# Patent

## Title
Spiro compound and organic luminescence device using the same

## Abstract

Provided are a novel spiro compound, and an organic luminescence device using the spiro compound and having an optical output with an extremely high efficiency and a high luminance, and an extremely high durability. The Spiro compound is represented by the following general formula [I]:




(wherein R1, R2, R3, and R4 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom, and R1, R2, R3, and R4 may be identical or different from each other; and Ar1 and Ar2 represent a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group, which may be identical or different from each other.)

## Background
TECHNICAL FIELD
The present invention relates to a novel organic compound and an organic luminescence device using the same.
BACKGROUND ART
An organic luminescence device is a device where a thin film including a fluorescent organic compound or a phosphorescent organic compound is sandwiched between an anode and a cathode, an electron and a hole are injected from the respective electrodes to generate an exciton of the fluorescent compound or the phosphorescent compound, and light which is emitted when the exciton returns to the ground state is utilized.
According to the study of Kodak company in 1987 (Appl. Phys. Lett. 51, 913 (1987)), there has been reported a luminescence with approximately 1000 cd/m2 at an applied voltage of approximately 10 V in a device having a separated-function type two-layer configuration using ITO as an anode, a magnesium-silver alloy as a cathode, an aluminum quinolinol complex as an electron-transporting material and a luminescent material, and a triphenyl amine derivative as a hole-transporting material. The related patents include U.S. Pat. Nos. 4,539,507, 4,720,432, 4,885,211, and so on.
In addition, it is possible to generate luminescence in the range of ultraviolet to infrared lights by changing the type of the fluorescent organic compound, and in recent years various types of compounds have been studied actively. For instance, it is described in U.S. Pat. Nos. 5,151,629, 5,409,783, 5,382,477, Japanese Patent Application Laid-Open Nos. 2-247278, 3-255190, 5-202356, 9-202878, 9-227576, and so on.
In recent years, many studies have been conducted using phosphorescent compounds as luminescent materials and using energies in triplet excitation states. A high luminescence efficiency shown by an organic luminescence device using an iridium complex as a luminescent material has been reported by a group of the Princeton University (Nature 395, 151 (1998)).
Furthermore, in addition to the organic luminescence device using the low molecular weight material as mentioned above, an organic luminescence device using a conjugate polymer has been reported by a group of the Cambridge University (Nature, 347, 539 (1990)). In this report, luminescence from a single layer is confirmed by the film formation of polyphenylene vinylene (PPV) using a coating system.
The related patents of the organic luminescence device using the conjugate polymer include U.S. Pat. Nos. 5,247,190, 5,514,878, 5,672,678, Japanese Patent Application Laid-Open Nos. 4-145192, 5-247460, and so on.
In this way, the recent progress in the organic luminescence device is remarkable, and the characteristics thereof suggest the possibility of applications for various purposes, which enable the luminescence device with a high luminance, a high-speed response, and a thin and lightweight form.
However, an optical output of higher luminance or higher conversion efficiency is required under the present conditions. In addition, many problems still remain to be solved regarding the durability with respect to a change with time due to a long-term usage, deterioration caused by an atmospheric gas including oxygen, moisture, or the like, and so on. Besides, it is not still insufficient for solving problems related to the needs for luminescences of blue, green, and red having good color purity in the case of considering the applications to a full color display and so on.
On the other hand, a spiro compound having a specific steric configuration has been attracting attention as an organic functional material in terms of the specific physical properties of the material (J. Am. Chem. Soc., vol. 110, page 5687, 1988). As an example of using a spiro compound as an organic luminescence device, Japanese Patent Application Laid-Open No. 7-278537 or the like can be given, but the characteristics thereof in being used as a luminescent material or an electron-transporting material are not sufficient.
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide a novel spiro compound.
Also, another object of the present invention is to provide an organic luminescence device using a specific spiro compound and having an optical output with an extremely high efficiency and a high luminance.
In addition, another object of the present invention is to provide an organic luminescence device having an extremely high durability. Furthermore, another object of the present invention is to provide an organic luminescence device which can be easily and comparatively inexpensively produced.
Therefore, a spiro compound according to the present invention is represented by one of the following general formula [I] and [II]:




(where R1, R2, R3, and R4 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom, and R1, R2, R3, and R4 may be identical or different from each other; and Ar1 and Ar2 represent a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group, which may be identical or different from each other); and





(where R5, R6, R7, and R8 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom, and R5, R6, R7, and R8 may be identical or different from each other; and Ar3 and Ar4 represent a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group, which may be identical or different from each other.)

Further, an organic luminescence device according to the present invention includes at least a pair of electrodes including an anode and a cathode and one or a plurality of layers containing an organic compound sandwiched between the pair of electrodes, in which at least one of the layers containing the organic compound preferably contains at least one spiro compound.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional diagram that illustrates an example of an organic luminescence device in accordance with the present invention.
FIG. 2 is a cross-sectional diagram that illustrates another example of the organic luminescence device in accordance with the present invention.
FIG. 3 is a cross-sectional diagram that illustrates another example of the organic luminescence device in accordance with the present invention.
FIG. 4 is a cross-sectional diagram that illustrates another example of the organic luminescence device in accordance with the present invention.
FIG. 5 is a cross-sectional diagram that illustrates another example of the organic luminescence device in accordance with the present invention.
FIG. 6 is a cross-sectional diagram that illustrates another example of the organic luminescence device in accordance with the present invention.



BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail.
At first, a spiro compound of the present invention will be described.
The spiro compound of the present invention is represented by the above general formula [I] or [II].
Here, at least one of Ar1 and Ar2, or at least one of Ar3 and Ar4 is preferably a condensed polycyclic aromatic group represented by one of the following general formula [III] to [IX]:




(where R9 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom; and R10 and R11 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, which may be identical or different from each other);





(where R12 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom; and R13 and R14 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, which may be identical or different from each other); and





(where R15 to R20 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom.)

Specific examples of substituents in the above general formula [I] to [IX] are shown below.
The alkyl group includes a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a tert-butyl group, an octyl group, and the like.
The aralkyl group includes a benzyl group, a phenethyl group, and the like.
The aryl group includes a phenyl group, a biphenyl group, a tert-phenyl group, and the like.
The heterocyclic group includes a thienyl group, a pyrrolyl group, a pyridyl group, an oxazolyl group, an oxadiazolyl group, a thiazolyl group, a thiadiazolyl group, a tert-thienyl group, and the like.
The substituted amino group includes a dimethylamino group, a diethylamino group, a dibenzylamino group, a diphenylamino group, a ditolylamino group, a dianisolylamino group, and the like.
The halogen atom includes fluorine, chlorine, bromine, iodine, and the like.
The condensed polycyclic aromatic group includes a fluorenyl group, a naphthyl group, a fluoranthenyl group, an anthryl group, a phenanthryl group, a pyrenyl group, a tetracenyl group, a pentacenyl group, a triphenylenyl group, a perylenyl group, and the like.
The condensed polycyclic heterocyclic group includes a carbazolyl group, a diazafluorenyl group, an acridinyl group, and the like.
The substituents which the above-mentioned substituents may have include alkyl groups such as a methyl group, an ethyl group, and a propyl group; aralkyl groups such as a benzyl group, and a phenethyl group; aryl groups such as a phenyl group, and a biphenyl group; heterocyclic groups such as a thienyl group, a pyrrolyl group, and a pyridyl group; amino groups such as a dimethylamino group, a diethylamino group, a dibenzylamino group, a diphenylamino group, a ditolylamino group, and a dianisolylamino group; alkoxyl groups such as a methoxyl group, an ethoxyl group, a propoxyl group, and a phenoxyl group; a cyano group; halogen atoms such as fluorine, chlorine, bromine, and iodine; and the like.
Next, although a typical example of the spiro compound of the present invention will be hereinafter given, the present invention is not limited thereto.
















The Spiro compound of the present invention can be synthesized by a generally well-known method, for example an intermediate of the spiro compound is obtained by a method described in J. Org. Chem., 61, 6906, 1996, J. Am. Chem. Soc., 80, 1883, 1958, or the like, and furthermore the intermediate can be synthesized by the suzuki coupling method (e.g., Chem. Rev. 1995, 95, 2457-2483) using a palladium catalyst, the Yamamoto method (e.g., Bull. Chem. Soc. Jpn. 51, 2091, 1978) using a nickel catalyst, a method in which a synthesis is performed by using a tin aryl compound (e.g., J. Org. Chem., 52, 4296, 1987), and so on.
As compared with the conventional compound, the spiro compound of the present invention is a compound having excellent electron-transporting property, luminescence property and durability, which is useful for organic compound-containing layers of an organic luminescence device, particularly an electron-transporting layer and a luminescent layer, and a layer formed by a vacuum evaporation method, a solution-coating method, or the like hardly causes crystallization or the like and is excellent in stability with time.
Next, the organic luminescence device of the present invention will be described in detail.
The organic luminescence device of the present invention includes at least a pair of electrodes including an anode and a cathode and one or plural organic compound-containing layers sandwiched between the pair of electrodes, in which at least one layer of the organic compound-containing layers contains at least one spiro compound represented by the above general formula [I] or the general formula [II].
In the organic luminescence device of the present invention, it is preferable that at least an electron-transporting layer or a luminescent layer among the organic-compound-containing layers contain at least one Spiro compound.
In the organic luminescence device of the present invention, the spiro compound represented by the above general formula [I] or the general formula [II] is formed between the anode and the cathode by the vacuum evaporation method or the solution-coating method. The thickness of the organic layer is smaller than 10 μm, and it is preferable to make the layer as a thin film with a thickness of preferably 0.5 μm or less, more preferably 0.01 to 0.5 μm.
Further, according to a preferable mode of the organic luminescence device of the present invention, at least a luminescent layer among the layers containing the organic compound includes at least one spiro compound and a fluorene compound represented by one of the following general formula [X] and [XI]:




(where R21 and R22 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, R21, themselves or R22 themselves, which are bonded to different fluorene groups, may be identical or different from each other, and R21 and R22 that are bonded to the same fluorene group may be identical or different from each other; R23 and R24 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a cyano group, or a halogen atom, and R23 themselves or R24 themselves, which are bonded to different fluorene groups, may be identical or different from each other, and R23 and R24 that are bonded to the same fluorene group may be identical or different from each other; Ar5, Ar6, Ar7, and Ar8 represent a substituted or unsubstituted aromatic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted condensed polycyclic heterocyclic group, which may be identical or different from each other, and Ar5 and Ar6 as well as Ar7 and Ar8 may be bonded with each other to form rings, respectively; and n represents an integral number of 1 to 10); and





(where R25 and R26 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, R25 themselves or R26 themselves, which are bonded to different fluorene groups, may be identical or different from each other, and R25 and R26 that are bonded to the same fluorene group may be identical or different from each other; R27 and R28 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a cyano group, or a halogen atom, and R27 themselves or R28 themselves, which are bonded to different fluorene groups, may be identical or different from each other, and R27 and R28 that are bonded to the same fluorene group may be identical or different from each other; Ar9 and Ar10 represent a substituted or unsubstituted divalent aromatic group or a substituted or unsubstituted divalent heterocyclic group, which may be identical or different from each other; Ar11, Ar12, Ar13, and Ar14 represent a substituted or unsubstituted aromatic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted condensed polycyclic heterocyclic group, which may be identical or different from each other, and Ar11 and Ar12 as well as Ar13 and Ar14 may be bonded with each other to form rings, respectively; and m represents an integral number of 1 to 10.)

