JP6249151B2 - Luminescent material and organic light emitting device using the same - Google Patents

Description

  The present invention relates to a light emitting material having high luminous efficiency and an organic light emitting device such as an organic electroluminescence device (organic EL device) using the same.

  Researches for increasing the light emission efficiency of organic light-emitting devices such as organic electroluminescence devices are being actively conducted. In particular, various efforts have been made to increase the light emission efficiency by newly developing and combining electron transport materials, hole transport materials, light emitting materials, and the like constituting the organic electroluminescence element. Among them, research on organic electroluminescence devices using compounds containing a carbazole structure or a 2,4,6-triphenyl-1,3,5-triazine structure can be found, and several proposals have been made so far. Has been made.

For example, Patent Document 1 describes that a compound having a structure represented by the following general formula is used as an electron transport material of an electron transport layer of an organic electroluminescence element. In the following general formula, n is 1 or 2, Ar is an arylene group or heteroarylene group, R ₃ and R ₄ are a hydrogen atom or an aryl group, and X _{1 to} X ₃ are ═CR— or ═ N-, R is a hydrogen atom or a substituent, and Cz is defined as a carbazolyl group.

As a compound represented by the above general formula, Patent Document 1 exemplifies Compound A having the following structure, and also describes an example of an organic electroluminescence device using the compound for an electron transport layer. However, no investigation has been made on compounds in which a substituent is introduced into the carbazolyl group of Compound A. Also, Patent Document 1 does not discuss the usefulness of Compound A as a light emitting material.

Patent Document 2 describes that a compound having a structure represented by the following general formula emits blue fluorescence, and that the compound is useful as a light emitting device material. In the following general formula, R ¹¹ and R ¹² are a hydrogen atom, an aliphatic hydrocarbon group, an aryl group or a heterocyclic group, R ¹ and R ² are substituents not containing a hydrogen atom or an amino group, and L Is defined as a linking group. Patent Document 2 describes that an organic light-emitting device using Compound A as a light-emitting material emits blue fluorescence. However, even in Patent Document 2, no study is made on a compound in which a substituent is introduced into the carbazolyl group of Compound A.

Patent Document 3 describes a compound having a partial structure in which three carbazole structures are linked, and an example in which a compound having such a partial structure is used as a host material of a light emitting layer of an organic light emitting device is specifically described. Have been described. In addition, as examples of compounds having a partial structure in which three carbazole structures are linked, compounds having the following structures are exemplified among many exemplified structures. However, there is no example using the compound, and there is no mention of the usefulness of the compound as a light emitting material.

JP 2009-21336 A JP 2002-193952 A WO2012 / 0797902

As described above, several studies have been made on compounds containing a carbazole structure and a 2,4,6-triphenyl-1,3,5-triazine structure, and there are few proposals for application to organic light-emitting devices. While being done. However, as in Patent Documents 1 to 3 above, there are many other documents that refer to compounds containing a carbazole structure and a 2,4,6-triphenyl-1,3,5-triazine structure. The usefulness of the entire group of compounds represented by a wide range of general formulas including these compounds is discussed, and in particular, both the carbazole structure and the 2,4,6-triphenyl-1,3,5-triazine structure The details are not examined by focusing on the compound group to be included. Therefore, in the research so far, the relationship between the chemical structure of the compound group including the carbazole structure and the 2,4,6-triphenyl-1,3,5-triazine structure and the usefulness of the compound as a light-emitting material is sufficient. It has not yet been elucidated, and it is difficult to predict the usefulness as a luminescent material based on the chemical structure. In particular, in Patent Documents 1 and 2, the usefulness of a compound as a light-emitting material has not been verified, so it is difficult to obtain suggestions regarding the usefulness as a light-emitting material based on these documents. Further, Patent Document 3 specifically describes the usefulness of Compound A as a luminescent material, but Compound A does not emit delayed fluorescence, and is sufficiently satisfactory in terms of luminous efficiency. is not.
In consideration of such problems, the present inventors have found that a compound containing a carbazole structure and a 2,4,6-triphenyl-1,3,5-triazine structure is useful as a light emitting material for an organic light emitting device. The study was advanced with the aim of evaluating the details in detail. In addition, a general formula of a compound that is particularly useful as a light-emitting material has been derived, and intensive studies have been conducted for the purpose of generalizing the structure of an organic light-emitting device having high luminous efficiency.

  As a result of diligent investigations to achieve the above object, the present inventors have obtained a compound containing a carbazole structure and a 2,4,6-triphenyl-1,3,5-triazine structure, which is a specific compound. It was clarified that a compound satisfying the structural condition is particularly useful as a light emitting material. Among them, an organic light emitting device having a high light emission efficiency has been found out that a compound containing a carbazole structure and a 2,4,6-triphenyl-1,3,5-triazine structure is useful as a delayed fluorescent material. It was clarified that can be provided at low cost. Based on these findings, the present inventors have provided the following present invention as means for solving the above problems.

［一般式（１）において、Ｒ¹〜Ｒ⁴は各々独立に置換もしくは無置換のカルバゾリル基、置換もしくは無置換のアリール基、置換もしくは無置換のヘテロアリール基、置換もしくは無置換のアルキル基、または置換もしくは無置換のシクロアルキル基を表し、
Ｒ⁵およびＲ⁶は各々独立に置換もしくは無置換のアルキル基を表し、
Ｒ⁷、Ｒ⁸およびＲ⁹は各々独立に置換もしくは無置換のアリール基、置換もしくは無置換のアルキル基、または置換もしくは無置換のカルバゾリル基を表し、
ｎ１〜ｎ４およびｎ７は各々独立に０〜４のいずれかの整数を表し、
ｎ５およびｎ６は０〜３のいずれかの整数を表し、
ｎ８およびｎ９は各々独立に０〜５のいずれかの整数を表す。
ｎ１〜ｎ９が２以上の整数であるとき、各ｎ１〜ｎ９に対応する複数のＲ¹〜Ｒ⁹はそれぞれ互いに同一であっても異なっていてもよい。］
［２］ 遅延蛍光を放射することを特徴とする［１］に記載の発光材料。
［３］ 一般式（１）におけるｎ１〜ｎ４の少なくとも１つが１〜４のいずれかの整数であることを特徴とする［１］または［２］に記載の発光材料。
［４］ 一般式（１）におけるｎ１〜ｎ４が各々独立に１〜４のいずれかの整数であることを特徴とする［１］または［２］に記載の発光材料。
［５］ 一般式（１）におけるＲ¹〜Ｒ⁴が各々独立に置換もしくは無置換の９−カルバゾリル基、置換もしくは無置換のフェニル基、置換もしくは無置換のピリジル基、炭素数１〜６のアルキル基、炭素数５〜７のシクロアルキル基であることを特徴とする［１］〜［４］のいずれか１項に記載の発光材料。
［６］ 一般式（１）におけるＲ¹〜Ｒ⁴が各々独立に９−カルバゾリル基、フェニル基、トリル基、ジメチルフェニル基、トリメチルフェニル基、ビフェニル基、ピリジル基、ピロリル基、tert−ブチル基、またはシクロヘキシル基であることを特徴とする［１］〜［４］のいずれか１項に記載の発光材料。
［７］ 一般式（１）におけるｎ５とｎ６がいずれも０であることを特徴とする［１］〜［６］のいずれか１項に記載の発光材料。
［８］ 一般式（１）におけるｎ７、ｎ８およびｎ９がいずれも０であることを特徴とする［１］〜［７］のいずれか１項に記載の発光材料。
［９］ 上記一般式（１）で表される構造を有する遅延蛍光体。
［１０］ 下記一般式（４）で表される化合物。

