Compound, composition, host material and organic light-emitting device

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]

[0001] The present invention relates to a compound useful as a host material or the like, a composition using the compound, and an organic light-emitting device. [Background technology]

[0002] Research and development of materials for use in organic light-emitting devices such as organic electroluminescent devices (organic EL devices) has been actively conducted. In particular, various attempts have been made to improve the device characteristics by newly developing and combining electron transport materials, hole transport materials, light-emitting materials, host materials, etc. that constitute organic electroluminescent devices. For example, with regard to host materials, PYD2Cz having the following structure has been widely recognized as a useful host material and has recently been the subject of research (see Non-Patent Document 1). [ka] [Prior art documents] [Patent documents]

[0003] [Non-Patent Document 1] Small Sci. 2021, 1, 2000057 Summary of the Invention [Problem to be solved by the invention]

[0004] However, even if a conventionally used host material is used, it may not necessarily be possible to provide a light-emitting device with excellent properties. For example, when combined with a delayed fluorescent material, even if a host material that is considered useful is used as is, it is often impossible to produce an organic light-emitting device with excellent properties. In particular, when used in an organic electroluminescence device, there is room for improvement in terms of device life and luminous efficiency. For this reason, the present inventors have conducted research with the aim of improving the properties of organic light-emitting devices by providing an excellent host material. [Means for solving the problem]

[0005] As a result of extensive research, the present inventors have found that the characteristics of an organic light-emitting device can be improved by using a compound having a specific structure. The present invention has been proposed based on this finding and specifically has the following configuration.

[0006] [1] A compound represented by the following general formula (1): [ka] [In general formula (1), R 1 and R 3 each independently represents a hydrogen atom, a deuterium atom, or an optionally deuterated alkyl group. R 2 each 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. Z 2 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 each groups bonded via a nitrogen atom constituting a carbazole ring.] [2] Z1 is a substituted or unsubstituted benzofurocarbazolyl group. [3] Z 1 is a substituted or unsubstituted carbazolyl group. [4] Z 2 The compound according to any one of [1] to [3], wherein is a substituted or unsubstituted dibenzofuryl group. [5] Z 2 The compound according to any one of [1] to [3], wherein is a substituted or unsubstituted benzofurocarbazolyl group. [6] 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. [7] Z 1 and Z 2 are each independently a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group. [8] Z 1 is a substituted or unsubstituted carbazolyl group, and Z 2 is a substituted or unsubstituted dibenzofuryl group. [9] The compound according to any one of [1] to [8], wherein 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.

[10] R 1 ~R 3 The compound according to any one of [1] to [9], wherein is a hydrogen atom.

[11] A host material comprising the compound according to any one of [1] to

[10] .

[12] The host material according to

[10] , for use together with a delayed fluorescent material.

[13] A composition obtained by doping the compound according to any one of [1] to

[10] with a delayed fluorescent 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 fluorescent material is a compound having a cyanobenzene structure in which one cyano group is substituted on a benzene ring.

[16] The composition according to

[13] or

[14] , wherein the delayed fluorescent material is a compound having a cyanobenzene structure in which two cyano groups are substituted on a benzene ring.

[17] The composition according to any one of

[13] to

[16] , further comprising a fluorescent compound having a minimum excited singlet energy lower than those of the host material and the delayed fluorescent material.

[18] An organic light-emitting device having a layer made of the composition according to any one of

[13] to

[17] .

[19] The organic light-emitting device according to

[18] , wherein the layer is composed 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 is composed 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 electroluminescence device.

[22] The organic light-emitting device according to any one of

[18] to

[21] , wherein the composition does not contain the fluorescent compound, and the largest component of the light emitted from the device is light emitted from the delayed fluorescent material.

[23] The organic light-emitting device according to any one of

[18] to

[21] , wherein the composition contains the fluorescent compound, and the largest component of the light emitted from the device is light emitted from the fluorescent compound. [Effects of the Invention]

[0007] By using the compound of the present invention, it is possible to provide an organic light-emitting device having excellent characteristics. For example, organic light-emitting devices using the compound of the present invention include organic light-emitting devices having a long device life and organic light-emitting devices having high luminous efficiency. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention will be described in detail below. The following description of the constituent elements may be based on representative embodiments or specific examples of the present invention, but the present invention is not limited to such embodiments or specific examples. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. Furthermore, there are no particular restrictions on the isotope species of hydrogen atoms present in the molecules of the compounds used in the present invention.

[0009] (Compound represented by general formula (1)) In the present invention, a compound represented by the following general formula (1) is used. [ka]

[0010] Z in general formula (1) 1 represents a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted benzofurocarbazolyl group, or a substituted or unsubstituted benzothienocarbazolyl group. 2 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 each groups bonded via a nitrogen atom constituting a carbazole ring.

[0011] Z 1 and Z 2 The benzofurocarbazolyl group and benzothienocarbazolyl group that can be used will be described below. In the present invention, the ring structure constituting the benzofurocarbazolyl group may be any of 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. These ring structures may or may not be fused with another ring. Preferably, they are fused with no other ring. Preferred benzofurocarbazolyl groups include groups having any of the following structures, in which the hydrogen atoms may or may not be substituted. However, no other rings are fused to the following structures. The wavy lines indicate the bonding positions. [ka]

[0012] In the present invention, the ring structure constituting the benzothienocarbazolyl group may be any of 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. These ring structures may or may not be fused with another ring. Preferably, they are fused with no other ring. Preferred benzothienocarbazolyl groups include groups having any of the following structures, in which the hydrogen atoms may or may not be substituted. However, no other rings are fused to the following structures. The wavy lines indicate the bonding positions. [ka]

[0013] Z 1 and Z 2The benzofurocarbazolyl group and benzothienocarbazolyl group which may be mentioned above may be substituted. They may also be unsubstituted. When substituted, the substituent may be selected from the following substituent group A, the following substituent group B, the following substituent group C, the following substituent group D, or the following substituent group E. Preferred are substituents selected from the substituent group E. For example, they may be substituted with only an alkyl group, only an aryl group, or both an alkyl group and an aryl group.

[0014] The "alkyl group" in this application may be linear, branched, or cyclic. It may also be a mixture of two or more of the linear, cyclic, and branched moieties. The number of carbon atoms in the alkyl group may be, for example, 1 or more, 2 or more, or 4 or more. The number of carbon atoms may be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. In one embodiment of the present invention, the alkyl group has 1 to 4 carbon atoms. In one embodiment of the present invention, the alkyl group is a methyl group. In one embodiment of the present invention, the alkyl group is an isopropyl group. In one embodiment of the present invention, the alkyl group is a tert-butyl group. When multiple alkyl groups are present in the molecule represented by general formula (1), these alkyl groups may be the same or different. In one embodiment 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, or 8 or more. The number of alkyl groups in the molecule represented by general 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 0. Note that the number of alkyl groups here includes the number of alkyl groups substituted with aryl groups. Furthermore, the alkyl groups may be optionally deuterated. In this application, an "optionally deuterated alkyl group" means that at least one hydrogen atom of the alkyl group may be substituted with a deuterium atom. All hydrogen atoms of the alkyl group may be substituted with deuterium atoms. For example, optionally deuterated methyl groups include CH, CDH, CDH, and CD. The "optionally deuterated alkyl group" is preferably an alkyl group that is not at all deuterated or an alkyl group in which all hydrogen atoms are substituted with deuterium atoms. In one embodiment of the present invention, the "optionally deuterated alkyl group" is an alkyl group that is not at all deuterated. In one embodiment of the present invention, the "optionally deuterated alkyl group" is an alkyl group in which all hydrogen atoms are substituted with deuterium atoms. In one embodiment of the present invention, the "optionally deuterated alkyl group" is an undeuterated methyl group [-CH], an undeuterated ethyl group [-CHCH], an undeuterated isopropyl group [-CH(CH)], an undeuterated tert-butyl group [-C(CH)], or a methyl group [-CD] in which all hydrogen atoms are deuterated. In one embodiment of the present invention, the "optionally deuterated alkyl group" is a non-deuterated methyl group [-CH3] or a methyl group [-CD3] in which all hydrogen atoms are deuterated. In one embodiment of the present invention, the molecule represented by general formula (1) contains at least one alkyl group in which at least one hydrogen atom is substituted with a deuterium atom.

[0015] The "aryl group" may be a monocyclic ring or a fused ring formed by condensing two or more rings. When the aryl group is a monocyclic ring, it is a phenyl group. When the fused ring is a fused ring, it is a group formed by condensing one or more rings to a phenyl group. The ring fused to the phenyl group may be any of an aromatic hydrocarbon ring, an aromatic heterocyclic ring, an aliphatic hydrocarbon ring, and an aliphatic heterocyclic ring, or a ring formed by condensing these. An aromatic hydrocarbon ring or an aromatic heterocyclic ring is preferred. An example of an aromatic hydrocarbon ring is a benzene 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 refers to a ring exhibiting aromaticity that contains a heteroatom as a ring skeleton-constituting atom, and is preferably a 5- to 7-membered ring. For example, a 5-membered ring or a 6-membered ring may be used. In one embodiment of the present invention, a furan ring, a thiophene ring, or a pyrrole ring may be used as the aromatic heterocyclic ring. Specific examples of the ring constituting the aryl group include a benzene ring and a naphthalene ring. Specific examples of the aryl group include a phenyl group, a naphthalene-1-yl group, and a naphthalene-2-yl group. These specific groups may be substituted. The aryl group may also be deuterated. In this application, an "optionally deuterated aryl group" means that at least one hydrogen atom of the aryl group may be substituted with a deuterium atom. All hydrogen atoms of the aryl group may be substituted with deuterium atoms. For example, optionally deuterated phenyl groups include CH, CHD, CHD, CHD, CHD, CHHD, CHHD, and CHD. The "optionally deuterated alkyl group" is preferably a completely undeuterated aryl group or an aryl group in which all hydrogen atoms are substituted with deuterium atoms. In one embodiment of the present invention, an "optionally deuterated aryl group" is selected as a completely undeuterated aryl group. In one embodiment of the present invention, an aryl group in which all hydrogen atoms are substituted with deuterium atoms is selected as an "optionally deuterated aryl group." In one embodiment of the present invention, the "optionally deuterated aryl group" is selected as a non-deuterated phenyl group [—CH], a non-deuterated naphthyl group [—C 10 H7], a phenyl group with all hydrogen atoms deuterated [-C6D5], a naphthyl group with all hydrogen atoms deuterated [-C 10 D7]. Specific examples of aryl groups which may be substituted are given below. However, the aryl groups which can be employed in the present invention should not be construed as being limited by the following specific examples. In the following specific examples, * indicates a bonding position. Also, methyl groups are omitted. Therefore, Ar2 to Ar7 represent structures substituted with methyl groups. [ka]

[0016] When the benzofurocarbazolyl group and the benzothienocarbazolyl group are substituted with deuterium atoms, only the substituents bonded to the benzofurocarbazole ring or the benzothienocarbazole ring may be substituted with deuterium atoms, or all of the hydrogen atoms present in the benzofurocarbazolyl group or the benzothienocarbazole ring may be substituted with deuterium atoms. For example, only the hydrogen atoms of the alkyl group bonded to the benzofurocarbazole ring or the benzothienocarbazole ring may be deuterated, or only the hydrogen atoms of the aryl group bonded to the benzofurocarbazole ring or the benzothienocarbazole ring may be deuterated. More specifically, the benzofurocarbazolyl group and the benzothienocarbazolyl group may be substituted with, for example, a deuterated methyl group (CD3) or a deuterated phenyl group (CD5).

