TW201443028A - Compound, light-emitting material and organic light-emitting device - Google Patents

Abstract

A compound represented by general formula (1) is useful as a luminescent material. Ar1 to Ar3 each represent an arylene group or a heteroarylene group, and D1 to D3 each represent a hydrogen atom or a substituent group. At least one of D1 to D3 is a diarylamino group that has been substituted by a diphenylamino group or the like.

Description

Compound, luminescent material and organic light-emitting element

The present invention relates to a compound which can be used as a light-emitting material and an organic light-emitting element using the same.

The industry has been actively researching to improve the luminous efficiency of organic light-emitting elements such as organic electroluminescent elements (organic EL (electro luminescence) elements). In particular, various studies have been made on improving the luminous efficiency by newly developing and combining an electron transporting material, a hole transporting material, a light-emitting material, and the like constituting the organic electroluminescent element. Among them, the study also uses the use of three An organic electroluminescent device having a ring and a diphenylamino group compound.

For example, Patent Document 1 discloses that a compound represented by the following formula is used as a main illuminant material in a light-emitting layer existing between one pair of electrodes constituting an organic electroluminescence device. In the following formula, L ^C1 represents a linking group, Z ^C1 represents an atomic group required to form an aromatic hydrocarbon ring or a heterocyclic ring, and n ^C1 represents an integer of 2 or more.

According to Patent Document 1, L ^C1 can take various kinds of linking groups, including 2, 4, 6-three. Three bases. Further, a case where a wide range of rings can be formed by Z ^C1 is described, but a case where a diphenylamine group substituted with a specific group is used as a substituent in the case of forming a benzene ring is not mentioned. In Patent Document 1, as L ^C1 is 2, 4, 6-three A compound having a triphenyl group formed by Z ^C1 and having a diphenylamino group substituted on the benzene ring is specifically described as the following two structures. Among them, regarding the compound A, the usefulness as a main illuminant material was confirmed in the examples.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-183303

As described above, Patent Document 1 describes the use of three The compound of the ring and the diphenylamine group serves as the main illuminant material of the light-emitting layer of the organic electroluminescence device. However, there is no disclosure as to whether or not the compound described in Patent Document 1 can function as a light-emitting material. Since the functions of the luminescent material and the main illuminant material are different from each other, the usefulness of the compound described in Patent Document 1 as a luminescent material is not clear. When the inventors of the present invention conducted research, the characteristics of the compound described in Patent Document 1 were not found to be remarkable.

In this case, the inventors and the like start to The ring and the diphenylamine group have not been studied in the structure disclosed in Patent Document 1, and have been repeatedly studied for the purpose of finding a compound having excellent luminescent properties. In addition, efforts have been made to deduce the general formula of a compound which can be used as a light-emitting material, and to make the composition of an organic light-emitting element having high light-emitting efficiency popular.

The inventors of the present invention have diligently studied, and as a result, a compound group having a specific structure has been successfully synthesized, and it has been found that such a compound group has excellent properties as a light-emitting material. Further, it has been found that there is a compound which can be used as a delayed fluorescent material in such a compound group, and it is clarified that an organic light-emitting element having high luminous efficiency can be provided at a low cost. The present inventors have found the following invention as a means for solving the above problems based on such knowledge.

[1] A compound represented by the following formula (1), [Chemical Formula 3] Formula (1)

[In the general formula (1), Ar ¹ , Ar ² and Ar ³ each independently represent a substituted or unsubstituted extended aryl group, a substituted or unsubstituted heteroaryl group or any two of them. a linking group; D ¹ , D ² and D ³ each independently represent a hydrogen atom or a substituent, and at least one of D ¹ , D ² and D ³ represents a group substituted with a group selected from the group 1-1 below. Diarylamine group,

(The hydrogen atom in each of the above structures may be substituted by a substituent)].

[2] The compound according to [1], wherein at least one of D ¹ , D ² and D ³ of the formula (1) represents a group substituent having a structure selected from the group 1-1 Bit or para-diphenylamino group.

[3] The compound according to [2], wherein at least one of D ¹ , D ² and D ³ of the formula (1) is a diaryl group substituted with a group selected from the group consisting of the following groups 1-2; Amino group, [Chemical 5] (Group 1-2)

(The hydrogen atom in each of the above structures may be substituted with a substituent).

[4] The compound according to [3], wherein at least one of D ¹ , D ² and D ³ of the formula (1) is a diaryl group substituted with a group selected from the group consisting of the following groups 1-3; Amino group, [Chem. 6] (Group 1-3)

(The hydrogen atom in each of the above structures may be substituted with a substituent).

[5] The compound according to any one of [1] to [4] wherein each of Ar ¹ , Ar ² and Ar ^{3 of the} formula (1) is independently a substituted or unsubstituted phenyl group, A linking group formed by linking a substituted pyridyl group or any two of them, which are substituted or unsubstituted.

[6] The compound according to [5], wherein Ar ¹ , Ar ² and Ar ^{3 of the} formula (1) are each independently a group selected from the group consisting of the following groups 2-1,

(The hydrogen atom in each of the above structures may be substituted with a substituent).

[7] of [1] to [6] A compound according to any one of, wherein: D Formula (1) of ^a selected substituted by the above-mentioned group of 1-1 diaryl group, And Ar ¹ is a substituted or unsubstituted pair of pendant phenyl groups.

[8] The compound according to [1], which has a structure represented by the following formula (2),

[In the formula (2), R ¹ to R ¹² and R ¹⁴ to R ²⁵ each independently represent a hydrogen atom or a substituent; and at least one of R ¹ to R ¹⁰ represents a group selected from the group 1-1 below. a substituted diarylamino group; R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁴ and R ⁵ , R ⁶ and R ⁷ , R ⁷ and R ⁸ , R ⁸ and R ⁹ And R ⁹ and R ¹⁰ , R ¹¹ and R ¹² , 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 may also be bonded to each other to form a ring structure,

(The hydrogen atom in each of the above structures may be substituted by a substituent)].

[9] The compound according to [8], wherein at least one of R ¹ to R ¹² and R ¹⁴ to R ²⁵ represents a diarylamine group substituted with a group selected from the above group 1-1, The other R ¹ to R ¹² and R ¹⁴ to R ²⁵ are a hydrogen atom.

[10] The compound according to [8] or [9], wherein at least one of R ² , R ³ , R ⁷ and R ⁸ represents a diaryl group substituted with a group selected from the above group 1-1. Amino group.

[11] A luminescent material comprising the compound according to any one of [1] to [10].

[12] A delayed phosphor comprising the compound according to any one of [1] to [10].

[13] An organic light-emitting device characterized in that it has a light-emitting layer containing a light-emitting material such as [11] on a substrate.

[14] The organic light-emitting device according to [13], characterized in that it emits delayed fluorescence.

[15] The organic light-emitting device according to [13] or [14], which is characterized in that it is an organic electroluminescence device.

The compounds of the invention are useful as luminescent materials. Further, a compound which emits delayed fluorescence is contained in the compound of the present invention. The organic light-emitting element using the compound of the present invention as a light-emitting material can achieve higher luminous efficiency.

