WO2015072537A1 - Light-emitting material, organic light-emitting element, and compound - Google Patents

Abstract

A compound represented by general formula (1) is useful as a light-emitting material. R¹ to R⁸ independently represent a hydrogen atom or a substituent, and R⁹ represents a substituent, wherein at least one of R¹ to R⁸ represents a group represented by general formula (2) or the like. L¹² represents a single bond or a bivalent linking group, and * represents a bonding site to a benzene ring in general formula (1). R¹¹ to R²⁰ independently represent a hydrogen atom or a substituent.

Description

Luminescent materials, organic light emitting devices and compounds

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. Among them, research on organic electroluminescence devices using a compound having a structure in which a substituent such as a carbazolyl group is bonded to a tricyclic structure having a heteraborine ring containing a boron atom and another heteroatom can be seen.

Non-Patent Document 1 describes the results of studying luminescence characteristics of a compound having a heteraboline ring containing a boron atom and a nitrogen atom. According to the document, it was described that when a cyclohexane solution or a solid film of a compound having the following structure was irradiated with excitation light, light emission was observed in the visible region (Hex ⁿ represents an n-hexyl group, and Tip represents Represents a 2,4,6-triisopropylphenyl group).
However, Non-Patent Document 1 does not describe a compound in which a heteroatom of a heteraboline ring is changed to a heteroatom other than a nitrogen atom such as an oxygen atom or a sulfur atom.

Further, Patent Document 1 discloses a compound having a tricyclic structure having a heterolabrin ring represented by the following general formula. R ₁ in the following general formula is a group containing two or more aryl groups or heteroaryl groups, R ₃ and R ₄ represent 1 to 5 substituents, R ₂ to R ₄ represent a hydrogen atom, an alkyl group, It is defined to represent an alkoxy group, amino group, alkenyl group, alkynyl group, aryl group, heteroaryl group. Here, a compound in which R _{1 in the following} general formula is a 2,4,6-triphenylphenyl group, R ₂ is a phenyl group, and R ₃ and R ₄ are hydrogen atoms is used as a pair of electrodes constituting an organic electroluminescence device. An example of using it as a host material in a light emitting layer existing between them and an example of using it in an electron transport layer are described. However, Patent Document 1 does not describe the light emission characteristics of the compound represented by this general formula, nor does it describe a compound in which the heteroatom of the heterolabrin ring is changed to a heteroatom other than a nitrogen atom. .

Non-Patent Document 2 describes the results of studying the emission characteristics of a compound having a heteraboline ring containing a boron atom and other heteroatoms, and light emission in the visible region was observed in a cyclohexane solution of a compound having the following structure. It is described. In the following formula, R represents a hydrogen atom or a methyl group, E represents an N-methyl group or a sulfur atom, and Mes represents a mesityl group. However, Non-Patent Document 1 does not describe a compound in which R is a substituted amino group such as a carbazolyl group.

WO2011 / 143563 Publication

As described above, Non-Patent Document 1 discloses that a compound in which a carbazolyl group is introduced into a tricyclic structure having a heteraboline ring (azaborin ring) containing a boron atom and a nitrogen atom emits light in the visible region. However, when the inventors actually evaluated the light emission characteristics of a compound in which a carbazolyl group substituted with a carbazolyl group, a methyl group, or the like was introduced into a tricyclic structure having an azaborin ring, the light emission characteristics can be sufficiently satisfied. It was proved that it was not (see Comparative Examples 1 to 3 below).
Therefore, the present inventors have started various studies on a compound group having a heteraboline ring, and are useful as a luminescent material for a compound group having a heteraboline ring containing a boron atom and an oxygen atom or a sulfur atom from many similar skeletons. I found that there was for the first time and decided to proceed with further study. As described above, it is described in Non-Patent Document 2 that light emission was observed in the visible region of a compound having a tricyclic structure having a heteraboline ring containing a boron atom and a sulfur atom. However, Non-Patent Document 2 does not describe a compound in which a substituted amino group such as a carbazole group is bonded to a tricyclic structure having a heterolabrin ring. For this reason, the usefulness as a light-emitting material of a compound in which a substituted amino group such as a carbazolyl group is bonded to a tricyclic structure having a heteraboline ring containing a boron atom and an oxygen atom or a sulfur atom cannot be predicted.

Under such circumstances, the present inventors have further investigated the usefulness of a compound having a heteraboline ring containing a boron atom and an oxygen atom or sulfur atom as a luminescent material, and found a compound having excellent luminescent properties. Aimed at research. 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 intensive investigations, the present inventors have found that compounds having a specific structure among the compounds having a heteraboline ring containing a boron atom and an oxygen atom or a sulfur atom have excellent properties as a luminescent material. 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.

[1] A light emitting material comprising a compound represented by the following general formula (1).

[In General Formula (1), X represents an oxygen atom or a sulfur atom. R ¹ ~ R ⁸ each independently represent a hydrogen atom or a substituent. However, at least one of R ¹ to R ⁸ is each independently a group represented by any one of the following general formulas (2) to (7). R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , R ⁷ and R ⁸ , R ⁸ and R ⁹ , R ⁹ and R ¹ are bonded to each other Thus, a ring structure may be formed. R ⁹ represents a substituent. When R ⁹ contains an atom having a lone pair of electrons that does not form a single bond with a boron atom, the atom may be coordinated with the boron atom to form a cyclic structure. ]

[In the general formulas (2) to (7), L ¹² to L ¹⁷ each independently represents a single bond or a divalent linking group, and * represents a bonding site to the benzene ring in the general formula (1). R ¹¹ to R ²⁰ , R ²¹ to R ²⁸ , 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 are each independently hydrogen Represents an atom or substituent. R ¹¹ and R ¹² , R ¹² and R ¹³ , R ¹³ and R ¹⁴ , R ¹⁴ and R ¹⁵ , R ¹⁶ and R ¹⁷ , R ¹⁷ and R ¹⁸ , R ¹⁸ and R ¹⁹ , R ¹⁹ and R ²⁰ , R ²¹ And R ²² , R ²² and R ²³ , R ²³ and R ²⁴ , R ²⁴ and R ²⁵ , R ²⁵ and R ²⁶ , R ²⁶ and R ²⁷ , R ²⁷ and R ²⁸ , 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, R45} and ^R46 , ^R46 and ^R47 , ^R47 and ^R48 , ^R51 and ^R52 , ^R52 and ^R53 , ^R53 and ^R54 , ^R55 and ^R56 , ^R56 and ^R57 , ^R57 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 are bonded to each other to form a cyclic structure. It may be. ]
[2] The luminescence according to [1], wherein at least one of R ¹ to R ^{8 in} the general formula (1) is a group represented by any one of the general formulas (3) to (7) material.
[3] When at least one of R ¹ to R ^{8 in} the general formula (1) is a group represented by the general formula (3), at least one of R ²¹ to R ^{28 in} the general formula (3) One is a substituent, The luminescent material as described in [1] or [2] characterized by the above-mentioned.
[4] It is characterized in that at least one of R ² , R ³ , R ⁶ and R ^{7 in} the general formula (1) is a group represented by any one of the general formulas (2) to (7). The light emitting material according to any one of [1] to [3].
[5] The luminescence according to [4], wherein at least one of R ³ and R ^{6 in} the general formula (1) is a group represented by any one of the general formulas (2) to (7) material.
[6] R ³ and R ⁶ in formula (1) is, according to each, characterized in that a group represented by any one of formulas independently (2) to (7) [5] Luminescent material.
[7] At least one of R ¹¹ to R ^{20 in} the general formula (2), at least one of R ²¹ to R ^{28 in} the general formula (3), and R ³¹ to R ^{38 in} the general formula (4) At least one, at least one of R ^3a and R ^3b , at least one of R ⁴¹ to R ⁴⁸ of the general formula (5), at least one of R ⁵¹ to R ⁵⁸ of the general formula (6), and The light emitting material according to any one of [1] to [6], wherein at least one of R ⁶¹ to R ^{68 in} the general formula (7) is a substituent.
[8] At least one of R ¹³ and R ^{18 in} the general formula (2), at least one of R ²³ and R ^{26 in} the general formula (3), and at least one of R ³³ and R ^{36 in} the general formula (4) And at least one of R ^3a and R ^3b , at least one of R ⁴³ and R ^{46 in} the general formula (5), at least one of R ⁵³ and R ^{56 in} the general formula (6), and the general formula (7) The luminescent material according to [7], wherein at least one of R ⁶³ and R ⁶⁶ is a substituent.
[9] At least one of R ¹³ and R ^{18 in} the general formula (2), at least one of R ²³ and R ^{26 in} the general formula (3), and at least one of R ³³ and R ^{36 in} the general formula (4) And at least one of R ^3a and R ^3b , at least one of R ⁴³ and R ^{46 in} the general formula (5), at least one of R ⁵³ and R ^{56 in} the general formula (6), and the general formula (7) The light emitting material according to [8], wherein at least one of R ⁶³ and R ⁶⁶ is a group represented by any one of the general formulas (2) to (7).
[10] The light emitting material according to any one of [1] to [9], wherein L ¹² to L ^{17 in the} general formulas (2) to (7) are single bonds.
[11] The light emitting material according to any one of [1] to [10], wherein X in the general formula (1) is an oxygen atom.
[12] The light-emitting material according to any one of [1] to [11], wherein R ^{9 in the} general formula (1) is a group represented by the following general formula (a).

[In formula (a), * represents the bonding site to the boron atom in the general formula (1). R ^9a , R ^9b , R ^9c , R ^9d and R ^9e each independently represent a hydrogen atom or a substituent. R ^9a and R ^9b , R ^9b and R ^9c , R ^9c and R ^9d , and R ^9d and R ^9e may be bonded to each other to form a cyclic structure. ]
[13] The luminescent material according to [12], wherein R ^9a and R ^{9e in} the general formula (a) are substituents.
[14] Any one of [1] to [13], wherein at least one of R ¹ to R ^{8 in} the general formula (1) is a group represented by the general formula (4). Luminescent material.
[15] R ³ and R ⁶ in formula (1) or R ² and R ^7, is characterized in that it is a group represented by the general formula (4) [1] to [4], [ [7] The luminescent material according to any one of [14] to [14].
[16] The light-emitting material according to [14] or [15], wherein R ^3a and R ^{3b in} the general formula (4) are substituents.
[17] The light-emitting material according to any one of [14] to [16], wherein the substituent is an alkyl group having 1 to 15 carbon atoms or a phenyl group.
[18] The luminescent material according to any one of [14] to [16], wherein R ^3a and R ^{3b in} the general formula (4) are bonded to each other to form a cyclic structure.
[19] A delayed phosphor comprising the compound represented by the general formula (1).
[20] An organic light-emitting device comprising the light-emitting material according to any one of [1] to [18].
[21] The organic light-emitting device according to [20], which emits delayed fluorescence.
[22] The organic light-emitting device according to [20] or [21], which is an organic electroluminescence device.
[23] A compound represented by the following general formula (1 ′).

