JP2005247791A - Metal complex compound and organic electroluminescent element by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescent element emitting blue color-based light, having a high luminescence efficiency and a long life, and a new metal complex compound capable of realizing the same. <P>SOLUTION: This electroluminescent element supporting a metal complex compound containing sp<SP>2</SP>type P atom and an organic thin membrane consisting of at least one layer or in a plurality of layers having a luminescent layer between a pair of electrodes is provided with that at least one layer of the organic thin membrane layers contains the metal complex compound and the organic electroluminescent element emits light by impressing an electric voltage between the two electrodes. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a novel metal complex compound and an organic electroluminescence (EL) device using the same, and more particularly to an organic EL device that emits blue light, has high emission efficiency, and has a long lifetime, and a novel metal complex compound that realizes the same. Is.

In recent years, the use of organic EL elements as color display devices replacing liquid crystals has been actively studied. However, the light emitting device performance is still insufficient to realize a large screen. As a means for improving the performance of this organic EL element, a green light-emitting element using an orthometalated iridium complex (fac-tris (2-phenylpyridine) iridium) as a phosphorescent light-emitting material has been proposed (for example, non-patent) Reference 1; Non-patent reference 2).
Since organic EL elements using phosphorescence emission are currently limited to green emission, the range of application as a color display is narrow. Therefore, development of elements having improved emission characteristics for other colors has been desired. . In particular, no blue light emitting element has been reported that has an external quantum yield exceeding 5%. If the blue light emitting element can be improved, full color and whitening can be achieved. Advance.
At present, as a phosphorescent complex used as a phosphorescent material, a compound containing Ir is actively developed, and the following compound (A) is known for a green light emitting device. On the other hand, the following compound (B) is known as a phosphorescent complex emitting blue light, but it is not practical in terms of the lifetime and efficiency of the device when used in an organic EL device. Therefore, development of a new phosphorescent complex emitting blue light has been desired.

D.F.O'Brien and M.A.Baldo et al "Improved energy transferin electrophosphorescent devices" Applied Physics letters Vol.74 No.3, pp442-444, January 18, 1999 M.A.Baldo et al "Very high-efficiencygreen organic light-emitting devices based on electrophosphorescence" Applied Physics letters Vol. 75 No.1, pp4-6, July 5, 1999

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an organic EL element that emits blue light, has high luminous efficiency, has a long lifetime, and a novel metal complex compound that realizes the organic EL element. .

As a result of intensive studies to achieve the above object, the present inventors have found that the emission wavelength is shortened by using a complex having a compound containing an sp ² type P atom as a ligand. The present invention has been completed by clarifying a novel structural factor of blue coloration. The organic EL device of the present invention utilizes the phosphorescence phenomenon and has reached an external quantum yield of 8%, exceeding the external quantum yield of 5%, which is said to be the limit of the conventional fluorescent light emitting device. doing.

That is, the present invention provides a metal complex compound having a partial structure represented by the following general formula (I).

[In the formula, the ring structure A is an aromatic ring residue having 6 to 20 carbon atoms which may have a substituent,
Ring structure B represents a ring structure having 5 to 20 carbon atoms including at least one carbon-nitrogen double bond, and may have a substituent,
X is an optionally substituted phosphorus (P) atom or nitrogen (N) atom, M is a group 7, 8 or 9 atom of the periodic table;
Z is an alkane residue having 2 to 10 carbon atoms, a cycloalkane residue having 4 to 20 carbon atoms, or a cycloalkene residue having 4 to 20 carbon atoms bonded to P and X by a double bond, respectively. And may be bonded to a substituent of P and / or X to form a ring.
Ring structure A and ring structure B are connected to each other by a carbon atom, the bond between M and ring structure A is a covalent bond, and the bond between M and ring structure B, P, and X is a π bond, and at least one P The atoms are sp ² type P atoms. ]

  In addition, the present invention provides an organic EL element in which an organic thin film layer composed of one or more layers having at least a light emitting layer is sandwiched between a pair of electrodes, and at least one of the organic thin film layers is the metal of the present invention. An organic EL device that contains a complex compound and emits light when a voltage is applied between both electrodes is provided.

