JP6835326B2 - Heteroreptic iridium complex, and light emitting materials and organic light emitting devices using the compound. - Google Patents

Description

The present disclosure relates to a novel red-emitting heteroreptic iridium complex useful as a light-emitting material for an organic light-emitting device (organic electroluminescent device, organic electrochemiluminescent device, etc.) and an organic light-emitting device using the compound.

In recent years, organic electroluminescent devices represented by organic electroluminescent devices have been attracting attention as display or lighting technology, and research for practical use is being actively promoted. In particular, improvement of luminous efficiency is an important research subject, and at present, as a light emitting material, a phosphorescent material that utilizes light emission from an excited triplet state is attracting attention.

When light emission from the excited singlet state is used, the generation ratio of the singlet exciton and the triplet exciton is 1: 3, so that the generation probability of the luminescent exciton is 25%. Further, since the light extraction efficiency is about 20%, the limit of the external extraction quantum efficiency is set to 5%. On the other hand, if the excited triplet state can also be used, the upper limit of the internal quantum efficiency is 100%, so that the luminous efficiency is quadrupled in principle as compared with the case of the excited singlet. Against this background, the development of phosphorescent materials for organic light emitting devices has been actively carried out. For example, as a phosphorescent material, a green luminescent iridium complex having a 2-phenylpyrimidine ligand is disclosed (see, for example, Patent Document 1). Further, a 2-phenylpyrimidine-based iridium complex having excellent solubility and suitable for a coating process is disclosed (see, for example, Patent Document 2).

JP-A-2009-40728 International Publication No. 2011/024737 Pamphlet International Publication No. 2012/172482 Japanese Unexamined Patent Publication No. 2004-189673 JP-A-2009-108041 Japanese Unexamined Patent Publication No. 2014-101307 International Publication No. 2012/166608 International Publication No. 2010/056669 International Publication No. 2010/111755 International Publication No. 2012/158851 International Publication No. 2010/028151

Tamayo A. B. J. Am. Chem. Soc. , 2003, 125, 7377

On the other hand, as a phosphorescent material suitable for the vacuum vapor deposition process, it is generally desirable that the phosphorescent material has excellent thermal stability and particularly good sublimation property. If the phosphorescent material has excellent sublimation properties, it is possible to further improve the compound purity by sublimation purification, and it is possible to stably produce an organic light emitting device by using vacuum deposition. is there. In the future, the development of phosphorescent materials having excellent thermal stability and sublimation properties is eagerly desired for the practical use of organic light emitting devices.

An object of the present disclosure is to provide a novel red-emitting heteroreptic iridium complex that can be applied to an organic electroluminescent device, an organic electrochemiluminescent device, or the like, is thermally stable, and has excellent sublimation properties. ..

As a result of intensive research in view of the above-mentioned actual conditions, the present inventors have shown that the iridium complex represented by the general formula (1) emits strong light in the visible light region (mainly the red region) at room temperature, and further heat. It was found that it is stable and has excellent sublimation properties. Then, it was demonstrated that an organic light emitting device exhibiting high luminous efficiency can be produced using the iridium complex of the present invention, and the present invention has been completed.

That is, according to this application, the following invention is provided.

（一般式（１）中、Ｎは窒素原子を表し、Ｉｒはイリジウム原子を表す。Ｒ^１〜Ｒ^１１、Ｒ^１３、Ｒ^１４およびＲ^１８は、各々独立に、水素原子、炭素数１〜３０のアルキル基、炭素数６〜３０のアリール基、ハロゲン原子またはシアノ基を表す。Ｒ^１２、Ｒ^１５〜Ｒ^１７およびＲ^１９は、各々独立に、水素原子、炭素数１〜３０のアルキル基、ハロゲン原子またはシアノ基を表す。上記アルキル基はアリール基、ハロゲン原子またはシアノ基で置換されてもよい。上記アリール基はアルキル基、ハロゲン原子またはシアノ基で置換されてもよい。但し、隣接するＲ^１２とＲ^１３、Ｒ^１３とＲ^１４、または、Ｒ^１４とＲ^１５の何れか１つが、各々結合して縮合環を形成している。ｍは１または２の整数であり、ｎは１または２の整数であり、ｍ＋ｎは３である。） The iridium complex according to the present invention is characterized by being represented by the following general formula (1).

(In the general formula (1), N represents a nitrogen atom and Ir represents an iridium atom. R ^{1 to} R ¹¹ , R ¹³ , R ¹⁴ and R ¹⁸ are independently hydrogen atoms and 1 to 30 carbon atoms, respectively. Represents an alkyl group, an aryl group having 6 to 30 carbon atoms, a halogen atom or a cyano group. R ¹² , R ^{15 to} R ¹⁷ and R ¹⁹ are independently hydrogen atoms and alkyl groups having 1 to 30 carbon atoms. Represents a halogen atom or a cyano group. The alkyl group may be substituted with an aryl group, a halogen atom or a cyano group. The aryl group may be substituted with an alkyl group, a halogen atom or a cyano group, provided that they are adjacent to each other. Any one of R ¹² and R ¹³ , R ¹³ and R ¹⁴ , or R ¹⁴ and R ¹⁵ is bonded to form a fused ring. M is an integer of 1 or 2, and n is 1. Or it is an integer of 2 and m + n is 3.)

In the iridium complex according to the present invention, R ^{12 to} R ¹⁹ are preferably hydrogen atoms or alkyl groups having 1 to 30 carbon atoms.

In the iridium complex according to the present invention, ^{it is preferable that R 12} and R ¹³ are bonded to form a condensed ring.

In the iridium complex according to the present invention, ^{it is preferable that R 14} and R ¹⁵ are bonded to form a condensed ring.

In the iridium complex according to the present invention, it is preferable that at least one of ^{R 12 to} R ^{19 is a halogen atom.}

In the iridium complex according to the present invention, ^{it is preferable that R 4} , R ⁵ , R ⁹ and R ¹⁰ are all hydrogen atoms.

In the iridium complex according to the present invention, m is preferably 2 and n is preferably 1.

In the iridium complex according to the present invention, m is preferably 1 and n is preferably 2.

The iridium complex according to the present invention is preferably a facial form.

The light emitting material according to the present invention is characterized by containing the iridium complex according to the present invention.

The organic light emitting device according to the present invention is characterized by containing the light emitting material according to the present invention.

According to the present disclosure, it is possible to provide a novel heteroreptic iridium complex having a red luminescence that is thermally stable and has excellent sublimation properties, which can be applied to an organic electroluminescent device, an organic electrochemiluminescent device, and the like.

The novel iridium complex of the present disclosure exhibits strong light emission in the visible light region (mainly the red region) at room temperature, and is excellent in thermal stability and sublimation, and is therefore suitable as a light emitting device material for various applications. Can be used for. Further, an organic light emitting device using the compound exhibits high-luminance light emission in a visible light region, and is therefore suitable for fields such as display elements, displays, backlights, and illumination light sources.

It is an EL spectrum of an organic electroluminescent device produced using the compound of the present invention (K-16) which is a facial body.

Next, the present invention will be described in detail by showing embodiments, but the present invention is not construed as being limited to these descriptions. The embodiments may be modified in various ways as long as the effects of the present invention are exhibited.

The hydrogen atom in the description of the general formula of the present invention also contains an isotope (deuterium atom, etc.), and the atom constituting the substituent also contains the isotope.

The iridium complex according to the present invention is represented by the general formula (1), and by incorporating these iridium complexes into the light emitting layer of the organic light emitting element or a plurality of organic compound layers including the light emitting layer by a vacuum vapor deposition method or the like, the iridium complex is mainly contained. An organic light emitting element exhibiting excellent light emission in the red region can be obtained.

Hereinafter, the present invention will be described in more detail.

The iridium complex of the present invention represented by the general formula (1) is specifically represented by a 2-phenylpyrimidine derivative ligand represented by the general formula (2) and a 2-phenylpyrimidine derivative represented by the general formula (3). It is a heteroreptic iridium complex having a specific structure having a phenylpyridine derivative ligand.

In the general formula (2) and ^(3), R 1 ^{to R 19} are the same as ^R 1 ^{to R 19} in the general formula (1), it is also desirable range same. * Is the bond position with iridium.

（一般式（４）中、Ｎは窒素原子を表し、Ｉｒはイリジウム原子を表す。Ｒ^１〜Ｒ^１１は、一般式（１）中のＲ^１〜Ｒ^１１と同義であり、望ましい範囲も同じである。） So far, a conventionally known 2-phenylpyrimidine-based homoreptic iridium complex represented by the general formula (4) has been known, but according to the findings of the present inventors, this iridium complex has poor sublimation property. Since decomposition is involved in the vacuum deposition process, improving sublimation has been a major issue.

(In the general formula (4), N represents a nitrogen atom, Ir ^.R 1 ^{to R 11} representing an iridium atom is represented by the general formula (1) has the same meaning as ^R 1 ^{to R 11} in the desired range is also the same Is.)

Further, a phosphorescent material that emits light in the red region (for example, an iridium complex having a 1-phenylisoquinoline ligand) has low sublimation property, and a large amount of residue is generated during sublimation purification. There is.

Based on the above technical background, the present inventors have enthusiastically developed a phosphorescent material having excellent thermal stability and sublimation property, and as a result, the heteroreptic iridium complex having a novel structure represented by the general formula (1) has been developed. However, it emits strong light in the visible light region (mainly the red region) at room temperature, and is particularly superior in thermal stability and sublimation property to the conventionally known homoreptic iridium complex represented by the general formula (4). I found that. Then, it was demonstrated that the iridium complex represented by the general formula (1) can be suitably used as a phosphorescent material for an organic light emitting device, and the present invention was conceived.

