or lower over 1 hour, and the mixture was stirred at −68 ° C. for 1 hour. Then, trimethyl borate (0.47 kg) was added dropwise at an internal temperature of −67 ° C. or lower, and the mixture was stirred for 1.5 hours while maintaining the temperature. Then, 3M hydrochloric acid (1.5L) was added dropwise, and the mixture was stirred overnight while returning to room temperature. Ethyl acetate (3L) was poured, the oil layer was separated, and the aqueous layer was further extracted with ethyl acetate (3L). The oil layers were combined, washed with saturated brine (2.5 L), dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated to obtain a brown oily crude (0.58 kg). When this crude product was purified by silica gel column chromatography (ethyl acetate / dichloromethane / hexane = 0/1/3 to 2/2/3), 0.31 kg of intermediate 8 was obtained.

Intermediate 8 (20.4 g), 3-bromo-3'-iodobiphenyl (28.6 g), 2M tripotassium phosphate aqueous solution (90 mL), toluene (140 mL) and ethanol (70 mL) in a reaction vessel under a nitrogen stream. Was added, and 1.68 g of [Pd (PPh ₃ ) ₄ ] was further added while stirring, and the mixture was stirred and refluxed at 100 ° C. for 3 hours. Then, the mixture was cooled to room temperature, water was added, and the mixture was separated and washed, and then the organic layer was dried over magnesium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (dichloromethane / hexane = 1/9) to obtain 27.8 g of a bromo compound. This was placed in another reaction vessel, and under a nitrogen stream, bispinacolat diboron (17.7 g), [PdCl ₂ (dppf)] CH ₂ Cl ₂ (1.71 g), potassium acetate (20.5 g), dehydration. Dimethyl sulfoxide (150 mL) was added and stirred in a 100 ° C. oil bath for 2 hours. Then, the mixture was cooled to room temperature, water and toluene were added, and the mixture was separated and washed, and then the oil phase was dried over sodium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (developing solution: dichloromethane / hexane = 3/7 to dichloromethane / hexane / ethyl acetate = 3/7 / 0.1) to obtain Intermediate 9 (23.4 g). ) Was obtained.

2-Bromopyridine (3.3 g), intermediate 9 (9.8 g), [Pd (PPh ₃ ) ₄ ] 0.44 g, tripotassium phosphate (9.0 g), distilled water (3.0 g) in a reaction vessel under a nitrogen stream. 20 g), toluene (50 mL) and ethanol (20 mL) were added, and the mixture was stirred in an oil bath at 100 ° C. for 3 hours. After cooling, water was added, the mixture was separated and washed, dried over magnesium sulfate, and purified by silica gel column chromatography (dichloromethane only) to obtain Intermediate 10 (10.0 g) as a colorless oily substance.

Intermediate 4 (5.5 g), intermediate 10 (2.8 g), and diglyme (42 mL) were placed in a reaction vessel under a nitrogen stream to bring the internal temperature to about 100 ° C. Silver trifluoromethanesulfonate (1.6 g) was added, and the internal temperature was immediately raised to 125 ° C. and the mixture was stirred for 2 hours. After cooling to room temperature, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (dichloromethane / hexane = 1/1). Compound D-2 was obtained in 1.6 g as a yellow solid.

<Synthesis example of compound (D-3)>

2- (3-Bromophenyl) pyridine (5.6 g), Intermediate 11 (synthesized by the method described in International Publication No. 2012/137985), 9.3 g, [Pd (PPh _{3 ) 4} ) in a reaction vessel under a nitrogen stream. ] 0.50 g, 27 mL of a 2M tripotassium phosphate aqueous solution, 50 mL of toluene and 25 mL of ethanol were added, and the mixture was stirred in an oil bath at 100 ° C. for 3 hours. After cooling, water and toluene were added, the mixture was separated and washed, dried over magnesium sulfate, and purified by silica gel column chromatography (dichloromethane only) to obtain Intermediate 12 (9.16 g) as a white solid.

Add intermediate 12 (8.9 g), iridium chloride n hydrate (3.4 g) and 2-ethoxyethanol (50 mL), diglyme (50 mL) and distilled water (13 mL) to the reaction vessel under a nitrogen stream, and add oil. The temperature of the bath was gradually increased from 135 ° C. to 150 ° C., and the mixture was stirred for a total of 10 hours. During that time, the refluxed liquid was removed from the side tube. An additional 60 mL of diglyme was added during the reaction. Then, the mixture was cooled to room temperature, the reaction solution was added to 500 mL of distilled water, the precipitated solid was filtered, washed with 500 mL of methanol, and dried. Intermediate 13 (10.5 g) was obtained as a yellow solid.