1‧‧‧Substrate

2‧‧‧Anode

3‧‧‧ hole injection layer

4‧‧‧ hole transport layer

5‧‧‧Lighting layer

6‧‧‧Electronic transport layer

7‧‧‧ cathode

Fig. 1 is a schematic cross-sectional view showing an example of a layer configuration of an organic electroluminescence device.

Figure 2 is a ¹ H NMR spectrum of Compound 1.

Figure 3 is a graph showing the luminescence spectrum of the toluene solution of Example 1.

4 is a transient decay curve of the toluene solution of Example 1.

Fig. 5 is a luminescence spectrum of a toluene solution of Comparative Example 1.

Figure 6 is a graph showing the transient decay curve of the toluene solution of Comparative Example 1.

Fig. 7 is a graph showing the luminescence spectrum of the thin film type organic photoluminescence device of Example 2.

Fig. 8 is a graph showing the transient decay curve of the thin film type organic photoluminescence device of Example 2.

Fig. 9 is a graph showing the luminescence spectrum of the organic electroluminescence device of Example 3.

Fig. 10 is a graph showing voltage-current density characteristics of the organic electroluminescence device of Example 3.

Fig. 11 is a graph showing the current density-external quantum efficiency characteristics of the organic electroluminescent device of Example 3.

Hereinafter, the contents of the present invention will be described in detail. The description of the constituent elements described below is based on representative embodiments or specific examples of the present invention, but the present invention is not limited to such embodiments or specific examples. In the present specification, the numerical range expressed by "~" means a range including the numerical values described before and after "~" as the lower limit and the upper limit. Further, the isotopic type of the hydrogen atom present in the molecule of the compound used in the present invention is not particularly limited. For example, all of the hydrogen atoms in the molecule may be ¹ H, and some or all of them may be ² H (氘D).

[Compound represented by the formula (1)]

The compound of the present invention is characterized by having a structure represented by the following formula (1).

D ¹ , D ² and D ³ in the formula (1) each independently represent a hydrogen atom or a substituent. Here, at least one of D ¹ , D ² and D ³ represents a diarylamine group substituted with a group selected from the group 1-1 below. The hydrogen atom in each structure described in Group 1-1 may be substituted with a substituent. Each of the groups of Group 1-1 is bonded to the aromatic ring of the diarylamine group by a nitrogen atom in its structure.

The two aryl groups constituting the above diarylamine group may be the same or different from each other. It is preferably the same. The aryl group may be a single ring or a condensed ring, and the ring preferably has a carbon number of 6 to 20, more preferably 6 to 12, and still more preferably 6 to 10. Examples of the diarylamine group include a diphenylamino group, a 1-naphthylphenylamino group, a bis(1-naphthyl)amino group, a 2-naphthylphenylamino group, and a di(2-naphthyl group). An amine group, preferably a diphenylamino group.

The group selected from the group 1-1 may be substituted at any position of the diarylamine group, preferably substituted or substituted with a benzene ring bonded to the amine nitrogen, and more preferably substituted at the para position.

The group selected from the group 1-1 may be substituted with only one of the diarylamine groups, or may be substituted with two or more. When there are two or more substitutions, it is preferred that one or more of each of the benzene rings bonded to the amine nitrogen is substituted. The number of substitutions selected from the group of Group 1-1 is preferably from 1 to 4, more preferably 1 or 2.

Examples of the structure of the diarylamine group substituted with a group selected from the group 1-1 include the following groups 1-2. The hydrogen atom in each structure described in Group 1-2 may be substituted with a substituent.

[12] (Group 1-2)

The diarylamine group substituted with a group selected from the group 1-1 is particularly preferably any of the following groups 1-3. The hydrogen atom in each structure described in Groups 1-3 may be substituted with a substituent.

[Chem. 13] (Group 1-3)

a hydrogen atom in each of the structures described in the above group 1-1, group 1-2, or group 1-3 or a diarylamine substituted in the group 1-1, group 1-2, and group 1-3 The hydrogen atom of the group may also be substituted with a substituent. The number of the substituents is not particularly limited, and a substituent may not be present. Further, when two or more substituents are present, the substituents may be the same or different from each other. Examples of the substituent include a hydroxyl group, a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, and a carbon number of 1 to 20. Alkyl-substituted amine group, fluorenyl group having 2 to 20 carbon atoms, aryl group having 6 to 40 carbon atoms, heteroaryl group having 3 to 40 carbon atoms, diarylamino group having 12 to 40 carbon atoms, carbon number 12 a substituted or unsubstituted carbazolyl group of ~40, 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, and an alkyl group having 1 to 10 carbon atoms Sulfhydrazinyl group, haloalkyl group having 1 to 10 carbon atoms, decylamino group, alkyl guanamine group having 2 to 10 carbon atoms, trialkylsulfonyl group having 3 to 20 carbon atoms, and tridecane having 4 to 20 carbon atoms The alkyl group is an alkylalkyl group, a trialkylsulfonylalkenyl group having 5 to 20 carbon atoms, a trialkylsulfonylalkynyl group having 5 to 20 carbon atoms, and a nitro group. Among these specific examples, those which may be further substituted with a substituent may be 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, or a substituted or unsubstituted carbon number of 6 to 40. An aryl group, a substituted or unsubstituted heteroaryl group having 3 to 40 carbon atoms, a substituted or unsubstituted diarylamino group having 12 to 40 carbon atoms, or a substituted or unsubstituted carbon number of 12 to 40 Substituted carbazolyl. Further preferred substituents are a fluorine atom, a chlorine atom, a cyano group, a substituted or unsubstituted carbon number of 1 to 10. Substituted alkyl group, substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, substituted or unsubstituted dialkylamino group having 1 to 10 carbon atoms, substituted with carbon number 6 to 15 Or unsubstituted aryl, substituted or unsubstituted heteroaryl having 3 to 12 carbon atoms.

The alkyl group described in the present specification may be any of a linear chain, a branched form, and a cyclic form, and more preferably has a carbon number of 1 to 6. Specific examples thereof include a methyl group, an ethyl group, a propyl group, and a butyl group. Base, tert-butyl, pentyl, hexyl, isopropyl. The aryl group may be a monocyclic ring or a fused ring, and specific examples thereof include a phenyl group and a naphthyl group. The alkoxy group may be any of a linear chain, a branched form, and a cyclic form, and more preferably has a carbon number of 1 to 6. Specific examples thereof include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. , a third butoxy group, a pentyloxy group, a hexyloxy group, an isopropoxy group. The two alkyl groups of the dialkylamino group may be the same or different from each other, and are preferably the same. The two alkyl groups of the dialkylamino group may each independently be linear, branched or cyclic, and more preferably have a carbon number of 1 to 6. Specific examples include methyl group and ethyl group. Propyl, butyl, pentyl, hexyl, isopropyl. The aryl group may be a monocyclic ring or a fused ring, and specific examples thereof include a phenyl group and a naphthyl group. The heteroaryl group may be a single ring or a fused ring, and specific examples thereof include a pyridyl group and a fluorene group. Base, pyrimidinyl, three Base, triazolyl, benzotriazolyl.

