JP6600064B1 - Light emitting element - Google Patents

Abstract

A light-emitting element with excellent external quantum efficiency is provided. An anode, a cathode, a first layer provided between the anode and the cathode, a second layer provided between the cathode and the first layer, and an anode and the first layer. The first layer is a layer containing a phosphorescent compound having a maximum peak wavelength of an emission spectrum of 380 nm or more and less than 495 nm, and the first layer, the second layer, and the third layer At least one of the layers contains a phosphorescent compound having a maximum peak wavelength of an emission spectrum of 570 nm or more and less than 750 nm, and at least one of the first layer, the second layer, and the third layer is represented by the following formula. The molecular weight (MA) of the phosphorescent compound having a maximum peak wavelength of the emission spectrum of 570 nm or more and less than 750 nm and the molecular weight (MB) of the compound represented by the formula (T-1) are 1500 ≦ MA + MB ≦ 10000, 0 Emitting element satisfying MB / MA ≦ 0.85. [Selection figure] None

Description

  The present invention relates to a light emitting element.

  Light-emitting elements such as organic electroluminescence elements 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, a light emitting layer containing a metal complex R1, and an electron transport layer containing a compound ET1. Patent Document 2 describes a light-emitting element having a light-emitting layer containing a metal complex B0 and a metal complex R1 and an electron transport layer containing a compound ET1.

International Publication No. 2012/153603 International Publication No. 2011/048956

However, the above-described light emitting device does not necessarily have sufficient external quantum efficiency.
Therefore, an object of the present invention is to provide a light-emitting element having excellent external quantum efficiency.

［式中、
ｎ^Ｔ１は、０以上５以下の整数を表す。ｎ^Ｔ１が複数存在する場合、それらは同一でも異なっていてもよい。
ｎ^Ｔ２は、１以上１０以下の整数を表す。
Ａｒ^Ｔ１は、環内に二重結合を有さない窒素原子及び＝Ｎ−で表される基を含む、縮合環の１価の複素環基であり、該基（１価の複素環基）は単一又は複数の置換基を有していてもよく、前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ａｒ^Ｔ１が複数存在する場合、それらは同一でも異なっていてもよい。
Ｌ^Ｔ１は、アルキレン基、シクロアルキレン基、アリーレン基、２価の複素環基、−ＮＲ^Ｔ１’−で表される基、酸素原子又は硫黄原子を表し、これらの基は単一又は複数の置換基を有していてもよく、前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ｒ^Ｔ１’は、水素原子、アルキル基、シクロアルキル基、アリール基又は１価の複素環基を表し、これらの基は単一又は複数の置換基を有していてもよく、前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ｌ^Ｔ１が複数存在する場合、それらは同一でも異なっていてもよい。
Ａｒ^Ｔ２は、芳香族炭化水素基又は複素環基を表し、これらの基は単一又は複数の置換基を有していてもよく、前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。］
［２］ 前記発光スペクトルの最大ピーク波長が５７０ｎｍ以上７５０ｎｍ未満である燐光発光性化合物が、式（１）で表される金属錯体である、［１］に記載の発光素子。

［式中、
Ｍ^１は、ロジウム原子、パラジウム原子、イリジウム原子又は白金原子を表す。
ｎ^１は１以上の整数を表し、ｎ^２は０以上の整数を表す。但し、Ｍ^１がロジウム原子又はイリジウム原子の場合、ｎ^１＋ｎ^２は３であり、Ｍ^１がパラジウム原子又は白金原子の場合、ｎ^１＋ｎ^２は２である。
Ｅ^Ｌは、炭素原子又は窒素原子を表す。Ｅ^Ｌが複数存在する場合、それらはそれぞれ同一でも異なっていてもよい。
環Ｌ^１は、６員の芳香族複素環を表し、この環は単一又は複数の置換基を有していてもよい。前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。環Ｌ^１が複数存在する場合、それらは同一でも異なっていてもよい。
環Ｌ^２は、芳香族炭化水素環又は芳香族複素環を表し、これらの環は単一又は複数の置換基を有していてもよい。前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。環Ｌ^２が複数存在する場合、それらは同一でも異なっていてもよい。
環Ｌ^１が有していてもよい置換基と環Ｌ^２が有していてもよい置換基とは、同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。
Ａ^１−Ｇ^１−Ａ^２は、アニオン性の２座配位子を表す。Ａ^１及びＡ^２は、それぞれ独立に、炭素原子、酸素原子又は窒素原子を表し、これらの原子は環を構成する原子であってもよい。Ｇ^１は、単結合、又は、Ａ^１及びＡ^２とともに２座配位子を構成する原子団を表す。Ａ^１−Ｇ^１−Ａ^２が複数存在する場合、それらは同一でも異なっていてもよい。］
［３］ 前記環Ｌ^１が、ピリジン環、ジアザベンゼン環、アザナフタレン環又はジアザナフタレン環であり、これらの環は単一又は複数の置換基を有していてもよく、且つ、前記環Ｌ^２が、ベンゼン環、ピリジン環又はジアザベンゼン環であり、これらの環は単一又は複数の置換基を有していてもよい、［１］又は［２］に記載の発光素子。
［４］ 前記環Ｌ^１及び前記環Ｌ^２のうちの少なくとも１つが、置換基として、式（１−Ｔ）で表される基を有し、前記式（１−Ｔ）で表される基が複数存在する場合、それらは同一でも異なっていてもよい、［１］〜［３］のいずれかに記載の発光素子。

［式中、Ｒ^１Ｔは、アルキル基、シクロアルキル基、アルコキシ基、シクロアルコキシ基、アリールオキシ基、アリール基、１価の複素環基、置換アミノ基又はハロゲン原子を表し、これらの基は単一又は複数の置換基を有していてもよい。前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。］
［５］ 前記第１の層及び前記第３の層の少なくとも１層が、前記発光スペクトルの最大ピーク波長が５７０ｎｍ以上７５０ｎｍ未満である燐光発光性化合物を含有する、［１］〜［４］に記載の発光素子。
［６］ 前記第２の層が、前記式（Ｔ−１）で表される化合物を含有する、［１］〜［５］のいずれかに記載の発光素子。
［７］ 前記Ａｒ^Ｔ１が、式（Ｔ１−１）で表される基である、［１］〜［６］のいずれかに記載の発光素子。

［式中、
Ｘ^Ｔ１は、単結合、酸素原子、硫黄原子、−Ｎ（Ｒ^ＸＴ１）−で表される基、又は、−Ｃ（Ｒ^ＸＴ１’）_２−で表される基を表す。Ｒ^ＸＴ１及びＲ^ＸＴ１’は、それぞれ独立に、水素原子、アルキル基、シクロアルキル基、アルコキシ基、シクロアルコキシ基、アリール基、アリールオキシ基、１価の複素環基、置換アミノ基、ハロゲン原子又はシアノ基を表し、これらの基は単一又は複数の置換基を有していてもよく、前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。複数存在するＲ^ＸＴ１’は、同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。
環Ｒ^Ｔ１及び環Ｒ^Ｔ２は、それぞれ独立に、芳香族炭化水素環又は複素環を表し、これらの環は単一又は複数の置換基を有していてもよく、前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。
但し、環Ｒ^Ｔ１及び環Ｒ^Ｔ２のうちの少なくとも一つは、環内に＝Ｎ−で表される基を含む複素環であり、該環は単一又は複数の置換基を有していてもよく、前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。］
［８］ 前記環Ｒ^Ｔ１が、芳香族炭化水素環又は環内に＝Ｎ−で表される基を含む複素環であり、これらの環は単一又は複数の置換基を有していてもよく、且つ、前記環Ｒ^Ｔ２が、環内に＝Ｎ−で表される基を含む複素環であり、該環は単一又は複数の置換基を有していてもよい、［７］に記載の発光素子。
［９］ 前記環Ｒ^Ｔ１が、単環式の芳香族炭化水素環又は環内に＝Ｎ−で表される基を含む単環式の複素環であり、これらの環は単一又は複数の置換基を有していてもよく、且つ、前記環Ｒ^Ｔ２が、環内に＝Ｎ−で表される基を含む単環式の複素環であり、該環は単一又は複数の置換基を有していてもよい、［８］に記載の発光素子。
［１０］ 前記環Ｒ^Ｔ１が、ベンゼン環、ピリジン環又はジアザベンゼン環であり、これらの環は単一又は複数の置換基を有していてもよく、且つ、前記環Ｒ^Ｔ２が、ピリジン環又はジアザベンゼン環であり、これらの環は単一又は複数の置換基を有していてもよい、［９］に記載の発光素子。
［１１］ 前記発光スペクトルの最大ピーク波長が３８０ｎｍ以上４９５ｎｍ未満である燐光発光性化合物が、式（２）で表される金属錯体である、［１］〜［１０］のいずれかに記載の発光素子。

［式中、
Ｍ^２は、ロジウム原子、パラジウム原子、イリジウム原子又は白金原子を表す。
ｎ^３は１以上の整数を表し、ｎ^４は０以上の整数を表す。但し、Ｍ^２がロジウム原子又はイリジウム原子の場合、ｎ^２＋ｎ^４は３であり、Ｍ^２がパラジウム原子又は白金原子の場合、ｎ^３＋ｎ^４は２である。
Ｅ^１及びＥ^２は、それぞれ独立に、炭素原子又は窒素原子を表す。Ｅ^１及びＥ^２が複数存在する場合、それらはそれぞれ同一でも異なっていてもよい。
環Ｒ^１は、５員の芳香族複素環を表し、この環は単一又は複数の置換基を有していてもよい。前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。環Ｒ^１が複数存在する場合、それらは同一でも異なっていてもよい。
環Ｒ^２は、芳香族炭化水素環又は芳香族複素環を表し、これらの環は単一又は複数の置換基を有していてもよい。前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。環Ｒ^２が複数存在する場合、それらは同一でも異なっていてもよい。
環Ｒ^１が有していてもよい置換基と環Ｒ^２が有していてもよい置換基とは、同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。
Ａ^３−Ｇ^２−Ａ^４は、アニオン性の２座配位子を表す。Ａ^３及びＡ^４は、それぞれ独立に、炭素原子、酸素原子又は窒素原子を表し、これらの原子は環を構成する原子であってもよい。Ｇ^２は、単結合、又は、Ａ^３及びＡ^４とともに２座配位子を構成する原子団を表す。Ａ^３−Ｇ^２−Ａ^４が複数存在する場合、それらは同一でも異なっていてもよい。］
［１２］ 前記環Ｒ^１が、ジアゾール環又はトリアゾール環であり、これらの環は単一又は複数の置換基を有していてもよく、且つ、前記環Ｒ^２が、ベンゼン環、ピリジン環又はジアザベンゼン環であり、これらの環は単一又は複数の置換基を有していてもよい、［１１］に記載の発光素子。
［１３］ 前記分子量（ＭＡ）と、前記分子量（ＭＢ）とが、式（Ｍ１−２）及び式（Ｍ２−２）を満たす、［１］〜［１２］のいずれかに記載の発光素子。

１５５０≦ＭＡ＋ＭＢ≦３０００ （Ｍ１−２）
０．２５≦ＭＢ／ＭＡ≦０．７０ （Ｍ２−２）
［１４］ 前記第１の層が、式（Ｈ−１）で表される化合物を更に含有する、［１］〜［１３］のいずれかに記載の発光素子。

［式中、
Ａｒ^Ｈ１及びＡｒ^Ｈ２は、それぞれ独立に、アリール基、１価の複素環基又は置換アミノ基を表し、これらの基は単一又は複数の置換基を有していてもよい。前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。
ｎ^Ｈ１は、０以上の整数を表す。
Ｌ^Ｈ１は、アリーレン基、２価の複素環基、アルキレン基又はシクロアルキレン基を表し、これらの基は単一又は複数の置換基を有していてもよい。前記置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ｌ^Ｈ１が複数存在する場合、それらは同一でも異なっていてもよい。］
［１５］ 前記第１の層と前記第２の層とが隣接しており、且つ、前記第１の層と前記第３の層とが隣接している、［１］〜［１４］のいずれかに記載の発光素子。 The present invention provides the following [1] to [15].
[1] An anode, a cathode, a first layer provided between the anode and the cathode, a second layer provided between the cathode and the first layer, the anode and the A light emitting device having a third layer provided between the first layers,
The first layer is a layer containing a phosphorescent compound having a maximum peak wavelength of an emission spectrum of 380 nm or more and less than 495 nm;
At least one of the first layer, the second layer, and the third layer contains a phosphorescent compound having a maximum peak wavelength of an emission spectrum of 570 nm or more and less than 750 nm,
At least one of the first layer, the second layer, and the third layer contains a compound represented by the formula (T-1),
The molecular weight (MA) of the phosphorescent compound having a maximum peak wavelength of the emission spectrum of 570 nm or more and less than 750 nm and the molecular weight (MB) of the compound represented by the formula (T-1) are represented by the formula (M1-1 ) And the formula (M2-1).

1500 ≦ MA + MB ≦ 10000 (M1-1)
0 <MB / MA ≦ 0.85 (M2-1)

[Where:
n ^T1 represents an integer of 0 or more and 5 or less. When a plurality of n ^T1 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 condensed monovalent heterocyclic group containing a nitrogen atom having no double bond in the ring and a group represented by ═N—, and this group (monovalent heterocyclic group) May have a single or a plurality of substituents, and when a plurality of the substituents are present, they may be the same or different and are bonded to each other to form a ring together with the atoms to which they are bonded. It may be. When a plurality of Ar ^T1 are present, they may be the same or different.
L ^T1 represents an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, a group represented by -NR ^T1 '-, an oxygen atom or a sulfur atom, and these groups are each a single or a plurality of substituted groups When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms 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 each may have a single or a plurality of substituents, When two or more are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of ^LT1 are present, 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 a plurality of the substituents are present, they are the same or different. 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 phosphorescent compound having a maximum peak wavelength of the emission spectrum of 570 nm or more and less than 750 nm is a metal complex represented by the formula (1).

