Compound, composition, host material, electron barrier material and organic light emitting element

Abstract

A compound represented by the general formula is useful as a host material and an electron barrier material. R1 to R5 are deuterium atoms or alkyl groups, but one or two of R4 and R5 are phenyl groups that may be substituted with alkyl groups. n1 and n3-5 are 0-4, and n2 is 0-3.

Description

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

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

[0002] Research into improving the luminous efficiency of light-emitting elements such as organic electroluminescence elements (organic EL elements) has been actively conducted. In particular, various efforts have been made to improve the luminous efficiency by newly developing and combining electron transport materials, hole transport materials, luminescent materials, host materials, etc. that constitute organic electroluminescence elements. Among these, organic electroluminescence elements using delayed fluorescent materials have been developed and are attracting attention (see Non-Patent Document 1).

[0003] A delayed fluorescent material is a material that, in an excited state, undergoes reverse intersystem crossing from an excited triplet state to an excited singlet state, and then emits fluorescence when returning from that excited singlet state to the ground state. Fluorescence via this route is observed later than fluorescence from the excited singlet state (normal fluorescence) directly generated from the ground state, and is therefore called delayed fluorescence. For example, when a light-emitting compound is excited by carrier injection, the probability of occurrence of the excited singlet state and the excited triplet state is statistically 25%:75%, so there is a limit to the improvement of luminous efficiency when only fluorescence from the directly generated excited singlet state is used. On the other hand, delayed fluorescent materials can utilize not only the excited singlet state but also the excited triplet state for fluorescence emission via the above-mentioned reverse intersystem crossing route, thereby achieving higher luminous efficiency than ordinary fluorescent materials. Delayed fluorescent materials with these characteristics are generally used together with a host material in the light-emitting layer of an organic electroluminescent device, and actually contribute to improving luminous efficiency.

[0004] Uoyama et al, Nature, 492, 234-238 (2012)

[0005] A host material to be combined with a delayed fluorescent material is selected that has a minimum excited singlet energy greater than that of the delayed fluorescent material. However, a host material that has been used in combination with a conventional fluorescent material that does not emit delayed fluorescence cannot achieve sufficient light-emitting performance even when directly combined with a delayed fluorescent material. In particular, organic electroluminescent elements using delayed fluorescent materials have room for improvement in terms of driving voltage and light-emitting life. For this reason, the present inventors have conducted research with the aim of achieving high light-emitting efficiency, reducing driving voltage, and extending light-emitting life in organic light-emitting elements using delayed fluorescent materials.

[0006] As a result of intensive research, the present inventors have found that by combining a material having a specific structure with a delayed fluorescent material, it is possible to achieve a long life while suppressing the driving voltage, and to realize high luminous efficiency. The present invention has been proposed based on this finding, and specifically has the following configuration.

[0007] [1] A compound represented by the following general formula (1): [In the formula, R 1 ~R 3 each independently represents a deuterium atom or an optionally deuterated alkyl group, R 4 and R 5 each independently represents a deuterium atom, an alkyl group which may be deuterated, or a phenyl group which may be substituted with an alkyl group which may be deuterated or a deuterium atom, provided that R 4 and R 5 One or two of R are an alkyl group which may be deuterated or a phenyl group which may be substituted with a deuterium atom. 1 ~R 5 is another R 1 ~R 5 does not bond to form a ring structure, and adjacent R 1 R, adjacent to each other 2 R, adjacent to each other 3 Neither do adjacent Rs bond to each other to form a ring structure. 4 may be bonded to each other to form a benzofuro skeleton or a benzothieno skeleton, and adjacent R 5may bond with each other to form a benzofuro skeleton or a benzothieno skeleton. n1, n3, n4, and n5 each independently represent an integer of 0 to 4, n2 represents an integer of 0 to 3, and the sum of n4 and n5 is 1 to 8.] [2] Adjacent R 4 R, adjacent to each other 5 The compound according to [1], wherein adjacent R 5 [4] The compound according to [1], wherein R 4 and R 5 are each independently a deuterium atom or a phenyl group, and the phenyl group may be substituted with a deuterium atom or an optionally deuterated alkyl group. [5] The compound according to any one of [1] to [3], 4 and one R 5 [6] The compound according to any one of [1] to [4], wherein only R are each independently an optionally deuterated alkyl group or an optionally deuterium atom-substituted phenyl group. 4 [7] The compound according to any one of [1] to [4], wherein only R is an optionally deuterated alkyl group or an optionally deuterium atom-substituted phenyl group. 1 ~R 3 [8] The compound according to any one of [1] to [6], wherein R is a deuterium atom. 4 at least one of R is a deuterium atom; 5 [9] The compound according to any one of [1] to [8], wherein n1 to n3 are each a deuterium atom.

[10] The compound according to any one of [1] to [9], wherein the dibenzofuran in general formula (1) is bonded to the phenylene group in general formula (1) at the 2-position.

[11] The compound according to any one of [1] to

[10] , wherein the compound is represented by the following general formula (2): [In the general formula (2), R 2 represents an alkyl group which may be deuterated, and n2 represents an integer of 0 to 3. 11 ~R18 R each independently represents a hydrogen atom, a deuterium atom, or an alkyl group which may be deuterated. 19 ~R 26 each independently represents a hydrogen atom, a deuterium atom, an alkyl group which may be deuterated, or a phenyl group which may be substituted with an alkyl group which may be deuterated or a deuterium atom, provided that R 19 ~R 26 One or two of R are an alkyl group which may be deuterated or a phenyl group which may be substituted with a deuterium atom. 19 and R 20 , R 20 and R 21 , R 21 and R 22 , R 23 and R 24 , R 24 and R 25 , R 25 and R 26 may be bonded to each other to form a benzofuro skeleton or a benzothieno skeleton.]

[12] Adjacent R 2 Comrade, R 11 and R 12 , R 12 and R 13 , R 13 and R 14 , R 15 and R 16 , R 16 and R 17 , R 19 and R 20 , R 20 and R 21 , R 21 and R 22 , R 23 and R 24 , R 24 and R 25 , R 25 and R 26

[13] The compound according to

[11] , wherein R 21 and R 24The compound according to

[11] or

[12] , wherein at least one of the groups is an optionally deuterated alkyl group or a phenyl group optionally substituted with a deuterium atom.

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

[13] .

[15] A host material according to

[14] for use together with a delayed fluorescent material.

[16] An electron blocking material comprising the compound according to any one of [1] to

[13] . An electron blocking material particularly for use in an electron blocking layer in contact with an emitting layer containing a delayed fluorescent material.

[17] A composition comprising the compound according to any one of [1] to

[13] doped with a delayed fluorescent material.

[18] The composition according to

[17] , which is in the form of a film.

[19] The composition according to

[17] or

[18] , wherein the delayed fluorescent material is a compound having a cyanobenzene structure in which one cyano group is substituted on the benzene ring.

[20] The composition according to

[17] or

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

[21] The composition according to any one of

[17] to

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

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

[17] to

[21] .

[23] The organic light-emitting device according to

[22] , 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.

[24] The organic light-emitting device according to

[23] , wherein the layer consists solely of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, and sulfur atoms.

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

[22] to

[24] , which is an organic electroluminescence device.

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

[22] to

[25] , 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.

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

[22] to

[25] , 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.

[0008] By using the compound of the present invention, it is possible to provide an organic light-emitting device that can be driven at a low voltage and has a long life.

[0009] FIG. 2 is a schematic cross-sectional view showing an example of a layer structure of an organic electroluminescence element.

[0010] 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 limitations on the isotopes of hydrogen atoms present in the molecules of the compounds used in the present invention.

[0011] (Compound Represented by General Formula (1)) In the present invention, a compound represented by the following general formula (1) is used.

