WO2022009651A1

WO2022009651A1 - Compound, light-emitting material, and light-emitting device

Info

Publication number: WO2022009651A1
Application number: PCT/JP2021/023285
Authority: WO
Inventors: 香織藤澤; ヨンジュジョ; 善丈鈴木
Original assignee: 株式会社Kyulux
Priority date: 2020-07-08
Filing date: 2021-06-21
Publication date: 2022-01-13
Also published as: CN115734996A

Abstract

A compound represented by general formula below is useful as a light-emitting material. Ar is a hydrogen atom, an aromatic hydrocarbocyclic group, or a nitrogen atom-containing aromatic heterocyclic group; 1-3 of R¹ to R⁴ are carbazole-9-yl groups condensed with a benzofuran ring; 1-3 of R¹ to R⁴ are other donor groups; and the rest are hydrogen atoms.

Description

Compounds, light emitting materials and light emitting devices

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

Research is being actively conducted to improve the luminous efficiency of light emitting elements such as organic electroluminescence elements (organic EL elements). In particular, various measures have been taken to improve the luminous efficiency by newly developing and combining electron transport materials, hole transport materials, light emitting materials and the like constituting organic electroluminescence devices. Among them, research on organic electroluminescence devices using delayed fluorescent materials can be seen.

The delayed fluorescent material is a material that emits fluorescence when returning from the excited singlet state to the ground state after an intersystem crossing from the excited triplet state to the excited singlet state occurs in the excited state. Fluorescence by such a pathway is called delayed fluorescence because it is observed later than the fluorescence from the excited singlet state directly generated from the ground state (normal fluorescence). Here, for example, when a luminescent compound is excited by injection of a carrier, the probability of occurrence of the excited singlet state and the excited triplet state is statistically 25%: 75%, so that the excited singlet state directly generated is used. There is a limit to the improvement of light emission efficiency only by the fluorescence of. On the other hand, in the delayed fluorescent material, not only the excited singlet state but also the excited triplet state can be used for fluorescence emission by the path via the above-mentioned inverse intersystem crossing, so that the emission is higher than that of the ordinary fluorescent material. Efficiency will be obtained.

Since such a principle was clarified, various delayed fluorescent materials have been discovered by various studies. However, any material that emits delayed fluorescence is not immediately useful as a light emitting material. Some delayed fluorescent materials are relatively unlikely to have an inverse intersystem crossing, and some have a long delayed fluorescence lifetime. In addition, excitons may accumulate in the high current density region to reduce the luminous efficiency, or the drive may deteriorate rapidly if the drive is continued for a long time. Therefore, the reality is that there are an extremely large number of delayed fluorescent materials that have room for improvement in terms of practicality. Therefore, it has been pointed out that the benzonitrile compound known as a delayed fluorescent material also has a problem. For example, although 2CzPN having the following structure is a material that emits delayed fluorescence, it has a problem that the luminous efficiency is not high and the luminous efficiency is significantly reduced in a high current density region (see Non-Patent Document 1). ).

Despite the fact that it has been pointed out that it has such problems, it cannot be said that the relationship between the chemical structure and properties of delayed fluorescent materials has been fully elucidated. Therefore, it is currently difficult to generalize the chemical structure of a compound useful as a light emitting material, and there are many unclear points.

Under such circumstances, the present inventors have conducted repeated studies for the purpose of providing a more useful compound as a light emitting material for a light emitting device. Then, we proceeded with diligent studies for the purpose of deriving and generalizing the general formulas of compounds that are more useful as luminescent materials.

As a result of diligent studies to achieve the above object, the present inventors have found that among benzonitrile derivatives, a compound having a structure satisfying a specific condition is useful as a light emitting material. The present invention has been proposed based on these findings, and specifically has the following configurations.

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

[In the general formula (1)
Ar represents a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon ring group, or a substituted or unsubstituted aromatic heterocyclic group containing a nitrogen atom as a ring skeleton constituent atom.
1 to 3 of R ¹ to R ⁴ each independently represent a carbazole-9-yl group D'(although the hydrogen atom may be substituted) in which a benzofuran ring is condensed.
1 to 3 of R ¹ to R ⁴ are each independently a donor group D (however, a carbazole-9-yl group fused with a benzofuran ring, a substituted or unsubstituted aromatic hydrocarbon ring group, and a substituted or unsubstituted aromatic hydrocarbon ring group, and Represents a substituted or unsubstituted aromatic heterocyclic group containing a nitrogen atom as a ring skeleton constituent atom).
The remaining 0 to 2 R ¹ to R ⁴ represent hydrogen atoms. ]
[2] The compound according to [1], which has any of the following structures.

[3] The compound according to [1], which has any of the following structures.

[4] The compound according to [1], which has any of the following structures.

[5] The compound according to [3] or [4], wherein a plurality of D'existing in the molecule have the same structure.
[6] The compound according to [2] or [3], wherein a plurality of Ds present in the molecule have the same structure.
[7] The compound according to any one of [1] to [6], wherein D'is condensed with the carbazolyl-9-yl group in the furan ring of the benzofuran ring.
[8] The compound according to [6], wherein D'has any of the following structures.

[Hydrogen atoms in each of the above structures may be substituted. ]
[9] The compound according to any one of [1] to [8], wherein D is a substituted or unsubstituted carbazolyl-9-yl group (excluding those condensed with a benzofuran ring).
[10] The compound according to any one of [1] to [9], wherein Ar is a hydrogen atom.
[11] The compound according to any one of [1] to [10], wherein none of ^{R 1} to R ^{4 is a hydrogen atom.}
[12] A luminescent material comprising the compound according to any one of [1] to [11].
[13] A light emitting device comprising the compound according to any one of [1] to [11].
[14] The light emitting device according to [13], wherein the light emitting device has a light emitting layer, and the light emitting layer contains the compound and a host material.
[15] The light emitting device according to [13], wherein the light emitting device has a light emitting layer, the light emitting layer contains the compound and the light emitting material, and mainly emits light from the light emitting material.

The compound of the present invention is useful as a light emitting material. Further, the compound of the present invention includes a compound that emits delayed fluorescence. The compound of the present invention is also useful as a material for an organic light emitting device.

It is a schematic cross-sectional view which shows the layer structure example of the organic electroluminescence element.

Hereinafter, the contents of the present invention will be described in detail. The description of the constituent elements described below may be based on typical embodiments and specific examples of the present invention, but the present invention is not limited to such embodiments and specific examples. In addition, the numerical range represented by using "-" in this specification means the range including the numerical values before and after "-" as the lower limit value and the upper limit value. Further, the isotope species of hydrogen atoms existing in the molecule of the compound used in the present invention are not particularly limited, and for example, all the hydrogen atoms in the molecule ^{may be 1} H, and some or all of them may be ² H. (Duterium D) may be used. For example, the hydrogen atom that Ar can take may be ² H (Duterium D).

[Compound represented by the general formula (1)]

Ar in the general formula (1) represents a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon ring group, or a substituted or unsubstituted aromatic heterocyclic group containing a nitrogen atom as a ring skeleton constituent atom. In a preferred embodiment of the invention, Ar is a hydrogen atom. Further, an embodiment in which Ar is a substituted or unsubstituted aromatic hydrocarbon ring group, and further, an embodiment in which Ar is a substituted or unsubstituted aromatic heterocyclic group containing a nitrogen atom can be adopted.

The "aromatic hydrocarbon ring group" as used in the present invention means a group in which the ring (one ring) to be bonded is an aromatic hydrocarbon ring. For example, it contains a phenyl group bonded by one carbon atom constituting the ring skeleton of the benzene ring. The hydrogen atoms constituting the bonded aromatic hydrocarbon ring may be substituted. Further, one or more rings may be condensed on the aromatic hydrocarbon ring to be bonded. Further, another ring may be condensed with the condensed ring. Examples of the ring to be condensed include an aromatic hydrocarbon ring, an aromatic heterocycle, an aliphatic hydrocarbon ring, and an aliphatic heterocycle. Examples of the aromatic hydrocarbon ring include a benzene ring. Examples of the aromatic heterocycle include a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, a pyrrole ring, a pyrazole ring, and an imidazole ring. Examples of the aliphatic hydrocarbon ring include a cyclopentane ring, a cyclohexane ring, and a cycloheptane ring. Examples of the aliphatic heterocycle include a piperidine ring, a pyrrolidine ring, and an imidazoline ring. Specific examples of the fused ring constituting the aromatic hydrocarbon ring include a naphthalene ring, an anthracene ring, a phenanthrene ring, a pyran ring, and a tetracene ring. Specific examples of the fused ring containing a hetero atom include an indole ring, an isoindole ring, a benzimidazole ring, a benzotriazole ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, and a cinnoline ring. However, in a specific example of these fused rings, they are bonded by carbon atoms constituting the benzene ring.
The number of carbon atoms of the substituted or unsubstituted aromatic hydrocarbon ring group that Ar can take is preferably 6 to 40, more preferably 6 to 30, and even more preferably 6 to 20. The number of ring skeleton constituent atoms of the ring to be bonded is preferably 6 to 14, more preferably 6 to 12, and even more preferably 6.

The "aromatic heterocyclic group" as used in the present invention means that the ring (one ring) to be bonded is an aromatic heterocycle and is bonded by one carbon atom constituting the ring skeleton of the aromatic heterocycle. It includes, for example, a pyridyl group bonded at one carbon atom constituting the ring skeleton of a pyridine ring. The ^{aromatic heterocycles that can be taken by R 1} to R ⁵ include a nitrogen atom as a ring skeleton constituent atom of the ring (one ring) to be bonded. The bonded ring may contain a heteroatom other than the nitrogen atom as a ring-skeleton-constituting atom, but it is preferable that the ring contains only a nitrogen atom as the ring-skeleton-constituting heteroatom. The number of heteroatoms contained in the ring to be bonded is preferably 1 to 3, and more preferably 1 or 2. Examples of the ring to be bonded include a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, a pyrrole ring, a pyrazole ring, and an imidazole ring. The hydrogen atoms constituting the bonded ring may be substituted. Further, one or more rings may be condensed. Further, another ring may be condensed on the condensed ring. Examples of the ring to be condensed include an aromatic hydrocarbon ring, an aromatic heterocycle, an aliphatic hydrocarbon ring, and an aliphatic heterocycle. For specific examples of the aromatic hydrocarbon ring, the aromatic heterocycle, the aliphatic hydrocarbon ring and the aliphatic heterocycle referred to here, refer to the corresponding description in the above description of the "aromatic hydrocarbon ring group". Can be done. Specific examples of the fused ring constituting the aromatic heterocycle include a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, a cinnoline ring, and a pteridine ring. However, in a specific example of these fused rings, they are bonded by carbon atoms constituting the ring skeleton of the heterocycle.
The number of carbon atoms of the substituted or unsubstituted aromatic heterocyclic group that Ar can adopt is preferably 3 to 30, more preferably 3 to 20, and even more preferably 4 to 15. The number of ring skeleton constituent atoms of the ring to be bonded is preferably 6 to 14, more preferably 6 to 12, and even more preferably 6.

