JP2009184993A - Benzofluorene compound, light emitting layer material and organic electroluminescent device using the compound - Google Patents

Abstract

For example, a benzofluorene compound that exhibits excellent performance when applied to an organic electroluminescent device is provided.
[Solution]
A benzofluorene compound having a spiro structure and having a specific substituent such as hydrogen, phenyl, naphthyl, biphenylyl, phenanthryl, anthryl, pyrenyl, chrysenyl, or triphenylenyl.
[Selection figure] None

Description

  The present invention relates to a benzofluorene compound, a light emitting layer material using the compound, and an organic electroluminescent device.

  The organic electroluminescent element is a self-luminous light emitting element and is expected as a light emitting element for display or illumination. 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 the organics with charge transport capability (possibility of becoming 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.

  An organic electroluminescent element has a structure which consists of a pair of electrode which consists of an anode and a cathode, and the one layer or several layer which is arrange | positioned between the said pair of electrodes and contains an organic compound. The layer containing an organic compound includes a light-emitting layer and a charge transport / injection layer that transports or injects charges such as holes and electrons. Various organic materials have been developed as the organic compound. For example, a compound having a benzofluorene structure in the molecule and an organic electroluminescence device using the compound in an organic compound layer have been reported (International Publication No. 2004/061047 pamphlet; Patent Document 1, International Publication No. 2004/061048). Pamphlet; Patent Literature 2, International Publication No. 2003/051092 Pamphlet; Patent Literature 3, International Publication No. 2007/119800 Pamphlet; Patent Literature 4). In particular, Patent Document 3 reports a compound in which an amino group is substituted on a dibenzofluorene skeleton and an organic electroluminescence device using the compound. Patent Document 4 reports a compound in which an amino group is substituted on a benzofluorene skeleton having a spiro structure and an organic electroluminescence device using the compound.

International Publication No. 2004/061047 Pamphlet International Publication No. 2004/061048 (Special Publication 2006-512395) International Publication No. 2003/051092 (Special Publication 2005-513713 Publication) International Publication No. 2007/119800 Pamphlet

  As described above, several materials for organic EL devices using a compound having a benzofluorene structure in the molecule are known. However, even if the organic materials described above are used, sufficient performance with respect to heat resistance, device lifetime, etc. The organic electroluminescent element which has is not yet obtained. Under such circumstances, it has been desired to develop an organic electroluminescent device having higher performance in terms of heat resistance, device life, and the like, that is, a compound capable of obtaining the device. In particular, blue light-emitting elements have not been obtained with a light-emitting layer material having superior characteristics compared to red and green light-emitting elements, and the development of light-emitting layer materials suitable for improving the characteristics of blue light-emitting elements has been developed. It is desired.

  As a result of intensive studies to solve the above problems, the present inventors have found that benzofluorene compounds represented by the following general formulas (1a), (1b) and (1c) (hereinafter referred to as “general formulas (1a) to (1c)”. The benzofluorene compound represented by) was successfully produced. In addition, it has been found that an organic electroluminescent device improved in heat resistance, device lifetime, and the like can be obtained by configuring an organic electroluminescent device by arranging a layer containing this benzofluorene compound between a pair of electrodes. The present invention has been completed. That is, the present invention provides the following benzofluorene compounds.

[1] A benzofluorene compound represented by the following general formula (1a), (1b) or (1c).
(In each formula, each Ar is independently hydrogen, optionally substituted phenyl, optionally substituted naphthyl, optionally substituted biphenylyl, optionally substituted phenanthryl, or substituted. Anthryl which may be substituted, pyrenyl which may be substituted, chrysenyl which may be substituted, or triphenylenyl which may be substituted, Ar is not hydrogen, and the substituents of Ar are each independently And phenyl, naphthyl, biphenylyl, phenanthryl, anthryl, pyrenyl, chrycenyl or triphenylenyl.)

[2] A benzofluorene compound represented by the general formula (1a), (1b) or (1c),
In each formula, Ar is independently hydrogen, optionally substituted phenyl, optionally substituted naphthyl, optionally substituted biphenylyl, optionally substituted phenanthryl, substituted An Ar is anthryl, Ar is not hydrogen together, and the substituents of Ar are each independently phenyl, naphthyl, biphenylyl, phenanthryl or anthryl.
The benzofluorene compound described in [1] above.

[3] A benzofluorene compound represented by the general formula (1a) or (1c),
In each formula, Ar is each independently an optionally substituted phenyl or an optionally substituted naphthyl, and each Ar substituent is independently a phenyl or naphthyl.
The benzofluorene compound described in [1] above.

[4] A benzofluorene compound represented by the general formula (1a) or (1c),
In each formula, Ar is both optionally substituted 2-naphthyl, and the substituent of Ar is phenyl or naphthyl.
The benzofluorene compound described in [1] above.

[5] A benzofluorene compound represented by the general formula (1a),
Ar is both 2-naphthyl,
The benzofluorene compound described in [1] above.

[6] A benzofluorene compound represented by the general formula (1c),
Ar is both 2-naphthyl,
The benzofluorene compound described in [1] above.

[7] A material for a light emitting layer of a light emitting device, the material for a light emitting layer containing the benzofluorene compound according to any one of [1] to [6].

[8] The light emitting layer according to the above [7], further comprising at least one selected from the group consisting of perylene derivatives, borane derivatives, aromatic amine derivatives, coumarin derivatives, pyran derivatives, iridium complexes and platinum complexes. Materials.

[9] The light emitting layer material according to the above [7], further comprising an aromatic amine derivative.

[10] Organic having a pair of electrodes composed of an anode and a cathode, and a light emitting layer disposed between the pair of electrodes and containing the light emitting layer material described in any one of [7] to [9] Electroluminescent device.

[11] Furthermore, it has an electron transport layer and / or an electron injection layer disposed between the cathode and the light emitting layer, and at least one of the electron transport layer and the electron injection layer is a quinolinol-based metal complex, The organic electroluminescence device according to [10] above, which contains at least one selected from the group consisting of a pyridine derivative and a phenanthroline derivative.

[12] Furthermore, an electron transport layer and / or an electron injection layer disposed between the cathode and the light emitting layer are provided, and at least one of the electron transport layer and the electron injection layer includes a quinolinol-based metal complex. The organic electroluminescent element as described in [10] above.

[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].
Claim

  According to a preferred embodiment of the present invention, for example, a benzofluorene compound having excellent characteristics as a light emitting layer material can be provided. Moreover, the organic electroluminescent element improved about heat resistance, element lifetime, etc. can be provided. The preferred benzofluorene compound of the present invention is particularly suitable as a blue light-emitting layer material. According to this light-emitting layer material, a blue color having the same level of heat resistance and device life as a red or green light-emitting device. The light emitting element can be manufactured. Furthermore, by using this organic electroluminescent element, a high-performance display device such as a full color display can be obtained.

The benzofluorene compound of the present invention will be described in detail.
The benzofluorene compound according to the present invention is a benzofluorene compound represented by the above general formulas (1a) to (1c).

1. Benzofluorene compounds represented by general formulas (1a) to (1c) First, the benzofluorene compounds represented by the above general formulas (1a) to (1c) will be described.

  In each formula, two Ar's are each independently hydrogen, optionally substituted phenyl, optionally substituted naphthyl, optionally substituted biphenylyl, optionally substituted phenanthryl, substituted Anthryl, which may be substituted, pyrenyl which may be substituted, chrysenyl which may be substituted, or triphenylenyl which may be substituted, may be appropriately selected. There is no.

Examples of the “optionally substituted phenyl” include unsubstituted phenyl. Furthermore, as substituted phenyl, at least one of the bonding positions (5 positions) other than the bonding position with the benzofluorene skeleton in phenyl is phenyl, (1- or 2-) naphthyl, (2-, 3- or 4-) biphenyl, (1-, 2-, 3-, 4- or 9-) phenanthryl, (1-, 2- or 9-) anthryl, (1-, 2- or 4-) pyrenyl, (1- , 2-, 3-, 4-, 5- or 6-) chrycenyl, or (1- or 2-) triphenylenyl substituted.
The substituents on phenyl may be the same or different when there are a plurality of substituents. However, the number of substituents on phenyl is preferably 3 or less, and more preferably 2 or less.