[0012] In general formula (1), R 1 ~R 3 each independently represents a deuterium atom or an optionally deuterated alkyl group, R 4 and R 5each independently represents a deuterium atom, an alkyl group which may be deuterated, or an alkyl group which may be deuterated or a phenyl group which may be substituted with a deuterium atom. n1, n3, n4, and n5 each independently represent an integer from 0 to 4, n2 represents an integer from 0 to 3, and the sum of n4 and n5 is 1 to 8. The "alkyl group" in this application may be linear, branched, or cyclic. It may also contain 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 also 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 a molecule represented by general formula (1), these alkyl groups may be the same or different from one another. In one embodiment of the present invention, all of the alkyl groups in a molecule represented by general formula (1) are the same. The number of alkyl groups in a 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 a 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 a molecule represented by general formula (1) may be 0. Note that the number of alkyl groups here includes the number of alkyl groups substituted on phenyl groups. R 4 and R 5The "phenyl group optionally substituted with an alkyl group" which can be any of the above means that at least one of the five hydrogen atoms present on the phenyl group may be substituted with an alkyl group. In one embodiment of the present invention, the phenyl group is substituted with 0 to 3 alkyl groups. For example, it is substituted with 0 to 2 alkyl groups. In one embodiment of the present invention, the phenyl group is not substituted with an alkyl group. The alkyl group substituting the phenyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms. Examples include a 4-methylphenyl group, a 3-methylphenyl group, a 3,5-dimethylphenyl group, a 2,4,6-trimethylphenyl group, a 2,3,4,5,6-heptamethylphenyl group, a 4-isopropylphenyl group, a 3-isopropylphenyl group, a 3,5-diisopropylphenyl group, a 4-tert-butylphenyl group, a 3-tert-butylphenyl group, and a 3,5-ditert-butylphenyl group. Furthermore, examples include groups in which all hydrogen atoms present on the alkyl substituents among these specific examples are substituted with deuterium atoms. Furthermore, groups in which all hydrogen atoms present in these specific examples are substituted with deuterium atoms can also be exemplified. In the present application, an "optionally deuterated alkyl group" means that at least one of the hydrogen atoms of the alkyl group may be substituted with a deuterium atom. All of the 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 deuterated at all or an alkyl group in which all hydrogen atoms are substituted with deuterium atoms. In one embodiment of the present invention, an alkyl group that is not deuterated at all is selected as the "optionally deuterated alkyl group." In one embodiment of the present invention, an alkyl group in which all hydrogen atoms are substituted with deuterium atoms is selected as the "optionally deuterated alkyl group."

[0013] The sum of n1 and n2 in general formula (1) is 0 to 7, and may be, for example, within the range of 1 to 7. For example, it may be within the range of 1 to 4. In one aspect of the present invention, n1 is an integer of 0 to 2, and n2 is an integer of 0 to 2. In one aspect of the present invention, n1 is 0 or 1, and n2 is 0 or 1. In one aspect of the present invention, both n1 and n2 are 0. In one aspect of the present invention, R 1 and R 2 are each independently a deuterium atom or an alkyl group having 1 to 6 carbon atoms which may be deuterated, and preferably R 1 and R 2 are each independently a deuterium atom or an optionally deuterated alkyl group having 1 to 4 carbon atoms. 1 and R 2 are each independently a deuterium atom or a deuterated alkyl group. 1 and R 2 is a deuterium atom. In one embodiment of the present invention, the sum of n1 and n2 is 7, and R 1 and R 2 is a deuterium atom. 1 ) n1 and (R 2 ) n2 Specific examples of dibenzofuranyl groups substituted with are listed below. However, the structures that can be employed in the present invention should not be construed as being limited by these specific examples. In this application, * indicates the bonding position to the metaphenylene group. Methyl groups are not represented as CH3, and CH3 is omitted. Therefore, B2, B4, B6, and B8 each have a methyl group.

[0014] The compounds obtained by substituting all hydrogen atoms of the above B1 to B8 with deuterium atoms are exemplified here as B1(D) to B8(D), respectively.

[0015] In general formula (1), n3 is 0 to 4. In one embodiment of the present invention, n3 is 0. In one embodiment of the present invention, n3 is 1 to 4. In one embodiment of the present invention, R 3 is a deuterium atom or an alkyl group having 1 to 6 carbon atoms which may be deuterated, and preferably R3 are each independently a deuterium atom or an optionally deuterated alkyl group having 1 to 4 carbon atoms. 3 is a deuterium atom or a deuterated alkyl group. 3 is a deuterium atom. In one aspect of the present invention, n3 is 4 and R 3 is a deuterium atom. 3 ) n3 Specific examples of metaphenylene groups substituted with are listed below, but the structures that can be employed in the present invention are not limited to these specific examples. In the specific examples below, one of the * marks represents the position of bonding to carbazole in general formula (1), and the other represents the position of bonding to dibenzofuran. In this application, methyl groups are omitted and not represented as CH3. For example, Ar2 to Ar6 are each substituted with a methyl group, Ar7 is substituted with an ethyl group, and Ar8 is substituted with an isopropyl group. t-Bu represents a tert-butyl group, and D represents a deuterium atom.

[0016] Examples of Ar1 to Ar9 in which all hydrogen atoms have been replaced with deuterium atoms are shown here as Ar1(D) to Ar9(D), respectively.

[0017] R in general formula (1) 4 and R 5 One or two of R are an optionally deuterated alkyl group or a phenyl group optionally substituted with a deuterium atom. In one embodiment of the present invention, the phenyl group referred to herein is substituted only with an optionally deuterated alkyl group. In one embodiment of the present invention, the phenyl group referred to herein is a phenyl group in which at least one hydrogen atom is substituted with a deuterium atom. In one embodiment of the present invention, the phenyl group referred to herein is a phenyl group substituted with an optionally deuterated alkyl group and also with a deuterium atom. In one embodiment of the present invention, the phenyl group referred to herein is an unsubstituted phenyl group. In one embodiment of the present invention, R 4In one embodiment of the present invention, only one of R is an optionally deuterated alkyl group or an optionally deuterium-substituted phenyl group. 5 In one embodiment of the present invention, only one of R is an optionally deuterated alkyl group or an optionally deuterium-substituted phenyl group. 4 and one R 5 are each independently an optionally deuterated alkyl group or an optionally deuterated phenyl group. 4 at least one of R is a deuterium atom; 5 At least one of n4 and n5 is a deuterium atom. In general formula (1), n4 and n5 each represent 0 to 4, for example, 1 to 4, for example, 1 to 3, for example, 1 or 2. The sum of n4 and n5 may be 1 to 8, for example, 1 to 4. In one embodiment of the present invention, the sum of n4 and n5 is 1 or 2. In one embodiment of the present invention, the sum of n4 and n5 is 3 or 4. In a preferred embodiment of the present invention, R 1 ~R 3 each independently represents a deuterium atom, R 4 and R 5 each independently represents a deuterium atom or a phenyl group optionally substituted with a deuterium atom, provided that R 4 and R 5 One or two of these are phenyl groups which may be substituted with a deuterium atom.

[0018] R in general formula (1) 1 ~R 5 is another R 1 ~R 5 It does not bond to form a ring structure. 1 is R 2 ~R 5 does not bond with R to form a cyclic structure, 2 , R 3 , R 4 , R 5 The same applies to adjacent R 1 They do not bond to each other to form a ring structure, and adjacent R 2 They do not bond to each other to form a ring structure, and adjacent R3 They do not bond to each other to form a ring structure. 4 may be bonded to each other to form a benzofuro skeleton or a benzothieno skeleton, and adjacent R 5 Adjacent R may be bonded to each other to form a benzofuro skeleton or a benzothieno skeleton. 4 are bonded to each other to form a benzofuro skeleton or a benzothieno skeleton, and R 4 When adjacent R are not bonded to each other to form a benzofuro skeleton or a benzothieno skeleton, the compound of general formula (1) has a structure represented by the following general formula (1a): 4 are bonded to each other to form a benzofuro skeleton or a benzothieno skeleton, and adjacent R 5 When they are bonded to each other to form a benzofuro skeleton or a benzothieno skeleton, the compound of general formula (1) has a structure represented by the following general formula (1b): 1 , X 2 R each independently represents an oxygen atom or a sulfur atom. 4a , R 5a Each of n4a and n5a independently represents a deuterium atom, an alkyl group which may be deuterated, or a phenyl group which may be substituted with an alkyl group which may be deuterated or a deuterium atom. n4a and n5a each independently represent an integer of 0 to 2, but the sum of n4a and n5 in general formula (1a) is 1 or more, and the sum of n4a and n5a in general formula (1b) is 1 or more. In addition, R in general formula (1a) 4a and R 5 and one or two of R in general formula (1b) 4a and R 5a One or two of R are an alkyl group which may be deuterated or a phenyl group which may be substituted with a deuterium atom. 6 and R 7 Each independently represents a deuterium atom or a substituent (the substituent here means an atom or atomic group other than a hydrogen atom or a deuterium atom). 6 and R 7are each independently a deuterium atom, an alkyl group which may be deuterated, or a phenyl group which may be substituted with an alkyl group which may be deuterated or a deuterium atom. 6 R, adjacent to each other 6 n6 and n7 each independently represent an integer of 0 to 4. 1 ~R 3 , R 5 , n1 to n3, and n5, the corresponding explanations for general formula (1) can be referred to.

[0019] In general formula (1a), a single bond extends downward and to the left from the ortho position of the benzene ring bonded above X. This single bond may be bonded to any of positions 1 to 4 of the carbazole structure. Furthermore, X may also be bonded to any of positions 1 to 4 of the carbazole structure. However, the single bond and X are bonded to adjacent carbon atoms constituting the skeleton of the carbazole structure. Therefore, when the single bond is bonded to position 2, X is bonded to position 1 or 3. When the single bond is bonded to position 3, X is bonded to position 2 or 4. When the single bond is bonded to position 1, X is bonded to position 2. When the single bond is bonded to position 4, X is bonded to position 3. In general formula (1a), X is written to the right of the single bond, but general formula (1a) also encompasses structures in which the single bond is located to the left of X. X in general formula (1b) 1 and X 2 is the same as X in general formula (1a).

