JP2007261969A - 2,6-fluorenyl-substituted pyridine compound and organic luminescent element using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic luminescent element with high luminance and high emission efficiency, and to provide a compound realizing the same. <P>SOLUTION: The new 2,6-fluorenyl-substituted pyridine compound and the organic luminescent element having the same are provided, respectively. The organic luminescent element affords high-luminance emission at a low applied voltage, being excellent in durability as well. Particularly, the organic layer of this luminescent element, containing the above compound, is excellent as an electron transport layer and as a luminescent layer as well. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a novel organic compound and an organic light-emitting device using the same.

  An organic electroluminescence element (hereinafter referred to as an organic light emitting element) is an element having a structure in which a thin film containing a fluorescent organic compound is sandwiched between an anode and a cathode. Then, by injecting electrons and holes (holes) from each electrode, excitons of the fluorescent compound are generated, and the device uses light emitted when the excitons return to the ground state.

In 1987, Kodak Research (Non-Patent Document 1) discloses an element using an alloy of ITO as an anode and magnesium silver as a cathode, and an aluminum quinolinol complex as an electron transport material and a light-emitting material. This device is a functionally separated two-layer device using a triphenylamine derivative as a hole transport material, and light emission of about 1000 cd / m ² is reported at an applied voltage of about 10V. Related patents include Patent Documents 1 to 3.

  In addition, by changing the type of the fluorescent organic compound, light emission from ultraviolet to infrared is possible, and recently, various compounds have been actively researched. For example, it is described in Patent Documents 4 to 11.

  In recent years, many studies have been made on using phosphorescent compounds as light emitting materials and using triplet state energy for EL light emission. A group of Princeton University reports that an organic light emitting device using an iridium complex as a light emitting material exhibits high luminous efficiency (Non-Patent Document 2).

  Recently, a phosphorescent organic light-emitting device using an iridium complex such as Ir (ppy) 3 (Non-patent Document 3) as a light-emitting material has attracted attention, and high luminous efficiency has been reported.

  Furthermore, in addition to the organic light emitting device using the low molecular material as described above, an organic light emitting device using a conjugated polymer has been reported by a group of Cambridge University (Non-Patent Document 4). In this report, light emission was confirmed in a single layer by forming a film of polyphenylene vinylene (PPV) in a coating system. Patents 12 to 16 and the like can be cited as related patents for organic light-emitting devices using conjugated polymers.

  As described above, recent advances in organic light-emitting devices are remarkable, and their features are high brightness, variety of emission wavelengths, high-speed response, low profile, and light-emitting devices with low applied voltage. Suggests the possibility to.

  However, at present, it is necessary to further improve the initial characteristics such as light emission efficiency and the durability characteristics such as luminance deterioration due to long-time light emission. These initial characteristics and durability characteristics are attributed to all layers such as a hole injection layer, a hole transport layer, a light emitting layer, a hole block layer, an electron transport layer, and an electron injection layer constituting the device.

Examples of materials used for the hole block layer, electron transport layer, and electron injection layer that have been known so far include phenanthroline compounds, aluminum quinolinol complexes, oxadiazole compounds, and triazole compounds. Examples of using these materials for the light-emitting layer or the electron transport layer include Patent Documents 17 to 25, but the initial characteristics and durability characteristics of these EL elements are not sufficient.
U.S. Pat. No. 4,539,507 U.S. Pat. No. 4,720,432 U.S. Pat. No. 4,885,211 US Pat. No. 5,151,629 US Pat. No. 5,409,783 US Pat. No. 5,382,477 JP-A-2-247278 JP-A-3-255190 JP-A-5-202356 JP-A-9-202878 JP-A-9-227576 US Pat. No. 5,247,190 US Pat. No. 5,514,878 US Pat. No. 5,672,678 JP-A-4-145192 Japanese Patent Application Laid-Open No. 5-247460 JP-A-5-331459 Japanese Patent Laid-Open No. 7-82551 JP 2001-267080 A JP 2001-131174 A JP-A-2-216791 JP-A-10-233284 U.S. Pat. No. 4,539,507 U.S. Pat. No. 4,720,432 US Pat. No. 4,885,211, Appl. Phys. Lett. 51,913 (1987) Nature, 395, 151 (1998) Appl. Phys. Lett. 75, 4 (1999) Nature, 347, 539 (1990)

  An object of the present invention is to provide a novel 2,6-fluorenyl-substituted pyridine compound.