Intermediate 13 (3.0 g), intermediate 10 (1.3 g) and diglyme (24 mL) were placed in a reaction vessel under a nitrogen stream to bring the internal temperature to about 100 ° C. Silver trifluoromethanesulfonate (0.85 g) was added, and the oil bath was immediately raised to 130 ° C. and stirred for 2 hours. After cooling to room temperature, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (dichloromethane / hexane = 1/1). 0.7 g of compound D-3 was obtained as a yellow solid.

<Synthesis example of compound (D-4)>

2- (3-Pinacolatoborylphenyl) pyridine (19.2 g), 3,3'-dibromobiphenyl (64.4 g), 2M tripotassium phosphate aqueous solution (260 mL), toluene (280 mL) in a reaction vessel under a nitrogen stream. ) And ethanol (140 mL) were added and nitrogen was bubbled for 30 minutes. Then, while stirring, _{6.0 g of [Pd (PPh 3} ) ₄ ] was further added, and the mixture was stirred at 100 ° C. for 3 hours and refluxed. Then, the mixture was cooled to room temperature, water was added, and the mixture was separated and washed, and then the organic layer was dried over magnesium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (dichloromethane / hexane = 4/6 to dichloromethane / hexane / ethyl acetate = 3/7 / 0.5) to obtain intermediate 14 (22.0 g). Obtained as a yellow oily substance.

Add intermediate 14 (10.2 g), intermediate 8 (7.80 g), 2M tripotassium phosphate aqueous solution (33 mL), toluene (60 mL) and ethanol (30 mL) to the reaction vessel under a nitrogen stream, and add 30 nitrogen. Bubbling for minutes. Then, while stirring, _{0.76 g of [Pd (PPh 3} ) ₄ ] was further added, and the mixture was stirred at 100 ° C. for 1.5 hours and refluxed. Then, the mixture was cooled to room temperature, water was added, and the mixture was separated and washed, and then the organic layer was dried over magnesium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (ethyl acetate / hexane = 2/8) to obtain Intermediate 15 (12.9 g) as a colorless oily substance.

Intermediate 15 (4.0 g), intermediate 4 (6.62 g) and diglyme (53 mL) were placed in a reaction vessel under a nitrogen stream to bring the internal temperature to about 100 ° C. Silver trifluoromethanesulfonate (1.89 g) was added, and the oil bath was immediately raised to 130 ° C. and stirred for 2 hours. After cooling to room temperature, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (dichloromethane / hexane = 1/1). Compound D-4 was obtained as a yellow solid in an amount of 2.49 g.

<Synthesis example of compound (D-7)>

Add m-terphenylboronic acid (44.5 g), m-bromoiodobenzene (45.9 g), 2M tripotassium phosphate aqueous solution (200 mL), toluene (300 mL) and ethanol (150 mL) to the reaction vessel under a nitrogen stream. In addition, nitrogen was bubbled for 30 minutes. Then, while stirring, _{4.67 g of Pd (PPh 3} ) ₄ ] was further added, and the mixture was stirred at 100 ° C. for 3.5 hours and refluxed. Then, the mixture was cooled to room temperature, water was added, and the mixture was separated and washed, and then the organic layer was dried over magnesium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (dichloromethane / hexane = 5/95 to 10/90) to obtain Intermediate 16 (48.0 g) as a colorless oily substance.

Intermediate 16 (36.8 g), bis (pinacolat) diboron (29.1 g), potassium acetate (33.8 g), and dehydrated dimethyl sulfoxide (330 mL) were added to the reaction vessel under a nitrogen stream, and nitrogen was bubbled for 30 minutes. .. Then, while stirring, [PdCl ₂ dichloromethane] CH ₂ Cl ₂ (2.81 g) was further added, and the mixture was stirred at 100 ° C. for 3.5 hours. Then, the mixture was cooled to room temperature, water was added, and the mixture was separated and washed, and then the organic layer was dried over magnesium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane / dichloromethane / ethyl acetate = 90/10/5 to 60/40/5) to obtain intermediate 17 (23.1 g) as a white solid. ..

Intermediate 17 (14.3 g), 2- (3-bromophenyl) pyridine (7.7 g), 2M tripotassium phosphate aqueous solution (42 mL), toluene (70 mL) and ethanol (35 mL) in a reaction vessel under a nitrogen stream. Was added and nitrogen was bubbled for 30 minutes. Then, while stirring, [Pd (PPh ₃ )] ₄ (0.95 g) was further added, and the mixture was stirred at 100 ° C. for 3 hours and refluxed. The mixture was cooled to room temperature, water was added, and the mixture was separated and washed, and then the organic layer was dried over magnesium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane / dichloromethane / ethyl acetate = 75/25/3 to 60/40/3) to obtain intermediate 18 (14.8 g) as a yellow solid substance. rice field.