[0020] As the benzofurocarbazol-9-yl group in general formula (1a), a substituted or unsubstituted benzofuro[2,3-a]carbazol-9-yl group can be used. Alternatively, a substituted or unsubstituted benzofuro[3,2-a]carbazol-9-yl group can also be used. Alternatively, a substituted or unsubstituted benzofuro[2,3-b]carbazol-9-yl group can also be used. Alternatively, a substituted or unsubstituted benzofuro[3,2-b]carbazol-9-yl group can also be used. Alternatively, a substituted or unsubstituted benzofuro[2,3-c]carbazol-9-yl group can also be used. Alternatively, a substituted or unsubstituted benzofuro[3,2-c]carbazol-9-yl group can also be used. As the benzothienocarbazol-9-yl group bonded to Ar in general formula (1a), a substituted or unsubstituted benzothieno[2,3-a]carbazol-9-yl group can be used. A substituted or unsubstituted benzothieno[3,2-a]carbazol-9-yl group can also be employed. A substituted or unsubstituted benzothieno[2,3-b]carbazol-9-yl group can also be employed. A substituted or unsubstituted benzothieno[3,2-b]carbazol-9-yl group can also be employed. A substituted or unsubstituted benzothieno[2,3-c]carbazol-9-yl group can also be employed. A substituted or unsubstituted benzothieno[3,2-c]carbazol-9-yl group can also be employed.

[0021] As the bisbenzofurocarbazol-9-yl group of general formula (1b), a substituted or unsubstituted bisbenzofuro[2,3-a:2',3'-f]carbazol-9-yl group can be used. A substituted or unsubstituted bisbenzofuro[3,2-a:3',2'-f]carbazol-9-yl group can also be used. A substituted or unsubstituted bisbenzofuro[2,3-b:2',3'-e]carbazol-9-yl group can also be used. A substituted or unsubstituted bisbenzofuro[3,2-b:3',2'-e]carbazol-9-yl group can also be used. A substituted or unsubstituted bisbenzofuro[2,3-c:2',3'-d]carbazol-9-yl group can also be used. A substituted or unsubstituted bisbenzofuro[3,2-c:3',2'-d]carbazol-9-yl group can also be used. As the bisbenzothienocarbazol-9-yl group of general formula (1b), a substituted or unsubstituted bisbenzothieno[2,3-a:2',3'-f]carbazol-9-yl group can be used. A substituted or unsubstituted bisbenzothieno[3,2-a:3',2'-f]carbazol-9-yl group can also be used. A substituted or unsubstituted bisbenzothieno[2,3-b:2',3'-e]carbazol-9-yl group can also be used. A substituted or unsubstituted bisbenzothieno[3,2-b:3',2'-e]carbazol-9-yl group can also be used. A substituted or unsubstituted bisbenzothieno[2,3-c:2',3'-d]carbazol-9-yl group can also be used. Alternatively, a substituted or unsubstituted bisbenzothieno[3,2-c:3',2'-d]carbazol-9-yl group can also be employed.

[0022] In one embodiment of the present invention, n4a in general formula (1a) is 0. In another embodiment of the present invention, n4a is 0, n5 is 1 or 2, and two R 5 In one embodiment of the present invention, n6 is 0 or n6 is 4 and at least one of R 6In one embodiment of the present invention, n6 is 1 or 2, and at least one R 6 is an optionally deuterated alkyl group or a phenyl group optionally substituted with a deuterium atom. In one aspect of the present invention, X is an oxygen atom. In one aspect of the present invention, X is a sulfur atom. In one aspect of the present invention, the sum of n4a and n5a in general formula (1b) is 1 or 2. In one aspect of the present invention, R 4a and R 5a In one embodiment of the present invention, n6 is 0 or n6 is 4 and four R 6 In one embodiment of the present invention, n7 is 0 or n7 is 4 and four R 7 In one embodiment of the present invention, n6 is 1 or 2, and at least one R 6 is an optionally deuterated alkyl group or a phenyl group optionally substituted with a deuterium atom. In one embodiment of the present invention, n7 is 1 or 2, and at least one R 7 is an optionally deuterated alkyl group or a phenyl group optionally substituted with a deuterium atom. In one embodiment of the present invention, X is an oxygen atom. In one embodiment of the present invention, X is a sulfur atom.

[0023] Specific examples of the benzofurocarbazol-9-yl group and benzothienocarbazol-9-yl group of general formula (1a), the bisbenzofurocarbazol-9-yl group and bisbenzothienocarbazol-9-yl group of general formula (1b), and their substituted derivatives are listed below. However, the structures that can be employed in the present invention should not be construed as being limited by these specific examples. * indicates the bonding position to the metaphenylene in general formula (1a) and general formula (1b). Ph indicates an unsubstituted phenyl group. Furthermore, in this application, a methyl group is not represented as CH3, but is represented by omitting CH3. For example, D7 has a methyl group.

[0024] Groups in which all hydrogen atoms in the methyl groups of D7 to D18 and D37 to D48 are substituted with deuterium atoms are disclosed herein as D7(d) to D18(d) and D37(d) to D48(d). Furthermore, groups in which all hydrogen atoms in the phenyl groups of D19 to D30 and D49 to D60 are substituted with deuterium atoms are disclosed herein as D19(d) to D30(d) and D49(d) to D60(d). Furthermore, groups in which all hydrogen atoms in D1 to D62 are substituted with deuterium atoms are disclosed herein as D1(D) to D62(D).

[0025] The dibenzofuran shown on the left side of general formula (1) may be bonded to the metanipherene group at any of the 1st to 4th positions. In a preferred embodiment of the present invention, the dibenzofuran is bonded to the metanipherene group at the 2nd position. In one embodiment of the present invention, the dibenzofuran is bonded to the metanipherene group at the 1st position. In one embodiment of the present invention, the dibenzofuran is bonded to the metanipherene group at the 3rd position. In one embodiment of the present invention, the dibenzofuran is bonded to the metanipherene group at the 4th position. The 1st to 4th positions of the dibenzofuran are as follows:

[0026] No cyano group is present in general formula (1). In a preferred embodiment of the present invention, general formula (1) consists only of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, and sulfur atoms. In a preferred embodiment of the present invention, general formula (1) consists only of carbon atoms, hydrogen atoms, nitrogen atoms, and oxygen atoms. The molecular weight of the compound represented by general formula (1) is 499 or more and preferably 800 or less, more preferably 700 or less, and even more preferably 600 or less, and may be, for example, 550 or less, or may be 530 or less.

[0027] A preferred example of the compound represented by general formula (1) is a compound represented by the following general formula (2).

[0028] In general formula (2), R 2 represents an alkyl group which may be deuterated, and n2 represents an integer of 0 to 3. 11 ~R 18R each independently represents a hydrogen atom, a deuterium atom, or an alkyl group which may be deuterated. 19 ~R 26 each independently represents a hydrogen atom, a deuterium atom, an alkyl group which may be deuterated, or a phenyl group which may be substituted with an alkyl group which may be deuterated or a deuterium atom, provided that R 19 ~R 26 One or two of R are an alkyl group which may be deuterated or a phenyl group which may be substituted with a deuterium atom. 19 and R 20 , R 20 and R 21 , R 21 and R 22 , R 23 and R 24 , R 24 and R 25 , R 25 and R 26 may be bonded to each other to form a benzofuro skeleton or a benzothieno skeleton. 21 and R 24 In a preferred embodiment of the present invention, at least one of R 21 and R 24 and R are both optionally deuterated alkyl groups or optionally deuterium-substituted phenyl groups. 21 and R 24 At least one of R is an unsubstituted phenyl group. 21 and R 24 In one embodiment of the present invention, both R 19 and R 20 , R 20 and R 21 , R 21 and R 22 , R 23 and R 24 , R 24 and R 25 , R 25 and R 26 are not bonded to each other to form a cyclic structure.19 and R 20 , R 20 and R 21 , R 21 and R 22 , R 23 and R 24 , R 24 and R 25 , R 25 and R 26 In one embodiment of the present invention, only one pair of R 19 and R 20 , R 20 and R 21 , R 21 and R 22 Only one pair of R 23 and R 24 , R 24 and R 25 , R 25 and R 26 In one embodiment of the present invention, only one pair of R 12 represents an alkyl group which may be deuterated.

[0029] 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. For each of the following structures, four types of compounds are specified depending on the bonding position of the dibenzofuran.