The aromatic hydrocarbon ring group and the aromatic heterocyclic group that Ar can take may be substituted. Examples of the substituent include an alkyl group, an alkenyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, a heteroaryloxy group, a heteroarylthio group and a cyano group. These substituents may be substituted with yet another substituent. Preferred groups of substituents include alkyl groups, aryl groups, alkoxy groups and alkylthio groups.
The "alkyl group" referred to here may be linear, branched or cyclic. Further, two or more of the linear portion, the annular portion and the branched portion may be mixed. The number of carbon atoms of the alkyl group can be, for example, 1 or more, 2 or more, and 4 or more. Further, the number of carbon atoms can be 30 or less, 20 or less, 10 or less, 6 or less, and 4 or less. Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, isopentyl group, n-hexyl group and isohexyl group. 2-Ethylhexyl group, n-heptyl group, isoheptyl group, n-octyl group, isooctyl group, n-nonyl group, isononyl group, n-decanyl group, isodecanyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group can be mentioned. can. The alkyl group as a substituent may be further substituted with an aryl group.
The "alkenyl group" may be linear, branched or cyclic. Further, two or more of the linear portion, the annular portion and the branched portion may be mixed. The carbon number of the alkenyl group can be, for example, 2 or more and 4 or more. Further, the number of carbon atoms can be 30 or less, 20 or less, 10 or less, 6 or less, and 4 or less. Specific examples of the alkenyl group include ethenyl group, n-propenyl group, isopropenyl group, n-butenyl group, isobutenyl group, n-pentenyl group, isopentenyl group, n-hexenyl group, isohexenyl group and 2-ethylhexenyl group. Can be mentioned. The alkenyl group as a substituent may be further substituted with a substituent.
The "aryl group" and the "heteroaryl group" may be a monocyclic ring or a condensed ring in which two or more rings are condensed. In the case of fused rings, the number of fused rings is preferably 2 to 6, and can be selected from, for example, 2 to 4. Specific examples of the ring include a benzene ring, a pyridine ring, a pyrimidine ring, a triazine ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a triphenylene ring, a quinoline ring, a pyrazine ring, a quinoxaline ring, and a naphthylidine ring. Specific examples of the arylene group or the heteroarylene group include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthrasenyl group, a 2-anthrasenyl group, a 9-anthrasenyl group, a 2-pyridyl group, a 3-pyridyl group, and 4 -Pyridyl groups can be mentioned.
For the alkyl moiety of the "alkoxy group" and the "alkylthio group", the above description and specific examples of the alkyl group can be referred to. For the aryl portion of the "aryloxy group" and the "arylthio group", the above description and specific examples of the aryl group can be referred to. For the heteroaryl portion of the "heteroaryloxy group" and the "heteroarylthio group", the above description and specific examples of the heteroaryl group can be referred to.

In the following, specific examples of a substituted or unsubstituted aromatic hydrocarbon ring group that can be adopted by Ar of the general formula (1) and a substituted or unsubstituted aromatic heterocyclic group containing a nitrogen atom as a ring skeleton constituent atom. An example is shown. Ar2 to Ar4 represent a tolyl group, Ar9 represents a 4-methoxyphenyl group, Ar10 represents a 4-methylthiophenyl group, and Ar15 represents a 2,4,6-trimethylphenyl group. When the structure is marked in the present invention, the methyl group is indicated in this manner. The wavy line indicates the position where Ar is combined.

^{1 to 3 of R 1} to R ⁴ of the general formula (1) each independently have a carbazole-9-yl group D'condensed with a benzofuran ring (however, the hydrogen atom may be substituted). show.
When ^{one of} R 1 to R ⁴ is D', it is preferable that R ^{3 is D'.} It is also preferable that ^{R 4 is D'.}
When two of R ¹ to R ⁴ are D', it is preferable that the two D'are the same as each other. However, different D's may be adopted. The two D's are preferably ^{R 1} and R ^4. However, it can also be ^{R 2} and R ^4. It can also be ^{R 3} and R ^4.
When ^{three of R 1} to R ⁴ are D', it is preferable that all three D'are the same. However, all three may be different D's, or two may be the same and one may be different. The three D'can be R ¹ , R ² and R ⁴ . It can also be ^{R 1} , R ^2, and R ^3.

D'is a carbazole-9-yl group fused with a benzofuran ring, preferably a group having a structure in which a benzofuran ring is directly condensed with at least one of two benzene rings constituting the carbazole-9-yl structure. It may be a group in which a benzofuran ring is directly condensed with both of the two benzene rings constituting the carbazole-9-yl structure. The benzofuran ring may be a furan ring that is fused to a benzene ring having a carbazolyl-9-yl structure, or a benzene ring that constitutes a benzofuran ring and is fused to a benzene ring having a carbazolyl-9-yl structure. May be good. The former is preferable.
Only one benzofuran ring may be condensed in the carbazolyl-9-yl structure of D', or two or more may be condensed. When two or more are condensed, their benzofuran rings may have the same structure or different structures. Further, the types of rings to be condensed may be the same or different. It is preferable that one benzofuran ring is condensed into two benzene rings having a carbazolyl-9-yl structure, or one benzofuran ring is condensed into only one of the two benzene rings.
The hydrogen atom constituting the carbazolyl-9-yl group fused with the benzofuran ring may be substituted. At this time, the hydrogen atom constituting the benzofuran ring may be substituted, or the hydrogen atom constituting the carbazolyl-9-yl structure may be substituted. Examples of the substituent include an alkyl group, an alkenyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, a heteroaryloxy group, a heteroarylthio group and a substituted amino group. Preferred substituents include an alkyl group, an aryl group and a substituted amino group. The description and preferable range of the alkyl group, the alkenyl group, the aryl group, the heteroaryl group, the alkoxy group, the alkylthio group, the aryloxy group, the arylthio group, the heteroaryloxy group and the heteroarylthio group are described here as substituents in Ar. The corresponding description of can be referred to. Further, in the above-mentioned substituted amino group, the substituent bonded to the nitrogen atom of the amino group is a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted. The heteroaryl group of the above is preferable, and a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group is more preferable. The substituted amino group is particularly preferably a substituted or unsubstituted diarylamino group or a substituted or unsubstituted diheteroarylamino group. Further, the two groups bonded to the nitrogen atom may be bonded to each other to form a cyclic structure (for example, a substituted or unsubstituted carbazole-9-yl group).
A ring other than the benzofuran ring may be condensed in the carbazolyl-9-yl structure. Such a ring may be any of an aromatic hydrocarbon ring, an aromatic heterocycle, an aliphatic hydrocarbon ring, and an aliphatic heterocycle, but is a group consisting of an aromatic hydrocarbon ring and an aliphatic hydrocarbon ring. It is preferable that only the ring is more selected, and more preferably only the aromatic hydrocarbon ring. Further, it is also preferable that no ring other than the benzofuran ring is condensed in the carbazolyl-9-yl structure. Further, it is also preferable that the carbazolyl-9-yl group condensed with the benzofuran ring is unsubstituted.

Hereinafter, specific examples of the carbazole-9-yl group D'condensed with a benzofuran ring, which can be taken from ^{R 1} to R ⁴ of the general formula (1), are shown. The wavy line indicates the position where D'combines. Among the following D'1 to D'42, D'1 to D'30 are preferable, D'1 to D'16 are more preferable, and D'1 to D'6 are further preferable. Further, a group of compounds in which the hydrogen atoms of D'1 to D'42 below may be substituted with a substituent is also preferable. Among such optionally substituted compound groups D'1 to D'42, the optionally substituted compound groups D'1 to D'30 are preferable, and the optionally substituted compound group D' 1 to D'16 are more preferable, and compound groups D'1 to D'6 which may be substituted are further preferable.

In addition to the above specific examples, D'1 to D'42 are substituted with a methyl group, D'1 to D'42 are substituted with an ethyl group, and D'1 to D'42 are substituted with an isopropyl group. Substituted compounds, D'1 to D'42 substituted with a tert-butyl group, D'1 to D'42 substituted with a phenyl group, and D'1 to D'42 having a benzene ring. A group of condensed compounds can also be exemplified.

^{1 to 3 of R 1} to R ⁴ of the general formula (1) are each independently a donor group D (however, a carbazole-9-yl group fused with a benzofuran ring, a substituted or unsubstituted aromatic hydrocarbon). Represents a hydrogen ring group and a substituted or unsubstituted aromatic heterocyclic group containing a nitrogen atom as a ring skeleton constituent atom).
When two of R ¹ to R ⁴ are D, it is preferable that the two Ds are the same as each other. However, different Ds may be adopted. When ^{three of R 1} to R ⁴ are D, it is preferable that all three D are the same. However, all three may be different Ds, or two may be the same and one may be different.

