JP2011168550A - Anthracene derivative and organic electroluminescent element using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent element having excellent life and drive voltage of light-emitting element. <P>SOLUTION: The organic electroluminescent element is produced by using an anthracene derivative that has a substituent obtained by bonding any two of pyridine, quinoline and isoquinoline and an unsymmetrical structure as an electron transport material. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an anthracene derivative and an organic electroluminescent element, a display device, and a lighting device using the anthracene derivative.

  2. Description of the Related Art Conventionally, display devices using light emitting elements that emit electroluminescence have been studied variously because they can be reduced in power and thinned. Further, organic electroluminescent elements made of organic materials can be easily reduced in weight and size. Therefore, it has been actively studied. In particular, the development of organic materials with light emission characteristics such as blue, which is one of the three primary colors of light, and organic materials that have charge transporting ability (such as semiconductors and superconductors) such as holes and electrons The development of materials has been actively studied so far, regardless of whether it is a high molecular compound or a low molecular compound.

  For example, an organic electroluminescent element using a nitrogen-containing heterocyclic derivative as an electron transport material (material for an electron injection layer or an electron transport layer) (2004-2297 (Patent Document 1)), a pyridyl group in the central skeleton of anthracene An organic electroluminescent device using a compound substituted with an aryl / heteroaryl group such as phenyl group is also reported (Japanese Patent Laid-Open No. 2005-170911 (Patent Document 2), Japanese Patent Laid-Open No. 2003-146951 (Patent Document). 3)). Furthermore, an organic electroluminescence device using a bipyridine derivative as an electron transport material has also been reported (Japanese Patent Laid-Open No. 2003-123983 (Patent Document 4)).

Japanese Patent Laid-Open No. 2004-2297 Japanese Unexamined Patent Publication No. 2005-170911 JP 2003-146951 A JP2003-123983

  As described above, several materials for light emitting devices of compounds having a nitrogen-containing heterocycle such as a bipyridyl group in the molecule and anthracene skeleton compounds are known, but these known materials are generally used as electron transport materials. The element lifetime of a light emitting element, which is required in particular, can be increased, a stable electron transport layer and / or an electron injection layer can be formed, and a stable light emitting element can be manufactured. It does not satisfy the characteristics such as lowering sufficiently and in a well-balanced manner. Under such circumstances, it is desired to develop an electron transport material having excellent lifetime, stability and driving voltage of the light emitting element. In addition, an electron transport material exhibiting excellent characteristics has not been obtained for a blue light-emitting element, and development of an electron transport material suitable for improving the characteristics of a blue light-emitting element is desired.

  As a result of diligent studies to solve the above problems, the present inventors have obtained the following formula as an electron transport material in order to obtain an organic electroluminescent device having excellent device life and stability and excellent balance with driving voltage ( It was found that it was effective to provide an organic layer containing an anthracene derivative represented by 1), and the present invention was completed. The present invention is constituted by the following items.

[1] An anthracene derivative represented by the following formula (1).
In the above formula (1), R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen, alkyl having 1 to 6 carbons, or optionally substituted phenyl, and Py ¹ and Py ² are each independently an intermediate group represented by any one of the following formula (L-1), formula (L-2) or formula (L-3), and the following formula (T-1) or formula (T -2) or a terminal group represented by formula (T-3) and Py ¹ and Py ² are not the same structure.

[2] In the above formula (1), R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen, alkyl having 1 to 6 carbons, or optionally substituted phenyl, Py ¹ and Py ² are each independently an intermediate group represented by the above formula (L-1) and any one of the above formula (T-1), formula (T-2), or formula (T-3). A group to which the terminal group represented is bonded, or an intermediate group represented by the above formula (L-2) or (L-3) and a terminal group represented by the above formula (T-1) are bonded. The anthracene derivative according to [1] above, wherein Py ¹ and Py ² are not the same structure.

[3] In the above formula (1), R ¹ , R ² , R ³ and R ⁴ are hydrogen, alkyl having 1 to 6 carbons, or phenyl, and Py ¹ and Py ² are each independently the following: The anthracene derivative according to [1] above, which is a group represented by any one of formulas (LT-1) to (LT-18), and Py ¹ and Py ² are not the same structure.

[4] In the above formula (1), R ¹ , R ² , R ³ and R ⁴ are hydrogen, and Py ¹ and Py ² are each independently the above formulas (LT-1) to (LT-18). ) is a group represented by any one of, Py ¹ and Py ² are not the same structure, and, while the above formula Py ¹ or Py ² (LT-13) in either ~ (LT-18) When it is a group represented, the other is an anthracene derivative as described in said [1] which is a group represented by either of the said formula (LT-1)-(LT-12).

[5] In the above formula (1), R ¹ is alkyl having 1 to 6 carbons or phenyl, R ² , R ³ and R ⁴ are hydrogen, and Py ¹ and Py ² are each independently An anthracene derivative according to the above [1], which is a group represented by any one of the above formulas (LT-13) to (LT-18), and Py ¹ and Py ² are not the same structure.

[6] The anthracene derivative according to [1], which is represented by the following formula (1-7).

[7] The anthracene derivative according to [1], which is represented by the following formula (1-14).

[8] The anthracene derivative according to the above [1], which is represented by the following formula (1-1).

[9] An electron transport material containing the anthracene derivative according to any one of [1] to [8].

[10] A pair of electrodes including an anode and a cathode, a light emitting layer disposed between the pair of electrodes, an electron transport material according to the above [9] disposed between the cathode and the light emitting layer. An organic electroluminescent device having an electron transport layer and / or an electron injection layer.

[11] At least one of the electron transport layer and the electron injection layer further includes at least one selected from the group consisting of a quinolinol-based metal complex, a pyridine derivative, a bipyridine derivative, a phenanthroline derivative, a borane derivative, and a benzimidazole derivative. The organic electroluminescent element as described in [10] above.

[12] At least one of the electron transport layer and the electron injection layer may further include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal oxide, an alkali metal halide, an alkaline earth metal oxide, At least one selected from the group consisting of alkaline earth metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes and rare earth metal organic complexes The organic electroluminescent element according to [10] or [11], which is contained.

[13] A display device comprising the organic electroluminescent element as described in any one of [10] to [12].

[14] An illumination device including the organic electroluminescent element according to any one of [10] to [12].

  A preferable electron transport material of the present invention has low crystallinity and can form a stable amorphous film, so that a stable electron transport layer and / or electron injection layer can be formed. Can be made. In addition, when the preferred electron transport material of the present invention is used, an organic electroluminescence device having excellent driving voltage characteristics can be obtained. Therefore, according to a preferred embodiment of the present invention, not only an excellent lifetime and stability of the light emitting element can be realized, but also the balance with the driving voltage can be made excellent. Further, the preferred electron transport material of the present invention is particularly suitable for a blue light emitting element, and according to this electron transport material, a blue light emitting element having an element life comparable to a red or green light emitting element can be produced. Can do. Furthermore, by using this organic electroluminescent element, a high-performance display device such as a full-color display can be obtained.

It is a schematic sectional drawing which shows the organic electroluminescent element which concerns on this embodiment.

1. Compound represented by Formula (1) The anthracene derivative of the present invention will be described in detail. The anthracene derivative of the present invention is a compound represented by the above formula (1).

R ¹ , R ² , R ³ and R ⁴ (hereinafter also referred to as “R ^{1 to} R ⁴ ”) in formula (1) are each independently hydrogen, alkyl having 1 to 6 carbons, or substituted. It may be appropriately selected from phenyls that may be present.

About C1-C6 alkyl in R < ¹ > -R < ⁴ > of Formula (1), C1-C6 alkyl may be any of a straight chain and a branched chain. That is, it is a linear alkyl having 1 to 6 carbon atoms or a branched alkyl having 3 to 6 carbon atoms. More preferred is alkyl having 1 to 4 carbon atoms (branched alkyl having 3 to 4 carbon atoms). Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, 1-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl and the like can be mentioned.

Specific examples of “optionally substituted phenyl” in R ^{1 to} R ⁴ of formula (1) include phenyl, (o-, m-, p-) tolyl, (2,3-, 2,4- , 2,5-, 2,6-, 3,4-, 3,5-) xylyl, mesityl (2,4,6-trimethylphenyl), (o-, m-, p-) cumenyl, terphenylyl (m -Terphenyl-2'-yl, m-terphenyl-4'-yl, m-terphenyl-5'-yl, o-terphenyl-3'-yl, o-terphenyl-4'-yl, p -Terphenyl-2'-yl, m-terphenyl-2-yl, m-terphenyl-3-yl, m-terphenyl-4-yl, o-terphenyl-2-yl, o-terphenyl- 3-yl, o-terphenyl-4-yl, p-terphenyl-2-yl, p-terphenyl-3 Yl,-4-p-terphenyl-yl) and the like. Preferably, it is phenyl.

As will be described later, the anthracene derivative according to the present invention forms an organic layer in an organic electroluminescent device by making Py ¹ and Py ² in formula (1) not have the same structure but an asymmetric molecular structure. In particular, the material is expected to have an effect of disturbing crystallization by disturbing the regularity of the arrangement of molecules. Accordingly, R ^{1 to} R ⁴ may all be the same or different, but considering that in addition to this effect, the anthracene derivative of the present invention can be produced by a simple method, R ^{1 to} R 4 Compounds in which all ⁴ are hydrogen are preferred.

However, group Py ¹ and Py ² in the formula (1) is also not identical structure represented by any one example both the above formula Py ¹ and Py ² of (LT-13) ~ (LT -18) In some cases, the asymmetry of the molecular structure may be reduced. Therefore, it is preferable to select one or more of R ^{1 to} R ⁴ to be different from others. An example of this is that R ^{2 to} R ⁴ are hydrogen and R ¹ is a group other than hydrogen.

Py ¹ and Py ² are each independently an intermediate group represented by any one of the above formula (L-1), formula (L-2) or formula (L-3) and the above formula (T-1). , A group bonded to a terminal group represented by either formula (T-2) or formula (T-3), and Py ¹ and Py ² are not the same structure. Among these, the intermediate group represented by the above formula (L-1) and the terminal group represented by any one of the above formula (T-1), formula (T-2), or formula (T-3) A bonded group or a group in which an intermediate group represented by the above formula (L-2) or (L-3) and a terminal group represented by the above formula (T-1) are bonded is preferable.

More preferably, Py ¹ and Py ² are the following formulas (LT-1) to (LT-18), the following formulas (LT-20) to (LT-34), and the following formulas (LT-40) to (LT-55). Among these, groups represented by the following formulas (LT-1) to (LT-18) are particularly preferable.

However, when both Py ¹ and Py ² are selected from the groups represented by any of the above formulas (LT-13) to (LT-18), as described above, the asymmetry of the molecular structure is Since it may decrease, it is preferable to select one or more of R ^{1 to} R ⁴ to be different from others. An example in which R ¹ is alkyl having 1 to 6 carbon atoms or phenyl, and R ² , R ^3, and R ⁴ are hydrogen is considered.

  Specific examples of the anthracene derivative represented by the above formula (1) include, for example, the anthracene derivatives represented by the following formula (1-1) to the formula (1-114), the following formula (1-201) to the formula ( Anthracene derivatives represented by 1-480). Among these, preferably the following formula (1-1), formula (1-2), formula (1-6) to formula (1-8), formula (1-12) to formula (1-14), formula (1-17), Formula (1-22) to Formula (1-24), Formula (1-28) to Formula (1-30), Formula (1-33), Formula (1-38), Formula ( 1-39), Formula (1-43) to Formula (1-45), Formula (1-48), Formula (1-60), Formula (1-64) to Formula (1-66), Formula (1) -73) to formula (1-75), formula (1-78), and formula (1-114), more preferably anthracene derivatives represented by formula (1-1) and formula (1-6) below. ~ Anthracene derivatives represented by Formula (1-8), Formula (1-12) to Formula (1-14), and Formula (1-17).