[0030] In one embodiment of the present invention, the compound represented by general formula (1) can be any of the above compounds 1 to 64. In one embodiment of the present invention, the compound represented by general formula (1) can be any of the above compounds 65 to 128. The compound represented by general formula (1) is useful as a host material for doping an emitting material. It is particularly useful as a host material for doping 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 an electron blocking material. It is particularly useful as an electron blocking material in organic light-emitting devices using a delayed fluorescent material. For example, it can be effectively used in an electron blocking layer in organic light-emitting devices such as organic electroluminescence devices. It can be particularly effectively used in an electron blocking layer adjacent to an emitting layer using a delayed fluorescent material. An analogous compound to general formula (1) is a compound represented by the following general formula (3), in which the metaphenylene linkage structure of general formula (1) is replaced with a biphenylene linkage structure. The compound represented by the general formula (3) is also useful as a host material and as an electron blocking material, but the compound represented by the general formula (1) is more effective as a host material and an electron blocking material than the compound represented by the general formula (3), and is therefore highly useful. 1 , R 2 , R 4 , R 5 For the explanation of n1, n2, n4, and n5, please refer to the corresponding explanation of general formula (1). 3a , R 3b Regarding R in general formula (1), 3 Further, specific examples of the general formula (3) include those in which the phenylene linking structure of the specific examples of the general formula (1) is replaced with a biphenylene linking structure.

[0031] (Delayed Fluorescent Material) The compound represented by general formula (1) is useful as a host material for use with a delayed fluorescent material. The "delayed fluorescent material" referred to here is 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, when the emission lifetime is measured using a fluorescence lifetime measurement system (such as a streak camera system manufactured by Hamamatsu Photonics KK), a delayed fluorescent material is one in which fluorescence with an emission lifetime of 100 ns (nanoseconds) or more is observed. 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 the excited singlet state and transitions to the excited singlet state. In addition, the delayed fluorescent material may receive energy from the compound represented by general formula (1) in the excited triplet state and transition to the excited triplet state. The delayed fluorescent material has a difference (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.

[0032] 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. 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.

[0033] In the present invention, the lowest excited singlet energy (E S1 ) and the lowest excited triplet energy (E T1 ) is a value determined by the following procedure. ST is E S1 -E T1 (1) The lowest excited singlet energy (E S1 ) Thin film or toluene solution of the compound to be measured (concentration 10 -5 A sample is prepared by preparing a solution of 1000 mol / L. The fluorescence spectrum of this sample is measured at room temperature (300K). The fluorescence spectrum has the vertical axis representing emission and the horizontal axis representing wavelength. 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 determined. This wavelength value is converted to an energy value using the following conversion formula, and the value is called E S1 Conversion formula: E S1 [eV] = 1239.85 / λedge. The emission spectra in the examples described below were measured using an LED light source (Thorlabs, M300L4) as the excitation light source and a detector (Hamamatsu Photonics, PMA-12 multichannel spectrometer C10027-01). (2) Lowest excited triplet energy (E T1 ) 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 on 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 determined. This wavelength value is converted to an energy value using the following conversion formula, and the value E T1 Conversion formula: E T1[eV] = 1239.85 / λedge A 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 among the spectral maxima, consider a 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 maximum is defined as the tangent to the rising edge of the phosphorescence spectrum on the short wavelength side. Note that maximum points having peak intensities that are 10% or less of the maximum peak intensity of the spectrum are not included in the shortest wavelength maximum, and the tangent drawn at the point where the slope is maximum and is closest to the shortest wavelength maximum is defined as the tangent to the rising edge of the phosphorescence spectrum on the short wavelength side.

[0034] In a preferred embodiment of the present invention, a compound (cyanobenzene derivative) having a cyanobenzene structure in which one cyano group is substituted on the benzene ring is used as the delayed fluorescence material. In another preferred embodiment of the present invention, a compound (dicyanobenzene derivative) having a dicyanobenzene structure in which two cyano groups are substituted on the benzene ring is used as the delayed fluorescence material. In another preferred embodiment of the present invention, a compound (azabenzene derivative) having an azabenzene structure in which at least one of the carbon atoms constituting the ring skeleton of the benzene ring is substituted with a nitrogen atom is used as the delayed fluorescence material.

[0035] In a preferred embodiment of the present invention, a compound represented by the following general formula (4) is used as the delayed fluorescent material. In general formula (4), R 21 ~R 23 one of R represents a cyano group or a group represented by the following general formula (5): 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 referred to here is not a cyano group, a group represented by the following general formula (5), or a group represented by the following general formula (6)). In general formula (5), L 1 represents a single bond or a divalent linking group, R 31 and R 32 each independently represents a hydrogen atom or a substituent, and * represents the bonding position. In general formula (6), L 2 represents a single bond or a divalent linking group, R 33 and R 34 each independently represents a hydrogen atom or a substituent, and * represents the bonding position.

[0036] 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). 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 the groups is a group represented by general formula (5).

[0037] 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 31 and R 32are 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 32 are identical.

[0038] 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 33 and R 34each 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 mentioned here 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 atoms constituting the ring skeleton), a heteroaryloxy group (e.g., having 5 to 30 atoms constituting the ring skeleton), and a heteroarylthi group. Examples of the substituents include one or a combination of two or more groups selected from the group consisting of an aryl group (e.g., 5 to 30 atoms constituting the ring skeleton), an acyl group (e.g., 1 to 40 carbon atoms), an alkenyl group (e.g., 1 to 40 carbon atoms), an alkynyl group (e.g., 1 to 40 carbon atoms), an alkoxycarbonyl group (e.g., 1 to 40 carbon atoms), an aryloxycarbonyl group (e.g., 1 to 40 carbon atoms), a heteroaryloxycarbonyl group (e.g., 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"). 33 and R 34 may be bonded to each other via a single bond or a linking group to form a cyclic structure. 33 and R 34 are aryl groups, they are preferably bonded to each other via a single bond or a linking group to form a cyclic structure. The linking group here includes —O—, —S—, —N(R 35 ) -, -C(R 36 ) (R 37 )-, -C(=O)-, and -O-, -S-, -N(R 35 ) -, -C(R 36 ) (R 37 )- is preferred, and —O—, —S—, —N(R 35 )- is more preferred.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 above-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.

[0039] The group represented by general formula (6) is preferably a group represented by the following general formula (7).

[0040] L in general formula (7) 11 represents a single bond or a divalent linking group. 11 For the description and preferred range of 2 The description and preferred range of R in general formula (7) can be referred to. 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 48may 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 be formed. Preferred examples include a benzofuran ring and a benzothiophene ring (a furan ring fused with a thiophene ring). 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. 41 ~R 48 In a preferred embodiment of the present invention, all of R in general formula (4) are hydrogen atoms. 21 ~R 25 are groups represented by general formula (7), and the groups represented by general formula (7) are not all the same, and are mutually R 41 ~R48 In a preferred embodiment of the present invention, at least one of R in general formula (4) is different. 21 ~R 25 are groups represented by general formula (7), and R 21 ~R 25 is a phenyl group which may be substituted with a deuterium atom or an alkyl group. In general formula (7), * represents the bonding position.

[0041] 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.

[0042] In a preferred embodiment of the present invention, a compound represented by the following general formula (8) is used as the delayed fluorescent material. In the general formula (8), Y 1 , Y 2 and Y 3 In one embodiment of the present invention, Y 1 is a nitrogen atom, and Y 2 and Y 3 is a methine group. 1 and Y 2 is a nitrogen atom, and Y 3 is a methine group. 1 ~Y 3 In general formula (8), all of Z 1 ~Z 3Each 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. 1 ~Z 3 At 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 are each independently a group represented by general formula (6) or (7). For details and preferred ranges of general formula (6) and general formula (7), reference can be made to the corresponding descriptions above. The remaining Z which are not a group 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.

[0043] In a preferred embodiment of the present invention, a compound represented by the following general formula (9) is used as the delayed fluorescent material. In the general formula (9), Ar 1 is the following A 1 and D 1 Ar forms a cyclic structure which may be substituted by Ar 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. 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 1 When present, they may be the same or different. 1 The substituents may be bonded to each other to form a ring structure.

[0044] 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.

[0045] In the present invention, other known delayed fluorescent materials can be used in appropriate combination with the compound represented by general formula (1). Even unknown delayed fluorescent materials can be used. Examples of delayed fluorescent materials include those described in paragraphs 0008 to 0048 and 0095 to 0133 of WO2013 / 154064, paragraphs 0007 to 0047 and 0073 to 0085 of WO2013 / 011955, paragraphs 0007 to 0033 and 0059 to 0066 of WO2013 / 081088, and 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 WO 2013 / 133359 A, paragraphs 0008 to 0032 of WO 2013 / 161437 A JP-A-2014-9352, paragraphs 0007 to 0041 and 0060 to 0069, JP-A-2014-9224, paragraphs 0008 to 0048 and 0067 to 0076, JP-A-2017-119663, paragraphs 0013 to 0025, JP-A-2017-119664, paragraphs 0013 to 0026, JP-A-2017- JP-A-2017-226838, paragraphs 0010 to 0050, JP-A-2018-100411, paragraphs 0012 to 0043, and WO 2018 / 047853, paragraphs 0016 to 0044. Compounds encompassed by the general formulas described in paragraphs 0012 to 0025, particularly exemplary compounds, which emit delayed fluorescence can be mentioned.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.

