JP7752866B2 - Compound, light-emitting material and light-emitting device - Google Patents

Description

The present invention relates to a compound useful as a light-emitting material and a light-emitting device using the same.

Research into improving the luminous efficiency of light-emitting elements such as organic electroluminescent elements (organic EL elements) is currently underway. In particular, various efforts have been made to improve luminous efficiency by developing and combining newly developed electron transport materials, hole transport materials, and luminescent materials that make up organic electroluminescent elements. Among these efforts, there is also research into organic electroluminescent elements that use delayed fluorescent materials.

Delayed fluorescent materials are materials that undergo reverse intersystem crossing from an excited triplet state to an excited singlet state in an excited state, and then emit fluorescence when returning from that excited singlet state to the ground state. Fluorescence via this pathway is observed later than fluorescence from the excited singlet state (normal fluorescence) that arises directly from the ground state, hence the term delayed fluorescence. For example, when a light-emitting compound is excited by carrier injection, the statistical probability of the excited singlet state and the excited triplet state occurring is 25%:75%, so there is a limit to how much improvement in luminous efficiency can be achieved using only the fluorescence from the directly arising excited singlet state. 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 pathway, resulting in higher luminous efficiency than normal fluorescent materials.

Since this principle was clarified, various research efforts have led to the discovery of a variety of delayed fluorescent materials. These include, for example, the following compound, in which two cyanophenyl groups and four substituted or unsubstituted carbazol-9-yl groups are substituted on a benzene ring (see Patent Document 1 and Non-Patent Document 1).

Chinese Patent Publication No. 112409240

Adv.Mater.2020,32,1908355

Even among materials that emit delayed fluorescence, none have been provided to date that have extremely good properties and no practical issues. For this reason, it would be useful to provide delayed fluorescent materials with even better luminescence properties than the delayed fluorescent materials described above. For example, if a light-emitting material with a shorter delayed fluorescence lifetime than the delayed fluorescent materials described above could be provided, its industrial applicability would be enhanced. However, improvements to delayed fluorescent materials are still in the trial and error stage, and it is not easy to generalize the chemical structure of a useful light-emitting material.

Under these circumstances, the inventors conducted extensive research with the aim of providing compounds that are more useful as light-emitting materials for light-emitting devices. They then conducted extensive research with the aim of deriving and generalizing a general formula for compounds that are more useful as light-emitting materials.

As a result of extensive research to achieve the above objective, the inventors have discovered that compounds having structures that satisfy specific conditions are useful as light-emitting materials. The present invention was proposed based on this finding, and specifically has the following configuration.

[1] A compound represented by the following general formula (1):
[In general formula (1), A represents a 2-cyanophenyl group, a 4-cyanophenyl group, or a cyanopyridyl group optionally substituted with a phenyl group or a naphthyl group, and a hydrogen atom in these groups may be substituted with a deuterium atom. One of ^R2 and ^R3 represents an acceptor group. The other of ^R2 and ^R3 , and at least one of ^R1 , ^R4 , and ^R5 , each independently represents a substituted or unsubstituted benzofuro-fused carbazol-9-yl group or a substituted or unsubstituted benzothieno-fused carbazol-9-yl group. The remaining ^R1 to ^R5 each independently represent a hydrogen atom, a deuterium atom, a substituted or unsubstituted aryl group, or a donor group (however, the donor group does not include an alkyl group, a substituted or unsubstituted benzofuro-fused carbazol-9-yl group, or a substituted or unsubstituted benzothieno-fused carbazol-9-yl group).]
[2] The compound according to [1], having a maximum emission wavelength in the range of 420 nm to 575 nm.
[3] The compound according to [1] or [2], wherein R ² is an acceptor group.
[4] The compound according to [1] or [2], wherein R ³ is an acceptor group.
[5] The compound according to any one of [1] to [4], wherein the acceptor group is a group having the same structure as A.
[6] The compound according to any one of [1] to [5], wherein the acceptor group is a substituted or unsubstituted heteroaryl group containing a nitrogen atom as a ring skeleton-constituting atom, or a cyano group.
[7] The compound according to any one of [1] to [6], wherein at least two of R ¹ to R ⁵ are each independently a substituted or unsubstituted benzofuro-fused carbazol-9-yl group, or a substituted or unsubstituted benzothieno-fused carbazol-9-yl group.
[8] The compound according to any one of [1] to [7], wherein R ² and R ⁵ each independently represent a donor group.
[9] The compound according to any one of [1] to [8], wherein the donor group is a substituted or unsubstituted diarylamino group (wherein the two aryl groups constituting the diarylamino group may be bonded to each other).
[10] The compound according to any one of [1] to [9], which has a symmetric structure.
[11] A light-emitting material comprising the compound according to any one of [1] to [10].
[12] A delayed fluorescent material comprising the compound according to any one of [1] to [10].
[13] A film containing the compound according to any one of [1] to [10].
[14] An organic semiconductor device comprising the compound according to any one of [1] to [10].
[15] An organic light-emitting device comprising the compound according to any one of [1] to [10].
[16] The organic light-emitting device according to [15], wherein the device has a layer containing the compound, and the layer also contains a host material.
[17] The layer containing the compound also contains a delayed fluorescent material in addition to the compound and the host material, and the lowest excited singlet energy of the delayed fluorescent material is lower than that of the host material and higher than that of the compound. The organic light-emitting element according to [16].
[18] The organic light-emitting device according to [16], wherein the device has a layer containing the compound, and the layer also contains a light-emitting material having a structure different from that of the compound.
[19] The organic light-emitting device according to any one of [16] to [18], wherein the compound has the greatest amount of light emission among the materials contained in the device.
[20] The organic light-emitting element according to [18], wherein the amount of light emitted from the light-emitting material is greater than the amount of light emitted from the compound.
[21] The organic light-emitting device according to any one of [15] to [20], which is an organic electroluminescence device.
[22] The organic light-emitting device according to any one of [15] to [21], which emits delayed fluorescence.

Compounds represented by general formula (1) have excellent light-emitting properties. General formula (1) includes light-emitting materials that emit deep blue light. General formula (1) also includes light-emitting materials that exhibit a short delayed fluorescence lifetime. By using compounds represented by general formula (1), it is possible to provide excellent organic light-emitting devices.

The present invention will be described in detail below. The following description of the constituent elements may be based on representative embodiments and specific examples of the present invention, but the present invention is not limited to such embodiments and specific examples. In this specification, 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, some or all of the hydrogen atoms present in the molecules of the compounds used in the present invention can be substituted with deuterium atoms ( ² H, deuterium D). In the chemical structural formulas herein, hydrogen atoms are represented as H or are omitted. For example, when the representation of atoms bonded to carbon atoms constituting the ring skeleton of a benzene ring is omitted, it is assumed that H is bonded to the carbon atom constituting the ring skeleton at the omitted location. In the chemical structural formulas herein, deuterium atoms are represented as D.

[Compound represented by general formula (1)]

In general formula (1), A represents a 2-cyanophenyl group, a 4-cyanophenyl group, or a cyanopyridyl group optionally substituted with a phenyl group or a naphthyl group. The hydrogen atoms of the 2-cyanophenyl group and the 4-cyanophenyl group may be substituted with deuterium atoms, but are not substituted with any other atoms or groups. In one embodiment of the present invention, A is a 2-cyanophenyl group. In a preferred embodiment of the present invention, A is a 4-cyanophenyl group.
The bonding position of the cyano group of the cyanopyridyl group represented by A may be any of the 2- to 4-positions of the pyridine ring. In a preferred embodiment of the present invention, the cyano group is located at the 2-position of the pyridine ring. In another embodiment of the present invention, the cyano group is located at the 3-position of the pyridine ring. In another embodiment of the present invention, the cyano group is located at the 4-position of the pyridine ring. The bonding site of the cyanopyridyl group may be any of the 2- to 6-positions of the pyridine ring. Each hydrogen atom of the cyanopyridyl group represented by A may be independently substituted with one or more atoms or groups selected from the group consisting of deuterium atoms, phenyl groups, and naphthyl groups. Some or all of the phenyl groups may be substituted with deuterium atoms. Some or all of the naphthyl groups may also be substituted with deuterium atoms. In one embodiment of the present invention, the cyanopyridyl group is substituted with at least one phenyl group. In another embodiment of the present invention, the cyanopyridyl group is substituted with at least one naphthyl group. In one preferred embodiment of the invention, the cyanopyridyl group is not substituted with a phenyl or naphthyl group.
In one embodiment of the present invention, A has at least one deuterium atom. In one embodiment of the present invention, all hydrogen atoms present in the 2-cyanophenyl group, 4-cyanophenyl group, and cyanopyridyl group optionally substituted with a phenyl group or a naphthyl group represented by A are substituted with deuterium atoms.

Specific examples of groups that can be used for A in general formula (1) are shown below. However, A that can be used in the present invention should not be construed as being limited by the following specific examples. In the following specific examples, * indicates a bonding position, and C ₆ D ₅ represents a phenyl group in which all hydrogen atoms are deuterated.

The compounds obtained by substituting all hydrogen atoms present in the above A1 to A95 with deuterium atoms are disclosed as A1(D) to A95(D).
In a preferred embodiment of the present invention, A in general formula (1) is selected from the group consisting of A1 to A95. In one embodiment of the present invention, A is selected from the group consisting of A78 to A95 and A1(D) to A95(D). In one embodiment of the present invention, A is selected from the group consisting of A3 to A95. In one embodiment of the present invention, A is selected from the group consisting of A3 to A14. In one embodiment of the present invention, A is selected from the group consisting of A15 to A95. In one embodiment of the present invention, A is selected from the group consisting of A3 to A6, A15 to A32, and A78 to A82. In one embodiment of the present invention, A is selected from the group consisting of A7 to A10, A33 to A59, and A83 to A91. In one embodiment of the present invention, A is selected from the group consisting of A11 to A14, A60 to A77, and A92 to A95.