  Another object of the present invention is to provide an organic light-emitting device using a novel 2,6-fluorenyl-substituted pyridine compound and having high emission luminance and high emission efficiency. It is another object of the present invention to provide an organic light emitting device that has high durability and little luminance deterioration due to long-time light emission.

  Another object of the present invention is to provide an organic light emitting device that can be easily manufactured and can be produced at a relatively low cost.

  That is, the 2,6-fluorenyl-substituted pyridine compound of the present invention is represented by the following general formula [I].

  Formula [I]

  In the formula, R1, R2 and R3 are each a hydrogen atom, a substituted or unsubstituted alkyl group, an aryl group, a heterocyclic group, a condensed polycyclic aromatic group, a condensed polycyclic heterocyclic group, an aryloxy group, a substituted amino group, Represents a group selected from a halogen atom, a trifluoromethyl group and a cyano group; R1, R2 and R3 may be the same or different. R1 to R3 may be bonded to each other to form a ring. R4 and R5 may be the same or different from each other in a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Ar1 and Ar2 represent a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group, or a substituted or unsubstituted condensed polycyclic heterocyclic group, and may be the same or different.

  Furthermore, the 2,6-fluorenyl substituted pyridine compound of the present invention is represented by the following general formula [II].

  Formula [II]

  In the formula, R6 may be a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, an oxygen atom, a substituted or unsubstituted nitrogen atom, a sulfur atom, a silicon atom, or a divalent bond. A group selected from a substituted or unsubstituted heterocyclic group, a divalent substituted or unsubstituted condensed polycyclic aromatic group, or a divalent substituted or unsubstituted condensed polycyclic heterocyclic group. R7 and R8 may be the same or different from each other in a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Ar3, Ar4, Ar5 and Ar6 each represents 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 the same or different. Good.

  The organic light-emitting device of the present invention is an organic light-emitting device having at least a layer containing a pair of electrodes composed of an anode and a cathode, and one or a plurality of organic compounds sandwiched between the pair of electrodes. At least one of the layers to be contained contains at least one of the above 2,6-fluorenyl-substituted pyridine compounds.

  The organic light emitting device using the 2,6-fluorenyl-substituted pyridine compound represented by the general formula [I] or the general formula [II] can emit light with high luminance at a low applied voltage and has excellent durability. In particular, the organic layer containing the 2,6-fluorenyl-substituted pyridine compound of the present invention is excellent as an electron transport layer and also as a light emitting layer.

  Furthermore, the device can be formed using vacuum deposition, casting method, or the like, and a device with a large area can be easily manufactured at a relatively low cost.

  Hereinafter, the present invention will be described in detail. Specific examples of the linking group and substituent in the above general formulas [I]-[II] are shown below.

  Examples of the alkyl group include, but are not limited to, a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a tertiary butyl group, and an octyl group.

  Aralkyl groups include, but are not limited to, benzyl and phenethyl groups.

  Examples of the aryl group include, but are not limited to, a phenyl group, a biphenyl group, and a terphenyl group.

  Examples of the heterocyclic group include, but are not limited to, a thienyl group, a pyrrolyl group, a pyridyl group, a bipyridyl group, a terpyridyl group, an oxazolyl group, an oxadiazolyl group, a thiazolyl group, and a thiadiazolyl group.

  Examples of the condensed polycyclic aromatic group include 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 perylenyl group, and a triphenylenyl group. Is not to be done.

  Examples of the condensed polycyclic heterocyclic group include, but are not limited to, a quinolyl group, a carbazolyl group, an acridinyl group, a phenazyl group, and a phenanthroyl group.

  Examples of the aryloxy group include, but are not limited to, a phenoxyl group, a fluorenoxyl group, and a naphthoxyl group.

  Examples of substituted amino groups include dimethylamino group, diethylamino group, dibenzylamino group, diphenylamino group, ditolylamino group, dianisolylamino group, fluorenylphenylamino group, difluorenyl group, naphthylphenylamino group, dinaphthylamino group. Of course, it is not limited to these.

  Examples of the halogen atom include fluorine, chlorine, bromine and iodine, but are not limited to these.

