JP2023069652A - Compound, composition, host material, and organic electroluminescent element - Google Patents

Abstract

To provide an organic electroluminescent element having excellent properties.SOLUTION: The organic electroluminescent element is provided by using a compound of the general formula in the figure, where R1 and R3 each represent a hydrogen atom, a deuterium atom, or an alkyl group; R2 represents a hydrogen atom or a deuterium atom; Z1 represents a carbazolyl group, a benzofurocarbazolyl group, or a benzothienocarbazolyl group; and Z2 represents a dibenzofuryl group, a benzofurocarbazolyl group, or a benzothienocarbazolyl group.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a compound useful as a host material or the like, and a composition and an organic light-emitting device using the compound.

Research and development of materials used for organic light-emitting devices such as organic electroluminescence devices (organic EL devices) have been actively conducted. In particular, various attempts have been made to improve the characteristics of the device by newly developing and combining electron-transporting materials, hole-transporting materials, light-emitting materials, host materials, etc. that constitute the organic electroluminescence device. For example, as a host material, PYD2Cz having the following structure has been widely recognized as a useful host material, and has recently been taken up as a research subject (see Non-Patent Document 1).

Small Sci. 2021, 1, 2000057

However, even if a host material that has been used conventionally is used, it may not always be possible to provide a light-emitting device having excellent characteristics. For example, when combined with a delayed fluorescence material, it is often not possible to produce an organic light-emitting device with excellent properties even if a useful host material is used as it is. Especially when it is used in an organic electroluminescence device, there is room for improvement in terms of device life and luminous efficiency. Therefore, the present inventors have made studies with the aim of improving the characteristics of the organic light-emitting device by providing an excellent host material.

As a result of intensive studies, the present inventors have found that the characteristics can be improved by using a compound having a specific structure in an organic light-emitting device. The present invention has been proposed based on these findings, and specifically has the following configurations.

［一般式（１）において、
Ｒ^１およびＲ^３は各々独立に水素原子、重水素原子、または重水素化されていてもよいアルキル基を表す。
Ｒ^２は各々独立に水素原子または重水素原子を表す。
Ｚ^１は、置換もしくは無置換のカルバゾリル基、置換もしくは無置換のベンゾフロカルバゾリル基、または置換もしくは無置換のベンゾチエノカルバゾリル基を表す。
Ｚ^２は、置換もしくは無置換のジベンゾフリル基、置換もしくは無置換のベンゾフロカルバゾリル基、または置換もしくは無置換のベンゾチエノカルバゾリル基を表す。
前記カルバゾリル基、前記ベンゾフロカルバゾリル基および前記ベンゾチエノカルバゾリル基は、それぞれカルバゾール環を構成する窒素原子で結合する基である。］
［２］ Ｚ^１が置換もしくは無置換のベンゾフロカルバゾリル基である、［１］に記載の化合物。
［３］ Ｚ^１が置換もしくは無置換のカルバゾリル基である、［１］に記載の化合物。
［４］ Ｚ^２が置換もしくは無置換のジベンゾフリル基である、［１］～［３］のいずれか１項に記載の化合物。
［５］ Ｚ^２が置換もしくは無置換のベンゾフロカルバゾリル基である、［１］～［３］のいずれか１項に記載の化合物。
［６］ Ｚ^１が置換もしくは無置換のカルバゾリル基であり、Ｚ^２が置換もしくは無置換のベンゾフロカルバゾリル基、または置換もしくは無置換のベンゾチエノカルバゾリル基である、［１］に記載の化合物。
［７］ Ｚ^１およびＺ^２が、各々独立に置換もしくは無置換のベンゾフロカルバゾリル基、または置換もしくは無置換のベンゾチエノカルバゾリル基である、［１］に記載の化合物。
［８］ Ｚ^１が置換もしくは無置換のカルバゾリル基であり、Ｚ^２が置換もしくは無置換のジベンゾフリル基である、［１］に記載の化合物。
［９］ 分子内に存在するカルバゾリル基、ベンゾフロカルバゾリル基、ベンゾチエノカルバゾリル基、およびジベンゾフリル基のうちの少なくとも１つがアリール基で置換されている、［１］～［８］のいずれか１項に記載の化合物。
［１０］ Ｒ^１～Ｒ^３が水素原子である、［１］～［９］のいずれか１項に記載の化合物。
［１１］ ［１］～［１０］のいずれか１つに記載の化合物を含むホスト材料。
［１２］ 遅延蛍光材料とともに用いるための［１０］に記載のホスト材料。
［１３］ ［１］～［１０］のいずれか１つに記載の化合物に遅延蛍光材料をドープした組成物。
［１４］ 膜状である、［１３］に記載の組成物。
［１５］ 前記遅延蛍光材料が、ベンゼン環に置換しているシアノ基の数が１つであるシアノベンゼン構造を有する化合物である、［１３］または［１４］に記載の組成物。
［１６］ 前記遅延蛍光材料が、ベンゼン環に置換しているシアノ基の数が２つであるシアノベンゼン構造を有する化合物である、［１３］または［１４］に記載の組成物。
［１７］ 前記ホスト材料および前記遅延蛍光材料よりも最低励起一重項エネルギーが低い蛍光性化合物をさらに含む、［１３］～［１６］のいずれか１つに記載の組成物。
［１８］ ［１３］～［１７］のいずれか１つに記載の組成物からなる層を有する有機発光素子。
［１９］ 前記層が、炭素原子、水素原子、窒素原子、酸素原子、硫黄原子、ホウ素原子およびハロゲン原子からなる群より選択される原子のみからなる、［１８］に記載の有機発光素子。
［２０］ 前記層が、炭素原子、水素原子、窒素原子、酸素原子および硫黄原子からなる群より選択される原子のみからなる、［１９］に記載の有機発光素子。
［２１］ 有機エレクトロルミネッセンス素子である、［１８］～［２０］のいずれか１つに記載の有機発光素子。
［２２］ 前記組成物が前記蛍光性化合物を含んでおらず、前記素子からの発光の最大成分は前記遅延蛍光材料からの発光である、［１８］～［２１］のいずれか１つに記載の有機発光素子。
［２３］ 前記組成物が前記蛍光性化合物を含んでおり、前記素子からの発光の最大成分は前記蛍光性化合物からの発光である、［１８］～［２１］のいずれか１つに記載の有機発光素子。 [1] A compound represented by the following general formula (1).

[In the general formula (1),
R ¹ and R ³ each independently represent a hydrogen atom, a deuterium atom, or an optionally deuterated alkyl group.
Each ^R2 independently represents a hydrogen atom or a deuterium atom.
Z ¹ represents a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzofurocarbazolyl group, or a substituted or unsubstituted benzothienocarbazolyl group.
^Z2 represents a substituted or unsubstituted dibenzofuryl group, a substituted or unsubstituted benzofurocarbazolyl group, or a substituted or unsubstituted benzothienocarbazolyl group.
The carbazolyl group, the benzofurocarbazolyl group, and the benzothienocarbazolyl group are groups bonded through a nitrogen atom constituting a carbazole ring. ]
[2] The compound according to [1], wherein Z ¹ is a substituted or unsubstituted benzofurocarbazolyl group.
[3] The compound of [1], wherein Z ¹ is a substituted or unsubstituted carbazolyl group.
[4] The compound according to any one of [1] to [3], wherein Z ² is a substituted or unsubstituted dibenzofuryl group.
[5] The compound according to any one of [1] to [3], wherein Z ² is a substituted or unsubstituted benzofurocarbazolyl group.
[6] to [1], wherein Z ¹ is a substituted or unsubstituted carbazolyl group and Z ² is a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group; Compound as described.
[7] The compound according to [1], wherein Z ¹ and Z ² are each independently a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group.
[8] The compound according to [1], wherein Z ¹ is a substituted or unsubstituted carbazolyl group and Z ² is a substituted or unsubstituted dibenzofuryl group.
[9] at least one of a carbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, and a dibenzofuryl group present in the molecule is substituted with an aryl group, [1] to [8] A compound according to any one of
[10] The compound according to any one of [1] to [9], wherein R ¹ to R ³ are hydrogen atoms.
[11] A host material containing the compound according to any one of [1] to [10].
[12] The host material of [10] for use with a delayed fluorescence material.
[13] A composition obtained by doping the compound according to any one of [1] to [10] with a delayed fluorescence material.
[14] The composition according to [13], which is in the form of a film.
[15] The composition according to [13] or [14], wherein the delayed fluorescence material is a compound having a cyanobenzene structure in which the benzene ring is substituted with one cyano group.
[16] The composition according to [13] or [14], wherein the delayed fluorescence material is a compound having a cyanobenzene structure in which two cyano groups are substituted on the benzene ring.
[17] The composition according to any one of [13] to [16], further comprising a fluorescent compound having a lower lowest excited singlet energy than the host material and the delayed fluorescent material.
[18] An organic light emitting device having a layer comprising the composition according to any one of [13] to [17].
[19] The organic light emitting device according to [18], wherein the layer consists only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, sulfur atoms, boron atoms and halogen atoms.
[20] The organic light emitting device according to [19], wherein the layer consists only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms and sulfur atoms.
[21] The organic light-emitting device according to any one of [18] to [20], which is an organic electroluminescent device.
[22] The composition according to any one of [18] to [21], wherein the composition does not contain the fluorescent compound, and the maximum component of light emission from the device is light emission from the delayed fluorescence material. organic light-emitting device.
[23] The composition according to any one of [18] to [21], wherein the composition contains the fluorescent compound, and the maximum component of light emission from the device is light emission from the fluorescent compound. Organic light-emitting device.

By using the compound of the present invention, an organic light-emitting device with excellent characteristics can be provided. For example, organic light-emitting devices using the compound of the present invention include organic light-emitting devices with long device life and organic light-emitting devices with high luminous efficiency.

The contents of the present invention will be described in detail below. The constituent elements described below may be explained based on representative embodiments and specific examples of the present invention, but the present invention is not limited to such embodiments and specific examples. In this specification, the numerical range represented by "-" means a range including the numerical values before and after "-" as lower and upper limits. Further, the isotopic species of the hydrogen atom present in the molecule of the compound used in the present invention is not particularly limited.

(Compound represented by general formula (1))
In the present invention, a compound represented by the following general formula (1) is used.

Z ¹ in general formula (1) represents a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzofurocarbazolyl group, or a substituted or unsubstituted benzothienocarbazolyl group. ^Z2 represents a substituted or unsubstituted dibenzofuryl group, a substituted or unsubstituted benzofurocarbazolyl group, or a substituted or unsubstituted benzothienocarbazolyl group. The carbazolyl group, the benzofurocarbazolyl group, and the benzothienocarbazolyl group are groups bonded through a nitrogen atom constituting a carbazole ring.

The benzofurocarbazolyl group and benzothienocarbazolyl group that Z ¹ and Z ² can take are explained.
In the present invention, the ring structure constituting the benzofurocarbazolyl group includes benzofuro[2,3-a]carbazole, benzofuro[3,2-a]carbazole, benzofuro[2,3-b]carbazole, benzofuro[3 ,2-b]carbazole, benzofuro[2,3-c]carbazole, and benzofuro[3,2-c]carbazole may be employed. These ring structures may or may not be condensed with another ring. Preferred is when further rings are not fused.
Preferred benzofurocarbazolyl groups include groups having any of the structures below, and hydrogen atoms in the structures below may or may not be substituted. However, the structures below are not further condensed with other rings. The wavy line represents the binding position.

In the present invention, the ring structure constituting the benzothienocarbazolyl group includes benzothieno[2,3-a]carbazole, benzothieno[3,2-a]carbazole, benzothieno[2,3-b]carbazole, benzothieno[3 ,2-b]carbazole, benzothieno[2,3-c]carbazole, and benzothieno[3,2-c]carbazole may be employed. These ring structures may or may not be condensed with another ring. Preferred is when further rings are not fused.
Preferred benzothienocarbazolyl groups include groups having any of the structures below, and hydrogen atoms in the structures below may or may not be substituted. However, the structures below are not further condensed with other rings. The wavy line represents the binding position.

The benzofurocarbazolyl group and benzothienocarbazolyl group that Z ¹ and Z ² can take may be substituted. It may be unsubstituted. The substituent when substituted may be selected from the following substituent group A, may be selected from the following substituent group B, or may be selected from the following substituent group C It may be selected, may be selected from Substituent Group D below, or may be selected from Substituent Group E below. Substituents selected from Substituent Group E are preferred. For example, it may be substituted only with an alkyl group, may be substituted only with an aryl group, or may be substituted with both an alkyl group and an aryl group.