[0046] 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.

[0047] In this specification, the terms alkyl group, alkenyl group, aryl group, heteroaryl group, etc., mean the following unless otherwise specified. An "alkyl group" may be linear, branched, or cyclic. Furthermore, two or more of the linear, cyclic, and branched groups may be mixed. The number of carbon atoms in an 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 alkyl groups 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 serving as a substituent may be further substituted with an aryl group. The alkyl portion of an "alkoxy group," "alkylthio group," "acyl group," and "alkoxycarbonyl group" may also be described with reference to the explanation of "alkyl group" herein. An "alkenyl group" may be linear, branched, or cyclic. It may also contain two or more of the linear, cyclic, and branched portions. The number of carbon atoms in an alkenyl group may be, for example, 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 alkenyl groups include ethenyl, n-propenyl, isopropenyl, n-butenyl, isobutenyl, n-pentenyl, isopentenyl, n-hexenyl, isohexenyl, and 2-ethylhexenyl. The alkenyl group serving as a substituent 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 explanation of the "aryl group" herein can be referenced for the aryl moiety of an "aryloxy group," an "arylthio group," and an "aryloxycarbonyl group." The explanation of the "heteroaryl group" herein can be referenced for the heteroaryl moiety of a "heteroaryloxy group," an "heteroarylthio group," and a "heteroaryloxycarbonyl group."

[0048] (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 greater 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 of the delayed fluorescent material, 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. In the composition of the present invention, it is preferable to select a delayed fluorescent material having an excited singlet energy lower than that 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, 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 a metal element. In one aspect 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 solely of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms, and sulfur atoms.

[0049] 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 the fluorescent compound in addition to the compound represented by formula (1) and the delayed fluorescent material.

[0050] 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 an excited singlet state, and from the delayed fluorescent material that has undergone reverse intersystem crossing from an excited triplet state to an excited singlet state, transitions to a singlet excited state, and then emits fluorescence when returning to the ground state. The fluorescent compound is not particularly limited as long as it can receive energy from the compound represented by 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.

[0051] 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 material with a higher lowest excited singlet energy functioning as an assist dopant, and the material 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 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 greater 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 (e.g., H. Uoyama, et al., Nature 492, 234 (2012) and K. Masui, et al., Org. Electron. 14, 2721, (2013)).

[0052] 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.

[0053]

[0054] 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.

[0055] 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 a second host material to be used 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.

[0056]

[0057] 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 film. A film 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, an emitting layer is formed. Wet processes include, but are not limited to, spin coating, slit coating, inkjet (spray) printing, 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 compounds contained in the composition of the present invention. A vacuum deposition method is 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 all compounds may be mixed and co-deposited from a single deposition source. When a single deposition source is used, a mixed powder of all compounds may be used, a compressed molded product of the mixed powder may be used, or a mixture of the compounds may be used that is heated, melted, mixed, and then cooled. In some embodiments, co-deposition can be 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 the multiple compounds contained in the deposition source. A film having a desired composition ratio can be easily formed by mixing multiple compounds in the same composition ratio as the composition ratio of the film to be formed and using the resulting deposition source. In some embodiments, a temperature at which the co-deposited compounds have the same weight loss rate can be specified, and this temperature can be used as the temperature during co-deposition. When forming a film 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.

[0058] (Organic Light-Emitting Device) By forming a light-emitting layer made of the composition of the present invention, excellent organic light-emitting devices such as organic photoluminescence devices (organic PL devices) and organic electroluminescence devices (organic EL devices) can be provided. 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. Organic photoluminescence devices have a structure in which at least a light-emitting layer is formed on a substrate. Organic electroluminescence devices have 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 solely of 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, an exciton-blocking layer, and the like. The hole transport layer may be a hole injection transport layer having a hole injection function, and the electron transport layer may be an electron injection transport layer having an electron injection function. A specific structural example of an organic electroluminescent device is shown in FIG. 1. In FIG. 1, 1 represents a substrate, 2 represents an anode, 3 represents a hole injection layer, 4 represents a hole transport layer, 5 represents an emitting layer, 6 represents an electron transport layer, and 7 represents a cathode. When the organic light-emitting device of the present invention is a multi-wavelength emission type organic light-emitting device, the shortest wavelength emission may include delayed fluorescence. Alternatively, the shortest wavelength emission may not include delayed fluorescence. When excited by thermal or electronic means, the organic light-emitting device using the composition 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 to 500 nm, 500 to 600 nm, or 600 to 700 nm), or the near-infrared region. For example, the organic light-emitting device can emit light in the red or orange region (e.g., 620 to 780 nm). For example, the organic light emitting device can emit light in the orange or yellow region (eg, 570-620 nm). For example, the organic light emitting device can emit light in the green region (eg, 490-575 nm).For example, an organic light-emitting device can emit light in the blue region (e.g., 400 to 490 nm). For example, an organic light-emitting device can emit light in the ultraviolet spectral region (e.g., 280 to 400 nm). For example, an organic light-emitting device can emit light in the infrared spectral region (e.g., 780 nm to 2 μm). The largest component of the light emitted from an organic light-emitting device using the composition of the present invention is preferably 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 (light-emitting layer) containing the composition of the present invention contains a fluorescent material as a third component, the largest component of the light emitted from the organic light-emitting device may be light emitted from the fluorescent material. In that 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.

[0059] Each component of the organic electroluminescence element and each layer other than the light-emitting layer will be described below.

[0060] Substrate: In some embodiments, the organic electroluminescent device of the present invention is supported by a substrate, which is not particularly limited and may be any material commonly used in organic electroluminescent devices, such as glass, transparent plastic, quartz, and silicon.

[0061] 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), SnO2, and ZnO. In some embodiments, an amorphous material capable of forming a transparent conductive film, such as IDIXO (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 photolithographic method. In some embodiments, if the pattern does not need to be highly accurate (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.

[0062] 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), an alloy, a conductive compound, or a combination thereof. In some embodiments, the electrode material is selected from sodium, sodium-potassium alloys, magnesium, lithium, a magnesium-copper mixture, a magnesium-silver mixture, a magnesium-aluminum mixture, a magnesium-indium mixture, an aluminum-aluminum oxide (Al2O3) mixture, indium, a lithium-aluminum mixture, and a rare earth element. 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 a magnesium-silver mixture, a magnesium-aluminum mixture, a magnesium-indium mixture, an aluminum-aluminum oxide (Al2O3) mixture, a lithium-aluminum mixture, and aluminum. In some embodiments, the mixture improves electron-injecting properties and resistance to oxidation. 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 semi-transparent to allow emitted light to pass through. In some embodiments, a transparent or semi-transparent 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.

[0063] Injection Layer: The injection layer is a layer between the electrode and the organic layer. In some embodiments, the injection layer reduces the driving voltage and enhances the 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. Below are examples of preferred compounds that can be used as hole injection materials:

[0064]

[0065] Next, examples of preferred compounds that can be used as the electron injection material will be given.

[0066] Barrier layer: A barrier layer is a layer that can prevent charges (electrons or holes) and / or excitons present in the light-emitting layer from diffusing 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 barrier 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 functions of an electron blocking layer and an exciton blocking layer.

[0067] Hole Blocking Layer: The hole blocking layer functions as an electron transporting layer. In some embodiments, during electron transport, the hole blocking layer prevents holes from reaching the electron transporting layer. 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 may be the same materials as those described above for the electron transporting layer. Examples of preferred compounds that can be used for the hole blocking layer are listed below.

[0068]

[0069] Electron Blocking 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 may 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.

[0070]

[0071] 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 allows for 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.

[0072] 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 the following properties: hole injection or transport and electron blocking. 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 a porphyrin compound, an aromatic tertiary amine compound, and a styrylamine compound. 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.

[0073]

[0074] 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.

[0075]

[0076] 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.

[0077]

[0078] 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.

[0079] Devices: In some embodiments, the light-emitting layer is incorporated into a device. For example, devices include, but are not limited to, OLED bulbs, OLED lamps, television displays, computer monitors, mobile phones, and tablets. In some embodiments, 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 the device and / or as hole transport materials. Such devices include, for example, 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-quenched devices (O-FQDs), light-emitting fuel cells (LECs), or organic laser diodes (O-lasers).

[0080] Bulb or Lamp: In some embodiments, an 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 comprises OLEDs of different colors. In some embodiments, the device comprises an array comprising 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 is an OLED light comprising: 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 an emissive 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 has multiple OLEDs mounted on the circuit board such that light is emitted in multiple directions. In some embodiments, a portion 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.