Add intermediate 18 (14.2 g), iridium chloride n hydrate (5.32 g) and 2-ethoxyethanol (68 mL), diglyme (68 mL) and distilled water (21 mL) to the reaction vessel under a nitrogen stream, and add oil. The temperature of the bath was gradually raised from 105 ° C. to 135 ° C., and the mixture was stirred for a total of 7 hours. During that time, the refluxed liquid was removed from the side tube. Then, the mixture was cooled to room temperature, the reaction solution was added to 400 mL of distilled water, the precipitated solid was filtered, washed with 200 mL of methanol, and dried. Intermediate 19 (16.0 g) was obtained as a yellow solid.

Intermediate 8 (100.0 g), 1-bromo-3-iodobenzene (120.3 g), 2M aqueous potassium carbonate solution (443 mL), 900 mL of (toluene) and ethanol (450 mL) were added to the reaction vessel under an argon stream. Further [Pd (PPh ₃ ) ₄ ] (12.31 g) was added with stirring, and the mixture was stirred and refluxed at 90 ° C. for 15 hours. Then, the mixture was cooled to room temperature, water was added, and the mixture was separated and washed, and then the organic layer was dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the obtained residue was subjected to silica gel column chromatography (dichloromethane / hexane = 1/19) to obtain 100.5 g of a bromo compound. Subsequently, this was placed in a 3 L reaction vessel, 1 L of dry THF was added under an argon air flow, the mixture was cooled to an internal temperature of −75 ° C., and 186 mL of a 1.65 M n-butyllithium hexane solution was added dropwise at an internal temperature of −66 ° C. or lower. The mixture was stirred at 70 ° C. for 1 hour. Then, 85.0 g of trimethylborate was added dropwise at an internal temperature of −64 ° C. over 50 minutes, and the mixture was stirred at −70 ° C. for 5 hours. 270 mL of 3M hydrochloric acid was added dropwise to the reaction mixture, and the mixture was stirred overnight while returning to room temperature, 500 mL of ethyl acetate was poured, oil and water were separated, and the aqueous layer was extracted with ethyl acetate. All the organic layers were combined, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated to obtain a crude yellow oil. This crude product was purified by silica gel column chromatography (ethyl acetate / dichloromethane / hexane = 1/0/4 to 1/2/0) to obtain 55.6 g of the intermediate 20 as a pale yellow solid.

Intermediate 12 (13.4 g), intermediate 20 (13.0 g), 45 mL of 2M tripotassium phosphate aqueous solution, 90 mL of toluene and 45 mL of ethanol were added to the reaction vessel under a nitrogen stream, and nitrogen was bubbled for 30 minutes. Then, while stirring, _{4 1.0 g of [Pd (PPh 3} )] was further added, and the mixture was stirred at 100 ° C. for 1.5 hours and refluxed. Then, the mixture was cooled to room temperature, water was added, and the mixture was separated and washed, and then the organic layer was dried over magnesium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (ethyl acetate / hexane = 2/8) to obtain Intermediate 21 (14.4 g) as a colorless oily substance.

Intermediate 19 (6.6 g), intermediate 21 (4.0 g), and 53 mL of diglyme were placed in a reaction vessel under a nitrogen stream to bring the internal temperature to about 100 ° C. 1.64 g of silver trifluoromethanesulfonate was added, and the oil bath was immediately raised to 134 ° C. and stirred for 1.5 hours. After cooling to room temperature, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (dichloromethane / hexane = 1/1). Compound D-7 was obtained as a yellow solid in an amount of 2.24 g.

<Synthesis example of compound (D-8)>

To the reaction vessel, add 40.3 g of 2- (3-bromophenyl) pyridine, 28.8 g of iridium chloride n hydrate, 200 mL of 2-ethoxyethanol and 60 mL of distilled water under a nitrogen stream, and set the temperature of the oil bath to 135 ° C. The mixture was stirred for 8 hours. During that time, the refluxed liquid was removed from the side tube. Then, the mixture was cooled to room temperature, 100 mL of methanol was added to the reaction solution, the precipitated solid was filtered, washed with 400 mL of methanol, and dried. Intermediate 22 (49.0 g) was obtained as a yellow solid.

Intermediate 22 (8.0 g), intermediate 15 (12.3 g) and 120 mL of DMF were placed in a reaction vessel under a nitrogen stream, and the temperature of the oil bath was set to 170 ° C. to make a weak reflux. 3.52 g of silver trifluoromethanesulfonate was added and stirred for 2 hours. After cooling to room temperature, the mixture was separated and washed with 300 mL of water, 300 mL of toluene, and 300 mL of dichloromethane, dried over magnesium sulfate, filtered, and the solvent was removed under reduced pressure. The residue was purified by silica gel column chromatography (dichloromethane / hexane = 1/1). Intermediate 23 was obtained in 4.3 g as a yellow solid.