In general formula (1), one of ^R2 and ^R3 represents an acceptor group. In one embodiment of the present invention, ^R2 is an acceptor group. In another embodiment of the present invention, ^R3 is an acceptor group.
The acceptor group which can be ^R2 and ^R3 may be a 2-cyanophenyl group, a 4-cyanophenyl group, or a cyanopyridyl group which may be substituted with a phenyl group or a naphthyl group (a hydrogen atom of these groups may be substituted with a deuterium atom). For descriptions of these groups and preferred ranges, please refer to the description of A above. In a preferred embodiment of the present invention, the acceptor group is the same group as A. In this case, A and ^R2 are the same group, or A and ^R3 are the same group. In one embodiment of the present invention, one of ^R2 and ^R3 is a 2-cyanophenyl group, a 4-cyanophenyl group, or a cyanopyridyl group which may be substituted with a phenyl group or a naphthyl group (a hydrogen atom of these groups may be substituted with a deuterium atom), but is a group different from A.
In one embodiment of the present invention, one of ^R2 and ^R3 is an acceptor group, but is not a 2-cyanophenyl group, a 4-cyanophenyl group, or a cyanopyridyl group optionally substituted with a phenyl group or a naphthyl group (the hydrogen atoms of these groups may be substituted with deuterium atoms). Such an acceptor group can be selected from groups having a positive Hammett σp value. The Hammett σp value was proposed by L. P. Hammett and quantifies the effect of a substituent on the reaction rate or equilibrium of a para-substituted benzene derivative. Specifically, the following equation holds between the substituent in a para-substituted benzene derivative and the reaction rate constant or equilibrium constant:
log(k/k ₀ ) = ρσp
or
log(K/K ₀ ) = ρσp
is a constant (σp) specific to the substituent in the reaction. In the above formula, k ₀ is the rate constant of the benzene derivative without a substituent, k is the rate constant of the benzene derivative substituted with a substituent, K ₀ is the equilibrium constant of the benzene derivative without a substituent, K is the equilibrium constant of the benzene derivative substituted with a substituent, and ρ is a reaction constant determined by the type and conditions of the reaction. For an explanation of the "Hammett σp value" in the present invention and the numerical values of each substituent, please refer to the description of the σp value in Hansch, C. et al., Chem. Rev., 91, 165-195 (1991).
The acceptor group which can be one of ^R2 and ^R3 preferably has a σp of 0.3 or more, more preferably 0.5 or more, and even more preferably 0.7 or more. For example, it may be selected from the range of 0.9 or more, or 1.1 or more.

An example of an acceptor group other than a 2-cyanophenyl group, a 4-cyanophenyl group, or a cyanopyridyl group optionally substituted with a phenyl group or a naphthyl group (the hydrogen atoms of these groups may be substituted with deuterium atoms) is a cyano group. Other typical acceptor groups include heteroaryl groups containing two or more nitrogen atoms as ring skeleton constituent atoms. Examples include triazinyl groups and pyrimidinyl groups. The hydrogen atoms of these heteroaryl groups may be substituted with deuterium atoms or substituents. The substituent may be selected from, for example, substituent group E, and examples thereof include unsubstituted aryl groups, preferably unsubstituted phenyl groups.

Specific examples of groups that can be used as the acceptor group in general formula (1) include the above-mentioned A1 to A95 and A1(D) to A95(D). Other typical examples of acceptor groups include those listed below. However, the acceptor groups that can be used in the present invention should not be construed as being limited by the following specific examples. In the following specific examples, * indicates the bonding position, and C ₆ D ₅ represents a phenyl group in which all hydrogen atoms are deuterated.

In general formula (1), the other of ^R2 and ^R3 (i.e., the one that is not an acceptor group), and at least one of ^R1 , ^R4 , and ^R5 each independently represent a substituted or unsubstituted benzofuro-fused carbazol-9-yl group, or a substituted or unsubstituted benzothieno-fused carbazol-9-yl group (hereinafter, these are collectively referred to as "fused carbazol-9-yl groups"). Of ^R1 to ^R5 , the number of fused carbazol-9-yl groups is 1 to 4, for example, 1 to 3, for example, 1 or 2. The number of fused carbazol-9-yl groups may be 2 to 4, or may be 2 or 3.
In one group of the present invention, R ³ is an acceptor group, and at least one of R ¹ , R ² , R ⁴ , and R ⁵ is each independently a fused carbazol-9-yl group. In one embodiment of the present invention, R ² is a fused carbazol-9-yl group. In one embodiment of the present invention, only R ² is a fused carbazol-9-yl group. In a preferred embodiment of the present invention, R ² and R ⁵ are fused carbazol-9-yl groups. In a preferred embodiment of the present invention, only R ² and R ⁵ are fused carbazol-9-yl groups. In a preferred embodiment of the present invention, R ² , R ⁴ , and R ⁵ are fused carbazol-9-yl groups. In one embodiment of the present invention, R ¹ to R ⁴ are fused carbazol-9-yl groups.
In another group of the present invention, R ² is an acceptor group, and at least one of R ¹ , R ³ , R ⁴ , and R ⁵ each independently represents a fused carbazol-9-yl group. In one embodiment of the present invention, R ¹ is a fused carbazol-9-yl group. In one embodiment of the present invention, R ³ is a fused carbazol-9-yl group. In one embodiment of the present invention, R ⁴ is a fused carbazol-9-yl group. In one embodiment of the present invention, R ⁵ is a fused carbazol-9-yl group. In one embodiment of the present invention, only R ³ is a fused carbazol-9-yl group. In one embodiment of the present invention, only R ⁴ is a fused carbazol-9-yl group. In one embodiment of the present invention, only R ⁵ is a fused carbazol-9-yl group. In a preferred embodiment of the present invention, R ³ and R ⁵ are fused carbazol-9-yl groups. In one embodiment of the present invention, R ³ and R ⁴ are fused carbazol-9-yl groups. In one embodiment of the present invention, R ⁴ and R ⁵ are fused carbazol-9-yl groups. In a preferred embodiment of the present invention, only R ³ and R ⁵ are fused carbazol-9-yl groups. In a preferred embodiment of the present invention, R ³ to R ⁵ are fused carbazol-9-yl groups. In one embodiment of the present invention, R ¹ , R ³ , R ⁴ and R ⁵ are fused carbazol-9-yl groups.
When multiple fused carbazol-9-yl groups are present, in a preferred embodiment of the present invention, the fused carbazol-9-yl groups are the same. In one embodiment of the present invention, the fused carbazol-9-yl groups are different from each other.
In a preferred embodiment of the present invention, the fused carbazol-9-yl group is a benzofuro-fused carbazol-9-yl group. In one embodiment of the present invention, the fused carbazol-9-yl group is a benzhieno-fused carbazol-9-yl group.

In the present invention, as the benzofuro-fused carbazol-9-yl group, a benzofuro[2,3-a]carbazol-9-yl group can be used. A benzofuro[3,2-a]carbazol-9-yl group can also be used. A benzofuro[2,3-b]carbazol-9-yl group can also be used. A benzofuro[3,2-b]carbazol-9-yl group can also be used. A benzofuro[2,3-c]carbazol-9-yl group can also be used. A benzofuro[3,2-c]carbazol-9-yl group can also be used.
A preferred benzofuro-fused carbazol-9-yl group is a carbazol-9-yl group in which only one benzofuran ring is fused at the 2- and 3-positions and no other rings are fused. Specifically, it is a group having any of the following structures, in which at least one hydrogen atom in the following structure may be substituted:

In the present invention, as the benzothieno-fused carbazol-9-yl group, a benzothieno[2,3-a]carbazol-9-yl group can be employed. A benzothieno[3,2-a]carbazol-9-yl group can also be employed. A benzothieno[2,3-b]carbazol-9-yl group can also be employed. A benzothieno[3,2-b]carbazol-9-yl group can also be employed. A benzothieno[2,3-c]carbazol-9-yl group can also be employed. A benzothieno[3,2-c]carbazol-9-yl group can also be employed.
A preferred benzoeno-fused carbazol-9-yl group is a carbazol-9-yl group having only one benzothiophene ring fused at the 2- and 3-positions and no other rings fused thereto. Specifically, it is a group having any of the following structures, in which at least one hydrogen atom in the following structure may be substituted:

The substituent of the fused carbazol-9-yl group may be selected from Substituent Group A, Substituent Group B, Substituent Group C, Substituent Group D, or Substituent Group E. In a preferred embodiment of the present invention, the fused carbazol-9-yl group is unsubstituted. In a preferred embodiment of the present invention, the substituent of the fused carbazol-9-yl group is substituted with an unsubstituted aryl group. In one embodiment of the present invention, the substituent of the fused carbazol-9-yl group is substituted with an unsubstituted alkyl group.
The "aryl group" may be a monocyclic 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 naphthalene ring, an anthracene ring, a phenanthrene ring, and a triphenylene ring. In one aspect of the present invention, the aryl group is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthalen-1-yl group, or a substituted or unsubstituted naphthalen-2-yl group, and is preferably a substituted or unsubstituted phenyl group. The substituent of the aryl group may be selected, for example, from Substituent Group A, Substituent Group B, Substituent Group C, Substituent Group D, or Substituent Group E. In one aspect of the present invention, the substituent of the aryl group is one or more selected from the group consisting of an alkyl group, an aryl group, and a deuterium atom. In a preferred aspect of the present invention, the aryl group is unsubstituted.
The "alkyl group" may be linear, branched, or cyclic. Two or more of the linear, cyclic, and branched groups may be present. The number of carbon atoms in the alkyl group may be, for example, 1 or more, 2 or more, or 4 or more. The number of carbon atoms may be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, an isohexyl group, a 2-ethylhexyl group, an n-heptyl group, an isoheptyl group, an n-octyl group, an isooctyl group, an n-nonyl group, an isononyl group, an n-decanyl group, an isodecanyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The alkyl group may be further substituted with, for example, a deuterium atom, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. In one embodiment of the present invention, the substituents on the alkyl group are one or more selected from the group consisting of an aryl group and a deuterium atom. In a preferred embodiment of the present invention, the alkyl group is unsubstituted.
The number of substituents substituted on the ring-fused carbazol-9-yl group is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 4, and may be, for example, 1 or 2. In a preferred embodiment of the present invention, the ring-fused carbazol-9-yl group is substituted at either the 3- or 6-position. In a preferred embodiment of the present invention, the ring-fused carbazol-9-yl group has at least one substituent at the para-position of the benzene ring relative to the heteroatom present in the ring-fused carbazol-9-yl group. In a preferred embodiment of the present invention, the ring-fused carbazol-9-yl group has at least one substituent only at the para-position of the benzene ring relative to the heteroatom present in the ring-fused carbazol-9-yl group. In a preferred embodiment of the present invention, the ring-fused carbazol-9-yl group has substituents at all of the substitutable para-positions of the benzene ring relative to the heteroatom present in the ring-fused carbazol-9-yl group.

