JP5250784B2 - Organic electroluminescence device - Google Patents

Description

  The present invention relates to an electroluminescence element (electroluminescence element).

Development of an organic electroluminescence element capable of emitting light with high luminance at a low voltage is being studied as a next-generation display element. However, blue light-emitting elements essential for full-color displays do not have sufficient light emission characteristics, and improvements in light emission luminance and light emission efficiency are required.
In order to improve the light emission luminance and the light emission efficiency, an organometallic compound used in the light emitting layer of the organic electroluminescence device has been studied. Of these, as an example of using an organic germanium compound, Patent Document 1 mentions the use of an organometallic compound having a germanium-germanium metal bond, but the organic germanium compound represented by the formula (1) is completely different. It was not known.
In addition, as for the use of an organic germanium compound in an organic electroluminescence device, the use of tetraphenyl germanium for a hole injection layer is described in Patent Document 2, but the use for other than the hole injection layer is completely known. It wasn't.

(In the formula, L represents an integer of 0 to 2, m represents an integer of 1 to 3, n represents an integer of 1 to 3, k represents an integer of 0 to 3. Ar represents an aryl group or a heteroaryl group, and is the same. Alternatively, any hydrogen atom may be substituted with a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxy group, or an aryloxy group. Ar may be bonded via a single bond, an ether bond, a thioether bond, an alkylene group, an oxaalkylene group or a thiaalkylene group, and R is an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an alkoxy group. X represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an alkoxy group, or an aryl group. Shea represents a group.)
JP 2003-77666 A Japanese Patent Laid-Open No. 10-95971 Nihon Chemical Journal, Vol. 84, 1963, p. 272

  An object of the present invention is to provide an organic electroluminescence device that emits light with excellent luminous efficiency and high luminance.

As a result of intensive studies, the present inventors have found that in an organic electroluminescence device in which a light emitting layer or a plurality of organic compound thin layers including a light emitting layer is formed between a pair of electrodes, the light emitting layer is represented by the formula (1). When it contains, it discovered that the efficiency of a blue light emitting element improved remarkably, and resulted in this invention.
That is, the present invention is an organic electroluminescence device in which a light emitting layer or a plurality of organic compound thin layers including a light emitting layer is formed between a pair of electrodes, wherein the light emitting layer is an organic germanium compound represented by the formula (1). It is related with the organic electroluminescent element characterized by containing.

  An organic electroluminescence device in which a light emitting layer or a plurality of organic compound thin layers including a light emitting layer is formed between a pair of electrodes of the present invention, wherein the light emitting layer contains an organic germanium compound represented by the formula (1) The organic electroluminescence device characterized by the above emits high luminance with excellent luminous efficiency.

Hereinafter, the present invention will be described in detail.
In the organic germanium compound represented by the formula (1) contained in the organic electroluminescence device of the present invention, L is an integer of 0 to 2, m is an integer of 1 to 3, n is an integer of 1 to 3, and k is 0. Represents an integer of ˜3, Ar represents an aryl group or a heteroaryl group, which may be the same or different, and any hydrogen atom thereof is a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an aralkyl group; , An alkoxy group or an aryloxy group may be substituted. Adjacent Ars may be bonded via a single bond, an ether bond, a thioether bond, an alkylene group, an oxaalkylene group, or a thiaalkylene group.
R represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an alkoxy group, or an aryloxy group.
X represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an alkoxy group, or an aryloxy group.

  Here, when Ar is an aryl group, examples of the aryl group include a phenyl group, a naphthyl group, a phenanthryl group, and an anthracenyl group.

  When Ar is a heteroaryl group, the heteroaryl group includes furyl, thiophenyl, pyrrolyl, imidazolyl, oxazolyl, pyridyl, thiazolyl, indolyl, quinolyl, isoquinolyl, quinazolyl, quinoxalyl Groups and the like.

  Any hydrogen atom of Ar (aryl group or heteroaryl group) may be substituted with a halogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxy group, or an aryloxy group. Further, adjacent Ar (aryl group or heteroaryl group) may be bonded via a single bond, an ether bond, a thioether bond, an alkylene group, an oxaalkylene group, or a thiaalkylene group.

  Here, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  As an alkyl group, a C1-C20 alkyl group, especially a C1-C12 alkyl group are preferable, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group. Group, nonyl group, decyl group, undecyl group, dodecyl group and the like. These substituents include isomers thereof.

  The cycloalkyl group is preferably a cycloalkyl group having 5 to 8 carbon atoms, and examples thereof include a cyclopentyl group, a cyclohexyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group.

  The alkenyl group is preferably an alkenyl group having 2 to 20 carbon atoms, particularly 2 to 12 carbon atoms. For example, vinyl group, propenyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, decenyl group. Group, undecenyl group, dodecenyl group and the like. These substituents include isomers thereof.

  As the aryl group, an aryl group having 6 to 12 carbon atoms is preferable. For example, phenyl group, tolyl group (and its isomer), xylyl group (and its isomer), naphthyl group (and its isomer), dimethylnaphthyl Groups (and isomers thereof) and the like.

  The aralkyl group is preferably an aralkyl group having 7 to 20 carbon atoms, and examples thereof include a benzyl group, a naphthylmethyl group, an indenylmethyl group, and a biphenylmethyl group.

  As the alkoxy group, an alkoxy group having 1 to 10 carbon atoms is preferable, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentanoxy group, a hexanoxy group, a heptanoxy group, an octanoxy group, a nonanoxy group, and a decanoxy group. It is done. These substituents include isomers thereof.

  The aryloxy group is preferably an aryloxy group having 6 to 14 carbon atoms, and examples thereof include a phenoxy group, a triloxy group, a xylyloxy group, a naphthoxy group, and a dimethylnaphthoxy group. These substituents include isomers thereof.

  When adjacent Ar (aryl group or heteroaryl group) is bonded through an alkylene group, the alkylene group is preferably an alkylene group having 1 to 6 carbon atoms, and includes a methylene group, a propylene group, a butylene group, a pentamethylene group, and Examples include a hexamethylene group.

  When adjacent Ar (aryl group or heteroaryl group) is bonded via an oxaalkylene group, the oxaalkylene group is preferably an oxaalkylene group having 1 to 5 carbon atoms, such as an oxamethylene group, an oxapropylene group, and an oxabutylene group. Oxapentamethylene group, oxahexamethylene group, dioxamethylene group, dioxapropylene group, dioxabutylene group, dioxapentamethylene group, dioxahexamethylene group and the like. These substituents include isomers thereof.

  When adjacent Ar (aryl group or heteroaryl group) is bonded via a thiaalkylene group, the thioalkylene group is preferably a thioalkylene group having 1 to 5 carbon atoms, and a thiamethylene group, a thiapropylene group, a thiabutylene group, Examples include a pentamethylene group, a thiahexamethylene group, a dithiamethylene group, a dithiapropylene group, a dithiabutylene group, a dithiapentamethylene group, and a dithiahexamethylene group. These substituents include isomers thereof.

  The alkyl group, cycloalkyl group, alkenyl group, aryl group, aralkyl group, alkoxy group, aryloxy group, and the alkylene group, oxaalkylene group, and thiaalkylene group linking adjacent Ar atoms are further bonded to the carbon atom. The hydrogen atom may be further substituted with a halogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, a nitro group, a cyano group, a dialkylamino group, or the like. Examples of these substituents are the same as those defined as the substituents for Ar (aryl group or heteroaryl group).

