JP2018039763A - Heteroleptic iridium complex, and luminescent material and organic light-emitting element employing that compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel Ir complex that can be applied to an organic electroluminescent element, an organic electrochemiluminescent element, and the like, is thermally stable and excellent in sublimability, and exhibits luminescence mainly in a red color region.SOLUTION: The Ir complex is represented by the general formula (1). (Rto Rare each H, an alkyl group, halogen, a cyano group, or the like; a condensed ring is formed in any position from Rto R; m and n are 1 or 2; and m+n=3.)SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a novel red light-emitting heteroleptic iridium complex useful as a light-emitting material of 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 light-emitting elements typified by organic electroluminescence elements have attracted attention as display or illumination technologies, and research for practical application is actively being promoted. In particular, improvement of luminous efficiency is an important research subject, and attention is currently focused on phosphorescent materials that utilize light emission from an excited triplet state as light emitting materials.

  In the case of using light emission from an excited singlet state, the generation ratio of singlet excitons to triplet excitons is 1: 3, and the generation probability of luminescent excitons 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 an excited triplet state can also be used, the upper limit of the internal quantum efficiency is 100%, so that in principle, the luminous efficiency is four times that of the excited singlet. Against this background, phosphorescent materials for organic light emitting devices have been actively developed so far. For example, a green light-emitting iridium complex having a 2-phenylpyrimidine ligand is disclosed as a phosphorescent material (see, for example, Patent Document 1). Further, a 2-phenylpyrimidine-based iridium complex that is excellent in solubility and suitable for a coating process has been disclosed (for example, see Patent Document 2).

JP 2009-40728 A International Publication No. 2011/024737 Pamphlet International Publication 2012/172482 JP 2004-189673 A JP 2009-108041 A JP, 2014-101307, A 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.I. B. J. et al. Am. Chem. Soc. , 2003, 125, 7377

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

  An object of the present disclosure is to provide a novel heteroleptic iridium complex that can be applied to organic electroluminescent devices, organic electroluminescent devices, and the like, is thermally stable, and has excellent sublimation properties. .

  As a result of intensive studies in view of the above situation, the present inventors have shown that the iridium complex represented by the general formula (1) exhibits strong emission in the visible light region (mainly the red region) at room temperature, It was found to be stable and excellent in sublimation. And it demonstrated that the organic light emitting element which shows high luminous efficiency was producible using the iridium complex of this invention, and came to complete this invention.

  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 represented by the following general formula (1).

(In 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 each independently a hydrogen atom or a carbon number of 1 to 30. An alkyl group, an aryl group having 6 to 30 carbon atoms, a halogen atom or a cyano group, wherein R ¹² , R ^{15 to} R ¹⁷ and R ¹⁹ are each independently a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, Represents a halogen atom or a cyano group, wherein the alkyl group may be substituted with an aryl group, a halogen atom or a cyano group, and 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 each other to form a condensed ring, m is an integer of 1 or 2, and n is 1 Or 2 And m + n is 3.)

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

In the iridium complex according to the present invention, R ¹² and R ¹³ are preferably bonded to form a condensed ring.

In the iridium complex according to the present invention, R ¹⁴ and R ¹⁵ are preferably 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, R ⁴ , R ⁵ , R ⁹ and R ¹⁰ are preferably 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 body.

  The luminescent material according to the present invention includes the iridium complex according to the present invention.

  The organic light emitting device according to the present invention includes the light emitting material according to the present invention.

  According to the present disclosure, it is possible to provide a novel heteroleptic iridium complex that can be applied to organic electroluminescent elements, organic electrochemiluminescent elements, and the like, is thermally stable, and has excellent sublimation properties.

  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 thus is suitable as a light emitting device material for various applications. Can be used. An organic light-emitting element using the compound exhibits high-luminance emission in the visible light region, and thus is suitable for fields such as a display element, a display, a backlight, or an illumination light source.

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

  Next, although an embodiment is shown and explained in detail about the present invention, the present invention is limited to these descriptions and is not interpreted. As long as the effect of the present invention is exhibited, the embodiment may be variously modified.

  In the description of the general formula of the present invention, a hydrogen atom includes an isotope (deuterium atom and the like), and an atom constituting a substituent further includes the isotope.

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

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

The iridium complex of the present invention represented by the general formula (1) specifically includes a 2-phenylpyrimidine derivative ligand represented by the general formula (2) and a 2-phenylpyrimidine derivative ligand represented by the general formula (3). It is a heteroleptic 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 a bonding 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 homoleptic iridium complex represented by the general formula (4) has been known, but according to the knowledge of the present inventors, this iridium complex is poor in sublimation, Improvement of sublimation has been a major issue because it involves decomposition during the vacuum deposition process.

(In General Formula (4), N represents a nitrogen atom and Ir represents an iridium atom. R ^{1 to} R ¹¹ are synonymous with R ^{1 to} R ¹¹ in General Formula (1), and the desirable range is also the same. .)