[0081] Displays or Screens: In some embodiments, the light-emitting layers of the present invention can be used in screens or displays. In some embodiments, the compounds of the present invention are deposited onto a substrate using processes such as, but not limited to, vacuum evaporation, deposition, 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 on 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 in pixel regions protects etching in certain areas until these specific patterns are undercut and removed from the substrate. At that time, all pixel areas experience similar etching rates, but their 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 a pixel, enabling the deep, localized etching required to create steep vertical bevel angles. A preferred material for the deposition mask is Invar. Invar is a metal alloy cold-rolled into long, thin sheets at steel mills. Invar cannot be electrodeposited onto a spin mandrel as a nickel mask. A suitable, low-cost method for creating open areas in a 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.

[0082] 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 planarization 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 planarization 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.

[0083] Another aspect of the present invention provides a method for manufacturing an organic light-emitting diode (OLED) display, the method including: forming a barrier layer on a base substrate of a mother panel; forming a plurality of display units on the barrier layer in cell panel units; forming an encapsulation layer on each of the display units of the cell panel; and applying an organic film to an interface between the cell panels. In some embodiments, the barrier layer is an inorganic film, for example, made of SiNx, and edges of the barrier layer are covered with an organic film made of polyimide or acrylic. In some embodiments, the organic film assists in soft cutting of the mother panel into cell panel units. 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 made of the same material as the planarization film and is formed simultaneously with the formation of the planarization film. In some embodiments, the light-emitting units are coupled to the TFT layer by a passivation layer, a planarization film therebetween, and an encapsulation layer that covers and protects the light-emitting units. In some embodiments of the manufacturing method, the organic film is not coupled to either the display unit or the encapsulation layer.

[0084] 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 a 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, like the organic film formed on the edge of the barrier layer, is formed of polyimide or acrylic. In some embodiments, the planarization film and the organic film are formed simultaneously during the manufacture of the OLED display. In some embodiments, the organic film may be formed on the edge of the barrier layer, such that a portion of the organic film is in direct contact with the base substrate and a remaining portion of the organic film is in contact with the barrier layer while surrounding the edge of the barrier layer.

[0085] In some embodiments, the light-emitting layer includes a pixel electrode, a counter electrode, and an organic light-emitting layer disposed between the pixel electrode and the counter electrode. In some embodiments, the pixel electrode is connected 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, an appropriate voltage is formed between the pixel electrode and the counter electrode, causing the organic light-emitting layer to emit light, thereby forming an image. Hereinafter, an image-forming unit including a TFT layer and a light-emitting unit is referred to as a display unit. In some embodiments, an encapsulation layer that covers the display unit 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 a distance from each of the multiple display units. In some embodiments, the organic film is formed 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.

[0086] In one embodiment, the OLED display is flexible and uses a flexible base substrate made of polyimide. In some embodiments, the base substrate is formed on a carrier substrate made of a glass material, and then the carrier substrate is separated. In some embodiments, a barrier layer is formed on the surface of the base substrate opposite the carrier substrate. In one embodiment, the barrier layer is patterned according to the size of each cell panel. For example, 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.

[0087] 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 into the base substrate. In some embodiments, a TFT layer of each cell panel is formed, and a passivation layer, which is an inorganic film, and a planarization film, which is an organic film, are disposed on and cover the TFT layer. At the same time as the planarization film, made of, for example, polyimide or acrylic, is formed, the grooves at the interface are covered with an organic film, made of, for example, 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 impact that occurs. That is, if all barrier layers were completely exposed without the organic film, the impact would be transmitted to the barrier layer when each cell panel is 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 impact that would otherwise be transmitted to the barrier layer, allowing each cell panel to be cut softly and preventing cracks from occurring in the barrier layer. In one embodiment, the organic film and the planarization film covering the groove of the interface portion are spaced apart from each other. For example, if the organic film and the planarization film are connected to each other as one layer, external moisture may penetrate into the display unit through the planarization film and the remaining portion of the organic film, so the organic film and the planarization film are spaced apart from each other such that the organic film is spaced apart from the display unit.

[0088] In some embodiments, the display units are formed by forming light-emitting units, and an encapsulation layer is disposed on the display units to cover the display units. Thus, after the mother panel is completely manufactured, the carrier substrate supporting the base substrate is separated from the base substrate. In some embodiments, a laser beam is irradiated onto the carrier substrate, causing the carrier substrate to separate 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 interfaces between the cell panels using a cutter. In some embodiments, the grooves at the interfaces along which the mother panel is cut are covered with an organic film, which absorbs impact during cutting. In some embodiments, cracks in the barrier layer can be prevented during cutting. In some embodiments, the method reduces the product defect rate and stabilizes its quality. Another aspect is an OLED display having a barrier layer formed on a base substrate, display units formed on the barrier layer, an encapsulation layer formed on the display units, and an organic film applied to edges of the barrier layer.

[0089] The features of the present invention will be explained in more detail below with reference to synthesis examples and examples. The materials, processing details, processing procedures, etc. shown 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 shown below. The emission characteristics were evaluated using a source meter (Keithley: 2400 series), a semiconductor parameter analyzer (Agilent Technologies: E5273A), an optical power meter measuring device (Newport: 1930C), an optical spectrometer (Ocean Optics: USB2000), a spectroradiometer (Topcon: SR-3), and a streak camera (Hamamatsu Photonics K.K.: C4334). The HOMO and LUMO energies were measured by atmospheric photoelectron spectroscopy (Riken Keiki AC-3, etc.). In the synthesis examples below, compounds represented by general formula (1) were synthesized.

[0090] (Synthesis Example 1) Synthesis of Compound 2

[0091] Under a nitrogen atmosphere, 2-(3-bromophenyl)dibenzofuran (20 g, 61.9 mmol), 3,6-diphenylcarbazole (19.8 g, 61.9 mmol), tris(dibenzylideneacetone)dipalladium(0) (5.67 g, 6.19 mmol), tri-tert-butylphosphonium tetrafluoroborate (3.59 g, 12.4 mmol), and sodium tert-butoxide (11.9 g, 123.8 mmol) were added to 400 ml of toluene and refluxed for 24 hours. The reaction solution was cooled to room temperature, and chloroform was added. The resulting organic layer was washed twice with water, dried over magnesium sulfate, and the solvent was removed. The resulting solid was purified by silica gel column chromatography (developing solvent: chloroform / n-hexane = 3:7). Further recrystallization (toluene / methanol) yielded a white solid (20 g, 58%). 1 H NMR (400MHz, CDCl3, δ): 8.43(s,2H), 8.22(s,1H), 7.99(d,J=8Hz,1H), 7.94(s,1H), 7.84-7.57(m,14H), 7.49(m,5H), 7.37(m,3H). MS (ASAP): 562.32 (M+H + ). Calcd for C 42 H 27 NO: 561.21.

[0092] (Synthesis Example 2) Synthesis of Compound 10

[0093] Under a nitrogen atmosphere, 2-(3-bromophenyl)dibenzofuran (1.96 g, 6.07 mmol), 3,6-di(phenyl-2,3,4,5,6-d5)-9H-carbazole (2 g, 6.07 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.56 g, 0.61 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.35 g, 1.21 mmol), and sodium tert-butoxide (1.17 g, 12.1 mmol) were added to 40 ml of toluene and refluxed for 24 hours. The reaction solution was cooled to room temperature, and chloroform was added. The resulting organic layer was washed twice with water, dried over magnesium sulfate, and the solvent was removed. The resulting solid was purified by silica gel column chromatography (developing solvent: chloroform / n-hexane = 3:7). Further recrystallization (toluene / methanol) yielded a white solid (2.55 g, 73%). 1 H NMR (400MHz, CDCl3, δ): 8.43(s,2H), 8.22(s,1H), 7.99(d,J=8Hz,1H), 7.94(s,1H), 7.84-7.56(m,10H), 7.49(t,J=8Hz,1H), 7.37(t,J=8Hz,1H). MS (ASAP): 572.40 (M+H + ). Calcd for C 42 H 17 D 10 NO: 571.27.

[0094] (Synthesis Example 3) Synthesis of Compound 30

[0095] Under a nitrogen atmosphere, 2-(3-bromophenyl)dibenzofuran (2 g, 6.19 mmol), 3-phenylcarbazole (1.51 g, 6.19 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.57 g, 0.62 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.36 g, 1.24 mmol), and sodium tert-butoxide (1.19 g, 12.4 mmol) were added to 50 mL of toluene and refluxed for 24 hours. The reaction solution was cooled to room temperature, and chloroform was added. The resulting organic layer was washed twice with water, dried over magnesium sulfate, and the solvent was removed. The resulting solid was purified by silica gel column chromatography (developing solvent: chloroform / n-hexane = 1:1). Further recrystallization (toluene / methanol) yielded a white solid (2.39 g, 80%). 1 H NMR (400MHz, CDCl3, δ): 8.38 (s, 1H), 8.23-8.21 (m, 2H), 7.99 (d, J = 8 Hz, 1H), 7.92 (s, 1H), 7.84-7.44 (m, 15H), 7.39-7.32 (m, 3H). MS (ASAP): 486.29 (M+H + ). Calcd for C 36 H 23 NO: 485.18.