[Where:
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. When a plurality of E ^L are present, they may be the same or different.
Ring L ¹ represents a 6-membered aromatic heterocyclic ring, and this ring may have a single or a plurality of substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of rings L ¹ are present, they may be the same or different.
Ring L ² represents an aromatic hydrocarbon ring or aromatic heterocyclic ring, these rings may have a single or more substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of 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 are bonded to each other to form a ring together with the atoms to which they are bonded. You may do it.
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 constituting a bidentate ligand together with A ¹ and A ² . When a plurality of A ¹ -G ¹ -A ² are present, they may be the same or different. ]
[3] 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 a benzene ring, a pyridine ring or a diazabenzene ring, and these rings may have a single or a plurality of substituents, [1] or [2].
[4] 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, and the group represented by the formula (1-T). When two or more exist, they may be same or different, The light emitting element in any one of [1]-[3].

[Wherein, 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. It may have one or more substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. ]
[5] In [1] to [4], at least one of the first layer and the third layer contains a phosphorescent compound having a maximum peak wavelength of the emission spectrum of 570 nm or more and less than 750 nm. The light emitting element of description.
[6] The light emitting device according to any one of [1] to [5], wherein the second layer contains a compound represented by the formula (T-1).
[7] The light-emitting element according to any one of [1] to [6], wherein the Ar ^T1 is a group represented by the formula (T1-1).

[Where:
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, alkyl group, cycloalkyl group, alkoxy group, cycloalkoxy group, aryl group, aryloxy group, monovalent heterocyclic group, substituted amino group, halogen atom or Represents a cyano group, and these groups may have one or a plurality of substituents, and when a plurality of the substituents are present, they may be the same or different, and are bonded to each other, You may form the ring with the atom to couple | bond. A plurality of R ^XT1 ′ may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded.
Ring R ^T1 and Ring R ^T2 each independently represent an aromatic hydrocarbon ring or a heterocyclic ring, and these rings may have a single or a plurality of substituents, and a plurality of the substituents are present. In this case, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded.
However, at least one of the ring R ^T1 and the ring R ^T2 is a heterocyclic ring containing a group represented by ═N— in the ring, and the ring has a single or a plurality of substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. ]
[8] The ring R ^T1 is an aromatic hydrocarbon ring or a heterocyclic ring containing a group represented by ═N— in the ring, and these rings may have a single or a plurality of substituents. 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, [7] The light emitting element of description.
[9] 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 may be single or plural. The ring R ^T2 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 is a single or a plurality of substituents. The light-emitting element according to [8], which may include:
[10] The ring R ^T1 is a benzene ring, a pyridine ring or a diazabenzene ring, these rings may have a single or a plurality of substituents, and the ring R ^T2 is a pyridine ring or The light-emitting element according to [9], which is a diazabenzene ring, and these rings may have a single or a plurality of substituents.
[11] The luminescence according to any one of [1] to [10], wherein the phosphorescent compound having a maximum peak wavelength of the emission spectrum of 380 nm or more and less than 495 nm is a metal complex represented by the formula (2). element.

[Where:
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 ² + 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 heterocyclic ring, and this ring may have a single or a plurality of substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of rings R ¹ are present, they may be the same or different.
Ring R ² represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring, and these rings may have a single or a plurality of substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of rings R ² are present, they may be the same or different.
The substituent that ring R ¹ may have and the substituent that ring R ² may have may be the same or different, and are bonded to each other to form a ring together with the atoms to which they are bonded. You may do it.
A ³ -G ² -A ⁴ represents a bidentate ligand of the anionic. 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 constituting a bidentate ligand together with A ³ and A ⁴ . When a plurality of A ³ -G ² -A ⁴ are present, they may be the same or different. ]
[12] 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 The light-emitting element according to [11], which is a diazabenzene ring, and these rings may have a single or a plurality of substituents.
[13] The light-emitting element according to any one of [1] to [12], wherein the molecular weight (MA) and the molecular weight (MB) satisfy Formula (M1-2) and Formula (M2-2).

1550 ≦ MA + MB ≦ 3000 (M1-2)
0.25 ≦ MB / MA ≦ 0.70 (M2-2)
[14] The light emitting device according to any one of [1] to [13], wherein the first layer further contains a compound represented by the formula (H-1).

[Where:
Ar ^H1 and Ar ^H2 each independently represent an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups optionally have a single or a plurality of substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together 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 optionally have a single or a plurality of substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of L ^H1 are present, they may be the same or different. ]
[15] Any of [1] to [14], wherein the first layer and the second layer are adjacent to each other, and the first layer and the third layer are adjacent to each other. A light emitting device according to any one of the above.

  According to the present invention, a light emitting device having excellent external quantum efficiency can be provided.

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

  Hereinafter, preferred embodiments of the present embodiment will be described in detail.

<Explanation of common terms>
Terms commonly used in this 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 having 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.
“Structural unit” means one or more units present in a polymer compound. In general, two or more structural units present in a polymer compound may be referred to as “repeating units”.

The “alkyl group” may be linear or branched. The carbon atom number of a linear alkyl group is 1-50 normally without including the carbon atom number of a substituent, Preferably it is 1-20, More preferably, it is 1-10. The number of carbon atoms of the branched alkyl group is usually from 3 to 50, preferably from 3 to 20, more preferably from 4 to 10, not including the number of carbon atoms of the substituent. The alkyl group may have a substituent, for example, methyl group, ethyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, 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 Examples include 5-di-hexylphenyl) propyl group and 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, more preferably 1 or more and 10 or less, excluding 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, excluding the number of carbon atoms of the substituent. The cycloalkylene group may have a substituent, and examples thereof include a cyclohexylene group.

“Aromatic hydrocarbon group” means a group obtained by removing one or more hydrogen atoms directly bonded to a carbon atom constituting a ring from an aromatic hydrocarbon. A group obtained by removing one hydrogen atom directly bonded to a carbon atom constituting 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 an “arylene group”.
The number of carbon atoms of the aromatic hydrocarbon group is usually 6 to 60, preferably 6 to 30, and more preferably 6 to 18 without including the number of carbon atoms of the substituent.
The “aromatic hydrocarbon group” is, for example, a monocyclic aromatic hydrocarbon (for example, benzene) or a polycyclic aromatic hydrocarbon (for example, bicyclic 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-cyclic aromatic hydrocarbons such as perylene and benzofluoranthene; 6-ring aromatic hydrocarbons such as spirobifluorene; and 7-ring aromatic hydrocarbons such as benzospirobifluorene and acenaphthofluoranthene Aromatic hydrocarbons)) from one or more hydrogen atoms directly bonded to the 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 a linear alkoxy group is 1-40 normally without including the carbon number of a substituent, Preferably it is 1-10. The number of carbon atoms of the branched alkoxy group is usually 3 to 40, preferably 4 to 10, not including the number of carbon atoms of the substituent. The alkoxy group may have a substituent, for example, methoxy group, ethoxy group, isopropyloxy group, butyloxy group, hexyloxy group, 2-ethylhexyloxy group, 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.

“Heterocyclic group” means a group obtained by removing one or more hydrogen atoms directly bonded to a carbon atom or a hetero atom 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 a carbon atom or a hetero atom 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 heterocyclic ring itself is aromatic, such as azole, thiophene, furan, pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene and carbazole, and phenoxazine Even if the heterocyclic ring itself such as phenothiazine and benzopyran does not show aromaticity, a compound in which the aromatic ring is condensed to the heterocyclic ring can be mentioned.
The carbon atom number of a heterocyclic group is 1-60 normally without including the carbon atom number of a substituent, Preferably it is 2-40, More preferably, it is 3-20. The number of heteroatoms of the heterocyclic group is usually 1 to 30, preferably 1 to 10, more preferably 1 to 3, not including the number of carbon atoms of 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 Or 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 tricyclic heterocyclic compound of the above; a tetracyclic heterocyclic compound such as hexaazatriphenylene, benzocarbazole and benzonaphthofuran; a pentacyclic heterocyclic compound such as dibenzocarbazole, indolocarbazole and indenocarbazole Compounds; hexacyclic heterocyclic compounds such as carbazolocarbazole, benzoindolocarbazole and benzoindenocarbazole; and 7-ring heterocyclic compounds such as dibenzoindolocarbazole). Examples thereof include groups in which one or more hydrogen atoms directly bonded to the constituent atoms are removed, and these groups may have a substituent. The heterocyclic group includes a group in which a plurality of these groups are bonded.

  “Halogen atom” refers to 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. As a substituent which an amino group has, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group is preferable.
Examples of the substituted amino group include a dialkylamino group, a dicycloalkylamino group, and a diarylamino group.
Examples of the 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.

The “alkenyl group” may be linear or branched. The carbon atom number of a linear alkenyl group is 2-30 normally without including the carbon atom number of a substituent, Preferably it is 3-20. 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, preferably 4 to 20, not including the number of carbon atoms of the substituent.
The alkenyl group and the 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 -The hexenyl group, 7-octenyl group, and the group in which these groups have a substituent are mentioned.

The “alkynyl group” may be linear or branched. The carbon atom number of an alkynyl group is 2-20 normally without including the carbon atom of a substituent, Preferably it is 3-20. The number of carbon atoms of the branched alkynyl group is usually 4 to 30, preferably 4 to 20, not including the carbon atom of the substituent.
The number of carbon atoms of the “cycloalkynyl group” is usually 4 to 30, preferably 4 to 20, not including the carbon atom of the substituent.
The alkynyl group and the cycloalkynyl group may have a substituent, for example, ethynyl group, propynyl group, butynyl group, pentynyl group, hexynyl group, 5-hexynyl group, and these groups have a substituent. Groups.

［式中、Ｒ^ＸＬは、メチレン基、酸素原子又は硫黄原子を表し、ｎ^ＸＬは、０〜５の整数を表す。Ｒ^ＸＬが複数存在する場合、それらは同一でも異なっていてもよい。ｎ^ＸＬが複数存在する場合、それらは同一でも異なっていてもよい。＊１は結合位置を表す。これらの架橋性基は単一又は複数の置換基を有していてもよく、該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する炭素原子とともに環を形成していてもよい。］ The “crosslinkable group” is a group capable of generating a new bond by being subjected to heating, ultraviolet irradiation, near ultraviolet irradiation, visible light irradiation, infrared irradiation, radical reaction, and the like. It is a group represented by any of (XL-1) to formula (XL-19). These groups may have a substituent.

[Wherein, R ^XL represents a methylene group, an oxygen atom or a sulfur atom, and n ^XL represents an integer of 0 to 5. When a plurality of R ^XL are present, they may be the same or different. When a plurality of n ^XL are present, they may be the same or different. * 1 represents a bonding position. These crosslinkable groups may have a single or a plurality of substituents, and when a plurality of such substituents are present, they may be the same or different, and are bonded to each other, and are bonded to each other. You may form the ring 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 include alkenyl group, cycloalkenyl group, alkynyl group and cycloalkynyl group. The substituent may be a crosslinkable group. The group having a substituent can have a single substituent 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 together with the atoms to which they are bonded, but it is preferable that no ring is formed.

“Phosphorescent compound” generally means a compound that exhibits phosphorescence at room temperature, and is preferably a metal complex that emits light from a triplet excited state at room temperature. The metal complex that emits light from the triplet excited state has a central metal atom and a ligand.
Examples of the central metal atom include a metal atom having an atomic number of 40 or more, a complex having a spin-orbit interaction, and capable of causing an intersystem crossing between a singlet state and a triplet state. Examples of the metal atom include a rhodium atom, a palladium atom, an iridium atom, and a platinum atom, and since the external quantum efficiency of the light emitting device of the present embodiment is more excellent, it is preferably an iridium atom or a platinum atom, more preferably. Iridium atom. That is, the phosphorescent compound is preferably an iridium complex since the external quantum efficiency of the light emitting device of this embodiment is more excellent.
As the ligand, for example, a neutral or anionic monodentate ligand that forms at least one bond selected from the group consisting of a coordination bond and a covalent bond with the central metal atom, or Neutral or anionic polydentate ligands may be mentioned. Examples of the bond between the central metal atom and the ligand include a metal-nitrogen bond, a metal-carbon bond, a metal-oxygen bond, a metal-phosphorus bond, a metal-sulfur bond, and a metal-halogen bond. The multidentate ligand is usually a bidentate to hexadentate ligand.

<Red phosphorescent compound>
A phosphorescent compound having a maximum peak wavelength of an emission spectrum of 570 nm or more and less than 750 nm (hereinafter also referred to as “red phosphorescent compound”) has a higher external quantum efficiency of the light-emitting element of the present embodiment, and thus has the formula ( It is preferable that it is a metal complex represented by 1).

[Metal Complex Represented by Formula (1)]
M ¹ is preferably an iridium atom or a platinum atom, and more preferably an iridium atom, because the external quantum efficiency of the light emitting device of this embodiment is more excellent.
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. Since the metal complex represented by the formula (1) can be easily synthesized, when a plurality of ^EL are present, they are preferably the same.

The number of carbon atoms of the 6-membered aromatic heterocyclic ring in ring L ¹ is usually 1 to 60, preferably 2 to 30, and more preferably 3 to 15 without including the number of carbon atoms of the substituent. is there.
The ring L ¹ is preferably a 6-membered aromatic heterocyclic ring having 1 to 4 nitrogen atoms as constituent atoms, more preferably, since the external quantum efficiency of the light emitting device of this embodiment is more excellent. , A pyridine ring, a diazabenzene ring, an azanaphthalene ring or a diazanaphthalene ring, more preferably a pyridine ring, a quinoline ring or an isoquinoline ring, and these rings may have a substituent.
Since the metal complex represented by formula (1) can be easily synthesized, wherein ring L ¹ there are a plurality of ring L ¹ there are a plurality of, preferably at least two are the same, it rings plurality of L More preferably, all of ¹ are the same.