Specific examples of substituents in the general formula [X] and [XI] are the same as those as in the cases of the above general formula [I] to [IX]. Typical examples of the fluorene compounds represented by the general formula [X] or [XI] will be given thereinafter, but the present invention is not limited thereto.

























Preferable examples of the organic luminescence device are shown in FIGS. 1 to 6, respectively.
FIG. 1 is a cross-sectional diagram that illustrates an example of the organic luminescence device of the present invention. In FIG. 1, the device comprises an anode 2, a luminescent layer 3, and a cathode 4, which are formed on a substrate 1 in that order. The luminescence device used herein is useful when it singly has a hole-transporting ability, an electron-transporting ability, and a luminescence property in itself or when it is used in combination with compounds having those characteristics.
FIG. 2 is a cross-sectional diagram that illustrates another example of the organic luminescence device of the present invention. In FIG. 2, the device comprises an anode 2, a hole-transporting layer 5, an electron-transporting layer 6, and a cathode 4, which are formed on a substrate 1 in that order. In this case, a luminescent material is useful when a material having one or both of a hole-transporting property and an electron-transporting property is used for the respective layers and is used in combination with a hole-transporting material or an electron-transporting material having no luminescence property. In addition, in this case, the luminescent layer 3 is composed of either the hole-transporting layer 5 or the electron-transporting layer 6.
FIG. 3 is a cross-sectional diagram that illustrates another example of the organic luminescence device of the present invention. In FIG. 3, the device comprises an anode 2, a hole-transporting layer 5, a luminescent layer 3, an electron-transporting layer 6, and a cathode 4, which are formed on a substrate 1 in that order. This is one in which a carrier-transporting function and a luminescence function are separated from each other, and is used appropriately in combination with compounds having a hole-transporting property, an electron-transporting property, and a luminescence property, respectively. Thus, the degree of freedom in selecting a material increases extremely. In addition, various kinds of compounds having different luminescent wavelengths can be used. Therefore, the diversity of luminescence hue can be allowed. Furthermore, it also becomes possible to increase the luminescence efficiency by effectively confining each carrier or exciton in the middle luminescent layer 3.
FIG. 4 is a cross-sectional diagram that illustrates another example of the organic luminescence device of the present invention. In FIG. 4, as compared with the example of FIG. 3, the device is constructed such that a hole-injection layer 7 is inserted in the anode 2 side. It is effective in the improvement of an adhesion between the anode 2 and the hole-transporting layer 5 or the improvement of an injection property of holes, so that it is effective in lowering voltage.
FIGS. 5 and 6 are cross-sectional diagrams that illustrate other examples of the organic luminescence device of the present invention, respectively. In FIGS. 5 and 6, as compared with the examples of FIGS. 3 and 4, the device is constructed such that a layer (a hole-blocking layer 8) that prevents a hole or an exciton from passing toward the cathode 4 side is inserted between the luminescent layer 3 and the electron-transporting layer 6. The use of a compound having an extremely high ionization-potential as the hole-blocking layer 8 allows a configuration effective to an improvement in luminescence efficiency.
However, in FIGS. 1 to 6, there are shown common basic device configurations. The configuration of the organic luminescence device using the compound of the present invention is not limited thereto. For instance, it is possible to adopt various layer configurations such as one in which an insulating layer is formed at the interface between the electrode and the organic layer, one in which an adhesive layer or an interference layer is formed, and one in which the hole-transporting layer is composed of two layers with different ionization potentials.
The spiro compounds represented by the general formula [I] or the general formula [II] to be used in the present invention are compounds each having excellent electron-transporting property, luminescence property, and durability as compared with the conventional compounds, and-they can be used in any modes of FIGS. 1 to 6.
In the present invention, the spiro compounds represented by the general formula [I] or the general formula [II] are used as structural components of the electron-transporting layer or the luminescent layer. However, hole-transporting compounds, luminescent compounds, electron-transporting compounds, or the like, which have been known, may be used together if required.
The examples of those compounds will be given below.
Hole-transporting Compound







