WO2018212251A1 - Iridium complex having phenyltriazole ligand and light-emitting material using said compound - Google Patents

Abstract

Provided is an iridium complex represented by general formula (1) having a phenyltriazole ligand that presents an emission spectrum that has a narrow half-value width in the visible light region (especially the blue region). (In general formula (1), Ir represents an iridium atom, and N represents a nitrogen atom. X1 represents N or C(R8), and C represents a carbon atom. Z1 represents N or C(R12). Z2 represents N or C(R13). However, when Z1 is N, Z2 is C(R13), and when Z1 is C(R12), Z2 is N. L represents an anionic bidentate ligand. When multiple L are present, each may be the same or different. m represents 1-3, and n represents 0-2. However, m + n = 3. The other symbols are as described in the specification.)

Description

Iridium complex having phenyltriazole ligand and luminescent material using the compound

The present invention relates to an iridium complex that is suitably used as a light-emitting material such as an organic electroluminescent element.

Organic electroluminescent devices are attracting attention as displays for televisions and mobile phones, and there is a strong demand for improving luminous efficiency for practical use in the future. Luminescent materials used for organic electroluminescent elements can be broadly classified into fluorescent materials that utilize light emission from an excited singlet state and phosphorescent materials that utilize light emission from an excited triplet state. In organic electroluminescent elements, the use of a phosphorescent material as a light emitting material results in four times the light emission efficiency in principle compared to conventional fluorescent materials, and therefore phosphorescent materials have been actively developed.

For example, iridium complexes having phenyltriazole ligands have been disclosed as phosphorescent materials that efficiently emit light in the blue region (see Patent Documents 1 to 4).

International Publication No. 2004/101707 Pamphlet International Publication No. 2016/006523 Pamphlet JP 2012-46479 A International Publication No. 2016/203350 Pamphlet

The iridium complexes having a phenyltriazole ligand described in Patent Documents 1 to 4 exhibit light emission in the blue region, but the emission spectrum has a broad shape and has a problem of poor blue purity. In a luminescent material for display applications, it is strongly desired to show a narrow emission spectrum with a full width at half maximum (Full Width at Half Maximum: FWHM).

An object of the present invention is to provide a phenyltriazole iridium complex exhibiting a light emission spectrum with a narrow half width, and a light emitting material using the compound.

In view of the above situation, the present inventors have conducted extensive research on the ligand structure of the phenyltriazole iridium complex, and as a result, the specific position of the phenyltriazole ligand (the para-position relative to the carbon atom of the phenyl group that binds to iridium). ), By introducing the specific substituent represented by the general formula (A), the emission spectrum of the iridium complex is unexpectedly sharpened (the half-value width is narrowed), and blue light emission with good color purity is achieved. As a result, the present invention has been completed.

（一般式（Ａ）中、＊はフェニルトリアゾールとの結合部位である。一般式（Ａ）中のＮ、Ｘ^１、Ｒ^６およびＲ^７は、後述する一般式（１）中のＮ、Ｘ^１、Ｒ^６およびＲ^７と同一である。） Formula (A)

(In General Formula (A), * is a bonding site with phenyltriazole. N, X ¹ , R ⁶ and R ^{7 in} General Formula (A) are N, X in General Formula (1) described later. ¹ , R ⁶ and R ⁷ are the same.)

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

（一般式（１）中、Ｉｒはイリジウム原子を表し、Ｎは窒素原子を表す。Ｘ^１は、ＮまたはＣ（Ｒ^８）を表し、Ｃは炭素原子を表す。Ｚ^１は、ＮまたはＣ（Ｒ^１２）を表す。Ｚ^２は、ＮまたはＣ（Ｒ^１３）を表す。但し、Ｚ^１がＮであるときはＺ^２がＣ（Ｒ^１３）であり、Ｚ^１がＣ（Ｒ^１２）であるときはＺ^２がＮである。Ｒ^１およびＲ^２は、各々独立に、水素原子、アルキル基、または、アリール基を表す。Ｒ^６およびＲ^７は、各々独立に、アルキル基を表す。Ｒ^３～Ｒ^５、および、Ｒ^８～Ｒ^１１は、各々独立に、水素原子、アルキル基、アリール基、アルキルシリル基、複素環基、アルコキシ基、アリールオキシ基、シアノ基、または、ハロゲン原子を表す。Ｒ^１２およびＲ^１３は、各々独立に、アルキル基、または、アリール基を表す。また隣り合ったＲ^１～Ｒ^１３は結合して環構造を形成してもよい。Ｌはアニオン性２座配位子を表す。Ｌが複数存在するときは、各々、同一でも異なっても良い。ｍ＝１～３を表し、ｎ＝０～２を表す。但し、ｍ＋ｎ＝３である。）
＜２＞Ｚ^１がＣ（Ｒ^１２）であり、Ｚ^２がＮであることを特徴とする、前記＜１＞に記載のイリジウム錯体。
＜３＞Ｚ^１がＮであり、Ｚ^２がＣ（Ｒ^１３）であることを特徴とする、前記＜１＞に記載のイリジウム錯体。
＜４＞Ｒ^１２およびＲ^１３が、各々独立に、アルキル基であることを特徴とする、前記＜１＞～＜３＞の何れかに記載のイリジウム錯体。
＜５＞Ｌが芳香族複素環２座配位子であることを特徴とする、前記＜１＞～＜４＞の何れかに記載のイリジウム錯体。
＜６＞Ｌが、下記一般式（Ｂ）～（Ｄ）の何れかから選ばれることを特徴とする前記＜１＞～＜５＞の何れかに記載のイリジウム錯体。

（一般式（Ｂ）～（Ｄ）中、Ｎは窒素原子を表す。Ｒ^１およびＲ^２は、各々独立に、水素原子、アルキル基、または、アリール基を表す。Ｒ^３～Ｒ^５、Ｒ^９～Ｒ^１１、Ｒ^ａ、Ｒ^ｘ、Ｒ^ｙ、および、Ｒ^ｚは、各々独立に、水素原子、アルキル基、アリール基、アルキルシリル基、複素環基、アルコキシ基、アリールオキシ基、シアノ基、または、ハロゲン原子を表す。Ｒ^１２およびＲ^１３は、各々独立に、アルキル基、または、アリール基を表す。また隣り合ったＲ^１～Ｒ^５、Ｒ^９～Ｒ^１１、Ｒ^ａ、Ｒ^ｘ、Ｒ^ｙ、および、Ｒ^ｚは結合して環構造を形成してもよい。＊はイリジウムとの結合部位を表す。）
＜７＞ｍ＝３、ｎ＝０であることを特徴とする、前記＜１＞～＜４＞の何れかに記載のイリジウム錯体。
＜８＞ｍ＝２、ｎ＝１であることを特徴とする、前記＜１＞～＜６＞の何れかに記載のイリジウム錯体。
＜９＞ｍ＝１、ｎ＝２であることを特徴とする、前記＜１＞～＜６＞の何れかに記載のイリジウム錯体。
＜１０＞室温下、ＴＨＦまたはトルエン中における発光スペクトルの半値幅が５５ｎｍ以下であることを特徴とする、前記＜１＞～＜９＞の何れかに記載のイリジウム錯体。
＜１１＞前記＜１＞～＜１０＞の何れかに記載のイリジウム錯体を含むことを特徴とする、発光材料。
＜１２＞前記＜１１＞に記載の発光材料を含むことを特徴とする、発光素子。 <1> An iridium complex represented by the following general formula (1).

(In the general formula (1), Ir represents an iridium atom, N represents a nitrogen atom, X ¹ represents N or C (R ⁸ ), C represents a carbon atom, Z ¹ represents N or C .Z ² representing the ^{(R 12)} represents an N or C ^{(R 13).} However, when ^{Z 1} is N is ^{Z 2} is C ^{(R 13), Z 1} is C ^{(R 12)} And Z ² is N. R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, or an aryl group, and R ⁶ and R ⁷ each independently represent an alkyl group. R ³ to R ⁵ and R ⁸ to R ¹¹ are each independently a hydrogen atom, an alkyl group, an aryl group, an alkylsilyl group, a heterocyclic group, an alkoxy group, an aryloxy group, a cyano group, or a halogen atom ^{.R 12} and ^{R 13} represent the atoms are each independently an alkyl group also Represents an aryl group. The R ^{1 ~} R ^13, which adjacent good be bonded to form a ring structure .L when .L representing an anionic bidentate ligand there is a plurality, respectively, They may be the same or different, m = 1 to 3 and n = 0 to 2, provided that m + n = 3.
<2> The iridium complex according to <1>, wherein Z ¹ is C (R ¹² ) and Z ² is N.
<3> The iridium complex according to <1>, wherein Z ¹ is N and Z ² is C (R ¹³ ).
<4> The iridium complex according to any one of <1> to <3>, wherein R ¹² and R ¹³ are each independently an alkyl group.
<5> The iridium complex according to any one of <1> to <4>, wherein L is an aromatic heterocyclic bidentate ligand.
<6> The iridium complex according to any one of <1> to <5>, wherein L is selected from any of the following general formulas (B) to (D):