The "alkyl group" in the present application may be linear, branched or cyclic. Moreover, two or more of the linear portion, the cyclic portion and the branched portion may be mixed. The number of carbon atoms in the alkyl group can be, for example, 1 or more, 2 or more, or 4 or more. Also, the number of carbon atoms can be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, cyclopentyl, A cyclohexyl group and a cycloheptyl group can be mentioned. In one aspect of the invention, the alkyl group has 1 to 4 carbon atoms. In one aspect of the invention, the alkyl group is a methyl group. In one aspect of the invention, the alkyl group is an isopropyl group. In one aspect of the invention, the alkyl group is a tert-butyl group. When multiple alkyl groups are present in the molecule represented by formula (1), the alkyl groups may be the same or different. In one aspect of the present invention, all alkyl groups in the molecule represented by general formula (1) are the same. The number of alkyl groups in the molecule represented by general formula (1) can be 0 or more, 1 or more, 2 or more, 4 or more, and 8 or more. The number of alkyl groups in the molecule represented by formula (1) may be 20 or less, 10 or less, 5 or less, or 3 or less. The number of alkyl groups in the molecule represented by general formula (1) may be zero. The number of alkyl groups referred to here also includes the number of alkyl groups substituted with aryl groups. Also, the alkyl group is an optionally deuterated alkyl group.
The "alkyl group which may be deuterated" in the present application means that at least one hydrogen atom of the alkyl group may be substituted with a deuterium atom. All hydrogen atoms in the alkyl group may be replaced with deuterium atoms. For example, optionally deuterated methyl groups include _CH3 , _CDH2 , _CD2H , _CD3 . The "optionally deuterated alkyl group" is preferably an alkyl group that is not deuterated at all or an alkyl group in which all hydrogen atoms are substituted with deuterium atoms. In one aspect of the present invention, an alkyl group that is not deuterated at all is selected as the "optionally deuterated alkyl group". In one aspect of the present invention, an alkyl group in which all hydrogen atoms are substituted with deuterium atoms is selected as the "optionally deuterated alkyl group". In one aspect of the present invention, the "optionally deuterated alkyl group" is a non-deuterated methyl group [--CH ₃ ], a non-deuterated ethyl group [--CH ₂ CH ₃ ] , non-deuterated isopropyl group [--CH(CH ₃ ) ₂ ], non-deuterated tert-butyl group [--C(CH ₃ ) ₃ ] or all hydrogen atoms deuterated methyl It is the group [-CD ₃ ]. In one aspect of the present invention, an “optionally deuterated alkyl group” is a methyl group that is not deuterated [—CH ₃ ] or a methyl group in which all hydrogen atoms are deuterated [—CD ₃ ]. In one aspect of the present invention, at least one alkyl group having at least one hydrogen atom substituted with a deuterium atom is present in the molecule represented by general formula (1).

An "aryl group" may be a monocyclic ring or a condensed ring in which two or more rings are condensed. When monocyclic, the aryl group is a phenyl group. When it is a condensed ring, the aryl group is a group in which one or more rings are further condensed to the phenyl group. The ring condensed to the phenyl group may be an aromatic hydrocarbon ring, an aromatic heterocyclic ring, an aliphatic hydrocarbon ring, or an aliphatic heterocyclic ring, or a ring in which these are condensed. Preferred are aromatic hydrocarbon rings and aromatic heterocycles. A benzene ring can be mentioned as an aromatic hydrocarbon ring. The benzene ring may be condensed with another benzene ring, or may be condensed with a heterocyclic ring such as a pyridine ring. The aromatic heterocyclic ring means an aromatic ring containing a heteroatom as a ring skeleton-constituting atom, and is preferably a 5- to 7-membered ring, such as a 5-membered ring or a 6-membered ring. can be adopted. In one aspect of the present invention, a furan ring, a thiophene ring, or a pyrrole ring can be employed as the aromatic heterocyclic ring.
Specific examples of rings that constitute the aryl group include a benzene ring and a naphthalene ring. Specific examples of aryl groups include phenyl, naphthalene-1-yl and naphthalene-2-yl groups. These groups given as specific examples may be substituted. Also, the aryl group is an aryl group that may be deuterated.
An "optionally deuterated aryl group" in the present application means that at least one hydrogen atom of the aryl group may be substituted with a deuterium atom. All of the hydrogen atoms in the aryl group may be replaced with deuterium atoms. For example, _optionally deuterated _phenyl groups _{include C6H5 , C6H4D} , _{C6H3D2 , C6H2D3 , C6HD4 , C6D5 .} included. The "optionally deuterated alkyl group" is preferably an aryl group that is not deuterated at all or an aryl group in which all hydrogen atoms are substituted with deuterium atoms. In one aspect of the present invention, an aryl group that is not deuterated at all is selected as the "optionally deuterated aryl group". In one aspect of the present invention, an aryl group in which all hydrogen atoms are substituted with deuterium atoms is selected as the “optionally deuterated aryl group”. In one aspect of the present invention, the “optionally deuterated aryl group” is a non-deuterated phenyl group [—C ₆ H ₅ ], a non-deuterated naphthyl group [—C ₁₀ H ₇ ], a phenyl group in which all hydrogen atoms are deuterated [--C ₆ D ₅ ], and a naphthyl group in which all hydrogen atoms are deuterated [--C ₁₀ D ₇ ].
Specific examples of optionally substituted aryl groups are given below. However, the aryl group that can be employed in the present invention is not limited to the following specific examples. In the following specific examples, * indicates the binding position. Moreover, the display of the methyl group is omitted. Therefore, Ar2 to Ar7 represent structures substituted with methyl groups.

When the benzoflocarbazolyl group and the benzothienocarbazolyl group are substituted with deuterium atoms, only the substituents attached to the benzoflocarbazole ring or benzothienocarbazole ring are substituted with deuterium atoms. Alternatively, all hydrogen atoms present in the benzofurocarbazolyl group or benzothienocarbazolyl group may be substituted with deuterium atoms. For example, only the hydrogen atom of the alkyl group bonded to the benzoflocarbazole ring or benzothienocarbazole ring may be deuterated, or the hydrogen atom of the aryl group bonded to the benzoflocarbazole ring or benzothienocarbazole ring may be deuterated. Only hydrogen atoms may be deuterated. More specifically, benzofurocarbazolyl and benzothienocarbazolyl groups may be substituted, for example, with deuterated methyl groups (CD ₃ ) or deuterated phenyl groups (C ₆ D ₅ ) may be substituted.

In one aspect of the invention, only Z ¹ is a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group.
In one aspect of the invention, only Z ² is a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group.
In one aspect of the present invention, both Z ¹ and Z ² are a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group. In one aspect of the invention, Z ¹ and Z ² are the same. In one aspect of the invention, Z ¹ and Z ² are different.
In one aspect of the invention, at least one of Z ¹ and Z ² is a substituted or unsubstituted benzofurocarbazolyl group. In one aspect of the invention, at least one of Z ¹ and Z ² is a substituted benzofurocarbazolyl group. In one aspect of the invention, at least one of Z ¹ and Z ² is an unsubstituted benzofurocarbazolyl group.
In one aspect of the invention, at least one of Z ¹ and Z ² is a substituted or unsubstituted benzothienocarbazolyl group. In one aspect of the invention, at least one of Z ¹ and Z ² is a substituted benzothienocarbazolyl group. In one aspect of the invention, at least one of Z ¹ and Z ² is an unsubstituted benzothienocarbazolyl group.
In one aspect of the invention, at least one of Z ¹ and Z ² is a substituted benzofurocarbazolyl group. In one aspect of the invention, at least one of Z ¹ and Z ² is a substituted or unsubstituted aryl-substituted benzofurocarbazolyl group. In one aspect of the invention, at least one of Z ¹ and Z ² is an unsubstituted aryl-substituted benzofurocarbazolyl group. In one aspect of the invention, at least one of Z ¹ and Z ² is an unsubstituted phenyl-substituted benzofurocarbazolyl group. In one aspect of the invention, at least one of Z ¹ and Z ² is a substituted benzothienocarbazolyl group. In one aspect of the invention, at least one of Z ¹ and Z ² is a substituted or unsubstituted aryl-substituted benzothienocarbazolyl group. In one aspect of the invention, at least one of Z ¹ and Z ² is an unsubstituted aryl-substituted benzothienocarbazolyl group. In one aspect of the invention, at least one of Z ¹ and Z ² is an unsubstituted phenyl-substituted benzothienocarbazolyl group.

Specific examples of the substituted or unsubstituted benzofurocarbazolyl group and the substituted or unsubstituted benzothienocarbazolyl group that Z ¹ and Z ² can take are given below. However, what can be employed in the present invention is not limitedly interpreted by the following specific examples. In the following specific examples, * indicates a binding position. Moreover, the display of the methyl group is omitted. Therefore, D75 to D92 and D167 to D184 represent structures substituted with methyl groups.

In addition to the above specific examples, D75(m) to _D92 ( _m ) and D167(m ) to D184(m). In addition, groups in which the phenyl groups (C ₆ H ₅ ) of D7 to D74 and D99 to D166 are substituted with deuterated C ₆ D ₅ are respectively D7(p) to D74(p) and D99(p) to exemplified here as D166(p). Furthermore, groups in which all hydrogen atoms of D1 to D184 are deuterated are exemplified here as D1(D) to D184(D), respectively.

Z ¹ in general formula (1) may be a substituted or unsubstituted carbazolyl group. The carbazolyl group referred to herein is a group bonded through a nitrogen atom constituting the ring skeleton of carbazole. One or both of the two benzene rings constituting the carbazolyl group may be condensed with a benzene ring or a hydrocarbon ring. Preferably, the two benzene rings constituting the carbazolyl group are not condensed with another ring.
The carbazolyl group that Z ¹ can take may be substituted. It may be unsubstituted. The substituent when substituted may be selected from the following substituent group A, may be selected from the following substituent group B, or may be selected from the following substituent group C It may be selected, may be selected from Substituent Group D below, or may be selected from Substituent Group E below. Substituents selected from Substituent Group E are preferred. For example, it may be substituted only with an alkyl group, may be substituted only with an aryl group, or may be substituted with both an alkyl group and an aryl group. For the description and preferred range of the alkyl group and aryl group, the description and preferred range of the alkyl group and aryl group as substituents of the benzofurocarbazolyl group and benzothienocarbazolyl group can be referred to.
In one aspect of the invention, Z ¹ is an unsubstituted carbazolyl group. In one aspect of the invention, Z ¹ is a substituted carbazolyl group. In one aspect of the invention, Z ¹ is an alkyl-substituted carbazolyl group. In one aspect of the invention, Z ¹ is an aryl-substituted carbazolyl group. In one aspect of the invention, Z ¹ is a phenyl-substituted carbazolyl group.

Specific examples of the substituted or unsubstituted carbazolyl group that Z ¹ can take are given below. However, what can be employed in the present invention is not limitedly interpreted by the following specific examples. In the following specific examples, * indicates a binding position. Moreover, the display of the methyl group is omitted. Therefore, C2, C3, C5, C7-C9 represent structures substituted with methyl groups.

In addition to the above specific examples, groups in which all hydrogen atoms of C2, C3, C5, and C7 to C12 alkyl groups have been deuterated are substituted with C2(m), C3(m), and C5(m), respectively. ), exemplified here as C7(m)-C12(m). Further, groups in which C4 to C6 phenyl groups (C ₆ H ₅ ) are substituted with deuterated C ₆ D ₅ are exemplified here as C4(p) to C6(p), respectively. Further, groups in which all hydrogen atoms of C1-C12 are deuterated are exemplified herein as C1(D)-C12(D), respectively.

Z ² in general formula (1) may be a substituted or unsubstituted dibenzofuryl group. The dibenzofuryl group referred to herein may be a group bonded at any position on the benzene ring. In one aspect of the invention, Z ¹ is a substituted or unsubstituted dibenzofuran-1-yl group. In one aspect of the invention, Z ¹ is a substituted or unsubstituted dibenzofuran-2-yl group. In one aspect of the invention, Z ¹ is a substituted or unsubstituted dibenzofuran-3-yl group. In one aspect of the invention, Z ¹ is a substituted or unsubstituted dibenzofuran-4-yl group.

The dibenzofuryl group that Z ² can take may be substituted. It may be unsubstituted. The substituent when substituted may be selected from the following substituent group A, may be selected from the following substituent group B, or may be selected from the following substituent group C It may be selected, may be selected from Substituent Group D below, or may be selected from Substituent Group E below. Substituents selected from Substituent Group E are preferred. For example, it may be substituted only with an alkyl group, may be substituted only with an aryl group, or may be substituted with both an alkyl group and an aryl group. For the description and preferred range of the alkyl group and aryl group, the description and preferred range of the alkyl group and aryl group as substituents of the benzofurocarbazolyl group and benzothienocarbazolyl group can be referred to.
In one aspect of the invention, Z ² is an unsubstituted dibenzofuryl group. In one aspect of the invention Z ² is a substituted dibenzofuryl group. In one aspect of the invention, Z ² is an alkyl-substituted dibenzofuryl group. In one aspect of the invention, Z ² is an aryl-substituted dibenzofuryl group. In one aspect of the invention, Z ² is a phenyl-substituted dibenzofuryl group.

Specific examples of the substituted or unsubstituted dibenzofuryl group that Z ² can take are given below. However, what can be employed in the present invention is not limitedly interpreted by the following specific examples. In the following specific examples, * indicates a binding position. Moreover, the display of the methyl group is omitted. Therefore, X20 represents a structure substituted with a methyl group.

In addition to the above specific examples, groups in which the methyl group (CH ₃ ) of X20 is substituted with deuterated CD ₃ are exemplified here as X20(m). Further, groups in which the phenyl groups (C ₆ H ₅ ) of X5 to X19 are substituted with deuterated C ₆ D ₅ are exemplified here as X5(p) to X19(p). Further, groups in which all hydrogen atoms of X1 to X20 are deuterated are exemplified here as X1(D) to X20(D), respectively.

^R2 in general formula (1) represents a hydrogen atom or a deuterium atom. In one aspect of the invention, ^R2 is a hydrogen atom. In one aspect of the invention, ^R2 is a deuterium atom.