The homoreptic iridium complex represented by the general formula (4) is characterized by having three of the same cyclometallated ligands, but because of its high symmetry, it has good crystallinity in the solid state, and therefore the complex. There was a problem that the energy to connect them was large and the sublimation temperature became high. On the other hand, the compound of the present invention represented by the general formula (1) is a heterorep having different types of cyclometallated ligands (ligands represented by the general formulas (2) and (3)). The present inventors consider that the tick iridium complex has low crystallinity in a solid state due to its low symmetry, the energy for binding the complexes to each other is small, and the sublimation property is improved.

Further, as an essential feature of the 2-phenylpyrimidine-based ligand, since the pyrimidine ring has two nitrogen atoms, there are a plurality of binding sites for iridium, which is a central metal. According to the findings of the present inventors, it has been found that this may cause a dimer complex (such as a dimer) to be formed, which may reduce the yield of the desired iridium complex. Therefore, by using the 2-phenyl-pyrimidine ligand having a specific structure represented by the general formula (2) in the present invention, the steric effect of the adjacent phenyl group, a bond with iridium at the position of R ⁴ It is also characterized by preventing and suppressing the formation of dinuclear complexes.

Among the iridium complexes represented by the general formula (1) according to the present invention, the emission quantum yield in a solution or a thin film state at room temperature is preferably 0.1 or more, preferably 0.4 or more. It is more preferable, and 0.6 or more is particularly preferable.

The luminescence quantum yield in the solution is measured after aerating argon gas or nitrogen gas into the solution in which the iridium complex is dissolved in order to remove dissolved oxygen, or after freezing and degassing the solution in which the luminescent material is dissolved. Good to do. As a method for measuring the emission quantum yield, either an absolute method or a relative method may be used. In the relative method, the emission quantum yield can be measured by comparing the emission spectrum with a standard substance (kinin sulfate or the like). In the absolute method, it is possible to measure the emission quantum yield in a solid state or in a solution by using a commercially available device (for example, an absolute PL quantum yield measuring device (C9920-02) manufactured by Hamamatsu Photonics Co., Ltd.). Is. The emission quantum yield in the solution can be measured using various solvents, but the iridium complex according to the present invention may achieve the above emission quantum yield in any of any solvents.

For the measurement of the emission quantum yield in the thin film state, for example, the iridium complex of the present invention is vacuum-deposited on quartz glass, and a commercially available device (for example, an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd.) ) Can be used. The emission quantum yield in a thin film can be measured by vapor-depositing the iridium complex of the present invention alone or by co-depositing with various host materials, but the iridium complex according to the present invention is described above under any of the conditions. It suffices if the emission quantum yield is achieved.

The iridium complex according to the present invention emits light mainly in the visible light region (particularly in the red region), and the wavelength region depends on the type or structure of the ligand. In particular, the maximum emission wavelength of the emission spectrum in a solution or a thin film at room temperature is preferably in the range of 580 nm to 900 nm, more preferably in the range of 580 nm to 800 nm, and in the range of 600 nm to 700 nm. Is particularly preferable, and the range of 600 nm to 650 nm is more particularly preferable.

The iridium complex according to the present invention is an octahedral hexacoordinated complex, and there are a facial form and a meridional form as geometric isomers. In fact, when synthesizing the iridium complex according to the present invention, it may be obtained as a mixture of a facial form and a meridional form. These geometric isomers can be separated, for example, by column chromatography or sublimation purification. The iridium complexes represented by the general formulas (5) and (6) and the iridium complexes represented by the general formulas (7) and (8) are in a geometric isomer relationship, respectively. The iridium complexes represented by the general formulas (5) and (7) are facials, and the iridium complexes represented by the general formulas (6) and (8) are meridionals.

（一般式（５）〜（８）中、Ｎは窒素原子を表し、Ｉｒはイリジウム原子を表す。Ｒ^１〜Ｒ^１９は、一般式（１）中のＲ^１〜Ｒ^１９と同義であり、望ましい範囲も同じである。）

(In the general formula (5) ~ (8), N represents a nitrogen atom, Ir is ^.R 1 ^{to R 19} representing iridium atom, in the formula (1) it has the same meaning as ^R 1 ^{to R 19} of The desired range is the same.)

So far, there have been various reports on the emission characteristics of the facial and meridional forms of the cyclometallated iridium complex, but there are cases where the facial form has a higher emission quantum yield (for example, Tamayo A.B.J. Am. It is known that there are cases in which the meridional form is higher (for example, International Publication No. 2012/172482 (Patent Document 3)) in some cases (Chem. Soc., 2003, 125, 7377 (Non-Patent Document 1)). ing.

When the present inventors investigated in detail the luminescence characteristics of the geometric isomer of the iridium complex represented by the general formula (1) according to the present invention, the facial isomer was compared with the meridional isomer and the luminescence quantum. It turned out that the yield was overwhelmingly high.

Therefore, the iridium complex represented by the general formula (1) according to the present invention is preferably a facial compound. The iridium complex according to the present invention preferably contains 50% or more of the facial compound, more preferably 80% or more, particularly preferably 90% or more, and 99% or more. It is more preferable that it is. The facial form or meridional form can be identified by NMR, mass spectrometry, X-ray crystal structure analysis, or the like. The content can be quantified by NMR or HPLC.

The meridional form of the iridium complex represented by the general formula (1) according to the present invention can be isomerized to a facial form. In particular, it is desirable to photoisomerize as shown in the formulas (A) and (B).

（式（Ａ）および（Ｂ）中、Ｎは窒素原子を表し、Ｉｒはイリジウム原子を表す。Ｒ^１〜Ｒ^１９は、一般式（１）中のＲ^１〜Ｒ^１９と同義であり、望ましい範囲も同じである。）

(In the formula (A) and (B), N represents a nitrogen atom, Ir is ^.R 1 ^{to R 19} representing iridium atom, in the formula (1) has the same meaning as ^R 1 ^{to R 19} of the desired The range is the same.)

For the photoisomerization reaction of the meridional form, refer to JP-A-2004-189673 (Patent Document 4), JP-A-2009-108041 (Patent Document 5), JP-A-2014-101307 (Patent Document 6), and the like. It can be done with reference.

The photoisomerization reaction of the meridional form will be described in more detail. It is characterized in that a meridional form or a solution containing the meridional form is irradiated with light to isomerize it into a facial form.

As the method of irradiating light, the method may be limited as long as the meridional body is exposed to light. The reaction solution containing the mixture of the meridional form and the facial form may be irradiated with light.

The photoisomerization reaction of the meridional form is preferably carried out in solution. As such a solvent, a solvent capable of dissolving the meridional compound is preferable, and a solvent that does not react with the raw material and the product is used. Specifically, saturated aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane or tridecane, halogenated aliphatic hydrocarbons such as dichloromethane, chloroform or dichloroethane, ketones such as acetone or methyl ethyl ketone, N, N. -Amids such as dimethylformamide or N-methylpyrrolidone, esters such as ethyl acetate or butyl acetate, aromatic hydrocarbons such as benzene or toluene, halogenated aromatic hydrocarbons such as chlorobenzene or dichlorobenzene, pyridine or picolin, etc. Nitrogen-containing aromatic compounds, ethers such as tetrahydrofuran (THF), dioxane or diethyl ether, nitriles such as acetonitrile, propionitrile or benzonitrile, alcohols such as methanol, ethanol, propanol, butanol or ethylene glycol, or Examples include various organic solvents such as dimethylsulfoxide. Of these, halogenated aliphatic hydrocarbons, ethers or dimethyl sulfoxide are preferable. Specific preferred solvents include dichloromethane, chloroform, tetrahydrofuran or dimethyl sulfoxide, more preferably dichloromethane, tetrahydrofuran or dimethyl sulfoxide, and particularly preferably tetrahydrofuran.

The photoisomerization reaction of the meridional is not particularly limited as long as the light irradiation is uniformly performed, but it is usually carried out at a concentration of 1 mol / L or less, preferably at a concentration of 0.01 mol / L or less. Is desirable. The lower limit of the concentration is not particularly limited, but is preferably 0.0001 mol / L or more.

The reaction vessel used for light irradiation may be any container as long as it can be irradiated with light, but a glass container, for example, a Pyrex® reaction vessel or a quartz reaction vessel having high UV permeability is used. Especially preferable.

The conditions for light irradiation are not particularly limited as temperature conditions, but usually, between the freezing point of the solvent used and the boiling point of the solvent, preferably −75 ° C. to the boiling point of the solvent, more preferably −5 ° C. to It is 50 ° C.

Light irradiation and post-treatment after light irradiation can be performed under atmospheric pressure, an atmosphere of an inert gas such as nitrogen or argon, or under reduced pressure or vacuum, but for light irradiation, nitrogen or argon or the like can be used. It is more preferable to carry out in an inert gas atmosphere.

The pressure condition is not particularly limited, but it is usually carried out under normal pressure.

The wavelength of the light used for light irradiation may be any wavelength that can be absorbed by the meridional body, and light in the range from ultraviolet light to visible light is preferable. Specifically, it is preferably 200 to 800 nm, more preferably 200 to 600 nm, particularly preferably 300 to 500 nm, and even more preferably 300 to 450 nm.

As the method of light irradiation, for example, the method described in "Photochemistry I" (author: Haruo Inoue et al., Publisher: Maruzen Co., Ltd.) may be referred to, and an external irradiation method of irradiating from the outside of the reaction vessel or an external irradiation method may be used. , Either of the internal irradiation method of irradiating from the inside of the reaction vessel.