［一般式（４）において、Ｒ¹¹〜Ｒ¹⁴は各々独立に置換もしくは無置換のカルバゾリル基、置換もしくは無置換のアリール基、置換もしくは無置換のヘテロアリール基、置換もしくは無置換のアルキル基、または置換もしくは無置換のシクロアルキル基を表し、
Ｒ¹⁵およびＲ¹⁶は各々独立にアルキル基を表し、
Ｒ¹⁷、Ｒ¹⁸およびＲ¹⁹は各々独立に置換もしくは無置換のアリール基、置換もしくは無置換のアルキル基、または置換もしくは無置換のカルバゾリル基を表し、
ｎ１１〜ｎ１４およびｎ１７は各々独立に０〜４のいずれかの整数を表し、
ｎ１５およびｎ１６は０〜３のいずれかの整数を表し、
ｎ１８およびｎ１９は各々独立に０〜５のいずれかの整数を表す。
ただし、ｎ１１〜ｎ１４の少なくとも１つは１〜４のいずれかの整数である。
ｎ１１〜ｎ１９が２以上の整数であるとき、各ｎ１１〜ｎ１９に対応する複数のＲ¹¹〜Ｒ¹⁹はそれぞれ互いに同一であっても異なっていてもよい。］
［１１］ ［１］〜［８］のいずれか１項に記載の発光材料を含む発光層を基板上に有することを特徴とする有機発光素子。
［１２］ 遅延蛍光を放射することを特徴とする［１１］に記載の有機発光素子。
［１３］ 有機エレクトロルミネッセンス素子であることを特徴とする［１１］または［１２］に記載の有機発光素子。 [1] A light emitting material comprising a compound represented by the following general formula (1).

[In General Formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group, Or a substituted or unsubstituted cycloalkyl group,
R ⁵ and R ⁶ each independently represents a substituted or unsubstituted alkyl group,
R ⁷ , R ⁸ and R ⁹ each independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted carbazolyl group;
n1 to n4 and n7 each independently represents an integer of 0 to 4,
n5 and n6 represent any integer of 0 to 3,
n8 and n9 each independently represents an integer of 0 to 5.
When n1~n9 is an integer of 2 or more, plural R ¹ to R ⁹ for each n1~n9 may each also being the same or different. ]
[2] The luminescent material according to [1], which emits delayed fluorescence.
[3] The luminescent material according to [1] or [2], wherein at least one of n1 to n4 in the general formula (1) is an integer of 1 to 4.
[4] The luminescent material according to [1] or [2], wherein n1 to n4 in the general formula (1) are each independently an integer of 1 to 4.
[5] R ^{1 to} R ⁴ in the general formula (1) are each independently a substituted or unsubstituted 9-carbazolyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted pyridyl group, and those having 1 to 6 carbon atoms. The luminescent material according to any one of [1] to [4], which is an alkyl group or a cycloalkyl group having 5 to 7 carbon atoms.
[6] R ^{1 to} R ⁴ in the general formula (1) are each independently 9-carbazolyl group, phenyl group, tolyl group, dimethylphenyl group, trimethylphenyl group, biphenyl group, pyridyl group, pyrrolyl group, tert-butyl group. Or a cyclohexyl group, The light emitting material according to any one of [1] to [4].
[7] The light-emitting material according to any one of [1] to [6], wherein both n5 and n6 in the general formula (1) are 0.
[8] The luminescent material according to any one of [1] to [7], wherein n7, n8 and n9 in the general formula (1) are all 0.
[9] A delayed phosphor having a structure represented by the general formula (1).
[10] A compound represented by the following general formula (4).

[In the general formula (4), R ^{11 to} R ¹⁴ are each independently a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group, Or a substituted or unsubstituted cycloalkyl group,
R ¹⁵ and R ¹⁶ each independently represents an alkyl group;
R ¹⁷ , R ¹⁸ and R ¹⁹ each independently represent a substituted or unsubstituted aryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted carbazolyl group;
n11 to n14 and n17 each independently represents an integer of 0 to 4,
n15 and n16 represent any integer of 0 to 3,
n18 and n19 each independently represents an integer of 0 to 5.
However, at least one of n11 to n14 is any integer of 1 to 4.
When n11~n19 is an integer of 2 or more, plural R ¹¹ to R ¹⁹ corresponding to each n11~n19 it may or may not be the same as each other, respectively. ]
[11] An organic light emitting device comprising a light emitting layer containing the light emitting material according to any one of [1] to [8] on a substrate.
[12] The organic light-emitting device according to [11], which emits delayed fluorescence.
[13] The organic light-emitting device according to [11] or [12], which is an organic electroluminescence device.

  The organic light emitting device of the present invention is characterized by high luminous efficiency. In addition, the compound and the light emitting material of the present invention are effectively used for producing such an organic light emitting device. In particular, the delayed phosphor of the present invention has a feature that when used as a light emitting layer of an organic light emitting device, the organic light emitting device can emit delayed fluorescence and the luminous efficiency can be dramatically increased.

It is a schematic sectional drawing which shows the layer structural example of an organic electroluminescent element. 2 is an emission spectrum of an organic photoluminescence element and an organic electroluminescence element using Compound 1. 2 is a time-resolved spectrum of an organic electroluminescence device using Compound 1. 5 is a graph showing voltage-current density characteristics of an organic electroluminescence element using Compound 1. 4 is a graph showing current density-external quantum efficiency characteristics of an organic electroluminescence device using Compound 1. 2 is an emission spectrum of an organic photoluminescence device and an organic electroluminescence device using Compound 2. 2 is a time-resolved spectrum of an organic electroluminescence device using Compound 2. 3 is a graph showing voltage-current density characteristics of an organic electroluminescence device using Compound 2. 4 is a graph showing current density-external quantum efficiency characteristics of an organic electroluminescence device using Compound 2. 2 is an emission spectrum of an organic photoluminescence device and an organic electroluminescence device using Compound 3. 2 is a time-resolved spectrum of an organic electroluminescence device using Compound 3. 4 is a graph showing voltage-current density characteristics of an organic electroluminescence element using Compound 3. 4 is a graph showing current density-external quantum efficiency characteristics of an organic electroluminescence device using Compound 3. 2 is an emission spectrum of a toluene solution of Compound A. 2 is a time-resolved spectrum of a toluene solution of Compound A.

  Hereinafter, the contents of the present invention will be described in detail. The description of the constituent elements described below may be made 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 the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

[Compound represented by general formula (1)]
The luminescent material of the present invention is characterized by comprising a compound represented by the following general formula (1). In addition, the organic light-emitting device of the present invention includes a compound represented by the following general formula (1) as a light-emitting material of the light-emitting layer. Therefore, first, the compound represented by the general formula (1) will be described.