  R represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an alkoxy group, or an aryloxy group. These may be the same as those defined as the substituent for Ar (aryl group or heteroaryl group).

  X represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, an alkoxy group, or an aryloxy group. Examples of these substituents are the same as those defined as the substituent for Ar.

  The organogermanium compound represented by the formula (1) contained in the organic electroluminescence device of the present invention is an organometallic compound represented by the formula (3), (4) or (5) according to the description of Non-Patent Document 1, for example. And organic germanium chloride (formula (2)) may be synthesized. Commercially available tetraphenylgermanium may be used.

(Wherein j is an integer of 0 to 3. Ar is as defined above.)

(In the formula, Ar is as defined above, and M represents Li or MgY. Here, Y represents chlorine, bromine, or iodine.)

(In the formula, R is as defined above, and M represents Li or MgY, where Y represents chlorine, bromine, or iodine.)

(Wherein X is as defined above, 1 is an integer of 2 to 3, k is an integer of 0 to 3, M is Li or MgY, where Y is as defined above.)

The organic electroluminescent element of the present invention is an organic electroluminescent element having a single-layer or multi-layer organic compound layer between a pair of electrodes, and the light-emitting layer is at least one of the organic germanium compounds represented by the formula (1). Contains seeds.
Further, the organic compound layer is a light emitting layer, an electron injection layer, or a hole transport layer, and the organic germanium compound having an aromatic substituent may be contained in the electron injection layer or the hole transport layer in addition to the light emitting layer. good.
Note that an organic electroluminescent element having a single organic compound layer between a pair of electrodes is a single-layer organic electroluminescent element, and an organic electroluminescent element having a multilayer organic compound layer between a pair of electrodes is a multi-layer organic. An electroluminescence element is described below.

  A single layer type organic electroluminescent element has a light emitting layer between an anode and a cathode. The light emitting layer contains a light emitting material, and may further contain a hole injecting material or an electron injecting material for transporting holes injected from the anode or electrons injected from the cathode to the light emitting material.

  Multi-layer type organic electroluminescence devices include, for example, (anode / hole injection layer / light emitting layer / cathode), (anode / light emitting layer / electron injection layer / cathode), (anode / hole injection layer / light emitting layer / electron). And those laminated in a multilayer structure such as injection layer / cathode).

  In addition to the organic germanium compound represented by the formula (1), the light emitting layer includes a known light emitting material, doping material, hole injecting material (phthalocyanine derivative, naphthalocyanine derivative, porphyrin derivative, oxazole, oxadiazole, triazole, Imidazole, imidazolone, imidazolethione, pyrazoline, pyrazolone, tetrahydroimidazole, oxazole, oxadiazole, hydrazone, acylhydrazone, polyarylalkane, stilbene, butadiene, benzidine type triphenylamine, styrylamine type triphenylamine, diamine type triphenyl Amines and their derivatives, polyvinyl carbazole, polysilane, polymer materials such as conductive polymers), electron injection materials (fluorenone, anthraquinodimethane, diphf) Nokinon, thiopyrandioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, deflection distyrylpyrazine, anthraquinodimethane, may be used and the like, and their derivatives) anthrone.

  The amount of the organic germanium compound represented by the formula (1) added to the light emitting layer is 5 to 98% by weight. In addition, the organic germanium compound represented by the formula (1) may be added to an organic compound layer other than the light emitting layer, and the addition amount when added to the organic compound layer other than the light emitting layer is 5 to 98% by weight. is there.

  In the multilayer organic electroluminescence device of the present invention, a light emitting material, another doping material, a hole injection material, and an electron injection material can be used in combination. Furthermore, each of the hole injection layer, the light emitting layer, and the electron injection layer may be formed with a layer structure of two or more layers. In that case, in the case of a hole injection layer, the layer that injects holes from the electrode is a hole injection layer, and the layer that receives holes from the hole injection layer and transports holes to the light emitting layer is a hole transport layer. Call. Similarly, in the case of an electron injection layer, a layer that injects electrons from an electrode is referred to as an electron injection layer, and a layer that receives electrons from the electron injection layer and transports electrons to a light emitting layer is referred to as an electron transport layer. Each of these layers is selected and used depending on factors such as the energy level of the material, heat resistance, adhesion with the organic compound layer or the metal electrode.

  Examples of the light emitting material or host material that can be used in the light emitting layer together with the organic germanium compound represented by the formula (1) include condensed polycyclic aromatics (anthracene, naphthalene, phenanthrene, pyrene, tetracene, pentacene, coronene, chrysene, fluorescein, perylene). , Rubrene and derivatives thereof), phthaloperylene, naphthaloperylene, perinone, phthaloperinone, naphthaloperinone, diphenylbutadiene, tetraphenylbutadiene, coumarin, oxadiazole, aldazine, bisbenzoxazoline, bisstyryl, pyrazine, cyclopentadiene, quinoline metal complex, Aminoquinoline metal complex, benzoquinoline metal complex, quinolylacetylene metal complex, quinoxalylacetylene metal complex, quinazolylacetylene metal complex, imi , Diphenylethylene, vinyl anthracene, diaminocarbazole, pyran, thiopyran, polymethine, merocyanine, imidazole chelated oxinoid compounds, quinacridone, rubrene, stilbene derivatives and fluorescent dyes.

  Of the known hole injection materials that can be used in the organic electroluminescence device of the present invention, more effective hole injection materials are aromatic tertiary amine derivatives or phthalocyanine derivatives. Specific embodiments of the aromatic tertiary amine derivative include triphenylamine, tolylamine, tolyldiphenylamine, N, N′-diphenyl-N, N ′-(3-methylphenyl) -1,1′-biphenyl-4 , 4′-diamine (hereinafter referred to as TPD), N, N, N ′, N ′-(4-methylphenyl) -1,1′-phenyl-4,4′-diamine, N, N, N ′ , N ′-(4-methylphenyl) -1,1′-biphenyl-4,4′-diamine, N, N′-diphenyl-N, N′-dinaphthyl-1,1′-biphenyl-4,4 ′ -Diamine, N, N '-(methylphenyl) -N, N'-(4-n-butylphenyl) -phenanthrene-9,10-diamine, N, N-bis (4-di-4-tolylaminophenyl) ) -4-phenyl-cyclohexane, etc. Ku is an oligomer or polymer having these aromatic tertiary amine skeletons, though not particularly limited thereto.

Specific embodiments of the phthalocyanine (Pc) derivative are H ₂ Pc, CuPc, CoPc, NiPc, ZnPc, PdPc, FePc, MnPc, ClAlPc, ClGaPc, ClInPc, ClSnPc, Cl2 SiPc, (HO) AlPc, (HO) GaPc. , Phthalocyanine derivatives such as VOPc, TiOPc, MoOPc, GaPc-O-GaPc, and naphthalocyanine derivatives, but are not limited thereto.