R ¹ and R ³ in general formula (1) each independently represent a hydrogen atom, a deuterium atom, or an optionally deuterated alkyl group. For the description and preferred range of the optionally deuterated alkyl group, the description and preferred range of the optionally deuterated alkyl group which is a substituent of the benzofurocarbazolyl group and the benzothienocarbazolyl group Ranges can be referenced.
In one aspect of the invention, R ¹ and R ³ are each independently a hydrogen atom or a deuterium atom. In one aspect of the invention, R ¹ and R ³ are hydrogen atoms. In one aspect of the invention, at least one of R ¹ and R ³ is a substituted or unsubstituted alkyl group. In one aspect of the invention, at least one of R ¹ and R ³ is an unsubstituted alkyl group. In one aspect of the invention, R ¹ is a hydrogen atom or a deuterium atom. In one aspect of the present invention, R ¹ is an optionally deuterated alkyl group. In one aspect of the invention, ^R3 is a hydrogen atom or a deuterium atom. In one aspect of the present invention, R ³ is an optionally deuterated alkyl group. In one aspect of the invention, R ¹ and R ³ are the same. In one aspect of the invention, R ¹ and R ³ are different. In one aspect of the invention, R ¹ -R ³ are each independently a hydrogen atom or a deuterium atom. In one aspect of the invention, R ¹ -R ³ are hydrogen atoms. In one aspect of the invention, R ¹ -R ³ are deuterium atoms.

In one aspect of the present invention, Z ¹ is a substituted or unsubstituted carbazolyl group and Z ² is a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group. In one aspect of the invention, Z ¹ is a substituted or unsubstituted carbazolyl group and Z ² is a substituted or unsubstituted benzofurocarbazolyl group. In one aspect of the invention, Z ¹ is an unsubstituted carbazolyl group and Z ² is an unsubstituted benzofurocarbazolyl group. In one aspect of the invention, Z ¹ is an unsubstituted carbazolyl group and Z ² is a substituted benzofurocarbazolyl group. In one aspect of the invention, Z ¹ is an unsubstituted carbazolyl group and Z ² is an aryl-substituted benzoflocarbazolyl group (eg, a phenyl-substituted benzoflocarbazolyl group). In one aspect of the invention, Z ¹ is a substituted carbazolyl group and Z ² is an unsubstituted benzofurocarbazolyl group. In one aspect of the invention, Z ¹ is a substituted carbazolyl group and Z ² is a substituted benzofurocarbazolyl group. In one aspect of the present invention, Z ¹ is a substituted or unsubstituted carbazolyl group and Z ² is a substituted or unsubstituted benzothienocarbazolyl group. In one aspect of the present invention, Z ¹ is an unsubstituted carbazolyl group and Z ² is an unsubstituted benzothienocarbazolyl group. In one aspect of the invention, Z ¹ is an unsubstituted carbazolyl group and Z ² is a substituted benzothienocarbazolyl group. In one aspect of the invention, Z ¹ is an unsubstituted carbazolyl group and Z ² is an aryl-substituted benzothienocarbazolyl group (eg, a phenyl-substituted benzothienocarbazolyl group). In one aspect of the invention, Z ¹ is a substituted carbazolyl group and Z ² is an unsubstituted benzothienocarbazolyl group. In one aspect of the invention, Z ¹ is a substituted carbazolyl group and Z ² is a substituted benzothienocarbazolyl group.

In one aspect of the present invention, Z ¹ and Z ² are each independently a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group. In one aspect of the invention, Z ¹ and Z ² are different benzofurocarbazolyl groups. In one aspect of the invention, Z ¹ and Z ² are the same benzofurocarbazolyl group. In one aspect of the invention, Z ¹ and Z ² are different benzothienocarbazolyl groups. In one aspect of the invention, Z ¹ and Z ² are the same benzothienocarbazolyl group. In one aspect of the present invention, at least one (preferably both) of Z ¹ and Z ² is a benzofurocarbazolyl group substituted with an aryl group. In one aspect of the present invention, at least one (preferably both) of Z ¹ and Z ² is a benzofurocarbazolyl group substituted with a phenyl group. In one aspect of the present invention, at least one (preferably both) of Z ¹ and Z ² is a benzothienocarbazolyl group substituted with an aryl group. In one aspect of the present invention, at least one (preferably both) of Z ¹ and Z ² is a benzothienocarbazolyl group substituted with a phenyl group.

In one aspect of the present invention, Z ¹ is a substituted or unsubstituted carbazolyl group and Z ² is a substituted or unsubstituted dibenzofuryl group. In one aspect of the present invention, Z ¹ is an unsubstituted carbazolyl group and Z ² is an unsubstituted dibenzofuryl group. In one aspect of the invention, Z ¹ is an unsubstituted carbazolyl group and Z ² is a substituted dibenzofuryl group. In one aspect of the invention, Z ¹ is an unsubstituted carbazolyl group and Z ² is an aryl-substituted dibenzofuryl group (eg, a phenyl-substituted dibenzofuryl group).
In one aspect of the invention, Z ¹ is a substituted carbazolyl group and Z ² is an unsubstituted dibenzofuryl group. In one aspect of the invention, Z ¹ is an aryl-substituted carbazolyl group (eg, a phenyl-substituted carbazolyl group) and Z ² is an unsubstituted dibenzofuryl group.

In one aspect of the present invention, the compound of general formula (1) is represented by general formula (2) below. Here, the description and preferred ranges of R ¹ , R ³ , Z ¹ and Z ² can be referred to the corresponding description of general formula (1).

In one aspect of the present invention, the compound of general formula (1) is represented by general formula (3) below. Here, for the explanation and preferred range of Z ¹ and Z ² , the corresponding description of general formula (1) can be referred to.

The compound represented by general formula (1) does not contain a metal element. In one aspect of the present invention, the compound represented by general formula (1) consists only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms and sulfur atoms. In one aspect of the present invention, the compound represented by general formula (1) consists only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms and oxygen atoms.

As used herein, "substituent group A" means a deuterium atom, a hydroxyl group, a halogen atom (e.g., fluorine atom, chlorine atom, bromine atom, iodine atom), an alkyl group (e.g., 1 to 40 carbon atoms), an alkoxy group. (eg, 1 to 40 carbon atoms), alkylthio groups (eg, 1 to 40 carbon atoms), aryl groups (eg, 6 to 30 carbon atoms), aryloxy groups (eg, 6 to 30 carbon atoms), arylthio groups (eg, 6 carbon atoms) to 30), heteroaryl groups (eg, 5 to 30 ring atoms), heteroaryloxy groups (eg, 5 to 30 ring atoms), heteroarylthio groups (eg, 5 to 30 ring atoms). , acyl group (eg, 1 to 40 carbon atoms), alkenyl group (eg, 1 to 40 carbon atoms), alkynyl group (eg, 1 to 40 carbon atoms), alkoxycarbonyl group (eg, 1 to 40 carbon atoms), aryloxycarbonyl group (eg, 1 to 40 carbon atoms), a heteroaryloxycarbonyl group (eg, 1 to 40 carbon atoms), a silyl group (eg, a trialkylsilyl group having 1 to 40 carbon atoms) and a nitro group. or a group in which two or more are combined.
As used herein, the term "substituent group B" refers to a deuterium atom, an alkyl group (eg, 1 to 40 carbon atoms), an alkoxy group (eg, 1 to 40 carbon atoms), an aryl group (eg, 6 to 30 carbon atoms), Aryloxy groups (eg, 6 to 30 carbon atoms), heteroaryl groups (eg, ring-skeleton atoms of 5 to 30), heteroaryloxy groups (eg, ring-skeleton atoms of 5 to 30), diarylaminoamino groups (eg, carbon It means a group consisting of one or a combination of two or more selected from the group consisting of 0 to 20 atoms).
As used herein, the term "substituent group C" refers to a deuterium atom, an alkyl group (eg, 1 to 20 carbon atoms), an aryl group (eg, 6 to 22 carbon atoms), a heteroaryl group (eg, a ring skeleton having 5 atoms). to 20), diarylamino groups (eg, having 12 to 20 carbon atoms), one or a combination of two or more selected from the group.
As used herein, the term "substituent group D" refers to a deuterium atom, an alkyl group (eg, 1 to 20 carbon atoms), an aryl group (eg, 6 to 22 carbon atoms) and a heteroaryl group (eg, a ring skeleton having 5 atoms). 1 to 20), or a group in which two or more are combined.
As used herein, "substituent group E" means one or two selected from the group consisting of a deuterium atom, an alkyl group (eg, 1 to 20 carbon atoms) and an aryl group (eg, 6 to 22 carbon atoms) It means a group in which the above are combined.

Specific examples of the compound represented by formula (1) are shown below, but the compounds that can be used in the present invention are not limited to these specific examples. Specific examples specified in Tables 1 to 5 below are compounds in which R ¹ to R ³ in general formula (1) are hydrogen atoms. Tables 1-5 identify each structure of compounds 1-38964 by defining Z ¹ and Z ² in each compound. In Table 1, one structure is defined by specifying one ^Z1 and ^{one Z2} in each row, and one compound number is given for each row.

Table 2 identifies each structure of compounds 1-1288 by defining Z ¹ and Z ² in each structure. Each row of Table 2 identifies, in order, 184 compounds with Z ¹ fixed and Z ² varied from D1 to D184. Compounds 1-736 of Table 2 identify the same as compounds 1-736 of Table 1.

Table 3 identifies each structure of compounds 1289-35144 by defining Z ¹ and Z ² in each structure. Each row of Table 3 identifies, in order, 184 compounds with Z ¹ fixed and Z ² varied from D1 to D184.

Table 4 identifies each structure of compounds 35145-35284 by defining Z ¹ and Z ² in each structure. Each row of Table 4 identifies, in order, 20 compounds with Z ¹ fixed and Z ² varied from X1 to X20.

Table 5 identifies each structure of compounds 35285-38964 by defining Z ¹ and Z ² in each structure. Each row of Table 5 identifies, in order, 20 compounds with Z ¹ fixed and Z ² varied from X1 to X20.

Compounds in which hydrogen atoms in compounds 1 to 38964 are replaced with deuterium atoms are exemplified as compounds 1(D) to 38964(D) in this order.
In one aspect of the invention, compounds are selected from compounds 1-1288.
In one aspect of the invention, compounds are selected from compounds 1289-35144. In one aspect of the invention, compounds are selected from compounds 1289-4968. In one aspect of the invention, compounds are selected from compounds 4969-8648. In one aspect of the invention, compounds are selected from compounds 8649-12328. In one aspect of the invention, compounds are selected from compounds 12329-16008. In one aspect of the invention, compounds are selected from compounds 16009-19688. In one aspect of the invention, compounds are selected from compounds 19689-23368. In one aspect of the invention, compounds are selected from compounds 23369-27048. In one aspect of the invention, compounds are selected from compounds 27049-30728. In one aspect of the invention, compounds are selected from compounds 30729-35144.
In one aspect of the invention, compounds are selected from compounds 35145-35284.
In one aspect of the invention, compounds are selected from compounds 35285-38964. In one aspect of the invention, compounds are selected from compounds 35285-35684. In one aspect of the invention, compounds are selected from compounds 35685-36084. In one aspect of the invention, compounds are selected from compounds 36085-36484. In one aspect of the invention, compounds are selected from compounds 36485-36884. In one aspect of the invention, compounds are selected from compounds 36885-37284. In one aspect of the invention, compounds are selected from compounds 37285-37684. In one aspect of the invention, compounds are selected from compounds 37685-38084. In one aspect of the invention, compounds are selected from compounds 38085-38484. In one aspect of the invention, compounds are selected from compounds 38485-38964.

An example of a preferred group of compounds represented by general formula (1) is shown below. Here, in each structure, compounds in which X is O and compounds in which X is S are separately disclosed. This group can be further subdivided into compounds in which X is O and compounds in which X is S.

An example of another preferred group of compounds represented by general formula (1) is given below. Here, in each structure, compounds in which X is O and compounds in which X is S are separately disclosed. This group can be further divided into compounds in which X is O and compounds in which X is S.

An example of another preferred group of compounds represented by general formula (1) is given below.

A compound represented by the general formula (1) is useful as a host material for doping a light-emitting material. It is particularly useful as a host material for doping a delayed fluorescence material. The material to be doped may be not only one kind but also plural kinds. A material to be doped is selected from those having a lowest excited singlet energy lower than that of the compound represented by the general formula (1).
The compound represented by general formula (1) is also useful as a carrier-blocking material, such as an electron-blocking material. It can be effectively used as a barrier layer (for example, an electron barrier layer) in an organic light-emitting device such as an organic electroluminescence device.

(delayed fluorescence material)
A compound represented by the general formula (1) is useful as a host material for use with a delayed fluorescence material.
The term "delayed fluorescence material" as used herein means that in an excited state, reverse intersystem crossing occurs from an excited triplet state to an excited singlet state, and delayed fluorescence is emitted when returning from the excited singlet state to the ground state. It is an organic compound. In the present invention, a delayed fluorescence material is defined as a material that emits fluorescence with an emission lifetime of 100 ns (nanoseconds) or more when measured by a fluorescence lifetime measurement system (such as a streak camera system manufactured by Hamamatsu Photonics).
When the compound represented by the general formula (1) and the delayed fluorescence material are used in combination, the delayed fluorescence material receives energy from the compound represented by the general formula (1) in the excited singlet state to the excited singlet state transition to Further, the delayed fluorescence material may receive energy from the compound represented by general formula (1) in the excited triplet state and transition to the excited triplet state. Since the delayed fluorescent material has a small difference ( _ΔEST ) between the excited singlet energy and the excited triplet energy, the delayed fluorescent material in the excited triplet state is likely to undergo reverse intersystem crossing to the delayed fluorescent material in the excited singlet state. The delayed fluorescent material in the excited singlet state generated by these pathways contributes to light emission.

