WO2020084919A1

WO2020084919A1 - Light-emitting element

Info

Publication number: WO2020084919A1
Application number: PCT/JP2019/034947
Authority: WO
Inventors: 敏明佐々田; 慎一稲員; 佑典石井
Original assignee: 住友化学株式会社
Priority date: 2018-10-25
Filing date: 2019-09-05
Publication date: 2020-04-30
Also published as: JP6692980B2; JP2020072256A

Abstract

The present invention provides a light-emitting element having excellent light emission efficiency.　Provided is a light-emitting element having an anode, a cathode, a first layer provided between the anode and the cathode, and a second layer provided between the cathode and the first layer, wherein the first layer contains two or more metal complexes represented by formula (1) and a metal complex represented by formula (2), and at least one layer from among the first layer and the second layer contains a compound represented by formula (T-1). Further provided is the aforementioned light-emitting element, wherein the second layer contains the compound represented by formula (T-1).

Description

Light emitting element

The present invention relates to a light emitting element.

Light emitting devices such as organic electroluminescent devices can be suitably used for display and lighting applications, and research and development are being conducted. For example, Patent Document 1 describes a light emitting device having a light emitting layer containing a metal complex B0-1, a metal complex G1 and a metal complex R1 and an electron transporting layer containing a compound ET1. Further, Patent Document 2 discloses a light emitting device having a light emitting layer containing a metal complex G2-1 and a metal complex R2, a light emitting layer containing a metal complex B0-2, and an electron transport layer containing a compound ET1. Have been described.

International Publication No. 2011/048956 JP, 2016-207954, A

However, the light emitting element described above does not always have sufficient luminous efficiency.
Therefore, it is an object of the present invention to provide a light emitting device having excellent luminous efficiency.

The present invention provides the following [1] to [13].
[1] A light emitting element having an anode, a cathode, a first layer provided between the anode and the cathode, and a second layer provided between the cathode and the first layer And
The first layer is a layer containing two or more kinds of the metal complex represented by the formula (1) and the metal complex represented by the formula (2),
A light emitting device, wherein at least one layer of the first layer and the second layer contains a compound represented by the formula (T-1).

[In the formula,
M ¹ represents a rhodium atom, a palladium atom, an iridium atom or a platinum atom.
n ¹ represents an integer of 1 or more, and n ² represents an integer of 0 or more. However, when M ¹ is a rhodium atom or an iridium atom, n ¹ + n ² is 3, and when M ¹ is a palladium atom or a platinum atom, n ¹ + n ² is 2.
E ^L represents a carbon atom or a nitrogen atom. If the E ^L there are a plurality, or different in each of them the same.
Ring L ¹ represents a 6-membered aromatic heterocycle, and this ring may have a single or a plurality of substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded. When there are a plurality of rings L ¹ , they may be the same or different.
Ring L ² represents an aromatic hydrocarbon ring or an aromatic heterocycle, and these rings may have a single or a plurality of substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded.
When multiple rings L ² are present, they may be the same or different.
The substituent that the ring L ¹ may have and the substituent that the ring L ² may have may be the same or different, and they are bonded to each other to form a ring together with the atom to which they are bonded. You may have.
However, at least one of the ring L ¹ and the ring L ² has a group represented by the formula (1-T) as a substituent. When there are a plurality of groups represented by formula (1-T), they may be the same or different.
A ¹ -G ¹ -A ² represents an anionic bidentate ligand. A ¹ and A ² each independently represent a carbon atom, an oxygen atom or a nitrogen atom, and these atoms may be atoms constituting a ring. G ¹ represents a single bond or an atomic group forming a bidentate ligand together with A ¹ and A ² . When there are a plurality of A ¹ -G ¹ -A ² , they may be the same or different. ]

[In the formula,
M ² represents a rhodium atom, a palladium atom, an iridium atom or a platinum atom.
n ³ represents an integer of 1 or more, and n ⁴ represents an integer of 0 or more. However, when M ² is a rhodium atom or an iridium atom, n ³ + n ⁴ is 3, and when M ² is a palladium atom or a platinum atom, n ³ + n ⁴ is 2.
E ¹ and E ² each independently represent a carbon atom or a nitrogen atom. When a plurality of E ¹ and E ² are present, they may be the same or different.
Ring R ¹ represents a 5-membered aromatic heterocycle, and this ring may have a single or a plurality of substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded. When multiple rings R ¹ are present, they may be the same or different.
Ring R ² represents an aromatic hydrocarbon ring or an aromatic heterocycle, and these rings may have a single or a plurality of substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded.
When there are a plurality of rings R ² , they may be the same or different.
The substituent that the ring R ¹ may have and the substituent that the ring R ² may have may be the same or different, and they are bonded to each other to form a ring together with the atom to which they are bonded. You may have.
A ³ -G ² -A ⁴ represents an anionic bidentate ligand. A ³ and A ⁴ each independently represent a carbon atom, an oxygen atom or a nitrogen atom, and these atoms may be atoms constituting a ring. G ² represents a single bond or an atomic group forming a bidentate ligand together with A ³ and A ⁴ . When there are a plurality of A ³ -G ² -A ⁴ , they may be the same or different. ]

[In the formula, R ^1T represents an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group, a substituted amino group or a halogen atom, and these groups are monovalent. It may have one or more substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded. ]

[In the formula,
n ^T1 represents an integer of 0 or more and 5 or less. When a plurality of n ^T1s are present, they may be the same or different.
n ^T2 represents an integer of 1 or more and 10 or less.
Ar ^T1 is a fused ring monovalent heterocyclic group containing a nitrogen atom having no double bond in the ring and a group represented by ═N—, and the group is a single or plural substituents. When there are a plurality of substituents, they may be the same or different, and they may be bonded to each other to form a ring together with the atom to which they are bonded. When a plurality of Ar ^T1s are present, they may be the same or different.
L ^T1 is an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -NR T1 ^'- represents a group represented by an oxygen atom or a sulfur atom, the these groups single or multiple substitutions When it has a plurality of substituents, they may be the same or different and may be bonded to each other to form a ring together with the atom to which they are bonded.
R ^{T1 ′} represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a single or a plurality of substituents, and the substituent is When a plurality of them are present, they may be the same or different and may be bonded to each other to form a ring with the atom to which each is bonded. When there are a plurality of L ^T1 , they may be the same or different.
Ar ^T2 represents an aromatic hydrocarbon group or a heterocyclic group, and these groups may have a single or a plurality of substituents, and when there are a plurality of the substituents, they may be the same or different. Alternatively, they may be bonded to each other to form a ring together with the atoms to which they are bonded. [2] The light-emitting device according to [1], wherein the second layer contains the compound represented by the formula (T-1).
[3] The light emitting device according to [1] or [2], wherein Ar ^T1 is a group represented by formula (T1-1).

[In the formula,
X ^T1 represents a single bond, an oxygen atom, a sulfur atom, a group represented by —N (R ^XT1 ) —, or a group represented by —C (R ^{XT1 ′} ) ₂ —. R ^XT1 and R ^{XT1 ′} are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group, a halogen atom or Represents a cyano group, these groups may have a single or a plurality of substituents, when there are a plurality of the substituents, they may be the same or different, and they are bonded to each other, It may form a ring together with the atom to be bonded. The plurality of R ^{XT1 ′ s that} are present may be the same or different and may be bonded to each other to form a ring together with the atom to which each is bonded.
The ring R ^T1 and the ring R ^T2 each independently represent an aromatic hydrocarbon ring or a heterocycle, and these rings may have a single or a plurality of substituents, and a plurality of the above substituents are present. In this case, they may be the same or different and may be bonded to each other to form a ring with the atom to which each is bonded.
Provided that at least one of the ring R ^T1 and the ring R ^T2 is a heterocycle containing a group represented by ═N— in the ring, and the ring has a single or a plurality of substituents. Alternatively, when there are a plurality of the above-mentioned substituents, they may be the same or different, and they may be bonded to each other to form a ring with the atoms to which they are bonded. ]
[4] The ring R ^T1 is an aromatic hydrocarbon ring or a heterocycle containing a group represented by ═N— in the ring, and these rings may have a single or a plurality of substituents. Well, and the ring R ^T2 is a heterocycle containing a group represented by ═N— in the ring, and the ring may have a single or a plurality of substituents. The light emitting device described.
[5] The ring R ^T1 is a monocyclic aromatic hydrocarbon ring or a monocyclic heterocycle containing a group represented by ═N— in the ring, and these rings are single or plural. It may have a substituent, and the ring R ^T2 is a monocyclic heterocycle containing a group represented by ═N— in the ring, and the ring has a single or a plurality of substituents. The light-emitting device according to [4], which may have:
[6] The ring R ^T1 is a benzene ring, a pyridine ring or a diazabenzene ring, and these rings may have a single or a plurality of substituents, and the ring R ^T2 is a pyridine ring or The light emitting device according to [5], which is a diazabenzene ring, and these rings may have a single or a plurality of substituents.
[7] The ring L ¹ is a pyridine ring, a diazabenzene ring, an azanaphthalene ring or a diazanaphthalene ring, and these rings may have a single or a plurality of substituents, and the ring L 1 ² is a benzene ring, a pyridine ring or a diazabenzene ring, and these rings may have a single or a plurality of substituents, wherein the light emitting device according to any one of [1] to [6].
[8] The light emitting device according to any one of [1] to [7], in which the maximum peak wavelength of the emission spectrum of the metal complex represented by the formula (1) is 495 nm or more and less than 750 nm.
[9] The ring R ¹ is a diazole ring or a triazole ring, and these rings may have a single or a plurality of substituents, and the ring R ² is a benzene ring, a pyridine ring or The light-emitting device according to any one of [1] to [9], which is a diazabenzene ring, and these rings may have a single or a plurality of substituents.
[10] The light-emitting device according to any one of [1] to [9], wherein the metal complex represented by the formula (2) has a maximum emission peak wavelength of 380 nm or more and less than 495 nm.
[11] The light-emitting device according to any one of [1] to [10], wherein the first layer further contains a compound represented by formula (H-1).

[In the formula,
Ar ^H1 and Ar ^H2 each independently represent an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or a plurality of substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded.
n ^H1 represents an integer of 0 or more.
L ^H1 represents an arylene group, a divalent heterocyclic group, an alkylene group or a cycloalkylene group, and these groups may have a single or a plurality of substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded. When a plurality of L ^H1 are present, they may be the same or different. ]
[12] The first layer further contains at least one selected from the group consisting of a hole transport material, a hole injection material, an electron transport material, an electron injection material, a light emitting material, and an antioxidant. ] The light emitting element in any one of [11].
[13] The light emitting device according to any one of [1] to [12], wherein the first layer and the second layer are adjacent to each other.

According to the present invention, it is possible to provide a light emitting element having excellent luminous efficiency.

FIG. 1 is a schematic cross-sectional view of a light emitting device according to one embodiment of the present invention.

Hereinafter, a preferred embodiment of this embodiment will be described in detail.

<Explanation of common terms>
The terms commonly used in the present specification have the following meanings unless otherwise specified.

“Room temperature” means 25 ° C.
Me represents a methyl group, i-Pr represents an isopropyl group, and t-Bu represents a tert-butyl group.
The hydrogen atom may be a deuterium atom or a light hydrogen atom.
In the formula representing the metal complex, the solid line representing the bond with the central metal means a covalent bond or a coordinate bond.

The “polymer compound” means a polymer having a molecular weight distribution and a polystyrene-equivalent number average molecular weight of 1 × 10 ³ to 1 × 10 ⁸ .
The “low molecular weight compound” means a compound having no molecular weight distribution and a molecular weight of 1 × 10 ⁴ or less.
The “constituent unit” means a unit present in one or more units in the polymer compound. The constitutional unit having two or more present in the polymer compound is generally called a "repeating unit".

The “alkyl group” may be linear or branched. The number of carbon atoms in the straight-chain alkyl group, not including the number of carbon atoms in the substituent, is usually 1 to 50, preferably 1 to 20, and more preferably 1 to 10. The number of carbon atoms of the branched alkyl group is usually 3 to 50, not including the number of carbon atoms of the substituent, preferably 3 to 20, and more preferably 4 to 10. The alkyl group may have a substituent, and examples thereof include a methyl group, an ethyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a 2- Ethylhexyl group, decyl group, 3,7-dimethyloctyl group, 2-ethyloctyl group, dodecyl group, trifluoromethyl group, 3-phenylpropyl group, 3- (4-methylphenyl) propyl group, 3- (3,3 Examples thereof include a 5-di-hexylphenyl) propyl group and a 6-ethyloxyhexyl group.
The number of carbon atoms of the “cycloalkyl group” is usually 3 to 50, preferably 4 to 10, not including the number of carbon atoms of the substituent. The cycloalkyl group may have a substituent, and examples thereof include a cyclohexyl group and a methylcyclohexyl group.
The number of carbon atoms of the “alkylene group” is usually 1 or more and 20 or less, preferably 1 or more and 15 or less, and more preferably 1 or more and 10 or less, not including the number of carbon atoms of the substituent.
The alkylene group may have a substituent, and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group and an octylene group.
The number of carbon atoms of the “cycloalkylene group” is usually 3 or more and 20 or less, not including the number of carbon atoms of the substituent. The cycloalkylene group may have a substituent, and examples thereof include a cyclohexylene group.

The “aromatic hydrocarbon group” means a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms constituting a ring from aromatic hydrocarbon. A group obtained by removing one hydrogen atom directly bonded to a carbon atom forming a ring from an aromatic hydrocarbon is also referred to as an "aryl group". A group obtained by removing two hydrogen atoms directly bonded to carbon atoms constituting a ring from an aromatic hydrocarbon is also referred to as "arylene group".
The number of carbon atoms of the aromatic hydrocarbon group, not including the number of carbon atoms of the substituent, is usually 6 to 60, preferably 6 to 30, and more preferably 6 to 18.
The “aromatic hydrocarbon group” is, for example, a monocyclic aromatic hydrocarbon (for example, benzene) or a polycyclic aromatic hydrocarbon (for example, a bicyclic group such as naphthalene and indene). Aromatic hydrocarbons; tricyclic aromatic hydrocarbons such as anthracene, phenanthrene, dihydrophenanthrene and fluorene; tetracyclic aromatic hydrocarbons such as triphenylene, naphthacene, benzofluorene, pyrene, chrysene and fluoranthene; dibenzofluorene , 5-ring aromatic hydrocarbons such as perylene and benzofluoranthene; 6-ring aromatic hydrocarbons such as spirobifluorene; and 7-ring aromatic hydrocarbons such as benzospirobifluorene and acenaphthofluoranthene From aromatic hydrocarbons), one or more hydrogen atoms directly bonded to carbon atoms constituting the ring There were group, and these groups may have a substituent. The aromatic hydrocarbon group includes a group in which a plurality of these groups are bonded.