The diarylamine group substituted with a group selected from the group 1-1 may be at least one of D ¹ , D ² and D ³ , and may be any two or three. In the case of two or more, the structures of the diarylamine groups substituted with a group selected from the group 1-1 may be the same or different from each other. When D ¹ , D ² and D ³ are each a diarylamine group substituted with a group selected from the group 1-1, it is also preferably a group represented by D ¹ -Ar ¹ -, D ² - A compound represented by Ar ² - and a group represented by D ³ -Ar ³ - are all the same.

In the formula (1), each of Ar ¹ , Ar ² and Ar ³ independently represents a substituted or unsubstituted extended aryl group, a substituted or unsubstituted heteroaryl group or the like. Linkage. The two linked linkages include two identical aryl-bonded groups, two different aryl-bonded groups, and two identical hetero-aryl groups. a group formed by a bond between two different heteroaryl groups, a aryl group and a heteroaryl group.

The aryl group which may be selected from Ar ¹ , Ar ² and Ar ³ may be a monocyclic aryl group or an aryl group of a condensed ring. Specific examples thereof include 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 1,2-anthranyl, 1,3-naphthyl, and 1,4. - anthranyl, 1,5-anthranyl, 1,8-anthranyl, preferably 1,4-phenyl, 1,4-naphthyl. The heteroaryl group which may be selected from Ar ¹ , Ar ² and Ar ³ may be a monocyclic heteroaryl group or a heterocyclic aryl group of a condensed ring. The heteroaryl group of the condensed ring also includes a condensed ring of a benzene ring and a hetero ring. Examples of the ring structure constituting the heteroaryl group include a pyridine ring and an anthracene. Ring, pyrimidine ring, three The ring, the triazole ring, and the benzotriazole ring are preferably a pyridine ring.

Ar ¹ , Ar ² and Ar ^{3 are} preferably a linking group which is independently a substituted or unsubstituted phenyl group, a substituted or unsubstituted pyridine group or any two of them, and the like. Preferably, each is independently selected from the group consisting of the following groups 2-1. The hydrogen atom in each structure described in Group 2-1 may be substituted with a substituent.

When D ^{1 of the} formula (1) represents a diarylamine group substituted with a group selected from the group 1-1, Ar ^{1 is} preferably a phenyl group, more preferably a 1,4-phenyl group. Similarly, when D ^{2 of the} formula (1) represents a diarylamine group substituted with a group selected from the group 1-1, Ar ^{2 is} preferably a phenyl group, more preferably a 1,4- benzene group. base. Further, when D ^{3 of the} formula (1) represents a diarylamine group substituted with a group selected from the group 1-1, Ar ^{3 is} preferably a phenyl group, more preferably a 1,4-phenyl group. .

Formula D (1) of Ar ¹ when the hydrogen atom is ^1, D ² is the hydrogen atom when Ar ^2, D ³ is the hydrogen atom when Ar ³ is preferably a group selected from the following group of 2-2. The hydrogen atom in each structure described in Group 2-2 may be substituted with a substituent.

The exoaryl or heteroaryl group which may be selected from Ar ¹ , Ar ² and Ar ³ may be substituted by a substituent, and the hydrogen atom in each of the structures described in the above group 2-1 and group 2-2 may also be subjected to Substituent substitution. The number of substituents is not particularly limited, and a substituent may not be present. Further, when two or more substituents are present, the substituents may be the same or different from each other. Examples of the substituent include a hydroxyl group, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylthio group having 1 to 20 carbon atoms, and an aryl group having 6 to 40 carbon atoms. a heteroaryl group having 3 to 40 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, a trialkylalkylene group having 3 to 20 carbon atoms, a trialkylsulfanylalkyl group having 4 to 20 carbon atoms, a trialkylsulfonylalkylene group having 5 to 20 carbon atoms, a trialkyldecylalkylalkyne group having 5 to 20 carbon atoms, and the like. Among these specific examples, those which may be further substituted with a substituent may be substituted. More preferred substituents are substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, substituted or unsubstituted aryl groups having 6 to 40 carbon atoms, and carbon number 3 ~40 substituted or unsubstituted heteroaryl. Further preferably, the substituent is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, or a substituted or unsubstituted carbon number of 6 to 15. Substituted aryl, substituted or unsubstituted heteroaryl having 3 to 12 carbon atoms.

Compounds of formula (1) is preferably represented by the D ¹ is selected from the group substituted by 1-1 of the diaryl group, Ar ¹ is a substituted or non-substituted para-phenylene, more preferably It is a structure represented by the following general formula (2).

In the formula (2), R ¹ to R ¹² and R ¹⁴ to R ²⁵ each independently represent a hydrogen atom or a substituent. At least one of R ¹ to R ¹⁰ represents a diarylamine group substituted with a group selected from the above group 1-1.

For the description and preferred ranges of the substituents which may be taken from R ¹ to R ¹² , reference may be made to the description of the substituents which may be taken for each of the structures described in the above group 1-1, group 1-2, group 1-3, and preferred. range. Further, for the description and preferred ranges of the substituents which may be taken for R ¹¹ , R ¹² and R ¹⁴ to R ²⁵ , reference may be made to the substitution of the above-mentioned Ar ¹ , Ar ² and Ar ³ which may be substituted with an aryl group or a heteroaryl group. Base description and preferred range.

R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁴ and R ⁵ , R ⁶ and R ⁷ , R ⁷ and R ⁸ , R ⁸ and R ⁹ , R ⁹ and R ¹⁰ , R ¹¹ And R ¹² , 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 may also be bonded to each other to form a ring structure. The cyclic structure may be an aromatic ring or an aliphatic ring, or may be a hetero atom, and the cyclic structure may also be a condensed ring of 2 or more rings. The hetero atom described herein is preferably selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom. Examples of the cyclic structure to be formed include a benzene ring, a naphthalene ring, a pyridine ring, and an anthracene. Ring, pyrimidine ring, pyridyl Ring, pyrrole ring, imidazole ring, pyrazole ring, triazole ring, imidazoline ring, Oxazole ring, different An azole ring, a thiazole ring, an isothiazole ring, a cyclohexadiene ring, a cyclohexene ring, a cyclopentene ring, a cycloheptatriene ring, a cycloheptadiene ring, a cycloheptene ring or the like.

As a preferred group of the compounds represented by the formula (2), at least one of R ¹ to R ¹² and R ¹⁴ to R ²⁵ is a diaryl group substituted with a group selected from the above group 1-1. Amine group, other compound groups in which R ¹ to R ¹² and R ¹⁴ to R ²⁵ are a hydrogen atom.

Further, as another preferred group of the compounds represented by the formula (2), at least one of R ² , R ³ , R ⁷ and R ⁸ is substituted with a group selected from the above group 1-1. A compound group of a diarylamine group.

Specific examples of the compound represented by the formula (1) are exemplified below. However, the compound represented by the formula (1) which can be used in the present invention should not be construed as being limited by the specific examples.