  Examples of the divalent heterocyclic group include dibenzofuranylene, dibenzothiophenylene, furylene group, pyrrolylene group, pyridylene group, terpyridylene group, thienylene group, tertienylene group, oxazolylene group, thiazolylene group, carbazolylene, etc. It is not limited to.

  Examples of the divalent arylene group include a phenylene group, a biphenylene group, a terphenylene group, and the like, but are not limited thereto.

  Examples of the trivalent arylene group include a phenylene group and a triphenylene group, but of course, the trivalent arylene group is not limited thereto.

  Examples of the substituent that the substituent may have include an alkyl group such as a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a tertiary butyl group, and an octyl group, a benzyl group, and a phenethyl group. Aryl groups such as aralkyl groups, phenyl groups, biphenyl groups, terphenyl groups, thienyl groups, pyrrolyl groups, pyridyl groups, bipyridyl groups, terpyridyl groups, oxazolyl groups, oxadiazolyl groups, thiazolyl groups, thiadiazolyl groups and other heterocyclic groups, fluorenyl Group, naphthyl group, fluoranthenyl group, anthryl group, phenanthryl group, pyrenyl group, tetracenyl group, pentacenyl group, perylenyl group, triphenylenyl group and other condensed polycyclic aromatic groups, quinolyl group, carbazolyl group, acridinyl group, phenazyl group , Phenanthroyl Condensed polycyclic heterocyclic groups, aryloxy groups such as phenoxyl group, fluorenoxyl group, naphthoxyl group, dimethylamino group, diethylamino group, dibenzylamino group, diphenylamino group, ditolylamino group, dianisolylamino group Substituted amino groups such as fluorenylphenylamino group, difluorenyl group, naphthylphenylamino group, dinaphthylamino group, halogen atoms such as fluorine, chlorine, bromine, iodine, trifluoromethyl group, cyano group, etc. Of course, it is not limited to these.

  Next, typical examples of the 2,6-fluorenyl-substituted pyridine compound of the present invention will be given below, but the present invention is not limited thereto.

  [Examples of compounds]

  The 2,6-fluorenyl-substituted pyridine compound of the present invention is a compound that is excellent in electron transport property, light emission property, and durability as compared with conventional compounds. It is also useful as a layer containing an organic compound in an organic light emitting device, particularly an electron transporting layer and a light emitting layer, and a layer formed by a vacuum deposition method or a solution coating method is less likely to crystallize and has excellent temporal stability. Yes.

Next, the organic light emitting device of the present invention will be described in detail.
The organic light-emitting device of the present invention includes the organic compound in an organic light-emitting device having at least a layer including a pair of electrodes composed of an anode and a cathode and one or more organic compounds sandwiched between the pair of electrodes. At least one of the layers contains at least one 2,6-fluorenyl-substituted pyridine compound represented by the above general formula [I] or general formula [II].

  In the organic light-emitting device of the present invention, it is preferable that at least the hole block layer, the electron transport layer, the electron injection layer, or the light-emitting layer among the layers containing an organic compound contains at least one of the 2,6-fluorenyl-substituted pyridine compounds. . Among the 2,6-fluorenyl-substituted pyridine compounds, those having a relatively low HOMO have a high hole blocking property and are particularly preferable as a hole blocking layer or an electron transporting layer.

  In the organic light-emitting device of the present invention, the 2,6-fluorenyl-substituted pyridine compound represented by the above general formula [I] or [II] is formed between the anode and the cathode by a vacuum deposition method or a solution coating method. The thickness of the organic layer is less than 10 μm, preferably 0.5 μm or less, more preferably 0.01 to 0.5 μm.

1 to 6 show preferred examples of the organic light emitting device of the present invention.
FIG. 1 is a cross-sectional view showing an example of the organic light emitting device of the present invention. FIG. 1 shows a structure in which an anode 2, a light emitting layer 3 and a cathode 4 are sequentially provided on a substrate 1. The light-emitting element used here is useful when it has a single hole transport ability, electron transport ability, and light-emitting performance, or when a compound having each characteristic is mixed.

  FIG. 2 is a cross-sectional view showing another example of the organic light emitting device of the present invention. FIG. 2 shows a configuration in which an anode 2, a hole transport layer 5, an electron transport layer 6 and a cathode 4 are sequentially provided on a substrate 1. In this case, the light-emitting substance is made of a material having either or both of the hole-transporting and electron-transporting functions, and used in combination with a simple hole-transporting substance or electron-transporting substance that does not emit light. Useful in cases. In this case, the light emitting layer 3 is composed of either the hole transport layer 5 or the electron transport layer 6.