[In General Formula (1 ′), X ′ represents an oxygen atom or a sulfur atom. R ¹ ′ to R ⁸ ′ each independently represents a hydrogen atom or a substituent. However, at least one of R ¹ ′ to R ⁸ ′ is a group independently represented by any one of the following general formulas (2 ′) to (7 ′). R ¹ 'and R ^2', R ² 'and R ^3', R ³ 'and R ^4', R ⁵ 'and R ^6', R ⁶ 'and R ^7', R ⁷ 'and R ^8', R ⁸ 'And R ⁹ ' and R ⁹ 'and R ¹ ' may be bonded to each other to form a cyclic structure. R ⁹ ′ represents a substituent. When R ⁹ ′ includes an atom having a lone pair of electrons that does not form a single bond with a boron atom, the atom may be coordinated with the boron atom to form a cyclic structure. ]

[In the general formulas (2 ′) to (7 ′), L ¹² ′ to L ¹⁷ ′ each independently represents a single bond or a divalent linking group, and * represents a bond to the benzene ring in the general formula (1 ′). Represents a site. ^{R 11 '~ R 20',} R 21 '~ R 28', R 31 '~ R 38', R 3a ', R 3b', R 41 '~ R 48', R 4a ', R 51' ~ R 58 ', R ⁶¹ ' to R ⁶⁸ 'each independently represents a hydrogen atom or a substituent. R ¹¹ 'and R ^12', R ¹² 'and R ^13', R ¹³ 'and R ^14', R ¹⁴ 'and R ^15', 'R ¹⁷ and' R ^16, R ¹⁷ 'and R ^18', R ¹⁸ 'And R ¹⁹ ', R ¹⁹ 'and R ²⁰ ', R ²¹ 'and R ²² ', R ²² 'and R ²³ ', R ²³ 'and R ²⁴ ', R ²⁴ 'and R ²⁵ ', R ²⁵ 'and R ²⁶ ', R ^26' and R ²⁷ ', R ^27' and R ²⁸ ', 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 ', ^R45 'and ^R46 ', ^R46 'and ^R47 ', ^R47 'and ^R48 ', ^R51 'and ^R52 ', ^R52 'and ^R53 ', ^R53 'and ^R54 ', ^R55 '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 ′ may be bonded to each other 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 emission spectrum of a solution of compound 5 in Example 1. 2 is an emission spectrum of a thin film type organic photoluminescence device of Compound 5 of Example 1. 2 is a transient decay curve of a solution of compound 5 of Example 1. It is the emission spectrum of the solution of the compound 6 of Example 2, and a thin film type organic photoluminescent element. 2 is an emission spectrum of a thin film type organic photoluminescence device of Compound 6 of Example 2. 4 is a transient decay curve of a solution of compound 6 of Example 2. 2 is an emission spectrum of a solution of the compound 18 of Example 3. 3 is a transient decay curve of a solution of the compound 18 of Example 3. 4 is an emission spectrum of a solution of the compound 59 of Example 4. 7 is an emission spectrum of a solution of the compound 65 of Example 5. 7 is an emission spectrum of a solution of the compound 67 of Example 6. 4 is an emission spectrum of a solution of compound 156 of Example 7. 4 is a transient decay curve of a solution of compound 156 of Example 7. 2 is an emission spectrum of a solution of Comparative Compound A of Comparative Example 1. 2 is a transient decay curve of a solution of Comparative Compound A of Comparative Example 1. 3 is an emission spectrum of a solution of Comparative Compound B of Comparative Example 2. 4 is a transient decay curve of a solution of Comparative Compound B of Comparative Example 2. 2 is an emission spectrum of a solution of Comparative Compound C of Comparative Example 3. 4 is a transient decay curve of a solution of Comparative Compound C of Comparative Example 3. 2 is an emission spectrum of an organic electroluminescent element of the compound 5 of Example 11. 6 is a graph showing current density-external quantum efficiency characteristics of an organic electroluminescent device of Compound 5 of Example 11. 7 is an emission spectrum of an organic electroluminescent element of the compound 6 of Example 12. 10 is a graph showing current density-external quantum efficiency characteristics of an organic electroluminescence device of Compound 6 of Example 12.

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.

[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), X represents an oxygen atom or a sulfur atom, and is preferably an oxygen atom.
In the general formula (1), R ¹ to R ⁸ each independently represents a hydrogen atom or a substituent. However, at least one of R ¹ to R ⁸ is each independently a group represented by any one of the following general formulas (2) to (7).
The group represented by any of the following general formulas (2) to (7) may be only one of R ¹ to R ⁸ , or may be two or more.
When the group represented by any one of the following general formulas (2) to (7) is only one of R ¹ to R ^8, any one of R ² , R ³ , R ⁶ and R ⁷ Is preferably a group represented by any one of the following general formulas (2) to (7), and R ³ or R ⁶ is a group represented by any one of the following general formulas (2) to (7). More preferably.
On the other hand, when two or more of R ¹ to R ⁸ are groups represented by any of the following general formulas (2) to (7), any one of the following general formulas (2) to (7) Is preferably at least one of R ¹ to R ⁴ and at least one of R ⁵ to R ⁸ . At this time, the groups represented by any of the following general formulas (2) to (7) are 1 to 3 of R ¹ to R ⁴ and 1 to 3 of R ⁵ to R ^8. It is preferably 1 or 2 of R ¹ to R ⁴ , and more preferably 1 or 2 of R ⁵ to R ⁸ . R ¹ to R ⁴ are represented by any of the general formulas (2) to (7), and R ⁵ to R ⁸ are represented by any of the general formulas (2) to (7). The number of groups may be the same or different, but is preferably the same. Among R ¹ to R ⁴ , at least one of R ² or R ³ is preferably a group represented by any one of the general formulas (2) to (7), and at least R ³ is a group represented by the general formula (2) A group represented by any one of (7) to (7) is more preferable. Of R ⁵ to R ⁸ , at least one of R ⁶ or R ⁷ is preferably a group represented by any one of the general formulas (2) to (7), and at least R ⁶ is a group represented by the general formula ( A group represented by any one of 2) to (7) is more preferable. Preferred compounds are those in which R ³ and R ^{6 in} the general formula (1) are groups represented by any one of the general formulas (2) to (7), and R ² and R ^{7 in} the general formula (1) are general. A compound which is a group represented by any one of formulas (2) to (7), wherein R ² , R ³ , R ⁶ and R ⁷ in formula (1) are any of formulas (2) to (7) A more preferred compound is a compound in which R ³ and R ⁶ are groups represented by any one of the general formulas (2) to (7). The groups represented by any of the plurality of general formulas (2) to (7) present in the general formula (1) may be the same or different, but are preferably the same. Moreover, it is also preferable that the group represented by the general formula (1) has a symmetrical structure. That is, R ¹ and R ⁸ , R ² and R ⁷ , R ³ and R ⁶ , and R ⁴ and R ⁵ are preferably the same.

In the general formulas (2) to (7), * represents a bonding site to the benzene ring in the general formula (1).
L ¹² to L ¹⁷ each independently represent a single bond or a divalent linking group, and preferably a single bond. When L ¹² to L ¹⁷ are a divalent linking group, examples of the divalent linking group include an aromatic hydrocarbon ring group having 6 to 18 carbon atoms and a heteroaromatic hydrocarbon ring group having 6 to 18 ring members. Can be mentioned. Preferred linking groups are a phenylene group, a biphenylene group, a fluorenylene group, a triphenylenylene group, and a thiophenylene group, a more preferred linking group is a phenylene group, and a more preferred linking group is a 1,4-phenylene group. . These linking groups may have a substituent introduced therein. For the explanation and preferred range of the substituent that can be introduced into the linking group, the explanation and preferred range of the substituent that can be taken by the following R ¹ to R ^{8 and the} like can be referred to.

In the general formulas (2) to (7), R ¹¹ to R ²⁰ , R ²¹ to R ²⁸ , 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 each independently represents a hydrogen atom or a substituent. The number of substituents is not particularly limited, and R ¹¹ to R ²⁰ , R ²¹ to R ²⁸ , R ³¹ to R ³⁸ , R ^3a , R ^3b , R ⁴¹ to R ⁴⁸ , R ^4a , R ⁵¹ to R ⁵⁸ , R All of ⁶¹ to R ⁶⁸ may be unsubstituted (that is, a hydrogen atom), but R ¹¹ to R ²⁰ , R ²¹ to R ²⁸ , R ³¹ to R ³⁸ , R ^3a and R ^3b , R ⁴¹ to R ⁴⁸ , R ⁵¹ to R ⁵⁸ , and R ⁶¹ to R ⁶⁸ are preferably a substituent, and R ¹³ and R ¹⁸ , R ²³ and R ²⁶ , R ³³ and R ³⁶ , R ^3a and More preferably, at least one of the respective groups of R ^3b , R ⁴³ and R ⁴⁶ , R ⁵³ and R ⁵⁶ , R ⁶³ and R ⁶⁶ is a substituent. In each of the general formulas (2) to (7), when there are two or more substituents, these substituents may be the same or different.