[0017] In one aspect of the present invention, Z 1 is a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group. In one aspect of the present invention, Z 2 is a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group. In one aspect of the present invention, Z 1 and Z 2 and Z are both substituted or unsubstituted benzofurocarbazolyl groups or substituted or unsubstituted benzothienocarbazolyl groups. 1 and Z 2 In one aspect of the invention, Z 1 and Z 2 is different. In one aspect of the present invention, Z 1 and Z 2 In one embodiment of the present invention, at least one of Z is a substituted or unsubstituted benzofurocarbazolyl group. 1 and Z 2 In one embodiment of the present invention, at least one of Z is a substituted benzofurocarbazolyl group. 1 and Z 2At least one of is an unsubstituted benzofurocarbazolyl group. In one aspect of the present invention, Z 1 and Z 2 In one embodiment of the present invention, at least one of Z is a substituted or unsubstituted benzothienocarbazolyl group. 1 and Z 2 In one embodiment of the present invention, at least one of Z is a substituted benzothienocarbazolyl group. 1 and Z 2 At least one of is an unsubstituted benzothienocarbazolyl group. In one aspect of the present invention, Z 1 and Z 2 In one embodiment of the present invention, at least one of Z is a substituted benzofurocarbazolyl group. 1 and Z 2 At least one of Z is a substituted or unsubstituted aryl-substituted benzofurocarbazolyl group. 1 and Z 2 At least one of Z is an unsubstituted aryl-substituted benzofurocarbazolyl group. 1 and Z 2 In one embodiment of the present invention, at least one of Z is an unsubstituted phenyl-substituted benzofurocarbazolyl group. 1 and Z 2 In one embodiment of the present invention, at least one of Z is a substituted benzothienocarbazolyl group. 1 and Z 2 At least one of Z is a substituted or unsubstituted aryl-substituted benzothienocarbazolyl group. 1 and Z 2 At least one of Z is an unsubstituted aryl-substituted benzothienocarbazolyl group. 1 and Z 2 At least one of is an unsubstituted phenyl-substituted benzothienocarbazolyl group.

[0018] In the following, Z 1 and Z 2Specific examples of substituted or unsubstituted benzofurocarbazolyl groups and substituted or unsubstituted benzothienocarbazolyl groups that can be used are listed below. However, what can be used in the present invention should not be construed as being limited by the following specific examples. In the following specific examples, * indicates the bonding position. Also, methyl groups are omitted. Therefore, D75 to D92 and D167 to D184 represent structures substituted with methyl groups. [ka] TIFF0007780178000008.tif207170TIFF0007780178000009.tif195170TIFF000 7780178000010.tif222170TIFF0007780178000011.tif244170TIFF0007780178 000012.tif204170TIFF0007780178000013.tif232170TIFF0007780178000014. tif212170TIFF0007780178000015.tif201170TIFF0007780178000016.tif90170

[0019] In addition to the specific examples above, groups in which the methyl groups (CH3) of D75 to D92 and D167 to D184 are replaced with deuterated CD3 are exemplified here as D75(m) to D92(m) and D167(m) to D184(m), respectively. Groups in which the phenyl groups (CH5) of D7 to D74 and D99 to D166 are replaced with deuterated CD5 are exemplified here as D7(p) to D74(p) and D99(p) to D166(p), respectively. Furthermore, groups in which all hydrogen atoms of D1 to D184 are deuterated are exemplified here as D1(D) to D184(D), respectively.

[0020] Z in general formula (1) 1may be a substituted or unsubstituted carbazolyl group. The carbazolyl group referred to here is a group bonded via a nitrogen atom constituting the ring skeleton of carbazole. In addition, a benzene ring or a hydrocarbon ring may be fused to one or both of the two benzene rings constituting the carbazolyl group referred to here. Preferably, the two benzene rings constituting the carbazolyl group are not fused to any other ring. Z 1 The carbazolyl group may be substituted. It may be unsubstituted. If substituted, the substituent may be selected from the following substituent group A, the following substituent group B, the following substituent group C, the following substituent group D, or the following substituent group E. Preferred are substituents selected from the following substituent group E. For example, it may be substituted with only an alkyl group, only an aryl group, or both an alkyl group and an aryl group. For the description and preferred ranges of the alkyl group and the aryl group, please refer to the description and preferred ranges of the alkyl group and the aryl group which are the substituents of the benzofurocarbazolyl group and the benzothienocarbazolyl group. In one aspect of the present invention, Z 1 is an unsubstituted carbazolyl group. In one embodiment of the present invention, Z 1 is a substituted carbazolyl group. In one aspect of the invention, Z 1 is an alkyl-substituted carbazolyl group. 1 is an aryl-substituted carbazolyl group. 1 is a phenyl-substituted carbazolyl group.

[0021] In the following, Z 1Specific examples of substituted or unsubstituted carbazolyl groups that can be used are listed below. However, what can be used in the present invention should not be construed as being limited by the following specific examples. In the following specific examples, * indicates the bonding position. Also, methyl groups are omitted. Therefore, C2, C3, C5, and C7 to C9 represent structures substituted with methyl groups. [ka]

[0022] In addition to the above specific examples, groups in which all hydrogen atoms of C2, C3, C5, and C7-C12 alkyl groups have been replaced with deuterated ones are exemplified here as C2(m), C3(m), C5(m), and C7(m)-C12(m), respectively. Groups in which a C4-C6 phenyl group (CH5) has been replaced with a deuterated C6D5 are exemplified here as C4(p)-C6(p), respectively. Furthermore, groups in which all hydrogen atoms of C1-C12 have been deuterated are exemplified here as C1(D)-C12(D), respectively.

[0023] Z in general formula (1) 2 may be a substituted or unsubstituted dibenzofuryl group. The dibenzofuryl group may be a group bonded at any position on the benzene ring. In one embodiment of the present invention, Z 1 is a substituted or unsubstituted dibenzofuran-1-yl group. 1 is a substituted or unsubstituted dibenzofuran-2-yl group. 1 is a substituted or unsubstituted dibenzofuran-3-yl group. 1 is a substituted or unsubstituted dibenzofuran-4-yl group.

[0024] Z 2The dibenzofuryl group may be substituted. It may also be unsubstituted. If substituted, the substituent may be selected from the following substituent group A, the following substituent group B, the following substituent group C, the following substituent group D, or the following substituent group E. Preferred are substituents selected from the following substituent group E. For example, it may be substituted with only an alkyl group, only an aryl group, or both an alkyl group and an aryl group. For the description and preferred ranges of the alkyl group and the aryl group, please refer to the description and preferred ranges of the alkyl group and the aryl group which are the substituents of the benzofurocarbazolyl group and the benzothienocarbazolyl group. In one aspect of the present invention, Z 2 is an unsubstituted dibenzofuryl group. 2 is a substituted dibenzofuryl group. In one aspect of the invention, Z 2 is an alkyl-substituted dibenzofuryl group. 2 is an aryl-substituted dibenzofuryl group. 2 is a phenyl-substituted dibenzofuryl group.

[0025] In the following, Z 2 Specific examples of substituted or unsubstituted dibenzofuryl groups that can be used are listed below. However, what can be used in the present invention should not be construed as being limited by the following specific examples. In the following specific examples, * indicates the bonding position. Also, methyl groups are omitted. Therefore, X20 represents a structure substituted with a methyl group. [ka]

[0026] In addition to the above specific examples, groups in which the methyl group (CH3) of X20 is replaced with deuterated CD3 are exemplified here as X20(m). Furthermore, groups in which the phenyl groups (C6H5) of X5 to X19 are replaced with deuterated CD5 are exemplified here as X5(p) to X19(p). Furthermore, groups in which all hydrogen atoms of X1 to X20 are deuterated are exemplified here as X1(D) to X20(D), respectively.

[0027] R in general formula (1) 2 represents a hydrogen atom or a deuterium atom. 2 is a hydrogen atom. In one aspect of the present invention, R 2 is a deuterium atom.

[0028] R in general formula (1) 1 and R 3 each independently represents a hydrogen atom, a deuterium atom, or an alkyl group which may be deuterated. For the description and preferred range of the alkyl group which may be deuterated, reference can be made to the description and preferred range of the alkyl group which may be deuterated as a substituent of the benzofurocarbazolyl group and the benzothienocarbazolyl group. In one aspect of the present invention, R 1 and R 3 are each independently a hydrogen atom or a deuterium atom. 1 and R 3 is a hydrogen atom. In one aspect of the present invention, R 1 and R 3 In one embodiment of the present invention, at least one of R 1 and R 3 In one embodiment of the present invention, at least one of R 1 is a hydrogen atom or a deuterium atom. 1 is an optionally deuterated alkyl group. 3 is a hydrogen atom or a deuterium atom. 3 is an optionally deuterated alkyl group.1 and R 3 In one aspect of the invention, R 1 and R 3 In one aspect of the invention, R 1 ~R 3 are each independently a hydrogen atom or a deuterium atom. 1 ~R 3 is a hydrogen atom. In one aspect of the present invention, R 1 ~R 3 is a deuterium atom.

[0029] 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. 1 is a substituted or unsubstituted carbazolyl group, and Z 2 is a substituted or unsubstituted benzofurocarbazolyl group. 1 is an unsubstituted carbazolyl group, and Z 2 is an unsubstituted benzofurocarbazolyl group. 1 is an unsubstituted carbazolyl group, and Z 2 is a substituted benzofurocarbazolyl group. 1 is an unsubstituted carbazolyl group, and Z 2 is an aryl-substituted benzofurocarbazolyl group (e.g., a phenyl-substituted benzofurocarbazolyl group). 1 is a substituted carbazolyl group, and Z 2 is an unsubstituted benzofurocarbazolyl group. 1 is a substituted carbazolyl group, and Z 2 is a substituted benzofurocarbazolyl group. 1 is a substituted or unsubstituted carbazolyl group, and Z 2 is a substituted or unsubstituted benzothienocarbazolyl group. 1 is an unsubstituted carbazolyl group, and Z2 is an unsubstituted benzothienocarbazolyl group. 1 is an unsubstituted carbazolyl group, and Z 2 is a substituted benzothienocarbazolyl group. 1 is an unsubstituted carbazolyl group, and Z 2 is an aryl-substituted benzothienocarbazolyl group (e.g., a phenyl-substituted benzothienocarbazolyl group). 1 is a substituted carbazolyl group, and Z 2 is an unsubstituted benzothienocarbazolyl group. 1 is a substituted carbazolyl group, and Z 2 is a substituted benzothienocarbazolyl group.