  FIG. 3 is a cross-sectional view showing another example of the organic light emitting device of the present invention. FIG. 3 shows a structure in which an anode 2, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6 and a cathode 4 are sequentially provided on a substrate 1. This is a separation of carrier transport and light emission functions. It is used in combination with compounds having hole transport properties, electron transport properties, and light emission properties in a timely manner. Since various compounds having different values can be used, it is possible to diversify the emission hue. In addition, it is possible to effectively confine each carrier or exciton in the central light emitting layer to improve the light emission efficiency.

  FIG. 4 is a cross-sectional view showing another example of the organic light emitting device of the present invention. FIG. 4 shows a configuration in which a hole injection layer 7 is inserted on the anode side with respect to FIG. 3, which is effective in improving the adhesion between the anode and the hole transport layer or improving the hole injection property, and effective in lowering the voltage. .

  5 and 6 are cross-sectional views showing other examples of the organic light-emitting device of the present invention. 5 and 6 show a structure in which a layer (hole blocking layer 8) that prevents holes or excitons (excitons) from passing to the cathode side is inserted between the light emitting layer and the electron transport layer, as compared with FIGS. It is. By using a compound having a very high ionization potential as the hole blocking layer 8, the structure is effective in improving the light emission efficiency.

  However, FIGS. 1 to 6 are very basic device configurations, and the configuration of the organic light-emitting device using the compound of the present invention is not limited thereto. For example, an adhesive layer or an interference layer is provided at the interface between the electrode and the organic layer. The hole transport layer is composed of two layers having different ionization potentials. Various layer configurations can be taken.

  The 2,6-fluorenyl-substituted pyridine compound represented by the general formula [I] or the general formula [II] used in the present invention is a compound excellent in electron transport property, light emitting property and durability as compared with conventional compounds, Any form of FIGS. 1 to 6 can be used.

  In particular, the organic layer using the 2,6-fluorenyl-substituted pyridine compound of the present invention is useful as a hole block layer, an electron transport layer, an electron injection layer, and a light emitting layer, and is formed by a vacuum deposition method or a solution coating method. The layer thus obtained is less susceptible to crystallization and has excellent temporal stability.

  In the present invention, a 2,6-fluorenyl-substituted pyridine compound represented by the general formula [I] or [II] is mainly used as a constituent component of the electron transport layer and the light-emitting layer. A hole-transporting compound, a light-emitting compound, an electron-transporting compound, or the like can be used together as necessary.

  Examples of these compounds are given below.

  The hole injecting and transporting material preferably has excellent mobility for facilitating the injection of holes from the anode and transporting the injected holes to the light emitting layer. Low molecular and high molecular weight materials having hole injection and transport performance include triarylamine derivatives, phenylenediamine derivatives, triazole derivatives, oxadiazole derivatives, imidazole derivatives, pyrazoline derivatives, pyrazolone derivatives, oxazole derivatives, fluorenone derivatives, hydrazones. Derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, and poly (vinyl carbazole), poly (silylene), poly (thiophene), and other conductive polymers are, of course, not limited thereto.

Examples of the material related to the light emitting function include the following compounds. Polycyclic fused aromatic compounds (eg naphthalene derivatives, phenanthrene derivatives, fluorene derivatives, pyrene derivatives, tetracene derivatives, coronene derivatives, chrysene derivatives, perylene derivatives, 9,10-diphenylanthracene derivatives, rubrene, etc.), quinacridone derivatives, acridone derivatives, Coumarin derivatives, pyran derivatives, Nile red, pyrazine derivatives, benzimidazole derivatives, benzothiazole derivatives, benzoxazole derivatives, stilbene derivatives, organometallic complexes (for example, organoaluminum complexes such as tris (8-quinolinolato) aluminum, organoberyllium complexes) And poly (phenylene vinylene) derivatives, poly (fluorene) derivatives, poly (phenylene) derivatives, poly (thienylene vinylene) derivatives, poly (acetylene) Examples of the electron injecting / transporting material other than the pyridine derivative compound used in the organic light-emitting device of the present invention include, but are not limited to, polymer derivatives such as conductors. Can be mentioned. Oxadiazole derivatives, oxazole derivatives, thiazole derivatives, thiadiazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, perylene derivatives, quinoline derivatives, quinoxaline derivatives, fluorenone derivatives, anthrone derivatives, phenanthroline derivatives, organometallic complexes, etc. Of course, it is not limited to these.