Since the light irradiation time required for the reaction largely depends on the type of the iridium complex or the reaction conditions, it may be appropriately determined while tracking the reaction using a method such as absorption spectrum, emission spectrum, HPLC or mass spectrometry. Specifically, 1 minute to 5 days is preferable, 1 minute to 72 hours is more preferable, 1 hour to 48 hours is particularly preferable, and 1 hour to 24 hours is particularly preferable.

The type of lamp used for light irradiation is not particularly limited, but high-pressure mercury lamp, low-pressure mercury lamp, ultra-high-pressure mercury lamp, halogen lamp, xenon lamp, laser, sunlight, incandescent bulb, deuterium lamp, UV lamp, etc. Can be mentioned.

^{The symbols (m, n, and R 1 to} R ¹⁹ ) described in the general formula (1) will be described below.

In the general formula (1), m is an integer of 1 or 2, n is an integer of 1 or 2, and m + n is 3. That is, when m is 1, n is 2, and when m is 2, n is 1.

R ^{1 to} R ¹¹ , R ¹³ , R ¹⁴ and R ¹⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, a halogen atom or a cyano group.

R ¹² , R ^{15 to} R ¹⁷ and R ¹⁹ each independently represent a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a halogen atom or a cyano group.

Further, any one of the adjacent R ¹² and R ¹³ , R ¹³ and R ¹⁴ , or R ¹⁴ and R ¹⁵ is bonded to each other to form a fused ring.

The alkyl group having 1 to 30 carbon atoms preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, particularly preferably 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms.

As the alkyl group having 1 to 30 carbon atoms, preferably, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an s-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group and an n- Hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n- Hexadecyl group, n-heptadecyl group, n-octadecyl group, neopentyl group, 1-methylpentyl group, 1-pentylhexyl group, 1-butylpentyl group, 1-heptyloctyl group, cyclohexyl group, cyclooctyl group, or 3, It is a 5-tetramethylcyclohexyl group. More preferably, it is a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an s-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, a neopentyl group, or a 1-methylpentyl group. .. A methyl group is particularly preferable. The alkyl group may be further substituted with an aryl group, a halogen atom or a cyano group, and an alkyl group substituted with fluorine is particularly preferable because the sublimation property of the iridium complex is improved.

The aryl group having 6 to 30 carbon atoms is preferably 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.

The tolyl group having 6 to 30 carbon atoms is preferably a phenyl group, a biphenyl-2-yl group, a biphenyl-3-yl group, a biphenyl-4-yl group, a p-phenyl-4-yl group, or a p-ter. Phenyl-3-yl group, p-Phenyl-2-yl group, m-Phenyl-4-yl group, m-Phenyl-3-yl group, m-Phenyl-2-yl group, o-tolyl Group, m-tolyl group, p-tolyl group, pt-butylphenyl group, p- (2-phenylpropyl) phenyl group, 4'-methylbiphenylyl group, 4 "-t-butyl-p-terphenyl -4-yl group, o-cumenyl group, m-cumenyl group, p-cumenyl group, 2,3-kisilyl group, 2,4-kisilyl group, 2,5-kisilyl group, 2,6-xsilyl group, 3, , 4-xylyl group, 3,5-xylyl group, mesityl group, m-quarterphenyl group, 1-naphthyl group, or 2-naphthyl group, more preferably phenyl group, o-tolyl group, m-tolyl. Group, p-tolyl group, 2,3-kisilyl group, 2,4-kisilyl group, 2,5-kisilyl group, 2,6-xsilyl group, 3,4-kisilyl group, 3,5-kisilyl group, or It is a mesityl group, particularly preferably a phenyl group. The aryl group may be further substituted with an alkyl group, a halogen atom or a cyano group, and the phenyl group substituted with an alkyl group improves the sublimation property of the iridium complex. It is particularly preferable because it does.

The halogen atom is preferably a chlorine atom, a bromine atom or a fluorine atom. More preferably, it is a bromine atom or a fluorine atom. Particularly preferably, it is a fluorine atom.

Hereinafter, R ^{1 to} R ¹⁹ will be described in more detail.

Among the above, as R ¹ , a hydrogen atom and an alkyl group having 1 to 30 carbon atoms are more preferable, a methyl group or a hydrogen atom is particularly preferable, and a hydrogen atom is more preferable. The desirable range for these substituents is as described above. That is, the alkyl group having 1 to 30 carbon atoms is preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, particularly preferably 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms.

The R ^2, a hydrogen atom among the above-mentioned alkyl group having 1 to 30 carbon atoms or more preferably an aryl group having 6 to 30 carbon atoms, a hydrogen atom or particularly preferably an alkyl group having 1 to 30 carbon atoms, hydrogen Atomic, methyl or ethyl groups are more preferred, and methyl or ethyl groups are most preferred. The desirable range for these substituents is as described above. That is, the alkyl group having 1 to 30 carbon atoms is preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, particularly preferably 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms. The aryl group having 6 to 30 carbon atoms is preferably 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.

As R ^3, a hydrogen atom among the above-mentioned alkyl group having 1 to 30 carbon atoms or more preferably an aryl group having 6 to 30 carbon atoms, a hydrogen atom or particularly preferably an alkyl group having 1 to 30 carbon atoms, hydrogen Atoms are more preferred. The desirable range for these substituents is as described above. That is, the alkyl group having 1 to 30 carbon atoms is preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, particularly preferably 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms. The aryl group having 6 to 30 carbon atoms is preferably 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.

Among the above, as R ⁴ , R ⁵ , R ⁹ , R ¹⁰ or R ¹¹ , a hydrogen atom or an alkyl group having 1 to 30 carbon atoms is more preferable, a methyl group or a hydrogen atom is particularly preferable, and a hydrogen atom is more particularly preferable. preferable. Most preferably, all of R ⁴ , R ⁵ , R ⁹ and R ^{10 are hydrogen atoms.} The desirable range for these substituents is as described above. That is, the alkyl group having 1 to 30 carbon atoms is preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, particularly preferably 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms.

Among the above, R ^{6 to} R ⁸ are more preferably a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms, and particularly a hydrogen atom or an alkyl group having 1 to 30 carbon atoms. Preferably, a hydrogen atom or a methyl group is more preferred. The desirable range for these substituents is as described above. That is, the alkyl group having 1 to 30 carbon atoms is preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, particularly preferably 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms. The aryl group having 6 to 30 carbon atoms is preferably 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.

Among the above, as R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ or R ¹⁹ , a hydrogen atom or an alkyl group having 1 to 30 carbon atoms is more preferable, a hydrogen atom or a methyl group is particularly preferable, and a hydrogen atom is more particularly preferable. preferable. The desirable range for these substituents is as described above. That is, the alkyl group having 1 to 30 carbon atoms is preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, particularly preferably 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms.

Among the above, R ¹³ , R ¹⁴ or R ¹⁸ is more preferably a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms, and a hydrogen atom, a methyl group, or 6 to 30 carbon atoms. Aryl groups are particularly preferred. The desirable range for these substituents is as described above. That is, the alkyl group having 1 to 30 carbon atoms is preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, particularly preferably 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms. The aryl group having 6 to 30 carbon atoms is preferably 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.

Any one of adjacent R ¹² and R ¹³ , R ¹³ and R ¹⁴ , or R ¹⁴ and R ¹⁵ is bonded to each other to form a fused ring. Among these, ^{it is preferable that any one of adjacent R 12} and R ¹³ or R ¹⁴ and R ¹⁵ is bonded to each other to form a fused ring, and R ¹⁴ and R ¹⁵ are bonded to each other. It is more preferable to form a fused ring. Among the condensed rings described above, it is preferable to form a 6-membered ring, and it is more preferable to form a benzene ring.

By forming the ring structure in this way, the stability of the iridium complex can be improved and the emission wavelength can be lengthened. When any one of the adjacent R ¹² and R ¹³ , R ¹³ and R ¹⁴ , or R ¹⁴ and R ¹⁵ is bonded to each other to form a fused ring, the iridium complex of the present invention is mainly in the red region (for example, 580). It shows strong light emission at ~ 800 nm). Further ^{, when any one of R 12} and R ¹³ or R ¹⁴ and R ¹⁵ is bonded to each other to form a fused ring, red light emission with good color purity is exhibited. When R ¹⁴ and R ¹⁵ are combined to form a fused ring, it is more preferable because it exhibits red light emission having particularly good color purity.

When the adjacent Rs ^{12 to} R ¹⁹ are combined to form a fused ring, it is preferably one of the following structures (L-1) to (L-3), and (L-1) or (L-1) or (. It is more preferably any one of L-3), and particularly preferably (L-3).

In the structural formulas (L-1) ~ (L -3), R 1 ~R 19 is synonymous with ^R 1 ^{to R 19} in the general formula (1), it is also desirable range same. R ^{20 to} R ³¹ represent a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, a halogen atom, or a cyano group. Among these, a hydrogen atom or an alkyl group having 1 to 30 carbon atoms is preferable, a hydrogen atom or an alkyl group having 1 to 10 carbon atoms is more preferable, and a hydrogen atom or a methyl group is particularly preferable. , Most preferably a hydrogen atom.

Further, the emission wavelength of the iridium complex can be controlled by a method of introducing a substituent into ^{R 1 to} R ^{19 of the} iridium complex represented by the general formula (1) according to the present invention. For example, the ^{introduction of a fluorine atom into R 16} or R ¹⁸ shifts the emission by a short wavelength. Further, when a ^{trifluoromethyl group or a cyano group is introduced into R 17} , the emission is shifted by a short wavelength.