R ¹¹ to R ²⁰ , R ²¹ to R ²⁸ , 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 ¹ to R ⁸ can be substituted with a substituent that can be introduced into L ¹² to L ¹⁷ , for example, a hydroxy group, a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, 20 alkoxy groups, alkylthio groups having 1 to 20 carbon atoms, alkyl-substituted amino groups having 1 to 20 carbon atoms, acyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 40 carbon atoms, heterocycles having 3 to 40 carbon atoms An aryl group, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, an alkoxycarbonyl group having 2 to 10 carbon atoms, an alkylsulfonyl group having 1 to 10 carbon atoms, a haloalkyl group having 1 to 10 carbon atoms, Amido group, C2-C10 alkylamide group, C3-C3 0 trialkylsilyl group, trialkylsilyl group having 4 to 20 carbon atoms, trialkylsilyl alkenyl group having 5 to 20 carbon atoms, 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. Alternatively, it is an unsubstituted aryl group or a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms.

R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , R ⁷ and R ⁸ , R ⁸ and R ⁹ , R ⁹ and R ¹ , R ¹¹ And R ¹² , R ¹² and R ¹³ , R ¹³ and R ¹⁴ , R ¹⁴ and R ¹⁵ , R ¹⁶ and R ¹⁷ , R ¹⁷ and R ¹⁸ , R ¹⁸ and R ¹⁹ , R ¹⁹ and R ²⁰ , R ²¹ and R ²² , R ²² and R ²³ , R ²³ and R ²⁴ , R ²⁴ and R ²⁵ , R ²⁵ and R ²⁶ , R ²⁶ and R ²⁷ , R ²⁷ and R ²⁸ , 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 may be bonded to each other to form a cyclic structure. Good. 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 ¹¹ to R ²⁰ , R ²¹ to R ²⁸ , R ³¹ to R ³⁸ , R ^3a , R ^3b , R ⁴¹ to R ⁴⁸ , R ^4a , R ⁵¹ to R ⁵⁸ , and R ⁶¹ to R ⁶⁸ are each independently A group represented by any one of the general formulas (2) to (7) is also preferable.

R ¹ to R ⁸ may be, for example, at least one selected from the groups represented by any of the general formulas (3) to (7), and at least one of the general formulas (4) to (7 ) May be selected. When at least one of R ¹ ~ R ⁸ is a group represented by the general formula (4), it is preferable that at least one of R ^3a and R ^3b in the formula (4) is a substituent, and R ^3a More preferably, both R ^3b are substituents. As the substituent, an alkyl group having 1 to 15 carbon atoms and a phenyl group are preferable, and an alkyl group having 1 to 15 carbon atoms is more preferable. R ^3a and R ^3b are preferably bonded to each other to form a cyclic structure. The cyclic structure is preferably a tricyclic structure such as a fluorene ring, a xanthene ring, or a thioxanthene ring.
In the general formula (1), R ⁹ represents a substituent. For the explanation and preferred range of the substituent represented by R ⁹ ,
Reference can be made to the description and preferred ranges of the substituents that can be taken by the above R ¹ to R ^{8 and the} like. Among these, R ⁹ is preferably a substituted or unsubstituted phenyl group represented by the following general formula (8).

In the general formula (8), * represents a bonding site to the boron atom in the general formula (1). R ^9a , R ^9b , R ^9c , R ^9d and R ^9e each independently represent a hydrogen atom or a substituent. The number of substituents is not particularly limited, and all of R ^9a , R ^9b , R ^9c , R ^9d , and R ^9e may be unsubstituted (that is, a hydrogen atom), but R ^9a , R ^9c , and R ^9e At least one of them is preferably a substituent, and R ^9a and R ^9e are more preferably substituents. In the general formula (8), when there are two or more substituents, these substituents may be the same or different. R ^9a and R ^9b , R ^9b and R ^9c , R ^9c and R ^9d , and R ^9d and R ^9e may be bonded to each other to form a cyclic structure. For the explanation and preferred ranges of the substituents that R ^9a , R ^9b , R ^9c , R ^9d , and R ^9e can take, see the explanations and preferred ranges of the substituents that can be taken by R ¹ to R ⁸ below. For the explanation and preferred examples of the cyclic structure, reference can be made to the explanation and preferred examples of the cyclic structure formed by combining R ¹ and R ² in the general formula (1).

Here, when R ⁹ is a substituent that includes an atom that does not form a single bond with a boron atom and has a lone pair, the atom coordinates with the boron atom to form a cyclic structure. It may be. Examples of the atoms that do not form a single bond with the boron atom and have a lone pair include oxygen atoms and nitrogen atoms. Further, the cyclic structure formed by coordination bonding of the atom with a boron atom is preferably a 5- to 7-membered ring, and more preferably a 5- or 6-membered ring. As specific compound examples, the following compounds 177 to 186 can be referred to. In these compounds, an oxygen atom or a nitrogen atom that does not form a single bond with a boron atom is coordinated with the boron atom to form a 5- or 6-membered ring.

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, by preparing a monomer containing a polymerizable functional group in any of R ¹ to R ^{9 in} the general formula (1) and polymerizing it alone or copolymerizing with other monomers, It is conceivable to obtain a polymer having a repeating unit and use the polymer as a light emitting material. Alternatively, it is also conceivable that dimers and trimers are obtained by reacting compounds having a structure represented by the general formula (1) and used as a luminescent material.

Examples of the polymer having a repeating unit containing a structure represented by the general formula (1) include a polymer containing a structure represented by the following general formula (9) or (10).

In General Formula (9) or (10), Q represents a group including the structure represented by General Formula (1), and L ¹ and L ² represent a linking group. The linking group preferably has 0 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and still more preferably 2 to 10 carbon atoms. 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 general formula (9) or (10), 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 ¹ to R ^{8 in} the structure of the general formula (1) constituting Q, any one of R ¹¹ to R ^{20 in} the general formula (2), Any one of R ²¹ to R ^{28 in} the structure of formula (3), any of R ³¹ to R ^{38 in} the structure of general formula (4), any of R ⁴¹ to R ^{48 in} the structure of general formula (5), It can be bonded to any one of R ⁵¹ to R ⁵⁸ of the structure of the general formula (6) and any of R ⁶¹ to R ⁶⁸ of the structure of the general formula (7). 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 (11) to (14).

In the polymer having a repeating unit containing these formulas (11) to (14), a hydroxy group is introduced into any ^one of R ¹ to R ⁹ of the structure of the general formula (1), and this is used as a linker as described below. It can be synthesized by reacting a compound to introduce a polymerizable group and polymerizing the polymerizable group.

The polymer containing the structure represented by the general formula (1) in the molecule may be a polymer 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.

[Synthesis Method of Compound Represented by General Formula (1 ′)]
The compound represented by the general formula (1) is a novel compound.

In the general formula (1 ′), X ′ represents an oxygen atom or a sulfur atom. R ¹ ′ to R ⁸ ′ each independently represents a hydrogen atom or a substituent. However, at least one of R ¹ ′ to R ⁸ ′ is a group independently represented by the following general formulas (2 ′) to (7 ′). R ¹ 'and R ^2', R ² 'and R ^3', R ³ 'and R ^4', R ⁵ 'and R ^6', R ⁶ 'and R ^7', R ⁷ 'and R ^8', R ⁸ 'And R ⁹ ' and R ⁹ 'and R ¹ ' may be bonded to each other to form a cyclic structure. R ⁹ ′ represents a substituent. When R ⁹ ′ includes an atom having a lone pair of electrons that does not form a single bond with a boron atom, the atom may be coordinated with the boron atom to form a cyclic structure.

In the general formulas (2 ′) to (7 ′), L ¹² ′ to L ¹⁷ ′ each independently represents a single bond or a divalent linking group, and * represents a binding site to the benzene ring in the general formula (1 ′). Represents. ^{R 11 '~ R 20',} R 21 '~ R 28', R 31 '~ R 38', R 3a ', R 3b', R 41 '~ R 48', R 4a ', R 51' ~ R 58 ', R ⁶¹ ' to R ⁶⁸ 'each independently represents a hydrogen atom or a substituent. R ¹¹ 'and R ^12', R ¹² 'and R ^13', R ¹³ 'and R ^14', R ¹⁴ 'and R ^15', 'R ¹⁷ and' R ^16, R ¹⁷ 'and R ^18', R ¹⁸ 'And R ¹⁹ ', R ¹⁹ 'and R ²⁰ ', R ²¹ 'and R ²² ', R ²² 'and R ²³ ', R ²³ 'and R ²⁴ ', R ²⁴ 'and R ²⁵ ', R ²⁵ 'and R ²⁶ ', R ^26' and R ²⁷ ', R ^27' and R ²⁸ ', 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 ', ^R45 'and ^R46 ', ^R46 'and ^R47 ', ^R47 'and ^R48 ', ^R51 'and ^R52 ', ^R52 'and ^R53 ', ^R53 'and ^R54 ', ^R55 '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 ′ may be bonded to each other to form a cyclic structure.
R ¹ ′ to R ⁸ ′ in general formula (1 ′) and R ¹¹ ′ to R ²⁰ ′, R ²¹ ′ to R ²⁸ ′, R ³¹ ′ to R ^{38 in} general formulas (2 ′) to (7 ′) R, R ^3a , R ^3b ′, R ⁴¹ ′ to R ⁴⁸ ′, R ^4a ′, R ⁵¹ ′ to R ⁵⁸ ′, R ⁶¹ ′ to R ⁶⁸ ′ are explained in general formula (1). The description of the compound represented by 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, a compound in which R ³ ′ and R ⁶ ′ in general formula (1 ′) are a group represented by general formula (4 ′) can be synthesized by reacting the following two compounds. .

For the explanation of R ¹ ′, R ² ′, R ⁴ ′, R ⁵ ′, R ⁷ ′ to R ⁹ ′, R ³¹ ′ to R ³⁸ ′, R ^3a ′, R ^3b ′ in the above reaction formula, Reference may be made to the corresponding description in formula (1 ′). A represents a halogen atom, and examples include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a chlorine atom, a bromine atom, and an iodine atom are 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 the organic electroluminescence element, carriers are injected into the 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, delayed fluorescent materials, after energy transition to an excited triplet state due to intersystem crossing, etc., are then crossed back to an excited singlet state due to triplet-triplet annihilation or absorption of thermal energy, and emit 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. 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) that can form 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 electroluminescence device and the organic photoluminescence 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, 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, thiopyrandioxide 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 electroluminescence device, the compound represented by the general formula (1) may be used not only for the light emitting layer but also for layers other than the 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. Note that 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. 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, preferred examples of compounds that can be used as the hole injection material are given.