The "donor group" in the present invention is a group having a negative Hammet's σp value. Here, the “hammet σp value” is L. P. Proposed by Hammett, it quantifies the effect of substituents on the reaction rate or equilibrium of para-substituted benzene derivatives. Specifically, the following equation holds between the substituent in the para-substituted benzene derivative and the reaction rate constant or the equilibrium constant:
log (k / k ₀ ) = ρσp
Or log (K / K ₀ ) = ρσp
It is a constant (σp) peculiar to the substituent in. In the above equation, k is the rate constant of the benzene derivative having no substituent, k ₀ is the rate constant of the benzene derivative substituted with the substituent, K is the equilibrium constant of the benzene derivative having no _{substituent, and K 0} is the substituent. The equilibrium constant of the benzene derivative substituted with, ρ represents the reaction constant determined by the type and conditions of the reaction. For the description of "Hammet's σp value" and the numerical value of each substituent in the present invention, refer to the description of σp value in Hansch, C.et.al., Chem.Rev., 91,165-195 (1991). can. Groups with a negative Hammett σp value tend to show electron donating properties (donor properties), and groups with a positive Hammett σp value tend to show electron attractor properties (acceptor properties).

The donor group in the present invention is preferably a group containing a substituted amino group. For the description and preferred range of the substituted amino group referred to here, the above description and preferred range of the substituted amino group in D'can be referred to. The donor group in the present invention may be a group bonded with a nitrogen atom of a substituted amino group or a group bonded with a group to which a substituted amino group is bonded. The group to which the substituted amino group is bonded is preferably a π-conjugated group. More preferred are groups bonded at the nitrogen atom of the substituted amino group.
Particularly preferred as the donor group in the present invention is a substituted or unsubstituted carbazole-9-yl group. It is preferable that the 1 to 3 donor groups D present in the general formula (1) are independently substituted or unsubstituted carbazole-9-yl groups. The substituent of the carbazole-9-yl group includes an alkyl group, an alkenyl group, an aryl group, a heteroaryl group, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, a heteroaryloxy group, a heteroarylthio group and a substituted amino. A group can be mentioned, and preferred substituents include an alkyl group, an aryl group, and a substituted amino group. For the description and preferred range of the substituents referred to herein, the description of the substituent of D'and the preferred range can be referred to. Further, the substituted amino group referred to here includes a substituted or unsubstituted carbazolyl group, and particularly includes a substituted or unsubstituted carbazole-9-yl group and a substituted or unsubstituted carbazole-3-yl group.
The donor group in the present invention preferably has 5 or more atoms other than hydrogen atoms, preferably 10 or more, and more preferably 13 or more. Further, it is preferably 80 or less, more preferably 60 or less, and further preferably 40 or less.

Hereinafter, specific examples of the donor group D that can be taken ^{by R 1} to R ⁴ of the general formula (1) are shown. The wavy line indicates the position where D joins. Among the following D1 to D20, D1 to D9 are preferable, and D1 to D4 are more preferable.

^{Of R 1} to R ⁴ of the general formula (1), those that are neither D nor D'are hydrogen atoms. The number of hydrogen atoms is 0 to 2, and may be 0 or 1. In a preferred embodiment of the present invention, ^{none of R 1} to R ⁴ is a hydrogen atom (the number of hydrogen atoms is 0).

The patterns of CN, Ar, D, and D'bonded to the central benzene ring of the general formula (1) are exemplified below as types 1 to 20.

Types

1 and 2 have 3 D and 1 D'pattern, types 3 and 6 have 2 D and 2 D'patterns, and types 7 and 8 have 1 D. D'is a pattern with 3 pieces, types 9 to 14 have 2 D's and 1 D'and 1 hydrogen atom, and types 15 to 20 have 1 D and 2'. It is a pattern with one hydrogen atom. A pattern in which a hydrogen atom is replaced with a deuterium atom can also be mentioned. Of the types 1 to 20, types 1 to 8 are preferable, and types 1 to 6 are more preferable.

In a preferred embodiment of the present invention, the compound represented by the general formula (1) is composed only of an atom selected from the group consisting of a carbon atom, a hydrogen atom, a nitrogen atom, an oxygen atom and a sulfur atom. In a preferred embodiment of the present invention, the compound represented by the general formula (1) is composed only of a carbon atom, a hydrogen atom, a nitrogen atom and an oxygen atom.

Hereinafter, specific examples of the compound represented by the general formula (1) will be shown.

The molecular weight of the compound represented by the general formula (1) is, for example, 1500 or less when the organic layer containing the compound represented by the general formula (1) is intended to be formed into a film by a vapor deposition method. It is preferably 1200 or less, 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 the general formula (1).
The compound represented by the general formula (1) may be formed into a film by a coating method regardless of the molecular weight. By using the coating method, it is possible to form a film even if the compound has a relatively large molecular weight. The compound represented by the general formula (1) has an advantage that it is easily dissolved in an organic solvent among the cyanobenzene compounds. Therefore, the compound represented by the general formula (1) is easy to apply the coating method and is easy to purify to increase the purity.

It is also conceivable to apply the present invention to obtain a compound containing a plurality of structures represented by the general formula (1) in the molecule.
For example, it is conceivable to use a polymer obtained by pre-existing a polymerizable group in the structure represented by the general formula (1) and polymerizing the polymerizable group as a light emitting material. ^{Specifically, a monomer containing a polymerizable functional group is prepared in any of R 1} to R ⁴ and Ar of the general formula (1), and this is polymerized alone or copolymerized with another monomer. Therefore, it is conceivable to obtain a polymer having a repeating unit and use the polymer as a light emitting material. Alternatively, it is also conceivable to obtain dimers and trimers by coupling compounds having a structure represented by the general formula (1) to each other and use them as a light emitting material.

As an example of a polymer having a repeating unit containing a structure represented by the general formula (1), a polymer containing a structure represented by the following general formula (2) or (3) can be mentioned.

In the general formula (2) or (3), Q represents a group containing the structure represented by the general formula (1), and L ¹ and L ² represent a linking group. The carbon number of the linking group is preferably 0 to 20, more preferably 1 to 15, and even more preferably 2 to 10. And preferably has a structure represented by - linking group ^-X 11 ^{-L 11.} Here, X ¹¹ represents an oxygen atom or a sulfur atom, and is preferably an oxygen atom. L ¹¹ represents a linking group, preferably a substituted or unsubstituted alkylene group, or a substituted or unsubstituted arylene group, and is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkylene group. It is more preferably a phenylene group.
In the general formula (2) or (3), R ¹⁰¹ , R ¹⁰² , R ¹⁰³ and R ¹⁰⁴ each independently represent a substituent. It is 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, and 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 and a chlorine atom, and more preferably an unsubstituted alkyl group having 1 to 3 carbon atoms and an unsubstituted alkoxy group having 1 to 3 carbon atoms.
The ^{linking group represented by L 1} and L ² can be bonded to any ^{of R 1} to R ⁴ and Ar of the general formula (1) constituting Q. Two or more linking groups may be linked to one Q to form a crosslinked structure or a network structure.

As a specific structural example of the repeating unit, the structures represented by the following equations (4) to (7) can be mentioned.

In the polymer having a repeating unit containing these formulas (4) to (7), a ^{hydroxy group is introduced into any of R 1} to R ⁴ and Ar of the general formula (1), and the polymer is used as a linker as described below. It can be synthesized by reacting a compound to introduce a polymerizable group and polymerizing the polymerizable group.

The polymer containing the structure represented by the general formula (1) in the molecule may be a polymer consisting only of repeating units having the structure represented by the general formula (1), or may have other structures. It may be a polymer containing a repeating unit having. Further, the repeating unit having the structure represented by the general formula (1) contained in the polymer may be a single type or two or more types. Examples of the repeating unit having no structure represented by the general formula (1) include those derived from a monomer used for ordinary copolymerization. For example, a repeating unit derived from a monomer having an ethylenically unsaturated bond such as ethylene and styrene can be mentioned.

In certain embodiments, the compound represented by the general formula (1) is a light emitting material.
In certain embodiments, the compound represented by the general formula (1) is a compound capable of emitting delayed fluorescence.
In one embodiment of the present disclosure, the compound represented by the general formula (1) is in the UV region, the blue, green, yellow, orange, red region of the visible spectrum when excited by thermal or electronic means. It can emit light (eg, about 420 nm to about 500 nm, about 500 nm to about 600 nm or about 600 nm to about 700 nm) or in the near infrared region.
In certain embodiments of the present disclosure, the compound of the general formula (1), when excited by thermal or electronic means, is in the red or orange region of the visible spectrum (eg, from about 620 nm to about 780 nm, about 780 nm). It can emit light at 650 nm).
In certain embodiments of the present disclosure, the compound of the general formula (1), when excited by thermal or electronic means, has an orange or yellow region of the visible spectrum (eg, from about 570 nm to about 620 nm, about 620 nm). It can emit light at 590 nm (about 570 nm).
In certain embodiments of the present disclosure, the compound of the general formula (1), when excited by thermal or electronic means, is in the green region of the visible spectrum (eg, from about 490 nm to about 575 nm, about 510 nm). Can emit light.
In certain embodiments of the present disclosure, the compound of the general formula (1), when excited by thermal or electronic means, is in the blue region of the visible spectrum (eg, from about 400 nm to about 490 nm, about 475 nm). Can emit light.
In certain embodiments of the present disclosure, the compound represented by the general formula (1) can emit light in the ultraviolet spectral region (eg, 280-400 nm) when excited by thermal or electronic means.
In certain embodiments of the present disclosure, the compound represented by the general formula (1) can emit light in the infrared spectral region (eg, 780 nm to 2 μm) when excited by thermal or electronic means.

The electronic properties of small molecule chemical libraries can be calculated using known ab initio quantum chemistry calculations. For example, the Hartree-Fock equation using a time-dependent density functional theory with a set of functions known as the 6-31G * and Becke's three parameters, the Lee-Yang-Parr hybrid functional theory, as the basis. (TD-DFT / B3LYP / 6-31G *) can be analyzed to screen molecular fragments (parts) with HOMO above a specific threshold and LUMO below a specific threshold, and the calculated triplet of that part. The term state is over 2.75 eV.
Thereby, for example, when there is HOMO energy (for example, ionization potential) of −6.5 eV or more, the donor portion (“D”) can be selected. Further, for example, when there is LUMO energy (for example, electron affinity) of −0.5 eV or less, the receptor moiety (“A”) can be selected. The bridge moiety (“B”) is, for example, a strong conjugated system that can severely limit the acceptor and donor moieties to specific conformations, resulting in overlap between the π-conjugated system of the donor and acceptor moieties. To prevent.
In certain embodiments, compound libraries are sorted using one or more of the following properties:
1. 1. Emission near a specific wavelength 2. Calculated triplet state above a specific energy level 3. Delta] E _ST value 4 below a certain value. Quantum yield above a specific value 5. HOMO level 6. The LUMO level certain embodiments, the difference between the lowest triplet excited state of the singlet excited state and the lowest in the 77K (ΔE _ST) 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 Delta] E _ST value some embodiments, 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 0.03eV , Less than about 0.02 eV or less than about 0.01 eV.
In certain embodiments, the compound represented by the general formula (1) is in excess of 25%, eg, 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 higher quantum yields.