  In addition, phosphorescent materials that emit light in the red region (for example, iridium complexes having a 1-phenylisoquinoline ligand) have low sublimation properties, and a large amount of residue is generated during sublimation purification. Yes.

  Based on the above technical background, the present inventors have intensively developed a phosphorescent material excellent in thermal stability and sublimation property. As a result, the heteroleptic iridium complex having a novel structure represented by the general formula (1) However, it exhibits strong light emission in the visible light region (mainly the red region) at room temperature, and is particularly superior in thermal stability and sublimation than the conventionally known homoleptic iridium complex represented by the general formula (4). I found out. And it demonstrated that the iridium complex represented by General formula (1) can be used suitably as a phosphorescent material of an organic light emitting element, and came up with this invention.

  The homoleptic iridium complex represented by the general formula (4) has the characteristic of having the same three cyclometalated ligands, but has high symmetry, and thus has good crystallinity in the solid state. There was a problem that the energy for linking each other was large and the sublimation temperature was high. On the other hand, the compound of the present invention represented by the general formula (1) is a heterolrep having different types of cyclometalated ligands (ligands represented by the general formula (2) and the general formula (3)). The present inventors consider that this is a tick iridium complex and has low symmetry, so that the crystallinity in the solid state is low, the energy for linking the complexes is reduced, and the sublimation property is improved.

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

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

  In order to remove dissolved oxygen, the measurement of the luminescence quantum yield in the solution is performed after passing argon gas or nitrogen gas through the solution in which the iridium complex is dissolved, or after freezing and degassing the solution in which the luminescent material is dissolved. Good to do. As a method for measuring the luminescence quantum yield, either an absolute method or a relative method may be used. In the relative method, the luminescence quantum yield can be measured by comparing the emission spectrum with a standard substance (such as quinine sulfate). In the absolute method, by using a commercially available device (for example, an absolute PL quantum yield measuring device (C9920-02) manufactured by Hamamatsu Photonics Co., Ltd.), the emission quantum yield in a solid state or in a solution can be measured. It is. Although the luminescence quantum yield in a solution can be measured using various solvents, the iridium complex according to the present invention only needs to achieve the luminescence quantum yield in any solvent.

  The measurement of the luminescence quantum yield in a thin film state is performed by, for example, vacuum-depositing the iridium complex of the present invention on quartz glass, and a commercially available device (for example, Hamamatsu Photonics Co., Ltd., absolute PL quantum yield measurement device (C9920)). ) Can be used. The luminescence quantum yield in a thin film can be measured by vapor-depositing the iridium complex of the present invention alone or by co-deposition with various host materials, but the iridium complex according to the present invention is It is sufficient that 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), but the wavelength region depends on the type or structure of the ligand. In particular, the emission maximum wavelength of the emission spectrum in solution or in 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 a range of 600 nm to 650 nm is particularly preferable.

  The iridium complex according to the present invention is an octahedral hexacoordinate complex, and there are a facial isomer and a meridional isomer as geometric isomers. Actually, when the iridium complex according to the present invention is synthesized, it may be obtained as a mixture of a facial body and a meridional body. These geometric isomers can be separated by, for example, 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. The iridium complexes represented by the general formulas (5) and (7) are facial bodies, and the iridium complexes represented by the general formulas (6) and (8) are meridional bodies.

（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) has the same meaning as ^R 1 ^{to R 19} of The desirable range is the same.)

  So far, various reports have been made on the light emission characteristics of the facial and meridional forms of the cyclometalated iridium complex, but the case of the facial form has a higher emission quantum yield (for example, Tamay A. B. J. Am. Chem. Soc., 2003, 125, 7377 (Non-patent Document 1)) and other cases where the meridional body is higher (for example, International Publication No. 2012/172482 (Patent Document 3)). ing.

  As for the geometric isomer of the iridium complex represented by the general formula (1) according to the present invention, the present inventors have examined the emission characteristics in detail. As a result, the facial isomer is more luminescent quantum than the meridional isomer. The yield was found to be overwhelmingly high.

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

The meridional body of the iridium complex represented by the general formula (1) according to the present invention can be isomerized to a facial body. 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.)

  The photoisomerization reaction of the meridional compound is disclosed in JP 2004-189673 A (Patent Document 4), JP 2009-108041 A (Patent Document 5), or JP 2014-101307 A (Patent Document 6). This can be done with reference.

  The photoisomerization reaction of the meridional compound will be described in more detail. It is characterized by irradiating a meridional body or a solution containing the meridional body with light to isomerize it into a facial body.

  The light irradiation method may be any method as long as the meridional body is exposed to light. You may light-irradiate the reaction solution containing the mixture of a meridional body and a facial body.

