JP6651041B1 - Light emitting element - Google Patents

Abstract

An object is to provide a light emitting element having excellent luminance life. The light-emitting element includes an anode, a cathode, a first layer provided between the anode and the cathode, and a second layer provided between the cathode and the first layer. The first layer contains a 5-membered aromatic heterocycle, a metal complex containing an aromatic hydrocarbon ring or an aromatic heterocycle, and a metal complex whose emission spectrum has a maximum peak wavelength of 550 nm or more and less than 750 nm. A light-emitting element which is a layer, wherein the second layer contains a heterocyclic ring containing nitrogen and a compound containing an aromatic hydrocarbon group or a heterocyclic group. [Selection diagram] None

Description

  The present invention relates to a light emitting device.

  A light-emitting element such as an organic electroluminescence element can be suitably used for display and lighting applications, and research and development have been conducted. For example, Patent Document 1 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. 2011/048956

However, the above-described light-emitting element does not always have a sufficient luminance life.
Therefore, an object of the present invention is to provide a light-emitting element having excellent luminance life.

［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^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一次置換基を有していてもよい。前記一次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一次置換基を有していてもよい。前記一次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一次置換基と環Ｒ^２が有していてもよい一次置換基とは、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。］

［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^３＋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^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一次置換基を有していてもよい。前記一次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一次置換基を有していてもよい。前記一次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一次置換基と環Ｌ^２が有していてもよい一次置換基とは、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。
但し、環Ｌ^１及び環Ｌ^２のうちの少なくとも１つは、一次置換基として、式（２−Ｔ）で表される基を有する。式（２−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。
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。］

［式中、Ｒ^２Ｔ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価の複素環基又は置換アミノ基を表し、これらの基は単一又は複数の二次置換基を有していてもよく、前記二次置換基は、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、アリール基、１価の複素環基又は置換アミノ基であり、これらの基は単一又は複数の三次置換基を有していてもよく、前記三次置換基は、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、アリール基、１価の複素環基又は置換アミノ基であり、これらの基は単一又は複数の四次置換基を有していてもよい。前記二次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。前記三次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。前記四次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。］

［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］ 前記式（２’）で表される金属錯体の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、［２］に記載の発光素子。
［３］ 前記式（１）で表される金属錯体の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、［１］又は［２］に記載の発光素子。
［４］ 前記環Ｒ^１における前記一次置換基が、式（１−Ｓ）で表される基であり、前記環Ｒ^２における前前記一次置換基が、式（１−Ｓ）で表される基であり、式（１−Ｓ）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^１Ｓ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二次置換基を有していてもよい。前記二次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］ 陽極と、陰極と、前記陽極及び前記陰極の間に設けられた第１の層と、前記陰極及び前記第１の層との間に設けられた第２の層とを有する発光素子であり、
前記第１の層が、式（１’）で表される金属錯体と、発光スペクトルの最大ピーク波長が５５０ｎｍ以上７５０ｎｍ未満である式（２）で表される金属錯体とを含有する層であり、
前記第２の層が、式（Ｔ−１）で表される化合物を含有する、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^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式（２−Ｓ）で表される基を有していてもよい。前記式（２−Ｓ）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式（２−Ｓ）で表される基を有していてもよい。前記式（２−Ｓ）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式（２−Ｓ）で表される基と環Ｒ^２が有していてもよい式（２−Ｓ）で表される基とは、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。］

［式中、Ｒ^２Ｓ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価の複素環基又は置換アミノ基を表し、これらの基は単一又は複数の二次置換基を有していてもよく、前記二次置換基は、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、アリール基、１価の複素環基又は置換アミノ基であり、これらの基は単一又は複数の三次置換基を有していてもよく、前記三次置換基は、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、アリール基、１価の複素環基又は置換アミノ基であり、これらの基は単一又は複数の四次置換基を有していてもよい。前記二次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。前記三次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。前記四次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。］

［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^３＋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^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一次置換基を有していてもよい。前記一次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一次置換基を有していてもよい。前記一次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一次置換基と環Ｌ^２が有していてもよい一次置換基とは、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。
但し、環Ｌ^１及び環Ｌ^２のうちの少なくとも１つは、一次置換基として、式（１−Ｔ）で表される基を有する。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。
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。］

［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。］

［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。］
［６］ 前記式（１−Ｔ）で表される基が、式（２−Ｔ）で表される基である、［５］に記載の発光素子。

［式中、Ｒ^２Ｔ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価の複素環基又は置換アミノ基を表し、これらの基は単一又は複数の二次置換基を有していてもよく、前記二次置換基は、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、アリール基、１価の複素環基又は置換アミノ基であり、これらの基は単一又は複数の三次置換基を有していてもよく、前記三次置換基は、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、アリール基、１価の複素環基又は置換アミノ基であり、これらの基は単一又は複数の四次置換基を有していてもよい。前記二次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。前記三次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。前記四次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。］
［７］ 前記式（２）で表される金属錯体の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、［５］又は［６］に記載の発光素子。
［８］ 前記式（１’）で表される金属錯体の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、［５］〜［７］のいずれかに記載の発光素子。
［９］ 前記環Ｒ^１における前記５員の芳香族複素環がジアゾール環又はトリアゾール環であり、且つ、前記環Ｒ^２における前記芳香族炭化水素環又は前記芳香族複素環が、ベンゼン環、ピリジン環又はジアザベンゼン環である、［１］〜［８］のいずれかに記載の発光素子。
［１０］ 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一次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一次置換基を有していてもよい、［１］〜［９］のいずれかに記載の発光素子。
［１１］ 前記Ｒ^２Ｔが、アルキル基、シクロアルキル基、アリール基、１価の複素環基又は置換アミノ基であり、これらの基は単一又は複数の二次置換基を有していてもよく、前記二次置換基が、アルキル基、シクロアルキル基、アリール基、１価の複素環基又は置換アミノ基であり、これらの基は単一又は複数の三次置換基を有していてもよく、前記三次置換基が、アルキル基、シクロアルキル基、アリール基、１価の複素環基又は置換アミノ基であり、これらの基は単一又は複数の四次置換基を有していてもよい、［１］〜［４］のいずれか又は［６］〜［１０］のいずれかに記載の発光素子。
［１２］ 前記Ｒ^２Ｓが、アルキル基、シクロアルキル基、アリール基、１価の複素環基又は置換アミノ基であり、これらの基は単一又は複数の二次置換基を有していてもよく、前記二次置換基が、アルキル基、シクロアルキル基、アリール基、１価の複素環基又は置換アミノ基であり、これらの基は単一又は複数の三次置換基を有していてもよく、前記三次置換基が、アルキル基、シクロアルキル基、アリール基、１価の複素環基又は置換アミノ基であり、これらの基は単一又は複数の四次置換基を有していてもよい、［５］〜［１１］のいずれかに記載の発光素子。
［１３］ 前記Ａｒ^Ｔ１が、式（Ｔ１−１）で表される基である、［１］〜［１２］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。］
［１４］ 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、［１３］に記載の発光素子。
［１５］ 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、［１４］に記載の発光素子。
［１６］ 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、［１５］に記載の発光素子。
［１７］ 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］〜［１６］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。］
［１８］ 前記第１の層と、前記第２の層とが、隣接している、［１］〜［１７］のいずれかに記載の発光素子。 The present invention provides the following [1] to [18].
[1] A light emitting element having an anode, a cathode, a first layer provided between the anode and the cathode, and a second layer provided between the cathode and the first layer And
The first layer is a layer containing a metal complex represented by the formula (1) and a metal complex represented by the formula (2 ′) whose emission spectrum has a maximum peak wavelength of 550 nm or more and less than 750 nm. ,
A light-emitting element, wherein the second layer contains a compound represented by the formula (T-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, ^{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 ¹ and E ² each independently represent a carbon atom or a nitrogen atom. When a plurality of E ¹ and E ² are present, they may be the same or different.
Ring R ¹ represents a 5-membered aromatic heterocycle, which may have one or more primary substituents. When a plurality of the primary 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 aromatic heterocyclic ring, these rings may have a single or plurality of primary substituent. When a plurality of the primary 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 ring R ² is plurally present, they may be the same or different.
The primary substituent that the ring R ¹ may have and the primary substituent that the 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. May be formed.
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, iridium atom or a platinum atom.
n ³ represents an integer of 1 or more, ^{n 4} represents an integer of 0 or more. However, when M ² is a rhodium atom or an iridium atom, n ³ + n ⁴ is 3, and when M ² is a palladium atom or a platinum atom, n ³ + n ⁴ is 2.
^EL represents a carbon atom or a nitrogen atom. When a plurality of ^ELs are present, they may be the same or different.
Ring L ¹ represents a 6-membered aromatic heterocyclic ring, and this ring may have one or more primary substituents. When a plurality of the primary 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 ring L ¹ there are a plurality, 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 plurality of primary substituent. When a plurality of the primary 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 ring L ² there are a plurality, they may be the same or different.
The primary substituent that the ring L ¹ may have and the primary 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. May be formed.
Provided that at least one of the ring L ¹ and the ring L ^2, as an additional substituent, having a group represented by the formula (2-T). When a plurality of groups represented by the formula (2-T) exist, they may be the same or different.
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 . If A ³ -G ² -A ⁴ there are a plurality, they may be the same or different. ]

[Wherein, R ^2T represents an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group; May have a secondary substituent, the secondary substituent is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, These groups may have a single or a plurality of tertiary substituents, the tertiary substituent is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or These are substituted amino groups, and these groups may have one or more quaternary substituents. When a plurality of the secondary 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 the tertiary 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 the quaternary 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. ]

[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.
^nT2 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 plural substituents. And when there are a plurality of the substituents, 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 ^T1s are present, they may be the same or different.
L ^T1 is an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -NR T1 ^'- represents a group represented by an oxygen atom or a sulfur atom, the these groups single or multiple substitutions It may have a group, and when there are a plurality of the substituents, 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 may have a single or plural substituents, and the substituent may be When there are a plurality of them, 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 ^LT1s exist, 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. When a plurality of the substituents are present, they are the same or different. And 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 [2], wherein the maximum peak wavelength of the emission spectrum of the metal complex represented by the formula (2 ′) is 570 nm or more and less than 750 nm.
[3] The light-emitting element according to [1] or [2], wherein a maximum peak wavelength of an emission spectrum of the metal complex represented by the formula (1) is 380 nm or more and less than 495 nm.
[4] The primary substituent in the ring R ¹ is a group represented by Formula (1-S), and the primary substituent in the ring R ² is represented by Formula (1-S). The light-emitting device according to any one of [1] to [3], wherein when there are a plurality of groups represented by the formula (1-S), they may be the same or different.

[Wherein, R ^1S 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 secondary substituents. When a plurality of the secondary 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] A light-emitting element having an anode, a cathode, a first layer provided between the anode and the cathode, and a second layer provided between the cathode and the first layer And
The first layer is a layer containing a metal complex represented by the formula (1 ′) and a metal complex represented by the formula (2) whose emission spectrum has a maximum peak wavelength of 550 nm or more and less than 750 nm. ,
A light-emitting element, wherein the second layer contains a compound represented by the formula (T-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, ^{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 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 one or more groups represented by formula (2-S). When a plurality of groups represented by the formula (2-S) 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 each is 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 aromatic heterocyclic ring, these rings may have a group represented by single or multiple expressions (2-S). When a plurality of groups represented by the formula (2-S) 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 each is bonded. When a ring R ² is plurally present, they may be the same or different.
The group represented by the formula (2-S) that the ring R ¹ may have and the group represented by the formula (2-S) that the ring R ² may have are the same or different. And may be bonded to each other to form a ring together with the atoms to which they are bonded.
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. ]

[Wherein, R ^2S represents an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group, or a substituted amino group; May have a secondary substituent, the secondary substituent is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, These groups may have a single or a plurality of tertiary substituents, the tertiary substituent is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or These are substituted amino groups, and these groups may have one or more quaternary substituents. When a plurality of the secondary 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 the tertiary 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 the quaternary 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. ]

[Where,
M ² represents a rhodium atom, a palladium atom, iridium atom or a platinum atom.
n ³ represents an integer of 1 or more, ^{n 4} represents an integer of 0 or more. However, when M ² is a rhodium atom or an iridium atom, n ³ + n ⁴ is 3, and when M ² is a palladium atom or a platinum atom, n ³ + n ⁴ is 2.
^EL represents a carbon atom or a nitrogen atom. When a plurality of ^ELs are present, they may be the same or different.
Ring L ¹ represents a 6-membered aromatic heterocyclic ring, and this ring may have one or more primary substituents. When a plurality of the primary 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 ring L ¹ there are a plurality, 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 plurality of primary substituent. When a plurality of the primary 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 ring L ² there are a plurality, they may be the same or different.
The primary substituent that the ring L ¹ may have and the primary 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. May be formed.
Provided that at least one of the ring L ¹ and the ring L ^2, as an additional substituent, having a group represented by the formula (1-T). When there are a plurality of groups represented by the formula (1-T), they may be the same or different.
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 . If A ³ -G ² -A ⁴ there are a plurality, they may be the same or different. ]

[In the formula, R ^1T represents an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group, a substituted amino group, or a halogen atom. 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. ]

[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.
^nT2 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 plural substituents. And when there are a plurality of the substituents, 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 ^T1s are present, they may be the same or different.
L ^T1 is an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -NR T1 ^'- represents a group represented by an oxygen atom or a sulfur atom, the these groups single or multiple substitutions It may have a group, and when there are a plurality of the substituents, 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 may have a single or plural substituents, and the substituent may be When there are a plurality of them, 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 ^LT1s exist, 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. When a plurality of the substituents are present, they are the same or different. And may be bonded to each other to form a ring together with the atoms to which they are bonded. ]
[6] The light emitting device according to [5], wherein the group represented by the formula (1-T) is a group represented by the formula (2-T).

