JP6469076B2 - Luminescent materials, organic light emitting devices and compounds - Google Patents

Description

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

  Researches for increasing the light emission efficiency of organic light emitting devices such as organic electroluminescence devices (organic EL 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. For example, compounds having a substituted amino group such as a carbazolyl group and a diphenylamino group are known as materials for the light emitting layer, and some of them have a fluorine atom.

Patent Document 1 describes that a compound having a carbazolyl group and a fluorine atom represented by the following formula can be used as a dopant material (light emitting material) of a light emitting layer.

Patent Document 2 describes that a compound having a diphenylamino group substituted with a methyl group and a fluorine atom, or a compound having a carbazolyl group and a fluorine atom, represented by the following formula, can be used as a light emitting material.

Japanese Patent No. 4125076 Japanese Patent No. 4311707

As described above, Patent Documents 1 and 2 describe that a compound having a diphenylamino group or carbazolyl group substituted with a methyl group and a fluorine atom can be used as a light emitting material. However, when the present inventors actually evaluated the light emission characteristics of a compound having a diphenylamino group or a carbazolyl group and a fluorine atom, the light emission characteristics were not sufficiently satisfactory (see Comparative Examples 1 and 2 below). ), It has been found that there is a need to provide a luminescent material with better luminescent properties.
Accordingly, the present inventors have started various studies on a group of compounds having a substituted amino group and a fluorine atom, and have repeated research aiming to find a compound having excellent luminescent properties from a number of similar compounds. In that research, I thought of examining a group of compounds having a substituted amino group having a structure in which three 6-membered rings are condensed and a fluorine atom. Patent Documents 1 and 2 describe a compound having a fluorine atom with a diphenylamino group or carbazolyl group substituted with a methyl group, but a substituted amino group having a structure in which three 6-membered rings are condensed and fluorine. It does not describe compounds having atoms. For this reason, the usefulness of these compounds as luminescent materials is completely unpredictable.

  Under such circumstances, the present inventors have further investigated the usefulness of a compound having a substituted amino group having a structure in which three 6-membered rings are condensed and a fluorine atom as a luminescent material, and has excellent luminescent properties. Research was conducted with the aim of finding compounds. And the general formula of the compound useful as a luminescent material was derived, and the earnest examination was advanced for the purpose of generalizing the structure of the organic light emitting element with high luminous efficiency.

  As a result of diligent investigation, the present inventors have found that a compound having a specific structure among compounds having a substituted amino group having a structure in which three 6-membered rings are condensed and a fluorine atom has excellent properties as a luminescent material. Found to have. In addition, it has been found that such a group of compounds is useful as a delayed fluorescent material, and it has been clarified that an organic light-emitting device having high emission efficiency 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、Ｒ³およびＲ⁵がフッ素原子を表すか、Ｒ¹、Ｒ²、Ｒ⁴およびＲ⁵がフッ素原子を表し、残りのＲ¹〜Ｒ⁶が各々独立に下記一般式（２）〜（６）のいずれかで表される基を表す。］

［一般式（２）〜（６）において、Ｌ¹⁴〜Ｌ¹⁸は単結合、または置換もしくは無置換のアリーレン基を表し、＊は一般式（１）におけるベンゼン環への結合部位を表す。Ｒ³¹〜Ｒ³⁸、Ｒ^3a、Ｒ^3b、Ｒ⁴¹〜Ｒ⁴⁸、Ｒ^4a、Ｒ⁵¹〜Ｒ⁵⁸、Ｒ⁶¹〜Ｒ⁶⁸、Ｒ⁷¹〜Ｒ⁷⁸は、各々独立に水素原子または置換基を表す。Ｒ³¹とＲ³²、Ｒ³²とＲ³³、Ｒ³³とＲ³⁴、Ｒ³⁵とＲ³⁶、Ｒ³⁶とＲ³⁷、Ｒ³⁷とＲ³⁸、Ｒ^3aとＲ^3b、Ｒ⁴¹とＲ⁴²、Ｒ⁴²とＲ⁴³、Ｒ⁴³とＲ⁴⁴、Ｒ⁴⁵とＲ⁴⁶、Ｒ⁴⁶とＲ⁴⁷、Ｒ⁴⁷とＲ⁴⁸、Ｒ⁵¹とＲ⁵²、Ｒ⁵²とＲ⁵³、Ｒ⁵³とＲ⁵⁴、Ｒ⁵⁵とＲ⁵⁶、Ｒ⁵⁶とＲ⁵⁷、Ｒ⁵⁷とＲ⁵⁸、Ｒ⁶¹とＲ⁶²、Ｒ⁶²とＲ⁶³、Ｒ⁶³とＲ⁶⁴、Ｒ⁶⁵とＲ⁶⁶、Ｒ⁶⁶とＲ⁶⁷、Ｒ⁶⁷とＲ⁶⁸、Ｒ⁷¹とＲ⁷²、Ｒ⁷²とＲ⁷³、Ｒ⁷³とＲ⁷⁴、Ｒ⁷⁵とＲ⁷⁶、Ｒ⁷⁶とＲ⁷⁷、Ｒ⁷⁷とＲ⁷⁸はそれぞれ互いに結合して環状構造を形成していてもよい。］[1] A light emitting material comprising a compound represented by the following general formula (1).

[In General Formula (1), R ¹ , R ³ and R ⁵ represent a fluorine atom, or R ¹ , R ² , R ⁴ and R ⁵ represent a fluorine atom, and the remaining R ^{1 to} R ⁶ are each independently Represents a group represented by any one of the following general formulas (2) to (6). ]

[In General Formulas (2) to (6), L ^{14 to} L ¹⁸ represent a single bond or a substituted or unsubstituted arylene group, and * represents a bonding site to the benzene ring in General Formula (1). R ^{31 to} R ³⁸ , R ^3a , R ^3b , R ^{41 to} R ⁴⁸ , R ^4a , R ^{51 to} R ⁵⁸ , R ^{61 to} R ⁶⁸ , and R ^{71 to} R ⁷⁸ each independently represent a hydrogen atom or a substituent. . R ³¹ and R ^32, R ³² and R ^33, R ³³ and R ^34, R ³⁵ and R ^36, R ³⁶ and R ^37, R ³⁷ and R ^38, R ^3a and R ^3b, R ⁴¹ and R ^42, R ⁴² And R ⁴³ , R ⁴³ and R ⁴⁴ , R ⁴⁵ and R ⁴⁶ , R ⁴⁶ and R ⁴⁷ , R ⁴⁷ and R ⁴⁸ , R ⁵¹ and R ⁵² , R ⁵² and R ⁵³ , R ⁵³ and R ⁵⁴ , R ⁵⁵ and R ⁵⁶ , R ⁵⁶ and R ⁵⁷ , R ⁵⁷ and R ⁵⁸ , R ⁶¹ and R ⁶² , R ⁶² and R ⁶³ , R ⁶³ and R ⁶⁴ , R ⁶⁵ and R ⁶⁶ , R ⁶⁶ and R ⁶⁷ , R ⁶⁷ and R ⁶⁸ , R ⁷¹ and R ⁷² , R ⁷² and R ⁷³ , R ⁷³ and R ⁷⁴ , R ⁷⁵ and R ⁷⁶ , R ⁷⁶ and R ⁷⁷ , and R ⁷⁷ and R ⁷⁸ may be bonded to each other to form a cyclic structure. . ]

[2] The luminescent material according to [1], wherein R ¹ , R ² , R ⁴ and R ^{5 in the} general formula (1) are fluorine atoms.
[3] The luminescent material according to [1], wherein R ¹ , R ³ and R ^{5 in the} general formula (1) are fluorine atoms.
[4] The light-emitting material according to any one of [1] to [3], wherein L ^{14 to} L ^{18 in the} general formulas (2) to (6) are substituted or unsubstituted phenylene groups. .
[5] Any one of [1] to [4], wherein the remaining R ^{1 to} R ^{6 of the} general formula (1) are all groups represented by the general formula (2). The luminescent material described in 1.
[6] Any one of [1] to [4], wherein the remaining R ^{1 to} R ^{6 of the} general formula (1) are all groups represented by the general formula (4). The luminescent material described in 1.
[7] The light-emitting material according to any one of [1] to [6], wherein the molecule has a rotationally symmetric structure.
[8] A delayed phosphor comprising the compound represented by the general formula (1).
[9] An organic light emitting device comprising the light emitting material according to any one of [1] to [7].
[10] The organic light-emitting device according to [9], which emits delayed fluorescence.
[11] The organic light-emitting device according to [9] or [10], which is an organic electroluminescence device.