In the general formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group, or Represents a substituted or unsubstituted cycloalkyl group.
The binding position of the carbazolyl group herein may be any, but is preferably a 9-carbazolyl group or a 3-carbazolyl group, and more preferably a 9-carbazolyl group.
The aryl group may be a single ring or a fused ring, and preferably has 6 to 14 carbon atoms, more preferably 6 to 10 carbon atoms. A preferred specific example is a phenyl group.
The heteroaryl group may be a single ring or a fused ring, and the number of carbon atoms is preferably 2 to 12, more preferably 3 to 10, and still more preferably 3 to 6. Specific examples include a pyridyl group and a pyrrolyl group. Among them, a 1-pyridyl group, a 2-pyridyl group, a 3-pyridyl group, a 1-pyrrolyl group, a 2-pyrrolyl group, and a 3-pyrrolyl group are preferable. it can.
The alkyl group may be linear or branched, and the number of carbon atoms is preferably 1 to 12, more preferably 1 to 6, and still more preferably 1 to 4. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group, and among them, a tert-butyl group can be preferably exemplified.
The cycloalkyl group may be a single ring or a fused ring, and preferably has 5 to 12 carbon atoms, more preferably 5 to 7 carbon atoms. Specific examples include a cycloheptyl group, a cyclohexyl group, and a cycloheptyl group, and among them, a cyclohexyl group can be preferably exemplified.

The carbazolyl group, aryl group, heteroaryl group, alkyl group and cycloalkyl group that R ^{1 to} R ⁴ can have may each have a substituent. The substitution position and the number of substitutions when having a substituent are not particularly limited. The number of substitution of each group is preferably 0 to 6, more preferably 0 to 4, and for example, preferably 0 to 2. When having a plurality of substituents, they may be the same or different from each other, but are preferably the same. Examples of the substituent include a hydroxy group, a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkylthio group having 1 to 12 carbon atoms, and an alkyl-substituted amino group having 1 to 12 carbon atoms. Group, an acyl group having 2 to 12 carbon atoms, an aryl group having 6 to 14 carbon atoms, a heteroaryl group having 3 to 13 carbon atoms, a diarylamino group having 12 to 20 carbon atoms, a substituted or unsubstituted group having 12 to 20 carbon atoms Carbazolyl group, alkenyl group having 2 to 10 carbon atoms, alkynyl group having 2 to 10 carbon atoms, alkoxycarbonyl group having 2 to 10 carbon atoms, alkylsulfonyl group having 1 to 10 carbon atoms, haloalkyl group having 1 to 10 carbon atoms Amide group, C2-C10 alkylamide group, C3-C12 trialkylsilyl group, C4-C12 trialkylsilylalkyl group, carbon Number 5-14 trialkylsilyl alkenyl group, and the like trialkylsilyl alkynyl group and a nitro group 5 to 14 carbon atoms. Among these specific examples, those that can be substituted with a substituent may be further substituted. The carbazolyl group, aryl group, heteroaryl group, alkyl group, and cycloalkyl group that can be taken by R ¹ and R ^{2 in} the general formula (1) are preferably unsubstituted. An alkyl-substituted aryl group is also preferable, and examples thereof include a tolyl group, a dialkylphenyl group, and a trialkylphenyl group. More specifically, a 1-tolyl group, a 2-tolyl group, a 3-tolyl group, 2, Examples include 6-dimethylphenyl group, 2,4-dimethylphenyl group, and 2,4,6-trimethylphenyl group.

R ^{1 to} R ⁴ in the general formula (1) are each independently a substituted or unsubstituted 9-carbazolyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted pyridyl group, or an alkyl group having 1 to 6 carbon atoms. And a cycloalkyl group having 5 to 7 carbon atoms is preferable. R ^{1 to} R ⁴ are each independently 9-carbazolyl group, phenyl group, tolyl group, dimethylphenyl group, trimethylphenyl group, biphenyl group, pyridyl group, pyrrolyl group, tert-butyl group, or cyclohexyl group. Is more preferable.

N1 to n4 in the general formula (1) each independently represents an integer of 0 to 4, preferably represents an integer of 0 to 3, and represents an integer of 0 to 2. Is more preferable. When n1 is 2 or more, the plurality of R ¹ may be the same or different, and when n2 is 2 or more, the plurality of R ² may be the same or different. When n3 is 2 or more, the plurality of R ³ may be the same or different, and when n4 is 2 or more, the plurality of R ⁴ may be the same or different. n1 to n4 may be the same or different. When they are the same, for example, the case where all are 0, the case where all are 1, and the case where both are 2 can be exemplified. In the case where n1 and n3 are 1 and n2 and n4 are 0, n1 and n2 are 1 and n3 and n4 are 0. As for n1-n4 in General formula (1), it is preferable that at least 1 is an integer in any one of 1-4. It is also preferable that n1 to n4 are each independently an integer of 1 to 4.

In the general formula (1), when at least one of R ^{1 to} R ⁴ is present, the bonding position may be any of 1 to 8 positions of the carbazole ring. The 2nd to 7th positions are preferable, the 3, 4, 6, and 7 positions are more preferable, and the 3 and 6 positions are more preferable. For example, only the 3-position or when the R ¹ is attached, the 3-position when R ² is bonded to R ¹ are bonded to 6-position, 3-position when R ¹ and R ³ are bonded Another example is a case where R ¹ and R ³ are bonded to the ^3- position and R ² and R ⁴ are bonded to the 6-position. In the general formula (1), when two or more R ^{1 to} R ⁴ are present, they may be the same or different from each other.

In the general formula (1), R ⁵ and R ⁶ each independently represents a substituted or unsubstituted alkyl group. For the explanation and preferred range of the alkyl group, reference can be made to the explanation of the alkyl group that R ^{1 to} R ⁴ can take. For example, an unsubstituted alkyl group can be employed as R ⁵ and R ⁶ , or a methyl group can be preferably employed.
n5 represents any integer of 0 to 3, and n6 represents any integer of 0 to 4. n5 and n6 are each independently preferably 0 to 2, more preferably 0 or 1, and both are preferably 0. When n5 is 2 or more, the plurality of R ⁵ may be the same or different. When n6 is 2 or more, the plurality of R ⁶ may be the same or different. n5 and n6 may be the same or different. When they are the same, for example, when all are 0, a case where both are 1 can be preferably exemplified.
The substitution position when R ⁵ is present may be any position as long as it is not substituted with a carbazolyl group among the 1 to 4 positions of the carbazole ring. The substitution position when R ⁶ is present may be any position as long as it is not substituted with the carbazolyl group among the 5 to 8 positions of the carbazole ring. The carbazolyl group is preferably substituted at the 3-position and 6-position of the carbazole ring.

In the general formula (1), R ⁷ , R ⁸ and R ⁹ each independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted carbazolyl group. For descriptions and preferred ranges of the aryl group, alkyl group, carbazolyl group and substituent, the corresponding descriptions of R ^{1 to} R ⁴ can be referred to.
n7 represents any integer of 0 to 4, and n8 and n9 each independently represents an integer of 0 to 5. n7 is preferably 0 to 2, more preferably 0 or 1, and also preferably 0. n8 and n9 are preferably 0 to 2, and more preferably 0 or 1. When n7 is 2 or more, the plurality of R ⁷ may be the same or different, and when n8 is 2 or more, the plurality of R ⁸ may be the same or different. When n9 is 2 or more, the plurality of R ⁹ may be the same or different. n8 and n9 may be the same or different. When they are the same, for example, when all are 0, a case where both are 1 can be preferably exemplified. Moreover, when different, the case where n8 is 1 and n9 is 0 can be illustrated.
The substitution position when R ⁷ is present may be any position on the benzene ring. Further, when R ⁸ or R ⁹ is present, the substitution position may be any of the 2-6 positions.