  The photoisomerization reaction of the meridional compound is preferably performed in a solution. As such a solvent, a solvent capable of dissolving the meridional form 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 -Amides 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 picoline, etc. Nitrogen-containing aromatic compounds, tetrahydrofuran (THF), ethers such as dioxane or diethyl ether, nitriles such as acetonitrile, propionitrile or benzonitrile, Nord, ethanol, propanol, alcohols such as butanol or ethylene glycol, or dimethyl sulfoxide, various organic solvents. Of these, halogenated aliphatic hydrocarbons, ethers or dimethyl sulfoxide are preferred. Specific examples of preferred solvents include dichloromethane, chloroform, tetrahydrofuran and dimethyl sulfoxide, more preferred examples include dichloromethane, tetrahydrofuran and dimethyl sulfoxide, and particularly preferred examples include tetrahydrofuran.

  The photoisomerization reaction of the meridional compound is not particularly limited as long as light irradiation is performed uniformly, but it is usually performed at a concentration of 1 mol / L or less, preferably 0.01 mol / L or less. Is desirable. Although the minimum of a density | concentration is not specifically limited, It is preferable that it is 0.0001 mol / L or more.

  The reaction vessel used for light irradiation may be any vessel that can irradiate light, but a glass vessel such as a Pyrex (registered trademark) reaction vessel or a quartz reaction vessel with high UV transparency is used. Particularly preferred.

  There are no particular limitations on the temperature conditions for the light irradiation 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 50 ° C.

  Light irradiation and post-treatment after light irradiation can be performed under atmospheric pressure, under an inert gas atmosphere such as nitrogen or argon, or under reduced pressure or under vacuum. More preferably, it is carried out in an inert gas atmosphere.

  Although there is no restriction | limiting in particular about pressure conditions, Usually, it carries out under a normal pressure.

  About the wavelength of the light used for light irradiation, what is necessary is just a wavelength which a meridional body can absorb, and the light of the range of 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 particularly preferably 300 to 450 nm.

  As a 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. Either of the internal irradiation methods of irradiating from the inside of the reaction vessel may be used.

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

  There are no particular restrictions on the type of lamp used for light irradiation, but high-pressure mercury lamp, low-pressure mercury lamp, ultrahigh-pressure mercury lamp, halogen lamp, xenon lamp, laser, sunlight, incandescent bulb, deuterium lamp, UV lamp, etc. Is mentioned.

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

  In 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 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 condensed ring.

  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 particularly preferably 1 to 6 carbon atoms.

  The alkyl group having 1 to 30 carbon atoms is preferably a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, n- Hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, 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, 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. . Particularly preferred is a methyl group. The alkyl group may be further substituted with an aryl group, a halogen atom or a cyano group. In particular, an alkyl group substituted with fluorine is 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 aryl 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-terphenyl-4-yl group, or a p-ter Phenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl Group, m-tolyl group, p-tolyl group, p-t-butylphenyl group, p- (2-phenylpropyl) phenyl group, 4'-methylbiphenylyl group, 4 "-t-butyl-p-terphenyl group -4-yl, o-cumenyl, m-cumenyl, p-cumenyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 3 , 4-xylyl group, 3,5-xylyl group, mesityl M-quaterphenyl group, 1-naphthyl group or 2-naphthyl group, more preferably phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 2,3-xylyl group, 2; , 4-xylyl group, 2,5-xylyl group, 2,6-xylyl group, 3,4-xylyl group, 3,5-xylyl group, or mesityl group, particularly preferably phenyl group. The group may be further substituted with an alkyl group, a halogen atom or a cyano group, and a phenyl group substituted with an alkyl group is particularly preferred because the sublimation property of the iridium complex is improved.

  The halogen atom is preferably a chlorine atom, a bromine atom or a fluorine atom. More preferably, they are a bromine atom or a fluorine atom. Particularly preferred is a fluorine atom.

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

R ¹ is more preferably a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, particularly preferably a methyl group or a hydrogen atom, and particularly preferably a hydrogen atom. Desirable ranges for these substituents are as described above. That is, 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 particularly preferably 1 to 6 carbon atoms.

R ² 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, particularly preferably a hydrogen atom or an alkyl group having 1 to 30 carbon atoms. An atom, a methyl group or an ethyl group is more particularly preferred, and a methyl group or an ethyl group is most preferred. Desirable ranges for these substituents are as described above. That is, 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 particularly preferably 1 to 6 carbon atoms. The aryl group having 6 to 30 carbon atoms preferably has 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.

R ³ 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, particularly preferably a hydrogen atom or an alkyl group having 1 to 30 carbon atoms. Atoms are more particularly preferred. Desirable ranges for these substituents are as described above. That is, 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 particularly preferably 1 to 6 carbon atoms. The aryl group having 6 to 30 carbon atoms preferably has 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.

As R ⁴ , R ⁵ , R ⁹ , R ¹⁰ or R ¹¹ , among them, 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. Desirable ranges for these substituents are as described above. That is, 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 particularly preferably 1 to 6 carbon atoms.

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, particularly a hydrogen atom or an alkyl group having 1 to 30 carbon atoms. Preferably, a hydrogen atom or a methyl group is more preferable. Desirable ranges for these substituents are as described above. That is, 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 particularly preferably 1 to 6 carbon atoms. The aryl group having 6 to 30 carbon atoms preferably has 6 to 20 carbon atoms, more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.

