JP7420116B2 - 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, and in particular, an iridium complex compound useful as a material for a light emitting layer of an organic electroluminescent device, a composition containing the compound and a solvent, an organic electroluminescent device containing the compound, and the organic electroluminescent device. The present invention relates to display devices and lighting including elements.

In recent years, various electronic devices using organic electroluminescent elements (hereinafter referred to as "organic EL elements"), such as organic EL lighting and organic EL displays, are being put into practical use. Since organic EL elements require low applied voltage, consume little power, and can emit light in three primary colors, their applications in lighting and displays are being considered. In order to achieve these goals, research has been actively conducted on light-emitting materials to not only adjust the emission wavelength but also improve the luminous efficiency and driving life of light-emitting elements.

For the purpose of improving luminous efficiency, it has been proposed to use a phosphorescent material in the luminescent layer of an organic EL element. Examples of phosphorescent materials include bis(2-phenylpyridinato-N,C2')iridium acetylacetonate (Ir(ppy) ₂ (acac)) and tris(2-phenylpyridinato-N,C2') Ortho-metallated iridium complexes including ')(Ir(ppy) ₃ )iridium are widely known.

Vacuum deposition is mainly used as a method for forming organic EL elements using phosphorescent materials. However, devices are usually manufactured by laminating multiple layers such as a light emitting layer, a charge injection layer, and a charge transport layer. For this reason, the vacuum evaporation method has the problem that the evaporation process is complicated, the productivity is poor, and it is extremely difficult to increase the size of lighting and display panels made of these elements.

On the other hand, an organic EL element can be formed by a coating method to form layers. The coating method can form a stable layer more easily than the vacuum evaporation method, so it is expected to be applied to mass production of displays and lighting devices and large devices.
In order to form a film by a coating method, it is necessary that the organic material contained in the layer be easily dissolved in an organic solvent. Usually a low boiling point, low viscosity solvent such as toluene is used. An ink made with such a solvent can be easily formed into a film by a spin coating method or the like.

For manufacturing organic EL devices by coating, 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). There is also an example in which solubility was improved by modifying 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 Publication No. 2014-74000

However, these patent documents only focus on the solubility of the phosphorescent material alone with respect to the ease of dissolving the phosphorescent material in an organic solvent. When a phosphorescent material is actually used as a light-emitting layer of an organic EL device, it is generally used as a composition in which a charge transport material is also mixed, but the solubility of such a composition in an organic solvent is No attention was paid to this. In other words, even if the phosphorescent material alone is dissolved in an organic solvent, does not precipitate as crystals even after long-term storage, and has good storage stability, in the state of a composition mixed with a charge transport material, It has been found that there is a possibility that problems may arise in the above-mentioned storage stability.
In addition, since the iridium complex, which is a phosphorescent material, is susceptible to reduction, when it receives electrons and becomes an anion, the iridium complex itself may deteriorate or the charge transporting material existing around the iridium complex in the light emitting layer may deteriorate. This poses a problem in that the luminous efficiency and driving life of the device are reduced.
Furthermore, as a further method of improving luminous efficiency and driving life, so-called heavy doping, which increases the concentration of iridium complex in the luminescent layer, may be performed. However, when we investigated a heavily doped device using the iridium complex specifically described in the above patent in addition to a device with a normal doping concentration, we found that the efficiency did not increase even with heavy doping because the original luminous efficiency was low. In other words, a problem was discovered in which the drive life was actually shortened.

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

As a result of intensive studies by the present inventors to solve the above problems, it was found that an 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 It has been discovered that the luminous efficiency and driving life of an organic electroluminescent device having a luminescent layer formed using the composition can be increased, and the present invention has been completed.
That is, the gist of the present invention resides 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 or heteroaromatic ring containing carbon atoms C ¹ and C ² ;
Ring ^Cy2 represents a 6-membered heteroaromatic ring containing carbon atom ^C3 and nitrogen atom ^N1 ,
Ring ^Cy3 represents an aromatic or heteroaromatic ring containing carbon atoms ^C4 and ^C5 ,
Ring Cy ⁴ represents a 6-membered heteroaromatic ring containing carbon atom C ⁶ and nitrogen atom N ² .
m=1 or 2,
m+n=3.
a, b, c, and d each independently represent an integer from 1 to 4.
R ¹ to R ⁴ each independently represent a hydrogen atom, 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, carbon 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, 3 carbon atoms -30 arylamino group, C7-40 aralkyl group, formula (2) or formula (3).
However, at least one of R ¹ or R ² is represented by the following formula (2), and at least one of R ³ or R ⁴ is represented by the following formula (3).

In formula (2), x represents an integer from 0 to 10.
h represents an integer from 1 to 3.
* represents a bond.
Each occurrence of R may be the same or different, and each R may be independently substituted with a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a cyano group, or a carbon number 1 which may be further substituted with a fluorine atom. -20 alkyl group, 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.
Each occurrence of R' may be the same or different, and each R' 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. and aralkyl groups having 1 to 40 carbon atoms.

In formula (3), k represents an integer from 0 to 5.
y represents an integer from 1 to 10.
* represents a bond.
R is synonymous with formula (2),
Each occurrence of R'' may be the same or different, and each independently represents a fluorine atom, an alkyl group having 1 to 20 carbon atoms that may be further substituted with a fluorine atom, or a fluorine atom, an alkyl group having 1 to 20 carbon atoms, and 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 groups R ¹ to R ⁴ other than the groups represented by the formula (2) and the formula (3) are further substituted with a fluorine atom, a chlorine atom, a bromine atom, or a carbon atom which may be further substituted with a fluorine atom. It may be substituted with an alkyl group having 1 to 30 carbon atoms, an aryl group having 3 to 30 carbon atoms which may be further substituted with an alkyl group having 1 to 30 carbon atoms, or an arylamino group having 3 to 30 carbon atoms.
When there is a plurality of each 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, the adjacent R ¹ to R ⁴ may be a direct bond or an alkylene group having 3 to 12 carbon atoms, an alkenylene group having 3 to 12 carbon atoms, or an alkenylene group having 6 to 12 carbon atoms. These rings may be bonded via 12 arylene groups to form a ring, and these rings may be further substituted with a fluorine atom, a chlorine atom, a bromine atom, or a fluorine atom having 1 to 30 carbon atoms. Alkyl group, alkoxy group having 1 to 30 carbon atoms, aryloxy group having 3 to 30 carbon atoms, aryl group having 3 to 30 carbon atoms which may be further substituted with an alkyl group having 1 to 30 carbon atoms, or 3 carbon atoms Optionally substituted with ~30 arylamino groups.
Further, R ¹ and R ² or R ³ and R ⁴ are bonded directly or through an alkylene group having 3 to 12 carbon atoms, an alkenylene group having 3 to 12 carbon atoms, or an arylene group having 6 to 12 carbon atoms. These rings may further include a fluorine atom, a chlorine atom, a bromine atom, an alkyl group having 1 to 30 carbon atoms which may be further substituted with a fluorine atom, and a ring having 1 to 30 carbon atoms. Substituted with an alkoxy group, an aryloxy group having 3 to 30 carbon atoms, an aryl group having 3 to 30 carbon atoms which may be further substituted with an alkyl group having 1 to 30 carbon atoms, or an arylamino group having 3 to 30 carbon atoms. You can leave it there.
[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 have the same meanings as in formula (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 have the same meanings as in formula (3).
[3] At least one of R ¹ is represented by formula (2) or formula (4), and at least one of R ³ is represented by formula (3) or formula (5) [1] Or 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 comprising the iridium complex compound according to any one of [1] to [5].
[8] A display device comprising the organic electroluminescent element according to [7].
[9] A lighting device comprising 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. Since the organic electroluminescent device containing the iridium complex compound has high luminous efficiency and long operating life, the iridium complex compound is useful as a material for organic electroluminescent device. Furthermore, organic electroluminescent devices obtained using the iridium complex compound are useful for display devices and lighting devices.

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

Embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist.
Here, in this specification, "mass %" and "weight %" and "mass parts" and "weight parts" have the same meaning, respectively.

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

Each configuration of equation (1) will be described in detail below.

<Ring Cy ¹ and Ring Cy ³ >
Ring Cy ¹ represents an aromatic ring or heteroaromatic ring containing carbon atoms C ¹ and C ² coordinated to an iridium atom, and ring Cy ³ represents an aromatic ring containing carbon atoms C ⁴ and C ⁵ coordinated to an iridium atom or Represents a heteroaromatic ring. Specifically, benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, fluoranthene 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, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, furopyrrole ring, Furofuran ring, thienofuran ring, benzisoxazole ring, benzisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, shinoline ring, quinoxaline ring, benzimidazole ring , perimidine ring, quinazoline ring, and quinazolinone ring are preferred. Among these, appropriate substituents are often introduced on these rings in order to improve the emission wavelength and solubility, control the wavelength of the device, and improve the durability. Preferably, it is a well-known ring. Ring Cy ¹ and ring Cy ³ are more preferably a hydrocarbon aromatic ring, more preferably a benzene ring or a naphthalene ring, and particularly preferably a benzene ring.

<Ring Cy ² and Ring Cy ⁴ >
Ring Cy ² represents a 6-membered heteroaromatic ring containing nitrogen atom N ¹ coordinated to carbon atom C ³ and iridium atom, and ring Cy ⁴ represents a nitrogen atom N ² coordinated to carbon atom C ⁶ and iridium atom. Represents a 6-membered heteroaromatic ring containing Specifically, preferred are a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a shinoline ring, a quinoxaline ring, a perimidine ring, a quinazoline ring, and a quinazolinone ring. Among these, pyridine is preferred because it is easy to introduce substituents and adjust the emission wavelength and solubility, and there are many known methods for synthesizing with good yield when complexing with iridium. ring, pyrazine ring, quinoline ring, isoquinoline ring, pyrimidine ring, triazine ring, quinoxaline ring, and quinazoline ring, and more preferably a pyridine ring, pyrimidine ring, quinoline ring, isoquinoline ring, and quinoxaline ring.