Preferable specific examples of R ⁸ and R ^{9 in} the general formula (1) include a phenyl group, a tolyl group, a dimethylphenyl group, and a trimethylphenyl group. More specifically, a phenyl group, a 1-tolyl group, Examples include 2-tolyl group, 3-tolyl group, 2,6-dimethylphenyl group, 2,4-dimethylphenyl group, and 2,4,6-trimethylphenyl group. It is also preferred that R ⁸ and R ^{9 in} the general formula (1) are substituted or unsubstituted carbazolyl groups. At this time, the substituted or unsubstituted carbazolyl group is preferably bonded to the 4-position of the phenyl group bonded to the triazine ring. Further, examples of the substituted carbazolyl group mentioned here include a carbazolyl group substituted with a carbazolyl group. For example, the structure represented by the following general formula (2) can be preferably exemplified.

In the above formula, D1 to D3 each independently have a structure represented by the following general formula (3). However, D3 may be a hydrogen atom, a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkyl group. R ^{7 ′} , R ^{8 ′} and R ^{9 ′} each independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted alkyl group. n7 ′, n8 ′ and n9 ′ each independently represents an integer of 0 to 4.

For the definitions and preferred ranges of R ^{1 to} R ⁶ and n1 to n6 in the general formula (3), the corresponding explanation in the general formula (1) can be referred to.

  D1 and D2 in the general formula (2) may be the same or different. Moreover, when D3 also has a structure represented by the general formula (2), D1 to D3 may all be the same, or any two may be the same or all may be different. A compound in which all of D1 to D3 are the same has an advantage that it is easy to synthesize.

  Hereinafter, specific examples of the compound represented by the general formula (1) will be exemplified, but the compound represented by the general formula (1) that can be used in the present invention is limitedly interpreted by these specific examples. It shouldn't be.

  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 by vapor deposition. Preferably, it is preferably 1200 or less, more preferably 1000 or less, and even more preferably 800 or less. The lower limit of the molecular weight is 804 or more.

By applying the present invention, a compound containing a plurality of structures represented by the general formula (1) in the molecule may be used for the light emitting layer of the organic light emitting device.
For example, it is conceivable to use a polymer obtained by polymerizing a polymerizable monomer having a structure represented by the general formula (1) for a light emitting layer of an organic light emitting device. Specifically, a monomer having a polymerizable functional group is prepared in any ^one of R ^{1 to} R ^{9 in} the general formula (1), preferably any of R ^{1 to} R ⁴ , R ⁸ and R ^9. It is considered that a polymer having a repeating unit is obtained by polymerizing the polymer alone or with other monomers, and the polymer is used in the light emitting layer of the organic light emitting device. Alternatively, it is also conceivable that dimers and trimers are obtained by coupling compounds having a structure represented by the general formula (1) and used in the light emitting layer of the organic light emitting device.

As a structural example of the repeating unit constituting the polymer including the structure represented by the general formula (1), any ^one of R ^{1 to} R ^{9 in} the general formula (1), preferably R ^{1 to} R ⁴ , R ⁸ , One of R ⁹ is a structure represented by the following general formula (17) or (18).

In the general formulas (17) and (18), L ¹ and L ² represent a linking group. Carbon number of a coupling group becomes like this. Preferably it is 0-20, More preferably, it is 1-15, More preferably, it is 2-10. 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 a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, or a substituted or unsubstituted group A phenylene group is more preferable.
In the general formulas (17) and (18), R ¹⁰¹ , R ¹⁰² , R ¹⁰³ and R ¹⁰⁴ each independently represent a substituent. Preferably, it is a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, or a halogen atom, more preferably an unsubstituted alkyl group having 1 to 3 carbon atoms. An unsubstituted alkoxy group having 1 to 3 carbon atoms, a fluorine atom, 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.

As a specific structural example of the repeating unit, any ^one of R ^{1 to} R ⁹ in general formula (1), preferably any one of R ^{1 to} R ⁴ , R ⁸ , and R ⁹ is represented by the following formulas (21) to (24 ). Two or more of R ^{1 to} R ⁹ may be represented by the following formulas (21) to (24), but preferably one of R ^{1 to} R ⁹ is represented by the following formulas (21) to (24 ).

The polymer having a repeating unit containing these formulas (21) to (24) is preferably at least one of R ^{1 to} R ⁹ , preferably R ^{1 to} R ⁴ , R ⁸ , R ⁹ of the general formula (1). It can be synthesized by leaving at least one hydroxyl group as a linker, reacting the following compound with it as a linker, introducing 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 composed only of repeating units having the structure represented by the general formula (1), or other structures may be used. It may be a polymer containing repeating units. The repeating unit having a 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 not having the structure represented by the general formula (1) include those derived from monomers used in ordinary copolymerization. Examples thereof include a repeating unit derived from a monomer having an ethylenically unsaturated bond such as ethylene and styrene.

[Compound represented by the general formula (4)]
Among the compounds represented by the general formula (1), the compound represented by the following general formula (4) is a novel compound.

In the general formula (4), R ^{11 to} R ¹⁴ are each independently a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group, or Represents a substituted or unsubstituted cycloalkyl group, R ¹⁵ and R ¹⁶ each independently represents an alkyl group, and R ¹⁷ , R ¹⁸ and R ¹⁹ each independently represent a substituted or unsubstituted aryl group, substituted or unsubstituted An alkyl group, or a substituted or unsubstituted carbazolyl group, n11 to n14 and n17 each independently represents an integer of 0 to 4, n15 and n16 each represents an integer of 0 to 3, and n18 And n19 each independently represents an integer of 0 to 5. However, at least one of n11 to n14 is any integer of 1 to 4. When n11~n19 is an integer of 2 or more, plural R ¹¹ to R ¹⁹ corresponding to each n11~n19 it may or may not be the same as each other, respectively.

The preferred range of R ¹¹ to R ¹⁹ and n11~n19 in formula (4) can be referred to the description of R ¹ to R ⁹ and n1~n9 in the general formula (1). However, in General formula (4), it differs from n1-n4 of General formula (1) by the point that at least 1 of n11-n14 is the integer in any one of 1-4. As for n11-n14 in General formula (4), it is more preferable that at least 2 is an integer in any one of 1-4. For example, it is also preferable that all of n11 to n14 are any integer of 1 to 4. For example, when n11 to n14 are all 1, n11 and n12 are 1, n13 and n14 are 0, n11 and n13 are 1, and n12 and n14 are 0. Can do. When R ^{11 to} R ¹⁴ are present, R ¹¹ and R ¹³ are preferably bonded to the 3-position of the carbazole ring, and R ¹² and R ¹⁴ are preferably bonded to the 6-position of the carbazole ring.

  A method for synthesizing the compound represented by the general formula (4) is not particularly limited. The synthesis of the compound represented by the general formula (4) can be performed by appropriately combining known synthesis methods and conditions. For example, the compound represented by the general formula (4) can be synthesized by the following reaction.

R ^{1 to} R ⁹ and n1 to n9 in the above formula are the same as defined in the general formula (1). X represents a halogen atom, preferably a chlorine atom, a bromine atom, or an iodine atom, and more preferably a bromine atom. Said reaction can be performed by optimizing suitably the conditions employ | adopted for the coupling reaction of a normal amine and a halide. In addition, amines and halides as reaction raw materials can be synthesized by utilizing known synthesis methods. For example, the synthesis method of carbazolylcarbazole can be synthesized with reference to Appl. Phys. Lett. 101, 093306 (2012). The details of the above reaction can be referred to the synthesis examples described below. Moreover, the compound represented by General formula (4) is compoundable also by combining another well-known synthetic reaction.

