KR102609664B1 - Iridium complex compound, organic electroluminescent element containing said compound, display device and lighting device - Google Patents

Abstract

The object of the present invention is to provide a novel iridium complex compound, an organic electroluminescent device whose device life is improved by manufacturing using the compound, and a display device and lighting device using the organic electroluminescent device. The present invention relates to an iridium complex compound represented by the following formula (1).

Description

Iridium complex compound, organic electroluminescent device, display device and lighting device containing the compound {IRIDIUM COMPLEX COMPOUND, ORGANIC ELECTROLUMINESCENT ELEMENT CONTAINING SAID COMPOUND, DISPLAY DEVICE AND LIGHTING DEVICE}

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 an organic electroluminescent device. It relates to a display device and lighting including a.

Recently, various electronic devices using organic electroluminescent elements (hereinafter referred to as “organic EL elements”), such as organic EL lighting and organic EL displays, have been put into practical use. Organic EL devices are being considered for application to lighting and displays because they require low applied voltage, consume little power, and are capable of emitting light in three primary colors. In order to realize these, active research is being conducted on not only adjusting the emission wavelength of light-emitting materials, but also improving the luminous efficiency and driving life of the light-emitting element.

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

As a method of forming an organic EL device using a phosphorescent material, a vacuum deposition method is mainly used. However, typically, devices are manufactured by stacking multiple layers such as a light-emitting layer, a charge injection layer, and a charge transport layer. Therefore, in the vacuum deposition method, there was a problem that the deposition process became complicated, productivity was low, and it was very difficult to enlarge lighting or display panels made of these elements.

On the other hand, the organic EL element can also be formed into a film by a coating method to form a layer. Since the coating method can form a stable layer more easily than the vacuum deposition method, it is expected to be applied to mass production of displays and lighting devices and large devices.

For film formation by a coating method, it is necessary that the organic material contained in the layer is easily soluble in an organic solvent. Typically, a low boiling point and low viscosity solvent such as toluene is used. Ink produced with such a solvent can be easily formed into a film by a spin coating method or the like.

For the production of organic EL devices by the coating method, it is mainly necessary to improve the solubility of the ortho-metalated iridium complex. In general, a specific functional group such as an alkyl group or aralkyl group can be introduced into the molecular structure as a solubilizing group (Patent Documents 1 and 2). Additionally, there is an example in which solubility was improved by studying 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 Publication No. 2014-74000

However, in these patent documents, the solubility of the phosphorescent material alone was focused on the easiness of dissolution of the phosphorescent material in an organic solvent. In practice, when using a phosphorescent material as a light emitting layer of an organic EL device, it is common to use a composition in which a charge transport material is mixed. However, no attention has been paid to the solubility of such a composition in organic solvents. In other words, even if the phosphorescent material alone is soluble in an organic solvent, does not precipitate as crystals even when stored for a long period of time, and has good storage stability, a problem with the storage stability may occur when the composition is mixed with a charge transport material. I could see that there was a possibility.

Additionally, since the iridium complex, which is a phosphorescent material, is weak to reduction, when it receives electrons and enters an anion state, the iridium complex itself is deteriorated or the charge transport material existing around the iridium complex in the light-emitting layer is deteriorated, thereby deteriorating the device. There was a problem of lowering luminous efficiency and driving life.

Additionally, as a better way to improve luminous efficiency or drive life, so-called heavy doping, which increases the concentration of iridium complex in the luminescent layer, is sometimes performed. However, as a result of examining heavily doped devices in addition to devices with typical dope concentrations using the iridium complex specifically described in the above patent, the original luminous efficiency was low, so heavy doping did not increase the efficiency. Alternatively, a problem was discovered in which the drive life was conversely reduced.

The present invention was made in view of the above problems, and provides an iridium complex that has good storage stability even in the state of a composition mixed with a charge transport material and has improved device characteristics of an organic electroluminescent device having a light-emitting layer formed using the composition. The task is to provide a compound.

Another object of the present invention is to provide an organic electroluminescent device with improved device life, and a display device and lighting device using the organic electroluminescent device.

As a result of intensive studies by the present inventors to solve the above problems, the iridium complex compound having a certain chemical structure has good storage stability even in the state of a composition mixed with a charge transport material, and can be formed using the composition. It was discovered that the luminous efficiency of an organic electroluminescent device having a light-emitting layer could be increased and the driving life could be extended, and the present invention was completed.

That is, the gist of the present invention lies in the following [1] to [9].

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

[Formula 1]

In formula (1), Ir represents an iridium atom.

Ring Cy ¹ represents an aromatic ring or heteroaromatic ring containing carbon atoms C ¹ and C ² ,

Ring Cy ² represents a 6-membered ring heteroaromatic ring containing carbon atom C ³ and nitrogen atom N ¹ ,

Ring Cy ³ represents an aromatic ring or heteroaromatic ring containing carbon atoms C ⁴ and C ⁵ ,

Ring Cy ⁴ represents a 6-membered ring heteroaromatic ring containing a carbon atom C ⁶ and a 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 are each independently hydrogen atom, fluorine atom, chlorine atom, bromine atom, amino group, hydroxyl group, mercapto group, alkyl group of 1 to 30 carbon atoms, alkoxy group of 1 to 30 carbon atoms, or 2 to 2 carbon atoms. Alkenyl group with 30 carbon atoms, alkylamino group with 1 to 30 carbon atoms, aryloxy group with 3 to 30 carbon atoms, aryl group with 3 to 30 carbon atoms, heteroaryl group with 3 to 30 carbon atoms, arylamino group with 3 to 30 carbon atoms, 7 to 7 carbon atoms An aralkyl group of 40 is selected from 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).

[Formula 2]

In formula (2), x represents an integer of 0 to 10.

h represents an integer from 1 to 3.

* indicates a binding hand.

R may be the same or different for each occurrence, and each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a cyano group, an alkyl group of 1 to 20 carbon atoms which may be further substituted with a fluorine atom, or an alkyl group of 1 to 20 carbon atoms. It is selected from an alkoxy group of 20 carbon atoms, an amino group that may be further substituted with an aryl group of 5 to 30 carbon atoms, or an acyl group of 1 to 20 carbon atoms.

R' may be the same or different at each occurrence, and are each independently selected from an alkyl group having 1 to 20 carbon atoms that may be further substituted with a fluorine atom or an aralkyl group having 1 to 40 carbon atoms that may be further substituted with a fluorine atom. do.

[Formula 3]

In formula (3), k represents an integer of 0 to 5.

y represents an integer from 1 to 10.

* indicates a binding hand.

R has the same meaning as equation (2),

R" may be the same or different depending on its appearance, 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, an alkyl group having 1 to 20 carbon atoms, or a naph that may be substituted with an aryl group. It is selected from a til group or a heteroaryl group having 1 to 20 carbon atoms.

The groups of R ¹ to R ⁴ , excluding the groups represented by the formulas (2) and (3), are also an alkyl group of 1 to 30 carbon atoms which may be further substituted with a fluorine atom, a chlorine atom, a bromine atom or a fluorine atom, It may be further substituted with an alkyl group with 1 to 30 carbon atoms, an aryl group with 3 to 30 carbon atoms, or an arylamino group with 3 to 30 carbon atoms.

When there are multiple R ¹ to R ⁴ , each 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 are directly bonded to each other or are formed by an alkylene group having 3 to 12 carbon atoms, an alkenylene group having 3 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms. They may be bonded through a lene group to form a ring, and these rings may be an alkyl group with 1 to 30 carbon atoms, an alkoxy group with 1 to 30 carbon atoms, which may be further substituted with a fluorine atom, a chlorine atom, a bromine atom or a fluorine atom, It may be substituted with an aryloxy group with 3 to 30 carbon atoms, an aryl group with 1 to 30 carbon atoms, an aryl group with 3 to 30 carbon atoms, or an arylamino group with 3 to 30 carbon atoms.

In addition, R ¹ and R ² or R ³ and R ⁴ are directly bonded or bonded through an alkylene group with 3 to 12 carbon atoms, an alkenylene group with 3 to 12 carbon atoms, or an arylene group with 6 to 12 carbon atoms, forming a ring. These rings may be formed of a fluorine atom, a chlorine atom, a bromine 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, which may be further substituted with a fluorine atom, It may be further substituted with an alkyl group with 1 to 30 carbon atoms, an aryl group with 3 to 30 carbon atoms, or an arylamino group with 3 to 30 carbon atoms.

[2] The iridium complex compound described in [1], wherein the formula (2) is represented by the formula (4), and the formula (3) is represented by the formula (5).

[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,

p+q+r is an integer from 0 to 10.

* indicates a binding hand.

R, R' and h have the same meaning as in equation (2).

[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,

s+t+u+w is an integer from 1 to 10.

* indicates a binding hand.

R, R" and k have the same meaning as in equation (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) in [1] or [2] The iridium complex compounds described.

[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 having the organic electroluminescent element according to [7].

[9] A lighting device having the organic electroluminescent element according to [7].

The iridium complex compound of the present invention is soluble in organic solvents, and an organic electroluminescent device can be produced by a coating method. Since the luminous efficiency of an organic electroluminescent device containing the iridium complex compound is high and the driving life is long, the iridium complex compound is useful as a material for an organic electroluminescent device. Additionally, organic electroluminescent elements obtained using the iridium complex compound are useful for display devices and lighting devices.

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

Below, embodiments of the present invention will be described in detail. However, 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” each have the same meaning.

＜Iridium complex compound＞

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

[Formula 6]

Hereinafter, each component of equation (1) will be described in detail.

<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, benzoyl ring. Furan 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, propyrole ring, propuran ring, thienofuran ring, benzoisoxazole ring, benzoisothiazole ring, benzimidazole ring, pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, cinnoline ring, quinoxaline ring, benzoimidazole ring, perimidine ring, quinazoline ring, quinazoly Non-rings are preferred. Among these, in order to improve the emission wavelength or solubility, control the wavelength of the device, and improve durability, rings in which appropriate substituents are often introduced on these rings, and methods for introducing such substituents are widely known, are preferable. Ring Cy ¹ and ring Cy ³ are more preferably hydrocarbon aromatic rings, more preferably benzene rings or naphthalene rings, and particularly preferably benzene rings.

<ring Cy ² and ring Cy ⁴ >

Ring Cy ² represents a 6-membered heteroaromatic ring containing a carbon atom C ³ and a nitrogen atom N ¹ coordinated to an iridium atom, and ring Cy ⁴ contains a carbon atom C ⁶ and a nitrogen atom N ² coordinated to an iridium atom. It represents a 6-membered heteroaromatic ring. Specifically, a pyridine ring, a pyrazine ring, a pyridazine ring, a pyrimidine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinoxaline ring, a perimidine ring, a quinazoline ring, and a quinazolinone ring. desirable. Among these, because it is easy to introduce a substituent, easy to adjust the emission wavelength and solubility, and many methods are known for synthesizing it with good yield when complexing with iridium, pyridine ring, pyrazine ring, They are a quinoline ring, an isoquinoline ring, a pyrimidine ring, a triazine ring, a quinoxaline ring, and a quinazoline ring, and more preferably, a pyridine ring, a pyrimidine ring, a quinoline ring, an isoquinoline ring, and a 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 two or more R ¹ , R ² , R ³ , and R ⁴ , they may be the same or different. R ¹ to R ⁴ are each independently hydrogen atom, fluorine atom, chlorine atom, bromine atom, amino group, hydroxyl group, mercapto group, alkyl group of 1 to 30 carbon atoms, alkoxy group of 1 to 30 carbon atoms, or 2 to 2 carbon atoms. Alkenyl group with 30 carbon atoms, alkylamino group with 1 to 30 carbon atoms, aryloxy group with 3 to 30 carbon atoms, aryl group with 3 to 30 carbon atoms, heteroaryl group with 3 to 30 carbon atoms, arylamino group with 3 to 30 carbon atoms, 7 to 7 carbon atoms An aralkyl group of 40 is selected from 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.