[化17]

[化18]

[Chemistry 19]

[Chemistry 20]

[Chem. 21]

[化22]

[化23]

[Chem. 24]

[化25]

[Chem. 26]

The molecular weight of the compound represented by the formula (1) is preferably 1,500 or less, more preferably 1,500 or less, when it is intended to form and use an organic layer containing the compound represented by the formula (1) by a vapor deposition method. 1200 or less, more preferably 1,000 or less, and even more preferably 800 or less. The lower limit of the molecular weight is the molecular weight of the smallest compound represented by the formula (1).

Regardless of the molecular weight, the compound represented by the formula (1) can be formed into a film by a coating method. When a coating method is used, a film having a relatively large molecular weight can be formed.

It is also considered to be possible to use the present invention as a light-emitting material using a compound having a plurality of structures represented by the formula (1) in its molecule.

For example, it is considered that a polymerizable group is preliminarily present in the structure represented by the general formula (1), and the polymerizable group is polymerized to obtain a polymer, and the polymer is used as a light-emitting material. Specifically, it is considered that a monomer having a polymerizable functional group in any one of Ar ¹ , Ar ² , Ar ³ , D ¹ , D ² , and D ³ of the formula (1) is prepared and polymerized separately. Alternatively, copolymerization is carried out together with other monomers, whereby a polymer having a repeating unit is obtained, and the polymer is used as a light-emitting material. Alternatively, it is considered that a dimer or a trimer is obtained by coupling a compound having a structure represented by the general formula (1) to each other, and the like is used as a light-emitting material.

Examples of the polymer having a repeating unit having a structure represented by the formula (1) include a polymer having a structure represented by the following formula (3) or (4).

In the general formulae (3) and (4), Q represents a group containing a structure represented by the formula (1), and L ¹ and L ² represent a linking group. The carbon number of the linking group is preferably from 0 to 20, more preferably from 1 to 15, and still more preferably from 2 to 10. The linking group is preferably a structure represented by -X ¹¹ -L ¹¹ -. Here, X ¹¹ represents an oxygen atom or a sulfur atom, preferably an oxygen atom. L ¹¹ represents a linking group, preferably a substituted or unsubstituted alkylene group, or a substituted or unsubstituted extended aryl group, more preferably a substituted or unsubstituted alkylene group having a carbon number of 1 to 10. A phenyl group, either substituted or unsubstituted.

In the general formulae (3) and (4), 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, a halogen atom, more preferably a carbon number of 1 to 3 Substituted alkyl group, unsubstituted alkoxy group having 1 to 3 carbon atoms, fluorine atom, chlorine atom, further preferably unsubstituted alkyl group having 1 to 3 carbon atoms, and having 1 to 3 carbon atoms Substituted alkoxy.

The linking group represented by L ¹ and L ² may be bonded to any one of Ar ¹ , Ar ² , Ar ³ , D ¹ , D ² , and D ³ of the structure of the general formula (1) constituting Q, and a general formula (2) Any of R ¹ to R ¹² and R ¹⁴ to R ²⁵ . Two or more linking groups may be bonded to one Q to form a crosslinked structure or a network structure.

Specific examples of the configuration of the repeating unit include the structures represented by the following formulas (5) to (8).

[化28]

A polymer having a repeating unit containing the above equations (5) to (8) can be synthesized by introducing a hydroxyl group into any one of A or D of the structure of the general formula (1) as a connection. The polymer is reacted with the following compound to introduce a polymerizable group, and the polymerizable group is polymerized.

The polymer having a structure represented by the formula (1) in the molecule may be a polymer composed only of a repeating unit having a structure represented by the formula (1), or may be a repeating unit having a structure other than the above. polymer. Further, the repeating unit having the structure represented by the formula (1) contained in the polymer may be a single type or two or more types. Examples of the repeating unit having no structure represented by the formula (1) include those derived from a monomer which is usually used for copolymerization. For example, a repeating unit derived from a monomer having an ethylenically unsaturated bond such as ethylene or styrene may be mentioned.

[Synthesis method of compound represented by general formula (1)]

The compound represented by the formula (1) can be synthesized by combining known reactions. For example, the synthesis can be performed according to the following procedure.

For the description of Ar ¹ , Ar ² , Ar ³ , D ² , and D ^{3 in} the above scheme, the description corresponding to the formula (1) can be referred to. D ¹ represents a diarylamine group substituted with a group selected from the group 1-1. X represents a halogen atom, and examples thereof 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 preferred.

The reaction in the above scheme employs a known coupling reaction, and a known reaction condition can be appropriately selected and used. For details of the above reaction, the following synthesis examples can be referred to. Further, the compound represented by the formula (1) can also be synthesized by combining other known synthesis reactions.

[Organic light-emitting element]

The compound represented by the formula (1) of the present invention can be used as a light-emitting material of an organic light-emitting element. Therefore, the compound represented by the formula (1) of the present invention can be effectively used as a light-emitting material for the light-emitting layer of the organic light-emitting element. The compound represented by the formula (1) contains a delayed fluorescent material (delayed phosphor) which emits delayed fluorescence. That is, the present invention also provides the invention of the delayed phosphor having the structure represented by the general formula (1), the invention using the compound represented by the general formula (1) as the delayed fluorescent body, and the use of the general formula (1). The invention of a method for delaying fluorescent light emission. An organic light-emitting element using such a compound as a light-emitting material has a feature of emitting delayed fluorescence and having high luminous efficiency. The principle of the organic electroluminescent device will be described below as an example.

In the organic electroluminescence device, a carrier is injected into the luminescent material from the positive and negative electrodes, and a luminescent material in an excited state is generated to emit light. Generally, in the case of a carrier-injection type organic electroluminescence device, among the excitons generated, 25% are excited to excite the singlet state, and the remaining 75% are excited to the excited triplet state. Therefore, when the light from the triplet state is excited, that is, phosphorescence, the energy utilization efficiency is high. However, since the lifetime of the excited triplet state is long, the saturation of the excited state or the energy inactivation caused by the interaction with the excited triplet exciton is often caused, and generally the quantum yield of phosphorescence is not high. On the other hand, the delayed fluorescent material is converted into an excitation by inter-system crossing or the like. After the triplet state, the triplet-triplet state is annihilated or the absorption of thermal energy is converted to the excited singlet state, thereby emitting fluorescence. Among the organic electroluminescence elements, heat-activated delayed fluorescent materials in which thermal energy absorption is utilized are considered to be particularly useful. In the case where a delayed fluorescent material is used for the organic electroluminescent element, excitons that excite singlet states emit fluorescence as usual. On the other hand, the heat generated by the exciton absorption device of the triplet state is excited to be converted into an excited singlet state, and the fluorescence is emitted. At this time, since it emits light from the excited singlet state, although it emits light of the same wavelength as the fluorescent light, the lifetime (light-emitting lifetime) of the generated light is converted by the inverse inter-system transition from the excited triplet state to the excited singlet state. It is longer than normal fluorescent or phosphorescent light, and is observed as a fluorescent light of equal delay. It can be defined as delayed fluorescence. If such a heat-activated exciton migration mechanism is used, the ratio of the compound which normally produces only 25% of the excited singlet state can be increased to 25% or more by absorption of thermal energy after the carrier is injected. If a compound that emits strong fluorescence and delayed fluorescence even at a low temperature of less than 100 ° C is used, the inter-system conversion of the self-excited triplet state to the excited singlet state is sufficiently generated by the heat of the device, thereby emitting a delay Fluorescent, so the luminous efficiency can be greatly improved.