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

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

Next, preferred examples of compounds that can be used as hole blocking materials are given.

Next, preferred compound examples that can be used as an electron transporting material are listed.

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

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

The organic electroluminescent 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.

Hereinafter, 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 of Intermediate]
Intermediates for synthesizing each compound of the examples were synthesized as follows.
(Synthesis of Intermediate 1a)

Methyl anthranilate (349.2 g, 2310 mmol), iodobenzene (428.4 g, 2100 mmol), potassium carbonate (348.3 g, 2520 mmol), and copper iodide (20.0 g, 105 mmol) were placed in a three-necked flask under a nitrogen atmosphere. The mixture was heated and stirred at 180 ° C.
After completion of the reaction, the mixture was cooled to room temperature, diluted with 500 ml of hexane, and filtered using celite. The obtained filtrate was purified by silica gel chromatography using a mixed solvent of hexane: dichloromethane = 8: 2 as a developing solvent, and the obtained fraction was vacuum-dried. As a result, the target pale yellow oily liquid (intermediate 1a) was obtained in a yield of 427.5 g and a yield of 90%.

(Synthesis of Intermediate 1b)

Intermediate 1a (109.08 g, 480 mmol) and 960 ml of dehydrated tetrahydrofuran were placed in a three-necked flask and cooled to −40 ° C. To this solution, a 3.0M diethyloxymethane solution (504 ml, 1512 mmol) of methyllithium was added dropwise over 30 minutes while paying attention to the generation of methane gas. The mixture was then stirred at 0 ° C. for 1 hour and then at room temperature overnight. Thereafter, methanol was carefully added dropwise to the mixture cooled to 0 ° C. to deactivate the remaining methyllithium.
The mixture was concentrated and then diluted with dichloromethane to obtain a solution. This solution was washed with water using a separatory funnel and dried over anhydrous magnesium sulfate. Thereafter, the solution was filtered, concentrated, and vacuum dried (60 ° C., 6 h) to obtain an oily liquid. This oily liquid was put into a three-necked flask, 960 ml of chloroform and 62.3 ml of methanesulfonic acid were added, and the mixture was refluxed for 3 hours in a nitrogen atmosphere.
After cooling this mixture to room temperature, it neutralized carefully using sodium hydrogencarbonate aqueous solution, and extracted with chloroform using the separatory funnel. The obtained extract was dried over anhydrous magnesium sulfate, filtered through a silica gel pad, and concentrated. This concentrate was purified by silica gel chromatography using a mixed solvent of hexane: dichloromethane = 1: 1 as a developing solvent. The concentrate obtained by concentrating the obtained fraction was recrystallized with a mixed solvent of toluene and hexane (1: 5 ml / g). As a result, the target intermediate 1b was obtained in a yield of 47.9 g and a yield of 48%.

(Synthesis of Intermediate 2a)

Intermediate 1a (38.18 g, 168 mmol) and 336 ml of dehydrated tetrahydrofuran were placed in a three-necked flask and cooled to 0 ° C., and 1.06 M cyclohexane-diethyl ether solution of phenyl lithium (500 ml, 529 mmol) was added to this solution over 30 minutes. It was dripped. The mixture was then stirred at 0 ° C. for 2 hours and then at room temperature overnight. Thereafter, methanol was carefully added dropwise to the mixture cooled to 0 ° C. to deactivate the residual phenyllithium.
The mixture was concentrated and then diluted with dichloromethane to obtain a solution. This solution was washed with water using a separatory funnel and dried over anhydrous magnesium sulfate. Thereafter, the solution was filtered, concentrated, and vacuum dried (60 ° C., 6 h) to obtain an oily substance. This oily substance was put into a three-necked flask, 672 ml of chloroform and 21.8 ml of methanesulfonic acid were added, and the mixture was refluxed for 3 hours in a nitrogen atmosphere.
The mixture was cooled to room temperature, then carefully neutralized with an aqueous sodium hydrogen carbonate solution, and extracted with dichloromethane using a separatory funnel. The extract was dried over anhydrous magnesium sulfate, filtered through a silica gel pad, and concentrated. This concentrate was recrystallized with a mixed solvent of toluene and hexane (5:10 ml / g). As a result, the target intermediate 2a was obtained in a yield of 27.9 g and a yield of 50%.

(Synthesis of Intermediate 3a)

1-bromo-2-fluoro-4-iodobenzene (25.3 g, 84 mmol), intermediate 1b (17.58 g, 84 mmol), sodium-tert-butoxide (12.11 g, 126 mmol), copper iodide (0. 32 g, 1.68 mmol), trans-1,2-diaminocyclohexane (1.01 ml, 8.4 mmol) and 84 ml of 1,4-dioxane were placed in a three-necked flask and refluxed for 24 hours under a nitrogen atmosphere.
After completion of the reaction, the mixture was diluted with 200 ml of toluene and filtered through celite. The resulting filtrate was filtered through a silica gel pad and concentrated. This concentrate was purified by silica gel chromatography using a mixed solvent of hexane: toluene = 6: 4 as a developing solvent. The concentrate obtained by concentrating the obtained fraction was recrystallized from hexane (5 ml / g, 5 ° C.). As a result, the target product Intermediate 3a was obtained in a yield of 19.68 g and a yield of 61%.

(Synthesis of Intermediate 3b)

Intermediate 3a (7.65 g, 20 mmol), potassium hydroxide (1.12 g, 20 mmol), potassium carbonate (2.76 g, 20 mmol), and 5 ml of triethylene glycol dimethyl ether were placed in a three-necked flask at 190 ° C. under a nitrogen atmosphere. The mixture was heated and stirred for 48 hours. After completion of the reaction, the mixture was cooled to room temperature, diluted with 200 ml of toluene, and further sonicated with 200 ml of water for 10 minutes.
The mixture was filtered using celite, and the filtrate was collected. The filtrate was transferred to a separatory funnel and washed twice with water to recover the organic phase. The obtained organic phase was dried over anhydrous magnesium sulfate, filtered through a silica gel pad, and concentrated. This concentrate was purified by silica gel chromatography using a mixed solvent of hexane: toluene = 6: 4 as a developing solvent, and the resulting fraction was concentrated to recrystallize with hexane. As a result, 4.16 g of a target intermediate 3b was obtained in a yield of 56%.

(Synthesis of Intermediate 3c)

2-Bromo-1,3,5-triisopropylbenzene (43.9 g, 155 mmol) and dehydrated tetrahydrofuran 155 ml were placed in a three-necked flask and cooled to -78 ° C. To this solution, a 1.60 M hexane solution of n-butyllithium (106.6 ml, 170.5 mmol) was added with a syringe and stirred at −78 ° C. for 10 minutes, and then trimethoxyborane (34.5 ml, 310 mmol) was added for 2 minutes. It was dripped over. The mixture was then stirred at −78 ° C. for 30 minutes and then at room temperature overnight.
The mixture was concentrated to about half by an evaporator, 300 ml of 1N hydrochloric acid aqueous solution was added, and the mixture was stirred at room temperature for 4 hours. The resulting solution was placed in a separatory funnel and extracted with dichloromethane. The extract was washed twice with water, dried over anhydrous magnesium sulfate, filtered and concentrated. This concentrate was put into a three-necked flask equipped with a Soxhlet extractor charged with molecular sieves, and 200 ml of toluene and 30 ml of methanol were added and refluxed for 12 hours. After completion of the reaction, the mixture was cooled to room temperature and concentrated with an evaporator. This concentrate was purified by silica gel chromatography using a mixed solvent of hexane: dichloromethane = 8: 2 as a developing solvent. The solvent of the obtained fraction was removed by vacuum drying, and the target colorless oily substance (intermediate 3c) was obtained in a yield of 31.88 g and a yield of 74%.

(Synthesis of Intermediate 4a)

1,4-dibromo-2-fluorobenzene (50.78 g, 200 mmol), potassium hydroxide (6.73 g, 120 mmol), potassium carbonate (27.64 g, 200 mmol), and 20 ml of triethylene glycol dimethyl ether were placed in a three-necked flask. The mixture was heated and stirred at 180 ° C. for 96 hours in a nitrogen atmosphere. After completion of the reaction, the mixture was cooled to room temperature, diluted by adding 500 ml of toluene, and further subjected to sonication for 10 minutes by adding 500 ml of water.
The mixture was filtered using celite, and the filtrate was collected. The filtrate was transferred to a separatory funnel and washed twice with water to recover the organic phase. The obtained organic phase was dried over anhydrous magnesium sulfate, filtered through a silica gel pad, and concentrated. The concentrate was purified by silica gel chromatography using a mixed solvent of hexane: dichloromethane = 7: 3 as a developing solvent, and the resulting fraction concentrate was recrystallized from hexane. As a result, the intermediate product 4a was obtained in a yield of 8.51 g and a yield of 18%.

(Synthesis of Intermediate 4b)

Intermediate 4a (2.91 g, 6 mmol) and 60 ml of dehydrated diethyl ether were suspended in a three-necked flask and cooled to 0 ° C. To this solution was added a 1.58M hexane solution (7.6 ml, 12 mmol) of n-butyllithium with a syringe, and the mixture was stirred at 0 ° C. for 10 minutes. Then, Intermediate 3c (1.66 g, 6 mmol) was dissolved in 6 ml of diethyl ether. The solution was added dropwise over 2 minutes. The mixture was then stirred at 0 ° C. for 30 minutes and then at room temperature overnight.
This mixture was concentrated by an evaporator, and the obtained concentrate was diluted with 100 ml of dichloromethane to obtain a solution. The resulting solution was filtered through a silica gel pad and the filtrate was concentrated. A sample precipitated by concentration was rinsed with hexane, collected by filtration, and vacuum-dried (50 ° C., 8 hours). As a result, the intermediate 4b as a target product was obtained in a yield of 1.58 g and a yield of 49%.