[一般式（１’）において、Ｒ¹’、Ｒ³’およびＲ⁵’がフッ素原子を表すか、Ｒ¹’、Ｒ²’、Ｒ⁴’およびＲ⁵’がフッ素原子を表し、残りのＲ¹’〜Ｒ⁶’が各々独立に下記一般式（２’）〜（６’）のいずれかで表される基を表す。］

［一般式（２’）〜（６’）において、Ｌ¹⁴’〜Ｌ¹⁸’は単結合、または置換もしくは無置換のアリーレン基を表し、＊は一般式（１）におけるベンゼン環への結合部位を表す。Ｒ³¹’〜Ｒ³⁸’、Ｒ^3a’、Ｒ^3b’、Ｒ⁴¹’〜Ｒ⁴⁸’、Ｒ^4a’、Ｒ⁵¹’〜Ｒ⁵⁸’、Ｒ⁶¹’〜Ｒ⁶⁸’、Ｒ⁷¹’〜Ｒ⁷⁸’は、各々独立に水素原子または置換基を表す。Ｒ³¹’とＲ³²’、Ｒ³²’とＲ³³’、Ｒ³³’とＲ³⁴’、Ｒ³⁵’とＲ³⁶’、Ｒ³⁶’とＲ³⁷’、Ｒ³⁷’とＲ³⁸’、Ｒ^3a’とＲ^3b’、Ｒ⁴¹’とＲ⁴²’、Ｒ⁴²’とＲ⁴³’、Ｒ⁴³’とＲ⁴⁴’、Ｒ⁴⁵’とＲ⁴⁶’、Ｒ⁴⁶’とＲ⁴⁷’、Ｒ⁴⁷’とＲ⁴⁸’、Ｒ⁵¹’とＲ⁵²’、Ｒ⁵²’とＲ⁵³’、Ｒ⁵³’とＲ⁵⁴’、Ｒ⁵⁵’とＲ⁵⁶’、Ｒ⁵⁶’とＲ⁵⁷’、Ｒ⁵⁷’とＲ⁵⁸’、Ｒ⁶¹’とＲ⁶²’、Ｒ⁶²’とＲ⁶³’、Ｒ⁶³’とＲ⁶⁴’、Ｒ⁶⁵’とＲ⁶⁶’、Ｒ⁶⁶’とＲ⁶⁷’、Ｒ⁶⁷’とＲ⁶⁸’、Ｒ⁷¹’とＲ⁷²’、Ｒ⁷²’とＲ⁷³’、Ｒ⁷³’とＲ⁷⁴’、Ｒ⁷⁵’とＲ⁷⁶’、Ｒ⁷⁶’とＲ⁷⁷’、Ｒ⁷⁷’とＲ⁷⁸’はそれぞれ互いに結合して環状構造を形成していてもよい。］[12] A compound represented by the following general formula (1 ′).

[In the general formula (1 ′), R ¹ ′, R ³ ′ and R ⁵ ′ represent a fluorine atom, or R ¹ ′, R ² ′, R ⁴ ′ and R ⁵ ′ represent a fluorine atom, R ¹ ′ to R ⁶ ′ each independently represents a group represented by any one of the following general formulas (2 ′) to (6 ′). ]

[In the general formulas (2 ′) to (6 ′), L ¹⁴ ′ to L ¹⁸ ′ represent a single bond or a substituted or unsubstituted arylene group, and * represents a bonding site to the benzene ring in the general formula (1). Represents. ^{R 31 '~R 38', R} 3a ', R 3b', R 41 '~R 48', R 4a ', R 51' ~R 58 ', R 61' ~R 68 ', R 71' ~R 78 'Each independently represents a hydrogen atom or a substituent. R ³¹ 'and R ^32', R ³² 'and R ^33', R ³³ 'and R ^34', R ³⁵ 'and R ^36', 'R ³⁷ and' R ^36, R ³⁷ 'and R ^38', R ^3a 'And R ^3b ', R ⁴¹ 'and R ⁴² ', R ⁴² 'and R ⁴³ ', R ⁴³ 'and R ⁴⁴ ', R ⁴⁵ 'and R ⁴⁶ ', R ⁴⁶ 'and R ⁴⁷ ', R ⁴⁷ 'and ^R48 ', ^R51 ' and ^R52 ', ^R52 ' and ^R53 ', ^R53 ' and ^R54 ', ^R55 ' and ^R56 ', ^R56 ' and ^R57 ', ^R57 ' and ^R58 ', R ⁶¹ ' and R ⁶² ', R ⁶² ' and R ⁶³ ', R ⁶³ ' and R ⁶⁴ ', R ⁶⁵ ' and R ⁶⁶ ', R ⁶⁶ ' and R ⁶⁷ ', R ⁶⁷ ' and R ⁶⁸ ', ^R71 'and ^R72 ', ^R72 'and ^R73 ', ^R73 'and ^R74 ', ^R75 'and ^R76 ', ^R76 'and ^R77 ', ^R77 'and ^R78 ' It may combine to form a cyclic structure. ]

  The compound of the present invention is useful as a light emitting material. The compounds of the present invention include those that emit delayed fluorescence. An organic light emitting device using the compound of the present invention as a light emitting material can realize high luminous efficiency.

It is a schematic sectional drawing which shows the layer structural example of an organic electroluminescent element. 2 is an absorption emission spectrum of a toluene solution of compound 1 of Example 1. 2 is an absorption emission spectrum of a toluene solution of compound 2 of Example 2. 2 is an absorption spectrum of a thin film type organic photoluminescence device of Compound 2 of Example 2. 2 is an emission spectrum of a thin film type organic photoluminescence device of Compound 2 of Example 2. It is an emission spectrum of the thin film type organic photoluminescence element of the compound 2 of Example 2 and mCP. It is an emission spectrum of the thin film type organic photoluminescence element of the compound 2 of Example 2 and DPEPO. It is the fluorescence spectrum and phosphorescence spectrum of the thin film type organic photoluminescence element of the compound 2 of Example 2 and DPEPO. 3 is a transient decay curve of a toluene solution of Compound 2 of Example 2. It is a transient attenuation | damping curve of the thin film type organic photoluminescent element of the compound 2 of Example 2, and DPEPO. 2 is an emission spectrum of an organic electroluminescence device using the compound 2 of Example 3. 4 is a graph showing voltage-current density characteristics of an organic electroluminescence device using the compound 2 of Example 3. 4 is a graph showing current density-external quantum efficiency characteristics of an organic electroluminescence device using Compound 2 of Example 3.