R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ or R ¹⁹ is more preferably a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom. preferable. Desirable ranges for these substituents are as described above. That is, 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 particularly preferably 1 to 6 carbon atoms.

R ¹³ , R ¹⁴ or R ¹⁸ is preferably a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms, more preferably a hydrogen atom, a methyl group, or 6 to 30 carbon atoms. Are particularly preferred. Desirable ranges for these substituents are as described above. That is, 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 particularly preferably 1 to 6 carbon atoms. The aryl group having 6 to 30 carbon atoms preferably has 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 condensed 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 form a condensed ring, and R ¹⁴ and R ¹⁵ are bonded to each other. More preferably, a condensed ring is formed. Among the above condensed rings, a 6-membered ring is preferably formed, and a benzene ring is more preferably formed.

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

When adjacent R ^{12 to} R ¹⁹ are each bonded to form a condensed ring, it is preferably any of the following structures (L-1) to (L-3), (L-1) or ( L-3) is more preferable, and (L-3) is particularly preferable.

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. And most preferably a hydrogen atom.

Further, the method of introducing a substituent to R ¹ to R ¹⁹ of the iridium complex represented by the general formula (1) according to the present invention, it is possible to control the emission wavelength of an iridium complex. For example, when a fluorine atom is introduced into R ¹⁶ or R ¹⁸ , light emission is shifted by a short wavelength. Further, when a trifluoromethyl group or a cyano group is introduced into R ¹⁷ , light emission is shifted by a short wavelength.

In addition, 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 commercially available boronic acid compound as shown by the formula (C) is used. Thus, 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 condensed 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 condensed 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 condensed 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 represents 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 substituent are the same as 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 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.

  In order 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).

  In addition to the iridium complex of the present invention represented by the general formula (1), International Publication No. 2012/166608 (Patent Document 7), International Publication No. 2010/056669 (Patent Document 8), International Publication 2010 / 111755 (Patent Document 9) or International Publication 2012/158851 (Patent Document 10) or other known documents.

In general, when synthesizing heteroleptic iridium complexes, scrambling of the ligand is likely to occur when different cyclometalated ligands are introduced, and the polarity of the resulting impurities is similar. Therefore, it is disclosed that separation and purification is very 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, for the iridium complex represented by the general formula (1) according to the present invention, it was revealed that ligand scrambling hardly occurs unexpectedly during the synthesis. Further, it has been found that even when ligand scrambling occurs during synthesis, a by-product can be easily separated using, for example, silica gel column chromatography.

About 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) The ligand represented by the general formula (3) and adjacent R ¹² and R ¹³ , R ¹³ and R ¹⁴ , or R ¹⁴ and R ^15. Any one of these are bonded to each other to form a condensed ring. Thus, in addition to the completely different basic skeletons of the two types of ligands represented by the general formulas (2) and (3), the polarities of these ligands are greatly different. The present inventors consider that the by-product generated by scrambling has also become easier to separate and purify.

  The iridium complex according to the present invention can be provided after being treated according to the post-treatment of a normal synthesis reaction, and if necessary, with or without purification. As a 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 or the like can be performed alone or in combination.

  Although the typical example of the iridium complex shown by General formula (1) based on this invention below is shown in Table 1-Table 3, this invention is not limited to these.

  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 material of an organic light emitting device. In addition, an organic light-emitting element (preferably an organic electroluminescent element) can be manufactured using a light-emitting material including the iridium complex of the present invention.

  In addition, by using the iridium complex represented by the general formula (1) according to the present invention, an organic light-emitting element, a light-emitting device, or a lighting device with high emission efficiency can be realized. Furthermore, an organic light-emitting element, a light-emitting device, or a lighting device with low power consumption can be realized.

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

  Next, the organic electroluminescent element produced using the iridium complex represented by the general formula (1) of the present invention will be described. The organic electroluminescent element is an element in which a plurality 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. In general, the light emitting layer is composed of a light emitting material and a host material.

As typical device configurations in the organic electroluminescent device of the present invention, for example, there are 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) Anode / 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 blocking 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 which comprises the organic electroluminescent element of this invention is demonstrated.

<Light emitting layer>
The light-emitting layer is a layer that recombines electrons and holes injected from the electrode and emits light via excitons. Even if the light-emitting portion is within the layer of the light-emitting layer, the light-emitting layer and the adjacent layer It may be an interface.

  As a film thickness of a light emitting layer, the range of 2 nm-1000 nm is preferable, More preferably, it is the range of 2-200 nm, More preferably, it is the range of 3-150 nm.

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

  As a luminescent material, the iridium complex represented by General formula (1) based on this invention may be contained individually or in multiple types, and another luminescent material 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, and 1 to 30%. Is more preferable, and 5 to 20% is particularly preferable.