The "alkoxy group" may be linear or branched. The number of carbon atoms of the straight-chain alkoxy group is usually 1 to 40, preferably 1 to 10, not including the number of carbon atoms of the substituent. The number of carbon atoms of the branched alkoxy group is usually 3 to 40, not including the number of carbon atoms of the substituent, and preferably 4 to 10. The alkoxy group may have a substituent, and examples thereof include a methoxy group, an ethoxy group, an isopropyloxy group, a butyloxy group, a hexyloxy group, a 2-ethylhexyloxy group, a 3,7-dimethyloctyloxy group, and lauryl. An oxy group is mentioned.
The number of carbon atoms of the “cycloalkoxy group” is usually 3 to 40, preferably 4 to 10, not including the number of carbon atoms of the substituent. The cycloalkoxy group may have a substituent, and examples thereof include a cyclohexyloxy group.
The number of carbon atoms of the “aryloxy group” is usually 6 to 60, preferably 6 to 48, not including the number of carbon atoms of the substituent. The aryloxy group may have a substituent, and examples thereof include a phenoxy group, a naphthyloxy group, an anthracenyloxy group, and a pyrenyloxy group.

The “heterocyclic group” means a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms or heteroatoms constituting a ring from a heterocyclic compound. Among the heterocyclic groups, an “aromatic heterocyclic group”, which is a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms or hetero atoms constituting a ring from an aromatic heterocyclic compound, is preferable. A group obtained by removing p hydrogen atoms (p represents an integer of 1 or more) directly bonded to a carbon atom or a hetero atom constituting a ring from a heterocyclic compound is also referred to as a “p-valent heterocyclic group”. A group obtained by removing p hydrogen atoms directly bonded to a carbon atom or a hetero atom constituting a ring from an aromatic heterocyclic compound is also referred to as a “p-valent aromatic heterocyclic group”.
Examples of the "aromatic heterocyclic compound" include compounds in which the heterocycle itself has aromaticity such as azole, thiophene, furan, pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene and carbazole, and phenoxazine. A compound in which a heterocyclic ring is condensed with a heterocyclic ring such as phenothiazine and benzopyran, even though the heterocyclic ring itself does not exhibit aromaticity.
The number of carbon atoms in the heterocyclic group is usually 1 to 60, preferably 2 to 40, more preferably 3 to 20, not including the number of carbon atoms in the substituent. The number of hetero atoms in the heterocyclic group is usually 1 to 30, preferably 1 to 10 and more preferably 1 to 3, not including the number of hetero atoms in the substituent.
The heterocyclic group may have a substituent, for example, a monocyclic heterocyclic compound (for example, furan, thiophene, oxadiazole, pyrrole, diazole, triazole, tetrazole, pyridine, diazabenzene and triazine are Or a polycyclic heterocyclic compound (for example, a bicyclic heterocyclic compound such as azanaphthalene, diazanaphthalene, benzofuran, benzothiophene, indole, benzodiazole and benzothiadiazole; dibenzofuran , Dibenzothiophene, carbazole, azacarbazole, diazacarbazole, phenoxazine, phenothiazine, 9,10-dihydroacridine, 5,10-dihydrophenazine, azaanthracene, diazaanthracene, azaphenanthrene and diazaphenanthrene A heterocyclic compound such as hexaazatriphenylene, benzocarbazole and benzonaphthofuran; a heterocyclic compound such as dibenzocarbazole, indolocarbazole and indenocarbazole A compound; a 6-ring heterocyclic compound such as carbazolocarbazole, benzoindrocarbazole and benzoindenocarbazole; and a 7-ring heterocyclic compound such as dibenzoindrocarbazole). Examples thereof include groups excluding one or more hydrogen atoms that are directly bonded to constituent atoms, and these groups may have a substituent. The heterocyclic group includes a group in which a plurality of these groups are bonded.

“Halogen atom” means a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

The "amino group" may have a substituent, and a substituted amino group is preferable. The substituent which the amino group has is preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group.
Examples of the substituted amino group include a dialkylamino group, a dicycloalkylamino group and a diarylamino group.
More specifically, examples of the substituted amino group include a dimethylamino group, a diethylamino group, a diphenylamino group, a bis (methylphenyl) amino group, and a bis (3,5-di-tert-butylphenyl) amino group. Can be mentioned.

The “alkenyl group” may be linear or branched. The number of carbon atoms of the straight-chain alkenyl group is usually 2 to 30, preferably 3 to 20, not including the number of carbon atoms of the substituent. The number of carbon atoms of the branched alkenyl group is usually 3 to 30, preferably 4 to 20, not including the number of carbon atoms of the substituent.
The number of carbon atoms of the “cycloalkenyl group” is usually 3 to 30, not including the number of carbon atoms of the substituent, and preferably 4 to 20.
The alkenyl group and cycloalkenyl group may have a substituent, for example, vinyl group, propenyl group, butenyl group, 3-butenyl group, 3-pentenyl group, 4-pentenyl group, 1-hexenyl group, 5 Examples thereof include a hexenyl group, a 7-octenyl group, and a group in which these groups have a substituent.

The "alkynyl group" may be linear or branched. The number of carbon atoms of the alkynyl group is usually 2 to 20, preferably 3 to 20, not including the carbon atoms of the substituent. The number of carbon atoms of the branched alkynyl group is usually 4 to 30, and preferably 4 to 20, not including the carbon atoms of the substituents.
The number of carbon atoms of the “cycloalkynyl group” is usually 4 to 30, and preferably 4 to 20, not including the carbon atoms of the substituents.
The alkynyl group and cycloalkynyl group may have a substituent, for example, an ethynyl group, a propynyl group, a butynyl group, a pentynyl group, a hexynyl group, a 5-hexynyl group, and these groups have a substituent. Groups.

The "crosslinkable group" is a group capable of forming a new bond by being subjected to heating, ultraviolet irradiation, near-ultraviolet irradiation, visible light irradiation, infrared irradiation, radical reaction, or the like, and preferably has the formula: A group represented by any one of (XL-1) to formula (XL-19). These groups may have a substituent.

[In the formula, R ^XL represents a methylene group, an oxygen atom or a sulfur atom, and n ^XL represents an integer of 0 to 5. When there are a plurality of R ^XL , they may be the same or different. When there are a plurality of n ^XL , they may be the same or different. * 1 represents a binding position. These crosslinkable groups may have a single or a plurality of substituents, and when there are a plurality of the substituents, they may be the same or different and are bonded to each other to form a carbon atom to which each is bonded. It may form a ring together with the atom. ]

Examples of the “substituent” include a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an amino group, a substituted amino group, Examples thereof include an alkenyl group, a cycloalkenyl group, an alkynyl group and a cycloalkynyl group. The substituent may be a crosslinkable group. The group having a substituent can have a single or a plurality of substituents. The ring having a substituent can have a single or a plurality of substituents. When there are a plurality of substituents, they may be the same or different, and they may be bonded to each other to form a ring with the atoms to which they are bonded, but it is preferable that they do not form a ring. .

<Metal Complex Represented by Formula (1)>
The metal complex represented by the formula (1) is usually a metal complex exhibiting phosphorescence emission at room temperature, and preferably a metal complex exhibiting light emission from a triplet excited state at room temperature.

M ¹ is preferably an iridium atom or a platinum atom, and more preferably an iridium atom, because the light emitting device of the present embodiment is more excellent in light emission efficiency.
When M ¹ is a rhodium atom or an iridium atom, n ¹ is preferably 2 or 3, and more preferably 3.
When M ¹ is a palladium atom or a platinum atom, n ¹ is preferably 2.
E ^L is preferably a carbon atom. When a plurality of ^ELs are present, they are preferably the same, because the metal complex represented by the formula (1) can be easily synthesized.

The number of carbon atoms of the 6-membered aromatic heterocycle in ring L ¹ is usually 1 to 60, preferably 2 to 30 and more preferably 3 to 15, not including the number of carbon atoms of the substituent. is there. The number of heteroatoms in the 6-membered aromatic heterocycle in the ring L ¹ is usually 1 to 30, preferably 1 to 10 and more preferably 1 to 3, not including the number of heteroatoms in the substituent. Is.
Examples of the ring L ¹ include a 6-membered aromatic heterocycle having one or more nitrogen atoms as constituent atoms among the aromatic heterocycles exemplified in the above-mentioned heterocyclic group, and the present embodiment The above-mentioned light emitting device is more excellent in light emission efficiency, and therefore, it is preferably a 6-membered aromatic heterocycle having one or more and four or less nitrogen atoms as constituent atoms, and more preferably a pyridine ring, diazabenzene ring or azanaphthalene. It is a ring or a diazanaphthalene ring, more preferably a pyridine ring, a quinoline ring or an isoquinoline ring, and these rings may have a substituent.
When a plurality of rings L ¹ are present, they are preferably the same, because the metal complex represented by the formula (1) can be easily synthesized. More specifically, if the ring L ¹ there are a plurality of ring L ¹ there are a plurality of, preferably at least two are the same, and more preferably all ring L ¹ that there are a plurality are identical.

The number of carbon atoms of the aromatic hydrocarbon ring in ring L ² is usually 6 to 60, preferably 6 to 30, and more preferably 6 to 18, not including the number of carbon atoms of the substituent.
Examples of the aromatic hydrocarbon ring in the ring L ² include the aromatic hydrocarbon ring exemplified in the above-mentioned aromatic hydrocarbon group, and preferably the aromatic hydrocarbon ring exemplified in the above-mentioned aromatic hydrocarbon group. , A monocyclic, bicyclic or tricyclic aromatic hydrocarbon ring, more preferably a benzene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring or a dihydrophenanthrene ring, and further preferably a benzene ring, It is a fluorene ring or a dihydrophenanthrene ring, particularly preferably a benzene ring, and these rings may have a substituent.
The number of carbon atoms of the aromatic heterocycle in the ring L ² is usually 1 to 60, preferably 2 to 30 and more preferably 3 to 15, not including the number of carbon atoms of the substituent. The number of hetero atoms of the aromatic heterocycle in the ring L ² is usually 1 to 30, preferably 1 to 10 and more preferably 1 to 3, not including the number of hetero atoms of the substituent.
Examples of the aromatic heterocycle in the ring L ² include the aromatic heterocycles exemplified in the above-mentioned section of the heterocyclic group, preferably the monocyclic group, 2 exemplified in the above-mentioned section of the heterocyclic group. A cyclic or tricyclic aromatic heterocycle, more preferably a pyridine ring, a diazabenzene ring, an azanaphthalene ring, a diazanaphthalene ring, an indole ring, a benzofuran ring, a benzothiophene ring, a carbazole ring, an azacarbazole ring, Diazacarbazole ring, dibenzofuran ring or dibenzothiophene ring, more preferably pyridine ring, diazabenzene ring, carbazole ring, dibenzofuran ring or dibenzothiophene ring, particularly preferably pyridine ring or diazabenzene ring, these The ring may have a substituent.
The ring L ² is preferably a benzene ring, a pyridine ring or a diazabenzene ring, more preferably a benzene ring, since the light emitting device of the present embodiment has a higher luminous efficiency, and these rings have a substituent. You may have.
When a plurality of rings L ² are present, they are preferably the same, because the metal complex represented by the formula (1) can be easily synthesized. More specifically, if the ring L ² there are a plurality of the rings L ² there are a plurality of, preferably at least two are the same, and more preferably all ring L ² that there are a plurality are identical.

Since the luminous efficiency of the light emitting device of the present embodiment is more excellent, the ring L ¹ is a pyridine ring, a diazabenzene ring, an azanaphthalene ring or a diazanaphthalene ring, and the ring L ² is a benzene ring, a pyridine ring or a diazabenzene ring. More preferably, the ring L ¹ is a pyridine ring, a quinoline ring or an isoquinoline ring, and the ring L ² is more preferably a benzene ring, and these rings may have a substituent.

"At least one of the ring L ¹ and the ring L ² are as substituents, formula having a group represented by (1-T)" and, atoms constituting the ring L ¹ and the ring L ² (preferably Is a carbon atom or a nitrogen atom, and more preferably a carbon atom.) Means that the group represented by the formula (1-T) is directly bonded. In the metal complex represented by the formula (1), when a plurality of rings L ¹ and L ² are present, at least one ring of the plurality of rings L ¹ and L ² is represented by the formula (1-T) As long as it has a group represented, the luminous efficiency of the light emitting device of the present embodiment is more excellent. Therefore, all the plural rings L ¹ exist, all the plural rings L ² exist, or the plural rings exist. It is preferable that all of the ring L ¹ and the ring L ² have a group represented by the formula (1-T), and all of the plurality of rings L ¹ or all of the plurality of rings L ² have the formula It is more preferable to have a group represented by (1-T).

In the metal complex represented by the formula (1), the number of the group represented by the formula (1-T) in at least one of the ring L ¹ and the ring L ² is usually 1 to 5, Since the metal complex represented by (1) can be easily synthesized, it is preferably 1 to 3, more preferably 1 or 2, and further preferably 1.
In the metal complex represented by the formula (1), when M ¹ is a rhodium atom or an iridium atom, the total number of groups represented by the formula (1-T) in the ring L ¹ and the ring L ² is usually 1 to 30, which is more excellent in light emission efficiency of the light emitting device of the present embodiment, and therefore is preferably 1 to 18, more preferably 2 to 12, and further preferably 3 to There are six.
In the metal complex represented by the formula (1), when M ¹ is a palladium atom or a platinum atom, the total number of groups represented by the formula (1-T) in the ring L ¹ and the ring L ² is usually 1 to 20, which is more excellent in light emission efficiency of the light emitting device of the present embodiment, and thus is preferably 1 to 12, more preferably 1 to 8, and further preferably 2 to There are four.

The substituent which the ring L ¹ and the ring L ² may have is preferably a group represented by the formula (1-T), because the light emitting element of the present embodiment is more excellent in light emission efficiency.
In the substituents which ring L ¹ and ring L ² may have, the substituent other than the group represented by formula (1-T) is preferably a cyano group, an alkenyl group or a cycloalkenyl group. The group may further have a substituent. Examples and preferred ranges of the substituents which the substituent other than the group represented by the formula (1-T) may further have are examples and preferred ranges of the substituents which R ^1T described later may have. Is the same as.

[Group represented by formula (1-T)]
The aryl group for R ^1T is preferably a group obtained by removing one hydrogen atom directly bonded to a carbon atom constituting a ring from a monocyclic, bicyclic or tricyclic aromatic hydrocarbon, and It is preferably a phenyl group, a naphthyl group or a fluorenyl group, more preferably a phenyl group, and these groups may have a substituent.
The monovalent heterocyclic group for R ^1T is preferably one hydrogen atom directly bonded to a carbon atom or a heteroatom constituting a ring from a monocyclic, bicyclic or tricyclic heterocyclic compound. It is a group removed, more preferably, a pyridine ring, a diazabenzene ring, a triazine ring, an azanaphthalene ring, a diazanaphthalene ring, a carbazole ring, a dibenzofuran ring or a dibenzothiophene ring directly bonded to a carbon atom or a hetero atom constituting the ring. Is a group excluding one hydrogen atom, more preferably a group excluding one hydrogen atom directly bonded to a carbon atom constituting the ring from a pyridine ring, a diazabenzene ring or a triazine ring, and these groups are It may have a substituent.
In the substituted amino group for R ^1T, the substituent that the amino group has is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may further have a substituent. Examples and preferred ranges of the aryl group that is the substituent of the amino group are the same as the examples and preferred ranges of the aryl group for R ^1T . Examples and preferred ranges of the monovalent heterocyclic group that is a substituent of the amino group are the same as the examples and preferred ranges of the monovalent heterocyclic group for R ^1T .