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. In addition, the isotope species of the hydrogen atom present in the molecule of the compound used in the present invention is not particularly limited. For example, all the hydrogen atoms in the molecule may be ¹ H, or a part or all of them are ² H. (Deuterium D) may be used.

一般式（１）において、Ｒ¹、Ｒ³およびＲ⁵がフッ素原子を表すか、Ｒ¹、Ｒ²、Ｒ⁴およびＲ⁵がフッ素原子を表し、残りのＲ¹〜Ｒ⁶が各々独立に下記一般式（２）〜（６）のいずれかで表される基を表す。すなわち、Ｒ¹、Ｒ³およびＲ⁵がフッ素原子であるとき、残りのＲ²、Ｒ⁴およびＲ⁶は各々独立に下記一般式（２）〜（６）のいずれかで表される基である。また、Ｒ¹、Ｒ²、Ｒ⁴およびＲ⁵がフッ素原子であるとき、残りのＲ³、Ｒ⁶は各々独立に下記一般式（２）〜（６）のいずれかで表される基である。
残りのＲ¹〜Ｒ⁶は、すべてが一般式（２）〜（６）のいずれか１つの一般式で表されるものであってもよいし、互いに異なる一般式で表されるものであってもよい。
残りのＲ¹〜Ｒ⁶のすべてが一般式（２）〜（６）のいずれか１つの一般式で表される場合は、残りのＲ¹〜Ｒ⁶のすべてが同じ構造を有する基であることが好ましい。残りのＲ¹〜Ｒ⁶のすべてが同じ構造を有する基であるとき、一般式（１）で表される化合物は回転対称構造を有することになる。残りのＲ¹〜Ｒ⁶のすべてが同じ構造を有する化合物は、例えばドーパントとして用いる場合などに有用である。
一方、残りのＲ¹〜Ｒ⁶の一部または全部が異なる構造である化合物も有用である。そのような化合物は、例えばその化合物のみからなる層（ニート膜）を形成して発光層として用いる場合などに有用である。[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 the general formula (1), R ¹ , R ³ and R ⁵ represent a fluorine atom, or R ¹ , R ² , R ⁴ and R ⁵ represent a fluorine atom, and the remaining R ^{1 to} R ⁶ are each independently A group represented by any one of the following general formulas (2) to (6) is represented. That is, when R ¹ , R ³ and R ⁵ are fluorine atoms, the remaining R ² , R ⁴ and R ⁶ are each independently a group represented by any one of the following general formulas (2) to (6). is there. When R ¹ , R ² , R ⁴ and R ⁵ are fluorine atoms, the remaining R ³ and R ⁶ are each independently a group represented by any one of the following general formulas (2) to (6). is there.
The remaining R ^{1 to} R ⁶ may all be represented by any one of the general formulas (2) to (6), or may be represented by different general formulas. May be.
When all of the remaining R ^{1 to} R ⁶ are represented by any one of the general formulas (2) to (6), all of the remaining R ^{1 to} R ⁶ are groups having the same structure. It is preferable. When all of the remaining R ^{1 to} R ⁶ are groups having the same structure, the compound represented by the general formula (1) has a rotationally symmetric structure. A compound in which all of the remaining R ^{1 to} R ⁶ have the same structure is useful, for example, when used as a dopant.
On the other hand, compounds in which some or all of the remaining R ^{1 to} R ⁶ have different structures are also useful. Such a compound is useful, for example, when a layer (neat film) made of only the compound is formed and used as a light emitting layer.

In the general formulas (2) to (6), L ^{14 to} L ¹⁸ represent a single bond or a substituted or unsubstituted arylene group, and * represents a bonding site to the benzene ring in the general formula (1). When L ^{14 to} L ¹⁸ are an arylene group, the arylene group is preferably an arylene group having 6 to 18 carbon atoms. Examples of the arylene group having 6 to 18 carbon atoms include a phenylene group, a biphenylene group, a fluorenylene group, and a triphenylenylene group. A more preferable linking group is a phenylene group, and a more preferable linking group is 1,4- A phenylene group. Regarding the explanation and preferred range of the substituent when the arylene group has a substituent, the explanation and preferred range of the substituent that can be taken by the following R ^{31 to} R ^{38 and the} like can be referred to. L ^{14 to} L ¹⁸ are preferably single bonds.
R ^{31 to} R ³⁸ , R ^3a , R ^3b , R ^{41 to} R ⁴⁸ , R ^4a , R ^{51 to} R ⁵⁸ , R ^{61 to} R ⁶⁸ , and R ^{71 to} R ⁷⁸ each independently represent a hydrogen atom or a substituent. . The number of substituents is not particularly limited, and all of R ^{31 to} R ³⁸ , R ^3a , R ^3b , R ^{41 to} R ⁴⁸ , R ^4a , R ^{51 to} R ⁵⁸ , R ^{61 to} R ⁶⁸ , R ^{71 to} R ⁷⁸ May be unsubstituted (ie, a hydrogen atom). In each of the general formulas (2) to (6), R ^{31 to} R ³⁸ , R ^3a , R ^3b , R ^{41 to} R ⁴⁸ , R ^4a , R ^{51 to} R ⁵⁸ , R ^{61 to} R ⁶⁸ , R ^{71 to} R ^When two or more of ⁷⁸ are substituents, the plurality of substituents may be the same as or different from each other.

R ^{31 to} R ³⁸ , R ^3a , R ^3b , R ^{41 to} R ⁴⁸ , R ^4a , R ^{51 to} R ⁵⁸ , R ^{61 to} R ⁶⁸ , R ^{71 to} R ⁷⁸ may be substituted with, for example, a hydroxy group, halogen Atom, cyano group, alkyl group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, alkylthio group having 1 to 20 carbon atoms, alkyl-substituted amino group having 1 to 20 carbon atoms, acyl having 2 to 20 carbon atoms Group, aryl group having 6 to 40 carbon atoms, heteroaryl group having 3 to 40 carbon atoms, alkenyl group having 2 to 10 carbon atoms, alkynyl group having 2 to 10 carbon atoms, alkoxycarbonyl group having 2 to 10 carbon atoms, carbon An alkylsulfonyl group having 1 to 10 carbon atoms, a haloalkyl group having 1 to 10 carbon atoms, an amide group, an alkylamide group having 2 to 10 carbon atoms, a trialkylsilyl group having 3 to 20 carbon atoms, and a trialkyl having 4 to 20 carbon atoms A silylalkyl group, Trialkylsilyl alkenyl group prime 5-20, and the like trialkylsilyl alkynyl group and a nitro group having 5 to 20 carbon atoms. Among these specific examples, those that can be substituted with a substituent may be further substituted. More preferred substituents are a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms, carbon A substituted or unsubstituted heteroaryl group having 3 to 40 carbon atoms and a dialkyl-substituted amino group having 1 to 20 carbon atoms. More preferable substituents are a fluorine atom, a chlorine atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, and a substituted group having 6 to 15 carbon atoms. Or it is an unsubstituted aryl group, a C3-C12 substituted or unsubstituted heteroaryl group.