(Synthesis of Intermediate 5a)

Intermediate 3a (7.65 g, 20 mmol), 2-bromophenol (13.84 g, 80 mmol), potassium carbonate (11.06 g, 80 mmol), and 10 ml of triethylene glycol dimethyl ether were placed in a three-necked flask and treated at 190 ° C. under a nitrogen atmosphere. And stirred for 72 hours. After completion of the reaction, the mixture was cooled to room temperature, diluted with 200 ml of toluene, and further 200 ml of water was added and sonication was performed for 10 minutes.
The mixture was filtered using celite, and the filtrate was collected. The filtrate was transferred to a separatory funnel and washed twice with water to recover the organic phase. The obtained organic phase was dried over anhydrous magnesium sulfate, filtered through a silica gel pad, and concentrated. This concentrate was purified by silica gel chromatography using a mixed solvent of hexane: toluene = 6: 4 as a developing solvent, and the obtained fraction was concentrated to obtain a white solid. This white solid was rinsed with hexane and then vacuum-dried to obtain 9.40 g of the target intermediate 5a in a yield of 88%.

(Synthesis of Intermediate 6a)

2,5-dibromofluorobenzene (25.39 g, 100 mmol), 2-bromophenol (25.95 g, 150 mmol), potassium carbonate (27.64 g, 200 mmol), and 10 ml of triethylene glycol dimethyl ether were placed in a three-necked flask and a nitrogen atmosphere. Under stirring at 190 ° C. for 72 hours. After completion of the reaction, the mixture was cooled to room temperature, diluted with 200 ml of toluene, and further sonicated with 200 ml of water for 10 minutes.
The mixture was filtered using celite, and the filtrate was collected. The filtrate was transferred to a separatory funnel and washed twice with water to recover the organic phase. The obtained organic phase was dried over anhydrous magnesium sulfate, filtered through a silica gel pad, and concentrated. This concentrate was purified by silica gel chromatography using a mixed solvent of hexane: dichloromethane = 9: 1 as a developing solvent, and concentrated. As a result, the target white solid (intermediate 6a) was obtained in a yield of 50.53 g and a yield of 89%.

(Synthesis of Intermediate 6b)

Intermediate 6a (32.55 g, 80 mmol) and dehydrated diethyl ether 400 ml were dissolved in a three-necked flask and cooled to 0 ° C. To this solution, a 1.60 M hexane solution of n-butyllithium (102.5 ml, 164 mmol) was added by syringe, and the mixture was stirred at 0 ° C. for 10 minutes. Thereafter, a solution of Intermediate 3c (22.10 g, 80 mmol) dissolved in 40 ml of diethyl ether was added dropwise to this mixture over 5 minutes, stirred at 0 ° C. for 30 minutes, and then stirred overnight at room temperature.
This mixture was concentrated by an evaporator and diluted with 500 ml of toluene to obtain a solution. This solution was washed twice with a separatory funnel, dried over anhydrous magnesium sulfate, filtered, and concentrated. This concentrate was purified by silica gel chromatography using a mixed solvent of hexane: dichloromethane = 9: 1 as a developing solvent. The obtained fraction was recrystallized at 5 ° C. using hexane. As a result, the intermediate product 6b was obtained in a yield of 16.51 g and a yield of 45%.
(Synthesis of Intermediate 7a)

2,5-dibromofluorobenzene (15.23 g, 60 mmol), 2-bromobenzenethiol (9.45 g, 50 mmol), potassium carbonate (13.82 g, 100 mmol), and 10 ml of triethylene glycol dimethyl ether were placed in a three-necked flask, and nitrogen was added. The mixture was heated and stirred at 180 ° C. for 24 hours in an atmosphere. After completion of the reaction, the mixture was cooled to room temperature, diluted with 100 ml of toluene, and further sonicated with 100 ml of water for 10 minutes.
The mixture was filtered using celite, and the filtrate was collected. The filtrate was transferred to a separatory funnel and washed twice with water to recover the organic phase. The obtained organic phase was dried over anhydrous magnesium sulfate, filtered and concentrated. This concentrate was purified by silica gel chromatography using hexane as a developing solvent. The obtained fraction was concentrated and vacuum-dried to obtain the desired colorless oily substance (intermediate 7a) in a yield of 14.01 g and a yield of 66%.

(Synthesis of Intermediate 7b)

Intermediate 7b was synthesized in the same manner as intermediate 6b except that intermediate 7a was used instead of intermediate 6a and the amount of each raw material was 0.41 times in terms of mole. The obtained intermediate 7b was 2.49 g in yield and 16% in yield.

(Synthesis of Intermediate 8a)

2-Bromo-4-methylaniline (50.23 g, 270 mmol), 4-iodotoluene (64.75 g, 297 mmol), sodium tert-butoxide (38.92 g, 405 mmol), palladium acetate (606 mg, 2.7 mmol) 1,1′-bis (diphenylphosphino) ferrocene (1.50 g, 2.7 mmol) and 540 ml of dehydrated toluene were placed in a three-necked flask and stirred at reflux under a nitrogen atmosphere for 8 hours.
After completion of the reaction, the mixture was cooled to room temperature, diluted with 500 ml of toluene, and the resulting solution was filtered using celite and concentrated. This concentrate was purified by silica gel chromatography using a mixed solvent of hexane: dichloromethane = 9: 1 as a developing solvent. The obtained fraction was concentrated and vacuum-dried to obtain the desired colorless oily liquid (intermediate 8a) in a yield of 54.85 g and a yield of 74%.

(Synthesis of Intermediate 8b)

Intermediate 8a (16.57 g, 60 mmol) and 240 ml of dehydrated tetrahydrofuran were placed in a three-necked flask and cooled to −78 ° C., and a 2.65 M hexane solution (47.5 ml, 126 mmol) of n-butyllithium was added to this solution with a syringe. added. Thereafter, the reaction solution was stirred at 0 ° C. for 50 minutes. Thereafter, xanthone powder (12.95 g, 66 mmol) was added to the reaction solution, stirred at 0 ° C. for 30 minutes, and then stirred at room temperature for 2 hours.
After completion of the reaction, the reaction solution was deactivated by adding a small amount of water, and extracted with dichloromethane using a separatory funnel. The obtained extract was dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain a reaction crude product.
This crude reaction product was placed in a three-necked flask, 600 ml of chloroform and 3.9 ml of methanesulfonic acid were added, and the mixture was refluxed for 3 hours in a nitrogen atmosphere. The mixture was cooled to room temperature and washed with water using a separatory funnel. The washed mixture was dried over anhydrous magnesium sulfate, filtered through a silica gel pad, and concentrated to obtain a precipitate. This precipitate was recrystallized with ethanol to obtain 10.2 g of a target intermediate 8b in a yield of 45%.

(Synthesis of Intermediate 9a)

Intermediate 9a was synthesized in the same manner as Intermediate 8a except that 2-bromoaniline (50.06 g, 291 mmol) and 4-iodobenzene (62.43 g, 306 mmol) were used as raw materials. The obtained intermediate 9a was 71.38 g in yield and 99% in yield.

(Synthesis of Intermediate 9b)

Intermediate 9b was synthesized in the same manner as intermediate 8b except that intermediate 9a (24.81 g, 100 mmol) and fluorenone (19.82 g, 110 mmol) were used as raw materials. The obtained intermediate 9b was 13.74 g in yield and 41% in yield.

(Synthesis of Intermediate 10a)

Intermediate 10a was synthesized in the same manner as Intermediate 9b, except that intermediate 9a (12.9 g, 52 mmol) was used as a raw material, and xanthone (11.22 g, 57.2 mmol) was used instead of fluorenone. did. The obtained intermediate 10a was 13.45 g in yield and 74% in yield.

(Synthesis of Intermediate 11a)

Diphenyl ether (17.02 g, 100 mmol), FeCl ₃ (0.81 g, 5 mmol), and 100 ml of nitrobenzene were placed in a three-necked flask, cooled to 0 ° C., and bromine (21.5 ml, 420 mmol) was added to the mixture over 15 minutes. It was dripped. The mixture was stirred at 0 ° C. for 30 minutes, then stirred at room temperature for 1 hour, and further heated and stirred at 120 ° C. for 24 hours. After completion of the reaction, the mixture was cooled to room temperature and diluted with 200 ml of dichloromethane. The resulting solution was washed with a separatory funnel, and then residual bromine was deactivated with a sodium thiosulfate / sodium hydroxide aqueous solution. The solution was dried over anhydrous magnesium sulfate, filtered through a silica gel pad, and concentrated. The obtained concentrate was purified by silica gel chromatography using hexane as a developing solvent. The resulting fraction concentrate was recrystallized from hexane. As a result, the target intermediate 11a was obtained in a yield of 38.29 g and a yield of 79%.

(Synthesis of Intermediate 11b)

Intermediate 11b was synthesized in the same manner as Compound 5 Synthesis Method A described later, except that Intermediate 11a (14.57 g, 30 mmol) was used as a raw material. The obtained intermediate 11b was 6.27 g in yield and 39% in yield.

(Synthesis of Intermediate 12a)

2,4,6-Triphenylbromobenzene (25.5 g, 66 mmol) and 264 ml of dehydrated tetrahydrofuran were placed in a three-necked flask, cooled to −80 ° C., and 1.60 M hexane solution (45. 4 ml, 72.6 mmol) was added via syringe. Thereafter, the reaction solution was stirred at −80 ° C. for 15 minutes, and then trimethoxyborane (14.7 ml, 132 mmol) was added by syringe and stirred overnight at room temperature. A small amount of water was added to the reaction solution to inactivate the reaction system, and then 400 ml of a 1N hydrochloric acid aqueous solution was added and stirred overnight. The reaction solution was extracted with dichloromethane using a separatory funnel and washed with water. The reaction solution washed with water was dried over anhydrous magnesium sulfate, filtered and concentrated. This concentrate was purified by silica gel chromatography using a mixed solvent of dichloromethane: ethyl acetate = 4: 1 as a developing solvent. 200 ml of hexane was added to the concentrate obtained by concentrating the obtained fraction to obtain a precipitate. The obtained precipitate was collected by filtration and dried in vacuo (50 ° C., 6 hours) to obtain the target intermediate 12a in a yield of 15.9 g and a yield of 69%.