Specific examples of substituted or unsubstituted benzofuro-fused carbazol-9-yl groups or substituted or unsubstituted benzothieno-fused carbazol-9-yl groups (i.e., fused carbazol-9-yl groups) that can be employed in general formula (1) are shown below. However, the fused carbazol-9-yl groups that can be employed in the present invention should not be construed as being limited by the following specific examples. In the following specific examples, * indicates the bonding position, Ph represents a phenyl group, and C ₆ D ₅ represents a phenyl group in which all hydrogen atoms are deuterated. Methyl groups are omitted. For this reason, for example, D7 to D18 have methyl groups.

The compounds D1 to D459 above in which all hydrogen atoms have been replaced with deuterium atoms are disclosed as D1(D) to D459(D).
In one embodiment of the present invention, the fused carbazol-9-yl group which can be taken by R ¹ to R ⁵ in general formula (1) is selected from the group consisting of D1 to D459. In one embodiment of the present invention, the fused carbazol-9-yl group which can be taken by R ¹ to R ⁵ in general formula (1) is selected from the group consisting of D1 to D30. In one embodiment of the present invention, the fused carbazol-9-yl group which can be taken by R ¹ to R ⁵ in general formula (1) is selected from the group consisting of D31 to D60. In one embodiment of the present invention, the fused carbazol-9-yl group which can be taken by R ¹ to R ⁵ in general formula (1) is selected from the group consisting of D61 to D84. In one embodiment of the present invention, the fused carbazol-9-yl group which can be taken by R ¹ to R ⁵ in general formula (1) is selected from the group consisting of D88 to D91, D95 to D198, D287 to D293, D306 to D317, and D330 to D459. In one embodiment of the present invention, the fused carbazol-9-yl group which can be taken by R ¹ to R ⁵ in general formula (1) is selected from the group consisting of D92, D93, and D199 to D286. In one embodiment of the present invention, the fused carbazol-9-yl group which can be taken by R ¹ to R ⁵ in general formula (1) is selected from the group consisting of D294 to D459.

The remaining R ¹ to R ⁵ in general formula (1) each independently represent a hydrogen atom, a deuterium atom, a substituted or unsubstituted aryl group, or a donor group (however, the donor group referred to here does not include an alkyl group, a substituted or unsubstituted benzofuro-fused carbazol-9-yl group, or a substituted or unsubstituted benzothieno-fused carbazol-9-yl group). Here, "the remaining R ¹ to R ⁵ " means one that is not an acceptor group, a substituted or unsubstituted benzofuro-fused carbazol-9-yl group, or a substituted or unsubstituted benzothieno-fused carbazol-9-yl group.
The remaining R ¹ to R ⁵ have a number of 0 to 3. In one embodiment of the present invention, the remaining R ¹ to R ⁵ are hydrogen atoms or deuterium atoms. In one embodiment of the present invention, the remaining R ¹ to R ⁵ comprise a substituted or unsubstituted aryl group. In one embodiment of the present invention, the remaining R ¹ to R ⁵ comprise a donor group. In one embodiment of the present invention, all of the remaining R ¹ to R ⁵ are donor groups. In one embodiment of the present invention, the remaining R ¹ to R ⁵ are hydrogen atoms, deuterium atoms, or donor groups. In one embodiment of the present invention, the remaining R ¹ to R ⁵ are hydrogen atoms, deuterium atoms, or substituted or unsubstituted aryl groups. In one embodiment of the present invention, the remaining R ¹ to R ⁵ comprise a deuterium atom.

For the description and preferred range of the substituted or unsubstituted aryl group which may be taken by the remaining R ¹ to R ⁵ , the description and preferred range of the aryl group as a substituent of the fused carbazol-9-yl group can be referred to. In one embodiment of the present invention, the substituted or unsubstituted aryl group which may be taken by the remaining R ^{1 to} R ⁵ is an unsubstituted aryl group, preferably an unsubstituted phenyl group. However, the aryl group which may be taken by the remaining R 1 to R ⁵ is not substituted with a cyano group.

The donor groups that can be taken by the remaining R ¹ to R ⁵ can be selected from groups having a negative Hammett σp value. The donor groups that can be taken by the remaining R ¹ to R ⁵ preferably have a σp of −0.3 or less, more preferably −0.5 or less, and even more preferably −0.7 or less. For example, they may be selected from the range of −0.9 or less, or −1.1 or less.
When the remaining R ¹ to R ⁵ have two or more donor groups, it is preferable that all of the donor groups are the same. In one embodiment of the present invention, the two or more donor groups are different from each other.
The donor groups that can be the remaining R ¹ to R ⁵ are preferably groups containing a substituted amino group. They may be substituted amino groups, or aryl groups to which a substituted amino group is bonded, particularly phenyl groups to which a substituted amino group is bonded. In a preferred embodiment of the present invention, the donor group is a substituted amino group.
The substituent bonded to the nitrogen atom of the substituted amino group is preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, and more preferably a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. The substituted amino group is particularly preferably a substituted or unsubstituted diarylamino group or a substituted or unsubstituted diheteroarylamino group. The two aryl groups constituting the diarylamino group may be bonded to each other, and the two heteroaryl groups constituting the diheteroarylamino group may be bonded to each other. For the description and preferred ranges of the aryl group and alkyl group referred to here, please refer to the description and preferred ranges of the aryl group and alkyl group as the substituent of the fused carbazol-9-yl group described above. The "heteroaryl group" referred to here may be a monocyclic ring or a fused ring in which two or more rings are fused. When the heteroaryl group is 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 pyridine ring and a pyrimidine ring, and these rings may be fused with another ring. Specific examples of the heteroaryl group include a 2-pyridyl group, a 3-pyridyl group, and a 4-pyridyl group. The number of atoms constituting the ring skeleton of the heteroaryl group is preferably 4 to 40, more preferably 5 to 20, and may be selected from the range of 5 to 14, or may be selected from the range of 5 to 10.

The remaining donor groups that can be represented by R ¹ to R ⁵ are preferably substituted or unsubstituted carbazol-9-yl groups (excluding substituted or unsubstituted benzofuro-fused carbazol-9-yl groups and substituted or unsubstituted benzothieno-fused carbazol-9-yl groups). In one embodiment of the present invention, a further benzene ring may be fused to the two benzene rings that constitute the carbazol-9-yl group. In one embodiment of the present invention, a pyridine ring may be fused to the two benzene rings that constitute the carbazol-9-yl group. In one embodiment of the present invention, at least one of the ring carbon atoms that constitute the carbazol-9-yl group is substituted with a nitrogen atom. When substituted, it is preferable that one ring carbon atom per benzene ring is substituted with a nitrogen atom. It is also preferable that one ring carbon atom is substituted with a nitrogen atom in the entire donor group. The substituent of the carbazol-9-yl group may be selected from Substituent Group A, Substituent Group B, Substituent Group C, Substituent Group D, or Substituent Group E. In a preferred embodiment of the present invention, the carbazol-9-yl groups which the remaining R ¹ to R ⁵ may have may be fused, but the hydrogen atoms are not substituted. In a preferred embodiment of the present invention, the carbazol-9-yl group which may have a fused ring is substituted with an unsubstituted aryl group. In one embodiment of the present invention, the carbazol-9-yl group which may have a fused ring is substituted with an unsubstituted alkyl group.

Specific examples of donor groups that can be used for the remaining R ¹ to R ⁵ are shown below. However, the donor groups that can be used in the present invention should not be construed as being limited by the following specific examples. In the following specific examples, * indicates the bonding position. Methyl groups are not shown, so for example, Z2 has one methyl group.

The above Z1 to Z36 are disclosed as Z1(D) to Z36(D) in which all hydrogen atoms present in the Z1 to Z36 are replaced with deuterium atoms.
In one embodiment of the present invention, the donor groups which the remaining R ¹ to R ⁵ in general formula (1) may take are selected from the group consisting of Z1 to Z36. In one embodiment of the present invention, the donor groups which the remaining R ¹ to R ⁵ in general formula (1) may take are selected from the group consisting of Z1 to Z6. In one embodiment of the present invention, the donor groups which the remaining R ¹ to R ⁵ in general formula (1) may take are selected from the group consisting of Z7 to Z36.

In general formula (1), R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , and R ⁴ and R ⁵ do not bond to each other to form a cyclic structure.
In a preferred embodiment of the present invention, the compound represented by general formula (1) has a symmetric structure. For example, the compound represented by general formula (1) has an axisymmetric structure. For example, the compound represented by general formula (1) has a rotationally symmetric structure. In one embodiment of the present invention, the compound represented by general formula (1) has an asymmetric structure.

In one embodiment of the present invention, the compound represented by general formula (1) contains at least one deuterium atom. In one embodiment of the present invention, it has a deuterated alkyl group (e.g., a deuterated methyl group, a deuterated ethyl group, or a deuterated cyclohexyl group). In one embodiment of the present invention, it has a deuterated aryl group (e.g., a deuterated phenyl group). In one embodiment of the present invention, all hydrogen atoms are deuterated.

The compound represented by general formula (1) preferably does not contain metal atoms, and may be a compound composed only of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, oxygen, and sulfur atoms. In a preferred embodiment of the present invention, the compound represented by general formula (1) is composed only of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, and oxygen atoms. The compound represented by general formula (1) may also be a compound composed only of atoms selected from the group consisting of carbon, hydrogen, deuterium, nitrogen, and sulfur atoms. The compound represented by general formula (1) may also be a compound composed only of atoms selected from the group consisting of carbon, hydrogen, deuterium, and nitrogen atoms. The compound represented by general formula (1) may also be a compound composed only of atoms selected from the group consisting of carbon, hydrogen, and nitrogen atoms. The compound represented by general formula (1) may also be a compound containing no hydrogen atoms but containing deuterium atoms.