In the delayed fluorescence material, the difference _ΔEST between the lowest excited singlet energy and the lowest excited triplet energy at 77K is preferably 0.3 eV or less, more preferably 0.25 eV or less, and 0.2 eV or less. is more preferably 0.15 eV or less, more preferably 0.1 eV or less, even more preferably 0.07 eV or less, and even more preferably 0.05 eV or less , is more preferably 0.03 eV or less, and particularly preferably 0.01 eV or less.
If _ΔEST is small, reverse intersystem crossing from the excited singlet state to the excited triplet state is likely to occur due to the absorption of thermal energy, and thus the material functions as a thermally activated delayed fluorescence material. A thermally activated delayed fluorescence material absorbs the heat emitted by the device and relatively easily undergoes reverse intersystem crossing from the excited triplet state to the excited singlet state, and efficiently contributes the excited triplet energy to light emission. can be done.

The lowest excited singlet energy (E _S1 ) and the lowest excited triplet energy (E _T1 ) of the compound in the present invention are values determined by the following procedure. ΔE _ST is a value obtained by calculating E _S1 -E _T1 .
(1) Lowest excited singlet energy (E _S1 )
A thin film or a toluene solution (concentration 10 ⁻⁵ mol/L) of the compound to be measured is prepared and used as a sample. The fluorescence spectrum of this sample is measured at room temperature (300K). In the fluorescence spectrum, the vertical axis is light emission and the horizontal axis is wavelength. A tangent line is drawn to the rise on the short wave side of the emission spectrum, and the wavelength value λedge [nm] at the intersection of the tangent line and the horizontal axis is obtained. A value obtained by converting this wavelength value into an energy value using the following conversion formula is assumed to be _ES1 .
Conversion formula: E _S1 [eV]=1239.85/λedge
The emission spectra in the examples described later were measured using an LED light source (Thorlabs, M300L4) as an excitation light source and a detector (Hamamatsu Photonics, PMA-12 multichannel spectrometer C10027-01).
(2) lowest excited triplet energy (E _T1 )
The same sample used in the measurement of the lowest excited singlet energy (E _S1 ) is cooled to 77 [K] with liquid nitrogen, the sample for phosphorescence measurement is irradiated with excitation light (300 nm), and a detector is used to Measure phosphorescence. Emission after 100 milliseconds from irradiation with excitation light is defined as a phosphorescence spectrum. A tangent line is drawn to the rising edge of the phosphorescence spectrum on the short wavelength side, and the wavelength value λedge [nm] at the intersection of the tangent line and the horizontal axis is obtained. A value obtained by converting this wavelength value into an energy value using the following conversion formula is defined as _ET1 .
Conversion formula: E _T1 [eV]=1239.85/λedge
A tangent line to the rise on the short wavelength side of the phosphorescence spectrum is drawn as follows. When moving on the spectrum curve from the short wavelength side of the phosphorescence spectrum to the maximum value on the shortest wavelength side among the maximum values of the spectrum, consider the tangent line at each point on the curve toward the long wavelength side. This tangent line increases in slope as the curve rises (ie as the vertical axis increases). The tangent line drawn at the point where the value of this slope takes the maximum value is taken as the tangent line to the rise on the short wavelength side of the phosphorescence spectrum.
In addition, the maximum point with a peak intensity of 10% or less of the maximum peak intensity of the spectrum is not included in the maximum value on the shortest wavelength side described above, and is closest to the maximum value on the short wavelength side. The tangent line drawn at the point where the value is taken is taken as the tangent line to the rise on the short wavelength side of the phosphorescence spectrum.

In a preferred embodiment of the present invention, a compound (cyanobenzene derivative) having a cyanobenzene structure in which the benzene ring is substituted with one cyano group is used as the delayed fluorescence material. In another preferred embodiment of the present invention, a compound (dicyanobenzene derivative) having a dicyanobenzene structure in which two cyano groups are substituted on the benzene ring is used as the delayed fluorescence material. In another preferred embodiment of the present invention, a compound (azabenzene derivative) having an azabenzene structure in which at least one carbon atom constituting the ring skeleton of a benzene ring is substituted with a nitrogen atom is used as the delayed fluorescence material.

一般式（４）において、Ｒ^２１～Ｒ^２３のうち１つはシアノ基または下記一般式（５）で表される基を表し、Ｒ^２１～Ｒ^２３の残りの２つとＲ^２４およびＲ^２５のうちの少なくとも１つは下記一般式（６）で表される基を表し、Ｒ^２１～Ｒ^２５の残りは水素原子または置換基（ただしここでいう置換基はシアノ基、下記一般式（５）で表される基、下記一般式（６）で表される基ではない）を表す。

一般式（５）において、Ｌ^１は単結合もしくは２価の連結基を表し、Ｒ^３１およびＲ^３２は各々独立に水素原子または置換基を表し、＊は結合位置を表す。

一般式（６）において、Ｌ^２は単結合または２価の連結基を表し、Ｒ^３３およびＲ^３４は各々独立に水素原子または置換基を表し、＊は結合位置を表す。 In a preferred embodiment of the present invention, a compound represented by the following general formula (4) is used as the delayed fluorescence material.

In general formula (4), one of R ²¹ to R ²³ represents a cyano group or a group represented by general formula (5) below, and the remaining two of R ²¹ to R ²³ and R ²⁴ and R ²⁵ At least one of them represents a group represented by the following general formula (6), and the rest of R ²¹ to R ²⁵ are hydrogen atoms or substituents (wherein the substituent here is a cyano group, the following general formula (5) is not a group represented by the following general formula (6)).

In general formula (5), L ¹ represents a single bond or a divalent linking group, R ³¹ and R ³² each independently represent a hydrogen atom or a substituent, and * represents a bonding position.

In general formula (6), ^L2 represents a single bond or a divalent linking group, ^R33 and ^R34 each independently represent a hydrogen atom or a substituent, and * represents a bonding position.

In one preferred aspect of the invention, R ²² is a cyano group. In a preferred embodiment of the present invention, R ²² is a group represented by general formula (5). In one aspect of the present invention, R ²¹ is a cyano group or a group represented by general formula (5). In one aspect of the present invention, R ²³ is a cyano group or a group represented by general formula (5). In one aspect of the invention, one of R ²¹ to R ²³ is a cyano group. In one aspect of the present invention, one of R ²¹ to R ²³ is a group represented by general formula (5).

In a preferred embodiment of the present invention, L ¹ in general formula (5) is a single bond. In one aspect of the present invention, L ¹ is a divalent linking group, preferably a substituted or unsubstituted arylene group or a substituted or unsubstituted heteroarylene group, more preferably a substituted or unsubstituted arylene group and more preferably a substituted or unsubstituted 1,4-phenylene group (for example, an alkyl group having 1 to 3 carbon atoms as a substituent).
In one aspect of the present invention, R ³¹ and R ³² in general formula (5) are each independently an alkyl group (eg, 1 to 40 carbon atoms), an aryl group (eg, 6 to 30 carbon atoms), a heteroaryl group (eg, one group selected from the group consisting of 5 to 30 ring skeleton atoms), an alkenyl group (for example, 1 to 40 carbon atoms) and an alkynyl group (for example, 1 to 40 carbon atoms), or a combination of two or more (these groups are hereinafter referred to as "substituent group A groups"). In a preferred embodiment of the present invention, each of R ³¹ and R ³² is independently a substituted or unsubstituted aryl group (eg, having 6 to 30 carbon atoms), and the substituent of the aryl group is a group of substituent group A. can be mentioned. In one preferred aspect of the invention, R ³¹ and R ³² are the same.

In a preferred embodiment of the present invention, ^L2 in general formula (6) is a single bond. In one aspect of the present invention, ^L2 is a divalent linking group, preferably a substituted or unsubstituted arylene group or a substituted or unsubstituted heteroarylene group, more preferably a substituted or unsubstituted arylene group and more preferably a substituted or unsubstituted 1,4-phenylene group (for example, an alkyl group having 1 to 3 carbon atoms as a substituent).
In one aspect of the present invention, R ³³ and R ³⁴ in general formula (6) are each independently a substituted or unsubstituted alkyl group (eg, 1 to 40 carbon atoms), a substituted or unsubstituted alkenyl group (eg, 1 to 40), a substituted or unsubstituted aryl group (eg, 6 to 30 carbon atoms), or a substituted or unsubstituted heteroaryl group (eg, 5 to 30 carbon atoms). Examples of substituents of the alkyl group, alkenyl group, aryl group, and heteroaryl group referred to herein include hydroxyl group, halogen atom (eg, fluorine atom, chlorine atom, bromine atom, iodine atom), alkyl group (eg, C 1-40 ), an alkoxy group (eg, 1 to 40 carbon atoms), an alkylthio group (eg, 1 to 40 carbon atoms), an aryl group (eg, 6 to 30 carbon atoms), an aryloxy group (eg, 6 to 30 carbon atoms), an arylthio group ( (e.g., 6 to 30 carbon atoms), heteroaryl groups (e.g., 5 to 30 ring atoms), heteroaryloxy groups (e.g., 5 to 30 ring atoms), heteroarylthio groups (e.g., ring atoms) 5 to 30), acyl groups (eg, 1 to 40 carbon atoms), alkenyl groups (eg, 1 to 40 carbon atoms), alkynyl groups (eg, 1 to 40 carbon atoms), alkoxycarbonyl groups (eg, 1 to 40 carbon atoms), consisting of an aryloxycarbonyl group (eg, 1 to 40 carbon atoms), a heteroaryloxycarbonyl group (eg, 1 to 40 carbon atoms), a silyl group (eg, a trialkylsilyl group having 1 to 40 carbon atoms), a nitro group and a cyano group; One group selected from the group or a combination of two or more groups can be mentioned (these groups are hereinafter referred to as "substituent group B groups").
R ³³ and R ³⁴ may be bonded to each other via a single bond or a linking group to form a cyclic structure. In particular, when R ³³ and R ³⁴ are aryl groups, they are preferably bonded to each other via a single bond or a linking group to form a cyclic structure. Examples of the linking group here include -O-, -S-, -N(R ³⁵ )-, -C(R ³⁶ )(R ³⁷ )-, -C(=O)-, and -O -, -S-, -N(R ³⁵ )- and -C(R ³⁶ )(R ³⁷ )- are preferred, and -O-, -S- and -N(R ³⁵ )- are more preferred. R ³⁵ to R ³⁷ each independently represent a hydrogen atom or a substituent. As the substituent, a group of the substituent group A can be selected, or a group of the substituent group B below can be selected, preferably an alkyl group having 1 to 10 carbon atoms and a group having 6 to 14 carbon atoms. It is one group or a combination of two or more groups selected from the group consisting of aryl groups.

The group represented by general formula (6) is preferably a group represented by general formula (7) below.

^L11 in general formula (7) represents a single bond or a divalent linking group. The description and preferred range of L ¹¹ can be referred to the description and preferred range of L ² above.
Each of R ⁴¹ to R ⁴⁸ in general formula (7) independently represents a hydrogen atom or a substituent. R ⁴¹ and R ⁴² , R ⁴² and R ⁴³ , R ⁴³ and R ⁴⁴ , R ⁴⁴ and R ⁴⁵ , R ⁴⁵ and R ⁴⁶ , R ⁴⁶ and R ⁴⁷ , R ⁴⁷ and R ⁴⁸ are bonded to each other to form a cyclic structure. may be formed. The cyclic structure formed by bonding to each other may be an aromatic ring or an alicyclic ring, or may contain a heteroatom, and the cyclic structure may be a condensed ring of two or more rings. . The heteroatoms referred to here are preferably those selected from the group consisting of nitrogen atoms, oxygen atoms and sulfur atoms. Examples of cyclic structures formed include benzene ring, naphthalene ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, pyrrole ring, imidazole ring, pyrazole ring, imidazoline ring, oxazole ring, isoxazole ring, thiazole ring, iso thiazole ring, cyclohexadiene ring, cyclohexene ring, cyclopentaene ring, cycloheptatriene ring, cycloheptadiene ring, cycloheptaene ring, furan ring, thiophene ring, naphthyridine ring, quinoxaline ring, quinoline ring and the like. . For example, a ring formed by condensing a large number of rings such as a phenanthrene ring or a triphenylene ring may be formed. The number of rings contained in the group represented by general formula (7) may be selected from the range of 3-5, or may be selected from the range of 5-7.
Examples of substituents that R ⁴¹ to R ⁴⁸ can take include the groups of the above substituent group B, preferably unsubstituted alkyl groups having 1 to 10 carbon atoms or unsubstituted alkyl groups having 1 to 10 carbon atoms. It is an aryl group having 6 to 10 carbon atoms which may be substituted with an alkyl group. In a preferred embodiment of the present invention, R ⁴¹ to R ⁴⁸ are hydrogen atoms or unsubstituted alkyl groups having 1 to 10 carbon atoms. In a preferred embodiment of the present invention, R ⁴¹ to R ⁴⁸ are hydrogen atoms or unsubstituted aryl groups having 6 to 10 carbon atoms. In a preferred embodiment of the present invention, all of R ⁴¹ to R ⁴⁸ are hydrogen atoms.
In general formula (7), * represents a bonding position.