<R ¹ , R ² , R ³ , R ⁴ >
R ¹ , R ² , R ³ and R ⁴ represent groups bonded to ring Cy ¹ , ring Cy ² , ring Cy ³ and ring Cy ⁴ , respectively. When there are a plurality of R ¹ , R ² , R ³ , and R ⁴ , each of them may be the same or different. R ¹ to R ⁴ each independently represent a hydrogen atom, 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, carbon 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, 3 carbon atoms -30 arylamino group, C7-40 aralkyl group, formula (2) or formula (3).
a, b, c, and d each independently represent an integer from 1 to 4.
a is preferably 1 to 2, and most preferably 1, from the viewpoint of sufficiently maintaining the solubility of the complex and having good hole transport properties.
b is preferably 0 to 2, more preferably 0 to 1, and most preferably 0 from the viewpoint of maintaining sufficient solubility of the complex and adjusting durability and luminescent color.
c is preferably 1 to 2, and most preferably 1, from the viewpoint of sufficiently maintaining the solubility of the complex and having good hole transport properties.
d is preferably 0 to 2, more preferably 0 to 1, and most preferably 0 from the viewpoint of maintaining sufficient solubility of the complex and adjusting durability and luminescent color.
However, at least one of R ¹ or R ² is a group represented by the following formula (2). Although the luminescent material can transport charges inside the device, it is believed that it plays a role in transporting holes, especially in heavily doped devices. If holes are difficult to transport, the positions for charge recombination in the light-emitting layer are limited, resulting in a reduction in luminous efficiency and, ultimately, a reduction in driving life. Since transport of holes largely depends on the ring Cy ¹ and its substituents, at least one R ¹ is preferably a group represented by formula (2) from the viewpoint of facilitating transport of holes.

x represents an integer of 0 to 10, and from the viewpoint of sufficiently maintaining the solubility of the complex and having good hole transport properties, x is preferably 0 or more, more preferably 1 or more, and even more preferably It is 2 or more. Further, it is preferably 10 or less, more preferably 8 or less, still more preferably 6 or less.
h represents an integer of 1 to 3, and is preferably 1 from the viewpoint of maintaining sufficient solubility of the complex.
* represents a bond.
Each occurrence of R may be the same or different, and each R may be independently substituted with a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a cyano group, or a carbon number 1 which may be further substituted with a fluorine atom. Selected from an alkyl group having ~20 carbon atoms, 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, preferably a hydrogen atom , a fluorine atom, a cyano group, and an alkyl group having 1 to 20 carbon atoms which may be further substituted with a fluorine atom. From the viewpoint of improving hole transport properties, it is more preferable that R is a hydrogen atom, and it is particularly preferable that all R are hydrogen atoms. Furthermore, from the viewpoint of shortening the emission wavelength, it is preferable that at least one R is 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; It is more preferable that only one or two of the R's of the two ligands are 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, Most preferably, only one of the R's in one ligand is a cyano group or an alkyl group having 1 to 20 carbon atoms which may be further substituted with a fluorine atom.
Each occurrence of R' may be the same or different, and each R' is independently 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. aralkyl groups having 4 to 40 carbon atoms, preferably linear alkyl groups having 5 to 12 carbon atoms or aralkyl groups having 4 to 40 carbon atoms, more preferably aralkyl groups having 4 to 40 carbon atoms. be.

Examples of alkyl groups having 4 to 20 carbon atoms include linear alkyl groups, branched alkyl groups, and cyclic alkyl groups. More specifically, n-butyl groups, n-pentyl groups, n- Examples include hexyl group, n-octyl group, isopropyl group, isobutyl group, and cyclohexyl group. From the viewpoint of solubility and durability, straight-chain alkyl groups are preferred, and straight-chain alkyl groups having 5 to 12 carbon atoms are more preferred.
Examples of aralkyl groups having 4 to 40 carbon atoms include 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 include 1-n-octyl group and 4-phenylcyclohexyl group.

If it is possible to maintain the solubility of the iridium complex, increase its affinity with the charge transport material in the light emitting layer, improve dispersibility, and prevent aggregation, the luminous efficiency and driving life of the device will be less likely to be impaired. . From that point of view, a preferable group as R' is an aralkyl group having 4 to 40 carbon atoms, which simultaneously has an alkylene moiety that ensures solubility and an aromatic group that has affinity with the charge transport material, and a more preferable group is a carbon 4 to 30 aralkyl groups, particularly preferably 1,1-dimethyl-1-phenylmethyl group, 5-phenyl-1-n-propyl group from the viewpoint of solubility in solvents and ease of synthesis. , 6-phenyl-1-n-hexyl group, 7-phenyl-1-n-heptyl group and 8-phenyl-1-n-octyl group.

Moreover, at least one of R ³ or R ⁴ is a group represented by the following formula (3). Although the luminescent material can transport charges inside the device, it is believed that it plays a role in transporting holes, especially in heavily doped devices. If holes are difficult to transport, the positions for charge recombination in the light-emitting layer are limited, resulting in a reduction in luminous efficiency and, ultimately, a reduction in driving life. Since transport of holes largely depends on ring Cy ³ and its substituents, at least one R ³ is preferably a group represented by formula (3) from the viewpoint of facilitating transport of holes.

y represents an integer from 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, it is preferably 8 or less, more preferably 6 or less. k represents an integer from 0 to 5, and is preferably 0 or 1 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 formula (3) has the same meaning as formula (2).
Each occurrence of R'' may be the same or different, and each independently represents a fluorine atom, an alkyl group having 1 to 20 carbon atoms that may be further substituted with a fluorine atom, or a fluorine atom, an alkyl group having 1 to 20 carbon atoms, and It is selected from a naphthyl group which may be substituted with 20 alkyl or aryl groups, or a heteroaryl group which may be substituted with an aryl group having 1 to 20 carbon atoms. From the viewpoint of promoting hole transportability, an alkyl group or naphthyl group having 1 to 20 carbon atoms is preferred, and an alkyl group or naphthyl group having 1 to 3 carbon atoms is more preferred.

Most preferably, at least one of R ¹ is represented by formula (2), and at least one of R ³ is represented by formula (3). In this case, the iridium complex in the present invention has at least one alkyl group or aralkyl group, preferably an aralkyl group, as R ¹ and at least one group in which two or more phenylene groups are linked as R ³ . This makes it easier to obtain the effects of the present invention, as will be described later.
The above groups of R ¹ to R ⁴ excluding the groups represented by formula (2) and formula (3) have a carbon number of 1 and may be further substituted with a fluorine atom, a chlorine atom, a bromine atom, or a fluorine atom. -30 alkyl group, an aryl group having 3 to 30 carbon atoms which may be further substituted with an alkyl group having 1 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 may be directly bonded, or may be an alkylene group having 3 to 12 carbon atoms, an alkenylene group having 3 to 12 carbon atoms, or an alkenylene group having 3 to 12 carbon atoms. They may be bonded via 6 to 12 arylene groups to form a ring, and these rings may further be substituted with a fluorine atom, a chlorine atom, a bromine atom, or a fluorine atom having 1 to 1 carbon atoms. It may be substituted with an alkyl group having 30 carbon atoms, an aryl group having 3 to 30 carbon atoms which may be further substituted with an alkyl group having 1 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 bonded directly or through an alkylene group having 3 to 12 carbon atoms, an alkenylene group having 3 to 12 carbon atoms, or an arylene group having 6 to 12 carbon atoms. These rings may further include a fluorine atom, a chlorine atom, a bromine atom, an alkyl group having 1 to 30 carbon atoms which may be further substituted with a fluorine atom, and a ring having 1 to 30 carbon atoms. It may be substituted with an aryl group having 3 to 30 carbon atoms or an arylamino group having 3 to 30 carbon atoms, which may be further substituted with an alkyl group.

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, a benzoquinoline ring, Examples include an azaphenanthrene ring, an azaanthracene ring, and an azatriphenylene ring. If the condensed ring structure in which π electrons are conjugated is too large, the emission wavelength will extend into the infrared region or the solubility will decrease. Therefore, it is preferable to use a fluorene ring, a carbazole ring, a quinoline ring, an isoquinoline ring, or a quinazoline ring. , azatriphenylene ring.
Examples of the alkyl group having 1 to 30 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, hexyl group, octyl group, and isobutyl group, with methyl group being preferred.

Examples of the alkoxy group having 1 to 30 carbon atoms include methoxy group, ethoxy group, propyloxy group, octyloxy group, etc. Among them, methoxy group is preferred.
Examples of the alkenyl group having 2 to 30 carbon atoms include vinyl group, allyl group, 3-buteno group, 2-buteno group, and 1,3-butadienyl group, with vinyl group being preferred.
Examples of the alkylamino group having 1 to 30 carbon atoms include methylamino group, dimethylamino group, diethylamino group, dibutylamino group, octylamino group, and dioctylamino group, among which methylamino group or dimethylamino group is preferred.

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

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, and a diphenylpyrimidyl group.
Examples of the arylamino group having 3 to 30 carbon atoms include a phenylamino group, a diphenylamino group, a ditolylamino group, and a di(2,6-dimethylphenyl)amino group.

Aralkyl groups having 7 to 40 carbon atoms include 1,1-dimethyl-1-phenylmethyl group, 1,1-di(n-butyl)-1-phenylmethyl group, 1,1-di(n-hexyl)- 1-phenylmethyl group, 1,1-dialkyl-1-phenylmethyl group exemplified by 1,1-di(n-octyl)-1-phenylmethyl group, phenylmethyl group, phenylethyl 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- Examples include phenyl-1-n-heptyl group, 8-phenyl-1-n-octyl group, and 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 hole transportability. Further, m+n=3.

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

In formula (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 have the same meanings as in formula (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 from 0 to 5.

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

In formula (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 an integer from 1 to 1. It is an integer of 10. * represents a bond. Note that R, R'' and k have the same meanings as in formula (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 above formula (4) and the above formula (5) are more preferable will be described. The above formula (2) and the above formula (3) are bonded via a phenylene ring. This binding mode includes ortho, meta, and para positions. Among these, when bonding at the ortho position, adjacent phenylene rings create steric hindrance to each other, resulting in large twisting. Although this twisting improves the solubility of the complex, it reduces the conjugation of the π electrons in the phenylene ring, which does not necessarily have a positive effect on the hole transport properties. 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, large π electron conjugation spreads from the iridium atom to the phenylene ring next to it, which has a favorable effect on hole transport properties.
Further, in the iridium complex of the present invention, it is more preferable that formula (2) is formula (4) and formula (3) is formula (5).
Moreover, it is more preferable that at least one of R ¹ is represented by formula (2) or formula (4), and at least one of R ³ is represented by formula (3) or formula (5). .
Further, it is more preferable that at least one of R ¹ is represented by formula (4) and at least one of R ³ is represented by formula (5).

<Specific example>
Preferred specific examples of the iridium complex compound of the present invention are shown below, but the present invention is not limited thereto.

<Structural features>
The coating solution for forming a light-emitting layer using the iridium complex compound of the present invention, that is, the storage stability is improved by maintaining a uniform state without precipitation in the state of a solution coexisting with a charge transport material, and the luminescence of the device The reason why element characteristics such as efficiency and drive life are improved is surmised as follows.
In order to increase the solubility in organic solvents, 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 assume many conformations, the energy for rearrangement increases during crystallization. Therefore, it is expected that the iridium complex compound will be less likely to crystallize and have improved solubility.

However, when these flexible structures are introduced into an iridium complex compound with good symmetry, that is, when a homoleptic type complex is created, the rearrangement energy for crystallization is lowered and crystallization becomes easier, resulting in sufficient solubility. The improvement effect will no longer be obtained.
Furthermore, the charge transporting material coexisting in the coating solution for forming a light-emitting layer usually does not have a group having such a flexible structure, 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 increased solubility by the above method, is Since it is not necessarily high, the coexistence of these compounds significantly lowers the solubility of any of the compounds, especially the charge transport material, in organic solvents, making them more likely to precipitate as solids.
In addition, since these groups having a flexible structure are essentially insulators, they inhibit the injection of charge into the iridium complex and the transport of charge between the iridium complexes or between the iridium complex and the host. Furthermore, since the group has high mobility, it provides a path for non-radiative deactivation from the excited state, resulting in a disadvantage in that the luminous efficiency deteriorates.