From the viewpoint of sufficiently maintaining the solubility of the complex and controlling durability and emission color, b is preferably 0 to 2, more preferably 0 to 1, and most preferably 0.

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 sufficiently maintaining the solubility of the complex and controlling durability and emission color.

However, at least one of R ¹ or R ² is a group represented by the following formula (2). Inside a device, the light-emitting material can transport charges, but it is thought that it plays a role in transporting holes, especially in heavy doped devices. If holes are not transported well, the location for charge recombination in the light-emitting layer is limited, and thus luminous efficiency and driving life decrease. Since hole transport largely depends on ring Cy ¹ and its substituents, it is preferable that at least one R ¹ is a group represented by formula (2) from the viewpoint of facilitating hole transport.

[Formula 7]

x represents an integer of 0 to 10, and is preferably 0 or more, more preferably 1 or more, and even more preferably 2 or more from the viewpoint of sufficiently maintaining the solubility of the complex and having good hole transport properties. Moreover, it is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less.

h represents an integer of 1 to 3, and is preferably 1 from the viewpoint of sufficiently maintaining the solubility of the complex.

* indicates a binding hand.

R may be the same or different for each occurrence, and each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a cyano group, an alkyl group of 1 to 20 carbon atoms which may be further substituted with a fluorine atom, or an alkyl group of 1 to 20 carbon atoms. It is selected from an alkoxy group of 20, an amino group which may be further substituted by an aryl group of 5 to 30 carbon atoms, or an acyl group of 1 to 20 carbon atoms, and is preferably further substituted by a hydrogen atom, a fluorine atom, a cyano group or a fluorine atom. It is an alkyl group having 1 to 20 carbon atoms. 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. Also, 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. Among the R that one ligand has, It is more preferable that only one or two R's 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, and among the R's possessed by one ligand, only one R is a cyano group, or Most preferably, it is an alkyl group having 1 to 20 carbon atoms which may be further substituted with a fluorine atom.

R' may be the same or different depending on their occurrence, and are each independently selected from an alkyl group having 4 to 20 carbon atoms which may be further substituted with a fluorine atom or an aralkyl group having 4 to 40 carbon atoms which may be further substituted with a fluorine atom. It is preferably a straight-chain alkyl group with 5 to 12 carbon atoms or an aralkyl group with 4 to 40 carbon atoms, and more preferably an aralkyl group with 4 to 40 carbon atoms.

Examples of alkyl groups having 4 to 20 carbon atoms include straight-chain alkyl groups, branched alkyl groups, and cyclic alkyl groups. More specifically, n-butyl group, n-pentyl group, n-hexyl group, and n-octyl group. , isopropyl group, isobutyl group, cyclohexyl group, etc. From the viewpoint of solubility and durability, a straight-chain alkyl group is preferable, and a straight-chain alkyl group having 5 to 12 carbon atoms is more preferable.

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-1-n-octyl group , 4-phenylcyclohexyl group, etc.

If the solubility of the iridium complex is maintained, affinity with the charge transport material in the light-emitting layer is increased, dispersibility is improved, and aggregation can be suppressed, the luminous efficiency and driving life of the device are 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 having both an alkylene moiety that ensures solubility and an aromatic group having affinity for the charge transport material, and a more preferable group is an aralkyl group having 4 to 30 carbon atoms. And, especially preferably, from the viewpoint of solubility in solvents and ease of synthesis, 1,1-dimethyl-1-phenylmethyl group, 5-phenyl-1-n-propyl group, 6-phenyl-1-n-hex. Syl 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). Inside a device, the light-emitting material can transport charges, but it is thought that it plays a role in transporting holes, especially in heavy doped devices. If holes are not transported well, the location for charge recombination in the light-emitting layer is limited, and thus luminous efficiency and driving life decrease. Since hole transport largely depends on the ring Cy ³ and its substituents, it is preferable that at least one R ³ is a group represented by formula (3) from the viewpoint of facilitating hole transport.

[Formula 8]

y represents an integer of 1 to 10, and is preferably 2 or more from the viewpoint of sufficiently maintaining the solubility of the complex and good hole transport. Moreover, it is preferably 8 or less, and more preferably 6 or less.

k represents an integer of 0 to 5, and is preferably 0 or 1 from the viewpoint of sufficiently maintaining the solubility of the complex and having good hole transport, and 0 is more preferable from the viewpoint of having better hole transport.

* indicates a binding hand.

R in formula (3) has the same meaning as formula (2).

R" may be the same or different depending on its appearance, 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, an alkyl group having 1 to 20 carbon atoms, or a naph that may be substituted with an aryl group. It is selected from a tyl group or a heteroaryl group which may be substituted with an aryl group having 1 to 20 carbon atoms. From the viewpoint of promoting hole transport, an alkyl group or naphthyl group having 1 to 20 carbon atoms is preferable, and an alkyl group or naphthyl group having 1 to 3 carbon atoms is more preferable.

It is most preferable that at least one of R ¹ is represented by formula (2), and at least one of R ³ is represented by formula (3). At this time, the iridium complex in the present invention has at least one alkyl group or aralkyl group, preferably an aralkyl group, as R ¹ and has at least one group of two or more phenylene groups connected as R ³ , it becomes easy 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 formulas (2) and (3), may also be an alkyl group of 1 to 30 carbon atoms, which may be further substituted with a fluorine atom, a chlorine atom, a bromine atom, or a fluorine atom, or an alkyl group with 1 carbon atom. The aryl group having 3 to 30 carbon atoms may be further substituted with an alkyl group having 3 to 30 carbon atoms, or the arylamino group having 3 to 30 carbon atoms.

Additionally, when a plurality of R ¹ to R ⁴ are adjacent to each other, the adjacent R ¹ to R ⁴ are directly bonded to each other, or are 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. may be bonded through an arylene group to form a ring, and these rings may be an alkyl group having 1 to 30 carbon atoms or an alkyl group having 1 to 30 carbon atoms which may be further substituted with a fluorine atom, a chlorine atom, a bromine atom or a fluorine atom. It may be substituted with an aryl group having 3 to 30 carbon atoms or an arylamino group having 3 to 30 carbon atoms.

In addition, R ¹ and R ² or R ³ and R ⁴ are directly bonded or bonded through an alkylene group with 3 to 12 carbon atoms, an alkenylene group with 3 to 12 carbon atoms, or an arylene group with 6 to 12 carbon atoms, forming a ring. may be formed, and these rings may be 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, or an alkyl group having 1 to 30 carbon atoms which may be further substituted with an alkyl group having 3 to 30 carbon atoms. It may be substituted with an aryl group or an arylamino group having 3 to 30 carbon atoms.

Specific examples of the rings include fluorene ring, carbazole ring, carboline ring, diazcarbazole ring, naphthalene ring, phenanthrene ring, anthracene ring, chrysene ring, triphenylene ring, quinoline ring, and isoquinoline. rings, quinazoline rings, benzoquinoline rings, azaphenanthrene rings, azaanthracene rings, and azatriphenylene rings. If the condensed ring structure to which π electrons are conjugated is too large, the emission wavelength will be extended to the infrared region or the solubility will be reduced, so it is preferably a fluorene ring, carbazole ring, quinoline ring, isoquinoline ring, quinazoline ring, selected from an 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, and among them, methyl group is preferable.

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 preferable.

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, and among these, vinyl group is preferable.

Examples of the alkylamino group having 1 to 30 carbon atoms include methylamino group, dimethylamino group, diethylamino group, dibutylamino group, octylamino group, dioctylamino group, etc. Among them, methylamino group or dimethylamino group is preferable.

Examples of the aryloxy group having 3 to 30 carbon atoms include allyloxy group, phenoxy group, and methylphenyloxy group, and among them, phenoxy group is preferable.

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, and among them, phenyl group, biphenyl group, and terphenyl group are preferable.

Examples of heteroaryl groups having 3 to 30 carbon atoms include pyridyl group, pyrimidyl group, triazine group, phenylpyridyl group, phenylpyrimidyl group, and diphenylpyrimidyl group.

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

Aralkyl groups having 7 to 40 carbon atoms include 1,1-dimethyl-1-phenylmethyl, 1,1-di(n-butyl)-1-phenylmethyl, and 1,1-di(n-hexyl)-1-phenyl. Methyl group, 1,1-di(n-octyl)-1-phenylmethyl group, exemplified by 1,1-dialkyl-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-phenyl-1-n-heptyl group, 8-phenyl-1-n-octyl group, 4-phenylcyclohexyl group, etc. are mentioned.

＜m, n＞

m is 1 or 2, but it is more preferable that m = 1 from the viewpoint of sufficiently maintaining the solubility of the complex and improving hole transport. Also, m+n = 3.

<About preferred embodiments of the above formula (2) and the above formula (3)>

The above formula (2) is preferably represented by the following formula (4).

[Formula 9]

In formula (4), p represents an integer of 0 to 2, q represents an integer of 0 to 10, r represents an integer of 0 to 2, and p+q+r is an integer of 0 to 10. * indicates a binding hand. Additionally, R, R' and h have the same meaning as in equation (2).

From the viewpoint of maintaining high solubility, p is more preferably 0 or 1, and r is more preferably 0 or 1.

From the viewpoint of maintaining high hole transport properties, it is more preferable that p+q+r is an integer of 0 to 5.

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

[Formula 10]

In formula (5), s represents an integer of 0 to 2, t represents an integer of 1 to 10, u represents an integer of 0 to 2, w represents an integer of 0 to 4, and s+t+u+w represents an integer of 1 to 10. It is an integer of 10. * indicates a binding hand. Additionally, R, R" and k have the same meaning as in equation (3).

From the viewpoint of maintaining high solubility, s is more preferably 0 or 1, and u is more preferably 0 or 1.

From the viewpoint of maintaining high hole transport properties, it is more preferable that s+t+u+w is an integer of 0 to 5.

The reasons 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) involve a bond via a phenylene ring. This binding form has ortho, meta, and para positions. Among these, when bonding at the ortho position, neighboring phenylene rings become sterically hindered from each other, resulting in large distortion. Although this distortion improves the solubility of the complex, it necessarily has a negative effect on hole transport because the conjugation of the π electrons of the phenylene ring becomes smaller. Therefore, the preferred binding mode is meta or para position. In particular, when the phenylene ring directly bonded to Cy ¹ or Cy ³ has a para-position bonding mode, the conjugation of large π electrons spreads from the iridium atom to the phenylene ring next to it, showing a desirable effect on hole transport.

Moreover, as for the iridium complex in this 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).

Moreover, 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＞

Below, preferred specific examples of the iridium complex compound of the present invention are shown, but the present invention is not limited to these.

[Formula 11]

[Formula 12]

[Formula 13]

＜Structural Features＞

The coating liquid for forming a light-emitting layer using the iridium complex compound of the present invention, that is, the storage stability of maintaining a uniform state without precipitating in the state of a solution coexisting with the charge transport material is improved, and the luminous efficiency of the device The reason why device characteristics such as driving life is improved is assumed as follows.

In order to increase solubility in organic solvents, it is generally practiced to introduce a group having a flexible structure containing an aliphatic hydrocarbon group such as an alkyl group or aralkyl group into the ligand of the iridium complex compound. Since these groups can take on many conformations, the energy for rearrangement increases during crystallization. Therefore, the iridium complex compound is expected to have the effect of improving solubility because it does not crystallize well.

However, when these flexible structures are introduced with good symmetry into the iridium complex compound, that is, when they are made into homoleptic complexes, the rearrangement energy for crystallization is lowered and crystallization becomes easier, so a sufficient solubility improvement effect is obtained. It becomes impossible to lose.