Since R ^1T is more excellent in the light emission efficiency of the light emitting device of the present embodiment, it is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, a substituted amino group or fluorine. Atoms, more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and still more preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group. A group, and these groups may have a substituent.

The substituent which R ^1T may have is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, a substituted amino group or a fluorine atom, More preferably, it is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, still more preferably an alkyl group, a cycloalkyl group or an aryl group, and these groups are further substituents. May have.
Examples and preferred ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in the substituent which R ^1T may have are the aryl group, the monovalent heterocyclic group and the substituted amino group in R ^1T , respectively. And the preferred range.

As the substituent which the substituent which R ^1T may have may further have, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group and a monovalent heterocyclic group are preferable. A substituted amino group or a fluorine atom, more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and further preferably an alkyl group or a cycloalkyl group, These groups may have a substituent, but preferably have no further substituents.
Examples and preferred ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in the substituent which the substituent that R ^1T may further have are the aryl group in R ^1T , It is the same as the examples and preferred ranges of the monovalent heterocyclic group and the substituted amino group.

[Anionic bidentate ligand]
Examples of the anionic bidentate ligand represented by A ¹ -G ¹ -A ² include a ligand represented by the following formula. However, the anionic bidentate ligand represented by A ¹ -G ¹ -A ² is different from the ligand whose number is defined by the subscript n ¹ .

Wherein * represents a site that binds to ^{M 1.} ]

Examples of the metal complex represented by the formula (1) include a metal complex represented by the following formula, and metal complexes G2, G3 and R2 to R5 described later.

<Metal Complex Represented by Formula (2)>
The metal complex represented by the formula (2) is usually a metal complex exhibiting phosphorescence emission property at room temperature, and preferably a metal complex exhibiting light emission from a triplet excited state at room temperature.

M ² is preferably an iridium atom or a platinum atom, and more preferably an iridium atom, because the light emitting element of the present embodiment is more excellent in light emission efficiency.
When M ² is a rhodium atom or an iridium atom, n ³ is preferably 2 or 3, and more preferably 3.
When M ² is a palladium atom or a platinum atom, n ³ is preferably 2.
E ¹ and E ² are preferably carbon atoms.
E ¹ and E ² are preferably the same because the metal complex represented by the formula (2) can be easily synthesized. Further, since the metal complex represented by the formula (2) can be easily synthesized, when a plurality of E ^1's are present, they are preferably the same. Further, since the metal complex represented by the formula (2) can be easily synthesized, when a plurality of E ^2's are present, they are preferably the same.

Examples of the ring R ¹ include a 5-membered aromatic heterocycle having at least one nitrogen atom as a constituent atom among the aromatic heterocycles exemplified in the above-mentioned section of the heterocyclic group, and preferably, It is a 5-membered monocyclic aromatic heterocycle, more preferably a diazole ring or a triazole ring, even more preferably a diazole ring, and these rings may have a substituent.
When a plurality of rings R ¹ are present, they are preferably the same, because the metal complex represented by the formula (2) can be easily synthesized. More specifically, if the ring R ¹ there are a plurality of the rings R ¹ there are a plurality of, preferably at least two are the same, and more preferably all ring R ¹ to plurality of are identical.
Examples and preferable ranges of the ring R ² are the same as examples and preferable ranges of the ring L ² .

The ring R ¹ is preferably a diazole ring or a triazole ring, and the ring R ² is preferably a benzene ring, a pyridine ring or a diazabenzene ring, because the light emitting device of the present embodiment is more excellent in luminous efficiency, and the ring R ¹ is It is more preferable that the ring R ² is a diazole ring or a triazole ring, the ring R ² is a benzene ring, the ring R ¹ is a diazole ring, and the ring R ² is a benzene ring. May have a substituent.

Examples and preferable ranges of the substituents that the ring R ¹ and ring R ² may have are the same as examples and preferable ranges of the substituents that the ring L ¹ and ring L ² may have.

At least one of the ring R ¹ and the ring R ² preferably has a substituent (preferably a group represented by the formula (1-T)).
Incidentally, a in the metal complex represented by formula (2), wherein ring R ¹ and ring R ² there are a plurality, at least one ring substituent of the rings R ¹ and ring R ² there are a plurality of However, since the light emitting device of the present embodiment is more excellent in light emission efficiency, all of the plurality of rings R ¹ and all of the plurality of rings R ² or the plurality of rings R ¹ and R ^{2 are present.} It is preferable that all of R ¹ have a substituent, all of the plurality of rings R ¹ or all of the plurality of rings of R ² have a substituent, all of the plurality of rings of R ¹ However, it is more preferable to have a substituent.

In the metal complex represented by the formula (2), the number of substituents contained in at least one of the ring R ¹ and the ring R ² is usually 1 to 5, and the metal complex represented by the formula (2) Is preferably 1 to 3, more preferably 1 or 2 and even more preferably 1 because it can be easily synthesized.
In the metal complex represented by the formula (2), when M ² is a rhodium atom or an iridium atom, the total number of substituents contained in the ring R ¹ and the ring R ² is usually 1 to 30, Since the light emitting device of the present embodiment is more excellent in light emission efficiency, it is preferably 1 to 18, more preferably 2 to 12, and further preferably 3 to 6.
In the metal complex represented by the formula (2), when M ² is a palladium atom or a platinum atom, the total number of substituents contained in the ring R ¹ and the ring R ² is usually 1 to 20, Since the luminous efficiency of the light emitting device of the present embodiment is more excellent, it is preferably 1 to 12, more preferably 1 to 8, and further preferably 2 to 4.

Examples and preferred ranges of the anionic bidentate ligand represented by A ³ -G ² -A ⁴ include the examples of the anionic bidentate ligand represented by A ¹ -G ¹ -A ² and It is the same as the preferred range. In the anionic bidentate ligand represented by A ³ -G ² -A ⁴ , * in the above formula represents a site that binds to M ² . However, the anionic bidentate ligand represented by A ³ -G ² -A ⁴ is different from the ligand whose number is defined by the subscript n ³ .

Examples of the metal complex represented by the formula (2) include a metal complex represented by the following formula and a metal complex B1 described later. In the formula, Z ^A represents a group represented by —CH═ or a group represented by —N═. When a plurality of Z ^A are present, they may be the same or different.

<Compound represented by formula (H-1)>
The molecular weight of the compound represented by formula (H-1) is usually 1 × 10 ² to 1 × 10 ⁴ , preferably 2 × 10 ² to 5 × 10 ³ , and more preferably 3 × 10 ² to It is 3 × 10 ³ , and more preferably 4 × 10 ² to 1 × 10 ³ . The compound represented by the formula (H-1) is a low molecular weight compound.

The aryl group in Ar ^H1 and Ar ^H2, and the arylene group in L ^H1 are preferably a hydrogen atom 1 directly bonded to a carbon atom forming a ring from a monocyclic or 2 to 6 ring aromatic hydrocarbon. Or two (however, in the case of an aryl group, it has one hydrogen atom, and in the case of an arylene group, it has two hydrogen atoms, and the same applies hereinafter), and more preferably a single group. A group obtained by removing one or two hydrogen atoms directly bonded to carbon atoms constituting a ring from a cyclic or 2 to 4 ring aromatic hydrocarbon, and more preferably benzene, naphthalene, fluorene, phenanthrene or It is a group in which one or two hydrogen atoms directly bonded to carbon atoms constituting a ring are removed from triphenylene, and these groups may have a substituent.
The monovalent heterocyclic group in Ar ^H1 and Ar ^H2, and the divalent heterocyclic group in L ^H1 are preferably carbons constituting a ring from a monocyclic or a 2 to 6 ring heterocyclic compound. 1 or 2 hydrogen atoms directly bonded to an atom or a heteroatom (however, in the case of a monovalent heterocyclic group, one hydrogen atom, and in the case of a divalent heterocyclic group, two hydrogen atoms, The same shall apply hereinafter), and more preferably a monocyclic, bicyclic, tricyclic or pentacyclic heterocyclic compound is directly attached to a carbon atom or a hetero atom constituting the ring. A group excluding one or two hydrogen atoms to be bonded, more preferably pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine, A group obtained by removing one or two hydrogen atoms directly bonded to carbon atoms or heteroatoms constituting a ring from benzocarbazole, indolocarbazole or indenocarbazole, and particularly preferably pyridine, diazabenzene, triazine and azanaphthalene. , Diazanaphthalene, carbazole, dibenzofuran or dibenzothiophene are groups in which one or two hydrogen atoms directly bonded to carbon atoms or heteroatoms constituting a ring are removed, and these groups have a substituent. Good.
In the substituted amino group in Ar ^H1 and Ar ^H2, the substituent that the amino group has is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups further have a substituent. Good. Examples and preferred ranges of the aryl group that is a substituent that the amino group has are the same as the examples and preferred ranges of the aryl group in Ar ^H1 and Ar ^H2 . Examples and preferred ranges of the monovalent heterocyclic group that is a substituent of the amino group are the same as the examples and preferred ranges of the monovalent heterocyclic group in Ar ^H1 and Ar ^H2 .

At least one of Ar ^H1 and Ar ^H2 is preferably an aryl group or a monovalent heterocyclic group, and is preferably a monovalent heterocyclic group, because the light emitting device of the present embodiment has higher luminous efficiency. A carbazolyl group, a dibenzothienyl group or a dibenzofuryl group is more preferable, a carbazolyl group is particularly preferable, and these groups may have a substituent.
Ar ^H1 and Ar ^H2 are preferably aryl groups or monovalent heterocyclic groups, and more preferably benzene, fluorene, pyridine, diazabenzene, triazine, since the light emitting device of the present embodiment has further excellent luminous efficiency. Carbazole, dibenzofuran or dibenzothiophene is a group obtained by removing one hydrogen atom directly bonded to a carbon atom or a hetero atom constituting a ring, and more preferably a phenyl group, a fluorenyl group, a dibenzothienyl group, a dibenzofuryl group or a carbazolyl group. A group, particularly preferably a carbazolyl group, and these groups may have a substituent.

At least one of L ^H1 is preferably an arylene group or a divalent heterocyclic group, and more preferably a divalent heterocyclic group, because the light emitting device of the present embodiment has higher emission efficiency. It is more preferable that carbazole, dibenzofuran, or dibenzothiophene is a group in which two hydrogen atoms directly bonded to carbon atoms or hetero atoms (preferably carbon atoms) constituting the ring are removed, and these groups further have a substituent. You may have.

L ^H1 is preferably an arylene group or a divalent heterocyclic group, and more preferably benzene, naphthalene, fluorene, pyridine, diazabenzene, triazine, aza, since the light emitting device of the present embodiment has further excellent luminous efficiency. Naphthalene, diazanaphthalene, carbazole, dibenzofuran or dibenzothiophene is a group obtained by removing two hydrogen atoms directly bonded to carbon atoms or heteroatoms (preferably carbon atoms) constituting a ring, and more preferably benzene and fluorene. , Pyridine, diazabenzene, triazine, carbazole, dibenzofuran or dibenzothiophene, a group in which two hydrogen atoms directly bonded to carbon atoms or heteroatoms (preferably carbon atoms) constituting the ring are removed, and particularly preferably dibenzofuran or Dibenzothiophene To a group excluding two hydrogen atoms directly bonded to carbon atoms constituting the ring, and these groups may have a substituent.

The substituent which Ar ^H1 , Ar ^H2 and L ^H1 may have is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group. Or a fluorine atom, more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and still more preferably an alkyl group, an aryl group or a monovalent heterocyclic group. And these groups may further have a substituent.
Examples and preferable ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in the substituent which Ar ^H1 , Ar ^H2 and L ^H1 may have are the aryl group in Ar ^H1 and Ar ^H2 , respectively. The same as the examples and preferred ranges of the valent heterocyclic group and the substituted amino group.

As the substituent which the substituent which Ar ^H1 , Ar ^H2 and L ^H1 may further have, is preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or It is a substituted amino group, more preferably an alkyl group or a cycloalkyl group, and these groups may further have a substituent, but preferably have no further substituents.
Examples and preferred ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in the substituent which the substituent which Ar ^H1 , Ar ^H2 and L ^H1 may further have are respectively: It is the same as the examples and preferred ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in Ar ^H1 and Ar ^H2 .

n ^H1 is generally an integer of 0 or more and 10 or less, preferably an integer of 0 or more and 5 or less, more preferably an integer of 1 or more and 3 or less, and particularly preferably 1.

Examples of the compound represented by the formula (H-1) include compounds represented by the following formula. In the formula, Z ^A has the same meaning as described above. In the formula, Z ^B represents an oxygen atom or a sulfur atom. When there are a plurality of Z ^B , they may be the same or different.

<Compound represented by Formula (T-1)>
The molecular weight of the compound represented by the formula (T-1) is usually 1 × 10 ² to 1 × 10 ⁴ , preferably 2 × 10 ² to 5 × 10 ³ , and more preferably 3 × 10 ² to It is 3 × 10 ³ , and more preferably 4 × 10 ² to 1.5 × 10 ³ . The compound represented by the formula (T-1) is a low molecular weight compound.

n ^T1 is preferably an integer of 0 or more and 3 or less, and more preferably 0 or 1, since the light emitting element of the present embodiment is more excellent in light emission efficiency.
n ^T2 is preferably an integer of 1 or more and 5 or less, more preferably an integer of 1 or more and 3 or less, and further preferably 2 because the light emitting element of the present embodiment is more excellent in light emission efficiency.

The "nitrogen atom having no double bond" means a nitrogen atom having only a single bond between the nitrogen atom and all the atoms bonded to the nitrogen atom.
The "in the ring containing the nitrogen atom that has no double bond", -N in the ring ^(-R N) - (. Wherein, R ^N represents a hydrogen atom or a substituent), or the formula:

It is meant to include a group represented by.

In a condensed ring monovalent heterocyclic group (hereinafter, also referred to as “heterocyclic group of Ar ^T1 ”) containing a nitrogen atom having no double bond in the ring and a group represented by ═N—, The number of nitrogen atoms having no double bond constituting the ring is usually 1 to 10, preferably 1 to 5, more preferably 1 to 3, and further preferably 1 or 2. . In the condensed monovalent heterocyclic group, the number of groups represented by ═N— constituting the ring is usually 1 to 10, preferably 1 to 5, and more preferably 1 to 3 and more preferably 1 or 2. In the monovalent heterocyclic group having a condensed ring, the number of carbon atoms constituting the ring is usually 2 to 60, preferably 5 to 30, and more preferably 8 to 25.

The heterocyclic group of Ar ^{T1 is} a heterocyclic ring containing a nitrogen atom having no double bond in the ring and not containing a group represented by ═N— (hereinafter, “donor heterocycle”). (Also referred to as “. A group in which one hydrogen atom directly bonded to a carbon atom or a hetero atom constituting a ring is removed from a heterocyclic compound condensed with preferably 5 or less, more preferably 3 or less, and further preferably 1) Is preferable, and these groups may have a substituent.