Examples of “optionally substituted naphthyl” include unsubstituted (1- or 2-) naphthyl. Furthermore, as substituted naphthyl, phenyl, (1- or 2-) naphthyl, at least one of the bonding positions (7 positions) other than the bonding position with the benzofluorene skeleton in (1- or 2-) naphthyl, (2-, 3- or 4-) biphenyl, (1-, 2-, 3-, 4- or 9-) phenanthryl, (1-, 2- or 9-) anthryl, (1-, 2- or 4 -) Pyrenyl, (1-, 2-, 3-, 4-, 5- or 6-) chrycenyl, or (1- or 2-) triphenylenyl substituted.
When there are a plurality of substituents for naphthyl, they may be the same or different. However, the number of substituents to naphthyl is preferably 3 or less, and more preferably 2 or less.

Examples of “optionally substituted biphenylyl” include unsubstituted (2-, 3- or 4-) biphenyl. Further, as substituted biphenylyl, at least one of the bonding positions (9 positions) other than the bonding position with the benzofluorene skeleton in (2-, 3- or 4-) biphenyl is phenyl, (1- or 2- ) Naphthyl, (2-, 3- or 4-) biphenyl, (1-, 2-, 3-, 4- or 9-) phenanthryl, (1-, 2- or 9-) anthryl, (1--2) -Or 4-) pyrenyl, (1-, 2-, 3-, 4-, 5- or 6-) chrycenyl, or (1- or 2-) triphenylenyl substituted.
When there are a plurality of substituents for biphenylyl, they may be the same or different. However, the number of substituents on biphenylyl is preferably 3 or less, and more preferably 2 or less.

Examples of the “optionally substituted phenanthryl” include unsubstituted (1-, 2-, 3-, 4- or 9-) phenanthryl. Furthermore, as substituted phenanthryl, at least one of the bonding positions (9 positions) other than the bonding position with the benzofluorene skeleton in (1-, 2-, 3-, 4- or 9-) phenanthryl is phenyl, (1- or 2-) naphthyl, (2-, 3- or 4-) biphenyl, (1-, 2-, 3-, 4- or 9-) phenanthryl, (1-, 2- or 9-) anthryl , (1-, 2- or 4-) pyrenyl, (1-, 2-, 3-, 4-, 5- or 6-) chrycenyl, or (1- or 2-) triphenylenyl substituted. .
When there are a plurality of substituents for phenanthryl, they may be the same or different. However, the number of substituents on phenanthryl is preferably 3 or less, and more preferably 2 or less.

Examples of the “optionally substituted anthryl” include unsubstituted (1-, 2- or 9-) anthryl. Furthermore, as the substituted anthryl, at least one of the bonding positions (9 positions) other than the bonding position with the benzofluorene skeleton in (1-, 2- or 9-) anthryl is phenyl, (1- or 2- ) Naphthyl, (2-, 3- or 4-) biphenyl, (1-, 2-, 3-, 4- or 9-) phenanthryl, (1-, 2- or 9-) anthryl, (1--2) -Or 4-) pyrenyl, (1-, 2-, 3-, 4-, 5- or 6-) chrycenyl, or (1- or 2-) triphenylenyl substituted.
When there are a plurality of anthryl substituents, they may be the same or different. However, the number of substituents on the anthryl is preferably 3 or less, and more preferably 2 or less.

Examples of the “optionally substituted pyrenyl” include unsubstituted (1-, 2- or 4-) pyrenyl. Furthermore, as substituted pyrenyl, at least one of the bonding positions (9 positions) other than the bonding position with the benzofluorene skeleton in (1-, 2- or 4-) pyrenyl is phenyl, (1- or 2- ) Naphthyl, (2-, 3- or 4-) biphenyl, (1-, 2-, 3-, 4- or 9-) phenanthryl, (1-, 2- or 9-) anthryl, (1--2) -Or 4-) pyrenyl, (1-, 2-, 3-, 4-, 5- or 6-) chrycenyl, or (1- or 2-) triphenylenyl substituted.
In the case of plural pyrenyl substituents, they may be the same or different. However, the number of substituents on pyrenyl is preferably 3 or less, and more preferably 2 or less.

Examples of the “optionally substituted chrysenyl” include unsubstituted (1-, 2-, 3-, 4-, 5- or 6-) chrysenyl. Furthermore, as substituted chrysenyl, at least one of the bonding positions (11 positions) other than the bonding position with the benzofluorene skeleton in (1-, 2-, 3-, 4-, 5- or 6-) chrycenyl , Phenyl, (1- or 2-) naphthyl, (2-, 3- or 4-) biphenyl, (1-, 2-, 3-, 4- or 9-) phenanthryl, (1-, 2- or 9 -) Anthryl, (1-, 2- or 4-) pyrenyl, (1-, 2-, 3-, 4-, 5- or 6-) chrysenyl, or (1- or 2-) triphenylenyl substituted Can be given.
When there are a plurality of substituents of chrysenyl, they may be the same or different. However, the number of substituents on chrysenyl is preferably 3 or less, and more preferably 2 or less.

Examples of the “optionally substituted triphenylenyl” include unsubstituted (1- or 2-) triphenylenyl. Further, as substituted triphenylenyl, at least one of the bonding positions (11 positions) other than the bonding position with the benzofluorene skeleton in (1- or 2-) triphenylenyl is phenyl, (1- or 2-) naphthyl, (2-, 3- or 4-) biphenyl, (1-, 2-, 3-, 4- or 9-) phenanthryl, (1-, 2- or 9-) anthryl, (1-, 2- or 4 -) Pyrenyl, (1-, 2-, 3-, 4-, 5- or 6-) chrycenyl, or (1- or 2-) triphenylenyl substituted.
When there are a plurality of triphenylenyl substituents, they may be the same or different. However, the number of substituents on triphenylenyl is preferably 3 or less, and more preferably 2 or less.

  Among the benzofluorene compounds represented by the general formulas (1a) to (1c), a benzofluorene compound represented by the general formula (1a) or (1c) is preferable.

  Specific examples of the compounds represented by the general formulas (1a) to (1c) include, for example, the following formulas (1a-1) to (1a-42), formulas (1b-1) to (1b-42), Examples thereof include compounds represented by formulas (1c-1) to (1c-42). Among the following compounds, particularly preferred compounds are represented by the following formulas (1a-1) to (1a-18), formulas (1b-1) to (1b-18), and formulas (1c-1) to (1c-18). It is a compound represented. Further preferred compounds are those represented by the following formulas (1a-1) to (1a-6), formulas (1a-12) to (1a-15), formulas (1c-1) to (1c-6), formula (1c -12) to (1c-15).

2. Production method of benzofluorene compound <Synthesis method of compound of general formula (1a): Scheme 1a>
<Scheme 1a> for synthesizing a benzofluorene compound (11H-benzo [a] fluorene-11-spiro-9′-fluorene derivative) represented by the general formula (1a) is illustrated below.
In the scheme, R is hydrogen or alkyl, X is hydrogen, halogen or alkoxy, M is Li, MgCl, MgBr or MgI, and Ar is the above-described substituent (hydrogen or aryls).

  First, a method for synthesizing the compound (intermediate) represented by the general formula (1a′-C) will be described. The compound of the general formula (1a′-C) can be obtained by reacting the compound of the general formula (1a′-A) or the compound of the general formula (1a′-B) with an acid. Examples of the acid that can be used for the reaction include inorganic acids such as sulfuric acid and polyphosphoric acid, and organic acids such as methanesulfonic acid and trifluoromethanesulfonic acid. Moreover, as a solvent which can be used for reaction, the acid used for reaction can be made into a solvent as it is, for example.