Electron-transporting Luminescent Material








Luminescent Material





Luminescent Layer Matrix Material and Electron-transporting Material





Polymeric Hole-transporting Material








Polymeric Luminescent Material and Charge-transporting Material





In the organic luminescence device of the present invention, the layer containing the spiro compound represented by the general formula [I] or the general formula [II] and the layer containing another organic compound are generally formed as thin films by a vacuum evaporation method, or by a coating method after being dissolved in an appropriate solvent. In particular, in the case of forming a film with a coating method, the film may be formed in combination with an appropriate binder resin.
The above binder resin can be selected from a wide variety of the binder resins including, for example, polyvinyl carbazole resin, polycarbonate resin, polyester resin, polyarylate resin, polystyrene resin, acrylic resin, methacryl resin, butyral resin, polyvinyl acetal resin, diallyl phthalate resin, phenol resin, epoxy resin, silicone resin, polysulfone resin, and urea resin, although not limited to them. In addition, those resins may be used solely or one or more resins may be combined with each other as a copolymer.
The anode material may be one preferably having a large work function. For example, a simple metal substance such as gold, platinum, nickel, palladium, cobalt, selenium, or vanadium, or an alloy thereof, or a metal oxide such as tin oxide, zinc oxide, indium tin oxide (ITO), or indium zinc oxide can be used. In addition, a conductive polymer such as polyaniline, polypyrrole, polythiophene, or polyphenylene sulfide can be also used. Those electrode substances may be used solely or two or more substances may be used together.
On the other hand, the cathode material may be one preferably having a small work function. For example, a simple metal substance such as lithium, sodium, potassium, cesium, calcium, magnesium, aluminum, indium, silver, lead, tin, or chromium, or an alloy of plural substances can be used. It is also possible to use a metal oxide such as indium tin oxide (ITO). In addition, the cathode may be constructed as a single layer or may have a multi-layer configuration.
The substance used in the present invention may be, although not particularly limited to, a non-transparent substrate such as a metallic substrate or a ceramic substrate, or a transparent substrate formed of glass, quartz, plastic sheets, or the like. In addition, it is also possible to control the luminescence color light by using a color filter film, a fluorescent color-converting filter film, or a dielectric reflection film as a substrate.
Furthermore, a protective layer or a sealing layer may be formed on the prepared device for preventing the device from contacting with oxygen, moisture, or the like. The protective layer may be a diamond thin film, a film made of an inorganic material such as a metal oxide or a metal nitride, or a polymer film made of a fluorocarbon resin, polyparaxylene, polyethylene, a silicone resin, or a polystyrene resin, or furthermore it may be a photo-curing resin. Furthermore, it is also possible to package the device itself with an appropriate sealing resin while covering it with a glass, a gas-impermeable film, a metal, or the like.
EXAMPLES
Hereinafter, the present invention will be described more specifically with examples. However, the present invention is not limited to those examples.
Synthesis Example 1
[Synthesis of Exemplified Compound No. 1]




In a 500-ml three-neck flask, 2.0 g (3.16 mmol) of 2,2′-7,7′-tetrabromo-9,9′-spirobifluorene [1]*1), 4.5 g (19.0 mmol) of 9,9-dimethylfluorene-2-boronic acid [2], 140 ml of toluene, and 70 ml of ethanol were added, and an aqueous solution of 25 g of sodium carbonate/130 ml of water was dropped thereto with stirring in a nitrogen atmosphere at room temperature, followed by the addition of 0.7 g (0.63 mmol) of tetrakis (triphenylphosphine) palladium (0). After stirring the mixture for 30 minutes at room temperature, the temperature is allowed to rise to 77° C., followed by stirring for 8 hours. After the reaction, an organic layer was extracted with chloroform and was then dried with anhydrous sodium sulfate, followed by purification with a silica gel column (hexane+toluene mixture developing solvent). Consequently, 2.5 g (73% yield) of the exemplified compound No. 1 (white crystal) was obtained.
Synthesis Example 2
[Synthesis of Exemplified Compound No. 7]




In a 500-ml three-neck flask, 2.0 g (3.16 mmol) of 2,2′-7,7′-tetrabromo-9,9′-spirobifluorene [1], 4.7 g (19.0 mmol) of pyrene-1-boronic acid [2], 140 ml of toluene, and 70 ml of ethanol were added, and an aqueous solution of 25 g of sodium carbonate/130 ml of water was dropped with stirring in a nitrogen atmosphere at room temperature, followed by the addition of 0.7 g (0.63 mmol) of tetrakis (triphenylphosphine) palladium (0). After stirring the mixture for 30 minutes at room temperature, the temperature is allowed to rise to 77° C., followed by stirring for 8 hours. After the reaction, an organic layer was extracted with chloroform and was then dried with anhydrous sodium sulfate, followed by purification with a silica gel column (hexane+toluene mixture developing solvent). Consequently, 2.3 g (65% yield) of the exemplified compound No. 7 (white crystal) was obtained.
Synthesis Example 3
[Synthesis of Exemplified Compound No. 14]




In a 300-ml three-neck flask, 2.0 g (3.16 mmol) of 2,2′-7,7′-tetrabromo-9,9′-spirobifluorene [1], 3.2 g (19.0 mmol) of carbazole [2], and 150 ml of xylene were added, and 2.0 g (20.9 mmol) of t-butoxy sodium was added thereto with stirring in a nitrogen atmosphere at room temperature, followed by heating the mixture to a temperature of 50° C. In this mixture, a 5-ml xylene solution of 0.035 g (0.16 mmol) of palladium acetate and 0.032 g (0.16 mmol) of tri-t-butylphosphine was added, followed by heating the mixture to 130° C. and stirring for 8 hours. After the reaction, an organic layer was extracted with chloroform and was then dried with anhydrous sodium sulfate, followed by purification with a silica gel column (hexane+toluene mixture developing solvent). Consequently, 1.7 g (55% yield) of the exemplified compound No. 14 (white crystal) was obtained.
Synthesis Example 4
[Synthesis of Exemplified Compound No. 20]