On the other hand, when introducing a substituent linked to an arylene group, such as an m-phenylene group, into a ligand, many conformations are possible, although not as many as with alkyl groups, so it is sufficient to suit the coating method. It can be made to have a good solubility. Furthermore, the luminescent material can transport charges inside the device, but by connecting the phenylene groups for a long time, the orbits of π electrons or empty orbits are expanded spatially, making it easier to transport charges. In particular, an iridium complex having a group in which long phenylene groups are connected easily receives holes. By using such an iridium complex as a light-emitting material in the light-emitting layer, the hole transport properties within the light-emitting layer can be improved. Furthermore, it is considered that the light emitting position within the light emitting layer can be adjusted by adjusting the doping concentration of such an iridium complex. The fact that charges are easily transported means that the positions for charge recombination in the light-emitting layer of the device are expanded, which is expected to improve luminous efficiency and driving life. However, at the same time, excellent electrical conductivity means that the interaction between iridium complexes within the light-emitting layer is not hindered, and especially when heavily doped, exciton annihilation due to interaction between excitons or excitons and charges, i.e., concentration Since quenching also occurs, the range of improvement in luminous efficiency is small or even decreases.

In order to compensate for these drawbacks, it is effective to make the above two types of ligands exist simultaneously in an appropriate state on one iridium complex as in the present invention. By forming a heteroleptic type complex, the symmetry of the iridium complex compound is lowered, and by the presence of a ligand having a group connected to a phenylene group that does not have a flexible structure, it is possible to increase the similarity to charge transport materials. By increasing this, the storage stability of the coating liquid for forming a light emitting layer can be improved.

Further, in the organic EL element using the iridium complex as a luminescent material in the luminescent layer according to the present invention, an effect of improving the driving life is expected. Its mechanism of action is thought to be as follows. Since an iridium complex having a group in which long phenylene groups are connected easily receives holes, it is thought that most of the iridium complexes in the light-emitting layer of the device during energization drive are in a state in which holes are received. Furthermore, the iridium complex in the present invention also has an insulating aralkyl group. The aralkyl group serves as an insulating spacer and moderately suppresses the hole transport properties of the iridium complex of the present invention. Therefore, the probability that it exists in a cation state, which is a state in which it has received holes, increases. It is thought that the iridium complex, which is in a cationic state, emits light as soon as it receives an electron, resulting in high luminous efficiency. Furthermore, since the iridium complex in the cation state is stable, it is thought that the driving life will be improved.

In the present invention, by arranging an appropriate substituent moiety mainly having a phenylene linkage and a solubilizing moiety in the ligand, the above-mentioned drawbacks are solved, and the luminous efficiency of the device is increased and the driving life is improved. It is possible to achieve both.

<Organic solvent>
In the wet film formation method, the organic material of the light-emitting layer is first dissolved in an organic solvent, then applied using a spin coating method or an inkjet method, and then the organic solvent is evaporated by heating, reducing pressure, or spraying an inert gas. This is a method of forming a film. If necessary, in order to make the organic material formed into a film insoluble in solvents, for example, by making a crosslinking group such as a C═C group, a C≡C group, or a benzocyclobutene group exist in the molecule of the organic material, It can also be crosslinked and insolubilized by known methods such as heating or light irradiation.

The organic solvents preferably used in such a wet film forming method include optionally substituted aliphatic hydrocarbons such as hexane, heptane, methyl ethyl ketone, ethyl acetate, and butyl acetate, toluene, xylene, phenylcyclohexane, and benzoin. Examples include aromatic hydrocarbons that may be substituted such as ethyl acid, and alicyclic hydrocarbons that may be substituted such as cyclohexane, cyclohexanone, methylcyclohexanone, and 3,3,5-trimethylcyclohexanone. . These may be used alone, or a plurality of types of solvents may be mixed and used as a composition in order to form a coating liquid suitable for the coating process. The type of organic solvent mainly used is preferably aromatic hydrocarbons or alicyclic hydrocarbons, and more preferably aromatic hydrocarbons. In particular, phenylcyclohexane is said to have a suitable viscosity and boiling point for wet film forming processes. Therefore, the solubility of the iridium complex compound suitably 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 of synthesizing iridium complex compound>
The iridium complex compound of the present invention can be synthesized by a combination of known methods. The ligand can be synthesized by combining known organic synthesis reactions such as the so-called Suzuki-Miyaura coupling reaction. An iridium complex compound can be synthesized using this ligand and an iridium compound.

Regarding the synthesis method of the iridium complex compound, for example, a method via a chlorine-bridged iridium dinuclear complex as shown in the following formula (A) (MG. Colombo, T.C. Brunold, T. Riedener, H.U. Gudel, Inorg. Chem., 1994, 33, 545-550), a method of converting the dinuclear complex of the following formula (B) into a mononuclear complex by exchanging the chlorine bridge with acetylacetonate, and then obtaining the desired product (S .Lamansky, P. Djurovich, D. Murphy, F. Abdel-Razzaq, R. Kwong, I. Tsyba, M. Borz, B. Mui, R. Bau, M. Thompson, Inorg. Chem., 2001, 40, 1704-1711), but are not limited to these. In addition, in formulas (A) and (B), R represents hydrogen or an arbitrary substituent, and a plurality of R's may be the same or different.

For example, conditions for a typical reaction represented by the following formula (A) are as follows. In the first step, a chlorine-bridged iridium dinuclear complex is synthesized by reacting two equivalents of the first ligand with one equivalent of iridium chloride n-hydrate. As the solvent, a mixed solvent of 2-ethoxyethanol and water is usually used, but no solvent or other solvents may be used. The reaction can also be promoted by using an excess amount of the ligand or by using an additive such as a base. Other bridging anionic ligands such as bromine can also be used in place of chlorine. There is no particular restriction on the reaction temperature, but it 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 a second ligand to obtain the desired complex. Ethoxyethanol or diclime is usually used as the solvent, but depending on the type of the ligand, no solvent or other solvents can be used, or a mixture of a plurality of solvents can also be used. Although the reaction may proceed without adding a halogen ion scavenger, it is not always necessary, but in order to increase the reaction yield and selectively synthesize a facial isomer with a higher quantum yield, the scavenger may be used. The addition of is advantageous. There is no particular restriction on the reaction temperature, but it is usually carried out within the range of 0°C to 250°C.

Further, typical reaction conditions represented by formula (B) will be explained. The first stage dinuclear complex can be synthesized in the same manner as in formula (A). In the second step, one equivalent or more of a 1,3-dione compound such as acetylacetone is added to the dinuclear complex, and one equivalent of a basic compound capable of extracting active hydrogen from the 1,3-dione compound such as sodium carbonate is added to the dinuclear complex. By reacting an equivalent amount or more, it is converted into a mononuclear complex coordinated with a 1,3-dionato ligand. Usually, a solvent such as ethoxyethanol or dichloromethane that can dissolve the raw material dinuclear complex is used, but if the ligand is liquid, it is also possible to carry out the reaction without a solvent. There is no particular restriction on the reaction temperature, but it is usually carried out within the range of 0°C to 200°C.

In the third step, one equivalent or more of the second ligand is reacted. The type and amount of the solvent are not particularly limited, and if the second ligand is liquid at the reaction temperature, no solvent may be used. There is no particular restriction on the reaction temperature, but since the reactivity is somewhat poor, the reaction is often carried out at a relatively high temperature of 100°C to 300°C. Therefore, a high boiling point solvent such as glycerin is preferably used.
After the final reaction, purification is performed to remove unreacted raw materials, reaction by-products, and solvents. Although purification operations in ordinary organic synthetic chemistry can be applied, purification is mainly performed by normal phase silica gel column chromatography as described in the above-mentioned non-patent literature. As the developing solution, a single solution or a mixture of hexane, heptane, dichloromethane, chloroform, ethyl acetate, toluene, methyl ethyl ketone, and methanol can be used. Purification may be performed multiple times under different conditions. Other chromatography techniques (reversed-phase silica gel chromatography, size exclusion chromatography, paper chromatography) and purification operations such as separation washing, reprecipitation, recrystallization, powder suspension washing, and vacuum drying are performed as necessary. It can be applied by

<Applications of iridium complex compounds>
The iridium complex compound of the present invention can be suitably used as a material used in an organic electroluminescent device, that is, an organic electroluminescent device material, and can also be suitably used as a light emitting material for organic electroluminescent devices and other light emitting devices. It 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 explained.

The iridium complex compound-containing composition of the present invention contains the above-described iridium complex compound of the present invention and a solvent. The iridium complex compound-containing composition of the present invention is usually used to form a layer or film by a wet film forming method, and is particularly preferably used to form 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, and usually 99.9% by mass or less, preferably 99% by mass or less. It is. By setting the content of the iridium complex compound in the composition within this range, holes and electrons can be efficiently injected from an adjacent layer (for example, a hole transport layer or a hole blocking layer) to a light emitting layer. Driving voltage can be reduced. In addition, the iridium complex compound of this invention may be contained in the iridium complex compound containing composition of 1 type, and may be contained in combination of 2 or more types.

When the iridium complex compound-containing composition of the present invention is used, for example, for an organic electroluminescent device, it contains, in addition to the above-mentioned iridium complex compound and solvent, a charge transporting compound used in the organic electroluminescent device, especially in the light emitting layer. be able to.
When forming a light-emitting layer of an organic electroluminescent device 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 other charge-transporting compounds are included as charge-transporting materials. It is preferable.

The solvent contained in the iridium complex compound-containing composition of the present invention is a volatile liquid component used to form a layer containing an iridium complex compound by wet film formation.
The solvent is not particularly limited as long as the iridium complex compound of the present invention, which is a solute, has a high solubility, so that the charge transporting compound described below can be well dissolved therein. Preferred solvents include, for example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; aromatic hydrocarbons such as toluene, xylene, methysylene, phenylcyclohexane, and tetralin; chlorobenzene, dichlorobenzene, and trichlorobenzene. Halogenated aromatic hydrocarbons such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 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 Alicyclic ketones such as non, fenchone; Alicyclic alcohols such as cyclohexanol and cyclooctanol; Aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; Aliphatic alcohols such as butanol and hexanol; Ethylene glycol dimethyl ether, ethylene Examples include aliphatic ethers such as glycol diethyl ether and propylene glycol-1-monomethyl ether acetate (PGMEA).

Among them, alkanes and aromatic hydrocarbons are preferred, and in particular, phenylcyclohexane has a preferable viscosity and boiling point in a wet film forming process.
One type of these solvents may be used alone, or two or more types 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 is less than this range, the stability of film formation may decrease due to evaporation of the solvent from the composition during wet film formation.