  Specific examples of other light-emitting materials include anthracene derivatives, pyrene derivatives, chrysene derivatives, fluoranthene derivatives, perylene derivatives, fluorene derivatives, arylacetylene derivatives, styrylarylene derivatives, styrylamine derivatives, arylamine derivatives, boron complexes, squalium. 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 mainly responsible for charge injection and transport in the light emitting layer. Moreover, it is preferable that the mass ratio in the layer among the compounds contained in a light emitting layer is 20% or more. More preferably, it is 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 preferred.

  One or more host materials may be used. By using a plurality of types of host compounds, charge transfer can be adjusted and the organic electroluminescence device can be made highly efficient.

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

  Specific examples of host materials include triarylamine derivatives, phenylene derivatives, condensed ring aromatic compounds (for example, naphthalene derivatives, phenanthrene derivatives, fluorene derivatives, pyrene derivatives, tetracene derivatives, coronene derivatives, chrysene derivatives, perylene derivatives, 9, 10-diphenylanthracene derivatives or rubrene), quinacridone derivatives, acridone derivatives, coumarin derivatives, pyran derivatives, nile red, pyrazine derivatives, benzimidazole derivatives, benzothiazole derivatives, benzoxazole derivatives, stilbene derivatives, organometallic complexes (for example, tris (8-quinolinolato) organic aluminum complexes such as aluminum, organic beryllium complexes, organic iridium complexes, or organic platinum complexes), or poly (phenol Vinylene) derivatives, poly (fluorene) derivatives, poly (phenylene) derivatives, poly (polymer derivatives such as thienylene vinylene) derivatives or poly (acetylene) derivatives.

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

  Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, it is the range of 2-5000 nm, More preferably, it is the range of 2-500 nm, More preferably, it is the range of 5-200 nm.

  As a material used for the electron transport layer (hereinafter referred to as an electron transport material), any material that has either an electron injection property or a transport property or a hole barrier property may be used. Any one can be selected and used.

  Specific examples of the electron transporting material include nitrogen-containing aromatic heterocyclic derivatives (carbazole derivatives, organoaluminum complexes such as tris (8-quinolinolato) aluminum, azacarbazole derivatives (one or more carbon atoms constituting the carbazole ring) Substituted with a nitrogen atom), pyridine derivatives, pyrimidine derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, oxazole derivatives, thiazole derivatives, oxadiazole derivatives, triazole derivatives, benzimidazole derivatives or benzoxazole derivatives, etc. ), Dibenzofuran derivatives, dibenzothiophene derivatives, or aromatic hydrocarbon ring derivatives (such as naphthalene derivatives, anthracene derivatives, or triphenylene).

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

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

  The 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 a material used for a hole-blocking layer, the material used for the above-mentioned electron carrying layer is used preferably, and the above-mentioned host material is also preferably used as a material of a hole-blocking layer.

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

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

  Specific examples of materials that are preferably used for the electron injection layer include metals (strontium or aluminum), alkali metal compounds (lithium fluoride or sodium fluoride, etc.), alkaline earth metal compounds (magnesium fluoride or calcium fluoride). Etc.), metal oxides (such as aluminum oxide), or metal complexes (such as lithium 8-hydroxyquinolate (Liq)). Further, the above-described electron transport material can also be used. Furthermore, examples of the electron injecting material include a phenanthroline derivative lithium complex (LiPB) and a phenoxypyridine lithium complex (LiPP).

<Hole transport layer>
The hole transport layer is 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.

  Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, it is the range of 2-5000 nm, More preferably, it is the range of 5-500 nm, More preferably, it is the range of 5-200 nm.

  A material used for the hole transport layer (hereinafter referred to as a hole transport material) may have any of a hole injection property or a transport property, or an electron barrier property. Any one can be selected and used.

  Specific examples of hole transporting materials include porphyrin derivatives; phthalocyanine derivatives; oxazole derivatives; phenylenediamine derivatives; stilbene derivatives; triarylamine derivatives; carbazole derivatives; indolocarbazole derivatives; acene derivatives such as anthracene or naphthalene; Fluorene derivatives; fluorenone derivatives; polymer materials or oligomers in which polyvinyl carbazole or aromatic amine is introduced into the main chain or side chain; polysilanes; conductive polymers or oligomers (eg PEDOT: PSS, aniline copolymers, polyaniline, polythiophene, etc.) ) And the like.

<Electron blocking layer>
The electron blocking layer is a layer having a function of a hole transport 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 transporting electrons while transporting holes. The probability of recombination of electrons and holes can be improved by blocking.

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

  Moreover, the structure of the above-mentioned hole transport layer can be used as an electron blocking layer as needed.

<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 lower the driving voltage or improve the light emission luminance.

  Examples of materials used for the hole injection layer include conductive materials such as phthalocyanine derivatives represented by copper phthalocyanine, hexaazatriphenylene derivatives, metal oxides represented by vanadium oxide, amorphous carbon, polyaniline (emeraldine), and polythiophene. Preferred are a high molecular weight polymer, a cyclometalated complex represented by a tris (2-phenylpyridine) iridium complex, or a triarylamine derivative.