In the organic electroluminescence device of the present invention, a more effective known electron injection material is a metal complex compound or a nitrogen-containing five-membered ring derivative. Specific embodiments of the metal complex compound include 8-hydroxyquinolinate lithium, bis (8-hydroxyquinolinato) zinc, bis (8-hydroxyquinolinato) copper, bis (8-hydroxyquinolinato) manganese, tris (8-hydroxyquinolinato) aluminum (hereinafter, Alq ₃ and described.), tris (2-methyl-8-hydroxyquinolinato) aluminum, tris (8-hydroxyquinolinato) gallium, bis (10 Hydroxybenzo [h] quinolinato) beryllium, bis (10-hydroxybenzo [h] quinolinato) zinc, bis (2-methyl-8-quinolinato) chlorogallium, bis (2-methyl-8-quinolinato) (o-cresolate) Gallium, bis (2-methyl-8-quinolinato) (1-naphtholato) al Examples thereof include, but are not limited to, minium and bis (2-methyl-8-quinolinato) (2-naphtholate) gallium.

  The nitrogen-containing five-membered derivative is preferably an oxazole, thiazole, oxadiazole, thiadiazole or triazole derivative. Specifically, 2,5-bis (1-phenyl) -1,3,4-oxazole and dimethyl POPOP (where POPOP represents 1,4-bis (5-phenyloxazol-2-yl) benzene). ), 2,5-bis (1-phenyl) -1,3,4-thiazole, 2,5-bis (1-phenyl) -1,3,4-oxadiazole, 2- (4′-tert- Butylphenyl) -5- (4 "-biphenyl) -1,3,4-oxadiazole, 2,5-bis (1-naphthyl) -1,3,4-oxadiazole, 1,4-bis [ 2- (5-phenyloxadiazolyl)] benzene, 1,4-bis [2- (5-phenyloxadiazolyl) -4-tert-butylbenzene], 2- (4′-tert-butylphenyl)- 5- (4 ″ -biphenyl) -1,3,4 Thiadiazole, 2,5-bis (1-naphthyl) -1,3,4-thiadiazole, 1,4-bis [2- (5-phenylthiadiazolyl)] benzene, 2- (4′-tert-butylphenyl) ) -5- (4 ″ -biphenyl) -1,3,4-triazole, 2,5-bis (1-naphthyl) -1,3,4-triazole, 1,4-bis [2- (5-phenyl) Triazolyl)] benzene and the like, but is not limited thereto.

  In the organic electroluminescence device of the present invention, an inorganic compound layer may be provided between the light emitting layer and the electrode in order to improve the charge injection property.

Examples of the inorganic compound layer include fluorides and oxides of alkali metals or alkaline earth metals such as LiF, Li ₂ O, RaO, SrO, BaF ₂ , and SrF ₂ .

  As the conductive material used for the anode of the organic electroluminescence device of the present invention, a material having a work function larger than 4 eV is suitable, and carbon atoms, aluminum, vanadium, iron, cobalt, nickel, tungsten, silver, gold , Platinum, palladium and their alloys, ITO (substance with 5-10% tin oxide added to indium oxide) substrate, tin oxide used for NESA substrate, metal oxide such as indium oxide, and organic such as polythiophene and polypyrrole A conductive resin can be used.

  As the conductive material used for the cathode, those having a work function smaller than 4 eV are suitable, and magnesium, calcium, tin, lead, titanium, yttrium, lithium, ruthenium, manganese, aluminum and the like and alloys thereof are used. It is done. Here, examples of the alloy include magnesium / silver, magnesium / indium, and lithium / aluminum. The ratio of the alloy is not particularly limited and is controlled by the temperature of the vapor deposition source, the atmosphere, the degree of vacuum, and the like.

  If necessary, the anode and the cathode may be formed of two or more layers.

  As for the organic electroluminescent element of this invention, it is desirable for at least one surface to be transparent in the light emission wavelength range of an element. The substrate is also preferably transparent.

  The transparent electrode is obtained by using the above-described conductive material and setting so as to ensure a predetermined translucency by a method such as vapor deposition or sputtering.

  The electrode on the light emitting surface preferably has a light transmittance of 10% or more.

  The substrate is not particularly limited as long as it has mechanical and thermal strength and has transparency, and examples thereof include a glass substrate and a transparent resin film.

  Transparent resin films include polyethylene, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polypropylene, polystyrene, polymethyl methacrylate, polyvinyl chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone. , Polysulfone, polyethersulfone, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, polyvinyl fluoride, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polychlorotrifluoroethylene, Polyvinylidene fluoride, polyester, polycarbonate, polyurethane, polyimide, polyetherimide, polyimide, polypropylene, etc. It is.

  The organic electroluminescence device of the present invention can be provided with a protective layer on the surface of the device or can be protected by silicon oil, resin, etc., in order to improve stability against temperature, humidity, atmosphere, etc. .

  In addition, the formation of each layer of the organic electroluminescence element is performed by applying any one of dry film formation methods such as vacuum deposition, sputtering, plasma, and ion plating, or wet film formation methods such as spin coating, dipping, and flow coating. Can do. The film thickness is not particularly limited, but the normal film thickness is in the range of 5 nm to 10 μm, and more preferably in the range of 10 nm to 0.2 μm.

  In the case of the wet film forming method, the thin film can be prepared by dissolving or dispersing the organic germanium compound represented by the formula (1) in a solvent such as ethanol, chloroform, tetrahydrofuran, or dioxane on each layer.

As a dry film-forming method, vacuum deposition is preferable, and a vacuum deposition apparatus is used, the degree of vacuum is 2 × 10 ⁻³ Pa or less, the substrate temperature is set to room temperature, and the dry deposition method is represented by the above formula (1) of the present invention placed in a deposition cell. A thin film can be prepared by heating the organic germanium compound and evaporating the material. At this time, in order to control the temperature of the vapor deposition source, a thermocouple or a non-contact infrared thermometer brought into contact with the vapor deposition cell is preferably used. A vapor deposition film thickness meter is preferably used to control the vapor deposition amount.

  As a vapor deposition film thickness meter, a quartz crystal unit installed opposite to a vapor deposition source is used, and the weight of the vapor deposition film adhering to the surface of the quartz crystal unit is measured from a change in the oscillation frequency of the crystal unit. From the above, the type in which the film thickness is obtained in real time is preferably used.

  Co-evaporation of the organic germanium compound represented by the formula (1) and the light emitting material or other host material can be performed by using an evaporation source for each and controlling the temperature independently.

  Here, any organic thin film layer is made of polystyrene, polycarbonate, polyacrylate, polyester, polyamide, polyurethane, polysulfone, polymethyl methacrylate, polymethyl acrylate, cellulose, etc. Insulating resins and copolymers thereof, photoconductive resins such as poly-N-vinylcarbazole and polysilane, resins such as conductive resins such as polythiophene and polypyrrole, antioxidants, ultraviolet absorbers, plasticizers, etc. Additives can be used.

  The organic electroluminescence device of the present invention is used in, for example, a flat light emitter such as a wall-mounted TV or a flat panel display of a mobile phone, a copying machine, a printer, a backlight of a liquid crystal display, or a light source such as an instrument, a display board, a marker lamp, etc. Available.

  The present invention will be specifically described below with reference to examples.