The content of the solvent 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 It is 99.9% by mass or less, particularly preferably 99% by mass or less. The thickness of the light-emitting layer is usually about 3 to 200 nm, but if the content of the solvent is below this lower limit, the viscosity of the composition may become too high and the film-forming workability may decrease. On the other hand, if it exceeds this upper limit, the thickness of the film obtained by removing the solvent after film formation cannot be increased, so film formation tends to become difficult.

As other charge transporting compounds that may be contained in the iridium complex compound-containing composition of the present invention, those conventionally used as materials for organic electroluminescent devices can be used. For example, pyridine, carbazole, naphthalene, perylene, pyrene, anthracene, chrysene, naphthacene, phenanthrene, coronene, fluoranthene, benzophenanthrene, fluorene, acetonaphthofluoranthene, coumarin, p-bis(2-phenylethenyl)benzene, and the like. derivatives, quinacridone derivatives, DCM (4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene, aryl Examples include fused aromatic ring compounds substituted with an amino group and styryl derivatives substituted with an arylamino group.

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

The iridium complex compound-containing composition of the present invention may further contain other compounds in addition to the above-mentioned compounds, etc., if necessary. For example, other solvents may be contained in addition to the above-mentioned solvents. Examples of such solvents include amides such as N,N-dimethylformamide and N,N-dimethylacetamide, and dimethylsulfoxide. One type of these may be used alone, or two or more types may be used in any combination and ratio.

<Organic electroluminescent device>
Embodiments of the organic electroluminescent device, organic electroluminescent lighting device, and organic electroluminescent display device of the present invention will be described in detail below, but the present invention is limited by these contents unless it exceeds the gist thereof. isn't it.

(substrate)
The substrate serves as a support for the organic electroluminescent element, and is usually a quartz or glass plate, a metal plate or metal foil, a plastic film or sheet, or the like. Among these, glass plates and plates made of transparent synthetic resins such as polyester, polymethacrylate, polycarbonate, and polysulfone are preferred. The substrate is preferably made of a material with high gas barrier properties, since deterioration of the organic electroluminescent element by outside air is unlikely to occur. For this reason, especially when using a material with low gas barrier properties such as a synthetic resin substrate, it is preferable to provide a dense silicon oxide film or the like on at least one side of the substrate to improve the gas barrier properties.

(anode)
The anode has the function of injecting holes into the layer on the light emitting layer side. The anode is typically made of metals such as aluminum, gold, silver, nickel, palladium, platinum; metal oxides such as indium and/or tin oxides; metal halides 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 evaporation method. In addition, 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., it is necessary to add a suitable binder resin solution to the anode. It can also be formed by dispersing it and coating it on the substrate. In the case of conductive polymers, it is also possible to form a thin film directly on the substrate by electrolytic polymerization, or to form an anode by coating 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 of the anode. The thickness of the anode may be determined depending on the required transparency, material, etc. When particularly high transparency is required, the thickness is preferably such that the visible light transmittance is 60% or more, and more preferably 80% or more. 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, if transparency is not required, the thickness of the anode may be set arbitrarily depending on the required strength, etc. In this case, the anode may have the same thickness as the substrate.
When forming a film on the surface of the anode, before the film is formed, impurities on the anode are removed by treatment with ultraviolet rays + ozone, oxygen plasma, argon plasma, etc., and the ionization potential is adjusted. It is preferable to improve the hole injection properties.

(hole injection layer)
A layer that has the 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 the 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. It is preferable to use a hole injection layer because it enhances the function of transporting holes from the anode to the light emitting layer. When using a hole injection layer, the hole injection layer is typically formed on the anode.

The 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 a vacuum evaporation method or a wet film formation method. In terms of excellent film-forming properties, it is preferable to form the film 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. Furthermore, it is preferable that the hole injection layer contains a cation radical compound, and it is particularly preferable that the hole injection layer contains a cation 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 becomes the hole injection layer. Further, in the case of a wet film forming method, a solvent is usually also contained. It is preferable that the composition for forming a hole injection layer has high hole transport properties and can efficiently transport injected holes. For this reason, it is preferable that the hole mobility is high and that impurities that become traps are difficult to generate during manufacturing or use. Further, it is preferable that the material has excellent stability, low ionization potential, and high transparency to visible light. In particular, when the hole injection layer is in contact with the light-emitting layer, it is preferable to use a material that does not quench light emitted from the light-emitting layer or a material that does not form an exciplex with the light-emitting layer and reduce luminous efficiency.

The hole transporting compound is preferably a compound having an ionization potential of 4.5 eV to 6.0 eV 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 tertiary amines are linked with fluorene groups, and hydrazone. Examples thereof include silazane-based compounds, silazane-based compounds, and quinacridone-based compounds.

Among the above-mentioned exemplary compounds, aromatic amine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred, from the viewpoint of amorphousness and visible light transparency. 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 an aromatic tertiary amine.
The type of aromatic tertiary amine compound is not particularly limited, but a polymeric compound with a weight average molecular weight of 1,000 or more and 1,000,000 or less (a polymeric compound with a series of repeating units) is preferred, since it is easy to obtain uniform light emission due to the surface smoothing effect. It is preferable to use Preferred examples of aromatic tertiary amine polymer compounds include polymer compounds having repeating units represented by the following formula (I).

(In formula (I), Ar ¹ and Ar ² each independently represent an aromatic hydrocarbon group that may have a substituent or an aromatic heterocyclic group that 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 is the following: Represents a linking group selected from the group of linking groups.Also, two groups bonded to the same N atom among Ar ¹ to Ar ⁵ may be bonded to each other to form a ring.
The linking group is shown below.

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

(electron-accepting compound)
The hole injection layer preferably contains an electron-accepting compound because the conductivity of the hole injection layer can be improved by oxidation of the hole-transporting compound.
As the electron-accepting compound, a compound having oxidizing power and the ability to accept one electron from the above-mentioned hole-transporting compound is preferable. Specifically, a compound having an electron affinity of 4 eV or more is preferable, and a compound having an electron affinity of 4 eV or more is preferable. More preferably, the compound is 5 eV or more.

Examples of such electron-accepting compounds include triarylboron compounds, metal halides, Lewis acids, organic acids, onium salts, salts of arylamines and metal halides, and salts of arylamines and Lewis acids. Examples include one or more compounds selected from the group. Specifically, onium salts substituted with organic groups such as 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pendafluorophenyl)borate and triphenylsulfonium tetrafluoroborate (International Publication No. 2005/089024); chloride High valence inorganic compounds such as iron (III) (Japanese Unexamined Patent Publication No. 11-251067), ammonium peroxodisulfate; cyano compounds such as tetracyanoethylene; tris(pendafluorophenyl)borane (Japanese Unexamined Patent Application No. 2003-2003) Examples thereof include aromatic boron compounds such as No. 31365); fullerene derivatives and iodine.

(cation radical compound)
The cation radical compound is preferably an ionic compound consisting of a cation radical, which is a chemical species obtained by removing one electron from a hole transporting compound, and a counter anion. 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 compound described above as a hole-transporting compound. A chemical species obtained by removing one electron from a compound preferable as a hole transporting compound is preferable from the viewpoint of amorphous property, visible light transmittance, heat resistance, solubility, and the like.
Here, the cation radical compound can be produced by mixing the above-described hole-transporting compound and electron-accepting compound. That is, by mixing the hole-transporting compound and the electron-accepting compound described above, electron transfer occurs from the hole-transporting compound to the electron-accepting compound, and the cation radical and counter anion of the hole-transporting compound are combined. A cationic ionic compound consisting of

Cation 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 herein refers to chemically or electrochemically oxidizing a monomer using peroxodisulfate or the like in an acidic solution. In the case of this oxidative polymerization (dehydrogenation polymerization), the monomer is oxidized to become a polymer, and a cation radical with one electron removed from the repeating unit of the polymer, which uses 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 forming a hole injection layer by a wet film formation method, the material for the hole injection layer is usually mixed with a soluble solvent (solvent for hole injection layer) to form a composition for film formation (hole injection layer solvent). Formed by preparing a hole-injection layer-forming composition (layer-forming composition), coating the hole-injection layer-forming composition on a layer corresponding to the layer below the hole-injection layer (usually an anode), forming a film, and drying. let

The concentration of the hole transporting compound in the composition for forming a hole injection layer is arbitrary as long as it does not significantly impair the effects of the present invention, but from the point of view of uniformity of the film thickness, a lower concentration is preferable; The higher the value, the more preferable it is 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 at most 60% by mass, more preferably at most 60% by mass, particularly preferably at most 50% by mass.

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

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

In addition to these, dimethyl sulfoxide and the like can also be used.
Formation of the hole injection layer 3 by a wet film forming method is usually performed by preparing a composition for forming the hole injection layer, and then applying it on a layer corresponding to the lower layer of the hole injection layer 3 (usually the anode 2). This is done by coating and drying. After forming the hole injection layer 3, the coating film is usually dried by heating, drying under reduced pressure, or the like.

<Formation of hole injection layer by vacuum evaporation method>
When forming the hole injection layer 3 by vacuum evaporation, one or more of the constituent materials of the hole injection layer 3 (the aforementioned hole transporting compound, electron accepting compound, etc.) are usually deposited in a vacuum. Place it in a crucible installed in a container (when using two or more types of materials, usually put each in a separate crucible), evacuate the inside of the vacuum container to about 10 ^-4 Pa with a vacuum pump, and then heat the crucible. (when using two or more types of materials, each crucible is usually heated), and the materials in the crucible are evaporated while controlling the amount of evaporation (when using two or more types of materials, each crucible is usually heated). (evaporate while controlling the amount of evaporation) to form a hole injection layer on the anode on the substrate placed facing the crucible. Note that when two or more types of materials are used, a mixture thereof can be placed in a crucible, heated, and evaporated to form a hole injection layer.

The degree of vacuum during vapor deposition is not limited as long as it does not significantly impair the effects of the present invention, but is usually 0.1×10 ⁻⁶ Torr (0.13×10 ⁻⁴ Pa) or more, 9.0×10 ⁻⁶ Torr ( 12.0×10 ⁻⁴ Pa) or less. The deposition rate is not limited as long as it does not significantly impair the effects of the present invention, but is usually 0.1 Å/sec or more and 5.0 Å/sec or less. The film forming temperature during vapor deposition is not limited as long as it does not significantly impair the effects of the present invention, but is preferably 10°C or higher and 50°C or lower.

(hole transport layer)
The hole transport layer is a layer that has the function of transporting holes from the anode side to the light emitting layer side. Although the hole transport layer is not an essential layer in the organic electroluminescent device of the present invention, it is preferable to use this layer in terms of strengthening the function of transporting holes from the anode to the light emitting layer. When using a hole transport layer, the hole transport layer is usually formed between the anode and the light emitting layer. Moreover, when the above-mentioned hole injection layer is present, it is formed between the hole injection layer and the light emitting layer.