  The organic electroluminescent element of the present invention is preferably supported on a substrate. There is no restriction | limiting in particular about the raw material of a board | substrate, For example, glass, such as alkali glass, alkali free glass, or quartz glass, or a transparent plastic currently used in the conventional organic electroluminescent element is mentioned.

  Specifically, the material constituting the anode is a simple metal such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium or tungsten, or an alloy thereof, tin oxide, zinc oxide, indium oxide, oxide Metal oxides such as indium tin (ITO) or zinc indium oxide can be used. Further, conductive polymers such as polyaniline, polypyrrole, polythiophene or polyphenylene sulfide can also be used. These electrode materials may be used alone or in combination. Moreover, the anode may be composed of a single layer or 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, an alloy such as lithium-indium, sodium-potassium, magnesium-silver, aluminum-lithium, aluminum-magnesium, or magnesium-indium can be used. In addition, metal oxides such as indium tin oxide (ITO) can be used. These electrode materials may be used alone or in combination. The cathode may have a single layer structure or a multilayer structure.

  The organic light emitting device containing the iridium complex represented by the general formula (1) according to the present invention can be manufactured 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 the light emitting layer containing the iridium complex represented by the general formula (1) according to the present invention by a vacuum deposition method.

The vacuum deposition conditions for forming each layer such as a hole transport layer, a light emitting layer or an electron transport layer by a vacuum 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 deposit at a boat temperature of about -50 to 300 ° C. and a deposition rate of about 0.01 to 50 nm / second. When each layer such as a hole transport layer, a light-emitting layer, or an electron transport layer is formed using a plurality of materials, it is preferable to co-evaporate 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 is not construed as being limited to the examples. In addition, the compound corresponding to an Example is called "this invention compound", and the compound corresponding to a comparative example is called "comparison compound."

<Example I-1>
Synthesis of the present compound (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 (Lb)

2.18 g (40.3 mmol) of 2-chloro-5-methylpyrimidine, 9.26 g (46.8 mmol) of 3-biphenylboronic acid, 95 ml of 2M aqueous potassium carbonate solution and 70 ml of 1,2-dimethoxyethane were placed in a three-necked flask. After bubbling argon gas, 2.25 g (1.95 mmol) of tetrakis (triphenylphosphine) palladium (0) was added, and the mixture was heated to reflux for 24 hours under an argon atmosphere. After the reaction solution was cooled to room temperature, the organic layer was collected, the solvent was distilled off under reduced pressure, and the residue was purified using silica gel column chromatography (eluent: dichloromethane) to obtain the ligand (Lb). Yield 8.40 g (yield 84.7%). The compound was identified using ¹ H-NMR. ¹ H-NMR data of the ligand (Lb) are shown below.
¹ H-NMR (400 MHz / 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 present compound (K-2)

4.11 g (11.6 mmol) of iridium trichloride nhydrate, 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 bubbled for 30 minutes. Thereafter, irradiation with microwaves (2450 MHz) was performed for 30 minutes. The reaction solution was cooled to room temperature, the solvent was distilled off under reduced pressure to about 10 ml, and a solid was precipitated by adding methanol and pure water to obtain an intermediate (E). Yield 8.00 g (95.8% yield). Intermediate (E) synthesized by the above method (5.82 g, 4.05 mmol) was dispersed in a mixed solvent of 500 ml of dichloromethane and 500 ml of methanol, and argon gas was bubbled through the dispersion for 30 minutes. Thereafter, 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 performed through a celite layer, and the filtrate was distilled off under reduced pressure to obtain an intermediate (F). Yield 6.93 g (95.5% yield). To 0.441 g (0.939 mmol) of intermediate (F), 0.465 g (2.27 mmol) of 2-phenylquinoline and 50 ml of ethanol were added, and the mixture was heated to reflux for 3 days under an argon atmosphere. After cooling to room temperature, the solvent was distilled off under reduced pressure, and the residue was dissolved in 25 ml of dichloromethane. This was irradiated with a UV lamp (wavelength: 365 nm) for 3 hours, and the solvent was distilled off under reduced pressure. This was purified using silica gel column chromatography (eluent: dichloromethane) to obtain the compound (K-2) of the present invention as a facial product. Yield 0.7 mg (yield 0.08%). The compound was identified using ¹ H-NMR. ¹ H-NMR data of the present compound (K-2) are shown below.
¹ H-NMR (400 MHz / 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 the present compound (K-4)