R ³¹ and R ^32, R ³² and R ^33, R ³³ and R ^34, R ³⁵ and R ^36, R ³⁶ and R ^37, R ³⁷ and R ^38, R ^3a and R ^3b, R ⁴¹ and R ^42, R ⁴² And R ⁴³ , R ⁴³ and R ⁴⁴ , R ⁴⁵ and R ⁴⁶ , R ⁴⁶ and R ⁴⁷ , R ⁴⁷ and R ⁴⁸ , R ⁵¹ and R ⁵² , R ⁵² and R ⁵³ , R ⁵³ and R ⁵⁴ , R ⁵⁵ and R ⁵⁶ , R ⁵⁶ and R ⁵⁷ , R ⁵⁷ and R ⁵⁸ , R ⁶¹ and R ⁶² , R ⁶² and R ⁶³ , R ⁶³ and R ⁶⁴ , R ⁶⁵ and R ⁶⁶ , R ⁶⁶ and R ⁶⁷ , R ⁶⁷ and R ⁶⁸ , R ⁷¹ and R ⁷² , R ⁷² and R ⁷³ , R ⁷³ and R ⁷⁴ , R ⁷⁵ and R ⁷⁶ , R ⁷⁶ and R ⁷⁷ , and R ⁷⁷ and R ⁷⁸ may be bonded to each other to form a cyclic structure. The cyclic structure may be an aromatic ring or an alicyclic ring, may contain a hetero atom, and the cyclic structure may be a condensed ring of two or more rings. The hetero atom here is preferably selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom. Examples of cyclic structures formed include benzene ring, naphthalene ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, pyrrole ring, imidazole ring, pyrazole ring, triazole ring, imidazoline ring, oxazole ring, isoxazole ring, thiazole And a ring, an isothiazole ring, a cyclohexadiene ring, a cyclohexene ring, a cyclopentaene ring, a cycloheptatriene ring, a cycloheptadiene ring, and a cycloheptaene ring.

R ^{31 to} R ³⁸ , R ^3a , R ^3b , R ^{41 to} R ⁴⁸ , R ^4a , R ^{51 to} R ⁵⁸ , R ^{61 to} R ⁶⁸ , and R ^{71 to} R ⁷⁸ are each independently represented by the general formula (2) to A group represented by any one of (6) is also preferred. R ^3a and R ^3b are preferably a substituted or unsubstituted alkyl group, and more preferably a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. When a substituent is present in the general formulas (2) to (6), the substituent is preferably any one of R ^{32 to} R ³⁷ , R ^3a , and R ^3b if the substituent is the general formula (2). , R ^3a and R ^3b are more preferable. If it is general formula (3), it is preferably any one of R ^{42 to} R ⁴⁷ , and if it is general formula (4), it is preferably any one of R ^{52 to} R ⁵⁷ , and in general formula (5) If present, any of R ^{62 to} R ⁶⁷ is preferable, and if it is general formula (6), any of R ^{72 to} R ⁷⁷ is preferable.

As preferred examples of the compound represented by the general formula (1), R ¹ , R ³ and R ⁵ are fluorine atoms, or R ¹ , R ² , R ⁴ and R ⁵ are fluorine atoms, and the remaining R can be all ¹ to R ⁶ is exemplified formula (2) or (4) a group represented by the compound.

Below, the specific example of a compound represented by General formula (1) is illustrated. However, the compound represented by the general formula (1) that can be used in the present invention should not be limitedly interpreted by these specific examples.

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 the molecular weight of the minimum compound represented by the general formula (1).
The compound represented by the general formula (1) may be formed by a coating method regardless of the molecular weight. If a coating method is used, a film can be formed even with a compound having a relatively large molecular weight.

By applying the present invention, it is also conceivable to use a compound containing a plurality of structures represented by the general formula (1) in the molecule as a light emitting material.
For example, it is conceivable to use a polymer obtained by previously polymerizing 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 ² , R ³ , R ⁴ , and R ^{6 in} the general formula (1), and this is polymerized alone or together with other monomers It is conceivable to obtain a polymer having repeating units by copolymerization and use the polymer as a light emitting material. Alternatively, it is also conceivable that dimers and trimers are obtained by reacting compounds having a structure represented by the general formula (1) and used as a luminescent material.

As an example of a polymer having a repeating unit including a structure represented by the general formula (1), a polymer including a structure represented by the following general formula (7) or (8) can be given.

In the general formula (7) or (8), Q represents a group including the structure represented by the general formula (1), and 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 formula (7) or (8), 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.
The linking group represented by L ¹ and L ² is any one of R ² , R ³ , R ⁴ and R ⁶ having the structure of the general formula (1) constituting Q, and R ^{31 having} the structure of the general formula (2). to R ^38, R ^3a, one of R ^3b, the general formula (3) R ⁴¹ to R ⁴⁸ of the structure, one of R ^4a, one of R ⁵¹ to R ⁵⁸ of the structural formula (4), It can be bonded to any one of R ^{61 to} R ⁶⁸ of the structure of the general formula (5), or to R ^{71 to} R ⁷⁸ of the structure of the general formula (6). Two or more linking groups may be linked to one Q to form a crosslinked structure or a network structure.

Specific examples of the structure of the repeating unit include structures represented by the following formulas (9) to (12).

In the polymer having a repeating unit containing these formulas (9) to (12), a hydroxy group is introduced into any one of R ² , R ³ , R ⁴ and R ⁶ in the structure of the general formula (1). Then, it can be synthesized by reacting the following compound as a linker 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 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 (1 ′)]
The compound represented by the following general formula (1 ′) is a novel compound.

In the general formula (1 ′), R ¹ ′, R ³ ′ and R ⁵ ′ represent a fluorine atom, or R ¹ ′, R ² ′, R ⁴ ′ and R ⁵ ′ represent a fluorine atom, and the remaining R ¹ ′ to R ⁶ ′ each independently represents a group represented by any one of the following general formulas (2 ′) to (6 ′).

一般式（２’）〜（６’）において、Ｌ¹⁴’〜Ｌ¹⁸’は単結合、または置換もしくは無置換のアリーレン基を表し、＊は一般式（１）におけるベンゼン環への結合部位を表す。Ｒ³¹’〜Ｒ³⁸’、Ｒ^3a’、Ｒ^3b’、Ｒ⁴¹’〜Ｒ⁴⁸’、Ｒ^4a’、Ｒ⁵¹’〜Ｒ⁵⁸’、Ｒ⁶¹’〜Ｒ⁶⁸’、Ｒ⁷¹’〜Ｒ⁷⁸’は、各々独立に水素原子または置換基を表す。Ｒ³¹’とＲ³²’、Ｒ³²’とＲ³³’、Ｒ³³’とＲ³⁴’、Ｒ³⁵’とＲ³⁶’、Ｒ³⁶’とＲ³⁷’、Ｒ³⁷’とＲ³⁸’、Ｒ^3a’とＲ^3b’、Ｒ⁴¹’とＲ⁴²’、Ｒ⁴²’とＲ⁴³’、Ｒ⁴³’とＲ⁴⁴’、Ｒ⁴⁵’とＲ⁴⁶’、Ｒ⁴⁶’とＲ⁴⁷’、Ｒ⁴⁷’とＲ⁴⁸’、Ｒ⁵¹’とＲ⁵²’、Ｒ⁵²’とＲ⁵³’、Ｒ⁵³’とＲ⁵⁴’、Ｒ⁵⁵’とＲ⁵⁶’、Ｒ⁵⁶’とＲ⁵⁷’、Ｒ⁵⁷’とＲ⁵⁸’、Ｒ⁶¹’とＲ⁶²’、Ｒ⁶²’とＲ⁶³’、Ｒ⁶³’とＲ⁶⁴’、Ｒ⁶⁵’とＲ⁶⁶’、Ｒ⁶⁶’とＲ⁶⁷’、Ｒ⁶⁷’とＲ⁶⁸’、Ｒ⁷¹’とＲ⁷²’、Ｒ⁷²’とＲ⁷³’、Ｒ⁷³’とＲ⁷⁴’、Ｒ⁷⁵’とＲ⁷⁶’、Ｒ⁷⁶’とＲ⁷⁷’、Ｒ⁷⁷’とＲ⁷⁸’はそれぞれ互いに結合して環状構造を形成していてもよい。
一般式（１’）におけるＲ¹'〜Ｒ⁶'と、一般式（２’）〜（６’）におけるＬ¹⁴’〜Ｌ¹⁸’、＊、
Ｒ³¹’〜Ｒ³⁸’、Ｒ^3a’、Ｒ^3b’、Ｒ⁴¹’〜Ｒ⁴⁸’、Ｒ^4a’、Ｒ⁵¹’〜Ｒ⁵⁸’、Ｒ⁶¹’〜Ｒ⁶⁸’、Ｒ⁷¹’〜Ｒ⁷⁸’の説明と好ましい範囲については、一般式（１）で表される化合物の説明を参照することができる。