The 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 a vacuum evaporation method or a wet film formation method. In terms of excellent film-forming properties, it is preferable to form the film by a wet film-forming method.
The hole transporting layer usually contains a hole transporting compound that becomes the hole transporting layer. In particular, the hole transporting compound contained in the hole transporting layer includes two or more tertiary amines represented by 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl. Aromatic diamine containing two or more fused aromatic rings substituted with nitrogen atoms (Japanese Unexamined Patent Publication No. 5-234681), 4,4',4''-tris(1-naphthylphenylamino)triphenyl Aromatic amine compounds having a starburst structure such as amines (J. Lumin., vol. 72-74, p. 985, 1997), aromatic amine compounds consisting of triphenylamine tetramers (Chem. Commun., 2175) p., 1996), spiro compounds such as 2,2',7,7'-tetrakis-(diphenylamino)-9,9'-spirobifluorene (Synth. Metals, Vol. 91, p. 209, 1997), Examples include carbazole derivatives such as 4,4'-N,N'-dicarbazole biphenyl. Also, for example, polyvinylcarbazole, polyvinyltriphenylamine (Japanese Unexamined Patent Publication No. 7-53953), 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 forming a hole transport layer by a wet film formation method, the hole injection layer is usually formed in the same way as in the case of forming a hole injection layer by a wet film formation method, in place of the hole injection layer forming composition. It is formed using a composition for forming a transport layer.
When forming a hole transport layer by a wet film forming method, the composition for forming a hole transport layer usually further contains a solvent. As the solvent used in the composition for forming a hole transport layer, the same solvent as that used in the above-mentioned composition for forming a hole injection layer can be used.

The concentration of the hole transporting compound in the composition for forming a hole transporting layer can be in the same range as the concentration of the hole transporting compound in the composition for forming a hole injection 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 evaporation method>
When forming a hole transport layer using a vacuum evaporation method, normally, in the same manner as when forming a hole injection layer using a vacuum evaporation method, a hole transport layer is used instead of the hole injection layer forming composition. It can be formed using a layer-forming composition. The film forming conditions such as the degree of vacuum, the vapor deposition rate, and the temperature during vapor deposition can be the same as those for the vacuum vapor 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 a pair of electrodes, and has the function of emitting light. The light emitting layer is a layer formed between the anode and the cathode, and if there is a hole injection layer on the anode, the light emitting layer is formed between the hole injection layer and the cathode, and the light emitting layer is a layer formed on the anode. If a hole transport layer is present, it is formed between the hole transport layer and the cathode.

The thickness of the light-emitting layer is arbitrary as long as it does not significantly impair the effects of the present invention, but a thicker layer is preferable because defects are less likely to occur in the layer, and a thinner layer is preferable because it facilitates lower driving voltage. For this reason, it is preferably 3 nm or more, more preferably 5 nm or more, and on the other hand, it is usually preferably 200 nm or less, and even more preferably 100 nm or less.
The light-emitting layer contains at least a material having light-emitting properties (light-emitting material), and preferably contains a material having charge-transporting properties (charge-transporting material).

(Light-emitting material)
The luminescent material is not particularly limited as long as it emits light at a desired emission wavelength and does not impair the effects of the present invention, and any known luminescent material can be used. The luminescent material may be a fluorescent material or a phosphorescent material, but a material with good luminous efficiency is preferable, and a phosphorescent 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 material include the following materials.
Examples of fluorescent materials that emit blue light (blue fluorescent materials) include naphthalene, perylene, pyrene, anthracene, coumarin, chrysene, p-bis(2-phenylethenyl)benzene, and derivatives thereof.
Examples of fluorescent materials that emit green light (green fluorescent materials) include quinacridone derivatives, coumarin derivatives, and aluminum complexes such as Al(C ₉ H ₆ NO) ₃ . Examples of the fluorescent material that emits yellow light (yellow fluorescent material) include rubrene, perimidone derivatives, and the like.

Examples of fluorescent materials that emit red light (red fluorescent materials) include DCM (4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran)-based compounds, benzopyran derivatives, and rhodamine derivatives. , benzothioxanthene derivatives, azabenzothioxanthene, and the like.

In addition, phosphorescent materials include, for example, items 7 to 11 of the long period periodic table (hereinafter, unless otherwise specified, the term "periodic table" refers to the long period periodic table). Examples include organometallic complexes containing metals selected from the group consisting of: Preferred examples of the metal selected from Groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold.

As the ligand of the organometallic complex, a ligand in which a (hetero)aryl group and pyridine, pyrazole, phenanthroline, etc. are linked, such as a (hetero)arylpyridine ligand and a (hetero)arylpyrazole ligand, is preferable. Particularly preferred are phenylpyridine ligands and phenylpyrazole ligands. Here, (hetero)aryl represents an aryl group or a heteroaryl group.

Preferred phosphorescent materials include, for example, tris(2-phenylpyridine)iridium, tris(2-phenylpyridine)ruthenium, tris(2-phenylpyridine)palladium, bis(2-phenylpyridine)platinum, and tris(2-phenylpyridine)platinum. Examples include phenylpyridine complexes such as (2-phenylpyridine)osmium and tris(2-phenylpyridine)rhenium, and porphyrin complexes such as octaethylplatinum porphyrin, octaphenylplatinum porphyrin, octaethylpalladium porphyrin, and octaphenylpalladium porphyrin.

Polymer-based luminescent materials include poly(9,9-dioctylfluorene-2,7-diyl), 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 polyphenylene vinylene materials such as poly[2-methoxy-5-(2-hetylhexyloxy)-1,4-phenylene vinylene].

(Charge transporting material)
The charge transporting material is a material having a property of transporting positive charges (holes) or negative charges (electrons), and is not particularly limited as long as it does not impair the effects of the present invention, and known light-emitting materials can be used.
As the charge-transporting material, compounds conventionally used in the light-emitting layer of organic electroluminescent devices can be used, and compounds used as host materials for the light-emitting layer are particularly preferred.

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 tertiary amines are linked with fluorene groups. , hydrazone compounds, silazane compounds, silanamine compounds, phosphamine compounds, quinacridone compounds, and other compounds exemplified as hole transporting compounds for the hole injection layer, as well as anthracene compounds, pyrene compounds, Examples include electron transporting compounds such as carbazole compounds, pyridine compounds, phenanthroline compounds, oxadiazole compounds, and silole compounds.

Also, 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 attached to the nitrogen atom. Aromatic amine compounds having a starburst structure (J Lumin., Vol. 72-74, p. 985, 1997), Aromatic amine compound consisting of a tetramer of triphenylamine (Chem. Commun., p. 2175, 1996), 2,2',7, Fluorene 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 for the hole transporting layer, such as carbazole compounds such as biphenyl, can also be preferably used.In addition, 2-(4-biphenylyl)-5-(p-tertial) Oxadiazole compounds such as butylphenyl)-1,3,4-oxadiazole (tBu-PBD), 2,5-bis(1-naphthyl)-1,3,4-oxadiazole (BND), Silole compounds such as 2,5-bis(6'-(2',2''-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), bathophenanthroline (BPhen), 2,9 -Dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP, bathocuproine) and other phenanthroline compounds are also included.

<Formation of light-emitting layer by wet film-forming method>
The light-emitting layer may be formed by a vacuum evaporation method or a wet film-forming method, but the wet film-forming method is preferable because it has excellent film-forming properties. In the present invention, the wet film forming method refers to a film forming method, that is, a coating method such as a spin coating method, dip coating method, die coating method, bar coating method, blade coating method, roll coating method, spray coating method, capillary coating method, etc. A method in which a wet film formation method such as a coating method, an inkjet method, a nozzle printing method, a screen printing method, a gravure printing method, or a flexographic printing method is used, and the coating film is dried to form a film. When forming a light-emitting layer by a wet film-forming method, the light-emitting layer and the hole-injection layer forming composition are usually used in the same manner as in the case of forming a hole-injecting layer using a wet film-forming method. The luminescent layer is formed using a composition for forming a luminescent layer, which is prepared by mixing a material with a soluble solvent (solvent for luminescent layer).
Examples of the solvent include ether solvents, ester solvents, aromatic hydrocarbon solvents, and amide solvents mentioned for forming the hole injection layer, as well as alkane solvents, halogenated aromatic hydrocarbon solvents, and aliphatic solvents. Examples include alcohol solvents, alicyclic alcohol solvents, aliphatic ketone solvents, and alicyclic ketone solvents. Specific examples of the solvent are listed below, but the solvent is not limited thereto as long as the effects of the present invention are 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, methysylene, cyclohexylbenzene, tetralin, 3-ylopropylbiphenyl, 1,2,3,4-tetramethyl Aromatic hydrocarbon solvents such as benzene, 1,4-diisopropylbenzene, cyclohexylbenzene, and methylnaphthalene; Amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; n-decane, cyclohexane, and ethylcyclohexane , decalin, bicyclohexane, etc.; halogenated aromatic hydrocarbon solvents such as chlorobenzene, dichlorobenzene, trichlorobenzene; aliphatic alcohol solvents such as butanol, hexanol; alicyclic solvents such as cyclohexanol, cyclooctanol, etc. Alcohol solvents; aliphatic ketone solvents such as methyl ethyl ketone and dibutyl ketone; alicyclic ketone solvents such as cyclohexanone, cyclooctanone, and fenchone. Among these, alkane solvents and aromatic hydrocarbon solvents are particularly preferred.

Furthermore, in order to obtain a more uniform film, it is preferable that the solvent evaporate from the liquid film immediately after film formation at an appropriate rate. 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 solvent to be used is arbitrary as long as it does not significantly impair the effects of the present invention, but the total content in the composition for forming a light-emitting layer is preferably large because it is easy to perform the film-forming operation due to its low viscosity. On the other hand, a lower value is preferable since it is easier to form a thick film. The content of the solvent 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 It is 99.9% by mass or less, particularly preferably 99% by mass or less.

Heating or reduced pressure can be used as a solvent removal method. As the heating means used in the heating method, a clean oven or a hot plate is preferable because they apply heat evenly to the entire film.
The heating temperature in the heating step is arbitrary as long as it does not significantly impair the effects of the present invention, but a higher temperature is preferable in terms of shortening the drying time, and a lower 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 not preferable because it is higher than the heat resistance of commonly used charge transport materials or phosphorescent materials and may cause decomposition or crystallization. If it is below the lower limit, it will take a long time to remove the solvent, which is not preferable. The heating time in the heating step is appropriately determined depending on the boiling point and vapor pressure of the solvent in the composition for forming a light emitting layer, the heat resistance of the material, and the heating conditions.