  Next, a method for synthesizing the compound (intermediate) represented by the general formula (1a′-E) will be described. The compound of general formula (1a′-E) can be obtained by reacting a ketone compound represented by general formula (1a′-C) with an organometallic compound represented by general formula (1a′-D). Examples of the solvent that can be used for the reaction include THF and ether solvents such as diethyl ether, dimethyl ether, and 1,2-dimethoxyethane.

The compound (intermediate) represented by the general formula (1a′-F) can be synthesized from the compound of the general formula (1a′-E) by a Friedel-Crafts reaction. Examples of the acid that can be used for the reaction include inorganic acids such as hydrochloric acid and sulfuric acid, and Lewis acids such as BF ₃ .OEt ₂ , BAr ₃ , AlCl ₃ , AlBr ₃ , EtAlCl ₂ , Et ₂ AlCl. Examples of the solvent that can be used for the reaction include acetic acid, CH ₂ Cl ₂ , nitrobenzene, CS _{2 and the} like.

  When X is alkoxy in the compound of the general formula (1a′-F) (intermediate), this compound is reacted with boron tribromide, trimethylsilyl iodide, etc. to convert the alkoxy to a hydroxyl group, and then further anhydrous. A general formula (1a′-F) compound in which X is triflate can be synthesized by sulfonylating the hydroxyl group with trifluoromethanesulfonic acid or trifluoromethanesulfonyl chloride.

Furthermore, when Ar is aryl in the compound represented by the general formula (1a), this compound can be synthesized by using a known reagent and referring to a known method. For example, in the compound of the general formula (1a′-F) (intermediate), from a compound in which X is halogen or triflate, a known document (Wiley-Vch, “Metal-Catalyzed Cross-Coupling Reactions—Second, Completely Revised and The method can be synthesized by referring to the method described in “Enlarged Edition” and the like, the method described in the examples of the present specification, and the like.
In the compound represented by the general formula (1a), when any one of two Ars is hydrogen, the compound represented by the general formula (1a′-A) or the general formula (1a′-B) which is a raw material compound A compound can be synthesized by leaving any desired X as hydrogen.

  The reaction is preferably performed in an inert gas, and examples of the inert gas that can be used for the reaction include nitrogen and argon. About reaction temperature, it can set suitably by the state of a reaction system, and it can be made to react at -150 degree-150 degree, Preferably it is -100 degree-100 degree. There is no restriction | limiting in particular about reaction time, What is necessary is just to stop reaction when reaction has fully progressed. The reaction can be traced by a general analytical means such as NMR or chromatography, and the end point of the reaction can be determined at an optimal time point.

<Synthesis Method of Compound of General Formula (1b): Scheme 1b>
<Scheme 1b> for synthesizing a benzofluorene compound (11H-benzo [b] fluorene-11-spiro-9′-fluorene derivative) represented by the general formula (1b) is illustrated below. The detailed synthesis method can refer to the synthesis method of the benzofluorene compound represented by the general formula (1a).

<Synthesis Method of Compound of General Formula (1c): Scheme 1c>
<Scheme 1c> for synthesizing a benzofluorene compound (11H-benzo [c] fluorene-11-spiro-9′-fluorene derivative) represented by the general formula (1c) is illustrated below. The detailed synthesis method can refer to the synthesis method of the benzofluorene compound represented by the general formula (1a).

3. Organic Electroluminescent Device The benzofluorene compound 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 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 layers are necessary, and the minimum structural unit is composed of the anode 102, the light emitting layer 105, and the cathode 108, and the hole injection layer 103, the hole transport layer 104, the electron transport layer 106, and the electron injection are included. The layer 107 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 / hole injection layer / hole transport layer / light emitting layer / cathode ”,“ substrate / anode / hole injection layer / light emitting layer / cathode ”,“ substrate / anode / hole transport ” Layer / light emitting layer / cathode ”,“ substrate / anode / light emitting layer / electron transport layer / cathode ”,“ substrate / anode / light emitting layer / electron injection layer / cathode ”,“ substrate / anode / light emitting layer / cathode ” An aspect may be sufficient.

<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, or a plastic sheet 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 particularly 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), etc.), halogenated compounds, and the like. Examples thereof include metals (such as copper iodide), copper sulfide, carbon black, ITO glass, and nesa glass. 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 particularly limited as long as a current sufficient for light emission of the light-emitting element can be supplied. 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 or more 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 manufacturing 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 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-1,1 ′ Diphenyl, 4,4 ', 4 "-tris (3-methylphenyl (phenyl) amino) triphenylamine and other triphenylamine derivatives, starburst amine derivatives, stilbene derivatives, phthalocyanine derivatives (metal free, copper phthalocyanine, etc.) , Pyrazoline derivatives, hydrazone compounds, benzofuran derivatives, thiophene derivatives, heterocyclic compounds such as oxadiazole derivatives, porphyrin derivatives, polysilanes, etc. In polymer systems, polycarbonates, styrene derivatives, polyvinyls having the above monomers in their side chains 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 further 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 strong light 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.

  In addition, the light emitting material of the light emitting element according to this embodiment may be either fluorescent or phosphorescent.

  As the host material, benzofluorene compounds represented by the above general formulas (1a) to (1c) can be used. Among these, compounds represented by the above formulas (1a-1) to (1a-42), formulas (1b-1) to (1b-42), and formulas (1c-1) to (1c-42) are preferable. . Among these specific compounds, particularly preferred compounds are the above formulas (1a-1) to (1a-18), formulas (1b-1) to (1b-18), and formulas (1c-1) to (1c). -18). Further preferred compounds are those represented by the above formulas (1a-1) to (1a-6), formulas (1a-12) to (1a-15), formulas (1c-1) to (1c-6), formula (1c -12) to (1c-15).

  Other host materials include, but are not limited to, metal chelated oxinoid compounds such as fused ring derivatives such as anthracene and pyrene, tris (8-quinolinolato) aluminum, which have been known as light emitters. Bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, cyclopentadiene derivatives, oxadiazole derivatives, thiadiazolopyridine derivatives, For pyrrolopyrrole derivatives and polymer systems, polyphenylene vinylene derivatives, polyparaphenylene derivatives, and polythiophene derivatives are preferably used.

  In addition, the host material can be appropriately selected from the compounds described in Chemical Industry, June 2004, page 13, and references cited therein.

  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 and rubrene, benzoxazole derivatives, benzthiazole derivatives, benzimidazole derivatives, benztriazole derivatives, oxazole derivatives, Bisstyryl derivatives such as oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazoline derivatives, stilbene derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, bisstyrylanthracene derivatives and distyrylbenzene derivatives (Kaihei 1-245087), bisstyrylarylene derivatives (JP-A-2-247278), Isobenzofuran derivatives such as azaindacene derivatives, furan derivatives, benzofuran derivatives, phenylisobenzofuran, dimesitylisobenzofuran, di (2-methylphenyl) isobenzofuran, di (2-trifluoromethylphenyl) isobenzofuran, phenylisobenzofuran, Dibenzofuran derivatives, 7-dialkylaminocoumarin derivatives, 7-piperidinocoumarin derivatives, 7-hydroxycoumarin derivatives, 7-methoxycoumarin derivatives, 7-acetoxycoumarin derivatives, 3-benzthiazolylcoumarin derivatives, 3-benzimidazolylcoumarin derivatives Derivatives, coumarin derivatives such as 3-benzoxazolyl coumarin derivatives, dicyanomethylenepyran derivatives, dicyanomethylenethiopyran derivatives, polymethine derivatives, cyanine 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, 1,2,5 -Thiadiazolopyrene derivatives, pyromethene derivatives, perinone derivatives, pyrrolopyrrole derivatives, squarylium derivatives, violanthrone derivatives, phenazine derivatives, acridone derivatives and deazaflavin derivatives.