By using the compound represented by the formula (1) of the present invention as a light-emitting material of the light-emitting layer, it is possible to provide an organic photoluminescent element (organic PL (photoluminescence) element) or an organic electroluminescence element (organic EL element). Organic light-emitting element. In this case, the compound represented by the formula (1) of the present invention may also function as a function of light emission of other luminescent materials contained in the auxiliary light-emitting layer as a so-called auxiliary dopant. That is, the compound represented by the formula (1) of the present invention contained in the light-emitting layer may have the lowest excited singlet energy level of the main illuminant material contained in the light-emitting layer and other luminescence contained in the luminescent layer. The lowest excited singlet energy level between the lowest excited singlet energy levels of the material.

The organic photoluminescent element has a structure in which at least a light-emitting layer is formed on a substrate. Further, the organic electroluminescence device has at least an anode, a cathode, and a structure of an organic layer formed between the anode and the cathode. The organic layer is at least a light-emitting layer, and may be composed only of a light-emitting layer The person may also have more than one organic layer in addition to the luminescent 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 also be a hole injection transport layer having a hole injection function, and the electron transport layer may also be an electron injection transport layer having an electron injection function. A specific structure of the organic electroluminescence device is shown in Fig. 1. In Fig. 1, 1 denotes a substrate, 2 denotes an anode, 3 denotes a hole injection layer, 4 denotes a hole transport layer, 5 denotes a light-emitting layer, 6 denotes an electron transport layer, and 7 denotes a cathode.

Hereinafter, each member and each layer of the organic electroluminescence device will be described. Further, the description of the substrate and the light-emitting layer corresponds to the substrate of the organic photoluminescent device and the light-emitting layer.

(substrate)

The organic electroluminescent device of the present invention is preferably supported by a substrate. The substrate is not particularly limited as long as it is conventionally used in an organic electroluminescence device, and for example, glass, transparent plastic, quartz, ruthenium or the like can be used.

(anode)

As the anode in the organic electroluminescence device, a metal having a large work function (4 eV or more), an alloy, a conductive compound, and the like can be preferably used as the electrode material. Specific examples of such an electrode material include a metal such as Au, and a conductive transparent material such as CuI, indium tin oxide (ITO), SnO ₂ or ZnO. Further, a material which is amorphous and can be made into a transparent conductive film such as IDIXO (In ₂ O ₃ -ZnO) can also be used. For the anode, the electrode materials can be formed into a thin film by vapor deposition or sputtering, and a pattern of a desired shape can be formed by photolithography, or when pattern precision is less required (about 100 μm). The above) may also form a pattern through a mask of a desired shape during vapor deposition or sputtering of the electrode material. Alternatively, when a material which can be applied as an organic conductive compound is used, a wet film formation method such as a printing method or a coating method may be employed. In the case of extracting the emitted light from the anode, it is preferable to make the transmittance higher than 10%, and the sheet resistance of the anode is preferably several hundreds 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 metal having a small work function (4 eV or less) (referred to as an electron injecting metal), an alloy, a conductive compound, and the like can be used as the electrode material. Specific examples of such an electrode material include sodium, sodium-potassium alloy, magnesium, lithium, magnesium/copper mixture, magnesium/silver mixture, magnesium/aluminum mixture, magnesium/indium mixture, and aluminum/aluminum oxide (Al _{2 ).} O ₃ ) a mixture, indium, a lithium/aluminum mixture, a rare earth metal, or the like. Among them, in terms of electron injectability and durability against oxidation, etc., it is preferred that the electron injecting metal and the work function have a value larger than the electron injecting metal and the stable metal, that is, the second metal mixture. For example, a magnesium/silver mixture, a magnesium/aluminum mixture, a magnesium/indium mixture, an aluminum/alumina (Al ₂ O ₃ ) mixture, a lithium/aluminum mixture, aluminum, and the like. The cathode can be produced by forming the electrode material into a thin film by a method such as vapor deposition or sputtering. Further, the sheet resistance of the cathode is preferably several hundred Ω/□ or less, and the film thickness is usually selected from the range of 10 nm to 5 μm, preferably 50 to 200 nm. Further, in order to transmit the emitted light, any one of the anode and the cathode of the organic electroluminescent element may be transparent or translucent, and thus the luminance of the light is improved, which is suitable.

Further, by using the conductive transparent material exemplified in the description of the anode for the cathode, a transparent or translucent cathode can be produced, and by using the material, an element having both an anode and a cathode can be produced.

(lighting layer)

The light-emitting layer is formed by recombining holes and electrons injected from the anode and the cathode to generate an exciton light-emitting layer, and the light-emitting material may be used alone in the light-emitting layer, and preferably includes a light-emitting material and a main light-emitting material. As the luminescent material, one or two or more selected from the group of compounds of the present invention represented by the formula (1) can be used. In order for the organic electroluminescent device and the organic photoluminescent device of the present invention to exhibit high luminous efficiency, it is important to enclose singlet excitons and triplet excitons generated in the luminescent material in the luminescent material. because Therefore, it is preferred to use a main illuminant material in addition to the luminescent material in the luminescent layer. As the main illuminant material, an organic compound having at least one of the excited singlet energy and the excited triplet energy having a value higher than that of the luminescent material of the present invention can be used. As a result, the singlet excitons and triplet excitons generated by the luminescent material of the present invention can be enclosed in the molecules of the luminescent material of the present invention, and the luminous efficiency can be sufficiently improved. However, even if singlet excitons and triplet excitons cannot be sufficiently closed, high luminous efficiency can be obtained. Therefore, as long as it is a main illuminant material capable of achieving high luminous efficiency, there is no particular limitation. Used in the present invention. In the organic light-emitting device or the organic electroluminescence device of the present invention, the light-emitting device is produced by the light-emitting material of the present invention contained in the light-emitting layer. The luminescence includes both fluorescent luminescence and delayed luminescence. However, one or a portion of the illumination may also include illumination from the primary illuminant material.

When the main illuminant material is used, the amount of the compound of the present invention as a luminescent material contained in the luminescent layer is preferably 0.1% by weight or more, more preferably 1% by weight or more, and still more preferably 50% by weight. Hereinafter, it is more preferably 20% by weight or less, still more preferably 10% by weight or less.

As the main illuminant material in the light-emitting layer, an organic compound having a hole transporting ability, an electron transporting ability, a long-wavelength preventing luminescence, and a high glass transition temperature is preferable.