Reference Example 1 Synthesis of luminescent material raw material (5-fluoro-8-quinolylacetylene [5F8QE]) (first step)
The inside of the 25 ml Schlenk tube was replaced with argon gas, and 592 mg (2 mmol) of 5-fluoro-8-trifluoromethanesulfonyloxyquinoline, 46.2 mg (0.04 mmol) of tetrakis (triphenylphosphine) palladium, 6 mL of piperidine, 2-methyl 290 μL (3 mmol) of -3-butyn-2-ol was added and stirred at 80 ° C. for 1.5 hours.
A saturated aqueous ammonium chloride solution (60 ml) was added to the reaction mixture, followed by extraction with methylene chloride (40 ml), and the solvent was distilled off under reduced pressure using an evaporator. The reaction crude product is purified by silica gel column chromatography (developing solvent: n-hexane / ethyl acetate = 100/0/1/1), whereby dimethylhydroxymethyl- (5-fluoro-8-quinolyl) acetylene is yellow. 0.27 g was obtained as an oil. (Yield 59%)

¹ H-NMR (300 MHz, CDCl ₃ ) δ: 1.71 (s, 6H),
3.85 ([s, 1H], 7.14-7.18 (m, 1H),
7.44-7.49 (m, 1H), 7.78-7.83 (m, 1H),
8.42 (dd, 1H), 9.10-9.12 (m, 1H)

EI-MS (M / e): 229 (M ^<+> ), CI-MS (M / z): 230 (MH ^<+> )

(Second step)
The inside of a 50 mL two-necked flask equipped with a reflux tube was replaced with argon gas, 0.27 g (1.17 mmol) of dimethylhydroxymethyl- (5-fluoro-8-quinolyl) acetylene, 56 mg (1.37 mmol) of sodium hydroxide. ) Toluene 9 ml was added here, and it recirculate | refluxed at 120 degreeC for 0.5 hour. Diethyl ether (20 ml) was added to the reaction mixture, washed with a saturated aqueous ammonium chloride solution (40 ml), and the solvent was distilled off under reduced pressure with an evaporator to obtain 0.19 g of 5-fluoro-8-quinolylethine as a yellow solid. (Yield 95%)

¹ H-NMR (300 MHz, CDCl ₃ ) δ: 3.55 (s, 1H),
7.17-7.23 (m, 1H), 7.51-7.55 (m, 1H),
7.90-7.95 (m, 1H), 8.44-8.49 (m, 1H),
9.10-9.12 (m, 1H)

EI-MS (M / e): 171 (M ^<+> ), CI-MS (M / e): 172 (MH ^<+> )

Reference Example 2 Synthesis of blue light-emitting material (5-fluoro-8-quinolylethynyl) (triphenylphosphine) gold [Au (PPh ₃ ) (5F8QE)] In an argon atmosphere, Au (PPh ₃ ) Cl (0.20 g) was added to a 25 ml Schlenk tube. , 0.40 mmol), 5-fluoro-8-quinolylethine (103 mg, 0.60 mmol), ethanol (8 ml), sodium ethoxide (165 μl, 0.42 mmol: concentration 2.55 mol / L (liter)). Ethanol solution) was added dropwise and stirred at room temperature for 17 hours. The white precipitate obtained after the reaction was filtered, washed successively with ethanol (5 ml × 3 times), water (5 ml × 4 times), and ethanol (5 ml × 3), and vacuum dried to obtain the target compound as a light yellow powder. 0.22 g was obtained. (Yield 88%)

The complex was dissolved in chloroform, the emission intensity when excited with excitation light of 330 nm was measured, and the concentration of 0.05 when the fluorescence quantum yield Φ when excited with excitation light of 330 nm was known (Φ = 0.55) From a comparison with quinine sulfate in a mol / L (liter) sulfuric acid aqueous solution, the relative quantum yield Φ _r of light emission of this complex was measured, and Φ _r = 0.50.

¹ H-NMR (400 MHz, CDCl ₃ ) δ: 9.11 (dd, 1H),
8.40 (dd, 1H), 7.91 (dd, 1H), 7.62-7.42 (m, 16H), 7.13 (dd, 1H)

³¹ P-NMR (160 MHz, CDCl ₃ ): 42.8
(FAB-MS) (M / z): 630 (M + H) ⁺
(Emission) (CHCl ₃ , 77 K, Ex 250 nm) λ (nm): 392, 534

(EA) Observed value C: 55.26, H: 3.34, N: 2.31
Theoretical value C: 55.34, H: 3.20, N: 2.23

Reference Example 3.4 Synthesis of 4-octylphenyltriphenylgermanium (Ph ₃ GePhC ₈ ) 540 μl (2.3 mmol) of 1-bromo-4-n-octylbenzene and 8.5 ml of tetrahydrofuran in a 20 ml Schlenk tube dried under an argon atmosphere. The colorless transparent solution to which was added was cooled to −78 ° C. with dry ice-ethanol, and 3.8 ml (5.7 mmol) of a tert-butyllithium pentane solution (f = 1.48) was added dropwise. After dropping, the reaction solution turned yellow was stirred for 1 hour while maintaining the reaction temperature at −78 ° C., and then 848 mg (2.5 mmol) of triphenyl germanium chloride was added. The mixture was stirred for 10 minutes while maintaining at -78 ° C, and then stirred at 0 ° C for 1 hour in an ice bath. After completion of the reaction, 40 ml of water and 80 ml of methylene chloride were added to the reaction solution for liquid separation, the aqueous layer was extracted twice with 20 ml of methylene chloride, and the organic layers obtained were combined and dried over 1.2 g of anhydrous magnesium sulfate. After filtration, methylene chloride was distilled off from the filtrate under reduced pressure, and the resulting residue was purified by silica gel column chromatography (developing solvent: n-hexane) to obtain the target compound as a white solid. (Yield 1.0 g, Yield 89%)

¹ H-NMR (300 MHz, CDCl ₃ ) δ: 7.56-7.51 (m, 6H),
7.45-7.42 (m, 2H), 7.41-7.32 (m, 9H),
7.22-7.18 (m, 2H), 2.61 (t, 2H),
1.62-1.59 (m, 2H), 1.31-1.27 (m, 10H),
0.874 (t, 3H)

EI-MS (m / e): 494 (M ^<+> )

Example 1. Fabrication of organic electroluminescence device containing tetraphenyl germanium (hereinafter referred to as Ph ₄ Ge) in the light emitting layer Vacuum-deposited device manufactured by ULVAC Kiko using glass with an indium tin oxide (hereinafter abbreviated as ITO) film manufactured by Etch Sea as a transparent electrode substrate And N, N′-bis (3-methylphenyl) -N, N′-bis- (phenyl) -benzidine (hereinafter referred to as TPD) at a vacuum of 2 × 10 ⁻³ Pa or less on the same substrate. The hole injection layer 3 made of (omitted) is 40 nm thick, the light emitting layer 4 containing 9 wt% Au (PPh ₃ ) (5F8QE) in Ph ₄ Ge is 20 nm thick, 3- (4-biphenylyl) -4 A hole blocking layer 5 made of phenyl-5-tert-butylphenyl-1,2,4-triazole (hereinafter abbreviated as TAZ) is 30 nm, and aluminum is used as the electrode 6 An electroluminescent device was fabricated by sequentially vacuum-depositing 100 nm of aluminum (Al).
The vacuum deposition was performed by charging the raw material in a crucible placed opposite to the substrate and heating the raw material together with the crucible.

When the voltage between the electrodes is increased by energizing with the ITO electrode 2 of the element as the positive electrode and the Al electrode 6 as the negative electrode, the element starts to emit blue light that is clearly visible to the naked eye from around +9 V, and is 16 cd / m ^{2 at} +15 V. Emitted light. The efficiency of the current related to light emission of this element was determined by the following equation.

  The current efficiency thus obtained was 0.017 cd / A at + 15V.