In addition, the charge transport material coexisted in the coating liquid for forming the light-emitting layer usually does not have a group having such a flexible structure and has a rigid structure with continuous benzene rings. It is known as a general tendency that compounds with similar chemical structures are highly soluble in each other. However, since the structural similarity between the iridium complex compound and the charge transport material whose solubility was increased by the method described above is not necessarily high, by allowing these compounds to coexist, which The solubility of the compound, especially the charge transport material, in organic solvents is significantly lowered, and it becomes easy to precipitate as a solid.

Moreover, since these groups having flexible structures are essentially insulators, they inhibit the injection of charges into the iridium complex and the transport of charges between the iridium complexes or between the iridium complex and the host. In addition, since the mobility of the group is high, there is a drawback in that it provides a path for non-radiative deactivation from the excited state, resulting in a deterioration in luminous efficiency.

On the other hand, when a substituent connected to an arylene group, such as an m-phenylene group, is introduced into the ligand, many conformations can be taken, although not as much as an alkyl group, so it can be made to have sufficient solubility suitable for the coating method. there is. In addition, the light-emitting material inside the device can transport charges, but by connecting long phenylene groups, the orbital or empty orbital of the π electron is spatially expanded, making it easier for charge transport to occur. In particular, an iridium complex having a long phenylene group is prone to receiving holes. By using such an iridium complex as a light-emitting material in the light-emitting layer, hole transport properties within the light-emitting layer can be improved. Additionally, it is believed that the light emission position in the light emitting layer can be adjusted by adjusting the dope concentration of the iridium complex. Easier transport of charges means that the position of charge recombination in the light-emitting layer of the device expands, so it is expected that the luminous efficiency and driving life will be improved. However, at the same time, the reason why the electrical conductivity is excellent is because the interaction between iridium complexes in the light-emitting layer is not disturbed, and especially in the case of heavy doping, exciton annihilation, or concentration quenching, occurs simultaneously due to interaction between excitons or between excitons and charges. The extent of improvement in luminous efficiency is small or rather decreases.

To compensate for these shortcomings, it is effective to simultaneously present the above two types of ligands in an appropriate state on one iridium complex as in the present invention. The symmetry of the iridium complex compound is lowered by forming a heteroleptic complex, and the presence of a ligand having a group connected to a phenylene group that does not have a flexible structure increases the similarity to the charge transport material, thereby improving the storage stability of the coating liquid for forming the light-emitting layer. can be improved.

In addition, in the organic EL device in which the iridium complex in the present invention is used as a light-emitting material in the light-emitting layer, an effect of improvement in drive life is expected. The mechanism of action is thought to be as follows. Since the iridium complex having a long phenylene group is likely to receive holes, it is believed that most of the iridium complexes in the light-emitting layer of the device being driven with electricity are in a state of receiving holes. Additionally, the iridium complex in the present invention has an insulating aralkyl group. The aralkyl group is an insulating spacer and moderately suppresses the hole transport property of the iridium complex of the present invention. Therefore, the probability of existing in the cation state, which is a state in which a hole has been received, increases. When the iridium complex in the cation state receives electrons, it immediately emits light, so it is thought that the luminous efficiency increases. Additionally, since the iridium complex in the cation state is stable, it is thought that the operating life is also improved.

In the present invention, by arranging appropriate substituent moieties and solubilizing moieties, mainly phenylene linkages, in the ligand, the above-mentioned drawbacks can be eliminated, and both the luminous efficiency of the device can be increased and the driving life can be improved.

＜Organic solvent＞

The wet film formation method is a method of forming a film by first dissolving the organic material of the light-emitting layer in an organic solvent, applying it by a spin coating method or an inkjet method, and then evaporating the organic solvent by heating, reducing pressure, or blowing an inert gas. . If necessary, in order to make the formed organic material solvent-insoluble, for example, by adding a crosslinking group such as a C=C group, C≡C group, or benzocyclobutene group in the molecules of the organic material, using known methods such as heating or light irradiation. It can also be made insolubilized by crosslinking.

Types of organic solvents preferably used in such a wet film formation method include optionally substituted aliphatic hydrocarbons such as hexane, heptane, methyl ethyl ketone, ethyl acetate, butyl acetate, toluene, xylene, phenylcyclohexane, and ethyl benzoate. and optionally substituted aromatic hydrocarbons such as cyclohexane, cyclohexanone, methylcyclohexanone, and 3,3,5-trimethylcyclohexanone. These may be used alone, or may be used as a composition by mixing multiple types of solvents to create a coating liquid suitable for the application process. The type of organic solvent mainly used is preferably an aromatic hydrocarbon or an alicyclic hydrocarbon, and more preferably an aromatic hydrocarbon. In particular, phenylcyclohexane is believed to have a desirable viscosity and boiling point for wet film formation 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 1.5% by mass, relative to phenylcyclohexane at 25°C under atmospheric pressure. It is more than mass%.

<Method for synthesizing iridium complex compounds>

The iridium complex compound of the present invention can be synthesized by a combination of known methods, etc. Ligands can be synthesized by combining known organic synthesis reactions such as the so-called Suzuki-Miyaura coupling reaction. Iridium complex compounds can be synthesized using this ligand and an iridium compound.

Regarding the method of synthesizing the iridium complex compound, for example, a method via a chlorine-crosslinked iridium dinuclear complex as shown in the following formula (A) (M. G. Colombo, T. C. Brunold, T. Riedener, H. U. Gudel, Inorg. Chem. , 1994, 33, 545-550), a method of obtaining the target object from the formula (B) binuclear complex by further exchanging the chlorine bridge with acetylacetonate and converting it into a mononuclear complex (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), etc. However, it is not limited to these. In addition, in formulas (A) and (B), R represents hydrogen or an arbitrary substituent, and multiple R's may be the same or different.

For example, typical reaction conditions represented by the following formula (A) are as follows. In the first step, a chlorine-crosslinked iridium dinuclear complex is synthesized by reacting 2 equivalents of the first ligand with 1 equivalent of iridium chloride n-hydrate. The solvent is usually a mixed solvent of 2-ethoxyethanol and water, but no solvent or another solvent may be used. The reaction may be promoted by using an excessive amount of ligand or by using additives such as bases. Instead of chlorine, other crosslinkable anionic ligands such as bromine may be used. There is no particular limitation on the reaction temperature, but it is usually in the range of 0°C to 250°C, preferably 50°C to 150°C.

[Formula 14]

In the second step, a halogen ion trapping agent such as silver trifluoromethanesulfonate is added and brought into contact with the second ligand to obtain the target complex. Ethoxyethanol or diglyme is usually used as a solvent, but depending on the type of ligand, no solvent or another solvent can be used, or a mixture of multiple solvents can be used. The reaction may proceed even without the addition of a halogen ion trapping agent, so although it is not absolutely necessary, the addition of the trapping agent is advantageous in order to increase the reaction yield and selectively synthesize facial isomers with higher quantum yields. There is no particular limitation on the reaction temperature, but it is usually carried out in the range of 0°C to 250°C.

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

[Formula 15]

In the third step, 1 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. The reaction temperature is also not particularly limited, but because the reaction is slightly lacking, the reaction is often carried out at a relatively high temperature of 100°C to 300°C. Therefore, a solvent with a high boiling point such as glycerin is preferably used.

After the final reaction, purification is performed to remove unreacted raw materials, reaction by-products, and solvents. 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 non-patent literature above. The developing solution may be a single or mixed solution of hexane, heptane, dichloromethane, chloroform, ethyl acetate, toluene, methyl ethyl ketone, and methanol. Purification may be performed multiple times under different conditions. Other chromatography techniques (reverse-phase silica gel chromatography, size exclusion chromatography, paper chromatography) and purification operations such as liquid separation washing, reprecipitation, recrystallization, powder suspension washing, and reduced pressure drying can be performed as needed. .

＜Uses 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 such as an organic electroluminescent device or other light-emitting devices.

<Composition containing iridium complex compound>

Since the iridium complex compound of the present invention has excellent solubility, it is preferable to use it with a solvent. Hereinafter, a composition containing the iridium complex compound of the present invention and a solvent (iridium complex compound-containing composition) will be described.

The iridium complex compound-containing composition of the present invention contains the iridium complex compound of the present invention and a solvent described above. The composition containing the iridium complex compound of the present invention is generally 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.

In short, the composition containing the iridium complex compound 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 mass% or more, preferably 0.01 mass% or more, usually 99.9 mass% or less, preferably 99 mass% or less. By setting the content of the iridium complex compound in the composition within this range, holes and electrons can be efficiently injected from the adjacent layer (for example, a hole transport layer or a hole blocking layer) into the light emitting layer, and the driving voltage can be reduced. Additionally, the iridium complex compound of the present invention may be contained in the iridium complex compound-containing composition alone, or may be contained in combination of two or more types.

When the iridium complex compound-containing composition of the present invention is used, for example, for an organic electroluminescent device, in addition to the iridium complex compound and solvent described above, it may contain a charge-transporting compound used in the organic electroluminescent device, especially the light-emitting layer. there is.

When forming a light-emitting layer of an organic electroluminescent device using the iridium complex compound-containing composition of the present invention, it is preferable to include the iridium complex compound of the present invention as a light-emitting material and another charge-transporting compound as a charge-transport material. do.

The solvent contained in the composition containing the iridium complex compound of the present invention is a volatile liquid component used to form a layer containing the iridium complex compound by wet film formation.

Since the iridium complex compound of the present invention, which is the solute, has high solubility, the solvent is not particularly limited as long as it is a solvent in which the charge-transporting compound described later is well dissolved. Preferred solvents include, for example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; aromatic hydrocarbons such as toluene, xylene, methisilene, phenylcyclohexane, and tetralin. ；Halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, and trichlorobenzene; 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene , aromatic ethers such as 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenyl ether; phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, n- benzoate. Aromatic esters such as butyl; alicyclic ketones such as cyclohexanone, cyclooctanone, and pencone; alicyclic alcohols such as cyclohexanol and cyclooctanol; aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; butanol, Aliphatic alcohols such as hexanol; Aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); and the like.

Among them, alkanes and aromatic hydrocarbons are preferable, and phenylcyclohexane in particular has a desirable viscosity and boiling point in the wet film formation process.

These solvents may be used individually, 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, and more preferably 230°C or lower. If it is below this range, film formation stability may decrease due to solvent evaporation from the composition during wet film formation.

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

As other charge-transporting compounds that the iridium complex compound-containing composition of the present invention can contain, 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 their derivatives, quinacridone derivatives, DCM (4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran) series compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene, condensed aromatic ring compounds having a substituted arylamino group, and styryl derivatives having a substituted arylamino group.

These may be used individually as one type, or two or more types may be used in any combination and ratio.

Additionally, the content of other charge-transporting compounds in the iridium complex compound-containing composition is usually 1000 parts by mass or less, preferably 100 parts by mass or less, based on 1 part by mass of the iridium complex compound of the present invention in the iridium complex compound-containing composition. It is preferably 50 parts by mass or less, and is usually 0.01 part by mass or more, preferably 0.1 part by mass or more, and more preferably 1 part by mass or more.

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

＜Organic electroluminescent device＞

Below, embodiments of the organic electroluminescent device, the organic electroluminescent lighting device, and the organic electroluminescent display device of the present invention will be described in detail, but the present invention is not limited by these contents as long as they do not exceed the gist thereof.

(Board)

The substrate serves as a support for the organic electroluminescent element, and usually a quartz or glass plate, a metal plate or metal foil, a plastic film or sheet, etc. are used. Among these, glass plates and plates of transparent synthetic resins such as polyester, polymethacrylate, polycarbonate, and polysulfone are preferable. The substrate is preferably made of a material with high gas barrier properties because deterioration of the organic electroluminescent element due to external air is less likely to occur. For this reason, especially when using a material with low gas barrier properties, such as a synthetic resin substrate, it is desirable to form a dense silicon oxide film on at least one side of the substrate to improve the gas barrier properties.