[Wherein, R ^2T represents an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group; May have a secondary substituent, the secondary substituent is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, These groups may have a single or a plurality of tertiary substituents, the tertiary substituent is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or These are substituted amino groups, and these groups may have one or more quaternary substituents. When a plurality of the secondary 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 the tertiary 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 the quaternary 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. ]
[7] The light-emitting element according to [5] or [6], wherein the metal complex represented by the formula (2) has a maximum peak wavelength of an emission spectrum of 570 nm or more and less than 750 nm.
[8] The light-emitting device according to any one of [5] to [7], wherein a maximum peak wavelength of an emission spectrum of the metal complex represented by the formula (1 ′) is 380 nm or more and less than 495 nm.
[9] aromatic heterocycle of the 5-membered in the ring R ¹ is a diazole ring or a triazole ring, and the aromatic hydrocarbon ring or the aromatic heterocyclic ring in the ring R ² is a benzene ring, pyridine The light-emitting device according to any one of [1] to [8], which is a ring or a diazabenzene ring.
[10] 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 primary substituents, and the ring L ² is a benzene ring, a pyridine ring or Jiazabenzen ring, these rings may have a single or plurality of primary substituent, the light emitting device according to any one of [1] to [9] .
[11] The above-mentioned R ^2T is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or a plurality of secondary substituents. Preferably, the secondary substituent is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or a plurality of tertiary substituents. Preferably, the tertiary substituent is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or a plurality of quaternary substituents. Good, the light emitting device according to any one of [1] to [4] or [6] to [10].
[12] The R ^2S is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or a plurality of secondary substituents. Preferably, the secondary substituent is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or a plurality of tertiary substituents. Preferably, the tertiary substituent is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or a plurality of quaternary substituents. Good, the light emitting device according to any one of [5] to [11].
[13] The light-emitting device according to any one of [1] to [12], wherein Ar ^T1 is a group represented by formula (T1-1).

[Where,
X ^T1 represents a single bond, an oxygen atom, a sulfur atom, -N ^{(R XT1)} - represents a group represented by -, a group represented by _{^{or, -C (R XT1 ') 2}} . R ^XT1 and R ^{XT1 ′} each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group, a halogen atom or Represents a cyano group, these groups may have a single or a plurality of substituents, when there are a plurality of said substituents, they may be the same or different, bonded to each other, A ring may be formed together with the bonding atom. A plurality of R ^XT1 ′ may be the same or different, and may combine with each other to form a ring together with the atoms to which each is attached.
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 such a 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. And when there are a plurality of the substituents, 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. ]
[14] 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 heterocyclic ring containing a group represented by = N- in the ring, and the ring may have a single or plural substituents. The light-emitting element according to any one of the preceding claims.
[15] 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 may be a single ring or a plurality of rings. May have a substituent, and the ring ^RT2 is a monocyclic heterocyclic ring containing a group represented by = N- in the ring, and the ring is a single or plural substituents. The light emitting device according to [14], which may have:
[16] The ring R ^T1 is a benzene ring, a pyridine ring or a diazabenzene ring, and these rings may have a single or a plurality of substituents, and the ring R ^T2 is a pyridine ring or The light-emitting element according to [15], which is a diazabenzene ring, and these rings may have a single or a plurality of substituents.
[17] The light emitting device according to any one of [1] to [16], 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 may have a single or plural 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 may have a single or plural 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. ]
[18] The light-emitting element according to any one of [1] to [17], wherein the first layer and the second layer are adjacent to each other.

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

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

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

<Explanation of common terms>
Terms 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, a solid line representing a bond with the central metal means a covalent bond or a coordinate bond.

“Polymer compound” means a polymer having a molecular weight distribution and a polystyrene equivalent number average molecular weight of 1 × 10 ³ to 1 × 10 ⁸ .
“Low molecular weight compound” means a compound having no molecular weight distribution and having a molecular weight of 1 × 10 ⁴ or less.
“Structural unit” means a unit present at least one in a polymer compound. A structural unit existing two or more times in a polymer compound may be generally called a “repeating unit”.

“Alkyl group” may be linear or branched. The number of carbon atoms of the linear alkyl group is usually 1 to 50, preferably 1 to 20, more preferably 1 to 10, excluding the number of carbon atoms of the substituent. 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, excluding 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, 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, excluding the number of carbon atoms of the substituent. The cycloalkyl group may have a substituent, for example, 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, without including the number of carbon atoms of the substituent. The alkylene group may have a substituent, and examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, and an octylene group.
The number of carbon atoms of the “cycloalkylene group” is usually 3 or more and 20 or less without including the number of carbon atoms of the substituent. The cycloalkylene group may have a substituent, for example, a cyclohexylene group.

“Aromatic hydrocarbon group” means a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms 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 from 6 to 60, preferably from 6 to 30, more preferably from 6 to 18, excluding 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 Pentacyclic aromatic hydrocarbons such as perylene and benzofluoranthene; hexacyclic aromatic hydrocarbons such as spirobifluorene; and 7-cyclic aromatic hydrocarbons such as benzospirobifluorene and acenaphthofluoranthene. Aromatic hydrocarbons), 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 the linear alkoxy group is usually from 1 to 40, preferably from 1 to 10, excluding the number of carbon atoms of the substituent. The number of carbon atoms of the branched alkoxy group is usually from 3 to 40, preferably from 4 to 10, excluding 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 Oxy groups are mentioned.
The number of carbon atoms of the "cycloalkoxy group" is usually from 3 to 40, preferably from 4 to 10, excluding the number of carbon atoms of the substituent. The cycloalkoxy group may have a substituent, for example, a cyclohexyloxy group.
The number of carbon atoms of the "aryloxy group" is usually from 6 to 60, preferably from 6 to 48, excluding the number of carbon atoms of the substituent. The aryloxy group may have a substituent, and examples 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 excluding 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 the heterocyclic compound is also referred to as a “p-valent heterocyclic group”. A group obtained by removing p hydrogen atoms directly bonded to carbon atoms or hetero atoms constituting a ring from an aromatic heterocyclic compound is also referred to as “p-valent aromatic heterocyclic group”.
As the "aromatic heterocyclic compound", for example, azole, thiophene, furan, pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole and other heterocyclic compound itself shows aromaticity, and phenoxazine And heterocyclic rings such as phenothiazine and benzopyran, which do not show aromaticity, but compounds in which an aromatic ring is condensed with the heterocyclic ring.
The number of carbon atoms of the heterocyclic group is usually 1 to 60, preferably 2 to 40, and more preferably 3 to 20 without including the number of carbon atoms of the substituent. The number of hetero atoms in the heterocyclic group is usually 1 to 30, preferably 1 to 10, more preferably 1 to 3, without including the number of hetero atoms in the substituent.
The heterocyclic group may have a substituent, for example, a monocyclic heterocyclic compound (for example, furan, thiophene, oxadiazole, pyrrole, diazole, triazole, tetrazole, pyridine, diazabenzene and triazine Or a polycyclic heterocyclic compound (for example, a bicyclic heterocyclic compound such as azanaphthalene, diazanaphthalene, benzofuran, benzothiophene, indole, benzodiazole and benzothiadiazole; dibenzofuran) , Dibenzothiophene, carbazole, azacarbazole, diazacarbazole, phenoxazine, phenothiazine, 9,10-dihydroacridine, 5,10-dihydrophenazine, azaanthracene, diazaanthracene, azaphenanthrene and diazaphenanthrene A tricyclic heterocyclic compound; 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 heptacyclic heterocyclic compounds such as dibenzoindolocarbazole.). Examples thereof include groups in which one or more hydrogen atoms directly bonded to constituent atoms have been 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” indicates 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 the substituent of the amino group, 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.
More specifically, examples of the substituted amino group include a dimethylamino group, a diethylamino group, a diphenylamino group, a bis (methylphenyl) amino group, and a bis (3,5-di-tert-butylphenyl) amino group. No.

The “alkenyl group” may be linear or branched. The number of carbon atoms of the linear alkenyl group is usually from 2 to 30, preferably from 3 to 20, excluding the number of carbon atoms of the substituent. The number of carbon atoms of the branched alkenyl group is usually 3 to 30, preferably 4 to 20, excluding the number of carbon atoms of the substituent.
The number of carbon atoms of the “cycloalkenyl group” is usually from 3 to 30, preferably from 4 to 20, excluding 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 -Hexenyl group, 7-octenyl group, and groups in which these groups have a substituent.

The “alkynyl group” may be linear or branched. The number of carbon atoms of the alkynyl group is usually 2 to 20, preferably 3 to 20, excluding the carbon atom of the substituent. The number of carbon atoms of the branched alkynyl group is usually 4 to 30, preferably 4 to 20, excluding the carbon atom of the substituent.
The number of carbon atoms of the "cycloalkynyl group" is usually 4 to 30, preferably 4 to 20, excluding the carbon atom of the substituent.
Alkynyl group and 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。］ "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, and is preferably a compound represented by the formula It is a group represented by any of (XL-1) to (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 ^XLs are present, they may be the same or different. When a plurality of n ^XLs 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 the substituents are present, they may be the same or different, and are bonded to each other to form a carbon atom to which each is bonded. It may form a ring with the atoms. ]

  As the “substituent (primary substituent, secondary substituent, tertiary substituent and quaternary substituent)”, for example, a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group Alkoxy group, cycloalkoxy group, aryloxy group, amino group, substituted amino group, alkenyl group, cycloalkenyl group, alkynyl group and cycloalkynyl group. The substituent may be a crosslinkable group. The group having a substituent may have a single or a plurality of substituents. The substituted ring may have a single or multiple substituents. When a plurality of substituents are present, they may be the same or different, and they may be bonded to each other to form a ring together with the atoms to which they are bonded, but it is preferable that they do not form a ring. .

<Metal complex represented by formula (2)>
The metal complex represented by the formula (2) is preferably a metal complex represented by the formula (2 ′) because the light-emitting element of this embodiment has more excellent luminance lifetime.
The metal complex represented by the formula (2) and the metal complex represented by the formula (2 ′) are usually metal complexes that exhibit phosphorescence at room temperature, and preferably emit light from a triplet excited state at room temperature. It is a metal complex which shows these.

M ² is preferably an iridium atom or a platinum atom, and more preferably an iridium atom, because the light emitting element of the present embodiment has a better luminance lifetime.
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 ^L is preferably a carbon atom. Since the metal complex represented by the formula (2) and the metal complex represented by the formula (2 ′) can be easily synthesized, when a plurality of ^ELs are present, they are preferably the same.

Ring L number of carbon atoms in the aromatic heterocycle 6-membered in ^1, not including the carbon atom number of substituent is usually 1 to 60, preferably 2 to 30, more preferably 3 to 15 is there. Ring L hetero atoms of an aromatic heterocyclic ring in ^1, not including the number of heteroatom substituents is usually 1 to 30, preferably 1 to 10, more preferably 1 to 3.
The ring L ¹ includes, for example, a 6-membered aromatic heterocyclic ring having at least one nitrogen atom as a constituent atom in the aromatic heterocyclic rings exemplified in the above-mentioned section of the heterocyclic group. Is preferably a 6-membered aromatic heterocycle having one or more and four or less nitrogen atoms as constituent atoms, and more preferably a pyridine ring, a diazabenzene ring, or an azanaphthalene. Or a diazanaphthalene ring, more preferably a pyridine ring, a quinoline ring or an isoquinoline ring, and these rings may have a substituent (primary substituent).
Since the metal complex represented by the formula (2) metal complex and (2 ') represented by the readily synthesized, wherein ring L ¹ is plurally present, they are preferably identical. More specifically, if the ring L ¹ there are a plurality of ring L ¹ there are a plurality of, preferably at least two are the same, and more preferably all ring L ¹ that there are a plurality are identical.

The number of carbon atoms 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, for example, include exemplified aromatic hydrocarbon rings in terms of aromatic hydrocarbon group described above, preferably, exemplified in the paragraph of the aromatic hydrocarbon group described above 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, further preferably a benzene ring, It is a fluorene ring or a dihydrophenanthrene ring, particularly preferably a benzene ring, and these rings may have a substituent (primary 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. Ring L hetero atoms of an aromatic heterocyclic ring in the ^2, not including the number of heteroatom substituents is usually 1 to 30, preferably 1 to 10, more preferably 1 to 3.
The aromatic heterocyclic ring in ring L ^2, for example, include exemplified aromatic heterocycle section heterocyclic group described above, preferably, exemplified in the section of the heterocyclic group described above, a monocyclic, 2 A cyclic or tricyclic aromatic heterocyclic ring, 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 (primary substituent).
Ring L ^2, since the luminance lifetime of the light emitting device of the present embodiment is more excellent, preferably a benzene ring, a pyridine ring or Jiazabenzen ring, more preferably a benzene ring, these rings substituent (primary A substituent).
Since the metal complex represented by the formula (2) metal complex and (2 ') represented by the readily synthesized, wherein ring L ² is plurally present, they are preferably identical. More specifically, if the ring L ² there are a plurality of the rings L ² there are a plurality of, preferably at least two are the same, and more preferably all ring L ² that there are a plurality are identical.

Since the luminance lifetime of the light emitting device of the present embodiment is more excellent, the ring L ¹ is a pyridine ring, a Jiazabenzen ring, aza naphthalene ring or diaza naphthalene ring, and the ring L ² is a benzene ring, pyridine ring or Jiazabenzen ring is preferably in the ring L ¹ is a pyridine ring, a quinoline ring or an isoquinoline ring, and, more preferably the ring L ² is a benzene ring, these rings have a substituent (primary substituent) You may.