  In the organic light emitting device of the present invention, the layer containing the 2,6-fluorenyl-substituted pyridine compound represented by the general formula [I] or the general formula [II] and the layer containing another organic compound are generally formed by a vacuum deposition method. Alternatively, it is dissolved in an appropriate solvent and a thin film is formed by a coating method. In particular, when a film is formed by a coating method, the film can be formed in combination with an appropriate binder resin.

  The binder resin can be selected from a wide range of binder resins such as polyvinyl carbazole resin, polycarbonate resin, polyester resin, polyarylate resin, polystyrene resin, acrylic resin, methacrylic resin, butyral resin, polyvinyl acetal resin, diallyl phthalate resin. , Phenol resin, epoxy resin, silicone resin, polysulfone resin, urea resin and the like, but are not limited thereto. Moreover, you may mix these 1 type, or 2 or more types as a single or copolymer polymer.

  As the anode material, a material having a work function as large as possible is preferable. For example, simple metals such as gold, silver, platinum, nickel, palladium, cobalt, selenium, vanadium or alloys thereof, tin oxide, zinc oxide, indium tin oxide (ITO) ), Metal oxides such as indium zinc oxide can be used. In addition, conductive polymers such as polyaniline, polypyrrole, polythiophene, and polyphenylene sulfide can also be used. These electrode materials may be used alone or in combination.

  On the other hand, the cathode material preferably has a small work function, such as lithium, sodium, potassium, cesium, calcium, magnesium, aluminum, indium, silver, lead, tin, chromium, or a simple metal or a plurality of alloys or salts thereof. Can be used. It is also possible to use metal oxidation such as indium tin oxide (ITO). Further, the cathode may have a single layer structure or a multilayer structure.

  Although it does not specifically limit as a board | substrate used by this invention, Transparent substrates, such as opaque board | substrates, such as a metal board | substrate and a ceramic board | substrate, glass, quartz, a plastic sheet, are used. It is also possible to control the color light by using a color filter film, a fluorescent color conversion filter film, a dielectric reflection film, or the like on the substrate.

  Note that a protective layer or a sealing layer can be provided on the prepared element for the purpose of preventing contact with oxygen or moisture. Examples of the protective layer include diamond thin films, inorganic material films such as metal oxides and metal nitrides, polymer films such as fluorine resin, polyparaxylene, polyethylene, silicone resin, polystyrene resin, and photo-curing resins. It is done. Further, it is possible to cover glass, a gas impermeable film, a metal, etc., and to package the element itself with an appropriate sealing resin.

  The element of the present invention can be formed by forming a thin film transistor (TFT) on a substrate and connecting it.

  Further, regarding the light extraction direction of the element, either a bottom emission configuration (configuration in which light is extracted from the substrate side) or a top emission (configuration in which light is extracted from the opposite side of the substrate) is possible.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

<Example 1>
[Exemplary Compound No. Production method 2]
Synthesis of intermediate [5]

  In a 200 ml three-necked flask, 5.0 g (12.5 mmol) of 2-bromo-7-iodo-9,9-dimethylfluorene [2], 2.15 g (12.5 mmol) of naphthalene-1-boronic acid [1], toluene 50 ml of ethanol and 25 ml of ethanol were added, and an aqueous solution of 2.7 g of sodium carbonate / 10 ml of water was added dropwise with stirring in a nitrogen atmosphere at room temperature. ) Was added. The mixture was stirred at room temperature for 30 minutes, heated to 77 ° C., and stirred for 3 hours. After the reaction, the organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and purified with a silica gel column (toluene developing solvent) to obtain 3.9 g of intermediate [3] (white crystals).

  In a 200 ml three-necked flask, [3] 3.9 g (9.79 mmol), 1,3-bis (diphenylphosphino) propane nickel (II) chloride 530 mg (1.04 mmol), triethylamine 4.8 ml (35 mmol), 50 ml of toluene was added, and 4.35 ml (30 mmol) of [4] was added dropwise with stirring at room temperature in a nitrogen atmosphere. The mixture was stirred at room temperature for 30 minutes, heated to 77 ° C., and stirred for 16 hours. After the reaction, the organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and purified with a silica gel column (toluene developing solvent) to obtain 2.8 g of intermediate [5] (white crystals).