3.00 g (8.23 mmol) of iridium trichloride 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 heated to reflux for 18 hours under an argon atmosphere. The reaction solution was cooled to room temperature, filtered, and washed with methanol and pure water to obtain intermediate (I). Yield 3.63 g (69.3% yield). Intermediate (I) 2.62 g (2.06 mmol), silver trifluoromethanesulfonate 1.15 g (4.48 mmol), methanol 140 ml and dichloromethane 220 ml were 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 a celite layer, and the filtrate was distilled off under reduced pressure to obtain an intermediate (J). Yield 3.31 g (98.8% yield). 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 to reflux for 2 days under an argon atmosphere. After cooling to room temperature, the solvent was distilled off under reduced pressure, and then the residue was dissolved in dichloromethane. This was 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 recrystallized by adding methanol. Thereafter, the product was recrystallized again with dichloromethane and methanol to obtain the compound (K-4) of the present invention which is a facial product. Yield 0.619 g (47.2% yield). The compound was identified using ¹ H-NMR. ¹ H-NMR data of the present compound (K-4) are shown below.
¹ H-NMR (400 MHz / 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 present compound (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。

Microwave (2450 MHz, 1000 W) while placing 21.7 g of iridium trichloride nhydrate, 28.4 g of 1-phenylisoquinoline, 440 ml of DMF and 60 ml of pure water in a three-necked flask, attaching a Dimroth condenser, and venting argon gas Was irradiated for 30 minutes. After the reaction solution was cooled to room temperature, the precipitate was collected by filtration and washed with pure water and methanol to obtain an intermediate (K) with a yield of 95%. Intermediate (K) 12.2 g, silver trifluoromethanesulfonate 5.15 g, methanol 400 ml and dichloromethane 1250 ml were placed in a three-necked flask and reacted at room temperature for 24 hours in 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) with a yield of 94%. Intermediate (L) 0.835 g, ligand (Lb) 0.504 g and ethanol 41 ml were added, and the mixture was reacted by heating at 95 ° C. for 30 hours in an argon atmosphere. After cooling the reaction solution to room temperature, the precipitate was collected by filtration and washed with methanol. This was dissolved in dichloromethane, filtered through Celite, the solvent was distilled off under reduced pressure, and the residue was purified using silica gel column chromatography (eluent: dichloromethane and hexane) to obtain facial forms (K-14) and (K- 16) were obtained in 1.6% and 15% yields, respectively.

¹ H-NMR data of the compound (K-14) of the present invention are shown below.
¹ H-NMR (400 MHz / 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).

¹ H-NMR data of the compound (K-16) of the present invention are shown below.
¹ H-NMR (400 MHz / 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 emission characteristics of the iridium complex according to the present invention will be described.

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

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

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

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

From the above, the compound of the present invention represented by the general formula (1) is bonded to any one of adjacent R ¹² and R ¹³ , R ¹³ and R ¹⁴ , or R ¹⁴ and R ^15. It has been found that by forming a condensed ring, light is efficiently emitted in the red region.

  Next, a sublimation purification experiment will be described 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.

<Example III-1>
Sublimation purification of the compound (K-4) of the present invention 153 mg of the compound (K-4) of the present invention was placed in a sublimation purification apparatus (P-200, manufactured by AE Technology Co., Ltd.), and the degree of vacuum was 1 × 10 ⁻⁴ Pa and the temperature was 310 to 310. When sublimation purification was performed over 9 hours under the condition of 340 ° C., the yield by sublimation purification was 95%, and no sublimation residue was present. In addition, when this invention compound (K-4) after sublimation purification was analyzed by HPLC, the purity fall by sublimation purification did not arise. It was revealed that the thermal stability and sublimation property of the compound (K-4) of the present invention are good.

<Example III-2>
Sublimation purification of the compound (K-16) of the present invention 93.5 mg of the compound (K-16) of the present invention was placed in a sublimation purification apparatus (P-200, manufactured by ALS Technology), and the degree of vacuum was 1 × 10 ⁻⁴ Pa, temperature When sublimation purification was performed over 9 hours under the conditions of 300 to 320 ° C., the yield by sublimation purification was 96%, and there was no sublimation residue. In addition, when the compound (K-16) of the present invention after sublimation purification was analyzed by HPLC, there was a slight decrease in purity due to sublimation purification, but it was only a decrease from purity 99.7% to purity 99.3%. It was. It was revealed that the compound (K-16) of the present invention has good thermal stability and sublimation properties.

<Comparative Example III-1>
Sublimation purification of comparative compound (1) 107 mg of comparative compound (1) is put into a sublimation purification apparatus (P-200, manufactured by AE Technology Co., Ltd.), under conditions of a vacuum degree of 1 × 10 ⁻⁴ Pa and a temperature of 300 to 335 ° C. Sublimation purification over 18 hours left much sublimation residue (10.2% of the input amount). In addition, when the comparative compound (1) after sublimation purification was analyzed by HPLC, purity reduction due to sublimation purification did not occur. 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 greatly reduced from the purity of 99.8% before the sublimation purification. Comparative compound (1) has a much slower sublimation rate than the compound of the present invention, and it was found that the decomposition reaction proceeds when sublimation purification is performed 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 the comparative compound (2) was put into a sublimation purification apparatus (P-200, manufactured by ALS Technology Co., Ltd.) and purified by sublimation 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). In addition, when the comparative compound (2) after sublimation purification was analyzed by HPLC, purity reduction due to sublimation purification occurred, and the purity decreased from 99.7% to 99.1%. Comparative compound (2) is lower in sublimability than the compound of the present invention, and requires a higher heating temperature and heating time. As a result, it can be seen that the decomposition reaction proceeds and the purity after sublimation purification decreases. It was.