[Method for synthesizing a compound represented by the general formula (1)]
The compound represented by the general formula (1) is a novel compound.
The compound represented by the general formula (1) can be synthesized by combining known reactions. For example, in the synthesis of a compound in which Ar is a hydrogen atom, DH is reacted with 2,3,5,6-tetrafluorinated cyanobenzene in dimethylformamide (DMF) to which potassium carbonate is added, and then D'-H is further synthesized. Can be synthesized by reacting with. Further, the reaction order of DH and D'H may be reversed, and D'H may be reacted first, and then DH may be reacted. The synthesis of a compound in which Ar is not a hydrogen atom can be carried out by changing the starting material to 2,3,5,6-tetrafluorocyanobenzene substituted with Ar at the 4-position. For specific reaction conditions and reaction procedures, the synthetic examples described below can be referred to.

[Constituent using a compound represented by the general formula (1)]
In certain embodiments, it is combined with a compound represented by the general formula (1), the compound is dispersed, covalently bonded to the compound, coated with the compound, carried or associated with the compound 1. Used with one or more materials (eg, small molecules, polymers, metals, metal complexes, etc.) to form solid films or layers. For example, the compound represented by the general formula (1) can be combined with an electrically active material to form a film. In some cases, the compound represented by the general formula (1) may be combined with the hole transport polymer. In some cases, the compound represented by the general formula (1) may be combined with the electron transport polymer. In some cases, the compound represented by the general formula (1) may be combined with the hole transport polymer and the electron transport polymer. In some cases, the compound represented by the general formula (1) may be combined with a copolymer having both a hole transport part and an electron transport part. According to the above embodiment, the electrons and / or holes formed in the solid film or layer can interact with the compound represented by the general formula (1).

[Film formation]
In certain embodiments, the film containing the compound of the present invention represented by the general formula (1) can be formed by a wet step. In the wet step, a solution containing the composition containing the compound of the present invention is applied to the surface, and a film is formed after removing the solvent. Examples of the wet process include, but are not limited to, a spin coating method, a slit coating method, an inkjet method (spray method), a gravure printing method, an offset printing method, and a flexographic printing method. In the wet step, an appropriate organic solvent capable of dissolving the composition containing the compound of the present invention is selected and used. In certain embodiments, a substituent (eg, an alkyl group) that increases the solubility in an organic solvent can be introduced into the compound contained in the composition.
In certain embodiments, the film containing the compound of the invention can be formed in a dry process. In certain embodiments, the vacuum deposition method can be employed as the dry process, without limitation. When the vacuum vapor deposition method is adopted, the compounds constituting the film may be co-deposited from individual vapor deposition sources, or may be co-deposited from a single vapor deposition source in which the compounds are mixed. When a single vapor deposition source is used, a mixed powder in which a powder of the compound is mixed may be used, a compression molded product obtained by compressing the mixed powder may be used, or each compound is heated and melted and cooled. A mixture may be used. In one embodiment, the composition ratio of the plurality of compounds contained in the vapor deposition source is obtained by performing co-evaporation under the condition that the vapor deposition rates (weight reduction rates) of the plurality of compounds contained in a single vapor deposition source are the same or almost the same. It is possible to form a film having a composition ratio corresponding to the above. If a plurality of compounds are mixed at the same composition ratio as the composition ratio of the film to be formed and used as a vapor deposition source, a film having a desired composition ratio can be easily formed. In one embodiment, a temperature at which each compound to be co-deposited has the same weight loss rate can be specified, and that temperature can be adopted as the temperature at the time of co-depositing.

[Example of use of compound represented by general formula (1)]
Organic light emitting diode:
One aspect of the present invention relates to the use of a compound represented by the general formula (1) of the present invention as a light emitting material for an organic light emitting device. In certain embodiments, the compound represented by the general formula (1) of the present invention can be effectively used as a light emitting material in the light emitting layer of the organic light emitting device. In certain embodiments, the compound represented by the general formula (1) comprises delayed fluorescence (delayed fluorescent material) that emits delayed fluorescence. In certain embodiments, the present invention provides a delayed fluorophore having a structure represented by the general formula (1). In certain embodiments, the present invention relates to the use of a compound represented by the general formula (1) as a delayed fluorophore. In certain embodiments, the compound of the present invention is represented by the general formula (1), which can be used as a host material and can be used with one or more light emitting materials, wherein the light emitting material is a fluorescent material. It may be a phosphorescent material or TADF. In certain embodiments, the compound represented by the general formula (1) can also be used as a hole transport material. In certain embodiments, the compound represented by the general formula (1) can be used as an electron transporting material. In certain embodiments, the present invention relates to a method of causing delayed fluorescence from a compound represented by the general formula (1). In certain embodiments, the organic light emitting element containing the compound as a light emitting material emits delayed fluorescence and exhibits high light emission efficiency.
In certain embodiments, the light emitting layer comprises a compound represented by the general formula (1), the compound represented by the general formula (1) being oriented parallel to the substrate. In certain embodiments, the substrate is a film-forming surface. In certain embodiments, the orientation of the compound represented by the general formula (1) with respect to the film-forming surface affects or determines the direction of propagation of the light emitted by the compound to be aligned. In certain embodiments, the efficiency of light extraction from the light emitting layer is improved by aligning the propagation directions of the light emitted by the compound represented by the general formula (1).
One aspect of the present invention relates to an organic light emitting device. In certain embodiments, the organic light emitting device comprises a light emitting layer. In certain embodiments, the light emitting layer comprises a compound represented by the general formula (1) as a light emitting material. In one embodiment, the organic light emitting device is an organic light luminescence device (organic PL element). In certain embodiments, the organic light emitting device is an organic electroluminescence device (organic EL device). In certain embodiments, the compound represented by the general formula (1) assists the light emission of other light emitting materials contained in the light emitting layer (as a so-called assist dopant). In one embodiment, the compound represented by the general formula (1) contained in the light emitting layer is at its lowest excited singlet energy level and with the lowest excited singlet energy level of the host material contained in the light emitting layer. It is included between the lowest excited singlet energy levels of other light emitting materials contained in the light emitting layer.
In certain embodiments, the organic light luminescence device comprises at least one light emitting layer. In certain embodiments, the organic electroluminescence device comprises at least an anode, a cathode, and an organic layer between the anode and the cathode. In certain embodiments, the organic layer comprises at least a light emitting layer. In certain embodiments, the organic layer comprises only a light emitting layer. In certain embodiments, the organic layer comprises one or more organic layers in addition to the light emitting layer. Examples of the organic layer include a hole transport layer, a hole injection layer, an electron barrier layer, a hole barrier layer, an electron injection layer, an electron transport layer and an exciton barrier layer. In certain 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. An example of an organic electroluminescence device is shown in FIG.

Light emitting layer:
In one embodiment, the light emitting layer is a layer in which holes and electrons injected from the anode and cathode, respectively, recombine to form excitons. In certain embodiments, the layer emits light.
In certain embodiments, only the light emitting material is used as the light emitting layer. In certain embodiments, the light emitting layer comprises a light emitting material and a host material. In certain embodiments, the light emitting material is one or more compounds of the general formula (1). In one embodiment, singlet and triplet exciters generated in a light emitting material are confined in the light emitting material in order to improve the light emission efficiency of the organic electroluminescence element and the organic photoluminescence element. In certain embodiments, a host material is used in addition to the light emitting material in the light emitting layer. In certain embodiments, the host material is an organic compound. In certain embodiments, the organic compound has an excited singlet energy and an excited triplet energy, at least one of which is higher than those of the light emitting materials of the present invention. In certain embodiments, the singlet and triplet excitons generated in the luminescent material of the invention are confined in the molecule of the luminescent material of the invention. In certain embodiments, singlet and triplet excitons are sufficiently confined to improve photoradiation efficiency. In certain embodiments, singlet and triplet excitons are not sufficiently confined, even though high photoradiation efficiency is still obtained, i.e., host materials capable of achieving high photoradiation efficiency are particularly limited. Can be used in the present invention without any need. In certain embodiments, light emission occurs in the light emitting material in the light emitting layer of the device of the present invention. In certain embodiments, the emitted light comprises both fluorescence and delayed fluorescence. In certain embodiments, the radiated light includes radiated light from the host material. In one embodiment, the radiated light consists of synchrotron radiation from the host material. In certain embodiments, the synchrotron radiation includes synchrotron radiation from a compound represented by the general formula (1) and synchrotron radiation from a host material. In certain embodiments, TADF molecules and host materials are used. In certain embodiments, TADF is an assist dopant.

When the compound represented by the general formula (1) is used as an assist dopant, various compounds can be adopted as a light emitting 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, stylben derivatives, fluorene derivatives, anthryl derivatives, pyrromethene derivatives, and terphenyl derivatives. , Turphenylene derivatives, fluoranthene derivatives, amine derivatives, quinacridone derivatives, oxadiazole derivatives, malononitrile derivatives, pyran derivatives, carbazole derivatives, durolysin derivatives, thiazole derivatives, derivatives having metals (Al, Zn), etc. can be used. be. These exemplary skeletons may or may not have substituents. Further, these exemplary skeletons may be combined with each other.
In the following, a light emitting material that can be used in combination with the assist dopant represented by the general formula (1) will be illustrated.

Further, the compound described in paragraphs 0220 to 0239 of WO2015 / 022974 can also be particularly preferably adopted as a light emitting material used together with the assist dopant represented by the general formula (1).