Intermediate 23 (4.3 g), bis (pinacolato) diboron 2.7 g, potassium acetate 2.7 g, and dehydrated dimethyl sulfoxide 400 mL were added to the reaction vessel under a nitrogen stream, and nitrogen was bubbled for 30 minutes. Then, [PdCl ₂ dppf] CH ₂ Cl ₂ (0.92 g) was further added with stirring, and the mixture was stirred at 100 ° C. for 7 hours. Then, the mixture was cooled to room temperature, 500 mL of water and 500 mL of dichloromethane were added, and the mixture was separated and washed, and then the organic layer was dried over magnesium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane / dichloromethane / ethyl acetate = 60/30/1 to 70/0/30) to obtain intermediate 24 (2.5 g) as a yellow solid. ..

To the reaction vessel, 10.4 g of 3,5-dibromobenzonitrile, 7.6 g of m-biphenylboronic acid, 50 mL of a 2M tripotassium phosphate aqueous solution, 60 mL of toluene and 30 mL of ethanol were added under a nitrogen stream, and nitrogen was bubbled for 30 minutes. Then, while stirring, _{1.2 g of [Pd (PPh 3} ) ₄ ] was further added, and the mixture was stirred at 100 ° C. for 2 hours and refluxed. Then, the mixture was cooled to room temperature, water was added, and the mixture was separated and washed, and then the organic layer was dried over magnesium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (dichloromethane / hexane = 3/7) to obtain Intermediate 25 (8.2 g) as a colorless oily substance.

Intermediate 24 (2.5 g), intermediate 25 (2.6 g), 18 mL of 2M tripotassium phosphate aqueous solution, 50 mL of toluene and 25 mL of ethanol were added to the reaction vessel under a nitrogen stream, and nitrogen was bubbled for 30 minutes. Then, while stirring, _{0.3 g of [Pd (PPh 3} ) ₄ ] was further added, and the mixture was stirred at 100 ° C. for 2.5 hours and refluxed. Then, the mixture was cooled to room temperature, water was added, and the mixture was separated and washed, and then the organic layer was dried over magnesium sulfate. Then, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (dichloromethane / hexane = 65/35) to obtain Compound D-8 (1.2 g) as a yellow solid substance.

<Reference example 1>
Compound D-9, which was synthesized by a method similar to that of compound D-1, precipitated rapidly when a 1 wt% solution of phenylcyclohexane prepared at 100 ° C. was cooled to room temperature. The solubility was so low that it could not be used as an ink.

<Manufacturing of organic electroluminescent device 1>
An organic electroluminescent device having the structure shown in FIG. 1 was manufactured by the following method. However, the iridium atom concentration in the light emitting layers in Examples 1 and 2 and Comparative Examples 1 and 2 was adjusted to be approximately 0.095 mmol / g. Similarly, the iridium atom concentration in the light emitting layers in Examples 3 and 4 and Comparative Examples 3 and 4 was adjusted to be approximately 0.19 mmol / g.

(Example 1)
A transparent conductive film of indium tin oxide (ITO) deposited on a glass substrate 1 to a thickness of 70 nm (a sputter-deposited product manufactured by Geomatec) is subjected to ordinary photolithography technology and hydrochloric acid etching. The anode 2 was formed by patterning into a stripe having a width of 2 mm. The patterned ITO substrate is washed in the order of ultrasonic cleaning with an aqueous surfactant solution, water washing with ultrapure water, ultrasonic cleaning with ultrapure water, and water washing with ultrapure water, dried with compressed air, and finally ultraviolet rays. Ozone cleaning was performed. This ITO functions as a transparent electrode 2.

Next, it contains an arylamine polymer represented by the structural formula (P-1) below, 4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate represented by the structural formula (A-1), and ethyl benzoate. A coating liquid for forming a hole injection layer was prepared. This coating liquid was formed on the anode by spin coating under the following conditions to obtain a hole injection layer 3 having a film thickness of 40 nm.

<Coating liquid for forming hole injection layer>
Solvent Ethyl benzoate Coating solution concentration P-1 2.5% by mass
A-1 0.4% by mass
<Conditions for forming the hole injection layer 3>
Spin coating atmosphere Atmosphere heating conditions Dry air 240 ° C for 1 hour

Next, a coating liquid for forming a hole transport layer containing a compound (P-2) having the structure shown below is prepared, formed by spin coating under the following conditions, and polymerized by heating to form a film thickness. A hole transport layer 4 having a diameter of 11 nm was formed.

<Coating liquid for forming hole transport layer>
Solvent phenylcyclohexane coating solution concentration 1.0% by mass
<Film formation conditions>
Spin coating atmosphere in dry nitrogen
Heating conditions 230 ° C, 1 hour (under dry nitrogen)

Next, in forming the light emitting layer, the organic compound (H-1) and the organic compound (H-2) shown below as the charge transport material, and the iridium complex compound (D) synthesized above as the light emitting material. The iridium complex compound-containing composition shown below was prepared using -1) and spin-coated on the hole transport layer under the conditions shown below to obtain a light emitting layer having a film thickness of 60 nm. The doping concentration of the iridium complex compound per unit weight of the light emitting layer is 0.096 mmol / g.