(In the general formulas (B) to (D), N represents a nitrogen atom. R ¹ and R ² each independently represents a hydrogen atom, an alkyl group, or an aryl group. R ³ to R ⁵ , R ⁹ to R ¹¹ , R ^a , R ^x , R ^y , and R ^z are each independently a hydrogen atom, an alkyl group, an aryl group, an alkylsilyl group, a heterocyclic group, an alkoxy group, an aryloxy group, or a cyano group. R ¹² and R ¹³ each independently represents an alkyl group or an aryl group, and adjacent R ¹ to R ⁵ , R ⁹ to R ¹¹ , R ^a , R ^x , R ^y , and R ^z may combine to form a ring structure, and * represents a binding site with iridium.)
<7> The iridium complex according to any one of <1> to <4>, wherein m = 3 and n = 0.
<8> The iridium complex according to any one of <1> to <6>, wherein m = 2 and n = 1.
<9> The iridium complex according to any one of <1> to <6>, wherein m = 1 and n = 2.
<10> The iridium complex according to any one of <1> to <9>, wherein a half-value width of an emission spectrum in THF or toluene at room temperature is 55 nm or less.
<11> A luminescent material comprising the iridium complex according to any one of <1> to <10>.
<12> A light emitting device comprising the light emitting material according to <11>.

Since the novel iridium complex of the present invention exhibits strong light emission in the visible light region (particularly the blue region) at room temperature, it can be suitably used as a light-emitting material for various applications. In addition, a light-emitting element using the compound exhibits sharp light emission with a narrow half width, and thus is suitable for display applications.

FIG. 3 is an emission spectrum of the compound (Ir-25) of the present invention and the comparative compound (1) in THF at room temperature. The solid line shows the emission spectrum of the compound (Ir-25) of the present invention, and the broken line shows the emission spectrum of the comparative compound (1).

Next, the present invention will be described in detail with reference to embodiments, but the present invention is not construed as being limited to these descriptions. 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 (such as a deuterium atom), and an atom constituting a substituent further includes the isotope.

First, symbols (Ir, N, C, X ¹ , Z ¹ , Z ² , R ¹ to R ¹³ , L, m, n) described in the general formula (1) will be described below.

Ir represents an iridium atom, N represents a nitrogen atom, and C represents a carbon atom.

X ¹ represents N or C (R ⁸ ). Z ¹ represents N or C (R ¹² ). Z ² represents N or C (R ¹³ ). However, when Z ¹ is N, Z ² is C (R ¹³ ), and when Z ¹ is C (R ¹² ), Z ² is N.

R ¹ and R ² each independently represents a hydrogen atom, an alkyl group, or an aryl group. Among these, an alkyl group or an aryl group is preferable, an alkyl group is more preferable, and an unsubstituted alkyl group is particularly preferable. Specifically, a methyl group or an iso-propyl group is more particularly preferable, and a methyl group is most preferable. R ¹ and R ² may be the same or different, and are preferably the same.

R ⁶ and R ⁷ each independently represents an alkyl group. Among these, an unsubstituted alkyl group is preferable, and a branched alkyl group is more preferable. Specifically, an iso-propyl group or a t-butyl group is more preferable, and a t-butyl group is particularly preferable. R ⁶ and R ⁷ may be the same or different and are preferably the same.

When R ⁶ and R ⁷ are alkyl groups (preferably branched alkyl groups), side reactions (reactions in which iridium is coordinated to the nitrogen atom of formula (A)) are suppressed due to steric hindrance. In this respect, the alkyl group is more preferably a branched alkyl group. For example, when R ⁶ and R ⁷ are t-butyl groups, as shown below, iridium can be coordinated to the triazole ring, but iridium is difficult to coordinate to the triazine ring due to steric hindrance of the branched alkyl group. It is. Therefore, it is more preferable that R ⁶ and R ⁷ are alkyl groups, preferably branched alkyl groups, because the yield of the iridium complex represented by the general formula (1) of the present invention is greatly improved.

On the other hand, when R ⁶ or R ⁷ is an aryl group (for example, a phenyl group), as shown below, iridium can also be coordinated with a triazine ring, and is represented by the desired general formula (1). Since the yield of an iridium complex falls remarkably, it is not preferable.

R ³ to R ⁵ and R ⁸ to R ¹¹ are each independently a hydrogen atom, an alkyl group, an aryl group, an alkylsilyl group, a heterocyclic group, an alkoxy group, an aryloxy group, a cyano group, or a halogen atom. And is preferably a hydrogen atom, an alkyl group, an aryl group, or a halogen atom, and more preferably a hydrogen atom, an alkyl group, or an aryl group.

Among these, R ³ and R ⁵ are each independently preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom. R ⁴ is particularly preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom or a methyl group. R ⁹ and R ¹⁰ are particularly preferably a hydrogen atom. R ⁸ and R ¹¹ are each independently preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

R ¹² and R ¹³ each independently represents an alkyl group or an aryl group. Among these, an alkyl group or an aryl group substituted with an alkyl group is preferable, an alkyl group is more preferable, and an unsubstituted alkyl group is particularly preferable. Specifically, a methyl group, an ethyl group, an n-propyl group, or an iso-propyl group is more preferable, and a methyl group or an n-propyl group is particularly preferable.

When R ¹² and R ¹³ are alkyl groups, of the two nitrogen atoms that are not bonded to the phenyl group on the triazole ring, the nitrogen atoms that do not coordinate with iridium (coordination-free nitrogen) are protected. With this structural feature, it is possible to suppress the oxidation of coordination-free nitrogen by oxygen or the like, and the formation of coordination bonds between coordination-free nitrogen and iridium, and the target iridium complex can be obtained with high yield. Furthermore, the thermal stability of the iridium complex is improved.

When R ¹² and R ¹³ are aryl groups, there are a plurality of iridium coordination patterns as described below, and therefore, a plurality of products may be obtained in addition to the desired iridium complex.

Therefore, when R ¹² and R ¹³ are an aryl group, in order to suppress coordination of iridium with the aryl group, for example, the aryl group may be substituted with an alkyl group as follows. preferable.

It is not preferable that R ¹² and R ¹³ are arylalkyl groups because the thermal stability of the iridium complex is lowered. In addition, since there are a plurality of coordination patterns of iridium as described below, there is a problem that the yield of the desired iridium complex decreases.

When R ¹² and R ¹³ are hydrogen atoms, the phenyltriazole ligand is thermally unstable and decomposes, so that a desired iridium complex can hardly be obtained.
From these viewpoints, selection of substituents for R ¹² and R ¹³ is particularly important for an iridium complex having a phenyltriazole ligand.

Adjacent R ¹ to R ¹³ may combine to form a ring structure. As the ring structure, a saturated carbocyclic ring or an unsaturated carbocyclic ring is preferable, an unsaturated carbocyclic ring is more preferable, and a benzene ring is particularly preferable. The ring structure may be substituted with an alkyl group or an aryl group.

L represents an anionic bidentate ligand. Among the anionic bidentate ligands, an aromatic heterocyclic bidentate ligand or a β-diketone ligand is preferable, and an aromatic heterocyclic bidentate ligand is more preferable. Aromatic heterocyclic bidentate ligands include 2-phenylpyridine, 2-phenylimidazole, 5-phenyl-1,2,4-triazole, 3-phenyl-1,2,4-triazole, 1-phenylpyrazole 2-phenylpyrimidine or imidazo [1,2-f] phenanthridine is preferable, 5-phenyl-1,2,4-triazole, 3-phenyl-1,2,4-triazole, 1-phenylpyrazole Or imidazo [1,2-f] phenanthridine, more preferably 5-phenyl-1,2,4-triazole, 3-phenyl-1,2,4-triazole or 1-phenylpyrazole. preferable. As the β-diketone ligand, 2,4-pentanedione, 2,6-dimethyl-3,5-heptanedione, and 2,2,6,6-tetramethyl-3,5-heptanedione are preferable. 1,4-pentanedione is more preferred. Further, when there are a plurality of L, they may be the same or different.

The above anionic bidentate ligand may have a substituent. Examples of the substituent include an alkyl group, an aryl group, an alkylsilyl group, a heterocyclic group, an alkoxy group, an aryloxy group, a cyano group, or a halogen atom, an alkyl group, an aryl group, an alkylsilyl group, a heterocyclic group, A cyano group or a halogen atom is preferred, an alkyl group, an aryl group or a halogen atom is more preferred, and an alkyl group or an aryl group is particularly preferred.