  Exemplified Compound No. Synthesis of 2

  [5] 1.15 g (2.58 mmol), 2,6-dibromopyridine [6] 298 mg (1.26 mmol), toluene 10 ml and ethanol 5 ml were placed in a 200 ml three-necked flask and stirred at room temperature in a nitrogen atmosphere. Then, an aqueous solution of 0.32 g of sodium carbonate / 3 ml of water was added dropwise, and then 0.15 g (0.12 mmol) of tetrakis (triphenylphosphine) palladium (0) was added. The mixture was stirred at room temperature for 30 minutes, heated to 77 ° C., and stirred for 8 hours. After the reaction, the organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and purified with a silica gel column (toluene + ethyl acetate developing solvent). 0.4 g of 2 (white crystals) was obtained.

<Example 2>
[Exemplary Compound No. 45 production method]
Chem. Ber, 122, 589 (1989) gave 2,4,6-tribromopyridine [6].

  In a 300 ml three-necked flask, 0.5 g (1.58 mmol) of 2,4,6-tribromopyridine [7], 2.8 g (6.33 mmol) of [5], 150 ml of toluene and 75 ml of ethanol were placed in a nitrogen atmosphere. While stirring at room temperature, an aqueous solution of 2 g of sodium carbonate / 35 ml of water was added dropwise, and then 0.50 g (0.43 mmol) of tetrakis (triphenylphosphine) palladium (0) was added. The mixture was stirred at room temperature for 30 minutes, heated to 77 ° C., and stirred for 6 hours. After the reaction, the organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and purified with a silica gel column (toluene + ethyl acetate mixed developing solvent). 45 (white crystals) 0.72 g was obtained.

<Example 3>
[Exemplary Compound No. 49 Manufacturing Method]
Tetrahedron, 56.5567. 2,4,6-trichloropyridine [8] was obtained by the synthesis method described in (2000).

  [5] 1.84 g (4.11 mmol), 2,4,6-trichloropyridine [8] 300 mg (1.64 mmol), toluene 30 ml and ethanol 15 ml were placed in a 200 ml three-necked flask. While stirring, an aqueous solution of sodium carbonate 0.5 g / water 10 ml was added dropwise, and then tetrakis (triphenylphosphine) palladium (0) 0.30 g (0.24 mmol) was added. After stirring at room temperature for 30 minutes, the temperature was raised to 77 ° C. and stirred for 5 hours. After the reaction, the organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and purified with a silica gel column (toluene + ethyl acetate developing solvent) to obtain 0.9 g of intermediate [9] (white crystals).

  In a 200 ml three-necked flask, [9] 0.5 g (0.67 mmol), [1] 180 mg (1.05 mmol), [10] 5 mg (0.05 mmol), tartariboxy potassium 150 mg (1.34 mmol), bisdi 3 mg of benzylideneacetone palladium and 10 ml of tetrahydrofuran were added, stirred in a nitrogen atmosphere at room temperature for 30 minutes, then heated to 60 ° C. and stirred for 8 hours. After the reaction, the organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and purified with a silica gel column (toluene + ethyl acetate developing solvent). 0.4 g of 49 (white crystals) was obtained.

<Example 4>
An element having the structure shown in FIG. 3 was prepared.
What formed indium tin oxide (ITO) as an anode 2 with a film thickness of 120 nm on a glass substrate as a substrate 1 by a sputtering method was used as a transparent conductive support substrate. This was ultrasonically washed successively with acetone and isopropyl alcohol (IPA), then boiled and washed with IPA and then dried. Furthermore, what was UV / ozone cleaned was used as a transparent conductive support substrate.

  On a transparent conductive support substrate, a chloroform solution of N, N′-bis (9,9-dimethyl-2-fluorenyl) N, N′-diphenyl-4,4′-biphenyldiamine is formed to a thickness of 20 nm by spin coating. Then, a hole transport layer 5 was formed.

Further, an Ir complex represented by the following structural formula and CBP (weight ratio 5:95) were formed into a film with a thickness of 20 nm by a vacuum deposition method, whereby the light emitting layer 3 was formed. The degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation rate was 0.2 to 0.3 nm / sec.