In certain embodiments, when the host material is used, the amount of the compound of the present invention as the light emitting material contained in the light emitting layer is 0.1% by weight or more. In certain embodiments, when the host material is used, the amount of the compound of the present invention as the light emitting material contained in the light emitting layer is 1% by weight or more. In certain embodiments, when the host material is used, the amount of the compound of the present invention as the light emitting material contained in the light emitting layer is 50% by weight or less. In certain embodiments, when the host material is used, the amount of the compound of the present invention as the light emitting material contained in the light emitting layer is 20% by weight or less. In certain embodiments, when the host material is used, the amount of the compound of the present invention as the light emitting material contained in the light emitting layer is 10% by weight or less.
In certain embodiments, the host material of the light emitting layer is an organic compound having a hole transport function and an electron transport function. In certain embodiments, the host material for the light emitting layer is an organic compound that prevents the wavelength of the synchrotron radiation from increasing. In certain embodiments, the host material for the light emitting layer is an organic compound with a high glass transition temperature.

In some embodiments, the host material is selected from the group consisting of:

In certain embodiments, the light emitting layer comprises two or more differently structured TADF molecules. For example, a light emitting layer containing these three materials in which the excited singlet energy level is higher in the order of the host material, the first TADF molecule, and the second TADF molecule can be obtained. At this time, the 1TADF molecule with a 2TADF molecule is preferably both a difference Delta] E _ST of the lowest excited triplet energy level of the lowest excited singlet energy level and 77K or less 0.3 eV, below 0.25eV It is more preferably 0.2 eV or less, more preferably 0.15 eV or less, further preferably 0.1 eV or less, still more preferably 0.07 eV or less. , 0.05 eV or less, even more preferably 0.03 eV or less, and particularly preferably 0.01 eV or less. The content of the first TADF molecule in the light emitting layer is preferably higher than the content of the second TADF molecule. Further, the content of the host material in the light emitting layer is preferably higher than the content of the second TADF molecule. The content of the first TADF molecule in the light emitting layer may be higher, lower, or the same as the content of the host material. In certain embodiments, the composition in the light emitting layer may be 10 to 70% by weight of the host material, 10 to 80% by weight of the first TADF molecule, and 0.1 to 30% by weight of the second TADF molecule. In certain embodiments, the composition in the light emitting layer may be 20 to 45% by weight of the host material, 50 to 75% by weight of the first TADF molecule, and 5 to 20% by weight of the second TADF molecule. In one embodiment, the emission quantum yield φPL1 (A) by photoexcitation of the co-deposited film of the first TADF molecule and the host material (the content of the first TADF molecule in this co-deposited film = A% by weight), and the second TADF molecule and the host. The emission quantum yield φPL2 (A) due to photoexcitation of the co-deposited film of the material (content of the second TADF molecule in this co-deposited film = A% by weight) satisfies the relational expression of φPL1 (A)> φPL2 (A). In one embodiment, the emission quantum yield φPL2 (B) by photoexcitation of the co-deposited film of the second TADF molecule and the host material (content of the second TADF molecule in this co-deposited film = B wt%) and the second TADF molecule alone. The emission quantum yield φPL2 (100) due to photoexcitation of the film satisfies the relational expression of φPL2 (B)> φPL2 (100). In certain embodiments, the light emitting layer can contain three structurally different TADF molecules. The compound of the present invention may be any of a plurality of TADF compounds contained in the light emitting layer.
In certain 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 certain embodiments, the light emitting layer is free of metallic elements. In certain embodiments, the light emitting layer can be composed of a material composed only of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms and sulfur atoms. Alternatively, the light emitting layer may be composed of a material composed 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 paragraphs 0008 to 0048 and 0995 to 0133 of WO2013 / 154064, paragraphs 0007 to 0047 and 0073 to 985 of WO2013 / 011954, and paragraphs 0007 to 0033 and 0059 to 0066 of WO2013 / 01955. , WO 2013/081088, paragraphs 0008 to 0071 and 0118 to 0133, Japanese Patent Laid-Open No. 2013-256490, paragraphs 0009 to 0046 and 093 to 0134, Japanese Patent Laid-Open No. 2013-116975, paragraphs 0008 to 0020 and 0038 to 0040. Paragraphs 0007 to 0032 and 0079 to 0084 of WO2013 / 133359A, paragraphs 0008 to 0054 and 0101 to 0121 of WO2013 / 161437, paragraphs 0007 to 0041 and 0060 to 0069 of JP-A-2014-9352, JP-A-2014. -Paragraphs 0008 to 0048 and 0067 to 0076 of JP-A-9224, paragraphs 0013-0025 of JP-A-2017-119663, paragraphs 0013-0026-0026 of JP-A-2017-119664, paragraphs 0012 of JP-A-2017-22623. -0025, paragraphs 0010 to 0050 of JP-A-2017-226838, paragraphs 0012-0043 of JP-A-2018-1441, paragraphs 0016-0044 of JP-A-2018 / 047853, compounds included in the general formula. In particular, exemplary compounds include those capable of emitting delayed fluorescence. Further, here, Japanese Patent Laid-Open Nos. 2013-253121, WO2013 / 133359, WO2014 / 034535, WO2014 / 115743, WO2014 / 122895, WO2014 / 126200, WO2014 / 136758, WO2014. / 133121, WO2014 / 136860, WO2014 / 196585, WO2014 / 189122, WO2014 / 168101, WO2015 / 008580, WO2014 / 203840, WO2015 / 002213, WO2015 / 016200 Publication No. WO2015 / 019725, WO2015 / 072470, WO2015 / 108049, WO2015 / 080182, WO2015 / 072537, WO2015 / 080183, JP2015-129240, WO2015 / 129714 Publication, WO2015 / 129715, WO2015 / 133501, WO2015 / 136880, WO2015 / 137244, WO2015 / 137202, WO2015 / 137136, WO2015 / 146541, WO2015 / 159541. Among the light emitting materials described in the above, those capable of emitting delayed fluorescence can be preferably adopted. The above publications described in this paragraph are hereby incorporated herein by reference.

Hereinafter, each member of the organic electroluminescence element and each layer other than the light emitting layer will be described.

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

anode:
In some embodiments, the anode of an organic electroluminescence device is manufactured from a metal, alloy, conductive compound or a combination thereof. In some embodiments, the metal, alloy or conductive compound has a high work function (4 eV or higher). In some embodiments, the metal is Au. In some embodiments, the conductive transparent material is selected from CuI, indium tin oxide (ITO), SnO ₂ and ZnO. In some embodiments, it uses an amorphous material capable of forming such _{_{IDIXO (In 2 O 3 -ZnO)}} , a transparent conductive film. In some embodiments, the anode is a thin film. In some embodiments, the thin film is made by vapor deposition 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 (eg, about 100 μm or larger), the pattern may be formed using a mask having a shape suitable for vapor deposition or sputtering on the electrode material. In some embodiments, when a coating material such as an organic conductive compound can be applied, a wet film forming method such as a printing method or a coating method is used. In some embodiments, when synchrotron radiation passes through the anode, the anode has a transmittance of greater than 10% and the anode has a sheet resistance of no more than a few hundred ohms per unit area. In some embodiments, the thickness of the anode is 10-1,000 nm. In some embodiments, the thickness of the anode is 10-200 nm. In some embodiments, the thickness of the anode will vary 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-injected metal), an alloy, a conductive compound or a combination thereof. In some embodiments, the electrode material is sodium, sodium-potassium alloy, magnesium, lithium, magnesium-copper mixture, magnesium-silver mixture, magnesium-aluminum mixture, magnesium-indium mixture, aluminum-aluminum oxide (Al _2). O ₃ ) Selected from mixtures, indium, lithium-aluminum mixtures and rare earth elements. In some embodiments, a mixture of the electron-injected metal and a second metal, which is a stable metal with a higher work function than the electron-injected 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 injection properties and resistance to oxidation. In some embodiments, the cathode is manufactured by forming the electrode material as a thin film by vapor deposition or sputtering. In some embodiments, the cathode has a sheet resistance of tens of ohms or less per unit area. In some embodiments, the cathode has a thickness of 10 nm to 5 μm. In some embodiments, the thickness of the cathode is 50-200 nm. In some embodiments, any one of the anode and cathode of the organic electroluminescence element is transparent or translucent in order to transmit synchrotron radiation. In some embodiments, the transparent or translucent electroluminescent device improves the light radiance.
In some embodiments, the cathode is formed of the conductive transparent material described above with respect to the anode to form a transparent or translucent cathode. In some embodiments, the device comprises an anode and a cathode, both of which are transparent or translucent.

Injection layer:
The injection layer is the layer between the electrode and the organic layer. In some embodiments, the injection layer reduces the drive voltage and enhances the light emission brightness. In some embodiments, the injection layer comprises a hole injection layer and an electron injection layer. The injection layer can be arranged between the anode and the light emitting layer or the hole transport layer, and between the cathode and the light emitting layer or the electron transport layer. In some embodiments, an injection layer is present. In some embodiments, there is no injection layer.
The following are examples of preferable compounds that can be used as hole injection materials.

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

Barrier layer:
The barrier layer is a layer capable of preventing charges (electrons or holes) and / or excitons present in the light emitting layer from diffusing outside the light emitting layer. In some embodiments, the electron barrier layer resides between the light emitting layer and the hole transport layer, preventing electrons from passing through the light emitting layer to the hole transport layer. In some embodiments, the hole barrier layer exists between the light emitting layer and the electron transport layer to prevent holes from passing through the light emitting layer to the electron transport layer. In some embodiments, the barrier layer prevents excitons from diffusing outside the light emitting layer. In some embodiments, the electron barrier layer and the hole barrier layer constitute an exciton barrier layer. As used herein, the term "electron barrier layer" or "exciton barrier layer" includes both an electron barrier layer and a layer having both the functions of an exciton barrier layer.

Hole barrier layer:
The hole barrier layer functions as an electron transport layer. In some embodiments, the hole barrier layer prevents holes from reaching the electron transport layer during electron transport. In some embodiments, the hole barrier layer increases the probability of electron-hole recombination in the light emitting layer. The material used for the hole barrier layer may be the same material as described above for the electron transport layer.
The following are examples of preferable compounds that can be used for the hole barrier layer.