<Coating liquid for forming a light emitting layer>
Solvent Phenylcyclohexane: 1900 parts by mass Light emitting layer composition H-1: 45 parts by mass
H-2: 55 parts by mass
D-1: 14.8 parts by mass
<Film formation conditions>
Spin coating atmosphere in dry nitrogen
Heating conditions 120 ° C x 20 minutes (under dry nitrogen)

Here, the substrate on which the light emitting layer is formed is transferred into a vacuum vapor deposition apparatus, ^{exhausted until the degree of vacuum in the apparatus becomes 2.0 × 10 -4} Pa or less, and then the compound (HB-1) is vacuum-deposited. The vapor deposition rate was controlled in the range of 0.8 to 1.0 Å / sec and laminated on the light emitting layer to obtain a hole blocking layer 6 having a film thickness of 10 nm.

Subsequently, the organic compound (ET-1) having the structure shown below was laminated on the hole blocking layer 6 by controlling the vapor deposition rate in the range of 0.8 to 1.0 Å / sec by a vacuum vapor deposition method. An electron transport layer 7 having a thickness of 20 nm was formed.

Here, the element that has been vapor-deposited up to the electron transport layer 7 is once taken out, installed in another vapor deposition apparatus, and a 2 mm wide striped shadow mask is used as a mask for cathode vapor deposition, which is orthogonal to the ITO stripe of the anode 2. The exhaust was performed in close contact with the element.
As the electron injection layer 8, first, lithium fluoride (LiF) was formed on the electron transport layer 7 with a film thickness of 0.5 nm using a molybdenum boat. Next, aluminum as the cathode 9 was similarly heated by a molybdenum boat to form an aluminum layer having a film thickness of 80 nm. The substrate temperature during the vapor deposition of the above two layers was maintained at room temperature.

Subsequently, in order to prevent the device from being deteriorated by moisture in the atmosphere during storage, the sealing treatment was carried out by the method described below.
In the nitrogen glove box, a photocurable resin 30Y-437 (manufactured by ThreeBond Co., Ltd.) is applied to the outer periphery of a glass plate having a size of 23 mm × 23 mm with a width of about 1 mm, and a moisture getter sheet (manufactured by Dynic Co., Ltd.) is applied to the central part. Was installed. On this, the substrate for which the cathode formation was completed was bonded so that the vapor-deposited surface faced the desiccant sheet. Then, only the region coated with the photocurable resin was irradiated with ultraviolet light to cure the resin.
As described above, an organic electroluminescent device having a light emitting area portion having a size of 2 mm × 2 mm was obtained.

(Example 2)
Except that in Example 1, compound D-1 used for forming the light emitting layer was changed to compound D-4, and the concentration in the coating liquid for forming the light emitting layer was changed to 16.5 parts by mass. The organic electroluminescent device shown in FIG. 1 was produced in the same manner as in Example 1.

(Comparative Example 1)
In Example 1, the compound D-1 used for forming the light emitting layer was changed to the compound D-5 represented by the following formula, and the concentration in the coating liquid for forming the light emitting layer was changed to 14.7 parts by mass. The organic electroluminescent device shown in FIG. 1 was produced in the same manner as in Example 1 except that it was changed to.

(Comparative Example 2)
In Example 1, the compound D-1 used for forming the light emitting layer was changed to the compound D-6 represented by the following formula, and the concentration in the coating liquid for forming the light emitting layer was changed to 15.0 parts by mass. The organic electroluminescent device shown in FIG. 1 was produced in the same manner as in Example 1 except that it was changed to.

(Example 3)
In Example 1, the organic electroluminescent device shown in FIG. 1 was produced in the same manner as in Example 1 except that the concentration of the light emitting material in the coating liquid for forming a light emitting layer was changed to 34.6 parts by mass.

(Example 4)
In Example 2, the organic electroluminescent device shown in FIG. 1 was produced in the same manner as in Example 2 except that the concentration of the light emitting material in the coating liquid for forming a light emitting layer was changed to 38.5 parts by mass.

(Comparative Example 3)
In Comparative Example 1, the organic electroluminescent device shown in FIG. 1 was produced in the same manner as in Comparative Example 1 except that the concentration of the light emitting material in the coating liquid for forming the light emitting layer was changed to 34.4 parts by mass.

(Comparative Example 4)
In Comparative Example 2, the organic electroluminescent device shown in FIG. 1 was produced in the same manner as in Example 2 except that the concentration of the light emitting material in the coating liquid for forming the light emitting layer was changed to 35.0 parts by mass.
The performance of the element thus obtained is shown in Tables 1 and 2.
Table 1 shows the luminous efficiency (cd / A) when the element is energized at 10 mA / cm ² as a relative value with Comparative Example 1 as 100.