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

Specific examples of compounds represented by general formula (1) are shown in Tables 1 and 2 below. However, the compounds represented by general formula (1) that can be used in the present invention should not be construed as being limited by these specific examples. In Tables 1 and 2, the structures of compounds 1 to 24786 are individually shown by specifying A and R ¹ to R ⁵ in general formula (1) below for each compound.

In Table 2, Ph represents a phenyl group.
In Table 2, the structures of Compounds 1 to 24786 are shown by collectively displaying the A and R ¹ to R ⁵ of multiple compounds in each row. For example, in the row of Compounds 1 to 459 in Table 2, Compounds 1 to 459 are identified in order by A and R ³ being A1, R ¹ and R ⁴ being fixed to Z1, and R ² and R ⁵ being the same and D1 to D459. That is, the row of Compounds 1 to 459 in Table 2 collectively displays Compounds 1 to 459 identified in Table 1. Similarly, in the row of Compounds 460 to 918 in Table 2, Compounds 460 to 918 are identified in order by A and R ³ being A1, R ¹ and R ⁴ being fixed to Z6, and R ² and R ⁵ being the same and D1 to D459. Compounds 919 to 8262 in Table 2 are also identified in the same manner.
Compounds 8263 to 16524 in Table 2 specify compounds in which ^R3 and ^R5 are the same and are D1 to D459. For example, in the row of compounds 8263 to 8721 in Table 2, compounds in which A and ^R2 are A1, ^R1 is a hydrogen atom (H), ^R4 is fixed to Z1, and ^R3 and ^R5 are the same and are D1 to D459 are designated as compounds 8263 to 8721, in that order.
Compounds 16525 to 20655 in Table 2 specify compounds in which R ³ to R ⁵ are the same and D1 to D459. For example, in the row of compounds 16525 to 16983 in Table 2, compounds in which A and R ² are A1, R ¹ is fixed to a hydrogen atom (H), R ³ to R ⁵ are the same, and D1 to D459 are designated as compounds 16525 to 16983, in that order.
Compounds 20656 to 24786 in Table 2 are specified as compounds in which ^R3 and ^R5 are the same and are D1 to D459. For example, in the row of compounds 20656 to 21114 in Table 2, compounds in which A and ^R2 are A1, ^R1 is a hydrogen atom (H), and ^R4 is fixed to a phenyl group (Ph), and compounds in which ^R3 and ^R5 are the same and are D1 to D459 are designated as compounds 20656 to 21114, in that order.

Compounds 1(D) to 24786(D) are disclosed in which all hydrogen atoms present in the molecules of the above compounds 1 to 24786 have been replaced with deuterium atoms.
All compounds identified by the above numbers are considered to be individually disclosed. In addition, when rotamers exist among the specific examples of the compounds, the mixture of rotamers and each separated rotamer are also considered to be disclosed in the present specification.

In one aspect of the present invention, the compound is selected from compounds 1 to 24786. In one aspect of the present invention, the compound is selected from compounds 1(D) to 24786(D).
In one aspect of the present invention, a compound is selected from compounds 1 to 1324. In one aspect of the present invention, a compound is selected from compounds 1325 to 2648. In one aspect of the present invention, a compound is selected from compounds 2649 to 3972. In one aspect of the present invention, a compound is selected from compounds 3973 to 5296.
In one aspect of the present invention, a compound is selected from compounds 1 to 8262. In one aspect of the present invention, a compound is selected from compounds 8263 to 16524. In one aspect of the present invention, a compound is selected from compounds 16525 to 20655. In one aspect of the present invention, a compound is selected from compounds 20656 to 24786.
In one embodiment of the present invention, the compound is selected from compounds 1 to 918, 2755 to 3672, 5509 to 6426, 8263 to 9180, 11017 to 11934, 13771 to 14688, 16525 to 16983, 17902 to 18360, 19279 to 19737, 20656 to 21114, 22033 to 22491, and 23410 to 23868. In one aspect of the present invention, the compound is selected from compounds 919-2754, 3673-5508, 6427-8262, 9181-11016, 11935-13770, 14689-16524, 16984-17901, 18361-19278, 19738-20655, 21115-22032, 22492-23409, and 23869-24786.

In a preferred embodiment of the present invention, the compound represented by general formula (1) is selected from the following group of compounds:

When it is intended to use an organic layer containing the compound represented by general formula (1) formed by a vapor deposition method, the molecular weight of the compound represented by general formula (1) 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 is the molecular weight of the smallest compound represented by general formula (1).
The compound represented by general formula (1) may be formed into a film by a coating method regardless of its molecular weight. By using the coating method, it is possible to form a film even from a compound with a relatively large molecular weight. The compound represented by general formula (1) has the advantage of being easily soluble in an organic solvent. Therefore, the compound represented by general formula (1) is easy to apply the coating method to, and is also easy to purify to increase its purity.

It is also conceivable that the present invention can be applied to use a compound containing a plurality of structures represented by general formula (1) in the molecule as a light-emitting material.
For example, a polymerizable group may be pre-existed in the structure represented by general formula (1), and the polymer obtained by polymerizing the polymerizable group may be used as a light-emitting material. For example, a monomer containing a polymerizable functional group at any site of general formula (1) may be prepared, and the monomer may be polymerized alone or copolymerized with other monomers to obtain a polymer having repeating units, and the polymer may be used as a light-emitting material. Alternatively, compounds having a structure represented by general formula (1) may be coupled to obtain dimers or trimers, and these may be used as light-emitting materials.

Examples of polymers having a repeating unit containing a structure represented by general formula (1) include polymers containing a structure represented by either of the following two general formulas.

In the above general formula, Q represents a group containing a structure represented by general formula (1), and ^L1 and ^L2 represent a linking group. The number of carbon atoms in the linking group is preferably 0 to 20, more preferably 1 to 15, and even more preferably 2 to 10. The linking group preferably has a structure represented by ^-X11 - ^L11- . Here, ^X11 represents an oxygen atom or a sulfur atom, and is preferably an oxygen atom. ^L11 represents a linking group, and is preferably a substituted or unsubstituted alkylene group or a substituted or unsubstituted arylene group, and more preferably a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, or a substituted or unsubstituted phenylene group.
In the above general formula, R ¹⁰¹ , R ¹⁰² , R ¹⁰³ and R ¹⁰⁴ each independently represent a substituent, preferably a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, or a halogen atom, more preferably an unsubstituted alkyl group having 1 to 3 carbon atoms, an unsubstituted alkoxy group having 1 to 3 carbon atoms, a fluorine atom, or a chlorine atom, and still more preferably an unsubstituted alkyl group having 1 to 3 carbon atoms, or an unsubstituted alkoxy group having 1 to 3 carbon atoms.
The linking groups represented by ^L1 and ^L2 can be bonded to any site of general formula (1) constituting Q. Two or more linking groups may be bonded to one Q to form a crosslinked structure or a network structure.

Specific structural examples of the repeating unit include structures represented by the following formulas.

A polymer having a repeating unit containing these formulas can be synthesized by introducing a hydroxy group into any site of general formula (1), reacting the hydroxy group as a linker with the following compound to introduce a polymerizable group, and polymerizing the polymerizable group.

A polymer containing a structure represented by general formula (1) within its molecule may be a polymer consisting solely of repeating units having the structure represented by general formula (1), or it may be a polymer containing repeating units having other structures. Furthermore, the repeating units having the structure represented by general formula (1) contained in the polymer may be of a single type, or may contain two or more types. Examples of repeating units that do not have the structure represented by general formula (1) include those derived from monomers used in ordinary copolymerization. Examples include repeating units derived from monomers having an ethylenically unsaturated bond, such as ethylene or styrene.

In some embodiments, the compound represented by formula (1) is a light-emitting material.
In an embodiment, the compound represented by general formula (1) is a compound capable of emitting delayed fluorescence.
In certain embodiments of the present disclosure, the compound represented by general formula (1) can emit light in the UV region, the blue region (e.g., about 420 nm to about 500 nm, particularly 420 nm to 480 nm), and the green region (e.g., about 490 nm to about 575 nm, about 510 nm) of the visible spectrum when excited by thermal or electronic means. In one aspect of the present invention, the maximum emission wavelength is in the range of 530 nm to 575 nm. In one aspect of the present invention, the maximum emission wavelength is in the range of 480 nm to 530 nm. In one aspect of the present invention, the maximum emission wavelength is in the range of 460 nm to 480 nm. In one aspect of the present invention, the maximum emission wavelength is in the range of 440 nm to 460 nm. In one aspect of the present invention, the maximum emission wavelength is in the range of 420 nm to 440 nm.
In certain embodiments of the present disclosure, compounds represented by general formula (1) are capable of emitting light in the ultraviolet spectral region (eg, 280-400 nm) when excited by thermal or electronic means.
In some embodiments of the present disclosure, an organic semiconductor device can be fabricated using a compound represented by general formula (1). The organic semiconductor device referred to here may be an organic optical device in which light is mediated, or an organic device in which light is not mediated. The organic optical device may be an organic light-emitting device that emits light, an organic light-receiving device that receives light, or an element in which light-mediated energy transfer occurs within the device. In some embodiments of the present disclosure, an organic optical device such as an organic electroluminescence device or a solid-state imaging device (e.g., a CMOS image sensor) can be fabricated using a compound represented by general formula (1). In some embodiments of the present disclosure, a CMOS (complementary metal-oxide semiconductor) can be fabricated using a compound represented by general formula (1).