Electronic barrier layer:
The electron barrier layer transports holes. In some embodiments, the electron barrier layer blocks electrons from reaching the hole transport layer during hole transport. In some embodiments, the electron barrier layer increases the probability of electron-hole recombination in the light emitting layer. The material used for the electron barrier layer may be the same material as described above for the hole transport layer.
Specific examples of preferable compounds that can be used as an electron barrier material are given below.

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

Hole transport layer:
The hole transport layer contains a hole transport material. In some embodiments, the hole transport layer is monolayer. In some embodiments, the hole transport layer has multiple layers.
In some embodiments, the hole transport material has one of the hole injection or transport properties and the electron barrier 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 are, but are not limited to, triazole derivatives, oxadiazole derivatives, imidazole derivatives, carbazole derivatives, indolocarbazole derivatives, polyarylalkane inducers, pyrazoline derivatives, pyrazolones. Derivatives, phenylenediamine derivatives, allylamine derivatives, amino-substituted calcon derivatives, oxazole derivatives, styrylanthracene inducers, fluorenone derivatives, hydrazone derivatives, stilben derivatives, silazane derivatives, aniline copolymers and conductive polymer oligomers (particularly thiophene oligomers), or combinations thereof. Can be mentioned. In some embodiments, the hole transport material is selected from porphyrin compounds, aromatic tertiary amine compounds and styrylamine compounds. In some embodiments, the hole transport material is an aromatic tertiary amine compound. Specific examples of preferable compounds that can be used as hole transport materials are given below.

Electron transport layer:
The electron transport layer contains 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 have the function of transporting the electrons injected from the cathode to the light emitting layer. In some embodiments, the electron transport material also functions as a hole barrier material. Examples of electron transport layers that can be used in the present invention are, but are not limited to, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbodiimides, fluorenylidene methane derivatives, anthracinodimethanes, antron derivatives, and oxadi. Examples thereof include azole derivatives, azole derivatives, azine derivatives or combinations thereof, or polymers thereof. In some embodiments, the electron transport material is a thiadiazole inducer or a quinoxaline derivative. In some embodiments, the electron transport material is a polymeric material. Specific examples of preferable compounds that can be used as electron transport materials are given below.

Further, examples of preferable compounds as materials that can be added to each organic layer are given. For example, it may be added as a stabilizing material.

Although preferred materials that can be used for organic electroluminescence devices have been specifically exemplified, the materials that can be used in the present invention are not limitedly interpreted by the following exemplified compounds. Further, even a compound exemplified as a material having a specific function can be diverted as a material having another function.

device:
In some embodiments, the light emitting layer is incorporated into the device. For example, devices include, but are not limited to, OLED valves, OLED lamps, television displays, computer monitors, mobile phones and tablets.
In some embodiments, the electronic device comprises an OLED having an anode, a cathode, and at least one organic layer comprising a light emitting layer between the anode and the cathode.
In some embodiments, the components described herein can be incorporated into a variety of photosensitive or photoactivating devices, such as OLEDs or optoelectronic devices. In some embodiments, the construct may be useful for facilitating charge transfer or energy transfer within the device and / or as a hole transport material. Examples of the device include an organic light emitting diode (OLED), an organic integrated line (OIC), an organic field effect transistor (O-FET), an organic thin film (O-TFT), an organic light emitting transistor (O-LET), and an organic solar cell. (O-SC), an organic optical detector, an organic photoreceiver, an organic field-quench device (O-FQD), a light emitting fuel cell (LEC) or an organic laser diode (O-laser).

Bulb or lamp:
In some embodiments, the electronic device comprises an OLED comprising an anode, a cathode, and at least one organic layer comprising a light emitting layer between the anode and the cathode.
In some embodiments, the device comprises an OLED of different colors. In some embodiments, the device comprises an array containing a combination of OLEDs. In some embodiments, the combination of OLEDs is a combination of three colors (eg RGB). In some embodiments, the combination of OLEDs is a combination of colors that are neither red nor green nor blue (eg, orange and yellow-green). In some embodiments, the combination of OLEDs is a combination of two colors, four colors or more.
In some embodiments, the device is
A circuit board having a first surface with a mounting surface and a second surface opposite the mounting surface and defining at least one opening.
A configuration in which at least one OLED on the mounting surface, wherein the at least one OLED comprises an anode, a cathode, and at least one organic layer including a light emitting layer between the anode and the cathode. With at least one OLED that has
The housing for the circuit board and
An OLED light comprising at least one connector located at the end of the housing, wherein the housing and the connector define a package suitable for mounting in lighting equipment.
In some embodiments, the OLED light has a plurality of OLEDs mounted on a circuit board such that light is emitted in multiple directions. In some embodiments, some light emitted in the first direction is polarized and emitted in the second direction. In some embodiments, a reflector is used to polarize 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 according to the invention are deposited onto a substrate using steps 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 in two-sided etching that provides pixels with a unique aspect ratio. The screen (also referred to as a mask) is used in the manufacturing process of an OLED display. The design of the corresponding artwork pattern allows the placement of very steep, narrow tie bars between pixels in the vertical direction, as well as large, wide-ranging bevel openings in the horizontal direction. This enables the fine pattern composition of pixels required for high resolution displays while optimizing chemical vapor deposition on the TFT backplane.
Pixel internal patterning makes it possible to construct 3D pixel openings with different aspect ratios in the horizontal and vertical directions. In addition, the use of imaged "stripe" or halftone circles in the pixel area protects the etching in the particular area until these particular patterns are undercut and removed from the substrate. At that time, all the pixel regions are processed at the same etching rate, but the depth varies depending on the halftone pattern. By changing the size and spacing of the halftone patterns, it is possible to etch with different protection rates within the pixel, allowing for the deep localized etching required to form steep vertical bevels. ..
The preferred material for the vapor deposition mask is Invar. Invar is a metal alloy that is cold-rolled in the form of a long thin sheet at a steel mill. Invar cannot be electrodeposited onto the spin mandrel as a nickel mask. A suitable and low-cost method for forming an opening region in a vapor deposition mask is a wet chemical etching method.
In some embodiments, the screen or display pattern is a pixel matrix on a substrate. In some embodiments, the screen or display pattern is processed using lithography (eg, photolithography and e-beam lithography). In some embodiments, the screen or display pattern is processed using wet chemical etching. In a further embodiment, the screen or display pattern is processed using plasma etching.

Device manufacturing method:
The OLED display is generally manufactured by forming a large mother panel and then cutting the mother panel in cell panel units. Normally, each cell panel on the mother panel forms a thin film transistor (TFT) having an active layer and a source / drain electrode on a base substrate, a flattening film is applied to the TFT, and a pixel electrode and a light emitting layer are applied. , The counter electrode and the encapsulating layer are formed in order over time, and are formed by cutting from the mother panel.
The OLED display is generally manufactured by forming a large mother panel and then cutting the mother panel in cell panel units. Normally, each cell panel on the mother panel forms a thin film transistor (TFT) having an active layer and a source / drain electrode on a base substrate, a flattening film is applied to the TFT, and a pixel electrode and a light emitting layer are applied. , The counter electrode and the encapsulating layer are formed in order over time, and are formed by cutting from the mother panel.

In another aspect of the invention, a method of manufacturing an organic light emitting diode (OLED) display is provided, wherein the method is:
The process of forming a barrier layer on the base base material of the mother panel,
A step of forming a plurality of display units on a cell panel unit on the barrier layer,
A step of forming an encapsulation layer on each of the display units of the cell panel,
A step of applying an organic film to the interface portion between the cell panels is included.
In some embodiments, the barrier layer is, for example, an inorganic film formed of SiNx, the ends of the barrier layer being coated with an organic film formed of polyimide or acrylic. In some embodiments, the organic film helps the mother panel to be softly cut in cell panel units.
In some embodiments, the thin film transistor (TFT) layer comprises a light emitting layer, a gate electrode, and a source / drain electrode. Each of the plurality of display units may have a thin film transistor (TFT) layer, a flattening film formed on the TFT layer, and a light emitting unit formed on the flattened film, and the interface portion may have a light emitting unit. The applied organic film is formed of the same material as the flattening film, and is formed at the same time as the flattening film is formed. In some embodiments, the light emitting unit is coupled to the TFT layer by a passivation layer, a flattening film in between, and an encapsulating layer that coats and protects the light emitting unit. In some embodiments of the manufacturing method, the organic film is not coupled to either the display unit or the encapsulation layer.

Each of the organic film and the flattening film may contain either polyimide or acrylic. In some embodiments, the barrier layer may be an inorganic film. In some embodiments, the base substrate may be made of polyimide. The method further comprises a step of attaching a carrier substrate made of a glass material to the other surface of the base substrate before forming a barrier layer on one surface of the base substrate made of polyimide. It may include a step of separating the carrier substrate from the base substrate prior to cutting along the interface portion. In some embodiments, the OLED display is a flexible display.
In some embodiments, the passivation layer is an organic film placed on the TFT layer for coating the TFT layer. In some embodiments, the flattening film is an organic film formed on the passivation layer. In some embodiments, the flattening film is made of polyimide or acrylic, similar to the organic film formed at the ends of the barrier layer. In some embodiments, the flattening film and the organic film are formed simultaneously during the manufacture of the OLED display. In some embodiments, the organic film may be formed at the edges of the barrier layer, whereby a portion of the organic film is in direct contact with the base substrate and the rest of the organic film is removed. , Surrounding the edge of the barrier layer and in contact with the barrier layer.

