JP4922696B2 - Tetrabenzanthracene derivative and organic electroluminescence device using the same - Google Patents

Description

  The present invention relates to a novel tetrabenzanthracene derivative and an organic electroluminescent device using the same.

  Organic light-emitting elements, particularly organic electroluminescent elements having an electroluminescent function (hereinafter sometimes referred to as “organic EL elements”) are advantageous for power saving, and can emit light with a wide viewing angle and high brightness. Due to its characteristics, it has attracted attention as a next-generation flat display element and its flat light source. In such an organic electroluminescent element, there is a need for multi-color display, full-color display, whitening, and the like, and the ripple effect is great.

  In putting an organic electroluminescence device into practical use, long-term driving stability and driving stability and storage stability under a high-temperature environment in a vehicle-mounted application are required. Among them, a major problem is that the constituent materials of the element are crystallized under these circumstances, and the uniformity of light emission is impaired. When the element is driven for a long time, the constituent material undergoes a large thermal fluctuation due to the temperature rise due to the heat generation of the element itself or the heat due to the external environment change. As a result, a phenomenon is known in which an organic compound which is a constituent material of the element is crystallized. Crystallization causes short circuits and defects in the device, which not only impairs the uniformity of the light emitting surface, but may also cause light emission to stop. For this reason, research on techniques for suppressing such crystallization has been made.

  The green and red light emitting elements can emit light with high color purity and high brightness by introducing a dopant into a host material such as an aluminum chelate compound. Further, the aluminum chelate compound has a high glass transition temperature of 180 ° C., and has excellent characteristics in heat resistance and life performance.

  On the other hand, there is a problem that a host material having both good color purity and a long driving life has not yet been developed for blue light-emitting elements constituting multicolor light emission, full color light emission, and white light emission of the element. The cause of the problem is that no material has been developed that can achieve a high level of characteristics that can supply excitation energy to a blue light-emitting material, such as a large band gap and a characteristic that can suppress crystallization. is doing. For example, Patent Document 1 describes an organic electroluminescent element using an aromatic amine compound having an aromatic group, and Patent Document 2 describes an organic electroluminescent element using an anthracene derivative.

  Non-Patent Documents 1 and 2 disclose tetrabenzanthracene derivatives.

International Publication No. 2002/20693 Pamphlet JP 2004-67528 A Muller et al., “Ange. Chem. Int. Ed. Engl.”, 1996, Vol. 886-888 Artal et al., “Journal of Materials Chemistry”, 2001, 11 pp. 2801-2807

  However, even if the compounds described in Patent Documents 1 and 2 are used as blue organic electroluminescent elements, characteristics sufficient for practical use have not been obtained. Further, the tetrabenzanthracene derivative described in Non-Patent Document 1 is used as a reaction intermediate of a condensed polycyclic aromatic compound, and the tetrabenzanthracene derivative described in Non-Patent Document 2 is used as a liquid crystalline material. Characteristics for use in organic electroluminescence devices such as properties and amorphousness are not considered.

  In addition, in order to improve the durability of the organic electroluminescent device, it is required that each material used for the organic layer has excellent thin film stability and heat resistance in addition to the blue light emitting material and the blue host material. It has been.

  The present invention provides a novel tetrabenzanthracene derivative excellent in heat resistance.

  The present invention also provides an organic electroluminescence device using such a tetrabenzanthracene derivative, having high luminous efficiency and excellent heat resistance.

（式（１）中、Ｘ_２及びＸ_３のうち１つ、Ｘ_６及びＸ_７のうち１つ、Ｘ_１０及びＸ_１１のうち１つ、Ｘ_１４及びＸ_１５のうち１つはそれぞれ独立して下記式（２）で示される置換基を、それらの残り及びＸ_１，Ｘ_４，Ｘ_５，Ｘ_８，Ｘ_９，Ｘ_１２，Ｘ_１３，Ｘ_１６，Ｘ_１７，Ｘ_１８は水素原子またはアルキル基を示し、あるいはＸ_６及びＸ_７のうち１つ、Ｘ_１４及びＸ_１５のうち１つはそれぞれ独立して下記式（２）で示される置換基を、それらの残り及びＸ_１〜Ｘ_５，Ｘ_８〜Ｘ_１３，Ｘ_１６〜Ｘ_１８は水素原子またはアルキル基を示し、あるいはＸ_２及びＸ_３のうち１つ、Ｘ_６及びＸ_７のうち１つはそれぞれ独立して下記式（２）で示される置換基を、それらの残り及びＸ_１，Ｘ_４，Ｘ_５，Ｘ_８〜Ｘ_１８は水素原子またはアルキル基を示し、あるいはＸ_２及びＸ_３のうち１つ、Ｘ_１４及びＸ_１５のうち１つはそれぞれ独立して下記式（２）で示される置換基を、それらの残り及びＸ_１，Ｘ_４〜Ｘ_１３，Ｘ_１６〜Ｘ_１８は水素原子またはアルキル基を示す。）

（式（２）中、Ｒ_１〜Ｒ_５はそれぞれ独立して水素原子、アルキル基、無置換またはアルキル基を有するアリール基、無置換またはアルキル基を有するヘテロアリール基を示し、Ｒ_１〜Ｒ_５の中の隣同士で環を形成してもよい。） The present invention is a tetrabenzanthracene derivative represented by the following formula (1).

(In the formula (1), one of X ₂ and X ₃ , one of X ₆ and X ₇ , one of X ₁₀ and X ₁₁ , and one of X ₁₄ and X ₁₅ are each independent. And the substituents represented by the following formula (2) are the remaining and X ₁ , X ₄ , X ₅ , X ₈ , X ₉ , X ₁₂ , X ₁₃ , X ₁₆ , X ₁₇ , X ₁₈ are hydrogen atoms or An alkyl group, or one of X ₆ and X ₇ , and one of X ₁₄ and X ₁₅ are each independently a substituent represented by the following formula (2), the rest thereof and X _{1 to} X ₅ , X _{8 to} X ₁₃ and X _{16 to} X _{18 each} represent a hydrogen atom or an alkyl group, or one of X ₂ and X ₃ and one of X ₆ and X ₇ are each independently represented by the following formula ( The substituents represented by 2) are substituted with the rest thereof and X ₁ , X ₄ , X ₅ , X _{8 to} X _{1. 8} represents a hydrogen atom or an alkyl group, or one of X ₂ and X ₃ and one of X ₁₄ and X ₁₅ each independently represent a substituent represented by the following formula (2), And X ₁ , X _{4 to} X ₁₃ and X _{16 to} X ₁₈ represent a hydrogen atom or an alkyl group.)

(In the formula (2), R ₁ ~R ₅ each independently represent hydrogen atom, an alkyl group, an aryl group having an unsubstituted or alkyl group, a heteroaryl group having an unsubstituted or alkyl group, R ₁ to R ₅ may form a ring next to each other in ₅ ).