The number of carbon atoms in the aromatic hydrocarbon ring in the ring L ² is not including the carbon atom number of substituent is usually 6 to 60, preferably 6 to 30, more preferably from 6 to 18.
Examples of the aromatic hydrocarbon ring in the ring L ² include the aromatic hydrocarbon rings exemplified in the aforementioned aromatic hydrocarbon group, and preferably exemplified in the aforementioned 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, still more 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.
Ring L number of carbon atoms in the aromatic heterocyclic ring in the ^2, not including the carbon atom number of substituent is usually 1 to 60, preferably 2 to 30, more preferably from 3 to 15. Hetero atoms of an aromatic heterocyclic ring in ring L ² is not including the carbon atom number of substituent is usually 1 to 30, preferably 1 to 10, more preferably 1 to 3.
Examples of the aromatic heterocycle in the ring L ² include the aromatic heterocycles exemplified in the above-mentioned heterocyclic group, preferably monocyclic, 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, A diazacarbazole ring, a dibenzofuran ring or a dibenzothiophene ring, more preferably a pyridine ring, a diazabenzene ring, a carbazole ring, a dibenzofuran ring or a dibenzothiophene ring, particularly preferably a pyridine ring or a diazabenzene ring. 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 these have better external quantum efficiency of the light-emitting device of the present embodiment, and these rings have substituents. You may have.
Since the metal complex represented by the formula (1) can be easily synthesized, when a plurality of rings L ² are present, they are preferably the same.

Since the external quantum efficiency of the light emitting device of this 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. Ring L ¹ is preferably a pyridine ring, a quinoline ring or an isoquinoline ring, and ring L ² is more preferably a benzene ring, and these rings may have a substituent.

The substituent that the ring L ¹ and the ring L ² may have is preferably a group represented by the formula (1-T) because the external quantum efficiency of the light emitting device of this embodiment is more excellent.
At least one of the ring L ¹ and the ring L ² preferably has a substituent since the light emitting efficiency of the light emitting device of this embodiment is more excellent, and the substituent is represented by the formula (1-T). It is more preferable to have a group.
“At least one of ring L ¹ and ring L ² has a substituent” means that at least one of the atoms (preferably a carbon atom or a nitrogen atom) constituting ring L ¹ and ring L ² . It means that a substituent is directly bonded to one. In the metal complex represented by formula (1), wherein ring L ¹ and the ring L ² there are a plurality, at least one ring of the ring L ¹ and the ring L ² there are a plurality of the long as the substituent However, since the external quantum efficiency of the light emitting device of this embodiment is more excellent, all of the plurality of rings L ¹ , all of the plurality of rings L ² , or a plurality of rings L ¹ and L ² are present. It is preferable that all have a substituent, and it is more preferable that all of the plurality of rings L ¹ or all of the plurality of rings L ² have a substituent.
If at least one of the substituents of the rings L ¹ and the ring L ^2, at least one number of the substituents having one of the ring L ¹ and the ring L ² is usually to five 1, wherein Since the metal complex represented by (1) can be easily synthesized, the number is preferably 1 to 3, more preferably 1 or 2, and still more preferably 1.
Has at least one substituent of the ring L ¹ and the ring L ^2, and in the case of M ¹ is rhodium atom or an iridium atom, the total number of substituents wherein the ring L ¹ and the ring L ² has usually 1 to 30 and since the external quantum efficiency of the light emitting device of this embodiment is more excellent, it is preferably 1 to 18, more preferably 2 to 12, and even more preferably 3. ~ 6.
Has at least one substituent of the ring L ¹ and the ring L ^2, and in the case of M ¹ palladium atom or platinum atom, the total number of substituents wherein the ring L ¹ and the ring L ² has usually 1 to 20, and since the external quantum efficiency of the light emitting device of this embodiment is more excellent, it is preferably 1 to 12, more preferably 1 to 8, and even more preferably 2. ~ 4.

[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 more Preferably, it is 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 in R ^1T is preferably a monocyclic, bicyclic, or tricyclic heterocyclic compound that has one hydrogen atom directly bonded to the carbon atom or heteroatom constituting the ring. More preferably, a pyridine ring, diazabenzene ring, triazine ring, azanaphthalene ring, diazanaphthalene ring, carbazole ring, dibenzofuran ring or dibenzothiophene ring is directly bonded to the carbon atom or hetero atom constituting the ring. And more preferably a group in which one hydrogen atom directly bonded to a carbon atom constituting the ring is removed 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 in 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 which is a substituent of the amino group are the same as those of the aryl group in R ^1T and preferred ranges. Examples and preferred ranges of monovalent heterocyclic groups that are substituents of the amino group are the same as examples and preferred ranges of monovalent heterocyclic groups in R ^1T .

R ^1T 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, because the external quantum efficiency of the light emitting device of this embodiment is more excellent. 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, a cycloalkyl group, an aryl group or a monovalent complex. These are cyclic groups, and these groups may have a substituent.

The substituent that 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, more preferably an alkyl group, a cycloalkyl group or an aryl group, and these groups are further substituted. You may have.
Examples of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent that R ^1T may have are the aryl group, monovalent heterocyclic group and substituted amino group in R ^1T , respectively. This is the same as the examples and preferred ranges.

The substituent that 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, or a monovalent heterocyclic group. 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, still more preferably an alkyl group or a cycloalkyl group, These groups may further have a substituent, but preferably have no further substituent.
Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent that the substituent that R ^1T may have further have, respectively, are the aryl group in R ^1T , Examples of the monovalent heterocyclic group and substituted amino group are the same as the preferred range.

[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 .

［式中、＊は、Ｍ^１と結合する部位を表す。］

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

  Examples of the red phosphorescent compound include metal complexes represented by the following formulas and metal complexes R1 to R6 described later.

<Blue phosphorescent compound>
A phosphorescent compound having a maximum peak wavelength of an emission spectrum of 380 nm or more and less than 495 nm (hereinafter also referred to as “blue phosphorescent compound”) has a higher external quantum efficiency of the light-emitting element of the present embodiment. It is preferable that it is a metal complex represented by 2).

[Metal Complex Represented by Formula (2)]
M ² is preferably an iridium atom or a platinum atom, and more preferably an iridium atom, since the external quantum efficiency of the light emitting device of this embodiment is more excellent.
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.
Since the metal complex represented by formula (2) can be easily synthesized, E ¹ and E ² are preferably the same. Further, since the metal complex represented by formula (2) it can be easily synthesized, if E ¹ is plurally present, they are preferably identical. Moreover, since the metal complex represented by Formula (2) is easily compoundable, when ^two or more E2 exists, they are preferably the same.

Ring R ¹ is preferably a 5-membered monocyclic aromatic heterocyclic ring, more preferably a diazole ring or a triazole ring, and still more preferably a diazole ring, and these rings have a substituent. You may have.
Since a metal complex represented by the formula (2) can be easily synthesized, when a plurality of rings R ¹ are present, they are preferably the same.
Examples and preferred ranges of ring R ² are the same as examples and preferred ranges of ring L ² .

Since the external quantum efficiency of the light emitting device of this embodiment is more excellent, 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, and the ring R ¹ Is a diazole ring, and the ring R ² is more preferably a benzene ring, and these rings may have a substituent.

Examples of the ring R ¹ and the substituent which may be ring R ² optionally has and preferred ranges are the same as examples of the ring R ¹ and the substituent which may be ring R ² optionally has and preferred ranges.

Examples of the anionic bidentate ligand represented by A ³ -G ² -A ⁴ and preferred ranges thereof include examples of the anionic bidentate ligand represented by A ¹ -G ¹ -A ² and It is the same as a preferable 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 blue phosphorescent compound 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═. If Z ^A is plurally present, they may be the same or different.

  <Compound represented by Formula (H-1)>

The molecular weight of the compound represented by the formula (H-1) is usually 1 × 10 ² to 1 × 10 ⁴ , preferably 2 × 10 ^{2 to} 5 × 10 ³ , more preferably 3 × 10 ² to 3 × 10 ³ , more preferably 4 × 10 ² to 1 × 10 ³ .

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 constituting a ring from a monocyclic or 2-6 cyclic aromatic hydrocarbon Or a group other than 1 or 2 (in the case of an aryl group, 1 hydrogen atom, and in the case of an arylene group, 2 hydrogen atoms, the same shall apply hereinafter). A group obtained by removing one or two hydrogen atoms directly bonded to carbon atoms constituting a ring from a cyclic or 2-4 cyclic aromatic hydrocarbon, and more preferably benzene, naphthalene, fluorene, phenanthrene or A group obtained by removing one or two hydrogen atoms directly bonded to carbon atoms constituting a ring 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 2-6 cyclic heterocyclic compound. 1 or 2 hydrogen atoms directly bonded to an atom or heteroatom (in the case of a monovalent heterocyclic group, 1 hydrogen atom; in the case of a divalent heterocyclic group, 2 hydrogen atoms, The same shall apply hereinafter)), and more preferably from a monocyclic, bicyclic, tricyclic or pentacyclic heterocyclic compound directly to the carbon atom or heteroatom constituting the ring. A group in which one or two hydrogen atoms to be bonded are removed, 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 a carbon atom or a hetero atom constituting a ring from benzocarbazole, indolocarbazole or indenocarbazole, particularly preferably pyridine, diazabenzene, triazine, azanaphthalene , Diazanaphthalene, carbazole, dibenzofuran or dibenzothiophene, a group in which one or two hydrogen atoms directly bonded to a carbon atom or a hetero atom constituting the ring are removed, and these groups have a substituent. Also 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. Also good. Examples and preferred ranges of the aryl group which is a substituent of the amino group are the same as those of the aryl group in Ar ^H1 and Ar ^H2 and preferred ranges. Examples and preferred ranges of monovalent heterocyclic groups which are substituents of the amino group are the same as examples and preferred ranges of monovalent heterocyclic groups in Ar ^H1 and Ar ^H2 .

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

Since the external quantum efficiency of the light emitting device of this embodiment is more excellent, at least one of L ^H1 is preferably an arylene group or a divalent heterocyclic group, and more preferably a divalent heterocyclic group. , Carbazole, dibenzofuran or dibenzothiophene, more preferably a group obtained by removing two hydrogen atoms directly bonded to a carbon atom or a hetero atom (preferably a carbon atom) constituting the ring, and these groups are further substituted. You may have.

L ^H1 is preferably an arylene group or a divalent heterocyclic group, more preferably benzene, naphthalene, fluorene, pyridine, diazabenzene, triazine, since the external quantum efficiency of the light emitting device of this embodiment is further excellent. Azanaphthalene, diazanaphthalene, carbazole, dibenzofuran or dibenzothiophene is a group obtained by removing two hydrogen atoms directly bonded to a carbon atom or a hetero atom constituting a ring, more preferably benzene, fluorene, pyridine, diazabenzene, A group obtained by removing two hydrogen atoms directly bonded to a carbon atom or hetero atom constituting a ring from triazine, carbazole, dibenzofuran or dibenzothiophene, particularly preferably a group directly formed from dibenzofuran or dibenzothiophene to a carbon atom constituting a ring. Combined water It is a group excluding two elemental atoms, and these groups may have a substituent.

As the substituent that Ar ^H1 , Ar ^H2 and L ^H1 may have, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, and a substituted amino group are preferable. 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. Yes, these groups may further have a substituent.
Examples of aryl groups, monovalent heterocyclic groups and substituted amino groups in the substituents that Ar ^H1 , Ar ^H2 and L ^H1 may have are the aryl groups in Ar ^H1 and Ar ^H2 , respectively. The examples are the same as the examples and preferred ranges of the valent heterocyclic group and substituted amino group.

As the substituent that the substituent which Ar ^H1 , Ar ^H2 and L ^H1 may further have, 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 substituent.
Examples of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent which the substituent which Ar ^H1 , Ar ^H2 and L ^H1 may have further have, and preferred ranges thereof, respectively, Examples of the aryl group, monovalent heterocyclic group, and substituted amino group in Ar ^H1 and Ar ^H2 are the same as the preferred range.

n ^H1 is usually 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.

As a compound represented by a formula (H-1), the compound represented by a following formula is mentioned, for example. In the formulas, Z ^A are as defined above. In the formula, Z ^B represents an oxygen atom or a sulfur atom. When a plurality of ^ZB are present, they may be the same or different.

<Compound represented by Formula (T-1)>
n ^T1 is preferably an integer of 0 or more and 3 or less, more preferably 0 or 1, since the external quantum efficiency of the light emitting device of this embodiment is more excellent.
n ^T2 is preferably an integer of 1 or more, 5 or less, more preferably an integer of 1 or more and 3 or less, and even more preferably 2, since the external quantum efficiency of the light emitting device of this embodiment is more excellent.

The “nitrogen atom having no double bond” means a nitrogen atom having only a single bond between the nitrogen atom and all atoms bonded to the nitrogen atom.
“Including a nitrogen atom having no double bond in the ring” means —N (—R ^N ) — (wherein R ^N represents a hydrogen atom or a substituent) in the ring or the formula:

で表される基を含むことを意味する。

It means that the group represented by these is included.

In a condensed monovalent heterocyclic group (hereinafter, also referred to as “Ar ^T1 heterocyclic group”) 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. . Moreover, in the monovalent heterocyclic group of the condensed ring, the number of groups represented by = N- constituting the ring is usually 1 to 10, preferably 1 to 5, more preferably 1 to 5. 3, more preferably 1 or 2. In the monovalent heterocyclic group of the 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 contains a nitrogen atom having no double bond in the ring and does not contain a group represented by ═N— in the ring (hereinafter referred to as “donor type heterocyclic ring”). 1 or more (preferably 5 or less, more preferably 3 or less, more preferably 1) and one or more heterocycles containing a group represented by = N- in the ring ( A group obtained by removing one hydrogen atom directly bonded to a carbon atom or hetero atom constituting a ring from a heterocyclic compound condensed with preferably 5 or less, more preferably 3 or less, and still more preferably 1) It is preferable that these groups may have a substituent.