　一般式（Ｂ）～（Ｄ）中の記号Ｒ^１～Ｒ^５、Ｒ^９～Ｒ^１１、および、Ｒ^１２、Ｒ^１３は、一般式（１）の記号と同じである。Ｒ^ａ、Ｒ^ｘ、Ｒ^ｙ、および、Ｒ^ｚは、各々独立に、一般式（１）中のＲ^３～Ｒ^５、および、Ｒ^８～Ｒ^１１と同じ原子又は置換基から選択される原子または置換基を表す。また隣り合ったＲ^１～Ｒ^５、Ｒ^９～Ｒ^１１、Ｒ^ａ、Ｒ^ｘ、Ｒ^ｙ、および、Ｒ^ｚは結合して環構造を形成してもよい。＊はイリジウムとの結合部位を表す。Ｒ^ａ、Ｒ^ｘ、Ｒ^ｙ、および、Ｒ^ｚとしては、水素原子、アルキル基、アリール基、複素環基、または、ハロゲン原子であることが好ましく、水素原子、アルキル基、または、アリール基であることがより好ましく、水素原子、または、アルキル基であることが特に好ましい。置換基として望ましい範囲は、Ｒ^３～Ｒ^５、および、Ｒ^８～Ｒ^１１と同様である。 It is also preferred that L is selected from any of the following general formulas (B) to (D).

The symbols R ¹ to R ⁵ , R ⁹ to R ¹¹ , and R ¹² and R ¹³ in the general formulas (B) to (D) are the same as the symbols in the general formula (1). R ^a , R ^x , R ^y , and R ^z are each independently an atom selected from the same atoms or substituents as R ³ to R ⁵ and R ⁸ to R ¹¹ in general formula (1) Or represents a substituent. Adjacent R ¹ to R ⁵ , R ⁹ to R ¹¹ , R ^a , R ^x , R ^y , and R ^z may combine to form a ring structure. * Represents a binding site with iridium. R ^a , R ^x , R ^y , and R ^z are preferably a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, or a halogen atom, and are a hydrogen atom, an alkyl group, or an aryl group. More preferably, it is particularly preferably a hydrogen atom or an alkyl group. Desirable ranges for the substituent are the same as those for R ³ to R ⁵ and R ⁸ to R ¹¹ .

M represents 1 to 3, m = 2 or 3 is preferable, and m = 3 is more preferable. n represents 0 to 2, preferably n = 0 or 1, and more preferably n = 0. However, m + n = 3. m = 2 is more preferable than m = 1 because the half-value width of the emission spectrum of the iridium complex of the present invention tends to be narrower. Furthermore, m = 2 is more preferable than m = 2 because the half-value width of the emission spectrum of the iridium complex of the present invention tends to be narrower.

The alkyl group in the present specification may be substituted with at least one selected from an alkylsilyl group, a heterocyclic group, an alkoxy group, an aryloxy group, or a halogen atom, and further substituted with these substituents. Also good.

The aryl group in the present specification may be substituted with at least one selected from an alkyl group, an aryl group, an alkylsilyl group, a heterocyclic group, an alkoxy group, an aryloxy group, a cyano group, or a halogen atom, These substituents may be further substituted.

The alkylsilyl group in the present specification may be substituted with at least one selected from an alkyl group, an aryl group, an alkylsilyl group, a heterocyclic group, an alkoxy group, an aryloxy group, a cyano group, or a halogen atom. Further, these substituents may be further substituted.

The heterocyclic group in the present specification may be substituted with at least one selected from an alkyl group, an aryl group, an alkylsilyl group, a heterocyclic group, an alkoxy group, an aryloxy group, a cyano group, or a halogen atom. Further, these substituents may be further substituted.

The alkoxy group in the present specification may be substituted with at least one selected from an alkyl group, an aryl group, an alkylsilyl group, a heterocyclic group, an alkoxy group, an aryloxy group, a cyano group, or a halogen atom, These substituents may be further substituted.

The aryloxy group in the present specification may be substituted with at least one selected from an alkyl group, an aryl group, an alkylsilyl group, a heterocyclic group, an alkoxy group, an aryloxy group, a cyano group, or a halogen atom. Further, these substituents may be further substituted.

The alkyl group in the present specification does not include the carbon number of the substituent, and preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, 1 to 6 is more particularly preferable.

As the alkyl group in the present specification, 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 are preferable. 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 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 methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s -Butyl group, isobutyl group, t-butyl group, n-pentyl group, neopentyl group or 1-methylpentyl group, particularly preferably a methyl group.

The aryl group in the present specification does not include the carbon number of the substituent, and preferably has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, 6 to 12 is more particularly preferable.

As the aryl group in the present specification, 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-terphenyl is preferable. -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, pt-butylphenyl group, p- (2-phenylpropyl) phenyl group, 4′-methylbiphenylyl group, 4 ″ -t-butyl-p-terphenyl- 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 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-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 alkylsilyl group in the present specification does not include the carbon number of the substituent, and preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, Numbers 1 to 6 are more particularly preferable.

The alkylsilyl group in the present specification is preferably a trimethylsilyl group, a triethylsilyl group, a triisopropylsilyl group, a dimethylphenyl group, a t-butyldimethylsilyl group, or a t-butyldiphenylsilyl group, and more preferably a trimethylsilyl group. An isopropylsilyl group, a t-butyldimethylsilyl group, and a t-butyldiphenylsilyl group.

The heterocyclic group in the present specification does not include the carbon number of the substituent, preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, Numbers 1 to 6 are more particularly preferable.

As the heterocyclic group in the present specification, preferably an imidazolyl group, a pyridyl group, a pyrimidyl group, a triazyl group, a pyrazyl group, a pyridazyl group, a quinolyl group, a furyl group, a thienyl group, a dibenzothienyl group, a piperidyl group, a morpholino group, A benzoxazolyl group, a benzimidazolyl group, a benzthiazolyl group, a carbazolyl group, or an azepinyl group;

The alkoxy group in the present specification does not include the carbon number of the substituent, preferably has 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms, 1 to 6 is more particularly preferable.

As the alkoxy group in the present specification, a methoxy group, an ethoxy group, an isopropoxy group, and a t-butoxy group are preferable.

In the present specification, aryloxy does not include the carbon number of the substituent, and preferably has 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, 6 to 12 is more particularly preferable.

As the aryloxy group in the present specification, preferably a phenoxy group, a 2-methylphenoxy group, a 4-methylphenoxy group, a 2,6-dimethylphenoxy group, a 2,4-di-t-butylphenoxy group, 2, 6-di-t-butylphenoxy group, 2,6-di-t-butyl-4-methylphenoxy group, 2,6-di-t-butyl-4-ethylphenoxy group, 2,6-diphenylphenoxy group, A 1-naphthoxy group, a 2-naphthoxy group, a 9-phenanthryloxy group, a 1-pyrenyloxy group, and a 7-methoxy-2-naphthoxy group, more preferably a phenoxy group.

The halogen atom in the present specification is preferably a chlorine atom, a bromine atom, an iodine atom, or a fluorine atom, and more preferably a bromine atom or a fluorine atom.

Hereinafter, the iridium complex represented by the general formula (1) of the present invention will be described in more detail.

In the general formula (1), when m = 3 and n = 0, iridium complexes represented by the general formulas (2) to (5) are preferable examples.

In the general formula (1), when m = 2 and n = 1, iridium complexes represented by the general formulas (6) to (13) are preferable examples.

In the general formula (1), when m = 1 and n = 2, preferred forms include iridium complexes represented by the general formulas (14) to (25).

（一般式（２）～（２５）中の記号Ｒ^１～Ｒ^１３は、一般式（１）の記号と同じである。Ｒ^ａ、Ｒ^ｘ、Ｒ^ｙ、およびＲ^ｚは、各々独立して、一般式（１）中のＲ^３～Ｒ^５、および、Ｒ^８～Ｒ^１１と同じ原子または置換基から選択される原子または置換基を表す。ｎ＝２であり、Ｌが２つのフェニルトリアゾール配位子であるとき、２つのフェニルトリアゾール配位子のＲ^１～Ｒ^５、Ｒ^９～Ｒ^１３、およびＲ^ａは、各々、同一でも異なっても良い。）

(The symbols R ¹ to R ¹³ in the general formulas (2) to (25) are the same as the symbols in the general formula (1). R ^a , R ^x , R ^y , and R ^z are each independently Represents an atom or substituent selected from the same atom or substituent as R ³ to R ⁵ and R ⁸ to R ¹¹ in the general formula (1), n = 2, and L is two phenyltriazoles When it is a ligand, R ¹ to R ⁵ , R ⁹ to R ¹³ , and R ^a of the two phenyltriazole ligands may be the same or different.)

One of the excellent properties of the iridium complex represented by the general formula (1) according to the present invention is extremely high thermal stability. The iridium complex of the present invention has a structural feature in which an aryl group is bonded to the nitrogen atom of the triazole ring, and a general formula in which an alkyl group (for example, a methyl group, an ethyl group, or a cyclohexyl group) is bonded to the nitrogen atom of the triazole ring. Compared with the iridium complex represented by (26), the thermal stability is high. It was revealed that the thermal stability of the iridium complex was dramatically improved by directly bonding the aryl group to the nitrogen atom of the triazole ring (see Examples described later).