[0030] 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. 1 and Z 2 are different benzofurocarbazolyl groups. 1 and Z 2 are the same benzofurocarbazolyl group. 1 and Z 2 are different benzothienocarbazolyl groups. 1 and Z 2 are the same benzothienocarbazolyl group. 1 and Z 2 In one embodiment of the present invention, at least one (preferably both) of Z is a benzofurocarbazolyl group substituted with an aryl group. 1 and Z 2 In one embodiment of the present invention, at least one (preferably both) of Z is a benzofurocarbazolyl group substituted with a phenyl group. 1 and Z 2In one embodiment of the present invention, at least one (preferably both) of Z is a benzothienocarbazolyl group substituted with an aryl group. 1 and Z 2 At least one (preferably both) of the groups is a benzothienocarbazolyl group substituted with a phenyl group.

[0031] 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. 1 is an unsubstituted carbazolyl group, and Z 2 is an unsubstituted dibenzofuryl group. 1 is an unsubstituted carbazolyl group, and Z 2 is a substituted dibenzofuryl group. 1 is an unsubstituted carbazolyl group, and Z 2 is an aryl-substituted dibenzofuryl group (for example, a phenyl-substituted dibenzofuryl group). In one aspect of the present invention, Z 1 is a substituted carbazolyl group, and Z 2 is an unsubstituted dibenzofuryl group. 1 is an aryl-substituted carbazolyl group (e.g., a phenyl-substituted carbazolyl group), and Z 2 is an unsubstituted dibenzofuryl group.

[0032] In one embodiment of the present invention, the compound of general formula (1) is represented by the following general formula (2): 1 , R 3 , Z 1 , Z 2 For the explanation and preferred range of , please refer to the corresponding description of general formula (1). [ka]

[0033] In one embodiment of the present invention, the compound of general formula (1) is represented by the following general formula (3): 1 , Z2 For the explanation and preferred range of , please refer to the corresponding description of general formula (1). [ka]

[0034] The compound represented by general formula (1) does not contain any metal element. In one embodiment 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 embodiment 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.

[0035] In the present specification, the term "substituent group A" refers to a deuterium atom, a hydroxyl group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkyl group (for example, having 1 to 40 carbon atoms), an alkoxy group (for example, having 1 to 40 carbon atoms), an alkylthio group (for example, having 1 to 40 carbon atoms), an aryl group (for example, having 6 to 30 carbon atoms), an aryloxy group (for example, having 6 to 30 carbon atoms), an arylthio group (for example, having 6 to 30 carbon atoms), a heteroaryl group (for example, having 5 to 30 ring skeleton atoms), a heteroaryloxy group (for example, having 5 to 3 ring skeleton atoms), a It means one or a combination of two or more selected from the group consisting of a heteroarylthio group (for example, a group having 5 to 30 atoms constituting the ring skeleton), an acyl group (for example, a group having 1 to 40 carbon atoms), an alkenyl group (for example, a group having 1 to 40 carbon atoms), an alkynyl group (for example, a group having 1 to 40 carbon atoms), an alkoxycarbonyl group (for example, a group having 1 to 40 carbon atoms), an aryloxycarbonyl group (for example, a group having 1 to 40 carbon atoms), a heteroaryloxycarbonyl group (for example, a group having 1 to 40 carbon atoms), a silyl group (for example, a trialkylsilyl group having 1 to 40 carbon atoms), and a nitro group. In this specification, the term "substituent group B" refers to one or a combination of two or more selected from the group consisting of a deuterium atom, an alkyl group (e.g., having 1 to 40 carbon atoms), an alkoxy group (e.g., having 1 to 40 carbon atoms), an aryl group (e.g., having 6 to 30 carbon atoms), an aryloxy group (e.g., having 6 to 30 carbon atoms), a heteroaryl group (e.g., having 5 to 30 ring skeleton atoms), a heteroaryloxy group (e.g., having 5 to 30 ring skeleton atoms), and a diarylaminoamino group (e.g., having 0 to 20 carbon atoms). In this specification, the term "substituent group C" refers to one or a combination of two or more selected from the group consisting of a deuterium atom, an alkyl group (e.g., having 1 to 20 carbon atoms), an aryl group (e.g., having 6 to 22 carbon atoms), a heteroaryl group (e.g., having 5 to 20 ring skeleton atoms), and a diarylamino group (e.g., having 12 to 20 carbon atoms). In this specification, the term "substituent group D" refers to one or a combination of two or more selected from the group consisting of a deuterium atom, an alkyl group (e.g., having 1 to 20 carbon atoms), an aryl group (e.g., having 6 to 22 carbon atoms), and a heteroaryl group (e.g., having 5 to 20 ring skeleton atoms). As used herein, the term "substituent group E" refers to one or a combination of two or more selected from the group consisting of deuterium atoms, alkyl groups (e.g., having 1 to 20 carbon atoms), and aryl groups (e.g., having 6 to 22 carbon atoms).

[0036] Specific examples of the compound represented by general formula (1) are listed below, but the compounds that can be used in the present invention are not limited to these specific examples. Specific examples specified in the following Tables 1 to 5 are compounds that are R 1 ~R 3 In Tables 1 to 5, Z in each compound is a hydrogen atom. 1 and Z 2 In Table 1, the structures of compounds 1 to 38964 are specified by specifying Z 1 and Z 2 Each of these is identified to define a structure, and each stage is assigned a compound number.

[0037] [Table 1] TIFF0007780178000022.tif255165TIFF0007780178000023.tif255166

[0038] In Table 2, Z in each structure 1 and Z 2 The structures of compounds 1 to 1288 are specified by specifying the following. 1 Fix Z 2 The 184 compounds in which the formula is changed to D1 to D184 are identified in order. Compounds 1 to 736 in Table 2 are identified as the same compounds 1 to 736 in Table 1.

[0039] [Table 2]

[0040] In Table 3, Z in each structure 1 and Z 2 The structures of compounds 1289 to 35144 are specified by specifying the Z 1 Fix Z 2 The 184 compounds were identified in order by changing the formula from D1 to D184.

[0041] [Table 3] TIFF0007780178000026.tif255146

[0042] In Table 4, Z in each structure 1 and Z 2 The structures of compounds 35145 to 35284 are specified by specifying the Z 1 Fix Z 2 The 20 compounds are identified in order by changing X1 to X20.

[0043] [Table 4]

[0044] In Table 5, Z in each structure 1 and Z 2 The structures of compounds 35285 to 38964 are specified by specifying the Z 1 Fix Z 2 The 20 compounds are identified in order by changing X1 to X20.

[0045] [Table 5] TIFF0007780178000029.tif255146

[0046] Compounds in which hydrogen atoms in compounds 1 to 38964 are substituted with deuterium atoms are exemplified here as compounds 1(D) to 38964(D) in this order. In one embodiment of the present invention, a compound is selected from compounds 1 to 1288. In one embodiment of the present invention, a compound is selected from compounds 1289 to 35144. In one embodiment of the present invention, a compound is selected from compounds 1289 to 4968. In one embodiment of the present invention, a compound is selected from compounds 4969 to 8648. In one embodiment of the present invention, a compound is selected from compounds 8649 to 12328. In one embodiment of the present invention, a compound is selected from compounds 12329 to 16008. In one embodiment of the present invention, a compound is selected from compounds 16009 to 19688. In one embodiment of the present invention, a compound is selected from compounds 19689 to 23368. In one embodiment of the present invention, a compound is selected from compounds 23369 to 27048. In one embodiment of the present invention, a compound is selected from compounds 27049 to 30728. In one embodiment of the present invention, a compound is selected from compounds 30729 to 35144. In one embodiment of the present invention, a compound is selected from compounds 35145 to 35284. In one embodiment of the present invention, a compound is selected from compounds 35285 to 38964. In one embodiment of the present invention, a compound is selected from compounds 35285 to 35684. In one embodiment of the present invention, a compound is selected from compounds 35685 to 36084. In one embodiment of the present invention, a compound is selected from compounds 36085 to 36484. In one embodiment of the present invention, a compound is selected from compounds 36485 to 36884. In one embodiment of the present invention, a compound is selected from compounds 36885 to 37284. In one embodiment of the present invention, a compound is selected from compounds 37285 to 37684. In one embodiment of the present invention, a compound is selected from compounds 37685 to 38084. In one embodiment of the present invention, a compound is selected from compounds 38085 to 38484. In one embodiment of the present invention, a compound is selected from compounds 38485 to 38964.

[0047] An example of a preferred group of compounds represented by general formula (1) is given below. Here, in each structure, a compound in which X is O and a compound in which X is S are separately disclosed. This group can be further divided into a compound group in which X is O and a compound group in which X is S. [ka] TIFF0007780178000031.tif185170

[0048] Below is an example of another preferred group of compounds represented by general formula (1). Here, in each structure, a compound where X is O and a compound where X is S are separately disclosed. This group can be further divided into a group of compounds where X is O and a group of compounds where X is S. [ka] TIFF0007780178000033.tif101170

[0049] Another preferred example of the compound group represented by general formula (1) is given below. [ka]

[0050] The compound represented by general formula (1) is useful as a host material for doping with a light-emitting material. In particular, it is useful as a host material for doping with a delayed fluorescent material. The doping material may be one or more types. The doping material is selected from those having a lower minimum excited singlet energy than the compound represented by general formula (1). The compound represented by general formula (1) is also useful as a carrier blocking material, for example, as an electron blocking material, and can be effectively used in a blocking layer (e.g., an electron blocking layer) in an organic light-emitting device such as an organic electroluminescence device.

[0051] (Delayed fluorescent material) The compound represented by the general formula (1) is useful as a host material to be used together with a delayed fluorescent material. The term "delayed fluorescent material" as used herein refers to an organic compound that undergoes reverse intersystem crossing from an excited triplet state to an excited singlet state in an excited state, and emits delayed fluorescence when returning from the excited singlet state to the ground state. In the present invention, a delayed fluorescent material is one that emits fluorescence with an emission lifetime of 100 ns (nanoseconds) or longer when its emission lifetime is measured using a fluorescence lifetime measurement system (such as a streak camera system manufactured by Hamamatsu Photonics KK). When a compound represented by general formula (1) is used in combination with a delayed fluorescent material, the delayed fluorescent material receives energy from the compound represented by general formula (1) in an excited singlet state and transitions to an excited singlet state. The delayed fluorescent material may also receive energy from the compound represented by general formula (1) in an excited triplet state and transition to an excited triplet state. The delayed fluorescent material has a difference between the excited singlet energy and the excited triplet energy (ΔE ST ) is small, 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.