[Organic light emitting device]
The compound represented by the general formula (1) of the present invention is useful as a light emitting material of an organic light emitting device. For this reason, the compound represented by General formula (1) of this invention can be effectively used as a luminescent material for the light emitting layer of an organic light emitting element. The compound represented by the general formula (1) includes a delayed fluorescent material (delayed phosphor) that emits delayed fluorescence. That is, the present invention relates to a delayed phosphor having the structure represented by the general formula (1), an invention using the compound represented by the general formula (1) as a delayed phosphor, and the general formula (1). An invention of a method for emitting delayed fluorescence using the represented compound is also provided. An organic light emitting device using such a compound as a light emitting material emits delayed fluorescence and has a feature of high luminous efficiency. The principle will be described below by taking an organic electroluminescence element as an example.

  In an organic electroluminescence element, carriers are injected into a light emitting material from both positive and negative electrodes to generate an excited light emitting material and emit light. In general, in the case of a carrier injection type organic electroluminescence element, 25% of the generated excitons are excited to the excited singlet state, and the remaining 75% are excited to the excited triplet state. Therefore, the use efficiency of energy is higher when phosphorescence, which is light emission from an excited triplet state, is used. However, since the excited triplet state has a long lifetime, energy saturation occurs due to saturation of the excited state and interaction with excitons in the excited triplet state, and in general, the quantum yield of phosphorescence is often not high. On the other hand, the delayed fluorescent material transitions to the excited triplet state due to intersystem crossing, etc., and then crosses back to the excited singlet state due to triplet-triplet annihilation or absorption of thermal energy, and emits fluorescence. To do. In the organic electroluminescence device, it is considered that a thermally activated delayed fluorescent material by absorption of thermal energy is particularly useful. When a delayed fluorescent material is used for the organic electroluminescence element, excitons in the excited singlet state emit fluorescence as usual. On the other hand, excitons in the excited triplet state absorb heat generated by the device and cross between the excited singlets to emit fluorescence. At this time, since the light is emitted from the excited singlet, the light is emitted at the same wavelength as the fluorescence, but the light lifetime (luminescence lifetime) generated by the reverse intersystem crossing from the excited triplet state to the excited singlet state is normal. Since the fluorescence becomes longer than the fluorescence and phosphorescence, it is observed as fluorescence delayed from these. This can be defined as delayed fluorescence. If such a heat-activated exciton transfer mechanism is used, the ratio of the compound in an excited singlet state, which normally generated only 25%, is increased to 25% or more by absorbing thermal energy after carrier injection. It can be raised. If a compound that emits strong fluorescence and delayed fluorescence even at a low temperature of less than 100 ° C is used, the heat of the device will sufficiently cause intersystem crossing from the excited triplet state to the excited singlet state and emit delayed fluorescence. Efficiency can be improved dramatically.

By using the compound represented by the general formula (1) of the present invention as a light-emitting material of a light-emitting layer, excellent organic light-emitting devices such as an organic photoluminescence device (organic PL device) and an organic electroluminescence device (organic EL device) Can be provided. The organic photoluminescence element has a structure in which at least a light emitting layer is formed on a substrate. The organic electroluminescence element has a structure in which an organic layer is formed at least between an anode, a cathode, and an anode and a cathode. The organic layer includes at least a light emitting layer, and may consist of only the light emitting layer, or may have one or more organic layers in addition to the light emitting layer. Examples of such other organic layers include a hole transport layer, a hole injection layer, an electron blocking layer, a hole blocking layer, an electron injection layer, an electron transport layer, and an exciton blocking layer. The hole transport layer may be a hole injection / transport layer having a hole injection function, and the electron transport layer may be an electron injection / transport layer having an electron injection function. A specific example of the structure of an organic electroluminescence element is shown in FIG. In FIG. 1, 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, 5 is a light emitting layer, 6 is an electron transport layer, and 7 is a cathode.
Below, each member and each layer of an organic electroluminescent element are demonstrated. In addition, description of a board | substrate and a light emitting layer corresponds also to the board | substrate and light emitting layer of an organic photo-luminescence element.

(substrate)
The organic electroluminescence device of the present invention is preferably supported on a substrate. The substrate is not particularly limited and may be any substrate conventionally used for organic electroluminescence elements. For example, a substrate made of glass, transparent plastic, quartz, silicon, or the like can be used.

(anode)
As the anode in the organic electroluminescence element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used. For the anode, a thin film may be formed by vapor deposition or sputtering of these electrode materials, and a pattern of a desired shape may be formed by photolithography, or when pattern accuracy is not so high (about 100 μm or more) ), A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material. Or when using the material which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

(cathode)
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include 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 ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function value than this, for example, a magnesium / silver mixture, Suitable are a magnesium / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, a lithium / aluminum mixture, aluminum and the like. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 to 200 nm. In order to transmit the emitted light, if either one of the anode or the cathode of the organic electroluminescence element is transparent or translucent, the emission luminance is advantageously improved.
In addition, by using the conductive transparent material mentioned in the description of the anode as a cathode, a transparent or semi-transparent cathode can be produced. By applying this, an element in which both the anode and the cathode are transparent is used. Can be produced.

(Light emitting layer)
The light emitting layer is a layer that emits light after excitons are generated by recombination of holes and electrons injected from each of the anode and the cathode, and the light emitting material may be used alone for the light emitting layer. , Preferably including a luminescent material and a host material. As a luminescent material, the 1 type (s) or 2 or more types chosen from the compound group of this invention represented by General formula (1) can be used. In order for the organic electroluminescent device and the organic photoluminescent device of the present invention to exhibit high luminous efficiency, it is important to confine singlet excitons and triplet excitons generated in the light emitting material in the light emitting material. Therefore, it is preferable to use a host material in addition to the light emitting material in the light emitting layer. As the host material, an organic compound having at least one of excited singlet energy and excited triplet energy higher than that of the light emitting material of the present invention can be used. As a result, singlet excitons and triplet excitons generated in the light emitting material of the present invention can be confined in the molecules of the light emitting material of the present invention, and the light emission efficiency can be sufficiently extracted. In the organic light emitting device or organic electroluminescent device of the present invention, light emission is generated from the light emitting material of the present invention contained in the light emitting layer. This emission includes both fluorescence and delayed fluorescence. However, light emission from the host material may be partly or partly emitted.
When the host material is used, the amount of the compound of the present invention, which is a light emitting material, is preferably 0.1% by weight or more, more preferably 1% by weight or more, and 50% or more. It is preferably no greater than wt%, more preferably no greater than 20 wt%, and even more preferably no greater than 10 wt%.
The host material in the light-emitting layer is preferably an organic compound that has a hole transporting ability and an electron transporting ability, prevents the emission of longer wavelengths, and has a high glass transition temperature.

(Injection layer)
The injection layer is a layer provided between the electrode and the organic layer for lowering the driving voltage and improving the luminance of light emission, and includes a hole injection layer and an electron injection layer, Further, it may be present between the cathode and the light emitting layer or the electron transport layer. The injection layer can be provided as necessary.

(Blocking layer)
The blocking layer is a layer that can prevent diffusion of charges (electrons or holes) and / or excitons existing in the light emitting layer to the outside of the light emitting layer. The electron blocking layer can be disposed between the light emitting layer and the hole transport layer and blocks electrons from passing through the light emitting layer toward the hole transport layer. Similarly, a hole blocking layer can be disposed between the light emitting layer and the electron transporting layer to prevent holes from passing through the light emitting layer toward the electron transporting layer. The blocking layer can also be used to block excitons from diffusing outside the light emitting layer. That is, each of the electron blocking layer and the hole blocking layer can also function as an exciton blocking layer. The term “electron blocking layer” or “exciton blocking layer” as used herein is used in the sense of including a layer having the functions of an electron blocking layer and an exciton blocking layer in one layer.