In a 300-ml three-neck flask, 3.0 g (9.02 mmol) of 5,5′-spirobi(dibenzosilole) [1]*2) and 100 ml of chloroform were added, and then 0.07 g (0.45 mmol) of iron chloride (III) was added with stirring at 0° C., followed by dropping 5.9 g (37.0 mmol) of bromine. After stirring the mixture for 6 hours at room temperature, an organic layer was extracted with chloroform and was then washed with a sodium thiosulfate aqueous solution, followed by drying with anhydrous sodium sulfate. A crystal obtained by distilling off the solvent was re-crystallized with chloroform, resulting in 4.0 g (69% yield) of tetrabromo-5,5′-spiro(dibenzosilole) [2] (white crystal).
Next, in a 500-ml three-neck flask, 2.0 g (3.09 mmol) of [2], 4.4 g (18.5 mmol) of 9,9-dimethylfluorene-2-boronic acid [3], 140 ml of toluene, and 70 ml of ethanol were added, and an aqueous solution of 25 g of sodium carbonate/130 ml of water was dropped in a nitrogen atmosphere, followed by the addition of 0.5 g (0.43 mmol) of tetrakis (triphenylphosphine) palladium (0). After stirring the mixture for 30 minutes at room temperature, the temperature is allowed to rise to 77° C., followed by stirring for 8 hours. After the reaction, an organic layer was extracted with chloroform and was then dried with anhydrous sodium sulfate, followed by purification with a silica gel column (hexane+toluene mixture developing solvent). Consequently, 2.2 g (64% yield) of the exemplified compound No. 20 (white crystal) was obtained.
Example 1
A device having the structure shown in FIG. 2 was prepared.
On a glass substrate as a substrate 1, indium tin oxide (ITO) is deposited into a film with a thickness of 120 nm by a sputtering method to obtain an anode 2, so that the substrate thus formed is used as a transparent conductive support substrate. This was sequentially subjected to ultrasonic cleanings with acetone and isopropyl alcohol (IPA), and was then washed with IPA by boiling, followed by drying. Furthermore, one subjected to UV/ozone cleaning was used as a transparent conductive support substrate.
On the transparent conductive support substrate, a chloroform solution of the compound represented by the following structural formula was coated into a film of 30 nm in thickness by a spin-coating method, resulting in a hole-transporting layer 5.




Furthermore, an electron-transporting layer 6 was formed by forming a film of 50 nm in thickness from a spiro compound represented by the exemplified compound No. 1 by a vacuum evaporation method. The film formation was performed under the conditions in which the degree of vacuum at the time of evaporation was 1.0×10−4Pa and the film formation rate was 0.2 to 0.3 nm/sec.
A metal layer film of 50 nm in thickness was formed on the above organic layer as a cathode 4 by using an evaporation material including aluminum and lithium (lithium concentration: 1% by atom) by a vacuum evaporation method, and further an aluminum layer of 150 nm in thickness was formed by a vacuum evaporation method. The film formation was performed under the conditions in which the degree of vacuum at the time of evaporation was 1.0×10−4Pa and the film formation rate was 1.0 to 1.2 nm/sec.
Furthermore, the resulting product was covered with a protective glass plate in a nitrogen atmosphere and was then sealed with an acrylic resin adhesive.
When a direct current voltage of 10 V was applied on the device obtained in this way with an ITO electrode (anode 2) provided as a positive electrode and an Al—Li electrode (cathode 4) provided as a negative electrode, the current was caused to flow into the device at a current density of 11.5 mA/cm2 and blue-colored luminescence at a luminance of 3800 cd/m2 was observed.
Furthermore, when the current density was kept at 10.0 mA/cm2 and the voltage was applied for 100 hours, an initial luminance of 3500 cd/m2 changed to a luminance of 3300 cd/m2 after 100 hours, indicating small deterioration of luminance.
Examples 2 to 10
Devices were prepared and evaluated in the same way as that of Example 1, except that the exemplified compounds shown in Table 1 were used in place of the exemplified compound No. 1. The results are shown in Table 1.
Comparative Examples 1 to 3
Devices were prepared and evaluated in the same way as that of Example 1, except that the compounds represented by the following structural formula were used in place of the exemplified compound No. 1. The results are shown in Table 1.
Comparative Compound No. 1




Comparative Compound No. 2





Comparative Compound No. 3















TABLE 1









Initial stage
Durability














Exemplified
Applied

Current
Initial
Luminance after



compound
voltage
Luminance
density
luminance
100-hour


Example No.
No.
(V)
(cd/m2)
(mA/cm2)
(cd/m2)
(cd/m2)
