[0052] The delayed fluorescent material has a difference ΔE between the lowest excited singlet energy and the lowest excited triplet energy at 77K. ST is preferably 0.3 eV or less, more preferably 0.25 eV or less, more preferably 0.2 eV or less, more preferably 0.15 eV or less, even more preferably 0.1 eV or less, even more preferably 0.07 eV or less, even more preferably 0.05 eV or less, even more preferably 0.03 eV or less, and particularly preferably 0.01 eV or less. ΔE ST If the δ is small, reverse intersystem crossing from the excited singlet state to the excited triplet state is easily achieved by absorbing thermal energy, and the material functions as a thermally activated delayed fluorescent material. Thermally activated delayed fluorescent materials absorb heat emitted by a device and relatively easily undergo reverse intersystem crossing from the excited triplet state to the excited singlet state, allowing the excited triplet energy to efficiently contribute to light emission.

[0053] In the present invention, the lowest excited singlet energy (E S1 ) and the lowest excited triplet energy (E T1 ) is a value calculated by the following procedure. ST is E S1 -E T1 This is the value obtained by calculating (1) The lowest excited singlet energy (E S1 ) Thin film or toluene solution (concentration 10 -5 A sample is prepared at a concentration of 1000 mol / L. The fluorescence spectrum of this sample is measured at room temperature (300K). The fluorescence spectrum has the emission on the vertical axis and the wavelength on the horizontal axis. A tangent line is drawn to the rising edge of the short wavelength side of this emission spectrum, and the wavelength value λedge [nm] at the intersection of this tangent line and the horizontal axis is found. This wavelength value is converted to an energy value using the following conversion formula and is called E. S1 Let's say. Conversion formula: E S1 [eV]=1239.85 / λedge In the examples described below, emission spectra were measured using an LED light source (M300L4, manufactured by Thorlabs) as the excitation light source and a detector (PMA-12 multichannel spectrometer C10027-01, manufactured by Hamamatsu Photonics KK). (2) The lowest excited triplet energy (E T1 ) The lowest excited singlet energy (E S1 The same sample used in the measurement of ) is cooled to 77[K] with liquid nitrogen, and the sample for phosphorescence measurement is irradiated with excitation light (300 nm), and the phosphorescence is measured using a detector. The emission from 100 milliseconds after irradiation with excitation light is taken as the phosphorescence spectrum. A tangent line is drawn to the rising edge of the short wavelength side of this phosphorescence spectrum, and the wavelength value λedge[nm] at the intersection of this tangent line and the horizontal axis is found. This wavelength value is converted to an energy value using the following conversion formula, and the value is called E T1 Let's say. Conversion formula: E T1 [eV]=1239.85 / λedge The tangent to the rising edge of the phosphorescence spectrum on the short wavelength side is drawn as follows: When moving along the spectral curve from the short wavelength side of the phosphorescence spectrum to the shortest maximum of the spectral maxima, consider the tangent at each point on the curve toward the long wavelength side. The slope of this tangent increases as the curve rises (i.e., as the vertical axis increases). The tangent drawn at the point where this slope is at its maximum is considered to be the tangent to the rising edge of the phosphorescence spectrum on the short wavelength side. Note that a maximum point having a peak intensity that is 10% or less of the maximum peak intensity of the spectrum is not included in the above-mentioned maximum value on the shortest wavelength side, and the tangent drawn at the point where the slope value is the maximum value that is closest to the maximum value on the shortest wavelength side is defined as the tangent to the rising edge on the short wavelength side of the phosphorescence spectrum.

[0054] In a preferred embodiment of the present invention, a compound (cyanobenzene derivative) having a cyanobenzene structure in which one cyano group is substituted on a benzene ring is used as the delayed fluorescent 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 a benzene ring is used as the delayed fluorescent material. In another preferred embodiment of the present invention, a compound (azabenzene derivative) having an azabenzene structure in which at least one of the carbon atoms constituting the ring skeleton of the benzene ring is substituted with a nitrogen atom is used as the delayed fluorescent material.

[0055] In a preferred embodiment of the present invention, a compound represented by the following general formula (4) is used as the delayed fluorescent material. [ka] In general formula (4), R 21 ~R 23 one of the groups represents a cyano group or a group represented by the following general formula (5), and R 21 ~R 23 The remaining two and R 24 and R 25 At least one of R represents a group represented by the following general formula (6): 21 ~R 25 The remainder represents a hydrogen atom or a substituent (however, the substituent here does not represent a cyano group, a group represented by the following general formula (5), or a group represented by the following general formula (6)). [ka] In general formula (5), L 1 represents a single bond or a divalent linking group, and R 31 and R 32 each independently represents a hydrogen atom or a substituent, and * represents the bonding position. [ka] In general formula (6), L 2 represents a single bond or a divalent linking group, and R 33 and R 34each independently represents a hydrogen atom or a substituent, and * represents the bonding position.

[0056] In a preferred embodiment of the present 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 embodiment of the present invention, R 21 is a cyano group or a group represented by general formula (5). 23 is a cyano group or a group represented by general formula (5). 21 ~R 23 In one embodiment of the present invention, one of R 21 ~R 23 One of these is a group represented by general formula (5).

[0057] In a preferred embodiment of the present invention, L in general formula (5) 1 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 even more preferably a substituted or unsubstituted 1,4-phenylene group (with, for example, an alkyl group having 1 to 3 carbon atoms as the substituent). In one embodiment of the present invention, R in general formula (5) 31 and R 32 are each independently one group or a combination of two or more groups selected from the group consisting of alkyl groups (e.g., having 1 to 40 carbon atoms), aryl groups (e.g., having 6 to 30 carbon atoms), heteroaryl groups (e.g., having 5 to 30 ring skeleton atoms), alkenyl groups (e.g., having 1 to 40 carbon atoms), and alkynyl groups (e.g., having 1 to 40 carbon atoms) (hereinafter, these groups are referred to as "groups of substituent group A"). In a preferred embodiment of the present invention, R 31 and R 32 are each independently a substituted or unsubstituted aryl group (e.g., having 6 to 30 carbon atoms), and examples of the substituent of the aryl group include the groups in Substituent Group A. In a preferred embodiment of the present invention, R 31 and R 32are identical.

[0058] In a preferred embodiment of the present invention, L in general formula (6) 2 is a single bond. In one aspect of the present invention, L 2 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 even more preferably a substituted or unsubstituted 1,4-phenylene group (with, for example, an alkyl group having 1 to 3 carbon atoms as the substituent). In one embodiment of the present invention, R in general formula (6) 33 and R 34 each independently represents a substituted or unsubstituted alkyl group (e.g., having 1 to 40 carbon atoms), a substituted or unsubstituted alkenyl group (e.g., having 1 to 40 carbon atoms), a substituted or unsubstituted aryl group (e.g., having 6 to 30 carbon atoms), or a substituted or unsubstituted heteroaryl group (e.g., having 5 to 30 carbon atoms). Examples of the substituents on the alkyl group, alkenyl group, aryl group, and heteroaryl group include a hydroxyl group, a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkyl group (e.g., having 1 to 40 carbon atoms), an alkoxy group (e.g., having 1 to 40 carbon atoms), an alkylthio group (e.g., having 1 to 40 carbon atoms), an aryl group (e.g., having 6 to 30 carbon atoms), an aryloxy group (e.g., having 6 to 30 carbon atoms), an arylthio group (e.g., having 6 to 30 carbon atoms), a heteroaryl group (e.g., having 5 to 30 ring skeleton atoms), a heteroaryloxy group (e.g., having 5 to 30 ring skeleton atoms), and a heteroarylthi group. Examples thereof include one group or a combination of two or more groups selected from the group consisting of an aryl group (e.g., having 5 to 30 ring skeleton atoms), an acyl group (e.g., having 1 to 40 carbon atoms), an alkenyl group (e.g., having 1 to 40 carbon atoms), an alkynyl group (e.g., having 1 to 40 carbon atoms), an alkoxycarbonyl group (e.g., having 1 to 40 carbon atoms), an aryloxycarbonyl group (e.g., having 1 to 40 carbon atoms), a heteroaryloxycarbonyl group (e.g., having 1 to 40 carbon atoms), a silyl group (e.g., a trialkylsilyl group having 1 to 40 carbon atoms), a nitro group, and a cyano group (hereinafter, these groups are referred to as "groups of substituent group B"). R 33 and R34 may be bonded to each other via a single bond or a linking group to form a cyclic structure. 33 and R 34 When R is an aryl group, they are preferably bonded to each other via a single bond or a linking group to form a cyclic structure. The linking group here includes -O-, -S-, -N(R 35 )-, -C(R 36 )(R 37 )-, -C(=O)-, -O-, -S-, -N(R 35 )-, -C(R 36 )(R 37 )- is preferred, and -O-, -S-, -N(R 35 )- is more preferred. R 35 ~R 37 each independently represents a hydrogen atom or a substituent. The substituent may be selected from the groups in the above-mentioned Substituent Group A or the groups in the below-mentioned Substituent Group B, and is preferably one group or a combination of two or more groups selected from the group consisting of alkyl groups having 1 to 10 carbon atoms and aryl groups having 6 to 14 carbon atoms.

[0059] The group represented by general formula (6) is preferably a group represented by the following general formula (7). [ka]

[0060] L in general formula (7) 11 represents a single bond or a divalent linking group. 11 For a description and preferred range of 2 Reference can be made to the description and preferred ranges of R in general formula (7) 41 ~R 48 R each independently represents a hydrogen atom or a substituent. 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 may be bonded to each other to form a cyclic structure. The cyclic structure formed by bonding to each other may be an aromatic ring or an aliphatic ring, may contain a heteroatom, and may further be a fused ring of two or more rings. The heteroatom referred to here is preferably selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom. Examples of the cyclic structure formed include a benzene ring, a naphthalene ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a pyrrole ring, an imidazole ring, a pyrazole ring, an imidazoline ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, a cyclohexadiene ring, a cyclohexene ring, a cyclopentaene ring, a cycloheptatriene ring, a cycloheptadiene ring, a cycloheptaene ring, a furan ring, a thiophene ring, a naphthyridine ring, a quinoxaline ring, and a quinoline ring. For example, a ring formed by condensing multiple rings, such as a phenanthrene ring or a triphenylene ring, may also be formed. The number of rings contained in the group represented by general formula (7) may be selected from the range of 3 to 5, or may be selected from the range of 5 to 7. R 41 ~R 48 Examples of the substituent that R may have include the groups in the above-mentioned substituent group B, and preferably an unsubstituted alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms which may be substituted with an unsubstituted alkyl group having 1 to 10 carbon atoms. In a preferred embodiment of the present invention, R 41 ~R 48 is a hydrogen atom or an unsubstituted alkyl group having 1 to 10 carbon atoms. In a preferred embodiment of the present invention, R 41 ~R 48 is a hydrogen atom or an unsubstituted aryl group having 6 to 10 carbon atoms. In a preferred embodiment of the present invention, R 41 ~R 48 are all hydrogen atoms. In the general formula (7), * represents a bonding position.