<Formation of light-emitting layer by vacuum evaporation method>
When forming a light-emitting layer by a vacuum evaporation method, one or more of the constituent materials of the light-emitting layer (the above-mentioned light-emitting material, charge-transporting compound, etc.) are usually placed in a crucible placed in a vacuum container. (When using two or more types of materials, each is usually placed in a separate crucible.) After evacuating the inside of the vacuum container to about 10 ^-4 Pa with a vacuum pump, the crucible is heated (when two or more types of materials are used, each is placed in a separate crucible). When used, each crucible is usually heated), and the materials in the crucible are evaporated while controlling the amount of evaporation (when two or more materials are used, they are usually evaporated while controlling the amount of evaporation independently of each other). ), a light emitting layer is formed on the hole injection transport layer placed facing the crucible. Note that when two or more types of materials are used, a mixture thereof may be placed in a crucible, heated, and evaporated to form a light-emitting layer.

The degree of vacuum during vapor deposition is not limited as long as it does not significantly impair the effects of the present invention, but is usually 0.1×10 ⁻⁶ Torr (0.13×10 ⁻⁴ Pa) or more, 9.0×10 ⁻⁶ Torr ( 12.0×10 ⁻⁴ Pa) or less. The deposition rate is not limited as long as it does not significantly impair the effects of the present invention, but is usually 0.1 Å/sec or more and 5.0 Å/sec or less. The film forming temperature during vapor deposition is not limited as long as it does not significantly impair the effects of the present invention, 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 an organic electroluminescent device that emits phosphorescence is 0.1 mmol/g or less of the iridium complex compound per unit weight of the light emitting layer. In the present invention, a dope concentration exceeding this concentration is referred to as a heavy dope concentration. In general, heavy doping has various effects on organic electroluminescent devices, and while it is expected to extend the device's operating life, it is well known that luminous efficiency may also decrease due to exciton annihilation between luminescent materials. ing.

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

Examples of materials for the hole blocking layer that satisfy these conditions include bis(2-methyl-8-quinolinolato)(phenolato)aluminum, bis(2-methyl-8-quinolinolato)(triphenylsilanolate)aluminum, etc. mixed ligand complexes, metal complexes such as bis(2-methyl-8-quinolato)aluminum-μ-oxo-bis-(2-methyl-8-quinolilato)aluminum dinuclear metal complexes, distyrylbiphenyl derivatives, etc. Styryl compounds (Japanese Unexamined Patent Publication No. 11-242996), triazole derivatives such as 3-(4-biphenylyl)-4-phenyl-5(4-tert-butylphenyl)-1,2,4-triazole (Japanese Examples include JP-A No. 7-41759), phenanthroline derivatives such as bathocuproine (Japanese Unexamined Patent Publication No. 10-79297), and the like. Furthermore, a compound having at least one pyridine ring substituted at the 2, 4, and 6 positions described in International Publication No. 2005/022962 is also preferable as a material for the hole blocking layer.

There is no restriction on the method for forming the hole blocking layer 6, and it can be formed in the same manner as the method for forming the light emitting layer described above.
The thickness of the hole blocking layer is arbitrary as long as it does not significantly impair the effects of the present invention, but it is usually 0.3 nm or more, preferably 0.5 nm or more, and usually 100 nm or less, preferably 50 nm or less. .

(electron 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 that can efficiently transport electrons injected from the cathode toward the light emitting layer between the electrodes to which an electric field is applied. The electron transporting compound used in the electron transporting layer is a compound that has high electron injection efficiency from the cathode or electron injection layer, has high electron mobility, and can efficiently transport the injected electrons. It is necessary.

The electron-transporting compound used in the electron-transporting layer is preferably a compound that usually has high electron injection efficiency from the cathode or the electron-injecting layer and can efficiently transport the injected electrons. Specifically, the electron transporting compound includes, for example, a metal complex such as an aluminum complex of 8-hydroxyquinoline (Japanese Unexamined Patent Publication No. 59-194393), a metal complex of 10-hydroxybenzo[h]quinoline, Oxadiazole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolylbenzene (US Pat. No. 5,645,948) , quinoxaline compound (Japanese Unexamined Patent Publication No. 6-207169), phenanthroline derivative (Japanese Unexamined Patent Publication No. 5-331459), 2-t-butyl-9,10-N,N'-dicyanoanthraquinone diimine, n Examples include hydrogenated amorphous silicon carbide, n-type zinc sulfide, and n-type zinc selenide.

The thickness of the electron transport layer is usually 1 nm or more, preferably 5 nm or more, and on the other hand, usually 300 nm or less, preferably 100 nm or less.
The electron transport layer is formed by laminating it on the hole blocking layer using a wet film formation method or a vacuum evaporation method in the same manner as described above. Usually, a vacuum evaporation 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 inject electrons, the material forming the electron injection layer is preferably a metal with a low work function. Examples include alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium. The film thickness is usually preferably 0.1 nm or more and 5 nm or less.

Furthermore, organic electron transport materials represented by nitrogen-containing heterocyclic compounds such as bathophenanthroline and metal complexes such as aluminum complexes of 8-hydroxyquinoline are doped with alkali metals such as sodium, potassium, cesium, lithium, and rubidium ( (described in Japanese Unexamined Patent Publication No. 10-270171, Japanese Unexamined Patent Publication No. 2002-100478, Japanese Unexamined Patent Application No. 2002-100482, etc.) also improves electron injection and transport properties and achieves excellent film quality. This is preferable because it makes it possible to

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 it on the light emitting layer or the hole blocking layer thereon using a wet film formation method or a vacuum evaporation method.
The details in the case of the wet film forming method are the same as in the case of the above-mentioned light emitting layer.

(cathode)
The cathode plays a role of injecting electrons into a layer on the light emitting layer side (such as an electron injection layer or a light emitting layer). As the material for the cathode, it is possible to use the materials used for the anode described above, but in order to efficiently inject electrons, it is preferable to use a metal with a low work function, such as tin, magnesium, indium, etc. , calcium, aluminum, silver, or an alloy thereof. Specific examples include low work function alloy electrodes such as magnesium-silver alloy, magnesium-indium alloy, and aluminum-lithium alloy.

From the viewpoint of device stability, it is preferable to protect the cathode made of a metal with a low work function by laminating a metal layer having a high work function and being stable against the atmosphere on the cathode. 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 other layers as long as the effects of the present invention are not significantly impaired. That is, any other layer mentioned above may be provided between the anode and the cathode.

<Other element configurations>
Note that it is also possible to have a structure opposite to that described above, that is, to laminate a cathode, an electron injection layer, a light emitting layer, a hole injection layer, and an anode in this order on the substrate.

<Others>
When applying the organic electroluminescent device of the present invention to an organic electroluminescent device, it may be used as a single organic electroluminescent device or in a configuration in which a plurality of organic electroluminescent devices are arranged in an array. A structure in which anodes and cathodes are arranged in an XY matrix may also be used.

<Display device and lighting device>
The display device and lighting device of the present invention use the organic electroluminescent device of the present invention as described above. There are no particular limitations on the format or structure of the display device and illumination device of the present invention, and they can be assembled using the organic electroluminescent device of the present invention according to conventional methods.
For example, the display device and the lighting device of the present invention can be manufactured using the method described in “Organic EL Display” (Ohmsha, published August 20, 2004, written by Shizushi Tokito, Chihaya Adachi, and Hideyuki Murata). can be formed.

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

2-(3-pinacolatoborylphenyl)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 in for 30 minutes. Thereafter, [Pd(PPh ₃ )] ₄ (1.21 g) was further added while stirring, and the mixture was stirred and refluxed at 105° C. for 1.5 hours. Thereafter, the mixture was cooled to room temperature, water was added, and the organic layer was washed with liquid separation, and the organic layer was dried over magnesium sulfate. The solvent was then removed under reduced pressure. The resulting residue was purified by silica gel column chromatography (dichloromethane/hexane = 1/1 to dichloromethane/hexane/ethyl acetate = 50/45/5) to obtain intermediate 2 (23.6 g) as a yellow oil. Obtained as a substance.

Under a nitrogen stream, 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, and the temperature of the oil bath was adjusted to 135 mL. The temperature was raised stepwise from °C to 150 °C and stirred for a total of 10 hours. During that time, the liquid that was refluxed was removed from the side tube. The amount of liquid removed at the end of the reaction was 46 mL. Thereafter, the mixture was cooled to room temperature, added with methanol (100 mL), filtered, washed with methanol (400 mL), and then 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) were added to the reaction vessel under a nitrogen stream, and after heating the oil bath to 120°C, 3,5-heptanedione was added. (14 g) and sodium carbonate (11.3 g) were added, followed by heating under reflux for about 2 hours. After cooling and removing the solvent under reduced pressure, dichloromethane (200 mL) was added, and after filtering through silica gel, the filtrate was concentrated under reduced pressure. Ethanol (150 mL) was added to the residue to precipitate 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 container under a nitrogen stream, and the internal temperature was raised from 218°C to 227°C. Stirred for 5.5 hours while warming to .degree. The by-produced 3,5-heptanedione was distilled off during the reaction. After cooling, water was added and 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 2L eggplant flask at room temperature, dried at 60°C for 2 hours, replaced with argon, cooled to room temperature, and dissolved in dry THF ( 0.9 L) was added and stirred for 2 hours to prepare a catalyst solution.
Into a 10L reactor, activated with nitrogen-sealed magnesium (190g), dry THF (0.3L), and a small amount of iodine pieces, was added dropwise over 2 hours to a solution of bromobenzene (1192g) in dry THF (3.5L). The mixture was further stirred under reflux for 1.5 hours to prepare a Grignard reagent solution. Put 1,5-dibromopentane (4365 g) and dry THF (5.2 L) in a 20 L reactor under nitrogen, add the catalyst solution prepared earlier, and after cooling to an internal temperature of 10°C, add the Grignard reagent prepared earlier. The solution was added dropwise over 1 hour so that the internal temperature was 10 to 45°C, and then stirred overnight at room temperature. 3M hydrochloric acid (3.5 L) was added, the oil layer was separated, and the aqueous layer was further extracted with ethyl acetate (3.5 x 2). The oil layer was dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated to obtain a crude brown oil (4.9 kg). This crude product was distilled under reduced pressure to obtain Intermediate 6 (0.94 kg) as a pale yellow transparent oil.

Into a 10 L reactor, put magnesium (107 g) under nitrogen and dry THF (0.5 L), activate it with iodine pieces (several tens of mg), and add intermediate 6 (0.91 kg) to dry THF (2.5 L). ) 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 previously prepared Grignard reagent solution was added dropwise over 45 minutes at an internal temperature of 10 to 35°C to bring the internal temperature to 45 to 58°C. The mixture was heated and stirred for 3 hours. The reaction mixture was added dropwise to 3M hydrochloric acid (4.3 L), cooled to room temperature, the oil layer was separated, and the aqueous layer was extracted with ethyl acetate (6 L). The oil layers were combined, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated to obtain a crude brown oil (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, and diglyme (5.1 L) was charged therein, and sodium hydroxide (0.19 kg) was added thereto. Next, hydrazine monohydrate (0.24 kg) was added dropwise over 30 minutes, the internal temperature was raised to 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 (3.6 L) was added, followed by hexane (3.5 L), and the oil layer was separated. The aqueous layer was extracted with hexane (2.5 L x 2), the oil layers were combined and washed with saturated brine (2.5 L), dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated to form a brown oil. A crude product (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.