Furthermore, Exemplified Compound No. 2 was formed into a film with a thickness of 40 nm by a vacuum evaporation method, and the electron transport layer 6 was formed. The degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation rate was 0.2 to 0.3 nm / sec.

Next, a metal layer film having a thickness of 50 nm is formed on the organic layer by a vacuum deposition method using a deposition material composed of aluminum and lithium (lithium concentration: 1 atomic%) as the cathode 4, and further a vacuum deposition method. Thus, an aluminum layer having a thickness of 150 nm was formed. The degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 1.0 to 1.2 nm / sec.
Further, a protective glass plate was placed in a nitrogen atmosphere and sealed with an acrylic resin adhesive.

When a direct current voltage of 8 V was applied to the device thus obtained with an ITO electrode (anode 2) as a positive electrode and an Al-Li electrode (cathode 4) as a negative electrode, current was applied at a current density of 15 mA / cm ^2. The emission of green light was observed at a luminance of 4300 cd / m ² .

Further, when a voltage was applied for 100 hours with the current density kept to 5.0 mA / cm ^2, after the initial luminance 900 cd / ^{m 2} 100 hours 870cd / ^{m 2} and luminance degradation was small.

<Examples 5 to 15>
Exemplified Compound No. In place of Exemplified Compound No. 2 Except for using 3, 5, 7, 17, 28, 32, 37, 51, 55, 61, an element was prepared in the same manner as in Example 1, and the same evaluation was performed. As a result, luminance degradation was small.
The results are shown in Table-1.

<Comparative Example 1>
Exemplified Compound No. A device was prepared in the same manner as in Example 1 except that a compound represented by the following structural formula was used in place of ² , and a similar evaluation was performed. As a result, green light emission was observed at a luminance of 3200 cd / m ² . .

Further, when a voltage was applied for 100 hours while maintaining the current density at 5.0 mA / cm ² , a luminance change of 350 cd / m ² was observed after 100 hours from the initial luminance of 720 cd / m ² .
The results are shown in Table-1.

  Comparative Compound No. 1

<Example 16>
An element having the structure shown in FIG. 6 was produced.
In the same manner as in Example 1, a hole transport layer 5 was formed on a transparent conductive support substrate.

Further, a fluorene compound represented by the following structural formula was formed into a film with a thickness of 20 nm by a vacuum vapor deposition method to form the light emitting layer 3. The degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation rate was 0.2 to 0.3 nm / sec.

Furthermore, Exemplified Compound No. A hole blocking layer 8 was formed by forming a film 22 with a film thickness of 20 nm by a vacuum deposition method. The degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation rate was 0.2 to 0.3 nm / sec.

Further, bathophenanthroline (BPhen) was formed to a thickness of 20 nm as the electron transport layer 6 by vacuum deposition. The degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 0.2 to 0.3 nm / sec.

Next, a metal layer film having a thickness of 50 nm is formed on the organic layer by a vacuum deposition method using a deposition material composed of aluminum and lithium (lithium concentration: 1 atomic%) as the cathode 4, and further a vacuum deposition method. Thus, an aluminum layer having a thickness of 150 nm was formed. The degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 1.0 to 1.2 nm / sec.

  Further, a protective glass plate was placed in a nitrogen atmosphere and sealed with an acrylic resin adhesive.

When a 6V DC voltage was applied to the device obtained in this manner with the ITO electrode (anode 2) as the positive electrode and the Al-Li electrode (cathode 4) as the negative electrode, the current flowed at a current density of 70 mA / cm ^2. A blue light emission was observed at a luminance of 3500 cd / m ² .

Further, when a voltage was applied for 100 hours while maintaining the current density at 20 mA / cm ² , the luminance deterioration was small, from the initial luminance of 1200 cd / m ² to 1100 cd / m ² after 100 hours.

<Examples 17 to 25>
Exemplified Compound No. Instead of Example Compound No. 22 Except for using 4,8,9,18,24,41,47,52,60, an element was prepared in the same manner as in Example 13 and the same evaluation was performed. As a result, the luminance degradation was small.
The results are shown in Table-2.

<Example 26>
An element having the structure shown in FIG. 2 was produced.
In the same manner as in Example 1, a hole transport layer 5 was formed on a transparent conductive support substrate.