[0061] In a preferred embodiment of the present invention, an azabenzene derivative is used as the delayed fluorescent material. In a preferred embodiment of the present invention, the azabenzene derivative has an azabenzene structure in which three of the carbon atoms constituting the ring skeleton 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 carbon atoms constituting the ring skeleton of the benzene ring are substituted with nitrogen atoms. For example, azabenzene derivatives having a pyridazine structure, pyrimidine structure, or pyrazine structure can be mentioned, and an azabenzene derivative having a pyrimidine structure can be preferably selected. In one embodiment of the present invention, the azabenzene derivative has a pyridine structure in which one of the carbon atoms constituting the ring skeleton of the benzene ring is substituted with a nitrogen atom.

[0062] In a preferred embodiment of the present invention, a compound represented by the following general formula (8) is used as the delayed fluorescent material. [ka] In the general formula (8), Y 1 , Y 2 and Y 3 At least one of Y represents a nitrogen atom and the rest represent methine groups. 1 is a nitrogen atom, and Y 2 and Y 3 is a methine group. Preferably, Y 1 and Y 2 is a nitrogen atom, and Y 3 is a methine group. More preferably, Y 1 ~Y 3 All of the atoms are nitrogen atoms. In general formula (8), Z 1 ~Z 3 Each of Z independently represents a hydrogen atom or a substituent, and at least one of them is a donor substituent. A donor substituent refers to a group having a negative Hammett σp value. Preferably, Z 1 ~Z 3At least one of Z is a group containing a diarylamino structure (two aryl groups bonded to a nitrogen atom may be bonded to each other), more preferably a group represented by the above general formula (6), for example a group represented by the above general formula (7). 1 ~Z 3 In one embodiment of the present invention, only one of Z is a group represented by general formula (6) or (7). 1 ~Z 3 In one embodiment of the present invention, only two of Z are independently a group represented by general formula (6) or (7). 1 ~Z 3 All of the groups are independently represented by general formula (6) or (7). For details and preferred ranges of general formula (6) and general formula (7), please refer to the corresponding descriptions above. The remaining Z that are not groups represented by general formula (6) or general formula (7) 1 ~Z 3 is preferably a substituted or unsubstituted aryl group (e.g., having 6 to 40 carbon atoms, preferably 6 to 20 carbon atoms), and examples of the substituent of the aryl group herein include one group selected from the group consisting of aryl groups (e.g., having 6 to 20 carbon atoms, preferably 6 to 14 carbon atoms) and alkyl groups (e.g., having 1 to 20 carbon atoms, preferably 1 to 6 carbon atoms), or a group consisting of a combination of two or more groups. In one embodiment of the present invention, general formula (8) does not contain a cyano group.

[0063] In a preferred embodiment of the present invention, a compound represented by the following general formula (9) is used as the delayed fluorescent material. [ka] In the general formula (9), Ar 1 is the following A 1 and D 1 and represents a benzene ring, a naphthalene ring, an anthracene ring, or a phenanthrene ring. 2 , Ar 3may each form a cyclic structure, and when a cyclic structure is formed, it represents a benzene ring, a naphthalene ring, a pyridine ring, or a benzene ring substituted with a cyano group. m1 represents an integer of 0 to 2, and m2 represents an integer of 0 to 1. A 1 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 fused carbazolyl group not containing a naphthalene structure, and there are multiple D 1 When present, they may be the same or different. 1 The substituents may be bonded to each other to form a ring structure.

[0064] Preferred compounds that can be used as delayed fluorescent materials are listed below, but the delayed fluorescent materials that can be used in the present invention are not limited to these specific examples. [ka] TIFF0007780178000042.tif219170TIFF0007780178000043.tif230170TIFF0007780178000044.tif20716 9TIFF0007780178000045.tif227170TIFF0007780178000046.tif212170TIFF0007780178000047.tif83170

[0065] In the present invention, other known delayed fluorescent materials can be used in appropriate combination with the compound represented by general formula (1), and unknown delayed fluorescent materials can also be used. As delayed fluorescent materials, 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 007 of WO2013 / 081088 1 and 0118 to 0133, paragraphs 0009 to 0046 and 0093 to 0134 of JP 2013-256490 A, paragraphs 0008 to 0020 and 0038 to 0040 of JP 2013-116975 A, paragraphs 0007 to 0032 and 0079 to 0084 of WO2013 / 133359 A, paragraphs 0008 to 0032 of WO2013 / 161437 A 0054 and 0101 to 0121, paragraphs 0007 to 0041 and 0060 to 0069 of JP 2014-9352 A, paragraphs 0008 to 0048 and 0067 to 0076 of JP 2014-9224 A, paragraphs 0013 to 0025 of JP 2017-119663 A, paragraphs 0013 to 0026 of JP 2017-119664 A, Examples include compounds encompassed by the general formulas described in paragraphs 0012 to 0025 of JP 222623 A, paragraphs 0010 to 0050 of JP 2017-226838 A, paragraphs 0012 to 0043 of JP 2018-100411 A, and paragraphs 0016 to 0044 of WO 2018 / 047853 A, particularly exemplary compounds that emit delayed fluorescence.Also, Japanese Patent Application Laid-Open No. 2013-253121, WO2013 / 133359, WO2014 / 034535, WO2014 / 115743, WO2014 / 122895, WO2014 / 126200, WO2014 / 136758, WO2014 / 133121, WO2014 / 136860, WO2014 / 196585, WO2014 / 189122, WO2014 / 168101, WO2015 / 00858 0 publication, WO2014 / 203840 publication, WO2015 / 002213 publication, WO2015 / 016200 publication, WO2015 / 019725 publication, WO2015 / 072470, WO2015 / 108049, WO2015 / 080182, WO2015 / 072537, WO2015 / 080183, JP2015-129240A, WO2015 / 129714, WO2015 / 129715, WO2015 / 133 It is also possible to employ luminescent materials that emit delayed fluorescence, such as those described in WO2015 / 136880, WO2015 / 137244, WO2015 / 137202, WO2015 / 137136, WO2015 / 146541, and WO2015 / 159541. The above publications described in this paragraph are incorporated herein by reference.

[0066] The delayed fluorescent material used in the present invention preferably does not contain metal atoms.For example, as the delayed fluorescent material, a compound consisting 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 fluorescent material, a compound consisting of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms and oxygen atoms can be selected.For example, as the delayed fluorescent material, a compound consisting of carbon atoms, hydrogen atoms and nitrogen atoms can be selected.

[0067] In this specification, alkyl groups, alkenyl groups, aryl groups, heteroaryl groups, etc. represent the following groups unless otherwise specified. The "alkyl group" may be linear, branched, or cyclic. It may also contain two or more of the linear, cyclic, and branched groups. The number of carbon atoms in the alkyl group may be, for example, 1 or more, 2 or more, or 4 or more. The number of carbon atoms may be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, 2-ethylhexyl, n-heptyl, isoheptyl, n-octyl, isooctyl, n-nonyl, isononyl, n-decanyl, isodecanyl, cyclopentyl, cyclohexyl, and cycloheptyl. The alkyl group may be further substituted with an aryl group. For the alkyl moieties of "alkoxy groups," "alkylthio groups," "acyl groups," and "alkoxycarbonyl groups," the explanation of "alkyl groups" herein can be referred to. The "alkenyl group" may be linear, branched, or cyclic. It may also contain two or more of the linear, cyclic, and branched moieties. The alkenyl group may have, for example, two or more carbon atoms, or four or more carbon atoms. It may also have 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less carbon atoms. Specific examples of the alkenyl group include ethenyl, n-propenyl, isopropenyl, n-butenyl, isobutenyl, n-pentenyl, isopentenyl, n-hexenyl, isohexenyl, and 2-ethylhexenyl. The substituted alkenyl group may be further substituted with a substituent. The "aryl group" and "heteroaryl group" may be a single ring or a fused ring in which two or more rings are fused. In the case of a fused ring, the number of fused rings is preferably 2 to 6, and can be selected from, for example, 2 to 4. Specific examples of the ring include a benzene ring, a pyridine ring, a pyrimidine ring, a triazine ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a triphenylene ring, a quinoline ring, a pyrazine ring, a quinoxaline ring, and a naphthyridine ring. Specific examples of the aryl group or heteroaryl group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthracenyl group, a 2-anthracenyl group, a 9-anthracenyl group, a 2-pyridyl group, a 3-pyridyl group, and a 4-pyridyl group. The terms "arylene group" and "heteroaryl group" can be used in the same manner as in the description of the aryl group and heteroaryl group, except that the valence is changed from 1 to 2. The aryl moiety of an "aryloxy group," an "arylthio group," and an "aryloxycarbonyl group" can also be referred to the explanation of the "aryl group" herein. The heteroaryl moiety of a "heteroaryloxy group," an "heteroarylthio group," and an "heteroaryloxycarbonyl group" can also be referred to the explanation of the "heteroaryl group" herein.

[0068] (composition) The composition of the present invention contains a compound represented by general formula (1) and a delayed fluorescent material. In one embodiment of the present invention, the composition is composed solely of one or more compounds represented by general formula (1) and one or more delayed fluorescent materials. In one embodiment of the present invention, the composition is composed solely of one compound represented by general formula (1) and one delayed fluorescent material. In one embodiment of the present invention, the composition contains a third component in addition to the compound represented by general formula (1) and the delayed fluorescent material. The third component here is neither a compound represented by general formula (1) nor a delayed fluorescent material. The third component may contain only one type, or may contain two or more types. The content of the third component in the composition may be selected from a range of 30% by weight or less, 10% by weight or less, 1% by weight or less, or 0.1% by weight or less. In one embodiment of the present invention, the third component does not emit light. In one embodiment of the present invention, the third component emits fluorescence. In a preferred embodiment of the present invention, the maximum component of light emitted from the composition of the present invention is fluorescence (including delayed fluorescence). In the composition of the present invention, the compound represented by general formula (1) is contained in a larger amount by weight than the delayed fluorescent material. The content of the compound represented by general formula (1) may be selected within a range of 3 times or more by weight, 10 times or more by weight, 100 times or more by weight, 1000 times or more by weight, or, for example, 10,000 times or less by weight of the delayed fluorescent material. In the composition of the present invention, it is preferable to select a delayed fluorescent material having a lower excited singlet energy than the excited singlet energy of the compound represented by general 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, or 2 eV or less, 1.5 eV or less, or 1.0 eV or less. The composition of the present invention preferably does not contain metal elements. In one embodiment of the present invention, the composition of the present invention 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. In one embodiment of the present invention, the composition of the present invention consists only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, and sulfur atoms.