[0096] (Synthesis Example 4) Synthesis of Compound 74

[0097] Under a nitrogen atmosphere, a toluene solution (45 mL) of 2-(3-bromophenyl)dibenzofuran (2 g, 6.19 mmol), 3-phenyl-12H-benzofuro[2,3-a]carbazole (2.06 g, 6.19 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.57 g, 0.62 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.36 g, 1.24 mmol), and sodium tert-butoxide (1.19 g, 12.4 mmol) was stirred at 130°C for 24 hours. The reaction solution was cooled to room temperature, and chloroform (300 mL) was added. The resulting organic layer was washed twice with water (300 mL), dried over magnesium sulfate, and the solvent was removed. The resulting solid was purified by silica gel column chromatography (chloroform:hexane = 1 / 1). Further recrystallization (toluene / methanol) gave Compound 74 (1.74 g, 49%). 1 H NMR (400MHz, CDCl3, δ): 8.43 (s, 1H), 8.32 (s, 1H), 8.11 (d, J = 8.0 Hz, 1H), 8.07 (m, 2H), 7.94-7.82 (m, 4H), 7.77-7.68 (m, 6H), 7.65 (d, J = 8.0 Hz, 1H), 7.58 (d, J = 8.0 Hz, 1H), 7.55-7.31 (m, 8H). MS (ASAP): 576.12 (M+H + ). Calcd for C 42 H 25 NO2: 575.91.

[0098] (Synthesis Example 5) Synthesis of Compound 82

[0099] Under a nitrogen atmosphere, a toluene solution (240 mL) of 2-(3-bromophenyl)dibenzofuran (10.6 g, 32.7 mmol), 6-phenyl-12H-benzofuro[2,3-a]carbazole (10.9 g, 32.7 mmol), tris(dibenzylideneacetone)dipalladium(0) (3.0 g, 3.2 mmol), tri-tert-butylphosphonium tetrafluoroborate (1.9 g, 6.5 mmol), and sodium tert-butoxide (6.3 g, 65.6 mmol) was stirred at 130°C for 14 hours. Toluene was added to the reaction solution, and the mixture was filtered through a Buchner funnel lined with Celite / silica gel / Celite. After removing the solvent, the mixture was washed with ethyl acetate and filtered to obtain a brown solid. The resulting solid was recrystallized from chlorobenzene and toluene to obtain Compound 82. (12.4 g, 65%) 1 H NMR (400MHz, CDCl3, δ): 8.32 (d, J = 2.0 Hz, 1H), 8.22 (d, J = 8.0 Hz, 1H), 8.07 (d, J = 1.7 Hz, 1H), 8.04 (s, 1H), 7.89-7.83 (m, 3H), 7.78-7.73 (m, 4H), 7.66 (d, J = 8.4 Hz, 2H), 7.61-7.57 (m, 3H), 7.54-7.44 (m, 5H), 7.38-7.30 (m, 3H), 7.17-7.13 (td, J = 7.4 Hz, 1.2 Hz, 1H) MS (ASAP): 576.37 (M+H + ). Calcd for C 42 H 25 NO2: 575.19.

[0100] (Synthesis Example 6) Synthesis of Compound 126

[0101] Under a nitrogen atmosphere, a toluene solution (15 mL) of 2-(3-bromophenyl)dibenzofuran (0.97 g, 3.00 mmol), 2-phenyl-5H-benzofuro[3,2-c]carbazole (1.0 g, 3.00 mmol), tris(dibenzylideneacetone)dipalladium(0) (0.27 g, 0.30 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.17 g, 0.60 mmol), and sodium tert-butoxide (0.58 g, 6.00 mmol) was stirred at 130°C for 17 hours. Chloroform was added to the reaction solution, and the mixture was filtered through a Buchner funnel lined with Celite. After removing the solvent, the mixture was washed with chloroform and filtered to obtain a brown solid. The resulting solid was purified by column chromatography (chloroform:hexane = 2:8) and further recrystallized (toluene / methanol) to obtain Compound 126. (1.09g, 63%) 1 H NMR (400MHz, CDCl3, δ): 8.81 (s, 1H), 8.24 (s, 1H), 8.02-7.97 (m, 4H), 7.89-7.82 (m, 3H), 7.80-7.74 (m, 4H), 7.69-7.61 (m, 4H), 7.66-7.44 (m, 5H), 7.42-7.35 (m, 3H). MS (ASAP): 575.21 (M + ). Calcd for C 42 H 25 NO2: 575.19.

[0102] (Example 1) On a glass substrate on which an anode made of indium tin oxide (ITO) with a film thickness of 50 nm was formed, the following thin films were deposited by vacuum deposition at a vacuum degree of 5.0 × 10 -5An organic electroluminescence device was fabricated by laminating the layers at 100 Pa. First, HAT-CN was formed on ITO to a thickness of 10 nm, NPD was formed thereon to a thickness of 30 nm, and EBL1 was further formed thereon to a thickness of 10 nm. Next, a delayed fluorescent material (TADF21) and Compound 2 were co-deposited from different evaporation sources to form a 40 nm thick layer as an emitting layer. The content of the delayed fluorescent material was 35% by mass, and the content of Compound 2 was 65% by mass. Next, SF3-TRZ was formed to a thickness of 10 nm, and then Liq and SF3-TRZ were co-deposited from different evaporation sources to form a 30 nm thick layer. The contents of Liq and SF3-TRZ in this layer were 30% by mass and 70% by mass, respectively. Furthermore, Liq was formed to a thickness of 2 nm, and then aluminum (Al) was evaporated to a thickness of 100 nm to form a cathode, and an organic electroluminescence device was fabricated. This device was designated EL device 1. Comparative EL device 1 was also fabricated using comparative compound A instead of compound 2. The current density of each of the fabricated organic electroluminescence devices was 6.3 mA / cm 2 The driving voltage of EL element 1 (the present invention) was 0.3 V lower than that of comparative EL element 1 (comparative example). This confirms that an organic electroluminescence element using the compound represented by general formula (1) as a host material of a delayed fluorescent material has good electrical conductivity.

[0103] (Example 2) An organic electroluminescence element was fabricated in the same manner as in Example 1, except that TADF18 was used instead of TADF21 used in EL element 1 in Example 1. This element was designated EL element 2. An organic electroluminescence element was fabricated in the same manner except that comparative compound B was used instead of compound 2 used in EL element 2. This element was designated comparative EL element 2. Each of the fabricated organic electroluminescence elements was subjected to a current density of 12.6 mA / cm 2The EL element was driven at 1000 V, and the time (LT95) until the luminous intensity reached 95% of that at the start of driving was measured. As a result, when the LT95 of EL element 2 was taken as 1, the LT95 of comparative EL element 2 was 0.6. This confirmed that the element life was extended when the compound represented by general formula (1) was used.

[0104] (Example 3) An organic electroluminescence element was fabricated in the same manner as in Example 1, except that TADF2 was used instead of TADF21 used in EL element 1 in Example 1. This element was designated EL element 3. An organic electroluminescence element was fabricated in the same manner except that comparative compound B was used instead of compound 2 used in EL element 3. This element was designated comparative EL element 3. Each of the fabricated organic electroluminescence elements was subjected to a current density of 5.5 mA / cm. 2 The EL element was driven at 100 V, and the time (LT95) until the luminous intensity reached 95% of that at the start of driving was measured. As a result, when the LT95 of EL element 3 was taken as 1, the LT95 of comparative EL element 3 was 0.8. This confirmed that the element life was extended when the compound represented by general formula (1) was used.

[0105] (Example 4) An organic electroluminescence element was fabricated in the same manner as in Example 1, except that Compound 2 was used instead of EBL1 used in Comparative EL element 1 (Comparative Example) in Example 1. This element was designated EL element 4, and a current density of 6.3 mA / cm was obtained in the same manner as in Example 1. 2 The driving voltage at 1000 kJ / cm2 was measured. The driving voltage of EL element 4 (invention) was 0.23 V lower than that of comparative EL element 1 (comparative example). This confirmed that the compound represented by general formula (1) is also useful as an electron blocking material. An organic electroluminescence element prepared in the same manner as in Example 1, except that Reference Compound a was used instead of EBL1 used in comparative EL element 1 (comparative example), also had a driving voltage lower than that of comparative EL element 1, but not as low as that of EL element 4, showing a clear difference.