Further, when a ^{halogen atom (preferably a bromine atom or an iodine atom) is introduced into R 1 to} R ¹⁹ , a Suzuki coupling reaction using a widely commercially available boronic acid compound as represented by the formula (C) is utilized. As a result, a carbon-carbon bond can be formed and various substituents (alkyl group, aryl group, etc.) can be easily introduced, so that it is also useful as a precursor for synthesizing a new iridium complex.

Among the iridium complexes represented by the general formula (1), when R ¹² and R ¹³ are bonded to form a fused ring, the iridium complex represented by the general formula (9) is particularly preferable.

Among the iridium complexes represented by the general formula (1), when R ¹³ and R ¹⁴ are bonded to form a fused ring, the iridium complex represented by the general formula (10) is particularly preferable.

Among the iridium complexes represented by the general formula (1), when R ¹⁴ and R ¹⁵ are bonded to form a fused ring, the iridium complex represented by the general formula (11) is particularly preferable.

^{The symbols (R 1 to} R ³¹ , m, n) described in the general formulas (9) to (11) will be described below.

R ¹ to R ¹⁹ are the same as ^R 1 ^{to R 19} in the general formula (1), it is the same desirable ranges.

R ^{20 to} R ³¹ each independently represent a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, a halogen atom or a cyano group. The definition and desirable range of the above-mentioned substituents are the same as those of R ^{1 to} R ¹⁹ in the general formula (1). R ^{20 to} R ³¹ are preferably a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and particularly preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. It is a methyl group, most preferably a hydrogen atom.

m is an integer of 1 or 2, n is an integer of 1 or 2, and m + n is 3. That is, when m is 1, n is 2, and when m is 2, n is 1.

To produce the iridium complex of the present invention represented by the general formula (1), for example, there is a route of the following formula (D) or formula (E).

Regarding the iridium complex of the present invention represented by the general formula (1), in addition to this, International Publication No. 2012/16666 (Patent Document 7), International Publication No. 2010/056669 (Patent Document 8), International Publication No. 2010 It can be synthesized with reference to known documents such as / 111755 (Patent Document 9) or 2012/158851 (Patent Document 10).

In general, when synthesizing a heteroreptic iridium complex, when different cyclometallated ligands are introduced, ligand scrambling is likely to occur, and the polarities of the generated impurities are similar. Therefore, it is disclosed that separation and purification are extremely difficult (see, for example, International Publication No. 2010/028151 (Patent Document 11)). Specific reaction examples are shown in formulas (F) and (G).

On the other hand, it has been clarified that the iridium complex represented by the general formula (1) according to the present invention is unexpectedly less likely to cause scrambling of the ligand during synthesis. They also found that even if ligand scrambling occurs during synthesis, by-products can be easily separated using, for example, silica gel column chromatography.

Regarding the iridium complex represented by the general formula (1) according to the present invention, two types of ligands represented by the general formulas (2) and (3) (2-phenylpyridine derivative ligand, 2-phenyl). For ligands that have a pyrimidine derivative ligand) and are represented by the general formula (3), adjacent R ¹² and R ¹³ , R ¹³ and R ¹⁴ , or R ¹⁴ and R ¹⁵ Any one of the above is bonded to each other to form a fused ring. As described above, the basic skeletons of the two types of ligands represented by the general formulas (2) and (3) are completely different, and the polarities of the ligands are significantly different. The present inventors also consider that the by-products produced by scrambling can be easily separated and purified.

The iridium complex according to the present invention can be provided after being treated according to a normal post-treatment of a synthetic reaction, and then purified or unpurified if necessary. As the post-treatment method, for example, extraction, cooling, crystallization by adding water or an organic solvent, or an operation of distilling off the solvent from the reaction mixture can be performed alone or in combination. As a purification method, recrystallization, distillation, sublimation, column chromatography and the like can be performed alone or in combination.

Representative examples of the iridium complex represented by the general formula (1) according to the present invention are shown in Tables 1 to 3, but the present invention is not limited thereto.

As described above, the iridium complex represented by the general formula (1) according to the present invention can efficiently emit phosphorescence in the visible light region (mainly the red region) at room temperature. It can be used as a light emitting material or a light emitting substance of an organic light emitting element. Further, an organic light emitting device (preferably an organic electroluminescent device) can be manufactured using the light emitting material composed of the iridium complex of the present invention.

Further, by using the iridium complex represented by the general formula (1) according to the present invention, an organic light emitting device, a light emitting device, or a lighting device having high luminous efficiency can be realized. Further, it is possible to realize an organic light emitting element, a light emitting device, or a lighting device having low power consumption.

When using the iridium complex represented by the general formula (1) according to the present invention, it is desirable to form a layer by vacuum vapor deposition because the iridium complex is thermally stable and has excellent sublimation properties.

Next, an organic electroluminescent device manufactured by using the iridium complex represented by the general formula (1) of the present invention will be described. The organic electroluminescent device is an device in which a plurality of layers of organic compounds are laminated between an anode and a cathode, and preferably contains an iridium complex represented by the general formula (1) as a light emitting material of the light emitting layer. Further, the light emitting layer is generally composed of a light emitting material and a host material.

Typical element configurations of the organic electroluminescent device of the present invention include, for example, the following configurations, but the present invention is not limited thereto.
(1) anode / light emitting layer / cathode (2) anode / light emitting layer / electron transport layer / cathode (3) anode / hole transport layer / light emitting layer / cathode (4) anode / hole transport layer / light emitting layer / electron Transport layer / cathode (5) anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (6) anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode ( 7) Anotopium / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode

Further, a hole blocking layer (also referred to as a hole barrier layer) may be provided between the light emitting layer and the cathode. Further, an electron blocking layer (also referred to as an electron barrier layer) may be provided between the light emitting layer and the anode.

Hereinafter, each layer constituting the organic electroluminescent device of the present invention will be described.

<Light emitting layer>
The light emitting layer is a layer in which electrons and holes injected from the electrodes are recombined and emit light via excitons, and even if the light emitting portion is inside the light emitting layer, the light emitting layer and the adjacent layer It may be the interface of.

The film thickness of the light emitting layer is preferably in the range of 2 nm to 1000 nm, more preferably in the range of 2 to 200 nm, and further preferably in the range of 3 to 150 nm.

In the present invention, the light emitting layer preferably contains a light emitting material and a host material.

As the luminescent material, the iridium complex represented by the general formula (1) according to the present invention may be contained alone or in a plurality of types, and other luminescent materials may be contained. Among the compounds contained in the light emitting layer, the total content of the iridium complex represented by the general formula (1) according to the present invention is preferably 1 to 50% by mass ratio, preferably 1 to 30%. It is more preferable, and it is particularly preferable that it is 5 to 20%.

Specific examples of other luminescent materials include anthracene derivatives, pyrene derivatives, chrysene derivatives, fluorantene derivatives, perylene derivatives, fluorene derivatives, arylacetylene derivatives, styrylarylene derivatives, styrylamine derivatives, arylamine derivatives, boron complexes, and squalium. Examples thereof include derivatives, oxobenzanthracene derivatives, fluorescein derivatives, perylene derivatives, polythiophene derivatives, rare earth complex compounds, iridium complexes, platinum complexes and the like.

The host material is a compound that is primarily responsible for charge injection and transport in the light emitting layer. Further, among the compounds contained in the light emitting layer, the mass ratio in the layer is preferably 20% or more. It is more preferably 50% or more, and particularly preferably 80% or more. Among the compounds contained in the light emitting layer, the upper limit of the content of the host material is preferably 99% or less, more preferably 95% or less, and particularly preferably 90% or less in terms of mass ratio. ..

The excited state energy (T ₁ level) of the host material is higher than _{the excited state energy (T 1} level) of the iridium complex represented by the general formula (1) according to the present invention contained in the same layer. Is preferable.

The host material may be used alone or in combination of two or more. By using a plurality of types of host compounds, charge transfer can be adjusted and the efficiency of the organic electroluminescent device can be improved.

The host material that can be used in the present invention is not particularly limited, and may be a low molecular weight compound or a high molecular weight compound having a repeating unit.

Specific examples of the host material include triarylamine derivatives, phenylene derivatives, fused ring aromatic compounds (for example, naphthalene derivatives, phenanthrene derivatives, fluorene derivatives, pyrene derivatives, tetracene derivatives, coronen derivatives, chrysene derivatives, perylene derivatives, 9, 10-Diphenylanthracene derivative or rubrene, etc.), quinacridone derivative, acridone derivative, coumarin derivative, pyran derivative, nile red, pyrazine derivative, benzoimidazole derivative, benzothiazole derivative, benzoxazole derivative, stillben derivative, organic metal complex (for example, Tris) Organic aluminum complex such as (8-quinolinolate) aluminum, organic beryllium complex, organic iridium complex, organic platinum complex, etc.), or poly (phenylene vinylene) derivative, poly (fluorene) derivative, poly (phenylene) derivative, poly (thieni) Examples thereof include polymer derivatives such as lembinylene) derivatives and poly (acetylene) derivatives.

<Electron transport layer>
The electron transport layer may be made of a material having a function of transporting electrons and may have a function of transmitting electrons injected from the cathode to the light emitting layer.

The film thickness of the electron transport layer is not particularly limited, but is usually in the range of 2 to 5000 nm, more preferably in the range of 2 to 500 nm, and further preferably in the range of 5 to 200 nm.