(injection layer)

The injection layer refers to a layer disposed between the electrode and the organic layer in order to lower the driving voltage or increase the luminance of the light, and has a hole injection layer and an electron injection layer, and may also exist in the anode and the light-emitting layer or the hole transport layer. Between, and between the cathode and the light-emitting layer or the electron transport layer. The injection layer can be set as needed.

(barrier layer)

The barrier layer is a layer that blocks charges (electrons or holes) and/or excitons present in the light-emitting layer from diffusing out of the light-emitting layer. The electron blocking layer can be disposed on the light emitting layer and the hole transport layer In between, the blocking electrons move toward the hole transport layer and pass through the light emitting layer. Similarly, the hole blocking layer may be disposed between the light emitting layer and the electron transport layer, and the blocking hole moves toward the electron transport layer to pass through the light emitting layer. The barrier layer can also be used to block the diffusion of excitons toward the outside of the luminescent layer. That is, the electron blocking layer and the hole blocking layer may each function as an exciton blocking layer. The electron blocking layer or exciton blocking layer described in the present specification is used in the sense that a layer having a function of an electron blocking layer and an exciton blocking layer is included in one layer.

(hole blocking layer)

The term "hole blocking layer" refers broadly to the function of having an electron transport layer. The hole blocking layer has the function of transmitting electrons and blocking the holes from reaching the electron transport layer, whereby the probability of recombination of electrons and holes in the light-emitting layer can be improved. As the material of the hole blocking layer, a material of an electron transport layer to be described later may be used as needed.

(electronic barrier layer)

The so-called electron blocking layer, in a broad sense, refers to the function of having a transmission hole. The electron blocking layer has a function of transmitting holes and blocking electrons from reaching the hole transport layer, whereby the probability of recombination of electrons and holes in the light-emitting layer can be improved.

(exciton blocking layer)

The exciton blocking layer refers to a layer for blocking diffusion of excitons generated by recombination of holes and electrons in the light-emitting layer to the charge transport layer, and the excitons can be effectively enclosed by light by inserting the layer. Within the layer, the luminous efficiency of the component can be improved. The exciton blocking layer may be inserted into either one of the anode side and the cathode side adjacent to the light emitting layer, or may be inserted on both sides at the same time. That is, in the case where the exciton blocking layer is provided on the anode side, the layer may be inserted adjacent to the light-emitting layer between the hole transport layer and the light-emitting layer, and between the light-emitting layer and the cathode when inserted into the cathode side. The layer is inserted adjacent to the light-emitting layer. Further, a hole injection layer or an electron blocking layer may be provided between the anode and the exciton blocking layer on the anode side of the adjacent light-emitting layer, and an electron may be present between the cathode and the exciton blocking layer on the cathode side of the adjacent light-emitting layer. Injection layer, electron transport layer, hole blocking layer, and the like. When the barrier layer is disposed, it is preferably used as a barrier layer. At least one of the excited singlet energy and the excited triplet energy is higher than the excited singlet energy and the excited triplet energy of the luminescent material.

(hole transport layer)

The hole transport layer includes a hole transport material having a function of transmitting a hole, and the hole transport layer may be provided with a single layer or a plurality of layers.

The material for the hole transporting means any one of the properties of the injection or transmission of the hole and the barrier property of the electron, and may be any of an organic substance and an inorganic substance. As a known hole transporting material which can be used, for example, a triazole derivative can be cited. Diazole derivatives, imidazole derivatives, carbazole derivatives, carbazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamines Derivatives, amine-substituted chalcone derivatives, An azole derivative, a styryl hydrazine derivative, an anthrone derivative, an anthracene derivative, an anthracene derivative, a decazane derivative, an aniline copolymer, and a conductive polymer oligomer, especially a thiophene oligomer Preferably, a porphyrin compound, an aromatic tertiary amine compound, and a styrylamine compound are used, and an aromatic tertiary amine compound is more preferably used.

(electronic transport layer)

The electron transport layer includes a material having a function of transmitting electrons, and the electron transport layer may be provided with a single layer or a plurality of layers.

As the electron transporting material (which also serves as a hole blocking material), it is only required to have a function of transporting electrons injected from the cathode to the light emitting layer. Examples of the electron transporting layer which can be used include a nitro-substituted anthracene derivative, a diphenylanthracene derivative, a thiouranium derivative, a carbodiimide, a fluorenylene methane derivative, and a quinodimethane. And anthrone derivatives, Diazole derivatives and the like. Further, above Among the oxadiazole derivatives, a thiadiazole derivative in which an oxygen atom of a oxazolyl ring is substituted with a sulfur atom, and a quinine known to be an electron withdrawing group Quinone ring The porphyrin derivative can also be used as an electron transporting material. Further, it is also possible to use these materials as a polymer material which is introduced into a polymer chain or which uses these materials as a polymer main chain.

In the production of the organic electroluminescence device, not only the compound represented by the formula (1) but also the layer other than the light-emitting layer can be used. In this case, the compound represented by the formula (1) used in the light-emitting layer may be the same as or different from the compound represented by the formula (1) used for the layer other than the light-emitting layer. For example, a compound represented by the formula (1) may be used in the injection layer, the barrier layer, the hole barrier layer, the electron blocking layer, the exciton blocking layer, the hole transport layer, the electron transport layer, and the like. The film forming method of the layers is not particularly limited, and it may be produced by any of a dry process or a wet process.

Hereinafter, preferred materials which can be used in the organic electroluminescence element are specifically exemplified. However, materials which can be used in the present invention are not to be construed as being limited by the following exemplified compounds. Further, even a compound exemplified as a material having a specific function can be used as a material having other functions. Further, in the structural formulae of the following exemplified compounds, R and R ₂ to R ₇ each independently represent a hydrogen atom or a substituent. n represents an integer from 3 to 5.

First, preferred compounds which can also be used as the main illuminant material of the luminescent layer are listed.

[化31]

[化32]

[化34]

[化35]

Next, an example of a preferred compound which can be used as a hole injecting material is listed.

[化36]

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

[化37]

[化38]

[39]

[化40]

[化41]

[化42]

Next, examples of preferred compounds which can be used as electron blocking materials are listed.

[化43]

Next, an example of a preferred compound which can be used as a barrier material for a hole is listed.

[化44]

Next, examples of preferred compounds which can be used as electron transport materials are listed.

[化45]

[Chem. 46]

[化47]

Next, examples of preferred compounds which can be used as electron injecting materials are listed.

Further, examples of the compound which is preferable as a material which can be added are listed. For example, it is considered to be added as a stable material or the like.

[化49]

The organic electroluminescent element produced by the above method emits light by applying an electric field between the anode and the cathode of the obtained element. At this time, if the light is emitted by the excitation singlet energy, the light corresponding to the wavelength of the energy level is confirmed as the fluorescent light emission and the delayed fluorescent light emission. Further, in the case of light emission caused by the excitation triplet energy, the wavelength corresponding to the energy level is confirmed as phosphorescence. Generally, the fluorescence lifetime is shorter than that of delayed fluorescence, so the luminescence lifetime can be distinguished by fluorescence and delayed fluorescence.