The electronic properties of small molecule chemical libraries can be calculated using known ab initio quantum chemical calculations. For example, time-dependent density functional theory using 6-31G* as a basis and a family of functionals known as the Becke three-parameter Lee-Yang-Parr hybrid functional can be used to solve the Hartree-Fock equations (TD-DFT/B3LYP/6-31G*) to screen for molecular fragments (moieties) with HOMOs above a certain threshold and LUMOs below a certain threshold.
Thus, the donor moiety ("D") can be selected for its HOMO energy (e.g., ionization potential) of, for example, -6.5 eV or greater. The acceptor moiety ("A") can be selected for its LUMO energy (e.g., electron affinity) of, for example, -0.5 eV or less. The bridging moiety ("B") prevents overlap between the π-conjugated systems of the donor and acceptor moieties, for example, by providing a strongly conjugated system that tightly restricts the acceptor and donor moieties to specific configurations.
In some embodiments, the compound library is screened using one or more of the following properties:
1. Emission near a specific wavelength 2. Calculated triplet state above a specific energy level 3. ΔE _ST value below a specific value 4. Quantum yield above a specific value 5. HOMO level 6. LUMO level In some embodiments, the difference between the lowest singlet excited state and the lowest triplet excited state (ΔE _ST ) at 77 K is less than about 0.5 eV, less than about 0.4 eV, less than about 0.3 eV, less than about 0.2 eV, or less than about 0.1 eV. In some embodiments, the ΔE _ST value is less than about 0.09 eV, less than about 0.08 eV, less than about 0.07 eV, less than about 0.06 eV, less than about 0.05 eV, less than about 0.04 eV, less than about 0.03 eV, less than about 0.02 eV, or less than about 0.01 eV.
In certain embodiments, the compounds of general formula (1) exhibit a quantum yield of greater than 25%, e.g., about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, about 90%, about 95% or more.

[Method for synthesizing a compound represented by general formula (1)]
The compounds represented by the general formula (1) include novel compounds.
The compound represented by general formula (1) can be synthesized by combining known reactions. For example, a compound of general formula (1) having a benzofuro-fused carbazole or a benzothieno-fused carbazole can be synthesized by reacting a benzene having ^A1 and an acceptor group with a benzofuro-fused carbazole or a benzothieno-fused carbazole. For details of the reaction conditions, please refer to the synthesis examples described below.

[Constructs using compounds represented by general formula (1)]
In some embodiments, the compound represented by Formula (1) may be combined with one or more materials (e.g., small molecules, polymers, metals, metal complexes, etc.) that disperse, covalently bond, coat, support, or associate with the compound to form a solid film or layer. For example, the compound represented by Formula (1) may be combined with an electroactive material to form a film. In some cases, the compound represented by Formula (1) may be combined with a hole transporting polymer. In some cases, the compound represented by Formula (1) may be combined with an electron transporting polymer. In some cases, the compound represented by Formula (1) may be combined with a hole transporting polymer and an electron transporting polymer. In some cases, the compound represented by Formula (1) may be combined with a copolymer having both a hole transporting moiety and an electron transporting moiety. In these embodiments, electrons and/or holes formed in the solid film or layer may interact with the compound represented by Formula (1).

[Film formation]
In some embodiments, a film containing a compound represented by general formula (1) can be formed by a wet process. In the wet process, a solution containing a composition containing the compound of the present invention is applied to a surface, and a film is formed after removing the solvent. Examples of wet processes include, but are not limited to, spin coating, slit coating, inkjet printing (spraying), gravure printing, offset printing, and flexographic printing. In the wet process, an appropriate organic solvent capable of dissolving the composition containing the compound of the present invention is selected and used. In some embodiments, a substituent (e.g., an alkyl group) that increases the solubility in organic solvents can be introduced into the compound contained in the composition.
In some embodiments, a film containing the compound of the present invention can be formed by a dry process. In some embodiments, a vacuum deposition method can be used as the dry process, but is not limited thereto. When a vacuum deposition method is used, the compounds constituting the film can be co-deposited from separate deposition sources, or from a single deposition source containing a mixture of compounds. When a single deposition source is used, a mixed powder of compound powders can be used, a compression molded body obtained by compressing the mixed powder, or a mixture obtained by heating, melting, and cooling each compound can be used. 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 the same or nearly the same, thereby forming a film having a composition ratio corresponding to the composition ratio of multiple compounds contained in the deposition source. By mixing multiple compounds in the same composition ratio as the composition ratio of the film to be formed and using the deposition source as a deposition source, a film having a desired composition ratio can be easily formed. In some embodiments, the temperature at which each of the co-deposited compounds has the same weight loss rate can be identified, and that temperature can be used as the temperature during co-deposition.

[Examples of use of the compound represented by formula (1)]
The compound represented by the general formula (1) is useful as a material for organic light-emitting devices, and is particularly preferably used for organic light-emitting diodes.
Organic light-emitting diode:
One aspect of the present invention relates to the use of a compound represented by general formula (1) of the present invention as an emitting material in an organic light-emitting device. In some embodiments, the compound represented by general formula (1) of the present invention can be effectively used as an emitting material in the emitting layer of an organic light-emitting device. In some embodiments, the compound represented by general formula (1) includes a delayed fluorescent material (delayed fluorescent material) that emits delayed fluorescence. In some embodiments, the present invention provides a delayed fluorescent material having a structure represented by general formula (1). In some embodiments, the present invention relates to the use of a compound represented by general formula (1) as a delayed fluorescent material. In some embodiments, the present invention can be used as a host material and can be used together with one or more emitting materials, which may be fluorescent materials, phosphorescent materials, or TADF. In some embodiments, the compound represented by general formula (1) can also be used as a hole transport material. In some embodiments, the compound represented by general formula (1) can be used as an electron transport material. In some embodiments, the present invention relates to a method for producing delayed fluorescence from a compound represented by general formula (1). In some embodiments, an organic light-emitting device containing the compound as an emitting material emits delayed fluorescence and exhibits high light emission efficiency.
In some embodiments, the light-emitting layer comprises a compound represented by Formula (1), and the compound represented by Formula (1) is aligned parallel to the substrate. In some embodiments, the substrate is a film-forming surface. In some embodiments, the orientation of the compound represented by Formula (1) relative to the film-forming surface influences or determines the propagation direction of light emitted by the aligned compound. In some embodiments, aligning the propagation direction of light emitted by the compound represented by Formula (1) improves light extraction efficiency from the light-emitting layer.
One aspect of the present invention relates to an organic light-emitting device. In some embodiments, the organic light-emitting device includes an emitting layer. In some embodiments, the emitting layer includes a compound represented by general formula (1) as an emitting material. In some embodiments, the organic light-emitting device is an organic photoluminescence device (organic PL device). In some embodiments, the organic light-emitting device is an organic electroluminescence device (organic EL device). In some embodiments, the compound represented by general formula (1) assists the light emission of other emitting materials included in the emitting layer (as a so-called assist dopant). In some embodiments, the compound represented by general formula (1) included in the emitting layer has its lowest excited singlet energy level, which is between the lowest excited singlet energy level of the host material included in the emitting layer and the lowest excited singlet energy level of the other emitting materials included in the emitting layer.
In some embodiments, the organic photoluminescent device includes at least one light-emitting layer. In some embodiments, the organic electroluminescent device includes at least an anode, a cathode, and an organic layer between the anode and the cathode. In some embodiments, the organic layer includes at least an light-emitting layer. In some embodiments, the organic layer includes only an light-emitting layer. In some embodiments, the organic layer includes one or more organic layers in addition to the light-emitting layer. Examples of organic layers include a hole transport layer, a hole injection layer, an electron blocking layer, a hole blocking layer, an electron injection layer, an electron transport layer, and an exciton blocking layer. In some embodiments, 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.

Emitting layer:
In some embodiments, the light-emitting layer is a layer in which holes and electrons injected from the anode and cathode, respectively, recombine to form excitons, hi some embodiments, the layer emits light.
In some embodiments, only an emitting material is used as the emitting layer. In some embodiments, the emitting layer includes an emitting material and a host material. In some embodiments, the emitting material is one or more compounds represented by general formula (1). In some embodiments, to improve the light emission efficiency of organic electroluminescent devices and organic photoluminescent devices, singlet and triplet excitons generated in the emitting material are confined within the emitting material. In some embodiments, a host material is used in addition to the emitting material in the emitting layer. In some embodiments, the host material is an organic compound. In some embodiments, the organic compound has excited singlet and triplet energies, at least one of which is higher than those of the emitting material of the present invention. In some embodiments, singlet and triplet excitons generated in the emitting material of the present invention are confined within the molecules of the emitting material of the present invention. In some embodiments, the singlet and triplet excitons are sufficiently confined to improve the light emission efficiency. In some embodiments, the singlet and triplet excitons are not sufficiently confined while still achieving high light emission efficiency. That is, any host material that can achieve high light emission efficiency can be used in the present invention without particular limitations. In some embodiments, light emission occurs in the light-emitting material in the light-emitting layer of the device of the present invention. In some embodiments, the emitted light includes both fluorescence and delayed fluorescence. In some embodiments, the emitted light includes light emitted from the host material. In some embodiments, the emitted light consists of light emitted from the host material. In some embodiments, the emitted light includes light emitted from the compound represented by general formula (1) and light emitted from the host material. In some embodiments, a TADF molecule and a host material are used. In some embodiments, TADF is an assist dopant, and has a lower excited singlet energy than the host material in the light-emitting layer and a higher excited singlet energy than the light-emitting material in the light-emitting layer.

When the compound represented by general formula (1) is used as an assist dopant, various compounds can be used as the luminescent material (preferably a fluorescent material). Examples of such luminescent materials 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, and derivatives containing metals (Al, Zn). These exemplary skeletons may or may not have a substituent. Furthermore, these exemplary skeletons may be combined with each other.
Examples of light-emitting materials that can be used in combination with the assist dopant having the structure represented by general formula (1) are given below.

The compounds described in paragraphs 0220 to 0239 of WO 2015/022974 are also particularly suitable as light-emitting materials used in combination with assist dopants having a structure represented by general formula (1).

Further preferred light-emitting materials include compounds represented by the following general formula (E1).

In general formula (E1), ^R1 and ^R3 to ^R16 each independently represent a hydrogen atom, a deuterium atom, or a substituent. ^R2 represents an acceptor group, or ^R1 and ^R2 are bonded together to form an acceptor group, or R2 and ^R3 are bonded together to form an acceptor group. ^{R3 and R4 , R4} and ^R5 , ^R5 and ^{R6 , R6 and R7, R7 and R8, R9 and R10, R10 and R11, R11 and R12 , R12 and R13 , R13 and R14 , R14 and R15 , and R15 and R16 may} be bonded together to form a cyclic structure. ^X1 represents O or NR, and R represents a substituent. Of ^X2 to ^X4 , at least one of ^X3 and ^X4 is O or NR, and the remaining ones may be O or NR or may not be linked. When they are not linked, both ends each independently represent a hydrogen atom, a deuterium atom, or a substituent. C-R1, C- ^R3 , C- ^R4 , C ^{- R5} , C- ^R6 , C- ^R7 , C- ^R8 , C- ^R9 , C- ^R10 , C- ^R11 , C- ^R12 , C- ^R13 , C- ^R14 , C- ^R15 , and C- ^R16 in general formula (1) may be substituted with N.