In the donor type heterocyclic 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 the donor type heterocyclic ring, 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 still more preferably. Is 1 or 2.
Examples of the donor type heterocyclic ring include a nitrogen atom having no double bond in the ring among the heterocyclic compounds exemplified in the above-mentioned heterocyclic group, and ═N— in the ring. Among them, preferred are monocyclic or 2 to 5 heterocyclic rings, more preferably monocyclic, bicyclic or tricyclic. More preferably, it is a monocyclic or bicyclic heterocyclic ring, and these rings may have a substituent.
Since the donor type heterocyclic ring is more excellent in the external quantum efficiency of the light emitting device of this embodiment, it is preferably a pyrrole ring, an indole ring, a carbazole ring, a 9,10-dihydroacridine ring, a 5,10-dihydrophenazine ring, a phenoxy ring. A sazine ring or a phenothiazine ring, more preferably a pyrrole ring, an indole ring or a carbazole ring, still more preferably a pyrrole ring or an indole ring, and these rings optionally have a substituent.
Examples and preferred ranges of the substituent that the donor-type heterocyclic ring may have are the same as examples and preferred ranges of the substituent that Ar ^H1 , Ar ^H2 and L ^H1 may have.

In the heterocyclic ring 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 the heterocyclic ring containing a group represented by = N- in the ring, the number of groups represented by = N- constituting the ring is usually 1 to 10, preferably 1 to 5, more Preferably it is 1-3, More preferably, it is 1 or 2.
Examples of the heterocyclic ring containing a group represented by = N- in the ring include, for example, a group represented by = N- in the ring in the heterocyclic compounds exemplified in the above-mentioned heterocyclic group. Among them, preferred are monocyclic, bicyclic or tricyclic heterocycles, and more preferred are monocyclic heterocycles, and these rings have a substituent. You may do it.
Since the heterocyclic ring containing a group represented by = N- in the ring is more excellent in external quantum efficiency of the light emitting device of the present embodiment, preferably a diazole ring, a triazole ring, a tetrazole ring, a pyridine ring, a diazabenzene ring, 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 , An azanaphthalene ring, a diazanaphthalene ring, an azacarbazole ring or a diazacarbazole ring, and more preferably a pyridine ring or a diazabenzene ring, and these rings may have a substituent.
Examples of the substituent that the heterocyclic ring containing a group represented by ═N— in the ring may have and preferred ranges thereof are examples of the substituent that Ar ^H1 , Ar ^H2, and L ^H1 may have. And the same as the preferred range.

As the heterocyclic group for Ar ^T1 , for example, azaindole, diazaindole, azacarbazole, diazacarbazole, or a group represented by = N- in the donor type heterocyclic ring and / or in the ring Directly bonded to a carbon atom or a hetero atom constituting a ring from a condensed heterocyclic compound containing 1 or more (preferably 5 or less, more preferably 3 or less, more preferably 1) heterocycles And a group in which one hydrogen atom directly bonded to a carbon atom or a hetero atom constituting the ring is removed from azacarbazole or diazacarbazole. The group may have a substituent.
Examples and preferred ranges of the substituent that the heterocyclic group of Ar ^T1 may have are the same as examples and preferred ranges of the substituent that Ar ^H1 , Ar ^H2, and L ^H1 may have.
Since a compound represented by the formula (T-1) can be easily synthesized, when a plurality of Ar ^T1 are present, they are preferably the same.

The heterocyclic group of Ar ^T1 is preferably a group represented by the formula (T1-1) because the external quantum efficiency of the light emitting device of this embodiment is more excellent.

[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, still more preferably a single bond. It is a bond.

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, still more 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, still more preferably an alkyl group. Yes, these groups may have a substituent.
A plurality of R ^XT1 ′ are preferably bonded to each other and do not form a ring with the carbon atom to which each is bonded.

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

The number of carbon atoms of the aromatic hydrocarbon ring in ring R ^T1 and ring R ^T2 does not include the number of carbon atoms of the substituent, and is usually 6 to 60, preferably 6 to 30, and more preferably 6 to 18.
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-described aromatic hydrocarbon group, and the external quantum efficiency of the light emitting device of this embodiment is Since it is more excellent, it is preferably a monocyclic, bicyclic or tricyclic aromatic hydrocarbon ring exemplified in the above-mentioned aromatic hydrocarbon group, and more preferably a monocyclic aromatic ring. It is a hydrocarbon ring, and these groups may have a substituent.
As the aromatic hydrocarbon ring in the ring R ^T1 and the ring R ^T2, the external quantum efficiency of the light emitting device of this embodiment is further excellent, and therefore, preferably a benzene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring or a dihydrophenanthrene ring. More preferably a benzene ring, a fluorene ring or a dihydrophenanthrene ring, still more preferably a benzene ring, which may have a substituent.
The number of carbon atoms of the heterocyclic ring in ring R ^T1 and ring R ^T2 is usually 1-60, preferably 2-30, more preferably 3-15, not including the number of carbon atoms of the substituent. . The number of heteroatoms of the heterocyclic ring in ring R ^T1 and ring R ^T2 is usually 1 to 30, preferably 1 to 10, more preferably 1 to 3, not including the number of carbon atoms of the substituent. is there.
Examples of the heterocyclic ring in the ring R ^T1 and the ring R ^T2 include, for example, the heterocyclic ring exemplified in the above-described heterocyclic group, and the external quantum efficiency of the light emitting device of this embodiment is more excellent. A monocyclic, bicyclic or tricyclic heterocyclic ring (preferably a donor type heterocyclic ring or a heterocyclic ring containing a group represented by = N- in the ring). More preferably, it is a heterocyclic ring containing a group represented by = N- in the ring. More preferably, it is a monocyclic heterocyclic ring (preferably a donor type heterocyclic ring or a ring = A heterocyclic ring containing a group represented by N-, more preferably a heterocyclic ring containing a group represented by = N- in the ring.) These rings have a substituent. May be.
As the heterocyclic ring in the ring R ^T1 and the ring R ^T2 , the external quantum efficiency of the light emitting device of the present embodiment is further excellent. Therefore, preferably, a carbazole ring, a 9,10-dihydroacridine ring, a 5,10-dihydrophenazine ring, Phenoxazine ring, phenothiazine ring, pyridine ring, diazabenzene ring, azanaphthalene ring, diazanaphthalene ring, azacarbazole ring, diazacarbazole ring, dibenzofuran ring or dibenzothiophene ring, more preferably a pyridine ring, diazabenzene ring, 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.

Ring R ^T1 is preferably an aromatic hydrocarbon ring or a heterocyclic ring containing a group represented by ═N— in the ring, more preferably, since the external quantum efficiency of the light emitting device of this embodiment is more excellent. 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 Is a benzene ring, and these rings may have a substituent.
The ring R ^T2 is preferably a heterocyclic ring containing a group represented by ═N— in the ring, and more preferably ═N— in the ring, because the external quantum efficiency of the light emitting device of this embodiment is more excellent. A monocyclic heterocycle containing a group represented by-, more preferably a pyridine ring or a diazabenzene ring, and particularly preferably a pyridine ring, and these rings may have a substituent. .
Since the external quantum efficiency of the light emitting device of this embodiment is further excellent, the ring R ^T1 is an aromatic hydrocarbon ring or a heterocyclic ring containing a group represented by ═N— in the ring, and the ring R ^T2 is , Preferably a heterocyclic ring containing a group represented by = N- in the ring, and ring R ^T1 contains a monocyclic aromatic hydrocarbon ring or a group represented by = N- in the ring More preferably, it is a monocyclic 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, More preferably, it is a pyridine ring or a diazabenzene ring, and the ring R ^T2 is more preferably a pyridine ring or a diazabenzene ring, the ring R ^T1 is a benzene ring, and the ring R ^T2 is particularly a pyridine ring. Preferably, 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 preferred ranges of the substituents that Ar ^H1 , Ar ^H2, and L ^H1 may have.

Examples and preferred ranges of the arylene group in L ^T1 are the same as examples and preferred ranges of the arylene group in the arylene group in L ^H1 .
Examples of the divalent heterocyclic group in L ^T1 and preferred ranges are the same as examples of the arylene group and the preferable range of the divalent heterocyclic group in L ^H1.

L ^T1 is preferably an arylene group or a divalent heterocyclic group, more preferably a ring from benzene, naphthalene, fluorene, pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran or dibenzothiophene. Is a group obtained by removing two hydrogen atoms directly bonded to a carbon atom or hetero atom, and more preferably a carbon atom constituting a ring from benzene, fluorene, pyridine, diazabenzene, triazine, carbazole, dibenzofuran or dibenzothiophene Or a group in which two hydrogen atoms directly bonded to a hetero atom are removed, particularly preferably a group in which two hydrogen atoms directly bonded to a carbon atom constituting a ring are removed from benzene, dibenzofuran or dibenzothiophene, Especially preferred Or a phenylene group, and these groups may have a substituent.
Since a compound represented by the formula (T-1) can be easily synthesized, when a plurality of ^LT1 are present, they are preferably the same.

Examples and preferred ranges of the substituent that L ^T1 may have are the same as examples and preferred ranges of the substituent 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 optionally have a substituent.
Examples and preferred ranges of the aryl group and monovalent heterocyclic group in R ^T1 ′ are the same as those of the aryl group and monovalent heterocyclic group in Ar ^H1 and Ar ^H2 , respectively.
Examples and preferred ranges of the substituent that R ^T1 ′ may have are the same as examples and preferred ranges of the substituent 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 a carbon atom constituting a ring from a monocyclic or 2-6 cyclic 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 more preferably benzene, naphthalene , Fluorene, phenanthrene or anthracene is a group obtained by removing one or more hydrogen atoms directly bonded to the carbon atoms constituting the ring, and these groups may have a substituent.
The heterocyclic group in Ar ^T2 is preferably a group obtained by removing one or more hydrogen atoms directly bonded to a carbon atom or a hetero atom constituting a ring from a monocyclic or 2-6 cyclic heterocyclic compound. More preferably, it is a group obtained by removing one or more hydrogen atoms directly bonded to a carbon atom or a hetero atom constituting a ring from a monocyclic, bicyclic or tricyclic heterocyclic compound, and more preferably , Pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine, azaanthracene, diazaanthracene, azaphenanthrene or diazaphenanthrene to carbon atoms or heteroatoms constituting the ring A group excluding one or more directly bonded hydrogen atoms, particularly preferably pyridine, One or more hydrogen atoms directly bonded to the ring carbon atom or hetero atom from diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, azaanthracene, diazaanthracene, azaphenanthrene, or diazaphenanthrene And these groups may have a substituent.
Ar ^T2 is more excellent in the external quantum efficiency of the light-emitting device of the present embodiment. Therefore, it is preferable that Ar ^T2 is directly bonded to a carbon atom or a hetero atom constituting a ring from benzene, fluorene, pyridine, diazabenzene, triazine, carbazole, dibenzofuran, or dibenzothiophene. A group obtained by removing one or more hydrogen atoms bonded, more preferably a group obtained by removing one or more hydrogen atoms directly bonded to a carbon atom constituting a ring from benzene, dibenzofuran or dibenzothiophene; May have a substituent.
Examples and preferred ranges of the substituent that Ar ^T2 may have are the same as examples and preferred ranges of the substituent that Ar ^H1 , Ar ^H2 and L ^H1 may have.

As a compound represented by a formula (T-1), the compound represented by a following formula and the below-mentioned compounds ET1-ET3 are mentioned, for example. In the formula, Z ^A and Z ^B represent the same meaning as described above.

<MA and MB>
The molecular weight (MA) of the red phosphorescent compound is usually 10,000 or less. When MA exceeds 10,000, it may be difficult to improve the purity of the red phosphorescent compound when the red phosphorescent compound is purified (for example, recrystallization and sublimation). It is considered that the external quantum efficiency of the light emitting device of this embodiment may be reduced. Moreover, MA is 500 or more normally. If MA is less than 500, the stability of the red phosphorescent compound may be lowered, and the external quantum efficiency of the light emitting device of this embodiment may be lowered.
Based on the above idea, from the viewpoint of improving the external quantum efficiency of the light emitting device of this embodiment, MA is preferably 840 or more and 5000 or less, more preferably 900 or more and 4000 or less, and further preferably 1000 or more and 3000. Or less, particularly preferably 1050 or more and 2000 or less.

The molecular weight (MB) of the compound represented by the formula (T-1) is usually 10,000 or less. When MB exceeds 10,000, when the compound represented by the formula (T-1) is purified (for example, recrystallization and sublimation), the purity of the compound represented by the formula (T-1) is increased. It may be difficult to improve, and it is considered that the external quantum efficiency of the light-emitting device of the present embodiment may be reduced, and the MB is usually 200 or more. If MB is less than 200, the stability of the compound represented by the formula (T-1) may be lowered, and the film quality of the layer containing the compound represented by the formula (T-1) may be reduced. It is considered that the external quantum efficiency of the light emitting device of this embodiment may be reduced.
Based on the above idea, from the viewpoint of improving the external quantum efficiency of the light emitting device of the present embodiment, MB is preferably 350 or more and 5000 or less, more preferably 400 or more and 3000 or less, and further preferably 450 or more and 2000. Or less, particularly preferably 500 or more and 1000 or less.