(Synthesis of Intermediate 12b)

Intermediate 12a (15.76 g, 45 mmol) was placed in a three-necked flask equipped with a Soxhlet extractor charged with molecular sieves, and 200 ml of toluene and 30 ml of methanol were added and refluxed for 12 hours. After completion of the reaction, the mixture was cooled to room temperature, concentrated with an evaporator, and further dried under vacuum. As a result, a colorless oily substance (intermediate 12b) as a target product was obtained.

(Synthesis of Intermediate 12c)

Intermediate 12c was synthesized in the same manner as Intermediate 6b, except that Intermediate 6a (10.74 g, 26.4 mmol) and Intermediate 12b (10.0 g, 26.4 mmol) were used as raw materials. The obtained intermediate 12c was 3.53 g in yield and 24% in yield.

[Examples of compound synthesis]
Synthesis Example 1 Synthesis of Compound 5 (Synthesis Method A)

Intermediate 3b (5.56 g, 7.5 mmol) and 150 ml of dehydrated diethyl ether were suspended in a three-necked flask and cooled to 0 ° C. To this solution, a 1.58 M hexane solution of n-butyllithium (9.5 ml, 15 mmol) was added by syringe. The mixture was stirred at 0 ° C. for 10 minutes, and then a solution of intermediate 3c (2.07 g, 7.5 mmol) dissolved in 15 ml of diethyl ether was added dropwise over 10 minutes. The mixture was then stirred at 0 ° C. for 30 minutes and then at room temperature overnight.
This mixture was concentrated by an evaporator and diluted with 200 ml of a mixed solvent of toluene: hexane = 1: 1 to obtain a solution. The resulting solution was filtered through a silica gel pad and the filtrate was concentrated. This filtrate was purified by silica gel chromatography using a mixed solvent of hexane: toluene = 6: 4 as a developing solvent. The concentrate of the obtained fraction was recrystallized with hexane to obtain 2.20 g of the target compound 5 in a yield of 37%.

Synthesis Example 2 Synthesis of Compound 5 (Synthesis Method B)

Intermediate 4b (1.58 g, 2.93 mmol), Intermediate 1b (1.47 g, 7.03 mmol), Sodium tert-butoxide (0.84 g, 8.79 mmol), Tris (dibenzylideneacetone) dipalladium ( 0) (54 mg, 59 μmol), tri-tert-butylphosphonium tetrafluoroborate (68 mg, 234 μmol), and 15 ml of dehydrated toluene were placed in a three-necked flask and stirred at reflux under a nitrogen atmosphere for 4 hours.
After completion of the reaction, the mixture was cooled to room temperature and diluted with 50 ml of toluene. The resulting solution was filtered using celite and concentrated. This concentrate was purified by silica gel chromatography using a mixed solvent of hexane: toluene = 6: 4 as a developing solvent. 30 ml of acetonitrile was added to the concentrate obtained by concentrating the obtained fraction, and sonication was performed for 30 minutes. A precipitate was collected from this mixture by filtration, rinsed with acetonitrile, and vacuum-dried (50 ° C., 6 hours) to obtain 2.14 g of the target compound in a yield of 92%.

(Synthesis Example 3) Synthesis of Compound 6

Compound 6 was synthesized in the same manner as Compound 5 Synthesis Method A, except that Intermediate 5a was used instead of Intermediate 3b, and the amount of raw material was changed to 2.33 times in terms of mole. The obtained compound 6 was 5.82 g in yield and 56% in yield.

Synthesis Example 4 Synthesis of Compound 18

Compound 18 was synthesized in the same manner as Compound 5 Synthesis Method B except that Intermediate 11b (2.70 g, 5 mmol) was used as a raw material. The obtained compound 18 was 3.65 g in yield and 92% in yield.

Synthesis Example 5 Synthesis of Compound 59

Intermediate 6b (2.31 g, 5 mmol), Intermediate 9b (1.99 g, 6 mmol), Sodium-tert-butoxide (1.15 g, 12 mmol), Tris (dibenzylideneacetone) dipalladium (0) (110 mg, 120 μmol) ), Tri-tert-butylphosphonium tetrafluoroborate (139 mg, (480 μmol)) and 30 ml of dehydrated toluene were placed in a three-necked flask and stirred at reflux under a nitrogen atmosphere for 8 hours.
After completion of the reaction, the mixture was cooled to room temperature and diluted by adding 50 ml of toluene to obtain a solution. The solution was filtered using celite and concentrated. This concentrate was purified by silica gel chromatography using a mixed solvent of hexane: toluene = 8: 2 as a developing solvent. The concentrate obtained by concentrating the obtained fraction was dissolved in a mixed solvent of ethyl acetate: hexane (v / v) = 2: 8 at 10 ml / g, recrystallized, and dried under vacuum (50 ° C., 6 hours). )did. As a result, 3.59 g of the target compound 59 was obtained in a yield of 89%.

Synthesis Example 6 Synthesis of Compound 65

Compound 65 was synthesized in the same manner as Compound 59 except that Intermediate 6b (2.31 g, 5 mmol) and Intermediate 10b (1.91 g, 5.5 mmol) were used as raw materials. The obtained compound 65 was 3.37 g in yield, 93% in yield.

Synthesis Example 7 Synthesis of Compound 67

Compound 67 was synthesized in the same manner as Compound 59 except that Intermediate 6b (3.69 g, 8 mmol) and Intermediate 8b (3.30 g, 8.8 mmol) were used as raw materials. The obtained compound 67 was 4.66 g in yield and 77% in yield.

Synthesis Example 8 Synthesis of Compound 88

Compound 88 was synthesized in the same manner as Compound 59 except that Intermediate 12c (563 mg, 1 mmol) and Intermediate 1b (319 mg, 1.1 mmol) were used as raw materials. The obtained compound 88 was 0.49 g in yield and 71% in yield.

Synthesis Example 9 Synthesis of Compound 116

Compound 116 was synthesized in the same manner as Compound 59 except that Intermediate 6b (2.77 g, 6 mmol) and Intermediate 2a (2.40 g, 7.2 mmol) were used as raw materials. The obtained compound 116 was 3.56 g in yield and 83% in yield.

Synthesis Example 10 Synthesis of Compound 156

Compound 156 was synthesized in the same manner as Compound 59 except that Intermediate 7b (3 mmol) and Intermediate 1b (3.6 mmol) were used as raw materials. The obtained compound 156 was 1.36 g in yield and 75% in yield.

Synthesis Example 11 Synthesis of Compound 176

Compound 176 was synthesized in the same manner as the compound 59 synthesis method, except that intermediate 7b (2.16 mmol) and intermediate 2a (2.59 mmol) were used as raw materials. The compound 176 obtained was 0.85 g in yield and 54% in yield.

[Production and evaluation of elements]
In the following, an organic photoluminescence element and an organic electroluminescence element were produced and evaluated.
Emission characteristics are evaluated by source meter (Keithley: 2400 series), semiconductor parameter analyzer (Agilent Technology: E5273A), optical power meter measuring device (Newport: 1930C), optical spectrometer (Ocean) Optics: USB2000), a spectroradiometer (Topcon: SR-3) and a streak camera (Hamamatsu Photonics C4334) were used.

The difference between the singlet energy of each material (E _S1) and triplet energy (E _T1) (ΔE _ST) calculates the triplet energy singlet energy (E _S1) in the following manner, Delta] E _ST = It was determined by E _S1 -E _T1 .
(1) Singlet energy E _S1
A sample having a thickness of 100 nm was prepared on a Si substrate by co-evaporating the measurement target compound and mCP so that the measurement target compound had a concentration of 6% by weight. The fluorescence spectrum of this sample was measured at room temperature (300K). By integrating the luminescence from immediately after the excitation light incidence to 100 nanoseconds after the incidence, a fluorescence spectrum having a luminescence intensity on the vertical axis and a wavelength on the horizontal axis was obtained. In the fluorescence spectrum, the vertical axis represents light emission and the horizontal axis represents wavelength. A tangent line was drawn with respect to the short-wave rise of the emission spectrum, and the wavelength value λedge [nm] at the intersection of the tangent line and the horizontal axis was obtained. A value obtained by converting this wavelength value into an energy value by the following conversion formula was defined as E _S1 .
Conversion formula: E _S1 [eV] = 1239.85 / λedge
For the measurement of the emission spectrum, a nitrogen laser (Lasertechnik Berlin, MNL200) was used as an excitation light source, and a streak camera (Hamamatsu Photonics, C4334) was used as a detector.
(2) Triplet energy E _T1
The same sample as the singlet energy E _S1 was cooled to 5 [K], the sample for phosphorescence measurement was irradiated with excitation light (337 nm), and the phosphorescence intensity was measured using a streak camera. By integrating the luminescence from 1 millisecond after the excitation light incidence to 10 milliseconds after the incidence, a phosphorescence spectrum having the luminescence intensity on the vertical axis and the wavelength on the horizontal axis was obtained. A tangent line was drawn with respect to the rising edge of the phosphorescence spectrum on the short wavelength side, and a wavelength value λ edge [nm] at the intersection of the tangent line and the horizontal axis was obtained. A value obtained by converting this wavelength value into an energy value by the following conversion formula was defined as _ET1 .
Conversion formula: E _T1 [eV] = 1239.85 / λedge
The tangent to the short wavelength rising edge of the phosphorescence spectrum was drawn as follows. When moving on the spectrum curve from the short wavelength side of the phosphorescence spectrum to the maximum value on the shortest wavelength side among the maximum values of the spectrum, tangents at each point on the curve are considered toward the long wavelength side. The slope of this tangent line increases as the curve rises (that is, as the vertical axis increases). The tangent drawn at the point where the value of the slope takes the maximum value was taken as the tangent to the rising edge of the phosphorescence spectrum on the short wavelength side.
In addition, the maximum point having a peak intensity of 10% or less of the maximum peak intensity of the spectrum is not included in the above-mentioned maximum value on the shortest wavelength side, and has the maximum slope value closest to the maximum value on the shortest wavelength side. The tangent drawn at the point where the value was taken was taken as the tangent to the rising edge of the phosphorescence spectrum on the short wavelength side.