Example 1
1
10
3800
10.0
3500
3300


2
5
10
4500
10.0
4100
3800


3
7
10
3500
10.0
3300
3200


4
10
10
2900
10.0
2700
2500


5
13
10
3800
10.0
3500
3400


6
16
10
2400
10.0
2200
1900


7
18
10
2400
10.0
2300
2200


8
21
10
3600
10.0
3500
3300


9
24
10
2700
10.0
2600
2200


10 
27
10
2300
10.0
2100
2000


Comparative
Comparative 1
10
850
10.0
800
550


Example 1


2
Comparative 2
10
700
10.0
650
250


3
Comparative 3
10
400
10.0
350
100









Example 11
A device having the structure shown in FIG. 3 was prepared.
In the same manner as in Example 1, a hole-transporting layer 5 was formed on the transparent conductive support substrate.
Further, a luminescent layer 3 was formed by forming a film of 20 nm in thickness from a spiro compound represented by the exemplified compound No. 3 by a vacuum evaporation method. The film formation was performed under the conditions in which the degree of vacuum at the time of evaporation was 1.0×10−4Pa and the film formation rate was 0.2 to 0.3 nm/sec.
Furthermore, an electron-transporting layer 6 was formed by forming a film of 40 nm in thickness from aluminum tris quinolinol by a vacuum evaporation method. The film formation was performed under the conditions in which the degree of vacuum at the time of evaporation was 1.0×10−4Pa and the film formation rate was 0.2 to 0.3 nm/sec.
Next, after forming a cathode 4 in the same manner as in Example 1, the resulting product was sealed.
When a direct current voltage of 8 V was applied on the device obtained in this way with an ITO electrode (anode 2) provided as a positive electrode and an Al—Li electrode (cathode 4) provided as a negative electrode, the current was caused to flow into the device at a current density of 12.0 MA/cm2 and blue-colored luminescence at a luminance of 6700 cd/m2 was observed.
Furthermore, when the current density was kept at 10.0 mA/cm2 and the voltage was applied for 100 hours, an initial luminance of 5500 cd/m2 changed to a luminance of 5200 cd/m2 after 100 hours, indicating small deterioration of luminance.
Examples 12 to 20
Devices were prepared and evaluated in the same way as that of Example 11, except that the exemplified compounds shown in Table 2 were used in place of the exemplified compound No. 3. The results are shown in Table 2.
Comparative Examples 4 to 6
Devices were prepared and evaluated in the same way as that of Example 11, except that the comparative compounds No. 1 to No. 3 were used in place of the exemplified compound No. 3. The results are shown in Table 2.










TABLE 2









Initial stage
Durability














Exemplified
Applied

Current
Initial
Luminance after



compound
voltage
Luminance
density
luminance
100-hour


Example No.
No.
(V)
(cd/m2)
(mA/cm2)
(cd/m2)
(cd/m2)
















Example 11
3
8
6700
10.0
5500
5200


12
6
8
6500
10.0
5200
4800


13
8
8
7300
10.0
6000
5700


14
11
8
5200
10.0
4400
4100


15
15
8
3900
10.0
3600
3400


16
19
8
5100
10.0
4200
4000


17
23
8
5600
10.0
4600
4300


18
25
8
3600
10.0
2700
2500


19
26
8
3800
10.0
2900
2600


20
28
8
5200
10.0
4100
3800


Comparative
Comparative 1
8
800
10.0
770
450


Example 4


 5
Comparative 2
8
500
10.0
400
150


 6
Comparative 3
8
1200
10.0
900
300









Example 21
A device having the structure shown in FIG. 3 was prepared.
On a transparent conductive support substrate similar to that in Example 1, a chloroform solution of a compound represented by the following structural formula was applied into a film of 20 nm in thickness by a spin-coating method, resulting in a hole-transporting layer 5.




Furthermore, the spiro compound represented as the exemplified compound No. 7 and the fluorene compound represented as the exemplified compound No. FL-1 (weight ratio of 100:1) were deposited into a film with a thickness of 20 nm by the vacuum evaporation method to form a luminescent layer 3. The film formation was performed under the conditions in which the degree of vacuum at the time of evaporation was 1.0×10−4Pa and the film formation rate was 0.2 to 0.3 nm/sec.
Furthermore, an electron-transporting layer 6 was formed by forming a film of 40 nm in thickness from aluminum tris quinolinol by a vacuum evaporation method. The film formation was performed under the conditions in which the degree of vacuum at the time of evaporation was 1.0×10−4Pa and the film formation rate was 0.2 to 0.3 nm/sec.
Next, after forming a cathode 4 in the same manner as in Example 1, the resulting product was sealed.
When a direct current voltage of 8 V was applied on the device obtained in this way with an ITO electrode (anode 2) provided as a positive electrode and an Al—Li electrode (cathode 4) provided as a negative electrode, the current was caused to flow into the device at a current density of 13.5 mA/cm2 and blue-colored luminescence at a luminance of 16000 cd/m2 was observed.
Furthermore, when the current density was kept at 10.0 mA/cm2 and the voltage was applied for 100 hours, the initial luminance of 12000 cd/m2 changed to a luminance of 9000 cd/m2 after 100 hours, indicating small deterioration of luminance.
Examples 22 to 53
Devices were prepared and evaluated in the same way as that of Example 21, except that the exemplified fluorene compound shown in Table 3 was used in place of the exemplified fluorene compound No. FL-1. The results are shown in Table 3.
Comparative Examples 7 to 9
Devices were prepared and evaluated in the same way as that of Example 21, except that the comparative compounds No. 1 to No. 3 were used in place of the exemplified compound No. 7. The results are shown in Table 3.










TABLE 3









Initial stage
Durability















Exemplified
Exemplified
Applied

Current
Initial
Luminance after



compound
fluorene
voltage
Luminance
density
luminance
100-hour


Example No.
No.
compound No.
(V)
(cd/m2)
(mA/cm2)
(cd/m2)
(cd/m2)

