2. Method for Producing Anthracene Derivative Represented by Formula (1) Next, a method for producing the anthracene derivative of the present invention will be described. The anthracene derivative of the present invention basically comprises a known compound and a known synthesis method such as Suzuki coupling reaction or Negishi coupling reaction (for example, “Metal-Catalyzed Cross-Coupling Reactions-Second, Completely Revised”). and Enlarged Edition ”). It can also be synthesized by combining both reactions. A scheme for synthesizing the anthracene derivative represented by the formula (1) by the Suzuki coupling reaction or the Negishi coupling reaction is illustrated below.

  When producing the anthracene derivative of the present invention, (1) a method of synthesizing a group in which an end group and an intermediate group are bonded, and bonding this to the 9,10-position of anthracene, (2) 9,9 of anthracene An example is a method in which an intermediate group is bonded to the 10-position and a terminal group is bonded to this intermediate group. In addition, in these methods, the bond between the intermediate group and the terminal group or the bond between the anthracene and the intermediate group basically includes a halogen functional group or a trifluoromethanesulfonate functional group, a zinc chloride complex, or a boronic acid (boron). A coupling reaction with an acid ester) can be used.

(1) A method of attaching a “terminal-intermediate” group to the 9,10-position of anthracene
<"Terminal-intermediate" group: synthesis of bipyridine having a reactive substituent>
First, a zinc chloride complex of pyridine is synthesized according to the following reaction formula (1), and then a zinc chloride complex of pyridine is reacted with 2,5-dibromopyridine according to the following reaction formula (2) to thereby give 5-bromo-2 , 2′-bipyridine and 6-bromo-3,2′-bipyridine can be synthesized. Both compounds can be isolated and purified by a known method such as column chromatography. In the reaction formula (1), “ZnCl ₂ · TMEDA” is a tetramethylethylenediamine complex of zinc chloride. In “RLi” and “RMgX” in the reaction formula (1), R represents a linear or branched alkyl group, preferably a linear or branched alkyl group having 1 to 4 carbon atoms. And X is a halogen.

  Here, the synthesis method using 2-bromopyridine as the raw material of the end group is illustrated, but it can be handled by using 3-bromopyridine or 4-bromopyridine as the raw material, and using iodide instead of bromide. The target object to be obtained can be obtained.

  In addition, here, the synthesis method using 2,5-dibromopyridine as a raw material for the intermediate group is illustrated, but by using pyridine substituted with two bromos at other positions as a raw material, dichloromethane instead of dibromo compound can be used. The corresponding target product can also be obtained by using a product, diiodide, bis (trifluoromethanesulfonate) or a mixture thereof (for example: 2-bromo-6-iodopyridine).

  Furthermore, for example, when 2,5-dibromopyridine and a zinc chloride complex of pyridine are reacted, the reaction between the 2-position bromo near the N and the zinc chloride complex becomes dominant, and 5-bromo-2,2 More '-bipyridine is obtained. In such a case, when it is desired to preferentially synthesize 6-bromo-3,2′-bipyridine, for example, 2-chloro-5-iodopyridine is used by utilizing the difference in halogen reactivity. The 5-position iodine can be preferentially reacted.

  Further, instead of reacting 2,5-dibromopyridine with a zinc chloride complex of pyridine, the above-mentioned target product can also be obtained by a coupling reaction in which 2,5-dibromopyridine is reacted with pyridylboronic acid or a pyridylboronic acid ester. it can.

<Method for Converting Reactive Substituent into Boronic Acid / Boronate Ester>
In accordance with the following reaction formula (3), 5-bromo-2,2′-bipyridine is lithiated using an organolithium reagent, or a Grignard reagent using magnesium or an organomagnesium reagent, trimethyl borate, triethyl borate. Alternatively, 2,2′-bipyridineboronic acid ester can be synthesized by reacting with triisopropyl borate or the like. Furthermore, 2,2′-bipyridineboronic acid can be synthesized by hydrolyzing the 2,2′-bipyridineboronic acid ester according to the following reaction formula (4). In “RLi” and “RMgX” in the reaction formula (3), R represents a linear or branched alkyl group, preferably a linear or branched alkyl group having 1 to 4 carbon atoms. And X is a halogen.

  Further, according to the following reaction formula (5), 5-bromo-2,2′-bipyridine is lithiated using an organolithium reagent, or converted to a Grignard reagent using magnesium or an organomagnesium reagent, and bis (pinacolato) diboron is used. Alternatively, other 2,2′-bipyridineboronic acid esters can be synthesized by reacting with 4,4,5,5-tetramethyl-1,3,2-dioxaborolane. Further, according to the following reaction formula (6), 5-bromo-2,2′-bipyridine and bis (pinacolato) diboron or 4,4,5,5-tetramethyl-1,3,2-dioxaborolane are converted into a palladium catalyst. A similar 2,2′-bipyridineboronic acid ester can be synthesized by performing a coupling reaction using and a base. In “RLi” and “RMgX” in the reaction formula (5), R represents a linear or branched alkyl group, preferably a linear or branched alkyl group having 1 to 4 carbon atoms. And X is a halogen.

  In the above reaction formula (3), (5) or (6), the corresponding boronic acid / boronic acid ester can be synthesized by using other positional isomers instead of 5-bromo-2,2′-bipyridine. can do. Furthermore, it can be similarly synthesized by using chloride, iodide or trifluoromethanesulfonate instead of bromide such as 5-bromo-2,2'-bipyridine.

<"Terminal-intermediate" group: Synthesis of pyridylquinoline having a reactive substituent>
First, a zinc chloride complex of pyridine is synthesized according to the following reaction formula (7). In the reaction formula (7), “ZnCl ₂ · TMEDA” is a tetramethylethylenediamine complex of zinc chloride, and R represents a linear or branched alkyl group, preferably a linear or branched chain having 1 to 4 carbon atoms. A branched alkyl group having 3 to 4 carbon atoms. In parallel, according to the following reaction formula (8), the hydroxy group of 5-quinolinol is protected with a methylating agent, and 8-bromo-5-methoxyquinoline is synthesized with an appropriate brominating agent. Suitable brominating agents include bromine or N-brominated succinimide (NBS). Although there are a plurality of brominated positions in 5-methoxyquinoline, the target product can be isolated and purified by a known method such as column chromatography. Next, according to the following reaction formula (9), 8- (3-pyridyl) -5-methoxyquinoline is obtained by reacting a zinc chloride complex of pyridine with 8-bromo-5-methoxyquinoline in the presence of a palladium catalyst. After synthesis, demethylation is performed with boron tribromide, pyridine hydrochloride, and the like, and further reacted with trifluoromethanesulfonic anhydride to obtain 8-pyridyl-5-trifluoromethanesulfonate quinoline.

  Here, the synthesis method using 3-bromopyridine as the raw material for the terminal group is exemplified, but by using 2-bromopyridine or 4-bromopyridine as the raw material, and also using iodide instead of bromide, Each corresponding object can be obtained. Moreover, although the synthesis method using 5-quinolinol as the raw material of the intermediate group was exemplified, by using quinoline substituted with a hydroxy group at another position as the raw material, or by using isoquinolinol instead of quinolinol, Each corresponding object can be obtained.

  Further, instead of reacting quinoline bromo with a pyridine zinc chloride complex (reaction formula (9)), it can also be obtained by a coupling reaction in which quinoline bromo is reacted with pyridylboronic acid or a pyridylboronic acid ester.

<Method for Converting Reactive Substituent into Boronic Acid / Boronate Ester>
According to the following reaction formula (10), 8-pyridyl-5-trifluoromethanesulfonate quinoline and bis (pinacolato) diboron or 4,4,5,5-tetramethyl-1,3,2-dioxaborolane and a palladium catalyst An 8-pyridyl-quinoline-5-boronic acid ester can be synthesized by a coupling reaction using a base.

<"Terminal-intermediate" group: Synthesis of quinolinylpyridine having a reactive substituent>
First, a zinc chloride complex of dibromopyridine is synthesized according to the following reaction formula (11). In these reactions, the above reaction formula (1) can be used as a reference, but it should be noted that regioisomers mainly produced can be selected depending on the solvent used during lithiation (Jinhua J. Song et al., ORGANIC LETTERS, Vo.6, No.26, 4905-4907 (2004)).

  As for the zinc chloride complexes of other positional isomers of dibromopyridine, for example, any compound having two bromo symmetry with respect to the N position such as 2,6- or 3,5-dibromopyridine. A complex having zinc chloride bonded to the position can be obtained. In addition, 2,4-dibromopyridine can be obtained by lithiation in a toluene solvent to obtain a complex in which bromo remains at the 4-position and zinc chloride is bonded at the 2-position. As for 2-chloro-4-iodopyridine, a complex in which zinc chloride is bonded to the iodo position having relatively high reactivity can be obtained.

  Alternatively, according to the following reaction formula (12), one bromo of dibromopyridine is selectively lithiated and then reacted with iodine to synthesize bromo-iodopyridine. In addition, what is generally marketed may be used for other regioisomer compounds including 2-bromo-5-iodopyridine and 2-iodo-5-bromopyridine obtained by the following reaction formula (12).

  In parallel, quinolinol is triflated according to the following reaction formula (13). For this reaction, the triflating reaction in the final stage of the above reaction formula (9) is helpful. Further, referring to the above reaction formula (10), this triflated quinoline is converted to bis (pinacolato) diboron or 4,4,5,5-tetramethyl-1,3,2- with a palladium catalyst and a base. A quinoline boronic acid ester can be synthesized by a coupling reaction with dioxaborolane. Note that quinoline bromide or iodide is used as a raw material instead of quinolinol, and these are lithiated with an organolithium reagent, or a Grignard reagent with magnesium or an organomagnesium reagent, and trialkyl borate, bis (pinacolato) diboron or 4,4 , 5,5-tetramethyl-1,3,2-dioxaborolane and the like can also be used to synthesize quinoline boronate esters.

  Finally, according to the following reaction formula (14) or (15), the bromo-iodopyridine obtained as described above and a boronic acid ester of quinoline are subjected to a coupling reaction, whereby the terminal group quinoline and the intermediate group pyridine are reacted. The bromo form of the group consisting of can be synthesized.

  In addition, according to the following reaction formula (16) or (17), the terminal group quinoline and the intermediate group pyridine can also be subjected to a coupling reaction between the zinc chloride complex of dibromopyridine obtained as described above and the triflated quinoline. The bromo form of the group consisting of can be synthesized.

  Here, a synthesis method using a compound in which a reactive substituent is bonded to the 5-position of quinoline as a raw material for the terminal group is exemplified, but by using a quinoline substituted with a reactive substituent at another position as a raw material, Further, by using isoquinoline to which a reactive substituent is bonded instead of quinoline to which a reactive substituent is bonded, a corresponding target product can be obtained. Moreover, although the synthesis method using the 2,5-bromo substitution product of pyridine as the raw material of the intermediate group was illustrated, by using a material in which bromo is substituted at another position as the raw material, iodide is used instead of bromide. In this way, the corresponding object can be obtained.

<Synthesis of a central skeleton anthracene having a reactive substituent>
<9,10-Dibromoanthracene>
As shown in the following reaction formula (18), 9,10-dibromoanthracene is obtained by brominating anthracene using an appropriate brominating agent. Suitable brominating agents include bromine or N-brominated succinimide (NBS).

<9,10-dianthracene zinc complex>
As shown in the following reaction formula (19), 9,10-dibromoanthracene is lithiated using an organolithium reagent or converted to a Grignard reagent using magnesium or an organomagnesium reagent, and zinc chloride or zinc chloride tetramethylethylenediamine is used. By reacting with a complex (ZnCl ₂ · TMEDA), a 9,10-dianthracene zinc complex can be synthesized. In the reaction formula (19), R represents a linear or branched alkyl group, preferably a linear or branched alkyl group having 1 to 4 carbon atoms. In addition, it can synthesize | combine similarly even if it uses a chloride or an iodide instead of bromide like 9,10- dibromoanthracene.