In the tetrabenzanthracene derivative, in Formula (1), one of X ₂ and X ₃ , one of X ₆ and X ₇ , one of X ₁₀ and X ₁₁ , X ₁₄ and X ₁₅ each independently represents a substituent represented by the above formula (2), the rest of them, and X ₁ , X ₄ , X ₅ , X ₈ , X ₉ , X ₁₂ , X ₁₃ , X ₁₆ , X ₁₇ and X _{18 each} represent a hydrogen atom, or one of X ₆ and X ₇ and one of X ₁₄ and X ₁₅ each independently represent a substituent represented by the formula (2). The remaining and X _{1 to} X ₅ , X _{8 to} X ₁₃ , and X _{16 to} X ₁₈ represent hydrogen atoms, or one of X ₂ and X ₃ , and one of X ₆ and X ₇ are each independently the substituent represented by the formula (2), the remaining thereof and _X 1, _{X 4 X 5,} X 8 ~X ₁₈ represents a hydrogen atom, or one of _{X 2} and _{X 3,} the substituents represented by the formula one are each independently of _{X 14} and _{X 15} (2) , The remainder thereof and X ₁ , X _{4 to} X ₁₃ , and X _{16 to} X ₁₈ preferably represent a hydrogen atom.

In the tetrabenzanthracene derivative, in the formula (1), X ₃ , X ₆ , X ₁₁ and X ₁₄ are each independently a substituent represented by the formula (2), X ₁ , X ₂ , X ₄ , X ₅ , X _{7 to} X ₁₀ , X ₁₂ , X ₁₃ , X _{15 to} X _{18 each} represent a hydrogen atom, or X ₆ and X ₁₄ are each independently a substituent represented by the formula (2) X _{1 to} X ₅ , X _{7 to} X ₁₃ , X _{15 to} X _{18 each} represents a hydrogen atom, or X ₃ and X ₆ each independently represent a substituent represented by the formula (2), X ₁ , X ₂ , X ₄ , X ₅ , X _{7 to} X _{18 each} represents a hydrogen atom, or X ₃ and X ₁₄ each independently represent a substituent represented by the formula (2), X ₁ , X ₂ , X _{4 to} X ₁₃ and X _{15 to} X ₁₈ are preferably hydrogen atoms. Yes.

In the tetrabenzanthracene derivative, R ₁ and R ₅ are preferably hydrogen atoms, and at least one of R ₂ , R ₃ and R ₄ is preferably an unsubstituted aryl group.

In the tetrabenzanthracene derivative, R ₁ , R ₃ , R ₅ are preferably hydrogen atoms, and at least one of R ₂ , R ₄ is preferably an unsubstituted aryl group.

  In the tetrabenzanthracene derivative, the unsubstituted aryl group is preferably a phenyl group or a biphenyl group.

  Moreover, this invention is an organic electroluminescent element provided with an organic layer, Comprising: The said tetrabenzanthracene derivative is included in the said organic layer.

  Moreover, this invention is an organic electroluminescent element provided with an electron carrying layer, Comprising: The said tetrabenzanthracene derivative is included in the said electron carrying layer.

  Moreover, this invention is an organic electroluminescent element provided with a light emitting layer, Comprising: The said tetrabenzanthracene derivative is included in the said light emitting layer.

  Moreover, this invention is an organic electroluminescent element, Comprising: The host material and the light emitting layer containing a dopant material are provided, The said host material contains the said tetrabenzanthracene derivative.

  Further, the present invention is an organic electroluminescent device, comprising a light emitting layer containing a host material and a blue light emitting dopant material, and the host material contains the tetrabenzanthracene derivative.

  In the present invention, a novel tetrabenzanthracene derivative having excellent heat resistance can be provided. This tetrabenzanthracene derivative is highly stable even when thinned.

  In addition, in an organic electroluminescent device having an organic layer, by including a tetrabenzanthracene derivative having such a specific structure in the organic layer, an organic electroluminescent device having high luminous efficiency and excellent heat resistance is realized. Can do.

  Embodiments of the present invention will be described below.

<Tetrabenzanthracene derivative>
The tetrabenzanthracene derivative according to the embodiment of the present invention is represented by the following formula (1).

（式（１）中、Ｘ_２及びＸ_３のうち１つ、Ｘ_６及びＸ_７のうち１つ、Ｘ_１０及びＸ_１１のうち１つ、Ｘ_１４及びＸ_１５のうち１つはそれぞれ独立して下記式（２）で示される置換基を、それらの残り及びＸ_１，Ｘ_４，Ｘ_５，Ｘ_８，Ｘ_９，Ｘ_１２，Ｘ_１３，Ｘ_１６，Ｘ_１７，Ｘ_１８は水素原子またはアルキル基を示し、あるいはＸ_６及びＸ_７のうち１つ、Ｘ_１４及びＸ_１５のうち１つはそれぞれ独立して下記式（２）で示される置換基を、それらの残り及びＸ_１〜Ｘ_５，Ｘ_８〜Ｘ_１３，Ｘ_１６〜Ｘ_１８は水素原子またはアルキル基を示し、あるいはＸ_２及びＸ_３のうち１つ、Ｘ_６及びＸ_７のうち１つはそれぞれ独立して下記式（２）で示される置換基を、それらの残り及びＸ_１，Ｘ_４，Ｘ_５，Ｘ_８〜Ｘ_１８は水素原子またはアルキル基を示し、あるいはＸ_２及びＸ_３のうち１つ、Ｘ_１４及びＸ_１５のうち１つはそれぞれ独立して下記式（２）で示される置換基を、それらの残り及びＸ_１，Ｘ_４〜Ｘ_１３，Ｘ_１６〜Ｘ_１８は水素原子またはアルキル基を示す。）

（式（２）中、Ｒ_１〜Ｒ_５はそれぞれ独立して水素原子、アルキル基、無置換またはアルキル基を有するアリール基、無置換またはアルキル基を有するヘテロアリール基を示し、Ｒ_１〜Ｒ_５の中の隣同士で環を形成してもよい。）

(In the formula (1), one of X ₂ and X ₃ , one of X ₆ and X ₇ , one of X ₁₀ and X ₁₁ , and one of X ₁₄ and X ₁₅ are each independent. And the substituents represented by the following formula (2) are the remaining and X ₁ , X ₄ , X ₅ , X ₈ , X ₉ , X ₁₂ , X ₁₃ , X ₁₆ , X ₁₇ , X ₁₈ are hydrogen atoms or An alkyl group, or one of X ₆ and X ₇ , and one of X ₁₄ and X ₁₅ are each independently a substituent represented by the following formula (2), the rest thereof and X _{1 to} X ₅ , X _{8 to} X ₁₃ and X _{16 to} X _{18 each} represent a hydrogen atom or an alkyl group, or one of X ₂ and X ₃ and one of X ₆ and X ₇ are each independently represented by the following formula ( The substituents represented by 2) are substituted with the rest thereof and X ₁ , X ₄ , X ₅ , X _{8 to} X _{1. 8} represents a hydrogen atom or an alkyl group, or one of X ₂ and X ₃ and one of X ₁₄ and X ₁₅ each independently represent a substituent represented by the following formula (2), And X ₁ , X _{4 to} X ₁₃ and X _{16 to} X ₁₈ represent a hydrogen atom or an alkyl group.)