Example 21
7
FL-1
8
16000
10.0
12000
9000


22
7
FL-2
8
15000
10.0
12000
8000


23
7
FL-3
8
17000
10.0
14000
10000


24
7
FL-4
8
12000
10.0
8500
7000


25
7
FL-5
8
9000
10.0
7000
6000


26
7
FL-6
8
19000
10.0
14000
11000


27
7
FL-7
8
20000
10.0
14000
12000


28
7
FL-9
8
22000
10.0
17000
13000


29
7
FL-10
8
21000
10.0
16000
13000


30
7
FL-12
8
17000
10.0
11000
8500


31
7
FL-13
8
13000
10.0
10000
7000


32
7
FL-14
8
18000
10.0
16000
14000


33
7
FL-15
8
19000
10.0
16000
14000


34
7
FL-18
8
19000
10.0
17000
15000


35
7
FL-21
8
23000
10.0
19000
16000


36
7
FL-24
8
24000
10.0
19000
17000


37
7
FL-26
8
9500
10.0
8000
6000


38
7
FL-27
8
17000
10.0
13000
11000


39
7
FL-28
8
10000
10.0
8000
6500


40
7
FL-29
8
8000
10.0
7000
6000


41
7
FL-30
8
9500
10.0
8000
6500


42
7
FL-31
8
12000
10.0
10000
7000


43
7
FL-32
8
23000
10.0
18000
15000


44
7
FL-33
8
23000
10.0
17000
14000


45
7
FL-36
8
25000
10.0
19000
16000


46
7
FL-37
8
25000
10.0
18000
15000


47
7
FL-38
8
20000
10.0
17000
14000


48
7
FL-39
8
24000
10.0
19000
16000


49
7
FL-41
8
26000
10.0
20000
16000


50
7
FL-42
8
26000
10.0
21000
17000


51
7
FL-44
8
15000
10.0
12000
9500


52
7
FL-45
8
12000
10.0
9000
7500


53
7
FL-46
8
13000
10.0
11000
7000


Comparative
Comparative
FL-1
8
3000
10.0
2500
900


Example 7
1


 8
Comparative
FL-1
8
2000
10.0
1500
200



2


 9
Comparative
FL-1
8
4500
10.0
3500
600



3









Example 54
A device having the structure shown in FIG. 3 was prepared.
On a transparent conductive support substrate similar to that in Example 1, a chloroform solution of a compound represented by the following structural formula was applied into a film of 20 nm in thickness by a spin-coating method, resulting in a hole-transporting layer 5.




Furthermore, the spiro compound represented as the exemplified compound No. 2 and a compound represented by the following structural formula (weight ratio of 100:5) were deposited into a film with a thickness of 20 nm by the vacuum evaporation method to form a luminescent layer 3. The film formation was performed under the conditions in which the degree of vacuum at the time of evaporation was 1.0×10−4Pa and the film formation rate was 0.2 to 0.3 nm/sec.




Furthermore, an electron-transporting layer 6 was formed by forming a film of 40 nm in thickness from bathophenanthroline (BPhen) by the vacuum evaporation method. The film formation was performed under the conditions in which the degree of vacuum at the time of evaporation was 1.0×10−4Pa and the film formation rate was 0.2 to 0.3 nm/sec.
Next, after forming a cathode 4 in the same manner as in Example 1, the resulting product was sealed.
When a direct current voltage of 8 V was applied on the device obtained in this way with an ITO electrode (anode 2) provided as a positive electrode and an Al—Li electrode (cathode 4) provided as a negative electrode, the current was caused to flow into the device at a current density of 10.5 mA/cm2 and green-colored luminescence at a luminance of 9000 cd/m2 was observed.
Furthermore, when the current density was kept at 7.0 mA/cm2 and the voltage was applied for 100 hours, the initial luminance of 7500 cd/m2 changed to a luminance of 6500 cd/m2 after 100 hours, indicating small deterioration of luminance.
Examples 55 to 63
Devices were prepared and evaluated in the same way as that of Example 54, except that the exemplified compound shown in Table 4 was used in place of the exemplified compound No. 2. The results are shown in Table 4.
Comparative Examples 10 to 12
Devices were prepared and evaluated in the same way as that of Example 54, except that the comparative compounds No. 1 to No. 3 were used in place of the exemplified compound No. 2. The results are shown in Table 4.










TABLE 4









Initial stage
Durability














Exemplified
Applied


Initial
Luminance



compound
voltage
Luminance
Current density
luminance
after 100-hour


Example No.
No.
(V)
(cd/m2)
(mA/cm2)
(cd/m2)
(cd/m2)
















Example 54
2
8
9000
7.0
7500
6500


55
4
8
9500
7.0
8000
6500


56
6
8
7000
7.0
6000
5000


57
12
8
8000
7.0
6000
5500


58
14
8
14000
7.0
11000
9000


59
15
8
10000
7.0
9000
7500


60
20
8
10000
7.0
8000
7000


61
22
8
9500
7.0
8000
7500


62
29
8
15000
7.0
13000
10000


63
30
8
8500
7.0
8000
7000


Comparative
Comparative 1
8
1300
7.0
900
300


Example 10


11
Comparative 2
8
1000
7.0
900
100


12
Comparative 3
8
2500
7.0
2000
700









Example 64
A device having the structure shown in FIG. 1 was prepared.
On a transparent conductive support substrate which was similar to that of Example 1, a solution prepared by dissolving 0.050 g of a spiro compound represented by the exemplified compound No. 1 and 1.00 g of poly-N-vinyl carbazole (a weight average molecular weight=63,000) in 80 ml of chloroform was applied into a film of 120 nm in thickness by a spin-coating method (rotation speed=2000 rpm) to form an organic layer (a luminescent layer 3).
Next, after forming a cathode 4 in the same manner as in Example 1, the resulting product was sealed.
When a direct current voltage of 10 V was applied on the device obtained in this way with an ITO electrode (anode 2) provided as a positive electrode and an Al—Li electrode (cathode 4) provided as a negative electrode, the current was caused to flow into the device at a current density of 8.0 mA/cm2 and blue-colored luminescence at a luminance of 1900 cd/m2 was observed.
Furthermore, when the current density was kept at 5.0 mA/cm2 and the voltage was applied for 100 hours in the nitrogen atmosphere, the initial luminance of 1000 cd/m2 changed to a luminance of 850 cd/m2 after 100 hours, indicating small deterioration of luminance.
Examples 65 to 68
Devices were prepared and evaluated in the same way as that of Example 64, except that the exemplified compound shown in Table 5 was used in place of the exemplified compound No. 1. The results are shown in Table 5.
Comparative Examples 13 to 15
Devices were prepared and evaluated in the same way as that of Example 64, except that the comparative compounds No. 1 to No. 3 were used in place of the exemplified compound No. 1. The results are shown in Table 5.