In some embodiments, the light emitting layer has a pixel electrode, a counter electrode, and an organic light emitting layer disposed between the pixel electrode and the counter electrode. In some embodiments, the pixel electrode is connected to a source / drain electrode in the TFT layer.
In some embodiments, when a voltage is applied to the pixel electrode through the TFT layer, an appropriate voltage is formed between the pixel electrode and the counter electrode so that the organic light emitting layer emits light, thereby the image. Is formed. Hereinafter, the image forming unit having the TFT layer and the light emitting unit will be referred to as a display unit.
In some embodiments, the encapsulation layer that covers the display unit and prevents the penetration of external moisture may be formed in a thin film encapsulation structure in which organic films and inorganic films are alternately laminated. In some embodiments, the encapsulation layer has a thin film encapsulation structure in which a plurality of thin films are laminated. In some embodiments, the organic film applied to the interface section is spaced apart from each of the plurality of display units. In some embodiments, the organic film is formed in such a manner that some of the organic films are in direct contact with the base substrate and the rest of the organic film surrounds the edges of the barrier layer while in contact with the barrier layer. Will be done.

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

In some embodiments, the manufacturing method further comprises the step of cutting along an interface portion, where a groove is formed in the barrier layer, at least a portion of the organic film is formed in the groove, and the groove is formed. Does not penetrate the base substrate. In some embodiments, a TFT layer of each cell panel is formed, and a passivation layer, which is an inorganic film, and a flattening film, which is an organic film, are placed on the TFT layer to cover the TFT layer. At the same time that a polyimide or acrylic flattening film is formed, for example, the groove of the interface portion is covered with an organic film made of polyimide or acrylic, for example. This prevents cracking by allowing the organic film to absorb the impact generated when each cell panel is cut along the groove at the interface section. That is, if all barrier layers are completely exposed without an organic film, there is a risk that when each cell panel is cut along the groove at the interface, the generated impact will be transmitted to the barrier layer, thereby causing cracks. Will increase. However, in one embodiment, the groove of the interface portion between the barrier layers is covered with an organic film to absorb the impact that can be transmitted to the barrier layer without the organic film, so that each cell panel is softly cut and the barrier layer is used. It may be prevented from cracking. In one embodiment, the organic film and the flattening film covering the grooves of the interface portion are arranged at intervals from each other. For example, when the organic film and the flattening film are interconnected as one layer, external moisture may infiltrate into the display unit through the flattening film and the portion where the organic film remains. The organic film and the flattening 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 the formation of a light emitting unit and the encapsulation layer is placed on the display unit to cover the display unit. As a result, after the mother panel is completely manufactured, the carrier base material that supports the base base material is separated from the base base material. In some embodiments, when the laser beam is radiated to the carrier substrate, the carrier substrate is separated from the base substrate due to the difference in the coefficient of thermal expansion between the carrier substrate and the base substrate.
In some embodiments, the mother panel is cut in cell panel units. In some embodiments, the mother panel is cut along the interface between the cell panels using a cutter. In some embodiments, the grooves in the interface section where the mother panel is cut are covered with an organic film so that the organic film absorbs the impact during cutting. In some embodiments, the barrier layer can be prevented from cracking during cutting.
In some embodiments, the method reduces the defective rate of the product and stabilizes its quality.
Another embodiment is a barrier layer formed on a base substrate, a display unit formed on the barrier layer, an encapsulating layer formed on the display unit, and an organic coating applied to the ends of the barrier layer. An OLED display with a film.

The features of the present invention will be described in more detail with reference to synthetic examples and examples below. The materials, treatment contents, treatment procedures, etc. shown below can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention should not be construed as limiting by the specific examples shown below. The emission characteristics are evaluated by a source meter (Caseley: 2400 series), a semiconductor parameter analyzer (Agilent Technology: E5273A), an optical power meter measuring device (Newport: 1930C), and an optical spectroscope. (Ocean Optics Co., Ltd .: USB2000), spectroradiometer (Topcon Co., Ltd .: SR-3) and streak camera (Hamamatsu Photonics Co., Ltd. C4334 type) were used.

(Synthesis Example 1) Synthesis of Compound 295 (1-1) Synthesis of Intermediate 1

DMF (80 mL) was added to 5.35 g (32.0 mmol) of 9H-carbazole and 6.22 g (45.0 mmol) of potassium carbonate under a nitrogen stream, and the mixture was stirred at room temperature for 1 hour. To the reaction mixture was added 1.75 g (10.0 mmol) of DMF solution (20 mL) of 2,3,5,6-tetrafluorobenzonitrile and stirred at 60 ° C. for 16 hours. The reaction solution was returned to room temperature, water was added, and the precipitate was filtered off. The filtrate was washed with methanol and vacuum dried. The residue was purified by silica gel column chromatography (hexane: chloroform = 1: 1) to obtain 2.48 g (4.03 mmol, yield 40%) of Intermediate 1 as a pale yellow solid.
¹ H NMR (400 MHz, CDCl ₃ , δ): 8.19 (d, J = 7.3 Hz, 2H), 8.07 (d, J = 9.6 Hz, 1H), 7.78-7.72 (m, 4H), 7.58 (t, J = 7.3 Hz, 2H), 7.44-7.40 (m, 4H), 7.18-7.04 (m, 12H)
APCI MS Spectrum Analysis: C ₄₃ H ₂₅ FN ₄ : Theoretical 616, Observed 617

(1-2) Synthesis of compound 295

DMF (15 mL) was added to 1.54 g (6.00 mmol) of 12H- [3,2-a] -benzoflocarbazole and 0.91 g (6.60 mmol) of potassium carbonate under a nitrogen stream, and the mixture was stirred at room temperature for 1 hour. .. The reaction mixture was added to a solution of Intermediate 1 (1.85 g, 3.00 mmol) in DMF (15 mL) at room temperature and stirred at 120 ° C. for 12 hours. The reaction solution was returned to room temperature, water was added, and the precipitate was filtered off. The filtrate was washed with methanol and vacuum dried. The crude product was purified by silica gel column chromatography (hexane: toluene = 1: 1) to obtain 2.48 g (2.90 mmol, 95% yield) of compound 295 as a pale yellow solid.
¹ H NMR (400 MHz, CDCl ₃ , δ): 8.36 (s, 1H), 7.83-7.58 (m, 10H), 7.45-7.32 (m, 5H), 7.20-7.09 (m, 9H), 7.06-6.97 (m, 3H), 6.92-6.88 (m, 2H), 6.84-6.76 (m, 2H), 6.58 (t, J = 7.3 Hz, 1H)
APCI MS Spectrum Analysis: C ₆₁ H ₃₅ N ₅ O Theoretical Value 853, Observed Value 854

(Synthesis Example 2) Synthesis of Compound 1174 (2-1) Synthesis of Intermediate 2

DMF (60 mL) was added to 4.88 g (19.0 mmol) of 12H- [3,2-a] -benzoflocarbazole and 3.16 g (22.8 mmol) of potassium carbonate under a nitrogen stream, and the mixture was stirred at room temperature for 1 hour. .. A DMF solution (16 mL) of 1.33 g (7.60 mmol) of 2,3,5,6-tetrafluorobenzonitrile was added to the reaction mixture, and the mixture was stirred at 60 ° C. for 20 hours. The reaction solution was returned to room temperature, water was added, and the precipitate was filtered off. The filtrate was washed with methanol and vacuum dried. The residue was purified by silica gel column chromatography (hexane: toluene = 3: 1-3: 2) to obtain 1.50 g (2.31 mmol, yield 30%) of Intermediate 2 as a pale yellow solid.
¹ H NMR (400 MHz, CDCl ₃ , δ): 8.27 (d, J = 8.2 Hz, 2H), 8.2 (d, J = 7.3 Hz, 2H), 7.73 (t, J = 8.2, 1H), 7.68 ( d, J = 8.7 Hz, 2H), 7.65 (d, J = 8.2 Hz, 2H), 7.51 (t, J = 7.3 Hz, 2H), 7.45 (t, J = 7.3 Hz, 2H), 7.36 (t, J = 7.3 Hz, 2H), 7.26 (s, 1H), 7.24, (s, 1H), 7.17 (d, J = 8.2 Hz, 2H), 6.83 (t, J = 7.3 Hz, 2H)
ASAP MS Spectral Analysis: C ₄₃ H ₂₅ FN ₄ : Theoretical 649.16, Observed 650.33

(2-2) Synthesis of compound 1174

DMF (15 mL) was added to 0.96 g (5.75 mmol) of 9H-carbazole and 0.95 g (6.90 mmol) of potassium carbonate under a nitrogen stream, and the mixture was stirred at room temperature for 1 hour. The reaction mixture was added to a solution of Intermediate 2 (1.49 g, 2.30 mmol) in DMF (18 mL) at room temperature and stirred at 120 ° C. for 12 hours. The reaction solution was returned to room temperature, water was added, and the precipitate was filtered off. The filtrate was washed with methanol and vacuum dried. The crude product was purified by silica gel column chromatography (hexane: toluene = 7: 3) to obtain 0.51 g (0.54 mmol, yield 23%) of compound 1174 as a pale yellow solid.
¹ H NMR (400 MHz, CDCl ₃ , δ): 8.40 (s, 1H), 7.82 (d, J = 8.2 Hz, 2H), 7.78-7.73 (m, 6H), 7.69-7.64 (m, 4H), 7.43 (t, J = 7.3 Hz, 2H), 7.36 (d, J = 8.2 Hz, 2H), 7.21-6.99 (m, 13H), 6.94 (t, J = 7.3 Hz, 2H), 6.87 (d, J) = 8.2 Hz, 2H), 6.61 (t, J = 8.2 Hz, 2H)
APCI MS Spectrum Analysis: C ₆₇ H ₃₇ N ₅ O ₂ Theoretical Value 943.29 Observed Value 944.53

(Synthesis Example 3) Synthesis of Compound 2 (3-1) Synthesis of Intermediate 3

DMF (150 mL) was added to 412 g (16.0 mmol) of 12H- [3,2-a] -benzoflocarbazole and 3.32 g (24.0 mmol) of potassium carbonate under a nitrogen stream, and the mixture was stirred at room temperature for 1 hour. .. To the reaction mixture was added 50 mL of a DMF solution of 3.50 g (20.0 mmol) of 2,3,5,6-tetrafluorobenzonitrile and stirred at 60 ° C. for 20 hours. The reaction solution was returned to room temperature, water was added, and the mixture was extracted with chloroform. The organic layer was washed with water, dried over anhydrous magnesium sulfate, and the solvent was distilled off. The residue was purified by silica gel column chromatography (hexane: toluene = 1: 1-7: 3) to obtain 1.46 g (3.53 mmol, yield 18%) of Intermediate 3 as a pale yellow solid.
¹ H NMR (400 MHz, CDCl ₃ , δ): 8.24 (d, J = 8.7 Hz, 2H), 8.18 (d, J = 8.2 Hz, 2H), 7.65 (d, J = 8.7 Hz, 1H), 7.63 (d, J = 8.2 Hz, 1H), 7.57 (q, J = 8.2 Hz, 1H), 7.47-7.38 (m, 3H), 7.12 (d, J = 8.2 Hz, 1H), 5.93 (t, J = 8.2 Hz, 1H),
ASAP MS Spectral Analysis: C ₂₅ H ₁₁ F ₃ N ₂ O: Theoretical value 412.08, Observed value 413.27