(In the formula (2), R ₁ ~R ₅ each independently represent hydrogen atom, an alkyl group, an aryl group having an unsubstituted or alkyl group, a heteroaryl group having an unsubstituted or alkyl group, R ₁ to R ₅ may form a ring next to each other in ₅ ).

  Among these, the type of substituent and the position of the substituent are selected from the tetrabenzanthracene derivatives represented by the formula (1) according to the intended absorption wavelength, heat resistance, sublimation temperature, and the like. do it.

The tetrabenzanthracene derivative according to the present embodiment has the formula (1) at a predetermined position of X ₂ , X ₃ , X ₆ , X ₇ , X ₁₀ , X ₁₁ , X ₁₄ , X _{15 in} the formula (1). 2), the benzene rings are less likely to form a ring when used for an element such as an organic EL element, for example, compared to the case where the o-position has the substituent of formula (2). It is electrochemically stable. When at least _{one of} X ₁ , X ₄ , X ₅ , X ₈ , X ₉ , X ₁₂ , X ₁₃ , X ₁₆ , X ₁₇ , X ₁₈ has the substituent of formula (2), for example When an organic EL element or the like is driven using the element such as an organic EL element, there is a possibility that the benzene rings may form a ring by reacting electrochemically.

In the tetrabenzanthracene derivative of the formula (1), in the formula (1), one of X ₂ and X ₃ , one of X ₆ and X ₇ , one of X ₁₀ and X ₁₁ , X _{One of 14} and X ₁₅ independently represents the substituent represented by the formula (2), the rest thereof and X ₁ , X ₄ , X ₅ , X ₈ , X ₉ , X ₁₂ , X ₁₃ , X ₁₆ , X ₁₇ and X ₁₈ represent a hydrogen atom, or one of X ₆ and X ₇ and one of X ₁₄ and X ₁₅ each independently represent a substituent represented by the formula (2). , The remainder thereof and X _{1 to} X ₅ , X _{8 to} X ₁₃ , X _{16 to} X ₁₈ represent a hydrogen atom, or one of X ₂ and X ₃ , and one of X ₆ and X ₇ is respectively Independently, the substituent represented by the formula (2) is substituted with the rest thereof and X ₁ , X ₄ , X ₅ , X _{8 to} X _{18 each} represent a hydrogen atom, or one of X ₂ and X ₃ and one of X ₁₄ and X ₁₅ are each independently a substituent represented by the formula (2) From the viewpoint of easiness of synthesis, it is preferable that the group, the remainder thereof, and X ₁ , X _{4 to} X ₁₃ , and X _{16 to} X ₁₈ represent a hydrogen atom.

In the tetrabenzanthracene derivative of the formula (1), in the formula (1), X ₃ , X ₆ , X ₁₁ and X ₁₄ are each independently a substituent represented by the formula (2), ₁ , X ₂ , X ₄ , X ₅ , X _{7 to} X ₁₀ , X ₁₂ , X ₁₃ , X _{15 to} X _{18 each} represent a hydrogen atom, or X ₆ and X ₁₄ are each independently the above formula (2) X _{1 to} X ₅ , X _{7 to} X ₁₃ , and X _{15 to} X _{18 each} represent a hydrogen atom, or X ₃ and X ₆ are each independently a substituent represented by the formula (2) X ₁ , X ₂ , X ₄ , X ₅ , X _{7 to} X ₁₈ represent a hydrogen atom, or X ₃ and X ₁₄ each independently represent a substituent represented by the formula (2), ₁ , X ₂ , X _{4 to} X ₁₃ , and X _{15 to} X ₁₈ are hydrogen atoms. It is more preferable from the viewpoint of ease of synthesis and the like.

That is, the tetrabenzanthracene derivative of the formula (1) is preferably a compound represented by the following formulas (3), (4), (5), (6). In the following formulas (3), (4), (5), (6), R _{6 to} R ₅₅ are the same as those defined for R _{1 to} R ₅ .

  Of the compounds represented by the formulas (3), (4), (5) and (6), the compound (3) has more substituted phenyl groups than the compounds (4), (5) and (6). Therefore, heat resistance and amorphous nature tend to be high. In addition, since the compounds (4), (5), and (6) have fewer substituted phenyl groups than the compound (3), the band gap is wide. For example, when used in the light emitting layer of a blue organic EL device, the color purity is low. It tends to be high.

R _{1 to} R ₅ in the formula (2) are each independently a hydrogen atom, an alkyl group, an unsubstituted or aryl group having an alkyl group, an unsubstituted or heteroaryl group having an alkyl group, and are easily synthesized. From the viewpoint of heat resistance, a hydrogen atom and an unsubstituted aryl group are preferable. From the viewpoint of heat resistance and the like, it is preferable that at least one of R _{1 to} R ₅ is an unsubstituted aryl group. From the viewpoint of the electrochemical stability, R ₁ and R ₅ are hydrogen atoms. Preferably there is. That is, it is more preferable that R ₁ and R ₅ are hydrogen atoms and at least one of R _{2 to} R ₄ is an unsubstituted aryl group. Further, it is more preferable that at least one of R ₂ and R ₄ is an unsubstituted aryl group because the planarity of the molecule is lowered and the amorphous property is increased. Therefore, it is particularly preferable that R ₁ , R ₃ and R ₅ are hydrogen atoms and at least one of R ₂ and R ₄ is an unsubstituted aryl group. When imparting solvent solubility to an organic solvent or the like to the tetrabenzanthracene derivative, it is preferable that at least one of R _{1 to} R ₅ is an alkyl group. The tetrabenzanthracene derivative of the formula (1) has a plurality of substituents represented by the formula (2). In the present specification, the substituents represented by R _{1 to} R ₅ are a plurality of substituents of the formula (2). May be the same or different.

Here, the alkyl group represented by the X _{1 to} X ₁₈ and the alkyl group included in the substituent represented by the formula (2) is preferably an alkyl group having 1 to 12 carbon atoms, such as a methyl group. An ethyl group, a linear, branched or cyclic propyl group, a linear, branched or cyclic butyl group, and the like, and a methyl group is more preferable. When the number of carbon atoms is large, the deposition temperature becomes high and it is difficult to perform vacuum deposition, or it is necessary to raise the temperature to a high temperature at the time of vacuum deposition and there is a possibility of decomposition, so the alkyl group is preferably a methyl group. In addition, since the alkyl chain has high insulating properties, the conductivity of electrons or holes may be lowered when the number of carbon atoms is large.

  The aryl group is preferably an aryl group having 6 to 30 carbon atoms, and examples thereof include an aryl group represented by the following structural formula. Among these, a phenyl group, a biphenyl group, and a naphthyl group are preferable from the viewpoint of easy synthesis. The alkyl group that the aryl group may have is the same as defined in the alkyl group.

  Examples of the heteroaryl group include an aryl group represented by the following structural formula. Among these, a pyridyl group and a thienyl group are preferable from the viewpoint of easy synthesis. The alkyl group that the heteroaryl group may have is the same as defined for the alkyl group.

Rings that may be formed next to each other among R _{1 to} R ₅ include aromatic rings such as benzene ring, naphthalene ring and anthracene ring, aliphatic rings such as cyclohexyl ring, thiophene ring, pyrrole ring, pyridine And heterocyclic rings such as rings.