"At least one of the ring L ¹ and the ring L ^2, as an additional substituent, having a group represented by the formula (1-T) (or formula (2-T), a group represented by)" and Is a group represented by the formula (1-T) in at least one of the atoms constituting the ring L ¹ and the ring L ² (preferably a carbon atom or a nitrogen atom, and more preferably a carbon atom). Or a group represented by the formula (2-T)). In the formula (metal complex represented by or formula (2 ')) metal complex represented by (2), wherein ring L ¹ and the ring L ² there are a plurality of ring L ¹ and the ring L ² there are a plurality of It is sufficient that at least one of the rings has a group represented by the formula (1-T) (or a group represented by the formula (2-T)). Is more excellent, all of the plurality of rings L ¹ , all of the plurality of rings L ² , or all of the plurality of rings L ¹ and L ² are a group represented by the formula (1-T): (or formula (group represented by 2-T)) preferably has a, all ring L ¹ there are a plurality of, or all of the ring L ² there are a plurality of is represented by the formula (1-T) It is more preferable to have a group (or a group represented by the formula (2-T)).

In the metal complex represented by the formula (2) (or the metal complex represented by the formula (2 ′)), a group represented by the formula (1-T) included in at least one of the ring L ¹ and the ring L ² ( Or the number of the group represented by the formula (2-T) is usually 1 to 5, and the metal complex represented by the formula (2) and the metal complex represented by the formula (2 ′) are Since it can be easily synthesized, the number is preferably 1 to 3, more preferably 1 or 2, and still more preferably 1.
In the formula (metal complex represented by or formula (2 ')) metal complex represented by (2), if M ² is a rhodium atom or an iridium atom, wherein with the ring L ¹ and the ring L ² (1- The total number of the group represented by T) (or the group represented by the formula (2-T)) is usually 1 to 30, and the light-emitting element of the present embodiment has more excellent luminance lifetime. , Preferably 1 to 18, more preferably 2 to 12, and still more preferably 3 to 6.
In the formula (metal complex represented by or formula (2 ')) metal complex represented by (2), when M ² is palladium atom or platinum atom, the formula with the ring L ¹ and the ring L ² (1- The total number of the group represented by T) (or the group represented by the formula (2-T)) is usually 1 to 20, and the light-emitting element of the present embodiment has more excellent luminance lifetime. , Preferably 1 to 12, more preferably 1 to 8, and still more preferably 2 to 4.

In the metal complex represented by the formula (2) and the metal complex represented by the formula (2 ′), the substituents (primary substituents) that the ring L ¹ and the ring L ² may have are in the present embodiment. Is preferably a group represented by the formula (1-T), and more preferably a group represented by the formula (2-T).
In the substituents (primary substituents) that the ring L ¹ and the ring L ² may have, as a substituent other than the group represented by the formula (1-T), a cyano group, an alkenyl group or a cycloalkenyl group Are preferred, and these groups may further have a substituent (secondary substituent). Examples and preferred ranges of the substituents (secondary substituents) that the substituents other than the group represented by the formula (1-T) may further have include the substituents that R ^1T described below may have. It is the same as the example of the group (secondary substituent) and the preferred range.

[Group represented by formula (1-T) and group represented by formula (2-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 preferably a phenyl group, a naphthyl group or a fluorenyl group, more preferably a phenyl group, and these groups may have a substituent (secondary substituent).
As the monovalent heterocyclic group for R ^1T , preferably, one hydrogen atom directly bonded to a carbon atom or a hetero atom constituting a ring from a monocyclic, bicyclic or tricyclic heterocyclic compound is used. It is a group excluded, more preferably a pyridine ring, a diazabenzene ring, a triazine ring, an azanaphthalene ring, a diazanaphthalene ring, a carbazole ring, a dibenzofuran ring or a dibenzothiophene ring, which is directly bonded to a carbon atom or a heteroatom constituting the ring. And more preferably a group obtained by removing one hydrogen atom directly bonded to a carbon atom constituting a ring from a pyridine ring, a diazabenzene ring or a triazine ring, and these groups are It may have a substituent (secondary substituent).
In the substituted amino group for R ^1T, the substituent of the amino group is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups further have a substituent (secondary substituent). You may have. 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 for R ^1T . Examples and preferred ranges of the monovalent heterocyclic group which is a substituent of the amino group are the same as the examples and preferred ranges of the monovalent heterocyclic group for R ^1T .

R ^1T may be 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, and an alkyl group, a cycloalkyl group, an alkoxy group, It may be a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, but is preferably an alkyl group, a cycloalkyl A group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a substituent (secondary substituent).
That is, since the luminance life of the light emitting device of this embodiment is more excellent, the group represented by the formula (1-T) is a group represented by the formula (2-T) (that is, R ^1T is R ^2T ) is preferable. Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in R ^2T are the same as the examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in R ^1T , respectively. .
R ^1T and R ^2T are preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and more preferably R ^1T and R ^2T , because the light-emitting element of this embodiment has a further excellent luminance lifetime. , An alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent (secondary substituent).

The substituent (secondary 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, or a substituted amino group. Or a fluorine atom, more 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, and still more preferably an alkyl group or a cycloalkyl group , An aryl group, a monovalent heterocyclic group or a substituted amino group, particularly preferably an alkyl group, a cycloalkyl group or an aryl group. These groups further have a substituent (tertiary substituent). Is also good.
The substituent (secondary substituent) that R ^2T may have is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group. And 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, a cycloalkyl group or an aryl group, and these groups are Further, it may have a substituent (tertiary substituent).
Aryl group for R ^1T and R ^2T may even have substituent (secondary substituent), a monovalent examples and preferred ranges of the heterocyclic group and the substituted amino group, respectively, the aryl group in R ^1T, 1 The examples and the preferred range of the valent heterocyclic group and the substituted amino group are the same.

As the substituents (tertiary substituents) that the substituents (secondary substituents) R ^1T may optionally have, preferably alkyl groups, cycloalkyl groups, alkoxy groups, and cycloalkoxy groups Group, aryl group, monovalent heterocyclic group, substituted amino group or fluorine atom, more preferably alkyl group, cycloalkyl group, alkoxy group, cycloalkoxy group, aryl group, monovalent heterocyclic group or substituted An amino group, more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and particularly preferably an alkyl group or a cycloalkyl group; It may have a substituent (quaternary substituent), but preferably does not further have a substituent (quaternary substituent).
As the substituents (tertiary substituents) which the substituents (secondary substituents) R ^2T may have, preferably, alkyl groups, cycloalkyl groups, alkoxy groups, and cycloalkoxy groups Group, an aryl group, a monovalent heterocyclic group or a substituted amino group, 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 A cycloalkyl group or an aryl group, and these groups may further have a substituent (quaternary substituent), but preferably have no further substituent (quaternary substituent).
The aryl group, the monovalent heterocyclic group and the substituted amino group in the substituent (tertiary substituent) which the substituent (secondary substituent) which R ^1T and R ^2T may have may further have Examples and preferred ranges are the same as the examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in R ^1T , respectively.
The quaternary substituent 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, more 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 a cycloalkyl group, and these groups preferably have no further substituent.

[Anionic bidentate ligand]
Examples of the anionic bidentate ligand represented by A ³ -G ² -A ⁴ include a ligand represented by the following formula. ^However, bidentate anionic represented by A 3 ^-G 2 -A ⁴ is different from the ligands defined that number by subscript ^{n 3.}

［式中、＊は、Ｍ^２と結合する部位を表す。］

Wherein * represents a site that binds to ^{M 2.} ]

  Examples of the metal complex represented by the formula (2) include a metal complex represented by the following formula and metal complexes R2 to R7 described below. Examples of the metal complex represented by the formula (2 ′) include a metal complex represented by the following formula and metal complexes R2 to R6 described below.

<Metal complex represented by formula (1)>
The metal complex represented by the formula (1) is preferably a metal complex represented by the formula (1 ′) because the light-emitting element of this embodiment has a better luminance lifetime.
The metal complex represented by the formula (1) and the metal complex represented by the formula (1 ′) are usually metal complexes that exhibit phosphorescence at room temperature, and preferably emit light from a triplet excited state at room temperature. It is a metal complex which shows these.

M ¹ is preferably an iridium atom or a platinum atom, and more preferably an iridium atom, because the light-emitting element of this embodiment has a better luminance lifetime.
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 ¹ and E ² are preferably carbon atoms.
Since the metal complex represented by the formula (1) and the metal complex represented by the formula (1 ′) can be easily synthesized, E ¹ and E ² are preferably the same. Further, since the metal complex represented by the formula (1) and the metal complex represented by the formula (1 ′) can be easily synthesized, when a plurality of E ¹ are present, they are preferably the same. Since it easily synthesized metal complex represented by formula (1) metal complex and (1 ') represented by, if E ² is plurally present, they are preferably identical.

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

Since the luminance lifetime 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 preferably More preferably, the ring is a diazole ring or a triazole ring, and the ring R ² is a benzene ring, the ring R ¹ is a diazole ring, and the ring R ² is a benzene ring. May have a substituent (primary substituent).

Examples of the substituents (primary substituents) that the ring R ¹ and the ring R ² may have (primary substituents) include the preferred ranges of the substituents (primary substituents) that the ring L ¹ and the ring L ² may have. Same as the examples and preferred ranges.
More specifically, since the luminance lifetime of the light-emitting element of this embodiment is more excellent, the substituent (primary substituent) that the ring R ¹ and the ring R ² may have is preferably a group represented by the formula (1-S) And more preferably a group represented by the formula (2-S).

[Group represented by formula (1-S) and group represented by formula (2-S)]
The examples and preferred ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in R ^1S and R ^2S are the examples and the preferred ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in R ^1T , respectively. Is the same.
Examples and preferred ranges of R ^1S are the same as those of R ^1T . The examples and preferred ranges of the secondary, tertiary and quaternary substituents for R ^1S are the same as the examples and preferred ranges of the secondary, tertiary and quaternary substituents for R ^1T . .
Examples and preferred ranges of R ^2S are the same as those of R ^2T . The examples and preferred ranges of the secondary, tertiary and quaternary substituents in R ^2S are the same as the examples and preferred ranges of the secondary, tertiary and quaternary substituents in R ^2T . .

At least one of the ring R ¹ and the ring R ² preferably has a substituent (primary substituent), and has a group represented by the formula (1-S) as the substituent (primary substituent). Is preferable, and more preferably has a group represented by the formula (2-S) as a substituent (primary substituent).
Note that in the metal complex represented by formula (1) metal complex and (1 ') represented by wherein ring R ¹ and ring R ² there are a plurality of rings R ¹ and ring R ² there are a plurality of It is sufficient that at least one of the rings has a substituent (primary substituent). However, since the luminance life of the light emitting device of the present embodiment is more excellent, all of a plurality of rings R ¹ and a plurality of rings R ¹ are present. It is preferable that all of R ² or all of the plurality of rings R ¹ and all of the rings R ² have a substituent (primary substituent), and all of the plurality of rings R ¹ or the plurality of rings R are present. More preferably, all ² have a substituent (primary substituent), and even more preferably, all of the plurality of rings R ¹ have a substituent (primary substituent).

In the metal complex represented by the formula (1) and the metal complex represented by the formula (1 ′), the number of substituents (primary substituents) of at least one of the rings R ¹ and R ² is usually 1 The number is preferably 1 to 3, more preferably 1 to 3, and more preferably 1 to 3, because the metal complex represented by the formula (1) and the metal complex represented by the formula (1 ′) can be easily synthesized. Or two, and more preferably one.
In the metal complex represented by the formula (1) and the metal complex represented by the formula (1 ′), when M ¹ is a rhodium atom or an iridium atom, the substituents (primary substituents) on the rings R ¹ and R ² have ) Is usually 1 to 30 and preferably 1 to 18, more preferably 2 to 12, since the light emitting device of the present embodiment has more excellent luminance lifetime. Yes, and more preferably 3 to 6.
In the metal complex represented by the formula (1) and the metal complex represented by the formula (1 ′), when M ¹ is a palladium atom or a platinum atom, the total number of substituents on the ring R ¹ and the ring R ² Is usually 1 to 20, and since the luminance life of the light emitting device of the present embodiment is more excellent, it is preferably 1 to 12, more preferably 1 to 8, and still more preferably Two to four.

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

Examples of the metal complex represented by the formula (1) include a metal complex represented by the following formula and metal complexes B1 to B8 described below. Examples of the metal complex represented by the formula (1 ′) include a metal complex represented by the following formula and metal complexes B1, B2, B4, and B6 described below. In the formulas, ^{Z A} represents a group represented by the group or -N represented by -CH = =. When a plurality of Z ^A are present, they may be the same or different.

  <Compound represented by Formula (H-1)>

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

The aryl group in Ar ^H1 and Ar ^H2 and the arylene group in L ^H1 are preferably a hydrogen atom directly bonded to a carbon atom constituting a ring from a monocyclic or 2 to 6 cyclic aromatic hydrocarbon. Or two (however, in the case of an aryl group, one hydrogen atom, and in the case of an arylene group, two hydrogen atoms, the same applies hereinafter). A group obtained by removing one or two hydrogen atoms directly bonded to a carbon atom constituting a ring from a cyclic or 2- to 4-cyclic aromatic hydrocarbon, more preferably benzene, naphthalene, fluorene, phenanthrene or A group in which one or two hydrogen atoms directly bonded to carbon atoms constituting a ring are removed from triphenylene, and these groups may have a substituent.
The monovalent heterocyclic group in Ar ^H1 and Ar ^H2 and the divalent heterocyclic group in L ^H1 are preferably a monocyclic or 2- to 6-cyclic heterocyclic compound constituting a ring. One or two hydrogen atoms directly bonded to an atom or a hetero atom (however, in the case of a monovalent heterocyclic group, one hydrogen atom, and in the case of a divalent heterocyclic group, two hydrogen atoms, The same applies to the following.), And more preferably, directly from a monocyclic, bicyclic, tricyclic or pentacyclic heterocyclic compound to a carbon atom or a hetero atom constituting a ring. A group excluding one or two hydrogen atoms to be bonded, more preferably pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine, A group obtained by removing one or two hydrogen atoms directly bonded to 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 obtained by removing one or two hydrogen atoms directly bonded to a carbon atom or a hetero atom constituting a ring, and these groups have a substituent. Is also good.
In the substituted amino group in Ar ^H1 and Ar ^H2, the substituent of the amino group is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups further have a substituent. Is also good. Examples and preferred ranges of the aryl group which is a substituent of the amino group are the same as the examples and preferred ranges of the aryl group in Ar ^H1 and Ar ^H2 . Examples and preferred ranges of the monovalent heterocyclic group which is a substituent of the amino group are the same as the examples and preferred ranges of the monovalent heterocyclic group in Ar ^H1 and Ar ^H2 .