<9,10-anthracene diboronic acid (or boronic ester)>
As shown in the following reaction formula (20), 9,10-dibromoanthracene is lithiated using an organolithium reagent or converted to a Grignard reagent using magnesium or an organomagnesium reagent, and trimethyl borate, triethyl borate or By reacting with triisopropyl borate or the like, 9,10-anthracene diboronic acid ester can be synthesized. Furthermore, 9,10-anthracene diboronic acid can be synthesized by hydrolyzing the 9,10-anthracene diboronic acid ester in the following reaction formula (21). In Reaction Formula (20), R represents a linear or branched alkyl group, preferably a linear or branched alkyl group having 1 to 4 carbon atoms.

  Further, as shown in the following reaction formula (22), 9,10-dibromoanthracene is lithiated using an organolithium reagent, or converted to a Grignard reagent using magnesium or an organomagnesium reagent, and bis (pinacolato) diboron or Other 9,10-anthracene diboronic acid esters can be synthesized by reacting with 4,4,5,5-tetramethyl-1,3,2-dioxaborolane. In addition, as shown in the following reaction formula (23), 9,10-dibromoanthracene and bis (pinacolato) diboron or 4,4,5,5-tetramethyl-1,3,2-dioxaborolane are combined with a palladium catalyst. A similar 9,10-anthracene diboronic acid ester can be synthesized by a coupling reaction using a base. In the reaction formula (22), R represents a linear or branched alkyl group, preferably a linear or branched alkyl group having 1 to 4 carbon atoms.

  In the above reaction formula (20), (22) or (23), the same synthesis can be performed by using chloride, iodide or triflate instead of bromide such as 9,10-dibromoanthracene. it can.

<Method of bonding an anthracene having a reactive substituent and a “terminal-intermediate” group>
As described above, for the “terminal-intermediate” group, bromo form of bipyridine (reaction formulas (1) to (2)), boronic acid, boronic acid ester (reaction formulas (3) to (6)), pyridylquinoline The triflate (reaction formulas (7) to (9)), boronic acid, boronate ester (reaction formula (10)), quinolinylpyridine bromo compound (reaction formulas (14) to (17)) As for anthracene having a reactive substituent, bromo form of anthracene (reaction formula (18)), zinc chloride complex (reaction formula (19)), boronic acid, boronate ester (reaction formula (20) to (23)) can be synthesized, and the anthracene derivative of the present invention can be synthesized by linking the “terminal-intermediate” group and anthracene with reference to the coupling reaction used in the above description. Can.

In this final coupling reaction, in order to make Py ¹ and Py ² of the anthracene derivative represented by the formula (1) different structures, first, anthracene having a reactive substituent and 1-fold molar equivalent of “ After reacting with a compound of a “terminal-intermediate” group and purifying to obtain the desired intermediate, this intermediate is reacted with a compound of a “terminal-intermediate” group different from the previous one (ie, divided into two steps). Reaction).

(2) A method of attaching an end group to an anthracene having an intermediate group bonded to the 9 and 10 positions In this method as well, referring to the various coupling reactions described above, an intermediate group is first bonded to the 9 and 10 positions of anthracene. And an end group may be bonded to the intermediate group. At this time, in order to make Py ¹ and Py ² of the anthracene derivative represented by the formula (1) have different structures, different intermediate groups are bonded in a two-step reaction in the step of bonding the intermediate group to anthracene A desired anthracene derivative can be synthesized by bonding different end groups in a two-step reaction in the step of bonding the end group to the intermediate group.

<About the reagents used in the reaction>
Specific examples of the palladium catalyst used in the coupling reaction include Pd (PPh ₃ ) ₄ , PdCl ₂ (PPh ₃ ) ₂ , Pd (OAc) ₂ , tris (dibenzylideneacetone) dipalladium (0), tris (di) Benzylideneacetone) dipalladium (0) chloroform complex, bis (dibenzylideneacetone) palladium (0), bis (tri-t-butylphosphino) palladium (0), or (1,1′-bis (diphenylphosphino) ferrocene ) Dichloropalladium (II).

  In order to accelerate the reaction, a phosphine compound may be added to these palladium compounds in some cases. Specific examples of the phosphine compound include tri (t-butyl) phosphine, tricyclohexylphosphine, 1- (N, N-dimethylaminomethyl) -2- (di-t-butylphosphino) ferrocene, 1- (N, N-dibutylaminomethyl) -2- (di-t-butylphosphino) ferrocene, 1- (methoxymethyl) -2- (di-t-butylphosphino) ferrocene, 1,1′-bis (di-t-butylphos Fino) ferrocene, 2,2′-bis (di-t-butylphosphino) -1,1′-binaphthyl, 2-methoxy-2 ′-(di-t-butylphosphino) -1,1′-binaphthyl, or An example is 2-dicyclohexylphosphino-2 ′, 6′-dimethoxybiphenyl.

  Specific examples of the base used in the reaction include sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, barium hydroxide, sodium ethoxide, sodium t-butoxide, sodium acetate, phosphoric acid. Examples include tripotassium or potassium fluoride.

  Specific examples of the solvent used in the reaction include benzene, toluene, xylene, 1,2,4-trimethylbenzene, N, N-dimethylformamide, tetrahydrofuran, diethyl ether, t-butyl methyl ether, 1,4- Examples include dioxane, methanol, ethanol, cyclopentyl methyl ether, and isopropyl alcohol. These solvents can be appropriately selected and may be used alone or as a mixed solvent.

3. Organic Electroluminescent Device The anthracene derivative according to the present invention can be used as a material for an organic electroluminescent device, for example. Below, the organic electroluminescent element which concerns on this embodiment is demonstrated in detail based on drawing. FIG. 1 is a schematic cross-sectional view showing an organic electroluminescent element according to this embodiment.

<Structure of organic electroluminescence device>
An organic electroluminescent device 100 shown in FIG. 1 includes a substrate 101, an anode 102 provided on the substrate 101, a hole injection layer 103 provided on the anode 102, and a hole injection layer 103. A hole transport layer 104 provided on the light emitting layer 105, a light emitting layer 105 provided on the hole transport layer 104, an electron transport layer 106 provided on the light emitting layer 105, and an electron transport layer 106. And the cathode 108 provided on the electron injection layer 107.

  The organic electroluminescent element 100 is manufactured in the reverse order, for example, the substrate 101, the cathode 108 provided on the substrate 101, the electron injection layer 107 provided on the cathode 108, and the electron injection layer. An electron transport layer 106 provided on 107, a light-emitting layer 105 provided on the electron transport layer 106, a hole transport layer 104 provided on the light-emitting layer 105, and a hole transport layer 104 A structure including the hole injection layer 103 provided above and the anode 102 provided on the hole injection layer 103 may be employed.

  Not all of the above-described layers are necessary, and the minimum structural unit is composed of the anode 102, the light emitting layer 105, the electron transport layer 106 and / or the electron injection layer 107 and the cathode 108. The hole transport layer 104 is an arbitrarily provided layer. Moreover, each said layer may consist of a single layer, respectively, and may consist of multiple layers.

  As an aspect of the layer constituting the organic electroluminescence device, in addition to the above-described configuration aspect of “substrate / anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode”, "Substrate / anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode", "substrate / anode / hole injection layer / light emitting layer / electron transport layer / electron injection layer / cathode", "substrate / Anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode ”,“ substrate / anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode ”,“ substrate ” / Anode / light emitting layer / electron transport layer / electron injection layer / cathode ”,“ substrate / anode / hole transport layer / light emitting layer / electron injection layer / cathode ”,“ substrate / anode / hole transport layer / light emitting layer / “Electron transport layer / cathode”, “substrate / anode / hole injection layer / light emitting layer / electron injection layer / cathode”, “substrate / anode / hole injection layer / light emitting layer / electron transport” Layer / cathode "," substrate / anode / light emitting layer / electron transporting layer / cathode "may be configured aspect of the" substrate / anode / light emitting layer / electron injection layer / cathode ".

<Substrate in organic electroluminescence device>
The substrate 101 serves as a support for the organic electroluminescent device 100, and usually quartz, glass, metal, plastic, or the like is used. The substrate 101 is formed into a plate shape, a film shape, or a sheet shape according to the purpose. For example, a glass plate, a metal plate, a metal foil, a plastic film, a plastic sheet, or the like is used. Of these, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, polysulfone and the like are preferable. In the case of a glass substrate, soda lime glass, non-alkali glass, or the like is used, and the thickness only needs to be sufficient to maintain the mechanical strength. The upper limit value of the thickness is, for example, 2 mm or less, preferably 1 mm or less. As for the material of the glass, non-alkali glass is preferred because it is better that there are fewer ions eluted from the glass, but soda-lime glass with a barrier coat such as SiO ₂ is also available on the market. it can. Further, the substrate 101 may be provided with a gas barrier film such as a dense silicon oxide film on at least one surface in order to improve the gas barrier property, and a synthetic resin plate, film or sheet having a low gas barrier property is used as the substrate 101. When used, it is preferable to provide a gas barrier film.

<Anode in organic electroluminescence device>
The anode 102 serves to inject holes into the light emitting layer 105. When the hole injection layer 103 and / or the hole transport layer 104 are provided between the anode 102 and the light emitting layer 105, holes are injected into the light emitting layer 105 through these layers. .

  Examples of the material for forming the anode 102 include inorganic compounds and organic compounds. Examples of inorganic compounds include metals (aluminum, gold, silver, nickel, palladium, chromium, etc.), metal oxides (indium oxide, tin oxide, indium-tin oxide (ITO), indium-zinc oxide). Products (IZO), metal halides (copper iodide, etc.), copper sulfide, carbon black, ITO glass, Nesa glass, and the like. Examples of the organic compound include polythiophene such as poly (3-methylthiophene), conductive polymer such as polypyrrole and polyaniline, and the like. In addition, it can select suitably from the substances currently used as an anode of an organic electroluminescent element, and can use it.

  The resistance of the transparent electrode is not limited as long as it can supply a sufficient current for light emission of the light emitting element, but is preferably low resistance from the viewpoint of power consumption of the light emitting element. For example, an ITO substrate of 300Ω / □ or less functions as an element electrode. However, since it is now possible to supply a substrate of about 10Ω / □, for example, 100-5Ω / □, preferably 50-5Ω. It is particularly desirable to use a low resistance product of / □. The thickness of ITO can be arbitrarily selected according to the resistance value, but is usually used in a range of 100 to 300 nm.

<Hole injection layer and hole transport layer in organic electroluminescence device>
The hole injection layer 103 plays a role of efficiently injecting holes moving from the anode 102 into the light emitting layer 105 or the hole transport layer 104. The hole transport layer 104 plays a role of efficiently transporting holes injected from the anode 102 or holes injected from the anode 102 through the hole injection layer 103 to the light emitting layer 105. The hole injection layer 103 and the hole transport layer 104 are each formed by laminating and mixing one kind or two or more kinds of hole injection / transport materials or a mixture of the hole injection / transport material and the polymer binder. Is done. In addition, an inorganic salt such as iron (III) chloride may be added to the hole injection / transport material to form a layer.

  As a hole injection / transport material, it is necessary to efficiently inject and transport holes from the positive electrode between electrodes to which an electric field is applied. The hole injection efficiency is high, and the injected holes are transported efficiently. It is desirable to do. For this purpose, it is preferable to use a substance that has a low ionization potential, a high hole mobility, excellent stability, and is less likely to generate trapping impurities during production and use.