On the other hand, regarding phosphorescence, a usual organic compound such as a compound of the present invention is converted into heat or the like due to instability of the excited triplet energy, and has a short life and immediately loses activity, so that it is hardly observed at room temperature. In order to determine the excited triplet energy of a typical organic compound, it can be determined by observing the luminescence under extremely low temperature conditions.

The organic electroluminescence device of the present invention can also be applied to any of a single element, an element including a structure arranged in an array, and a structure in which an anode and a cathode are arranged in an X-Y matrix. According to the present invention, an organic light-emitting device in which the light-emitting efficiency is greatly improved can be obtained by including the compound represented by the formula (1) in the light-emitting layer. The organic light-emitting element such as the organic electroluminescence device of the present invention can be further applied to various applications. For example, an organic electroluminescence display device can be manufactured using the organic electroluminescence device of the present invention, and for details, "Organic EL Display" (Ohmsha), which was co-authored by Jing Shi, Anda Chiba, and Murata. Further, in particular, the organic electroluminescence device of the present invention can also be applied to an organic electroluminescence illumination or a backlight device which is in great demand.

[Examples]

Hereinafter, the features of the present invention will be more specifically described by way of Synthesis Examples and Examples. The materials, processing contents, processing procedures, and the like shown below may be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the invention should not be construed as being limited by the specific examples shown below.

(Synthesis Example 1) Synthesis of Compound 1

2-(4-bromophenyl)-4,6-diphenyl three 2.00 g (5.15 mmol), sodium butoxide sodium 0.594 g (6.18 mmol), diphenylamine 1.31 g (7.73 mmol), tris(dibenzylideneacetone) dipalladium (0) 99.7 mg (0.109 mmol) added The inside of the flask was purged with nitrogen in a 100 ml three-necked flask. To the mixture was added 1.0 mL of toluene solution of 30 mL of toluene and a concentration of 0.75 mol/L of tris(t-butyl)phosphine. After nitrogen gas was passed through the mixture for 30 minutes, the mixture was stirred at 80 ° C for 20 hours under a nitrogen atmosphere. After stirring, the mixture was passed through diatomaceous earth and silica gel, and subjected to suction filtration to obtain a filtrate. Water was added to the obtained filtrate to carry out washing. After washing, the organic layer and the aqueous layer were separated, and magnesium sulfate was added to the organic layer to dry. After drying, the mixture was subjected to suction filtration to obtain a filtrate. The obtained filtrate was concentrated, and the obtained solid was washed with a mixed solvent of acetone and methanol to obtain Compound 1 in a yield of 2.40 g and a yield of 97.8%. Fig. 2 shows a ¹ H-NMR spectrum (CDCl ₃ , 500 MHz).

4-(4,6-diphenyl-1,3,5-three 2.00 g (5.03 mmol) of triphenylamine, 20 mL of tetrahydrofuran, and 20 mL of ethyl acetate were added to a 100 mL Erlenmeyer flask and stirred. After the solution was cooled to 0 ° C, 2.08 g (11.7 mmol) of N-bromosuccinimide was gradually added in small portions. The solution was stirred at room temperature for 24 hours, and as a result, a solid was precipitated. After stirring, water was added to the mixture and stirred. After stirring, the organic layer of the mixture was concentrated, and 100 mL of water was added thereto for stirring, followed by suction filtration to obtain a solid. The obtained solid was washed with a mixed solvent of acetone and methanol, and as a result, a powdery pale yellow solid of the object was obtained in a yield of 2.97 g and a yield of 93.1%.

4,4'-dibromo-4"-(4,6-diphenyl-1,3,5-three 2-yl)triphenylamine 1.50 g (2.36 mmol), diphenylamine 1.00 g (5.91 mmol), tris(dibenzylideneacetone)dipalladium (0) 43.2 mg (0.0472 mmol), third 0.681 g (7.09 mmol) of sodium alkoxide was added to a 100 ml three-necked flask, and the inside of the flask was purged with nitrogen. To the mixture was added 1.0 mL of toluene solution of 20 mL of toluene and a concentration of 0.75 mol/L of tris(t-butyl)phosphine. The mixture was stirred at 80 ° C for 20 hours under a nitrogen atmosphere. After stirring, the mixture was added to 100 mL of water and 100 mL of toluene and stirred. After stirring, the aqueous layer of the mixture was removed and passed through diatomaceous earth and tannin extract for suction filtration. Water was added to the obtained filtrate to carry out washing. After washing, the organic layer and the aqueous layer were separated, and magnesium sulfate was added to the organic layer to dry. After drying, the mixture was subjected to suction filtration to obtain a filtrate. The obtained filtrate was concentrated, and the obtained solid was washed with a mixed solvent of acetone and methanol to obtain Compound 1 as a powdery yellow solid in a yield of 1.71 g and a yield of 89.3%.

_{^{1 H NMR (500MHz, CDCl 3}} ): δ 8.75 (d, J = 8.5Hz, 4H), 8.62 (d, J = 9.0Hz, 2H), 7.61-7.53 (m, 6H), 7.29-7.26 (m, 8H), 7.17-7.05 (m, 22H).

(Example 1) Production and evaluation of an organic photoluminescent device (solution)

A toluene solution (concentration: 10 ^-5 mol/L) of the compound 1 synthesized in Synthesis Example 1 was prepared, and ultraviolet light was irradiated at 300 K while introducing nitrogen gas. As a result, fluorescence having a peak wavelength of 565 nm was observed as shown in FIG. . The photoluminescence quantum efficiency in the toluene solution of Compound 1 was measured at 300 K by an absolute PL quantum yield measuring device (Quantaurus-QY manufactured by Hamamatsu Photonics Co., Ltd.), and the result was 34.8% before the introduction of nitrogen gas. It became 44.5% after nitrogen and was found to increase by about 10%. Figure 4 shows the transient decay curve after nitrogen is passed. The transient decay curve represents the measurement result of the luminescence lifetime in the process of measuring the excitation light of the compound to gradually deactivate the luminescence intensity. In the case of normal single-component luminescence (fluorescence or phosphorescence), the luminescence intensity is attenuated by a single exponential function. It means that the line is attenuated when the vertical axis of the graph is a semi log. In the transient decay curve of Compound 1, such a linear component (fluorescence) was observed at the beginning of the observation, but thereafter a component deviating from the linearity occurred. It is the luminescence of the delayed component, and the signal added to the initial component becomes a gentle curve that is dragged to the long-term side. By measuring the luminescence lifetime in this manner, it was confirmed that the compound 1 is an illuminant containing a retardation component in addition to the fluorescent component.

(Comparative Example 1) Production and evaluation of an organic photoluminescence device (solution)

A toluene solution was prepared in the same manner as in Example 1 except that the above Compound A was used instead of Compound 1 as a comparative compound. The luminescence spectrum is shown in Fig. 5, and the transient attenuation curve is shown in Fig. 6. No difference was observed before and after the introduction of nitrogen gas, and delayed fluorescence was not confirmed.