[0106] Example 5 On a glass substrate on which an anode made of indium tin oxide (ITO) with a thickness of 50 nm was formed, the following thin films were deposited by vacuum deposition at a vacuum degree of 5.0×10 -5 An organic electroluminescence device was fabricated by laminating the layers at 100 Pa. First, HAT-CN was formed to a thickness of 10 nm on ITO, NPD was formed thereon to a thickness of 30 nm, and Tris-PCz was further formed thereon to a thickness of 10 nm. Next, a delayed fluorescent material (TADF72) and Compound 74 were co-deposited from different evaporation sources to form a 40 nm thick layer as an emitting layer. The content of the delayed fluorescent material was 35% by mass, and the content of Compound 74 was 65% by mass. Next, SF3-TRZ was formed to a thickness of 10 nm, and then Liq and SF3-TRZ were co-deposited from different evaporation sources to form a 30 nm thick layer. The contents of Liq and SF3-TRZ in this layer were 30% by mass and 70% by mass, respectively. Further, Liq was formed to a thickness of 2 nm, and then aluminum (Al) was vapor-deposited to a thickness of 100 nm to form a cathode, thereby preparing an organic electroluminescence device. This device was designated EL device 5. EL device 6 was prepared by using compound 82 instead of compound 74, and EL device 7 was prepared by using compound 126 instead of compound 74. The current density of each of the prepared organic electroluminescence devices was 6.3 mA / cm. 2 Driving voltage and external quantum efficiency (EQE) at a current density of 12.6 mA / cm 2 The results of measuring the device lifetime (LT95) at 2000 kJ / s are shown in the table below as relative values ​​based on EL device 6. The results in the table confirm that all organic electroluminescent devices using the compound represented by general formula (1) as a host material have good electrical conductivity, and achieve high luminous efficiency and long lifetime.

[0107]

[0108] Example 6 On a glass substrate on which an anode made of indium tin oxide (ITO) with a thickness of 50 nm was formed, the following thin films were deposited by vacuum deposition at a vacuum degree of 5.0×10 -5An organic electroluminescence device was fabricated by laminating the layers at 100 Pa. First, HAT-CN was formed on ITO to a thickness of 10 nm, NPD was formed thereon to a thickness of 30 nm, and Compound 2 was further formed thereon to a thickness of 10 nm. Next, a delayed fluorescent material (TADF21) and comparative compound A were co-deposited from different evaporation sources to form a 40 nm thick layer as an emitting layer. The content of the delayed fluorescent material was 35% by mass, and the content of comparative compound A was 65% by mass. Next, SF3-TRZ was formed to a thickness of 10 nm, and then Liq and SF3-TRZ were co-deposited from different evaporation sources to form a 30 nm thick layer. The contents of Liq and SF3-TRZ in this layer were 30% by mass and 70% by mass, respectively. Furthermore, Liq was formed to a thickness of 2 nm, and then aluminum (Al) was evaporated to a thickness of 100 nm to form a cathode, and an organic electroluminescence device was fabricated. This device was designated EL device 8. EL device 9 was also prepared by using compound 30 instead of compound 2. Comparative EL device 5 was also prepared by using comparative compound A instead of compound 2. The current density of each of the prepared organic electroluminescence devices was 6.3 mA / cm. 2 The results of measuring the driving voltage and external quantum efficiency (EQE) at 1000 kJ / s and 1000 kJ / s are shown in the table below as relative values ​​based on Comparative EL Device 5. The results in the table confirm that an organic electroluminescence device using a compound represented by general formula (1) as an electron blocking material has good electrical conductivity and achieves high luminous efficiency.

[0109] REFERENCE SIGNS LIST 1 substrate 2 anode 3 hole injection layer 4 hole transport layer 5 light emitting layer 6 electron transport layer 7 cathode

Claims

1. A compound represented by the following general formula (1): 【Chemistry 1】 [In the formula, R １ ~R ３ each independently represents a deuterium atom or an alkyl group which may be deuterated; R ４ and R ５ each independently represents a deuterium atom, an alkyl group which may be deuterated, or a phenyl group which may be substituted with an alkyl group which may be deuterated or a deuterium atom, provided that R ４ and R ５ One or two of R are an optionally deuterated alkyl group or an optionally deuterated phenyl group. １ ~R ５ is another R １ ~R ５ does not bond to form a ring structure, and adjacent R １ R, adjacent to each other ２ R, adjacent to each other ３ Neither do adjacent Rs bond to each other to form a ring structure. ４ may be bonded to each other to form a benzofuro skeleton or a benzothieno skeleton, and adjacent R ５ may be bonded to each other to form a benzofuro skeleton or a benzothieno skeleton. n1, n3, n4, and n5 each independently represent an integer of 0 to 4, n2 represents an integer of 0 to 3, and the sum of n4 and n5 is 1 to 8.]

2. Adjacent R ４ R, adjacent to each other ５ The compound of claim 1 , wherein the ring structures are not linked to each other to form a ring structure.

3. Adjacent R ５ The compound according to claim 1, wherein each of them is bonded to each other to form a benzofuro skeleton or a benzothieno skeleton.

4. R ４ and R ５ The compound according to claim 1 , wherein each of the groups independently represents a deuterium atom or a phenyl group, and the phenyl group may be substituted with a deuterium atom or an alkyl group which may be deuterated.

5. One R ４ and one R ５ 2. The compound of claim 1, wherein only each of the groups is independently an optionally deuterated alkyl group or an optionally deuterium-substituted phenyl group.

6. One R ４ 2. The compound according to claim 1, wherein only one of the groups is an optionally deuterated alkyl group or a phenyl group optionally substituted with a deuterium atom.

7. R １ ~R ３ The compound according to claim 1 , wherein is a deuterium atom.

8. R ４ At least one of R is a deuterium atom; ５ The compound according to claim 1 , wherein at least one of is a deuterium atom.

9. The compound according to claim 1, wherein n1 to n3 are 0.

10. The compound according to claim 1, wherein the dibenzofuran in general formula (1) is bonded to the phenylene group in general formula (1) at the 2-position.

11. The compound according to claim 1 , wherein the compound is represented by the following general formula (2): 【Chemistry 2】 [In the general formula (2), R ２ represents an alkyl group which may be deuterated, and n2 represents an integer of 0 to 3. １１ ~R １８ R each independently represents a hydrogen atom, a deuterium atom, or an alkyl group which may be deuterated. １９ ~R ２６ each independently represents a hydrogen atom, a deuterium atom, an alkyl group which may be deuterated, or a phenyl group which may be substituted with an alkyl group which may be deuterated or a deuterium atom, provided that R １９ ~R ２６ One or two of R are an optionally deuterated alkyl group or an optionally deuterated phenyl group. １９ and R ２０ , R ２０ and R ２１ , R ２１ and R ２２ , R ２３ and R ２４ , R ２４ and R ２５ , R ２５ and R ２６ may be bonded to each other to form a benzofuro skeleton or a benzothieno skeleton.

12. Adjacent R ２ Comrade, R １１ and R １２ , R １２ and R １３ , R １３ and R １４ , R １５ and R １６ , R １６ and R １７ , R １９ and R ２０ , R ２０ and R ２１ , R ２１ and R ２２ , R ２３ and R ２４ , R ２４ and R ２５ , R ２５ and R ２６ The compound according to claim 11 , wherein none of the groups are bonded to each other to form a cyclic structure.

13. R ２１ and R ２４ The compound according to claim 11, wherein at least one of the following is an optionally deuterated alkyl group or a phenyl group optionally substituted with a deuterium atom:

14. A host material comprising the compound according to any one of claims 1 to 13.

15. The host material according to claim 14 for use with a delayed fluorescent material.

16. An electron blocking material comprising the compound according to any one of claims 1 to 13.

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

18. The composition of claim 17 in the form of a film.

19. The composition according to claim 17, wherein the delayed fluorescent material is a compound having a cyanobenzene structure in which one cyano group is substituted on a benzene ring.

20. The composition according to claim 17, wherein the delayed fluorescent material is a compound having a dicyanobenzene structure in which two cyano groups are substituted on a benzene ring.

21. The composition according to claim 17, further comprising a fluorescent compound having a lower minimum excited singlet energy than the compound and the delayed fluorescent material.

22. An organic light-emitting device comprising a layer made of the composition according to claim 17.

23. 23. The organic light-emitting device according to claim 22, 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.

24. 24. The organic light-emitting device according to claim 23, wherein the layer consists solely of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms and sulfur atoms.

25. 23. The organic light-emitting device according to claim 22, which is an organic electroluminescent device.

26. 23. The organic light-emitting device according to claim 22, wherein the composition does not include the fluorescent compound, and the largest component of the emission from the device is the emission from the delayed fluorescent material.

27. 23. The organic light-emitting device of claim 22, wherein the composition comprises the fluorescent compound, and a maximum component of the emission from the device is the emission from the fluorescent compound.

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