  As a material for forming the hole injection layer 103 and the hole transport layer 104, in a photoconductive material, a compound conventionally used as a charge transport material for holes, a p-type semiconductor, and a hole injection of an organic electroluminescent element are used. Any known material used for the layer and the hole transport layer can be selected and used. Specific examples thereof include carbazole derivatives (N-phenylcarbazole, polyvinylcarbazole, etc.), biscarbazole derivatives such as bis (N-allylcarbazole) or bis (N-alkylcarbazole), triarylamine derivatives (aromatic tertiary class). Polymer having amino group in main chain or side chain, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N, N′-diphenyl-N, N′-di (3-methylphenyl)- 4,4′-diaminobiphenyl, N, N′-diphenyl-N, N′-dinaphthyl-4,4′-diaminobiphenyl, N, N′-diphenyl-N, N′-di (3-methylphenyl)- 4,4′-diphenyl-1,1′-diamine, N, N′-dinaphthyl-N, N′-diphenyl-4,4′-diphenyl-1 Triphenylamine derivatives such as 1′-diamine, 4,4 ′, 4 ″ -tris (3-methylphenyl (phenyl) amino) triphenylamine, starburstamine derivatives, stilbene derivatives, phthalocyanine derivatives (metal-free, copper Phthalocyanines, etc.), pyrazoline derivatives, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, heterocyclic compounds such as porphyrin derivatives, polysilanes, etc. In the polymer system, polycarbonate and styrene having the above monomers in the side chain Derivatives, polyvinyl carbazole, polysilane, and the like are preferable, but there is no particular limitation as long as it is a compound that forms a thin film necessary for manufacturing a light-emitting element, can inject holes from the anode, and can transport holes.

  It is also known that the conductivity of organic semiconductors is strongly influenced by the doping. Such an organic semiconductor matrix material is composed of a compound having a good electron donating property or a compound having a good electron accepting property. Strong electron acceptors such as tetracyanoquinone dimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone dimethane (F4TCNQ) are known for doping of electron donor materials. (For example, the document “M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73 (22), 3202-3204 (1998)”) and the document “J. Blochwitz, M Pheiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73 (6), 729-731 (1998)). These generate so-called holes by an electron transfer process in an electron donating base material (hole transport material). Depending on the number and mobility of holes, the conductivity of the base material varies considerably. Known matrix substances having hole transporting properties include, for example, benzidine derivatives (TPD and the like), starburst amine derivatives (TDATA and the like), and specific metal phthalocyanines (particularly zinc phthalocyanine ZnPc and the like). 2005-167175).

<Light emitting layer in organic electroluminescent element>
The light emitting layer 105 emits light by recombining holes injected from the anode 102 and electrons injected from the cathode 108 between electrodes to which an electric field is applied. The material for forming the light-emitting layer 105 may be a compound that emits light by being excited by recombination of holes and electrons (a light-emitting compound), can form a stable thin film shape, and is in a solid state It is preferable that the compound exhibits a high emission (fluorescence and / or phosphorescence) efficiency.

  The light emitting layer may be either a single layer or a plurality of layers, and each is formed of a light emitting material (host material, dopant material). Each of the host material and the dopant material may be one kind or a plurality of combinations. The dopant material may be included in the host material as a whole, or may be included partially. As a doping method, it can be formed by a co-evaporation method with a host material, but it may be pre-mixed with the host material and then simultaneously deposited.

  The amount of the host material used varies depending on the type of the host material, and may be determined according to the characteristics of the host material. The amount of the host material used is preferably 50 to 99.999% by weight of the entire light emitting material, more preferably 80 to 99.95% by weight, and still more preferably 90 to 99.9% by weight. .

  The amount of the dopant material used varies depending on the type of the dopant material, and may be determined according to the characteristics of the dopant material (for example, if the amount used is too large, there is a risk of concentration quenching). The standard of the amount of the dopant used is preferably 0.001 to 50% by weight, more preferably 0.05 to 20% by weight, and further preferably 0.1 to 10% by weight of the entire light emitting material.

  The light emitting material of the light emitting element according to the present embodiment may be either fluorescent or phosphorescent.

  The host material is not particularly limited, but has previously been known as a light emitter, such as fused ring derivatives such as anthracene and pyrene, metal chelated oxinoid compounds such as tris (8-quinolinolato) aluminum, bis Bisstyryl derivatives such as styryl anthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, cyclopentadiene derivatives, oxadiazole derivatives, thiadiazolopyridine derivatives, pyrrolopyrrole In derivatives, fluorene derivatives, benzofluorene derivatives, and polymer systems, polyphenylene vinylene derivatives, polyparaphenylene derivatives, and polythiophene derivatives are preferably used.

  In addition, as a host material, it can select and use suitably from the compound etc. which were described in the chemical industry June, 2004 issue page 13, and the reference cited up.

  Moreover, it does not specifically limit as dopant material, A known compound can be used and it can select from various materials according to a desired luminescent color. Specifically, for example, condensed ring derivatives such as phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopylene, dibenzopyrene, rubrene and chrysene, benzoxazole derivatives, benzthiazole derivatives, benzimidazole derivatives, benztriazole derivatives, oxazoles Derivatives, oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazoline derivatives, stilbene derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives, distyrylbenzene derivatives, etc. (JP-A-1-245087), bisstyrylarylene derivatives (JP-A-2-24727) Gazette), diazaindacene derivatives, furan derivatives, benzofuran derivatives, phenylisobenzofuran, dimesitylisobenzofuran, di (2-methylphenyl) isobenzofuran, di (2-trifluoromethylphenyl) isobenzofuran, phenylisobenzofuran, etc. Isobenzofuran derivatives, dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinocoumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzthiazolylcoumarin derivatives, 3 -Coumarin derivatives such as benzimidazolyl coumarin derivatives and 3-benzoxazolyl coumarin derivatives, dicyanomethylenepyran derivatives, dicyanomethylenethiopyran derivatives, polymethine derivatives, Nin derivatives, oxobenzanthracene derivatives, xanthene derivatives, rhodamine derivatives, fluorescein derivatives, pyrylium derivatives, carbostyril derivatives, acridine derivatives, oxazine derivatives, phenylene oxide derivatives, quinacridone derivatives, quinazoline derivatives, pyrrolopyridine derivatives, furopyridine derivatives, 1, Examples include 2,5-thiadiazolopyrene derivatives, pyromethene derivatives, perinone derivatives, pyrrolopyrrole derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, acridone derivatives, deazaflavin derivatives, fluorene derivatives, and benzofluorene derivatives.

  Illustrated for each color light, blue to blue-green dopant materials include naphthalene, anthracene, phenanthrene, pyrene, triphenylene, perylene, fluorene, indene, chrysene and other aromatic hydrocarbon compounds and derivatives thereof, furan, pyrrole, thiophene, Aromatic heterocycles such as silole, 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, thioxanthene Ring compounds and their derivatives, distyrylbenzene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, coumarin derivatives, imidazoles, thiazoles, thiadiazos Azole derivatives such as sulfazole, carbazole, oxazole, oxadiazole, triazole and metal complexes thereof and N, N′-diphenyl-N, N′-di (3-methylphenyl) -4,4′-diphenyl-1,1 Examples include aromatic amine derivatives represented by '-diamine.

  Examples of green to yellow dopant materials include coumarin derivatives, phthalimide derivatives, naphthalimide derivatives, perinone derivatives, pyrrolopyrrole derivatives, cyclopentadiene derivatives, acridone derivatives, quinacridone derivatives, and naphthacene derivatives such as rubrene, and the above blue A compound in which a substituent capable of increasing the wavelength such as an aryl group, a heteroaryl group, an arylvinyl group, an amino group, or a cyano group is introduced into the compound exemplified as the blue-green dopant material is also a suitable example.

  Further, examples of the orange to red dopant material include naphthalimide derivatives such as bis (diisopropylphenyl) perylenetetracarboxylic imide, perinone derivatives, rare earth complexes such as Eu complexes having acetylacetone, benzoylacetone and phenanthroline as ligands, 4 -(Dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran and its analogs, metal phthalocyanine derivatives such as magnesium phthalocyanine and aluminum chlorophthalocyanine, rhodamine compounds, deazaflavin derivatives, coumarin derivatives, quinacridone Derivatives, phenoxazine derivatives, oxazine derivatives, quinazoline derivatives, pyrrolopyridine derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, phenoxazones Conductors and thiadiazolopyrene derivatives, etc., and longer wavelengths such as aryl groups, heteroaryl groups, arylvinyl groups, amino groups, and cyano groups can be added to the compounds exemplified above as blue to blue-green and green to yellow dopant materials. A compound into which a substituent is introduced is also a suitable example. Furthermore, a phosphorescent metal complex having iridium represented by tris (2-phenylpyridine) iridium (III) or platinum as a central metal is also a suitable example.

  In addition, as a dopant, it can select and use suitably from the compound etc. which were described in the chemical industry June, 2004 issue page 13, and the reference cited up.

  Among the dopant materials described above, perylene derivatives, borane derivatives, amine-containing styryl derivatives, aromatic amine derivatives, coumarin derivatives, pyran derivatives, iridium complexes, or platinum complexes are particularly preferable.

Examples of perylene derivatives include 3,10-bis (2,6-dimethylphenyl) perylene, 3,10-bis (2,4,6-trimethylphenyl) perylene, 3,10-diphenylperylene, 3,4- Diphenylperylene, 2,5,8,11-tetra-t-butylperylene, 3,4,9,10-tetraphenylperylene, 3- (1'-pyrenyl) -8,11-di (t-butyl) perylene 3- (9′-anthryl) -8,11-di (t-butyl) perylene, 3,3′-bis (8,11-di (t-butyl) perylenyl), and the like.
JP-A-11-97178, JP-A-2000-133457, JP-A-2000-26324, JP-A-2001-267079, JP-A-2001-267078, JP-A-2001-267076, Perylene derivatives described in JP-A No. 2000-34234, JP-A No. 2001-267075, JP-A No. 2001-217077 and the like may be used.

Examples of the borane derivative include 1,8-diphenyl-10- (dimesitylboryl) anthracene, 9-phenyl-10- (dimesitylboryl) anthracene, 4- (9′-anthryl) dimesitylborylnaphthalene, 4- (10 ′). -Phenyl-9'-anthryl) dimesitylborylnaphthalene, 9- (dimesitylboryl) anthracene, 9- (4'-biphenylyl) -10- (dimesitylboryl) anthracene, 9- (4 '-(N-carbazolyl) phenyl) -10- (Dimesitylboryl) anthracene and the like.
Moreover, you may use the borane derivative described in the international publication 2000/40586 pamphlet.

  Examples of the amine-containing styryl derivative include N, N, N ′, N′-tetra (4-biphenylyl) -4,4′-diaminostilbene, N, N, N ′, N′-tetra (1-naphthyl). -4,4'-diaminostilbene, N, N, N ', N'-tetra (2-naphthyl) -4,4'-diaminostilbene, N, N'-di (2-naphthyl) -N, N' -Diphenyl-4,4'-diaminostilbene, N, N'-di (9-phenanthryl) -N, N'-diphenyl-4,4'-diaminostilbene, 4,4'-bis [4 "-bis ( Diphenylamino) styryl] -biphenyl, 1,4-bis [4′-bis (diphenylamino) styryl] -benzene, 2,7-bis [4′-bis (diphenylamino) styryl] -9,9-dimethylfluorene , 4,4'-bis ( -Ethyl-3-carbazovinylene) -biphenyl, 4,4′-bis (9-phenyl-3-carbazovinylene) -biphenyl, etc. In addition, JP 2003-347056 A and JP 2001-307884 A Amine-containing styryl derivatives described in the above may be used.