At least one of Ar ^H1 and Ar ^H2 is preferably an aryl group or a monovalent heterocyclic group, and more preferably a monovalent heterocyclic group, since the light-emitting element of this embodiment has a higher luminance lifetime. More preferably, it is still more preferably a carbazolyl group, a dibenzothienyl group or a dibenzofuryl group, particularly preferably a carbazolyl group, and these groups may have a substituent.
Ar ^H1 and Ar ^H2 are preferably an aryl group or a monovalent heterocyclic group, and more preferably benzene, fluorene, pyridine, diazabenzene, triazine, or the like. A group obtained by removing one hydrogen atom directly bonded to a carbon atom or a hetero atom constituting a ring from carbazole, dibenzofuran or dibenzothiophene, more preferably a phenyl group, a fluorenyl group, a dibenzothienyl group, a dibenzofuryl group or a carbazolyl group And particularly preferably a carbazolyl group, and these groups may have a substituent.

At least one of L ^H1 is preferably an arylene group or a divalent heterocyclic group, more preferably a divalent heterocyclic group, since the light emitting element of the present embodiment has a higher luminance lifetime. More preferably, it is a group obtained by removing two hydrogen atoms directly bonded to a ring-forming carbon atom or a hetero atom (preferably a carbon atom) from carbazole, dibenzofuran or dibenzothiophene, and these groups further have a substituent. You may have.

L ^H1 is preferably an arylene group or a divalent heterocyclic group, and more preferably benzene, naphthalene, fluorene, pyridine, diazabenzene, triazine, or aza. A group obtained by removing two hydrogen atoms directly bonded to a ring-forming carbon atom or a hetero atom (preferably a carbon atom) from naphthalene, diazanaphthalene, carbazole, dibenzofuran, or dibenzothiophene; more preferably, benzene or fluorene; , Pyridine, diazabenzene, triazine, carbazole, dibenzofuran or dibenzothiophene, a group obtained by removing two hydrogen atoms directly bonded to a carbon atom or a hetero atom (preferably a carbon atom) constituting a ring, particularly preferably dibenzofuran or Dibenzothiophene From which two hydrogen atoms directly bonded to the carbon atoms constituting the ring are excluded, and these groups may have a substituent.

As the substituent which Ar ^H1 , Ar ^H2 and L ^H1 may have, 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 an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and still more preferably an alkyl group or a cycloalkyl group , An aryl group, a monovalent heterocyclic group or a substituted amino group, particularly preferably an alkyl group, an aryl group or a monovalent heterocyclic group, and these groups may further have a substituent. .
Examples and preferred ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in the substituent which Ar ^H1 , Ar ^H2 and L ^H1 may have are the aryl group and the aryl group in Ar ^H1 and Ar ^H2 , respectively. The examples and the preferred range of the valent heterocyclic group and the substituted amino group are the same.

As the substituent which Ar ^H1 , Ar ^H2 and L ^H1 may further have, the alkyl group, cycloalkyl group, aryl group, monovalent heterocyclic group or It is a substituted amino group, 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, the monovalent heterocyclic group and the substituted amino group in the substituent which the substituents which Ar ^H1 , Ar ^H2 and L ^H1 optionally have may further have are respectively The same as the examples and preferred ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in Ar ^H1 and Ar ^H2 .

n ^H1 is 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.

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

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

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

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

で表される基を含むことを意味する。

It is meant to include a group represented by

In 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- (hereinafter also referred to as "heterocyclic group of Ar ^T1 "), 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 1 or 2. . Further, 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, and 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 is} a heterocyclic ring containing a nitrogen atom having no double bond in the ring and not containing a group represented by = N- in the ring (hereinafter referred to as "donor heterocyclic ring"). ) And one or more (preferably 5 or less, more preferably 3 or less, and still more preferably 1) heterocyclic ring (s) containing a group represented by = N- in the ring. A group obtained by removing one hydrogen atom directly bonded to a carbon atom or a 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) And 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, in the heterocyclic compounds exemplified in the above-mentioned heterocyclic group, a nitrogen atom having no double bond in the ring, and ＝ N- in the ring. And a heterocyclic ring containing no group represented by the following, and among them, a monocyclic or 2- to 5-cyclic heterocyclic ring is preferable, and a monocyclic, bicyclic or tricyclic is more preferable. And more preferably a monocyclic or bicyclic heterocyclic ring, and these rings may have a substituent.
The donor-type heterocyclic ring is more excellent in the luminance lifetime of the light-emitting element of the present embodiment. Or a phenothiazine ring, more preferably a pyrrole ring, an indole ring or a carbazole ring, even more preferably a pyrrole ring or an indole ring, and these rings may have a substituent.
Examples and preferred ranges of the substituents that the donor-type heterocyclic ring may have are the same as those of the substituents 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 a 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, and It is preferably 1 to 3, and more preferably 1 or 2.
Examples of the heterocycle containing a group represented by = N- in the ring include, for example, a group represented by = N- in the ring in the heterocyclic compounds exemplified in the above-mentioned section of the heterocyclic group. And among them, preferably a monocyclic, bicyclic or tricyclic heterocyclic ring, more preferably a monocyclic heterocyclic ring, and these rings have a substituent. You may have.
The heterocyclic ring containing a group represented by = N- in the ring is more preferable because the light-emitting element of the present embodiment has a better luminance lifetime, and is therefore preferably a diazole ring, a triazole ring, a tetrazole ring, a pyridine ring, a diazabenzene ring, or a triazine. Ring, azanaphthalene ring, diazanaphthalene ring, azacarbazole ring, diazacarbazole ring, azaanthracene ring, diazaanthracene ring, azaphenanthrene ring or diazaphenanthrene ring, more preferably pyridine ring, diazabenzene ring, It is an azanaphthalene ring, a diazanaphthalene ring, an azacarbazole ring or a diazacarbazole ring, more preferably a pyridine ring or a diazabenzene ring, and these rings may have a substituent.
Examples and preferred ranges of the substituent which the heterocyclic ring containing the group represented by = N- in the ring may have are, for example, the examples of the substituent which Ar ^H1 , Ar ^H2 and L ^H1 may have. And the same as the preferred range.

Examples of the heterocyclic group of Ar ^T1 include azaindole, diazaindole, azacarbazole, diazacarbazole, or a donor-type heterocycle in these rings and / or a group represented by = N- in the ring. A heterocyclic compound containing one or more (preferably 5 or less, more preferably 3 or less, and still more preferably 1) heterocyclic ring (s) is directly bonded to a carbon atom or a hetero atom constituting the ring. And a group in which one hydrogen atom directly bonded to a carbon atom or a hetero atom constituting a ring is removed from azacarbazole or diazacarbazole, and these groups are preferred. The group may have a substituent.
The examples and preferred ranges of the substituents that the heterocyclic group of Ar ^T1 may have are the same as the examples and preferred ranges of the substituents that Ar ^H1 , Ar ^H2, and L ^H1 may have.
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), since the light-emitting element of this embodiment has a better luminance lifetime.

[Group represented by formula (T1-1)]
X ^T1 is preferably a single bond, an oxygen atom, a sulfur atom or a group represented by —C (R ^{XT1 ′} ) ₂ —, more preferably a single bond, an oxygen atom or a sulfur atom, and further preferably a single bond. It is a union.

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, further preferably an aryl group. And 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. And these groups may have a substituent.
It is preferable that a plurality of R ^{XT1 ′} are bonded to each other and do not form a ring together with the carbon atom to which each is bonded.

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

The number of carbon atoms of the aromatic hydrocarbon ring in the ring R ^T1 and the ring R ^T2 is usually 6 to 60, preferably 6 to 30, more preferably 6 to 30, excluding the number of carbon atoms of the substituent. Eighteen.
Examples of the aromatic hydrocarbon ring in the ring R ^T1 and the ring R ^T2 include the aromatic hydrocarbon rings exemplified in the above-described section of the aromatic hydrocarbon group. Since it is excellent, it is preferably a monocyclic, bicyclic or tricyclic aromatic hydrocarbon ring exemplified in the above-mentioned section of the aromatic hydrocarbon group, and more preferably a monocyclic aromatic hydrocarbon ring. These are hydrogen rings, and these groups may have a substituent.
The aromatic hydrocarbon ring in the ring R ^T1 and the ring R ^T2 is preferably a benzene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring or a dihydrophenanthrene ring because the light-emitting element of this embodiment has a further excellent luminance lifetime. And more preferably a benzene ring, a fluorene ring or a dihydrophenanthrene ring, and still more preferably a benzene ring, and these rings may have a substituent.
The carbon number of the heterocyclic ring in the ring R ^T1 and the ring R ^T2 is usually 1 to 60, preferably 2 to 30, more preferably 3 to 15, excluding the carbon number of the substituent. . The number of hetero atoms in the hetero ring of the ring R ^T1 and the ring R ^T2 is usually 1 to 30, preferably 1 to 10, more preferably 1 to 3, excluding the number of hetero atoms of the substituent. is there.
As the heterocycle in the ring R ^T1 and the ring R ^T2 , for example, the heterocycle exemplified in the above-mentioned section of the heterocyclic group can be cited, and the light-emitting element of the present embodiment has a higher luminance lifetime. As exemplified in the section of the heterocyclic group, a monocyclic, bicyclic or tricyclic heterocycle (preferably a donor-type heterocycle or a heterocycle 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 ＝ N- A heterocyclic ring containing a group represented by-, more preferably a heterocyclic ring containing a group represented by = N- in the ring), and these rings have a substituent. Is also good.
As the hetero ring in the ring R ^T1 and the ring R ^T2 , the light-emitting element of the present embodiment is more excellent in luminance lifetime, and therefore, preferably a carbazole ring, a 9,10-dihydroacridine ring, a 5,10-dihydrophenazine ring, or a phenoxy ring. Sazine ring, phenothiazine ring, pyridine ring, diazabenzene ring, azanaphthalene ring, diazanaphthalene ring, azacarbazole ring, diazacarbazole ring, dibenzofuran ring or dibenzothiophene ring, more preferably pyridine ring, diazabenzene ring, aza It is a naphthalene ring, a diazanaphthalene ring, an azacarbazole ring or a diazacarbazole ring, more preferably a pyridine ring or a diazabenzene ring, and these rings may have a substituent.

The ring R ^T1 is preferably an aromatic hydrocarbon ring or a heterocyclic ring containing a group represented by = N- in the ring, because the light-emitting element of the present embodiment is more excellent in luminance lifetime. A monocyclic aromatic hydrocarbon ring or a monocyclic heterocyclic ring containing a group represented by = N- in the ring, more preferably a benzene ring, a pyridine ring or a diazabenzene ring, particularly preferably These are benzene rings, and these rings may have a substituent.
The ring ^RT2 is preferably a heterocyclic ring containing a group represented by = N- in the ring, and more preferably = N- And more preferably a pyridine ring or a diazabenzene ring, particularly preferably a pyridine ring, and these rings may have a substituent.
Since the light emitting device of the present embodiment has a further excellent luminance lifetime, 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 It is preferably a heterocyclic ring containing a group represented by = N- in the ring, and the ring ^RT1 is a monocyclic aromatic hydrocarbon ring or a single ring containing a group represented by = N- in the ring. More preferably, the ring is a heterocyclic ring, and the ring R ^T2 is a monocyclic hetero ring containing a group represented by = N- in the ring, and the ring R ^T1 is a benzene ring or a pyridine ring. More preferably, the ring R ^T2 is a pyridine ring or a diazabenzene ring, and the ring R ^T1 is a benzene ring, and the ring R ^T2 is a pyridine ring. And these rings may have a substituent.

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

Examples of the arylene group and the preferable range of L ^T1 is the same as the example 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.

^LT1 is preferably an arylene group or a divalent heterocyclic group, more preferably a ring formed 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 a hetero atom, and more preferably a carbon atom forming a ring from benzene, fluorene, pyridine, diazabenzene, triazine, carbazole, dibenzofuran or dibenzothiophene. Or a group obtained by removing two hydrogen atoms directly bonded to a hetero atom, particularly preferably a group obtained by removing two hydrogen atoms directly bonded to a carbon atom constituting a ring 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 ^LT1s are present, they are preferably the same.

L Examples and preferred ranges of ^T1 substituent which may be possessed are the same as Ar ^H1, examples of Ar ^H2 and the substituent which may be L ^H1 is had and preferred ranges.

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

The aromatic hydrocarbon group in 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 to 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 still more preferably benzene, naphthalene , Fluorene, phenanthrene, or anthracene except for 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 to 6 cyclic heterocyclic compound. And more 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, bicyclic or tricyclic heterocyclic compound, and still more preferably , Pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine, azaanthracene, diazaanthracene, azaphenanthrene or diazaphenanthrene to a carbon atom or a heteroatom constituting a ring. A group in which one or more hydrogen atoms directly bonded are removed, particularly preferably pyridine, One or more hydrogen atoms directly bonded to a carbon atom or a hetero atom constituting a ring from diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, azaanthracene, diazaanthracene, azaphenanthrene or diazaphenanthrene. And these groups may have a substituent.
Since Ar ^T2 has a better luminance lifetime of the light emitting device of the present embodiment, preferably, it is directly bonded to a carbon atom or a hetero atom constituting a ring from benzene, fluorene, pyridine, diazabenzene, triazine, carbazole, dibenzofuran or dibenzothiophene. And more preferably a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms constituting a ring from benzene, dibenzofuran or dibenzothiophene, and these groups are It may have a substituent.
Examples and preferred ranges of the substituents that Ar ^T2 may have are the same as those of the substituents that Ar ^H1 , Ar ^H2, and L ^H1 may have.