  The molecular weight of the tetrabenzanthracene derivative represented by the formula (1) is preferably 1200 or less, and more preferably 1000 or less. When the molecular weight exceeds 1300, it is not preferable because sublimation tends to be difficult when forming a deposited film. In the present embodiment, it is preferable to make the molecular weight of the tetrabenzanthracene derivative within a specific range because it is easy to form a thin film, thin film stability, and heat resistance can be realized at the same time.

  Specific examples of the tetrabenzanthracene derivative represented by the formula (1) according to this embodiment include compounds represented by the following formulas (7) to (25), but are not limited thereto. Among the following compounds (7) to (9), the compound (8) has a lower planarity than the compound (7), and the compound (9) has a lower amorphousness, so that the amorphous property is high and preferable.

  Next, the synthesis of the tetrabenzanthracene derivative represented by the formula (1) will be described.

  First, a precursor of a tetrabenzanthracene derivative is synthesized by, for example, the following reaction formulas (I) to (III). Thereafter, the tetrabenzanthracene derivative according to this embodiment can be obtained by the following reaction formula (IV). Further, as shown in the following reaction formula (V), a tetrabenzanthracene derivative according to this embodiment may be obtained by introducing a substituent into a tetrabenzanthracene derivative synthesized by another method.

(Reaction Formula (I))
Compound (i) and compound (ii) are reacted under the following reaction condition A to synthesize 1,2,4,5-tetraphenylbenzene derivative compound (iii), which is a precursor of a tetrabenzanthracene derivative.

(Reaction Formula (II))
Alternatively, the compound (iv) and the compound (v) are reacted under the following reaction condition A to synthesize a kinkephenyl derivative compound (vi) which is a precursor of a tetrabenzanthracene derivative.

(Reaction Formula (III))
Alternatively, the compound (vii) and the compound (v) are reacted under the following reaction condition A to synthesize a kinkephenyl derivative compound (viii) which is a precursor of a tetrabenzanthracene derivative.

  Here, the compound (ii) or the compound (v) used in each of the above reactions may be one type or two or more types, but it is one type because the compound to be obtained is uniquely determined and purification is easy. It is preferable.

Reaction condition A is a general cross-coupling biaryl synthesis condition. For cross-coupled biaryl synthesis, Suzuki reaction, Kharasch reaction, Negishi reaction, Stille reaction, Grignard reaction, Ullmann reaction, etc. can be used, and other metals (for example, Pd, Cu, Ti, Sn, Ni, Pt) and metals Complexes (for example Pd (PPh ₃ ) ₄ , Pd (OAc) ₂ , Pd ₂ (dba) ₃ , Pd (PPh ₃ ) ₂ Cl ₂ , Pd (dppf) ₂ Cl ₂ , Pd / C, Ni (PPh ₃ ) ₂ Cl ₂ , Ni (PPh ₃ ) ₄ , Ni (dppp) Cl ₂ , Ni (dppe) Cl ₂ , Ni (acac) ₂ ) catalyst, functional group W, base (eg Na ₂ CO ₃ , K ₂ CO ₃ , organic such as an inorganic base _{or, NEt 3, NH (i-} Pr) 2, NHEt 2, NHMe 2, NMe 3, DBU, DMAP, pyridine, such as _{Cs 2 CO 3, Ba (OH} ) 2 Base) and a solvent (toluene examples, benzene, dimethylformamide, ethanol, methanol, isopropyl alcohol, water, dimethyl formamide, etc.) and _{PPh 3, P (o-Tol} ) 3, P (t-Bu) 3, the PEt ₃ It may be used at room temperature or synthesized by heating. Further, in order to improve the yield of the cross-coupling biaryl synthesis reaction and the reaction position selectivity, a reaction for converting the functional group W into another functional group may be incorporated. Examples of these functional group conversions include, but are not limited to, conversion from bromide to boric acid. Me represents a methyl group, Et represents an ethyl group, Pr represents a propyl group, Bu represents a butyl group, Ph represents a phenyl group, and Tol represents a tolyl group.

(Reaction Formula (IV))
Next, the obtained compounds (iii), (vi), (viii) are reacted under the following reaction condition B to synthesize a tetrabenzanthracene derivative (ix). Since the compound to be obtained is uniquely determined and can be easily purified, it is possible to use the compound (iii) by using the reaction formula (I), the reaction formulas (II), (III) and the compound (vi). , (Viii) is preferred.

(Reaction Formula (V))
Alternatively, the tetrabenzanthracene derivative (ix) may be synthesized by introducing a substituent into the tetrabenzanthracene derivative compound (x) synthesized by another technique using the reaction condition A or another technique.

  With respect to the reaction condition B, if one or two of the two substituents Y to be eliminated are functional groups W, the reaction condition A can be used. Further, if both of the two substituents Y to be eliminated are hydrogen atoms, the following cyclization reaction involving proton elimination can be used. For example, the compounds (iii), (vi), (viii) are added to methylene chloride, toluene, benzene, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, chlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1 , 4-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, 1,3,4-trichlorobenzene, 1,3,5-trichlorobenzene, 1,2,3,4- In solvents such as tetrachlorobenzene, 1,2,4,5-tetrachlorobenzene, 1,2,3,6-tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, carbon disulfide, iron (III) chloride, aluminum chloride, copper chloride 1 type or 2 or more types of catalysts such as directly or as a solution such as nitromethane And pressure, can be synthesized by reacting at room temperature or under heating.

In the reaction formulas (I) to (V), X _{1 to} X ₁₈ are substituents defined in the same manner as in the formula (1) or substituents represented by the formula (2). W _{1 to} W ₁₀ are halogen groups such as Cl, Br, and I, sulfonic acid groups such as OSO ₂ CF ₃ , OSO ₂ F, and OSO ₂ Me, and boric acids such as B (OH) ₂ and B (OMe) ₂ Group, Li (lithio group), MgBr, MgCl, ZnBr, ZnCl, SnBu ₃ , SnMe ₃ , SnPh ₃ , CuI and other functional groups such as the following substituents.

Y _{1 to} Y ₁₁ are each independently a hydrogen atom or a substituent defined by W _{1 to} W ₁₀ . Z _{1 to} Z ₁₈ are each independently a substituent defined by X _{1 to} X ₁₈ or W _{1 to} W ₁₀ .

  The tetrabenzanthracene derivative according to the present embodiment has a relatively large molecular weight and large steric hindrance due to substituents introduced into the tetrabenzanthracene skeleton, which is the basic skeleton, and therefore can maintain an amorphous state up to a high temperature, High nature. For this reason, when used for an element such as an organic EL element, the stability of the element is improved even in a high temperature environment. Furthermore, when the thin film is formed using the tetrabenzanthracene derivative according to the present embodiment, the thin film has good amorphous properties, and when used in an element such as an organic EL element, the stability of the element is improved. Moreover, since the tetrabenzanthracene derivative according to this embodiment has a wide band gap, it can be suitably used as a host material for blue light emission.