Further preferred light-emitting materials include compounds represented by the following general formula (E2).

In general formula (E2), ^R1 and ^R2 each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, and ^R3 to ^R16 each independently represent a hydrogen atom, a deuterium atom, or a substituent. ^{R1 and R3 , R3} and ^R4 , ^R4 and ^R5 , ^R5 and ^R6 , R6 and ^R7 , ^R7 and ^R8 , ^R8 and ^R9 , ^R9 and ^{R2 ,} R2 and ^R10 , ^R10 and ^R11 , ^R11 and ^R12 , ^R12 and ^R13 , ^R13 and ^R14 , ^R14 and ^R15 , ^R15 and ^R16 , ^{and R16 and R1} may be bonded to each other to form a cyclic structure. In general formula (1), C-R ³ , C-R ⁴ , C-R ⁵ , C-R ⁶ , C-R ⁷ , C-R ⁸ , C-R ⁹ , C-R ¹⁰ , C-R ¹¹ , C-R ¹² , C-R ¹³ , C-R ¹⁴ , C-R ¹⁵ and C-R ¹⁶ may be substituted with N.

Further preferred light-emitting materials include compounds represented by the following general formula (E3).

In general formula (E3), ^Z1 and ^Z2 each independently represent a substituted or unsubstituted aromatic ring or a substituted or unsubstituted heteroaromatic ring, and ^R1 to ^R9 each independently represent a hydrogen atom, a deuterium atom, or a substituent. R1 and ^R2 , ^R2 and ^R3 , ^R3 and ^R4 , ^R4 and ^R5 , ^R5 and ^R6 , ^R7 and ^R8 , and ^R8 and ^R9 may be bonded to each other to form ^a cyclic structure. However, at least one of Z ¹ , Z ² , the ring formed by bonding together of R ¹ and R ² , the ring formed by bonding together of R ² and R ³ , the ring formed by bonding together of R ⁴ and R ⁵ , and the ring formed by bonding together of R ⁵ and R ⁶ is a furan ring of substituted or unsubstituted benzofuran, a thiophene ring of substituted or unsubstituted benzothiophene, or a pyrrole ring of substituted or unsubstituted indole, and at least one of R ¹ to R ⁹ is a substituted or unsubstituted aryl group or an acceptor group, or at least one of Z ¹ and Z ² is a ring having an aryl group or an acceptor group as a substituent. Among the carbon atoms constituting the benzene ring skeleton constituting the benzofuran ring, the benzothiophene ring, and the indole ring, substitutable carbon atoms may be substituted with nitrogen atoms. In general formula (1), C-R ¹ , C-R ² , C-R ³ , C-R ⁴ , C-R ⁵ , C-R ⁶ , C-R ⁷ , C-R ⁸ and C-R ⁹ may be substituted with N.

Further preferred light-emitting materials include compounds represented by the following general formula (E4).

In general formula (E4), ^Z1 represents a furan ring fused with a substituted or unsubstituted benzene ring, a thiophene ring fused with a substituted or unsubstituted benzene ring, or an N-substituted pyrrole ring fused with a substituted or unsubstituted benzene ring; ^Z2 and ^Z3 each independently represent a substituted or unsubstituted aromatic ring or a substituted or unsubstituted heteroaromatic ring; ^R1 represents a hydrogen atom, a deuterium atom, or a substituent; and ^R2 and ^R3 each independently represent a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. Z1 and ^R1 , ^R2 and ^Z2 , ^Z2 and ^Z3 , and ^Z3 and ^R3 may be bonded to each other to form a cyclic structure ^; provided that at least one pair of R2 and ^Z2 , ^{Z2 and Z3} , or ^Z3 and ^R3 is bonded to each other to form a cyclic structure.

Further preferred light-emitting materials include compounds represented by the following general formula (E5).

In general formula (E5), ^R1 and ^R2 each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, ^Z1 and ^Z2 each independently represent a substituted or unsubstituted aromatic ring or a substituted or unsubstituted heteroaromatic ring, and ^R3 to ^R9 each independently represent a hydrogen atom, a deuterium atom, or a substituent, provided that at least one of ^R1 , ^R2 , ^Z1 , and ^Z2 contains a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted benzothiophene ring, or a substituted or unsubstituted indole ring. R1 and ^Z1 , ^Z1 and ^R3 , ^R3 and ^R4 , ^R4 and ^R5 , R5 and ^Z2 , ^Z2 and ^R2 , ^R2 and ^R6 , ^R6 and ^R7 , ^{R7 and R8 ,} R8 and ^R9 , and ^{R9 and R1 may} be bonded to each other to form a cyclic structure. Of the carbon atoms constituting the benzene ring skeleton constituting the benzofuran ring, the benzothiophene ring, ^and the indole ring, substitutable carbon atoms may be substituted with nitrogen atoms. C- ^R3 , C- ^R4 , C- ^R5 , C- ^R6 , C- ^R7 , C- ^R8 , and C- ^R9 in general formula (1) may be substituted with N.

Further preferred light-emitting materials include compounds represented by the following general formula (E6).

In formula (E6), one of X ¹ and X ² is a nitrogen atom and the other is a boron atom, and R ¹ to R ²⁶ , A ¹ and A ² each independently represent a hydrogen atom, a deuterium atom or a substituent. R1 and ^R2 , ^R2 and ^R3 , ^{R3 and R4 ,} R4 and ^R5 , ^R5 and ^R6 , ^R6 and ^R7 , ^R7 and ^R8 , R8 and ^R9 , ^{R9 and R10 , R10} and ^R11 , ^R11 and ^R12 , R13 and ^R14 , R14 and ^R15 , ^R15 and ^R16 , ^R16 and ^R17 , ^R17 and ^R18 , ^R18 and ^R19 , ^R19 and ^R20 , ^R20 and ^R21 , ^R21 and ^R22 , ^R22 and ^R23 , ^{R23 and R24 , R24 and R25 , R25} and ^R and ²⁶ may be bonded to each other to form a cyclic structure. However, when X ¹ is a nitrogen atom, R ¹⁷ and R ¹⁸ are bonded to each other via a single bond to form a pyrrole ring, and when X ² is a nitrogen atom, R ²¹ and R ²² are bonded to each other via a single bond to form a pyrrole ring. However, when X ¹ is a nitrogen atom, R ⁷ and R ⁸ and R ²¹ and R ²² are bonded to each other via a nitrogen atom to form a 6-membered ring, and R ¹⁷ and R ¹⁸ are bonded to each other to form a single bond, at least one of R ¹ to R ⁶ is a substituted or unsubstituted aryl group, or any of R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁴ and R ⁵ , or R ⁵ and R ⁶ is bonded to each other to form an aromatic ring or a heteroaromatic ring.

Further preferred light-emitting materials include compounds represented by the following general formula (E7).

In general formula (E7), R ²⁰¹ to R ²²¹ each independently represent a hydrogen atom, a deuterium atom, or a substituent, preferably a hydrogen atom, a deuterium atom, an alkyl group, an aryl group, or a group in which an alkyl group and an aryl group are bonded. At least one pair of ^{R 201} and R ²⁰² , R ²⁰² and R ²⁰³ , R ²⁰³ and R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ , R ²⁰⁶ and R ²⁰⁷ , R ²⁰⁷ and R ^{208 , R 214 and} R ²¹⁵ , R ²¹⁵ and R ²¹⁶ , R ²¹⁶ and R ²¹⁷ , R ²¹⁸ and R ²¹⁹ , R 219 and R ²²⁰ , and R 220 and R ²²¹ are bonded to each other to form a benzofuro structure or a benzothieno structure. Preferably, one or two pairs of ^R201 and ^R202 , ^R202 and ^R203 , ^R203 and ^R204 , ^R205 and ^R206 , R206 and ^R207 , or ^R207 and ^R208 , and one or two pairs of ^R214 and ^R215 , ^R215 and ^R216 , ^R216 and ^R217 , ^R218 and ^R219 , ^R219 and ^R220 , or ^{R220 and R221 are} bonded to each other to form a benzofuro structure or a benzothieno structure. More preferably, R ²⁰³ and R ²⁰⁴ are bonded to each other to form a benzofuro structure or a benzothieno structure, and even more preferably, R ²⁰³ and R ²⁰⁴ , and R ²¹⁶ and R ²¹⁷ are bonded to each other to form a benzofuro structure or a benzothieno structure. Particularly preferably, R ²⁰³ and R ²⁰⁴ , and R ²¹⁶ and R ²¹⁷ are bonded to each other to form a benzofuro structure or a benzothieno structure, and R ²⁰⁶ and R ²¹⁹ are substituted or unsubstituted aryl groups (preferably substituted or unsubstituted phenyl groups, more preferably unsubstituted phenyl groups).

Furthermore, compounds represented by general formula (1) described in the specifications of Japanese Patent Application Nos. 2021-103698, 2021-103699, 2021-103700, 2021-081332, 2021-103701, 2021-151805, and 2021-188860 can be used as light-emitting materials. These descriptions of general formula (1) and specific compounds are incorporated herein by reference as part of this specification.

In some embodiments, when a host material is used, the amount of the compound of the present invention as the light-emitting material in the light-emitting layer is 0.1% by weight or more. In some embodiments, when a host material is used, the amount of the compound of the present invention as the light-emitting material in the light-emitting layer is 1% by weight or more. In some embodiments, when a host material is used, the amount of the compound of the present invention as the light-emitting material in the light-emitting layer is 50% by weight or less. In some embodiments, when a host material is used, the amount of the compound of the present invention as the light-emitting material in the light-emitting layer is 20% by weight or less. In some embodiments, when a host material is used, the amount of the compound of the present invention as the light-emitting material in the light-emitting layer is 10% by weight or less.
In some embodiments, the host material of the light-emitting layer is an organic compound that has hole-transporting and electron-transporting functions. In some embodiments, the host material of the light-emitting layer is an organic compound that prevents the wavelength of emitted light from increasing. In some embodiments, the host material of the light-emitting layer is an organic compound that has a high glass transition temperature.