  Illustratively for each color light, blue to blue-green dopant materials include naphthalene, anthracene, phenanthrene, pyrene, triphenylene, perylene, fluorene, indene and other aromatic hydrocarbon compounds and derivatives thereof, furan, pyrrole, thiophene, silole, Aromatic heterocyclic compounds such as 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, thioxanthene And its derivatives, distyrylbenzene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, coumarin derivatives, imidazole, thiazole, thiadiazole, cal Azole derivatives such as sol, oxazole, oxadiazole, triazole and metal complexes thereof, and N, N′-diphenyl-N, N′-di (3-methylphenyl) -4,4′-diphenyl-1,1′- Examples thereof 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. 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 further increase the wavelength of aryl, heteroaryl, arylvinyl, amino, and cyano groups to the compounds exemplified as the blue-blue-green and green-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.

  As dopant materials suitable for the light emitting layer material of the present invention, among the dopant materials described above, perylene derivatives, borane derivatives, aromatic amine derivatives (including amine-containing styryl derivatives), coumarin derivatives, pyran derivatives, iridium Complexes or platinum complexes are preferred.

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 2000-34234 A, JP 2001-267075 A, JP 2001-217077 A and the like may be used.

Examples of the borane derivatives 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 aromatic amine derivatives (including amine-containing styryl derivatives) 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'-bi (9-ethyl-3-carbazovinylene) -biphenyl, 4,4′-bis (9-phenyl-3-carbazovinylene) -biphenyl, and the like.
Further, for example, N, N, N, N-tetraphenylanthracene-9,10-diamine, 9,10-bis (4-diphenylamino-phenyl) anthracene, 9,10-bis (4-di (1-naphthyl) Amino) 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-diphenylamino-phenyl) naphthalene -1-yl] -diphenylamine, [4- (4-diphenylamino-phenyl) naphthalen-1-yl] -di Phenylamine, [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-diphenylaminonaphthalen-2-yl] ] -P-terphenyl and the like.
In addition, aromatic amine derivatives described in JP2003-347056A, JP2001-307884A, JP2006-156888A, and the like may be used.

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.
JP-A-2005-126399, JP-A-2005-097283, JP-A-2002-234892, JP-A-2001-220577, JP-A-2001-081090, and JP-A-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, 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.

  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 literature etc. which were raised to it.

<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 injecting / transporting layer is a layer that administers electrons injected from the cathode and further transports electrons. It is desirable that the electron injecting electrons have high efficiency and efficiently transport the injected electrons. 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.

  Materials used for the electron transport layer and the electron injection layer include compounds conventionally used as electron transport compounds in photoconductive materials, and known compounds used for the electron injection layer and the electron transport layer of organic electroluminescence devices. Any of these can be selected and used.

  Specifically, pyridine derivatives, naphthalene derivatives, anthracene derivatives, phenanthroline derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, anthraquinone derivatives, diphenoquinone derivatives, diphenylquinone derivatives, perylene derivatives, thiophene derivatives, thiadiazole derivatives, quinoxaline derivatives, quinoxaline Derivative polymers, benzazole compounds, pyrazole derivatives, perfluorinated phenylene derivatives, triazine derivatives, pyrazine derivatives, imidazopyridine derivatives, borane derivatives, benzoxazole derivatives, benzthiazole derivatives, quinoline derivatives, aldazine derivatives, carbazole derivatives, indole derivatives, Examples thereof include phosphorus oxide derivatives and bisstyryl derivatives. In addition, oxadiazole derivatives (1,3-bis [(4-t-butylphenyl) 1,3,4-oxadiazolyl] phenylene, etc.), triazole derivatives (N-naphthyl-2,5-diphenyl-1,3, etc.) 4-triazole, etc.), benzoquinoline derivatives (2,2′-bis (benzo [h] quinolin-2-yl) -9,9′-spirobifluorene, etc.), benzimidazole derivatives (tris (N-phenylbenzimidazole, etc.) -2-yl) benzene), bipyridine derivatives, terpyridine derivatives (1,3-bis (4 ′-(2,2 ′: 6′2 ″ -terpyridinyl)) benzene, etc.), naphthyridine derivatives (bis (1-naphthyl) ) -4- (1,8-naphthyridin-2-yl) phenylphosphine oxide, etc.) These materials are But it used but may be used in admixture with different materials.

  In addition, a metal complex having an electron-accepting nitrogen can be used, for example, a hydroxyazole complex such as a quinolinol-based metal complex or a hydroxyphenyloxazole complex, an azomethine complex, a tropolone metal complex, a flavonol metal complex, or a benzoquinoline metal complex. can give. These materials can be used alone or in combination with different materials.

  Among these, quinolinol-based metal complexes, pyridine derivatives, or phenanthroline derivatives are preferable.

The quinolinol-based metal complex is a compound represented by the following general formula (E-1).
In the formula, each of R _{1 to} R ₆ independently represents hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkoxy, optionally substituted aryl, or optionally substituted. Heteroaryl, optionally substituted cycloalkyl, halogen or cyano, M is Al, Ga, Be or Zn, and n is an integer of 2 or 3.

  The “alkyl” in the “optionally substituted alkyl” may be straight chain, branched chain, or cyclic, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl Pentyl, cyclopentyl, hexyl, cyclohexyl, heptyl, cycloheptyl, octyl, cyclooctyl and the like.

  “Alkenyl” of “optionally substituted alkenyl” may be linear or branched, and examples thereof include vinyl, propenyl, isopropenyl, allyl, butenyl, pentenyl, geranyl, farnesyl and the like.

  “Alkoxy” in “optionally substituted alkoxy” includes, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, s-butoxy, t-butoxy, pentyloxy, cyclopentyloxy, hexyloxy, cyclohexyloxy , Heptyloxy, cycloheptyloxy, octyloxy, cyclooctyloxy, phenoxy and the like.

  Examples of “aryl” in “optionally substituted aryl” include phenyl, tolyl, xylyl, biphenylyl, naphthyl, anthracenyl, phenanthryl, terphenylyl, fluorenyl, pyrenyl and the like.

  “Heteroaryl” in “optionally substituted heteroaryl” is, for example, a heterocyclic group containing 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen atoms in addition to carbon atoms as ring-constituting atoms. Etc. For example, furyl, thienyl, pyrrolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, pyrazolyl, oxadiazolyl, furazanyl, thiadiazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, benzofuranyl, isobenzofuranyl, benzo [b ] Thienyl, indolyl, isoindolyl, 1H-indazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, 1H-benzotriazolyl, quinolyl, isoquinolyl, cinnolyl, quinazolyl, quinoxalinyl, phthalazinyl, naphthyridinyl, purinyl, pteridinyl, carbazolyl, acridinyl Phenoxazinyl, phenothiazinyl, phenazinyl, phenoxathinyl, Antoreniru, indolizinyl, etc. phenanthrolinyl the like.

  Examples of “cycloalkyl” of “optionally substituted cycloalkyl” include cyclopropyl, cyclobutyl, cyclopentyl, methylcyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, cycloheptyl, and cyclooctyl.

  “Halogen” includes F, Cl, Br, I and the like.

Examples of the “substituent” in R _{1 to} R ₆ include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, heptyl, cycloheptyl, octyl, Alkyl such as cyclooctyl and trifluoromethyl; aryl such as phenyl, naphthyl, anthracenyl and phenanthryl; methylphenyl, ethylphenyl, s-butylphenyl, t-butylphenyl, 1-methylnaphthyl, 2-methylnaphthyl and 4-methyl Alkylaryl such as naphthyl, 1,6-dimethylnaphthyl, 4-t-butylnaphthyl; pyridyl, quinazolinyl, quinolyl, pyrimidinyl, furyl, thienyl, pyrrolyl, imidazolyl, tetrazolyl, phenanthrolinyl, etc. Heterocyclic; and cyano. The number of substituents is, for example, the maximum possible number of substitution, preferably 1 to 3, more preferably 1 to 2, and still more preferably 1.