[0069] In one embodiment of the present invention, the compound represented by formula (1) is useful as a host material for use together with a delayed fluorescent material and a fluorescent compound. Therefore, in one embodiment of the present invention, the composition of the present invention includes a fluorescent compound in addition to the compound represented by formula (1) and the delayed fluorescent material.

[0070] The fluorescent compound has a lowest excited singlet energy (E S1 ) is preferably small. The fluorescent compound receives energy from the compound represented by general formula (1) and the delayed fluorescent material in the excited singlet state, and from the delayed fluorescent material that has undergone reverse intersystem crossing from the excited triplet state to the excited singlet state, transitions to the 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 general formula (1) and the delayed fluorescent material and emit fluorescence, and the emission may be either fluorescence or delayed fluorescence. In particular, it is preferable that the light emitter used as the fluorescent compound 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 in combination, it is possible to emit light of a desired color. Examples of fluorescent compounds that can be used 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, terphenylene derivatives, fluoranthene derivatives, amine derivatives, quinacridone derivatives, oxadiazole derivatives, malononitrile derivatives, pyran derivatives, carbazole derivatives, julolidine derivatives, thiazole derivatives, derivatives containing metals (Al, Zn), and compounds having a boron-containing polycyclic aromatic skeleton such as diazaboranaphthoanthracene, and other compounds that exhibit a multiple resonance effect. These exemplary skeletons may or may not have a substituent. These exemplary skeletons may also be combined with each other.

[0071] Specific examples of fluorescent compounds include the compounds listed as specific examples of delayed fluorescent materials. In this case, the composition of the present invention contains two or more delayed fluorescent materials, with the one with a higher lowest excited singlet energy functioning as an assist dopant and the one with a lower lowest excited singlet energy functioning as the primary emitting fluorescent compound. The compound used as the fluorescent compound preferably exhibits a PL emission quantum yield of 60% or more, more preferably 80% or more. Furthermore, 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 here refers to the emission lifetime of the component that decays most rapidly among multiple exponential decay components observed when measuring the emission lifetime of a compound exhibiting thermally activated delayed fluorescence. Furthermore, the compound used as the third compound preferably has a fluorescence emission rate from the lowest excited singlet (S1) to the ground state that is faster than the intersystem crossing rate from S1 to the lowest excited triplet (T1). For a method for calculating the rate constant of a compound, reference can be made to known literature on thermally activated delayed fluorescent materials (H. Uoyama, et al., Nature 492, 234 (2012), K. Masui, et al., Org. Electron. 14, 2721, (2013), etc.).

[0072] Preferred compounds that can be used as the fluorescent compound together with the delayed fluorescent material are listed below, but the fluorescent compounds that can be used in the present invention should not be construed as being limited to these specific examples.

[0073] [ka] TIFF0007780178000049.tif215170TIFF0007780178000050.tif143170

[0074] Furthermore, the compounds described in paragraphs 0220 to 0239 of WO2015 / 022974 can also be particularly preferably used as the fluorescent compound of the present invention.

[0075] In one embodiment of the present invention, the compound represented by general formula (1) can be used together with other host materials to form an emitting layer (composition) containing multiple host materials. That is, in one embodiment of the present invention, the composition of the present invention contains multiple host materials including the compound represented by general formula (1). The composition of the present invention may contain multiple types of compounds represented by general formula (1), or may use a compound represented by general formula (1) in combination with a host material not represented by general formula (1). Preferred compounds that can be used as the second host material together with the compound represented by general formula (1) are listed below, but the second host material that can be used in the present invention should not be construed as being limited by these specific examples.

[0076] [ka] TIFF0007780178000052.tif245170

[0077] The form of the composition of the present invention is not particularly limited. In a particularly preferred embodiment of the present invention, the composition of the present invention is in the form of a membrane (film). The membrane made of the composition of the present invention may be formed by a wet process or a dry process. In a wet process, a solution containing the composition of the present invention is applied to a surface, and after removing the solvent, a light-emitting layer is formed. Examples of wet processes include, but are not limited to, spin coating, slit coating, inkjet printing (spraying), gravure printing, offset printing, and flexographic printing. In a wet process, an appropriate organic solvent capable of dissolving the composition of the present invention is selected and used. In some embodiments, a substituent (e.g., an alkyl group) that increases the solubility in organic solvents can be introduced into the compound contained in the composition of the present invention. A vacuum deposition method can be preferably used as the dry process. When using a vacuum deposition method, the compounds constituting the composition of the present invention may be co-deposited from separate deposition sources, or from a single deposition source containing a mixture of all compounds. When a single deposition source is used, a mixed powder containing all the compounds may be used, or a compressed compact obtained by compressing the mixed powder may be used, or a mixture obtained by heating, melting, mixing, and then cooling may be used. In some embodiments, co-deposition is performed under conditions where the deposition rates (weight loss rates) of multiple compounds contained in a single deposition source are identical or nearly identical, thereby forming a film having a composition ratio corresponding to the composition ratio of multiple compounds contained in the deposition source. By mixing multiple compounds in the same composition ratio as the composition ratio of the film to be formed and using the deposition source as a deposition source, a film having a desired composition ratio can be easily formed. In some embodiments, the temperature at which each compound to be co-deposited has the same weight loss rate can be identified, and that temperature can be 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, even more preferably 1000 or less, and even more preferably 900 or less. The lower limit of the molecular weight may be, for example, 450, 500, or 600.

[0078] (organic light-emitting element) By forming a light-emitting layer made of the composition of the present invention, it is possible to provide excellent organic light-emitting devices such as organic photoluminescence devices (organic PL devices) and organic electroluminescence devices (organic EL devices). 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 (fluorescence here includes delayed fluorescence). The thickness of the light-emitting layer can be, for example, 1 to 15 nm, 2 to 10 nm, or 3 to 7 nm. An organic photoluminescence element has a structure in which at least a light-emitting layer is formed on a substrate. An 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. Examples of such other organic layers include a hole transport layer, a hole injection layer, an electron blocking layer, a hole blocking layer, an electron injection layer, an electron transport layer, and an exciton blocking layer. 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 element of the present invention is a multi-wavelength light-emitting organic light-emitting element, the emission with the shortest wavelength may include delayed fluorescence. Alternatively, the emission with the shortest wavelength may not include delayed fluorescence. When excited by thermal or electronic means, organic light-emitting devices using the compositions of the present invention can emit light in the ultraviolet region, the blue, green, yellow, orange, or red region of the visible spectrum (e.g., 420-500 nm, 500-600 nm, or 600-700 nm), or the near-infrared region. For example, organic light-emitting devices can emit light in the red or orange region (e.g., 620-780 nm). For example, organic light-emitting devices can emit light in the orange or yellow region (e.g., 570-620 nm). For example, organic light-emitting devices can emit light in the green region (e.g., 490-575 nm). For example, organic light-emitting devices can emit light in the blue region (e.g., 400-490 nm). For example, organic light-emitting devices can emit light in the ultraviolet spectral region (e.g., 280-400 nm). For example, organic light-emitting devices can emit light in the infrared spectral region (e.g., 780 nm-2 μm). The largest component of the light emitted from an organic light-emitting device using the composition of the present invention is preferably the light emitted from the delayed fluorescent material contained in the composition of the present invention. The light emitted from the compound represented by general formula (1) is preferably less than 10% of the light emitted from the organic light-emitting device, and may be, for example, less than 1%, less than 0.1%, less than 0.01%, or even below the detection limit. The light emitted from the delayed fluorescent material may be, for example, more than 50%, more than 90%, or more than 99% of the light emitted from the organic light-emitting device. When the layer containing the composition of the present invention (light-emitting layer) contains a fluorescent material as a third component, the largest component of the light emitted from the organic light-emitting device may be the light emitted from the fluorescent material. In this case, the light emitted from the light-emitting material may be, for example, more than 50%, more than 90%, or more than 99% of the light emitted from the organic light-emitting device.

[0079] Each component of the organic electroluminescence element and each layer other than the light-emitting layer will be described below.

[0080] Base material: In some embodiments, the organic electroluminescent device of the present invention is supported by a substrate, and the substrate is not particularly limited and may be any material commonly used in organic electroluminescent devices, such as glass, transparent plastic, quartz, and silicon.

[0081] anode: In some embodiments, the anode of the organic electroluminescent device is made of a metal, an alloy, a conductive compound, or a combination 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), SnO, and ZnO. In some embodiments, an amorphous material capable of forming a transparent conductive film, such as In2O3-ZnO, is used. In some embodiments, the anode is a thin film. In some embodiments, the thin film is formed by evaporation or sputtering. In some embodiments, the film is patterned by a photolithography method. In some embodiments, if the pattern does not need to be highly precise (e.g., greater than about 100 μm), the pattern may be formed using a mask with a shape suitable for evaporation or sputtering of the electrode material. In some embodiments, when a coating material, such as an organic conductive compound, can be applied, a wet film formation method, such as a printing method or a coating method, is used. In some embodiments, the anode has a transmittance of greater than 10% when emitted light passes through it, and the anode has a sheet resistance of several hundred ohms per unit area or less. In some embodiments, the anode has a thickness of 10 to 1,000 nm. In some embodiments, the anode has a thickness of 10 to 200 nm. In some embodiments, the thickness of the anode varies depending on the material used.

[0082] cathode: In some embodiments, the cathode is made of an electrode material such as a metal with a low work function (4 eV or less) (referred to as an electron-injecting metal), alloy, conductive compound, or a combination thereof. In some embodiments, the electrode material is selected from sodium, sodium-potassium alloy, magnesium, lithium, magnesium-copper mixture, magnesium-silver mixture, magnesium-aluminum mixture, magnesium-indium mixture, aluminum-aluminum oxide (Al2O3) mixture, indium, lithium-aluminum mixture, and rare earth elements. In some embodiments, a mixture of an electron-injecting metal and a second metal, which is a stable metal having a higher work function than the electron-injecting metal, is used. In some embodiments, the mixture is selected from magnesium-silver mixture, magnesium-aluminum mixture, magnesium-indium mixture, aluminum-aluminum oxide (Al2O3) mixture, lithium-aluminum mixture, and aluminum. In some embodiments, the mixture improves electron-injecting properties and oxidation resistance. In some embodiments, the cathode is fabricated by forming the electrode material as a thin film by evaporation or sputtering. In some embodiments, the cathode has a sheet resistance of several hundred ohms per unit area or less. In some embodiments, the cathode has a thickness of 10 nm to 5 μm. In some embodiments, the cathode has a thickness of 50 to 200 nm. In some embodiments, one of the anode and cathode of the organic electroluminescent device is transparent or semitransparent to transmit emitted light. In some embodiments, a transparent or semitransparent electroluminescent device improves light radiance. In some embodiments, the cathode is formed from a conductive, transparent material as described above for the anode, thereby forming a transparent or semi-transparent cathode. In some embodiments, a device includes an anode and a cathode, both of which are transparent or semi-transparent.