TABLE 5









Initial stage
Durability














Exemplified
Applied

Current
Initial
Luminance after 100-



compound
voltage
Luminance
density
luminance
hour


Example No.
No.
(V)
(cd/m2)
(mA/cm2)
(cd/m2)
(cd/m2)
















Example 64
1
10
1900
5.0
1000
850


65
7
10
2500
5.0
1600
1400


66
19
10
1400
5.0
1000
800


67
20
10
1800
5.0
1400
1300


68
24
10
1900
5.0
1200
950


Comparative
Comparative 1
10
300
5.0
200
No luminescence


Example 13


14
Comparative 2
10
200
5.0
150
No luminescence


15
Comparative 3
10
550
5.0
400
50









As described with reference to the embodiments and the examples, the organic luminescence device using the spiro compound represented by the general formula [I] or the general formula [II] provides luminescence with a high luminance by the application of a low voltage and is excellent in durability.
In particular, the organic layer containing the spiro compound of the present invention is excellent as an electron-transporting layer and is also excellent as a luminescent layer.
Furthermore, the device can be prepared by using a vacuum evaporation method or a casting method, so that the device having a large area can be easily prepared at a comparatively low cost.

## Claims

1. An organic luminescence device comprising at least a pair of electrodes including an anode and a cathode and one or a plurality of layers containing an organic compound sandwiched between the pair of electrodes, wherein at least one of the layers containing the organic compound contains at least one spiro compound represented by the following general formula [II]:



wherein R5, R6, R7, and R8 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, cyano group, or a halogen atom, and R5, R6, R7, and R8, may be identical or different from each other; and Ar3 and Ar4 represent a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group, which may be identical or different from each other and wherein at least one of Ar3 and Ar4 is a condensed polycyclic aromatic group represented by one of the following general formula [III] to [VIII]:




wherein R9 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom; and R10 and R11 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, which may be identical or different from each other;




wherein R12 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom; and R13 and R14 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, which may be identical or different from each other; and




wherein R15 to R18 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom; and
wherein at least a luminescent layer among the layers containing the organic compound contains at least one of the spiro compounds and a fluorene compound represented by the following general formula [X]:




wherein R21 and R22 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, R21 themselves or R22 themselves, which are bonded to different fluorene groups, may be identical or different from each other, and R21 and R22 that are bonded to the same fluorene group may be identical or different from each other; R23 and R24 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a cyano group, or a halogen atom, and R23 themselves or R24 themselves, which are bonded to different fluorene groups, may be identical or different from each other, and R23 and R24 that are bonded to the same fluorene group may be identical or different from each other; Ar5, Ar6, Ar7, and Ar8 represent a substituted or unsubstituted aromatic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted condensed polycyclic heterocyclic group, which may be identical or different from each other, and Ar5 and Ar6 as well as Ar7 and Ar8 may be bonded with each other to form rings, respectively; and n represents an integral number of 1 to 10.

2. An organic luminescence device comprising at least a pair of electrodes including an anode and a cathode and one or a plurality of layers containing an organic compound sandwiched between the pair of electrodes, wherein at least one of the layers containing the organic compound contains at least one spiro compound represented by the following general formula [II]:



wherein R5, R6, R7, and R8 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, cyano group, or a halogen atom, and R5, R6, R7, and R8 may be identical or different from each other; and Ar3 and Ar4 represent a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group, which may be identical or different from each other and wherein at least one of Ar3 and Ar4 is a condensed polycyclic aromatic group represented by one of the following general formula [III] to [VIII]:




wherein R9 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom; and R10 and R11 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, which may be identical or different from each other;




wherein R12 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom; and R13 and R14 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, which may be identical or different from each other; and




wherein R15 to R18 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group, a cyano group, or a halogen atom; and
wherein at least a luminescent layer among the layers containing the organic compound contains at least one of the spiro compounds and a fluorene compound represented by the following general formula [XI]:




(wherein R25 and R26 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, R25 themselves or R26 themselves, which are bonded to different fluorene groups, may be identical or different from each other, and R25 and R26 that are bonded to the same fluorene group may be identical or different from each other; R27 and R28 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a cyano group, or a halogen atom, and R27 themselves or R28 themselves, which are bonded to different fluorene groups, may be identical or different from each other, and R27 and R28 that are bonded to the same fluorene group may be identical or different from each other; Ar9 and Ar10 represent a substituted or unsubstituted divalent aromatic group or a substituted or unsubstituted divalent heterocyclic group, which may be identical or different from each other; Ar11, Ar12, Ar13, and Ar14 represent a substituted or unsubstituted aromatic group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted condensed polycyclic heterocyclic group, which may be identical or different from each other, and Ar11 and Ar12 as well as Ar13 and Ar14 may be bonded with each other to form rings, respecdvely; and m represents an integral number of 1 to 10.)