  The tetrabenzanthracene derivative represented by the above formula (1) according to the present embodiment is not limited to an organic EL element, but a display element such as a display element, a computer, a television, a mobile phone, a digital camera, a PDA, a car navigation system, a backlight, and an illumination. , Interiors, signs, traffic lights, signboards, CD, DVD and other recording light sources, reading light sources, copying machines, scanners and other light sources, CD-R, DVD-R and other recording optical disc recording layers, and laser dyes It can be suitably used in a wide range of fields such as sensitizing dyes and fluorescent drugs for medical diagnosis.

<Organic EL device>
Next, an embodiment of an organic EL device using the tetrabenzanthracene derivative according to an embodiment of the present invention will be described.

  FIG. 1 shows a schematic cross-sectional structure of an example of an organic EL element according to an embodiment of the present invention. A transparent electrode 12 is formed on a transparent substrate 10 such as glass or plastic using ITO (Indium Tin Oxide) or the like. Here, the transparent electrode 12 functions as an anode. At least one organic layer 20 is formed on the transparent electrode 12.

  The organic layer 20 includes at least a light emitting layer 26, and the layer structure differs depending on the function of the tetrabenzanthracene derivative used. Besides the single layer structure of the light emitting layer, it is possible to adopt a multilayer structure such as a hole transport layer / light emitting layer, a light emitting layer / electron transport layer, a hole transport layer / light emitting layer / electron transport layer, etc. Not limited to. In the present embodiment, the hole injection layer 22 / the hole transport layer 24 / the light emitting layer 26 / the electron transport layer 28 are laminated in order from the transparent electrode 12 side. Although not shown, a hole blocking layer may be formed between the light emitting layer 26 and the electron transport layer 28.

  A metal electrode 14 is formed on the organic layer 20. Here, the metal electrode 14 functions as a cathode. For example, the metal electrode 14 can be formed of a laminate of a LiF layer (electron injection layer 16) and an Al electrode 18 as shown in FIG. Moreover, the metal electrode 14 can also be comprised by the single layer of Al electrode. In addition to Al, for example, an Mg—Ag alloy, an Al—Li alloy, or the like can be used.

  In the present embodiment, the tetrabenzanthracene derivative represented by the formula (1) is used in the organic EL element having the above configuration. This tetrabenzanthracene derivative can be used as a material for organic thin films such as a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, etc. It can be preferably used as a material for the transport layer, and particularly preferably used as a material for the electron transport layer.

  That is, in the organic electroluminescent element according to this embodiment, it is preferable that the organic layer contains an electron transport layer, and the tetrabenzanthracene derivative represented by the formula (1) is included in the electron transport layer. Moreover, it is preferable that an organic layer contains a light emitting layer and contains the tetrabenzanthracene derivative represented by said Formula (1) in a light emitting layer. Moreover, it is preferable that an organic layer contains an electron carrying layer and a light emitting layer, and contains the tetrabenzanthracene derivative represented by said Formula (1) in an electron carrying layer and a light emitting layer. The light emitting layer preferably contains a host material and a dopant material, and the host material preferably contains a tetrabenzanthracene derivative represented by the formula (1). The light-emitting layer preferably contains a host material and a blue light-emitting dopant material, and the host material preferably contains a tetrabenzanthracene derivative represented by the formula (1). Thereby, it is possible to realize an organic electroluminescent element having high luminous efficiency and excellent heat resistance, in particular, a blue organic electroluminescent element having high luminous efficiency and excellent heat resistance.

  Here, the tetrabenzanthracene derivative is capable of highly efficient electron transport, and by using this compound as an electron transport material, a highly efficient organic EL device can be realized. When used as a material for the electron transport layer, the type of substituent, the position of the substituent, and the like may be selected from the tetrabenzanthracene derivatives represented by the above formula (1) according to the target characteristics.

  Further, the tetrabenzanthracene derivative is capable of high-efficiency fluorescent emission or phosphorescence emission. By using this compound as a light-emitting material, a high-efficiency fluorescent emission organic EL element or a high-efficiency phosphorescence emission-type organic EL element is used. Can be realized. In particular, it is more preferable to use it as a material for the light emitting layer of a phosphorescent organic EL device because a highly efficient device can be realized. The tetrabenzanthracene derivative can be used alone as a material for the light-emitting layer 26, but it is used as a host material from the viewpoint of light emission efficiency, driving power reduction, color purity improvement of light emission color, etc. It is preferable that the light emitting layer 26 is obtained by quantitative doping. Alternatively, the tetrabenzanthracene derivative may be used as the electron transport material of the light emitting layer 26 and mixed with the hole transport material to serve as a host material. When used as a material for the light-emitting layer, the type of substituent, the position of the substituent, and the like may be selected from the tetrabenzanthracene derivatives represented by the above formula (1) according to the target color.

  Next, examples of materials that can be used for the organic layer 20 of the organic EL element together with the tetrabenzanthracene derivative will be described. First, when this tetrabenzanthracene derivative is used as the host material of the light emitting layer 26, examples of the dopant material include compounds represented by the following formulas (a) and (b) for blue phosphorescence. Examples of the green phosphorescent compound include compounds represented by the following formula (c). Examples of red phosphorescent compounds include compounds represented by the following formula (d). Examples of blue fluorescence include compounds represented by the following formula (e). Moreover, when using the said tetrabenzanthracene derivative as a host material of the light emitting layer 26, you may mix with the hole transport material mentioned later, and may use it in combination with a dopant material.

Here, the compound represented by the above formula (a) is represented by FIrpic (Iridium (III) bis (2- (4,6-difluorophenyl) pyridinato-N, C ^{2 ′} ) picolinate) and the above formula (b). The compound is FIr6 (Bis (4 ′, 6′-difluorophenylpyridinato) tetrakis (1-pyrazolyl) borate), and the compound represented by the above formula (c) is Ir (ppy) ₃ (tris (2-phenylpyridine) iridium (III )), The compound represented by the above formula (d) is Ir (piq) ₃ (tris (2-phenylisoquinoline) iridium (III)), and the compound represented by the above formula (e) is Bis [4- (N, N-diphenylamino) styryl] -9,10-Anthracene.

  The material used for the hole injection layer 22 is not particularly limited as long as it has a hole injection function. For example, copper phthalocyanine (CuPc), starburst amine, vanadate, and the like can be used.

  Further, the material used for the hole transport layer 24 is not particularly limited as long as it has a hole transport function. For example, a tertiary amine compound such as a triphenylamine multimer can be used. Are α-NPD (4,4′-Bis [N- (1-naphthyl) -N-phenyl-amino] biphenyl) represented by the following formula (f) and TPTE (triphenylamine tetramer) represented by the following formula (g). Can be used.

The material used for the electron transport layer 28 is not particularly limited as long as it has an electron transport function. For example, in addition to the tetrabenzanthracene derivative, for example, an aluminum quinolinol complex represented by the following formula (h) (Alq ₃ : Tris (8-hydroxyquinolinato) aluminum (III))) can be used.