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

<Light emitting element>
The light-emitting element of this embodiment includes a light-emitting element including an anode, a cathode, a first layer provided between the anode and the cathode, and a second layer provided between the cathode and the first layer. An element, wherein the first layer is represented by a metal complex represented by the formula (1) and a formula (2) in which a maximum peak wavelength of an emission spectrum is 550 nm or more and less than 750 nm (preferably 570 nm or more and less than 750 nm). A metal complex, wherein at least one of the first layer and the second layer contains a compound represented by the formula (T-1).
The light-emitting element of the present embodiment is more excellent in the luminance life of the light-emitting element of the present embodiment, so that an anode, a cathode, a first layer provided between the anode and the cathode, Wherein the first layer has a metal complex represented by the formula (1) and a maximum peak wavelength of an emission spectrum of 550 nm or more and less than 750 nm (preferably 570 nm or more and less than 750 nm) and a metal complex represented by the formula (2 ′), wherein the second layer contains a compound represented by the formula (T-1). Preferably, there is.
The light-emitting element of the present embodiment is more excellent in the luminance life of the light-emitting element of the present embodiment, so that an anode, a cathode, a first layer provided between the anode and the cathode, Wherein the first layer has a metal complex represented by the formula (1 ′) and a maximum peak wavelength of an emission spectrum of 550 nm or more and less than 750 nm (preferably Is a layer containing a metal complex represented by the formula (2), which is 570 nm or more and less than 750 nm), and wherein the second layer contains a compound represented by the formula (T-1). Preferably, there is.
The light-emitting element of the present embodiment has a further excellent luminance lifetime of the light-emitting element of the present embodiment. Therefore, the anode, the cathode, the first layer provided between the anode and the cathode, and the cathode and the first layer Wherein the first layer has a metal complex represented by the formula (1 ′) and a maximum peak wavelength of an emission spectrum of 550 nm or more and less than 750 nm (preferably Is a layer containing a metal complex represented by the formula (2 ′), which is 570 nm or more and less than 750 nm), and the second layer contains a compound represented by the formula (T-1). It is preferable that

(First layer)
The first layer is a layer containing the metal complex represented by the formula (1) and the metal complex represented by the formula (2). Preferably, a layer containing the metal complex represented by the formula (1) and the metal complex represented by the formula (2 '), the metal complex represented by the formula (1') and the layer represented by the formula (2) Or a layer containing a metal complex represented by the formula (1 ′) and a metal complex represented by the formula (2 ′), and more preferably a layer containing the metal complex represented by the formula (1 ′). ) And a metal complex represented by the formula (2 ′).
The first layer may contain one kind of the metal complex represented by the formula (1) alone, or may contain two or more kinds. The first layer may contain one kind of the metal complex represented by the formula (1 ′) alone, or may contain two or more kinds. The first layer may contain one kind of the metal complex represented by the formula (2) alone, or may contain two or more kinds. The first layer may contain one kind of the metal complex represented by the formula (2 ′) alone, or may contain two or more kinds.
In the first layer, a metal complex represented by the formula (1) (or a metal complex represented by the formula (1 ′)) and a metal complex represented by the formula (2) (or a metal complex represented by the formula (2 ′)) Metal complex) may be in the range where the function as the first layer is achieved. For example, a metal complex represented by the formula (1) (or a metal complex represented by the formula (1 ′)) and a metal complex represented by the formula (2) (or a metal complex represented by the formula (2 ′)) ) May be 0.01% by mass or more and 100% by mass or less, 0.1% by mass or more and 99% by mass or less, and may be 1% by mass or less based on the total amount of the first layer. % To 70% by mass, more preferably 5% by mass to 50% by mass, even more preferably 10% by mass to 35% by mass.

In the light emitting device of the present embodiment, the content of the metal complex represented by the formula (1) (or the metal complex represented by the formula (1 ′)) and the content of the metal complex represented by the formula (2) By adjusting the ratio to the content of the (metal complex represented by (2 ′)), the emission color of the light-emitting element can be adjusted, and the emission color can be adjusted to white. The emission color of the light-emitting element can be confirmed by measuring the emission chromaticity of the light-emitting element to obtain chromaticity coordinates (CIE chromaticity coordinates). In the white emission color, it is preferable that X of chromaticity coordinates is in the range of 0.25 to 0.55, and Y of chromaticity coordinates is in the range of 0.25 to 0.55.
The CIE chromaticity coordinates (x, y) are based on the XYZ color system, which is an international display method established 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 device of the present embodiment (particularly, the viewpoint of adjusting the emission color to white, and the same applies hereinafter), the metal complex represented by the formula (1) and the formula (1) The maximum peak wavelength of the emission spectrum of the metal complex represented by ') is usually 380 nm or more and less than 495 nm, preferably 400 nm or more and less than 495 nm, more preferably 420 nm or more and less than 495 nm, and further preferably 440 nm or more and 495 nm. And particularly preferably 450 nm or more and less than 495 nm. The maximum peak wavelength of the emission spectrum of the metal complex represented by the formula (1) and the metal complex represented by the formula (1 ′) is usually 380 nm or more and less than 495 nm, and may be 400 nm or more and 490 nm or less. , 420 nm to 485 nm, or 450 nm to 480 nm.

  The maximum peak wavelength of the emission spectrum of the metal complex represented by the formula (2) and the metal complex represented by the formula (2 ′) is preferably 570 nm or more from the viewpoint of adjusting the emission color of the light emitting device of the present embodiment. It is less than 750 nm, more preferably 570 nm or more and 680 nm or less, and further preferably 575 nm or more and 640 nm or less. The maximum peak wavelength of the emission spectrum of the metal complex represented by the formula (2) and the metal complex represented by the formula (2 ′) may be 550 nm to 680 nm, or 550 nm to 640 nm. Is also good.

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

  From the viewpoint of adjusting the emission color of the light emitting device of the present embodiment, the content of the metal complex represented by the formula (2) (or the metal complex represented by the formula (2 ′)) is expressed by the formula (1). When the content of the metal complex (or the metal complex represented by the formula (1 ′)) is 100 parts by mass, the content is preferably 0.01 to 50 parts by mass, and more preferably 0.02 to 50 parts by mass. It is from 30 parts by mass to 30 parts by mass, more preferably from 0.05 part by mass to 10 parts by mass, particularly preferably from 0.1 part by mass to 5 parts by mass.

  As the metal complex represented by the formula (2) (or the metal complex represented by the formula (2 ′)), the light-emitting element of this embodiment can be manufactured by a wet method. Those that show solubility in a solvent capable of dissolving the complex (or the metal complex represented by the formula (1 ′)) are preferred.

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

[Host material]
Since the light-emitting element of this embodiment has a higher luminance lifetime, the first layer further includes 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. It is preferred to include. The first layer may contain one kind of the host material alone, or may contain two or more kinds of the host material.

When the first layer further contains a host material, the content of the host material is determined by using a metal complex represented by the formula (1) (or a metal complex represented by the formula (1 ′)) or a metal complex represented by the formula (2 ′). When the total content of the metal complex represented (or the metal complex represented by the formula (2 ′)) and the host material is 100 parts by mass, it is usually 1 part by mass or more and 99 parts by mass or less. It is preferably from 10 parts by mass to 95 parts by mass, more preferably from 30 parts by mass to 90 parts by mass, even more preferably from 50 parts by mass to 85 parts by mass.
When the first layer further contains a host material, the lowest excited triplet state (T ₁ ) of the host material is represented by the formula (1) because the light emitting device of this embodiment has a better luminance lifetime. An energy level higher than the lowest excited triplet state (T ₁ ) of the metal complex (or the metal complex represented by the formula (1 ′)) and / or the metal complex represented by the formula (2) (or the formula (2)) The energy level is preferably higher than the lowest excited triplet state (T ₁ ) of the metal complex represented by (2 ′), and the metal complex represented by formula (1) (or formula (1 ′)) It is more preferable that the energy level is higher than the lowest excited triplet state (T ₁ ) of the metal complex represented by In the case where the first layer further contains a host material, the light-emitting element of this embodiment has a more excellent luminance lifetime. Therefore, the lowest excited triplet state (T ₁ ) of the host material is expressed by the following equation (1). Has a higher energy level than the lowest excited triplet state (T ₁ ) of the metal complex represented by the formula (1 ′), and the metal complex represented by the formula (1): Or the lowest excited triplet state (T ₁ ) of the metal complex represented by the formula (1 ′) is a metal complex represented by the formula (2) (or a metal complex represented by the formula (2 ′)) Preferably, the energy level is higher than the lowest excited triplet state (T ₁ ) of the compound.
When the first layer further includes a host material, the light-emitting element of this embodiment can be manufactured by a wet method as the host material; therefore, the metal complex represented by the formula (1) (or the formula (1 ′)) Those which show solubility in a solvent capable of dissolving the metal complex represented by the formula (2) and the metal complex represented by the formula (2) (or the metal complex represented by the formula (2 ′)) are preferable.

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

[First composition]
The first layer includes a metal complex represented by the formula (1) (or a metal complex represented by the formula (1 ′)) and a metal complex represented by the formula (2) (or a metal complex represented by the formula (2 ′)). A composition comprising the above-described host material, hole transport material, hole injection material, electron transport material, electron injection material, light emitting material, and antioxidant. It may be a layer containing a substance (hereinafter, also referred to as a “first composition”). Note that in the first composition, the light-emitting material includes a metal complex represented by the formula (1) (or a metal complex represented by the formula (1 ′)) and a metal complex represented by the formula (2) (or (A metal complex represented by the formula (2 ′)).

[Hole transport material]
Hole transport materials are classified into low molecular weight compounds and high molecular weight compounds, and are preferably high molecular weight compounds. The hole transporting material may have a crosslinkable group.
Examples of low molecular compounds include triphenylamine and derivatives thereof, N, N′-di-1-naphthyl-N, N′-diphenylbenzidine (α-NPD), and N, N′-diphenyl-N, Aromatic amine compounds such as N′-di (m-tolyl) benzidine (TPD) are exemplified.
Examples of the polymer compound include polyvinyl carbazole and derivatives thereof; polyarylene having an aromatic amine structure in a side chain or a main chain and derivatives thereof. The polymer compound may be a compound having an electron-accepting site bound thereto. Examples of the electron accepting site include fullerene, tetrafluorotetracyanoquinodimethane, tetracyanoethylene, trinitrofluorenone, and the like, and preferably fullerene.
In the first composition, the content of the hole transporting material is determined by the metal complex represented by the formula (1) (or the metal complex represented by the formula (1 ′)) and the metal represented by the formula (2). When the total content of the complex (or the metal complex represented by the formula (2 ′)) is 100 parts by mass, it is usually 1 part by mass or more and 10,000 parts by mass or less.
The hole transport materials may be used alone or in combination of two or more.

[Electron transport materials]
Electron transport materials are classified into low molecular weight compounds and high molecular weight compounds. The electron transporting material may have a crosslinkable group.
Examples of the low molecular compound include a metal complex having 8-hydroxyquinoline as a ligand, oxadiazole, anthraquinodimethane, benzoquinone, naphthoquinone, anthraquinone, tetracyanoanthraquinodimethane, fluorenone, diphenyldicyanoethylene, and diphenoquinone. And their derivatives.
Examples of the polymer compound include polyphenylene, polyfluorene, and derivatives thereof. The polymer compound may be doped with a metal.
In the first composition, the content of the electron transporting material is determined by the metal complex represented by the formula (1) (or the metal complex represented by the formula (1 ′)) and the metal complex represented by the formula (2) When the total content of (or the metal complex represented by the formula (2 ′)) is 100 parts by mass, it is usually from 1 part by mass to 10,000 parts by mass.
The electron transport material may be used alone or in combination of two or more.

[Hole injection material and electron injection material]
The hole injection material and the electron injection material are classified into a low molecular compound and a high molecular compound, respectively. The hole injection material and the electron injection material may have a crosslinkable group.
Examples of the low molecular 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 high molecular 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. Functional polymers.
In the first composition, the content of the hole injecting material and the content of the electron injecting material are respectively the metal complex represented by the formula (1) (or the metal complex represented by the formula (1 ′)) and the formula (2). When the total content of the metal complex represented by the formula (2) is 100 parts by mass, it is usually from 1 part by mass to 10,000 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 contains a conductive polymer, the 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 make the electric conductivity of the conductive polymer fall within the above 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 a polystyrene sulfonate ion, an alkylbenzene sulfonate ion, and a camphor sulfonate ion. Examples of the cation include a lithium ion, a sodium ion, a potassium ion, and a tetrabutylammonium ion.
The ions to be doped may be used alone or in combination of two or more.

[Light-emitting material]
Light emitting materials are classified into low molecular weight compounds and high molecular weight compounds. The light emitting material may have a crosslinkable group.
Examples of the low molecular weight compound include naphthalene and its derivatives, anthracene and its derivatives, perylene and its derivatives, and a triplet light-emitting complex having iridium, platinum, or europium as a central metal.
Examples of the triplet light emitting complex include the following metal complexes and metal complexes G2 and G3 described below.

Examples of the high molecular compound include arylene groups such as a phenylene group, a naphthalenediyl group, a fluorenediyl group, a phenanthylene diyl group, a dihydrophenanthylene diyl group, an anthracene diyl group, and a pyrylene diyl group; and two hydrogen atoms from an aromatic amine. A high molecular compound containing a divalent heterocyclic group such as an aromatic amine residue such as a removed group; and a carbazolediyl group, a phenoxazinediyl group, and a phenothiazinediyl group.
In the first composition, the content of the light-emitting material depends on the metal complex represented by the formula (1) (or the metal complex represented by the formula (1 ′)) and the metal complex represented by the formula (2) ( Or, when the total content of the metal complex represented by the formula (2 ′)) is 100 parts by mass, it is usually 1 part by mass or more and 10,000 parts by mass or less.
The luminescent materials may be used alone or in combination of two or more.