（一般式（２６）中の記号Ｘ^１、Ｚ^１、Ｚ^２、Ｒ^６、Ｒ^７、Ｒ^９～Ｒ^１１、Ｌ、ｍおよびｎは、一般式（１）の記号と同じである。Ｒ^ｂはアルキル基を表す。）

(The symbols X ¹ , Z ¹ , Z ² , R ⁶ , R ⁷ , R ⁹ to R ¹¹ , L, m and n in the general formula (26) are the same as the symbols in the general formula (1). ^b represents an alkyl group.)

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 is preferably 0.1 or more at room temperature (1 to 30 ° C.), It is more preferably 0.3 or more, particularly preferably 0.5 or more, and particularly preferably 0.7 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 emission quantum yield can be measured by comparing the emission spectrum with a standard substance (such as quinine sulfate). 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.). It is. The emission quantum yield in solution is various solvents (for example, tetrahydrofuran, 2-methyltetrahydrofuran, dichloromethane, chloroform, acetonitrile, toluene, 1,2-dichloroethane, hexane, xylene, benzene, DMF, DMSO, preferably , Tetrahydrofuran, 2-methyltetrahydrofuran, dichloromethane, chloroform, toluene, 1,2-dichloroethane, more preferably tetrahydrofuran or toluene.), The iridium complex according to the present invention is The above-mentioned emission quantum yield should just be achieved 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.

Among the iridium complexes represented by the general formula (1) according to the present invention, the half-value width (Full Width at Half Maximum: FWHM) of the emission spectrum in the solution at room temperature (1 to 30 ° C.) is 55 nm or less. It is preferably 52 nm or less, more preferably 50 nm or less, particularly preferably 48 nm or less, and most preferably 45 nm or less. In the iridium complex according to the present invention, the half width described above may be achieved under any of the conditions used in the measurement of the emission quantum yield.

Among the iridium complexes represented by the general formula (1) according to the present invention, from the viewpoint of blue purity, the emission maximum wavelength in the solution at room temperature (1 to 30 ° C.) is 400 nm or more and less than 500 nm. Preferably, it is 420 nm or more and less than 480 nm, more preferably 430 nm or more and less than 478 nm, particularly preferably 440 nm or more and less than 474 nm, and particularly preferably 440 nm or more and less than 470 nm. When there are a plurality of light emission maximum wavelengths, it is preferable that the light emission maximum wavelength on the shortest wavelength side is within the above range. The iridium complex according to the present invention only needs to achieve the above-described maximum emission wavelength under any of the conditions used in the measurement of the emission quantum yield.

The iridium complex represented by the general formula (1) according to the present invention is an octahedral 6-coordination complex, and there are a facial isomer and a meridional isomer as geometric isomers.

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 separated and purified using a technique such as column chromatography or recrystallization, and can be identified by NMR, mass spectrometry, X-ray crystal structure analysis, or the like. The content can be quantified by NMR or HPLC.

It is also preferable to irradiate the meridional isomer of the iridium complex represented by the general formula (1) according to the present invention or a solution containing the meridional isomer to isomerize to a facial isomer.

Regarding the iridium complex represented by the general formula (1) according to the present invention, WO 2004/101707 pamphlet, WO 2016/006523 pamphlet, JP 2012-46479, WO 2016/203350. It can be synthesized with reference to known documents such as pamphlets.

The iridium complex represented by the general formula (1) according to the present invention can be provided after being treated according to the post-treatment of a normal synthesis reaction, and if necessary, purified or not purified. 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.

By including the iridium complex represented by the general formula (1) according to the present invention in a light emitting layer of a light emitting element or a plurality of organic compound layers including a light emitting layer by a vacuum deposition method, a spin coating method, or the like, a visible light region is obtained. A light-emitting element that exhibits sharp light emission with a narrow half-value width in the blue region in particular can be obtained.

Regarding the fact that the iridium complex represented by the general formula (1) according to the present invention exhibits a sharp emission spectrum with a narrow half-value width at room temperature, the present inventors have identified a specific position of the phenyltriazole ligand (with iridium and By introducing the substituent represented by the general formula (A) into the para-position to the carbon atom to be bonded, the π-π ^* property in the lowest excited state of the iridium complex of the present invention is increased, and the ground state It is thought that the fact that the structural change in the excited state is small has a strong influence.

Hereinafter, representative examples of the iridium complex represented by the general formula (1) according to the present invention are shown in Tables 1 to 7, but the present invention is not limited thereto.

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

　ＩｒＣｌ_３・ｎＨ_２Ｏ　１００．０ｍｇ、フェニルトリアゾール配位子（ａ－１）３００．７ｍｇ、２－エトキシエタノール３．９ｍｌ、水１．３ｍｌを三口フラスコに入れ、アルゴン雰囲気下、１９時間加熱還流させた。反応溶液を室温まで冷却後、ジクロロメタンと水を加えてから抽出し有機層を回収した。有機層を減圧濃縮し析出した黄色固体をジクロロメタンとヘキサンを用いて再結晶し、中間体（ｅ－１）を２２５ｍｇ、収率６７％で得た。
　引き続いて、中間体（ｅ－１）１００．０ｍｇ、フェニルトリアゾール配位子（ａ－１）８０．９ｍｇ、トリフルオロメタンスルホン酸銀２３．７ｍｇ、ジエチレングリコールジメチルエーテル（ジグライム）０．３ｍｌをシュレンク管に入れ、アルゴン雰囲気下、１６６℃で２４時間加熱反応させた。反応混合物を室温まで冷却後、ジクロロメタンを加えて、セライト層を通してろ過した。ろ液を減圧乾固し析出した固体をシリカゲルクロマトグラフィー（移動相：ジクロロメタンと酢酸エチルの混合溶媒）で分離精製し、本発明化合物（Ｉｒ－２５）を１３７ｍｇ、収率８８％で得た。 Example 1-1 (Synthesis of Compound (Ir-25) of the Present Invention)

IrCl ₃ · nH ₂ O 100.0 mg, phenyltriazole ligand (a-1) 300.7 mg, 2-ethoxyethanol 3.9 ml, water 1.3 ml were placed in a three-necked flask and heated to reflux for 19 hours under an argon atmosphere. I let you. The reaction solution was cooled to room temperature, extracted with dichloromethane and water, and the organic layer was recovered. The organic layer was concentrated under reduced pressure and the precipitated yellow solid was recrystallized using dichloromethane and hexane to obtain 225 mg of intermediate (e-1) in a yield of 67%.
Subsequently, 100.0 mg of intermediate (e-1), 80.9 mg of phenyltriazole ligand (a-1), 23.7 mg of silver trifluoromethanesulfonate, and 0.3 ml of diethylene glycol dimethyl ether (diglyme) were placed in a Schlenk tube. Then, the reaction was performed by heating at 166 ° C. for 24 hours in an argon atmosphere. The reaction mixture was cooled to room temperature, dichloromethane was added, and the mixture was filtered through a celite layer. The filtrate was dried under reduced pressure and the precipitated solid was separated and purified by silica gel chromatography (mobile phase: mixed solvent of dichloromethane and ethyl acetate) to obtain 137 mg of the present compound (Ir-25) in a yield of 88%.

¹ H-NMR data of the compound of the present invention (Ir-25) are shown below.
¹ H-NMR (400 MHz / acetone-d ₆ ): δ (ppm) 7.96 (d, 3H), 7.92 (s, 3H), 7.51 (t, 3H), 7.46 (d, 3H), 7.33 (d, 3H), 7.19 (s, 3H), 6.86 (d, 3H), 2.57-2.65 (m, 3H), 2.40-2.47 (M, 3H), 2.34 (s, 9H), 1.86 (s, 9H), 1.74-1.80 (m, 6H), 1.28 (s, 54H), 0.93 ( t, 9H).

　酢酸イリジウム５７．０ｍｇとフェニルトリアゾール配位子（ａ－２）３６３．６ｍｇを、エチレングリコール５ｍｌ中、窒素雰囲気下で４時間加熱還流した。反応液を酢酸エチルで抽出し、有機層を飽和食塩水で洗浄した。有機層を硫酸マグネシウム乾燥後、乾燥剤をろ過し、ろ液を濃縮後、シリカゲルカラムクロマトグラフィー（移動相：酢酸エチル：ヘキサン＝１：４）で精製後、酢酸エチルから再結晶し、本発明化合物（Ｉｒ－１）を７．８ｍｇ、収率２％で得た。 Example 1-2 (Synthesis of Compound (Ir-1) of the Present Invention)

57.0 mg of iridium acetate and 363.6 mg of phenyltriazole ligand (a-2) were heated to reflux for 4 hours in 5 ml of ethylene glycol under a nitrogen atmosphere. The reaction solution was extracted with ethyl acetate, and the organic layer was washed with saturated brine. The organic layer is dried over magnesium sulfate, the desiccant is filtered, the filtrate is concentrated, purified by silica gel column chromatography (mobile phase: ethyl acetate: hexane = 1: 4), recrystallized from ethyl acetate, and the present invention. 7.8 mg of compound (Ir-1) was obtained with a yield of 2%.