  Specific examples of the quinolinol-based metal complex include tris (8-quinolinolato) aluminum (hereinafter abbreviated as ALQ), tris (4-methyl-8-quinolinolato) aluminum, and 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-quinolinolate) (4- Tylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (2-phenylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (3-phenylphenolate) aluminum, bis (2-methyl- 8-quinolinolato) (4-phenylphenolato) aluminum, bis (2-methyl-8-quinolinolato) (2,3-dimethylphenolato) aluminum, bis (2-methyl-8-quinolinolato) (2,6-dimethyl) Phenolate) 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- Tylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (2,6-diphenylphenolate) aluminum, bis (2-methyl-8-quinolinolato) (2,4,6-triphenylphenolate) 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-phenyl) Phenolate) aluminum, bis (2,4-dimethyl-8-quinolinola) G) (3-phenylphenolate) aluminum, bis (2,4-dimethyl-8-quinolinolato) (4-phenylphenolato) aluminum, bis (2,4-dimethyl-8-quinolinolato) (3,5-dimethyl) Phenolate) 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-) -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.

The pyridine derivative is a compound represented by the following general formula (E-2-1) or (E-2-2).
In the formula, each of R _{1 to} R ₅ is independently hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkoxy, optionally substituted aryl, or optionally substituted. Heteroaryl, optionally substituted cycloalkyl, halogen or cyano, 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 It is an integer of 2-8.
For each of the above-mentioned substituents listed as R _{1 to} R _{5 in the} general formula (E-2-1) or (E-2-2), the quinolinol-based metal complex (the above general formula (E-1)) is used. The description in R _{1 to} R ₆ can be used.

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

  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 (hereinafter abbreviated as ET1), 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) -2-phenylanthracene, 9,10-di (2,2′-bipyridyl-5-yl) -2-phenylanthracene, 3,4-diphenyl-2,5-di (2,2′- Bipyridyl-6-yl) thiophene, 3,4-dipheni -2,5-di (2,3'-bipyridyl-5-yl) thiophene, 6'6 "-di (2-pyridyl) 2,2 ': 4', 4": 2 ", 2" '-qua Examples include terpyridine.

The phenanthroline derivative is a compound represented by the following general formula (E-3-1) or (E-3-2).
In the formula, each of R _{1 to} R ₈ independently represents hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkoxy, optionally substituted aryl, or optionally substituted. Heteroaryl, optionally substituted cycloalkyl, halogen or cyano, 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 It is an integer of 2-8.
For each of the above-mentioned substituents listed as R _{1 to} R _{8 in the} general formula (E-3-1) or (E-3-2), the quinolinol-based metal complex (the above general formula (E-1)) is used. The description in R _{1 to} R ₆ can be used. Examples of G in the general formula (E-3-2) include the same ones as described in the column of pyridine derivatives.

  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.

<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 alloy, and aluminum-lithium alloys such as lithium fluoride / aluminum). 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 substances 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, the hole transport layer, the light emitting layer, the electron transport layer and the 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 It can be used by dispersing 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. It is also 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, and the like. 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 on this 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 including an organic electroluminescent element or a lighting device including an organic electroluminescent element.
The display device or the illumination device including the 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, Japanese Patent Application Laid-Open No. 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.

  The matrix system (type) refers to a display in which pixels for display are arranged two-dimensionally, such as a grid or a mosaic, and a character or image is displayed by 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, but 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, and the like can be mentioned.

  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, Japanese Patent Application Laid-Open Nos. 2003-257621, 2003-277741, and 2004-119211). 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 board, 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.

<Synthesis example of benzofluorene compound>
Hereinafter, a compound represented by formula (1a-1) (hereinafter also referred to as compound (1a-1)), a compound represented by formula (1a-2) (hereinafter also referred to as compound (1a-2)), Synthesis of compound represented by formula (1a-3) (hereinafter also referred to as compound (1a-3)) and compound represented by formula (1c-1) (hereinafter also referred to as compound (1c-1)) An example will be described.

<Synthesis Example of Compound (1a-1)>
First, 3,9-bis (trifluoromethanesulfonyloxy) -11H-benzo [a] fluorene-11-spiro-9′-fluorene, which is an intermediate for synthesizing the compound (1a-1), is shown below. Synthesized according to the scheme. In this scheme, the raw material compound and intermediate in <Scheme 1a> described above are used as specific compounds.

<Synthesis of Compound (1a'-C)>
Under a nitrogen atmosphere, methanesulfonic acid (150 mL) was added to 5-methoxy-2- (6-methoxynaphthalen-2-yl) -benzoic acid methyl ester (compound (1a′-A)) (24.2 g), and 65 The mixture was heated and stirred at ° C for 1.5 hours. The reaction mixture was added to ice water, and the precipitated solid was separated by filtration and washed with methanol. The obtained solid (21.3 g) was purified by silica gel column chromatography (developing solvent: toluene) and recrystallization (solvent: ethyl acetate) to obtain compound (1a′-C) (17.6 g) ( Yield 81%).

<Synthesis of Compound (1a'-E)>
Under a nitrogen atmosphere, 2-bromobiphenyl (25.8 g), magnesium (2.69 g) and THF (225 mL) were added to a suspension of compound (1a′-C) (17.6 g) in THF (300 mL). The prepared THF solution of 2-biphenylmagnesium bromide was added dropwise at 0 ° C., and the mixture was further heated and stirred at reflux temperature for 3 hours. Water was added to the reaction mixture, the target component was extracted with toluene, and the organic layer was concentrated to obtain a solid crude product (29.7 g) of the target component. The obtained solid was purified by recrystallization (solvent: toluene) and silica gel column chromatography (developing solvent: toluene / ethyl acetate = 20/1 (volume ratio)) to obtain compound (1a′-E) (22.4 g ) Was obtained (yield 86%).

<Synthesis of Compound (1a'-F1)>
Concentrated sulfuric acid (0.1 mL) was added to a suspension of compound (1a′-E) (22.4 g) in acetic acid (300 mL) at room temperature under a nitrogen atmosphere, and the mixture was further heated and stirred at 100 ° C. for 2 hours. Water was added to the reaction mixture, and the precipitated solid was separated by filtration. The obtained solid was washed with methanol to obtain compound (1a′-F1) (20.3 g) (yield 94%).

<Synthesis of Compound (1a'-F2)>
Under a nitrogen atmosphere, a 1 mol / L boron tribromide / dichloromethane solution (103 mL) was added dropwise at 0 ° C. to a dichloromethane (300 mL) solution of the compound (1a′-F1) (20.0 g). Stir at room temperature for 1 hour. Water was added to the reaction mixture, the target component was extracted with ethyl acetate, and the organic layer was concentrated to obtain a solid crude product (20.4 g) of the target component. The obtained solid was washed with heptane to obtain compound (1a′-F2) (18.3 g) (yield 98%).

<Synthesis of Compound (1a'-F3)>
Under a nitrogen atmosphere, trifluoromethanesulfonic anhydride (38.9 g) was added dropwise at 0 ° C. to a solution of compound (1a′-F2) (18.3 g) in pyridine (300 mL), and the mixture was further stirred overnight at room temperature. did. Water was added to the reaction mixture, the target component was extracted with ethyl acetate, and the organic layer was concentrated to obtain a solid crude product (34.5 g) of the target component. The obtained solid was purified by silica gel column chromatography (developing solvent: toluene) to obtain compound (1a′-F3) (29.3 g) (yield 96%).
The compound (1a′-F3) is 3,9-bis (trifluoromethanesulfonyloxy) -11H-benzo [a] fluorene-11-spiro-9′-fluorene.