  The organic EL device using the novel metal complex compound of the present invention emits blue light, has high luminous efficiency, and has a long lifetime.

The metal complex compound of the present invention has a partial structure represented by the following general formula (I).

In the general formula (I), the ring structure A is an aromatic ring residue having 6 to 20 carbon atoms which may have a substituent. Examples of this aromatic ring include benzene, naphthalene, anthracene, phenanthrene, pyrene and the like, and benzene is preferred.
In the general formula (I), the ring structure B represents a ring structure having 5 to 20 carbon atoms including at least one carbon-nitrogen double bond, and may have a substituent.
Examples of the ring structure include monovalent groups such as pyridine, quinoline, isoquinoline, pyrimidine, pyrazine, pyridazine, imidazole, oxazole, isoxazole, thiazole, and isothiazole, and pyridine is preferable.
In general formula (I), X is a phosphorus (P) atom or a nitrogen (N) atom which may have a substituent.
In the general formula (I), M is a Group 7, Group 8 or Group 9 atom in the periodic table, preferably a Group 9 atom, and particularly preferably iridium (Ir).

In the general formula (I), Z is an alkane residue having 2 to 10 carbon atoms, a cycloalkane residue having 4 to 20 carbon atoms, or a cycloalkene having 4 to 20 carbon atoms bonded to P and X by a double bond, respectively. It is a residue, may have a substituent, and may combine with a substituent of P and / or X to form a ring.
Examples of the alkane of Z include methane, ethane, propane, n-butane, i-butane and the like, with ethane being preferred.
Examples of the cycloalkane of Z include cyclobutane, cyclopentane, cyclohexane and the like, with cyclobutane being preferred.
Examples of the cycloalkene of Z include cyclobutene, cyclopentene, cyclohexene and the like, and cyclobutene and the like are preferable.
The ring formed by combining Z and the substituent of P and / or X is monovalent such as pyridine, quinoline, isoquinoline, pyrimidine, pyrazine, pyridazine, imidazole, oxazole, isoxazole, thiazole, isothiazole and the like. The group of is mentioned.

Examples of the substituent of the ring structure A, ring structure B, P, X, and Z include a halogen atom, hydroxyl group, substituted or unsubstituted amino group, nitro group, cyano group, substituted or unsubstituted alkyl group, substituted or An unsubstituted alkenyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxyl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted arylalkyl group, a substituted or unsubstituted aryloxy group, Examples thereof include a substituted or unsubstituted alkoxycarbonyl group and a carboxyl group.
In general formula (I), ring structure A and ring structure B are connected to each other by a carbon atom, the bond between M and ring structure A is a covalent bond, and the bond between M and ring structure B, P and X is a π bond And at least one P atom is an sp ² type P atom.
The sp ² type P atom is a trivalent P atom having a double bond on the P atom.

The metal complex compound of the present invention preferably has a partial structure represented by the following general formula (II) or (III).

In the general formulas (II) and (III), R ^{1 to} R ¹² and R ¹ ′ to R ⁶ ′ each independently represent a hydrogen atom or a C 1-12 alkyl which may have a substituent. Represents an aromatic ring group having 6 to 20 carbon atoms, a halogen atom, a cyano group or a nitro group, which may have a group or a substituent. In addition, adjacent ones of R ^{5 to} R ¹² may be bonded to each other to form a ring.
Examples of the alkyl group include a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, n-hexyl group, n- A heptyl group, n-octyl group, etc. are mentioned, The alkyl group substituted by the fluorine atom is preferable.
Examples of the aromatic ring group include benzene, naphthalene, anthracene, phenanthrene, pyrene, coronene, biphenyl, terphenyl, pyrrole, furan, thiophene, benzothiophene, oxadiazoline, diphenylanthracene, indoline, carbazole, pyridine, benzoquinone Monovalent residues such as fluoranthene and acenaphthofluoranthene.
Examples of the halogen atom include fluorine, chlorine, bromine and iodine.
Examples of the substituent for the alkyl group and the aromatic ring group include a halogen atom, a hydroxyl group, a substituted or unsubstituted amino group, a nitro group, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, Substituted or unsubstituted cycloalkyl group, substituted or unsubstituted alkoxyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted arylalkyl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkoxy A carbonyl group, a carboxyl group, etc. are mentioned.