Example 1 Preparation and Evaluation of Organic Photoluminescence Device Using Compound 5 A toluene solution (concentration 10 ⁻⁵ mol / L) and a hexane solution (concentration 10 ⁻⁵ mol / L) of compound ⁵ were prepared in the atmosphere. Then, after deoxygenation by bubbling with nitrogen for 15 minutes, it was used for measurement of light emission characteristics.
In addition, a thin film of compound 5 was formed to a thickness of 100 nm on a quartz substrate by a vacuum deposition method under a vacuum degree of 10 ⁻⁴ Pa or less to obtain an organic photoluminescence device.
The result of measuring the emission spectrum of the toluene solution and the hexane solution of Compound 5 is shown in FIG. 2, and the result of measuring the emission spectrum of the organic photoluminescence device having a thin film of Compound 5 is shown in FIG.
The photoluminescence quantum yield φ was 0.97 for the toluene solution, 0.54 for the hexane solution, and 0.83 for the organic photoluminescence device having a thin film of Compound 5. Energy difference Delta] E _ST of the singlet excited state and a triplet excited state as determined from the fluorescence spectrum and phosphorescence spectrum was 0.05 eV.
Moreover, the transient decay curve of the toluene solution of compound 5 and a hexane solution is shown in FIG. This transient decay curve shows the result of measuring the luminescence lifetime obtained by measuring the process in which the emission intensity is deactivated by applying excitation light to the compound. 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 5 shown in FIG. 4, 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. By measuring the luminescence lifetime in this way, it was confirmed that Compound 5 is a luminescent material containing a delay component in addition to the fluorescent component. The emission lifetime τ1 of the immediate fluorescence component in the toluene solution is 35 ns, the emission lifetime τ2 of the delayed fluorescence component is 1.35 μs, the emission lifetime τ1 of the immediate fluorescence component in the hexane solution is 21 ns, and the emission lifetime τ2 of the delay fluorescence component is 2.09 μs.

(Example 2) Production and evaluation of organic photoluminescence device using compound 6 By changing the point of using compound 6 instead of compound 5, a toluene solution and a hexane solution of compound 6 by the same method as in Example 1, An organic photoluminescence device having a thin film of Compound 6 was produced.
Further, a thin film in which the concentration of compound 6 is 6.0% by weight is deposited on a quartz substrate by a vacuum deposition method under the condition of a vacuum degree of 10 ⁻⁴ Pa or less from different deposition sources. An organic photoluminescence device was formed with a thickness of 100 nm.
FIG. 5 shows the results of measuring the emission spectrum of an organic photoluminescence device having a toluene solution and a hexane solution of compound 6 and a thin film of compound 6 and mCP. The results are shown in FIG.
The photoluminescence quantum yield φ was 1.00 for the toluene solution, 0.54 for the hexane solution, and 0.88 for the organic photoluminescence device having a thin film of compound 6 alone. Energy difference Delta] E _ST of the singlet excited state and a triplet excited state as determined from the fluorescence spectrum and phosphorescence spectrum was 0.08 eV.
Moreover, the transient decay curve of the toluene solution of compound 6 and a hexane solution is shown in FIG. The emission lifetime τ1 of the immediate fluorescence component in the toluene solution is 33 ns, the emission lifetime τ2 of the delayed fluorescence component is 1.60 μs, the emission lifetime τ1 of the immediate fluorescence component in the hexane solution is 20 ns, and the emission lifetime τ2 of the delay fluorescence component is 1.29 μs.

Example 3 Preparation and Evaluation of Organic Photoluminescence Device Using Compound 18 A toluene solution of Compound 18 was prepared in the same manner as in Example 1 except that Compound 18 was used instead of Compound 5. The emission spectrum and transient decay curve of this toluene solution were measured. The measured emission spectrum is shown in FIG. 8, and the transient decay curve is shown in FIG. The photoluminescence quantum yield φ of the toluene solution of compound 18 was 0.81. Further, the emission lifetime τ1 of the immediate fluorescence component was 89.3 ns, and the emission lifetime τ2 of the delayed fluorescence component was 39.5 μs.

Example 4 Production and Evaluation of Organic Photoluminescence Device Using Compound 59 A toluene solution of compound 59 was prepared in the same manner as in Example 1, except that compound 59 was used instead of compound 5. The emission spectrum and transient decay curve of this toluene solution were measured. The measured emission spectrum is shown in FIG. The photoluminescence quantum yield φ of the toluene solution of compound 59 was 0.76. Further, the emission lifetime τ1 of the immediate fluorescence component was 27.7 ns, and the emission lifetime τ2 of the delayed fluorescence component was 4.02 μs.

Example 5 Production and Evaluation of Organic Photoluminescence Device Using Compound 65 A toluene solution of compound 65 was prepared by the same method as in Example 1 except that compound 65 was used instead of compound 5. The emission spectrum and transient decay curve of this toluene solution were measured. The measured emission spectrum is shown in FIG. The photoluminescence quantum yield φ of the toluene solution of compound 65 was 0.56. Further, the emission lifetime τ1 of the immediate fluorescence component was 25.9 ns, and the emission lifetime τ2 of the delayed fluorescence component was 2.06 μs.

Example 6 Production and Evaluation of Organic Photoluminescence Device Using Compound 67 A toluene solution of compound 67 was prepared in the same manner as in Example 1 except that compound 67 was used instead of compound 5. The emission spectrum and transient decay curve of this toluene solution were measured. The measured emission spectrum is shown in FIG. The photoluminescence quantum yield φ of the toluene solution of compound 67 was 1.00. Further, the emission lifetime τ1 of the immediate fluorescence component was 35 ns, and the emission lifetime τ2 of the delayed fluorescence component was 2.33 μs.

Example 7 Production and Evaluation of Organic Photoluminescence Device Using Compound 156 A toluene solution of compound 156 was prepared in the same manner as in Example 1 except that compound 156 was used instead of compound 5. The emission spectrum and transient decay curve of this toluene solution were measured. The measured emission spectrum is shown in FIG. 13, and the transient decay curve is shown in FIG. The photoluminescence quantum yield φ of the toluene solution of compound 156 was 1.00. Further, the emission lifetime τ1 of the immediate fluorescence component was 3.2 ns, and the emission lifetime τ2 of the delayed fluorescence component was 1.61 μs.

(Examples 8 to 10)
A toluene solution was prepared in the same manner as in Example 1, except that the compounds 88, 116, and 176 were used instead of the compound 5. The emission spectrum and transient decay curve of this toluene solution were measured. Table 1 shows the photoluminescence quantum yield φ and the emission lifetime determined from the measured emission spectrum and transient decay curve. As shown in Table 1, all the toluene solutions of the compounds 88, 116, and 176 obtained a sufficient photoluminescence quantum yield φ, and confirmed delayed fluorescence.

(Comparative Example 1) Preparation and Evaluation of Organic Photoluminescence Device Using Comparative Compound A Using Comparative Compound A having the following structure instead of Compound 1, a toluene solution of Comparative Compound A was prepared in the same manner as Example 1. Prepared. The emission spectrum and transient decay curve of this toluene solution were measured. The measured emission spectrum is shown in FIG. 15, and the transient decay curve is shown in FIG. The emission lifetime was 16.0 ns, and no delayed fluorescence was observed.

(Comparative Example 2) Preparation and Evaluation of Organic Photoluminescence Element Using Comparative Compound B Using Comparative Compound B having the following structure instead of Compound 1, a toluene solution of Comparative Compound A was prepared in the same manner as Example 1. Prepared. The emission spectrum and transient decay curve of this toluene solution were measured. The measured emission spectrum is shown in FIG. 17, and the transient decay curve is shown in FIG. The photoluminescence quantum yield φ of the toluene solution of Comparative Compound B was 0.27. Moreover, the light emission lifetime was 8.1 ns, and no delayed fluorescence was observed.

(Comparative Example 3) Preparation and Evaluation of Organic Photoluminescence Device Using Comparative Compound C Using Comparative Compound C having the following structure instead of Compound 1, a toluene solution of Comparative Compound C was prepared in the same manner as Example 1. Prepared. The emission spectrum and transient decay curve of this toluene solution were measured. The measured emission spectrum is shown in FIG. 19, and the transient decay curve is shown in FIG. The photoluminescence quantum yield φ of the toluene solution of Comparative Compound C was 0.26. The emission lifetime was 12.7 ns, and no delayed fluorescence was observed.

(Example 11) Production and evaluation of organic electroluminescence device using compound 5 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 5.0 × 10 ⁻⁴ Pa or less. First, α-NPD was formed on ITO with a thickness of 30 nm, and mCP was formed thereon with a thickness of 10 nm. Next, Compound 5 and (Cz) ₂ DBF were co-evaporated from different vapor deposition sources to form a layer having a thickness of 15 nm as a light emitting layer. At this time, the concentration of Compound 5 was 6.0% by weight. Next, PPT was formed to a thickness of 10 nm, and TPBi was formed thereon to a thickness of 40 nm. Further, lithium fluoride (LiF) was vacuum-deposited at 0.8 nm, and then aluminum (Al) was evaporated at a thickness of 100 nm to form a cathode, thereby obtaining an organic electroluminescence device.
The emission spectrum of the produced organic electroluminescence device is shown in FIG. 21, and the current density-external quantum efficiency characteristic is shown in FIG. The organic electroluminescence device using Compound 5 as the light emitting material achieved a high external quantum efficiency of 15.3%. 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 fluorescence 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. Therefore, the organic electroluminescence device of the present invention using Compound 5 is extremely excellent in that high external quantum efficiency exceeding the theoretical limit value is realized.

(Example 12) Production and evaluation of organic electroluminescence device using compound 6 An organic electroluminescence device was produced in the same manner as in Example 4 using compound 6 instead of compound 5.
The emission spectrum of the produced organic electroluminescence element is shown in FIG. 23, and the current density-external quantum efficiency characteristic is shown in FIG. The organic electroluminescence device using Compound 5 as the light emitting material achieved a high external quantum efficiency of 8.9%.