(Hole blocking layer)
The hole blocking layer has a function of an electron transport layer in a broad sense. The hole blocking layer has a role of blocking holes from reaching the electron transport layer while transporting electrons, thereby improving the recombination probability of electrons and holes in the light emitting layer. As the material for the hole blocking layer, the material for the electron transport layer described later can be used as necessary.

(Electron blocking layer)
The electron blocking layer has a function of transporting holes in a broad sense. The electron blocking layer has a role to block electrons from reaching the hole transport layer while transporting holes, thereby improving the probability of recombination of electrons and holes in the light emitting layer. .

(Exciton blocking layer)
The exciton blocking layer is a layer for preventing excitons generated by recombination of holes and electrons in the light emitting layer from diffusing into the charge transport layer. It becomes possible to efficiently confine in the light emitting layer, and the light emission efficiency of the device can be improved. The exciton blocking layer can be inserted on either the anode side or the cathode side adjacent to the light emitting layer, or both can be inserted simultaneously. That is, when the exciton blocking layer is provided on the anode side, the layer can be inserted adjacent to the light emitting layer between the hole transport layer and the light emitting layer, and when inserted on the cathode side, the light emitting layer and the cathode Between the luminescent layer and the light-emitting layer. Further, a hole injection layer, an electron blocking layer, or the like can be provided between the anode and the exciton blocking layer adjacent to the anode side of the light emitting layer, and the excitation adjacent to the cathode and the cathode side of the light emitting layer can be provided. Between the child blocking layer, an electron injection layer, an electron transport layer, a hole blocking layer, and the like can be provided. When the blocking layer is disposed, at least one of the excited singlet energy and the excited triplet energy of the material used as the blocking layer is preferably higher than the excited singlet energy and the excited triplet energy of the light emitting material.

(Hole transport layer)
The hole transport layer is made of a hole transport material having a function of transporting holes, and the hole transport layer can be provided as a single layer or a plurality of layers.
The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. Known hole transport materials that can be used include, for example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, carbazole derivatives, indolocarbazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, Examples include amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers. An aromatic tertiary amine compound and an styrylamine compound are preferably used, and an aromatic tertiary amine compound is more preferably used.

(Electron transport layer)
The electron transport layer is made of a material having a function of transporting electrons, and the electron transport layer can be provided as a single layer or a plurality of layers.
The electron transport material (which may also serve as a hole blocking material) may have a function of transmitting electrons injected from the cathode to the light emitting layer. Examples of the electron transport layer that can be used include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide oxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, and the like. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  When producing an organic electroluminescent element, you may use not only the compound represented by General formula (1) for a light emitting layer but layers other than a light emitting layer. In that case, the compound represented by General formula (1) used for a light emitting layer and the compound represented by General formula (1) used for layers other than a light emitting layer may be same or different. For example, the compound represented by the general formula (1) may be used for the injection layer, blocking layer, hole blocking layer, electron blocking layer, exciton blocking layer, hole transporting layer, electron transporting layer, and the like. . The method for forming these layers is not particularly limited, and the layer may be formed by either a dry process or a wet process.

Below, the preferable material which can be used for an organic electroluminescent element is illustrated concretely. However, the material that can be used in the present invention is not limited to the following exemplary compounds. Moreover, even if it is a compound illustrated as a material which has a specific function, it can also be diverted as a material which has another function. In addition, R, R ′, and R _{1 to} R ₁₀ in the structural formulas of the following exemplary compounds each independently represent a hydrogen atom or a substituent. X represents a carbon atom or a hetero atom forming a ring skeleton, n represents an integer of 3 to 5, Y represents a substituent, and m represents an integer of 0 or more.

  First, preferred compounds that can also be used as a host material for the light emitting layer are listed.

  Next, examples of preferable compounds that can be used as the hole injection material will be given.

  Next, examples of preferred compounds that can be used as a hole transport material are listed.

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

  Next, preferred compound examples that can be used as a hole blocking material are listed.

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

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

  Furthermore, preferable compound examples are given as materials that can be added. For example, adding as a stabilizing material can be considered.

The organic electroluminescence device produced by the above-described method emits light by applying an electric field between the anode and the cathode of the obtained device. At this time, if the light is emitted by excited singlet energy, light having a wavelength corresponding to the energy level is confirmed as fluorescence emission and delayed fluorescence emission. In addition, in the case of light emission by excited triplet energy, a wavelength corresponding to the energy level is confirmed as phosphorescence. Since normal fluorescence has a shorter fluorescence lifetime than delayed fluorescence, the emission lifetime can be distinguished from fluorescence and delayed fluorescence.
On the other hand, with respect to phosphorescence, in ordinary organic compounds such as the compounds of the present invention, the excited triplet energy is unstable and is converted into heat and the like, and the lifetime is short and it is immediately deactivated. In order to measure the excited triplet energy of a normal organic compound, it can be measured by observing light emission under extremely low temperature conditions.

  The organic electroluminescence element of the present invention can be applied to any of a single element, an element having a structure arranged in an array, and a structure in which an anode and a cathode are arranged in an XY matrix. According to the present invention, an organic light emitting device with greatly improved light emission efficiency can be obtained by containing the compound represented by the general formula (1) in the light emitting layer. The organic light emitting device such as the organic electroluminescence device of the present invention can be further applied to various uses. For example, it is possible to produce an organic electroluminescence display device using the organic electroluminescence element of the present invention. For details, see “Organic EL Display” (Ohm Co., Ltd.) written by Shizushi Tokito, Chiba Adachi and Hideyuki Murata. ) Can be referred to. In particular, the organic electroluminescence device of the present invention can be applied to organic electroluminescence illumination and backlights that are in great demand.

  The features of the present invention will be described more specifically with reference to synthesis examples and examples. The following materials, processing details, processing procedures, and the like can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

(Synthesis Example 1)
In this synthesis example, compound 2 was synthesized according to the following scheme.

[Scheme 1] Synthesis of 9-tosyl-3,3 ″, 6,6 ″ -tetraphenyl-3 ′, 6′-dicarbazolylcarbazole 3,6-dibromo-9-tosylcarbazole (1.92 g, 4 0.0 mmol), 3,6-diphenylcarbazole (2.58 g, 8.08 mmol) and copper oxide (1.39 g, 9.7 mmol) were added dodecylbenzene (3.5 ml) and reacted at 220 ° C. overnight. . After completion of the reaction, the mixture was extracted with dichloromethane, and the organic layer was dried with magnesium sulfate and concentrated with an evaporator. Purification by column chromatography on silica gel (eluent: hexane / dichloromethane = 70/30) (yield 1.42 g, yield 19.0%).
¹ H NMR (500 MHz, CDCl ₃ ): δ (ppm) 8.66 (d, J = 9.0Hz, 2H), 8.40 (d, J = 2.0Hz, 4H), 8.18 (d, J = 2.0Hz, 2H) , 7.97 (d, J = 8.50Hz, 2H), 7.82 (dd, J = 2.0Hz, J = 2.0Hz, 2H), 7.72 (d, J = 7.0Hz, 8H), 7.67 (dd, J = 2.0Hz , J = 2.0Hz, 4H), 7.48-7.46 (m, 12H), 7.36-7.33 (m, 6H), 2.42 (s, 3H)