In the donor type heterocycle, the number of carbon atoms constituting the ring is usually 1 to 60, preferably 2 to 30, and more preferably 3 to 15. In the donor type heterocycle, the number of nitrogen atoms having no double bond constituting the ring is usually 1 to 10, preferably 1 to 5, more preferably 1 to 3, and further preferably Is 1 or 2.
The donor type heterocycle includes, for example, in the heterocyclic compounds exemplified in the above-mentioned heterocyclic group, a nitrogen atom having no double bond in the ring, and = N- Examples of the heterocyclic ring do not include a group represented by: Of these, a monocyclic or a 2-5 ring heterocyclic ring is preferable, and a monocyclic, bicyclic or tricyclic ring is more preferable. And more preferably a monocyclic or bicyclic heterocycle, and these rings may have a substituent.
The donor type heterocycle is more preferable in the luminous efficiency of the light emitting device of the present embodiment, and therefore, the pyrrole ring, the indole ring, the carbazole ring, the 9,10-dihydroacridine ring, the 5,10-dihydrophenazine ring, and the phenoxazine are preferable. It is a ring or a phenothiazine ring, more preferably a pyrrole ring, an indole ring or a carbazole ring, even more preferably a pyrrole ring or an indole ring, and these rings may have a substituent.
Examples and preferred ranges of the substituents that the donor heterocycle may have are the same as examples and preferred ranges of the substituents that Ar ^H1 , Ar ^H2 and L ^H1 may have.

In the heterocycle containing a group represented by = N- in the ring, the number of carbon atoms constituting the ring is usually 1 to 60, preferably 2 to 30, and more preferably 3 to 15. . In a heterocycle containing a group represented by = N- in the ring, the number of groups represented by = N- constituting the ring is usually 1 to 10, and preferably 1 to 5, It is preferably 1 to 3, and more preferably 1 or 2.
Examples of the heterocycle containing a group represented by = N- in the ring include a group represented by = N- in the ring among the heterocyclic compounds exemplified in the above-mentioned section of the heterocyclic group. Examples of the heterocyclic ring include: among them, a monocyclic, bicyclic or tricyclic heterocyclic ring is preferable, and a monocyclic heterocyclic ring is more preferable, and these rings have a substituent. You may have.
The heterocycle containing a group represented by = N- in the ring is more preferable in the light emitting efficiency of the light emitting device of the present embodiment, and therefore, it is preferably a diazole ring, a triazole ring, a tetrazole ring, a pyridine ring, a diazabenzene ring or a triazine. Ring, azanaphthalene ring, diazanaphthalene ring, azacarbazole ring, diazacarbazole ring, azaanthracene ring, diazaanthracene ring, azaphenanthrene ring or diazaphenanthrene ring, more preferably pyridine ring, diazabenzene ring, It is an azanaphthalene ring, a diazanaphthalene ring, an azacarbazole ring or a diazacarbazole ring, more preferably a pyridine ring or a diazabenzene ring, and these rings may have a substituent.
Examples and preferred ranges of the substituents that the heterocycle containing a group represented by = N- may have are examples of the substituents that Ar ^H1 , Ar ^H2 and L ^H1 may have. And the same as the preferable range.

As the heterocyclic group of Ar ^T1 , for example, azaindole, diazaindole, azacarbazole, diazacarbazole, or a group represented by a donor heterocycle in these rings and / or = N- in the ring is used. 1 or more (preferably 5 or less, more preferably 3 or less, further preferably 1) fused heterocyclic compound is directly bonded to a carbon atom or a hetero atom constituting the ring. A group in which one hydrogen atom is removed, and a group in which one hydrogen atom directly bonded to a carbon atom or a hetero atom constituting a ring is removed from azacarbazole or diazacarbazole is preferable. The group may have a substituent.
Examples and preferable ranges of the substituents that the heterocyclic group of Ar ^T1 may have are the same as the examples and preferable ranges of the substituents that Ar ^H1 , Ar ^H2 and L ^H1 may have.
When a plurality of Ar ^T1s are present, they are preferably the same so that the compound represented by the formula (T-1) can be easily synthesized.

The heterocyclic group of Ar ^T1 is preferably a group represented by the formula (T1-1) because the light emitting element of the present embodiment is more excellent in light emission efficiency.

[Group represented by formula (T1-1)]
X ^T1 is preferably a single bond, an oxygen atom, a sulfur atom or a group represented by —C (R ^{XT1 ′} ) _2- , more preferably a single bond, an oxygen atom or a sulfur atom, and further preferably a single bond. It is a combination.

R ^XT1 is preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, more preferably an aryl group or a monovalent heterocyclic group, and further preferably an aryl group. , These groups may have a substituent.
R ^{XT1 ′} is preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, more preferably an alkyl group or an aryl group, and further preferably an alkyl group. And these groups may have a substituent.
It is preferable that a plurality of R ^{XT1 ′ 's that} are present are bonded to each other and do not form a ring together with the carbon atom to which they are bonded.

Examples and preferred ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in R ^XT1 and R ^{XT1 ′} are the aryl group, the monovalent heterocyclic group and the substituted amino group in Ar ^H1 and Ar ^H2 , respectively. And the same as the preferable range.
Examples and preferred ranges of the substituents that R ^XT1 and R ^{XT1 ′} may have are the same as the examples and preferred ranges of the substituents that Ar ^H1 , Ar ^H2 and L ^H1 may have.

The number of carbon atoms of the aromatic hydrocarbon ring in the ring R ^T1 and the ring R ^T2 is usually 6 to 60, preferably 6 to 30 and more preferably 6 to 6, not including the number of carbon atoms of the substituent. Eighteen.
Examples of the aromatic hydrocarbon ring in the ring R ^T1 and the ring R ^T2 include the aromatic hydrocarbon rings exemplified in the above-mentioned aromatic hydrocarbon group, and the luminous efficiency of the light emitting device of the present embodiment is more improved. Since it is excellent, it is preferably a monocyclic, bicyclic or tricyclic aromatic hydrocarbon ring exemplified in the section of the aromatic hydrocarbon group described above, and more preferably a monocyclic aromatic hydrocarbon ring. It is a hydrogen ring, and these groups may have a substituent.
The aromatic hydrocarbon ring in the ring R ^T1 and the ring R ^T2 is preferably a benzene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring or a dihydrophenanthrene ring, because the light emitting element of the present embodiment is more excellent in the luminous efficiency. , More preferably a benzene ring, a fluorene ring or a dihydrophenanthrene ring, even more preferably a benzene ring, and these rings may have a substituent.
The number of carbon atoms of the heterocyclic ring in the ring R ^T1 and the ring R ^T2 is usually 1 to 60, preferably 2 to 30 and more preferably 3 to 15, not including the number of carbon atoms of the substituent. .
The number of hetero atoms in the hetero ring in the ring R ^T1 and the ring R ^T2 does not include the number of hetero atoms in the substituent, and is usually 1 to 30, preferably 1 to 10, and more preferably 1 to 3. is there.
Examples of the heterocyclic ring in the ring R ^T1 and the ring R ^T2 include the heterocyclic rings exemplified in the above-mentioned section of the heterocyclic group, and the luminous efficiency of the light emitting device of the present embodiment is more excellent. The monocyclic, bicyclic or tricyclic heterocycle exemplified in the section of the heterocyclic group (preferably a donor heterocycle or a heterocycle containing a group represented by = N- in the ring, More preferably, it is a heterocycle containing a group represented by = N- in the ring, and more preferably a monocyclic heterocycle (preferably a donor heterocycle or = N in the ring). A heterocycle containing a group represented by-, more preferably a heterocycle containing a group represented by = N- in the ring), and these rings each have a substituent. Good.
The heterocycle in the ring R ^T1 and the ring R ^T2 is preferably a carbazole ring, a 9,10-dihydroacridine ring, a 5,10-dihydrophenazine ring, or a phenoxy ring, because the light emitting element of the present embodiment is more excellent in the luminous efficiency. Sazine ring, phenothiazine ring, pyridine ring, diazabenzene ring, azanaphthalene ring, diazanaphthalene ring, azacarbazole ring, diazacarbazole ring, dibenzofuran ring or dibenzothiophene ring, more preferably pyridine ring, diazabenzene ring, aza ring It is a naphthalene ring, a diazanaphthalene ring, an azacarbazole ring or a diazacarbazole ring, more preferably a pyridine ring or a diazabenzene ring, and these rings may have a substituent.

The ring R ^T1 is preferably an aromatic hydrocarbon ring or a heterocycle containing a group represented by ═N— in the ring, because the light emitting element of the present embodiment is more excellent in light emission efficiency, and more preferably, A monocyclic aromatic hydrocarbon ring or a monocyclic heterocycle containing a group represented by = N- in the ring, more preferably a benzene ring, a pyridine ring or a diazabenzene ring, particularly preferably It is a benzene ring, and these rings may have a substituent.
The ring R ^T2 is preferably a heterocycle containing a group represented by ═N— in the ring, and more preferably ═N— in the ring, because the light emitting element of the present embodiment has higher emission efficiency. It is a monocyclic heterocycle containing a group represented by, more preferably a pyridine ring or a diazabenzene ring, particularly preferably a pyridine ring, and these rings may have a substituent.
Since the luminous efficiency of the light emitting device of the present embodiment is further excellent, the ring R ^T1 is an aromatic hydrocarbon ring or a heterocycle containing a group represented by ═N— in the ring, and the ring R ^T2 is A heterocyclic ring containing a group represented by = N- is preferred, and the ring R ^T1 is a monocyclic aromatic hydrocarbon ring or a monocyclic aromatic hydrocarbon ring containing a group represented by = N-. It is more preferable that the ring R ^T2 is a cyclic heterocycle and the ring R ^T2 is a monocyclic heterocycle containing a group represented by ═N— in the ring, and the ring R ^T1 is a benzene ring or pyridine. More preferably, it is a ring or a diazabenzene ring, and ring R ^T2 is a pyridine ring or a diazabenzene ring, ring R ^T1 is a benzene ring, and ring R ^T2 is a pyridine ring. , These rings may have a substituent.

Examples and preferred ranges of the substituents that the ring R ^T1 and ring R ^T2 may have are the same as the examples and the preferred ranges of the substituents that Ar ^H1 , Ar ^H2 and L ^H1 may have.

The examples and preferred ranges of the arylene group for L ^T1 are the same as the examples and preferred ranges of the arylene group for the arylene group for L ^H1 .
The examples and preferred ranges of the divalent heterocyclic group for L ^T1 are the same as the examples and preferred ranges of the arylene group for the divalent heterocyclic group for L ^H1 .

L ^T1 is preferably an arylene group or a divalent heterocyclic group, and more preferably a ring derived from benzene, naphthalene, fluorene, pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran or dibenzothiophene. Is a group excluding two hydrogen atoms directly bonded to a carbon atom or a heteroatom constituting, and more preferably a carbon atom constituting a ring from benzene, fluorene, pyridine, diazabenzene, triazine, carbazole, dibenzofuran or dibenzothiophene. Or a group excluding two hydrogen atoms directly bonded to a hetero atom, particularly preferably a group excluding two hydrogen atoms directly bonded to carbon atoms constituting a ring from benzene, dibenzofuran or dibenzothiophene, Especially preferred Or, it is a phenylene group, and these groups may have a substituent.
When a plurality of L ^T1s are present, they are preferably the same, because the compound represented by the formula (T-1) can be easily synthesized.

Examples and preferred ranges of the substituents that L ^T1 may have are the same as the examples and preferred ranges of the substituents that Ar ^H1 , Ar ^H2 and L ^H1 may have.

R ^{T1 ′} is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may have a substituent.
Examples and preferred ranges of the aryl group and monovalent heterocyclic group for R ^{T1 ′} are the same as the examples and preferred ranges of the aryl group and monovalent heterocyclic group for Ar ^H1 and Ar ^H2 , respectively.
Examples and preferred ranges of the substituents that R ^{T1 ′} may have are the same as the examples and preferred ranges of the substituents that Ar ^H1 , Ar ^H2 and L ^H1 may have.

The aromatic hydrocarbon group for Ar ^T2 is preferably a group obtained by removing one or more hydrogen atoms directly bonded to the carbon atoms constituting the ring from a monocyclic or 2-6 ring aromatic hydrocarbon, More preferably, it is a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms constituting a ring from a monocyclic, bicyclic or tricyclic aromatic hydrocarbon, and even more preferably benzene or naphthalene. , Fluorene, phenanthrene or anthracene except for one or more hydrogen atoms directly bonded to carbon atoms constituting the ring, and these groups may have a substituent.
The heterocyclic group for Ar ^T2 is preferably a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms or heteroatoms constituting the ring from a monocyclic or 2 to 6 ring heterocyclic compound. More preferably, it is a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms or heteroatoms constituting a ring from a monocyclic, bicyclic or tricyclic heterocyclic compound, and further preferably , Pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine, azaanthracene, diazaanthracene, azaphenanthrene or diazaphenanthrene to a carbon atom or a heteroatom constituting a ring. A group excluding one or more hydrogen atoms directly bonded, particularly preferably pyridine, One or more hydrogen atom directly bonded to a carbon atom or hetero atom forming a ring from diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, azaanthracene, diazaanthracene, azaphenanthrene or diazaphenanthrene Is a group except for, and these groups may have a substituent.
Since Ar ^T2 is more excellent in light emission efficiency of the light emitting device of the present embodiment, it is preferable that Ar ^T2 is directly bonded to a carbon atom or a hetero atom forming a ring from benzene, fluorene, pyridine, diazabenzene, triazine, carbazole, dibenzofuran or dibenzothiophene. Is a group excluding one or more hydrogen atoms, more preferably a group excluding one or more hydrogen atoms directly bonded to carbon atoms constituting a ring from benzene, dibenzofuran or dibenzothiophene, and these groups are It may have a substituent.
Examples and preferred ranges of the substituents that Ar ^T2 may have are the same as the examples and preferred ranges of the substituents that Ar ^H1 , Ar ^H2 and L ^H1 may have.

Examples of the compound represented by the formula (T-1) include a compound represented by the following formula, and compounds ET1 to ET3 described later. In the formula, Z ^A and Z ^B have the same meanings as described above.

<Light emitting element>
The light-emitting element of this embodiment has an anode, a cathode, a first layer provided between the anode and the cathode, and a second layer provided between the cathode and the first layer. In the device, the first layer is a layer containing two or more kinds of the metal complex represented by the formula (1), and at least one layer of the first layer and the second layer is represented by the formula ( A light-emitting device containing a compound represented by T-1).

The light emitting element of the present embodiment is an anode from the viewpoint of adjusting the emission color of the light emitting element of the present embodiment (particularly from the viewpoint of adjusting the emission color to white) and the viewpoint of improving the light emission efficiency of the light emitting element of the present embodiment. A light emitting element having a cathode, a first layer provided between the anode and the cathode, and a second layer provided between the cathode and the first layer, the first layer comprising: A layer containing two or more kinds of the metal complex represented by the formula (1) and a metal complex represented by the formula (2), wherein at least one layer of the first layer and the second layer is A light emitting device containing a compound represented by formula (T-1) is preferable.