(anode)

The anode serves the function of injecting holes into the layer on the light-emitting layer side. Anodes are usually metals such as aluminum, gold, silver, nickel, palladium, and platinum; metal oxides such as oxides of indium and/or tin; metal halides such as copper iodide; carbon black and poly(3-methylthiophene) ), and conductive polymers such as polypyrrole and polyaniline. The formation of the anode is usually performed by dry methods such as sputtering and vacuum deposition. 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., they are dispersed in an appropriate binder resin solution and applied on the substrate. It can also be formed. Additionally, in the case of conductive polymers, a thin film can be formed directly on the substrate by electrolytic polymerization, or the anode can be formed by applying the conductive polymer on the substrate (Appl. Phys. Lett., Vol. 60, Page 2711, 1992 year).

The anode usually has a single-layer structure, but may also have a laminated structure as appropriate. When the anode has a laminated structure, different conductive materials may be laminated on the first layer anode.

The thickness of the anode may be determined depending on the required transparency and material. In particular, when high transparency is required, a thickness with a visible light transmittance of 60% or more is preferable, and a thickness of 80% or more is more preferable. The thickness of the anode is usually 5 nm or more, preferably 10 nm or more, and is usually 1000 nm or less, preferably 500 nm or less. On the other hand, when transparency is not required, the thickness of the anode may be arbitrarily determined 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 an anode, treatment with ultraviolet rays + ozone, oxygen plasma, argon plasma, etc. is performed before film formation to remove impurities on the anode and adjust its ionization potential to improve hole injection properties. It is desirable.

(hole injection layer)

The layer responsible for transporting holes from the anode side to the light emitting layer side is usually called a hole injection and transport layer or a hole transport layer. Additionally, when there are two or more layers responsible for transporting holes from the anode side to the light emitting layer side, the layer closer to the anode side may be called a hole injection layer. The hole injection layer is preferably used because it enhances the function of transporting holes from the anode to the light emitting layer. When using a hole injection layer, the hole injection layer is typically formed on the anode.

The film thickness of the hole injection layer is usually 1 nm or more, preferably 5 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

The method for forming the hole injection layer may be a vacuum deposition method or a wet film forming method. In terms of excellent film forming properties, it is preferable to form 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 especially preferable that it contains a cation radical compound and a hole transport compound.

(Hole transport compound)

The composition for forming a hole injection layer usually contains a hole transport compound that becomes the hole injection layer. In addition, in the case of a wet film forming method, a solvent is usually additionally contained. The composition for forming a hole injection layer preferably has high hole transport properties and is capable of efficiently transporting injected holes. For this reason, it is desirable that the hole mobility is high and that impurities that become traps are not easily generated during manufacturing or use. Additionally, it is desirable to have excellent stability, small 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 not to quench the light emission from the light-emitting layer or to form an exciplex with the light-emitting layer and not reduce the light emission efficiency.

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

Among the above-mentioned exemplary compounds, aromatic amine compounds are preferable, and aromatic tertiary amine compounds are particularly preferable from the viewpoint of amorphousness and visible light transparency. Here, the aromatic tertiary amine compound refers to 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 since it is easy to obtain uniform light emission due to the surface smoothing effect, a polymer compound (polymerized compound with continuous repeating units) with a weight average molecular weight of 1,000 to 1,000,000 is used. It is desirable to do so. Preferred examples of aromatic tertiary amine polymer compounds include polymer compounds having a repeating unit represented by the following formula (I).

[Formula 16]

(In formula (I), Ar ¹ and Ar ² each independently represent an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Ar ³ to Ar ⁵ each independently represent a substituent. represents an aromatic hydrocarbon group that may have an aromatic hydrocarbon group or an aromatic heterocyclic group that may have a substituent. Y represents a linking group selected from the following linking group group. Also, among Ar ¹ to Ar ⁵ , two are bonded to the same N atom. Groups may combine with each other to form a ring.

The linking group is shown below.

[Formula 17]

(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 include benzene ring, naphthalene ring, phenanthrene ring, and thiophene in terms of solubility, heat resistance, and hole injection and transport properties of the polymer compound. A group derived from a ring or a pyridine ring is preferable, and a group derived from a benzene ring or a naphthalene ring is more preferable.

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 that has oxidizing power and the ability to accept one electron from the hole-transporting compound described above is preferable. Specifically, a compound having an electron affinity of 4 eV or more is preferable, and a compound having an electron affinity of 5 eV or more is preferable. Compounds are more preferred.

Such electron-accepting compounds include, for example, one selected from the group consisting of triaryl boron compounds, metal halides, Lewis acids, organic acids, onium salts, salts of arylamines and metal halides, and salts of arylamines and Lewis acids. A species or two or more types of compounds can be mentioned. Specifically, onium salts substituted with organic groups such as 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pendafluorophenyl)borate and triphenylsulfonium tetrafluoroborate (International Publication No. 2005/089024) ); High-valence inorganic compounds such as iron (III) chloride (Japanese Patent Application Publication No. 11-251067), ammonium peroxodisulfate; Cyano compounds such as tetracyanoethylene; Tris(pendafluorophenyl)borane Aromatic boron compounds such as (Japanese Patent Application Publication No. 2003-31365); fullerene derivatives, iodine, etc. are mentioned.

(cation radical compound)

The cation radical compound is preferably an ionic compound consisting of a cation radical, which is a chemical species in which one electron is removed 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 the hole-transporting compound. As a hole-transporting compound, a chemical species obtained by removing one electron from a preferred compound is suitable in terms of amorphousness, visible light transmittance, heat resistance, and solubility.

Here, the cation radical compound can be produced by mixing the hole-transporting compound and the electron-accepting compound described above. 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 a cation ion compound composed of the cation radical and counter anion of the hole-transporting compound is generated.

Cation radical compounds derived from polymer compounds such as PEDOT/PSS (Adv. Mater., 2000, vol. 12, p. 481) or emeraldine hydrochloride (J. Phys. Chem., 1990, vol. 94, p. 7716) are , It can also be produced through oxidative polymerization (dehydrogenation polymerization).

Oxidative polymerization as referred to here means oxidizing a monomer chemically or electrochemically in an acidic solution using peroxodisulfate or the like. In the case of this oxidation 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 the anion derived from the acidic solution as a counter anion, is generated.

<Formation of hole injection layer by wet film forming method>

When forming a hole injection layer by a wet film formation method, a material for forming the hole injection layer is usually mixed with a soluble solvent (solvent for the hole injection layer) to prepare a composition for film formation (composition for forming a hole injection layer). , this composition for forming a hole injection layer is formed by applying it on the layer corresponding to the lower layer of the hole injection layer (usually the anode), forming it into a film, and drying it.

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

Examples of solvents include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents.

Ether-based solvents include, for example, 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- Aromatic ethers such as dimethoxybenzene, anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole. You can.

Examples of the ester-based solvent include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.

Examples of aromatic hydrocarbon solvents include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, and cyclohexyl. Benzene, methylnaphthalene, etc. can be mentioned. Examples of amide-based solvents include N,N-dimethylformamide, N,N-dimethylacetamide, and the like.

In addition to these, dimethyl sulfoxide and the like can also be used.

The formation of the hole injection layer 3 by a wet film formation method usually involves preparing a composition for forming the hole injection layer, and then forming this into a layer corresponding to the lower layer of the hole injection layer 3 (usually, the anode (2) )) It is carried out by applying a film on top and drying it. After forming the hole injection layer 3, the coating film is usually dried by heating or reduced-pressure drying.

<Formation of hole injection layer by vacuum deposition method>

When forming the hole injection layer 3 by a vacuum deposition method, one or two or more types of constituent materials of the hole injection layer 3 (the above-mentioned hole transporting compound, electron accepting compound, etc.) are usually placed in a vacuum container. Put them in a crucible installed inside (when using two or more types of materials, each is usually placed in a different crucible), evacuate the inside of the vacuum container to about 10 ^-4 Pa with a vacuum pump, and then heat the crucible (two types) When using the above materials, they are evaporated while controlling the evaporation amount of the material in the crucible (usually by heating each crucible) (when using two or more types of materials, they are usually evaporated while controlling the evaporation amount independently) ), a hole injection layer is formed on the anode on the substrate facing the crucible. Additionally, when using two or more types of materials, their mixture can be placed in a crucible, heated, and evaporated to form a hole injection layer.

The degree of vacuum during deposition is not limited as long as it does not significantly impair the effect 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 effect of the present invention, but is usually 0.1 Å/sec or more and 5.0 Å/sec or less. The film formation temperature during vapor deposition is not limited as long as it does not significantly impair the effect of the present invention, but is preferably performed at 10°C or higher and 50°C or lower.

(Hole transport layer)

The hole transport layer is a layer that functions to transport 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 because it enhances 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 film thickness of the hole transport layer is usually 5 nm or more, preferably 10 nm or more, and is usually 300 nm or less, preferably 100 nm or less.

The method for forming the hole transport layer may be a vacuum deposition method or a wet film forming method. In terms of excellent film forming properties, it is preferable to form by a wet film forming method.

The hole transport layer usually contains a hole transport compound that serves as the hole transport layer. Hole-transporting compounds contained in the hole-transporting layer include, in particular, two or more tertiary amines, such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl, and 2 Starburst structures such as aromatic diamines in which two or more condensed aromatic rings are replaced with nitrogen atoms (Japanese Patent Application Laid-Open No. 5-234681), 4,4',4"-tris(1-naphthylphenylamino)triphenylamine, etc. Aromatic amine compounds having (J. Lumin., vol. 72-74, 985 pages, 1997), aromatic amine compounds consisting of tetramers of triphenylamine (Chem. Commun., 2175 pages, 1996), 2,2' Spiro compounds such as ,7,7'-tetrakis-(diphenylamino)-9,9'-spirobifluorene (Synth. Metals, Volume 91, Page 209, 1997), 4,4'-N, Carbazole derivatives such as N'-dicarbazole biphenyl, etc. can be mentioned. Also, for example, polyvinylcarbazole, polyvinyltriphenylamine (Japanese Patent Laid-Open No. 7-53953), polyarylene ether sulfone containing tetraphenylbenzidine (Polym. Adv. Tech., Vol. 7, 33 Page, 1996) can also be used preferably.

<Formation of hole transport layer by wet film forming method>

When forming a hole transport layer by a wet film deposition method, usually, in the same manner as in the case of forming the above-described hole injection layer by a wet film formation method, a composition for forming a hole transport layer is used instead of the composition for forming a hole injection layer. form.

When forming a hole transport layer by a wet film forming method, the composition for forming the hole transport layer usually further contains a solvent. The solvent used in the composition for forming a hole transport layer can be the same as the solvent used in the composition for forming a hole injection layer described above.

The concentration of the hole transporting compound in the composition for forming a hole transport layer can be within the same range as the concentration of the hole transporting compound in the composition for forming a hole injection layer.

Formation of the hole transport layer by a wet film formation method can be performed in the same manner as the hole injection layer film formation method described above.

＜Formation of hole transport layer by vacuum deposition method＞

In the case of forming a hole transport layer by a vacuum deposition method, it is usually formed in the same manner as in the case of forming the hole injection layer described above by a vacuum deposition method, using a composition for forming a hole transport layer instead of the composition for forming a hole injection layer. You can do it. Film formation conditions such as vacuum degree, deposition rate, and temperature during deposition can be the same as those for vacuum deposition of the hole injection layer.

(Emitting layer)

The light-emitting layer is a layer that functions to emit light by being 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. The light-emitting layer is a layer formed between the anode and the cathode. When there is a hole injection layer on the anode, the light-emitting layer is formed between the hole injection layer and the cathode. When there is a hole transport layer on the anode, the light-emitting layer is formed between the hole transport layer and the cathode. It is formed between the cathodes.