By the way, the tetrabenzanthracene derivative used as a host material of the light emitting layer 26 often has a high polar property. When a hyperpolar compound is used as the host material of the light emitting layer 26, holes are prevented between the light emitting layer 26 and the electron transport layer 28 in order to prevent holes from flowing from the light emitting layer 26 to the electron transport layer 28. It is preferable to form a block layer. When Alq ₃ or the like is used for the electron transport layer 28, holes flow into the electron transport layer 28 so that the Alq ₃ or the like emits light, or the holes cannot be confined in the light emitting layer 26, and the light emission efficiency is improved. Problems such as reduction can be prevented. As a material used for the hole blocking layer, TPBI (2,2 ′, 2 ″-(1,3,5-phenylene) tris [1-phenyl-1H-benzimidazole) represented by the following formula (i), Bathocuproine (BCP) represented by the formula (j), BAlq (Aluminum (III) bis (2-methyl-8-quinolinato) 4-phenylphenolate) represented by the following formula (k), C ₆₀ F represented by the following formula (l) ₄₂ -X, C ₆₀ F ₄₂ -Y shown in the following formula (m), and the like can be mentioned.

  In order to prevent electrons from flowing from the light emitting layer 26 to the hole transporting layer 24, it is preferable to form an electron blocking layer between the light emitting layer 26 and the hole transporting layer 24. Examples of materials used for the electron blocking layer include TCTA (4,4 ′, 4 ″ -Tris (carbazol-9-yl) -triphenylamine) represented by the following formula (n), and Irppz (tris) represented by the following formula (o). (phenylpyrazole) iridium) and the like.

  Each of these layers can be sequentially formed on the transparent substrate 10 by sputtering or vapor deposition. Each layer of the organic layer 20 can be sequentially formed by an evaporation method or the like.

  Next, the light emission principle of the organic EL device according to this embodiment using the tetrabenzanthracene derivative as a host material for phosphorescence emission will be described.

  When holes and electrons are injected into the organic layer 20 from the transparent electrode 12 functioning as the anode and the metal electrode 14 functioning as the cathode, the holes pass through the hole transport layer 24 and the electrons pass through the electron transport layer 28. Then, the light reaches the light emitting layer 26, and holes and electrons recombine. By the recombination of holes and electrons, the tetrabenzanthracene derivative, which is the host material in the light emitting layer 26, is first excited. This excited state is considered to be 25% in the singlet excited state and 75% in the triplet excited state. The excitation energy of such a ratio of the host material is transferred to the dopant material, and the dopant material becomes a singlet excited state and a triplet excited state, respectively. The singlet excited state of the dopant material further moves to the triplet excited state, and finally phosphorescence emission from the triplet excited state is mainly performed. As a result, almost all of the generated excited state energy is used as emission energy. And the emitted light is taken out from the transparent substrate 10 side and visually recognized.

  In the present embodiment, when the tetrabenzanthracene derivative is used as a host material, the phosphorescent dopant material used together, for example, the materials exemplified as the formulas (a), (b), (c), and (d) Thus, blue, green, and red phosphorescence can be obtained with high color purity and high efficiency. In addition, the band gap width (absorption wavelength) of the tetrabenzanthracene derivative is adjusted by changing the substituent of the tetrabenzanthracene derivative or by forming a ring with adjacent substituents on the phenyl group. It is possible to design a host material optimized for blue, green, and red phosphorescent dopant materials. In particular, since the tetrabenzanthracene derivative has a high film stability and a wide band gap, the phosphorescent host material has an excellent blue phosphorescence compared to a blue phosphorescent host material that has not been sufficiently durable. It can be used as a luminescent host material.

  Here, an example in which the tetrabenzanthracene derivative is used as a host material for phosphorescence emission has been described, but it can also be used as a host material for fluorescence emission. Depending on the fluorescent dopant material used together, for example, the material exemplified as the formula (e), blue, green, and red fluorescence can be obtained with high color purity and high efficiency. In particular, the tetrabenzanthracene derivative can be suitably used as a host material for blue fluorescent light emission.

  Further, by changing the substituent of the tetrabenzanthracene derivative or forming a ring with adjacent substituents on the phenyl group, blue, green and red phosphorescent materials, fluorescent materials It is possible to design a light emitting material optimized for the above.

  In the organic EL device according to this embodiment, the tetrabenzanthracene derivative contained in the organic layer has a relatively large molecular weight and a large steric hindrance due to substituents of the tetrabenzanthracene skeleton, so that the amorphous state is maintained up to a high temperature. It has high heat resistance. For this reason, when used for an organic EL element, the stability of the element is improved even under a high temperature environment. Furthermore, when the thin film is formed using the tetrabenzanthracene derivative according to the present embodiment, the thin film has good amorphous properties, and when used in an organic EL device, the stability of the device is improved. Further, since the tetrabenzanthracene derivative has a large band gap, the tetrabenzanthracene derivative has a band gap that can be a blue host material capable of transferring energy to the blue light-emitting material. Therefore, the organic EL element using the tetrabenzanthracene derivative has high color purity and can emit blue light with high durability.

  The organic EL device according to this embodiment is suitable for display devices, computers, televisions, mobile phones, digital cameras, PDAs, car navigation displays, light sources such as backlights, lighting, interiors, signs, traffic lights, signboards, etc. Can be used for

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

Example 1
<Synthesis of 1,2,4,5-tetrakis (m-terphenyl-4-yl) benzene>
In a mixed solvent of 200 mL of toluene and 100 mL of methanol, 1,2,4,5-tetrakis (4-iodophenyl) benzene (2.21 g, 2.50 mmol) and 3-biphenylboric acid (2.97 g, 15. 0 mmol), palladium acetate (0.111 g, 0.49 mmol), tri (o-tolyl) phosphine (0.307 g, 1.01 mmol), and potassium carbonate (0.830 g, 6.01 mmol) are suspended. The mixture was heated and stirred at 75 ° C. for 24 hours under a nitrogen atmosphere. The reaction mixture was subjected to suction filtration, and by continuous extraction with hot chloroform using a Soxhlet apparatus from the filtered solid, 1,2,4,5-tetrakis (m-terphenyl-4-l) represented by the following structural formula as a white solid. Yl) benzene was obtained (yield: 1.77 g, 71% yield). The compound was identified by MASS spectrum (MALDI TOF MASS).
MALDI TOF MS (DPBD): m / z = 990.39 (calcd = 990.42)

<Synthesis of 3,6,12,15-tetrakis (3-biphenylyl) tetrabenz [a, c, h, j] anthracene>
The 1,2,4,5-tetrakis (m-terphenyl-4-yl) benzene (0.642 g, 0.648 mmol) was added to 65 mL of 1,2,4-trichlorobenzene and heated at 150 ° C. When dissolved, it was quenched in a water bath and a solution of iron (III) chloride (1.05 g, 6.47 mmol) in nitromethane (13 mL) was added. The reaction mixture was stirred at room temperature for 1 hour under a nitrogen atmosphere, and methanol was added to terminate the reaction. The solid deposited by suction filtration was separated by filtration and washed with methanol. The obtained solid was purified by sublimation at 520 ° C., and 3,6,12,15-tetrakis (3-biphenylyl) tetrabenz [a, c, h, j] represented by the following structural formula (8) as a yellowish white solid. Anthracene was obtained (yield: 0.298 g, yield: 47%). The compound was identified by MASS spectrum (MALDI TOF MASS).
MALDI TOF MS (DPBD): m / z = 986.34 (calcd = 986.39)

<Absorption spectrum measurement>
On the quartz substrate, the tetrabenzanthracene derivative (8) synthesized in Example 1 was vacuum deposited by 100 nm. The absorption spectrum of this sample was measured with a spectrophotometer (manufactured by Hitachi, HITACHI 330 Spectrophotometer). The measurement result of the absorption spectrum is shown in FIG. The band gap value obtained from this absorption spectrum was 3.0 eV. This value is higher than the energy value (2.76 eV) of blue (450 nm), and it was found that there is a sufficient band gap as a host material for blue light emission.