In some embodiments, the host material is selected from the group consisting of:
In some embodiments, the emitting layer comprises two or more types of TADF molecules with different structures.For example, the emitting layer can be made to comprise three materials, with the excited singlet energy level being higher in the order of host material, first TADF molecule, and second TADF molecule.At this time, the difference ΔE _ST between the lowest excited singlet energy level and the lowest excited triplet energy level at 77K of both the first TADF molecule and the second TADF molecule 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.The concentration of the first TADF molecule in the emitting layer is preferably greater than the concentration of the second TADF molecule. Furthermore, the concentration of the host material in the light-emitting layer is preferably greater than the concentration of the second TADF molecules. The concentration of the first TADF molecules in the light-emitting layer may be greater than, less than, or the same as the concentration of the host material. In some embodiments, the composition in the light-emitting layer may be 10 to 70 wt % of the host material, 10 to 80 wt % of the first TADF molecules, and 0.1 to 30 wt % of the second TADF molecules. In some embodiments, the composition in the light-emitting layer may be 20 to 45 wt % of the host material, 50 to 75 wt % of the first TADF molecules, and 5 to 20 wt % of the second TADF molecules. In one embodiment, the luminescence quantum yield φPL1(A) upon photoexcitation of a co-deposited film of the first TADF molecule and the host material (the concentration of the first TADF molecule in this co-deposited film is A wt%) and the luminescence quantum yield φPL2(A) upon photoexcitation of a co-deposited film of the second TADF molecule and the host material (the concentration of the second TADF molecule in this co-deposited film is A wt%) satisfy the relationship φPL1(A) > φPL2(A). In one embodiment, the luminescence quantum yield φPL2(B) upon photoexcitation of a co-deposited film of the second TADF molecule and the host material (the concentration of the second TADF molecule in this co-deposited film is B wt%) and the luminescence quantum yield φPL2(100) upon photoexcitation of a single film of the second TADF molecule satisfy the relationship φPL2(B) > φPL2(100). In one embodiment, the light-emitting layer can contain three types of TADF molecules with different structures. The compound of the present invention may be any of the multiple TADF compounds contained in the light-emitting layer.
In some embodiments, the light-emitting layer can be composed of a material selected from the group consisting of a host material, an assist dopant, and a light-emitting material. In some embodiments, the light-emitting layer does not contain a metal element. In some embodiments, the light-emitting layer can be composed of a material consisting only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, oxygen atoms, and sulfur atoms. Alternatively, the light-emitting layer can be composed of a material consisting only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, deuterium atoms, nitrogen atoms, and oxygen atoms. Alternatively, the light-emitting layer can be composed of a material consisting only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, and oxygen atoms.
When the light-emitting layer contains a TADF material other than the compound of the present invention, the TADF material may be a known delayed fluorescent material. Preferred 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 WO2013/011954, paragraphs 0007 to 0033 and 0059 to 0066 of WO2013/011955, and paragraph 0008 of WO2013/081088. to 0071 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, paragraph 0 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-2017-119665, Compounds encompassed by the general formulas described in paragraphs 0012 to 0025 of JP-A No. 017-222623, paragraphs 0010 to 0050 of JP-A No. 2017-226838, paragraphs 0012 to 0043 of JP-A No. 2018-100411, and paragraphs 0016 to 0044 of WO2018/047853, particularly exemplified compounds, which are capable of emitting delayed fluorescence, are included. Further, here, the following patent documents are disclosed: JP 2013-253121 A, WO 2013/133359 A, WO 2014/034535 A, WO 2014/115743 A, WO 2014/122895 A, WO 2014/126200 A, WO 2014/136758 A, WO 2014/133121 A, WO 20 14/136860, WO2014/196585, WO2014/189122, WO2014/168101, WO2015/008 580 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, WO2015/13350 Preferably, the luminescent materials capable of emitting delayed fluorescence are 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.

The following describes each component of the organic electroluminescent element and each layer other than the light-emitting layer.

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

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 photolithography 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.

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 alloy, magnesium, lithium, a magnesium-copper mixture, a magnesium-silver mixture, a magnesium-aluminum mixture, a magnesium-indium mixture, an aluminum-aluminum oxide (Al ₂ O ₃ ) 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 (Al ₂ O ₃ ) mixture, a lithium-aluminum mixture, and aluminum. In some embodiments, the mixture improves electron-injecting properties and oxidation resistance. In some embodiments, the cathode is fabricated by forming the electrode material as a thin film by evaporation or sputtering. In some embodiments, the cathode has a sheet resistance of several hundred ohms per unit area or less. In some embodiments, the cathode has a thickness of 10 nm to 5 μm. In some embodiments, the cathode has a thickness of 50 to 200 nm. In some embodiments, either the anode or the 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.

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

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

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

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

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

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

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

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.

Furthermore, examples of preferred compounds that can be added to each organic layer are listed below. For example, they can be added as stabilizing materials.

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 exemplified compounds below. Furthermore, even compounds exemplified as materials with specific functions can be diverted to be used as materials with other functions.

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

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

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

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

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

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

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

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

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, such that the groove does not penetrate the base substrate. In some embodiments, a TFT layer for 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 that the planarization film, made of, for example, polyimide or acrylic, is formed, the groove in the interface is 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 groove at the interface by allowing the organic film to absorb any impact that occurs. In other words, if all of the barrier layers were completely exposed without the organic film, the impact would be transmitted to the barrier layer when each cell panel was cut along the groove 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 impacts that would otherwise be transmitted to the barrier layers, allowing each cell panel to be cut softly and preventing cracks from occurring in the barrier layers. In one embodiment, the organic film and planarization film covering the grooves at the interface are spaced apart from each other. For example, if the organic film and planarization film were connected to each other as a single layer, external moisture could enter the display unit through the planarization film and the remaining portion of the organic film. Therefore, the organic film and planarization film are spaced apart from each other so that the organic film is spaced apart from the display unit.

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

The features of the present invention will be explained in more detail below with reference to synthesis examples and working 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 model).
In the following synthesis examples, compounds within the general formula (1) were synthesized.

(Synthesis Example 1) Synthesis of Compound 3

Compound A
Under a nitrogen stream, a 1 M aqueous potassium carbonate solution (50 mL) and tetrakistriphenylphosphinepalladium(0) (0.93 g, 0.81 mmol) were added to a solution of 1,4-dibromotetrafluorobenzene (5.01 g, 16.2 mmol) and 4-cyanophenylboronic acid (5.25 g, 35.7 mmol) in tetrahydrofuran (200 mL), and the mixture was stirred at 80°C for 15 hours. The reaction solution was returned to room temperature, extracted with chloroform, and then dried over anhydrous magnesium sulfate. The solvent was evaporated, and the residue was purified by silica gel column chromatography (hexane:toluene=1:4) to obtain 2.00 g (5.68 mmol, yield 35%) of Compound A as a white solid.
^1H -NMR (400 MHz, CDCl ₃ ): δ 7.83 (d, J= 8.0 Hz, 4H), 7.65 (d, J = 8.0 Hz, 4H).
ASAP MS _spectrum analysis: _C20H8F4N2 : Calculated _352.06 , Observed 353.22 [M+H ⁺ _]

Compound B
Potassium carbonate (0.60 g, 4.37 mmol) was added to a solution of compound A (0.77 g, 2.18 mmol) and carbazole (0.73 g, 4.37 mmol) in N,N-dimethylformamide (150 mL) under a nitrogen stream, and the mixture was stirred at 100°C for 15 hours. The reaction mixture was returned to room temperature, water and methanol were added, and the mixture was filtered. The residue was purified by silica gel column chromatography (hexane:chloroform=1:9) to obtain 0.95 g (1.47 mmol, 67% yield) of compound B as a yellow solid.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 8.06 (d, J = 7.8 Hz, 4H), 7.39 (t, J = 7.8 Hz, 4H), 7.31-7.28 (m, 8H), 7.23 (d, J = 7.2 Hz, 4H), 7.16 (d, J = 7.8Hz, 4H).
ASAP MS spectrum analysis: C ₄₄ H ₂₄ F ₂ N ₄ : Calculated 646.20, Observed 647.48 [M+H ⁺ ]

Compound 3
Under a nitrogen stream, potassium carbonate (0.37 g, 2.71 mmol) was added to a solution of compound B (0.70 g, 1.08 mmol) and 5H-benzofuro[3,2-C]carbazole (0.70 g, 2.71 mmol) in N,N-dimethylformamide (140 mL), and the mixture was stirred at 150°C for 15 hours. The reaction mixture was returned to room temperature, and water and methanol were added, followed by filtration. The residue was purified by silica gel column chromatography (hexane:chloroform:ethyl acetate=1:1:0.1), yielding 0.56 g (0.50 mmol, 46% yield) of compound 3 as a pale yellow solid.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 8.06 (d, J = 7.2 Hz, 2H), 7.87 (d, J = 7.2 Hz, 2H), 7.61-7.56 (m, 8H), 7.39 (t, J = 7.8 Hz, 2H), 7.33 (t, J = 7.2 Hz, 2H), 7.22-6.89 (m, 20H), 6.80-6.77 (m, 4H) 6.67-6.62 (m, 4H).
ASAP MS spectrum analysis: C ₈₀ H ₄₄ N ₆ O ₂ : Calculated 1120.35, Observed 1121.84 [M+H ⁺ ]

(Synthesis Example 2) Synthesis of Compound 19281

Compound C
To a solution of 1,5-dibromo-2,3,4-trifluorobenzene (5.80 g, 20.0 mmol) and bis(pinacolato)diboron (12.7 g, 50.0 mmol) in 1,4-dioxane (100 mL), [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (0.88 g, 1.20 mmol) and potassium acetate (9.82 g, 100 mmol) were added under a nitrogen stream and stirred at 110°C. After 15 hours, the reaction mixture was allowed to cool to room temperature, and the solvent was distilled off. The residue was purified by silica gel column chromatography (hexane:ethyl acetate = 4:1) to obtain compound C (7.36 g, 19.2 mmol, 96% yield) as a brown solid.
ASAP mass spectrometry analysis: Theoretical value: 384.19, observed value: 385.21.