Examples of the aromatic amine derivative include N, N, N, N-tetraphenylanthracene-9,10-diamine, 9,10-bis (4-diphenylamino-phenyl) anthracene, and 9,10-bis (4- Di (1-naphthylamino) phenyl) anthracene, 9,10-bis (4-di (2-naphthylamino) phenyl) anthracene, 10-di-p-tolylamino-9- (4-di-p-tolylamino-1) -Naphthyl) anthracene, 10-diphenylamino-9- (4-diphenylamino-1-naphthyl) anthracene, 10-diphenylamino-9- (6-diphenylamino-2-naphthyl) anthracene, [4- (4-diphenyl) Amino-phenyl) naphthalen-1-yl] -diphenylamine, [4- (4-diphenylamino-phenyl) na Talen-1-yl] -diphenylamine, [6- (4-diphenylamino-phenyl) naphthalen-2-yl] -diphenylamine, 4,4′-bis [4-diphenylaminonaphthalen-1-yl] biphenyl, 4, 4'-bis [6-diphenylaminonaphthalen-2-yl] biphenyl, 4,4 "-bis [4-diphenylaminonaphthalen-1-yl] -p-terphenyl, 4,4" -bis [6-diphenyl Aminonaphthalen-2-yl] -p-terphenyl and the like.
Moreover, you may use the aromatic amine derivative described in Unexamined-Japanese-Patent No. 2006-156888.

Examples of the coumarin derivative include coumarin-6 and coumarin-334.
Moreover, you may use the coumarin derivative described in Unexamined-Japanese-Patent No. 2004-43646, Unexamined-Japanese-Patent No. 2001-76876, and Unexamined-Japanese-Patent No. 6-298758.

Examples of the pyran derivative include the following DCM and DCJTB.
Also, JP 2005-126399, JP 2005-097283, JP 2002-234892, JP 2001-220577, JP 2001-081090, and JP 2001-052869. Alternatively, pyran derivatives described in the above may be used.

Examples of the iridium complex include Ir (ppy) _{3 described} below.
Further, the iridium complexes described in JP-A-2006-089398, JP-A-2006-080419, JP-A-2005-298483, JP-A-2005-097263, JP-A-2004-111379, etc. It may be used.

Examples of the platinum complex include the following PtOEP.
Further, the platinum complexes described in JP-A-2006-190718, JP-A-2006-128634, JP-A-2006-093542, JP-A-2004-335122, JP-A-2004-331508, etc. It may be used.

<Electron injection layer and electron transport layer in organic electroluminescence device>
The electron injection layer 107 plays a role of efficiently injecting electrons moving from the cathode 108 into the light emitting layer 105 or the electron transport layer 106. The electron transport layer 106 plays a role of efficiently transporting electrons injected from the cathode 108 or electrons injected from the cathode 108 through the electron injection layer 107 to the light emitting layer 105. The electron transport layer 106 and the electron injection layer 107 are each formed by laminating and mixing one or more electron transport / injection materials or a mixture of the electron transport / injection material and the polymer binder.

  The electron injection / transport layer is a layer that is responsible for injecting electrons from the cathode and further transporting the electrons. It is desirable that the electron injection efficiency is high and the injected electrons are transported efficiently. For this purpose, it is preferable to use a substance that has a high electron affinity, a high electron mobility, excellent stability, and is unlikely to generate trapping impurities during production and use. However, considering the transport balance between holes and electrons, if the role of effectively preventing the holes from the anode from flowing to the cathode side without recombination is mainly played, the electron transport capability is much higher. Even if it is not high, the effect of improving the luminous efficiency is equivalent to that of a material having a high electron transport capability. Therefore, the electron injection / transport layer in this embodiment may include a function of a layer that can efficiently block the movement of holes.

As a material (electron transport material) for forming the electron transport layer 106 or the electron injection layer 107, a compound represented by the above formula (1) can be used. Of these, anthracene derivatives represented by the above formulas (1-1) to (1-114) and anthracene derivatives represented by the above formulas (1-201) to (1-480) are preferable.
The content of the anthracene derivative represented by the above formula (1) in the electron transport layer 106 or the electron injection layer 107 differs depending on the type of the derivative and may be determined according to the characteristics of the derivative. The standard of the content of the anthracene derivative represented by the above formula (1) is preferably 1 to 100% by weight, more preferably 10 to 100% of the whole electron transport layer material (or electron injection layer material). % By weight, more preferably 50 to 100% by weight, and particularly preferably 80 to 100% by weight. When the anthracene derivative represented by the above formula (1) is not used alone (100% by weight), other materials described in detail below may be mixed.

  Other materials for forming the electron transport layer or electron injection layer include compounds conventionally used as electron transport compounds in photoconductive materials, and known materials used for electron injection layers and electron transport layers of organic electroluminescent devices. Any of these compounds can be selected and used.

  Materials used for the electron transport layer or the electron injection layer include compounds composed of aromatic rings or heteroaromatic rings composed of one or more atoms selected from carbon, hydrogen, oxygen, sulfur, silicon, and phosphorus, and pyrrole derivatives. And at least one selected from the condensed ring derivatives thereof and metal complexes having electron-accepting nitrogen. Specifically, condensed ring aromatic ring derivatives such as naphthalene and anthracene (excluding the derivatives of the present invention), styryl aromatic ring derivatives represented by 4,4′-bis (diphenylethenyl) biphenyl, perinone derivatives, Coumarin derivatives, naphthalimide derivatives, quinone derivatives such as anthraquinone and diphenoquinone, phosphorus oxide derivatives, carbazole derivatives, and indole derivatives. Examples of metal complexes having electron-accepting nitrogen include hydroxyazole complexes such as hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. These materials can be used alone or in combination with different materials. Among them, anthracene derivatives such as 9,10-bis (2-naphthyl) anthracene, styryl aromatic ring derivatives such as 4,4′-bis (diphenylethenyl) biphenyl, 4,4′-bis (N-carbazolyl) biphenyl A carbazole derivative such as 1,3,5-tris (N-carbazolyl) benzene is preferably used from the viewpoint of durability.

  Specific examples of other electron transfer compounds include pyridine derivatives (excluding derivatives of the present invention), naphthalene derivatives, anthracene derivatives (excluding derivatives of the present invention), phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, Anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, oxadiazole derivatives (such as 1,3-bis [(4-t-butylphenyl) 1,3,4-oxadiazolyl] phenylene), thiophene derivatives, triazole derivatives ( N-naphthyl-2,5-diphenyl-1,3,4-triazole, etc.), thiadiazole derivatives, metal complexes of oxine derivatives, quinolinol metal complexes, quinoxaline derivatives, polymers of quinoxaline derivatives, benzazole compounds, Complex, pyrazole derivative, perfluorinated phenylene derivative, triazine derivative, pyrazine derivative, benzoquinoline derivative (2,2′-bis (benzo [h] quinolin-2-yl) -9,9′-spirobifluorene, etc.) , Imidazopyridine derivatives, borane derivatives, benzimidazole derivatives (such as tris (N-phenylbenzimidazol-2-yl) benzene), benzoxazole derivatives, benzthiazole derivatives, quinoline derivatives (excluding the derivatives of the present invention), terpyridine, etc. Oligopyridine derivatives, bipyridine derivatives (excluding derivatives of the present invention), terpyridine derivatives (1,3-bis (4 ′-(2,2 ′: 6′2 ″ -terpyridinyl)) benzene, etc.), naphthyridine derivatives (bis ( 1-naphthyl) -4- (1,8-naphthyl) Such as down-yl) phenylphosphine oxide), aldazine derivatives, carbazole derivatives, indole derivatives, phosphorus oxide derivatives, such as bis-styryl derivatives.

  In addition, metal complexes having electron-accepting nitrogen can also be used, such as hydroxyazole complexes such as quinolinol-based metal complexes and hydroxyphenyloxazole complexes, azomethine complexes, tropolone metal complexes, flavonol metal complexes, and benzoquinoline metal complexes. can give.

  Although the above-mentioned materials are used alone, they may be mixed with different materials.

  Among the materials described above, quinolinol metal complexes, bipyridine derivatives, phenanthroline derivatives, borane derivatives or benzimidazole derivatives are preferable.

The quinolinol-based metal complex is a compound represented by the following general formula (E-1).
In the formula, R ^{1 to} R ⁶ are hydrogen or a substituent, M is Al, Ga, Be, or Zn, and n is an integer of 2 or 3.

  Specific examples of the quinolinol-based metal complex include tris (8-quinolinolato) aluminum, tris (4-methyl-8-quinolinolato) aluminum, tris (5-methyl-8-quinolinolato) aluminum, tris (3,4-dimethyl- 8-quinolinolato) aluminum, tris (4,5-dimethyl-8-quinolinolato) aluminum, tris (4,6-dimethyl-8-quinolinolato) aluminum, bis (2-methyl-8-quinolinolato) (phenolate) aluminum, bis (2-methyl-8-quinolinolato) (2-methylphenolato) aluminum, bis (2-methyl-8-quinolinolato) (3-methylphenolato) aluminum, bis (2-methyl-8-quinolinolato) (4- Methyl phenolate) alumini Bis (2-methyl-8-quinolinolato) (2-phenylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (3-phenylphenolato) aluminum, bis (2-methyl-8-quinolinolato) (4-Phenylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (2,3-dimethylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (2,6-dimethylphenolate) aluminum Bis (2-methyl-8-quinolinolato) (3,4-dimethylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (3,5-dimethylphenolate) aluminum, bis (2-methyl-8) -Quinolinolate) (3,5-di-t-butylphenolate) alumini Bis (2-methyl-8-quinolinolato) (2,6-diphenylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (2,4,6-triphenylphenolato) aluminum, bis (2 -Methyl-8-quinolinolato) (2,4,6-trimethylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (2,4,5,6-tetramethylphenolato) aluminum, bis (2- Methyl-8-quinolinolato) (1-naphtholato) aluminum, bis (2-methyl-8-quinolinolato) (2-naphtholato) aluminum, bis (2,4-dimethyl-8-quinolinolato) (2-phenylphenolato) aluminum Bis (2,4-dimethyl-8-quinolinolate) (3-phenylphenola) G) Aluminum, bis (2,4-dimethyl-8-quinolinolato) (4-phenylphenolate) aluminum, bis (2,4-dimethyl-8-quinolinolato) (3,5-dimethylphenolate) aluminum, bis ( 2,4-dimethyl-8-quinolinolato) (3,5-di-t-butylphenolate) aluminum, bis (2-methyl-8-quinolinolato) aluminum-μ-oxo-bis (2-methyl-8-quinolinolato) ) Aluminum, bis (2,4-dimethyl-8-quinolinolato) aluminum-μ-oxo-bis (2,4-dimethyl-8-quinolinolato) aluminum, bis (2-methyl-4-ethyl-8-quinolinolato) aluminum -Μ-oxo-bis (2-methyl-4-ethyl-8-quinolinolato) aluminum Bis (2-methyl-4-methoxy-8-quinolinolato) aluminum-μ-oxo-bis (2-methyl-4-methoxy-8-quinolinolato) aluminum, bis (2-methyl-5-cyano-8- Quinolinolato) aluminum-μ-oxo-bis (2-methyl-5-cyano-8-quinolinolato) aluminum, bis (2-methyl-5-trifluoromethyl-8-quinolinolato) aluminum-μ-oxo-bis (2- Methyl-5-trifluoromethyl-8-quinolinolato) aluminum, bis (10-hydroxybenzo [h] quinoline) beryllium and the like.

A bipyridine derivative is a compound represented by the following general formula (E-2).
In the formula, G represents a simple bond or an n-valent linking group, and n is an integer of 2 to 8. Carbon atoms that are not used for bonding of pyridine-pyridine or pyridine-G may be substituted.

Examples of G in the general formula (E-2) include the following structural formulas. In addition, R in the following structural formula is each independently hydrogen, methyl, ethyl, isopropyl, cyclohexyl, phenyl, 1-naphthyl, 2-naphthyl, biphenylyl, or terphenylyl.