  The emission spectrum of this device was measured using an FP-6300 spectrofluorometer manufactured by JASCO Corporation. The measurement was performed by placing an electroluminescent element facing the detection part of the spectrometer and then applying a predetermined voltage to the element to emit light. From the spectrum obtained at an interelectrode voltage of +10 V, the values of chromaticity coordinates determined by JIS Z8701 were x = 0.16, y = 0.03, and z = 0.81.

Example 2 Preparation of organic electroluminescence device containing Ph ₄ Ge in light emitting layer (2)
An electroluminescent device was produced in the same manner as in Example 1 except that the light emitting layer 4 containing 20 wt% Au (PPh ₃ ) (5F8QE) in Ph ₄ Ge was vacuum deposited.

When the ITO electrode 2 of the device is used as a positive electrode and the Al electrode 6 is used as a negative electrode and the voltage between the electrodes is increased, the device starts emitting blue light from the vicinity of + 10V to the extent that it can be clearly seen with the naked eye, and is 16 cd / m ^{2 at} + 16V. Emitted light. The maximum current efficiency of this element was 0.02 cd / A at + 11V.

Example 3 Preparation of organic electroluminescence device containing Ph ₄ Ge in light emitting layer (3)
An electroluminescent device similar to that of Example 2 except that an electron injection layer 7 made of tris- (8-hydroxyquinoline) aluminum (hereinafter abbreviated as Alq) was vacuum-deposited by 30 nm between the hole blocking layer 5 and the electrode 6. Was made.

When the ITO electrode 2 of the device is used as a positive electrode and the Al electrode 6 is used as a negative electrode and the voltage between the electrodes is increased, the device starts emitting blue light to the extent that it can be clearly seen with the naked eye from around + 11V, and 64 cd / m ^{2 at} + 21V. Emitted light. The maximum current efficiency of this element was 0.14 cd / A at + 19V.

Example 4 Fabrication of organic electroluminescence device containing Ph ₄ Ge in light emitting layer (4)
An electroluminescent device was fabricated in the same manner as in Example 3 except that the light emitting layer 4 containing 5 wt% Au (PPh ₃ ) (5F8QE) in Ph 4 Ge was vacuum deposited.

When the voltage between the electrodes is increased by energizing with the ITO electrode 2 of the element as the positive electrode and the Al electrode 6 as the negative electrode, the element starts to emit blue light that is clearly visible to the naked eye from around + 11V, and is 91 cd / m ^{2 at} + 20V. Emitted light. The maximum current efficiency of this element was 0.25 cd / A at + 14V.

Example 5 FIG. Preparation of organic electroluminescence device containing Ph ₄ Ge in light emitting layer (5)
An electroluminescent device was produced in the same manner as in Example 4 except that the light emitting layer 4 containing 9% by weight of Au (PPh ₃ ) (5F8QE) in Ph 4 Ge was vacuum deposited.
When the voltage between the electrodes is increased by energizing with the ITO electrode 2 of the element as the positive electrode and the Al electrode 6 as the negative electrode, the element starts to emit blue light that is clearly visible to the naked eye from around + 10V, and is 102 cd / m ^{2 at} + 16V. Emitted light. The maximum current efficiency of this element was 0.87 cd / A at + 14V.

  The values of the chromaticity coordinates obtained from the emission spectrum when the interelectrode voltage of this element was +15 V were x = 0.15, y = 0.09, and z = 0.76. The value of the chromaticity coordinate hardly changed even when the voltage between the electrodes was changed.

Example 6 Except that vacuum deposition of _Au (PPh 3) luminescent layer 4 comprising (5F8QE) 9 wt% of Ph ₃ GePhC ₈ during fabrication Ph ₃ GePhC ₈ of the organic electroluminescence element including a light-emitting layer in the same manner as in Example 1 An electroluminescence element was produced.

When the ITO electrode 2 of the element is used as a positive electrode and the Al electrode 6 is used as a negative electrode and the voltage between the electrodes is increased, the element starts to emit blue light that is clearly visible to the naked eye from around + 13V, and 79 cd / m ^{2 at} + 18V. Emitted light. The maximum current efficiency of this element was 0.18 cd / A at + 17V.

Example 7 Preparation of organic electroluminescence device containing Ph ₃ GePhC ₈ in light emitting layer (2)
An electroluminescent device was produced in the same manner as in Example 5 except that the light emitting layer 4 containing 9% by weight of Au (PPh ₃ ) (5F8QE) in Ph ₃ GePhC ₈ was vacuum deposited.
When the ITO electrode 2 of the element is used as a positive electrode and the Al electrode 6 is used as a negative electrode and the voltage between the electrodes is increased, the element starts emitting blue light to the extent that it can be clearly seen with the naked eye from around + 11V, and 135 cd / m ^{2 at} + 22V. Emitted light. The maximum current efficiency of this element was 0.73 cd / A at + 19V.

Comparative Example 1 Preparation of organic electroluminescent device using 4,4′-bis (carbazol-9-yl) biphenyl (CBP) instead of organic germanium compound having aromatic substituent Au in general light emitting layer material CBP An electroluminescent device was produced in the same manner as in Example 5 except that the light emitting layer 4 containing 9% by weight of (PPh ₃ ) (5F8QE) was vacuum deposited.
The maximum current efficiency of this element was 0.12 cd / A, which was significantly lower than that of Example 5.

Comparative Example 2 Preparation of organic electroluminescence device using 1,3-biscarbazolylbenzene (mCP) instead of organic germanium compound having aromatic substituent Au (PPh ₃ ) in mCP which is a general light emitting layer material An electroluminescent device was produced in the same manner as in Example 5 except that the light emitting layer 4 containing 9% by weight of 5F8QE) was vacuum deposited.
The maximum current efficiency of this element was 0.21 cd / A, which was a lower efficiency than that of Example 5.

Example 8. Production of an organic electroluminescence device containing 4-methylphenyltriphenylgermanium (Ph ₃ GePhC1) as a host in an organic light emitting layer A glass with an indium tin oxide (hereinafter abbreviated as ITO) film manufactured by Etch Sea was used as a transparent electrode. N, N'-di (naphthalen-1-yl) -N, N'- is used as a substrate, using a vacuum evaporation device manufactured by ULVAC-KIKO at a vacuum degree of 2 × 10 ⁻³ Pa or less on the substrate. The hole transport layer 3 made of diphenylbenzidine (hereinafter abbreviated as αNPD) has a thickness of 40 nm, the light-emitting layer 4 containing 9.7 wt% Au (PPh3) (5F8QE) in Ph3GePhC1 has a thickness of 30 nm, and 3- (4-biphenyl) Yl) -4-phenyl-5-tert-butylphenyl-1,2,4-triazole (hereinafter abbreviated as TAZ) The electron blocking layer 5 is 20 nm, the electron transport layer 6 made of tris- (8-hydroxyquinoline) aluminum (hereinafter abbreviated as Alq) is 30 nm, and the electrode 7 is 100 nm of aluminum (Al), which is sequentially vacuum-deposited. Produced.
The vacuum deposition was performed by charging the raw material in a crucible placed opposite to the substrate and heating the raw material together with the crucible.
When the ITO electrode 2 of the element is used as the positive electrode and the Al electrode 7 is used as the negative electrode and the voltage between the electrodes is increased, the element starts emitting blue light from the vicinity of + 6V to the extent that it can be clearly seen with the naked eye, and 142 cd / m ^{2 at} + 20V. Emitted light. The current efficiency of this element was 0.33 cd / A at + 13V.
The chromaticity coordinate value determined by JIS Z8701 from the spectrum obtained for the emission color of this element at the interelectrode voltage +20 V was x = 0.16 and y = 0.12.