The film thickness of the light-emitting layer is arbitrary as long as it does not significantly impair the effect of the present invention, but a thicker one is preferable because defects are less likely to occur in the film, and a thinner one is preferable because it is easier to achieve a low driving voltage. do. For this reason, it is preferable that it is 3 nm or more, and it is more preferable that it is 5 nm or more, and on the other hand, it is generally preferable that it is 200 nm or less, and it is more preferable that it is 100 nm or less.

The light-emitting layer contains at least a material (light-emitting material) that has the property of emitting light, and preferably contains a material (charge-transport material) that has charge-transport properties.

(Luminescent material)

The luminescent material is not particularly limited as long as it emits light at a desired luminescent wavelength and does not impair the effect of the present invention, and any known luminescent material can be applied. The luminescent material may be a fluorescent luminescent material or a phosphorescent luminescent material, but a material with good luminous efficiency is preferable, and a phosphorescent luminescent 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.

Fluorescent materials that emit blue light (blue fluorescent materials) include, for example, naphthalene, perylene, pyrene, anthracene, coumarin, chrysene, p-bis(2-phenylethenyl)benzene, and their derivatives. I can hear it.

Examples of fluorescent materials that impart green light emission (green fluorescent materials) include quinacridone derivatives, coumarin derivatives, and aluminum complexes such as Al(C ₉ H ₆ NO) ₃ . Examples of fluorescent materials that emit yellow light (yellow fluorescent materials) include rubrene and perimidone derivatives.

Fluorescent materials that impart red light (red fluorescent materials) include, for example, DCM (4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran)-based compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, and azabenzothioxanthene.

Additionally, phosphorescent materials include, for example, groups 7 to 11 of the long periodic table (hereinafter, unless otherwise specified, the term “periodic table” refers to the long periodic table). and organometallic complexes containing selected metals. Metals selected from groups 7 to 11 of the periodic table are preferably ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold.

As the ligand for the organometallic complex, a ligand in which a (hetero)aryl group, such as a (hetero)arylpyridine ligand or a (hetero)arylpyrazole ligand, is linked to a pyridine, pyrazole, or phenanthroline, is preferable, and in particular, a phenylpyridine ligand. , a phenylpyrazole ligand is preferred. Here, (hetero)aryl refers to an aryl group or heteroaryl group.

Preferred phosphorescent materials include, specifically, tris(2-phenylpyridine)iridium, tris(2-phenylpyridine)ruthenium, tris(2-phenylpyridine)palladium, bis(2-phenylpyridine)platinum, phenylpyridine complexes such as tris(2-phenylpyridine)osmium and tris(2-phenylpyridine)rhenium, and porphyrin complexes such as octaethylplatinum porphyrin, octaphenylplatinum porphyrin, octaethylpalladiumporphyrin, and octaphenylpalladiumporphyrin. there is.

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)], polyfluorene-based materials, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], etc. Examples include polyphenylene vinylene-based materials.

(charge transport material)

The charge-transporting material is a material having positive charge (hole) or negative charge (electron) transportability. There is no particular limitation, and any known light-emitting material can be applied as long as it does not impair the effect of the present invention.

The charge-transporting material can be a compound conventionally used in the light-emitting layer of an organic electroluminescent device, and compounds used as a host material for the light-emitting layer are particularly preferable.

The charge transport material specifically includes aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, and compounds in which a tertiary amine is linked to a fluorene group. , hydrazone-based compounds, silazane-based compounds, silanamine-based compounds, phosphamine-based compounds, and quinacridone-based compounds, in addition to compounds exemplified as hole transport compounds of the hole injection layer, such as anthracene-based compounds and pyrene. Electron-transporting compounds such as type compounds, carbazole-based compounds, pyridine-based compounds, phenanthroline-based compounds, oxadiazole-based compounds, and silol-based compounds can be mentioned.

In addition, for example, two or more condensed aromatic rings, including two or more tertiary amines such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl, are represented by a nitrogen atom. Aromatic amine compounds having a starburst structure such as substituted aromatic diamine (Japanese Patent Application Publication No. 5-234681) and 4,4',4"-tris(1-naphthylphenylamino)triphenylamine (J. Lumin., Volume 72-74, Page 985, 1997), Aromatic amine compound consisting of tetramer of triphenylamine (Chem. Commun., Page 2175, 1996), 2,2',7,7'- Fluorene-based compounds such as tetrakis-(diphenylamino)-9,9'-spirobifluorene (Synth. Metals, Volume 91, Page 209, 1997), 4,4'-N,N'-dicar Compounds exemplified as hole-transporting compounds of the hole-transporting layer, such as carbazole-based compounds such as levazole biphenyl, can also be preferably used. In addition, 2-(4-biphenylyl)-5-(p-tertiarybutylphenyl)-1,3,4-oxadiazole (tBu-PBD), 2,5-bis(1-naph) Oxadiazole-based compounds such as til)-1,3,4-oxadiazole (BND), 2,5-bis(6'-(2',2"-bipyridyl))-1,1-dimethyl- Silol-based compounds such as 3,4-diphenylsilol (PyPySPyPy), Vasophenanthroline (BPhen), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP, Vasocupro) Phenothroline-based compounds such as phosphorus) can also be mentioned.

<Formation of light-emitting layer by wet film forming method>

The method for forming the light emitting layer may be a vacuum deposition method or a wet film forming method, but the wet film forming method is preferable because of excellent film forming properties. In the present invention, the wet film forming method refers to a film forming method, that is, an application method, including, for example, spin coating method, dip coating method, die coating method, bar coating method, blade coating method, roll coating method, spray coating method, This refers to a method of forming a film by employing a wet film forming method such as the capillary coating method, inkjet method, nozzle printing method, screen printing method, gravure printing method, or flexo printing method, and drying the coating film. When forming a light-emitting layer by a wet film formation method, normally, in the same manner as in the case of forming the above-described hole injection layer by a wet film formation method, instead of the composition for forming the hole injection layer, a material that becomes the light-emitting layer is used. It is formed using a composition for forming a light-emitting layer prepared by mixing with a solvent (solvent for the light-emitting layer).

Solvents include, for example, ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents exemplified for forming the hole injection layer, as well as alkane-based solvents, halogenated aromatic hydrocarbon-based solvents, and aliphatic alcohol-based solvents. Alicyclic alcohol-based solvents, aliphatic ketone-based solvents, and alicyclic ketone-based solvents can be mentioned. Specific examples of solvents are given below, but they are not limited to these as long as they do not impair the effect of the present invention.

For example, aliphatic ether solvents such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, Aromatic ether solvents such as anisole, phenetol, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenyl ether; Aromatic ester solvents such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; toluene, xylene, methisilene, cyclohexylbenzene, tetralin, 3-isopropylbiphenyl, 1 , Aromatic hydrocarbon solvents such as 2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, and methylnaphthalene; N,N-dimethylformamide, N,N-dimethylacetamide, etc. Amide-based solvents; Alkanes-based solvents such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; Halogenated aromatic hydrocarbon-based solvents such as chlorobenzene, dichlorobenzene, and trichlorobenzene; Aliphatic solvents such as butanol and hexanol Alcohol-based solvents; Alicyclic alcohol-based solvents such as cyclohexanol and cyclooctanol; Aliphatic ketone-based solvents such as methyl ethyl ketone and dibutyl ketone; Alicyclic ketone-based solvents such as cyclohexanone, cyclooctanone, and pencone, etc. can be mentioned. Among these, alkane-based solvents and aromatic hydrocarbon-based solvents are particularly preferable.

Additionally, in order to obtain a more uniform film, it is preferable that the solvent evaporates from the liquid film immediately after film formation at an appropriate rate. For this reason, 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, and more preferably 230°C or lower. am.

The amount of solvent used is optional as long as it does not significantly impair the effect of the present invention, but the total content in the composition for forming a light-emitting layer is preferably higher because it has low viscosity and makes film forming work easy. On the other hand, a thick film ( A lower temperature is preferable because it is easier to form a thick film. The content of the solvent in the composition containing the iridium complex compound is preferably 1 mass% or more, more preferably 10 mass% or more, particularly preferably 50 mass% or more, and preferably 99.99 mass% or less, more preferably. Preferably it is 99.9% by mass or less, particularly preferably 99% by mass or less.

As a solvent removal method, heating or reduced pressure can be used. As a heating means used in the heating method, a clean oven or a hot plate is preferable because it applies heat evenly to the entire film.

The heating temperature in the heating process is arbitrary as long as it does not significantly impair the effect of the present invention, but a higher temperature is preferable in terms of shortening the drying time, and a lower temperature is preferable in that it causes 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. Temperatures above the upper limit are undesirable because they are higher than the heat resistance of commonly used charge transport materials or phosphorescent materials and may cause decomposition or crystallization. Below the lower limit, it is undesirable because a long time is required to remove the solvent. The heating time in the heating process is appropriately determined depending on the boiling point or vapor pressure of the solvent in the composition for forming a light-emitting layer, the heat resistance of the material, and heating conditions.

＜Formation of light-emitting layer by vacuum deposition method＞

When forming a light-emitting layer by a vacuum deposition method, one or two or more types of constituent materials of the light-emitting layer (the above-mentioned light-emitting materials, charge-transporting compounds, etc.) are usually placed in a crucible installed in a vacuum container (two or more types of materials) When using them, each is usually placed in a different crucible), the inside of the vacuum container is evacuated to about 10 ^-4 Pa with a vacuum pump, and then the crucible is heated (when two or more types of materials are used, each is usually placed in a different crucible). (by heating the crucible), evaporating while controlling the evaporation amount of the material in the crucible (when using two or more types of materials, usually evaporating while controlling the evaporation amount independently), and on the hole injection transport layer placed facing the crucible. Form a light emitting layer. Additionally, when using two or more types of materials, their mixture can be placed in a crucible, heated, and evaporated to form a light-emitting layer.

The degree of vacuum during deposition is not limited as long as it does not significantly impair the effect 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 effect of the present invention, but is usually 0.1 Å/sec or more and 5.0 Å/sec or less. The film formation temperature during vapor deposition is not limited as long as it does not significantly impair the effect of the present invention, but is preferably performed at 10°C or higher and 50°C or lower.

(Heavy Dope)

A typical dope concentration of the iridium complex compound in the light-emitting layer of an organic electroluminescent device that emits phosphorescence is a concentration of 0.1 mmol/g or less of the iridium complex compound per unit weight of the light-emitting layer. In the present invention, the dope concentration exceeding this concentration is called the heavy dope concentration. In general, the effects of heavy dopes on organic electroluminescent devices are diverse, and while an increase in the driving life of the device is expected, it is well known that luminous efficiency is reduced due to pair annihilation of excitons between luminescent materials. .

(hole blocking layer)

A hole blocking layer may be formed between the light emitting layer and the electron injection layer described later. The hole blocking layer is a layer laminated on the light emitting layer so as to be in contact with the interface on the cathode side of the light emitting layer.

This hole blocking layer has a role of preventing holes moving from the anode from reaching the cathode and a role of efficiently transporting electrons injected from the cathode toward the light emitting layer. The physical properties required for the material constituting the hole blocking layer 6 include high electron mobility and low hole mobility, a large energy gap (difference between HOMO and LUMO), and an excitation triplet level (T1). You can lift something high.