[0083] Injection layer: An injection layer is a layer between an electrode and an organic layer. In some embodiments, the injection layer reduces driving 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 disposed between the anode and the emissive layer or the hole transport layer, and between the cathode and the emissive layer or the electron transport layer. In some embodiments, an injection layer is present. In some embodiments, an injection layer is not present. Preferred examples of compounds that can be used as hole injection materials are listed below.

[0084] [ka]

[0085] Next, preferred examples of compounds that can be used as the electron injection material will be listed. [ka]

[0086] Barrier layer: A blocking layer is a layer that can prevent charges (electrons or holes) and / or excitons present in the light-emitting layer from diffusing outside the light-emitting layer. In some embodiments, an electron blocking layer is present between the light-emitting layer and the hole transport layer and prevents electrons from passing through the light-emitting layer to the hole transport layer. In some embodiments, a hole blocking layer is present between the light-emitting layer and the electron transport layer and prevents holes from passing through the light-emitting layer to the electron transport layer. In some embodiments, a blocking layer prevents excitons from diffusing outside the light-emitting 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 both the functionality of an electron blocking layer and an exciton blocking layer.

[0087] Hole blocking layer: The hole blocking layer functions as an electron transport layer. In some embodiments, the hole blocking layer prevents 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 light-emitting layer. The materials used for the hole blocking layer can be the same materials as those described above for the electron transport layer. Preferred examples of compounds that can be used in the hole blocking layer are listed below.

[0088] [ka]

[0089] Electron barrier layer: The electron blocking layer transports holes. In some embodiments, during hole transport, the electron blocking layer prevents electrons from reaching the hole transport layer. In some embodiments, the electron blocking layer increases the probability of recombination of electrons and holes in the light-emitting layer. The materials used for the electron blocking layer can be the same materials as those described above for the hole transport layer. Specific examples of preferred compounds that can be used as electron blocking materials are listed below.

[0090] [ka]

[0091] Exciton blocking layer: The exciton blocking layer prevents excitons generated through the recombination of holes and electrons in the emissive layer from diffusing to the charge transport layer. In some embodiments, the exciton blocking layer enables effective confinement of excitons in the emissive layer. In some embodiments, the light emission efficiency of the device is improved. In some embodiments, the exciton blocking layer is adjacent to the emissive layer on either the anode side or the cathode side, and on both sides. In some embodiments, when the exciton blocking layer is present on the anode side, it may be present between the hole transport layer and the emissive layer and adjacent to the emissive layer. In some embodiments, when the exciton blocking layer is present on the cathode side, it may be present between the emissive layer and the cathode and adjacent to the emissive layer. In some embodiments, a hole injection layer, an electron blocking layer, or a similar layer is present between the anode and the exciton blocking layer adjacent to the emissive layer on the anode side. In some embodiments, a hole injection layer, an electron blocking layer, a hole blocking layer, or a similar layer is present between the cathode and the 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 excited triplet energy, respectively, of the light-emitting material.

[0092] Hole transport layer: The hole transport layer comprises a hole transport 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 of hole injection or transport properties and electron blocking properties. 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, pyrazolone 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. 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 hole transport materials are listed below.

[0093] [ka]

[0094] Electron transport layer: The electron transport layer comprises 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 transport material only needs to transport electrons injected from the cathode to the light-emitting layer. In some embodiments, the electron transport material also functions as a hole-blocking material. Examples of electron transport 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, fluorenylidenemethane derivatives, anthraquinodimethanes, anthrone derivatives, oxadiazole 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 polymer material. Specific examples of preferred compounds that can be used as electron transport materials are listed below.

[0095] [ka]

[0096] Furthermore, examples of compounds that can be added to each organic layer are given below, which may be added as a stabilizing material, for example.

[0097] [ka]

[0098] Although specific examples of preferred materials that can be used in organic electroluminescence devices have been given, the materials that can be used in the present invention should not be construed as being limited to the following exemplary compounds. Furthermore, even compounds exemplified as materials having specific functions can be diverted to be used as materials having other functions.

[0099] device: In some embodiments, the light-emitting layer is incorporated into a device, including, but not limited to, an OLED bulb, an OLED lamp, a television display, a computer monitor, a mobile phone, and a tablet. In some embodiments, the electronic device comprises an OLED having an anode, a cathode, and at least one organic layer comprising an emissive layer between the anode and the cathode. In some embodiments, the compositions described herein can be incorporated into various photosensitive or photoactivated devices, such as OLEDs or optoelectronic devices. In some embodiments, the compositions can be useful for facilitating charge or energy transfer within devices and / or as hole transport materials, such as 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), organic solar cells (O-SCs), organic optical detectors, organic photoreceptors, organic field-quench devices (O-FQDs), light-emitting fuel cells (LECs), or organic laser diodes (O-lasers).

[0100] Bulb or Lamp: In some embodiments, the electronic device comprises an OLED comprising an anode, a cathode, and at least one organic layer comprising an emissive 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 a combination of OLEDs. In some embodiments, the combination of OLEDs is a three-color combination (e.g., RGB). In some embodiments, the combination of OLEDs is a combination of colors that are not red, green, or blue (e.g., orange and yellow-green). In some embodiments, the combination of OLEDs is a two-color, four-color, or more-color combination. In some embodiments, the device comprises: a circuit board having a first side with a mounting surface and an opposite second side, the circuit board defining at least one opening; at least one OLED on the mounting surface, the at least one OLED having a light-emitting configuration including an anode, a cathode, and at least one organic layer including a light-emitting layer between the anode and the cathode; a housing for the circuit board; and at least one connector disposed on an end of the housing, the housing and the 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 of the light emitted in a first direction is polarized and emitted in a second direction. In some embodiments, a reflector is used to polarize the light emitted in the first direction.

[0101] Display or Screen: In some embodiments, the light-emitting layer of the present invention can be used in a screen or display. 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, vapor deposition, or chemical vapor deposition (CVD). In some embodiments, the substrate is a photoplate structure useful for two-sided etching to provide pixels with unique aspect ratios. The screen (also called a mask) is used in the manufacturing process of OLED displays. The corresponding artwork pattern design allows for the placement of very steep, narrow tie bars between pixels in the vertical direction and large, 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 onto the TFT backplane. Internal pixel patterning allows for the construction of three-dimensional pixel openings with various aspect ratios in the horizontal and vertical directions. Furthermore, the use of imaged "stripes" or halftone circles within the pixel area protects etching in specific regions until these specific patterns are undercut and removed from the substrate. At that point, all pixel areas are subjected to similar etch rates, but the depth varies depending on the halftone pattern. Varying the size and spacing of the halftone patterns allows for etching with varying degrees of protection within the pixel, enabling the deep, localized etching required to create steep vertical bevels. The preferred material for the deposition mask is Invar, a metal alloy that is cold-rolled into long, thin sheets at steel mills. Invar cannot be electrodeposited onto the spin mandrel as a nickel mask. A suitable, low-cost method for forming open areas in the deposition mask is by wet chemical etching. In some embodiments, the screen or display pattern is a pixel matrix on a substrate. In some embodiments, the screen or display pattern is fabricated using lithography (e.g., photolithography and e-beam lithography). In some embodiments, the screen or display pattern is fabricated using wet chemical etching. In further embodiments, the screen or display pattern is fabricated using plasma etching.

[0102] Device manufacturing method: OLED displays are generally manufactured by forming a large mother panel and then cutting the mother panel into cell panels. Typically, each cell panel on the mother panel is formed by forming a thin film transistor (TFT) having an active layer and source / drain electrodes on a base substrate, applying a planarizing film to the TFT, sequentially forming a pixel electrode, an emissive layer, a counter electrode, and an encapsulation layer, and then cutting the mother panel. OLED displays are generally manufactured by forming a large mother panel and then cutting the mother panel into cell panels. Typically, each cell panel on the mother panel is formed by forming a thin film transistor (TFT) having an active layer and source / drain electrodes on a base substrate, applying a planarizing film to the TFT, sequentially forming a pixel electrode, an emissive layer, a counter electrode, and an encapsulation layer, and then cutting the mother panel.

[0103] In another aspect of the present invention, there is provided a method for manufacturing an organic light emitting diode (OLED) display, the method comprising: forming a barrier layer on a 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 interface between the cell panels. In some embodiments, the barrier layer is an inorganic film, for example, 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 individual cell panels. In some embodiments, the thin film transistor (TFT) layer includes a light-emitting layer, a gate electrode, and source / drain electrodes. Each of the plurality of display units may include a thin film transistor (TFT) layer, a planarization film formed on the TFT layer, and a light-emitting unit formed on the planarization film, and the organic film applied to the interface is formed of the same material as the planarization film and is formed simultaneously with the planarization film. In some embodiments, the light-emitting unit is connected to the TFT layer by a passivation layer, the planarization 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 either the display unit or the encapsulation layer.

[0104] Each of the organic film and the planarization film may comprise 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 may further include attaching a carrier substrate formed of a glass material to one surface of the base substrate formed of polyimide before forming the barrier layer on the other surface of the base substrate, and separating the carrier substrate from the base substrate before cutting along the interface. In some embodiments, the OLED display is a flexible display. In some embodiments, the passivation layer is an organic film disposed on the TFT layer to cover the TFT layer. In some embodiments, the planarization film is an organic film formed on the passivation layer. In some embodiments, the planarization film is formed of polyimide or acrylic, as is the organic film formed on the edge of the barrier layer. In some embodiments, the planarization film and the 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 directly contacts the base substrate and a remaining portion of the organic film contacts the barrier layer while surrounding the edge of the barrier layer.

[0105] In some embodiments, the light-emitting layer comprises a pixel electrode, a counter electrode, and an organic light-emitting layer disposed between the pixel electrode and the counter electrode, hi some embodiments, the pixel electrode is coupled to a source / drain electrode 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, which causes the organic light-emitting layer to emit light, thereby forming an image. Hereinafter, an image-forming unit having a TFT layer and a light-emitting unit is referred to as a display unit. In some embodiments, the encapsulation layer that covers the display units and prevents penetration of external moisture may be formed into a thin-film encapsulation structure in which organic films and inorganic films are alternately stacked. In some embodiments, the encapsulation layer has a thin-film encapsulation structure in which multiple thin films are stacked. In some embodiments, the organic film applied to the interface portion is disposed at an interval with each of the multiple display units. In some embodiments, the organic film is formed in such a manner that a portion of the organic film directly contacts the base substrate and the remaining portion of the organic film contacts the barrier layer while surrounding the edge of the barrier layer.

[0106] In one embodiment, the OLED display is flexible and uses a flexible base substrate formed of polyimide, hi some embodiments, the base substrate is formed on a carrier substrate formed of a glass material, and the carrier substrate is then 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, while the base substrate is formed on all surfaces of the mother panel, the barrier layer is 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 grooves.