¹ H-NMR data of the compound (Ir-1) of the present invention are shown below.
¹ H-NMR (400 MHz / C ₆ D ₆ ): δ (ppm) 8.49 (dd, 3H), 8.39 (s, 3H), 7.51 (d, 3H), 6.88 (s, 3H), 6.68 (s, 3H), 2.21 (d, 18H), 2.07 (s, 9H), 1.78 (s, 9H), 1.43 (s, 54H).

　国際公開第２００７／０９７１５３号に記載の方法で合成した（ｅ－２）２０１．４ｍｇとトリフルオロメタンスルホン酸銀６９．２ｍｇをジクロロメタン２０ｍｌとメタノール０．５ｍｌの混合溶媒に加え遮光し、室温下で２６時間撹拌した。不溶物をろ過し、ろ液の溶媒を留去した。残渣にフェニルトリアゾール配位子（ａ－２）３００．１ｍｇとエタノール６ｍｌを加え、窒素雰囲気下９０℃で１００時間加熱還流した。室温まで冷却後、不溶物をろ過し、ろ液を濃縮し残渣をシリカゲルカラムクロマトグラフィー（移動相：酢酸エチル：ヘキサン = １：２）で精製後、酢酸エチル－メタノールから再結晶し本発明化合物（Ｉｒ－６７）を１０．８ｍｇ、収率３％で得た。 Example 1-3 (Synthesis of Compound (Ir-67) of the Present Invention)

201.4 mg of (e-2) synthesized by the method described in International Publication No. 2007/097153 and 69.2 mg of silver trifluoromethanesulfonate were added to a mixed solvent of 20 ml of dichloromethane and 0.5 ml of methanol and protected from light. Stir for 26 hours. Insoluble matter was filtered, and the solvent of the filtrate was distilled off. To the residue were added 300.1 mg of phenyltriazole ligand (a-2) and 6 ml of ethanol, and the mixture was heated to reflux at 90 ° C. for 100 hours under a nitrogen atmosphere. After cooling to room temperature, the insoluble matter is filtered off, the filtrate is concentrated, and the residue is purified by silica gel column chromatography (mobile phase: ethyl acetate: hexane = 1: 2) and then recrystallized from ethyl acetate-methanol. 10.8 mg (Ir-67) was obtained in a yield of 3%.

¹ H-NMR data of the compound of the present invention (Ir-67) are shown below.
¹ H-NMR (400 MHz / acetone-d ₆ ): δ (ppm) 7.93 (dd, 1H), 7.89 (dd, 1H), 7.25 (s, 1H), 7.22 (s, 2H), 7.14 (s, 3H), 6.84 (dd, 1H), 6.64 (m, 6H), 6.49 (m, 2H), 2.45 (s, 3H), 2. 42 (s, 6H), 2.21 (s, 3H), 2.17 (s, 6H), 2.15 (s, 3H), 2.14 (s, 3H), 2.12 (s, 3H) ), 1.78 (d, 3H), 1.77 (s, 3H), 1.76 (s, 3H), 1.31 (s, 18H).

　国際公開第２００７／０９７１５３号に記載の方法で合成した（ｅ－２）２．２ｇとトリフルオロメタンスルホン酸銀７９７．０ｍｇをジクロロメタン１００ｍｌとメタノール２．３ｍｌの混合溶媒に加え遮光し、室温下で２６時間撹拌した。不溶物をろ過し、ろ液の溶媒を留去した。残渣にフェニルトリアゾール配位子（ａ－３）３．１９７ｇとエタノール６０ｍｌを加え、窒素雰囲気下９０℃で１４日間加熱還流した。室温まで冷却後、ろ液を濃縮し、残渣をシリカゲルカラムクロマトグラフィー（移動相：ジクロロメタンと酢酸エチルの混合溶媒）で精製した。さらに、ジクロロメタン－ヘキサンから再結晶し本発明化合物（Ｉｒ－８９）を１．７３２ｇ、収率５１％で得た。 Example 1-4 (Synthesis of Compound (Ir-89) of the Present Invention)

(E-2) 2.2 g synthesized by the method described in International Publication No. 2007/097153 and 797.0 mg of silver trifluoromethanesulfonate were added to a mixed solvent of 100 ml of dichloromethane and 2.3 ml of methanol. Stir for 26 hours. Insoluble matter was filtered, and the solvent of the filtrate was distilled off. To the residue were added 3.197 g of phenyltriazole ligand (a-3) and 60 ml of ethanol, and the mixture was heated to reflux at 90 ° C. for 14 days in a nitrogen atmosphere. After cooling to room temperature, the filtrate was concentrated, and the residue was purified by silica gel column chromatography (mobile phase: mixed solvent of dichloromethane and ethyl acetate). Further, recrystallization from dichloromethane-hexane gave 1.732 g of the present compound (Ir-89) in a yield of 51%.

¹ H-NMR data of the compound of the present invention (Ir-89) are shown below.
¹ H-NMR (400 MHz / acetone-d ₆ ): δ (ppm) 7.90 (dd, 1H), 7.85 (d, 1H), 7.50 (t, 1H), 7.43 (d, 1H), 7.31 (d, 1H), 7.21 (s, 2H), 7.18 (s, 1H), 7.14 (s, 2H), 6.78 (d, 2H), 6. 56-6.68 (m, 6H), 6.48 (t, 2H), 2.41 (s, 6H), 2.26 (s, 3H), 2.17 (s, 6H), 2.15 (S, 6H), 2.13 (s, 3H), 1.83 (s, 3H), 1.78 (s, 3H), 1.77 (s, 3H), 1.27 (s, 18H) .

　ＩｒＣｌ_３・ｎＨ_２Ｏ　１．１２４ｇ、フェニルトリアゾール配位子（ｃ－１）２．１ｇ、２－エトキシエタノール４５ｍｌ、水１５ｍｌを三口フラスコに入れ、アルゴン雰囲気下、２０時間加熱還流させた。反応溶液を室温まで冷却後、析出した固体を回収し、メタノールで洗浄した。さらに、ジクロロメタンとメタノールを用いて再結晶し、中間体（ｅ－３）を２．２０６ｇ、収率９４％で得た。
　引き続いて、中間体（ｅ－３）０．２０ｇとトリフルオロメタンスルホン酸銀７５．１ｍｇをジクロロメタン２０ｍｌとメタノール０．５ｍｌの混合溶媒に加え遮光し、室温下で２６時間撹拌した。不溶物をろ過し、ろ液の溶媒を留去した。残渣にフェニルトリアゾール配位子（ａ－３）０．２３９８ｇとエタノール５．７ｍｌを加え、窒素雰囲気下９０℃で２０４時間加熱還流した。室温まで冷却後、ろ液を濃縮し、残渣をシリカゲルカラムクロマトグラフィー（移動相：ヘキサンと酢酸エチルの混合溶媒）で精製した。さらに、ジクロロメタン－ヘキサンから再結晶し本発明化合物（Ｉｒ－９０）を０．０４５４ｇ、収率１５％で得た。 Example 1-5 (Synthesis of the present compound (Ir-90))

IrCl ₃ · nH ₂ O (1.124 g), phenyltriazole ligand (c-1) (2.1 g), 2-ethoxyethanol (45 ml) and water (15 ml) were placed in a three-necked flask and heated to reflux for 20 hours under an argon atmosphere. After cooling the reaction solution to room temperature, the precipitated solid was collected and washed with methanol. Further, recrystallization was performed using dichloromethane and methanol to obtain 2.206 g of intermediate (e-3) in a yield of 94%.
Subsequently, 0.20 g of intermediate (e-3) and 75.1 mg of silver trifluoromethanesulfonate were added to a mixed solvent of 20 ml of dichloromethane and 0.5 ml of methanol, and the mixture was protected from light and stirred at room temperature for 26 hours. Insoluble matter was filtered, and the solvent of the filtrate was distilled off. To the residue were added 0.2398 g of phenyltriazole ligand (a-3) and 5.7 ml of ethanol, and the mixture was heated to reflux at 90 ° C. for 204 hours under a nitrogen atmosphere. After cooling to room temperature, the filtrate was concentrated, and the residue was purified by silica gel column chromatography (mobile phase: mixed solvent of hexane and ethyl acetate). Further, recrystallization from dichloromethane-hexane gave 0.0454 g of the present compound (Ir-90) in a yield of 15%.

¹ H-NMR data of the compound of the present invention (Ir-90) are shown below.
¹ H-NMR (400 MHz / acetone-d ₆ ): δ (ppm) 7.91 (dd, 1H), 7.86 (d, 1H), 7.40-7.52 (m, 6H), 7. 31-7.33 (m, 3H), 7.18 (s, 1H), 6.78 (d, 1H), 6.55-6.69 (m, 6H), 6.42 (t, 2H) , 2.27 (s, 3H), 2.22 (s, 6H), 2.17 (s, 6H), 2.15 (s, 3H), 1.83 (s, 6H), 1.81 ( s, 3H), 1.27 (s, 18H).