  FIG. 3 shows the results of DSC (differential scanning calorimetry) measurement of the tetrabenzanthracene derivative (8) synthesized. The melting point obtained for the compound (8) was 345 ° C., which was sufficiently higher than the temperature at which the organic EL device was driven (usually 120 ° C.). FIG. 4 shows the results of thermogravimetric analysis of the tetrabenzanthracene derivative (8). Compound (8) showed no change in weight up to 500 ° C. and was stable. From these results, it was found that the compound (8) was excellent in thermal durability. The DSC measurement was performed using a differential scanning calorimeter (TA Instruments, DSCQ1000 type) under a nitrogen atmosphere at a heating rate of 5 ° C./min. The TG-DTA measurement was performed using thermogravimetric / differential thermal analysis. Using an apparatus (manufactured by Rigaku Corporation, THERMO PLUS type), the sample amount was 10.0 mg, under a nitrogen atmosphere, at a temperature rising rate of 10 ° C./min.

(Example 2)
<Production and Evaluation of Blue Light-Emitting Organic Electroluminescent Device>
A transparent electrode of ITO was formed on a glass substrate with a film thickness of 150 nm, and organic cleaning, pure water cleaning, drying, and UV ozone treatment were performed. The substrate was immediately introduced into the vacuum chamber, and then Ar and O ₂ plasma treatment was performed.

Copper phthalocyanine was deposited by vacuum vapor deposition (degree of vacuum 5 × 10 ⁻⁷ Torr; 1 Torr≈133 Pa) to form a hole injection layer. Next, a tertiary amine compound was deposited to form a hole transport layer. Furthermore, the compound (8) obtained in Example 1 which is an electron transporting material as a host material of the light emitting layer and a tertiary amine compound which is a hole transporting material and a light emitting additive material as a dopant are mixed. A light emitting layer was formed by simultaneous vapor deposition. Furthermore, an electron transport layer was deposited using the compound (8). Thereafter, a LiF layer was deposited to 0.5 nm as an electron injection layer and Al was deposited to 150 nm as a metal electrode. Thus, an element part in which a hole injection layer / hole transport layer / light emitting layer / electron transport layer was laminated between a pair of electrodes was obtained. Here, as a tertiary amine compound which is a hole transporting material contained in the hole transport layer and the light emitting layer, a compound having a glass transition temperature of 100 ° C. or more is used for the purpose of ensuring heat resistance of 100 ° C. or more. did.

  The substrate on which such an element portion was formed was transferred to a chamber evacuated to high vacuum in-situ, and the chamber was made an isolated system, and then replaced with high-pressure nitrogen at 1 atm. After that, the end of the sealing glass is bonded to the transparent electrode using the UV curable resin, and the surface of the glass substrate other than the terminal is bonded to the element forming side, and the resin is irradiated with UV using a UV lamp. The element part was sealed.

A direct current was applied to the organic EL device thus obtained and continuously driven to measure the relationship between the emission spectrum (EL spectrum), injection current density, emission luminance, and applied voltage. In addition, current was injected so that the initial luminance was 2400 cd / m ^2, and the dependency of luminance on driving time was measured. The emission spectrum (EL spectrum) of this device is shown in FIG. As can be seen from FIG. 5, an emission spectrum having a peak at 460 nm was obtained. The chromaticity coordinates are (x, y) = (0.15, 0.25), and almost blue light emission is obtained. FIG. 6 shows the relationship between the injection current density, the light emission luminance, and the applied voltage. In addition, FIG. 7 shows the dependency of luminance on driving time. FIG. 7 shows that the half-life is 50 hours, which is favorable as a blue light emitting device. Table 1 summarizes the luminance when the current density is 11 mA / cm ² , the luminance half time when the initial luminance is 2400 cd / m ^2, and chromaticity coordinates.

(Comparative Example 1)
<Production and Evaluation of Blue Light-Emitting Organic Electroluminescent Device>
Instead of the compound (8) used for the light emitting layer and the electron transport layer, the same procedure as in Example 2 was conducted except that 1,3-bis [4- (1-pyrenyl) phenyl] adamantane represented by the following formula was used. Thus, an organic EL element was produced. FIG. 7 shows the driving time dependency of luminance. Table 1 summarizes the luminance when the current density is 11 mA / cm ² , the luminance half time when the initial luminance is 2400 cd / m ^2, and chromaticity coordinates. Both the luminance and the luminance half time were inferior to those of Example 2.

(Example 3)
<Production and Evaluation of Blue Light-Emitting Organic Electroluminescent Device>
A transparent electrode of ITO was formed on a glass substrate with a film thickness of 150 nm, and organic cleaning, pure water cleaning, drying, and UV ozone treatment were performed. The substrate was immediately introduced into the vacuum chamber, and then Ar and O ₂ plasma treatment was performed.

Copper phthalocyanine was deposited to a thickness of 10 nm by vacuum deposition (vacuum degree: 5 × 10 ⁻⁷ Torr; 1 Torr≈133 Pa) to form a hole injection layer. Next, 30 nm of TEL022 represented by the following structural formula was deposited as a tertiary amine compound to form a hole transport layer. On top of that, compound (8) as a host material of the light emitting layer and a light blue dopant as a dopant were mixed and used, and co-evaporated to form a light emitting layer with a thickness of 40 nm. Further, an electron transport layer was deposited to 40 nm using Alq _{3 represented} by the structural formula (h). Thereafter, a LiF layer was deposited to 0.5 nm as an electron injection layer and Al was deposited to 150 nm as a metal electrode. Thus, an element part in which a hole injection layer / hole transport layer / light emitting layer / electron transport layer was laminated between a pair of electrodes was obtained. Thereafter, in the same manner as in Example 2, the element portion was sealed.

In the same manner as in Example 2, the emission spectrum (EL spectrum), the relationship between the injection current density and the emission luminance and the applied voltage, and the drive time dependency of the luminance were measured. The emission spectrum (EL spectrum) of this device is shown in FIG. As can be seen from FIG. 8, an emission spectrum having a peak at 470 nm was obtained. The chromaticity coordinates are (x, y) = (0.20, 0.38), and light blue light emission is obtained. FIG. 9 shows the relationship between the injection current density, the light emission luminance, and the applied voltage. In addition, FIG. 10 shows the dependency of luminance on driving time. From FIG. 10, it was found that the half life was 160 hours, and a good life was obtained. Table 1 summarizes the luminance when the current density is 11 mA / cm ² , the luminance half time when the initial luminance is 2400 cd / m ^2, and chromaticity coordinates.