Furthermore, Exemplified Compound No. 30 was formed into a film having a thickness of 40 nm by a vacuum vapor deposition method to form a light emitting layer / electron transport layer 6. The degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa and the film formation rate was 0.2 to 0.3 nm / sec.

Next, a metal layer film having a thickness of 50 nm is formed on the organic layer by a vacuum deposition method using a deposition material composed of aluminum and lithium (lithium concentration: 1 atomic%) as the cathode 4, and further a vacuum deposition method. Thus, an aluminum layer having a thickness of 150 nm was formed. The degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 1.0 to 1.2 nm / sec.

  Further, a protective glass plate was placed in a nitrogen atmosphere and sealed with an acrylic resin adhesive.

When a 4V DC voltage was applied to the device obtained in this manner, with the ITO electrode (anode 2) as the positive electrode and the Al-Li electrode (cathode 4) as the negative electrode, the current flowed at a current density of 40 mA / cm ^2. A blue light emission was observed at a luminance of 1600 cd / m ² .

Further, when a voltage was applied for 100 hours with the current density kept to 40 mA / cm ^2, after the initial luminance 2000 cd / ^{m 2} 100 hours 1750cd / ^{m 2} and luminance degradation was small.

It is sectional drawing which shows an example of the organic light emitting element in this invention. It is sectional drawing which shows the other example of the organic light emitting element in this invention. It is sectional drawing which shows the other example of the organic light emitting element in this invention. It is sectional drawing which shows the other example of the organic light emitting element in this invention. It is sectional drawing which shows the other example of the organic light emitting element in this invention. It is sectional drawing which shows the other example of the organic light emitting element in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Light emitting layer 4 Cathode 5 Hole transport layer 6 Electron transport layer 7 Hole injection layer 8 Hole / exciton blocking layer

Claims (5)

A 2,6-fluorenyl-substituted pyridine compound represented by the following general formula [I].
Formula [I]

(In the formula, R1, R2 and R3 are a hydrogen atom, a substituted or unsubstituted alkyl group, an aryl group, a heterocyclic group, a condensed polycyclic aromatic group, a condensed polycyclic heterocyclic group, an aryloxy group, and a substituted amino group. Represents a group selected from a halogen atom, a trifluoromethyl group or a cyano group, R1, R2 and R3 may be the same or different, and R1 to R3 are bonded to each other to form a ring; R4 and R5 may be a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, which may be the same or different, Ar1 and Ar2 are substituted or unsubstituted heterocyclic groups, substituted Alternatively, it represents an unsubstituted fused polycyclic aromatic group or a substituted or unsubstituted fused polycyclic heterocyclic group, which may be the same or different. The 2,6-fluorenyl-substituted pyridine compound according to claim 1 represented by the following general formula [II].
Formula [II]

(In the formula, R6 may be a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, an oxygen atom, a substituted or unsubstituted nitrogen atom, a sulfur atom, a silicon atom, or a divalent bond. A substituted or unsubstituted heterocyclic group, a divalent substituted or unsubstituted condensed polycyclic aromatic group, or a divalent substituted or unsubstituted condensed polycyclic heterocyclic group, and R7 and R8. , A hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, which may be the same or different, Ar3, Ar4, Ar5 and Ar6 are substituted or unsubstituted heterocyclic groups, substituted or unsubstituted A condensed polycyclic aromatic group, a substituted or unsubstituted condensed polycyclic heterocyclic group, which may be the same or different.   In the organic light emitting device having at least a pair of electrodes composed of an anode and a cathode and a layer composed of one or a plurality of organic compounds sandwiched between the pair of electrodes, at least one of the layers containing the organic compound is at least one layer. 2. An organic light-emitting device comprising at least one 2,6-fluorenyl-substituted pyridine compound represented by the general formula [I] or the general formula [II] according to any one of 2 above.   At least the hole block layer, the electron transport layer, or the electron injection layer among the layers made of the organic compound contains at least one 2,6-fluorenyl-substituted pyridine compound represented by the general formula [I] or the general formula [II]. The organic light-emitting device according to claim 3. The light emitting layer among the layers made of an organic compound contains at least one of 2,6-fluorenyl-substituted pyridine compounds represented by the general formula [I] or the general formula [II]. Organic light emitting device.

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