In a preferred embodiment of the present invention, an azabenzene derivative is used as the delayed fluorescence material. In a preferred embodiment of the present invention, the azabenzene derivative has an azabenzene structure in which three of the ring skeleton-constituting carbon atoms of the benzene ring are substituted with nitrogen atoms. For example, an azabenzene derivative having a 1,3,5-triazine structure can be preferably selected. In a preferred embodiment of the present invention, the azabenzene derivative has an azabenzene structure in which two of the ring skeleton-constituting carbon atoms of the benzene ring are substituted with nitrogen atoms. For example, azabenzene derivatives having a pyridazine structure, a pyrimidine structure, and a pyrazine structure can be mentioned, and azabenzene derivatives having a pyrimidine structure can be preferably selected. In one aspect of the present invention, the azabenzene derivative has a pyridine structure in which one of the ring skeleton-constituting carbon atoms of the benzene ring is substituted with a nitrogen atom.

一般式（８）において、Ｙ^１、Ｙ^２およびＹ^３は、少なくとも１つが窒素原子で残りがメチン基を表す。本発明の一態様では、Ｙ^１が窒素原子で、Ｙ^２およびＹ^３がメチン基である。好ましくはＹ^１およびＹ^２が窒素原子で、Ｙ^３がメチン基である。より好ましくは、Ｙ^１～Ｙ^３のすべてが窒素原子である。
一般式（８）において、Ｚ^１～Ｚ^３は、各々独立に水素原子または置換基を表すが、少なくとも１つはドナー性の置換基である。ドナー性の置換基は、ハメットのσｐ値が負の基を意味する。好ましくは、Ｚ^１～Ｚ^３の少なくとも１つは、ジアリールアミノ構造（窒素原子に結合する２つのアリール基は互いに結合していてもよい）を含む基であり、より好ましくは上記一般式（６）で表される基であり、例えば上記一般式（７）で表される基である。本発明の一態様では、Ｚ^１～Ｚ^３の１つだけが一般式（６）または（７）で表される基である。本発明の一態様では、Ｚ^１～Ｚ^３の２つだけが各々独立に一般式（６）または（７）で表される基である。本発明の一態様では、Ｚ^１～Ｚ^３のすべてが各々独立に一般式（６）または（７）で表される基である。一般式（６）および一般式（７）の詳細と好ましい範囲については、上記の対応する記載を参照することができる。一般式（６）および一般式（７）で表される基ではない、残りのＺ^１～Ｚ^３は、置換もしくは無置換のアリール基（例えば炭素数６～４０、好ましくは６～２０）であることが好ましく、ここでいうアリール基の置換基としては、アリール基（例えば炭素数６～２０、好ましくは６～１４）およびアルキル基（例えば炭素数１～２０、好ましくは１～６）からなる群より選択される１つの基または２つ以上を組み合わせた基を例示することができる。本発明の一態様では、一般式（８）はシアノ基を含まない。 In a preferred embodiment of the present invention, a compound represented by the following general formula (8) is used as the delayed fluorescence material.

In general formula (8), at least one of Y ¹ , Y ² and Y ³ represents a nitrogen atom and the rest represent methine groups. In one aspect of the invention, Y ¹ is a nitrogen atom and Y ² and Y ³ are methine groups. Y ¹ and Y ² are preferably nitrogen atoms and Y ³ is preferably a methine group. More preferably, all of Y ¹ to Y ³ are nitrogen atoms.
In general formula (8), Z ¹ to Z ³ each independently represent a hydrogen atom or a substituent, at least one of which is a donor substituent. A donor substituent means a group having a negative Hammett's σp value. Preferably, at least one of Z ¹ to Z ³ is a group containing a diarylamino structure (two aryl groups bonded to the nitrogen atom may be bonded to each other), more preferably the general formula (6 ), for example, a group represented by the general formula (7). In one aspect of the present invention, only one of Z ¹ to Z ³ is a group represented by general formula (6) or (7). In one aspect of the present invention, only two of Z ¹ to Z ³ are each independently a group represented by general formula (6) or (7). In one aspect of the present invention, all of Z ¹ to Z ³ are each independently a group represented by general formula (6) or (7). For details and preferred ranges of general formulas (6) and (7), reference can be made to the corresponding description above. The remaining Z ¹ to Z ³ that are not groups represented by general formulas (6) and (7) are substituted or unsubstituted aryl groups (eg, 6 to 40 carbon atoms, preferably 6 to 20 carbon atoms). The substituents of the aryl group referred to herein include an aryl group (eg, 6 to 20 carbon atoms, preferably 6 to 14 carbon atoms) and an alkyl group (eg, 1 to 20 carbon atoms, preferably 1 to 6). One group selected from the following group or a combination of two or more groups can be exemplified. In one aspect of the present invention, general formula (8) does not contain a cyano group.

一般式（９）において、Ａｒ¹は、下記Ａ^１およびＤ^１に置換されていてもよい環状構造を形成し、ベンゼン環、ナフタレン環、アントラセン環、またはフェナントレン環を表す。Ａｒ^２、Ａｒ^３は、それぞれ環状構造を形成していてもよく、環状構造を形成している場合はベンゼン環、ナフタレン環、ピリジン環、またはシアノ基で置換されたベンゼン環を表す。ｍ１は０～２のいずれかの整数を表し、ｍ２は０～１のいずれかの整数を表す。Ａ^１はシアノ基、フェニル基、ピリミジル基、トリアジル基、もしくはベンゾニトリル基を表す。Ｄ^１は、置換もしくは無置換の５Ｈ－インドロ［３，２，１－ｄｅ］フェナジンー５－イル基、またはナフタレン構造を含まない置換もしくは無置換のヘテロ環縮合カルバゾリル基を表し、一般式（９）中に複数のＤ^１が存在する場合それらは同一でも異なっていてもよい。また、Ｄ^１の置換基は、互いに結合して環状構造を形成していてもよい。 In a preferred embodiment of the present invention, a compound represented by the following general formula (9) is used as the delayed fluorescence material.

In general formula (9), Ar ¹ forms a cyclic structure that may be substituted with A ¹ and D ¹ below, and represents a benzene ring, naphthalene ring, anthracene ring, or phenanthrene ring. Ar ² and Ar ³ each may form a cyclic structure, and when they form a cyclic structure, they represent a benzene ring, a naphthalene ring, a pyridine ring, or a cyano-substituted benzene ring. m1 represents an integer of 0 to 2; m2 represents an integer of 0 to 1; ^A1 represents a cyano group, a phenyl group, a pyrimidyl group, a triazyl group, or a benzonitrile group. D ¹ represents a substituted or unsubstituted 5H-indolo[3,2,1-de]phenazin-5-yl group or a substituted or unsubstituted heterocyclic condensed carbazolyl group containing no naphthalene structure; ), they may be the ^same or different. Also, the substituents of D ¹ may be bonded to each other to form a cyclic structure.

Preferred compounds that can be used as the delayed fluorescence material are listed below, but the delayed fluorescence material that can be used in the present invention is not limited to these specific examples.

In the present invention, known delayed fluorescence materials other than those described above can be used in appropriate combination with the compound represented by general formula (1). Moreover, even unknown delayed fluorescence materials can be used.
As the delayed fluorescence material, paragraphs 0008 to 0048 and 0095 to 0133 of WO2013/154064, paragraphs 0007 to 0047 and 0073 to 0085 of WO2013/011954, paragraphs 0007 to 0033 and 0059 to 0066 of WO2013/011955, Paragraphs 0008 to 0071 and 0118 to 0133 of WO2013/081088, paragraphs 0009 to 0046 and 0093 to 0134 of JP 2013-256490, paragraphs 0008 to 0020 and 0038 to 0040 of JP 2013-116975, WO2013 / Paragraphs 0007 to 0032 and 0079 to 0084 of 133359, paragraphs 0008 to 0054 and 0101 to 0121 of WO2013/161437, paragraphs 0007 to 0041 and 0060 to 0069 of JP 2014-9352, JP 2014- 9224, paragraphs 0008 to 0048 and 0067 to 0076, JP 2017-119663, paragraphs 0013 to 0025, JP 2017-119664, paragraphs 0013 to 0026, JP 2017-222623, paragraph 0012 to 0025, paragraphs 0010 to 0050 of JP-A-2017-226838, paragraphs 0012-0043 of JP-A-2018-100411, and compounds included in the general formulas described in paragraphs 0016-0044 of WO2018/047853, In particular, exemplary compounds that emit delayed fluorescence can be mentioned. Further, JP 2013-253121, WO2013/133359, WO2014/034535, WO2014/115743, WO2014/122895, WO2014/126200, WO2014/136758, WO2014/13 3121 Publications, WO2014/136860, WO2014/196585, WO2014/189122, WO2014/168101, WO2015/008580, WO2014/203840, WO2015/002213, WO2015/ 016200 publication, WO2015/019725, WO2015/072470, WO2015/108049, WO2015/080182, WO2015/072537, WO2015/080183, JP 2015-129240, WO2015/129 714 publication, WO2015/129715, WO2015/133501, WO2015/136880, WO2015/137244, WO2015/137202, WO2015/137136, WO2015/146541, WO2015/15 9541 publication A luminescent material that emits delayed fluorescence can also be employed. The above publications mentioned in this paragraph are hereby incorporated by reference as part of this specification.

The delayed fluorescence material used in the present invention preferably does not contain metal atoms. For example, as the delayed fluorescence material, a compound composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms and sulfur atoms can be selected. For example, as the delayed fluorescence material, a compound composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms and oxygen atoms can be selected. For example, a compound composed of carbon atoms, hydrogen atoms and nitrogen atoms can be selected as the delayed fluorescence material.

Alkyl groups, alkenyl groups, aryl groups, heteroaryl groups, and the like in the present specification have the following meanings unless otherwise specified.
The "alkyl group" may be linear, branched or cyclic. Moreover, two or more of the linear portion, the cyclic portion and the branched portion may be mixed. The number of carbon atoms in the alkyl group can be, for example, 1 or more, 2 or more, or 4 or more. Also, the number of carbon atoms can be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, n-hexyl group, isohexyl group, 2-ethylhexyl group, n-heptyl group, isoheptyl group, n-octyl group, isooctyl group, n-nonyl group, isononyl group, n-decanyl group, isodecanyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group. can. The alkyl group as a substituent may be further substituted with an aryl group. For the alkyl moieties of "alkoxy group", "alkylthio group", "acyl group" and "alkoxycarbonyl group", the description of "alkyl group" herein can also be referred to.
An "alkenyl group" may be linear, branched, or cyclic. Moreover, two or more of the linear portion, the cyclic portion and the branched portion may be mixed. The number of carbon atoms in the alkenyl group can be, for example, 2 or more and 4 or more. Also, the number of carbon atoms can be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of alkenyl groups include ethenyl, n-propenyl, isopropenyl, n-butenyl, isobutenyl, n-pentenyl, isopentenyl, n-hexenyl, isohexenyl, and 2-ethylhexenyl groups. can be mentioned. The alkenyl group as a substituent may be further substituted with a substituent.
The “aryl group” and “heteroaryl group” may be monocyclic or condensed rings in which two or more rings are condensed. In the case of condensed rings, the number of condensed rings is preferably 2 to 6, and can be selected from 2 to 4, for example. Specific examples of rings include benzene ring, pyridine ring, pyrimidine ring, triazine ring, naphthalene ring, anthracene ring, phenanthrene ring, triphenylene ring, quinoline ring, pyrazine ring, quinoxaline ring, and naphthyridine ring. Specific examples of aryl or heteroaryl groups include phenyl, 1-naphthyl, 2-naphthyl, 1-anthracenyl, 2-anthracenyl, 9-anthracenyl, 2-pyridyl, 3-pyridyl, 4 - pyridyl group. "Arylene group" and "heteroaryl group" can be read by changing the valence number from 1 to 2 in the description of the aryl group and heteroaryl group. For the aryl moieties of the "aryloxy group", "arylthio group" and "aryloxycarbonyl group", the description of the "aryl group" herein can also be referred to. For the heteroaryl portion of the "heteroaryloxy group", "heteroarylthio group" and "heteroaryloxycarbonyl group", the description of the "heteroaryl group" can be referred to.

(Composition)
The composition of the present invention contains a compound represented by formula (1) and a delayed fluorescence material. In one aspect of the present invention, the composition is composed only of one or more compounds represented by general formula (1) and one or more delayed fluorescence materials. In one aspect of the present invention, the composition comprises only one type of compound represented by general formula (1) and one type of delayed fluorescence material. In one aspect of the present invention, the composition contains a third component in addition to the compound represented by formula (1) and the delayed fluorescence material. The third component here is neither the compound represented by the general formula (1) nor the delayed fluorescence material. Only one type of the third component may be contained, or two or more types may be contained. The content of the third component in the composition may be selected within the range of 30% by weight or less, may be selected within the range of 10% by weight or less, or may be selected within the range of 1% by weight or less. It may be selected, or may be selected within the range of 0.1% by weight or less. In one aspect of the invention, the third component does not emit light. In one aspect of the invention, the third component emits fluorescence. In one preferred aspect of the present invention, the largest component of luminescence from the composition of the present invention is fluorescence (including delayed fluorescence).
In the composition of the present invention, the content of the compound represented by general formula (1) is greater than that of the delayed fluorescence material on a weight basis. The content of the compound represented by the general formula (1) may be selected within a range of 3 times or more by weight the content of the delayed fluorescence material, or may be selected within a range of 10 times or more by weight. However, it may be selected within a range of 100 times by weight or more, may be selected within a range of 1000 times by weight or more, or may be selected within a range of, for example, 10000 times by weight or less.
In the composition of the present invention, it is preferable to select a delayed fluorescence material having an excited singlet energy smaller than the excited singlet energy of the compound represented by formula (1). The difference in excited singlet energy may be 0.1 eV or more, 0.3 eV or more, or 0.5 eV or more, and may be 2 eV or less, 1.5 eV or less, or 1.0 eV or less. You can
The composition of the present invention preferably does not contain metal elements. In one aspect of the invention, the composition of the invention consists exclusively of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, sulfur atoms, boron atoms and halogen atoms. In one aspect of the invention, the composition of the invention consists exclusively of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms and sulfur atoms.