It can be seen that both the device in which the compound of the present invention is doped in the light emitting layer at a normal doping concentration and the device in which the compound of the present invention is doped at a heavy doping concentration have high luminous efficiency. Table 2 shows the relative values of the initial brightness (cd / m ² ) when the element is energized at 15 mA / cm ² with Comparative Example 1 as 100, and after the element is driven at a constant current ^{of 15 mA / cm 2 for 120 hours.} The brightness retention rate is obtained by dividing the brightness of the above by the initial brightness, and the relative value when the brightness retention rate of Comparative Example 1 is 100 is shown.

From Examples 1 to 4 and Comparative Examples 1 to 3, it was found that both the device in which the compound of the present invention was doped in the light emitting layer at a normal doping concentration and the device in which the compound of the present invention was doped at a heavy doping concentration were devices having a high drive life. ..
Further, in particular, it was found that the device obtained by doping the light emitting layer with the compound of the present invention at a heavy doping concentration has high luminous efficiency and a long drive life.

<Storage stability of coating liquid for forming a light emitting layer>
In the storage stability test of the coating liquid, if it can be visually confirmed that the liquid is not turbid and that the Tyndall phenomenon is not observed by irradiating the red laser light, the solution state is maintained in a uniform state. I decided.
(Example 5) The coating liquid for forming a light emitting layer prepared in the same manner as in Example 3 was heated at 150 ° C. for 30 minutes to confirm a uniform state, and then allowed to stand at 45 ° C. for 4 hours to maintain the uniform state. rice field.
(Example 6) The coating liquid for forming a light emitting layer prepared in the same manner as in Example 4 was heated at 150 ° C. for 30 minutes to confirm a uniform state, and then allowed to stand at 45 ° C. for 4 hours to maintain the uniform state. rice field.
(Example 7) The same as in Example 5 except that compound D-1 was changed to compound D-7 and the concentration in the coating liquid for forming a light emitting layer was changed to 44.4 parts by mass in Example 5. The coating liquid for forming a light emitting layer prepared in 1 was heated at 150 ° C. for 30 minutes to confirm a uniform state, and then allowed to stand at 45 ° C. for 4 hours to maintain the uniform state.
(Example 8) In Example 5, the same as in Example 5 except that compound D-1 was changed to compound D-8 and the concentration in the coating liquid for forming a light emitting layer was changed to 39.8 parts by mass. The coating liquid for forming a light emitting layer prepared in 1 was heated at 150 ° C. for 30 minutes to confirm a uniform state, and then allowed to stand at 45 ° C. for 4 hours to maintain the uniform state.
(Reference Example 2) The coating liquid for forming a light emitting layer prepared in the same manner as in Comparative Example 3 was heated at 150 ° C. for 30 minutes to confirm a uniform state, and then allowed to stand at 45 ° C. for 4 hours to maintain the uniform state. rice field.
(Comparative Example 5) When the coating liquid for forming a light emitting layer prepared in the same manner as in Comparative Example 4 was heated at 150 ° C. for 30 minutes to confirm a uniform state and then allowed to stand at 45 ° C. for 4 hours, precipitation of a solid was observed. rice field.
(Comparative Example 6) In Comparative Example 3, the compound D-5 was changed to the compound D-10 shown in the following formula, and the concentration in the coating liquid for forming a light emitting layer was changed to 47.0 parts by mass. The coating liquid for forming a light emitting layer prepared in the same manner as in Example 3 was heated at 150 ° C. for 30 minutes to confirm a uniform state, and then allowed to stand at 45 ° C. for 4 hours. As a result, solid precipitation was observed.
<Compound D-10>

(Comparative Example 7) In Comparative Example 3, the compound D-5 was changed to the compound D-11 shown in the following formula, and the concentration in the coating liquid for forming a light emitting layer was changed to 28.0 parts by mass. The coating liquid for forming a light emitting layer prepared in the same manner as in Example 3 was heated at 150 ° C. for 30 minutes to confirm a uniform state, and then allowed to stand at 45 ° C. for 4 hours. As a result, solid precipitation was observed.

<Compound D-11>

The above results are shown in Table 3.

From Examples 5 to 8 and Comparative Examples 5 to 7, it can be seen that the composition in which the compound of the present invention is used in the coating liquid for forming a light emitting layer at a heavy dope concentration has good storage stability.

<Manufacturing of organic electroluminescent device 2>
(Example 9)
An organic electroluminescent device having the structure shown in FIG. 1 was manufactured by the following method. However, the iridium atom concentration in the light emitting layer was adjusted to be about 0.19 mmol / g.

The glass substrate 1 and the transparent electrode 2 were produced in the same manner as in the production 1 of the organic electroluminescent device in Example 3.

Next, the arylamine polymer represented by the structural formula (P-3) below, 4-isopropyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate represented by the structural formula (A-1), and ethyl benzoate are added. A coating liquid for forming a hole injection layer to be contained was prepared. This coating liquid was formed on the anode by spin coating under the following conditions to obtain a hole injection layer 3 having a film thickness of 29 nm.