<Synthesis of Compound (1a-1)>
Finally, 3,9-dinaphthalen-2-yl-11H-benzo [a] fluorene-11-spiro-9′-fluorene, which is the compound (1a-1), was synthesized as follows.
Under a nitrogen atmosphere, a mixed solution of compound (1a′-F3) (6.63 g), 2-naphthyleneboronic acid (3.78 g), potassium phosphate (12.7 g), tetrahydrofuran (20 mL) and isopropyl alcohol (80 mL) was added. Tetrakis (triphenylphosphine) palladium (0) (1.16 g) was added, and the mixture was heated and stirred at reflux temperature for 7.5 hours. Water was added to the reaction mixture, the target component was extracted with toluene, and the organic layer was concentrated to obtain a solid crude product (9.00 g) of the target component. The obtained solid was purified by silica gel column chromatography (developing solvent: heptane / toluene = 2/1 (volume ratio)) and recrystallization (solvent: toluene) to obtain the desired compound (1a-1) (2.95 g). ) Was obtained (yield 48%).
The glass transition temperature (Tg) of the obtained compound was 153 ° C. The glass transition temperature was measured using a Diamond DSC manufactured by PerkinElmer (measuring conditions: cooling rate 200 ° C./min, heating rate 10 ° C./min). Moreover, the structure of the compound obtained by NMR measurement was confirmed.
¹ H-NMR (CDCl ₃ ) σ = 6.79 to 6.85 (m, 3H), 7.03 (s, 1H), 7.09 to 7.12 (m, 2H), 7.40 to 7 .49 (m, 7H), 7.56 to 7.58 (d, 1H), 7.73 to 7.88 (m, 9H), 8.02 to 8.03 (m, 4H), 8.07 ~ 8.14 (m, 2H), 8.17 (s, 1H)

<Synthesis Example of Compound (1a-2)>
Compound (1a-2), 3,9-dinaphthalen-1-yl-11H-benzo [a] fluorene-11-spiro-9′-fluorene, was synthesized as follows.
Under a nitrogen atmosphere, compound (1a′-F3) (3.31 g), 1-naphthyleneboronic acid (1.89 g), potassium phosphate (4.25 g), lithium chloride (0.424 g), 1,2-dimethoxyethane ( To a mixed solution of 50 mL) and water (10 mL), tetrakis (triphenylphosphine) palladium (0) (0.347 g) was added, and the mixture was heated and stirred at reflux temperature for 13 hours. Water was added to the reaction mixture, the target component was extracted with toluene, and the organic layer was concentrated to obtain a solid crude product (4.20 g) of the target component. The obtained solid was purified by silica gel column chromatography (developing solvent: heptane / toluene = 2/1 (volume ratio)) and recrystallization (solvent: toluene) to obtain the desired compound (1a-2) (0.660 g ) Was obtained (yield 21%).
The glass transition temperature (Tg) of the obtained compound was 160 ° C. Moreover, the structure of the compound obtained by NMR measurement was confirmed.
¹ H-NMR (CDCl ₃ ) σ = 6.80 to 6.86 (m, 4H), 7.11 to 7.14 (m, 2H), 7.18 to 7.20 (d, 1H), 7 .23-7.48 (m, 10H), 7.53-7.54 (d, 1H), 7.70-7.75 (m, 2H), 7.80-7.96 (m, 7H) 8.02 to 8.04 (m, 2H), 8.14 to 8.16 (d, 1H)

<Synthesis Example of Compound (1a-3)>
Compound (1a-3), 3,9-diphenyl-11H-benzo [a] fluorene-11-spiro-9′-fluorene, was synthesized as follows.
Under a nitrogen atmosphere, a solution of compound (1a′-F3) (0.663 g), [1,1′-bis (diphenylphosphino) ferrocene] dichloropalladium (II) (0.0817 g) in THF (10 mL) was added 1 A 0.08 mol / L phenylmagnesium bromide / THF solution (3.9 mL) was added dropwise at room temperature, and the mixture was further heated and stirred at reflux temperature for 1 hour. Water was added to the reaction mixture, the target component was extracted with toluene, and the organic layer was concentrated to obtain a solid crude product (0.695 g) of the target component. The obtained solid was purified by silica gel column chromatography (developing solvent: heptane / toluene = 2/1 (volume ratio)) and recrystallization (solvent: toluene / heptane) to obtain the target compound (1a-3) (0 239 g) (yield 46%).
The glass transition temperature (Tg) of the obtained compound was 137 ° C. Moreover, the structure of the compound obtained by NMR measurement was confirmed.
¹ H-NMR (CDCl ₃ ) σ = 6.73 to 6.79 (m, 3H), 6.87 (s, 1H), 7.05 to 7.08 (m, 2H), 7.21 to 7 .40 (m, 11H), 7.54 to 7.63 (m, 3H), 7.95 to 8.09 (m, 6H)

<Synthesis Example of Compound (1c-1)>
First, 5,9-bis (trifluoromethanesulfonyloxy) -7H-benzo [c] fluorene-7-spiro-9′-fluorene, which is an intermediate for synthesizing the compound (1c-1), is shown below. Synthesized according to the scheme. In this scheme, the raw material compound and intermediate in <Scheme 1c> described above are used as specific compounds.

<Synthesis of Compound (1c'-C)>
Under a nitrogen atmosphere, methanesulfonic acid (130 mL) was added to 5-methoxy-2- (4-methoxynaphthalen-1-yl) -benzoic acid methyl ester (compound (1c′-A)) (21.0 g), and 65 The mixture was heated and stirred at ° C for 1.5 hours. The reaction mixture was added to ice water, and the precipitated solid was separated by filtration and washed with methanol. The obtained solid (22.5 g) was purified by recrystallization (solvent: ethyl acetate) to obtain compound (1c′-C) (14.6 g) (yield 77%).

<Synthesis of Compound (1c'-E)>
Under a nitrogen atmosphere, 2-bromobiphenyl (17.0 g), magnesium (1.77 g) and THF (150 mL) were added to a suspension of compound (1c′-C) (13.2 g) in THF (120 mL). The prepared THF solution of 2-biphenylmagnesium bromide was added dropwise at 0 ° C., and the mixture was further heated and stirred at reflux temperature for 1.5 hours. Water was added to the reaction mixture, the target component was extracted with toluene, and the organic layer was concentrated to obtain a solid crude product (25.4 g) of the target component. The obtained solid was purified by silica gel column chromatography (developing solvent: toluene / ethyl acetate = 9/1 (volume ratio)) to obtain compound (1c′-E) (17.4 g) (yield 86 %).

<Synthesis of Compound (1c'-F1)>
Under a nitrogen atmosphere, concentrated sulfuric acid (0.1 mL) was added to a suspension of compound (1c′-E) (17.4 g) in acetic acid (230 mL) at room temperature, and the mixture was further heated and stirred at 100 ° C. for 3 hours. Water was added to the reaction mixture, and the precipitated solid was separated by filtration. The obtained solid was washed with methanol to obtain compound (1c′-F1) (16.2 g) (yield 97%).

<Synthesis of Compound (1c'-F2)>
Under a nitrogen atmosphere, a 1 mol / L boron tribromide / dichloromethane solution (100 mL) was added dropwise to a dichloromethane (250 mL) solution of the compound (1c′-F1) (16.2 g) at 0 ° C. Stir at room temperature overnight. Water was added to the reaction mixture, the target component was extracted with ethyl acetate, and the organic layer was concentrated to obtain a solid crude product of the target component. The obtained solid was washed with heptane to obtain compound (1c′-F2) (15.1 g) (yield 100%).

<Synthesis of Compound (1c'-F3)>
Under a nitrogen atmosphere, trifluoromethanesulfonic anhydride (32.2 g) was added dropwise at 0 ° C. to a pyridine (200 mL) solution of the compound (1c′-F2) (15.1 g), and the mixture was further stirred overnight at room temperature. did. Water was added to the reaction mixture, and the precipitated solid was separated by filtration. The obtained solid was purified by silica gel column chromatography (developing solvent: toluene) to obtain compound (1c′-F3) (23.6 g) (yield 94%).
The compound (1c′-F3) is 5,9-bis (trifluoromethanesulfonyloxy) -7H-benzo [c] fluorene-7-spiro-9′-fluorene.