The total of MA and MB (MA + MB) is preferably 1550 or more because the external quantum efficiency of the light emitting device of this embodiment is more excellent. MA + MB is preferably 7000 or less, more preferably 5000 or less, even more preferably 4000 or less, and particularly preferably 3000 or less, because the external quantum efficiency of the light emitting device of this embodiment is more excellent. Especially preferably, it is 2600 or less.
MA + MB satisfies the formula (M1-2) and more preferably satisfies the formula (M1-3) because the external quantum efficiency of the light emitting device of this embodiment is further excellent.
1550 ≦ MA + MB ≦ 2600 (M1-3)

The ratio of MB to MA (MB / MA) is preferably 0.05 or more, more preferably 0.10 or more, since the external quantum efficiency of the light emitting device of this embodiment is more excellent. Is more preferably 0.15 or more, particularly preferably 0.20 or more, and particularly preferably 0.25 or more. MB / MA is preferably 0.80 or less, more preferably 0.75 or less, and 0.70 or less, because the external quantum efficiency of the light emitting device of this embodiment is more excellent. Is more preferable.
MA + MB preferably satisfies the formula (M2-2) because the external quantum efficiency of the light emitting device of this embodiment is further excellent.

  MA and MB preferably satisfy the formula (M1-2) and the formula (M2-2) because the external quantum efficiency of the light emitting device of this embodiment is more excellent, and the formula (M1-3) and the formula ( It is more preferable to satisfy M2-2).

<Light emitting element>
The light emitting device of this embodiment includes an anode, a cathode, a first layer provided between the anode and the cathode, a second layer provided between the cathode and the first layer, an anode, And a third layer provided between the first layer, the first layer is a layer containing a blue phosphorescent compound, the first layer, and the second layer. And at least one of the third layers contains a red phosphorescent compound, and at least one of the first layer, the second layer, and the third layer is represented by the formula (T-1). The molecular weight (MA) of the red phosphorescent compound containing the compound and the molecular weight (MB) of the compound represented by the formula (T-1) are represented by the formula (M1-1) and the formula (M2-1). The light-emitting element satisfies the above.

The compound represented by the formula (T-1) is preferably contained in the first layer or the second layer because the external quantum efficiency of the light emitting device of the present embodiment is more excellent. More preferably it is contained.
The red phosphorescent compound is preferably contained in the first layer or the third layer because the external quantum efficiency of the light emitting device of this embodiment is more excellent.

In the light-emitting element of this embodiment, the emission color of the light-emitting element can be adjusted by adjusting the ratio of the content of the blue phosphorescent compound and the content of the red phosphorescent compound, and thus the light emission. It is also possible to adjust the color to white. The light emission color of the light emitting element can be confirmed by measuring the light emission chromaticity of the light emitting element and obtaining chromaticity coordinates (CIE chromaticity coordinates). The white luminescent color preferably has a chromaticity coordinate X in the range of 0.24 to 0.55 and a chromaticity coordinate Y in the range of 0.24 to 0.55.
Note that the CIE chromaticity coordinates (x, y) are xy chromaticity coordinates (x, y) based on the XYZ color system, which is an international display method formulated in 1931 by the International Commission on Illumination CIE (Commission Internationale de l'Eclairage). y).

From the viewpoint of adjusting the emission color of the light-emitting element of the present embodiment (in particular, from the viewpoint of adjusting the emission color to white, hereinafter the same), the maximum peak wavelength of the emission spectrum of the blue phosphorescent compound is: Preferably they are 400 nm or more and 490 nm or less, More preferably, they are 420 nm or more and 485 nm or less, More preferably, they are 450 nm or more and 480 nm or less.
From the viewpoint of adjusting the emission color of the light emitting device of this embodiment, the maximum peak wavelength of the emission spectrum of the red phosphorescent compound is preferably 570 nm or more and 680 nm or less, and more preferably 575 nm or more and 640 nm or less.

The maximum peak wavelength of the emission spectrum of the phosphorescent compound is obtained by dissolving the metal complex in an organic solvent such as xylene, toluene, chloroform, tetrahydrofuran, etc. to prepare a dilute solution (concentration is, for example, 1 × 10 ⁻⁶ mass% or more 1 × 10 ⁻³ mass% or less.), And the PL spectrum of the diluted solution can be evaluated by measuring at room temperature. Xylene is preferred as the organic solvent for dissolving the metal complex.

<First layer>
The first layer is a layer containing a blue phosphorescent compound. The first layer may contain one type of blue phosphorescent compound alone, or may contain two or more types.
In the first layer, the content of the blue phosphorescent compound may be in a range in which the function as the first layer is achieved. For example, the content of the blue phosphorescent compound may be from 0.1% by mass to 99% by mass based on the total amount of the first layer, and preferably from 1% by mass to 70% by mass. The content is more preferably no less than 50% by mass and no greater than 50% by mass, and still more preferably no less than 10% by mass and no greater than 35% by mass.

  When the first layer is a layer containing a blue phosphorescent compound and a red phosphorescent compound, from the viewpoint of adjusting the emission color of the light emitting device of the present embodiment, the content of the red phosphorescent compound is: When the content of the blue phosphorescent compound is 100 parts by mass, it is preferably 0.01 parts by mass or more and 50 parts by mass or less, more preferably 0.02 parts by mass or more and 30 parts by mass or less, and further preferably They are 0.05 mass part or more and 10 mass parts or less, Especially preferably, they are 0.1 mass part or more and 5 mass parts or less. When the first layer is a layer containing a blue phosphorescent compound and a red phosphorescent compound, the first layer may contain one kind of red phosphorescent compound alone. It may contain seeds or more.

  In the light emitting device of the present embodiment, when the first layer contains a compound represented by the formula (T-1), it is preferably contained in the first layer as a host material described later. The 1st layer may contain individually 1 type of a compound denoted by a formula (T-1), and may contain 2 or more types.

[Host material]
Since the external quantum efficiency of the light emitting device of this embodiment is more excellent, the first layer is made of a host material having at least one function selected from a hole injection property, a hole transport property, an electron injection property, and an electron transport property. Furthermore, it is preferable to include. The 1st layer may contain 1 type of host materials independently, and may contain 2 or more types.

When the first layer further contains a host material, the content of the host material is usually 1 part by mass or more and 99 parts by mass when the total content of the blue phosphorescent compound and the host material is 100 parts by mass. Or less, preferably 10 to 95 parts by mass, more preferably 30 to 90 parts by mass, and still more preferably 50 to 85 parts by mass.
The lowest excited triplet state (T ₁ ) of the host material has a higher external quantum efficiency of the light emitting device of the present embodiment, and therefore has a higher energy level than the lowest excited triplet state (T ₁ ) of the blue phosphorescent compound. Is preferred.
As the host material, since the light-emitting element of this embodiment can be manufactured by a wet method, a material showing solubility in a solvent capable of dissolving the blue phosphorescent compound is preferable.

The host material is classified into a low molecular compound (low molecular host) and a high molecular compound (polymer host), and the first layer may contain any host material. The host material that may be contained in the first layer is preferably a low molecular compound.
Examples of the low-molecular host include a low-molecular compound that is a hole transporting material described later and a low-molecular compound that is an electron transporting material described later. Preferably, the compound represented by the formula (H-1) or It is a compound represented by a formula (T-1), More preferably, it is a compound represented by a formula (H-1).
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.

[Composition 1]
The first layer includes a blue phosphorescent compound, the host material, the red phosphorescent compound, a hole transport material, a hole injection material, an electron transport material, an electron injection material, a light emitting material, and an antioxidant. The layer formed from the composition (henceforth "the composition 1") containing at least 1 sort (s) chosen from the group which consists of may be sufficient. However, in the composition 1, the light emitting material is different from the blue phosphorescent compound and the red phosphorescent compound.

[Hole transport material]
The hole transport material is classified into a low molecular compound and a high molecular compound, and is preferably a high molecular compound. The hole transport material may have a crosslinkable group.
Examples of the low molecular weight compound include triphenylamine and derivatives thereof, N, N′-di-1-naphthyl-N, N′-diphenylbenzidine (α-NPD), and N, N′-diphenyl-N, An aromatic amine compound such as N′-di (m-tolyl) benzidine (TPD) can be used.
Examples of the polymer compound include polyvinyl carbazole and derivatives thereof; polyarylene having an aromatic amine structure in the side chain or main chain and derivatives thereof. The polymer compound may be a compound to which an electron accepting site is bonded. Examples of the electron accepting site include fullerene, tetrafluorotetracyanoquinodimethane, tetracyanoethylene, trinitrofluorenone, and fullerene is preferable.
In composition 1, the content of the hole transport material is usually 1 part by mass or more and 10000 parts by mass or less when the content of the blue phosphorescent compound is 100 parts by mass.
A hole transport material may be used individually by 1 type, or may use 2 or more types together.

[Electron transport materials]
Electron transport materials are classified into low-molecular compounds and high-molecular 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. As well as these derivatives.
Examples of the polymer compound include polyphenylene, polyfluorene, and derivatives thereof. The polymer compound may be doped with a metal.
In the composition 1, the content of the electron transport material is usually 1 part by mass or more and 10000 parts by mass or less when the content of the blue phosphorescent compound is 100 parts by mass.
An electron transport material may be used individually by 1 type, or may use 2 or more types together.

[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 compound include metal phthalocyanines such as copper phthalocyanine; carbon; metal oxides such as molybdenum and tungsten; and 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 polymers such as polymers containing an aromatic amine structure in the main chain or side chain. A functional polymer.
In composition 1, the content of the hole injection material and the electron injection material is usually 1 part by mass or more and 10000 parts by mass or less when the content of the blue phosphorescent compound is 100 parts by mass.
Each of the electron injection material and the hole injection material may be used alone or in combination of two or more.

[Ion dope]
When the hole injection material or the electron injection material includes a conductive polymer, the electrical conductivity of the conductive polymer is preferably 1 × 10 ⁻⁵ S / cm or more and 1 × 10 ³ S / cm or less. In order to set the electric conductivity of the conductive polymer within such a range, the conductive polymer can be doped with an appropriate amount of ions.
The type of ions to be doped is an anion for a hole injection material and a cation for an electron injection material. 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.
Doping ions may be used alone or in combination of two or more.

[Light emitting material]
Luminescent materials are classified into low molecular compounds and high molecular compounds. The light emitting material may have a crosslinkable group.
Examples of the low molecular weight compound include naphthalene and derivatives thereof, anthracene and derivatives thereof, perylene and derivatives thereof, and triplet light-emitting complexes having iridium, platinum, or europium as a central metal.
As a triplet light emission complex, the metal complex shown below and the below-mentioned metal complexes G1-G3 are mentioned, for example.

Examples of the polymer compound include arylene groups such as phenylene group, naphthalenediyl group, fluorenediyl group, phenanthrene diyl group, dihydrophenanthrene diyl group, anthracenediyl group, and pyrenediyl group; two hydrogen atoms from aromatic amine Examples thereof include a polymer compound containing an aromatic amine residue such as a group to be removed; and a divalent heterocyclic group such as a carbazolediyl group, a phenoxazinediyl group and a phenothiazinediyl group.
In the first composition, the content of the luminescent material is usually 1 part by mass or more and 10000 parts by mass or less when the content of the blue phosphorescent compound is 100 parts by mass.
A luminescent material may be used individually by 1 type, or may use 2 or more types together.

[Antioxidant]
The antioxidant may be any compound that is soluble in the same solvent as the blue phosphorescent compound and does not inhibit light emission and charge transport, and examples thereof include phenol-based antioxidants and phosphorus-based antioxidants.
In the composition 1, the amount of the antioxidant is usually 0.00001 parts by mass or more and 10 parts by mass or less when the content of the blue phosphorescent compound is 100 parts by mass.
Antioxidants may be used alone or in combination of two or more.

[Ink 1]
The first layer can be formed using, for example, a composition containing a blue phosphorescent compound and a solvent (hereinafter also referred to as “ink 1”). Ink 1 is 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, flexographic printing method, offset. It can be suitably used for wet methods such as a printing method, an ink jet printing method, a capillary coating method, a nozzle coating method and the like.
The viscosity of the ink 1 may be adjusted according to the type of wet method. However, when a solution such as an ink jet printing method is applied to a printing method that passes through a discharge device, clogging and flight bending at the time of discharge are less likely to occur. Preferably, it is 1 mPa · s or more and 20 mPa · s or less at 25 ° C.
The solvent contained in the ink 1 is preferably a solvent that can dissolve or uniformly disperse the solid content in the ink. Examples of the solvent include chlorine solvents, ether solvents, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, ketone solvents, ester solvents, polyhydric alcohol solvents, alcohol solvents, sulfoxide solvents and Examples include amide solvents. A solvent may be used individually by 1 type, or may use 2 or more types together.
In the ink 1, the content of the solvent is usually 1000 parts by mass or more and 1000000 parts by mass or less when the content of the blue phosphorescent compound is 100 parts by mass.

<Second layer>
In the light emitting device of this embodiment, since the external quantum efficiency of the light emitting device of this embodiment is excellent, the second layer preferably contains a compound represented by the formula (T-1). The 2nd layer may contain individually 1 type of the compound represented by Formula (T-1), and may contain 2 or more types.
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 as the second layer. As long as the function is achieved, it may be within a range. 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 second layer. It is preferably 60% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and particularly preferably 100% by mass.

In the light emitting device of this embodiment, when the second layer contains a red phosphorescent compound, the second layer may contain one kind of red phosphorescent compound alone, or two or more kinds. May be contained.
In the light emitting device of the present embodiment, when the second layer contains a red phosphorescent compound, the content of the red phosphorescent compound may be in a range where the function as the second layer is achieved. For example, the content of the red phosphorescent compound may be 0.01% by mass or more and 99% by mass or less, and preferably 0.1% by mass or more and 80% by mass or less based on the total amount of the second layer. It is more preferably 1% by mass or more and 60% by mass or less, and further preferably 10% by mass or more and 40% by mass or less.