[Antioxidant]
The antioxidant is a metal complex represented by the formula (1) (or a metal complex represented by the formula (1 ′)) and a metal complex represented by the formula (2) (or represented by the formula (2 ′)). Compounds that are soluble in the same solvent as the metal complex) and do not inhibit light emission and charge transport. Examples thereof include a phenolic antioxidant and a phosphorus antioxidant.
In the first composition, the compounding amount of the antioxidant is determined based on the metal complex represented by the formula (1) (or the metal complex represented by the formula (1 ′)) and the metal complex represented by the formula (2). When the total content of (or the metal complex represented by the formula (2 ′)) is 100 parts by mass, it is usually from 0.00001 to 10 parts by mass.
Antioxidants may be used alone or in combination of two or more.

[First ink]
The first layer includes a metal complex represented by the formula (1) (or a metal complex represented by the formula (1 ′)) and a metal complex represented by the formula (2) (or a metal complex represented by the formula (2 ′)). It can be formed using a composition (hereinafter, also referred to as “first ink”) containing a metal complex represented by the formula (1) and a solvent. The first ink is a spin coating method, a casting method, a microgravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, a spray coating method, a screen printing method, a flexographic printing method. It can be suitably used for a wet method such as an offset printing method, an ink jet printing method, a capillary coating method and a nozzle coating method.
The viscosity of the first ink may be adjusted according to the type of the wet method. However, when a solution such as an ink jet printing method is applied to a printing method that passes through a discharging device, clogging at the time of discharging and flight bending may occur. Therefore, it is preferably 1 mPa · s or more and 20 mPa · s or less at 25 ° C.
The solvent contained in the first ink is preferably a solvent capable of dissolving or uniformly dispersing the solid content in the ink. As the solvent, for example, a chlorinated solvent, an ether solvent, an aromatic hydrocarbon solvent, an aliphatic hydrocarbon solvent, a ketone solvent, an ester solvent, a polyhydric alcohol solvent, an alcohol solvent, a sulfoxide solvent and Amide solvents are exemplified. The solvents may be used alone or in combination of two or more.
In the first ink, the content of the solvent depends on the metal complex represented by the formula (1) (or the metal complex represented by the formula (1 ′)) and the metal complex represented by the formula (2) (or the formula (2)). When the total content of (the metal complex represented by (2 ′)) is 100 parts by mass, it is usually from 1,000 parts by mass to 1,000,000 parts by mass.

<Second layer>
In the light-emitting element of this embodiment, at least one of the first layer and the second layer contains the compound represented by the formula (T-1). Is preferable, the second layer preferably contains the compound represented by the formula (T-1). That is, the second layer is preferably a layer containing the compound represented by the formula (T-1).
In the light emitting device of the present embodiment, since the luminance life of the light emitting device of the present embodiment is more excellent, the second layer contains the compound represented by the formula (T-1), and the first layer has the formula It is preferable not to contain the compound represented by (T-1), and it is more preferable that only the second layer contains the compound represented by formula (T-1).
The second layer may contain one kind of the compound represented by the formula (T-1) alone, or may contain two or more kinds.
In the light-emitting element 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 It is sufficient that the range of the function is achieved. For example, the content of the compound represented by the formula (T-1) may be 1% by mass or more and 100% by mass or less, and 30% by mass or more and 100% by mass or less based on the total amount of the first layer. Is preferably 60% by mass or more and 100% by mass or less, further preferably 90% by mass or more and 100% by mass or less, and particularly preferably 100% by mass or less.

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

Examples and preferred ranges of the hole transporting material, the electron transporting material, the hole injecting material and the electron injecting material contained in the second composition are the hole transporting material and the electron transporting material contained in the first composition. , Hole injection material and electron injection material, and the same as the preferred range.
Examples of the light-emitting material contained in the second composition include a light-emitting material that the first composition may contain, a metal complex represented by the formula (2) (or a metal complex represented by the formula (2 ′)). And a metal complex represented by the formula (1) (or a metal complex represented by the formula (1 ′)). The luminescent materials may be used alone or in combination of two or more.

  In the second composition, the content of each of the hole-transporting material, the electron-transporting material, the hole-injecting material, the electron-injecting material, and the light-emitting material is such that the compound represented by the formula (T-1) is 100 parts by mass. In this case, the amount is usually 1 part by mass or more and 1000 parts by mass or less.

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

When the second layer contains the compound represented by the formula (T-1), the second layer contains a compound containing the compound represented by the formula (T-1) and a solvent (hereinafter, referred to as a compound containing the compound represented by the formula (T-1)). (Also referred to as “second ink”). The second ink can be suitably used in the wet method described in the section of the first ink. The preferred range of the viscosity of the second ink is the same as the preferred range of the viscosity of the first ink. Examples and preferred ranges of the solvent contained in the second ink are the same as those of the solvent contained in the first ink.
In the second ink, the content of the solvent is usually 1,000 parts by mass or more and 100,000 parts by mass or less when the compound represented by the formula (T-1) is 100 parts by mass.

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

In the light-emitting device of the present embodiment, the second layer 13 is preferably a second light-emitting layer, an electron transport layer or an electron injection layer provided between the cathode 14 and the first layer 12. More preferably, the electron transport layer is provided between the first layer 12 and the first layer 12.
In the light emitting device of the present embodiment, the first layer 12 and the second layer 13 are preferably adjacent to each other because the light emitting device of the present embodiment has a better luminance lifetime.

In the light emitting device of the present embodiment, since the luminance life of the light emitting device of the present embodiment is more excellent, at least one of the hole injection layer and the hole transport layer is provided between the anode 11 and the first layer 12. It is preferable to further have a layer.
In the light-emitting device of the present embodiment, when the second layer 13 is the second light-emitting layer provided between the cathode 14 and the first layer 12, the light-emitting device of the present embodiment has a better luminance lifetime. Preferably, at least one of an electron transport layer and an electron injection layer is further provided between the cathode 14 and the second layer 13.
In the light emitting device of the present embodiment, when the second layer 13 is an electron transporting layer provided between the cathode 14 and the first layer 12, the light emitting device of the present embodiment has a better luminance life, It is preferable that an electron injection layer is further provided between the second layer 13 and the second layer 13.
In the light emitting device of the present embodiment, when the second layer 13 is an electron injection layer provided between the cathode 14 and the first layer 12, the light emitting device of the present embodiment has a better luminance life, It is preferable that an electron transport layer is further provided between the first layer 12 and the second layer 13.

  As a specific layer configuration of the light emitting device of the present embodiment, for example, the layer configurations represented by (D1) to (D9) can be mentioned. The light-emitting device of the present embodiment usually has a substrate, but may be stacked on the substrate from the anode or stacked on the substrate from the cathode.

(D1) anode / hole injection layer / hole transport layer / first light emitting layer (first layer) / electron transport layer (second layer) / electron injection layer / cathode (D2) anode / hole injection Layer / hole transport layer / first light emitting layer (first layer) / electron transport layer / electron injection layer (second layer) / cathode (D3) anode / hole injection layer / hole transport layer / second layer No. 1 light emitting layer (first layer) / second light emitting layer (second layer) / electron transport layer / electron injection layer / cathode (D4) anode / hole injection layer / hole transport layer / first Light emitting layer (first layer) / second light emitting layer / electron transport layer (second layer) / electron injection layer / cathode (D5) anode / hole injection layer / hole transport layer / first light emitting layer (First layer) / second light emitting layer / electron transport layer / electron injection layer (second layer) / cathode (D6) anode / hole injection layer / second light emitting layer / first light emitting layer ( (First layer) / electron transport layer (second layer) / electron injection layer / negative (D7) anode / hole injection layer / second light emitting layer / first light emitting layer (first layer) / electron transport layer / electron injection layer (second layer) / cathode (D8) anode / hole Injection layer / hole transport layer / second light emitting layer / first light emitting layer (first layer) / electron transport layer (second layer) / electron injection layer / cathode (D9) anode / hole injection layer / Hole transport layer / second light emitting layer / first light emitting layer (first layer) / electron transport layer / electron injection layer (second layer) / cathode

  In (D1) to (D9), “/” means that the preceding and following layers are adjacently stacked. Specifically, “first light-emitting layer (first layer) / electron transport layer (second layer)” refers to a first light-emitting layer (first layer) and an electron transport layer (second layer). Layer) adjacent to each other.

In the light emitting device of this embodiment, the anode, the hole injection layer, the hole transport layer, the second light emitting layer, the electron transport layer, the electron injection layer, and the cathode are each provided with two or more layers as necessary. You may.
When there are a plurality of anodes, hole injection layers, hole transport layers, second light emitting layers, electron transport layers, electron injection layers, and cathodes, they may be the same or different.
The thickness of the anode, the hole injection layer, the hole transport layer, the first light emitting layer, the second light emitting layer, the electron transport layer, the electron injection layer, and the cathode is usually 1 nm or more and 1 μm or less, preferably 2 nm. Or more and 500 nm or less, more preferably 5 nm or more and 150 nm or less.
In the light-emitting 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]
The second light emitting layer is usually the second layer or a layer containing a light emitting material, preferably a layer containing a light emitting material. When the second light-emitting layer is a layer containing a light-emitting material, examples of the light-emitting material contained in the second light-emitting layer include a light-emitting material that may be contained in the above-described second composition. Can be The light-emitting material contained in the second light-emitting layer may be used alone or in combination of two or more.
When the light emitting device of this embodiment has a second light emitting layer, and the second layer is not an electron transport layer described later or an electron injection layer described later, the second light emitting layer is a second layer. Is preferred.

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

[Electron transport layer]
The electron transporting layer is usually a second layer or a layer containing an electron transporting material, and is preferably the second layer. When the electron transporting layer is a layer containing an electron transporting material, examples of the electron transporting material contained in the electron transporting layer include the electron transporting material that may be contained in the first composition described above. . The electron transporting material contained in the electron transporting layer may be used alone or in combination of two or more.
When the light emitting device of this embodiment has an electron transport layer, and the second layer is not the above-described second light emitting layer or 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 a layer containing a hole injection material. Examples of the hole injection material contained in the hole injection layer include a hole injection material that may be contained in the first composition described above. The hole injection material contained in the hole injection layer may be contained singly or in combination of two or more.
The electron injection layer is the second layer or a layer containing an electron injection material, and is preferably a layer containing an electron injection material. When the electron injecting layer is a layer containing an electron injecting material, examples of the electron injecting material contained in the electron injecting layer include an electron injecting material that may be contained in the first composition described above. . The electron injecting material contained in the electron injecting layer may be contained alone 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 on which an electrode can be formed and which does not chemically change when a layer is formed, for example, a substrate made of a material such as glass, plastic, or silicon. . If an opaque substrate is used, it is preferred that the electrode furthest from the substrate be transparent or translucent.

  Examples of the material of the anode include a conductive metal oxide and a translucent metal, and preferably, indium oxide, zinc oxide, and tin oxide; indium tin oxide (ITO), indium zinc oxide, and the like A complex of silver, palladium, and copper (APC); NESA, gold, platinum, silver, and copper.

  Examples of the cathode material include metals such as lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, zinc, and indium; alloys of two or more thereof; Alloys of at least one species with one or more 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 the present 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 lamination method.

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

When the first layer is formed by a wet method, it is preferable to use the first ink. The first layer is preferably formed by a wet method because the manufacture of the light-emitting element of this embodiment is facilitated.
When the second layer is formed by a wet method, it is preferable to use the second ink. 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 the present 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 and the like are provided thereon. A light-emitting element can be manufactured by providing a layer and further laminating a cathode thereon. As another manufacturing method, a cathode is provided on a substrate, and an electron injection layer, an electron transport layer, a light emitting layer, a hole transport layer, a hole injection layer, and other layers are provided thereon, and an anode is further provided thereon. By stacking, a light-emitting element can be manufactured. As still another manufacturing method, it is possible to manufacture by facing and joining an anode or an anode-side substrate obtained by laminating each layer on the anode and a cathode or a cathode-side substrate obtained by laminating each layer on the cathode. it can.

  In the manufacture of the light-emitting element of this embodiment, a material used for forming a hole injection layer, a material used for forming a light-emitting layer, a material used for forming a hole transport layer, a material used for forming an electron transport layer, and an electron When the material used for forming the injection layer is dissolved in a solvent used for forming a hole injection layer, a light emitting layer, a hole transport layer, an electron transport layer, and a layer adjacent to the electron injection layer, the solvent Preferably, 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 of an adjacent layer in a solvent 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. In the method ii), for example, when an electron transporting layer is laminated on the light emitting layer by utilizing the difference in solubility, the electron transporting is performed by using an ink having low solubility in the light emitting layer. Layers can be laminated on the light emitting layer.

[Use of light emitting element]
In order to obtain planar light emission using a light-emitting element, a planar anode and a planar cathode may be arranged so as to overlap with each other. In order to obtain patterned light emission, a method of installing a mask having a patterned window on the surface of a planar light emitting element, forming a layer to be a non-light emitting portion 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 of these methods and arranging some electrodes so that they can be turned ON / OFF independently, a segment type display device capable of displaying numbers, characters, and the like can be obtained. In order to form a dot matrix display device, both the anode and the cathode may be formed in a stripe shape and arranged orthogonally. A partial color display and a multi-color display can be performed by a method of separately applying a plurality of types of polymer compounds having different emission colors, 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 a TFT or the like. These display devices can be used for displays of computers, televisions, mobile terminals, and the like. The planar light-emitting element can be suitably used as a planar light source for a backlight of a liquid crystal display device or a planar illumination light source. If a flexible substrate is used, it can be used as a curved light source and a display device.