Materials for the hole blocking layer that satisfy these conditions include, for example, bis(2-methyl-8-quinolinolato)(phenolato)aluminum and bis(2-methyl-8-quinolinolato). Mixed ligand complexes such as (triphenylsilanolato)aluminum, bis(2-methyl-8-quinolato)aluminum-μ-oxo-bis-(2-methyl-8-quinolilato)aluminum 2-nuclear metal complex metal complexes such as styryl compounds such as distyryl biphenyl derivatives (Japanese Patent Application Laid-Open No. 11-242996), 3-(4-biphenylyl)-4-phenyl-5(4-tert-butylphenyl)- Triazole derivatives such as 1,2,4-triazole (Japanese Patent Application Publication No. 7-41759), phenanthroline derivatives such as vasocuproin (Japanese Patent Application Publication No. 10-79297), etc. there is. Additionally, compounds having at least one pyridine ring substituted at the 2, 4, and 6 positions described in International Publication No. 2005/022962 are also preferable as materials for the hole blocking layer.

There is no limitation to the method of forming the hole blocking layer 6, and it can be formed in the same manner as the method of forming the above-described light-emitting layer.

The film thickness of the hole blocking layer is arbitrary as long as it does not significantly impair the effect of the present invention, but is usually 0.3 nm or more, preferably 0.5 nm or more, and is usually 100 nm or less, preferably 50 nm or less. am.

(electron transport layer)

The electron transport layer is formed 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 from a compound that can efficiently transport electrons injected from the cathode in the direction of the light-emitting layer between electrodes to which an electric field is applied. The electron transport compound used in the electron transport layer is required to be a compound that has high electron injection efficiency from the cathode or electron injection layer and that has high electron mobility and can efficiently transport the injected electrons.

The electron transporting compound used in the electron transport layer is preferably a compound that has high electron injection efficiency from the cathode or electron injection layer and can transport the injected electrons efficiently. Electron-transporting compounds include, specifically, metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Application Laid-Open No. 59-194393), and metal complexes of 10-hydroxybenzo[h]quinoline. , oxadiazole derivatives, distyrylbiphenyl derivatives, silol derivatives, 3-hydroxy flavone metal complex, 5-hydroxy flavone metal complex, benzoxazole metal complex, benzothiazole metal complex, trisbenzimidazolylbenzene (USA) Patent No. 5645948 specification), quinoxaline compound (Japanese Patent Application Laid-Open No. 6-207169), phenanthroline derivative (Japanese Patent Application Laid-Open No. 5-331459), 2-t-butyl-9,10-N, N'-dicyanoanthraquinone diimine, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, n-type zinc selenide, etc. are mentioned.

The film thickness of the electron transport layer is usually 1 nm or more, preferably 5 nm or more, and is usually 300 nm or less, preferably 100 nm or less.

The electron transport layer is formed by laminating the electron transport layer on the hole blocking layer using a wet film forming method or a vacuum deposition method in the same manner as above. Typically, a vacuum deposition method is used.

(electron injection layer)

The electron injection layer serves to efficiently inject electrons injected from the cathode into the electron transport layer or the light emitting layer.

In order to perform electron injection efficiently, 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.

Additionally, organic electron transport materials such as nitrogen-containing heterocyclic compounds such as vasophenanthroline 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 Patent Publication No. 10-270171, Japanese Patent Publication 2002-100478, Japanese Patent Publication 2002-100482, etc.) is because electron injection and transport properties are improved, making it possible to achieve excellent film quality. desirable.

The film thickness is usually 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 the light emitting layer or the hole blocking layer thereon by a wet film forming method or a vacuum deposition method.

The details in the case of the wet film forming method are the same as in the case of the above-described light emitting layer.

(cathode)

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

In terms of device stability, it is desirable to protect the cathode made of a low work function metal by laminating a metal layer with a high work function and stable against the atmosphere on the cathode. Examples of metals 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 floors)

The organic electroluminescent device of the present invention may have another layer as long as the effect of the present invention is not significantly impaired. That is, between the anode and the cathode, you may have any of the other layers described above.

＜Other element composition＞

In addition, it is also possible to have a structure opposite to the above description, that is, to stack the cathode, electron injection layer, light emitting layer, hole injection layer, and anode in that order on the substrate.

＜Other＞

When applying the organic electroluminescent element of the present invention to an organic electroluminescent device, it may be used as a single organic electroluminescent element, or may be used in a configuration in which a plurality of organic electroluminescent elements are arranged in an array, and an anode and It may be used in a configuration where the cathode is arranged in an X-Y matrix.

＜Display and lighting devices＞

The display device and lighting device of the present invention use the organic electroluminescent element of the present invention as described above. There are no particular restrictions on the form or structure of the display device and lighting device of the present invention, and they can be assembled by conventional methods using the organic electroluminescent device of the present invention.

For example, the display device and lighting device of the present invention are formed by the method described in "Organic EL Display" (Oumsa, published on August 20, 2016, by Shizuo Tokito, Chihaya Adachi, and Hideyuki Murata). can do.

Example

Hereinafter, the present invention will be described in more detail by referring to examples. However, the present invention is not limited to the following examples, and the present invention can be implemented with any modification as long as it does not deviate from the gist.

<Synthesis example of compound (D-1)>

[Formula 18]

In a reaction vessel under nitrogen flow, 2-(3-pinacholateborylphenyl)pyridine (17.4 g), intermediate 1 (19.2 g), 2M tripotassium phosphate aqueous solution (77 ml), toluene (120 ml), and ethanol (60 ml) ) was added, and nitrogen was bubbled for 30 minutes. After that, [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. Afterwards, it was cooled to room temperature, water was added, liquid separation and washing were performed, and the organic layer was dried over magnesium sulfate. Afterwards, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (dichloromethane/hexane = 1/1 to dichloromethane/hexane/ethyl acetate = 50/45/5) to obtain Intermediate 2 (23.6 g) as a yellow oily substance.

[Formula 19]

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

[Formula 20]

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 the oil bath was heated to 120°C, followed by 3 , 5-heptanedione (14 g) and sodium carbonate (11.3 g) were added, and the mixture was continuously heated and refluxed for about 2 hours. After cooling and removing the solvent under reduced pressure, dichloromethane (200 ml) was added, filtered through silica gel, and the filtrate was concentrated under reduced pressure. Ethanol (150 ml) was added to the residue, the powder was precipitated, and then filtered.

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

[Formula 21]

In a reaction vessel, under a nitrogen stream, 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, and the internal temperature was heated from 218°C to 227°C. It was stirred for 5.5 hours. The by-produced 3,5-heptanedione was removed by distillation while reacting. After cooling, water was added, the solvent was removed by decantation, and the residue was purified by silica gel column chromatography (dichloromethane/hexane = 1/1) to obtain compound D-1 (0.70 g) as a yellow solid.

<Synthesis example of compound (D-2)>

[Formula 22]

At room temperature, copper (I) bromide (54.5 g) and anhydrous lithium bromide (65.9 g) were added to a 2 liter eggplant flask, dried at 60°C for 2 hours, replaced with argon, cooled to room temperature, and dried with THF (0.9 ℓ). was added and stirred for 2 hours to prepare a catalyst solution.

In a 10 L reactor, scrap magnesium (190 g), dry THF (0.3 L), and a trace amount of iodine were activated under nitrogen and added to a dry THF (3.5 L) solution of bromobenzene (1192 g). It was added dropwise over time and refluxed and stirred for an additional 1.5 hours to prepare a Grignard reagent solution. In a 20 L reactor, under nitrogen, 1,5-dibromopentane (4365 g) and dry THF (5.2 L) were added, the previously prepared catalyst solution was added, and after cooling to an internal temperature of 10°C, the previously prepared Grignard reagent solution was added. was added dropwise over 1 hour so that the internal temperature was 10 to 45°C, and then stirred at room temperature overnight. 3M hydrochloric acid (3.5 L) was added, the oil layer was separated, and the water layer was extracted with ethyl acetate (3.5 × 2 times). The oil layer was dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated to obtain a brown oily crude product (4.9 kg). This crude product was distilled under reduced pressure to obtain Intermediate 6 (0.94 kg) as a slightly yellow transparent oil.

[Formula 23]

In a 10 L reactor, scrap magnesium (107 g) and dry THF (0.5 L) were placed under nitrogen, activated with iodine pieces (tens of mg), and a dry THF (2.5 L) solution of intermediate 6 (0.91 kg) was added. It was added dropwise over 2 hours and heated and stirred at an internal temperature of 55°C for an additional 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, and heated and stirred at an internal temperature of 45 to 58°C for 3 hours. did. The above reaction solution 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 brown oily crude product (2.0 kg). This crude product was purified by silica gel column chromatography (ethyl acetate/hexane = 1/9-1/4) to obtain a light yellow transparent oil (0.74 kg). It was then transferred to a 20 L reactor, diglyme (5.1 L) was added, and sodium hydroxide (0.19 kg) was added. Next, hydrazine monohydrate (0.24 kg) was added dropwise over 30 minutes, the temperature was raised to an internal temperature of 80°C over 1 hour, and the mixture was stirred at an internal temperature of 123°C for 4 hours. After cooling, 2M hydrochloric acid (3.6 L) was added, then hexane (3.5 L) was added, and the oil layer was separated. The aqueous layer was extracted with hexane (2.5 L ) 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.

[Formula 24]

In a 20 L reactor, Intermediate 7 (0.45 kg) and dry THF (4.5 L) were added under nitrogen, cooled to an internal temperature of -77°C, and a 1.65 M n-butyllithium/n-hexane solution (1.0 L) was added to the internal temperature. It was added dropwise over 1 hour at -68°C or lower, and 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 temperature was maintained and stirred for 1.5 hours. After that, 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 water layer was extracted with ethyl acetate (3 L). The oil layers were combined, washed with saturated saline solution (2.5 L), dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated to obtain a brown oily crude product (0.58 kg). This crude product was purified by silica gel column chromatography (ethyl acetate/dichloromethane/hexane = 0/1/3 to 2/2/3), and 0.31 kg of Intermediate 8 was obtained.

[Formula 25]

In a reaction vessel under 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) ) 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. Afterwards, it was cooled to room temperature, water was added, liquid separation and washing were performed, and the organic layer was dried over magnesium sulfate. Afterwards, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (dichloromethane/hexane = 1/9) to obtain 27.8 g of bromobody. This was placed in another reaction vessel, and under a nitrogen stream, bispinacholate diboron (17.7 g), [PdCl ₂ (dppf)]CH ₂ Cl ₂ (1.71 g), potassium acetate (20.5 g), and dehydrated dimethyl sulfoxide (150 g) were added to the reaction vessel. mL) was added and stirred in a 100°C oil bath for 2 hours. After that, it was cooled to room temperature, water and toluene were added, the liquid was separated and washed, and the oil phase was dried with sodium sulfate. Afterwards, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (eluent: dichloromethane/hexane = 3/7 to dichloromethane/hexane/ethyl acetate = 3/7/0.1) to give Intermediate 9 (23.4 g) as a white solid. got it

[Formula 26]

In a reaction vessel, 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), and 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 separated and washed by adding water, dried over magnesium sulfate, and purified by silica gel column chromatography (dichloromethane only) to obtain Intermediate 10 (10.0 g) as a colorless oily substance.

[Formula 27]

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 approximately 100°C. Silver trifluoromethanesulfonate (1.6 g) was added, and the internal temperature was immediately raised to 125°C and stirred for 2 hours. After cooling to room temperature, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (dichloromethane/hexane = 1/1). Compound D-2 was obtained in the amount of 1.6 g as a yellow solid.

<Synthesis example of compound (D-3)>

[Formula 28]

In a reaction vessel, under a stream of nitrogen, 2-(3-bromophenyl)pyridine (5.6 g), 9.3 g of intermediate 11 (synthesized by the method described in International Publication No. 2012/137958), [Pd(PPh ₃ ) ₄ ] 0.50 g, 27 mL of 2M tripotassium phosphate aqueous solution, 50 mL of toluene, and 25 mL of ethanol were added, and the mixture was stirred in a 100°C oil bath for 3 hours. After cooling, the mixture was separated and washed by adding water and toluene, dried over magnesium sulfate, and purified by silica gel column chromatography (dichloromethane only) to obtain Intermediate 12 (9.16 g) as a white solid.