Moreover, in one aspect of the present invention, the compound represented by the general formula (1) is useful as a host material for use together with the delayed fluorescence material and the fluorescent compound. Therefore, in one aspect of the present invention, the composition of the present invention contains a fluorescent compound in addition to the compound represented by formula (1) and the delayed fluorescent material.

The fluorescent compound preferably has a lower lowest excited singlet energy (E _S1 ) than the compound represented by formula (1) and the delayed fluorescent material. The fluorescent compound absorbs energy from the compound represented by general formula (1) in the excited singlet state, the delayed fluorescent material, and the delayed fluorescent material in the excited singlet state through inverse intersystem crossing from the excited triplet state. It receives and transitions to a singlet excited state, and then emits fluorescence when returning to the ground state. The fluorescent compound is not particularly limited as long as it can receive energy from the compound represented by the general formula (1) and the delayed fluorescence material and emit fluorescence. It may be delayed fluorescence. Among them, the luminescent material used as the fluorescent compound preferably emits fluorescence when returning from the lowest excited singlet energy level to the ground energy level. Two or more fluorescent compounds may be used. For example, by using two or more fluorescent compounds with different emission colors, it is possible to emit light of a desired color.
Examples of fluorescent compounds include anthracene derivatives, tetracene derivatives, naphthacene derivatives, pyrene derivatives, perylene derivatives, chrysene derivatives, rubrene derivatives, coumarin derivatives, pyran derivatives, stilbene derivatives, fluorene derivatives, anthryl derivatives, pyrromethene derivatives, terphenyl derivatives, terphenyl derivatives, Phenylene derivatives, fluoranthene derivatives, amine derivatives, quinacridone derivatives, oxadiazole derivatives, malononitrile derivatives, pyran derivatives, carbazole derivatives, julolidine derivatives, thiazole derivatives, derivatives containing metals (Al, Zn), diazaboranaphthoanthracene, etc. A compound having a multiple resonance effect such as a compound having a boron polycyclic aromatic skeleton can be used. These exemplified skeletons may or may not have a substituent. Also, these exemplary skeletons may be combined.

Specific examples of the fluorescent compound include the compounds given as specific examples of the delayed fluorescence material. At this time, the composition of the present invention contains two or more delayed fluorescence materials, and the one with the higher lowest singlet excited energy functions as an assist dopant, and the one with the lower lowest singlet excited energy functions as a fluorescent compound that mainly emits light. The compound used as the fluorescent compound preferably exhibits a PL emission quantum yield of 60% or more, more preferably 80% or more. The compound used as the fluorescent compound preferably exhibits an instantaneous fluorescence lifetime of 50 ns or less, more preferably 20 ns or less. The instantaneous fluorescence lifetime at this time is the luminescence lifetime of the fastest decaying component among multiple exponentially decaying components observed when luminescence lifetime measurement is performed for a compound exhibiting thermally activated delayed fluorescence. The compound used as the third compound preferably has a fluorescence emission rate from the lowest excited singlet (S1) to the ground state higher than an intersystem crossing rate from S1 to the lowest excited triplet (T1). Methods for calculating the rate constant of a compound are described in known literature on thermally activated delayed fluorescence materials (H. Uoyama, et al., Nature 492, 234 (2012) and K. Masui, et al., Org. Electron. 14 , 2721, (2013), etc.).

Preferred compounds that can be used as the fluorescent compound used together with the delayed fluorescent material are listed below, but the fluorescent compound that can be used in the present invention is not limited to these specific examples.

Compounds described in paragraphs 0220 to 0239 of WO2015/022974 can also be particularly preferably employed as the fluorescent compound of the present invention.

In one embodiment of the present invention, the compound represented by General Formula (1) can be used together with another host material for a light-emitting layer (composition) containing a plurality of host materials. That is, in one aspect of the present invention, the composition of the present invention contains multiple host materials containing the compound represented by general formula (1). In the composition of the present invention, a plurality of types of compounds represented by general formula (1) may be used, or a compound represented by general formula (1) and a host material not represented by general formula (1) may be used. They may be used in combination.
Preferred compounds that can be used as the second host material together with the compound represented by the general formula (1) are listed below. It should not be interpreted restrictively.

The form of the composition of the present invention is not particularly limited. In a particularly preferred embodiment of the invention, the composition of the invention is in the form of a film. A film comprising the composition of the present invention may be formed by a wet process or a dry process.
In the wet process, a solution in which the composition of the present invention is dissolved is applied to the surface, and the luminescent layer is formed after removing the solvent. Examples of wet processes include spin coating, slit coating, inkjet (spray), gravure printing, offset printing, and flexographic printing, but are not limited to these. In the wet process, a suitable organic solvent is selected and used that is capable of dissolving the composition of the present invention. In certain embodiments, compounds included in compositions of the present invention can be introduced with substituents (eg, alkyl groups) that increase their solubility in organic solvents.
A vacuum vapor deposition method can be preferably employed as the dry process. When a vacuum deposition method is employed, each compound constituting the composition of the present invention may be co-deposited from individual deposition sources, or all the compounds may be co-deposited from a single deposition source mixed. . When a single vapor deposition source is used, a mixed powder obtained by mixing powders of all the compounds may be used, a compression molding obtained by compressing the mixed powder may be used, or each compound may be heat-melted and mixed. A mixture that has been cooled after heating may be used. In one embodiment, the composition ratio of the plurality of compounds contained in the vapor deposition source is reduced by performing co-deposition under conditions in which the vapor deposition rates (weight reduction rates) of the plurality of compounds contained in the single vapor deposition source match or substantially match. It is possible to form a film having a composition ratio corresponding to A film having a desired composition ratio can be easily formed by mixing a plurality of compounds at the same composition ratio as that of the film to be formed, and using this as an evaporation source. In one embodiment, the temperature at which each of the co-deposited compounds has the same weight loss rate can be identified and used as the temperature during co-deposition. When the film is formed by a vapor deposition method, the molecular weight of each compound constituting the composition is preferably 1500 or less, more preferably 1200 or less, further preferably 1000 or less, and 900 or less. It is even more preferred to have The lower limit of the molecular weight may be 450, 500, or 600, for example.

(Organic light-emitting device)
Excellent organic light-emitting devices such as organic photoluminescence devices (organic PL devices) and organic electroluminescence devices (organic EL devices) can be provided by forming a light-emitting layer comprising the composition of the present invention. The organic light-emitting device of the present invention is a fluorescent light-emitting device, and the largest component of light emitted from the device is fluorescence (the fluorescence referred to herein includes delayed fluorescence).
The thickness of the light-emitting layer can be, for example, 1-15 nm, 2-10 nm, or 3-7 nm.
An organic photoluminescence device has a structure in which at least a light-emitting layer is formed on a substrate. Also, the organic electroluminescence element has a structure in which at least an anode, a cathode, and an organic layer are formed between the anode and the cathode. The organic layer includes at least a light-emitting layer, and may consist of only the light-emitting layer, or may have one or more organic layers in addition to the light-emitting layer. Such other organic layers can include hole transport layers, hole injection layers, electron blocking layers, hole blocking layers, electron injection layers, electron transport layers, exciton blocking layers, and the like. The hole transport layer may be a hole injection transport layer having a hole injection function, and the electron transport layer may be an electron injection transport layer having an electron injection function.
When the organic light-emitting device of the present invention is a multi-wavelength light-emitting organic light-emitting device, the emission with the shortest wavelength may include delayed fluorescence. In addition, it is also possible that the emission with the shortest wavelength does not contain delayed fluorescence.
An organic light-emitting device using the composition of the present invention, when excited by thermal or electronic means, has a blue, green, yellow, orange, and red region (for example, 420-500 nm, 500 nm) in the ultraviolet region and the visible spectrum. ~600 nm or 600-700 nm) or in the near infrared region. For example, organic light emitting devices can emit light in the red or orange region (eg, 620-780 nm). For example, organic light emitting devices can emit light in the orange or yellow region (eg, 570-620 nm). For example, an organic light emitting device can emit light in the green region (eg, 490-575 nm). For example, an organic light emitting device can emit light in the blue region (eg, 400-490 nm). For example, organic light emitting devices can emit light in the ultraviolet spectral region (eg, 280-400 nm). For example, organic light emitting devices can emit light in the infrared spectral region (eg, 780 nm to 2 μm).
It is preferable that the largest component of light emitted from the organic light-emitting device using the composition of the present invention is light emitted from the delayed fluorescence material contained in the composition of the present invention. Emission from the compound represented by the general formula (1) is preferably less than 10% of the light emission from the organic light-emitting device, for example, less than 1%, less than 0.1%, less than 0.01%, detection limit It may be below. Emission from the delayed fluorescence material may be, for example, greater than 50%, greater than 90%, greater than 99% of the emission from the organic light emitting device. When the layer containing the composition of the present invention (light-emitting layer) contains a fluorescent material as the third component, the maximum component of light emitted from the organic light-emitting device may be light emitted from the fluorescent material. In that case, the emission from the luminescent material may be, for example, greater than 50%, greater than 90%, greater than 99% of the emission from the organic light emitting device.

Each member of the organic electroluminescence element and each layer other than the light-emitting layer will be described below.

Base material:
In some embodiments, the organic electroluminescent device of the present invention is held by a substrate, which is not particularly limited and commonly used in organic electroluminescent devices such as glass, transparent plastic, quartz and silicon. Any material formed by

anode:
In some embodiments, the anode of the organic electroluminescent device is made from metals, alloys, conductive compounds, or combinations thereof. In some embodiments, the metal, alloy or conductive compound has a high work function (4 eV or greater). In some embodiments, the metal is Au. In some embodiments, the conductive transparent material is selected from CuI, indium tin oxide (ITO), _SnO2 and ZnO. Some embodiments use amorphous materials that can form transparent conductive films, such as IDIXO (In ₂ O ₃ —ZnO). In some embodiments, the anode is a thin film. In some embodiments, the thin film is made by evaporation or sputtering. In some embodiments, the film is patterned by photolithographic methods. In some embodiments, if the pattern does not need to be highly precise (eg, about 100 μm or greater), the pattern may be formed using a mask with a shape suitable for vapor deposition or sputtering onto the electrode material. In some embodiments, wet film forming methods such as printing and coating methods are used when coating materials such as organic conductive compounds can be applied. In some embodiments, the anode has a transmittance of greater than 10% when emitted light passes through the anode, and the anode has a sheet resistance of several hundred ohms per unit area or less. In some embodiments, the thickness of the anode is 10-1,000 nm. In some embodiments, the thickness of the anode is 10-200 nm. In some embodiments, the thickness of the anode varies depending on the material used.

cathode:
In some embodiments, the cathode is made of electrode materials such as metals with a low work function (4 eV or less) (referred to as electron-injecting metals), alloys, conductive compounds, or combinations thereof. In some embodiments, the electrode material is sodium, sodium-potassium alloys, magnesium, lithium, magnesium-copper mixtures, magnesium-silver mixtures, magnesium-aluminum mixtures, magnesium-indium mixtures, aluminum-aluminum oxide ( _Al2 O ₃ ) mixtures, indium, lithium-aluminum mixtures and rare earth elements. In some embodiments, a mixture of an electron-injecting metal and a second metal that is a stable metal with a higher work function than the electron-injecting metal is used. In some embodiments, the mixture is selected from magnesium-silver mixtures, magnesium-aluminum mixtures, magnesium-indium mixtures, aluminum-aluminum oxide (Al ₂ O ₃ ) mixtures, lithium-aluminum mixtures and aluminum. In some embodiments, the mixture improves electron injection properties and resistance to oxidation. In some embodiments, the cathode is manufactured by depositing or sputtering the electrode material as a thin film. In some embodiments, the cathode has a sheet resistance of no more than several hundred ohms per unit area. In some embodiments, the thickness of said cathode is between 10 nm and 5 μm. In some embodiments, the thickness of the cathode is 50-200 nm. In some embodiments, either one of the anode and cathode of the organic electroluminescent device is transparent or translucent to allow transmission of emitted light. In some embodiments, transparent or translucent electroluminescent elements enhance light radiance.
In some embodiments, the cathode is formed of a conductive transparent material as described above for the anode, thereby forming a transparent or translucent cathode. In some embodiments, the device includes an anode and a cathode, both transparent or translucent.

Injection layer:
The injection layer is the layer between the electrode and the organic layer. In some embodiments, the injection layer reduces drive voltage and enhances light radiance. In some embodiments, the injection layer comprises a hole injection layer and an electron injection layer. The injection layer can be placed between the anode and the light-emitting layer or hole-transporting layer and between the cathode and the light-emitting layer or electron-transporting layer. In some embodiments, an injection layer is present. In some embodiments, there is no injection layer.
Preferred examples of compounds that can be used as the hole injection material are given below.

Next, preferred examples of compounds that can be used as the electron injection material are given.