  Thus, by using the tetrabenzanthracene derivative of the above formula (8) as the host material of the light emitting layer and the electron transporting material of the electron transport layer, or as the host material of the light emitting layer, the luminous efficiency is high and the heat resistance is high. It was possible to obtain an organic electroluminescent device having excellent resistance.

It is sectional drawing which shows schematic structure of an example of the organic electroluminescent element which concerns on embodiment of this invention. It is a figure which shows the absorption spectrum of the compound (8) obtained in Example 1 of this invention. It is a figure which shows the measurement result of the differential scanning calorimetry of the compound (8) obtained in Example 1 of this invention. It is a figure which shows the measurement result of the thermogravimetric analysis of the compound (8) obtained in Example 1 of this invention. It is a figure which shows the emission spectrum of the element of Example 2 of this invention. It is a figure which shows the relationship between the injection current density of the element of Example 2 of this invention, light emission luminance, and an applied voltage. It is a figure which shows the drive time dependence of the brightness | luminance of the element of Example 2 and Comparative Example 1 of this invention. It is a figure which shows the emission spectrum of the element of Example 3 of this invention. It is a figure which shows the relationship between the injection current density of the element of Example 3 of this invention, light emission luminance, and an applied voltage. It is a figure which shows the drive time dependence of the brightness | luminance of the element of Example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Transparent substrate, 12 Transparent electrode (anode), 14 Metal electrode (cathode), 16 Electron injection layer, 18 Al electrode, 20 Organic layer, 22 Hole injection layer, 24 Hole transport layer, 26 Light emitting layer, 28 Electron transport layer.

Claims (11)

A tetrabenzanthracene derivative represented by the following formula (1):

(In the formula (1), one of X ₂ and X ₃ , one of X ₆ and X ₇ , one of X ₁₀ and X ₁₁ , and one of X ₁₄ and X ₁₅ are each independent. And the substituents represented by the following formula (2) are the remaining and X ₁ , X ₄ , X ₅ , X ₈ , X ₉ , X ₁₂ , X ₁₃ , X ₁₆ , X ₁₇ , X ₁₈ are hydrogen atoms or An alkyl group, or one of X ₆ and X ₇ , and one of X ₁₄ and X ₁₅ are each independently a substituent represented by the following formula (2), the rest thereof and X _{1 to} X ₅ , X _{8 to} X ₁₃ and X _{16 to} X _{18 each} represent a hydrogen atom or an alkyl group, or one of X ₂ and X ₃ and one of X ₆ and X ₇ are each independently represented by the following formula ( The substituents represented by 2) are substituted with the rest thereof and X ₁ , X ₄ , X ₅ , X _{8 to} X _{1. 8} represents a hydrogen atom or an alkyl group, or one of X ₂ and X ₃ and one of X ₁₄ and X ₁₅ each independently represent a substituent represented by the following formula (2), And X ₁ , X _{4 to} X ₁₃ and X _{16 to} X ₁₈ represent a hydrogen atom or an alkyl group.)

(In the formula (2), R ₁ ~R ₅ each independently represent hydrogen atom, an alkyl group, an aryl group having an unsubstituted or alkyl group, a heteroaryl group having an unsubstituted or alkyl group, R ₁ to R ₅ may form a ring next to each other in ₅ ). The tetrabenzanthracene derivative according to claim 1,
In the formula (1), one of X ₂ and X ₃ , one of X ₆ and X ₇ , one of X ₁₀ and X ₁₁ , and one of X ₁₄ and X ₁₅ are each independent. And the substituents represented by the formula (2) are the same as those of X ₁ , X ₄ , X ₅ , X ₈ , X ₉ , X ₁₂ , X ₁₃ , X ₁₆ , X ₁₇ , and X _18. Or one of X ₆ and X ₇ , and one of X ₁₄ and X ₁₅ are each independently the substituent represented by the above formula (2), the rest thereof and X _{1 to} X ₅ , X _{8 to} X ₁₃ and X _{16 to} X _{18 each} represent a hydrogen atom, or one of X ₂ and X ₃ and one of X ₆ and X ₇ are each independently a substituent represented by the formula (2) The radicals thereof and the rest thereof and X ₁ , X ₄ , X ₅ , X _{8 to} X ₁₈ represent hydrogen atoms, or X _{1 of 2} and X ₃ , and one of X ₁₄ and X ₁₅ each independently represent the substituent represented by the formula (2), the rest thereof, and X ₁ , X _{4 to} X ₁₃ , X _16. to X ₁₈ tetra benzanthracene derivative, characterized in that a hydrogen atom. A tetrabenzanthracene derivative according to claim 2,
In the formula (1), X ₃ , X ₆ , X ₁₁ and X ₁₄ are each independently a substituent represented by the formula (2), X ₁ , X ₂ , X ₄ , X ₅ , X ₇ to X ₁₀ , X ₁₂ , X ₁₃ , X _{15 to} X _{18 each} represent a hydrogen atom, or X ₆ and X ₁₄ each independently represent a substituent represented by the formula (2), X _{1 to} X ₅ , X _{7 to} X ₁₃ and X _{15 to} X _{18 each} represent a hydrogen atom, or X ₃ and X ₆ each independently represent a substituent represented by the formula (2), X ₁ , X ₂ , X ₄ , X ₅ , X _{7 to} X _{18 each} represent a hydrogen atom, or X ₃ and X ₁₄ each independently represent a substituent represented by the formula (2), X ₁ , X ₂ , X _{4 to} X ₁₃ , X ₁₅ to A tetrabenzanthracene derivative, wherein X ₁₈ represents a hydrogen atom. The tetrabenzanthracene derivative according to any one of claims 1 to 3,
The tetrabenzanthracene derivative, wherein R ₁ and R ₅ are hydrogen atoms, and at least one of R ₂ , R ₃ and R ₄ is an unsubstituted aryl group. The tetrabenzanthracene derivative according to any one of claims 1 to 3,
The tetrabenzanthracene derivative, wherein R ₁ , R ₃ and R ₅ are hydrogen atoms, and at least one of R ₂ and R ₄ is an unsubstituted aryl group. A tetrabenzanthracene derivative according to claim 4 or 5,
The tetrabenzanthracene derivative, wherein the unsubstituted aryl group is a phenyl group or a biphenyl group. An organic electroluminescent device comprising an organic layer,
An organic electroluminescence device comprising the tetrabenzanthracene derivative according to any one of claims 1 to 6 in the organic layer. An organic electroluminescent device comprising an electron transport layer,
An organic electroluminescent element comprising the tetrabenzanthracene derivative according to any one of claims 1 to 6 in the electron transport layer. An organic electroluminescent device comprising a light emitting layer,
An organic electroluminescent device comprising the tetrabenzanthracene derivative according to any one of claims 1 to 6 in the light emitting layer. An organic electroluminescent device,
A light emitting layer comprising a host material and a dopant material,
The organic electroluminescent element characterized by the said host material containing the tetrabenzanthracene derivative as described in any one of Claims 1-6. An organic electroluminescent device,
A light emitting layer including a host material and a blue light emitting dopant material;
The organic electroluminescent element characterized by the said host material containing the tetrabenzanthracene derivative as described in any one of Claims 1-6.

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