<Coating liquid for forming hole injection layer>
Solvent Ethyl benzoate Coating solution concentration P-3 2.0% by mass
A-1 0.4% by mass
<Conditions for forming the hole injection layer 3>
Spin coating atmosphere Atmosphere heating conditions Dry air 230 ° C for 1 hour

Next, a coating liquid for forming a hole transport layer containing a compound (P-4) having the structure shown below is prepared, formed by spin coating under the following conditions, and polymerized by heating to form a film thickness. A 20 nm hole transport layer 4 was formed.

<Coating liquid for forming hole transport layer>
Solvent phenylcyclohexane coating solution concentration 1.5% by mass
<Film formation conditions>
Spin coating atmosphere in dry nitrogen
Heating conditions 230 ° C, 1 hour (under dry nitrogen)

From the formation of the light emitting layer to the final sealing treatment, the same procedure as in Example 3 was carried out to prepare an element.

(Example 10)
In Example 9, the organic electroluminescent device shown in FIG. 1 was produced in the same manner as in Example 9 except that the coating liquid for forming a light emitting layer was changed to the composition of Example 6.

(Example 11)
In Example 9, the organic electroluminescent device shown in FIG. 1 was produced in the same manner as in Example 9 except that the coating liquid for forming a light emitting layer was changed to the composition of Example 7.

(Comparative Example 8)
In Example 9, the organic electroluminescent device shown in FIG. 1 was produced in the same manner as in Example 9 except that the coating liquid for forming a light emitting layer was changed to the composition of Comparative Example 3.
The element thus obtained ^{is driven with a constant current at 15 mA / cm 2} , the time when the brightness is reduced to 90% is obtained as LT90 (h), and the relative value when LT90 of Comparative Example 8 is set to 100. Is shown in Table 4.

As shown in Reference Example 2, the compound D-5 used in Comparative Example 8 had good storage stability as a coating liquid for forming a light emitting layer, but its drive life was inferior to that of Examples 9 to 11. It has been found that by using the compound of the present invention for the light emitting layer, both excellent storage stability as a coating liquid for forming a light emitting layer and a long drive life as an element can be achieved.

(Example 12)
In Example 9, the organic electroluminescent device shown in FIG. 1 was produced in the same manner as in Example 9 except that the coating liquid for forming the light emitting layer was changed to the composition of Example 8, and the maximum wavelength of the device was 517 nm. there were.

Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on a Japanese patent application filed on May 29, 2015 (Japanese Patent Application No. 2015-11255), the contents of which are incorporated herein by reference.

In addition to materials for organic devices such as organic electroluminescent elements, the present invention relates to various fields in which organic electroluminescent elements are used, such as flat panel displays (for example, for OA computers and wall-mounted televisions) and surface emission. It can be suitably used in the fields of light sources (for example, light sources of copying machines, backlight sources of liquid crystal displays and instruments), display boards, indicator lights, lighting devices, etc. that make the best use of the characteristics of the body.

1 board
2 Anode
3 hole injection layer
4 hole transport layer
5 Light emitting layer
6 Hole blocking layer
7 Electron transport layer
8 electron injection layer
9 Cathode

Claims (6)

An iridium complex compound represented by the following formula (1).

In formula (1), Ir represents an iridium atom.
Ring Cy ¹ represents a benzene ring containing carbon atoms C ¹ and C ^2.
Ring Cy ² represents a pyridine ring containing carbon atom C ³ and nitrogen atom N ^1.
Ring Cy ³ represents a benzene ring containing carbon atoms C ⁴ and C ^5.
Ring Cy ⁴ represents a pyridine ring containing carbon atom C ⁶ and nitrogen atom N ^2.
m = 1 and
m + n = 3.
a and c independently represent an integer of 1 to 2, and b and d independently represent an integer of 0 to 2.
one of a number of R ¹ is represented by the following formula (2), one of c number of R ³ is represented by the following formula (3), to each of the other ^{R 1} and ^{R 3} are independently a hydrogen atom , Fluorine atom, chlorine atom, bromine atom, amino group, hydroxy group, mercapto group, alkyl group having 1 to 30 carbon atoms, alkoxy group having 1 to 30 carbon atoms, alkenyl group having 2 to 30 carbon atoms, 1 to 1 carbon atoms. An alkylamino group of 30, an aryloxy group having 3 to 30 carbon atoms, an aryl group having 3 to 30 carbon atoms, a heteroaryl group having 3 to 30 carbon atoms, an arylamino group having 3 to 30 carbon atoms, and an arylamino group having 7 to 7 carbon atoms. Selected from 40 arylyl groups , R ² and R ⁴ are independently fluorine atoms, chlorine atoms, bromine atoms, amino groups, hydroxy groups, mercapto groups, alkyl groups with 1 to 30 carbon atoms, and 1 to 30 carbon atoms, respectively. Alkoxy group, alkenyl group having 2 to 30 carbon atoms, alkylamino group having 1 to 30 carbon atoms, aryloxy group having 3 to 30 carbon atoms, aryl group having 3 to 30 carbon atoms, heteroaryl group having 3 to 30 carbon atoms. It is selected from a group, an arylamino group having 3 to 30 carbon atoms, and an aralkyl group having 7 to 40 carbon atoms.