[Composition 2 and Composition 2 ′]
When the second layer contains a compound represented by the formula (T-1), the second layer includes a compound represented by the formula (T-1), a hole transport material, a hole injection material, Even a layer containing a 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 (hereinafter also referred to as “composition 2”). Good. However, in the composition 2, the electron transport material and the electron injection material are different from the compound represented by the formula (T-1).
When the second layer contains a red phosphorescent compound, the second layer includes the red phosphorescent compound, the host material, the hole transport material, the hole injection material, the electron transport material, and the electron injection material described above. And a layer containing a composition containing at least one material selected from the group consisting of a light emitting material and an antioxidant (hereinafter, also referred to as “composition 2 ′”). However, in the composition 2 ′, the light emitting material is different from the red phosphorescent compound.

Examples and preferred ranges of the hole transport material, the electron transport material, the hole injection material, and the electron injection material contained in the composition 2 and the composition 2 ′ are the hole transport material contained in the first composition, Examples and preferred ranges of the electron transport material, the hole injection material, and the electron injection material are the same.
Examples of the light-emitting material contained in the composition 2 and the composition 2 ′ include a light-emitting material and a blue phosphorescent compound that may be contained in the composition 1. A luminescent material may be used individually by 1 type, or may use 2 or more types together.
Examples and preferred ranges of the host material contained in the composition 2 ′ are the same as the examples and preferred ranges of the host material contained in the composition 1, but the lowest excited triplet state (T ₁ ) of the host material. Since the external quantum efficiency of the light emitting device of this embodiment is more excellent, the energy level is preferably higher than the lowest excited triplet state (T ₁ ) of the red phosphorescent compound.

In the composition 2, the contents of the hole transport material, the electron transport material, the hole injection material, the electron injection material, and the light emitting material are each 100 parts by mass of the compound represented by the formula (T-1) Usually, it is 1 to 1000 parts by mass.
In the composition 2 ′, the content of the hole transport material, the electron transport material, the hole injection material, the electron injection material, and the light emitting material is usually 1 mass when the red phosphorescent compound is 100 parts by mass. Part to 10000 parts by mass.
In the composition 2 ′, the content of the host material is usually 1 part by mass or more and 99 parts by mass or less, preferably 10 parts by mass, when the total content of the red phosphorescent compound and the host material is 100 parts by mass. The mass is from 95 parts by mass to 95 parts by mass, more preferably from 30 parts by mass to 90 parts by mass, and still more preferably from 50 parts by mass to 85 parts by mass.

  Examples and preferred ranges of the antioxidant contained in the composition 2 and the composition 2 ′ are the same as examples and preferred ranges of the antioxidant contained in the composition 1. In the composition 2, 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. In the composition 2 ', the content of the antioxidant is usually 0.00001 parts by mass or more and 10 parts by mass or less when the red phosphorescent compound is 100 parts by mass.

When the second layer contains a compound represented by the formula (T-1), the second layer contains, for example, a compound represented by the formula (T-1) and a solvent. (Hereinafter also referred to as “ink 2”).
When the second layer contains a red phosphorescent compound, the second layer is, for example, a composition containing a red phosphorescent compound and a solvent (hereinafter also referred to as “ink 2 ′”). Can be used.
The ink 2 and the ink 2 ′ can be suitably used in the wet method described in the section of the ink 1. The preferable range of the viscosity of the ink 2 and the ink 2 ′ is the same as the preferable range of the viscosity of the ink 1. Examples and preferred ranges of the solvent contained in the ink 2 and the ink 2 ′ are the same as the examples and preferred ranges of the solvent contained in the ink 1,
In the ink 2, 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. In the ink 2 ′, the content of the solvent is usually 1000 parts by mass or more and 1000000 parts by mass or less when the red phosphorescent compound is 100 parts by mass.

<Third layer>
In the light emitting device of this embodiment, since the external quantum efficiency of the light emitting device of this embodiment is excellent, the third layer preferably contains a red phosphorescent compound. The third layer may contain one kind of red phosphorescent compound alone or may contain two or more kinds.
In the light emitting device of the present embodiment, when the third layer contains a red phosphorescent compound, the content of the red phosphorescent compound may be in a range where the function as the third layer is achieved. For example, the content of the red phosphorescent compound may be 0.01% by mass or more and 99% by mass or less, and preferably 0.1% by mass or more and 80% by mass or less based on the total amount of the third layer. It is more preferably 1% by mass or more and 60% by mass or less, and further preferably 10% by mass or more and 40% by mass or less.

In the light-emitting element of this embodiment, when the third layer contains the compound represented by the formula (T-1), the third layer contains one type of the compound represented by the formula (T-1). It may contain independently and may contain 2 or more types.
In the light-emitting device of this embodiment, when the third layer contains the compound represented by the formula (T-1), the content of the compound represented by the formula (T-1) is as the third layer. As long as the function of the above 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 third layer. It is preferably 60% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and particularly preferably 100% by mass.

[Composition 3 and Composition 3 ′]
When the third layer contains the compound represented by the formula (T-1), the third layer includes a compound represented by the formula (T-1), a hole transport material, a hole injection material, Even a layer containing a 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 (hereinafter also referred to as “composition 3”). Good. However, in the composition 3, the electron transport material and the electron injection material are different from the compound represented by the formula (T-1).
When the third layer contains a red phosphorescent compound, the third layer includes the red phosphorescent compound, the host material, the hole transport material, the hole injection material, the electron transport material, and the electron injection material described above. And a layer containing a composition containing at least one material selected from the group consisting of a light emitting material and an antioxidant (hereinafter also referred to as “composition 3 ′”). However, in the composition 3 ′, the luminescent material is different from the red phosphorescent compound.

Examples and preferred ranges of the hole transport material, the electron transport material, the hole injection material, the electron injection material, and the light emitting material contained in the composition 3 and the composition 3 ′ are contained in the composition 2 and the composition 2 ′. Examples of the hole transporting material, electron transporting material, hole injecting material, electron injecting material, and light emitting material are the same as the examples and preferred ranges.
Examples and preferred ranges of the host material contained in the composition 3 ′ are the same as the examples and preferred ranges of the host material contained in the composition 1, but the lowest excited triplet state (T ₁ ) of the host material. Since the external quantum efficiency of the light emitting device of this embodiment is more excellent, the energy level is preferably higher than the lowest excited triplet state (T ₁ ) of the red phosphorescent compound.

In composition 3, when the content 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), respectively Usually, it is 1 to 1000 parts by mass.
In the composition 3 ′, the content of the hole transport material, the electron transport material, the hole injection material, the electron injection material, and the light emitting material is usually 1 mass when the red phosphorescent compound is 100 parts by mass. Part to 10000 parts by mass.
In the composition 3 ′, the content of the host material is usually 1 part by mass or more and 99 parts by mass or less, preferably 10 parts by mass, when the total content of the red phosphorescent compound and the host material is 100 parts by mass. The mass is from 95 parts by mass to 95 parts by mass, more preferably from 30 parts by mass to 90 parts by mass, and still more preferably from 50 parts by mass to 85 parts by mass.

  Examples and preferred ranges of the antioxidant contained in the composition 3 and the composition 3 ′ are the same as examples and preferred ranges of the antioxidant contained in the composition 1. In the composition 3, 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. In the composition 3 ', the content of the antioxidant is usually 0.00001 parts by mass or more and 10 parts by mass or less when the red phosphorescent compound is 100 parts by mass.

When the third layer contains a compound represented by the formula (T-1), the third layer contains, for example, a compound represented by the formula (T-1) and a solvent. (Hereinafter also referred to as “ink 3”).
When the third layer contains a red phosphorescent compound, the third layer is, for example, a composition containing a metal complex represented by the formula (1) and a solvent (hereinafter referred to as “ink 3 ′”). ").
The ink 3 and the ink 3 ′ can be suitably used in the wet method described in the section of the ink 1. The preferable range of the viscosity of the ink 3 and the ink 3 ′ is the same as the preferable range of the viscosity of the ink 1. Examples and preferred ranges of the solvent contained in the ink 3 and the ink 3 ′ are the same as the examples and preferred ranges of the solvent contained in the ink 1,
In the ink 3, 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. In the ink 3 ′, the content of the solvent is usually 1000 parts by mass or more and 1000000 parts by mass or less when the red phosphorescent compound is 100 parts by mass.

<Layer structure of light emitting element>
FIG. 1 is a schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention. The light emitting element 10 shown in FIG. 1 is provided between the anode 11, the cathode 15, the first layer 14 provided between the anode 11 and the cathode 15, and the cathode 15 and the first layer 13. It has a second layer 14 and a third layer 12 provided between the anode 11 and the first layer 13.
The light emitting element of this embodiment may have layers other than the anode 11, the cathode 15, the first layer 13, the second layer 14, and the third layer 12.
In the light emitting element of this embodiment, the first layer 13 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 14 is usually a light emitting layer (a light emitting layer separate from the first light emitting layer, hereinafter referred to as “second light emitting layer”), electron transport. A layer or an electron injection layer, and more preferably an electron transport layer.
In the light emitting device of the present embodiment, the third layer 12 is usually a light emitting layer (a light emitting layer separate from the first light emitting layer and the second light emitting layer, hereinafter referred to as “third light emitting layer”). That is, a hole transport layer or a hole injection layer, more preferably a third light-emitting layer or a hole transport layer, and still more preferably a third light-emitting layer.

In the light emitting device of this embodiment, the second layer 14 is preferably a second light emitting layer, an electron transport layer or an electron injection layer provided between the cathode 15 and the first layer 13. And an electron transport layer provided between the first layer 13 and the first layer 13 is more preferable.
In the light emitting device of this embodiment, the first layer 13 and the second layer 14 are preferably adjacent to each other because the external quantum efficiency of the light emitting device of this embodiment is more excellent.

In the light emitting device of the present embodiment, the third layer 12 is preferably a third light emitting layer, a hole transport layer or a hole injection layer provided between the anode 11 and the first layer 13. A third light emitting layer or a hole transport layer provided between the anode 15 and the first layer 13 is more preferable.
In the light emitting device of this embodiment, the first layer 13 and the third layer 12 are preferably adjacent to each other because the external quantum efficiency of the light emitting device of this embodiment is more excellent.
In the light emitting device of this embodiment, the first layer 13, the second layer 14, and the third layer 12 are adjacent to each other because the external quantum efficiency of the light emitting device of this embodiment is further excellent. preferable.

Since the external quantum efficiency of the light emitting device of this embodiment is more excellent, the light emitting device of this embodiment has at least one of a hole injection layer and a hole transport layer between the anode 11 and the first light emitting layer. It is preferable to further have one layer. Since the external quantum efficiency of the light emitting device of this embodiment is more excellent, the light emitting device of this embodiment has at least one of an electron injection layer and an electron transport layer between the cathode 15 and the first light emitting layer. It is preferable to further have.
When the light emitting device of this embodiment has the second light emitting layer, the external quantum efficiency of the light emitting device of this embodiment is more excellent. Therefore, the light emitting device of this embodiment is provided between the anode 11 and the first light emitting layer. It is preferable to further include at least one of a hole injection layer and a hole transport layer. Since the external quantum efficiency of the light emitting device of this embodiment is more excellent, the light emitting device of this embodiment has at least one of an electron injection layer and an electron transport layer between the cathode 15 and the second light emitting layer. It is preferable to further have.
When the light emitting device of this embodiment has the third light emitting layer, the external quantum efficiency of the light emitting device of this embodiment is more excellent. Therefore, the light emitting device of this embodiment is provided between the anode 11 and the third light emitting layer. It is preferable to further include at least one of a hole injection layer and a hole transport layer. Since the external quantum efficiency of the light emitting device of this embodiment is more excellent, the light emitting device of this embodiment has at least one of an electron injection layer and an electron transport layer between the cathode 15 and the first light emitting layer. It is preferable to further have.
When the light-emitting element of this embodiment has the second light-emitting layer and the third light-emitting layer, the external quantum efficiency of the light-emitting element of this embodiment is more excellent. Therefore, the light-emitting element of this embodiment includes the anode 11 and the third light emitting element. It is preferable to further have at least one of a hole injection layer and a hole transport layer between the light emitting layer and the light emitting layer. Since the external quantum efficiency of the light emitting device of this embodiment is more excellent, the light emitting device of this embodiment has at least one of an electron injection layer and an electron transport layer between the cathode 15 and the second light emitting layer. It is preferable to further have.

  As a specific layer structure of the light emitting device of the present embodiment, for example, layer structures represented by (D1) to (D12) can be given. The light emitting device of this embodiment usually has a substrate, but may be laminated from the anode on the substrate, or may be laminated from the cathode on the substrate.