(First layer)
The first layer is a layer containing two or more kinds of metal complexes represented by the formula (1). In the first layer, the total content of the metal complex represented by the formula (1) may be within the range in which the function as the first layer is exhibited. For example, the total content of the metal complex represented by the formula (1) may be 0.001% by mass or more and 100% by mass or less based on the total amount of the first layer, and 0.01% by mass or more and 50% by mass or less. It may be the following, preferably 0.05% by mass or more and 30% by mass or less, more preferably 0.1% by mass or more and 10% by mass or less, and 0.5% by mass or more and 5% by mass or less. More preferably,
The first layer may contain only two kinds or three or more kinds of the metal complex represented by the formula (1).

In the light-emitting device of this embodiment, at least one of the first layer and the second layer contains the compound represented by the formula (T-1), but the first layer contains the compound represented by the formula (T- When the compound represented by 1) is contained, it is preferably contained in the first layer as a host material described later. The first layer may contain one type of the compound represented by formula (T-1) alone, or may contain two or more types.

From the viewpoint of adjusting the emission color of the light emitting element of the present embodiment (especially from the viewpoint of adjusting the emission color to white, the same applies hereinafter), the first layer is represented by Formula (2). It is preferable to further include a metal complex.
More specifically, from the viewpoint of adjusting the emission color of the light emitting device of the present embodiment and improving the light emission efficiency of the light emitting device of the present embodiment, the first layer is made of the metal complex represented by the formula (1). It is preferable that the layer contains two or more kinds and the metal complex represented by the formula (2).
When the first layer further contains the metal complex represented by the formula (2), the total content of the metal complex represented by the formula (1) and the metal complex represented by the formula (2) is contained in the first layer. The amount may be in the range where the function as the first layer is achieved. For example, the total content of the metal complex represented by the formula (1) and the metal complex represented by the formula (2) is 0.01% by mass or more and 100% by mass or less based on the total amount of the first layer. It is preferably 0.1% by mass or more and 70% by mass or less, more preferably 1% by mass or more and 50% by mass or less, and further preferably 10% by mass or more and 30% by mass or less.
The first layer may contain one kind of the metal complex represented by the formula (2) alone, or may contain two kinds or more.
When the first layer contains the metal complex represented by the formula (2), the total content of the metal complex represented by the formula (2) and the total content of the metal complex represented by the formula (1). By adjusting the ratio with the amount, it is possible to adjust the emission color of the light emitting element of the present embodiment, and it is also possible to adjust the emission color to white.
Here, the emission color of the light emitting element can be confirmed by measuring the emission chromaticity of the light emitting element and obtaining the chromaticity coordinates (CIE chromaticity coordinates). It is preferable that the emission color of white has an X of chromaticity coordinates in the range of 0.25 to 0.55 and a Y of chromaticity coordinates in the range of 0.25 to 0.55.
The CIE chromaticity coordinates (x, y) are the xy chromaticity coordinates (x, y) based on the XYZ color system, which is an international labeling method established by the International Commission on Illumination CIE (Commission Internationale de l'Eclairage) in 1931. y).

When the first layer contains the metal complex represented by the formula (2), from the viewpoint of adjusting the emission color of the light emitting device of the present embodiment, the maximum peak of the emission spectrum of the metal complex represented by the formula (2). The wavelength is usually 380 nm or more and less than 495 nm, preferably 400 nm or more and 490 nm or less, more preferably 420 nm or more and 485 nm or less, and further preferably 450 nm or more and 480 nm or less.

When the first layer contains the metal complex represented by the formula (2), the maximum peak of the emission spectrum of the metal complex represented by the formula (1) from the viewpoint of adjusting the emission color of the light emitting device of the present embodiment. The wavelength is usually 495 nm or more and less than 750 nm, preferably 500 nm or more and 680 nm or less, and more preferably 505 nm or more and 640 nm or less.
Further, from the viewpoint of adjusting the emission color of the light emitting device of the present embodiment, at least two kinds of formulas (1) among the two or more kinds of metal complexes represented by the formula (1) contained in the first layer are used. The maximum peak wavelengths of the emission spectra of the metal complexes represented are preferably different from each other, and the difference between the different maximum peak wavelengths is preferably 10 to 200 nm, more preferably 20 to 150 nm, and further preferably 40 to It is 120 nm.
Further, from the viewpoint of adjusting the emission color of the light emitting device of the present embodiment, at least two kinds of formulas (1) among the two or more kinds of metal complexes represented by the formula (1) contained in the first layer are used. When the maximum peak wavelength of the emission spectrum of the metal complex represented is different, the maximum peak wavelength of the emission spectrum of the metal complex represented by the formula (1) on the short wavelength side is preferably 500 nm or more. It is less than 570 nm, more preferably 505 nm or more and 560 nm or less. The maximum peak wavelength of the emission spectrum of the metal complex represented by the formula (1) on the long wavelength side is preferably 570 nm or more and 680 nm or less, more preferably 575 nm or more and 660 nm or less. And more preferably 590 nm or more and 640 nm or less.

The maximum peak wavelength of the emission spectrum of the metal complex is obtained by dissolving the metal complex in an organic solvent such as xylene, toluene, chloroform, or tetrahydrofuran to prepare a dilute solution (concentration is, for example, 1 × 10 ⁻⁶ mass% or more 1 × 10 ^-3 wt% or less.), can be assessed by measuring at room temperature the PL spectra of rare-thin solution. Xylene is preferable as the organic solvent for dissolving the metal complex.

When the first layer contains the metal complex represented by the formula (2), the total content of the metal complex represented by the formula (1) is from the viewpoint of adjusting the emission color of the light emitting device of the present embodiment. When the content of the metal complex represented by the formula (2) is 100 parts by mass, it is preferably 0.01 parts by mass or more and 50 parts by mass or less, more preferably 0.1 parts by mass or more and 30 parts by mass or less. It is more preferably 0.5 part by mass or more and 10 parts by mass or less, and particularly preferably 1 part by mass or more and 5 parts by mass or less.
Further, from the viewpoint of adjusting the emission color of the light emitting device of the present embodiment, at least two kinds of formulas (1) among the two or more kinds of metal complexes represented by the formula (1) contained in the first layer are used. When the maximum peak wavelength of the emission spectrum of the metal complex represented is different, the content of the metal complex represented by the formula (1) on the long wavelength side of the emission spectrum has a short maximum peak wavelength of the emission spectrum. When the metal complex represented by the formula (1) on the wavelength side is 100 parts by mass, the amount is usually 1 part by mass or more and 10000 parts by mass or less, and the color reproducibility of the light emitting device of the present embodiment is excellent, and therefore it is preferable. The amount is 0.5 parts by mass or more and 1000 parts by mass or less, more preferably 1 part by mass or more and 100 parts by mass or less, and further preferably 5 parts by mass or more and 50 parts by mass or less.

When the first layer contains the metal complex represented by the formula (2), the metal complex represented by the formula (2) can be produced by the wet method for the light-emitting element of the present embodiment. Those which exhibit solubility in a solvent capable of dissolving the metal complex represented by

Since the light emitting device of the present embodiment is more excellent in light emission efficiency, it is represented by at least one kind of formula (1) among the two or more kinds of metal complexes represented by formula (1) contained in the first layer. In the metal complex, ring L ¹ is preferably a pyridine ring, quinoline ring or isoquinoline ring, and ring L ² is preferably a benzene ring, ring L ¹ is a pyridine ring, and ring L ² is a benzene ring. Is more preferable, and these rings may have a substituent.

Since the light emitting device of the present embodiment is more excellent in light emission efficiency, it is represented by at least two types of formula (1) among the two or more types of metal complexes represented by formula (1) contained in the first layer. In the metal complex, it is preferable that the ring L ¹ is a pyridine ring, a quinoline ring or an isoquinoline ring, and the ring L ² is a benzene ring, the ring L ¹ is a pyridine ring or an isoquinoline ring, and the ring L ² Is more preferably a benzene ring, and these rings may have a substituent.

[Host material]
Since the light emitting device of the present embodiment has higher luminous efficiency, the first layer further comprises a host material having at least one function selected from hole injection property, hole transport property, electron injection property and electron transport property. It is preferable to contain, and it is more preferable to further contain the host material and the metal complex represented by the formula (2). The first layer may contain one kind of the host material alone, or may contain two or more kinds thereof.

When the first layer further contains a host material, the total content of the metal complex represented by the formula (1) is 100 parts by mass based on the total amount of the metal complex represented by the formula (1) and the host material. In general, the amount is 0.01 parts by mass or more and 50 parts by mass or less, preferably 0.05 parts by mass or more and 30 parts by mass or less, more preferably 0.1 parts by mass or more and 10 parts by mass or less, and It is preferably 0.5 parts by mass or more and 5 parts by mass or less.
When the first layer further contains the host material and the metal complex represented by the formula (2), the total content of the metal complexes represented by the formula (1) is the metal represented by the formula (1). When the total amount of the complex, the metal complex represented by the formula (2) and the host material is 100 parts by mass, it is usually 0.001 part by mass or more and 50 parts by mass or less, preferably 0.01 part by mass or more and 30 parts by mass. Parts or less, more preferably 0.1 parts by mass or more and 10 parts by mass or less, further preferably 0.2 parts by mass or more and 5 parts by mass or less, particularly preferably 0.5 parts by mass or more and 3 parts by mass or less. Is.

The lowest excited triplet state (T ₁ ) of the host material has a higher emission efficiency of the light emitting device of this embodiment, and thus the lowest excited triplet state (T ₁ ) of the metal complex represented by the formula (1) is obtained. Higher energy levels are preferred.
In addition, when the first layer further contains the host material and the metal complex represented by the formula (2), the lowest excited triplet state (T ₁ ) of the host material has a luminous efficiency of the light emitting element of this embodiment. Is more excellent, the energy level is preferably higher than the lowest excited triplet state (T ₁ ) of the metal complex represented by the formula (2), and the lowest energy level of the metal complex represented by the formula (2). a higher energy level than the excited triplet state (T _1), and, more preferably lowest excited triplet state (T ₁₎ higher energy levels possessed by the metal complex represented by the formula (1) .
In addition, when the first layer further contains the host material and the metal complex represented by the formula (2), the light emitting element of the present embodiment has further excellent light emission efficiency, and thus the lowest excited triplet state ( T ₁ ) is an energy level higher than the lowest excited triplet state (T ₁ ) of the metal complex represented by the formula (2), and the lowest excitation of the metal complex represented by the formula (2). The triplet state (T ₁ ) is preferably an energy level higher than the lowest excited triplet state (T ₁ ) of the metal complex represented by the formula (1).

As the host material, the light emitting element of this embodiment can be produced by a wet method, and therefore, a material that exhibits solubility in a solvent capable of dissolving the metal complex represented by the formula (1) is preferable.
When the first layer further contains the host material and the metal complex represented by the formula (2), the host material and the metal complex represented by the formula (2) can be obtained by using the light emitting element of the present embodiment as a wet type. Since it can be prepared by the method, a solvent having solubility in a solvent capable of dissolving the metal complex represented by the formula (1) is preferable.

The host material is classified into a low molecular weight compound (low molecular weight host) and a high molecular weight compound (polymeric host), and the first layer may contain any host material. As the host material that may be contained in the first layer, a low molecular weight compound is preferable.
The low molecular weight host is preferably a compound represented by the formula (H-1) or a compound represented by the formula (T-1), and more preferably a compound represented by the formula (H-1). is there.
Examples of the polymer host include a polymer compound which is a hole transport material described later and a polymer compound which is an electron transport material described later.

[First composition (a) and first composition (b)]
The first layer includes two or more kinds of metal complexes represented by the formula (1), the host material described above, the metal complex represented by the formula (2) described above, a hole transport material, a hole injection material, A layer containing a composition (hereinafter, also referred to as “first composition (a)”) containing at least one selected from the group consisting of an electron transport material, an electron injection material, a light emitting material, and an antioxidant. It may be.
However, in the first composition (a), the light emitting material is different from the metal complex represented by the formula (1) and the metal complex represented by the formula (2).
Since the luminous efficiency of the light emitting device of the present embodiment is more excellent, the first composition (a) includes two or more kinds of the metal complex represented by the formula (1) and the metal complex represented by the formula (2). And a composition containing at least one selected from the group consisting of the above-mentioned host material, hole-transporting material, hole-injecting material, electron-transporting material, electron-injecting material, light-emitting material, and antioxidant (hereinafter referred to as " 1) (also referred to as the composition (b) ”of 1). Hereinafter, the first composition (a) and the first composition (b) may be collectively referred to as the first composition.

[Hole transport material]
The hole transport material is classified into low molecular weight compounds and high molecular weight compounds, and preferably high molecular weight compounds. The hole transport material may have a crosslinkable group.
Examples of the low molecular weight compound include triphenylamine and its derivatives, N, N′-di-1-naphthyl-N, N′-diphenylbenzidine (α-NPD), and N, N′-diphenyl-N, Examples thereof include aromatic amine compounds such as N'-di (m-tolyl) benzidine (TPD).
Examples of the polymer compound include polyvinylcarbazole and its derivative; polyarylene having an aromatic amine structure in its side chain or main chain and its derivative. The polymer compound may be a compound having an electron-accepting site bound thereto. Examples of the electron-accepting site include fullerene, tetrafluorotetracyanoquinodimethane, tetracyanoethylene, trinitrofluorenone, and the like, with fullerene being preferred.
In the first composition (a), the content of the hole transport material is usually 1 part by mass or more and 10000 parts by mass or less when the total amount of the metal complex represented by the formula (1) is 100 parts by mass. is there.
In the first composition (b), the content of the hole transport material is such that the total amount of the metal complex represented by the formula (1) and the metal complex represented by the formula (2) is 100 parts by mass, Usually, it is 1 part by mass or more and 10000 parts by mass or less.
The hole transport materials may be used alone or in combination of two or more.

[Electron transport material]
Electron transport materials are classified into low molecular weight compounds and high molecular weight compounds. The electron transport material may have a crosslinkable group.
Examples of the low molecular weight compound include metal complexes having 8-hydroxyquinoline as a ligand, oxadiazole, anthraquinodimethane, benzoquinone, naphthoquinone, anthraquinone, tetracyanoanthraquinodimethane, fluorenone, diphenyldicyanoethylene and diphenoquinone. , And derivatives thereof.
Examples of the polymer compound include polyphenylene, polyfluorene, and derivatives thereof. The polymer compound may be doped with a metal.
In the first composition (a), the content of the electron transport material is usually 1 part by mass or more and 10000 parts by mass or less, when the total amount of the metal complex represented by the formula (1) is 100 parts by mass. .
In the first composition (b), the content of the electron-transporting material is usually, when the total amount of the metal complex represented by the formula (1) and the metal complex represented by the formula (2) is 100 parts by mass. It is 1 part by mass or more and 10000 parts by mass or less.
The electron transport materials may be used alone or in combination of two or more.

[Hole injection material and electron injection material]
The hole injection material and the electron injection material are classified into a low molecular compound and a high molecular compound, respectively. The hole injection material and the electron injection material may have a crosslinkable group.
Examples of the low molecular weight compounds include metal phthalocyanines such as copper phthalocyanine; carbon; metal oxides such as molybdenum and tungsten; metal fluorides such as lithium fluoride, sodium fluoride, cesium fluoride and potassium fluoride.
Examples of the polymer compound include polyaniline, polythiophene, polypyrrole, polyphenylene vinylene, polythienylene vinylene, polyquinoline and polyquinoxaline, and derivatives thereof; conductive materials such as polymers containing an aromatic amine structure in its main chain or side chain. Polymers are mentioned.
In the first composition (a), the content of the hole injecting material and the content of the electron injecting material are each usually 1 part by mass when the total amount of the metal complex represented by the formula (1) is 100 parts by mass. It is above 10000 parts by mass.
In the first composition (b), the content of the hole injecting material and the content of the electron injecting material are each 100 in total of the metal complex represented by the formula (1) and the metal complex represented by the formula (2). When it is defined as parts by mass, it is usually 1 part by mass or more and 10000 parts by mass or less.
Each of the electron injection material and the hole injection material may be used alone or in combination of two or more kinds.