In the general formulas (2 ′) to (6 ′), L ¹⁴ ′ to L ¹⁸ ′ represent a single bond or a substituted or unsubstituted arylene group, and * represents a bonding site to the benzene ring in the general formula (1). Represent. ^{R 31 '~R 38', R} 3a ', R 3b', R 41 '~R 48', R 4a ', R 51' ~R 58 ', R 61' ~R 68 ', R 71' ~R 78 'Each independently represents a hydrogen atom or a substituent. R ³¹ 'and R ^32', R ³² 'and R ^33', R ³³ 'and R ^34', R ³⁵ 'and R ^36', 'R ³⁷ and' R ^36, R ³⁷ 'and R ^38', R ^3a 'And R ^3b ', R ⁴¹ 'and R ⁴² ', R ⁴² 'and R ⁴³ ', R ⁴³ 'and R ⁴⁴ ', R ⁴⁵ 'and R ⁴⁶ ', R ⁴⁶ 'and R ⁴⁷ ', R ⁴⁷ 'and ^R48 ', ^R51 ' and ^R52 ', ^R52 ' and ^R53 ', ^R53 ' and ^R54 ', ^R55 ' and ^R56 ', ^R56 ' and ^R57 ', ^R57 ' and ^R58 ', R ⁶¹ ' and R ⁶² ', R ⁶² ' and R ⁶³ ', R ⁶³ ' and R ⁶⁴ ', R ⁶⁵ ' and R ⁶⁶ ', R ⁶⁶ ' and R ⁶⁷ ', R ⁶⁷ ' and R ⁶⁸ ', ^R71 'and ^R72 ', ^R72 'and ^R73 ', ^R73 'and ^R74 ', ^R75 'and ^R76 ', ^R76 'and ^R77 ', ^R77 'and ^R78 ' It may combine to form a cyclic structure.
R ¹ ′ to R ⁶ ′ in general formula (1 ′), L ¹⁴ ′ to L ¹⁸ ′ in general formulas (2 ′) to (6 ′), *,
^{R 31 '~R 38', R} 3a ', R 3b', R 41 '~R 48', R 4a ', R 51' ~R 58 ', R 61' ~R 68 ', R 71' ~R 78 For the explanation and preferred range of ', the explanation of the compound represented by formula (1) can be referred to.

[Synthesis Method of Compound Represented by General Formula (1 ′)]
The compound represented by the general formula (1 ′) can be synthesized by combining known reactions. For example, R ¹ ′, R ² ′, R ⁴ ′, R ⁵ ′ in the general formula (1 ′) are fluorine atoms, and R ³ ′, R ⁶ ′ are groups represented by the general formula (2 ′). A compound in which L ¹⁶ ′ is a 1,4-phenylene group can be synthesized by reacting the following two compounds.

For the explanation of R ³¹ ′ to R ³⁸ ′, R ^3a and R ^{3b in} the above reaction formula, the corresponding description in the general formula (1 ′) can be referred to. X represents a halogen atom other than a fluorine atom, and examples include a chlorine atom, a bromine atom, and an iodine atom, and a bromine atom is preferable.
The above reaction is an application of a known reaction, and known reaction conditions can be appropriately selected and used. The details of the above reaction can be referred to the synthesis examples described below. The compound represented by the general formula (1 ′) can also be synthesized by combining other known synthesis reactions.

[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 a structure represented by the general formula (1), an invention using a compound represented by the general formula (1) as a delayed phosphor, and a 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.

  Moreover, when the compound represented by the general formula (1) of the present invention is formed as a light emitting layer, it tends to exhibit good orientation with respect to the film forming surface. When the orientation of the compound with respect to the film-forming surface is excellent, there is an advantage that the traveling direction of light emitted from the compound is aligned and the light extraction efficiency from the light emitting layer is easily improved.

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. At this time, the compound represented by the general formula (1) of the present invention may have a function of assisting light emission of another light emitting material included in the light emitting layer as a so-called assist dopant. That is, the compound represented by the general formula (1) of the present invention contained in the light emitting layer includes the lowest excitation singlet energy level of the host material contained in the light emitting layer and the lowest excitation of other light emitting materials contained in the light emitting layer. It may have the lowest excited singlet energy level between singlet energy levels.
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. However, even if singlet excitons and triplet excitons cannot be sufficiently confined, there are cases where high luminous efficiency can be obtained, so that host materials that can achieve high luminous efficiency are particularly limited. And can be used in the present invention. 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. There are a hole injection layer and an electron injection layer, and between the anode and the light emitting layer or the hole transport 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 the structural formulas of the following exemplary compounds, R and R _{1 to} R ₁₀ each independently represent a hydrogen atom or a substituent. n represents an integer of 3 to 5.

  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.

θは基板の法線方向と分子がなす角度の平均値、ｋ_o，ｋ_eはそれぞれ基板に対して水平方向および法線方向に遷移双極子を持つ分子の消衰係数である。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. In addition, the evaluation of the light emission characteristics was performed using a high performance ultraviolet visible near infrared spectrophotometer (Perkin Elmer: Lambda 950), a fluorescence spectrophotometer (Horiba, Ltd .: FluoroMax-4), an absolute PL quantum yield measuring device (Hamamatsu). Photonics: C11347), source meter (Ceethley: 2400 series), semiconductor parameter analyzer (Agilent Technology: E5273A), optical power meter measuring device (Newport: 1930C), optical spectrometer ( The measurement was performed using a spectroradiometer (manufactured by Topcon Co., Ltd .: SR-3) and a streak camera (C4334 manufactured by Hamamatsu Photonics Co., Ltd.). Further, the molecular orientation was measured using an ellipsometer ( M-2000 manufactured by JA Woollam). Construction of the optical model, fitting for minimizing the mean square error between the optical model and the actual measurement value, etc. were performed using WASE32 (manufactured by JA Woollam Co., Ltd.) which is software for ellipsometry data analysis. The order parameter S for evaluating the degree of orientation was defined by the following equation.

Mean value of the angle θ is formed by the normal direction and the molecules of the substrate, which is k _o, k _e extinction coefficient of the molecules with the transition dipole in the horizontal direction and the normal direction respectively with respect to the substrate.