(D1) Anode / hole injection layer / third light emitting layer (third layer) / first light emitting layer (first layer) / electron transport layer (second layer) / electron injection layer / cathode ( D2) Anode / hole injection layer / third light emitting layer (third layer) / first light emitting layer (first layer) / electron transport layer / electron injection layer (second layer) / cathode (D3) ) Anode / hole injection layer / third light emitting layer (third layer) / first light emitting layer (first layer) / second light emitting layer (second layer) / electron transport layer / electron injection Layer / cathode (D4) anode / hole injection layer / third luminescent layer (third layer) / first luminescent layer (first layer) / second luminescent layer / electron transport layer (second Layer) / electron injection layer / cathode (D5) anode / hole injection layer / hole transport layer (third layer) / first light emitting layer (first layer) / electron transport layer (second layer) / Electron injection layer / cathode (D6) anode / hole injection layer (third layer) / hole transport layer / 1 light emitting layer (first layer) / electron transport layer (second layer) / electron injection layer / cathode (D7) anode / hole injection layer / hole transport layer (third layer) / first Light emitting layer (first layer) / electron transport layer / electron injection layer (second layer) / cathode (D8) anode / hole injection layer / hole transport layer / third light emitting layer (third layer) / First light-emitting layer (first layer) / electron transport layer (second layer) / electron injection layer / cathode (D9) anode / hole injection layer / hole transport layer / third light-emitting layer (first 3 layer) / first light emitting layer (first layer) / second light emitting layer (second layer) / electron transport layer / electron injection layer / cathode (D10) anode / hole injection layer / hole Transport layer (third layer) / first light emitting layer (first layer) / second light emitting layer (second layer) / electron transport layer / electron injection layer / cathode (D11) anode / hole injection Layer / hole transport layer / third light emitting layer (third layer) / first light emitting layer First layer) / second light emitting layer / electron transport layer (second layer) / electron injection layer (second layer) / cathode (D12) anode / hole injection layer / hole transport layer (third Layer) / third light emitting layer / first light emitting layer (first layer) / second light emitting layer / electron transport layer (second layer) / electron injection layer (second layer) / cathode

  In (D1) to (D12), “/” means that the front and back layers are adjacently stacked. Specifically, “third light-emitting layer (third layer) / first light-emitting layer (first layer) / electron transport layer (second layer)” means the third light-emitting layer (first layer). 3 layer), the first light emitting layer (first layer), and the electron transport layer (second layer) are adjacently laminated in this order.

In the light emitting device of the present embodiment, the anode, the hole injection layer, the hole transport layer, the second light emitting layer, the third light emitting layer, the electron transport layer, the electron injection layer, and the cathode, Two or more layers may be provided.
When there are a plurality of anodes, hole injection layers, hole transport layers, second light emitting layers, third 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 to 1 μm, preferably 2 nm to It is 500 nm, More preferably, it is 5 nm-150 nm.
In the light-emitting element of this embodiment, the order, number, and thickness of the layers to be stacked may be adjusted in consideration of the light-emitting efficiency, drive voltage, and element life of the light-emitting element.

[Second light emitting layer]
A 2nd light emitting layer is a layer containing a 2nd layer or a luminescent material normally, Preferably, it is a layer containing a luminescent 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 the light emitting material that may be contained in the composition 2 described above. The light emitting materials contained in the second light emitting layer may be contained singly or in combination of two or more.
When the light emitting element of this embodiment has a second light emitting layer, and the second layer is not an electron transport layer described later and an electron injection layer described later, the second light emitting layer is the second layer. It is preferable.

[Third light emitting layer]
The third light emitting layer is usually a third layer or a layer containing a light emitting material. When the third light emitting layer is a layer containing a light emitting material, examples of the light emitting material contained in the third light emitting layer include the light emitting material that may be contained in the composition 3 described above. The light emitting material contained in the third light emitting layer may be contained singly or in combination of two or more.
When the light emitting device of this embodiment has a third light emitting layer, and the third layer is not a hole transport layer described later and a hole injection layer described later, the third light emitting layer is the third layer. It is preferable that

[Hole transport layer]
The hole transport layer is usually a third layer or a layer containing a hole transport material. When the hole transport layer is a layer containing a hole transport material, examples of the hole transport material contained in the hole transport layer include the hole transport material that may be contained in the composition 1 described above. Is mentioned. The hole transport material contained in the hole transport layer may be contained singly or in combination of two or more.
When the light-emitting element of this embodiment has a hole transport layer and the third layer is not the above-described third light-emitting layer and the hole injection layer described later, the hole transport layer is the third layer. Preferably there is.

[Electron transport layer]
The electron transport layer is usually a second layer or a layer containing an electron transport material, and is preferably the second layer. When the electron transport layer is a layer containing an electron transport material, examples of the electron transport material contained in the electron transport layer include the electron transport material that may be contained in the composition 1 described above. The electron transport material contained in the electron transport layer may be contained singly or in combination of two or more.
When the light-emitting element of the present embodiment has an electron transport layer and the second layer is not the above-described second light-emitting layer and an electron injection layer described later, the electron transport layer may be the second layer. preferable.

[Hole injection layer and electron injection layer]
The hole injection layer is usually a third layer or a layer containing a hole injection material. When 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 holes that may be contained in the first composition described above. An injection material may be mentioned. The hole injection material contained in the hole injection layer may be contained singly or in combination of two or more.
When the light emitting device of this embodiment has a hole injection layer and the third layer is not the third light emitting layer and the hole transport layer, the hole injection layer is the third layer. Preferably there is.
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 that may be contained in the composition 1 described above. The electron injection material contained in the electron injection layer may be contained singly or in combination of two or more.
When the light-emitting element of this embodiment has an electron injection layer and the second layer is not the above-described second light-emitting layer and the above-described electron transport layer, the electron injection layer may be the second layer. preferable.

[Substrate / Electrode]
The substrate in the light-emitting element may be a substrate that can form an electrode and does not change chemically when forming a layer. For example, the substrate may be made of a material such as glass, plastic, or silicon. . When an opaque substrate is used, it is preferable that the electrode farthest from the substrate is transparent or translucent.

  Examples of the material for the anode include conductive metal oxides and translucent metals, preferably indium oxide, zinc oxide, tin oxide; indium tin oxide (ITO), indium zinc oxide, etc. A composite of silver, palladium and copper (APC); NESA, gold, platinum, silver and copper.

  Examples of the material of the cathode include metals such as lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, zinc, indium; two or more kinds of these alloys; Alloys of at least one species and at least one of silver, copper, manganese, titanium, cobalt, nickel, tungsten, and tin; and graphite and graphite intercalation compounds. Examples of the alloy include a magnesium-silver alloy, a magnesium-indium alloy, a magnesium-aluminum alloy, an indium-silver alloy, a lithium-aluminum alloy, a lithium-magnesium alloy, a lithium-indium alloy, and a calcium-aluminum alloy.

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

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

When the first layer is formed by a wet method, it is preferable to use ink 1. The first layer is preferably formed by a wet method because the manufacture of the light emitting device of this embodiment is facilitated.
When the second layer is formed by a wet method, it is preferable to use the ink 2 or the ink 2 ′, and it is more preferable to use the ink 2. The second layer is preferably formed by a wet method because the manufacture of the light emitting device of this embodiment is facilitated.
When the third layer is formed by a wet method, it is preferable to use ink 3 or ink 3 ′, and more preferable to use ink 3 ′. The second layer is preferably formed by a wet method because the manufacture of the light emitting device of this embodiment is facilitated.

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

  In manufacturing the light-emitting element of this embodiment, the material used for forming the hole injection layer, the material used for forming the light-emitting layer, the material used for forming the hole-transport layer, the material used for forming the electron-transport layer, and the electrons When the material used for forming the injection layer is dissolved in the solvent used when forming the hole injection layer, the light emitting layer, the hole transport layer, the electron transport layer, and the layer adjacent to the electron injection layer, It is preferred that dissolution of the material is avoided. As a method for avoiding dissolution of the material, i) a method using a material having a crosslinkable group, or ii) a method of providing a difference in solubility in a solvent of an adjacent layer is preferable. In the method i), after forming a layer using a material having a crosslinkable group, the layer can be insolubilized by crosslinking the crosslinkable group. As the method ii), for example, when an electron transport layer is laminated on the light emitting layer using a difference in solubility, an electron transport is performed by using an ink having low solubility in the light emitting layer. The layer can be laminated on the light emitting layer.

[Uses of light emitting elements]
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 pattern-like light emission, a method in which a mask having a pattern-like window is provided on the surface of a planar light-emitting element, a layer that is desired to be a non-light-emitting portion is formed extremely thick and 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 one of these methods and arranging several electrodes so that they can be turned on and off independently, a segment type display device capable of displaying numbers, characters, and the like 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 orthogonally. Partial color display and multicolor display are possible by a method of separately coating a plurality of types of polymer compounds having different emission colors, or a method using a color filter or a fluorescence conversion filter. The dot matrix display device can be driven passively or can be driven actively in combination with TFTs. These display devices can be used for displays of computers, televisions, portable terminals and the like. The planar light emitting element can be suitably used as a planar light source for backlight of a liquid crystal display device or a planar illumination light source. If a flexible substrate is used, it can be used as a curved light source and display device.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this 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 for 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 run at a flow rate of 2.0 mL / min. As a column, PLgel MIXED-B (manufactured by Polymer Laboratories) was used. 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 to a concentration of about 2 mg / mL, and about 1 μL was injected into LC-MS (manufactured by Agilent, trade names: 1290 Infinity LC and 6230 TOF LC / MS). The LC-MS mobile phase was used while changing the ratio of acetonitrile and tetrahydrofuran and was allowed to flow at a flow rate of 1.0 mL / min. The column used was SUMPAX ODS Z-CLUE (manufactured by Sumika Chemical Analysis Center, inner diameter: 4.6 mm, length: 250 mm, particle size 3 μm).

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

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

  In the present Example, MA and MB were calculated using the value of Molecular Weight of ChemDraw Professional 16.0 (manufactured by Hulinks).

In this example, the maximum peak wavelength of the emission spectrum of the metal complex was measured at room temperature with a spectrophotometer (manufactured by JASCO Corporation, FP-6500). 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. As excitation light, UV light having a wavelength of 325 nm was used.

<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 International Publication No. 2013/146806.
Compound M3 was synthesized according to the method described in WO2005 / 049546.

<Synthesis Example HTL> Synthesis of Polymer Compound HTL-1 Polymer compound HTL-1 was synthesized using Compound M1, Compound M2, and Compound M3 according to the method described in International Publication No. 2015/145871. The high molecular compound HTL-1 was Mn = 2.3 * 10 < ⁴ > and Mw = 1.2 * 10 < ⁵ >.
The theoretical value obtained from the amount of the raw material used for the polymer compound HTL-1 is 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 constituted by a molar ratio of 45: 5: 50.

<Compound HM-1 and Compound HTM-1>
Compound HM-1 and Compound HTM-1 were purchased from Luminescence Technology.

<Synthesis Example B> Synthesis of Metal Complex B1 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 R> Synthesis and Acquisition of Metal Complexes R1 to R6 Metal Complex R1 was purchased from American Dye Source.
Metal complex R2 and metal complex R6 were purchased from Luminescence 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 JP2008-179617A.
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.
The maximum peak wavelength of the emission spectrum of the metal complex R6 was 580 nm.

  The MA of the metal complex R1 was 805.0. The MA of the metal complex R2 was 1057.5. MA of metal complex R3 was 1826.5. MA of metal complex R4 was 1685.2. MA of metal complex R5 was 1732.3. MA of metal complex R6 was 1057.5.

<Synthesis Example G> Synthesis and Acquisition of Metal Complexes G1 to G3 Metal Complex G1 was purchased from Luminescence 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 International Publication No. 2009/131255.

The maximum peak wavelength of the emission spectrum of 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 Compound G3 was 514 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 ET1 had an MB of 716.8. The MB of compound ET3 was 514.6.

  <Compound ET2> Synthesis of Compound ET2

  After the inside of the reaction vessel was filled with an inert gas atmosphere, compound ET2a (8.7 g), compound ET2b (8.1 g), dimethyl sulfoxide (218 mL), copper (I) oxide (1.3 g), tripotassium phosphate ( 16.7 g) and dipivaloylmethane (3.2 g) were added and stirred at 150 ° C. for 10 hours. After cooling the obtained reaction liquid to room temperature, toluene and ion-exchange water were added, and it filtered with the glass filter which spread Celite. The obtained filtrate was washed with ion-exchanged water, and then 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 at 50 ° C. under reduced pressure to obtain Compound ET2 (8.0 g). The HPLC area percentage value of Compound ET2 was 99.5% or more.

The analysis results of 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).

  Compound ET2 had an MB of 572.7.

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

(Formation of third 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 spin coating and heated on a hot plate at 180 ° C. for 60 minutes in a nitrogen gas atmosphere. 3 layers (hole transport layer) were formed. By this heating, the polymer compound HTL-1 became a crosslinked product.

(Formation of the first layer)
Toluene, Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal Complex R3 (Compound HM-1 / Metal Complex B1 / Metal Complex G3 / Metal Complex R3 = 73.9% by mass / 25% by mass / 1% by mass) /0.1 mass%) was dissolved at a concentration of 2 mass%. Using the obtained toluene solution, a film having a thickness of 80 nm was formed on the third layer by spin coating, and the first layer (light emission) was heated at 130 ° C. for 10 minutes in a nitrogen gas atmosphere. Layer).

(Formation of second layer)
Compound ET1 was dissolved in 2,2,3,3,4,4,5,5-octafluoro-1-pentanol at a concentration of 0.25% by 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. In a nitrogen gas atmosphere, the second layer (electron transport layer) was formed by heating at 130 ° C. for 10 minutes.

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

(Evaluation of light emitting element)
EL light emission was observed by applying a voltage to the light emitting element D1. External quantum efficiency [%] and CIE chromaticity coordinates (x, y) at 1000 cd / m ² 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 Example D1 (Formation of First Layer)” Light-emitting elements D2 to D4 and CD1 were produced in the same manner as in Example D1, except that the materials listed in Table 1 were used instead of the complex R3 ".
EL light emission was observed by applying a voltage to the light emitting elements D2 to D4 and CD1. External quantum efficiency [%] and CIE chromaticity coordinates (x, y) at 1000 cd / m ² were measured.

  The results of Examples D1 to D4 and Comparative Example CD1 are shown in Table 1. The relative value of the external quantum efficiency of the light emitting elements D1 to D4 when the external quantum efficiency of the light emitting element CD1 is 1.00 is shown.

<Example D5 and Comparative Example CD2> Production and Evaluation of Light-Emitting Element D5 and CD2 In “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal Complex R3” in (Formation of First Layer) in Example D1 Instead of using the materials shown in Table 2, and using “Compound ET2” instead of “Compound ET1” in (Formation of the second layer) of Example D1, the same as Example D1 Thus, light emitting elements D5 and CD2 were produced.
EL light emission was observed by applying a voltage to the light emitting elements D5 and CD2. External quantum efficiency [%] and CIE chromaticity coordinates (x, y) at 8000 cd / m ² were measured.