Barrier layer:
A barrier layer is a layer that can prevent charges (electrons or holes) and/or excitons present in the light-emitting layer from diffusing out of the light-emitting layer. In some embodiments, an electron blocking layer is between the light-emitting layer and the hole-transporting layer to block electrons from passing through the light-emitting layer to the hole-transporting layer. In some embodiments, a hole blocking layer is between the emissive layer and the electron transport layer and blocks holes from passing through the emissive layer to the electron transport layer. In some embodiments, the barrier layer prevents excitons from diffusing out of the emissive layer. In some embodiments, the electron blocking layer and the hole blocking layer constitute an exciton blocking layer. As used herein, the terms "electron blocking layer" or "exciton blocking layer" include layers that have the functionality of both an electron blocking layer and an exciton blocking layer.

Hole blocking layer:
A hole blocking layer functions as an electron transport layer. In some embodiments, the hole blocking layer blocks holes from reaching the electron transport layer during electron transport. In some embodiments, the hole blocking layer increases the probability of recombination of electrons and holes in the emissive layer. The materials used for the hole blocking layer can be the same materials as described above for the electron transport layer.
Preferred examples of compounds that can be used in the hole blocking layer are given below.

Electron barrier layer:
The electron blocking layer transports holes. In some embodiments, the electron blocking layer prevents electrons from reaching the hole transport layer during hole transport. In some embodiments, the electron blocking layer increases the probability of recombination of electrons and holes in the emissive layer. The materials used for the electron blocking layer may be the same materials as described above for the hole transport layer.
Specific examples of preferred compounds that can be used as the electron barrier material are given below.

Exciton barrier layer:
The exciton blocking layer prevents excitons generated through recombination of holes and electrons in the light emitting layer from diffusing to the charge transport layer. In some embodiments, the exciton blocking layer allows effective confinement of excitons in the emissive layer. In some embodiments, the light emission efficiency of the device is improved. In some embodiments, an exciton blocking layer is adjacent to the emissive layer on either the anode side or the cathode side, and on both sides thereof. In some embodiments, when an exciton blocking layer is present on the anode side, it may be present between and adjacent to the hole-transporting layer and the light-emitting layer. In some embodiments, when an exciton blocking layer is present on the cathode side, it may be between and adjacent to the emissive layer and the cathode. In some embodiments, a hole-injection layer, electron-blocking layer, or similar layer is present between the anode and an exciton-blocking layer adjacent to the light-emitting layer on the anode side. In some embodiments, a hole injection layer, electron blocking layer, hole blocking layer or similar layer is present between the cathode and an exciton blocking layer adjacent to the emissive layer on the cathode side. In some embodiments, the exciton blocking layer comprises an excited singlet energy and an excited triplet energy, at least one of which is higher than the excited singlet energy and triplet energy, respectively, of the emissive material.

Hole transport layer:
The hole-transporting layer comprises a hole-transporting material. In some embodiments, the hole transport layer is a single layer. In some embodiments, the hole transport layer has multiple layers.
In some embodiments, the hole transport material has one property of a hole injection or transport property and an electron barrier property. In some embodiments, the hole transport material is an organic material. In some embodiments, the hole transport material is an inorganic material. Examples of known hole transport materials that can be used in the present invention include, but are not limited to, triazole derivatives, oxadiazole derivatives, imidazole derivatives, carbazole derivatives, indolocarbazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolones. derivatives, phenylenediamine derivatives, allylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers and conductive polymer oligomers (especially thiophene oligomers), or combinations thereof. is mentioned. In some embodiments, the hole transport material is selected from porphyrin compounds, aromatic tertiary amine compounds and styrylamine compounds. In some embodiments, the hole transport material is an aromatic tertiary amine compound. Specific examples of preferred compounds that can be used as the hole-transporting material are given below.

Electron transport layer:
The electron transport layer includes an electron transport material. In some embodiments, the electron transport layer is a single layer. In some embodiments, the electron transport layer has multiple layers.
In some embodiments, the electron-transporting material need only function to transport electrons injected from the cathode to the emissive layer. In some embodiments, the electron transport material also functions as a hole blocking material. Examples of electron-transporting layers that can be used in the present invention include, but are not limited to, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidene methane derivatives, anthraquinodimethanes, anthrone derivatives, oxazide Azole derivatives, azole derivatives, azine derivatives or combinations thereof, or polymers thereof. In some embodiments, the electron transport material is a thiadiazole derivative or a quinoxaline derivative. In some embodiments, the electron transport material is a polymeric material. Specific examples of preferred compounds that can be used as the electron-transporting material are given below.

Furthermore, preferred compound examples are given as materials that can be added to each organic layer. For example, it may be added as a stabilizing material.

Preferred materials that can be used in organic electroluminescence devices are specifically exemplified, but materials that can be used in the present invention are not limitedly interpreted by the following exemplified compounds. Moreover, even compounds exemplified as materials having specific functions can be used as materials having other functions.

device:
In some embodiments, the emissive layer is incorporated into the device. For example, devices include, but are not limited to, OLED bulbs, OLED lamps, television displays, computer monitors, mobile phones and tablets.
In some embodiments, an electronic device includes an OLED having at least one organic layer including an anode, a cathode, and a light-emitting layer between the anode and the cathode.
In some embodiments, compositions described herein can be incorporated into various photosensitive or photoactivated devices, such as OLEDs or optoelectronic devices. In some embodiments, the composition may be useful in facilitating charge or energy transfer within a device and/or as a hole transport material. Examples of such devices include organic light emitting diodes (OLEDs), organic integrated circuits (OICs), organic field effect transistors (O-FETs), organic thin film transistors (O-TFTs), organic light emitting transistors (O-LETs), and organic solar cells. (O-SC), organic optical detectors, organic photoreceptors, organic field-quench devices (O-FQD), luminescent fuel cells (LEC) or organic laser diodes (O-lasers).

Bulb or Lamp:
In some embodiments, an electronic device includes an OLED including at least one organic layer including an anode, a cathode, and a light-emitting layer between the anode and the cathode.
In some embodiments, the device includes OLEDs of different colors. In some embodiments, the device includes an array including combinations of OLEDs. In some embodiments, said combination of OLEDs is a combination of three colors (eg RGB). In some embodiments, the combination of OLEDs is a combination of colors other than red, green, and blue (eg, orange and yellow-green). In some embodiments, said combination of OLEDs is a combination of two, four or more colors.
In some embodiments, the device
a circuit board having a first side with a mounting surface and a second opposite side and defining at least one opening;
at least one OLED on the mounting surface, wherein the at least one OLED comprises at least one organic layer comprising an anode, a cathode, and a light-emitting layer between the anode and the cathode to emit light; at least one OLED comprising
a housing for the circuit board;
at least one connector disposed at an end of said housing, said housing and said connector defining a package suitable for attachment to a lighting fixture.
In some embodiments, the OLED light comprises multiple OLEDs mounted on a circuit board such that light is emitted in multiple directions. In some embodiments, some light emitted in the first direction is polarized and emitted in the second direction. In some embodiments, a reflector is used to polarize light emitted in the first direction.

Display or screen:
In some embodiments, the emissive layers of the invention can be used in screens or displays. In some embodiments, the compounds of the present invention are deposited onto a substrate using processes such as, but not limited to, vacuum evaporation, deposition, evaporation or chemical vapor deposition (CVD). In some embodiments, the substrate is a photoplate structure useful in two-sided etching to provide unique aspect ratio pixels. Said screens (also called masks) are used in the manufacturing process of OLED displays. The corresponding artwork pattern design allows placement of very steep narrow tie-bars between pixels in the vertical direction as well as large and wide beveled openings in the horizontal direction. This allows for the fine patterning of pixels required for high resolution displays while optimizing chemical vapor deposition on the TFT backplane.
The internal patterning of the pixels makes it possible to construct three-dimensional pixel openings with various aspect ratios in the horizontal and vertical directions. Further, the use of imaged "stripes" or halftone circles in pixel areas protects etching in specific areas until these specific patterns are undercut and removed from the substrate. All pixel areas are then treated with a similar etch rate, but their depth varies with the halftone pattern. Varying the size and spacing of the halftone patterns allows etching with varying degrees of protection within the pixel, allowing for the localized deep etching necessary to form steep vertical bevels. .
A preferred material for the evaporation mask is Invar. Invar is a metal alloy that is cold rolled into long thin sheets in steel mills. Invar cannot be electrodeposited onto a spin mandrel as a nickel mask. A suitable and low-cost method for forming the open areas in the deposition mask is by wet chemical etching.
In some embodiments, the screen or display pattern is a matrix of pixels on a substrate. In some embodiments, screen or display patterns are fabricated using lithography (eg, photolithography and e-beam lithography). In some embodiments, the screen or display pattern is processed using wet chemical etching. In a further embodiment the screen or display pattern is fabricated using plasma etching.

Device manufacturing method:
An OLED display is generally manufactured by forming a large mother panel and then cutting the mother panel into cell panels. Generally, each cell panel on a mother panel is formed by forming a thin film transistor (TFT) having an active layer and source/drain electrodes on a base substrate, coating the TFT with a planarizing film, pixel electrodes, and a light emitting layer. , a counter electrode and an encapsulation layer, are sequentially formed and cut from the mother panel.
An OLED display is generally manufactured by forming a large mother panel and then cutting the mother panel into cell panels. Generally, each cell panel on a mother panel is formed by forming a thin film transistor (TFT) having an active layer and source/drain electrodes on a base substrate, coating the TFT with a planarizing film, pixel electrodes, and a light emitting layer. , a counter electrode and an encapsulation layer, are sequentially formed and cut from the mother panel.

In another aspect of the invention, there is provided a method of manufacturing an organic light emitting diode (OLED) display, the method comprising:
forming a barrier layer on the base substrate of the mother panel;
forming a plurality of display units on the barrier layer in cell panel units;
forming an encapsulation layer over each of the display units of the cell panel;
and applying an organic film to the interfaces between the cell panels.
In some embodiments, the barrier layer is an inorganic film, eg, made of SiNx, and the edges of the barrier layer are covered with an organic film, made of polyimide or acrylic. In some embodiments, the organic film helps the mother panel to be softly cut into cell panels.
In some embodiments, a thin film transistor (TFT) layer has an emissive layer, a gate electrode, and source/drain electrodes. Each of the plurality of display units may have a thin film transistor (TFT) layer, a planarization film formed on the TFT layer, and a light-emitting unit formed on the planarization film; The applied organic film is made of the same material as the material of the planarizing film and is formed at the same time as the planarizing film is formed. In some embodiments, the light-emitting unit is coupled with the TFT layer by a passivation layer, a planarizing film therebetween, and an encapsulation layer that covers and protects the light-emitting unit. In some embodiments of the manufacturing method, the organic film is not connected to the display unit or encapsulation layer.

Each of the organic film and the planarizing film may include one of polyimide and acrylic. In some embodiments, the barrier layer may be an inorganic film. In some embodiments, the base substrate may be formed of polyimide. The method further includes attaching a carrier substrate made of a glass material to one surface of the base substrate made of polyimide before forming the barrier layer on another surface of the base substrate; separating the carrier substrate from the base substrate prior to cutting along the interface. In some embodiments, the OLED display is a flexible display.
In some embodiments, the passivation layer is an organic film placed on the TFT layer to cover the TFT layer. In some embodiments, the planarizing film is an organic film formed over a passivation layer. In some embodiments, the planarizing film is formed of polyimide or acrylic, as is the organic film formed on the edge of the barrier layer. In some embodiments, the planarizing film and organic film are formed simultaneously during the manufacture of an OLED display. In some embodiments, the organic film may be formed on the edge of the barrier layer such that a portion of the organic film is in direct contact with the base substrate and the remainder of the organic film is in contact with the base substrate. , in contact with the barrier layer while surrounding the edges of the barrier layer.

In some embodiments, the emissive layer comprises a pixel electrode, a counter electrode, and an organic emissive layer disposed between the pixel electrode and the counter electrode. In some embodiments, the pixel electrodes are connected to source/drain electrodes of the TFT layer.
In some embodiments, when a voltage is applied to the pixel electrode through the TFT layer, a suitable voltage is formed between the pixel electrode and the counter electrode, causing the organic light emitting layer to emit light, thereby displaying an image. is formed. An image forming unit having a TFT layer and a light emitting unit is hereinafter referred to as a display unit.
In some embodiments, the encapsulation layer that covers the display unit and prevents the penetration of external moisture may be formed into a thin encapsulation structure in which organic films and inorganic films are alternately laminated. In some embodiments, the encapsulation layer has a thin film-like encapsulation structure in which multiple thin films are stacked. In some embodiments, the organic film applied to the interface portion is spaced apart from each of the plurality of display units. In some embodiments, the organic film is formed such that a portion of the organic film is in direct contact with the base substrate and the remaining portion of the organic film is in contact with the barrier layer while surrounding the edges of the barrier layer. be done.

In one embodiment, the OLED display is flexible and uses a flexible base substrate made of polyimide. In some embodiments, the base substrate is formed on a carrier substrate made of glass material, and then the carrier substrate is separated.
In some embodiments, a barrier layer is formed on the surface of the base substrate opposite the carrier substrate. In one embodiment, the barrier layer is patterned according to the size of each cell panel. For example, a base substrate is formed on all surfaces of a mother panel, while barrier layers are formed according to the size of each cell panel, thereby forming grooves at the interfaces between the barrier layers of the cell panels. Each cell panel can be cut along the groove.