The material used for the electron transport layer (hereinafter referred to as an electron transport material) may have either electron injection property or transport property, or hole barrier property, and is available from among conventionally known compounds. Any one can be selected and used.

Specific examples of the electron-transporting material include a nitrogen-containing aromatic heterocyclic derivative (carbazole derivative, an organic aluminum complex such as tris (8-quinolinolate) aluminum, and an azacarbazole derivative (one or more carbon atoms constituting the carbazole ring). Is replaced with a nitrogen atom), pyridine derivative, pyrimidine derivative, triazine derivative, quinoline derivative, quinoxalin derivative, phenanthroline derivative, oxazole derivative, thiazole derivative, oxaziazole derivative, triazole derivative, benzimidazole derivative or benzoxazole derivative, etc. ), Dibenzofuran derivative, dibenzothiophene derivative, aromatic hydrocarbon ring derivative (naphthalene derivative, anthracene derivative, triphenylene, etc.) and the like.

<Hole blocking layer>
The hole blocking layer is a layer having a function of an electron transporting layer in a broad sense, and is preferably made of a material having a function of transporting electrons and a small ability to transport holes, and holes while transporting electrons. It is possible to improve the recombination probability of electrons and holes by blocking the above.

The hole blocking layer is preferably provided adjacent to the cathode side of the light emitting layer.

The film thickness of the hole blocking layer is preferably in the range of 3 to 100 nm, and more preferably in the range of 5 to 30 nm.

As the material used for the hole blocking layer, the material used for the above-mentioned electron transport layer is preferably used, and the above-mentioned host material is also preferably used as the material for the hole blocking layer.

<Electron injection layer>
The electron injection layer (also referred to as “cathode buffer layer”) is a layer provided between the cathode and the light emitting layer in order to reduce the driving voltage or improve the emission brightness.

The film thickness of the electron injection layer is preferably in the range of 0.1 to 5 nm. More preferably, it is in the range of 0.1 to 1 nm.

Specific examples of materials preferably used for the electron injection layer include metals (strontium, aluminum, etc.), alkali metal compounds (lithium fluoride, sodium fluoride, etc.), and alkaline earth metal compounds (magnesium fluoride, calcium fluoride, etc.). Etc.), metal oxides (aluminum oxide, etc.), metal complexes (lithium 8-hydroxyquinolate (Liq), etc.) and the like. It is also possible to use the above-mentioned electron transport material. Further, examples of the electron injection material include a lithium complex of a phenanthroline derivative (LiPB) and a lithium complex of phenoxypyridine (LiPP).

<Hole transport layer>
The hole transport layer may be made of a material having a function of transporting holes and may have a function of transmitting holes injected from the anode to the light emitting layer.

The film thickness of the hole transport layer is not particularly limited, but is usually in the range of 2 to 5000 nm, more preferably in the range of 5 to 500 nm, and further preferably in the range of 5 to 200 nm.

The material used for the hole transport layer (hereinafter referred to as the hole transport material) may have either hole injection property or transport property, or electron barrier property, and is a conventionally known compound. Any one can be selected and used from the above.

Specific examples of the hole-transporting material include porphyrin derivatives; phthalocyanine derivatives; oxazole derivatives; phenylenediamine derivatives; stillben derivatives; triarylamine derivatives; carbazole derivatives; indolocarbazole derivatives; acene-based derivatives such as anthracene or naphthalene; Fluolene derivatives; Fluolenone derivatives; Polymer materials or oligomers with polyvinylcarbazole or aromatic amines introduced into the main or side chains; Polysilanes; Conductive polymers or oligomers (eg PEDOT: PSS, aniline copolymers, polyaniline, polythiophene, etc.) ) Etc. can be mentioned.

<Electronic blocking layer>
The electron blocking layer is a layer having a function of a hole transporting layer in a broad sense, and is preferably made of a material having a function of transporting holes and a small ability to transport electrons, and is composed of a material having a small ability to transport electrons while transporting holes. It is possible to improve the recombination probability of electrons and holes by blocking the above.

The film thickness of the electron blocking layer is preferably in the range of 3 to 100 nm, and more preferably in the range of 5 to 30 nm.

In addition, the structure of the hole transport layer described above can be used as an electron blocking layer, if necessary.

<Hole injection layer>
In the present invention, the hole injection layer (also referred to as “anode buffer layer”) is a layer provided between the anode and the light emitting layer in order to reduce the driving voltage or improve the emission brightness.

Examples of the material used for the hole injection layer include phthalocyanine derivatives typified by copper phthalocyanine, hexaazatriphenylene derivatives, metal oxides typified by vanadium oxide, amorphous carbon, polyaniline (emeraldine), and conductive polythiophene. A polypolymer, a cyclometallated complex typified by a tris (2-phenylpyridine) iridium complex, a triarylamine derivative, or the like is preferable.

The organic electroluminescent device of the present invention is preferably supported by a substrate. The material of the substrate is not particularly limited, and examples thereof include alkaline glass, non-alkali glass, glass such as quartz glass, and transparent plastic, which are commonly used in conventional organic electroluminescent elements.

Specific examples of the material constituting the anode include simple metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium or tungsten, or alloys thereof, tin oxide, zinc oxide, indium oxide, and oxidation. Metal oxides such as tin indium (ITO) or zinc oxide indium can be used. Conductive polymers such as polyaniline, polypyrrole, polythiophene or polyphenylene sulfide can also be used. These electrode substances may be used alone or in combination of two or more. Further, the anode may be composed of one layer or may be composed of a plurality of layers.

Specific examples of the material constituting the cathode include simple metals such as lithium, sodium, potassium, calcium, magnesium, aluminum, indium, ruthenium, titanium, manganese, yttrium, silver, lead, tin and chromium. Further, these metals may be combined to form an alloy. For example, alloys such as lithium-indium, sodium-potassium, magnesium-silver, aluminum-lithium, aluminum-magnesium, or magnesium-indium can be used. Furthermore, metal oxides such as indium tin oxide (ITO) can also be used. These electrode substances may be used alone or in combination of two or more. Further, the cathode may have a single-layer structure or a multi-layer structure.

The organic light emitting device containing the iridium complex represented by the general formula (1) according to the present invention can be produced by a vacuum deposition method, a solution coating method, a transfer method using a laser or the like, or a spray method. In particular, it is desirable to form a light emitting layer containing an iridium complex represented by the general formula (1) according to the present invention by a vacuum vapor deposition method.

The vacuum vapor deposition conditions when each layer such as a hole transport layer, a light emitting layer, or an electron transport layer is formed by the vacuum vapor deposition method are not particularly limited, but are about 50 to 500 ° C. under a vacuum of about ^10-4 to ^{10-5 Pa.} It is preferable to perform vapor deposition at a vapor deposition rate of about 0.01 to 50 nm / sec at a boat temperature of about −50 to 300 ° C. and a substrate temperature of about −50 to 300 ° C. When each layer such as a hole transport layer, a light emitting layer, or an electron transport layer is formed by using a plurality of materials, it is preferable to co-deposit the boats containing the materials while controlling the temperature.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention will not be construed as being limited to Examples. The compound corresponding to the examples is referred to as "the compound of the present invention", and the compound corresponding to the comparative example is referred to as "comparative compound".

<Example I-1>
Synthesis of compound of the present invention (K-2)

２−クロロ−５−メチルピリミジン５．１８ｇ（４０．３ｍｍｏｌ）、３−ビフェニルボロン酸９．２６ｇ（４６．８ｍｍｏｌ）、２Ｍ炭酸カリウム水溶液９５ｍｌおよび１，２−ジメトキシエタン７０ｍｌを三口フラスコに入れ、アルゴンガスを通気した後、テトラキス（トリフェニルホスフィン）パラジウム（０）２．２５ｇ（１．９５ｍｍｏｌ）を加え、アルゴン雰囲気下で２４時間加熱還流させた。反応溶液を室温まで冷却した後、有機層を回収し、溶媒を減圧留去し、シリカゲルカラムクロマトグラフィー（溶離液：ジクロロメタン）を用いて精製し、配位子（Ｌ−ｂ）を得た。収量８．４０ｇ（収率８４．７％）。化合物の同定は^１Ｈ−ＮＭＲを用いて行った。配位子（Ｌ−ｂ）の^１Ｈ−ＮＭＲデータを以下に示す。
^１Ｈ−ＮＭＲ（４００ＭＨｚ／ＣＤＣｌ_３）δ：８．６６−８．６８（ｍ，３Ｈ），８．３９（ｄ，１Ｈ），７．７０−７．７２（ｍ，３Ｈ），７．５６（ｔ，１Ｈ），７．４６（ｔ，２Ｈ），７．３７（ｔ，１Ｈ），２．３６（ｓ，３Ｈ）． Step 1 Synthesis of ligand (L-b)

5.18 g (40.3 mmol) of 2-chloro-5-methylpyrimidine, 9.26 g (46.8 mmol) of 3-biphenylboronic acid, 95 ml of 2M potassium carbonate aqueous solution and 70 ml of 1,2-dimethoxyethane were placed in a three-mouthed flask. After aeration with argon gas, 2.25 g (1.95 mmol) of tetrakis (triphenylphosphine) palladium (0) was added, and the mixture was heated under reflux in an argon atmosphere for 24 hours. After cooling the reaction solution to room temperature, the organic layer was recovered, the solvent was distilled off under reduced pressure, and purification was performed using silica gel column chromatography (eluent: dichloromethane) to obtain a ligand (LB). Yield 8.40 g (yield 84.7%). The compounds were identified ^{using 1 1} H-NMR. ^{The 1} H-NMR data of the ligand (L-b) is shown below.
^{1 1} H-NMR (400MHz / CDCl ₃ ) δ: 8.66-8.68 (m, 3H), 8.39 (d, 1H), 7.70-7.72 (m, 3H), 7.56 (T, 1H), 7.46 (t, 2H), 7.37 (t, 1H), 2.36 (s, 3H).