　ＩｒＣｌ_３・ｎＨ_２Ｏ　１７６．３ｍｇ、フェニルトリアゾール配位子（ａ－３）５００．０ｍｇ、２－エトキシエタノール６．９ｍｌ、水２．３ｍｌを三口フラスコに入れ、アルゴン雰囲気下、２０時間加熱還流させた。反応溶液を室温まで冷却後、析出した固体を回収し、メタノールで洗浄した。さらに、ジクロロメタンとメタノールを用いて再結晶し、中間体（ｅ－４）を０．４９２ｇ、収率９８％で得た。
　引き続いて、中間体（ｅ－４）０．４８ｇとトリフルオロメタンスルホン酸銀１３５．５ｍｇをジクロロメタン３６ｍｌとメタノール０．９ｍｌの混合溶媒に加え遮光し、室温下で２６時間撹拌した。不溶物をろ過し、ろ液の溶媒を留去した。残渣にフェニルトリアゾール配位子（ｃ－２）０．４０９ｇとエタノール１０ｍｌを加え、窒素雰囲気下９０℃で１８０時間加熱還流した。室温まで冷却後、ろ液を濃縮し、残渣をシリカゲルカラムクロマトグラフィー（移動相：ジクロロメタンと酢酸エチルの混合溶媒）で精製した。本発明化合物（Ｉｒ－９５）を０．６８９ｇ、収率３５％で得た。
　本発明化合物（Ｉｒ－９５）０．２４６ｇ、化合物（ｆ）０．０８７１ｇ、Ｋ_３ＰＯ_４ ０．１０７７ｇ、２－ジシクロヘキシルホスフィノ－２’，６’－ジメトキシビフェニル０．０１３８ｇ、トリス（ジベンジリデンアセトン）ジパラジウム（０）７．７４ｍｇ、トルエン２ｍｌ、水 ０．２ｍｌを、アルゴン雰囲気下、１１０℃で１９時間反応させた。反応溶液を室温まで冷却後に、酢酸エチルと水を加えて抽出した。有機層を回収し濃縮して得られた生成物を、シリカゲルカラムクロマトグラフィー（溶離液：酢酸エチルとジクロロメタンの混合溶媒）を用いて分離精製した。本発明化合物（Ｉｒ－９１）を０．１１５ｇ、収率４０％で得た。
　本発明化合物（Ｉｒ－９１）の同定はＥＳＩ－ＭＳ（エレクトロスプレーイオン化質量分析）を用いて行った。本発明化合物（Ｉｒ－９１）の分析データは以下の通りである。
ＥＳＩ－ＭＳ（ｍ／ｚ）：１７００．５（［Ｍ＋Ｈ］^＋） Example 1-6 (Synthesis of the present compound (Ir-91))

176.3 mg of IrCl ₃ · nH ₂ O, 500.0 mg of phenyltriazole ligand (a-3), 6.9 ml of 2-ethoxyethanol, and 2.3 ml of water were placed in a three-necked flask and heated under reflux for 20 hours under an argon atmosphere. I let you. After cooling the reaction solution to room temperature, the precipitated solid was collected and washed with methanol. Further, recrystallization was performed using dichloromethane and methanol to obtain 0.492 g of intermediate (e-4) in a yield of 98%.
Subsequently, 0.48 g of the intermediate (e-4) and 135.5 mg of silver trifluoromethanesulfonate were added to a mixed solvent of 36 ml of dichloromethane and 0.9 ml of methanol, protected from light, and stirred at room temperature for 26 hours. Insoluble matter was filtered, and the solvent of the filtrate was distilled off. To the residue were added 0.409 g of phenyltriazole ligand (c-2) and 10 ml of ethanol, and the mixture was heated to reflux at 90 ° C. for 180 hours under a nitrogen atmosphere. After cooling to room temperature, the filtrate was concentrated, and the residue was purified by silica gel column chromatography (mobile phase: mixed solvent of dichloromethane and ethyl acetate). 0.689 g of the compound (Ir-95) of the present invention was obtained in a yield of 35%.
Compound (Ir-95) 0.246 g, Compound (f) 0.0871 g, K ₃ PO ₄ 0.1077 g, 2-dicyclohexylphosphino-2 ′, 6′-dimethoxybiphenyl 0.0138 g, tris (dibenzylidene) Acetone) dipalladium (0) 7.74 mg, toluene 2 ml, and water 0.2 ml were reacted at 110 ° C. for 19 hours in an argon atmosphere. The reaction solution was cooled to room temperature, and extracted with ethyl acetate and water. The product obtained by collecting and concentrating the organic layer was separated and purified using silica gel column chromatography (eluent: mixed solvent of ethyl acetate and dichloromethane). 0.115 g of the compound of the present invention (Ir-91) was obtained with a yield of 40%.
The compound of the present invention (Ir-91) was identified using ESI-MS (electrospray ionization mass spectrometry). Analysis data of the compound of the present invention (Ir-91) are as follows.
ESI-MS (m / z): 1700.5 ([M + H] ⁺ )

　トリス（アセチルアセトナート）イリジウム（III）３７．５ｍｇ（０．０７７ｍｍｏｌ）、フェニルトリアゾール配位子（ｃ－３）２０１．３ｍｇ（０．７２５ｍｍｏｌ）、および、フェニルトリアゾール配位子（ａ－４）３３９．１ｍｇ（０．７２６ｍｍｏｌ）を耐圧試験管に入れ、アルゴン雰囲気下で密閉し、３００℃で２４時間加熱した。反応物を室温まで冷却後、反応混合物をアミノ基修飾シリカゲルカラムクロマトグラフィーにより精製し（移動相：酢酸エチル）、本発明化合物（Ｉｒ－９４）を８．１ｍｇ、収率９％で得た。 Example 1-7 (Synthesis of the present compound (Ir-94))

Tris (acetylacetonato) iridium (III) 37.5 mg (0.077 mmol), phenyltriazole ligand (c-3) 201.3 mg (0.725 mmol), and phenyltriazole ligand (a-4) 339.1 mg (0.726 mmol) was put in a pressure test tube, sealed in an argon atmosphere, and heated at 300 ° C. for 24 hours. After the reaction product was cooled to room temperature, the reaction mixture was purified by amino group-modified silica gel column chromatography (mobile phase: ethyl acetate) to obtain 8.1 mg of the present compound (Ir-94) in a yield of 9%.

¹ H-NMR data of the compound of the present invention (Ir-94) are shown below.
¹ H-NMR (400 MHz / acetone-d ₆ ): δ (ppm) 7.86 (dd, 1H), 7.77 (d, 1H), 7.22 (t, 4H), 7.19 (s, 2H), 7.13 (d, 1H), 6.91 (dd, 1H), 6.85 (dd, 1H), 6.62 (m, 2H), 6.51 (q, 2H), 6. 31 (q, 2H), 2.84 (s, 3H), 2.80 (s, 6H), 2.45 (s, 3H), 2.42 (s, 6H), 2.17 (s, 3H) ), 2.14 (s, 6H), 1.86 (s, 3H), 1.83 (s, 3H), 1.80 (s, 3H), 1.31 (s, 18H).

Example 1-8 (Synthesis of the present compound (Ir-33))

69.2 mg of tris (acetylacetonato) iridium (III) and 397.2 mg of phenyltriazole ligand (a-4) were put in a pressure-resistant test tube, sealed with no solvent in an argon atmosphere, and sealed at 240 ° C. for 30 minutes. The reaction was heated for an hour. After cooling the reaction solution to room temperature, the reaction mixture was separated and purified by silica gel column chromatography (mobile phase: ethyl acetate → methanol) and recrystallized from benzene-hexane to give 138 mg of the present compound (Ir-33) in a yield. Obtained at 61%.

¹ H-NMR data of the compound of the present invention (Ir-33) are shown below.
¹ H-NMR (400 MHz / DMSO-d ₆ ): δ (ppm) 7.78 (dd, 3H, J = 8.1, 1.8 Hz), 7.60 (d, 3H, J = 1.8 Hz) , 7.23 (s, 3H), 7.19 (s, 3H), 6.96 (d, 3H, J = 8.1 Hz), 2.39 (s, 9H), 2.10 (s, 9H) ), 2.05 (s, 9H), 1.79 (s, 9H), 1.26 (s, 54H).

Comparative Example 1-1 (Synthesis of Comparative Compound (A1))

Synthesis was performed in the same manner as in Example 1-8 except that the phenyltriazole ligand (g) was used instead of the phenyltriazole ligand (a-4). g) was decomposed, and no comparative compound (g3) could be obtained.