(3-2) Synthesis of compound 2

DMF (10 mL) was added to 1.63 g (9.75 mmol) of 9H-carbazole and 1.62 g (11.7 mmol) of potassium carbonate under a nitrogen stream, and the mixture was stirred at room temperature for 1 hour. The reaction mixture was added to a solution of Intermediate 3 (0.80 g, 1.95 mmol) in DMF (10 mL) at room temperature and stirred at 60 ° C. for 2 hours. Subsequently, the temperature was raised to 100 ° C. and the mixture was stirred for 15 hours. The reaction solution was returned to room temperature, water was added, and the precipitate was filtered off. The filtrate was dissolved in dichloromethane, methanol was added, the precipitate was collected by filtration and dried in vacuum. The crude product was purified by silica gel column chromatography (hexane: toluene = 2: 3) to obtain 1.35 g (1.58 mmol, yield 81%) of compound 2 as a pale yellow solid.
¹ H NMR (400 MHz, CDCl ₃ , δ): 8.46 (s, 1H), 7.87 (d, J = 8.7 Hz, 1H), 7.82-7.66 (m, 8H), 7.61 (t, J = 8.2 Hz, 1H), 7.48 (d, J = 8.2 Hz, 1H), 7.43-7.04 (m, 18H), 6.99 (d, J = 8.2 Hz, 1H), 6.95-6.88 (m, 3H), 6.56 (t, J) = 8.2 Hz, 1H)
ASAP MS Spectrum Analysis: C ₆₁ H ₃₅ N ₅ O Theoretical Value 853.28 Observed Value 854.52

(Examples 1 to 3, Comparative Example 1) Fabrication and evaluation of thin film ^{Compound 295 is vapor-deposited on a quartz substrate by a vacuum vapor deposition method under conditions of a vacuum degree of less than 1 × 10 -3} Pa, and consists of only compound 295. The thin film was formed to have a thickness of 100 nm and used as the neat thin film of Example 1. Separately, compound 295 and PYD2Cz or PPF are deposited from different vapor deposition sources on a quartz substrate by a vacuum vapor deposition method ^{under conditions of a vacuum degree of less than 1 × 10 -3 Pa, and the concentration of compound 295 is 20 weight.} A thin film of% was formed to have a thickness of 100 nm and used as a dope thin film of Example 1.
Using compound 1174, compound 2 and comparative compound 1 instead of compound 295, thin films of Example 2, Example 3 and Comparative Example 1 were obtained.
The characteristics of each of the obtained thin films were evaluated by irradiating them with 300 nm excitation light. The emission spectrum was observed using a neat thin film, and the peak wavelength (λ _max ) was read. In addition, the photoluminescence quantum efficiency (PLQY) was measured using a doped thin film, and the lifetime of delayed fluorescence (τ _d ) was obtained from the transient attenuation curve of light emission. Furthermore, the lowest excited singlet energy _{(E S1)} and the lowest excited triplet energy _{(E T1)} found through the following procedure _to obtain a Delta] E _ST by calculating E S1 _{-E T1.}
(1) Minimum excitation singlet energy ( _ES1 )
The fluorescence spectrum of the thin film was measured at room temperature (300 K) (vertical axis: emission intensity, horizontal axis: wavelength). A tangent line was drawn for the rising edge of the emission spectrum on the short wave side, and the wavelength value λedge [nm] at the intersection of the tangent line and the horizontal axis was obtained. The value obtained by converting this wavelength value into an energy value by the following conversion formula was defined as _ES1 .
Conversion _{formula: E S1 [eV] = 1239.85} / λedge
(2) Minimum excited triplet energy ( _ET1 )
The same thin film was cooled to 77 [K] with liquid nitrogen, the sample for phosphorescence measurement was irradiated with excitation light (300 nm), and phosphorescence was measured using a detector. The emission spectrum after 100 milliseconds after the irradiation with the excitation light was defined as the phosphorescence spectrum. A tangent line was drawn for the rising edge of the phosphorescence spectrum on the short wavelength side, and the wavelength value λedge [nm] at the intersection of the tangent line and the horizontal axis was obtained. The value obtained by converting this wavelength value into an energy value using the above conversion formula was defined as _ET1 .
The tangent to the rising edge of the phosphorescence spectrum on the short wavelength side was drawn as follows. When moving on the spectrum curve from the short wavelength side of the phosphorescence spectrum to the maximum value on the shortest wavelength side of the maximum values of the spectrum, tangents at each point on the curve were considered toward the long wavelength side. This tangent increases in slope as the curve rises (ie, as the vertical axis increases). The tangent line drawn at the point where the value of the slope reaches the maximum value was taken as the tangent line with respect to the rising edge of the phosphorescence spectrum on the short wavelength side.
The maximum point having a peak intensity of 10% or less of the maximum peak intensity of the spectrum is not included in the above-mentioned maximum value on the shortest wavelength side, and the value of the gradient closest to the maximum value on the shortest wavelength side is the maximum. The tangent line drawn at the point where the value was taken was taken as the tangent line to the rising edge of the phosphorescent spectrum on the short wavelength side.

The Delta] E _ST and the measured peak wavelength (lambda _max) using the neat thin film of Comparative Example 1 and Examples 1-3, delayed fluorescence using each two kinds of doped thin film of Comparative Example 1 and Examples 1-3 The lifetime (τ _d ) was measured. The results are shown in Table 2 below. Thin film of Example 1-3 as compared with the thin film of Comparative Example 1, both a small Delta] E _ST, delayed fluorescence lifetime (tau _d) is short.

(Examples 4 to 6, Comparative Example 2) Fabrication and evaluation of organic electroluminescence device Each thin film is vacuum-deposited on a glass substrate on which an anode made of indium tin oxide (ITO) having a film thickness of 100 nm is formed. The stacking was performed at a vacuum degree of 1 × 10 ^{-6 Pa.} First, a first hole injection layer made of a first hole injection material is formed on ITO, a second hole injection layer made of a second hole injection material is formed on the first hole injection layer, and hole transport is formed on the second hole injection layer. A hole transport layer made of a material was formed, and an electron blocking layer made of an electron blocking material was further formed on the hole transport layer. On it, compound 295 and the host material were co-deposited from different vapor deposition sources to form a light emitting layer having a concentration of compound 295 of 30% by weight. Next, a hole blocking layer made of a hole blocking material was formed, an electron transport layer was formed on the hole blocking layer, and an electrode was further formed on the electron transport layer. By the above procedure, the organic electroluminescence device of Example 4 was produced.
Further, using Compound 1174, Compound 2, and Comparative Compound 1 instead of Compound 295, the organic electroluminescence devices of Example 5, Example 6, and Comparative Example 2 were produced by the same procedure.
Each of the organic electroluminescence devices of Examples 4 to 6 exhibits high luminous efficiency, a low driving voltage, a long device life (device durability), and high heat resistance.
Further, by using other compounds of the present invention, it is possible to provide an organic electroluminescence device having the same effect.

According to the present invention, it is possible to provide an excellent light emitting material and an organic light emitting device using the same. Therefore, the present invention has high industrial applicability.

1 Base material 2 Anode 3 Hole injection layer 4 Hole transport layer 5 Light emitting layer 6 Electron transport layer 7 Cathode

Claims

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

[In the general formula (1)
Ar represents a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon ring group, or a substituted or unsubstituted aromatic heterocyclic group containing a nitrogen atom as a ring skeleton constituent atom.
1 to 3 of R 1 to R 4 each independently represent a carbazole-9-yl group D'(although the hydrogen atom may be substituted) in which a benzofuran ring is condensed.
1 to 3 of R 1 to R 4 are each independently a donor group D (however, a carbazole-9-yl group fused with a benzofuran ring, a substituted or unsubstituted aromatic hydrocarbon ring group, and a substituted or unsubstituted aromatic hydrocarbon ring group, and Represents a substituted or unsubstituted aromatic heterocyclic group containing a nitrogen atom as a ring skeleton constituent atom).
The remaining 0 to 2 R 1 to R 4 represent hydrogen atoms. ]
The compound according to claim 1, which has any of the following structures.
The compound according to claim 1, which has any of the following structures.
The compound according to claim 1, which has any of the following structures.
The compound according to claim 3 or 4, wherein a plurality of D'existing in the molecule have the same structure.
The compound according to claim 2 or 3, wherein a plurality of Ds existing in the molecule have the same structure.
The compound according to any one of claims 1 to 6, wherein D'is condensed with the carbazolyl-9-yl group in the furan ring of the benzofuran ring.
The compound according to claim 6, wherein D'has any of the following structures.

[Hydrogen atoms in each of the above structures may be substituted. ]
The compound according to any one of claims 1 to 8, wherein D is a substituted or unsubstituted carbazolyl-9-yl group (excluding those condensed with a benzofuran ring).
The compound according to any one of claims 1 to 9, wherein Ar is a hydrogen atom.
The compound according to any one of claims 1 to 10, wherein none of R 1 to R 4 is a hydrogen atom.
A luminescent material made of the compound according to any one of claims 1 to 11.
A light emitting device comprising the compound according to any one of claims 1 to 11.
The light emitting element according to claim 13, wherein the light emitting element has a light emitting layer, and the light emitting layer contains the compound and a host material.
The light emitting element according to claim 13, wherein the light emitting element has a light emitting layer, the light emitting layer contains the compound and the light emitting material, and mainly emits light from the light emitting material.