[Scheme 2] Synthesis of 3,3 ", 6,6" tetraphenyl-3 ', 6'-dicarbazolylcarbazole 9-tosyl-3,3 ", 6,6"tetraphenyl-3', 6 ' -Dicarbazolylcarbazole (0.25 g, 0.25 mmol), potassium hydroxide (0.14 g, 2.5 mmol) to THF (2.3 ml), DMSO (1.4 ml), water (0.3 ml). In addition, the mixture was heated to reflux for 4 hours. After completion of the reaction, the mixture was neutralized with 1N HCl. Extraction was performed with water and dichloromethane, and the organic layer was dried over magnesium sulfate. The organic layer was concentrated with an evaporator. Recrystallization from hexane and dichloromethane (yield 0.16 g, yield 80.0%).
¹ H NMR (500 MHz, CDCl ₃ ): δ (ppm) 8.52 (s, 1H), 8.42 (d, J = 2.0Hz, 4H), 8.30 (d, J = 2.0Hz, 2H), 7.77 (d, J = 8.5Hz, 2H), 7.73 (d, J = 8.0Hz, 8H), 7.70 (d, J = 2.0Hz, 1H), 7.67 (dd, J = 2.0Hz, J = 1.5Hz, 5H), 7.49 -7.46 (m, 12H), 7.35-7.33 (m, 4H)

_{[Scheme 3] 9 '- (} 4- (4,6- diphenyl-1,3,5-triazin-2-yl) _{phenyl) -9' H- (3 '6} ' - diphenyl carbazolyl) carbazole 3, 3 ″, 6,6 ″ tetraphenyl-3 ′, 6′-dicarbazolylcarbazole (0.97 g, 1.2 mmol), diphenyltriazine (0.47 g, 1.21 mmol), copper iodide (0.004 g , 0.02 mmol), 18-crown-6-ether (0.035 g, 0.13 mmol), potassium carbonate (0.17 g, 1.43 mmol) was added dodecylbenzene (1.2 ml), and 220 ° C. for 2 days. Reacted. After completion of the reaction, the mixture was extracted with dichloromethane, and the organic layer was dried with magnesium sulfate and concentrated with an evaporator. Compound 2 was obtained by purification by column chromatography on silica gel (eluent: hexane / dichloromethane = 70/30) (yield 0.20 g, 15.3%).
¹ H NMR (500MHz, d6-DMSO): δ (ppm) 9.16 (d, J = 9.0Hz, 2H), 8.87-8.83 (m, 6H), 8.77 (d, J = 8.5Hz, 4H), 8.23 ( d, J = 8.5Hz, 2H), 7.96 (d, J = 8.5Hz, 2H), 7.86-7.80 (m, 16H), 7.76-7.71 (m, 4H), 7.55 (d, J = 8.5Hz, 4H ), 7.52-7.49 (m, 8H), 7.37-7.34 (m, 4H)

(Synthesis Example 2)
In this synthesis example, compound 3 was synthesized according to the following scheme.

[Scheme 1] 3,3 ", 6,6 " - tetra -tert-butyl -9 _'- tosyl -3',
Synthesis of 6′-dicarbazolylcarbazole 3,6-ditert-butylcarbazole (2.69 g, 9.59 mmol), 3,6-dibromocarbazole (2.40 g, 5.00 mmol), copper oxide (1. 71 g, 12.3 mmol) were added dodecylbenzene (4 ml) and NMP (1 ml), and reacted at 220 ° C. overnight. After completion of the reaction, the copper oxide was removed by filtration and concentrated with an evaporator. When purified by column chromatography on silica gel (cyclohexane / dichloromethane = 50/50), the expected product was about 0.44 g (yield of about 10%). Further, 0.85 g (5.94 mmol) of copper (II) oxide and dodecylbenzene (2 ml) were added to the product containing the mono-form and raw materials, and the mixture was heated to reflux overnight at 220 ° C. (yield 1.02 g, yield 23 .3%).
¹ H NMR (500 MHz, CDCl ₃ ): (ppm) 8.56 (d, J = 8.5 Hz, 2H), 8.14 (d, J = 1.5 Hz, 4H), 8.05 (d, J = 2.0 Hz, 2H), 7.91 (d, J = 8.5Hz, 2H), 7.73 (dd, J = 2.0Hz, J = 2.0Hz, 2H), 7.44 (dd, J = 2.0Hz, J = 2.0Hz, 4H), 7.33-7.2. 8 (m, 6H), 2.39 (s, 3H), 1.45 (s, 36H)

[Scheme 2] (3,6-di (3,6-di-tert- butyl-carbazolyl)) - Synthesis of carbazole 3,3 ", 6,6" - tetra -tert- butyl -9 _'- tosyl -3 Add ', 6'-dicarbazolylcarbazole (4.78 g, 5.45 mmol), potassium hydroxide (2.41 g, 56 mmol) to THF (49 ml), DMSO (24 ml), water (5 ml) and add 3 Stirred for hours. After completion of the reaction, the mixture was neutralized with 1N HCl and extracted with dichloromethane. The organic layer was dried over magnesium sulfate and concentrated with an evaporator. The product was purified by column chromatography on silica gel (developing solvent: cyclohexane / dichloromethane = 70/30). Recrystallization from hexane (yield 2.95, 75% yield).
¹ H NMR (500 MHz, CDCl ₃ ): (ppm) 8.42 (s, 1H), 8.17-8.15 (m, 6H), 7.69-7.67 (m,
1H), 7.61 (d, J = 8.5Hz, 2H), 7.65-7.55 (m, 1H), 7.47-7.43 (m, 4H), 7.32-7.30 (m, 4H), 1.48-1.46 (m, 36H)

[Scheme 3] 9 '-(4- (4,6-diphenyl-1,3,5-triazin-2-yl) phenyl) -9'H- (3'6'-ditert-butylcarbazolyl) Carbazole (3,6-di (3,6-di (tert-butylcarbazolyl))-carbazole (0.51 g, 0.7 mmol), 3,6-dibromo-9-tosylcarbazole (0.31 g, 0 .81 mmol), copper iodide (0.007 g, 0.04 mmol), 18-crown-6-ether (0.02 g, 0.08 mmol), potassium carbonate (0.09 g, 0.65 mmol) and dodecylbenzene (0 6 ml), and refluxed overnight.After the reaction, dichloromethane was added and filtered through celite.After concentration, the organic layer was dried over magnesium sulfate and concentrated with an evaporator.Silica gel column Purification by chromatography (eluent: hexane / dichloromethane = 50/50) gave compound 3 (yield 0.16 g, yield 22.5%).
MALDI-TOF-MS: m / z = 1030 ([M + 1] ⁺ )

Example 1
In this example, each toluene solution (concentration 10 ⁻⁵ mol / L) of compounds 1 to 3 was prepared and irradiated with light at 300 K while bubbling nitrogen, and light emission was observed. The absorption wavelength, emission wavelength, and quantum yield were as shown in Table 1. In addition, delayed fluorescence was observed in each toluene solution.

(Example 2)
In this example, an organic photoluminescence element was produced and its characteristics were evaluated.
Compound 1 and DPEPO were deposited from different deposition sources on a silicon substrate by a vacuum deposition method under a vacuum degree of 5.0 × 10 ⁻⁴ Pa, and a thin film having a concentration of Compound 1 of 6% by weight was obtained. The film was formed at a thickness of 100 nm at 3 nm / second to obtain an organic photoluminescence device.
An organic photoluminescence device was produced in the same manner using each of the compounds 2 and 3 instead of the compound 1.