　Ｊ．Ａｍ．Ｃｈｅｍ．Ｓｏｃ．，２００３年、１２５巻、７３７７～７３８７ページに記載の方法で合成した（ｅ－５）２１７．５ｍｇとトリフルオロメタンスルホン酸銀１１９．５ｍｇをジクロロメタン１５ｍｌとメタノール０．３ｍｌの混合溶媒に加え遮光し、室温下で２６時間撹拌した。不溶物をろ過し、ろ液の溶媒を留去した。残渣にフェニルトリアゾール配位子（ｈ）４０８．６ｍｇとエタノール２ｍｌを加え、窒素雰囲気下９０℃で２５８時間加熱還流した。室温まで冷却後、ろ液を濃縮し、残渣をシリカゲルカラムクロマトグラフィー（移動相：ジクロロメタンと酢酸エチルの混合溶媒）で精製し、黄色固体を得た。
　引き続いて、この黄色固体６９．６ｍｇ、化合物（ｉ）１２．２ｍｇ、Ｋ_３ＰＯ_４ ５１．１ｍｇ、２－ジシクロヘキシルホスフィノ－２’，６’－ジメトキシビフェニル６．６ｍｇ、トリス（ジベンジリデンアセトン）ジパラジウム（０）３．７ｍｇ、トルエン１．５ｍｌ、水 ０．１５ｍｌを、アルゴン雰囲気下、１１０℃で２４時間反応させた。反応溶液を室温まで冷却後に、酢酸エチルと水を加えて抽出した。有機層を回収し濃縮して得られた生成物を、シリカゲルカラムクロマトグラフィー（溶離液：酢酸エチルとジクロロメタンの混合溶媒）を用いて分離精製した。本発明化合物（Ｉｒ－９８）を２．２ｍｇ、収率０．５％で得た。
　本発明化合物（Ｉｒ－９８）の同定はＥＳＩ－ＭＳ（エレクトロスプレーイオン化質量分析）を用いて行った。本発明化合物（Ｉｒ－９８）の分析データは以下の通りである。
　ＥＳＩ－ＭＳ（ｍ／ｚ）：１０５１．３（［Ｍ＋Ｈ］^＋） Example 1-9 (Synthesis of the present compound (Ir-98))

J. et al. Am. Chem. Soc. , 2003, 125, 7377-7387 (e-5) 217.5 mg and silver trifluoromethanesulfonate 119.5 mg were added to a mixed solvent of 15 ml dichloromethane and 0.3 ml methanol to protect against light. The mixture was stirred at room temperature for 26 hours. Insoluble matter was filtered, and the solvent of the filtrate was distilled off. To the residue were added 408.6 mg of phenyltriazole ligand (h) and 2 ml of ethanol, and the mixture was refluxed with heating at 90 ° C. for 258 hours under a nitrogen atmosphere. After cooling to room temperature, the filtrate was concentrated, and the residue was purified by silica gel column chromatography (mobile phase: mixed solvent of dichloromethane and ethyl acetate) to obtain a yellow solid.
Subsequently, 69.6 mg of this yellow solid, Compound (i) 12.2 mg, K ₃ PO ₄ 51.1 mg, 2-dicyclohexylphosphino-2 ′, 6′-dimethoxybiphenyl 6.6 mg, Tris (dibenzylideneacetone) 3.7 mg of dipalladium (0), 1.5 ml of toluene, and 0.15 ml of water were reacted at 110 ° C. for 24 hours under an argon atmosphere. The reaction solution was cooled to room temperature, and extracted with ethyl acetate and water. The product obtained by collecting and concentrating the organic layer was separated and purified using silica gel column chromatography (eluent: mixed solvent of ethyl acetate and dichloromethane). The compound of the present invention (Ir-98) was obtained in 2.2 mg in a yield of 0.5%.
The compound of the present invention (Ir-98) was identified using ESI-MS (electrospray ionization mass spectrometry). The analytical data of the compound of the present invention (Ir-98) are as follows.
ESI-MS (m / z): 1051.3 ([M + H] ⁺ )

Next, the light emission characteristics of the iridium complex of the present invention will be described.

Example 2-1 (Emission of Compound of the Invention (Ir-25) in THF)
The compound (Ir-25) of the present invention was dissolved in THF and aerated with argon gas, and then the emission spectrum (excitation wavelength) at room temperature was measured using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd. : 350 nm), blue light emission (emission maximum wavelength: 461 nm) was observed. The emission quantum yield was 0.91. The half width of the emission spectrum was 44 nm. The CIE chromaticity coordinates were (x, y) = (0.14, 0.20).

  比較化合物（１）をＴＨＦに溶解させ、アルゴンガスを通気した後、浜松ホトニクス株式会社製の絶対ＰＬ量子収率測定装置（Ｃ９９２０）を用いて、室温下での発光スペクトル（励起波長：３５０ｎｍ）を測定したところ、青色発光（発光極大波長：４５９ｎｍ）を示した。発光量子収率は０．８３であった。発光スペクトルの半値幅は５６ｎｍであった。ＣＩＥ色度座標は（ｘ，ｙ）＝（０．１６，０．２３）であった。 Comparative Example 2-1 (Luminescence of Comparative Compound (1) in THF)

After the comparative compound (1) was dissolved in THF and argon gas was bubbled through, an emission spectrum at room temperature (excitation wavelength: 350 nm) using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd. As a result, blue light emission (emission maximum wavelength: 459 nm) was exhibited. The emission quantum yield was 0.83. The half width of the emission spectrum was 56 nm. The CIE chromaticity coordinates were (x, y) = (0.16, 0.23).

FIG. 1 shows the emission spectra of the present compound (Ir-25) and the comparative compound (1) in THF. The emission spectrum of the compound (Ir-25) of the present invention (indicated by a solid line) was found to have a sharp shape with a narrow half-value width from the emission spectrum of the comparative compound (1) (indicated by a broken line). . In addition, in the emission spectrum of the compound (Ir-25) of the present invention, the component in the green region (500 nm or more) is greatly reduced as compared with the comparative compound (1). As a result, the value of y in the CIE chromaticity coordinate of the compound (Ir-25) of the present invention was smaller than that of the comparative compound (1), and showed a better blue purity than the comparative compound (1). With respect to the luminescent properties of the compound (Ir-25) of the present invention, the substituent represented by the general formula (A) was introduced at a specific position of the phenyltriazole ligand (para position with respect to the carbon atom bonded to iridium). This is the first manifestation.

Next, the half width of the emission spectrum of the compound of the present invention represented by the general formula (1) and a conventionally known phenyltriazole iridium complex is compared.

　特開２０１３－１４７５５１号に記載の比較化合物（２）をＴＨＦに溶解させ、アルゴンガスを通気した後、浜松ホトニクス株式会社製の絶対ＰＬ量子収率測定装置（Ｃ９９２０）を用いて、室温下での発光スペクトル（励起波長：３５０ｎｍ）を測定したところ、青色発光（発光極大波長：４７５ｎｍ）を示した。発光量子収率は０．８４であった。発光スペクトルの半値幅は６２ｎｍであった。 Comparative Example 2-2 (Luminescence of Comparative Compound (2) in THF)

A comparative compound (2) described in JP2013-147551A is dissolved in THF, and argon gas is passed through, and then an absolute PL quantum yield measuring apparatus (C9920) manufactured by Hamamatsu Photonics Co., Ltd. is used at room temperature. When the emission spectrum (excitation wavelength: 350 nm) was measured, blue emission (maximum emission wavelength: 475 nm) was shown. The emission quantum yield was 0.84. The half width of the emission spectrum was 62 nm.

　特開２０１３－１４７５５１号に記載の比較化合物（３）をＴＨＦに溶解させ、アルゴンガスを通気した後、浜松ホトニクス株式会社製の絶対ＰＬ量子収率測定装置（Ｃ９９２０）を用いて、室温下での発光スペクトル（励起波長：３５０ｎｍ）を測定したところ、青色発光（発光極大波長：４４３ｎｍ、４６５ｎｍ）を示した。発光量子収率は０．６７であった。発光スペクトルの半値幅は７０ｎｍであった。 Comparative Example 2-3 (Luminescence of Comparative Compound (3) in THF)

A comparative compound (3) described in JP2013-147551A is dissolved in THF, and argon gas is passed through, and then an absolute PL quantum yield measuring apparatus (C9920) manufactured by Hamamatsu Photonics Co., Ltd. is used at room temperature. When the emission spectrum (excitation wavelength: 350 nm) was measured, blue emission (maximum emission wavelength: 443 nm, 465 nm) was exhibited. The emission quantum yield was 0.67. The half width of the emission spectrum was 70 nm.

　特開２０１３－１４７５５１号に記載の比較化合物（４）をＴＨＦに溶解させ、アルゴンガスを通気した後、浜松ホトニクス株式会社製の絶対ＰＬ量子収率測定装置（Ｃ９９２０）を用いて、室温下での発光スペクトル（励起波長：３５０ｎｍ）を測定したところ、青色発光（発光極大波長：４７５ｎｍ）を示した。発光量子収率は０．８２であった。発光スペクトルの半値幅は５７ｎｍであった。 Comparative Example 2-4 (Emission of Comparative Compound (4) in THF)

A comparative compound (4) described in JP2013-147551A is dissolved in THF, and argon gas is passed through, and then an absolute PL quantum yield measuring apparatus (C9920) manufactured by Hamamatsu Photonics Co., Ltd. is used at room temperature. When the emission spectrum (excitation wavelength: 350 nm) was measured, blue emission (maximum emission wavelength: 475 nm) was shown. The emission quantum yield was 0.82. The half width of the emission spectrum was 57 nm.