３塩化イリジウムｎ水和物４．１１ｇ（１１．６ｍｍｏｌ）と配位子（Ｌ−ｂ）６．００ｇ（２４．４ｍｍｏｌ）とＤＭＦ２２５ｍｌと純水２５ｍｌとを投入し、アルゴンガスを３０分間通気した後、マイクロ波（２４５０ＭＨｚ）を３０分間照射した。反応溶液を室温まで冷却し、溶媒を約１０ｍｌまで減圧留去し、メタノールと純水とを加えることで固体を析出させ、中間体（Ｅ）を得た。収量８．００ｇ（収率９５．８％）。上記方法で合成した中間体（Ｅ）５．８２ｇ（４．０５ｍｍｏｌ）をジクロロメタン５００ｍｌおよびメタノール５００ｍｌの混合溶媒に分散させ、この分散液にアルゴンガスを３０分間通気した。その後、この分散液にトリフルオロメタンスルホン酸銀２．２４ｇ（８．７２ｍｍｏｌ）を加え、室温で１６時間撹拌させた。セライト層を通してろ過を行い、ろ液を減圧留去して、中間体（Ｆ）を得た。収量６．９３ｇ（収率９５．５％）。中間体（Ｆ）０．８４１ｇ（０．９３９ｍｍｏｌ）に、２−フェニルキノリン０．４６５ｇ（２．２７ｍｍｏｌ）、エタノール５０ｍｌを加え、アルゴン雰囲気下で３日間加熱還流させた。室温まで冷却し、溶媒を減圧留去した後、ジクロロメタン２５ｍｌに溶解し、これにＵＶランプ（波長：３６５ｎｍ）を３時間照射し、溶媒を減圧留去した。これをシリカゲルカラムクロマトグラフィー（溶離液：ジクロロメタン）を用いて精製し、フェイシャル体である本発明化合物（Ｋ−２）を得た。収量０．７ｍｇ（収率０．０８％）。化合物の同定は^１Ｈ−ＮＭＲを用いて行った。本発明化合物（Ｋ−２）の^１Ｈ−ＮＭＲデータを以下に示す。
^１Ｈ−ＮＭＲ（４００ＭＨｚ／ＤＭＳＯ−ｄ_６）δ：８．７５（ｔ，２Ｈ），８．４４（ｓ，２Ｈ），８．２７（ｄ，１Ｈ），８．２１（ｄ，１Ｈ），８．１４（ｄ，１Ｈ），８．０７（ｄ，１Ｈ），７．９６（ｄ，１Ｈ），７．７４（ｄ，１Ｈ），７．６４−７．６６（ｍ，３Ｈ），７．５７（ｄ，２Ｈ），７．３４−７．４６（ｍ，５Ｈ），７．２２−７．３０（ｍ，３Ｈ），７．１７（ｄｄ，１Ｈ），７．０７（ｄｄ，１Ｈ），６．９５（ｔ，１Ｈ），６．７６（ｔ，１Ｈ），６．６１（ｄ，１Ｈ），６．５０（ｄｄ，２Ｈ），２．２４（ｓ，３Ｈ），２．０６（ｓ，３Ｈ）． Step 2 Synthesis of the compound of the present invention (K-2)

4.11 g (11.6 mmol) of tridium iridium chloride n hydrate, 6.00 g (24.4 mmol) of ligand (LB), 225 ml of DMF and 25 ml of pure water were added, and argon gas was aerated for 30 minutes. After that, it was irradiated with microwaves (2450 MHz) for 30 minutes. The reaction solution was cooled to room temperature, the solvent was distilled off under reduced pressure to about 10 ml, and methanol and pure water were added to precipitate a solid to obtain an intermediate (E). Yield 8.00 g (yield 95.8%). 5.82 g (4.05 mmol) of the intermediate (E) synthesized by the above method was dispersed in a mixed solvent of 500 ml of dichloromethane and 500 ml of methanol, and argon gas was aerated in this dispersion for 30 minutes. Then, 2.24 g (8.72 mmol) of silver trifluoromethanesulfonate was added to this dispersion, and the mixture was stirred at room temperature for 16 hours. Filtration was carried out through the Celite layer, and the filtrate was distilled off under reduced pressure to obtain an intermediate (F). Yield 6.93 g (yield 95.5%). To 0.841 g (0.939 mmol) of the intermediate (F), 0.465 g (2.27 mmol) of 2-phenylquinoline and 50 ml of ethanol were added, and the mixture was heated under reflux for 3 days under an argon atmosphere. After cooling to room temperature and distilling off the solvent under reduced pressure, the mixture was dissolved in 25 ml of dichloromethane, irradiated with a UV lamp (wavelength: 365 nm) for 3 hours, and the solvent was distilled off under reduced pressure. This was purified by silica gel column chromatography (eluent: dichloromethane) to obtain a facial compound of the present invention (K-2). Yield 0.7 mg (yield 0.08%). The compounds were identified ^{using 1 1} H-NMR. ^{The 1} H-NMR data of the compound of the present invention (K-2) is shown below.
^{1 1} H-NMR (400MHz / DMSO-d ₆ ) δ: 8.75 (t, 2H), 8.44 (s, 2H), 8.27 (d, 1H), 8.21 (d, 1H), 8.14 (d, 1H), 8.07 (d, 1H), 7.96 (d, 1H), 7.74 (d, 1H), 7.64-7.66 (m, 3H), 7 .57 (d, 2H), 7.34-7.46 (m, 5H), 7.22-7.30 (m, 3H), 7.17 (dd, 1H), 7.07 (dd, 1H) ), 6.95 (t, 1H), 6.76 (t, 1H), 6.61 (d, 1H), 6.50 (dd, 2H), 2.24 (s, 3H), 2.06 (S, 3H).

３塩化イリジウムｎ水和物３．００ｇ（８．２３ｍｍｏｌ）、２−フェニルキノリン３．７４ｇ、２−エトキシエタノール８０ｍｌ、純水２０ｍｌを三口フラスコに入れ、アルゴン雰囲気下で１８時間加熱還流させた。反応溶液を室温まで冷却させた後、ろ過し、メタノールと純水で洗浄して、中間体（Ｉ）を得た。収量３．６３ｇ（収率６９．３％）。中間体（Ｉ）２．６２ｇ（２．０６ｍｍｏｌ）、トリフルオロメタンスルホン酸銀１．１５ｇ（４．４８ｍｍｏｌ）、メタノール１４０ｍｌおよびジクロロメタン２２０ｍｌを三口フラスコに入れ、アルゴンガス雰囲気下、室温で２４時間撹拌させた。反応溶液をセライト層を通してろ過し、ろ液を減圧留去して、中間体（Ｊ）を得た。収量３．３１ｇ（収率９８．８％）。中間体（Ｊ）１．２６ｇ（１．５５ｍｍｏｌ）に、配位子（Ｌ−ｂ）０．９２０ｇ（３．７４ｍｍｏｌ）、エタノール８０ｍｌを加え、アルゴン雰囲気下で２日間加熱還流させた。室温まで冷却し、溶媒を減圧留去した後、ジクロロメタンに溶解し、これにＵＶランプ（波長：３６５ｎｍ）を３時間照射し、溶媒を減圧留去した。得られた固体をジクロロメタンに溶解させメタノールを加えて再結晶した。その後さらにもう一度ジクロロメタンとメタノールで再結晶し、フェイシャル体である本発明化合物（Ｋ−４）を得た。収量０．６１９ｇ（収率４７．２％）。化合物の同定は^１Ｈ−ＮＭＲを用いて行った。本発明化合物（Ｋ−４）の^１Ｈ−ＮＭＲデータを以下に示す。
^１Ｈ−ＮＭＲ（４００ＭＨｚ／ＤＭＳＯ−ｄ_６）δ：８．６９（ｄ，１Ｈ），８．５２（ｑ，２Ｈ），８．４１（ｑ，２Ｈ），８．１０（ｄ，１Ｈ），８．０３（ｄ，１Ｈ），８．０１（ｄ，１Ｈ），７．８９−７．９５（ｍ，３Ｈ），７．７２（ｄ，１Ｈ），７．５９（ｄ，１Ｈ），７．５４（ｄ，２Ｈ），７．３９（ｔ，１Ｈ），７．３４（ｔ，２Ｈ），７．２９（ｔ，１Ｈ），７．２２（ｔ，１Ｈ），７．１５（ｔ，１Ｈ），７．０６（ｄｄ，１Ｈ），６．９４（ｔ，１Ｈ），６．８７（ｔ，１Ｈ），６．６２−６．７２（ｍ，３Ｈ），６．３８−６．４６（ｍ，３Ｈ），２．１０（ｓ，３Ｈ）． <Example I-2>
Synthesis of compound of the present invention (K-4)