The compound of the present invention is useful as a luminescent 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 (23)

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

   

   [In General Formula (1), X represents an oxygen atom or a sulfur atom. R ¹ ~ R ⁸ each independently represent a hydrogen atom or a substituent. However, at least one of R ¹ to R ⁸ is each independently a group represented by any one of the following general formulas (2) to (7). R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , R ⁷ and R ⁸ , R ⁸ and R ⁹ , R ⁹ and R ¹ are bonded to each other Thus, a ring structure may be formed. R ⁹ represents a substituent. When R ⁹ contains an atom having a lone pair of electrons that does not form a single bond with a boron atom, the atom may be coordinated with the boron atom to form a cyclic structure. ]
   

   

   

   [In the general formulas (2) to (7), L ¹² to L ¹⁷ each independently represents a single bond or a divalent linking group, and * represents a bonding site to the benzene ring in the general formula (1). R ¹¹ to R ²⁰ , R ²¹ to R ²⁸ , 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 are each independently hydrogen Represents an atom or substituent. R ¹¹ and R ¹² , R ¹² and R ¹³ , R ¹³ and R ¹⁴ , R ¹⁴ and R ¹⁵ , R ¹⁶ and R ¹⁷ , R ¹⁷ and R ¹⁸ , R ¹⁸ and R ¹⁹ , R ¹⁹ and R ²⁰ , R ²¹ And R ²² , R ²² and R ²³ , R ²³ and R ²⁴ , R ²⁴ and R ²⁵ , R ²⁵ and R ²⁶ , R ²⁶ and R ²⁷ , R ²⁷ and R ²⁸ , 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, R45} and ^R46 , ^R46 and ^R47 , ^R47 and ^R48 , ^R51 and ^R52 , ^R52 and ^R53 , ^R53 and ^R54 , ^R55 and ^R56 , ^R56 and ^R57 , ^R57 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 are bonded to each other to form a cyclic structure. It may be. ]
2. 2. The luminescent material according to claim 1, wherein at least one of R ¹ to R ^{8 in} the general formula (1) is a group represented by any one of the general formulas (3) to (7).
3. When at least one of R ¹ to R ^{8 in} the general formula (1) is a group represented by the general formula (3), at least one of R ²¹ to R ^{28 in} the general formula (3) is substituted. The luminescent material according to claim 1, wherein the luminescent material is a group.
4. ^{2. At} least one of R ² , R ³ , R ⁶ , and R ^{7 in} the general formula (1) is a group represented by any one of the general formulas (2) to (7). 4. The light emitting material according to any one of items 1 to 3.
5. The luminescent material according to claim 4, wherein at least one of R ³ and R ^{6 in} the general formula (1) is a group represented by any one of the general formulas (2) to (7).
6. 6. The luminescent material according to claim 5, wherein R ³ and R ^{6 in} the general formula (1) are each independently a group represented by any one of the general formulas (2) to (7).
7. At least one of R ¹¹ to R ^{20 in} the general formula (2), at least one of R ²¹ to R ^{28 in} the general formula (3), and at least one of R ³¹ to R ^{38 in} the general formula (4); , R ^3a and R ^3b , at least one of R ⁴¹ to R ^{48 in} the general formula (5), at least one of R ⁵¹ to R ^{58 in} the general formula (6), and the general formula ( The luminescent material according to any one of claims 1 to 6, wherein at least one of R ⁶¹ to R ^{68 in} 7) is a substituent.
8. At least one of R ¹³ and R ^{18 in} the general formula (2), at least one of R ²³ and R ^{26 in} the general formula (3), at least one of R ³³ and R ^{36 in} the general formula (4), and R ^At least one of ^3a and R ^3b , at least one of R ⁴³ and R ^{46 in} the general formula (5), at least one of R ⁵³ and R ^{56 in} the general formula (6), and R ^{63 in the} general formula (7). The luminescent material according to claim 7, wherein at least one of R ⁶⁶ and R ⁶⁶ is a substituent.
9. At least one of R ¹³ and R ^{18 in} the general formula (2), at least one of R ²³ and R ^{26 in} the general formula (3), at least one of R ³³ and R ^{36 in} the general formula (4), and R ^At least one of ^3a and R ^3b , at least one of R ⁴³ and R ^{46 in} the general formula (5), at least one of R ⁵³ and R ^{56 in} the general formula (6), and R ^{63 in the} general formula (7). 9. The luminescent material according to claim 8, wherein at least one of R ⁶⁶ and R ⁶⁶ is a group represented by any one of the general formulas (2) to (7).
10. 10. The luminescent material according to claim 1, wherein L ¹² to L ^{17 in the} general formulas (2) to (7) are single bonds.
11. 11. The luminescent material according to claim 1, wherein X in the general formula (1) is an oxygen atom.
12. The luminescent material according to any one of claims 1 to 11, wherein R ^{9 in the} general formula (1) is a group represented by the following general formula (a).
    

    

    [In formula (a), * represents the bonding site to the boron atom in the general formula (1). R ^9a , R ^9b , R ^9c , R ^9d and R ^9e each independently represent a hydrogen atom or a substituent. R ^9a and R ^9b , R ^9b and R ^9c , R ^9c and R ^9d , and R ^9d and R ^9e may be bonded to each other to form a cyclic structure. ]
13. The luminescent material according to claim 12, wherein R ^9a and R ^{9e in} the general formula (a) are substituents.
14. The luminescent material according to any one of claims 1 to 13, wherein at least one of R ¹ to R ^{8 in} the general formula (1) is a group represented by the general formula (4).
15. R ³ and R ⁶ or R ² and R ^7, the general formula (1) is any one of claims 1 to 4 and 7 to 14, which is a group represented by the general formula (4) 2. The light emitting material according to item 1.
16. 16. The light emitting material according to claim 14, wherein R ^3a and R ^{3b in} the general formula (4) are substituents.
17. The luminescent material according to any one of claims 14 to 16, wherein the substituent is an alkyl group having 1 to 15 carbon atoms or a phenyl group.
18. The luminescent material according to any one of claims 14 to 16, wherein R ^3a and R ^{3b in} the general formula (4) are bonded to each other to form a cyclic structure.
19. A delayed phosphor comprising a compound represented by the following general formula (1).
    

    

    [In General Formula (1), X represents an oxygen atom or a sulfur atom. R ¹ ~ R ⁸ each independently represent a hydrogen atom or a substituent. However, at least one of R ¹ to R ⁸ is each independently a group represented by any one of the following general formulas (2) to (7). R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁵ and R ⁶ , R ⁶ and R ⁷ , R ⁷ and R ⁸ , R ⁸ and R ⁹ , R ⁹ and R ¹ are bonded to each other Thus, a ring structure may be formed. R ⁹ represents a substituent. When R ⁹ contains an atom having a lone pair of electrons that does not form a single bond with a boron atom, the atom may be coordinated with the boron atom to form a cyclic structure. ]
    

    

    

    [In the general formulas (2) to (7), L ¹² to L ¹⁷ represent a single bond or a divalent linking group, and * represents a bonding site to the benzene ring in the general formula (1). R ¹¹ to R ²⁰ , R ²¹ to R ²⁸ , 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 are each independently hydrogen Represents an atom or substituent. R ¹¹ and R ¹² , R ¹² and R ¹³ , R ¹³ and R ¹⁴ , R ¹⁴ and R ¹⁵ , R ¹⁶ and R ¹⁷ , R ¹⁷ and R ¹⁸ , R ¹⁸ and R ¹⁹ , R ¹⁹ and R ²⁰ , R ²¹ And R ²² , R ²² and R ²³ , R ²³ and R ²⁴ , R ²⁴ and R ²⁵ , R ²⁵ and R ²⁶ , R ²⁶ and R ²⁷ , R ²⁷ and R ²⁸ , 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, R45} and ^R46 , ^R46 and ^R47 , ^R47 and ^R48 , ^R51 and ^R52 , ^R52 and ^R53 , ^R53 and ^R54 , ^R55 and ^R56 , ^R56 and ^R57 , ^R57 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 are bonded to each other to form a cyclic structure. It may be. ]
20. An organic light emitting device comprising the light emitting material according to any one of claims 1 to 18.
21. The organic light-emitting device according to claim 20, which emits delayed fluorescence.
22. The organic light-emitting device according to claim 20 or 21, wherein the organic light-emitting device is an organic electroluminescence device.
23. A compound represented by the following general formula (1 ′).
    

    

    [In General Formula (1 ′), X ′ represents an oxygen atom or a sulfur atom. R ¹ ′ to R ⁸ ′ each independently represents a hydrogen atom or a substituent. However, at least one of R ¹ ′ to R ⁸ ′ is a group independently represented by any one of the following general formulas (2 ′) to (7 ′). R ¹ 'and R ^2', R ² 'and R ^3', R ³ 'and R ^4', R ⁵ 'and R ^6', R ⁶ 'and R ^7', R ⁷ 'and R ^8', R ⁸ 'And R ⁹ ' and R ⁹ 'and R ¹ ' may be bonded to each other to form a cyclic structure. R ⁹ ′ represents a substituent. When R ⁹ ′ includes an atom having a lone pair of electrons that does not form a single bond with a boron atom, the atom may be coordinated with the boron atom to form a cyclic structure. ]
    

    

    

    [In the general formulas (2 ′) to (7 ′), L ¹² ′ to L ¹⁷ ′ each independently represents a single bond or a divalent linking group, and * represents a bond to the benzene ring in the general formula (1 ′). Represents a site. ^{R 11 '~ R 20',} R 21 '~ R 28', R 31 '~ R 38', R 3a ', R 3b', R 41 '~ R 48', R 4a ', R 51' ~ R 58 ', R ⁶¹ ' to R ⁶⁸ 'each independently represents a hydrogen atom or a substituent. R ¹¹ 'and R ^12', R ¹² 'and R ^13', R ¹³ 'and R ^14', R ¹⁴ 'and R ^15', 'R ¹⁷ and' R ^16, R ¹⁷ 'and R ^18', R ¹⁸ 'And R ¹⁹ ', R ¹⁹ 'and R ²⁰ ', R ²¹ 'and R ²² ', R ²² 'and R ²³ ', R ²³ 'and R ²⁴ ', R ²⁴ 'and R ²⁵ ', R ²⁵ 'and R ²⁶ ', R ^26' and R ²⁷ ', R ^27' and R ²⁸ ', 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 ', ^R45 'and ^R46 ', ^R46 'and ^R47 ', ^R47 'and ^R48 ', ^R51 'and ^R52 ', ^R52 'and ^R53 ', ^R53 'and ^R54 ', ^R55 '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 ′ may be bonded to each other to form a cyclic structure. ]

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