Table 1 summarizes the emission colors and emission spectrum half-value widths of the compound (Ir-25) of the present invention and the comparative compounds (1) to (4). Although all the compounds emit light in the blue region, it can be seen that there is a large difference in the half-value width of the emission spectrum. The half width of the compound (Ir-25) of the present invention is 44 nm, which is very narrow compared with the half width (56 to 70 nm) of the conventionally known comparative compounds (1) to (4). It can be suitably used as a blue phosphorescent material.

Japanese Patent Application Laid-Open No. 2011-121874 discloses that, for an iridium complex having a phenylimidazole ligand, the half width of the emission spectrum is narrowed by introducing a substituent represented by the general formula (A). . However, by introducing the substituent represented by the general formula (A), the emission maximum wavelength of the iridium complex is increased by 20 nm from 467 nm to 487 nm, and there is a problem that is not preferable as a blue phosphorescent material.

On the other hand, the emission maximum wavelength of the iridium complex having the phenyltriazole ligand of the present invention is represented by the general formula (A) in addition to being present on the shorter wavelength side than the aforementioned iridium complex having the phenylimidazole ligand. Even if such a substituent is introduced, the influence on the light emission maximum wavelength is very small, so that it can be said to be a suitable material as a blue phosphorescent material.

Next, the emission characteristics of other compounds of the present invention will be described.

Example 2-2 (Emission of Compound of the Invention (Ir-1) in Toluene)
The compound (Ir-1) of the present invention was dissolved in toluene and argon gas was passed through, and then the emission spectrum (excitation wavelength) at room temperature was measured using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd. : 350 nm), blue light emission (emission maximum wavelength: 459 nm) was observed. The emission quantum yield was 0.85. The half width of the emission spectrum was 25 nm.

Example 2-3 (Luminescence of Compound (Ir-67) of the Present Invention in Toluene)
The compound of the present invention (Ir-67) was dissolved in toluene and argon gas was passed through, and then the emission spectrum (excitation wavelength) at room temperature was measured using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd. : 350 nm), blue light emission (emission maximum wavelength: 465 nm) was observed. The emission quantum yield was 0.73. The half width of the emission spectrum was 44 nm.

Example 2-4 (Emission of Compound of the Invention (Ir-90) in THF)
The compound (Ir-90) of the present invention was dissolved in THF and aerated with argon gas, and then the emission spectrum (excitation wavelength) at room temperature was measured using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd. : 350 nm), blue light emission (emission maximum wavelength: 462 nm) was observed. The emission quantum yield was 0.91. The half width of the emission spectrum was 49 nm.

Example 2-5 (Emission of Compound of the Present Invention (Ir-89) in THF)
The compound (Ir-89) of the present invention was dissolved in THF and aerated with argon gas, and then the emission spectrum (excitation wavelength) at room temperature was measured using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd. : 350 nm), blue light emission (emission maximum wavelength: 463 nm) was observed. The emission quantum yield was 0.92. The half width of the emission spectrum was 48 nm.

Example 2-6 (Emission of Compound of the Invention (Ir-94) in Toluene)
The compound of the present invention (Ir-94) was dissolved in toluene and argon gas was passed through, and then the emission spectrum (excitation wavelength) at room temperature was measured using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd. : 350 nm), blue light emission (maximum emission wavelength: 483 nm) was observed. The emission quantum yield was 0.75. The half width of the emission spectrum was 48 nm.

Example 2-7 (Emission of Compound of the Invention (Ir-33) in Toluene)
The compound of the present invention (Ir-33) was dissolved in toluene and argon gas was passed through, and then the emission spectrum (excitation wavelength) at room temperature was measured using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd. : 350 nm), blue light emission (emission maximum wavelength: 474 nm) was observed. The emission quantum yield was 0.87. The half width of the emission spectrum was 42 nm.

Example 2-8 (Emission of Compound of the Invention (Ir-98) in THF)
The compound of the present invention (Ir-98) was dissolved in THF and argon gas was passed through, and then the emission spectrum (excitation wavelength) at room temperature was measured using an absolute PL quantum yield measuring device (C9920) manufactured by Hamamatsu Photonics Co., Ltd. : 350 nm), blue light emission (emission maximum wavelength: 461 nm) was observed. The emission quantum yield was 0.79. The half width of the emission spectrum was 52 nm.

From the above Examples 2-2 to 2-8, it can be seen that the half width of the emission spectrum of the compound of the present invention is very narrow (FWHM = 25 to 52 nm). By introducing the substituent represented by the general formula (A) at a specific position of the phenyltriazole ligand (para position with respect to the carbon atom bonded to iridium), the shape of the emission spectrum of the iridium complex is sharpened. Thus, it became clear that it would be useful as a luminescent material for display applications.

Next, the thermal stability of the iridium complex of the present invention will be described.

Example 3-1 (Thermal Stability of the Compound (Ir-25) of the Present Invention)
The decomposition temperature of the compound (Ir-25) of the present invention was measured with a TG / DTA simultaneous measurement apparatus (DTG-60, manufactured by Shimadzu Corporation). When the temperature elevation rate was set to 10 ° C./min and the temperature was elevated at normal pressure in a nitrogen gas atmosphere, a 5% weight loss was observed at 455 ° C.

Comparative Example 3-1 (Thermal Stability of Comparative Compound (5))
The decomposition temperature of the comparative compound (5) was measured with a TG / DTA simultaneous measurement apparatus (DTG-60, manufactured by Shimadzu Corporation). When the temperature elevation rate was set to 15 ° C./min and the temperature was elevated at normal pressure in a nitrogen gas atmosphere, a 5% weight loss was observed at 293 ° C.

From the above results, it was revealed that the compound (Ir-25) of the present invention has a 5% weight loss temperature higher by 160 ° C. or more than the comparative compound (5), and is extremely excellent in thermal stability. The compound of the present invention represented by the general formula (1) is considered to have greatly improved thermal stability of the iridium complex as compared with the comparative compound due to the structural feature in which the aryl group is directly bonded to the nitrogen atom of the triazole ring. . Since the compound of the present invention has very high thermal stability, it is possible to produce a highly durable light emitting device.

Claims (12)

The iridium complex represented by following General formula (1).

(In the general formula (1), Ir represents an iridium atom, N represents a nitrogen atom, X ¹ represents N or C (R ⁸ ), C represents a carbon atom, Z ¹ represents N or C .Z ² representing the ^{(R 12)} represents an N or C ^{(R 13).} However, when ^{Z 1} is N is ^{Z 2} is C ^{(R 13), Z 1} is C ^{(R 12)} And Z ² is N. R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, or an aryl group, and R ⁶ and R ⁷ each independently represent an alkyl group. R ³ to R ⁵ and R ⁸ to R ¹¹ are each independently a hydrogen atom, an alkyl group, an aryl group, an alkylsilyl group, a heterocyclic group, an alkoxy group, an aryloxy group, a cyano group, or a halogen atom ^{.R 12} and ^{R 13} represent the atoms are each independently an alkyl group also Represents an aryl group. The R ^{1 ~} R ^13, which adjacent good be bonded to form a ring structure .L when .L representing an anionic bidentate ligand there is a plurality, respectively, They may be the same or different, m = 1 to 3 and n = 0 to 2, provided that m + n = 3. The iridium complex according to claim 1, wherein Z ¹ is C (R ¹² ) and Z ² is N. The iridium complex according to claim 1, wherein Z ¹ is N and Z ² is C (R ¹³ ). The iridium complex according to any one of claims 1 to 3, wherein R ¹² and R ¹³ are each independently an alkyl group. The iridium complex according to any one of claims 1 to 4, wherein L is an aromatic heterocyclic bidentate ligand. 6. The iridium complex according to claim 1, wherein L is selected from any one of the following general formulas (B) to (D).

(In the general formulas (B) to (D), N represents a nitrogen atom. R ¹ and R ² each independently represents a hydrogen atom, an alkyl group, or an aryl group. R ³ to R ⁵ , R ⁹ to R ¹¹ , R ^a , R ^x , R ^y , and R ^z are each independently a hydrogen atom, an alkyl group, an aryl group, an alkylsilyl group, a heterocyclic group, an alkoxy group, an aryloxy group, or a cyano group. R ¹² and R ¹³ each independently represents an alkyl group or an aryl group, and adjacent R ¹ to R ⁵ , R ⁹ to R ¹¹ , R ^a , R ^x , R ^y , and R ^z may combine to form a ring structure, and * represents a binding site with iridium.) 5. The iridium complex according to claim 1, wherein m = 3 and n = 0. The iridium complex according to any one of claims 1 to 6, wherein m = 2 and n = 1. 7. The iridium complex according to claim 1, wherein m = 1 and n = 2. The iridium complex according to any one of claims 1 to 9, wherein the half-value width of an emission spectrum in THF or toluene at room temperature is 55 nm or less. A light emitting material comprising the iridium complex according to any one of claims 1 to 10. A light emitting device comprising the light emitting material according to claim 11.

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