<Synthesis of Compound (1c-1)>
Finally, 5,9-dinaphthalen-2-yl-7H-benzo [c] fluorene-7-spiro-9′-fluorene, which is the compound (1c-1), was synthesized as follows.
Under a nitrogen atmosphere, a mixed solution of compound (1c′-F3) (6.63 g), 2-naphthyleneboronic acid (3.78 g), potassium phosphate (12.7 g), tetrahydrofuran (20 mL) and isopropyl alcohol (80 mL) was added. Tetrakis (triphenylphosphine) palladium (0) (1.16 g) was added, and the mixture was heated and stirred at reflux temperature for 7.5 hours. Water was added to the reaction mixture, the target component was extracted with toluene, and the organic layer was concentrated to obtain a solid crude product (8.90 g) of the target component. The obtained solid was purified by silica gel column chromatography (developing solvent: heptane / toluene = 2/1 (volume ratio)) and recrystallization (solvent: ethyl acetate) to obtain the target compound (1c-1) (2. 28 g) was obtained (yield 37%).
The glass transition temperature (Tg) of the obtained compound was 164 ° C. Moreover, the structure of the compound obtained by NMR measurement was confirmed.
¹ H-NMR (CDCl ₃ ) σ = 6.86 to 6.87 (m, 3H), 7.12 to 7.17 (m, 3H), 7.37 to 7.53 (m, 8H), 7 .62 to 7.64 (dd, 1H), 7.76 to 7.93 (m, 12H), 8.02 to 8.04 (d, 1H), 8.58 to 8.60 (d, 1H) , 8.99 to 9.01 (d, 1H).

  By appropriately selecting the raw material compound, another benzofluorene compound of the present invention can be synthesized by a method according to the synthesis example described above.

Next, a compound represented by the formula (H1) (hereinafter also referred to as the compound (H1)) and a compound represented by the formula (H2) (hereinafter also referred to as the compound (H2)), which are benzofluorene compounds of comparative examples. And a synthesis example of a compound represented by the formula (H3) (hereinafter also referred to as a compound (H3)).

<Synthesis Example of Compound (H1)>
The synthesis method of 3,9-dinaphthalen-2-yl-11,11-diphenyl-11H-benzo [a] fluorene, which is the compound (H1), is as follows.
Under a nitrogen atmosphere, 11,11-diphenyl-3,9-bis (trifluoromethanesulfonyloxy) -11H-benzo [a] fluorene (6.66 g) and 2-naphthyleneboronic acid (5.16 g) were added to tetrahydrofuran and isopropyl alcohol ( Tetrakis (triphenylphosphine) palladium (0) (1.16 g) was added and stirred for 5 minutes, and then potassium phosphate was dissolved in a mixed solvent (100 mL) of tetrahydrofuran / isopropyl alcohol = 1/4 (volume ratio). (12.7 g) was added and refluxed for 4 hours. After the reaction, 50 mL of the solvent was removed, and the precipitate obtained by adding 100 mL of water was filtered. This precipitate was further washed with water and methanol to obtain a crude product of compound (H1). The crude product was subjected to column purification with silica gel (solvent: heptane / toluene = 3/1 (volume ratio)) and then purified by sublimation to obtain the target compound (H1) (4.2 g). (Rate: 67.6%).
The glass transition temperature (Tg) of the obtained compound was 140 ° C. Moreover, the structure of the compound obtained by NMR measurement was confirmed.
¹ H-NMR (CDCl ₃ ) σ = 7.22 to 7.27 (m, 6H), 7.42 to 7.51 (m, 8H), 7.67 to 7.98 (m, 14H), 8 .08 to 8.10 (m, 3H), 8.23 (d, 1H)

<Synthesis Example of Compound (H2)>
In the method for synthesizing the compound (1a-2) described above, “1-naphthyleneboronic acid” is converted to “diphenyl- [4- (4,4,5,5-tetramethyl- [1,3,2] dioxaborolan-2-yl”. The compound was synthesized in the same manner except that it was replaced with “) -phenyl] -amine”.
The obtained compound had a glass transition temperature (Tg) of 174 ° C. Moreover, the structure of the compound obtained by NMR measurement was confirmed.
¹ H-NMR (CDCl ₃ ) σ = 6.73 to 6.74 (m, 3H), 6.84 (s, 1H), 6.97 to 7.11 (m, 18H), 7.19 to 7 .28 (m, 11H), 7.38 to 7.43 (m, 4H), 7.57 to 7.59 (m, 1H), 7.91 to 8.06 (m, 6H)

<Synthesis Example of Compound (H3)>
The synthesis method of 5,9-dinaphthalen-2-yl-7,7-diphenyl-7H-benzo [c] fluorene, which is the compound (H3), is as follows.
Under a nitrogen atmosphere, 7,7-diphenyl-5,9-bis (trifluoromethanesulfonyloxy) -7H-benzo [c] fluorene (6.66 g) and 2-naphthyleneboronic acid (5.16 g) were added to tetrahydrofuran and isopropyl alcohol ( Tetrakis (triphenylphosphine) palladium (0) (1.16 g) was added and stirred for 5 minutes, and then potassium phosphate was dissolved in a mixed solvent (100 mL) of tetrahydrofuran / isopropyl alcohol = 1/4 (volume ratio). (12.7 g) was added and refluxed for 4 hours. After the reaction, 50 mL of the solvent was removed, and the precipitate obtained by adding 100 mL of water was filtered. The precipitate was further washed with water and methanol to obtain a crude product of compound (H3). The crude product was subjected to column purification with silica gel (solvent: heptane / toluene = 3/1 (volume ratio)) and then purified by sublimation to obtain the desired compound (H3) (5.0 g). Rate: 80.5%).
The obtained compound had a glass transition temperature (Tg) of 151 ° C. Moreover, the structure of the compound obtained by NMR measurement was confirmed.
¹ H-NMR (CDCl ₃ ) σ = 7.21 to 7.93 (m, 28H), 8.04 to 8.06 (m, 2H), 8.53 (d, 1H), 8.93 (d , 1H)

<About heat resistance comparison>
As described above, compound (1a-1), compound (1a-2), compound (1a-3), compound (1c-1), compound (H1), compound (H2) and compound (H3) Was synthesized. Regarding the glass transition temperature, which is an index of heat resistance, the compound (1a-1) (Tg = 153 ° C.) is clearly more compound (1c-1) (Tg = 140 ° C.) than the compound (H1) (Tg = 140 ° C.). It can be seen that Tg = 164 ° C. is superior to compound (H3) (Tg = 151 ° C.). The compound (1a-2) (Tg = 153 ° C.) is also excellent in heat resistance. There are several possible causes for this, but one of them is considered to be because the compound (1a-1) or the compound (1c-1) has a spiro structure.

Electroluminescent devices according to Examples 1 and 2 and Comparative Examples 1, 2, and 3 were prepared, and voltage (V), current density (mA / cm ² ), and luminous efficiency, which are characteristics at the time of light emission of 1000 cd / m ² , respectively. (Lm / W), measurement of current efficiency (cd / A), emission wavelength (nm) and chromaticity (x, y), measurement of external quantum efficiency (%), 70 when initial luminance is 2000 cd / m ² The elapsed time at% luminance retention was measured. Hereinafter, Examples 1 and 2 and Comparative Examples 1, 2, and 3 will be described in detail.

Table 1 below shows the material configuration of each layer in the electroluminescent elements according to the manufactured Examples 1 and 2 and Comparative Examples 1, 2, and 3.

  In Table 1, “CuPc” is copper phthalocyanine, “NPD” is N, N′-di (1-naphthyl) -N, N′-diphenylbenzidine, “D1” is N, N, N ′, N′-tetra. (4-Biphenylyl) -4,4-diaminostilbene, “ALQ” is tris (8-quinolinolato) aluminum, each having the following chemical structural formula.

<Example 1>
A glass substrate of 26 mm × 28 mm × 0.7 mm on which ITO was deposited to a thickness of 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, a molybdenum vapor deposition boat containing CuPc, a molybdenum vapor deposition boat containing NPD, and a molybdenum vapor deposition containing compound (1a-1) A boat, a molybdenum vapor deposition boat containing D1, a molybdenum vapor deposition boat containing ALQ, a molybdenum vapor deposition boat containing lithium fluoride, and a tungsten vapor deposition boat containing aluminum were mounted.