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

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

LC-MS was measured by the following method.
The measurement sample was dissolved in tetrahydrofuran to a concentration of about 2 mg / mL, and about 1 μL was injected into LC-MS (manufactured by Agilent, trade name: 1290 Infinity LC and 6230 TOF LC / MS). The mobile phase of LC-MS was used while changing the ratio of acetonitrile and tetrahydrofuran, and flowed at a flow rate of 1.0 mL / min. The column used was SUMIPAX ODS Z-CLUE (manufactured by Sumika Chemical Analysis Service, 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).

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

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

<Synthesis Example M> Synthesis of Compounds M1 to M3 Compound M1 was synthesized according to the method described in International Publication WO2015 / 145871.
Compound M2 was synthesized according to the method described in WO 2013/146806.
Compound M3 was synthesized according to the method described in WO 2005/049546.

<Synthesis example HTL> Synthesis | combination of the high molecular compound HTL-1 The high molecular compound HTL-1 was synthesize | combined according to the method of the international publication 2015/1458731 using the compound M1, the compound M2, and the compound M3. The polymer compound HTL-1 had Mn = 2.3 × 10 ⁴ and Mw = 1.2 × 10 ⁵ .
The polymer compound HTL-1 has a theoretical value determined from the amount of the charged raw materials, a structural unit derived from the compound M1, a structural unit derived from the compound M2, and a structural unit derived from the compound M3. It is a copolymer composed of a molar ratio of 45: 5: 50.

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

<Synthesis Example B> Synthesis of Metal Complexes B1 to B8 The metal complex B1 was synthesized according to the method described in International Publication WO 2006/121811 and JP-A-2013-048190.
Metal complex B2 was synthesized according to the method described in WO 2016/125560.
Metal complex B3 was synthesized according to the method described in JP-A-2017-052709.
The metal complexes B4 to B8 were synthesized according to the method described in JP-A-2013-147551.

The maximum peak wavelength of the emission spectrum of the metal complex B1 was 471 nm.
The maximum peak wavelength of the emission spectrum of the metal complex B2 was 492 nm.
The maximum peak wavelength of the emission spectrum of the metal complex B3 was 469 nm.
The maximum peak wavelength of the emission spectrum of the metal complex B4 was 475 nm.
The maximum peak wavelength of the emission spectrum of the metal complex B5 was 440 nm.
The maximum peak wavelength of the emission spectrum of the metal complex B6 was 450 nm.
The maximum peak wavelength of the emission spectrum of the metal complex B7 was 464 nm.
The maximum peak wavelength of the emission spectrum of the metal complex B8 was 443 nm.

<Synthesis Example G> Synthesis and Availability of Metal Complexes G1 to G3 The metal complex G1 was purchased from Luminescence Technology.
The metal complex G2 was synthesized according to the method described in JP-A-2013-237789.
Metal complex G3 was synthesized according to the method described in WO 2009/131255.

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

<Synthesis Example R> Synthesis and Obtaining of Metal Complexes R1 to R7 The metal complex R1 was purchased from American Dye Source.
The metal complex R2, the metal complex R6, and the metal complex R7 were purchased from Luminescence Technology.
Metal complex R3 was synthesized according to the method described in JP-A-2006-188673.
Metal complex R4 was synthesized according to the method described in JP-A-2008-179617.
Metal complex R5 was synthesized according to the method described in JP-A-2011-105701.

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 maximum peak wavelength of the emission spectrum of the metal complex R7 was 553 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-A-2010-235575.

  <Compound ET2> Synthesis of Compound ET2

  After setting the inside of the reaction vessel to an inert gas atmosphere, compound ET2a (8.7 g), compound ET2b (8.1 g), dimethyl sulfoxide (218 mL), copper (I) oxide (1.3 g), and tripotassium phosphate ( 16.7 g) and dipivaloylmethane (3.2 g) were added, and the mixture was stirred at 150 ° C. for 10 hours. After cooling the obtained reaction solution to room temperature, toluene and ion-exchanged water were added, and the mixture was filtered through a glass filter covered with Celite. After the obtained filtrate was washed with ion exchanged water, the obtained organic layer was concentrated to obtain a crude product. The obtained crude product was purified by silica gel column chromatography (a 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 the compound ET2 were as follows.
LC-MS (ESI, positive): m / z = 573 [M + H] ^+
1 H-NMR (400 MHz, THF-d ₈ ): δ (ppm) = 1.01 (t, 3H), 1.58-1.68 (m, 2H), 1.95-2.05 (m, 2H), 3.14-3.19 (m, 2H), 7.32-7.39 (m, 4H), 7.49-7.57 (m, 4H), 7.72 (s, 1H). , 7.79-7.88 (m, 3H), 8.34-8.42 (m, 3H), 8.55-8.68 (m, 4H).

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

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

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

(Formation of the 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. By heating at 130 ° C. for 10 minutes in a nitrogen gas atmosphere, a second layer (electron transport layer) was formed.

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

(Evaluation of light emitting element)
EL emission was observed by applying a voltage to the light-emitting element D1. CIE chromaticity coordinates (x, y) at 10 mA / cm ² were measured. In addition, constant current driving was performed at 10 mA / cm ² , and the time until the luminance reached 80% of the initial luminance was measured.

<Example D2 and Comparative Example CD1> Production and Evaluation of Light-Emitting Devices D2 and CD1 "Compound HM-1, metal complex B1, metal complex G3, and metal complex R5 (compound in Example 1) (formation of first layer)" HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.9% by mass / 25% by mass / 1% by mass / 0.1% by mass), and the materials shown in Table 1 were used. Light emitting elements D2 and CD1 were fabricated in the same manner as in Example D1 except for the above.
EL emission was observed by applying a voltage to the light emitting elements D2 and CD1. CIE chromaticity coordinates (x, y) at 10 mA / cm ² were measured. In addition, constant current driving was performed at 10 mA / cm ² , and the time until the luminance reached 80% of the initial luminance was measured.

  Table 1 shows the results of Example D1, Example D2, and Comparative Example CD1. The time (luminance life) until the luminance of the light emitting elements D1 and D2 reaches 80% of the initial luminance when the time until the luminance of the light emitting element CD1 reaches 80% of the initial luminance (luminance life) is 1.0. Shows the relative value of

<Example D3 and Comparative Example CD2> Production and Evaluation of Light-Emitting Elements D3 and CD2 “Compound HM-1, Metal Complex B1, Metal Complex G3, and Metal Complex R5 (Compound HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.9% by mass / 25% by mass / 1% by mass / 0.1% by mass)), and the materials shown in Table 2 were used. Further, light-emitting elements D3 and CD2 were produced in the same manner as in Example D1, except that “Compound ET2” was used instead of “Compound ET1” in (Formation of Second Layer) in Example D1.
EL emission was observed by applying a voltage to the light emitting elements D3 and CD2. CIE chromaticity coordinates (x, y) at 10 mA / cm ² were measured. In addition, constant current driving was performed at 10 mA / cm ² , and the time until the luminance became 95% of the initial luminance was measured.

  Table 2 shows the results of Example D3 and Comparative Example CD2. The relative time (luminance life) until the luminance of the light emitting element D3 reaches 95% of the initial luminance when the time until the luminance of the light emitting element CD2 becomes 95% of the initial luminance (luminance life) is 1.0. Indicates a value.

<Examples D4 to D5 and Comparative Example CD3> Production and Evaluation of Light-Emitting Elements D4, D5, and CD3 “Compound HM-1, metal complex B1, metal complex G3, and metal in Example D1 (Formation of First Layer)” Complex R5 (compound HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.9% by mass / 25% by mass / 1% by mass / 0.1% by mass)) and described in Table 3 Light-emitting elements D4 and D5 were formed in the same manner as in Example D1 except that the material was used, and “Compound ET3” was used instead of “Compound ET1” in (Formation of Second Layer) in Example D1. And CD3.
EL emission was observed by applying a voltage to the light-emitting elements D4, D5, and CD3. CIE chromaticity coordinates (x, y) at 10 mA / cm ² were measured. In addition, constant current driving was performed at 10 mA / cm ² , and the time until the luminance became 50% of the initial luminance was measured.

  Table 3 shows the results of Example D4, Example D5, and Comparative Example CD3. The time (luminance life) until the luminance of the light emitting elements D4 and D5 becomes 50% of the initial luminance when the time until the luminance of the light emitting element CD3 becomes 50% of the initial luminance (luminance life) is 1.0. Shows the relative value of

<Examples D6 to D9 and Comparative Example CD4> Production and Evaluation of Light-Emitting Elements D6 to D9 and CD5 "Compound HM-1, metal complex B1, metal complex G3, and metal in Example D1 (Formation of First Layer)" Complex R5 (compound HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.9% by mass / 25% by mass / 1% by mass / 0.1% by mass) ”and described in Table 4 Light emitting devices D6 to D9 and CD4 were produced in the same manner as in Example D1, except that the material and the composition ratio (% by mass) were used.
EL light emission was observed by applying a voltage to the light-emitting elements D6 to D9 and CD4. CIE chromaticity coordinates (x, y) at 1 mA / cm ² were measured. In addition, constant current driving was performed at 10 mA / cm ² , and the time until the luminance became 75% of the initial luminance was measured.

  Table 4 shows the results of Examples D6 to D9 and Comparative Example CD4. The time (luminance life) until the luminance of the light-emitting elements D6 to D9 reaches 75% of the initial luminance when the time until the luminance of the light-emitting element CD4 reaches 75% of the initial luminance (luminance life) is 1.0. Shows the relative value of

<Examples D10 to D12 and Comparative Example CD5> Production and Evaluation of Light-Emitting Devices D10 to D12 and CD5 "Compound HM-1, metal complex B1, metal complex G3, and metal in Example D1 (Formation of First Layer)" Complex R5 (compound HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.9% by mass / 25% by mass / 1% by mass / 0.1% by mass) ”and described in Table 5 In the same manner as in Example D1 except that the compound and the composition ratio (% by mass) were used and “Compound ET2” was used instead of “Compound ET1” in (Formation of Second Layer) in Example D1. Thus, light-emitting elements D10 to D12 and CD5 were produced.
By applying a voltage to the light emitting elements D10 to D12 and CD5, EL light emission was observed. CIE chromaticity coordinates (x, y) at 1 mA / cm ² were measured. In addition, constant current driving was performed at 10 mA / cm ² , and the time until the luminance became 90% of the initial luminance was measured.

  Table 5 shows the results of Examples D10 to D12 and Comparative Example CD5. The time (luminance life) until the luminance of the light-emitting elements D10 to D12 reaches 90% of the initial luminance when the time until the luminance of the light-emitting element CD5 becomes 90% of the initial luminance (luminance life) is 1.0. Shows the relative value of

<Examples D13 to D14 and Comparative Example CD6> Production and Evaluation of Light-Emitting Devices D13, D14, and CD6 "Compound HM-1, metal complex B1, metal complex G3, and metal in Example D1 (Formation of First Layer)" Complex R5 (compound HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.9% by mass / 25% by mass / 1% by mass / 0.1% by mass) ”and described in Table 6 In the same manner as in Example D1 except that the compound and the composition ratio (% by mass) were used and “Compound ET3” was used instead of “Compound ET1” in (Formation of Second Layer) in Example D1. Thus, light emitting elements D13, D14 and CD6 were produced.
EL emission was observed by applying a voltage to the light-emitting elements D13, D14, and CD6. CIE chromaticity coordinates (x, y) at 1 mA / cm ² were measured. In addition, constant current driving was performed at 10 mA / cm ² , and the time until the luminance became 50% of the initial luminance was measured.

  Table 6 shows the results of Example D13, Example D14, and Comparative Example CD6. The time (luminance life) until the luminance of the light emitting elements D13 and D14 becomes 50% of the initial luminance when the time until the luminance of the light emitting element CD6 becomes 50% of the initial luminance (luminance life) is 1.0. Shows the relative value of

<Examples D15 to D18 and Comparative Example CD7> Production and Evaluation of Light-Emitting Elements D15 to D18 and CD7 "Compound HM-1, metal complex B1, metal complex G3, and metal in Example D1 (Formation of First Layer)" Complex R5 (compound HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.9% by mass / 25% by mass / 1% by mass / 0.1% by mass) ”and described in Table 7 Light-emitting elements D15, D16, D18 and CD7 were produced in the same manner as in Example D1, except that the material and the composition ratio (% by mass) were used.
"Compound HM-1, metal complex B1, metal complex G3, and metal complex R5 (compound HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.times.)" In Example D1 (Formation of First Layer). 9% by mass / 25% by mass / 1% by mass / 0.1% by mass) ”, and the materials and composition ratios (% by mass) shown in Table 7 are used. The light emitting device D17 was fabricated in the same manner as in Example D1, except that “Compound ET3” was used instead of “Compound ET1” in (Formation of).
By applying a voltage to the light-emitting elements D15 to D18 and CD7, EL light emission was observed. CIE chromaticity coordinates (x, y) at 1 mA / cm ² were measured. Further, a constant current drive was performed at 10 mA / cm ² , and a time until the luminance reached 65% of the initial luminance was measured.

  Table 7 shows the results of Examples D15 to D18 and Comparative Example CD7. The time (luminance life) until the luminance of the light-emitting elements D15 to D18 reaches 65% of the initial luminance when the time until the luminance of the light-emitting element CD7 reaches 65% of the initial luminance (luminance life) is 1.0. Shows the relative value of

<Examples D19 to D20 and Comparative Example CD8> Production and Evaluation of Light-Emitting Devices D19, D20, and CD8 "Compound HM-1, metal complex B1, metal complex G3, and metal in Example D1 (Formation of First Layer)" Complex R5 (compound HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.9% by mass / 25% by mass / 1% by mass / 0.1% by mass)) was replaced with a compound described in Table 8 In the same manner as in Example D1 except that the compound and the composition ratio (% by mass) were used and “Compound ET2” was used instead of “Compound ET1” in (Formation of Second Layer) in Example D1. Thus, light-emitting elements D19, D20 and CD8 were produced.
By applying a voltage to the light emitting elements D19, D20 and CD8, EL light emission was observed. CIE chromaticity coordinates (x, y) at 1 mA / cm ² were measured. In addition, constant current driving was performed at 10 mA / cm ² , and the time until the luminance became 95% of the initial luminance was measured.