Synthesis Example 1 Synthesis of Compound 1

1,4-dibromo-2,3,5,6-tetrafluorobenzene (0.240 g, 0.78 mmol), 2- (4- (9H-phenoxazin-9-yl) phenyl-1-yl) -4 , 4,5,5-tetramethyl-1,3,2-dioxaborolane (0.05 g, 0.13 mmol), tetrahydrofuran (17 ml), Pd (PPh ₃ ) ₄ (0.08 g, 0.07 mmol), 2M K ₂ CO ₃ aq (5 mL) was placed in a 50 ml three-necked flask and degassed. The degassed solution was heated to 66 ° C. under a nitrogen stream and further 2- (4- (9H-phenoxazin-9-yl) phenyl-1-yl) -4,4,5,5-tetramethyl. A solution of -1,3,2-dioxaborolane (550 g, 1.4 mmol) dissolved in 5 ml of tetrahydrofuran was added dropwise over 10 hours, and the mixture was stirred for 40 hours while maintaining the temperature at 66 ° C. After returning this reaction solution to room temperature, tetrahydrofuran was removed from the reaction solution using an evaporator to obtain a precipitate. This precipitate was added to 150 ml of dichloromethane to form a solution. This solution was washed with 150 ml of water and 150 ml of saturated brine, and then the organic layer was dried over anhydrous magnesium sulfate, and the solvent was removed using evaporation. The obtained residue was recrystallized with a mixed solvent of dichloromethane / n-hexane, and 1,4-bis (4- (9H-phenoxazin-9-yl) phenyl-1-yl)-was obtained as a white solid (Compound 1). 90 mg (0.14 mmol) of 2,3,5,6-tetrafluorobenzene was obtained in a yield of 18%.
¹ H-NMR (500 MHz, DMSO-d6): δ = 5.96 (m, 4H; ArH), 6.71-6.80 (m, 12H; ArH), 7.68 (dd, J _ortho = 6 .6 Hz, J _meta = 1.9 Hz, 4H; Ar H ), 7.92 (d, J = 8.2 Hz, 4H; ArH). ¹⁹ F-NMR (500 MHz, DMSO-d6): δ = -143.8.

Synthesis Example 2 Synthesis of Compound 2

1,4-dibromo-2,3,5,6-tetrafluorobenzene (0.308 g, 1 mmol), 2- (4- (9H-10,10-dimethylacridin-9-yl) phenyl-1-yl) −4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.10 g, 0.2 mmol), tetrahydrofuran (50 ml), Pd (PPh ₃ ) ₄ (0.20 g, 0.17 mmol), 2M K ₂ CO ₃ aq (12 mL) was placed in a 200 ml three-necked flask and degassed. The degassed solution was heated to 66 ° C. under a nitrogen stream, and further 1,4- {4- (9H-10,10-dimethylacridan-9-yl) phenyl-1-yl} -4,4 , 5,5-tetramethyl-1,3,2-dioxaborolane (755 g, 1.7 mmol) in 10 ml of tetrahydrofuran was added dropwise over 8 hours, and the mixture was stirred for 40 hours while maintaining the temperature at 66 ° C. After returning this reaction solution to room temperature, tetrahydrofuran was removed from the reaction solution using an evaporator to obtain a precipitate. This precipitate was added to 150 ml of dichloromethane to form a solution. This solution was washed with 150 ml of water and 150 ml of saturated brine, and then the organic layer was dried over anhydrous magnesium sulfate, and the solvent was removed using evaporation. The obtained residue was recrystallized with a mixed solvent of dichloromethane / n-hexane, and 1,4-bis (4- (9H-10,10-dimethylacridin-9-yl) phenyl-1 was obtained as a white solid (Compound 2). -Yl) -2,3,5,6-tetrafluorobenzene was obtained in a yield of 332 mg (46 mmol) and a yield of 46%.
¹ H-NMR (500 MHz, CDCl ₃ ): δ = 1.72 (s, 12H; C H ₃ ), 6.37 (dd, J _ortho = 8.2 Hz, J _meta = 1.2 Hz, 4H; Ar H ), 6.96 (dt, J _ortho = 7.4 Hz, J _meta = 1.2 Hz, 4H; Ar H ), 7.04 (dt, J _ortho = 7.4 Hz, J _meta = 1.5 Hz, 4H; Ar H ), 7.49 (dd, J _ortho = 7.8 Hz, J _meta = 1.5 Hz, 4 H; Ar H ), 7.52 (td, J _ortho = 8.5 Hz, J _meta = 1.9 Hz, 4H; Ar H ), 7.83 (d, J = 8.2 Hz, 4H; Ar H ). ¹⁹ F-NMR (500 MHz, CDCl ₃ ): δ = −143.57. _{Anal.Calcd for C 48 H 36 F 4} N 2: C, 80.43; H, 5.06; N, 3.91%. Found: C, 80.54; H, 5.06; N, 3.95%.

(Comparative Synthesis Example 1) Synthesis of Comparative Compound 1

1,3,5-tribromo-2,4,6-trifluorobenzene (0.738 g, 2 mmol), 2- {4- (9H-carbazolyl-9-yl) phenyl-1-yl} -4,4 5,5-tetramethyl-1,3,2-dioxaborolane (0.52 g, 1.4 mmol), tetrahydrofuran (55 ml), tetrakis (triphenylphosphine) palladium (Pd (PPh ₃ ) ₄ : 0.30 g, 0. 26 mmol), and 2M K ₂ CO ₃ aq (15 mL) were placed in a 200 ml three-necked flask and degassed. The degassed solution was heated to 66 ° C. under a nitrogen stream and further 1,4- {4- (9H-carbazolyl-9-yl) phenyl-1-yl} -4,4,5,5-tetra A solution of methyl-1,3,2-dioxaborolane (1.70 g, 4.6 mmol) in 20 ml of tetrahydrofuran was added dropwise over 12 hours, and the mixture was stirred for 6 days while maintaining the temperature at 66 ° C. After returning this reaction solution to room temperature, tetrahydrofuran was removed from the reaction solution using an evaporator to obtain a precipitate. The precipitate was collected by filtration, washed with water, and dried in vacuo. The obtained solid was added to 200 ml of heated dichloromethane to form a solution, which was filtered and concentrated. N-hexane was added to the obtained concentrate to precipitate a white powder, and the precipitated white powder (intermediate 1) was collected by filtration. By the above steps, 1,3,5- (4- (9H-carbazolyl-9-yl) phenyl-1-yl) -2,4,6-trifluorobenzene of Comparative Compound 1 was obtained in a yield of 683 mg (0.80 mmol). ), And the yield was 40%.
¹ H-NMR (500 MHz, CDCl ₃ ): δ = 7.33 (t, J = 7.4 Hz, 6H; Ar H ), 7.46 (dt, J _ortho = 7.6 Hz, J _meta = 1.0 Hz) , 6H; Ar H), 7.55 (d, J = 8.2Hz, 6H; Ar H), 7.76 (d, J = 8.4Hz, 6H; Ar H), 7.84 (d, J = 8.2 Hz, 6H; Ar H ), 8.17 (d, J = 7.8 Hz, 6H; Ar H ). ¹⁹ F-NMR (500 MHz, CDCl ₃ ): δ = −115.32.

(Comparative Synthesis Example 2) Synthesis of Comparative Compound 2 Except for using 1,4-dibromo-2,3,5,6-tetrafluorobenzene instead of 1,3,5-tribromo-2,4,6-trifluorobenzene Was synthesized in the same manner as in the synthesis step of Comparative Compound 1 in Comparative Synthesis Example 1.

Example 1 Preparation and Evaluation of Solution Using Compound 1 A toluene solution of Compound 1 was prepared in a glove box under an Ar atmosphere. An emission spectrum by 337 nm excitation light was measured. The measured emission spectrum is shown in FIG. The maximum emission wavelength of the toluene solution of Compound 1 was 505 nm, and the photoluminescence quantum efficiency was 17.2% in air and 45.4% after deaeration.
Moreover, when the transient decay curve was measured about the toluene solution of the compound 1, the light emission lifetime (tau) in the air was 8.22 ns. In the transient decay curve of the toluene solution after deaeration, two types of fluorescence (immediate fluorescence and delayed fluorescence) can be observed, the emission lifetime τ _{1 of} immediate fluorescence is 19.6 ns, and the emission lifetime τ _{2 of} delayed fluorescence is 8 .52 μs.