In equation (2), x represents an integer from 0 to 10.
h represents an integer of 1 to 3.
* Represents a bond.
R is an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and carbon which may be further substituted with a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a cyano group, and a fluorine atom, respectively. It is selected from an amino group which may be further substituted with an aryl group of several 5 to 30 and an acyl group having 1 to 20 carbon atoms.
R'independently may be further substituted with a fluorine atom , phenylmethyl group, phenylethyl group, 1,1-dimethyl-1-phenylmethyl group, 3-phenyl-1-propyl group, 4-phenyl. -1-n-butyl group, 1-methyl-1-phenylethyl group, 5-phenyl-1-n-propyl group, 6-phenyl-1-n-hexyl group, 7-phenyl-1-n-heptyl group , 8-Phenyl-1-n-octyl group, and 4-phenylcyclohexyl group .

In equation (3), k represents an integer from 0 to 5.
y represents an integer of 1-10.
* Represents a bond.
R is synonymous with equation (2) and
R'' may be the same or different for each appearance, and may be independently further substituted with a fluorine atom or a fluorine atom. Alkyl group having 1 to 20 carbon atoms, carbon number 1 to 1 20 alkyl or aryl naphthyl group which may be substituted with a group, and is selected from heteroaryl groups having 1 to 20 carbon atoms.
Except for the hydrogen atom, the fluorine atom, the chlorine atom, the bromine atom, and the groups represented by the formulas (2) and (3), the groups of R ^{1 to} R ⁴ are further composed of fluorine. An alkyl group having 1 to 30 carbon atoms which may be further substituted with an atom, a chlorine atom, a bromine atom or a fluorine atom, and an aryl having 3 to 30 carbon atoms which may be further substituted with an alkyl group having 1 to 30 carbon atoms. It may be substituted with a group or an arylamino group having 3 to 30 carbon atoms.
When ^{there are a plurality of R 1 to} R ⁴ , they may be the same or different.
When a plurality of R ^{1 to} R ⁴ are adjacent to each other on the same ring, the adjacent R ^{1 to} R ⁴ are directly bonded or have an alkylene group having 3 to 12 carbon atoms and an alkaneylene having 3 to 12 carbon atoms. Rings may be formed by bonding via a group or an arylene group having 6 to 12 carbon atoms, and these rings may be further substituted with a fluorine atom, a chlorine atom, a bromine atom, or a fluorine atom. Alkyl groups having 1 to 30 carbon atoms, alkoxy groups having 1 to 30 carbon atoms, aryloxy groups having 3 to 30 carbon atoms, and alkyl groups having 1 to 30 carbon atoms may be further substituted with 3 to 30 carbon atoms. It may be substituted with an aryl group or an arylamino group having 3 to 30 carbon atoms.
Further, R ¹ and R ² or R ³ and R ⁴ are directly bonded or bonded via an alkylene group having 3 to 12 carbon atoms, an alkaneylene group having 3 to 12 carbon atoms, or an arylene group having 6 to 12 carbon atoms. These rings may be further substituted with a fluorine atom, a chlorine atom, a bromine atom, or a fluorine atom, and have an alkyl group having 1 to 30 carbon atoms and 1 to 30 carbon atoms. It is further substituted with an alkoxy group, an aryloxy group having 3 to 30 carbon atoms, an alkyl group having 1 to 30 carbon atoms, an aryl group having 3 to 30 carbon atoms or an arylamino group having 3 to 30 carbon atoms. May be. The iridium complex compound according to claim 1, wherein the formula (2) is represented by the following formula (4), and the formula (3) is represented by the following formula (5).

p represents an integer from 0 to 2
q represents an integer from 0 to 10
r represents an integer from 0 to 2
p + q + r is an integer from 0 to 10.
* Represents a bond.
R, R'and h are synonymous with equation (2).

s represents an integer from 0 to 2
t represents an integer from 1 to 10
u represents an integer from 0 to 2
w represents an integer from 0 to 4
s + t + u + w is an integer from 1 to 10.
* Represents a bond.
R, R'' and k are synonymous with equation (3). A composition containing the iridium complex compound according to claim 1 or 2 and an organic solvent. An organic electroluminescent device comprising the iridium complex compound according to claim 1 or 2. A display device having the organic electroluminescent element according to claim 4. A lighting device having the organic electroluminescent element according to claim 4.

Images