Depressurize the vacuum chamber to 5 × 10 ⁻⁴ Pa, heat the vapor deposition boat containing CuPc, deposit CuPc to a film thickness of 50 nm, and form a hole injection layer. The evaporation boat was heated to deposit NPD so as to have a film thickness of 30 nm to form a hole transport layer. Next, a molybdenum vapor deposition boat containing the compound (1a-1) and a molybdenum vapor deposition boat containing D1 are heated to form a light emitting layer by co-depositing both compounds to a film thickness of 35 nm. did. At this time, the doping concentration of D1 was about 5% by weight. Next, the evaporation boat containing ALQ was heated, and ALQ was evaporated to a film thickness of 15 nm to form an electron transport layer. The above deposition rate was 0.01-1 nm / second.

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

Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 6.2 V, the current density was 21 mA / cm ² , the emission efficiency was 2.4 lm / W, and the current efficiency was 4 0.8 cd / A, emission wavelength 457 nm, and chromaticity (0.14, 0.16). The external quantum efficiency was 4.4%, and the current density at that time was 20 mA / cm ² . Further, when a constant current driving test was performed at a current density for obtaining an initial luminance of 2000 cd / m ² , the elapsed time when the luminance retention rate was 70% was 790 hours.

<Comparative Example 1>
An organic EL device was obtained by the method according to Example 1 except that the compound (1a-1) used as the light emitting layer material (host) in Example 1 was replaced with the compound (H1). Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 6.2 V, the current density was 21 mA / cm ² , the emission efficiency was 2.4 lm / W, and the current efficiency was 4 0.7 cd / A, emission wavelength 455 nm, and chromaticity (0.14, 0.15). The external quantum efficiency was 4.6%, and the current density at that time was 21 mA / cm ² . Further, when a constant current driving test was performed at a current density for obtaining an initial luminance of 2000 cd / m ² , the elapsed time when the luminance retention rate was 70% was 190 hours.

<Comparative Example 2>
An organic EL device was obtained by the method according to Example 1 except that the compound (1a-1) used as the light emitting layer material (host) in Example 1 was replaced with the compound (H2). Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 5.9 V, the current density was 128 mA / cm ² , the emission efficiency was 0.42 lm / W, and the current efficiency was 0. It was .78 cd / A, an emission wavelength of 522 nm, and chromaticity (0.24, 0.53). The external quantum efficiency was 0.25%, and the current density at that time was 14 mA / cm ² . However, this light emission was due to ALQ of the electron transport layer.

<Example 2>
An organic EL device was obtained by the method according to Example 1 except that the compound (1a-1) used as the light emitting layer material (host) in Example 1 was replaced with the compound (1c-1). Using the ITO electrode as the anode and the lithium fluoride / aluminum electrode as the cathode, the characteristics at 1000 cd / m ² emission were measured. The voltage was 6.2 V, the current density was 19 mA / cm ² , the emission efficiency was 2.6 lm / W, and the current efficiency was 5 0.2 cd / A, emission wavelength 455 nm, and chromaticity (0.14, 0.14). The external quantum efficiency was 5.0%, and the current density at that time was 19 mA / cm ² . Further, when a constant current driving test was performed with a current density for obtaining an initial luminance of 2000 cd / m ² , the elapsed time when the luminance retention rate was 70% was 530 hours.

<Comparative Example 3>
An organic EL device was obtained by the method according to Example 1 except that the compound (1a-1) used as the light emitting layer material (host) in Example 1 was replaced with the compound (H2). The ITO electrode as the anode, a cathode and lithium fluoride / aluminum electrode, when measuring the characteristics at 1000 cd / m ² light emission, voltage 6.3V, a current density of 19 mA / cm ^2, luminous efficiency 2.6Lm / W, the current efficiency 5 0.2 cd / A, emission wavelength 455 nm, and chromaticity (0.14, 0.15). The external quantum efficiency was 4.9%, and the current density at that time was 18 mA / cm ² . Further, when a constant current driving test was performed with a current density for obtaining an initial luminance of 2000 cd / m ² , the elapsed time at a luminance retention rate of 70% was 210 hours.

Table 2 below summarizes the performance evaluation of the electroluminescent elements according to Examples 1 and 2 and Comparative Examples 1, 2, and 3 described above.

  From the results of Example 1 and Comparative Example 1, and Example 2 and Comparative Example 3, it was found that an organic EL device having an extremely excellent lifetime can be obtained by using a benzofluorene compound having a spiro structure. Further, as can be seen from the results of Comparative Example 2, it was also found that even if the benzofluorene compound having a spiro structure is substituted with an amine or the like as Ar, it does not function as an element. Therefore, it can be seen that in order to obtain an excellent organic EL element, it is extremely important not only to select a spiro structure, but also to select appropriate Ar in addition thereto.

  According to a preferred aspect of the present invention, it is possible to provide an organic electroluminescent element having good performance in at least one of heat resistance and element lifetime, a display device including the same, a lighting device including the same, and the like.

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

Explanation of symbols

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)

A benzofluorene compound represented by the following general formula (1a), (1b) or (1c).
(In each formula, each Ar is independently hydrogen, optionally substituted phenyl, optionally substituted naphthyl, optionally substituted biphenylyl, optionally substituted phenanthryl, or substituted. Anthryl which may be substituted, pyrenyl which may be substituted, chrysenyl which may be substituted, or triphenylenyl which may be substituted, Ar is not hydrogen together, and the substituents of Ar are each independently And phenyl, naphthyl, biphenylyl, phenanthryl, anthryl, pyrenyl, chrycenyl or triphenylenyl.) A benzofluorene compound represented by the general formula (1a), (1b) or (1c),
In each formula, Ar is independently hydrogen, optionally substituted phenyl, optionally substituted naphthyl, optionally substituted biphenylyl, optionally substituted phenanthryl, substituted An Ar is anthryl, Ar is not hydrogen together, and the substituents of Ar are each independently phenyl, naphthyl, biphenylyl, phenanthryl or anthryl.
The benzofluorene compound according to claim 1. A benzofluorene compound represented by the general formula (1a) or (1c),
In each formula, Ar is each independently an optionally substituted phenyl or an optionally substituted naphthyl, and each Ar substituent is independently a phenyl or naphthyl.
The benzofluorene compound according to claim 1. A benzofluorene compound represented by the general formula (1a) or (1c),
In each formula, Ar is both optionally substituted 2-naphthyl, and the substituent of Ar is phenyl or naphthyl.
The benzofluorene compound according to claim 1. A benzofluorene compound represented by the general formula (1a),
Ar is both 2-naphthyl,
The benzofluorene compound according to claim 1. A benzofluorene compound represented by the general formula (1c),
Ar is both 2-naphthyl,
The benzofluorene compound according to claim 1.   A material for a light emitting layer of a light emitting element, the material for a light emitting layer containing the benzofluorene compound according to any one of claims 1 to 6.   The light emitting layer material according to claim 7, further comprising at least one selected from the group consisting of perylene derivatives, borane derivatives, aromatic amine derivatives, coumarin derivatives, pyran derivatives, iridium complexes, and platinum complexes.   Furthermore, the material for light emitting layers of Claim 7 containing an aromatic amine derivative.   The organic electroluminescent element which has a pair of electrode which consists of an anode and a cathode, and the light emitting layer which is arrange | positioned between this pair of electrodes and contains the material for light emitting layers in any one of Claims 7-9.   And an electron transport layer and / or an electron injection layer disposed between the cathode and the light emitting layer, wherein at least one of the electron transport layer and the electron injection layer includes a quinolinol-based metal complex, a pyridine derivative, and The organic electroluminescent device according to claim 10, comprising at least one selected from the group consisting of phenanthroline derivatives.   Furthermore, it has an electron transport layer and / or an electron injection layer disposed between the cathode and the light emitting layer, and at least one of the electron transport layer and the electron injection layer contains a quinolinol-based metal complex. The organic electroluminescent element according to claim 10.   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.