Example 9 Fabrication of organic electroluminescence device containing Ph3GePhC1 as a host in the organic light emitting layer (2)
Except that the light emitting layer 4 containing 9.6% by weight of Au (PPh ₃ ) (5F8QE) in Ph ₃ GePhC1 was deposited to a thickness of 20 nm, the hole blocking layer 5 made of TAZ was deposited to 30 nm, and vacuum deposition was performed in the same manner as in Example 8. An electroluminescence element was produced.
When the ITO electrode 2 of the device is used as a positive electrode and the Al electrode 7 is used as a negative electrode and the voltage between the electrodes is increased, the device starts emitting blue light from the vicinity of +9 V, which is clearly visible to the naked eye, and at 6.8 cd / + 22 V. Light was emitted at m ² . The maximum current efficiency for light emission of this element was 0.18 cd / A at + 20V. From the emission spectrum of the device obtained at this time, the value of the chromaticity coordinate determined by JIS Z8701 was x = 0.22, y = 0.16.

Example 10. Production of an organic electroluminescent device containing 0.1-naphthyltriphenylgermanium (Ph ₃ Ge-1-Nap) in an organic light emitting layer as a host Au (PPh ₃ ) (5F8QE) in Ph ₃ Ge-1-Nap Was produced in the same manner as in Example 9 except that the light emitting layer 4 containing 9.6% by weight was vacuum-deposited with a film thickness of 20 nm.
When the ITO electrode 2 of the device is used as a positive electrode and the Al electrode 7 is used as a negative electrode to increase the voltage between the electrodes, the device starts to emit blue light that is clearly visible to the naked eye from around + 11V, and 12.9 cd / at + 27V. Light was emitted at m ² . The maximum current efficiency of this element was 0.17 cd / A at + 24V.

Example 11. Production of an organic electroluminescence device containing 1.3-phenylphenyltriphenylgermanium (Ph ₃ GePh-3-Ph) in an organic light emitting layer as a host The hole transport layer 3 made of αNPD on the ITO substrate has a thickness of 40 nm. The light-emitting layer 4 containing 9.6% by weight of Au (PPh ₃ ) (5F8QE) in Ph ₃ GePh-3-Ph is 20 nm thick, the hole blocking layer 5 made of TAZ is 30 nm, the electrode 7 is 100 nm of Al in order An electroluminescence element was manufactured by vacuum deposition.
When the ITO electrode 2 of the device is used as a positive electrode and the Al electrode 6 is used as a negative electrode and the voltage between the electrodes is increased, the device starts emitting blue light to the extent that it can be clearly seen with the naked eye from around +8 V, and 22 cd / m ^{2 at} +18 V. Emitted light. The maximum current efficiency of this element was 0.12 cd / A at + 17V.

Example 12 Production of organic electroluminescence device containing Ph ₃ GePh-3-Ph as host in organic light emitting layer (2)
An electroluminescence device was produced in the same manner as in Example 11 except that the electron transport layer 7 made of Alq was vacuum-deposited by 30 nm between the hole block layer 5 made of TAZ and the aluminum electrode 7.
When the ITO electrode 2 of the element is used as a positive electrode and the Al electrode 6 is used as a negative electrode and the voltage between the electrodes is increased, the element starts emitting blue light from the vicinity of + 12V to the extent that it can be clearly seen with the naked eye. Light was emitted at m ² . The current efficiency for light emission of this element was 0.11 cd / A at + 20V.

Example 13. Production of organic electroluminescent device containing 4-phenylphenyltriphenylgermanium (Ph ₃ GePh-4-Ph) in organic light emitting layer as host The hole transport layer 3 made of αNPD was formed on the ITO substrate to a film thickness of 40 nm. The light emitting layer 4 containing 9.7 wt% Au (PPh ₃ ) (5F8QE) in Ph ₃ GePh-4-Ph is 20 nm thick, the hole blocking layer 5 made of TAZ is 30 nm, and the electron transport layer 6 made of Alq is 30 nm. Then, an electroluminescence element was produced in the same manner as in Example 8 except that vacuum deposition was sequentially performed.
When the ITO electrode 2 of the device is used as a positive electrode and the Al electrode 7 is used as a negative electrode and the voltage between the electrodes is increased, the device starts to emit blue light that is clearly visible to the naked eye from around +10 V, and reaches 1.9 cd / at +24 V. Light was emitted at m ² . The maximum current efficiency of this element was 0.08 cd / A at + 15V.

Example 14. Production of an organic electroluminescence device containing 4-phenoxyphenyltriphenylgermanium (Ph ₃ GePhOPh) as a host in an organic light emitting layer A hole made of αNPD at a vacuum of 2 × 10 ⁻³ Pa or less on an ITO substrate The transport layer 3 is 40 nm thick, the light emitting layer 4 containing 9.8 wt% Au (PPh ₃ ) (5F8QE) in Ph ₃ GePhOPh is 30 nm thick, the hole blocking layer 5 made of TAZ is 20 nm, and the electrode 7 is made of Al. Was made in the same manner as in Example 8 except that 100 nm was sequentially deposited by vacuum evaporation.
When the ITO electrode 2 of the element is used as a positive electrode and the Al electrode 6 is used as a negative electrode to increase the voltage between the electrodes, the element starts to emit blue light that is clearly visible to the naked eye from around + 10V, and 23.1 cd / at + 18V. Light was emitted at m ² . The maximum current efficiency of this element was 0.11 cd / A at + 16V.
The value of the chromaticity coordinate determined by JIS Z8701 from the emission spectrum of the element measured at an interelectrode voltage of +20 V was x = 0.16 and y = 0.097.

Example 15. Fabrication of organic electroluminescent device containing Ph ₃ GePhOPh as organic host in organic light emitting layer (2)
An electroluminescent device was produced in the same manner as in Example 14 except that the electron transport layer 7 made of Alq was vacuum-deposited by 30 nm between the hole block layer 5 made of TAZ and the aluminum electrode 6.
When the ITO electrode 2 of the device was used as the positive electrode and the Al electrode 6 was used as the negative electrode and the voltage between the electrodes was increased, the device started to emit blue light that was clearly visible to the naked eye from around + 12V, and 1.1 cd / at + 22V. Light was emitted at m ² . The current efficiency of light emission of this element was 0.03 cd / A at + 22V.
From the spectrum obtained at the voltage between the electrodes +20 V, the value of the chromaticity coordinate determined by JIS Z8701 was x = 0.14, y = 0.17.