  Specific examples of the pyridine derivative include 2,5-bis (2,2′-bipyridyl-6-yl) -1,1-dimethyl-3,4-diphenylsilole, 2,5-bis (2,2′- Bipyridyl-6-yl) -1,1-dimethyl-3,4-dimesitylsilole, 2,5-bis (2,2′-bipyridyl-5-yl) -1,1-dimethyl-3,4 Diphenylsilole, 2,5-bis (2,2′-bipyridyl-5-yl) -1,1-dimethyl-3,4-dimesitylsilole 9,10-di (2,2′-bipyridyl-6- Yl) anthracene, 9,10-di (2,2′-bipyridyl-5-yl) anthracene, 9,10-di (2,3′-bipyridyl-6-yl) anthracene, 9,10-di (2, 3'-bipyridyl-5-yl) anthracene, 9,10-di (2,3 -Bipyridyl-6-yl) -2-phenylanthracene, 9,10-di (2,3'-bipyridyl-5-yl) -2-phenylanthracene, 9,10-di (2,2'-bipyridyl-6) -Yl) -2-phenylanthracene, 9,10-di (2,2'-bipyridyl-5-yl) -2-phenylanthracene, 9,10-di (2,4'-bipyridyl-6-yl)- 2-Phenylanthracene, 9,10-di (2,4′-bipyridyl-5-yl) -2-phenylanthracene, 9,10-di (3,4′-bipyridyl-6-yl) -2-phenylanthracene 9,10-di (3,4'-bipyridyl-5-yl) -2-phenylanthracene, 3,4-diphenyl-2,5-di (2,2'-bipyridyl-6-yl) thiophene, 3, , 4-Diphenyl 2,5-di (2,3′-bipyridyl-5-yl) thiophene, 6′6 ″ -di (2-pyridyl) 2,2 ′: 4 ′, 4 ″: 2 ″, 2 ″ ′-quater Examples include pyridine.

A phenanthroline derivative is a compound represented by the following general formula (E-3-1) or (E-3-2).
In the formula, R ^{1 to} R ⁸ are hydrogen or a substituent, adjacent groups may be bonded to each other to form a condensed ring, G represents a simple bond or an n-valent linking group, and n represents 2 It is an integer of ~ 8. Moreover, as G of general formula (E-3-2), the same thing as what was demonstrated in the column of the bipyridine derivative is mention | raise | lifted, for example.

  Specific examples of the phenanthroline derivative include 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 9,10-di (1,10-phenanthroline- 2-yl) anthracene, 2,6-di (1,10-phenanthroline-5-yl) pyridine, 1,3,5-tri (1,10-phenanthroline-5-yl) benzene, 9,9′-difluor -Bis (1,10-phenanthroline-5-yl), bathocuproin, 1,3-bis (2-phenyl-1,10-phenanthroline-9-yl) benzene and the like.

  In particular, the case where a phenanthroline derivative is used for an electron transport layer and an electron injection layer will be described. In order to obtain stable light emission over a long period of time, a material excellent in thermal stability and thin film formation is desired, and among phenanthroline derivatives, the substituent itself has a three-dimensional structure, or a phenanthroline skeleton or Those having a three-dimensional structure by steric repulsion with an adjacent substituent or those having a plurality of phenanthroline skeletons linked to each other are preferred. Furthermore, when linking a plurality of phenanthroline skeletons, a compound containing a conjugated bond, a substituted or unsubstituted aromatic hydrocarbon, or a substituted or unsubstituted aromatic heterocycle in the linking unit is more preferable.

The borane derivative is a compound represented by the following general formula (E-4), and is disclosed in detail in JP-A-2007-27587.
In the formula, each of R ¹¹ and R ¹² independently represents a hydrogen atom, an alkyl group, an optionally substituted aryl group, a substituted silyl group, an optionally substituted nitrogen-containing heterocyclic group, or a cyano group. And at least one, R ^{13 to} R ¹⁶ are each independently an optionally substituted alkyl group or an optionally substituted aryl group, and X is an optionally substituted arylene group And Y is an optionally substituted aryl group having 16 or less carbon atoms, a substituted boryl group, or an optionally substituted carbazole group, and n is each independently an integer of 0 to 3 is there.

Among the compounds represented by the general formula (E-4), the compounds represented by the following general formula (E-4-1), and further the following general formulas (E-4-1-1) to (E-4) The compound represented by -1-4) is preferable. Specific examples include 9- [4- (4-Dimesitylborylnaphthalen-1-yl) phenyl] carbazole, 9- [4- (4-Dimesitylborylnaphthalen-1-yl) naphthalen-1-yl. Carbazole and the like.
In the formula, each of R ¹¹ and R ¹² independently represents a hydrogen atom, an alkyl group, an optionally substituted aryl group, a substituted silyl group, an optionally substituted nitrogen-containing heterocyclic group, or a cyano group. At least one, R ^{13 to} R ¹⁶ are each independently an optionally substituted alkyl group or an optionally substituted aryl group, and R ²¹ and R ²² are each independently Each independently is at least one of a hydrogen atom, an alkyl group, an optionally substituted aryl group, a substituted silyl group, an optionally substituted nitrogen-containing heterocyclic group, or a cyano group, and X ¹ is , An optionally substituted arylene group having 20 or less carbon atoms, n is each independently an integer of 0 to 3, and m is each independently an integer of 0 to 4.

In each formula, R ^{31 to} R ³⁴ are each independently methyl, isopropyl or phenyl, and R ³⁵ and R ³⁶ are each independently hydrogen, methyl, isopropyl or phenyl. It is.

Among the compounds represented by the general formula (E-4), a compound represented by the following general formula (E-4-2), and a compound represented by the following general formula (E-4-2-1) Is preferred.
In the formula, each of R ¹¹ and R ¹² independently represents a hydrogen atom, an alkyl group, an optionally substituted aryl group, a substituted silyl group, an optionally substituted nitrogen-containing heterocyclic group, or a cyano group. And at least one, R ^{13 to} R ¹⁶ are each independently an optionally substituted alkyl group or an optionally substituted aryl group, and X ¹ is an optionally substituted carbon. An arylene group having a number of 20 or less, and each n is independently an integer of 0 to 3.

Wherein R ^{31 to} R ³⁴ are each independently methyl, isopropyl or phenyl, and R ³⁵ and R ³⁶ are each independently hydrogen, methyl, isopropyl or phenyl. It is.

Among the compounds represented by the general formula (E-4), a compound represented by the following general formula (E-4-3-3), and further, the following general formula (E-4-3-1) or (E-4) The compound represented by -3-2) is preferable.
In the formula, each of R ¹¹ and R ¹² independently represents a hydrogen atom, an alkyl group, an optionally substituted aryl group, a substituted silyl group, an optionally substituted nitrogen-containing heterocyclic group, or a cyano group. And at least one, R ^{13 to} R ¹⁶ are each independently an optionally substituted alkyl group or an optionally substituted aryl group, and X ¹ is an optionally substituted carbon. It is an arylene group of several tens or less, Y ¹ is an optionally substituted aryl group having 14 or less carbon atoms, and n is each independently an integer of 0 to 3.

In each formula, R ^{31 to} R ³⁴ are each independently methyl, isopropyl or phenyl, and R ³⁵ and R ³⁶ are each independently hydrogen, methyl, isopropyl or phenyl. It is.

The benzimidazole derivative is a compound represented by the following general formula (E-5).
In the formula, Ar ^{1 to} Ar ³ are each independently hydrogen or aryl having 6 to 30 carbon atoms which may be substituted. In particular, a benzimidazole derivative which is anthryl optionally substituted with Ar ¹ is preferable.

  Specific examples of the aryl having 6 to 30 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, acenaphthylene-1-yl, acenaphthylene-3-yl, acenaphthylene-4-yl, acenaphthylene-5-yl, and fluorene-1- Yl, fluoren-2-yl, fluoren-3-yl, fluoren-4-yl, fluoren-9-yl, phenalen-1-yl, phenalen-2-yl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, 1-anthryl, 2-anthryl, 9-anthryl, fluoranthen-1-yl, fluoranthen-2-yl, fluoranthen-3-yl, fluoranthen-7-yl, fluoranthen-8-yl, Triphenylene-1-yl, triphenylene-2-yl, pyreth -1-yl, pyren-2-yl, pyren-4-yl, chrysen-1-yl, chrysen-2-yl, chrysen-3-yl, chrysen-4-yl, chrysen-5-yl, chrysene-6 -Yl, naphthacene-1-yl, naphthacene-2-yl, naphthacene-5-yl, perylene-1-yl, perylene-2-yl, perylene-3-yl, pentacene-1-yl, pentasen-2-yl , Pentacene-5-yl and pentacene-6-yl.

  Specific examples of the benzimidazole derivative include 1-phenyl-2- (4- (10-phenylanthracen-9-yl) phenyl) -1H-benzo [d] imidazole, 2- (4- (10- (naphthalene-2) -Yl) anthracen-9-yl) phenyl) -1-phenyl-1H-benzo [d] imidazole, 2- (3- (10- (naphthalen-2-yl) anthracen-9-yl) phenyl) -1- Phenyl-1H-benzo [d] imidazole, 5- (10- (naphthalen-2-yl) anthracen-9-yl) -1,2-diphenyl-1H-benzo [d] imidazole, 1- (4- (10 -(Naphthalen-2-yl) anthracen-9-yl) phenyl) -2-phenyl-1H-benzo [d] imidazole, 2- (4- (9,10-di (naphthalene) 2-yl) anthracen-2-yl) phenyl) -1-phenyl-1H-benzo [d] imidazole, 1- (4- (9,10-di (naphthalen-2-yl) anthracen-2-yl) phenyl ) -2-phenyl-1H-benzo [d] imidazole, 5- (9,10-di (naphthalen-2-yl) anthracen-2-yl) -1,2-diphenyl-1H-benzo [d] imidazole is there.

The electron transport layer or the electron injection layer may further contain a substance capable of reducing the material forming the electron transport layer or the electron injection layer. As this reducing substance, various substances can be used as long as they have a certain reducing ability. For example, alkali metal, alkaline earth metal, rare earth metal, alkali metal oxide, alkali metal halide, alkali From the group consisting of earth metal oxides, alkaline earth metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes and rare earth metal organic complexes At least one selected can be suitably used.
Preferred reducing substances include alkali metals such as Na (work function 2.36 eV), K (2.28 eV), Rb (2.16 eV) or Cs (1.95 eV), and Ca (2. 9eV), Sr (2.0 to 2.5 eV) or Ba (2.52 eV), and alkaline earth metals such as those having a work function of 2.9 eV or less are particularly preferable. Among these, a more preferable reducing substance is an alkali metal of K, Rb or Cs, more preferably Rb or Cs, and most preferably Cs. These alkali metals have particularly high reducing ability, and by adding a relatively small amount to the material forming the electron transport layer or the electron injection layer, the luminance of the organic EL element can be improved and the lifetime can be extended. Further, as a reducing substance having a work function of 2.9 eV or less, a combination of two or more alkali metals is also preferable. Particularly, a combination containing Cs, such as Cs and Na, Cs and K, Cs and Rb, or A combination of Cs, Na and K is preferred. By containing Cs, the reducing ability can be efficiently exhibited, and by adding to the material for forming the electron transport layer or the electron injection layer, the luminance of the organic EL element can be improved and the lifetime can be extended.

<Cathode in organic electroluminescence device>
The cathode 108 serves to inject electrons into the light emitting layer 105 through the electron injection layer 107 and the electron transport layer 106.