[Ion dope]
When the hole injection material or the electron injection material contains a conductive polymer, the electric conductivity of the conductive polymer is preferably 1 × 10 ⁻⁵ S / cm or more and 1 × 10 ³ S / cm or less. The conductive polymer can be doped with an appropriate amount of ions in order to set the electric conductivity of the conductive polymer in such a range.
The types of ions to be doped are anions for hole injection materials and cations for electron injection materials. Examples of the anion include polystyrene sulfonate ion, alkylbenzene sulfonate ion, and camphor sulfonate ion. Examples of the cation include lithium ion, sodium ion, potassium ion, and tetrabutylammonium ion.
The ions to be doped may be used alone or in combination of two or more.

[Luminescent material]
Light emitting materials are classified into low molecular weight compounds and high molecular weight compounds. The light emitting material may have a crosslinkable group.
Examples of the low molecular weight compound include naphthalene and its derivative, anthracene and its derivative, perylene and its derivative, and a triplet light emitting complex having iridium, platinum or europium as a central metal.
Examples of the triplet light emitting complex include the following metal complexes.

As the polymer compound, for example, an arylene group such as a phenylene group, a naphthalene diyl group, a fluorenediyl group, a phenanthrene diyl group, a dihydrophenanthren diyl group, an anthracene diyl group and a pyrenediyl group; two hydrogen atoms from an aromatic amine Examples thereof include aromatic amine residues such as removed groups; and polymer compounds containing a divalent heterocyclic group such as carbazolediyl group, phenoxazinediyl group and phenothiazinediyl group.
In the first composition (a), the content of the light emitting material is usually 1 part by mass or more and 10000 parts by mass or less when the total amount of the metal complex represented by the formula (1) is 100 parts by mass.
In the first composition (b), the content of the light emitting material is usually, when the total amount of the metal complex represented by the formula (1) and the metal complex represented by the formula (2) is 100 parts by mass. It is 1 part by mass or more and 10000 parts by mass or less.
The light emitting materials may be used alone or in combination of two or more.

[Antioxidant]
The antioxidant may be any compound as long as it is soluble in the same solvent as the metal complex represented by the formula (1) and does not inhibit light emission and charge transport, and examples thereof include a phenol-based antioxidant and a phosphorus-based antioxidant. Is mentioned.
In the first composition (a), the compounding amount of the antioxidant is usually 0.00001 parts by mass or more and 10 parts by mass or less when the total amount of the metal complex represented by the formula (1) is 100 parts by mass. Is.
In the first composition (b), the compounding amount of the antioxidant is usually when the total amount of the metal complex represented by the formula (1) and the metal complex represented by the formula (2) is 100 parts by mass. , 0.00001 parts by mass or more and 10 parts by mass or less.
The antioxidants may be used alone or in combination of two or more.

[First Ink (a) and First Ink (b)]
The first layer is formed by using a composition containing two or more kinds of metal complexes represented by formula (1) and a solvent (hereinafter, also referred to as “first ink (a)”). be able to. The first ink (a) is a spin coating method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, dip coating method, spray coating method, screen printing method, It can be suitably used for a wet method such as a flexographic printing method, an offset printing method, an inkjet printing method, a capillary coating method, and a nozzle coating method.
The first ink (a) is a composition containing two or more kinds of metal complexes represented by formula (1), a metal complex represented by formula (2), and a solvent (hereinafter, referred to as “first Ink (b) ”). Hereinafter, the first ink (a) and the first ink (b) may be collectively referred to as the first ink.
The viscosity of the first ink may be adjusted according to the type of the wet method, but when applied to a printing method in which a solution such as an inkjet printing method passes through an ejection device, clogging and flight bending occur during ejection. Since it is difficult, it is preferably 1 mPa · s or more and 20 mPa · s or less at 25 ° C.
The solvent contained in the first ink is preferably a solvent that can dissolve or uniformly disperse the solid content in the ink. Examples of the solvent include chlorine-based solvents, ether-based solvents, aromatic hydrocarbon-based solvents, aliphatic hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, polyhydric alcohol-based solvents, alcohol-based solvents, sulfoxide-based solvents and An amide solvent may be used. The solvent may be used alone or in combination of two or more.
In the first ink (a), the content of the solvent is usually 1,000 parts by mass or more and 1,000,000 parts by mass or less, when the total amount of the metal complex represented by the formula (1) is 100 parts by mass.
In the first ink (b), the content of the solvent is usually 1000 parts by mass when the total amount of the metal complex represented by the formula (1) and the metal complex represented by the formula (2) is 100 parts by mass. It is from 1 part to 1,000,000 parts by mass.

<Second layer>
In the light emitting device of the present embodiment, at least one of the first layer and the second layer contains the compound represented by the formula (T-1), but the light emitting efficiency of the light emitting device of the present embodiment Therefore, it is preferable that the second layer contains the compound represented by formula (T-1), and the second layer contains the compound represented by formula (T-1), and It is more preferable that the first layer does not contain the compound represented by formula (T-1), and it is further preferable that only the second layer contains the compound represented by formula (T-1). The second layer may contain one kind of the compound represented by the formula (T-1) alone, or may contain two or more kinds thereof.
In the light emitting device of this embodiment, when the second layer contains the compound represented by the formula (T-1), the content of the compound represented by the formula (T-1) is the same as that of the second layer. It may be within the range where the function of (1) is achieved. For example, the content of the compound represented by the formula (T-1) may be 1% by mass or more and 100% by mass or less, and 30% by mass or more and 100% by mass or less based on the total amount of the first layer. Is more preferable, 60% by mass or more and 100% by mass or less is more preferable, 90% by mass or more and 100% by mass or less is further preferable, and 100% by mass is particularly preferable.

[Second composition]
When the second layer contains the compound represented by formula (T-1), the second layer contains the compound represented by formula (T-1), a hole transport material, a hole injection material, A layer containing a composition (hereinafter, also referred to as “second composition”) containing at least one material selected from the group consisting of an electron transport material, an electron injection material, a light emitting material, and an antioxidant. May be. However, in the second composition, the electron transport material and the electron injection material are different from the compound represented by the formula (T-1).

Examples and preferred ranges of the hole transport material, electron transport material, hole injection material and electron injection material contained in the second composition are the hole transport material and electron transport material contained in the first composition. The same as the examples and preferable ranges of the hole injection material and the electron injection material.
Examples of the light emitting material contained in the second composition are represented by the light emitting material which the first composition may contain, the metal complex represented by the formula (2), and the formula (1). A metal complex is mentioned. The light emitting materials may be used alone or in combination of two or more.

In the second composition, the content of each of the hole transport material, the electron transport material, the hole injection material, the electron injection material, and the light emitting material is 100 parts by mass of the compound represented by the formula (T-1). When it does, it is 1 mass part or more and 1000 mass parts or less normally.

The example and the preferable range of the antioxidant contained in the second composition are the same as the example and the preferable range of the antioxidant contained in the first composition. In the second composition, the content of the antioxidant is usually 0.001 part by mass or more and 10 parts by mass or less when the compound represented by the formula (T-1) is 100 parts by mass.

When the second layer contains a compound represented by the formula (T-1), the second layer contains a compound represented by the formula (T-1) and a solvent (hereinafter, referred to as a composition). It is also possible to use a "second ink"). The second ink can be preferably used in the wet method described in the section of the first ink. The preferable range of the viscosity of the second ink is the same as the preferable range of the viscosity of the first ink. The example and the preferable range of the solvent contained in the second ink are the same as the example and the preferable range of the solvent contained in the first ink.
In the second ink, the content of the solvent is usually 1000 parts by mass or more and 100000 parts by mass or less, when the compound represented by the formula (T-1) is 100 parts by mass.

<Layer structure of light emitting element>
FIG. 1 is a schematic cross-sectional view of a light emitting device according to one embodiment of the present invention. The light-emitting element 10 shown in FIG. 1 is provided between an anode 11, a cathode 14, a first layer 12 provided between the anode 11 and the cathode 14, and a cathode 14 and the first layer 12. And a second layer 13.
The light emitting device of this embodiment may have layers other than the anode 11, the cathode 14, the first layer 12, and the second layer 13.
In the light emitting device of the present embodiment, the first layer 12 is usually a light emitting layer (hereinafter, referred to as “first light emitting layer”).
In the light emitting device of the present embodiment, the second layer 13 is usually a light emitting layer (a light emitting layer separate from the first light emitting layer, and hereinafter referred to as “second light emitting layer”) and electron transport. It is a layer or an electron injection layer, more preferably an electron transport layer.

In the light emitting device of the present embodiment, the second layer 13 is preferably a second light emitting layer, an electron transport layer or an electron injection layer provided between the cathode 14 and the first layer 12, and the cathode 14 And the electron transport layer provided between the first layer 12 is more preferable.
In the light emitting element of the present embodiment, the first layer 12 and the second layer 13 are preferably adjacent to each other because the light emitting element of the present embodiment has a higher light emitting efficiency.

In the light emitting device of this embodiment, since the light emitting device of this embodiment is more excellent in light emission efficiency, at least one of a hole injection layer and a hole transport layer is provided between the anode 11 and the first layer 12. It is preferable to further have a layer.
In the light emitting element of the present embodiment, when the second layer 13 is the second light emitting layer provided between the cathode 14 and the first layer 12, the light emitting element of the present embodiment has higher luminous efficiency. It is preferable to further include at least one layer of an electron transport layer and an electron injection layer between the cathode 14 and the second layer 13.
In the light emitting device of the present embodiment, when the second layer 13 is an electron transport layer provided between the cathode 14 and the first layer 12, the light emitting device of the present embodiment is more excellent in light emission efficiency. It is preferable to further include an electron injection layer between 14 and the second layer 13.
In the light emitting device of the present embodiment, when the second layer 13 is an electron injection layer provided between the cathode 14 and the first layer 12, the light emitting device of the present embodiment is more excellent in light emission efficiency. It is preferable to further include an electron transport layer between the first layer 12 and the second layer 13.

Specific examples of the layer structure of the light emitting device of this embodiment include layer structures represented by (D1) to (D9). The light emitting device of the present embodiment usually has a substrate, but may be laminated on the substrate from the anode, or may be laminated on the substrate from the cathode.

(D1) Anode / hole injection layer / hole transport layer / first light emitting layer (first layer) / electron transport layer (second layer) / electron injection layer / cathode (D2) anode / hole injection Layer / hole transport layer / first light emitting layer (first layer) / electron transport layer / electron injection layer (second layer) / cathode (D3) anode / hole injection layer / hole transport layer / first 1 light emitting layer (first layer) / second light emitting layer (second layer) / electron transport layer / electron injection layer / cathode (D4) anode / hole injection layer / hole transport layer / first Light emitting layer (first layer) / second light emitting layer / electron transport layer (second layer) / electron injection layer / cathode (D5) anode / hole injection layer / hole transport layer / first light emitting layer (First layer) / second light emitting layer / electron transport layer / electron injection layer (second layer) / cathode (D6) anode / hole injection layer / second light emitting layer / first light emitting layer ( First layer) / electron transport layer (second layer) / electron injection layer / shade (D7) Anode / hole injection layer / second light emitting layer / first light emitting layer (first layer) / electron transport layer / electron injection layer (second layer) / cathode (D8) anode / hole Injection layer / hole transport layer / second emission layer / first emission layer (first layer) / electron transport layer (second layer) / electron injection layer / cathode (D9) anode / hole injection layer / Hole transport layer / Second light emitting layer / First light emitting layer (first layer) / Electron transport layer / Electron injection layer (second layer) / Cathode

In (D1) to (D9), “/” means that the layers before and after that are adjacently stacked. Specifically, the “first light emitting layer (first layer) / electron transport layer (second layer)” means the first light emitting layer (first layer) and the electron transport layer (second layer). Layer) means that they are laminated adjacent to each other.

In the light emitting device of this embodiment, two or more layers are provided for each of the anode, the hole injection layer, the hole transport layer, the second light emitting layer, the electron transport layer, the electron injection layer, and the cathode, if necessary. May be.
When there are a plurality of anodes, hole injection layers, hole transport layers, second light emitting layers, electron transport layers, electron injection layers and cathodes, they may be the same or different.
The thickness of the anode, the hole injection layer, the hole transport layer, the first light emitting layer, the second light emitting layer, the electron transport layer, the electron injection layer, and the cathode is usually 1 nm or more and 1 μm or less, preferably 2 nm. Or more and 500 nm or less, more preferably 5 nm or more and 150 nm or less.
In the light emitting device of this embodiment, the order, the number, and the thickness of the layers to be stacked may be adjusted in consideration of the light emission efficiency of the light emitting device, the driving voltage, and the life of the device.

[Second light emitting layer]
The second light emitting layer is usually the second layer or a layer containing a light emitting material, and preferably a layer containing a light emitting material. When the second light emitting layer is a layer containing a light emitting material, examples of the light emitting material contained in the second light emitting layer include a light emitting material which may be contained in the second composition. To be The light emitting material contained in the second light emitting layer may be contained alone or in combination of two or more.
When the light emitting device of the present embodiment has the second light emitting layer and the second layer is not the electron transporting layer or electron injecting layer described later, the second light emitting layer is the second layer. It is preferable.

[Hole transport layer]
The hole transport layer is usually a layer containing a hole transport material. Examples of the hole transporting material contained in the hole transporting layer include the hole transporting material which may be contained in the above-mentioned first composition. The hole transport material contained in the hole transport layer may be contained alone or in combination of two or more.

[Electron transport layer]
The electron transport layer is usually a second layer or a layer containing an electron transport material, and preferably the second layer. When the electron-transporting layer is a layer containing an electron-transporting material, examples of the electron-transporting material contained in the electron-transporting layer include the electron-transporting material that the first composition may contain. .. The electron transport material contained in the electron transport layer may be contained alone or in combination of two or more.
When the light emitting device of the present embodiment has an electron transport layer and the second layer is not the above-mentioned second light emitting layer or electron injection layer described later, the electron transport layer is the second layer. preferable.

[Hole injection layer and electron injection layer]
The hole injection layer is a layer containing a hole injection material. Examples of the hole injection material contained in the hole injection layer include the hole injection material which the first composition may contain. The hole injection material contained in the hole injection layer may be contained alone or in combination of two or more.
The electron injection layer is a second layer or a layer containing an electron injection material, and preferably a layer containing an electron injection material. When the electron injection layer is a layer containing an electron injection material, examples of the electron injection material contained in the electron injection layer include the electron injection material which the above-mentioned first composition may contain. . The electron injection material contained in the electron injection layer may be contained alone or in combination of two or more.
When the light emitting device of the present embodiment has the electron injection layer and the second layer is not the above-mentioned second light emitting layer and the above-mentioned electron transport layer, the electron injection layer is the second layer. preferable.