[Formula 29]

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 the reaction vessel under a nitrogen stream, and oil The temperature of the bath was gradually raised from 135°C to 150°C and stirred for a total of 10 hours. In the meantime, the refluxing liquid was removed from the side pipe. An additional 60 ml of diglyme was added during the reaction. Afterwards, it was cooled to room temperature, the reaction solution was added to 500 ml of distilled water, and the precipitated solid was filtered, washed with 500 ml of methanol, and dried. Intermediate 13 (10.5 g) was obtained as a yellow solid.

[Formula 30]

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 approximately 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). Compound D-3 was obtained in the amount of 0.7 g as a yellow solid.

<Synthesis example of compound (D-4)>

[Formula 31]

In a reaction vessel, under a stream of nitrogen, 2-(3-pinacholateborylphenyl)pyridine (19.2 g), 3,3'-dibromoviphenyl (64.4 g), 2M tripotassium phosphate aqueous solution (260 ml), toluene (280 ml) mL) and ethanol (140 mL) were added and nitrogen was bubbled for 30 minutes. After that, 6.0 g of [Pd(PPh ₃ ) ₄ ] was added while stirring, and the mixture was stirred and refluxed at 100°C for 3 hours. Afterwards, it was cooled to room temperature, water was added, liquid separation and washing were performed, and the organic layer was dried over magnesium sulfate. Afterwards, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (dichloromethane/hexane = 4/6 to dichloromethane/hexane/ethyl acetate = 3/7/0.5) to obtain Intermediate 14 (22.0 g) as a yellow oily substance.

[Formula 32]

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 the reaction vessel under a nitrogen stream, and nitrogen was added for 30 minutes. It bubbled. After that, 0.76 g of [Pd(PPh ₃ ) ₄ ] was added while stirring, and the mixture was stirred and refluxed at 100°C for 1.5 hours. Afterwards, it was cooled to room temperature, water was added, liquid separation and washing were performed, and the organic layer was dried over magnesium sulfate. Afterwards, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (ethyl acetate/hexane = 2/8) to obtain Intermediate 15 (12.9 g) as a colorless oily substance.

[Formula 33]

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 approximately 100°C. Silver trifluoromethanesulfonate (1.89 g) was added, and the oil bath was immediately raised to 130°C and stirred for 2 hours. After cooling to room temperature, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (dichloromethane/hexane = 1/1). Compound D-4 was obtained as 2.49 g of a yellow solid.

<Synthesis example of compound (D-7)>

[Formula 34]

In a reaction vessel under nitrogen flow, 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). was added, and nitrogen was bubbled for 30 minutes. After that, 4.67 g of [Pd(PPh ₃ ) ₄ ] was added while stirring, and the mixture was stirred and refluxed at 100°C for 3.5 hours. Afterwards, it was cooled to room temperature, water was added, liquid separation and washing were performed, and the organic layer was dried over magnesium sulfate. Afterwards, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (dichloromethane/hexane = 5/95 to 10/90) to obtain Intermediate 16 (48.0 g) as a colorless oily substance.

[Formula 35]

Intermediate 16 (36.8 g), bis(pinacholate)diborone (29.1 g), potassium acetate (33.8 g), and dehydrated dimethyl sulfoxide (330 mL) were added to the reaction vessel under a nitrogen stream, and nitrogen was bubbled for 30 minutes. Ringed. After that, [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. Afterwards, it was cooled to room temperature, water was added, liquid separation and washing were performed, and the organic layer was dried over magnesium sulfate. Afterwards, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane/dichloromethane/ethyl acetate = 90/10/5 to 60/40/5) to obtain Intermediate 17 (23.1 g) as a white solid.

[Formula 36]

In a reaction vessel, under nitrogen flow, 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). was added, and nitrogen was bubbled for 30 minutes. After that, [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, liquid separation and washing were performed, and the organic layer was dried over magnesium sulfate. Afterwards, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane/dichloromethane/ethyl acetate = 75/25/3 to 60/40/3) to obtain Intermediate 18 (14.8 g) as a yellow solid material.

[Formula 37]

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 the reaction vessel under a nitrogen stream, and oil The temperature of the bath was gradually raised from 105°C to 135°C and stirred for a total of 7 hours. In the meantime, the refluxing liquid was removed from the side pipe. Afterwards, it was cooled to room temperature, the reaction solution was added to 400 ml of distilled water, and the precipitated solid was filtered, washed with 200 ml of methanol, and dried. Intermediate 19 (16.0 g) was obtained as a yellow solid.

[Formula 38]

Add 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) to the reaction vessel under an argon stream. Then, [Pd(PPh ₃ ) ₄ ] (12.31 g) was further added while stirring, and the mixture was stirred and refluxed at 90°C for 15 hours. Afterwards, it was cooled to room temperature, water was added, liquid separation and washing were performed, and 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 bromobody. This was then placed in a 3 L reaction vessel, 1 L of dry THF was added under an argon stream, cooled to an internal temperature of -75°C, and 186 mL of a 1.65 M n-butyllithium hexane solution was added dropwise at an internal temperature of -66°C or lower. , and 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 the mixture was stirred overnight while returning to room temperature, then 500 ml of ethyl acetate was poured, oil and water were separated, and the aqueous layer was extracted with ethyl acetate. All organic layers were combined, washed with saturated saline solution, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated to obtain a yellow oily crude product. This crude product was purified by subjecting it to silica gel column chromatography (ethyl acetate/dichloromethane/hexane = 1/0/4 to 1/2/0), and 55.6 g of Intermediate 20 was obtained as a light yellow solid.

[Formula 39]

Intermediate 12 (13.4 g), intermediate 20 (13.0 g), 45 ml of 2M tripotassium phosphate aqueous solution, 90 ml of toluene, and 45 ml of ethanol were added to the reaction vessel under a nitrogen stream, and nitrogen was bubbled for 30 minutes. After that, 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. Afterwards, it was cooled to room temperature, water was added, liquid separation and washing were performed, and the organic layer was dried over magnesium sulfate. Afterwards, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (ethyl acetate/hexane = 2/8) to obtain Intermediate 21 (14.4 g) as a colorless oily substance.

[Formula 40]

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 adjusted to approximately 100°C. 1.64 g of trifluoromethanesulfonic acid was added, and the oil bath was immediately raised to 134°C and stirred for 1.5 hours. After cooling to room temperature, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (dichloromethane/hexane = 1/1). Compound D-7 was obtained as 2.24 g of a yellow solid.

<Synthesis example of compound (D-8)>

[Formula 41]

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. This was stirred for 8 hours. In the meantime, the refluxing liquid was removed from the side pipe. Afterwards, 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 dried. Intermediate 22 (49.0 g) was obtained as a yellow solid.

[Formula 42]

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, the temperature of the oil bath was set to 170°C, and the temperature of the oil bath was set to mild reflux. 3.52 g of trifluoromethanesulfonic acid was added and stirred for 2 hours. After cooling to room temperature, the solution was separated and washed with 300 ml of water, 300 ml of toluene, and 300 ml of dichloromethane, dried over magnesium sulfate, filtered, and the solvent was removed under reduced pressure. The residue was purified by silica gel column chromatography (dichloromethane/hexane = 1/1). 4.3 g of Intermediate 23 was obtained as a yellow solid.

[Formula 43]

Intermediate 23 (4.3 g), 2.7 g of bis(pinacholate)diborone, 2.7 g of potassium acetate, and 400 ml of dehydrated dimethyl sulfoxide were added to the reaction vessel under a nitrogen stream, and nitrogen was bubbled for 30 minutes. After that, [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. After that, it was cooled to room temperature, and 500 ml of water and 500 ml of dichloromethane were added to separate and wash the organic layer, followed by drying the organic layer with magnesium sulfate. Afterwards, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane/dichloromethane/ethyl acetate = 60/30/1 to 70/0/30) to obtain Intermediate 24 (2.5 g) as a yellow solid.

[Formula 44]

Under a nitrogen stream, 10.4 g of 3,5-dibromobenzonitrile, 7.6 g of m-biphenylboronic acid, 50 ml of 2M aqueous solution of potassium phosphate, 60 ml of toluene, and 30 ml of ethanol were added to the reaction vessel, and nitrogen was added to 30 ml. Minutes were bubbled. After that, 1.2 g of [Pd(PPh ₃ ) ₄ ] was added while stirring, and the mixture was stirred and refluxed at 100°C for 2 hours. Afterwards, it was cooled to room temperature, water was added, liquid separation and washing were performed, and the organic layer was dried over magnesium sulfate. Afterwards, the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (dichloromethane/hexane = 3/7) to obtain Intermediate 25 (8.2 g) as a colorless oily substance.

[Formula 45]

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

＜Reference Example 1＞

Compound D-9, synthesized in a similar manner to Compound D-1, rapidly precipitated when a 1 wt% solution of phenylcyclohexane adjusted at 100°C was cooled to room temperature. It had very low solubility and could not be used as ink.

[Formula 46]

＜Manufacture of organic electroluminescent device 1＞

An organic electroluminescent device having the structure shown in FIG. 1 was manufactured by the following method. However, the iridium atom concentration in the light emitting 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 be approximately 0.19 mmol/g.

(Example 1)

On the glass substrate (1), an indium tin oxide (ITO) transparent conductive film was deposited to a thickness of 70 nm (manufactured by Geomatec, sputter deposition product), and a 2 mm thick film was deposited using a conventional photolithography technique and hydrochloric acid etching. The anode (2) was formed by patterning into stripes of different widths. The patterned ITO substrate was cleaned in the following order: ultrasonic cleaning with an aqueous surfactant solution, washing with ultrapure water, ultrasonic cleaning with ultrapure water, and washing with ultrapure water, followed by drying with compressed air, and finally ultraviolet ozone cleaning. . This ITO functions as the transparent electrode 2.

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

[Formula 47]

＜Coating liquid for forming hole injection layer＞

Solvent Ethyl benzoate

Coating solution concentration P-1 2.5 mass%

A-1 0.4% by mass

<Film formation conditions of hole injection layer (3)>

Waiting for spin court atmosphere

Heating conditions 240℃ 1 hour in dry air

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

[Formula 48]

＜Coating liquid for forming hole transport layer＞

Solvent Phenylcyclohexane

Coating liquid concentration 1.0 mass%

＜Tabernacle conditions＞

Spin coat in dry nitrogen atmosphere

Heating conditions: 230°C, 1 hour (under dry nitrogen)

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

[Formula 49]

＜Coating liquid for forming light-emitting layer＞

Solvent phenylcyclohexane: 1900 parts by mass

Emitting layer composition H-1: 45 parts by mass

H-2: 55 parts by mass

D-1: 14.8 parts by mass

＜Tabernacle conditions＞

Spin coat in dry nitrogen atmosphere

Heating conditions: 120°C × 20 minutes (under dry nitrogen)

Here, the substrate on which the light-emitting layer has been deposited is transferred into a vacuum deposition device, and the vacuum inside the device is evacuated until the degree of vacuum becomes ^2.0 It was controlled in the range of Å/sec and laminated on the light emitting layer to obtain a hole blocking layer 6 with a film thickness of 10 nm.

[Formula 50]

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

[Formula 51]

Here, the element on which the electron transport layer 7 has been deposited is taken out, installed in another deposition apparatus, and a stripe-shaped shadow mask with a width of 2 mm is used as a mask for cathode deposition, orthogonal to the ITO stripe of the anode 2. Exhaust was carried out by keeping the device in close contact with the device.