In some embodiments, the manufacturing method further comprises cutting along the interface, wherein a groove is formed in the barrier layer, at least a portion of the organic film is formed with the groove, and the groove is Does not penetrate the base substrate. In some embodiments, a TFT layer of each cell panel is formed, and a passivation layer, which is an inorganic film, and a planarization film, which is an organic film, are placed on and cover the TFT layer. At the same time that the planarizing film, eg made of polyimide or acrylic, is formed, the interface grooves are covered with an organic film, eg made of polyimide or acrylic. This prevents cracking by having the organic film absorb the impact that occurs when each cell panel is cut along the groove at the interface. That is, if all the barrier layers are completely exposed without an organic film, when each cell panel is cut along the groove at the interface, the resulting impact will be transferred to the barrier layers, thereby creating a risk of cracking. increases. However, in one embodiment, the grooves at the interfaces between the barrier layers are coated with an organic film to absorb shocks that might otherwise be transmitted to the barrier layers, so that each cell panel is softly cut and the barrier layers It may prevent cracks from forming. In one embodiment, the organic film covering the groove of the interface and the planarizing film are spaced apart from each other. For example, when the organic film and the planarizing film are connected to each other as a single layer, external moisture may enter the display unit through the planarizing film and the portion where the organic film remains. The organic film and planarizing film are spaced from each other such that the organic film is spaced from the display unit.

In some embodiments, the display unit is formed by forming a light-emitting unit and an encapsulating layer is placed over the display unit to cover the display unit. Thereby, after the mother panel is completely manufactured, the carrier substrate carrying the base substrate is separated from the base substrate. In some embodiments, when the laser beam is directed at the carrier substrate, the carrier substrate separates from the base substrate due to the difference in coefficient of thermal expansion between the carrier substrate and the base substrate.
In some embodiments, the mother panel is cut into cell panels. In some embodiments, the mother panel is cut along the interfaces between the cell panels using a cutter. In some embodiments, the interface groove along which the mother panel is cut is coated with an organic film so that the organic film absorbs impact during cutting. In some embodiments, the barrier layer can be prevented from cracking during cutting.
In some embodiments, the method reduces the reject rate of the product and stabilizes its quality.
Another embodiment includes a barrier layer formed on a base substrate, a display unit formed on the barrier layer, an encapsulation layer formed on the display unit, and an organic layer applied to the edges of the barrier layer. An OLED display comprising a film.

The features of the present invention will be more specifically described below with reference to Synthesis Examples and Examples. The materials, processing details, processing procedures, etc. described below can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed to be limited by the specific examples shown below. In addition, the evaluation of the light emission characteristics was performed using a source meter (manufactured by Keithley: 2400 series), a semiconductor parameter analyzer (manufactured by Agilent Technologies: E5273A), an optical power meter measuring device (manufactured by Newport: 1930C), and an optical spectrometer. (Ocean Optics: USB2000), a spectroradiometer (Topcon: SR-3) and a streak camera (Hamamatsu Photonics, Model C4334). The HOMO and LUMO energies were measured by atmospheric photoelectron spectroscopy (AC-3 manufactured by Riken Keiki Co., Ltd.).
In the following Synthesis Examples, compounds included in the general formula (1) were synthesized.

(Synthesis Example 1) Synthesis of Compound 6

Under a nitrogen atmosphere, 2,6-difluoropyridine (2 g, 17.4 mmol), 5H-benzofuro[3,2-c]carbazole (2.24 g, 8.69 mmol) and 60% NaH (0.52 g, 13 mmol) were added. It was added to 40 ml of tetrahydrofuran and stirred at room temperature for 12 hours. Water was slowly added to the reaction solution and the organic solvent was removed to obtain a solid. The obtained solid was purified by silica gel column chromatography (developing solvent: chloroform/n-hexane=1:4 to 3:7). Further recrystallization (chloroform/methanol) gave intermediate a as a white solid (2.02 g, 66%).
¹ H NMR (400MHz, CDCl ₃ , δ): 8.57 (d, J = 8 Hz, 1H), 8.11-7.90 (m, 5H), 7.74 (d, J = 8 Hz, 1H), 7.63 (d, J = 8 Hz, 1H), 7.56-7.45 (m, 3H), 7.40 (t, J = 8 Hz, 1H), 6.99 (d, J= 8 Hz, 1H).
MS ₍ ASAP): 353.22 ( _M +H ⁺ ). Calcd for _C23H13FN2O : 352.10.

Under nitrogen atmosphere, 5-(6-fluoropyridin-2-yl)-5H-benzofuro[3,2-c]carbazole (intermediate a, 1.10 g, 3.13 mmol), carbazole (0.784 g, 4. 69 mmol), potassium carbonate (1.30 g, 9.38 mmol) was added to 10 ml of N-methyl-2-pyrrolidone and stirred at 100° C. for 12 hours. The reaction solution was cooled to room temperature and water was added. The resulting precipitate was filtered and dried. The resulting solid was purified by silica gel column chromatography (developing solvent: chloroform/n-hexane=1:4). Further, the solid was washed with methanol to obtain compound 6 as a white solid (1 g, 64%).
¹ H NMR (400MHz, CDCl ₃ , δ): 8.59 (d, J= 8 Hz, 1H), 8.21-8.13 (m, 3H), 8.08-7.93 (m, 6H), 7.77-7.68 (m, 3H) , 7.51-7.33 (m, 8H).
MS ₍ ASAP): 500.32 (M+H ⁺ ). _Calcd for _C35H21N3O : 499.17.

(Synthesis Example 2) Synthesis of compound 1110 Same as Synthesis Example 1 except that instead of the carbazole used in Synthesis Example 1, deuterated carbazole in which all hydrogen atoms of carbazole are replaced with deuterium atoms is used. The procedure provided compound 1110 below.

(Synthesis Example 3) Synthesis of Compound 2214

Under nitrogen atmosphere, 2,6-difluoropyridine (0.5 g, 4.34 mmol), 5H-benzofuro[3,2-c]carbazole (2.79 g, 10.9 mmol), potassium carbonate (1.80 g, 13. mmol) was added to 6 ml of N-methyl-2-pyrrolidone and stirred at 100° C. for 12 hours. The reaction solution was cooled to room temperature and water was added. The resulting precipitate was filtered, washed with ethyl acetate and dried. The resulting solid was recrystallized (o-dichlorobenzene/methanol) to give compound 2214 as a white solid (2.19 g, 86%).
MS ₍ ASAP _{) :} 590.32 (M+H ⁺ ). Calcd for _C41H23N3O2 : 589.18.

(Synthesis Example 4) Synthesis of compound 35159

Under nitrogen atmosphere, 9-(6-bromo-2-pyridinyl)-9H-carbazole (intermediate c, 1.71 g, 5.29 mmol), 2-phenyl-8-(4,4,5,5-tetramethyl -1,3,2-dioxaboran-2-yl)-dibenzofuran (intermediate b, 1.96g, 5.29mmol), tetrakis(triphenylphosphine)palladium(0) (0.30g, 0.26mmol), carbonic acid Potassium (2.19g, 15.87mmol) was added to tetrahydrofuran/water (50ml/25ml) and stirred at 75°C for 12 hours. The reaction solution was cooled to room temperature and chloroform was added. The organic layer was washed with water to remove the solvent. The resulting solid was purified by silica gel column chromatography (developing solvent: toluene/n-hexane=2:3). Furthermore, recrystallization was performed with toluene/methanol to obtain compound 35159 as a white solid (2.21 g, 86%).
MS ₍ ASAP): 487.79.32 ( _M +H ⁺ ). Calcd for _C35H22N2O : 486.17.

(Example 1) Preparation of organic electroluminescence element Each thin film was deposited on a glass substrate on which an anode made of indium tin oxide (ITO) with a thickness of 50 nm was formed, by vacuum deposition, and the degree of vacuum was 1 × 10. Laminated at ^-5 Pa. First, HATCN was formed to a thickness of 10 nm on ITO, and NPD was formed thereon to a thickness of 30 nm. Then, TrisPCz was formed thereon to a thickness of 10 nm. Next, compound 6 and TADF19 were co-evaporated from different deposition sources at 65% by mass and 35% by mass, respectively, to form a light-emitting layer with a thickness of 40 nm. SF3TRZ was formed thereon to a thickness of 10 nm, and SF3TRZ and Liq were co-deposited thereon from different vapor deposition sources at 30% by mass and 70% by mass, respectively, to form a 30 nm thick film. Furthermore, Liq was formed to a thickness of 2 nm, and then aluminum (Al) was deposited to a thickness of 100 nm to form a cathode. The organic electroluminescence device of Example 1 was produced by the above procedure.
(Example 2)
An organic electroluminescence device of Comparative Example 1 was produced in the same manner as in Example 1 except that Compound 2214 was used instead of Compound 6 used in Example 1.
(Comparative Example 1) Preparation of Comparative Organic Electroluminescence Device The organic electroluminescence device of Comparative Example 1 was prepared in the same manner as in Example 1 except that PYD2Cz was used instead of Compound 6 used in Example 1. was made.
(evaluation)
Each organic electroluminescence element of Example 1, Example 2 and Comparative Example 1 was energized at 12.6 mA/cm ² . Assuming that the emission intensity immediately after energization was 100, the time until the emission intensity fell below 95 was measured and defined as LT95. When LT95 of Comparative Example 1 is 1, Example 1 is 2.3 times higher and Example 2 is 1.8 times higher. It was confirmed that when the compound represented by the general formula (1) was used, the life of the device was lengthened.

(Example 3) Fabrication of organic electroluminescence device Example 1 was carried out with the exception that the compound 35159 and TADF2 were used to form the light-emitting layer in place of the compound 6 and TADF19 used to form the light-emitting layer in Example 1. An organic electroluminescence device of Example 3 was produced by the same procedure as in 1.
(Comparative example 2)
An organic electroluminescence device of Comparative Example 2 was produced in the same manner as in Example 3 except that PYD2Cz was used instead of compound 35159 used in Example 3.
(evaluation)
The external quantum efficiency (EQE) of each organic electroluminescence device of Example 3 and Comparative Example 2 was measured when a current of 6.3 mA/cm ² was applied. As a result, the external quantum efficiency (EQE) of the organic electroluminescence device of Example 3 was higher than that of Comparative Example 2 by 1.8%. It was confirmed that when the compound represented by the general formula (1) was used, the luminous efficiency was increased.

Compounds represented by general formula (1) are useful, for example, as host materials. An organic light-emitting device using the compound represented by general formula (1) has excellent properties. Therefore, the present invention has high industrial applicability.

Claims (23)

A compound represented by the following general formula (1).

[In the general formula (1),
R ¹ and R ³ each independently represent a hydrogen atom, a deuterium atom, or an optionally deuterated alkyl group.
Each ^R2 independently represents a hydrogen atom or a deuterium atom.
Z ¹ represents a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzofurocarbazolyl group, or a substituted or unsubstituted benzothienocarbazolyl group.
^Z2 represents a substituted or unsubstituted dibenzofuryl group, a substituted or unsubstituted benzofurocarbazolyl group, or a substituted or unsubstituted benzothienocarbazolyl group.
The carbazolyl group, the benzofurocarbazolyl group, and the benzothienocarbazolyl group are groups bonded through a nitrogen atom constituting a carbazole ring. ] 2. The compound of claim ¹ , wherein Z1 is a substituted or unsubstituted benzofurocarbazolyl group. 2. The compound of claim ¹ , wherein Z1 is a substituted or unsubstituted carbazolyl group. A compound according to any one of claims 1 to 3, wherein Z ² is a substituted or unsubstituted dibenzofuryl group. A compound according to any one of claims 1 to 3, wherein Z ² is a substituted or unsubstituted benzofurocarbazolyl group. 2. The compound according to claim 1, wherein Z ¹ is a substituted or unsubstituted carbazolyl group and Z ² is a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group. . 2. The compound according to claim 1, wherein ^Z1 and ^Z2 are each independently a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group. 2. The compound of claim ¹ , wherein Z1 is a substituted or unsubstituted carbazolyl group and ^Z2 is a substituted or unsubstituted dibenzofuryl group. 9. Any one of claims 1 to 8, wherein at least one of carbazolyl group, benzofurocarbazolyl group, benzothienocarbazolyl group and dibenzofuryl group present in the molecule is substituted with an aryl group. The compound described in . A compound according to any one of claims 1 to 9, wherein R ¹ to R ³ are hydrogen atoms. A host material comprising a compound according to any one of claims 1-10. 12. A host material according to claim 11 for use with a delayed fluorescence material. A composition in which the compound according to any one of claims 1 to 10 is doped with a delayed fluorescence material. 14. The composition according to claim 13, which is in the form of a film. The composition according to claim 13 or 14, wherein the delayed fluorescence material is a compound having a cyanobenzene structure in which the benzene ring is substituted with one cyano group. The composition according to claim 13 or 14, wherein the delayed fluorescence material is a compound having a cyanobenzene structure in which two cyano groups are substituted on the benzene ring. The composition according to any one of claims 13 to 16, further comprising a fluorescent compound having a lowest excited singlet energy lower than that of said host material and said delayed fluorescent material. An organic light-emitting device comprising a layer comprising the composition according to any one of claims 13-17. 19. The organic light-emitting device according to claim 18, wherein said layer consists only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, sulfur atoms, boron atoms and halogen atoms. 20. The organic light-emitting device according to claim 19, wherein said layer consists only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms and sulfur atoms. The organic light-emitting device according to any one of claims 18 to 20, which is an organic electroluminescence device. The organic light-emitting device according to any one of claims 18 to 21, wherein the composition does not contain the fluorescent compound, and the maximum component of light emission from the device is light emission from the delayed fluorescence material. The organic light-emitting device according to any one of claims 18 to 21, wherein the composition comprises the fluorescent compound, and the largest component of light emission from the device is light emission from the fluorescent compound.