[0107] In some embodiments, the manufacturing method further includes a step of cutting along the interface, in which a groove is formed in the barrier layer and at least a portion of the organic film is formed in the groove, so that the groove does not penetrate the base substrate. In some embodiments, the TFT layer of each cell panel is formed, and a passivation layer (an inorganic film) and a planarization film (an organic film) are disposed on and cover the TFT layer. At the same time as the planarization film (e.g., polyimide or acrylic) is formed, the grooves at the interface are covered with an organic film (e.g., polyimide or acrylic). This prevents cracks from occurring when each cell panel is cut along the grooves at the interface by allowing the organic film to absorb any impacts that may occur. That is, if all barrier layers were completely exposed without the organic film, the impacts would be transmitted to the barrier layers when each cell panel was cut along the grooves at the interface, thereby increasing the risk of cracks. However, in one embodiment, the grooves at the interface between the barrier layers are covered with an organic film to absorb any impacts that would otherwise be transmitted to the barrier layers, allowing each cell panel to be cut softly and preventing cracks from occurring in the barrier layers. In one embodiment, the organic film and the planarizing film covering the groove of the interface portion are spaced apart from each other. For example, if the organic film and the planarizing film are connected to each other as one layer, external moisture may penetrate into the display unit through the planarizing film and the remaining portion of the organic film, so the organic film and the planarizing film are spaced apart from each other so that the organic film is spaced apart from the display unit.

[0108] In some embodiments, the display unit is formed by forming a light-emitting unit, and an encapsulation layer is disposed on the display unit to cover the display unit. Thus, after the mother panel is completely manufactured, the carrier substrate carrying the base substrate is separated from the base substrate. In some embodiments, when a laser beam is irradiated onto the carrier substrate, the carrier substrate is separated from the base substrate due to the difference in thermal expansion coefficient between the carrier substrate and the base substrate. In some embodiments, the mother panel is cut into individual cell panels. In some embodiments, the mother panel is cut along the interface between the cell panels using a cutter. In some embodiments, the grooves at the interface along which the mother panel is cut are covered with an organic film, which absorbs shock during cutting. In some embodiments, this can prevent cracks from occurring in the barrier layer during cutting. In some embodiments, the method reduces product rejection rates and stabilizes product quality. Another embodiment is an OLED display having 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 film applied to the edges of the barrier layer. [Example]

[0109] The following synthesis examples and working examples will further illustrate the features of the present invention. The materials, processing details, processing procedures, etc. described below can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples described below. The emission characteristics were evaluated using a source meter (Keithley: 2400 Series), a semiconductor parameter analyzer (Agilent Technologies: E5273A), an optical power meter (Newport: 1930C), an optical spectrometer (Ocean Optics: USB2000), a spectroradiometer (Topcon: SR-3), and a streak camera (Hamamatsu Photonics: C4334). The HOMO and LUMO energies were measured by atmospheric photoelectron spectroscopy (Riken Keiki AC-3, etc.). In the following synthesis examples, compounds within the general formula (1) were synthesized.

[0110] (Synthesis Example 1) Synthesis of Compound 6 [ka]

[0111] 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 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 resulting solid was purified by silica gel column chromatography (developing solvent: chloroform / n-hexane = 1:4 to 3:7). Further recrystallization (chloroform / methanol) yielded intermediate a (2.02 g, 66%) as a white solid. 1H NMR (400MHz, CDCl3, 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 C 23 H 13 FN2O: 352.10.

[0112] [ka]

[0113] Under a 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), and potassium carbonate (1.30 g, 9.38 mmol) were 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). The solid was further washed with methanol to give compound 6 (1 g, 64%) as a white solid. 1 H NMR (400MHz, CDCl3, 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 C 35 H 21 N3O: 499.17.

[0114] (Synthesis Example 2) Synthesis of Compound 1110 The following compound 1110 was obtained by the same procedure as in Synthesis Example 1, except that deuterated carbazole, in which all hydrogen atoms of carbazole were substituted with deuterium atoms, was used instead of the carbazole used in Synthesis Example 1. [ka]

[0115] (Synthesis Example 3) Synthesis of Compound 2214 [ka]

[0116] Under a nitrogen atmosphere, 2,6-difluoropyridine (0.5 g, 4.34 mmol), 5H-benzofuro[3,2-c]carbazole (2.79 g, 10.9 mmol), and potassium carbonate (1.80 g, 13 mmol) were 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 (2.19 g, 86%) as a white solid. MS (ASAP): 590.32 (M+H + ). Calcd for C 41 H 23 N3O2: 589.18.

[0117] (Synthesis Example 4) Synthesis of Compound 35159 [ka]

[0118] Under a 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, 1.96 g, 5.29 mmol), tetrakis(triphenylphosphine)palladium(0) (0.30 g, 0.26 mmol), and potassium carbonate (2.19 g, 15.87 mmol) were added to tetrahydrofuran / water (50 ml / 25 ml) 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). Further, recrystallization from toluene / methanol gave compound 35159 (2.21 g, 86%) as a white solid. MS (ASAP): 487.79.32 (M+H + ). Calcd for C 35 H 22 N2O: 486.17.

[0119] Example 1: Fabrication of an organic electroluminescence device Each thin film was deposited by vacuum deposition on a glass substrate with an anode made of indium tin oxide (ITO) with a thickness of 50 nm, at a vacuum of 1×10 -5 The layers were laminated with Pa. First, HATCN was formed to a thickness of 10 nm on ITO, and NPD was formed thereon to a thickness of 30 nm. Next, TrisPCz was formed thereon to a thickness of 10 nm. Next, Compound 6 and TADF19 were co-deposited from different evaporation sources at 65% by mass and 35% by mass, respectively, to form a 40-nm-thick light-emitting layer. SF3TRZ was formed thereon to a thickness of 10 nm, and SF3TRZ and Liq were co-deposited from different evaporation sources at 30% by mass and 70% by mass, respectively, to form a 30-nm-thick layer. Liq was then 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 electroluminescent device of Example 1 was fabricated using the above procedures. 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 An organic electroluminescence device of Comparative Example 1 was produced in the same manner as in Example 1, except that PYD2Cz was used instead of Compound 6 used in Example 1. (evaluation) The organic electroluminescence devices of Examples 1, 2 and Comparative Example 1 were each subjected to a current of 12.6 mA / cm 2 A current was applied. The luminous intensity immediately after application of the current was taken as 100, and the time until the luminous intensity fell below 95 was measured and taken as LT95. When the LT95 of Comparative Example 1 was taken as 1, the LT95 of Example 1 was 2.3 times, and the LT95 of Example 2 was 1.8 times. It was confirmed that the device life was extended when the compound represented by general formula (1) was used.

[0120] Example 3: Fabrication of an organic electroluminescence device An organic electroluminescence device of Example 3 was fabricated by the same procedure as in Example 1, except that the light-emitting layer was formed using compound 35159 and TADF2 instead of compound 6 and TADF19 used in Example 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 the compound 35159 used in Example 3. (evaluation) The organic electroluminescence devices of Example 3 and Comparative Example 2 were each tested at 6.3 mA / cm 2 The external quantum efficiency (EQE) was measured when a current was applied at 1000 kJ / s. As a result, the organic electroluminescence device of Example 3 had an external quantum efficiency (EQE) that was 1.8% higher than that of Comparative Example 2. It was confirmed that the use of the compound represented by general formula (1) resulted in higher luminous efficiency.

[0121] [ka] [Industrial Applicability]

[0122] The compound represented by general formula (1) is useful, for example, as a host material. 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

1. A compound represented by the following general formula (1): 【Chemistry 1】 [In general formula (1), R １ and R ３ each independently represents a hydrogen atom, a deuterium atom, or an optionally deuterated alkyl group. R ２ each 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. Z ２ 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 each a group bonded via a nitrogen atom constituting a carbazole ring. However, the compound represented by the general formula (1) satisfies at least one of the following conditions (A) to (D). (A)Z １ is a substituted or unsubstituted benzofurocarbazolyl group. (B)Z ２ is a substituted or unsubstituted benzofurocarbazolyl group. (C)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. (D)Z １ and Z ２ are each independently a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group.

2. Z １ The compound according to claim 1 , wherein is a substituted or unsubstituted benzofurocarbazolyl group.

3. Z １ The compound according to claim 1 , wherein is a substituted or unsubstituted carbazolyl group.

4. Z ２ The compound according to any one of claims 1 to 3, wherein is a substituted or unsubstituted dibenzofuryl group.

5. Z ２ The compound according to any one of claims 1 to 3, wherein is a substituted or unsubstituted benzofurocarbazolyl group.

6. Z １ is a substituted or unsubstituted carbazolyl group, and Z ２ The compound according to claim 1 , wherein is a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group.

7. Z １ and Z ２ and each independently represent a substituted or unsubstituted benzofurocarbazolyl group or a substituted or unsubstituted benzothienocarbazolyl group.

8. Z １ is a substituted or unsubstituted carbazolyl group, and Z ２ The compound according to claim 1 , wherein is a substituted or unsubstituted dibenzofuryl group.

9. The compound according to any one of claims 1 to 8, wherein 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.

10. R １ ~R ３ The compound according to any one of claims 1 to 9, wherein is a hydrogen atom.

11. A host material comprising the compound according to any one of claims 1 to 10.

12. The host material according to claim 11 for use together with a delayed fluorescent material.

13. A composition in which the compound according to any one of claims 1 to 10 is doped with a delayed fluorescent material.

14. The composition of claim 13 in the form of a film.

15. The composition according to claim 13 or 14, wherein the delayed fluorescent material is a compound having a cyanobenzene structure in which one cyano group is substituted on a benzene ring.

16. The composition according to claim 13 or 14, wherein the delayed fluorescent material is a compound having a cyanobenzene structure in which two cyano groups are substituted on a benzene ring.

17. 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 the compound and the delayed fluorescent material.

18. An organic light-emitting device comprising a layer made of the composition according to any one of claims 13 to 16.

19. 19. The organic light-emitting device according to claim 18, wherein the layer consists solely of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, sulfur atoms, boron atoms, and halogen atoms.

20. 20. The organic light-emitting device according to claim 19, wherein the layer consists solely 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 claims 18 to 20, which is an organic electroluminescence device.

22. The composition does not contain a fluorescent compound having a lower minimum excited singlet energy than the delayed fluorescent material, and the largest component of light emitted from the element is light emitted from the delayed fluorescent material. The organic light-emitting element according to any one of claims 18 to 21.

23. The composition contains a fluorescent compound having a lowest excited singlet energy lower than that of the delayed fluorescent material, and the largest component of light emitted from the element is light emitted from the fluorescent compound. The organic light-emitting element according to any one of claims 18 to 21.

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