3.00 g (8.23 mmol) of tridium iridium chloride n hydrate, 3.74 g of 2-phenylquinoline, 80 ml of 2-ethoxyethanol, and 20 ml of pure water were placed in a three-necked flask and refluxed by heating under an argon atmosphere for 18 hours. The reaction solution was cooled to room temperature, filtered, and washed with methanol and pure water to obtain Intermediate (I). Yield 3.63 g (yield 69.3%). 2.62 g (2.06 mmol) of intermediate (I), 1.15 g (4.48 mmol) of silver trifluoromethanesulfonate, 140 ml of methanol and 220 ml of dichloromethane are placed in a three-necked flask and stirred at room temperature for 24 hours under an argon gas atmosphere. It was. The reaction solution was filtered through the Celite layer, and the filtrate was distilled off under reduced pressure to obtain an intermediate (J). Yield 3.31 g (yield 98.8%). To 1.26 g (1.55 mmol) of the intermediate (J), 0.920 g (3.74 mmol) of the ligand (Lb) and 80 ml of ethanol were added, and the mixture was heated under reflux for 2 days under an argon atmosphere. After cooling to room temperature and distilling off the solvent under reduced pressure, it was dissolved in dichloromethane, irradiated with a UV lamp (wavelength: 365 nm) for 3 hours, and the solvent was distilled off under reduced pressure. The obtained solid was dissolved in dichloromethane and methanol was added for recrystallization. Then, it was recrystallized again with dichloromethane and methanol to obtain a facial compound of the present invention (K-4). Yield 0.619 g (yield 47.2%). The compounds were identified ^{using 1 1} H-NMR. ^{The 1} H-NMR data of the compound of the present invention (K-4) is shown below.
^{1 1} H-NMR (400MHz / DMSO-d ₆ ) δ: 8.69 (d, 1H), 8.52 (q, 2H), 8.41 (q, 2H), 8.10 (d, 1H), 8.03 (d, 1H), 8.01 (d, 1H), 7.89-7.95 (m, 3H), 7.72 (d, 1H), 7.59 (d, 1H), 7 .54 (d, 2H), 7.39 (t, 1H), 7.34 (t, 2H), 7.29 (t, 1H), 7.22 (t, 1H), 7.15 (t, 1H), 7.06 (dd, 1H), 6.94 (t, 1H), 6.87 (t, 1H), 6.62-6.72 (m, 3H), 6.38-6.46 (M, 3H), 2.10 (s, 3H).

<Example I-3>
Synthesis of the compounds of the present invention (K-14) and (K-16)

３塩化イリジウムｎ水和物２１．７ｇ、１−フェニルイソキノリン２８．４ｇ、ＤＭＦ４４０ｍｌおよび純水６０ｍｌを三口フラスコに入れ、ジムロート冷却器を取り付け、アルゴンガスを通気しながら、マイクロ波（２４５０ＭＨｚ、１０００Ｗ）を３０分間照射した。反応溶液を室温まで冷却させた後、沈殿をろ取し、純水およびメタノールで洗浄して、中間体（Ｋ）を収率９５％で得た。中間体（Ｋ）１２．２ｇ、トリフルオロメタンスルホン酸銀５．１５ｇ、メタノール４００ｍｌおよびジクロロメタン１２５０ｍｌを三口フラスコに入れ、アルゴンガス雰囲気下、室温で２４時間反応させた。反応溶液をセライトろ過し、溶媒を減圧留去して、中間体（Ｌ）を収率９４％で得た。中間体（Ｌ）０．８３５ｇ、配位子（Ｌ−ｂ）０．５０４ｇ、エタノール４１ｍｌを加え、アルゴン雰囲気下、９５℃で３０時間加熱反応させた。反応溶液の液温を室温まで冷却後、沈殿をろ取し、メタノールで洗浄した。これをジクロロメタンに溶解後、セライトろ過し、溶媒を減圧留去した後、シリカゲルカラムクロマトグラフィー（溶離液：ジクロロメタンとヘキサン）を用いて精製し、フェイシャル体である（Ｋ−１４）と（Ｋ−１６）を、それぞれ収率１．６％及び１５％で得た。

3 Iridium chloride n hydrate 21.7 g, 1-phenylisoquinoline 28.4 g, DMF 440 ml and pure water 60 ml are placed in a three-necked flask, a Dimroth condenser is attached, and microwaves (2450 MHz, 1000 W) while aerating argon gas. Was irradiated for 30 minutes. After cooling the reaction solution to room temperature, the precipitate was collected by filtration and washed with pure water and methanol to obtain the intermediate (K) in a yield of 95%. 12.2 g of Intermediate (K), 5.15 g of silver trifluoromethanesulfonate, 400 ml of methanol and 1250 ml of dichloromethane were placed in a three-necked flask and reacted at room temperature for 24 hours under an argon gas atmosphere. The reaction solution was filtered through Celite, and the solvent was distilled off under reduced pressure to obtain an intermediate (L) in a yield of 94%. 0.835 g of the intermediate (L), 0.504 g of the ligand (Lb) and 41 ml of ethanol were added, and the mixture was heated and reacted at 95 ° C. for 30 hours under an argon atmosphere. After cooling the temperature of the reaction solution to room temperature, the precipitate was collected by filtration and washed with methanol. This is dissolved in dichloromethane, filtered through Celite, the solvent is distilled off under reduced pressure, and then purified using silica gel column chromatography (eluents: dichloromethane and hexane) to form facials (K-14) and (K-). 16) were obtained in yields of 1.6% and 15%, respectively.

^{The 1} H-NMR data of the compound of the present invention (K-14) is shown below.
^{1 1} H-NMR (400MHz / DMSO-d ₆ ) δ: 8.94-8.96 (m, 1H), 8.74 (dd, 2H), 8.21-8.26 (m, 3H), 7 .96-8.02 (m, 2H), 7.77-7.83 (m, 2H), 7.69 (d, 1H), 7.58-7.65 (m, 6H), 7.36 -7.43 (m, 4H), 7.23-7.29 (m, 2H), 7.18 (dd, 1H), 7.12 (dd, 1H), 6.98 (t, 1H), 6.78-6.86 (m, 2H), 6.73 (d, 2H), 2.23 (s, 3H), 2.06 (s, 3H).

^{The 1} H-NMR data of the compound of the present invention (K-16) is shown below.
^{1 1} H-NMR (400MHz / DMSO-d ₆ ) δ: 8.93 (t, 2H), 8.73 (d, 1H), 8.17-8.27 (m, 3H), 8.00-8 .02 (m, 1H), 7.92-7.95 (m, 1H), 7.76-7.83 (m, 4H), 7.67 (d, 1H), 7.59-7.61 (M, 4H), 7.48 (d, 1H), 7.36-7.40 (m, 3H), 7.25 (t, 1H), 7.11 (dd, 1H), 6.90- 6.99 (m, 2H), 6.72-6.87 (m, 4H), 6.68 (d, 1H), 2.07 (s, 3H).

Next, the light emitting characteristics of the iridium complex according to the present invention will be described.

<Example II-1>
Emission characteristics of the compound of the present invention (K-4) in chloroform After dissolving the compound of the present invention (K-4) in chloroform and aerating argon gas, an absolute PL quantum yield measuring device manufactured by Hamamatsu Photonics Co., Ltd. ( When the emission spectrum (excitation wavelength: 350 nm) at room temperature was measured using C9920), red emission (maximum emission wavelength: 622 nm) was exhibited. The emission quantum yield was 0.65.

<Example II-2>
Emission characteristics of the compound of the present invention (K-14) in chloroform After dissolving the compound of the present invention (K-14) in chloroform and aerating argon gas, an absolute PL quantum yield measuring device manufactured by Hamamatsu Photonics Co., Ltd. When the emission spectrum (excitation wavelength: 340 nm) at room temperature was measured using (C9920), red emission (maximum emission wavelength: 628 nm) was exhibited. The emission quantum yield was 0.55.

<Example II-3>
Emission characteristics of the compound of the present invention (K-16) in chloroform After dissolving the compound of the present invention (K-16) in chloroform and aerating argon gas, an absolute PL quantum yield measuring device manufactured by Hamamatsu Photonics Co., Ltd. When the emission spectrum (excitation wavelength: 340 nm) at room temperature was measured using (C9920), red emission (maximum emission wavelength: 631 nm) was exhibited. The emission quantum yield was 0.61.

<Comparative Example II-1>
Emission characteristics of comparative compound (1) in THF After dissolving comparative compound (1) in THF and aerating argon gas, using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd., room temperature. When the emission spectrum (excitation wavelength: 350 nm) was measured, it showed green emission (maximum emission wavelength: 527 nm). The emission quantum yield was 0.64.

From the above, in the compound of the present invention represented by the general formula (1), any one of adjacent R ¹² and R ¹³ , R ¹³ and R ¹⁴ , or R ¹⁴ and R ¹⁵ is bound to each other. It was found that by forming a fused ring, it efficiently emits light in the red region.

Next, in order to confirm the thermal stability and sublimation property of the iridium complex represented by the general formula (1) according to the present invention, a sublimation purification experiment will be described.

<Example III-1>
Sublimation purification of the compound of the present invention (K-4) 153 mg of the compound of the present invention (K-4) was placed in a sublimation purification apparatus (P-200, manufactured by LS Technology Co., Ltd.), and the degree of vacuum was 1 × 10 ^-4 Pa, and the temperature was 30-10. When sublimation purification was carried out over 9 hours under the condition of 340 ° C., the yield by sublimation purification was 95%, and there was no sublimation residue. When the compound of the present invention (K-4) after sublimation purification was analyzed by HPLC, the purity did not decrease due to sublimation purification. It was revealed that the thermal stability and sublimation property of the compound of the present invention (K-4) were good.