Example 2 Production and Evaluation of Organic Photoluminescence Device Using Compound 2 A toluene solution of Compound 2 was prepared by changing the point where Compound 2 was used instead of Compound 1.
Further, a thin film of Compound 2 having a thickness of 50 nm was formed on a quartz substrate by a vacuum vapor deposition method under a vacuum degree of 4.0 × 10 ⁻⁴ Pa or less to obtain an organic photoluminescence device.
Separately, Compound 2 and mCP are deposited on a quartz substrate by a vacuum deposition method under a vacuum degree of 4.0 × 10 ⁻⁴ Pa or less from different deposition sources, and the concentration of Compound 2 is 6.0 weight. % Thin film was formed with a thickness of 50 nm to obtain an organic photoluminescence device.
Separately, Compound 2 and DPEPO are vapor-deposited from a different vapor deposition source on a quartz substrate by a vacuum vapor deposition method under a vacuum degree of 4.0 × 10 ⁻⁴ Pa or less. A thin film of 0% by weight was formed with a thickness of 50 nm to obtain an organic photoluminescence device.
When the orientation of the organic photoluminescence device having a thin film of only Compound 2 was measured by ellipsometry spectroscopy, the orientation angle of the molecule relative to the film-forming surface of Compound 2 was 16.0 °.
Moreover, the emission spectrum by 337 nm excitation light was measured about the sample using these compounds 2. The absorption emission spectrum of the toluene solution is shown in FIG. An absorption spectrum of an organic photoluminescence device having a thin film of only Compound 2 is shown in FIG. 4, and an emission spectrum is shown in FIG. An emission spectrum of an organic photoluminescence device having a thin film of Compound 2 and mCP is shown in FIG. An emission spectrum of an organic photoluminescence device having a thin film of Compound 2 and DPEPO is shown in FIG. 7, and a fluorescence spectrum and a phosphorescence spectrum are shown in FIG.
In the toluene solution, the maximum emission wavelength was 457 nm, the photoluminescence quantum efficiency was 11.5% in air, and 18% after deaeration. The photoluminescence quantum efficiency of the organic photoluminescence device is 31.1% for a device having a thin film of compound 2 only, 30% for a device having a thin film of compound 2 and mCP, and 48% of a device having a thin film of compound 2 and DPEPO. Met. Further, for the device having the thin film of Compound 2 and DPEPO, the difference ΔEst between the energy in the excited singlet state and the energy in the excited triplet state obtained from the fluorescence spectrum and the phosphorescence spectrum was 0.351 eV.
Moreover, the result of having measured the transient attenuation | damping curve about the toluene solution of the compound 2 is shown in FIG. 9, and the result of having measured the transient attenuation | damping curve about the organic photoluminescent element which has the thin film of the compound 2 and DPEPO is shown in FIG. These transient decay curves show the results of luminescence lifetime measurement in which the process in which the emission intensity is deactivated by applying excitation light to the compound is measured. In the case of normal single component light emission (fluorescence or phosphorescence), the light emission intensity decays in a single exponential manner. This means that if the vertical axis of the graph is semi-log, it will decay linearly. In the transient decay curve of Compound 2, such a linear component (fluorescence) is observed at the beginning of observation, but a component deviating from linearity appears after several μsec. This is light emission of the delay component, and the signal added to the initial component becomes a loose curve with a tail on the long time side. Thus, by measuring the luminescence lifetime, it was confirmed that Compound 2 was a luminescent material containing a delay component in addition to the fluorescent component. In the toluene solution, the emission lifetime τ in air was 4.79 ns, and the emission lifetime τ ₁ after deaeration was 6.51 ns. In an organic photoluminescence device having a thin film of Compound 2 and DPEPO, two types of fluorescence (immediate fluorescence and delayed fluorescence) can be observed, the emission lifetime τ _{1 of} immediate fluorescence is 4.64 ns, and the emission lifetime τ of delayed fluorescence. ₂ was 2.9 ms.

(Comparative Example 1) Preparation and Evaluation of Organic Photoluminescence Device Using Comparative Compound 1 The point of using Comparative Compound 1 instead of Compound 1 was changed, and a dichloromethane solution of Comparative Compound 1 and a thin film only of Comparative Compound 1 were used. An organic photoluminescence device having the above was produced.
The emission wavelength peak of the degassed dichloromethane solution was 363 nm, and the emission quantum yield was 48%. The light emission lifetime τ was 4.795 ns, and no delay component was observed. The neat thin film had an emission wavelength peak of 381 nm and an emission quantum yield of 30%. The light emission lifetime was 4.993 ns, and no delay component was observed.

(Comparative Example 2) Production and Evaluation of Organic Photoluminescence Device Using Comparative Compound 2 By changing the point of using Comparative Compound 2 instead of Compound 1, a dichloromethane solution of Comparative Compound 2 and a thin film only of Comparative Compound 2 were prepared. An organic photoluminescence element having the same was produced.
The emission wavelength peak of the degassed dichloromethane solution was 447 nm, and the emission quantum yield was 92%. The emission lifetime τ was 2.133 ns, and no delay component was observed. The neat thin film had an emission wavelength peak of 429 nm and an emission quantum yield of 30%. The emission lifetime was 1.296 ns, and no delay component was observed.

(Example 3) Production and evaluation of organic electroluminescence device using compound 2 Each thin film was formed by vacuum deposition on a glass substrate on which an anode made of indium tin oxide (ITO) having a thickness of 100 nm was formed. And a degree of vacuum of 4 × 10 ⁻⁴ Pa. First, α-NPD was formed to a thickness of 40 nm on ITO. Next, Compound 2 and DPEPO were co-evaporated from different vapor deposition sources to form a layer having a thickness of 30 nm to form a light emitting layer. At this time, the concentration of Compound 2 was 6.0% by weight. Next, DPEPO is formed to a thickness of 5 nm, TPBi is formed to a thickness of 30 nm, lithium fluoride (LiF) is vacuum-deposited to 0.5 nm, and aluminum (Al) is then evaporated to a thickness of 100 nm. Thus, a cathode was formed, and an organic electroluminescence element was obtained.
The emission spectrum of the manufactured organic electroluminescence element is shown in FIG. 11, the voltage-current density characteristic is shown in FIG. 12, and the current density-external quantum efficiency characteristic is shown in FIG. The organic electroluminescence device using Compound 2 as the light emitting material achieved a high external quantum efficiency of 8.3%. Assuming that an ideal organic electroluminescence device balanced using a fluorescent material having a light emission quantum efficiency of 100% is prototyped, if the light extraction efficiency is 20 to 30%, the external quantum efficiency of fluorescent light emission is 5 -7.5%. This value is generally regarded as a theoretical limit value of the external quantum efficiency of an organic electroluminescence device using a fluorescent material. The organic electroluminescence device of the present invention using Compound 2 is extremely excellent in that high external quantum efficiency exceeding the theoretical limit value is realized.