The emission spectrum from the thin film when each organic photoluminescence device produced was irradiated with light of 337 nm by an N ₂ laser was evaluated at 300K.
The emission spectrum of the organic photoluminescence device using Compound 1 is shown in FIG. 2, the emission spectrum of the organic photoluminescence device using Compound 2 is shown in FIG. 6, and the emission spectrum of the organic photoluminescence device using Compound 3 is shown. 10 shows.

(Example 3)
In this example, an organic electroluminescence element was produced and its characteristics were evaluated.
Each thin film was laminated at a vacuum degree of 5.0 × 10 ⁻⁴ Pa by a vacuum deposition method on a glass substrate on which an anode made of indium tin oxide (ITO) having a thickness of 100 nm was formed. First, α-NPD was formed on ITO with a thickness of 35 nm, and CBP was formed thereon with a thickness of 10 nm. Further thereon, Compound 1 and DPEPO were deposited from different deposition sources, and a thin film having a concentration of Compound 1 of 6% by weight was formed to a thickness of 15 nm. On top of that, TPBi is formed to a thickness of 40 nm, further lithium fluoride (LiF) is vacuum-deposited to 0.8 nm, and then aluminum (Al) is evaporated to a thickness of 80 nm to form a cathode. A luminescence element was obtained.
An organic electroluminescence device was produced in the same manner using Compound 2 and Compound 3 instead of Compound 1.

Each of the produced organic electroluminescence elements was subjected to a semiconductor parameter analyzer (manufactured by Agilent Technologies: E5273A), an optical power meter measuring device (manufactured by Newport: 1930C), an optical spectrometer (manufactured by Ocean Optics: USB2000), and a streak. Measurement was performed using a camera (C4334 type manufactured by Hamamatsu Photonics Co., Ltd.).
The emission spectrum of the organic electroluminescence device using Compound 1 is shown in FIG. 2, the time-resolved spectrum under normal pressure and in vacuum is shown in FIG. 3, the voltage-current density characteristics are shown in FIG. 4, and the current density-external quantum efficiency. The characteristics are shown in FIG. The emission spectrum of the organic electroluminescence device using Compound 2 is shown in FIG. 6, the time-resolved spectrum under normal pressure and in vacuum is shown in FIG. 7, the voltage-current density characteristics are shown in FIG. 8, and the current density-external quantum efficiency. The characteristics are shown in FIG. The emission spectrum of the organic electroluminescence device using Compound 3 is shown in FIG. 10, the time-resolved spectrum under normal pressure and in vacuum is shown in FIG. 11, the voltage-current density characteristics are shown in FIG. 12, and the current density-external quantum efficiency. The characteristics are shown in FIG.

(Comparative Example 1)
In this comparative example, a toluene solution (concentration 10 ⁻⁵ mol / L) of the following compound A described in JP2009-213362A and JP2002-193952A was prepared, and 300K while bubbling nitrogen. The light emission spectrum shown in FIG. 14 was obtained. The time-resolved spectrum of this solution is as shown in FIG. 15, and no delayed fluorescence component was observed.

  The organic light emitting device of the present invention can achieve high luminous efficiency. The compound represented by the general formula (1) is useful as a light emitting material for such an organic light emitting device. For this reason, this invention has high industrial applicability.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Hole injection layer 4 Hole transport layer 5 Light emitting layer 6 Electron transport layer 7 Cathode

Claims (13)

A luminescent material comprising a compound represented by the following general formula (1).

[In the general formula ^(1), R 1 ~R ⁴ each independently substitution or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group or a substituted or unsubstituted, cycloalkyl Represents an alkyl group,
R ⁵ and R ⁶ each independently represents a substituted or unsubstituted alkyl group,
R ⁷ , R ⁸ and R ⁹ each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkyl group ;
n1 to n4 and n7 each independently represents an integer of 0 to 4,
n5 and n6 represent any integer of 0 to 3,
n8 and n9 each independently represents an integer of 0 to 5.
When n1~n9 is an integer of 2 or more, plural R ¹ to R ⁹ for each n1~n9 may each also being the same or different. ]   The luminescent material according to claim 1, which emits delayed fluorescence.   The luminescent material according to claim 1 or 2, wherein at least one of n1 to n4 in the general formula (1) is an integer of 1 to 4.   3. The light emitting material according to claim 1, wherein n1 to n4 in the general formula (1) are each independently an integer of 1 to 4. Formula ⁽¹⁾ R 1 ~R ⁴ in are each independently substitution or unsubstituted phenyl group, a substituted or unsubstituted pyridyl group, an alkyl group having 1 to 6 carbon atoms, cycloalkyl group having 5 to 7 carbon atoms The luminescent material according to claim 1, wherein the luminescent material is a light-emitting material. Formula (1) in R ¹ to R ⁴ are each independently a full Eniru group, a tolyl group, dimethylphenyl group, trimethylphenyl group, a biphenyl group, a pyridyl group, a pyrrolyl group, tert- butyl group or a cyclohexyl group, The luminescent material according to claim 1, wherein:   7. The luminescent material according to claim 1, wherein both n5 and n6 in the general formula (1) are 0.   N7, n8, and n9 in General formula (1) are all 0, The luminescent material of any one of Claims 1-7 characterized by the above-mentioned. A delayed phosphor having a structure represented by the following general formula (1).

[In the general formula ^(1), R 1 ~R ⁴ each independently substitution or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group or a substituted or unsubstituted, cycloalkyl Represents an alkyl group,
R ⁵ and R ⁶ each independently represents a substituted or unsubstituted alkyl group,
R ⁷ , R ⁸ and R ⁹ each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkyl group ;
n1 to n4 and n7 each independently represents an integer of 0 to 4,
n5 and n6 represent any integer of 0 to 3,
n8 and n9 each independently represents an integer of 0 to 5.
When n1~n9 is an integer of 2 or more, plural R ¹ to R ⁹ for each n1~n9 may each also being the same or different. ] A compound represented by the following general formula (4).

[In the general formula (4), R ¹¹ ~R ¹⁴ each independently substitution or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group or a substituted or unsubstituted, cycloalkyl Represents an alkyl group,
R ¹⁵ and R ¹⁶ each independently represents an alkyl group;
R ¹⁷ , R ¹⁸ and R ¹⁹ each independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted alkyl group ;
n11 to n14 and n17 each independently represents an integer of 0 to 4,
n15 and n16 represent any integer of 0 to 3,
n18 and n19 each independently represents an integer of 0 to 5.
However, at least one of n11 to n14 is any integer of 1 to 4.
When n11~n19 is an integer of 2 or more, plural R ¹¹ to R ¹⁹ corresponding to each n11~n19 it may or may not be the same as each other, respectively. ] An organic light-emitting element having a light-emitting layer containing a light-emitting material made of a compound represented by the following general formula (1) on a substrate.

[In the general formula (1), R ^{1 to} R ⁴ are each independently a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted cycloalkyl. Represents a group,
R ⁵ and R ⁶ each independently represents a substituted or unsubstituted alkyl group,
R ⁷ , R ⁸ and R ⁹ each independently represents a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkyl group;
n1 to n4 and n7 each independently represents an integer of 0 to 4,
n5 and n6 represent any integer of 0 to 3,
n8 and n9 each independently represents an integer of 0 to 5.
However, at least 1 of n1-n4 is an integer in any one of 1-4.
When n1~n9 is an integer of 2 or more, plural R ¹ to R ⁹ for each n1~n9 may each also being the same or different. ]   The organic light emitting device according to claim 11, which emits delayed fluorescence.   The organic light-emitting device according to claim 11, wherein the organic light-emitting device is an organic electroluminescence device.

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