  The material for forming the cathode 108 is not particularly limited as long as it can efficiently inject electrons into the organic layer, but the same material as that for forming the anode 102 can be used. Among them, metals such as tin, magnesium, indium, calcium, aluminum, silver, copper, nickel, chromium, gold, platinum, iron, zinc, lithium, sodium, potassium, cesium and magnesium or alloys thereof (magnesium-silver alloy) , Magnesium-indium alloys, aluminum-lithium alloys such as lithium fluoride / aluminum) are preferred. Lithium, sodium, potassium, cesium, calcium, magnesium, or alloys containing these low work function metals are effective for increasing the electron injection efficiency and improving device characteristics. However, these low work function metals are often often unstable in the atmosphere. In order to improve this point, for example, a method is known in which an organic layer is doped with a small amount of lithium, cesium or magnesium and a highly stable electrode is used. As other dopants, inorganic salts such as lithium fluoride, cesium fluoride, lithium oxide, and cesium oxide can also be used. However, it is not limited to these.

  Furthermore, for electrode protection, metals such as platinum, gold, silver, copper, iron, tin, aluminum and indium, or alloys using these metals, and inorganic materials such as silica, titania and silicon nitride, polyvinyl alcohol, vinyl chloride Lamination of hydrocarbon polymer compounds and the like is a preferred example. The method for producing these electrodes is not particularly limited as long as conduction can be achieved, such as resistance heating, electron beam, sputtering, ion plating, and coating.

<Binder that may be used in each layer>
The materials used for the hole injection layer, hole transport layer, light emitting layer, electron transport layer and electron injection layer can form each layer alone, but as a polymer binder, polyvinyl chloride, polycarbonate, Polystyrene, poly (N-vinylcarbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polysulfone, polyamide, ethyl cellulose, vinyl acetate resin, ABS resin , Dispersed in solvent-soluble resins such as polyurethane resin, curable resins such as phenol resin, xylene resin, petroleum resin, urea resin, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, silicone resin, etc. To be possible.

<Method for producing organic electroluminescent element>
Each layer constituting the organic electroluminescent element is formed by a method such as vapor deposition, resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination method, printing method, spin coating method or cast method, coating method, etc. It can be formed by using a thin film. The thickness of each layer formed in this way is not particularly limited and can be appropriately set according to the properties of the material, but is usually in the range of 2 nm to 5000 nm. The film thickness can usually be measured with a crystal oscillation type film thickness measuring device or the like. When a thin film is formed using a vapor deposition method, the vapor deposition conditions vary depending on the type of material, the target crystal structure and association structure of the film. Deposition conditions generally include boat heating temperature of 50 to 400 ° C., vacuum degree of 10 ⁻⁶ to 10 ⁻³ Pa, deposition rate of 0.01 to 50 nm / second, substrate temperature of −150 to + 300 ° C., and film thickness of 2 nm to 5 μm. It is preferable to set appropriately within the range.

  Next, as an example of a method for producing an organic electroluminescent device, an organic electric field composed of an anode / hole injection layer / hole transport layer / a light emitting layer composed of a host material and a dopant material / electron transport layer / electron injection layer / cathode. A method for manufacturing a light-emitting element will be described. A thin film of an anode material is formed on a suitable substrate by vapor deposition or the like to produce an anode, and then a thin film of a hole injection layer and a hole transport layer is formed on the anode. A host material and a dopant material are co-evaporated to form a thin film to form a light emitting layer. An electron transport layer and an electron injection layer are formed on the light emitting layer, and a thin film made of a cathode material is formed by vapor deposition. By forming it as a cathode, a desired organic electroluminescent element can be obtained. In the preparation of the above-described organic electroluminescence device, the order of preparation may be reversed, and the cathode, electron injection layer, electron transport layer, light emitting layer, hole transport layer, hole injection layer, and anode may be fabricated in this order. Is possible.

  When a DC voltage is applied to the organic electroluminescent device thus obtained, the anode may be applied with a positive polarity and the cathode with a negative polarity. When a voltage of about 2 to 40 V is applied, the organic electroluminescent device is transparent or translucent. Luminescence can be observed from the electrode side (anode or cathode, and both). The organic electroluminescence device emits light when a pulse current or an alternating current is applied. The alternating current waveform to be applied may be arbitrary.

<Application examples of organic electroluminescent devices>
The present invention can also be applied to a display device provided with an organic electroluminescent element or a lighting device provided with an organic electroluminescent element.
A display device or an illuminating device including an organic electroluminescent element can be manufactured by a known method such as connecting the organic electroluminescent element according to the present embodiment and a known driving device, such as direct current driving, pulse driving, or alternating current. It can be driven by appropriately using a known driving method such as driving.

  Examples of the display device include a panel display such as a color flat panel display, and a flexible display such as a flexible color organic electroluminescence (EL) display (for example, JP-A-10-335066 and JP-A-2003-321546). Gazette, JP-A-2004-281086, etc.). Examples of the display method of the display include a matrix and / or segment method. Note that the matrix display and the segment display may coexist in the same panel.

  A matrix means a pixel in which pixels for display are two-dimensionally arranged such as a lattice or a mosaic, and displays a character or an image with a set of pixels. The shape and size of the pixel are determined by the application. For example, a square pixel with a side of 300 μm or less is usually used for displaying images and characters on a personal computer, monitor, TV, and a pixel with a side of mm order for a large display such as a display panel. become. In monochrome display, pixels of the same color may be arranged. However, in color display, red, green, and blue pixels are displayed side by side. In this case, there are typically a delta type and a stripe type. The matrix driving method may be either a line sequential driving method or an active matrix. The line-sequential driving has an advantage that the structure is simple. However, the active matrix may be superior in consideration of the operation characteristics, so that it is necessary to properly use it depending on the application.

  In the segment system (type), a pattern is formed so as to display predetermined information, and a predetermined region is caused to emit light. For example, the time and temperature display in a digital clock or a thermometer, the operation state display of an audio device or an electromagnetic cooker, the panel display of an automobile, etc.

  Examples of the illuminating device include an illuminating device such as indoor lighting, a backlight of a liquid crystal display device, and the like (for example, JP 2003-257621 A, JP 2003-277741 A, JP 2004-119211 A). Etc.) The backlight is used mainly for the purpose of improving the visibility of a display device that does not emit light, and is used for a liquid crystal display device, a clock, an audio device, an automobile panel, a display panel, a sign, and the like. In particular, as a backlight for liquid crystal display devices, especially personal computers for which thinning is an issue, considering that conventional methods are made of fluorescent lamps and light guide plates, it is difficult to reduce the thickness. The backlight using the light emitting element according to the embodiment is thin and lightweight.

  Hereinafter, the present invention will be described in more detail based on examples. First, synthesis examples of anthracene derivatives used in the examples are described below.

<Synthesis Example of Anthracene Derivative Represented by Formula (1-7)>
9,10-bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) anthracene (3.0 g), 5-bromo-2,2′-bipyridine (1.65 g) ), Pd (PPh ₃ ) ₄ (0.24 g), potassium phosphate (2.97 g), dioxane (75 ml), and water (15 ml) were heated and stirred at 80 ° C. for 7.5 hours. After cooling to room temperature, 6-bromo-2,3′-bipyridine (3.3 g) was added, and the mixture was further heated and stirred at reflux temperature for 1 hour. After the reaction solution was cooled to room temperature, the reaction solution was concentrated with an evaporator, and the salt was removed by washing with water. An organic substance was extracted from the obtained solid with toluene, and the obtained organic substance was purified by activated alumina column chromatography (developing solution: toluene / ethyl acetate mixed solvent). At this time, referring to the method described in “Chemical Doujin Shuppan Co., Ltd., page 94”, the ratio of ethyl acetate in the developing solution was gradually increased. The target product was eluted by increasing the amount to 1. Furthermore, 5- (10- (2,3′-bipyridin-6-yl) anthracen-9-yl) -2,2 which is an anthracene derivative represented by the formula (1-7) is obtained by recrystallization from toluene. '-Bipyridine (0.27 g) was obtained.

The glass transition temperature (Tg) determined by DSC measurement was 117 ° C.
Moreover, the structure of the anthracene derivative obtained by NMR measurement was confirmed.
¹ H-NMR (CDCl ₃ ): 9.3 (m, 1H), 8.8 (m, 2H), 8.7 (m, 2H), 8.6 (m, 1H), 8.4 (m , 1H), 8.1 (t, 1H), 7.9-8.0 (m, 3H), 7.7 (m, 4H), 7.6 (m, 1H), 7.4 (m, 6H).

<Synthesis Example of Anthracene Derivative Represented by Formula (1-14)>
9,10-bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) anthracene (4.0 g), 5-bromo-2,2′-bipyridine (3.6 g) ), 5-bromo-3,4'-bipyridine (4.8 g), Pd ₂ (dba) ₃ (0.22 g), tricyclohexylphosphine (0.16 g), potassium phosphate (11.9 g) and 1, A flask containing 2,4-trimethylbenzene (25 ml) was heated and stirred at 175 ° C. for 20 hours. The reaction solution was cooled to room temperature, and the solution from which the precipitate was removed by suction filtration was purified by activated alumina column chromatography (developing solution: toluene / ethyl acetate mixed solvent). At this time, referring to the method described in “Chemical Doujin Shuppan Co., Ltd., page 94”, the ratio of ethyl acetate in the developing solution was gradually increased. The target product was eluted by increasing the amount to 1. Furthermore, 5- (10- (2,2′-bipyridin-5-yl) anthracen-9-yl) -3, which is an anthracene derivative represented by the formula (1-14), is recrystallized from THF / ethanol. , 4′-bipyridine (0.86 g) was obtained.

The glass transition temperature (Tg) determined by DSC measurement was 122 ° C.
Moreover, the structure of the anthracene derivative obtained by NMR measurement was confirmed.
¹ H-NMR (CDCl ₃ ): 9.15 (m, 1H), 8.75-8.85 (m, 5H), 8.7 (m, 1H), 8.6 (m, 1H), 8 .1 (m, 1H), 8.0 (m, 1H), 7.95 (t, 1H), 7.8 (m, 2H), 7.7 (m, 2H), 7.65 (m, 2H), 7.4-7.5 (m, 5H).

<Synthesis Example of Anthracene Derivative Represented by Formula (1-1)>
9,10-bis (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) anthracene (4.0 g), 5-bromo-2,2′-bipyridine (5.47 g) ), 5-bromo-2,3′-bipyridine (4.37 g), Pd ₂ (dba) ₃ (0.17 g), tricyclohexylphosphine (0.10 g), potassium phosphate (11.9 g) and 1, A flask containing 2,4-trimethylbenzene (20 ml) was heated and stirred at 175 ° C. for 22 hours. The reaction solution was cooled to room temperature, and the solution from which the precipitate was removed by suction filtration was purified by activated alumina column chromatography (developing solution: toluene / ethyl acetate mixed solvent). At this time, referring to the method described in “Chemical Doujin Shuppan Co., Ltd., page 94”, the ratio of ethyl acetate in the developing solution was gradually increased. The target product was eluted by increasing the amount to 1. Further, by recrystallization from THF, 5- (10- (2,3′-bipyridin-5-yl) anthracen-9-yl) -2,2 which is an anthracene derivative represented by the formula (1-1) '-Bipyridine (0.98 g) was obtained.

The structure of the anthracene derivative obtained by NMR measurement was confirmed.
¹ H-NMR (CDCl ₃ ): 9.4 (s, 1H), 8.7-8.9 (m, 5H), 8.55 (m, 2H), 8.05 (m, 1H), 8 0.0 (m, 2H), 7.9 (m, 1H), 7.75 (m, 4H), 7.5 (m, 1H), 7.4 (m, 5H).

  By appropriately changing the raw material compound, other anthracene derivatives of the present invention can be synthesized by a method according to the synthesis example described above.

  Hereinafter, each example will be shown to describe the present invention in more detail, but the present invention is not limited thereto.

  The electroluminescent elements according to Example 1 and Comparative Examples 1 and 2 were manufactured, and the drive start voltage (V) in the constant current drive test and the time (h) until the 10% brightness attenuated from the initial brightness were measured. went. Hereinafter, examples and comparative examples will be described in detail.