Intermediate 7 (0.45 kg) and dry THF (4.5 L) were added to a 20 L reactor under nitrogen, cooled to an internal temperature of -77°C, and a 1.65 M n-butyllithium/n-hexane solution (1 .0L) was added dropwise over 1 hour at an internal temperature of -68°C or lower, and the mixture was stirred at -68°C for 1 hour. Next, 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. Thereafter, 3M hydrochloric acid (1.5 L) was added dropwise, and the mixture was stirred overnight while returning to room temperature. Ethyl acetate (3 L) was poured, the oil layer was separated, and the aqueous layer was further extracted with ethyl acetate (3 L). 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 crude brown oil (0.58 kg). This crude product was purified by silica gel column chromatography (ethyl acetate/dichloromethane/hexane = 0/1/3 to 2/2/3) to obtain 0.31 kg of Intermediate 8.

In a reaction vessel under a nitrogen stream, 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) were added. was added, and while stirring, 1.68 g of [Pd(PPh ₃ ) ₄ ] was further added, and the mixture was stirred and refluxed at 100° C. for 3 hours. Thereafter, the mixture was cooled to room temperature, water was added, and the organic layer was washed with liquid separation, and the organic layer was dried over magnesium sulfate. The solvent was then removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (dichloromethane/hexane = 1/9) to obtain 27.8 g of bromo compound. This was placed in another reaction vessel, and under a nitrogen stream, bispinacolate diboron (17.7 g), [PdCl ₂ (dppf)] CH ₂ Cl ₂ (1.71 g), potassium acetate (20.5 g), and dehydrated Dimethyl sulfoxide (150 mL) was added, and the mixture was stirred in a 100°C oil bath for 2 hours. Thereafter, the mixture was cooled to room temperature, water and toluene were added, and the oil phase was separated and washed, and the oil phase was dried over sodium sulfate. The solvent was then removed under reduced pressure. Intermediate 9 (23.4 g ) was obtained as a white solid.

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

Intermediate 4 (5.5 g), Intermediate 10 (2.8 g), and diglyme (42 mL) were placed in a reaction vessel under a nitrogen stream, and the internal temperature was adjusted to about 100°C. Silver trifluoromethanesulfonate (1.6 g) was added, 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). 1.6 g of Compound D-2 was obtained as a yellow solid.

<Synthesis example of compound (D-3)>

In a reaction vessel under a nitrogen stream, 2-(3-bromophenyl)pyridine (5.6 g), Intermediate 11 (synthesized by the method described in WO 2012/137958) 9.3 g, [Pd(PPh ₃ ) ₄ ]0.50 g, 27 mL of 2M aqueous tripotassium phosphate 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 for separation washing, drying over magnesium sulfate, and purification by silica gel column chromatography (dichloromethane only) to obtain Intermediate 12 (9.16 g) as a white solid.

Under a nitrogen stream, intermediate 12 (8.9 g), iridium chloride n-hydrate (3.4 g), 2-ethoxyethanol (50 mL), diglyme (50 mL) and distilled water (13 mL) were added to a reaction vessel, and the oil The temperature of the bath was raised stepwise from 135°C to 150°C and stirred for a total of 10 hours. During that time, the liquid that was refluxed was removed from the side tube. An additional 60 mL of diglyme was added during the reaction. Thereafter, it was cooled to room temperature, and the reaction solution was poured into 500 mL of distilled water, and the precipitated solid was filtered, washed with 500 mL of methanol, and then 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, and the internal temperature was adjusted 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), and toluene (280 mL) were added to a reaction vessel under a nitrogen stream. ) and ethanol (140 mL) were added, and nitrogen was bubbled through for 30 minutes. Thereafter, 6.0 g of [Pd(PPh ₃ ) ₄ ] was further added while stirring, and the mixture was stirred and refluxed at 100° C. for 3 hours. Thereafter, the mixture was cooled to room temperature, water was added, and the organic layer was washed with liquid separation, and the organic layer was dried over magnesium sulfate. The solvent was then removed under reduced pressure. The resulting 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 oil.

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

Intermediate 15 (4.0 g), Intermediate 4 (6.62 g), and diglyme (53 mL) were placed in a reaction vessel under a nitrogen stream, and the internal temperature was adjusted 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). 2.49 g of Compound D-4 was obtained as a yellow solid.

<Synthesis example of compound (D-7)>

In a reaction vessel under a nitrogen stream, 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) were added. and nitrogen was bubbled in for 30 minutes. Thereafter, 4.67 g of Pd(PPh ₃ ) ₄ ] was further added while stirring, and the mixture was stirred and refluxed at 100° C. for 3.5 hours. Thereafter, the mixture was cooled to room temperature, water was added, and the organic layer was washed with liquid separation, and the organic layer was dried over magnesium sulfate. The solvent was then removed under reduced pressure. The resulting 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 oil.

Intermediate 16 (36.8 g), bis(pinacolato)diboron (29.1 g), potassium acetate (33.8 g), and dehydrated dimethyl sulfoxide (330 mL) were added to a reaction vessel under a nitrogen stream, and nitrogen was bubbled for 30 minutes. . Thereafter, [PdCl ₂ dppf]CH ₂ Cl ₂ (2.81 g) was further added while stirring, and the mixture was stirred at 100° C. for 3.5 hours. Thereafter, the mixture was cooled to room temperature, water was added, and the organic layer was washed with liquid separation, and the organic layer was dried over magnesium sulfate. The solvent was then removed under reduced pressure. The resulting 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. .

In a reaction vessel under a nitrogen stream, 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) were added. was added and nitrogen was bubbled for 30 minutes. Thereafter, [Pd(PPh ₃ )] ₄ (0.95 g) was further added while stirring, and the mixture was stirred and refluxed at 100° C. for 3 hours. After cooling to room temperature, water was added and the organic layer was washed with liquid separation, and the organic layer was dried over magnesium sulfate. The solvent was then removed under reduced pressure. The resulting 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. Ta.

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

Under an argon atmosphere, intermediate 8 (100.0 g), 1-bromo-3-iodobenzene (120.3 g), 2M potassium carbonate aqueous solution (443 mL), (toluene) 900 mL and ethanol (450 mL) were added to a reaction vessel. While stirring, [Pd(PPh ₃ ) ₄ ] (12.31 g) was further added, and the mixture was stirred and refluxed at 90° C. for 15 hours. Thereafter, the mixture was cooled to room temperature, water was added, and after separation and washing, the organic layer was dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting residue was subjected to silica gel column chromatography (dichloromethane/hexane = 1/19) to obtain 100.5 g of bromo compound. Subsequently, this was placed in a 3L reaction vessel, 1L of dry THF was added under an argon stream, the internal temperature was cooled to -75°C, 186mL of a 1.65M n-butyllithium hexane solution was added dropwise at an internal temperature of -66°C or lower, and - The mixture was stirred at 70°C for 1 hour. Next, 85.0 g of trimethyl borate was added dropwise over 50 minutes at an internal temperature of -64°C, 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 after stirring 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 yellow oily crude product. 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 Intermediate 20 as a pale yellow solid.

Under a nitrogen stream, 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 a reaction vessel under nitrogen flow, and nitrogen was bubbled through the mixture for 30 minutes. Thereafter, 1.0 g of [Pd(PPh ₃ )] ₄ was further added while stirring, and the mixture was stirred and refluxed at 100° C. for 1.5 hours. Thereafter, the mixture was cooled to room temperature, water was added, and the organic layer was washed with liquid separation, and the organic layer was dried over magnesium sulfate. The solvent was then removed under reduced pressure. The resulting residue was purified by silica gel column chromatography (ethyl acetate/hexane = 2/8) to obtain Intermediate 21 (14.4 g) as a colorless oil.

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, and the internal temperature was brought 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). 2.24 g of Compound D-7 was obtained as a yellow solid.

<Synthesis example of compound (D-8)>

Under a nitrogen stream, 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 were added to the reaction vessel under a nitrogen stream, and the temperature of the oil bath was set to 135°C. Stirred for 8 hours. During that time, the liquid that was refluxed was removed from the side tube. Thereafter, it was cooled to room temperature, and 100 mL of methanol was added to the reaction solution, and the precipitated solid was filtered, washed with 400 mL of methanol, and then 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 create a weak reflux. 3.52 g of silver trifluoromethanesulfonate was added and stirred for 2 hours. After cooling to room temperature, the mixture was 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). 4.3 g of Intermediate 23 was obtained 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 therein for 30 minutes. Thereafter, [PdCl ₂ dppf]CH ₂ Cl ₂ (0.92 g) was further added while stirring, and the mixture was stirred at 100° C. for 7 hours. Thereafter, the mixture was cooled to room temperature, 500 mL of water and 500 mL of dichloromethane were added, and after liquid separation washing, the organic layer was dried over magnesium sulfate. The solvent was then removed under reduced pressure. The resulting 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. .

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

Under a nitrogen stream, 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 therein for 30 minutes. Thereafter, 0.3 g of [Pd(PPh ₃ ) ₄ ] was further added while stirring, and the mixture was stirred and refluxed at 100° C. for 2.5 hours. Thereafter, the mixture was cooled to room temperature, water was added, and the organic layer was washed with liquid separation, and the organic layer was dried over magnesium sulfate. The solvent was then 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 in a similar manner to Compound D-1, precipitated immediately when a 1 wt % solution of phenylcyclohexane prepared at 100° C. was cooled to room temperature. It had very low solubility and could not be made into ink.

<Preparation of organic electroluminescent device 1>
An organic electroluminescent device having the structure shown in FIG. 1 was produced by the following method. However, the iridium atom concentration in the light emitting layer 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 layer in Examples 3 and 4 and Comparative Examples 3 and 4 was adjusted to approximately 0.19 mmol/g.

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

Next, the arylamine polymer shown in the structural formula (P-1) below, containing 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate and ethyl benzoate shown in the structural formula (A-1) A coating solution for forming a hole injection layer was prepared. This coating solution was applied to the anode by spin coating under the following conditions to obtain a hole injection layer 3 having a thickness of 40 nm.

<Coating liquid for hole injection layer formation>
Solvent Ethyl benzoate Coating solution concentration P-1 2.5% by mass
A-1 0.4% by mass
<Film formation conditions for hole injection layer 3>
Spin coating atmosphere In air Heating conditions In dry air 240℃ 1 hour

Next, a coating solution for forming a hole transport layer containing a compound (P-2) having the structure shown below was prepared, and a film was formed by spin coating under the following conditions, and the film was thickened by polymerizing by heating. A hole transport layer 4 of 11 nm was formed.

<Coating liquid for hole transport layer formation>
Solvent: Phenylcyclohexane Coating solution concentration: 1.0% by mass
<Film formation conditions>
Spin coating atmosphere: dry nitrogen
Heating conditions: 230℃, 1 hour (under dry nitrogen)

Next, in forming the light-emitting layer, the organic compound (H-1) and organic compound (H-2) shown below are used as charge transport materials, and the iridium complex compound (D -1) was used to prepare the iridium complex compound-containing composition shown below and spin coat it on the hole transport layer under the conditions shown below to obtain a light emitting layer with a film thickness of 60 nm. The doping concentration of the iridium complex compound per unit weight of this light emitting layer was 0.096 mmol/g.