  The results of Example D5 and Comparative Example CD2 are shown in Table 2. The relative value of the external quantum efficiency of the light emitting element D5 when the external quantum efficiency of the light emitting element CD2 is 1.00 is shown.

<Examples D6 to D7 and Comparative Example CD3> Production and Evaluation of Light-Emitting Elements D6, D7, and CD3 “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal in Example D1 (Formation of First Layer)” The procedure described in Table 3 was used in place of “Complex R3”, and “Compound ET3” was used in place of “Compound ET1” in Example D1 (Formation of the second layer). In the same manner as in Example D1, light emitting elements D6, D7, and CD3 were produced.
EL light emission was observed by applying a voltage to the light emitting elements D6, D7 and CD3. External quantum efficiency [%] and CIE chromaticity coordinates (x, y) at 500 cd / m ² were measured.

  Table 3 shows the results of Examples D6 to D7 and Comparative Example CD3. The relative values of the external quantum efficiencies of the light emitting elements D6 and D7 when the external quantum efficiency of the light emitting element CD3 is set to 1.00 are shown.

<Examples D8 to D9 and Comparative Example CD4> Production and Evaluation of Light-Emitting Elements D8, D9, and CD4 “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal in Example D1 (Formation of First Layer)” Light-emitting elements D8, D9 and CD4 were produced in the same manner as in Example D1, except that the materials (ratio) shown in Table 4 were used instead of the complex R3 ".
EL light emission was observed by applying a voltage to the light emitting elements D8, D9 and CD4. External quantum efficiency [%] and CIE chromaticity coordinates (x, y) at 200 cd / m ² were measured.

  Table 4 shows the results of Examples D8 to D9 and Comparative Example CD4. The relative value of the external quantum efficiency of the light emitting elements D8 and D9 when the external quantum efficiency of the light emitting element CD4 is 1.00 is shown.

<Examples D10 to D12 and Comparative Example CD5> Production and Evaluation of Light-Emitting Elements D10 to D12 and CD5 “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal in Example D1 (Formation of First Layer)” In place of “Compound R3”, the materials (ratio) shown in Table 5 were used, and “Compound ET2” was used instead of “Compound ET1” in (Formation of second layer) in Example D1. Produced the light emitting elements D10 to D12 and CD5 in the same manner as in Example D1.
EL light emission was observed by applying a voltage to the light emitting elements D10 to D12 and CD5. External quantum efficiency [%] and CIE chromaticity coordinates (x, y) at 1000 cd / m ² were measured.

  Table 5 shows the results of Examples D10 to D12 and Comparative Example CD5. The relative value of the external quantum efficiency of the light emitting elements D10 to D12 when the external quantum efficiency of the light emitting element CD5 is 1.00 is shown.

<Examples D13 to D15 and Comparative Example CD6> Production and Evaluation of Light-Emitting Elements D13 to D15 and CD6 "Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal in Example D1 (Formation of First Layer)" In place of “Compound R3”, the materials (ratio) shown in Table 6 were used, and “Compound ET3” was used instead of “Compound ET1” in (Formation of second layer) in Example D1. Produced the light emitting elements D10 to D12 and CD6 in the same manner as in Example D1.
EL light emission was observed by applying a voltage to the light emitting elements D13 to D15 and CD6. External quantum efficiency [%] and CIE chromaticity coordinates (x, y) at 1000 cd / m ² were measured.

  Table 6 shows the results of Examples D13 to D15 and Comparative Example CD6. The relative value of the external quantum efficiency of the light emitting elements D13 to D15 when the external quantum efficiency of the light emitting element CD6 is 1.00 is shown.

<Example D16> Fabrication and evaluation of light-emitting element D16 (formation of anode and hole injection layer)
An anode was formed by attaching an ITO film with a thickness of 45 nm to the glass substrate by sputtering. On the anode, ND-3202 (manufactured by Nissan Chemical Industries) as a hole injection material was formed into a film with a thickness of 35 nm by a spin coating method. In an air atmosphere, a hole injection layer was formed by heating on a hot plate at 50 ° C. for 3 minutes and further heating at 230 ° C. for 15 minutes.

(Formation of third layer)
Polymer compound HTL-1 and metal complex R4 (polymer compound HTL-1 / metal complex R4 = 65 mass% / 35 mass%) were dissolved in xylene at a concentration of 0.7 mass%. Using the obtained xylene solution, a film having a thickness of 20 nm was formed on the hole injection layer by spin coating and heated on a hot plate at 180 ° C. for 60 minutes in a nitrogen gas atmosphere. 3 layers (light emitting layer) were formed. By this heating, the polymer compound HTL-1 became a crosslinked product.

(Formation of the first layer)
Compound HM-1 and metal complex B1 (compound HM-1 / metal complex B1 = 75% by mass / 25% by mass) were dissolved in toluene at a concentration of 2% by mass. Using the obtained toluene solution, a film having a thickness of 80 nm was formed on the second layer by spin coating, and the first layer (light emission) was heated at 130 ° C. for 10 minutes in a nitrogen gas atmosphere. Layer).

(Formation of second layer)
Compound ET1 was dissolved in 2,2,3,3,4,4,5,5-octafluoro-1-pentanol at a concentration of 0.25% by 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. In a nitrogen gas atmosphere, the second layer (electron transport layer) was formed by heating at 130 ° C. for 10 minutes.

(Formation of cathode)
The substrate on which the first layer is formed is depressurized to 1.0 × 10 ⁻⁴ Pa or less in a vapor deposition machine, and then, as a cathode, sodium fluoride is about 4 nm on the second layer and then sodium fluoride. About 80 nm of aluminum was deposited on the layer. After vapor deposition, the light emitting element D16 was produced by sealing using a glass substrate.

(Evaluation of light emitting element)
EL light emission was observed by applying a voltage to the light emitting element D16. External quantum efficiency [%] and CIE chromaticity coordinates (x, y) at 1000 cd / m ² were measured.

<Examples D17 to D19 and Comparative Example CD7> Production and Evaluation of Light-Emitting Elements D17 to D19 and CD7 In place of “Polymer Compound HTL-1 and Metal Complex R4” in (Formation of Third Layer) of Example D16 The light emitting devices D17 to D19 and CD7 were produced in the same manner as in Example D16 except that the materials listed in Table 7 were used.
EL light emission was observed by applying a voltage to the light emitting elements D17 to D19 and CD7. External quantum efficiency [%] and CIE chromaticity coordinates (x, y) at 1000 cd / m ² were measured.

  Table 7 shows the results of Examples D16 to D19 and Comparative Example CD7. The relative value of the external quantum efficiency of the light emitting elements D16 to D19 when the external quantum efficiency of the light emitting element CD7 is set to 1.00 is shown.

<Examples D20 to D22 and Comparative Example CD8> Production and Evaluation of Light-Emitting Elements D20 to D22 and CD8 In place of “Polymer Compound HTL-1 and Metal Complex R4” in (Formation of Third Layer) of Example D1 The light emitting devices D20 to D22 and CD8 were produced in the same manner as in Example D1, except that the materials listed in Table 8 were used.
EL light emission was observed by applying a voltage to the light emitting elements D20 to D22 and CD8. External quantum efficiency [%] and CIE chromaticity coordinates (x, y) at 400 cd / m ² were measured.

  Table 8 shows the results of Examples D20 to D22 and Comparative Example CD8. The relative value of the external quantum efficiency of the light emitting elements D20 to D22 when the external quantum efficiency of the light emitting element CD8 is set to 1.00 is shown.

  DESCRIPTION OF SYMBOLS 10 Light emitting element, 11 Anode, 12 3rd layer, 13 1st layer, 14 2nd layer, 15 Cathode.

Claims (12)

An anode, a cathode, a first layer provided between the anode and the cathode, a second layer provided between the cathode and the first layer, the anode and the first A light-emitting element having a third layer provided between the layers,
The first layer is a layer containing a phosphorescent compound having a maximum peak wavelength of an emission spectrum of 380 nm to less than 495 nm and a phosphorescent compound having a maximum peak wavelength of an emission spectrum of from 570 nm to less than 750 nm,
Before Stories second layer contains a compound represented by the formula (T-1),
The molecular weight (MA) of the phosphorescent compound having a maximum peak wavelength of the emission spectrum of 570 nm or more and less than 750 nm and the molecular weight (MB) of the compound represented by the formula (T-1) are represented by the formula (M1-1 ) and meet the formula (M2-1),
The phosphorescent compound having a maximum peak wavelength of the emission spectrum of 570 nm or more and less than 750 nm is a metal complex represented by the formula (1),
The light emitting element whose phosphorescent compound whose maximum peak wavelength of the said emission spectrum is 380 nm or more and less than 495 nm is a metal complex represented by Formula (2) .

1500 ≦ MA + MB ≦ 10000 (M1-1)
0 <MB / MA ≦ 0.85 (M2-1)

[Where:
n ^T1 represents an integer of 0 or more and 5 or less. When a plurality of n ^T1 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 monovalent heterocyclic group of a condensed ring containing a nitrogen atom having no double bond in the ring and a group represented by ═N—, and the group is a single or a plurality of substituents. And when a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of Ar ^T1 are present, they may be the same or different.
L ^T1 represents an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, a group represented by -NR ^T1 '-, an oxygen atom or a sulfur atom, and these groups are each a single or a plurality of substituted groups When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms 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 each may have a single or a plurality of substituents, When two or more are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of ^LT1 are present, 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 a plurality of the substituents are present, they are the same or different. They may be bonded to each other to form a ring together with the atoms to which they are bonded. ]

[Where:
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. When a plurality of E ^L are present, they may be the same or different.
Ring L ¹ represents a 6-membered aromatic heterocyclic ring, and this ring may have a single or a plurality of substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of rings L ¹ are present, they may be the same or different.
Ring L ² represents an aromatic hydrocarbon ring or aromatic heterocyclic ring, these rings may have a single or more substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of 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 are bonded to each other to form a ring together with the atoms to which they are bonded. You may do it.
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 constituting a bidentate ligand together with A ¹ and A ² . When a plurality of A ¹ -G ¹ -A ² are present, they may be the same or different. ]

[Where:
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 ² + 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 heterocyclic ring, and this ring may have a single or a plurality of substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of rings R ¹ are present, they may be the same or different.
Ring R ² represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring, and these rings may have a single or a plurality of substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of rings R ² are present, they may be the same or different.
The substituent that ring R ¹ may have and the substituent that ring R ² may have may be the same or different, and are bonded to each other to form a ring together with the atoms to which they are bonded. You may do it.
A ³ -G ² -A ⁴ represents a bidentate ligand of the anionic. 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 constituting a bidentate ligand together with A ³ and A ⁴ . When a plurality of A ³ -G ² -A ⁴ are present, they may be the same or different. ] The ring L ¹ is a pyridine ring, a diazabenzene ring, an azanaphthalene ring or a diazanaphthalene ring, these rings may have a single or a plurality of substituents, and the ring L ² is 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. 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, and a plurality of groups represented by the formula (1-T) are present. When doing, they may be same or different, The light emitting element of Claim 1 or 2 .

[Wherein, 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. It may have one or more substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. ] Wherein ^{Ar T1} is a group represented by the formula (T1-1), light-emitting device according to any one of claims 1-3.

[Where:
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, alkyl group, cycloalkyl group, alkoxy group, cycloalkoxy group, aryl group, aryloxy group, monovalent heterocyclic group, substituted amino group, halogen atom or Represents a cyano group, and these groups may have one or a plurality of substituents, and when a plurality of the substituents are present, they may be the same or different, and are bonded to each other, You may form the ring with the atom to couple | bond. A plurality of R ^XT1 ′ may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded.
Ring R ^T1 and Ring R ^T2 each independently represent an aromatic hydrocarbon ring or a heterocyclic ring, and these rings may have a single or a plurality of substituents, and a plurality of the substituents are present. In this case, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded.
However, at least one of the ring R ^T1 and the ring R ^T2 is a heterocyclic ring containing a group represented by ═N— in the ring, and the ring has a single or a plurality of substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. ] The ring R ^T1 is an aromatic hydrocarbon ring or a heterocyclic ring containing a group represented by ═N— in the ring, and these rings may have a single or a plurality of substituents; The light emission according to claim 4 , wherein the ring R ^T2 is a heterocyclic ring 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 heterocyclic ring containing a group represented by ═N— in the ring, and these rings 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 element according to claim 5, which may be provided. The ring R ^T1 is a benzene ring, a pyridine ring or a diazabenzene ring, these rings may have a single or a plurality of substituents, and the ring R ^T2 is a pyridine ring or a diazabenzene ring. The light-emitting element according to claim 6 , wherein these rings may have a single substituent or a plurality of substituents. 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. There, these rings may have a single or more substituents, the light emitting device according to any one of claims 1 to 7. The molecular weight (MA), the molecular weight (MB), but satisfies the formula (M1-2) and formula (M2-2), light-emitting device according to any one of claims 1-8.

1550 ≦ MA + MB ≦ 3000 (M1-2)
0.25 ≦ MB / MA ≦ 0.70 (M2-2) The light emitting element according to any one of claims 1 to 9 , wherein the first layer further contains a compound represented by the formula (H-1).

[Where:
Ar ^H1 and Ar ^H2 each independently represent an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups optionally have a single or a plurality of substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together 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 optionally have a single or a plurality of substituents. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When a plurality of L ^H1 are present, they may be the same or different. ] Wherein and the first layer and the second layer are adjacent, and the first layer and the third layer is adjacent, according to any one of claims 1-10 Light emitting element. The light emitting element according to any one of claims 1 to 11, wherein the first layer and the third layer do not contain the compound represented by the formula (T-1).

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