Table 1 below shows the material configuration of each layer in the electroluminescent elements according to the manufactured Example 1 and Comparative Examples 1 and 2.

  In Table 1, “CuPc” is copper phthalocyanine, “NPD” is N, N′-diphenyl-N, N′-dinaphthyl-4,4′-diaminobiphenyl, and compound (A) is 9-phenyl-10- [6 -(1,1 '; 3,1 ") terphenyl-5'-yl] naphthalen-2-ylanthracene, compound (B) is N, N, N', N'-tetra (4-biphenylyl) -4 , 4′-diaminostilbene, compound (C) is 5,5 ′-(2-phenylanthracene-9,10-diyl) di-2,2′-bipyridine, compound (D) is 6,6 ′-(2 -Phenylanthracene-9,10-diyl) di-2,3'-bipyridine, each having the following chemical structure.

<Example 1>
A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) obtained by polishing ITO deposited to a thickness of 180 nm by sputtering to 150 nm was used as a transparent support substrate. This transparent support substrate is fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Vacuum Kiko Co., Ltd.), and a molybdenum vapor deposition boat containing CuPc, a molybdenum vapor deposition boat containing NPD, and a compound (A) are placed therein. Molybdenum vapor deposition boat, molybdenum vapor deposition boat containing compound (B), molybdenum vapor deposition boat containing anthracene derivative represented by formula (1-7), molybdenum vapor deposition containing lithium fluoride And a tungsten vapor deposition boat containing aluminum.

The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was depressurized to 5 × 10 ⁻⁴ Pa, first, the vapor deposition boat containing CuPc was heated to form a hole injection layer by vapor deposition to a film thickness of 50 nm, and then NPD entered. The vapor deposition boat was heated and vapor-deposited so that it might become a film thickness of 30 nm, and the positive hole transport layer was formed. Next, the vapor deposition boat containing the compound (A) and the vapor deposition boat containing the compound (B) were heated at the same time to form a light emitting layer by vapor deposition to a film thickness of 35 nm. The deposition rate was adjusted so that the weight ratio of compound (A) to compound (B) was approximately 95 to 5. Next, the evaporation boat containing the anthracene derivative represented by the formula (1-7) was heated and evaporated to a thickness of 15 nm to form an electron transport layer. The deposition rate of each layer was 0.01 to 1 nm / second.

  Thereafter, the vapor deposition boat containing lithium fluoride is heated to deposit at a deposition rate of 0.003 to 0.1 nm / second so that the film thickness becomes 0.5 nm, and then the vapor deposition boat containing aluminum is heated. The cathode was formed by vapor deposition at a deposition rate of 0.01 to 10 nm / second so that the film thickness was 100 nm, and an organic electroluminescent element was obtained.

When a direct current voltage was applied using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, blue light emission with a wavelength of about 455 nm was obtained. In addition, a constant current driving test was performed at a current density for obtaining an initial luminance of 1000 cd / m ² . As a result, the drive test start voltage was 4.89 V, and the time until the 10% luminance attenuated from the initial luminance was 48 hours.

<Comparative Example 1>
An organic EL device was obtained in the same manner as in Example 1 except that the anthracene derivative represented by the formula (1-7) was changed to the compound (C). A constant current driving test was performed with an ITO electrode as an anode and a lithium fluoride / aluminum electrode as a cathode at a current density for obtaining an initial luminance of 1000 cd / m ² . As a result, the driving test start voltage was 5.09 V, and the time from the initial luminance to the 10% luminance decay was 18 hours.

<Comparative example 2>
An organic EL device was obtained in the same manner as in Example 1 except that the anthracene derivative represented by the formula (1-7) was changed to the compound (D). A constant current driving test was performed with an ITO electrode as an anode and a lithium fluoride / aluminum electrode as a cathode at a current density for obtaining an initial luminance of 1000 cd / m ² . As a result, the driving test start voltage was 5.64 V, and the time from the initial luminance to the 10% luminance decay was 30 hours.

  Next, the electroluminescent elements according to Examples 2 and 3 and Comparative Example 3 were manufactured, and the driving start voltage (V) in the constant current driving test and the time (h) until the 10% luminance attenuated from the initial luminance, respectively Measurements were made. Hereinafter, examples and comparative examples will be described in detail.

Table 2 below shows the material configuration of each layer in the electroluminescent devices according to Examples 2 and 3 and Comparative Example 3 that were manufactured.

In Table 2, compound (E) is 5,9-bis (diphenylamino) -7,7-diphenyl-7H-benzo [c] fluorene and has the following chemical structure.

<Example 2>
A 26 mm × 28 mm × 0.7 mm glass substrate (manufactured by Optoscience Co., Ltd.) obtained by polishing ITO deposited to a thickness of 180 nm by sputtering to 150 nm was used as a transparent support substrate. This transparent support substrate is fixed to a substrate holder of a commercially available vapor deposition apparatus (manufactured by Vacuum Kiko Co., Ltd.), and a molybdenum vapor deposition boat containing CuPc, a molybdenum vapor deposition boat containing NPD, and a compound (A) are placed therein. Molybdenum vapor deposition boat, molybdenum vapor deposition boat containing compound (E), molybdenum vapor deposition boat containing anthracene derivative represented by formula (1-14), molybdenum vapor deposition containing lithium fluoride And a tungsten vapor deposition boat containing aluminum.

The following layers were sequentially formed on the ITO film of the transparent support substrate. The vacuum chamber was depressurized to 5 × 10 ⁻⁴ Pa, first, the vapor deposition boat containing CuPc was heated to form a hole injection layer by vapor deposition to a film thickness of 50 nm, and then NPD entered. The vapor deposition boat was heated and vapor-deposited so that it might become a film thickness of 30 nm, and the positive hole transport layer was formed. Next, the vapor deposition boat containing the compound (A) and the vapor deposition boat containing the compound (E) were heated at the same time to form a light emitting layer by vapor deposition to a film thickness of 35 nm. The deposition rate was adjusted so that the weight ratio of compound (A) to compound (E) was approximately 95 to 5. Next, the evaporation boat containing the anthracene derivative represented by the formula (1-14) was heated and evaporated to a film thickness of 15 nm to form an electron transport layer. The deposition rate of each layer was 0.01 to 1 nm / second.

  Thereafter, the vapor deposition boat containing lithium fluoride is heated to deposit at a deposition rate of 0.003 to 0.1 nm / second so that the film thickness becomes 0.5 nm, and then the vapor deposition boat containing aluminum is heated. The cathode was formed by vapor deposition at a deposition rate of 0.01 to 10 nm / second so that the film thickness was 100 nm, and an organic electroluminescent element was obtained.

When a direct current voltage was applied using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, blue light emission with a wavelength of about 460 nm was obtained. In addition, a constant current driving test was performed at a current density for obtaining an initial luminance of 2000 cd / m ² . As a result, the drive test start voltage was 5.51 V, and the time until the 10% luminance attenuated from the initial luminance was 132 hours.

<Example 3>
An organic EL device was obtained in the same manner as in Example 2 except that the anthracene derivative represented by the formula (1-14) was changed to the anthracene derivative represented by the formula (1-1). A constant current driving test was carried out using an ITO electrode as an anode and a lithium fluoride / aluminum electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . As a result, the driving test start voltage was 4.86 V, and the time until the 10% luminance attenuated from the initial luminance was 65 hours.

<Comparative Example 3>
An organic EL device was obtained in the same manner as in Example 2 except that the anthracene derivative represented by the formula (1-14) was changed to the compound (C). A constant current driving test was carried out using an ITO electrode as an anode and a lithium fluoride / aluminum electrode as a cathode at a current density for obtaining an initial luminance of 2000 cd / m ² . As a result, the drive test start voltage was 4.54 V, and the time from the initial luminance to the 10% luminance decay was 51 hours.

  According to a preferred aspect of the present invention, it is possible to provide an organic electroluminescent element that improves the lifetime of the light emitting element and has an excellent balance with the driving voltage, a display device including the organic electroluminescent element, and a lighting device including the organic electroluminescent element. it can.

DESCRIPTION OF SYMBOLS 100 Organic electroluminescent element 101 Substrate 102 Anode 103 Hole injection layer 104 Hole transport layer 105 Light emitting layer 106 Electron transport layer 107 Electron injection layer 108 Cathode

Claims (14)

An anthracene derivative represented by the following formula (1).
In the above formula (1), R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen, alkyl having 1 to 6 carbons, or optionally substituted phenyl, and Py ¹ and Py ² are each independently an intermediate group represented by any one of the following formula (L-1), formula (L-2) or formula (L-3), and the following formula (T-1) or formula (T -2) or a terminal group represented by formula (T-3) and Py ¹ and Py ² are not the same structure.
In the above formula (1), R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen, alkyl having 1 to 6 carbons, or optionally substituted phenyl, and Py ¹ and Py ² are each independently represented by an intermediate group represented by the above formula (L-1) and any one of the above formula (T-1), formula (T-2) or formula (T-3). A group in which a terminal group is bonded, or a group in which an intermediate group represented by the above formula (L-2) or (L-3) and a terminal group represented by the above formula (T-1) are bonded. The anthracene derivative according to claim ¹ , wherein Py ¹ and Py ² are not the same structure. In the above formula (1), R ¹ , R ² , R ³ and R ⁴ are hydrogen, alkyl having 1 to 6 carbons, or phenyl, and Py ¹ and Py ² are each independently represented by the following formula (LT -1) ~ (LT-18) a group represented by any one of, and, Py ¹ and Py ² are not the same structure, an anthracene derivative according to claim 1.
In the above formula (1), R ¹ , R ² , R ³ and R ⁴ are hydrogen, and Py ¹ and Py ² are each independently any of the above formulas (LT-1) to (LT-18). Py ¹ and Py ² are not the same structure, and one of Py ¹ or Py ² is represented by any of the above formulas (LT-13) to (LT-18) When it is a group, the other is an anthracene derivative according to claim 1, wherein the other is a group represented by any one of the above formulas (LT-1) to (LT-12). In the above formula (1), R ¹ is alkyl having 1 to 6 carbons or phenyl, R ² , R ³ and R ⁴ are hydrogen, and Py ¹ and Py ² are each independently (LT-13) ~ (LT -18) a group represented by any one of, and, Py ¹ and Py ² are not the same structure, an anthracene derivative according to claim 1. The anthracene derivative according to claim 1, which is represented by the following formula (1-7).
The anthracene derivative according to claim 1, which is represented by the following formula (1-14).
The anthracene derivative according to claim 1, which is represented by the following formula (1-1).
  The electron transport material containing the anthracene derivative in any one of Claims 1-8.   The electron transport containing the electron transport material of Claim 9 arrange | positioned between a pair of electrode which consists of an anode and a cathode, the light emitting layer arrange | positioned between this pair of electrodes, and the said cathode and this light emitting layer An organic electroluminescent device having a layer and / or an electron injection layer.   At least one of the electron transport layer and the electron injection layer further contains at least one selected from the group consisting of quinolinol-based metal complexes, pyridine derivatives, bipyridine derivatives, phenanthroline derivatives, borane derivatives, and benzimidazole derivatives. The organic electroluminescent element according to claim 10.   At least one of the electron transport layer and the electron injection layer may further include an alkali metal, alkaline earth metal, rare earth metal, alkali metal oxide, alkali metal halide, alkaline earth metal oxide, alkaline earth Containing at least one selected from the group consisting of metal halides, rare earth metal oxides, rare earth metal halides, alkali metal organic complexes, alkaline earth metal organic complexes and rare earth metal organic complexes, The organic electroluminescent element according to claim 10 or 11.   The display apparatus provided with the organic electroluminescent element in any one of Claims 10-12.   The illuminating device provided with the organic electroluminescent element in any one of Claims 10-12.