(Example 2) Production and evaluation of organic photoluminescent device (film)

Silicon based on the board, by a vacuum deposition method 5.0 × 10 ^-4 at a degree of vacuum _- deposited from different evaporation sources Compound 1 and mCBP (3,3'-di (9H- carbazol-9-yl Pa under the conditions Biphenyl, 3,3'-bis(9H-carbazol-9-yl)biphenyl), formed into a film having a concentration of compound 1 of 6.0% by weight at a thickness of 100 nm at 0.3 nm/sec. Light-emitting element. The luminescence spectrum obtained by using the same measuring apparatus as in Example 1 is shown in Fig. 7 (peak wavelength 539 nm). Further, the measurement was carried out at 300 K, 250 K, 200 K, and 150 K using a small fluorescence lifetime measuring device (Quantaurus-tau manufactured by Hamamatsu Photonics Co., Ltd.) to obtain a transient decay curve shown in Fig. 8. According to Fig. 8, it was confirmed that it is a thermally active type delayed fluorescence in which the delayed fluorescent component is decreased as the temperature is lowered. The photoluminescence quantum efficiency was 100% at 300 K under nitrogen flow.

(Example 3) Production and evaluation of organic electroluminescence device

Each film was laminated on a glass substrate on which an anode containing indium tin oxide (ITO) having a film thickness of 100 nm was formed by a vacuum deposition method at a vacuum of 5.0 × 10 ^-4 Pa. First, α-NPD (N, N'-dinaphthyl-N, N'-diphenylbenzidine, N, N'-dinaphthyl-N,N'-diphenylbenzidine) was formed on ITO at a thickness of 35 nm. Next, the compound 1 and mCBP 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 the compound 1 was set to 6.0% by weight. Next, TPBi (1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 1,3,5-tris(1-phenyl-1H-benzimidazole-2) was formed at a thickness of 65 nm. Further, phenyl) was further vapor-deposited with 0.8 nm of lithium fluoride (LiF), followed by vapor deposition of aluminum (Al) at a thickness of 100 nm to form a cathode, thereby preparing an organic electroluminescence device.

The manufactured organic electroluminescent device was measured using a semiconductor parameter analyzer (manufactured by Agilent Technologies, Inc.: E5273A), an optical power meter measuring device (manufactured by Newport: 1930C), and an optical spectroscope (manufactured by Ocean Optics: USB2000). As a result, as shown in Fig. 9, the light emission at 548 nm was confirmed. The voltage-current density characteristics are shown in Fig. 10, and the current density-external quantum efficiency characteristics are shown in Fig. 11. The organic electroluminescent element using Compound 1 as a luminescent material achieved a higher external quantum efficiency of 15.44%. Assuming that a well-balanced organic electroluminescent device is produced using a fluorescent material having a luminescence quantum efficiency of 100%, if the light extraction efficiency is 20 to 30%, the external quantum efficiency of the luminescence is 5 to 7.5%. This value is generally considered to be the theoretical limit of the external quantum efficiency of an organic electroluminescent element using a fluorescent material. The organic electroluminescence device of the present invention using the compound 1 is extremely excellent in achieving a higher external quantum efficiency exceeding a theoretical limit value.

[Industrial availability]

The compounds of the invention are useful as luminescent materials. Therefore, the compound of the present invention can be effectively used as a light-emitting material for an organic light-emitting element such as an organic electroluminescence device. The compound of the present invention also contains an organic light-emitting device which emits delayed fluorescence and thus provides high luminous efficiency. Therefore, the industrial availability of the present invention is high.

1‧‧‧Substrate

2‧‧‧Anode

3‧‧‧ hole injection layer

4‧‧‧ hole transport layer

5‧‧‧Lighting layer

6‧‧‧Electronic transport layer

7‧‧‧ cathode

Claims (15)

a compound represented by the following formula (1), [In the general formula (1), Ar ¹ , Ar ² and Ar ³ each independently represent a substituted or unsubstituted extended aryl group, a substituted or unsubstituted heteroaryl group or any two of them. a linking group; D ¹ , D ² and D ³ each independently represent a hydrogen atom or a substituent, and at least one of D ¹ , D ² and D ³ represents a group substituted with a group selected from the group 1-1 below. Diarylamine group, (The hydrogen atom in each of the above structures may be substituted by a substituent)]. The compound of claim 1, wherein at least one of D ¹ , D ² and D ³ of the formula (1) represents a di- or meta-position having a substituent selected from the group selected from the group 1-1 Phenylamino group. The compound of claim 2, wherein at least one of D ¹ , D ² and D ³ of the formula (1) is a diarylamine group substituted with a group selected from the group consisting of the following groups 1-2, (The hydrogen atom in each of the above structures may be substituted with a substituent). The compound of claim 3, wherein at least one of D ¹ , D ² and D ³ of the formula (1) is a diarylamine group substituted with a group selected from the group consisting of the following groups 1-3, 4] (Group 1-3) (The hydrogen atom in each of the above structures may be substituted with a substituent). The compound according to any one of claims 1 to 4, wherein each of Ar ¹ , Ar ² and Ar ^{3 of the} formula (1) is independently substituted or unsubstituted phenyl, substituted or unsubstituted. A linking group formed by linking any two of pyridyl groups or the like. The compound of claim 5, wherein each of Ar ¹ , Ar ² and Ar ^{3 of the} formula (1) is independently a group selected from the group consisting of 2-1, (The hydrogen atom in each of the above structures may be substituted with a substituent). The compound according to any one of claims 1 to 4, wherein D ¹ of the formula (1) is a diarylamine group substituted with a group selected from the above group 1-1, and Ar ¹ is substituted or not Replace the phenyl group. The compound of claim 1, which has a structure represented by the following formula (2), [In the formula (2), R ¹ to R ¹² and R ¹⁴ to R ²⁵ each independently represent a hydrogen atom or a substituent; and at least one of R ¹ to R ¹⁰ represents a group selected from the group 1-1 below. a substituted diarylamino group; R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁴ and R ⁵ , R ⁶ and R ⁷ , R ⁷ and R ⁸ , R ⁸ and R ⁹ And R ⁹ and R ¹⁰ , R ¹¹ and R ¹² , 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 may also be bonded to each other to form a ring structure, (The hydrogen atom in each of the above structures may be substituted by a substituent)]. The compound of claim 8, wherein at least one of R ¹ to R ¹² and R ¹⁴ to R ²⁵ represents a diarylamine group substituted with a group selected from the group 1-1, and the other R ¹ to R ¹² and R ¹⁴ to R ²⁵ are a hydrogen atom. A compound according to claim 8 or 9, wherein at least one of R ² , R ³ , R ⁷ and R ⁸ represents a diarylamine group substituted with a group selected from the above group 1-1. A luminescent material comprising the compound of any one of claims 1 to 10. A delayed phosphor comprising the compound of any one of claims 1 to 10. An organic light-emitting element characterized in that it has a light-emitting layer containing a light-emitting material as claimed in claim 11 on a substrate. The organic light-emitting element of claim 13, which emits delayed fluorescence. An organic light-emitting element according to claim 13 or 14, which is an organic electroluminescence element.