  The compound of the present invention is useful as a light emitting material. For this reason, the compound of this invention is effectively used as a luminescent material for organic light emitting elements, such as an organic electroluminescent element. Since the compounds of the present invention include those that emit delayed fluorescence, it is also possible to provide an organic light-emitting device with high luminous efficiency. 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 (12)

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

[In General Formula (1), R ¹ , R ³ and R ⁵ represent a fluorine atom, or R ¹ , R ² , R ⁴ and R ⁵ represent a fluorine atom, and the remaining R ^{1 to} R ⁶ are each independently Represents a group represented by any one of the following general formulas (2) to (6). ]

[In General Formulas (2) to (6), L ^{14 to} L ¹⁸ represent a single bond or a substituted or unsubstituted arylene group, and * represents a bonding site to the benzene ring in General Formula (1). R ^{31 to} R ³⁸ , R ^3a , R ^3b , R ^{41 to} R ⁴⁸ , R ^4a , R ^{51 to} R ⁵⁸ , R ^{61 to} R ⁶⁸ , and R ^{71 to} R ⁷⁸ each independently represent a hydrogen atom or a substituent. . R ³¹ and R ^32, R ³² and R ^33, R ³³ and R ^34, R ³⁵ and R ^36, R ³⁶ and R ^37, R ³⁷ and R ^38, R ^3a and R ^3b, R ⁴¹ and R ^42, R ⁴² And R ⁴³ , R ⁴³ and R ⁴⁴ , R ⁴⁵ and R ⁴⁶ , R ⁴⁶ and R ⁴⁷ , R ⁴⁷ and R ⁴⁸ , R ⁵¹ and R ⁵² , R ⁵² and R ⁵³ , R ⁵³ and R ⁵⁴ , R ⁵⁵ and R ⁵⁶ , R ⁵⁶ and R ⁵⁷ , R ⁵⁷ and R ⁵⁸ , R ⁶¹ and R ⁶² , R ⁶² and R ⁶³ , R ⁶³ and R ⁶⁴ , R ⁶⁵ and R ⁶⁶ , R ⁶⁶ and R ⁶⁷ , R ⁶⁷ and R ⁶⁸ , R ⁷¹ and R ⁷² , R ⁷² and R ⁷³ , R ⁷³ and R ⁷⁴ , R ⁷⁵ and R ⁷⁶ , R ⁷⁶ and R ⁷⁷ , and R ⁷⁷ and R ⁷⁸ may be bonded to each other to form a cyclic structure. . ] The luminescent material according to claim ¹ , wherein R ¹ , R ² , R ⁴ and R ^{5 in the} general formula (1) are fluorine atoms. The luminescent material according to claim ¹ , wherein R ¹ , R ³ and R ^{5 in the} general formula (1) are fluorine atoms. The luminescent material according to claim 1, wherein L ^{14 to} L ^{18 in the} general formulas (2) to (6) are substituted or unsubstituted phenylene groups. 5. The luminescent material according to claim 1, wherein the remaining R ^{1 to} R ⁶ of the general formula (1) are all groups represented by the general formula (2). . 5. The luminescent material according to claim 1, wherein the remaining R ^{1 to} R ⁶ of the general formula (1) are all groups represented by the general formula (4). .   The luminescent material according to claim 1, wherein the molecule has a rotationally symmetric structure. A delayed phosphor comprising a compound represented by the following general formula (1).

[In General Formula (1), R ¹ , R ³ and R ⁵ represent a fluorine atom, or R ¹ , R ² , R ⁴ and R ⁵ represent a fluorine atom, and the remaining R ^{1 to} R ⁶ are each independently Represents a group represented by any one of the following general formulas (2) to (6). ]

[In General Formulas (2) to (6), L ^{14 to} L ¹⁸ represent a single bond or a substituted or unsubstituted arylene group, and * represents a bonding site to the benzene ring in General Formula (1). R ^{31 to} R ³⁸ , R ^3a , R ^3b , R ^{41 to} R ⁴⁸ , R ^4a , R ^{51 to} R ⁵⁸ , R ^{61 to} R ⁶⁸ , and R ^{71 to} R ⁷⁸ each independently represent a hydrogen atom or a substituent. . R ³¹ and R ^32, R ³² and R ^33, R ³³ and R ^34, R ³⁵ and R ^36, R ³⁶ and R ^37, R ³⁷ and R ^38, R ^3a and R ^3b, R ⁴¹ and R ^42, R ⁴² And R ⁴³ , R ⁴³ and R ⁴⁴ , R ⁴⁵ and R ⁴⁶ , R ⁴⁶ and R ⁴⁷ , R ⁴⁷ and R ⁴⁸ , R ⁵¹ and R ⁵² , R ⁵² and R ⁵³ , R ⁵³ and R ⁵⁴ , R ⁵⁵ and R ⁵⁶ , R ⁵⁶ and R ⁵⁷ , R ⁵⁷ and R ⁵⁸ , R ⁶¹ and R ⁶² , R ⁶² and R ⁶³ , R ⁶³ and R ⁶⁴ , R ⁶⁵ and R ⁶⁶ , R ⁶⁶ and R ⁶⁷ , R ⁶⁷ and R ⁶⁸ , R ⁷¹ and R ⁷² , R ⁷² and R ⁷³ , R ⁷³ and R ⁷⁴ , R ⁷⁵ and R ⁷⁶ , R ⁷⁶ and R ⁷⁷ , and R ⁷⁷ and R ⁷⁸ may be bonded to each other to form a cyclic structure. . ]   An organic light-emitting device comprising the light-emitting material according to claim 1.   The organic light-emitting device according to claim 9, which emits delayed fluorescence.   The organic light-emitting device according to claim 9, wherein the organic light-emitting device is an organic electroluminescence device. A compound represented by the following general formula (1 ′).

[In the general formula (1 ′), R ¹ ′, R ³ ′ and R ⁵ ′ represent a fluorine atom, or R ¹ ′, R ² ′, R ⁴ ′ and R ⁵ ′ represent a fluorine atom, R ¹ ′ to R ⁶ ′ each independently represents a group represented by any one of the following general formulas (2 ′) to (6 ′). ]

[In the general formulas (2 ′) to (6 ′), L ¹⁴ ′ to L ¹⁸ ′ represent a single bond or a substituted or unsubstituted arylene group, and * represents a bonding site to the benzene ring in the general formula (1). Represents. ^{R 31 '~R 38', R} 3a ', R 3b', R 41 '~R 48', R 4a ', R 51' ~R 58 ', R 61' ~R 68 ', R 71' ~R 78 'Each independently represents a hydrogen atom or a substituent. R ³¹ 'and R ^32', R ³² 'and R ^33', R ³³ 'and R ^34', R ³⁵ 'and R ^36', 'R ³⁷ and' R ^36, R ³⁷ 'and R ^38', R ^3a 'And R ^3b ', R ⁴¹ 'and R ⁴² ', R ⁴² 'and R ⁴³ ', R ⁴³ 'and R ⁴⁴ ', R ⁴⁵ 'and R ⁴⁶ ', R ⁴⁶ 'and R ⁴⁷ ', R ⁴⁷ 'and ^R48 ', ^R51 ' and ^R52 ', ^R52 ' and ^R53 ', ^R53 ' and ^R54 ', ^R55 ' and ^R56 ', ^R56 ' and ^R57 ', ^R57 ' and ^R58 ', R ⁶¹ ' and R ⁶² ', R ⁶² ' and R ⁶³ ', R ⁶³ ' and R ⁶⁴ ', R ⁶⁵ ' and R ⁶⁶ ', R ⁶⁶ ' and R ⁶⁷ ', R ⁶⁷ ' and R ⁶⁸ ', ^R71 'and ^R72 ', ^R72 'and ^R73 ', ^R73 'and ^R74 ', ^R75 'and ^R76 ', ^R76 'and ^R77 ', ^R77 'and ^R78 ' It may combine to form a cyclic structure. ]

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