Example 16. Production of an organic electroluminescent device containing _4- benzylphenyltriphenylgermanium (Ph ₃ GePhCH ₂ Ph) in an organic light emitting layer as a host On the ITO substrate, a hole transport layer 3 made of αNPD was formed to a thickness of 40 nm, Ph ₃ GePhCH ₂ Ph includes 9.4% by weight of Au (PPh ₃ ) (5F8QE), the light emitting layer 4 is 30 nm thick, the hole blocking layer 5 made of TAZ is 30 nm, the electron transport layer 6 made of Alq is 30 nm, the electrode 7 was produced in the same manner as in Example 8 except that Al was sequentially vacuum-deposited with 100 nm of Al.
When the ITO electrode 2 of the element is used as a positive electrode and the Al electrode 7 is used as a negative electrode to increase the voltage between the electrodes, the element starts to emit blue light that is clearly visible to the naked eye from around +5 V, and 135 cd / m ^{2 at} +22 V. Emitted light. The maximum current efficiency of this element was 1.03 cd / A at + 10V.
From the emission spectrum of this device obtained at an interelectrode voltage of +20 V, the value of chromaticity coordinates determined by JIS Z8701 was x = 0.22, y = 0.16.

Example 17. Preparation of organic electroluminescence device containing n-butyltriphenylgermanium (nBuGePh ₃ ) in organic light emitting layer as host The hole transport layer 3 made of αNPD is formed on the ITO substrate with a film thickness of 40 nm, and Au (PPh ₃ ) in nBuGePh ₃ An electroluminescent device was produced in the same manner as in Example 8 except that the light emitting layer 4 containing 9.6% by weight of (5F8QE) was successively vacuum-deposited with a film thickness of 30 nm and a hole blocking layer 5 made of TAZ of 20 nm.
When the ITO electrode 2 of the element is used as a positive electrode and the Al electrode 7 is used as a negative electrode to increase the voltage between the electrodes, the element starts to emit blue light that is clearly visible to the naked eye from around + 6V, and 144 cd / m ^{2 at} + 21V. Emitted light. The maximum current efficiency of this element was 0.32 cd / A at + 15V.
From the emission spectrum of this device obtained at an interelectrode voltage of +20 V, the value of chromaticity coordinates determined by JIS Z8701 was x = 0.16 and y = 0.12.

Example 18 Fabrication of organic electroluminescence device containing nBuGePh ₃ as host in organic light emitting layer (2)
On the ITO substrate, thickness of the hole transport layer 3 made of [alpha] NPD 40 nm, _Au in _{nBuGePh 3 (PPh 3) (5F8QE} ) a containing 9.7% by weight light-emitting layer 4 a thickness of 20 nm, a hole blocking layer made of TAZ 5 was 30 nm and Al was 100 nm as the electrode 7 in order by vacuum evaporation to produce an electroluminescent device.
The vacuum deposition was performed by charging the raw material in a crucible placed opposite to the substrate and heating the raw material together with the crucible.
When the ITO electrode 2 of the element is used as a positive electrode and the Al electrode 6 is used as a negative electrode and the voltage between the electrodes is increased, the element starts to emit blue light that is clearly visible to the naked eye from around +5 V, and reaches 41.6 cd / at +17 V. Light was emitted at m ² . The maximum current efficiency of this element was 0.13 cd / A at + 11V.
From the emission spectrum of this device obtained at an interelectrode voltage of +20 V, the value of chromaticity coordinates determined by JIS Z8701 was x = 0.16 and y = 0.097.

Example 19. Fabrication of organic electroluminescence device containing nBuGePh ₃ as host in organic light emitting layer (3)
An electroluminescence element was produced in the same manner as in Example 18 except that the electron transport layer 7 made of Alq was vacuum-deposited by 30 nm between the hole block layer 5 made of TAZ and the aluminum electrode 6.
When the ITO electrode 2 of the element is used as the positive electrode and the Al electrode 6 is used as the negative electrode and the voltage between the electrodes is increased, the element starts to emit blue light that is clearly visible to the naked eye from around +9 V, and is 126 cd / m ^{2 at} +22 V. Emitted light. The current efficiency related to light emission of this element was 0.58 cd / A at + 12V.
From the emission spectrum of this device obtained at an interelectrode voltage of +20 V, the values of chromaticity coordinates determined according to JIS Z8701 were x = 0.17 and y = 0.16.

Reference Example 4.4 Synthesis of 4-methylphenyltriphenylgermanium (Ph ₃ GePhC1) A colorless transparent solution in which 388 μl (2.3 mmol) of p-bromotoluene and 8.5 ml of tetrahydrofuran were added to a 20 ml Schlenk tube dried under an Ar atmosphere. After cooling to -78 ° C with dry ice-ethanol, 3.8 ml (5.7 mmol) of a tert-butyllithium pentane solution (f = 1.48) was added dropwise. After dropping, the reaction solution turned yellow was stirred for 0.5 hours while maintaining the reaction temperature at -78 ° C, and then 848 mg (2.5 mmol) of triphenyl germanium chloride was added. The mixture was stirred for 5 minutes while maintaining at -78 ° C, and then stirred at 0 ° C for 1 hour in an ice bath. After completion of the reaction, 40 ml of water and 80 ml of methylene chloride were added to the reaction solution for liquid separation, the aqueous layer was extracted twice with 20 ml of methylene chloride, and the organic layers obtained were combined and dried over 1.2 g of anhydrous magnesium sulfate. After filtration, methylene chloride was distilled off from the filtrate under reduced pressure, and the resulting residue was purified by silica gel column chromatography (developing solvent: n-hexane) to obtain the target compound as a white solid. (Yield 0.86g, Yield 96%)

¹ H-NMR (300 MHz, CDCl ₃ ) δ: 7.55 to 6.90 (m, 19H), 2.37 (S, 3H)
EI-MS (m / e): 396 (M ^<+> )

Reference Example 5.1 Synthesis of 1-naphthyltriphenylgermanium (Ph ₃ Ge-1-Nap) A colorless transparent solution in which 298 μl (2.1 mmol) of 1-bromonaphthalene and 8 ml of tetrahydrofuran were added to a 20 ml Schlenk tube dried under an Ar atmosphere. Was cooled to −78 ° C. with dry ice-ethanol, and 3.6 ml (5.4 mmol) of a tert-butyllithium pentane solution (f = 1.48) was added dropwise. After the dropwise addition, the reaction solution turned yellow was stirred for 1 hour while maintaining the reaction temperature at -78 ° C., and then 800 mg (2.4 mmol) of triphenyl germanium chloride was added. The mixture was stirred for 10 minutes while maintaining at -78 ° C, and then stirred at 0 ° C for 1 hour in an ice bath. After completion of the reaction, 40 ml of water and 80 ml of methylene chloride were added to the reaction solution for liquid separation, the aqueous layer was extracted twice with 20 ml of methylene chloride, and the organic layers obtained were combined and dried over 1.2 g of anhydrous magnesium sulfate. After filtration, methylene chloride was distilled off from the filtrate under reduced pressure, and the resulting residue was purified by silica gel column chromatography (developing solvent: n-hexane → ethyl acetate) to obtain the target compound as a white solid. (Yield 0.74g, Yield 80%)

¹ H-NMR (300 MHz, CDCl ₃ ) δ: 7.94-7.83 (m, 3H), 7.56-7.20 (m, 19H)
EI-MS (m / e): 431 (M ^<+> )