[Substrate / Electrode]
The substrate in the light emitting element may be any substrate that can form an electrode and does not chemically change when forming a layer, and may be a substrate made of a material such as glass, plastic, or silicon. . If an opaque substrate is used, the electrodes furthest from the substrate are preferably transparent or translucent.

Examples of the material of the anode include conductive metal oxides and semitransparent metals, and preferably indium oxide, zinc oxide, tin oxide; indium tin oxide (ITO), indium zinc oxide, etc. Conductive compound; a complex of silver, palladium, and copper (APC); NESA, gold, platinum, silver, and copper.

Examples of materials for the cathode include metals such as lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, zinc and indium; alloys of two or more of them; Alloys of one or more with one or more of silver, copper, manganese, titanium, cobalt, nickel, tungsten, tin; and graphite and graphite intercalation compounds. Examples of the alloy include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, and calcium-aluminum alloy.

In the light emitting device of this embodiment, at least one of the anode and the cathode is usually transparent or semitransparent, but the anode is preferably transparent or semitransparent.
Examples of the method of forming the anode and the cathode include a vacuum vapor deposition method, a sputtering method, an ion plating method, a plating method and a laminating method.

[Method of manufacturing light emitting device]
In the light emitting device of the present embodiment, as a method of forming the first layer, the second layer, and other layers, when a low molecular compound is used, for example, a dry method such as a vacuum deposition method and the first ink are used. The wet method described in the section 1) is used, and when the polymer compound is used, for example, the wet method described in the section of the first ink is used. The first layer, the second layer, and the other layers may be formed by the wet method described in the section of the first ink, using the above-described various inks and inks containing various materials. Alternatively, it may be formed by a dry method such as a vacuum vapor deposition method.

When the first layer is formed by the wet method, it is preferable to use the first ink. The first layer is preferably formed by a wet method because the light emitting device of this embodiment can be easily manufactured.
When the second layer is formed by the wet method, it is preferable to use the second ink. The second layer is preferably formed by a wet method because the light emitting device of this embodiment can be easily manufactured.

The light emitting device of this embodiment can be manufactured by, for example, sequentially laminating each layer on a substrate. Specifically, an anode is provided on a substrate, layers such as a hole injection layer and a hole transport layer are provided thereon, and a light emitting layer is provided thereon, and an electron transport layer, an electron injection layer, and the like are provided thereon. A light emitting device can be manufactured by providing a layer and further laminating a cathode thereon. As another manufacturing method, a cathode is provided on a substrate, a layer such as an electron injection layer, an electron transport layer, a light emitting layer, a hole transport layer, and a hole injection layer is provided thereon, and an anode is further provided thereon. A light emitting element can be manufactured by stacking. As still another manufacturing method, an anode or an anode-side base material in which each layer is laminated on the anode and a cathode or a cathode-side base material in which each layer is laminated on the cathode are opposed to each other to be manufactured. it can.

In the production of the light emitting element of this embodiment, a material used for forming a hole injection layer, a material used for forming a light emitting layer, a material used for forming a hole transport layer, a material used for forming an electron transport layer, and an electron When the materials used for forming the injection layer are each soluble in the solvent used when forming the layer adjacent to the hole injection layer, the light emitting layer, the hole transport layer, the electron transport layer and the electron injection layer, It is preferred that the material is avoided to dissolve. As a method of avoiding dissolution of the material, i) a method of using a material having a crosslinkable group, or ii) a method of providing a difference in solubility between adjacent layers in a solvent is preferable. In the above method i), the layer can be insolubilized by forming a layer using a material having a crosslinkable group and then crosslinking the crosslinkable group. In addition, as the method of ii), for example, when an electron transport layer is laminated on the light emitting layer by utilizing the difference in solubility, the ink having low solubility in the light emitting layer is used to transport electron. The layer can be laminated on the light emitting layer.

[Uses of light emitting device]
In order to obtain planar light emission using the light emitting element, the planar anode and cathode may be arranged so as to overlap each other. In order to obtain patterned light emission, a method of installing a mask having a patterned window on the surface of a planar light emitting element, and forming a layer to be a non-light emitting portion with an extremely thick layer to make it substantially non-light emitting There is a method, a method of forming an anode or a cathode, or both electrodes in a pattern. By forming a pattern by any of these methods and arranging some electrodes so that they can be turned ON / OFF independently, a segment type display device capable of displaying numbers, characters, etc. can be obtained. In order to obtain a dot matrix display device, both the anode and the cathode may be formed in stripes and arranged so as to be orthogonal to each other. Partial color display and multi-color display are possible by a method of separately applying a plurality of types of polymer compounds having different emission colors, and a method of using a color filter or a fluorescence conversion filter. The dot matrix display device can be passively driven or can be actively driven in combination with a TFT or the like. These display devices can be used for displays of computers, televisions, mobile terminals and the like. The planar light emitting element can be suitably used as a planar light source for a backlight of a liquid crystal display device or a planar light source for illumination. If a flexible substrate is used, it can be used as a curved light source and a display device.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

In the examples, the polystyrene-equivalent number average molecular weight (Mn) and polystyrene-equivalent weight average molecular weight (Mw) of the polymer compound were determined by size exclusion chromatography (SEC) using tetrahydrofuran as the mobile phase. The measurement conditions of SEC are as follows.
The polymer compound to be measured was dissolved in tetrahydrofuran at a concentration of about 0.05% by mass, and 10 μL was injected into SEC. The mobile phase was flowed at a flow rate of 2.0 mL / min. PLgel MIXED-B (manufactured by Polymer Laboratories) was used as a column. A UV-VIS detector (manufactured by Shimadzu Corporation, trade name: SPD-10Avp) was used as the detector.

LC-MS was measured by the following method.
The measurement sample was dissolved in tetrahydrofuran so as to have a concentration of about 2 mg / mL, and about 1 μL was injected into LC-MS (manufactured by Agilent, trade name: 1290 Infinity LC and 6230 TOF LC / MS). As the mobile phase of LC-MS, acetonitrile and tetrahydrofuran were used while changing the ratio, and flowed at a flow rate of 1.0 mL / min. As the column, SUMIPAX ODS Z-CLUE (manufactured by Sumika Analytical Center, inner diameter: 4.6 mm, length: 250 mm, particle diameter 3 μm) was used.

NMR was measured by the following method.
A measurement sample of 5 to 10 mg was dissolved in about 0.5 mL of heavy tetrahydrofuran, and the measurement was performed using an NMR apparatus (manufactured by JEOL RESONANCE, trade name: JNM-ECZ400S / L1).

The value of high performance liquid chromatography (HPLC) area percentage was used as an index of the purity of the compound. This value is a value at UV = 254 nm in HPLC (manufactured by Shimadzu Corporation, trade name: LC-20A) unless otherwise specified. At this time, the compound to be measured was dissolved in tetrahydrofuran so as to have a concentration of 0.01 to 0.2% by mass, and 1 to 10 μL was injected into HPLC depending on the concentration. The mobile phase of HPLC was used while changing the ratio of acetonitrile / tetrahydrofuran from 100/0 to 0/100 (volume ratio), and flowed at a flow rate of 1.0 mL / min. As the column, SUMIPAX ODS Z-CLUE (manufactured by Sumika Chemical Analysis Service, inner diameter: 4.6 mm, length: 250 mm, particle diameter 3 μm) was used. A photodiode array detector (manufactured by Shimadzu Corporation, trade name: SPD-M20A) was used as the detector.

In this example, the maximum peak wavelength of the emission spectrum of the metal complex was measured at room temperature with a spectrophotometer (FP-6500 manufactured by JASCO Corporation). A xylene solution in which the compound was dissolved in xylene at a concentration of about 0.8 × 10 ⁻⁴ mass% was used as a sample. UV light having a wavelength of 325 nm was used as the excitation light.

<Synthesis Example M> Synthesis of Compounds M1 to M3 Compound M1 was synthesized according to the method described in International Publication No. 2015/145871.
Compound M2 was synthesized according to the method described in WO 2013/146806.
Compound M3 was synthesized according to the method described in WO 2005/049546.

<Synthesis example HTL> Synthesis of polymer compound HTL-1 The polymer compound HTL-1 was synthesized by using the compound M1, the compound M2 and the compound M3 according to the method described in International Publication No. 2015/145871. The polymer compound HTL-1 had Mn = 2.3 × 10 ⁴ and Mw = 1.2 × 10 ⁵ .
In the polymer compound HTL-1, the theoretical value obtained from the amount of the charged raw material indicates that the structural unit derived from the compound M1, the structural unit derived from the compound M2, and the structural unit derived from the compound M3 are It is a copolymer composed of a molar ratio of 45: 5: 50.

<Compound HM-1>
Compound HM-1 was purchased from Luminescence Technology.

<Synthesis Example B> Synthesis of Metal Complex B1 The metal complex B1 was synthesized according to the methods described in International Publication No. 2006/121811 and JP2013-048190A. The maximum peak wavelength of the emission spectrum of the metal complex B1 was 471 nm.

<Synthesis Example G> Synthesis and acquisition of metal complexes G1 to G3 The metal complex G1 was purchased from Luminescience Technology.
The metal complex G2 was synthesized according to the method described in JP2013-237789A.
The metal complex G3 was synthesized according to the method described in WO 2009/131255.

The maximum peak wavelength of the emission spectrum of the compound G1 was 510 nm.
The maximum peak wavelength of the emission spectrum of compound G2 was 508 nm.
The maximum peak wavelength of the emission spectrum of the compound G3 was 514 nm.

<Synthesis Example R> Synthesis and Acquisition of Metal Complexes R1 to R5 The metal complex R1 was purchased from American Dye Source.
The metal complex R2 was purchased from Luminescience Technology.
The metal complex R3 was synthesized according to the method described in JP-A-2006-188673.
The metal complex R4 was synthesized according to the method described in JP-A-2008-179617.
The metal complex R5 was synthesized according to the method described in JP2011-105701A.

The maximum peak wavelength of the emission spectrum of the metal complex R1 was 618 nm.
The maximum peak wavelength of the emission spectrum of the metal complex R2 was 620 nm.
The maximum peak wavelength of the emission spectrum of the metal complex R3 was 619 nm.
The maximum peak wavelength of the emission spectrum of the metal complex R4 was 594 nm.
The maximum peak wavelength of the emission spectrum of the metal complex R5 was 611 nm.

<Synthesis Example ET1> Synthesis of Compound ET1 and Compound ET3 Compound ET1 and Compound ET3 were synthesized according to the method described in JP 2010-235575 A.

<Compound ET2> Synthesis of compound ET2

After making the inside of the reaction vessel an inert gas atmosphere, the compound ET2a (8.7 g), the compound ET2b (8.1 g), dimethyl sulfoxide (218 mL), copper (I) oxide (1.3 g), tripotassium phosphate ( 16.7g) and dipivaloyl methane (3.2g) were added, and it stirred at 150 degreeC for 10 hours. The obtained reaction liquid was cooled to room temperature, toluene and ion-exchanged water were added, and the mixture was filtered through a glass filter lined with Celite. The obtained filtrate was washed with ion-exchanged water, and the obtained organic layer was concentrated to obtain a crude product. The obtained crude product was purified by silica gel column chromatography (mixed solvent of hexane and ethyl acetate), and then crystallized using a mixed solvent of acetonitrile and toluene. The obtained solid was dried under reduced pressure at 50 ° C. to obtain compound ET2 (8.0 g). The HPLC area percentage value of the compound ET2 was 99.5% or more.

The analysis results of the compound ET2 were as follows.
LC-MS (ESI, positive): m / z = 573 [M + H] ⁺
¹ H-NMR (400 MHz, THF-d ₈ ): δ (ppm) = 1.01 (t, 3H), 1.58-1.68 (m, 2H), 1.95-2.05 (m, 2H), 3.14-3.19 (m, 2H), 7.32-7.39 (m, 4H), 7.49-7.57 (m, 4H), 7.72 (s, 1H) , 7.79-7.88 (m, 3H), 8.34-8.42 (m, 3H), 8.55-8.68 (m, 4H).

<Example D1> Production and evaluation of light-emitting element D1 (formation of anode and hole injection layer)
An anode was formed by attaching an ITO film having a thickness of 45 nm on a glass substrate by a sputtering method. A film of ND-3202 (manufactured by Nissan Chemical Industries, Ltd.), which is a hole injection material, was formed on the anode by a spin coating method to a thickness of 35 nm. In an air atmosphere, a hole injection layer was formed by heating on a hot plate at 50 ° C. for 3 minutes and further at 230 ° C. for 15 minutes.

(Formation of hole transport layer)
The polymer compound HTL-1 was dissolved in xylene at a concentration of 0.7% by mass. Using the obtained xylene solution, a film having a thickness of 20 nm was formed on the hole injection layer by a spin coating method, and heated at 180 ° C. for 60 minutes on a hot plate in a nitrogen gas atmosphere to form a positive film. A pore transport layer was formed. By this heating, the polymer compound HTL-1 became a crosslinked product.

(Formation of first layer)
In toluene, the compound HM-1, the metal complex B1, the metal complex G3, and the metal complex R5 (compound HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.9 mass% / 25 mass% / 1 mass% /0.1% by mass) was dissolved at a concentration of 2% by mass. Using the obtained toluene solution, a film having a thickness of 80 nm was formed on the hole transport layer by spin coating, and heated in a nitrogen gas atmosphere at 130 ° C. for 10 minutes to form the first layer (emission). Layers) were formed.

(Formation of second layer)
The compound ET1 was dissolved in 2,2,3,3,4,4,5,5-octafluoro-1-pentanol at a concentration of 0.25 mass%. Using the obtained 2,2,3,3,4,4,5,5-octafluoro-1-pentanol solution, a film having a thickness of 10 nm was formed on the first layer by spin coating. The second layer (electron transport layer) was formed by heating at 130 ° C. for 10 minutes in a nitrogen gas atmosphere.

(Formation of cathode)
After depressurizing the substrate on which the first layer was formed to 1.0 × 10 ⁻⁴ Pa or less in a vapor deposition machine, sodium fluoride was deposited on the second layer to a thickness of about 4 nm as a cathode, and then sodium fluoride was formed. Aluminum was evaporated to about 80 nm on the layer. After vapor deposition, the light emitting element D1 was produced by sealing with a glass substrate.

(Evaluation of light emitting element)
EL light emission was observed by applying a voltage to the light emitting device D1. The luminous efficiency at 5000 cd / m ² [lm / W] and the CIE chromaticity coordinates were measured.

<Examples D2 to D4 and Comparative Example CD1> Production and Evaluation of Light-Emitting Elements D2 to D4 and CD1 “Compound HM-1, Metal Complex B1, Metal Complex G3 and Metal” in (Formation of First Layer) of Example D1 Light-emitting elements D2 to D4 and CD1 were produced in the same manner as in Example D1 except that the materials shown in Table 1 were used instead of the “complex R5”.
EL light emission was observed by applying a voltage to the light emitting devices D2 to D4 and CD1. The luminous efficiency at 5000 cd / m ² [lm / W] and the CIE chromaticity coordinates were measured.