Compound D
To a solution of compound C (3.84 g, 10.0 mmol) and 3-bromo-2-pyridinecarbonitrile (4.21 g, 23.0 mmol) in toluene/water (90 mL/10 mL), 2-dicyclohexylphosphino-2',6'-dimethoxysibiphenyl (82.0 mg, 0.20 mmol), tris(dibenzylideneacetone)dipalladium(0) (92.0 mg, 0.10 mmol), and tripotassium phosphate (4.25 g, 20.0 mmol) were added under a nitrogen stream and stirred at room temperature for 15 hours. The mixture was returned to room temperature, and the reaction solution was washed with saturated aqueous ammonium chloride and saturated brine. After drying over anhydrous magnesium sulfate, the solvent was distilled off. The resulting mixture was purified by silica gel column chromatography (hexane:ethyl acetate = 2:1) to obtain compound D (0.51 g, 1.50 mmol, 15% yield) as a white solid.
¹ H-NMR (400 MHz, CDCl ₃ ): δ 8.81 (dd, J = 4.8, 1.5 Hz, 2H), 7.96 (dd, J = 8.0, 1.3 Hz, 2H), 7.68 (d, J = 8.0 Hz, 1H), 7.67 (d, J= 8.0 Hz, 1H), 7.38 (td, J = 7.1, 2.4 Hz, 1H).
ASAP mass spectrum analysis: theoretical value 336.06, observed value 338.18

Compound 19281 and Compound E
Under a nitrogen stream, 2.26 g (8.80 mmol) of 5H-benzofuro[3,2-c]carbazole and 1.66 g (12.0 mmol) of potassium carbonate were added to N,N-dimethylformamide (25 mL) and stirred at room temperature for 1 hour. 1.35 g (4.00 mmol) of compound D was added to the reaction mixture, and the mixture was stirred at room temperature for 15 hours. After that, the mixture was heated to 60°C and stirred for 24 hours. The reaction solution was returned to room temperature, water was added, and the precipitate was filtered off. The residue was washed with methanol and dried under vacuum. The residue was purified by silica gel column chromatography (toluene:ethyl acetate=85:15) to obtain compound 19281 (1.32 g, 1.26 mmol, yield 32%) and compound E (0.89 g, 1.10 mmol, yield 27%) as pale yellow solids.
Compound 19281: ¹ H NMR (400 MHz, CDCl ₃ ,): δ 8.49 (s, 1H), 8.39-8.29 (m, 2H), 8.07-7.94 (m, 4H), 7.74-7.15 (m, 18H), 7.01-6.98 (m, 5H), 6.89-6.79 (m, 5H), 6.69-6.62 (m, 2H).
ASAP MS spectrum analysis: Calculated 1047.30, Observed 1048.53
Compound E: ¹ H NMR (400 MHz, CDCl ₃ ): δ 8.45 (d, J = 7.7 Hz, 2H), 8.41-8.04 (m, 2H), 8.05 (s, 1H), 7.98 (t, J = 8.1 Hz, 4H), 7.70 (d, J = 8.1 Hz, 2H), 7.54-7.29 (m, 17H), 7.03-6.98 (m, 2H).
ASAP MS spectrum analysis: Calculated 810.22, Observed 811.39

(Synthesis Example 3) Synthesis of Compound 13773

Compound 13773
Under a nitrogen stream, N,N-dimethylformamide (25 mL) was added to 9H-carbazole (0.33 g, 1.95 mmol) and potassium carbonate (0.31 g, 2.25 mmol), and the mixture was stirred at room temperature for 1 hour. Compound E (1.22 g, 1.50 mmol) was added to the reaction mixture, and the mixture was stirred at 100°C for 20 hours. The reaction solution was returned to room temperature, water was added, and the precipitate was filtered off. The residue was washed with methanol and dried under vacuum. The residue was purified by silica gel column chromatography (toluene:ethyl acetate=98:2) to obtain compound 13773 (1.09 g, 1.14 mmol, 76% yield) as a pale yellow solid.
¹ H NMR (400 MHz, CDCl ₃ ): δ 8.45 (s, 1H), 8.33 (s, 2H), 8.04-7.97 (m, 4H), 7.73-7.72 (m, 1H), 7.57-7.51 (m, 5H), 7.39 (d, J = 6.4 Hz, 4H), 7.17-7.13 (m, 3H), 6.99 (t, 5H), 6.82-6.77 (m, 2H), 6.76-6.65 (td, 4H), 6.60 (t, J = 7.2 Hz, 1H).
ASAP MS spectrum analysis: Calculated 957.29, Observed 958.46

By the same procedures as in Synthesis Examples 1 to 3, the following Compound 23430, Compound 15609, Compound 19740, Compound 921, Reference Compound 1 and Reference Compound 2 were also synthesized.

Example 1 Preparation and Evaluation of Thin Film Compound 3 was deposited on a quartz substrate by vacuum deposition under conditions of a vacuum degree of less than 1×10 ⁻³ Pa to form a neat thin film of Compound 3 with a thickness of 100 nm.
Separately, Compound 3 and PYD2Cz were deposited from different deposition sources on a quartz substrate by vacuum deposition under a vacuum of less than 1×10 ⁻³ Pa to form a doped thin film with a thickness of 100 nm and a concentration of Compound 3 of 20 wt %.
Using Compound 13773 and Compound 19281 instead of Compound 3, neat thin films and doped thin films were formed in the same manner.
The minimum excited singlet energy and the minimum excited triplet energy were measured using each neat thin film formed, and the difference ΔE _ST was calculated. Furthermore, the maximum emission wavelength (λmax) and photoluminescence quantum yield (PLQY) were measured when each doped thin film formed was irradiated with 300 nm excitation light. The results are shown in Table 3. The maximum emission wavelengths of Reference Compound 1 and Reference Compound 2 were also measured in the same manner, and were found to be 458 nm and 469 nm. It was confirmed that Compound 3, Compound 13773, Compound 19281, Reference Compound 1, and Reference Compound 2 all had a good deep blue emission color.

Doped thin films were formed according to the above method using the following comparative compounds 1 to 4. For comparative compounds 1 to 3, DPEPO was used as the host material. The lifetime of delayed fluorescence was measured using the doped thin films prepared, including those of compound 3, compound 13773, and compound 19281. The results are shown in Table 4.

Compound 3, compound 13773, and compound 19281, represented by general formula (1), had shorter delayed fluorescence lifetimes than comparative compounds 1 to 3. Comparative compound 4 had a delayed fluorescence lifetime comparable to that of compound 13773, but had a low photoluminescence quantum yield (PLQY) of 26%, and did not exhibit the superior luminescence properties of compounds 3, 13773, and 19281. Furthermore, the photoluminescence quantum yields (PLQY) of compounds 3, 13773, and 19281 were higher than those of comparative compounds 1 and 2, confirming their superior luminescence properties.

(Example 2) Preparation of Organic Electroluminescence Device Each thin film was laminated by vacuum deposition at a vacuum of 5.0 × 10 ^-5 Pa on a glass substrate with an anode made of indium tin oxide (ITO) with a thickness of 50 nm. First, HAT-CN was formed to a thickness of 10 nm on the ITO, NPD was formed to a thickness of 35 nm on top of that, and PTCz was formed to a thickness of 10 nm on top of that. Next, PYD2Cz and Compound 3 were co-deposited from different deposition sources to form a 40 nm thick layer as an emitting layer. The concentration of Compound 3 in the emitting layer was 30% by mass. Next, ET1 was formed to a thickness of 10 nm, and then Liq and SF3-TRZ were co-deposited from different deposition sources to form a 20 nm thick layer. The concentrations 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 completing an organic electroluminescence device.

The compound represented by general formula (1) has good light-emitting performance. Therefore, by using the compound represented by general formula (1), it is possible to provide an excellent organic light-emitting device. Therefore, the present invention has high industrial applicability.

Claims (15)

A compound represented by the following general formula (1):
[In general formula (1), A represents a cyanopyridyl group, and a hydrogen atom of the cyanopyridyl group may be substituted with a deuterium atom. ^R2 represents an acceptor group, and the acceptor group is a substituted or unsubstituted heteroaryl group or cyano group containing a nitrogen atom as a ring skeleton-constituting atom. At least two of ^R1 , ^R3 , ^R4 , and ^R5 each independently represent a substituted or unsubstituted benzofuro-fused carbazol-9-yl group.] The remaining R ¹ to R ⁵ each independently represent a hydrogen atom, a deuterium atom, an unsubstituted aryl group, or a donor group, and the donor group is a substituted or unsubstituted diarylamino group (however, the two aryl groups constituting the diarylamino group may be bonded to each other, and the substituted or unsubstituted diarylamino group does not include a substituted or unsubstituted benzofuro-fused carbazol-9-yl group and a substituted or unsubstituted benzothieno-fused carbazol-9-yl group). The compound according to claim 1, having a maximum emission wavelength in the range of 420 nm to 480 nm. The compound of claim 1 or 2, having a symmetrical structure. A light-emitting material comprising the compound described in any one of claims 1 to 3. A delayed fluorescent material comprising the compound according to any one of claims 1 to 3 . A film comprising the compound according to any one of claims 1 to 3 . An organic semiconductor device comprising the compound according to any one of claims 1 to 3 . An organic light-emitting device comprising the compound according to any one of claims 1 to 3 . The organic light-emitting device of claim 8, wherein the device has a layer containing the compound, the layer also containing a host material. The organic light-emitting device according to claim 9, wherein the layer containing the compound also contains a delayed fluorescent material in addition to the compound and the host material, and the lowest excited singlet energy of the delayed fluorescent material is lower than that of the host material and higher than that of the compound. The organic light-emitting device according to claim 9, wherein the device has a layer containing the compound, and the layer also contains a light-emitting material having a structure different from that of the compound. The organic light-emitting device described in any one of claims 9 to 11, wherein the compound emits the greatest amount of light among the materials contained in the device. The organic light-emitting device according to claim 11, wherein the amount of light emitted from the light-emitting material is greater than the amount of light emitted from the compound. The organic light-emitting device according to any one of claims 8 to 13, which is an organic electroluminescence device. The organic light-emitting device according to any one of claims 8 to 14, which emits delayed fluorescence.