As the electron injection layer 8, lithium fluoride (LiF) was first formed into a film on the electron transport layer 7 with a film thickness of 0.5 nm using a molybdenum boat. Next, aluminum as the cathode 9 was similarly heated using a molybdenum boat to form an aluminum layer with a film thickness of 80 nm. The substrate temperature during 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 air during storage, a sealing treatment was performed using the method described below.

In a nitrogen glove box, photocurable resin 30Y-437 (manufactured by Three Bond Company) was applied to the outer periphery of a glass plate of size 23 mm was installed. On this, the substrate on which the cathode formation was completed was bonded so that the vapor-deposited surface faced the desiccant sheet. Afterwards, ultraviolet light was irradiated only to the area where the photocurable resin was applied, and the resin was cured.

As described above, an organic electroluminescent element having a light emitting area portion of 2 mm x 2 mm in size was obtained.

(Example 2)

In Example 1, the compound D-1 used in forming the light-emitting layer was changed to compound D-4, and the concentration in the coating liquid for forming the light-emitting layer was changed to 16.5 parts by mass. The organic electroluminescent device shown in 1 was manufactured.

(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 formula below, and the concentration in the coating liquid for forming the light-emitting layer was changed to 14.7 parts by mass. In the same manner, the organic electroluminescent device shown in FIG. 1 was manufactured.

[Formula 52]

(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 formula below, and the concentration in the coating liquid for forming the light-emitting layer was changed to 15.0 parts by mass. In the same manner, the organic electroluminescent device shown in FIG. 1 was manufactured.

[Formula 53]

(Example 3)

The organic electroluminescent device shown in FIG. 1 was manufactured in the same manner as in Example 1, except that the concentration of the light-emitting material in the coating liquid for forming the light-emitting layer was changed to 34.6 parts by mass.

(Example 4)

The organic electroluminescent device shown in FIG. 1 was manufactured in the same manner as in Example 2, except that the concentration of the light-emitting material in the coating liquid for forming the light-emitting layer was changed to 38.5 parts by mass.

(Comparative Example 3)

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

(Comparative Example 4)

In Comparative Example 2, the organic electroluminescent device shown in FIG. 1 was manufactured in the same manner as in Example 2, except that the concentration of the light-emitting material in the coating liquid for forming the light-emitting layer was changed to 35.0 parts by mass.

The performance of the devices obtained in this way is shown in Tables 1 and 2.

In Table 1, the luminous efficiency (cd/A) when 10 mA/cm2 current is applied to the device is shown as a relative value with Comparative Example 1 set to 100.

It can be seen that the luminous efficiency is high for both devices in which the light-emitting layer is doped with the compound of the present invention at a normal dope concentration and devices in which the light-emitting layer is doped at a heavy dope concentration. In Table 2, the initial luminance (cd/m2) when energizing the device at 15 mA/cm2 is relative to Comparative Example 1 as 100, and the luminance after driving the device at a constant current of 15 mA/cm2 for 120 hours. The luminance maintenance rate is obtained by dividing by the initial luminance, and the relative value when the luminance retention rate of Comparative Example 1 is set to 100 is shown.

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 dope concentration and devices in which the light emitting layer was doped at a heavy dope concentration had a high operating life. .

In particular, it was found that a device in which the light-emitting layer was doped with the compound of the present invention at a heavy dope concentration had high luminous efficiency and a high driving life.

＜Storage stability of coating liquid for forming luminescent layer＞

In the storage stability test of the coating liquid, if it was visually confirmed that there was no cloudiness in the liquid and that the Tyndall phenomenon was not observed by irradiating red laser light, it was judged that the solution was maintained in a uniform state.

(Example 5) The coating liquid for forming an emitting layer prepared in the same manner as in Example 3 was heated at 150°C for 30 minutes, confirmed to be uniform, and left at 45°C for 4 hours. As a result, the uniformity was maintained. there was.

(Example 6) The coating liquid for forming the light emitting layer prepared in the same manner as in Example 4 was heated at 150°C for 30 minutes, confirmed to be uniform, and left to stand at 45°C for 4 hours. As a result, the uniformity was maintained.

(Example 7) Formation of a light-emitting layer prepared in the same manner as in Example 5, except that Compound D-1 was changed to Compound D-7 and the concentration in the coating liquid for forming the light-emitting layer was changed to 44.4 parts by mass. The coating solution was heated at 150°C for 30 minutes, confirmed to be uniform, and then allowed to stand at 45°C for 4 hours. As a result, the uniformity was maintained.

(Example 8) Formation of a light-emitting layer prepared in the same manner as in Example 5, except that Compound D-1 was changed to Compound D-8 and the concentration in the coating liquid for forming the light-emitting layer was changed to 39.8 parts by mass. The coating liquid was heated at 150°C for 30 minutes, confirmed to be uniform, and then allowed to stand at 45°C for 4 hours. As a result, the uniformity was maintained.

(Reference Example 2) The coating liquid for forming the light emitting layer prepared in the same manner as in Comparative Example 3 was heated at 150°C for 30 minutes, confirmed to be uniform, and left to stand at 45°C for 4 hours. As a result, the uniformity was maintained.

(Comparative Example 5) The coating liquid for forming an emitting layer prepared in the same manner as in Comparative Example 4 was heated at 150°C for 30 minutes, confirmed to be uniform, and left to stand at 45°C for 4 hours. As a result, precipitation of solids was confirmed.

(Comparative Example 6) In the same manner as Comparative Example 3, except that Compound D-5 was changed to Compound D-10 shown in the formula below, and the concentration in the coating liquid for forming the emitting layer was changed to 47.0 parts by mass. The prepared coating liquid for forming a light emitting layer was heated at 150°C for 30 minutes, confirmed to be uniform, and then allowed to stand at 45°C for 4 hours. As a result, precipitation of solids was confirmed.

＜Compound D-10＞

[Formula 54]

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

＜Compound D-11＞

[Formula 55]

The above results are shown in Table 3.

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

＜Manufacture of organic electroluminescent devices 2＞

(Example 9)

An organic electroluminescent device having the structure shown in FIG. 1 was manufactured by the following method. However, the iridium atom concentration in the light emitting layer was adjusted to be approximately 0.19 mmol/g.

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

Next, an arylamine polymer shown in the structural formula (P-3) below, 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate and benzoic acid shown in the structural formula (A-1) above. A coating liquid for forming a hole injection layer containing ethyl was prepared. This coating liquid was formed into a film on the anode by spin coating under the following conditions to obtain a hole injection layer 3 with a film thickness of 29 nm.

[Formula 56]

＜Coating liquid for forming hole injection layer＞

Solvent Ethyl benzoate

Coating solution concentration P-3 2.0 mass%

A-1 0.4% by mass

<Film formation conditions of hole injection layer (3)>

Waiting for spin court atmosphere

Heating conditions 230℃ 1 hour in dry air

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

[Formula 57]

＜Coating liquid for forming hole transport layer＞

Solvent Phenylcyclohexane

Coating liquid concentration 1.5% by mass

＜Tabernacle conditions＞

Spin coat in dry nitrogen atmosphere

Heating conditions: 230°C, 1 hour (under dry nitrogen)

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

(Example 10)

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

(Example 11)

The organic electroluminescent device shown in FIG. 1 was manufactured in the same manner as in Example 9, except that the coating liquid for forming the light-emitting layer was changed to the composition of Example 7.

(Comparative Example 8)

The organic electroluminescent device shown in FIG. 1 was manufactured in the same manner as in Example 9, except that the coating liquid for forming the light-emitting layer was changed to the composition of Comparative Example 3.

The device obtained in this way was driven at a constant current of 15 mA/cm2, the time when the luminance decreased to 90% was determined as LT90 (h), and the relative values when LT90 of Comparative Example 8 was set to 100 are shown in Table 4. indicates.

Compound D-5 used in Comparative Example 8, as shown in Reference Example 2, had good storage stability as a coating liquid for forming a light-emitting layer, but its operating life was inferior to that of Examples 9 to 11, making the compound of the present invention It was found that by using it in the light-emitting layer, it was possible to achieve both excellent storage stability as a coating liquid for forming a light-emitting layer and a high operating life as a device.

(Example 12)

In Example 9, the organic electroluminescent device shown in FIG. 1 was manufactured in the same manner as in Example 9 except that the coating liquid for forming the light emitting layer was changed to the composition of Example 8. As a result, the maximum wavelength of the device was 517 nm. .

Although the present invention has been described in detail and with reference to specific embodiments, it is clear to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Japanese patent application 2015-110255) filed on May 29, 2015, the contents of which are incorporated herein by reference.

The present invention relates to materials for organic devices, including organic electroluminescent devices, as well as various fields in which organic electroluminescent devices are used, such as flat panels and displays (for example, for OA computers and wall-mounted TVs) and as surface light emitters. It can be suitably used in fields such as light sources (for example, light sources of copiers, backlight light sources of liquid crystal displays or instruments), display boards, sign lights, and lighting devices.

1: substrate
2: anode
3: hole injection layer
4: hole transport layer
5: light emitting layer
6: hole blocking layer
7: electron transport layer
8: electron injection layer
9: cathode

Claims (9)

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

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

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

In formula (3), k represents an integer of 0 to 5.
y represents an integer from 1 to 10.
* indicates a binding hand.
R has the same meaning as equation (2),
R" may be the same or different depending on its appearance, 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, an alkyl group having 1 to 20 carbon atoms, or a naph that may be substituted with an aryl group. It is selected from a til group or a heteroaryl group having 1 to 20 carbon atoms.
The groups of R ¹ to R ⁴ , excluding the groups represented by the formulas (2) and (3), are also an alkyl group of 1 to 30 carbon atoms which may be further substituted with a fluorine atom, a chlorine atom, a bromine atom or a fluorine atom, It may be further substituted with an alkyl group with 1 to 30 carbon atoms, an aryl group with 3 to 30 carbon atoms, or an arylamino group with 3 to 30 carbon atoms.
When there are multiple R ¹ to R ⁴ , each may be the same or different.
When a plurality of R ¹ to R ⁴ are adjacent to each other on the same ring, the adjacent R ¹ to R ⁴ are directly bonded to each other or are connected to 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. Rings may be formed by bonding through a 12-membered arylene group, and these rings may be an alkyl group with 1 to 30 carbon atoms or an alkyl group with 1 to 30 carbon atoms that may be further substituted with a fluorine atom, a chlorine atom, a bromine atom or a fluorine atom. It may be substituted with an alkoxy group, an aryloxy group with 3 to 30 carbon atoms, an alkyl group with 1 to 30 carbon atoms, an aryl group with 3 to 30 carbon atoms, or an arylamino group with 3 to 30 carbon atoms.
In addition, R ¹ and R ² or R ³ and R ⁴ are directly bonded or bonded through an alkylene group with 3 to 12 carbon atoms, an alkenylene group with 3 to 12 carbon atoms, or an arylene group with 6 to 12 carbon atoms, forming a ring. These rings may be formed of a fluorine atom, a chlorine atom, a bromine 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, which may be further substituted with a fluorine atom, It may be further substituted with an alkyl group with 1 to 30 carbon atoms, an aryl group with 3 to 30 carbon atoms, or an arylamino group with 3 to 30 carbon atoms. According to claim 1,
An iridium complex compound in which the formula (2) is represented by the formula (4), and the formula (3) is represented by the 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.
* indicates a binding hand.
R, R' and h have the same meaning as in equation (2).

s represents an integer from 0 to 2,
t represents an integer from 1 to 10,
u represents an integer from 0 to 2,
w represents an integer from 0 to 4,
s+t+u+w is an integer from 1 to 10.
* indicates a binding hand.
R, R" and k have the same meaning as in equation (3). A composition containing the iridium complex compound according to claim 1 or 2 and an organic solvent. An organic electroluminescent device comprising the iridium complex compound according to claim 1 or 2. A display device having the organic electroluminescent element according to claim 4. A lighting device having the organic electroluminescent element according to claim 4. delete delete delete

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