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

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

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

<Comparative Example IV-1>
Luminescence characteristics in the co-deposited film of the comparative compound (1) with CBP The comparative compound (1) and CBP (E-3), which is a known host material, are applied on a quartz substrate at a vacuum degree of 1 × 10 ⁻⁴ Pa. 5:95 (mass concentration ratio) was co-evaporated (30 nm), and an 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 emitted green light (emission maximum wavelength: 526 nm). The emission quantum yield was 0.82.

  From the above, it has been clarified that the compound of the present invention has good sublimation properties and can be suitably used as a red light-emitting material by making it into a thin film state.

  Next, the characteristic of the organic electroluminescent element produced using the iridium complex represented by General formula (1) based on this invention is described.

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

On the transparent conductive support substrate, the following organic layers (a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, and an electron transport layer) are resistively heated in a vacuum chamber of 1 × 10 ⁻⁴ Pa. Are sequentially formed by vacuum evaporation, and then the mask is changed, and electrode layers (electron injection layer and metal electrode layer) having a line width of 2 mm are sequentially formed to form an organic electroluminescent element (element shape: 2 mm × 2 mm square, Element area; 0.04 cm ² ) was produced. Next, an operation of sealing in a glove box in a nitrogen atmosphere was performed so that the element was not exposed to the air. A UV curable epoxy resin denatite R (manufactured by Nagase Chemitech) is applied to the periphery of a sealing glass (manufactured by Senyo Shoji Co., Ltd.) with a 1.5 mm dug in the center of a 3 mm thick glass plate and vapor deposited. After the element was covered and pressure-bonded, the element portion was covered with an aluminum plate and masked, and then irradiated with a UV irradiation apparatus with a shutter for 1 minute and then sealed for 1 minute by repeating the shielding cycle 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%) are 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

  Structural formulas of compounds (E-1) to (E-6) are shown below.

The obtained organic electroluminescence device is set in a sample holder of an integrating sphere unit A10094 for EL external quantum yield measurement manufactured by Hamamatsu Photonics, and a direct current constant voltage is applied to emit light by using a source meter 2400 manufactured by Keithley. The brightness, emission wavelength, and CIE chromaticity coordinates were measured using a multichannel spectrometer PMA-12 manufactured by Hamamatsu Photonics. 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 Organic Electroluminescent Device Produced Using Compound (K-16) of the Present Invention The compound (K-16) of the present invention was used in place of the compound (K-4) of the present invention used in Example V-1. Except for the above, an organic electroluminescent element was produced in the same manner and evaluated for characteristics. 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. FIG. 1 shows an EL spectrum of an organic electroluminescence device produced using the compound (K-16) of the present invention.

  As described above, the iridium complex represented by the general formula (1) according to the present invention is a novel compound that is excellent in thermal stability and sublimation properties and exhibits a high emission quantum yield mainly 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. An organic light emitting device using the compound exhibits high luminance light emission in the visible light region (mainly red region), and thus is suitable for fields such as a display device, a display, a backlight, and an illumination light source.

Claims (11)

An iridium complex represented by the following general formula (1):

(In 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 each independently a hydrogen atom or a carbon number of 1 to 30. An alkyl group, an aryl group having 6 to 30 carbon atoms, a halogen atom or a cyano group, wherein R ¹² , R ^{15 to} R ¹⁷ and R ¹⁹ are each independently a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, Represents a halogen atom or a cyano group, wherein the alkyl group may be substituted with an aryl group, a halogen atom or a cyano group, and 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 each other to form a condensed ring, m is an integer of 1 or 2, and n is 1 Or 2 And m + n is 3.) Iridium complex according to claim 1, R ¹² to R ¹⁹ is characterized in that it is a hydrogen atom or an alkyl group of 1 to 30 carbon atoms. The iridium complex according to claim 1, wherein R ¹² and R ¹³ are bonded to form a condensed ring. The iridium complex according to claim 1 or 2, wherein R ¹⁴ and R ¹⁵ are bonded to form a condensed ring. At least one iridium complex according to any one of claims 1 to 4, characterized in that the halogen atom of R ¹² to R ^{19. R 4, R 5, R 9} , iridium complex according to any one of claims 1-5, characterized in that ^{R 10} are both hydrogen atoms.   The iridium complex according to any one of claims 1 to 6, wherein m is 2 and n is 1.   The iridium complex according to any one of claims 1 to 6, wherein m is 1 and n is 2.   It is a facial body, The iridium complex as described in any one of Claims 1-8 characterized by the above-mentioned.   A luminescent material comprising the iridium complex according to claim 1.   An organic light emitting device comprising the light emitting material according to claim 10.

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