<Example III-2>
Sublimation purification of the compound of the present invention (K-16) 93.5 mg of the compound of the present invention (K-16) was placed in a sublimation purification apparatus (P-200, manufactured by LS Technology Co., Ltd.), and the degree of vacuum was 1 × 10 ^-4 Pa, temperature. When sublimation purification was carried out over 9 hours under the conditions of 300 to 320 ° C., the yield by sublimation purification was 96%, and there was no sublimation residue. When the compound of the present invention (K-16) after sublimation purification was analyzed by HPLC, a slight decrease in purity due to sublimation purification occurred, but the purity decreased from 99.7% to 99.3%. It was. It was revealed that the thermal stability and sublimation property of the compound of the present invention (K-16) were good.

<Comparative Example III-1>
Sublimation Purification of Comparative Compound (1) 107 mg of Comparative Compound (1) was placed in a sublimation purification apparatus (P-200, manufactured by ALS Technology Co., Ltd.) ^{under the conditions of a vacuum degree of 1 × 10 -4} Pa and a temperature of 300 to 335 ° C. After 18 hours of sublimation purification, a large amount of sublimation residue remained (10.2% of the input amount). When the comparative compound (1) after sublimation purification was analyzed by HPLC, the purity did not decrease due to sublimation purification. On the other hand, when the sublimation residue (10.2% of the input amount) was analyzed by HPLC, the purity was 93.1%, which was significantly lower than the purity of 99.8% before the sublimation purification. It was found that the comparative compound (1) had a much slower sublimation rate than the compound of the present invention, and the decomposition reaction proceeded when sublimated and purified under the same conditions as the compound of the present invention.

<Comparative Example III-2>
Sublimation purification of comparative compound (2)

2.91 g of Comparative Compound (2) was placed in a sublimation purification apparatus (P-200, manufactured by ALS Technology Co., Ltd.) and sublimated and purified over 26 hours under the conditions of a ^{vacuum degree of 1 × 10 -4 Pa and a temperature of 340 ° C.} However, a large amount of sublimation residue remained (12.1% of the input amount). When the comparative compound (2) after sublimation purification was analyzed by HPLC, the purity was lowered by the sublimation purification, and the purity was lowered from 99.7% to 99.1%. It was found that the comparative compound (2) has lower sublimation property than the compound of the present invention, requires a higher heating temperature and heating time, and as a result, promotes a decomposition reaction and lowers the purity after sublimation purification. It was.

Next, the light emitting characteristics of the iridium complex according to the present invention in a thin film will be described.

<Example IV-1>
Emission characteristics of the compound of the present invention (K-4) in a co-deposited film with CBP The compound of the present invention (K-4) and CBP (E-3), which is a known host material, have a vacuum degree of 1 × 10 ^-4 Pa. Then, co-evaporation (30 nm) was performed on a quartz substrate at a ratio of 5:95 (mass concentration ratio), and an emission spectrum (excitation wavelength) at room temperature was used using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd. : 340 nm), it showed red emission (maximum emission wavelength: 600 nm). The emission quantum yield was 0.88.

<Example IV-2>
Emission characteristics of the compound of the present invention (K-16) in a co-deposited film with CBP The compound of the present invention (K-16) and CBP (E-3), which is a known host material, have a vacuum degree of 1 × 10 ^-4 Pa. Then, co-evaporation (30 nm) was performed on a quartz substrate at a ratio of 5:95 (mass concentration ratio), and an emission spectrum (excitation wavelength) at room temperature was used using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd. : 340 nm), it showed red emission (maximum emission wavelength: 619 nm). The emission quantum yield was 0.68.

<Comparative Example IV-1>
Emission characteristics of comparative compound (1) in a co-deposited film with CBP The comparative compound (1) and CBP (E-3), which is a known host material, are placed on a quartz substrate ^{at a vacuum degree of 1 × 10 -4 Pa.} Co-deposited (30 nm) at 5:95 (mass concentration ratio), and the emission spectrum (excitation wavelength: 340 nm) at room temperature was measured using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd. However, it showed green emission (maximum emission wavelength: 526 nm). The emission quantum yield was 0.82.

From the above, it was clarified that the compound of the present invention has good sublimation property and can be suitably used as a red light emitting material by forming a thin film.

Next, the characteristics of the organic electroluminescent device produced by using the iridium complex represented by the general formula (1) according to the present invention will be described.

<Example V-1>
Characteristic evaluation of an organic electroluminescent device produced using the compound of the present invention (K-4) An alkali-free film formed by patterning indium tin oxide (ITO) with a film thickness of 100 nm into a comb shape with a line width of 2 mm as an anode. A glass substrate (manufactured by Atsugi Micro Co., Ltd.) was used as a transparent conductive support substrate. This was sequentially ultrasonically washed with ultrapure water, acetone, and isopropyl alcohol (IPA), then boiled and washed with IPA, and then dried. Then, the UV / ozone-cleaned one was used as a transparent conductive support substrate.

The following organic layers (hole injection layer, hole transport layer, light emitting layer, hole blocking layer and electron transport layer) are resistance-heated in a vacuum chamber ^{of 1 × 10 -4 Pa on the transparent conductive support substrate.} The electrode layer (electron injection layer and metal electrode layer) having a line width of 2 mm is sequentially formed by sequentially forming a film by vacuum vapor deposition using the above, and then the mask is replaced to form an organic electroluminescent device (element shape; 2 mm × 2 mm square). Element area; 0.04 cm ² ) was prepared. Next, a work was performed to seal the device in a glove box having a nitrogen atmosphere so that the device would not be exposed to the atmosphere. UV curable epoxy resin Denatite R (manufactured by Nagase Chemitec) is applied and vapor-deposited around a sealed glass (manufactured by Izumiyo Shoji Co., Ltd.) with a 1.5 mm digging in the center of a glass plate with a thickness of 3 mm. After covering and crimping the finished element, the element portion was covered with an aluminum plate to mask it, irradiated with a UV irradiation device with a shutter for 1 minute, and then sealed for 1 minute by repeating a cycle of shielding 5 times.

Hole injection layer (10 nm): Compound (E-1)
Hole transport layer (40 nm): Compound (E-2)
Light emitting layer (20 nm): Compound (K-4) of the present invention (mass concentration 15%) and compound (E-3) (mass concentration 85%) co-deposited hole blocking layer (10 nm): compound (E-4) )
Electron transport layer (30 nm): Compound (E-5)
Electron injection layer (0.5 nm): Compound (E-6)
Metal electrode layer (100 nm): Al

The structural formulas of the compounds (E-1) to (E-6) are shown below.

The obtained organic electroluminescent element is set in the sample holder of the integrating sphere unit A10094 for EL external quantum yield measurement manufactured by Hamamatsu Photonics Co., Ltd., and a constant DC voltage is applied to emit light using a source meter 2400 manufactured by Keithley Co., Ltd. The brightness, emission wavelength, and CIE chromaticity coordinates were measured using a multi-channel spectroscope PMA-12 manufactured by Hamamatsu Photonics Co., Ltd. Emission peak wavelength obtained red light 600 nm, the maximum luminance and the external quantum efficiency at ^{60000cd / m 2, 100cd / m} 2 is 14.2% and a very good light emission characteristics are obtained.

<Example V-2>
Characteristic evaluation of an organic electroluminescent device produced using the compound of the present invention (K-16) The compound of the present invention (K-16) was used in place of the compound of the present invention (K-4) used in Example V-1. Except for the above, an organic electroluminescent device was produced in the same manner and its characteristics were evaluated. Emission peak wavelength obtained red light 621 nm, the maximum luminance and the external quantum efficiency at ^{25800cd / m 2, 100cd / m} 2 is 11.3% and a very good light emission characteristics are obtained. The EL spectrum of the organic electroluminescent device produced by using the compound of the present invention (K-16) is shown in FIG.

As described above, the iridium complex represented by the general formula (1) according to the present invention is a novel compound which is excellent in thermal stability and sublimation property and mainly exhibits a high emission quantum yield in the red region. When used in an organic light emitting device, an organic light emitting device having good light emitting characteristics can be produced. Further, an organic light emitting element using the compound exhibits high-luminance light emission in a visible light region (mainly a red region), and is therefore suitable for fields such as display elements, displays, backlights, and illumination light sources.

Claims (9)

An iridium complex represented by the following general formula ( 9 ) and having red light emitting property.

(In the general formula ( 9 ), N represents a nitrogen atom and Ir represents an iridium atom. R ^{1 to} R ¹¹ , R ^{14 to} R ¹⁹ , and R ^{20 to} R ²³ are independent hydrogen atoms and carbon atoms, respectively. Represents an alkyl group of number 1 to 30, an aryl group of 6 to 30 carbon atoms, a halogen atom or a cyano group. The alkyl group may be substituted with an aryl group, a halogen atom or a cyano group. The aryl group may be an alkyl group. , May be substituted with a halogen atom or a cyano group. M is an integer of 1 or 2, n is an integer of 1 or 2, and m + n is 3.) The iridium complex according to claim 1, wherein R ^{14 to} R ¹⁹ are hydrogen atoms or alkyl groups having 1 to 30 carbon atoms. The iridium complex according to claim 1 or 2 , wherein at least one of R ^{14 to} R ^{19 is a halogen atom.} The iridium complex according to any one of claims 1 to 3 , wherein R ⁴ , R ⁵ , R ⁹ and R ¹⁰ are all hydrogen atoms. The iridium complex according to any one of claims 1 to 4 , wherein m is 2 and n is 1. The iridium complex according to any one of claims 1 to 4 , wherein m is 1 and n is 2. The iridium complex according to any one of claims 1 to 6 , which is a facial form. A luminescent material containing the iridium complex according to any one of claims 1 to 7. An organic light emitting device comprising the light emitting material according to claim 8.

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