  Table 8 shows the results of Examples D19 to D20 and Comparative Example CD8. The time (luminance life) until the luminance of the light emitting elements D19 and D20 reaches 95% of the initial luminance when the time until the luminance of the light emitting element CD8 becomes 95% of the initial luminance (luminance life) is 1.0. Shows the relative value of

<Examples D21, D22 and Comparative Example CD9> Production and Evaluation of Light-Emitting Elements D21, D22, and CD9 "Compound HM-1, metal complex B1, metal complex G3, and metal in Example D1 (Formation of First Layer)" Complex R5 (compound HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.9% by mass / 25% by mass / 1% by mass / 0.1% by mass) ”and described in Table 9 Light-emitting elements D21, D22, and CD9 were produced in the same manner as in Example D1, except that the material and the composition ratio (% by mass) were used.
EL emission was observed by applying a voltage to the light-emitting elements D21, D22, and CD9. CIE chromaticity coordinates (x, y) at 10 mA / cm ² were measured. In addition, constant current driving was performed at 10 mA / cm ² , and the time until the luminance reached 80% of the initial luminance was measured.

  Table 9 shows the results of Examples D21 and D22 and Comparative Example CD9. The time (luminance life) until the luminance of the light emitting elements D21 and D22 becomes 80% of the initial luminance when the time until the luminance of the light emitting element CD9 becomes 80% of the initial luminance (luminance life) is 1.0. Shows the relative value of

<Example D23 and Comparative Example CD10> Production and Evaluation of Light-Emitting Devices D23 and CD10 “Compound HM-1, metal complex B1, metal complex G3, and metal complex R5 (compound HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.9% by mass / 25% by mass / 1% by mass / 0.1% by mass)) and the materials and composition ratios shown in Table 10. Light-emitting elements D23 and CD10 were produced in the same manner as in Example D1, except that (% by mass) was used.
By applying a voltage to the light-emitting elements D23 and CD10, EL light emission was observed. CIE chromaticity coordinates (x, y) at 10 mA / cm ² were measured. In addition, constant current driving was performed at 10 mA / cm ² , and the time until the luminance became 70% of the initial luminance was measured.

  Table 10 shows the results of Example D23 and Comparative Example CD10. Relative to the time (luminance life) until the luminance of the light emitting element D23 reaches 70% of the initial luminance when the time until the luminance of the light emitting element CD10 becomes 70% of the initial luminance (luminance life) is 1.0. Indicates a value.

<Examples D24 to D27 and Comparative Example CD11> Production and Evaluation of Light-Emitting Elements D24 to D27 and CD11 "Compound HM-1, metal complex B1, metal complex G3, and metal in Example D1 (Formation of First Layer)" Complex R5 (compound HM-1 / metal complex B1 / metal complex G3 / metal complex R5 = 73.9% by mass / 25% by mass / 1% by mass / 0.1% by mass) ”and described in Table 11 Light emitting devices D24 to D27 and CD11 were produced in the same manner as in Example D1, except that the material and the composition ratio (% by mass) were used.
EL emission was observed by applying a voltage to the light-emitting elements D24 to D27 and CD11. CIE chromaticity coordinates (x, y) at 10 mA / cm ² were measured. In addition, constant current driving was performed at 10 mA / cm ² , and a time required for the luminance to reach 85% of the initial luminance was measured.

  Table 11 shows the results of Examples D24 to D27 and Comparative Example CD11. The time (luminance life) until the luminance of the light emitting elements D24 to D27 becomes 85% of the initial luminance when the time until the luminance of the light emitting element CD11 becomes 85% of the initial luminance (luminance life) is 1.0. Shows the relative value of

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

  Reference Signs List 10 light emitting element, 11 anode, 12 first layer, 13 second layer, 14 cathode.

Claims (19)

An anode, a cathode, a light-emitting element including a first layer provided between the anode and the cathode, and a second layer provided between the cathode and the first layer,
The first layer is a layer containing a metal complex represented by the formula (1) and a metal complex represented by the formula (2 ′) whose emission spectrum has a maximum peak wavelength of 550 nm or more and less than 750 nm. ,
A light-emitting element, wherein the second layer contains a compound represented by the formula (T-1).

[Where,
M ¹ represents the Lee Rijiumu original child.
n ¹ represents an integer of 1 or more, ^{n 2} represents an integer of 0 or more. However, ⁿ 1 + ^{n 2} is 3.
E ¹ and E ² each independently represent a carbon atom or a nitrogen atom. When a plurality of E ¹ and E ² are present, they may be the same or different.
Ring R ¹ represents a 5-membered aromatic heterocycle, which may have one or more primary substituents. When a plurality of the primary 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 aromatic heterocyclic ring, these rings may have a single or plurality of primary substituent. When a plurality of the primary 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 ring R ² is plurally present, they may be the same or different.
The primary substituent that the ring R ¹ may have and the primary substituent that the 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. May be formed.
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 the Lee Rijiumu original child.
n ³ represents an integer of 1 or more, ^{n 4} represents an integer of 0 or more. However, ⁿ 3 + ^{n 4} is 3.
^EL represents a carbon atom or a nitrogen atom. When a plurality of ^ELs are present, they may be the same or different.
Ring L ¹ represents a 6-membered aromatic heterocyclic ring, and this ring may have one or more primary substituents. When a plurality of the primary 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 ring L ¹ there are a plurality, 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 plurality of primary substituent. When a plurality of the primary 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 ring L ² there are a plurality, they may be the same or different.
The primary substituent that the ring L ¹ may have and the primary 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. May be formed.
Provided that at least one of the ring L ¹ and the ring L ^2, as an additional substituent, having a group represented by the formula (2-T). When a plurality of groups represented by the formula (2-T) exist, they may be the same or different.
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 . If A ³ -G ² -A ⁴ there are a plurality, they may be the same or different. ]

Wherein, R ^2T represents an alkyl group, a cycloalkyl group, the aryl group, a monovalent heterocyclic group or a substituted amino group, these groups have a single or plurality of secondary substituent The secondary substituent may be an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may be a single or a plurality of tertiary groups. May have a substituent, the tertiary substituent is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups are It may have one or more quaternary substituents. When a plurality of the secondary 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 the tertiary 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 the quaternary 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. ]

[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.
^nT2 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 plural substituents. And when there are a plurality of the substituents, 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 ^T1s are present, they may be the same or different.
L ^T1 is an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -NR T1 ^'- represents a group represented by an oxygen atom or a sulfur atom, the these groups single or multiple substitutions It may have a group, and when there are a plurality of the substituents, 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 may have a single or plural substituents, and the substituent may be When there are a plurality of them, 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 ^LT1s exist, 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. When a plurality of the substituents are present, they are 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 R ^2T Is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or a plurality of tertiary substituents. The tertiary substituent is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or plural quaternary substituents The light emitting device according to claim 1. Formula maximum peak wavelength of the emission spectrum of a metal complex represented by (2 ') is less than 750nm or 570 nm, the light emitting device according to claim 1 or 2. The light emitting device according to any one of claims 1 to 3, wherein a maximum peak wavelength of an emission spectrum of the metal complex represented by the formula (1) is 380 nm or more and less than 495 nm. Said primary substituent in the ring R ¹ is a group represented by the formula (1-S), wherein the primary substituent in the ring R ² is a group represented by the formula (1-S), The light emitting device according to any one of claims 1 to 4 , wherein when a plurality of groups represented by the formula (1-S) are present, they may be the same or different.

[Wherein, R ^1S 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 secondary substituents. When a plurality of the secondary 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. ] An anode, a cathode, a light-emitting element including a first layer provided between the anode and the cathode, and a second layer provided between the cathode and the first layer,
The first layer is a layer containing a metal complex represented by the formula (1 ′) and a metal complex represented by the formula (2) whose emission spectrum has a maximum peak wavelength of 550 nm or more and less than 750 nm. ,
A light-emitting element, wherein the second layer contains a compound represented by the formula (T-1).

[Where,
M ¹ represents the Lee Rijiumu original child.
n ¹ represents an integer of 1 or more, ^{n 2} represents an integer of 0 or more. However, ⁿ 1 + ^{n 2} is 3.
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 one or more groups represented by formula (2-S). When a plurality of groups represented by the formula (2-S) 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 each is 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 aromatic heterocyclic ring, these rings may have a group represented by single or multiple expressions (2-S). When a plurality of groups represented by the formula (2-S) 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 each is bonded. When a ring R ² is plurally present, they may be the same or different.
The group represented by the formula (2-S) that the ring R ¹ may have and the group represented by the formula (2-S) that the ring R ² may have are the same or different. And may be bonded to each other to form a ring together with the atoms to which they are bonded.
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. ]

[Wherein, R ^2S represents an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group, or a substituted amino group; May have a secondary substituent, the secondary substituent is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, These groups may have a single or a plurality of tertiary substituents, the tertiary substituent is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or These are substituted amino groups, and these groups may have one or more quaternary substituents. When a plurality of the secondary 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 the tertiary 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 the quaternary 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. ]

[Where,
M ² represents the Lee Rijiumu original child.
n ³ represents an integer of 1 or more, ^{n 4} represents an integer of 0 or more. However, ⁿ 3 + ^{n 4} is 3.
^EL represents a carbon atom or a nitrogen atom. When a plurality of ^ELs are present, they may be the same or different.
Ring L ¹ represents a 6-membered aromatic heterocyclic ring, and this ring may have one or more primary substituents. When a plurality of the primary 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 ring L ¹ there are a plurality, 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 plurality of primary substituent. When a plurality of the primary 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 ring L ² there are a plurality, they may be the same or different.
The primary substituent that the ring L ¹ may have and the primary 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. May be formed.
Provided that at least one of the ring L ¹ and the ring L ^2, as an additional substituent, having a group represented by the formula (1-T). When there are a plurality of groups represented by the formula (1-T), they may be the same or different.
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 . If A ³ -G ² -A ⁴ there are a plurality, they may be the same or different. ]

Wherein, R ^1T is an alkyl group, a cycloalkyl group, the aryl group, monovalent heterocyclic group, a substituted amino group or a halogen atom, these groups have a single or more substituents You may. 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. ]

[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.
^nT2 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 plural substituents. And when there are a plurality of the substituents, 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 ^T1s are present, they may be the same or different.
L ^T1 is an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -NR T1 ^'- represents a group represented by an oxygen atom or a sulfur atom, the these groups single or multiple substitutions It may have a group, and when there are a plurality of the substituents, 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 may have a single or plural substituents, and the substituent may be When there are a plurality of them, 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 ^LT1s exist, 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. When a plurality of the substituents are present, they are 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 R ^2S Is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or a plurality of secondary substituents, The group is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or plural tertiary substituents; Is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or plural quaternary substituents. The light-emitting element according to any one of the preceding claims. The light emitting device according to claim 6 , wherein the group represented by the formula (1-T) is a group represented by the formula (2-T).

Wherein, R ^2T represents an alkyl group, a cycloalkyl group, the aryl group, a monovalent heterocyclic group or a substituted amino group, these groups have a single or plurality of secondary substituent The secondary substituent may be an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may be a single or a plurality of tertiary groups. May have a substituent, the tertiary substituent is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups are It may have one or more quaternary substituents. When a plurality of the secondary 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 the tertiary 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 the quaternary 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 R ^2T Is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or a plurality of tertiary substituents. The tertiary substituent is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a single or plural quaternary substituents The light emitting device according to claim 8. The light emitting device according to any one of claims 6 to 9, wherein a maximum peak wavelength of an emission spectrum of the metal complex represented by the formula (2) is 570 nm or more and less than 750 nm. The light emitting device according to any one of claims 6 to 10 , wherein a maximum peak wavelength of an emission spectrum of the metal complex represented by the formula (1 ') is 380 nm or more and less than 495 nm. The aromatic heterocyclic ring of the 5-membered in the ring R ¹ is a diazole ring or a triazole ring, and the aromatic hydrocarbon ring or the aromatic heterocyclic ring in the ring R ² is a benzene ring, a pyridine ring or Jiazabenzen The light-emitting device according to any one of claims 1 to 11 , which is a ring. 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 primary substituents, and the ring L ² , a benzene ring, a pyridine ring or Jiazabenzen ring, these rings may have a single or plurality of primary substituent, light-emitting device according to any one of claims 1 to 12. Wherein ^{Ar T1} is a group represented by the formula (T1-1), light-emitting device according to any one of claims 1 to 1 3.

[Where,
X ^T1 represents a single bond, an oxygen atom, a sulfur atom, -N ^{(R XT1)} - represents a group represented by -, a group represented by _{^{or, -C (R XT1 ') 2}} . R ^XT1 and R ^{XT1 ′} each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group, a halogen atom or Represents a cyano group, these groups may have a single or a plurality of substituents, when there are a plurality of said substituents, they may be the same or different, bonded to each other, A ring may be formed together with the bonding atom. A plurality of R ^XT1 ′ may be the same or different, and may combine with each other to form a ring together with the atoms to which each is attached.
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 such a 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. And when there are a plurality of the substituents, 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 plural substituents; The light emission according to claim 14 , wherein the ring ^RT2 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 plural substituents. And the ring R ^T2 is a monocyclic heterocyclic ring containing a group represented by = N- in the ring, and the ring has a single or plural substituents. The light emitting device according to claim 15, which may be used. The ring R ^T1 is a benzene ring, a pyridine ring or a diazabenzene ring, these rings may have one or more substituents, and the ring R ^T2 is a pyridine ring or a diazabenzene ring. 17. The light emitting device according to claim 16 , wherein these rings may have a single or a plurality of substituents. The light emitting device according to any one of claims 1 to 17 , 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 may have a single or plural 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 may have a single or plural 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. ] The light emitting device according to any one of claims 1 to 18 , wherein the first layer and the second layer are adjacent to each other.

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