Table 1 shows the results of Examples D1 to D4 and Comparative Example CD1. The relative values of the luminous efficiencies of the light emitting elements D1 to D4 when the luminous efficiency of the light emitting element CD1 is 1.00 are shown.

<Examples D5 to D6 and Comparative Example CD2> Production and Evaluation of Light-Emitting Elements D5, D6, and CD2 “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal” in (Formation of First Layer) of Example D1 Example 2 was carried out except that the materials shown in Table 2 were used instead of the “complex R5”, and that the “compound ET2” was used instead of the “compound ET1” in (Formation of the second layer) of Example D1. Light emitting devices D5, D6 and CD2 were produced in the same manner as in Example D1.
EL light emission was observed by applying a voltage to the light emitting devices D5, D6 and CD2. The luminous efficiency at 5000 cd / m ² [lm / W] and the CIE chromaticity coordinates were measured.

Table 2 shows the results of Example D5, Example D6 and Comparative Example CD2. The relative value of the light emission efficiency of the light emitting elements D5 and D6 is shown when the light emission efficiency of the light emitting element CD2 is 1.00.

<Examples D7 to D8 and Comparative Example CD3> Production and Evaluation of Light-Emitting Elements D7, D8, and CD3 “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal” in (Formation of First Layer) of Example D1 In place of “Complex R5”, the materials shown in Table 3 were used, and “Compound ET3” was used instead of “Compound ET1” in (Formation of Second Layer) of Example D1. Light emitting devices D7, D8 and CD3 were produced in the same manner as in Example D1.
EL light emission was observed by applying a voltage to the light emitting devices D7, D8 and CD3. The luminous efficiency at 5000 cd / m ² [lm / W] and the CIE chromaticity coordinates were measured.

Table 3 shows the results of Example D7, Example D8, and Comparative Example CD3. The relative value of the light emission efficiency of the light emitting elements D7 and D8 when the light emission efficiency of the light emitting element CD3 is 1.00 is shown.

<Examples D9 and D10> Production and Evaluation of Light-Emitting Elements D9 and D10 Instead of “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal Complex R5” in (Formation of First Layer) of Example D1 Light-emitting elements D9 and D10 were produced in the same manner as in Example D1 except that the materials shown in Table 4 were used.
EL light emission was observed by applying a voltage to the light emitting devices D9 and D10. Luminous efficiency [lm / W] at 100 cd / m ² and CIE chromaticity coordinates were measured.

<Comparative Examples CD4 and CD5> Production and Evaluation of Light-Emitting Elements CD4 and CD5 Instead of “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal Complex R5” in (Formation of First Layer) of Example D1 , Using the materials and composition ratios (% by mass) shown in Table 4, and further substituting the materials shown in Table 4 for the “polymer compound HTL-1” in (Formation of hole transport layer) of Example D1. Further, light emitting devices CD4 and CD5 were produced in the same manner as in Example D1 except that the composition ratio (mass%) was used.
EL light emission was observed by applying a voltage to the light emitting devices CD4 and CD5. Luminous efficiency [lm / W] at 100 cd / m ² and CIE chromaticity coordinates were measured.

Table 4 shows the results of Example D9, Example D10, Comparative Example CD4 and Comparative Example CD5. The relative value of the light emission efficiency of the light emitting elements D9, D10 and CD5 when the light emission efficiency of the light emitting element CD4 is 1.0 is shown.

<Examples D11 and D12> Production and Evaluation of Light-Emitting Elements D11 and D12 Instead of “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal Complex R5” in (Formation of First Layer) of Example D1 In the same manner as in Example D1 except that the compounds shown in Table 5 were used and "Compound ET2" was used instead of "Compound ET1" in (Formation of the second layer) of Example D1. The light emitting devices D11 and D12 were produced.
EL light emission was observed by applying a voltage to the light emitting devices D11 and D12. Luminous efficiency [lm / W] at 100 cd / m ² and CIE chromaticity coordinates were measured.

<Comparative Example CD6> Production and Evaluation of Light-Emitting Element CD6 Instead of “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal Complex R5” in (Formation of First Layer) of Example D1, the results are shown in Table 5. Using the described materials and composition ratios (% by mass), “Compound ET2” was used instead of “Compound ET1” in (Formation of second layer) of Example D1, and further, (hole of Example D1 was used. A light emitting device CD6 was produced in the same manner as in Example D1 except that the material and the composition ratio (% by mass) shown in Table 5 were used instead of the “polymer compound HTL-1” in (Formation of Transport Layer). did.
EL light emission was observed by applying a voltage to the light emitting device CD6. Luminous efficiency [lm / W] at 100 cd / m ² and CIE chromaticity coordinates were measured.

Table 5 shows the results of Example D11, Example D12, and Comparative Example CD6. The relative value of the light emission efficiency of the light emitting elements D11 and D12 when the light emission efficiency of the light emitting element CD6 is 1.0 is shown.

Example D13 Production and Evaluation of Light-Emitting Element D13 Instead of “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal Complex R5” in (Formation of First Layer) of Example D1, the results are shown in Table 6. Light-emitting element D13 was prepared in the same manner as in Example D1, except that the above-mentioned materials were used and "Compound ET3" was used instead of "Compound ET1" in (Formation of the second layer) of Example D1. Was produced.
EL light emission was observed by applying a voltage to the light emitting device D13. Luminous efficiency [lm / W] at 100 cd / m ² and CIE chromaticity coordinates were measured.

<Comparative Example CD7> Production and Evaluation of Light-Emitting Element CD7 In Table 6, instead of “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal Complex R5” in (Formation of First Layer) of Example D1, Using the materials and composition ratios (% by mass) described, using “Compound ET3” in place of “Compound ET1” in (Formation of the second layer) of Example D1, and further using (hole A light emitting device CD7 was produced in the same manner as in Example D1 except that the material and the composition ratio (% by mass) shown in Table 6 were used instead of the “polymer compound HTL-1” in (Formation of Transport Layer). did.
EL light emission was observed by applying a voltage to the light emitting device CD7. Luminous efficiency [lm / W] at 100 cd / m ² and CIE chromaticity coordinates were measured.

Table 6 shows the results of Example D13 and Comparative Example CD7. The relative value of the light emission efficiency of the light emitting element D13 when the light emission efficiency of the light emitting element CD7 is 1.0 is shown.

According to the present invention, it is possible to provide a light emitting element having excellent luminous efficiency. A light emitting element having excellent light emitting efficiency has effects such as resource saving and energy saving.

10 light emitting elements, 11 anodes, 12 first layers, 13 second layers, 14 cathodes.

Claims

A light emitting device having an anode, a cathode, a first layer provided between the anode and the cathode, and a second layer provided between the cathode and the first layer,
The first layer is a layer containing two or more kinds of the metal complex represented by the formula (1) and the metal complex represented by the formula (2),
A light emitting device, wherein at least one layer of the first layer and the second layer contains a compound represented by the formula (T-1).

[In the formula,
M 1 represents a rhodium atom, a palladium atom, an iridium atom or a platinum atom.
n 1 represents an integer of 1 or more, and n 2 represents an integer of 0 or more. However, when M 1 is a rhodium atom or an iridium atom, n 1 + n 2 is 3, and when M 1 is a palladium atom or a platinum atom, n 1 + n 2 is 2.
E L represents a carbon atom or a nitrogen atom. If the E L there are a plurality, or different in each of them the same.
Ring L 1 represents a 6-membered aromatic heterocycle, and this ring may have a single or a plurality of substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded. When there are a plurality of rings L 1 , they may be the same or different.
Ring L 2 represents an aromatic hydrocarbon ring or an aromatic heterocycle, and these rings may have a single or a plurality of substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded.
When multiple rings L 2 are present, they may be the same or different.
The substituent that the ring L 1 may have and the substituent that the ring L 2 may have may be the same or different, and they are bonded to each other to form a ring together with the atom to which they are bonded. You may have.
However, at least one of the ring L 1 and the ring L 2 has a group represented by the formula (1-T) as a substituent. When there are a plurality of groups represented by formula (1-T), they may be the same or different.
A 1 -G 1 -A 2 represents an anionic bidentate ligand. A 1 and A 2 each independently represent a carbon atom, an oxygen atom or a nitrogen atom, and these atoms may be atoms constituting a ring. G 1 represents a single bond or an atomic group forming a bidentate ligand together with A 1 and A 2 . When there are a plurality of A 1 -G 1 -A 2 , they may be the same or different. ]

[In the formula,
M 2 represents a rhodium atom, a palladium atom, an iridium atom or a platinum atom.
n 3 represents an integer of 1 or more, and n 4 represents an integer of 0 or more. However, when M 2 is a rhodium atom or an iridium atom, n 3 + n 4 is 3, and when M 2 is a palladium atom or a platinum atom, n 3 + n 4 is 2.
E 1 and E 2 each independently represent a carbon atom or a nitrogen atom. When a plurality of E 1 and E 2 are present, they may be the same or different.
Ring R 1 represents a 5-membered aromatic heterocycle, and this ring may have a single or a plurality of substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded. When multiple rings R 1 are present, they may be the same or different.
Ring R 2 represents an aromatic hydrocarbon ring or an aromatic heterocycle, and these rings may have a single or a plurality of substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded.
When there are a plurality of rings R 2 , they may be the same or different.
The substituent that the ring R 1 may have and the substituent that the ring R 2 may have may be the same or different, and they are bonded to each other to form a ring together with the atom to which they are bonded. You may have.
A 3 -G 2 -A 4 represents an anionic bidentate ligand. A 3 and A 4 each independently represent a carbon atom, an oxygen atom or a nitrogen atom, and these atoms may be atoms constituting a ring. G 2 represents a single bond or an atomic group forming a bidentate ligand together with A 3 and A 4 . When there are a plurality of A 3 -G 2 -A 4 , they may be the same or different. ]

[In the formula, R 1T represents an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group, a substituted amino group or a halogen atom, and these groups are monovalent. It may have one or more substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded. ]

[In the formula,
n T1 represents an integer of 0 or more and 5 or less. When a plurality of n T1s are present, they may be the same or different.
n T2 represents an integer of 1 or more and 10 or less.
Ar T1 is a fused ring monovalent heterocyclic group containing a nitrogen atom having no double bond in the ring and a group represented by ═N—, and the group is a single or plural substituents. When there are a plurality of substituents, they may be the same or different, and they may be bonded to each other to form a ring together with the atom to which they are bonded. When a plurality of Ar T1s are present, they may be the same or different.
L T1 is an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -NR T1 '- represents a group represented by an oxygen atom or a sulfur atom, the these groups single or multiple substitutions When it has a plurality of substituents, they may be the same or different and may be bonded to each other to form a ring together with the atom to which they are bonded.
R T1 ′ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a single or a plurality of substituents, and the substituent is When a plurality of them are present, they may be the same or different and may be bonded to each other to form a ring with the atom to which each is bonded. When there are a plurality of L T1 , they may be the same or different.
Ar T2 represents an aromatic hydrocarbon group or a heterocyclic group, and these groups may have a single or a plurality of substituents, and when there are a plurality of the substituents, they may be the same or different. Alternatively, they may be bonded to each other to form a ring together with the atoms to which they are bonded. ]
The light emitting device according to claim 1, wherein the second layer contains a compound represented by the formula (T-1).
The light emitting device according to claim 1, wherein the Ar T1 is a group represented by the formula (T1-1).

[In the formula,
X T1 represents a single bond, an oxygen atom, a sulfur atom, a group represented by —N (R XT1 ) —, or a group represented by —C (R XT1 ′ ) 2 —. R XT1 and R XT1 ′ are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group, a halogen atom or Represents a cyano group, these groups may have a single or a plurality of substituents, when there are a plurality of the substituents, they may be the same or different, and they are bonded to each other, It may form a ring together with the atom to be bonded. The plurality of R XT1 ′ s that are present may be the same or different and may be bonded to each other to form a ring together with the atom to which each is bonded.
The ring R T1 and the ring R T2 each independently represent an aromatic hydrocarbon ring or a heterocycle, and these rings may have a single or a plurality of substituents, and a plurality of the above substituents are present. In this case, they may be the same or different and may be bonded to each other to form a ring with the atom to which each is bonded.
Provided that at least one of the ring R T1 and the ring R T2 is a heterocycle containing a group represented by ═N— in the ring, and the ring has a single or a plurality of substituents. Alternatively, when there are a plurality of the above-mentioned substituents, they may be the same or different, and they may be bonded to each other to form a ring with the atoms to which they are bonded. ]
The ring R T1 is an aromatic hydrocarbon ring or a heterocycle containing a group represented by ═N— in the ring, and these rings may have a single or a plurality of substituents, and The luminescence according to claim 3, wherein the ring R T2 is a heterocycle containing a group represented by = N- in the ring, and the ring may have a single or a plurality of substituents. element.
The ring R T1 is a monocyclic aromatic hydrocarbon ring or a monocyclic heterocycle containing a group represented by ═N— in the ring, and these rings each have a single or a plurality of substituents. And the ring R T2 is a monocyclic heterocycle containing a group represented by ═N— in the ring, and the ring has a single or a plurality of substituents. The light emitting device according to claim 4, which may be included.
The ring R T1 is a benzene ring, a pyridine ring or a diazabenzene ring, and these rings may have a single or plural substituents, and the ring R T2 is a pyridine ring or a diazabenzene ring. The light emitting device according to claim 5, wherein these rings may have a single or a plurality of substituents.
The ring L 1 is a pyridine ring, a diazabenzene ring, an azanaphthalene ring or a diazanaphthalene ring, and these rings may have a single or a plurality of substituents, and the ring L 2 is 7. The light emitting device according to claim 1, which is a benzene ring, a pyridine ring or a diazabenzene ring, and these rings may have a single or a plurality of substituents.
The light emitting device according to any one of claims 1 to 7, wherein a maximum peak wavelength of an emission spectrum of the metal complex represented by the formula (1) is 495 nm or more and less than 750 nm.
The ring R 1 is a diazole ring or a triazole ring, these rings may have a single or a plurality of substituents, and the ring R 2 is a benzene ring, a pyridine ring or a diazabenzene ring. The light emitting device according to any one of claims 1 to 8, wherein these rings may have a single or a plurality of substituents.
The light emitting device according to any one of claims 1 to 9, wherein a maximum peak wavelength of an emission spectrum of the metal complex represented by the formula (2) is 380 nm or more and less than 495 nm.
The light emitting device according to any one of claims 1 to 10, wherein the first layer further contains a compound represented by the formula (H-1).

[In the formula,
Ar H1 and Ar H2 each independently represent an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or a plurality of substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded.
n H1 represents an integer of 0 or more.
L H1 represents an arylene group, a divalent heterocyclic group, an alkylene group or a cycloalkylene group, and these groups may have a single or a plurality of substituents. When a plurality of substituents are present, they may be the same or different and may be bonded to each other to form a ring with the atoms to which they are bonded. When a plurality of L H1 are present, they may be the same or different. ]
12. The first layer further contains at least one selected from the group consisting of a hole transport material, a hole injection material, an electron transport material, an electron injection material, a light emitting material and an antioxidant. The light emitting device according to any one of 1.
The light emitting device according to any one of claims 1 to 12, wherein the first layer and the second layer are adjacent to each other.