<Coating liquid for forming luminescent layer>
Solvent Phenylcyclohexane: 1900 parts by mass Luminescent 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: dry nitrogen
Heating conditions: 120℃ x 20 minutes (under dry nitrogen)

Here, the substrate on which the film up to the light-emitting layer has been formed is transferred into a vacuum evaporation apparatus, and after evacuating the apparatus until the degree of vacuum in the apparatus becomes 2.0x10 ^-4 Pa or less, the compound (HB-1) is deposited using a vacuum evaporation method. The deposition rate was controlled in the range of 0.8 to 1.0 Å/sec, and the hole blocking layer 6 was laminated on the light emitting layer to obtain a hole blocking layer 6 with a thickness of 10 nm.

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

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

Subsequently, in order to prevent the element from deteriorating due to moisture in the atmosphere during storage, sealing treatment was performed using the method described below.
In a nitrogen glove box, apply photocurable resin 30Y-437 (manufactured by Three Bond) to a width of approximately 1 mm on the outer periphery of a 23 mm x 23 mm glass plate, and place a moisture getter sheet (manufactured by Dynic) in the center. was installed. On top of this, the substrate on which the cathode had been formed was bonded so that the surface on which the vapor deposition was applied faced the desiccant sheet. Thereafter, only the area coated with the photocurable resin was irradiated with ultraviolet light to cure the resin.
In the manner described above, an organic electroluminescent device having a light emitting area of 2 mm x 2 mm in size was obtained.

(Example 2)
In Example 1, the compound D-1 used when 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. An 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 in forming the light-emitting layer was changed to compound D-5 represented by the following formula, and the concentration in the coating liquid for forming the light-emitting layer was 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 .

(Comparative example 2)
In Example 1, the compound D-1 used in forming the light emitting layer was changed to compound D-6 represented by the following formula, and the concentration in the coating liquid for forming the light emitting layer was 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 .

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

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

(Comparative example 3)
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 luminescent material in the coating liquid for forming a luminescent 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 luminescent material in the coating liquid for forming a luminescent layer was changed to 35.0 parts by mass.
The performance of the device thus obtained is shown in Tables 1 and 2.
Table 1 shows the luminous efficiency (cd/A) when a current of 10 mA/cm ² is applied to the device as a relative value with Comparative Example 1 as 100.

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

From Examples 1 to 4 and Comparative Examples 1 to 3, it was found that both devices in which the light-emitting layer was doped with the compound of the present invention at a normal doping concentration and devices in which the compound was doped at a heavy doping concentration had a high driving life. .
In particular, it has been found that an element in which the light-emitting layer is doped with the compound of the present invention at a heavy doping concentration has high luminous efficiency and a long driving life.

<Storage stability of coating liquid for forming light emitting layer>
In the storage stability test of the coating solution, if it is visually confirmed that there is no turbidity in the solution and that no Tyndall phenomenon is observed when exposed to red laser light, the solution state is maintained in a uniform state. I decided that.
(Example 5) A coating solution 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. Ta.
(Example 6) A coating solution 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. Ta.
(Example 7) Same as Example 5 except that Compound D-1 was changed to Compound D-7 and its concentration in the coating liquid for forming a light emitting layer was changed to 44.4 parts by mass. The coating solution for forming a luminescent 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, and the uniform state was maintained.
(Example 8) Same as Example 5 except that Compound D-1 was changed to Compound D-8 and its concentration in the coating liquid for forming a light emitting layer was changed to 39.8 parts by mass. The coating solution for forming a luminescent 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, and the uniform state was maintained.
(Reference Example 2) A coating solution for forming a light-emitting layer prepared in the same manner as 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. Ta.
(Comparative Example 5) A coating solution for forming a light-emitting layer prepared in the same manner as 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. As a result, solid precipitation was observed. Ta.
(Comparative Example 6) Comparative Example 3 except that Compound D-5 was changed to Compound D-10 shown in the following formula, and its concentration in the coating solution for forming a light emitting layer was changed to 47.0 parts by mass. A coating solution for forming a light-emitting layer prepared in the same manner as in Example 3 was heated at 150° C. for 30 minutes, a uniform state was confirmed, and then allowed to stand at 45° C. for 4 hours, and solid precipitation was observed.
<Compound D-10>

(Comparative Example 7) In Comparative Example 3, Compound D-5 was changed to Compound D-11 shown in the following formula, and its concentration in the coating solution for forming a light emitting layer was changed to 28.0 parts by mass. A coating solution for forming a light-emitting layer prepared in the same manner as in Example 3 was heated at 150° C. for 30 minutes, a uniform state was confirmed, and then allowed to stand at 45° C. for 4 hours, and 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 compositions in which the compound of the present invention was used in the coating liquid for forming a luminescent layer at a heavy doping concentration had good storage stability.

<Preparation of organic electroluminescent device 2>
(Example 9)
An organic electroluminescent device having the structure shown in FIG. 1 was produced by the following method. However, the iridium atom concentration in the light emitting layer was adjusted to approximately 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 shown in the structural formula (P-3) below, the 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate shown in the structural formula (A-1), and ethyl benzoate were added. A coating solution for forming a hole injection layer containing the following was prepared. This coating solution was applied to the anode by spin coating under the following conditions to obtain a hole injection layer 3 having a thickness of 29 nm.

<Coating liquid for hole injection layer formation>
Solvent Ethyl benzoate Coating solution concentration P-3 2.0% by mass
A-1 0.4% by mass
<Film formation conditions for hole injection layer 3>
Spin coating atmosphere In air Heating conditions In dry air 230℃ 1 hour

Next, a coating solution for forming a hole transport layer containing a compound (P-4) having the structure shown below was prepared, and a film was formed by spin coating under the following conditions, and the film was thickened by polymerizing by heating. A hole transport layer 4 with a thickness of 20 nm was formed.

<Coating liquid for hole transport layer formation>
Solvent: Phenylcyclohexane Coating solution concentration: 1.5% by mass
<Film formation conditions>
Spin coating atmosphere: dry nitrogen
Heating conditions: 230℃, 1 hour (under dry nitrogen)

A device was produced in the same manner as in Example 3 from the formation of the light emitting layer to the final sealing treatment.

(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 composition of the coating liquid for forming a light emitting layer was changed to that 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 composition of the coating liquid for forming a light emitting layer was changed to that 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 composition of the coating liquid for forming a light emitting layer was changed to that of Comparative Example 3.
The element thus obtained was driven at a constant current of 15 mA/ ^cm2 , and the time at which the luminance decreased to 90% was determined as LT90 (h), a relative value when LT90 of Comparative Example 8 was set as 100. are shown in Table 4.

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

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

Although the 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 (Japanese Patent Application No. 2015-110255) filed on May 29, 2015, the contents of which are incorporated herein by reference.

The present invention is applicable not only to materials for organic devices including organic electroluminescent elements, but also to various fields where organic electroluminescent elements are used, such as flat panel displays (for example, for office automation computers and wall-mounted TVs) and surface emitting devices. It can be suitably used in the fields of light sources that make use of the characteristics of the body (for example, light sources for copying machines, backlight sources for liquid crystal displays and instruments), display boards, sign lights, lighting devices, etc.

1 board
2 Anode
3 Hole injection layer
4 Hole transport layer
5 Luminescent layer
6 Hole blocking layer
7 Electron transport layer
8 Electron injection layer
9 Cathode

Claims (8)

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 ^Cy2 represents a pyridine ring , containing carbon atom ^C3 and nitrogen atom ^N1 ,
Ring ^Cy3 represents a benzene ring containing carbon atoms ^C4 and ^C5 ,
Ring Cy ⁴ represents a pyridine ring containing carbon atom C ⁶ and nitrogen atom N ² .
m= 1 ,
n=2 .
a and c each independently represent 1, and b and d each independently represent an integer from 0 to 2.
R ¹ is represented by the following formula (2), R ³ is represented by the following formula (3) , and R ² and R ⁴ each independently represent a fluorine atom, a chlorine atom, a bromine atom, an amino group, a hydroxy group, a mercapto group. 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, alkylamino group having 1 to 30 carbon atoms, aryloxy group having 3 to 30 carbon atoms, carbon It is selected from 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 aralkyl group having 7 to 40 carbon atoms.

In formula (2), x represents an integer from 0 to 10.
h represents an integer from 1 to 3.
* represents a bond.
R is each independently a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a cyano group, an alkyl group having 1 to 20 carbon atoms which may be further substituted with a fluorine atom, an alkoxy group having 1 to 20 carbon atoms, carbon It is selected from an amino group which may be further substituted with an aryl group having 5 to 30 carbon atoms, and an acyl group having 1 to 20 carbon atoms.
Each R' is independently selected from aralkyl groups having 4 to 40 carbon atoms which may be further substituted with a fluorine atom.

In formula (3), k represents 0 .
y represents an integer from 1 to 10.
* represents a bond.
R has the same meaning as in formula (2).
The R ² and R 4 groups excluding the hydrogen atom, the fluorine atom, the chlorine atom, the bromine atom, and the groups represented by the formula (2) and the formula ( ³ ) further include fluorine atom, an alkyl group having 1 to 30 carbon atoms which may be further substituted with a chlorine atom, a bromine atom, or a fluorine atom, 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 is a plurality of each of R ² to R ⁴ , they may be the same or different.
When a plurality of R ² and R ⁴ are adjacent to each other on the same ring, the adjacent R ² and R ⁴ are a direct bond or an alkylene group having 3 to 12 carbon atoms, or an alkenylene group having 3 to 12 carbon atoms. may be bonded via a group or an arylene group having 6 to 12 carbon atoms to form a ring, and these rings may be further substituted with a fluorine atom, a chlorine atom, a bromine atom, or a fluorine atom. An alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryloxy group having 3 to 30 carbon atoms, and an alkyl group 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 an aryl group or an arylamino group having 3 to 30 carbon atoms . 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 have the same meanings as in formula (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 have the same meanings as in formula (3). A composition comprising the iridium complex compound according to claim 1 or 2 and an organic solvent. A method for manufacturing an organic electroluminescent device having an anode and a cathode on a substrate, and a light emitting layer between the anode and the cathode, the method comprising:
A method for producing an organic electroluminescent device, wherein the light-emitting layer is formed by wet film-forming of the composition according to claim 3. 5. The method for manufacturing an organic electroluminescent device according to claim 4, wherein the concentration of the iridium complex compound per unit weight of the light emitting layer exceeds 0.1 mmol/g. An organic electroluminescent device comprising the iridium complex compound according to claim 1 or 2. A display device comprising the organic electroluminescent element according to claim 6. A lighting device comprising the organic electroluminescent element according to claim 6.

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