Reference Example 6. Synthesis of 3-phenylphenyltriphenylgermanium (Ph ₃ GePh-3-Ph) colorless and transparent in which 354 μl (2.1 mmol) of 3-bromobiphenyl and 8 ml of tetrahydrofuran were added to a 20 ml Schlenk tube dried in an Ar atmosphere The solution was cooled to -78 ° C. with dry ice-ethanol, and 3.6 ml (5.4 mmol) of a tert-butyllithium pentane solution (f = 1.48) was added dropwise. After the dropwise addition, the reaction solution turned yellow was stirred for 1 hour while maintaining the reaction temperature at -78 ° C., and then 800 mg (2.4 mmol) of triphenyl germanium chloride was added. The mixture was stirred for 10 minutes while maintaining at -78 ° C, and then stirred at 0 ° C for 1 hour in an ice bath. After completion of the reaction, 40 ml of water and 80 ml of methylene chloride were added to the reaction solution for liquid separation, the aqueous layer was extracted twice with 20 ml of methylene chloride, and the organic layers obtained were combined and dried over 1.2 g of anhydrous magnesium sulfate. After filtration, methylene chloride was distilled off from the filtrate under reduced pressure, and the resulting residue was purified by silica gel column chromatography (developing solvent: n-hexane) to obtain the target compound as a white solid. (Yield 0.9g, Yield 91%)

¹ H-NMR (300 MHz, CDCl ₃ ) δ: 7.78-7.77 (m, 1H), 7.62-7.24 (m, 23H)
CI-MS (m / e): 458 (M + 1 ⁺ )

Reference Example 7. Synthesis of 4-phenylphenyltriphenylgermanium (Ph ₃ GePh-4-Ph) The same operation as in Reference Example 6 was performed except that 3-bromobiphenyl was changed to 499 mg (2.1 mmol) of 4-bromobiphenyl. The target compound was obtained as a white solid by purification by silica gel column chromatography (developing solvent: n-hexane → n-hexane / ethyl acetate = 4/1). (Yield 0.5g, Yield 54%)

¹ H-NMR (300 MHz, CDCl ₃ ) δ: 7.62-7.53 (m, 12H), 7.47-7.27 (m, 12H)
CI-MS (m / e): 458 (M + 1 ⁺ )

Reference Example 8. Synthesis of 4-phenoxyphenyltriphenylgermanium (Ph ₃ GePhOPh) A colorless transparent solution obtained by adding 400 μl (2.3 mmol) of 4-bromodiphenyl ether and 8.5 ml of tetrahydrofuran to a dry 20 ml Schlenk tube under an argon atmosphere. After cooling to -78 ° C with dry ice-ethanol, 3.4 ml (5.7 mmol) of a tert-butyllithium pentane solution (f = 1.7) was added dropwise. After dropping, the reaction solution turned yellow was stirred for 1 hour while maintaining the reaction temperature at −78 ° C., and then 848 mg (2.5 mmol) of triphenyl germanium chloride was added. The mixture was stirred for 10 minutes while maintaining at -78 ° C, and then stirred at 0 ° C for 2 hours in an ice bath. After completion of the reaction, 40 ml of water and 80 ml of methylene chloride were added to the reaction solution for liquid separation, the aqueous layer was extracted twice with 20 ml of methylene chloride, and the organic layers obtained were combined and dried over 1.2 g of anhydrous magnesium sulfate. After filtration, methylene chloride is distilled off from the filtrate under reduced pressure, and the resulting residue is purified by silica gel column chromatography (developing solvent: n-hexane / ethyl acetate = 30/1) and then recrystallized from n-hexane. This gave the target compound as a white solid. (Yield 0.93g, Yield 87%)

¹ H-NMR (300 MHz, CDCl ₃ ) δ: 7.55-7.00 (m, 24H)
EI-MS (m / e): 474 (M ⁺ )

Reference Example 9 Synthesis of 4-benzylphenyltriphenylgermanium (Ph ₃ GePhCH ₂ Ph) Under an argon atmosphere, 420 μl (2.3 mmol) of 4-bromodiphenylmethane and 8.5 ml of tetrahydrofuran were added to a 20 ml Schlenk tube dried and colorless and transparent. The solution was cooled to −78 ° C. with dry ice-ethanol, and 3.8 ml (5.7 mmol) of a tert-butyllithium pentane solution (f = 1.48) was added dropwise. After dropping, the reaction solution turned orange was stirred for 1 hour while maintaining the reaction temperature at −78 ° C., and 848 mg (2.5 mmol) of triphenylgermanium chloride was added. The mixture was stirred for 10 minutes while maintaining at -78 ° C, and then stirred at 0 ° C for 2 hours in an ice bath. After completion of the reaction, 40 ml of water and 80 ml of methylene chloride were added to the reaction solution for liquid separation, the aqueous layer was extracted twice with 20 ml of methylene chloride, and the organic layers obtained were combined and dried over 1.2 g of anhydrous magnesium sulfate. After filtration, methylene chloride was distilled off from the filtrate under reduced pressure, and the resulting residue was purified by silica gel column chromatography (developing solvent: n-hexane) and then recrystallized (n-hexane: ethyl acetate = 10: 1). The target compound was obtained as a white solid. (Yield 0.4g, Yield 37%)

¹ H-NMR (300 MHz, CDCl ₃ ) δ: 7.54-7.19 (m, 24H), 3.99 (s, 2H)
EI-MS (m / e): 472 (M ^<+> )

Reference Example 10 Synthesis of n-butyltriphenylgermanium (nBuGePh ₃ ) In an Ar atmosphere, 8.5 ml of tetrahydrofuran was cooled to −78 ° C. with dry ice-ethanol in a dry 20 ml Schlenk tube, and a hexane solution of n-butyllithium (f = 1) .59) 1.6 ml (2.5 mmol) was added dropwise. After the dropwise addition, 848 mg (2.5 mmol) of triphenyl germanium chloride was added. The mixture was stirred for 10 minutes while maintaining at -78 ° C, and then stirred at 0 ° C for 1 hour in an ice bath. After completion of the reaction, 40 ml of water and 80 ml of methylene chloride were added to the reaction solution for liquid separation, the aqueous layer was extracted twice with 20 ml of methylene chloride, and the organic layers obtained were combined and dried over 1.2 g of anhydrous magnesium sulfate. After filtration, methylene chloride was distilled off from the filtrate under reduced pressure, and the resulting residue was purified by silica gel column chromatography (developing solvent: n-hexane) to obtain the target compound as a white solid. (Yield 0.5g, Yield 55%)

¹ H-NMR (300 MHz, CDCl ₃ ) δ: 7.52-7.23 (m, 15H), 1.54-1.48 (m, 6H), 0.866 (t, 3H)
CI-MS (M / E): 305 (M + -C ₄ H ₉ )

Emission spectrum when the interelectrode voltage of the element described in Example 1 is +10 V with the ITO electrode 2 as the positive electrode and the Al electrode 6 as the negative electrode. Schematic diagram of electroluminescent device described in Example 1 Schematic diagram of electroluminescent device described in Example 3 Emission spectrum when the interelectrode voltage of the element described in Example 5 is +15 V with the ITO electrode 2 as the positive electrode and the Al electrode 6 as the negative electrode.

Explanation of symbols

1: Glass substrate 2: ITO coating (positive electrode)
3: Hole injection layer 4: Light emitting layer 5: Hole block layer 6: Al electrode 7: Electron injection layer

Claims (1)

An organic electroluminescence device in which a light emitting layer or a plurality of organic compound thin films including a light emitting layer is formed between a pair of electrodes, the light emitting layer being tetraphenyl germanium, triphenyl (4-octylphenyl) germanium, 4-benzylphenyl tri An electroluminescent device comprising phenylgermanium or n-butyltriphenylgermanium and (5-fluoro-8-quinolinoethynyl) (triphenylphosphine) gold .

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