Furthermore, the metal complex compound of the present invention preferably has a partial structure represented by the following general formula (II ′) or (III ′).

In the general formulas (II ′) and (III ′), R ^{1 to} R ¹² and R ¹ ′ to R ⁶ ′ are the same as described above, and specific examples, substituents, and the like are also the same.
In the general formulas (II ′) and (III ′), L represents an anion having a valence of −1 containing any of the elements in Groups 13 to 16 of the periodic table. Specific examples include PF ₆ ⁻ , ClO. ₄ ⁻ , SbF ₆ ⁻ , OTf ⁻ , OTs ⁻ , BF ₄ ⁻ , BPh ₄ ⁻ , B (C ₆ F ₅ ) ₄ ^{− and the} like are mentioned, and OTs ⁻ and PF ₆ ⁻ are preferable.

で表される構造が、

のいずれかで表される構造であると好ましく、 In the general formula (I)

The structure represented by

Preferably, the structure is represented by any of the following:

で表される構造が、

のいずれかで表される構造であると好ましい。

The structure represented by

It is preferable that it is a structure represented by either.

Specific examples of the metal complex compound having a partial structure represented by the general formula (I) of the present invention are illustrated below, but are not limited to these exemplary compounds.

The organic EL device of the present invention is an organic EL device in which an organic thin film layer comprising at least one light emitting layer or a plurality of layers is sandwiched between a pair of electrodes comprising an anode and a cathode, and at least one of the organic thin film layers However, it contains the metal complex compound of the present invention and emits light when a voltage is applied between both electrodes.
As content of the metal complex compound of this invention in the said organic thin film layer, it is 0.1-100 weight% normally with respect to the mass of the whole organic thin film layer, and it is preferable in it being 1-30 weight%.
In the organic EL device of the present invention, the light emitting layer preferably contains the metal complex compound of the present invention. In addition, the layer containing the metal complex compound of the present invention is usually thinned by vacuum deposition or coating, but it is preferable that the layer is formed by coating because the manufacturing process can be simplified.

  In the organic EL device of the present invention, the organic thin film layer is a light emitting layer when the organic thin film layer is a single layer type, and this light emitting layer contains the metal complex compound of the present invention. In addition, multilayer organic EL elements include (anode / hole injection layer (hole transport layer) / light emitting layer / cathode), (anode / light emitting layer / electron injection layer (electron transport layer) / cathode), ( Anode / hole injection layer (hole transport layer) / light emitting layer / electron injection layer (electron transport layer) / cathode) and the like.

  The anode of the organic EL device of the present invention supplies holes to a hole injection layer, a hole transport layer, a light emitting layer, and the like. Examples of the anode material include metals, alloys, metal oxides, and electrical conductivity. A compound or a mixture thereof can be used. Specific examples of the material of the anode include conductive metal oxides such as tin oxide, zinc oxide, indium oxide, and indium tin oxide (ITO), or metals such as gold, silver, chromium, nickel, and these conductive metals. Preferred examples include a mixture or laminate of oxide and metal, inorganic conductive materials such as copper iodide and copper sulfide, organic conductive materials such as polyaniline, polythiophene and polypyrrole, and laminates of these with ITO. Is a conductive metal oxide, and in particular, ITO is preferably used from the viewpoint of productivity, high conductivity, transparency, and the like. The film thickness of the anode can be appropriately selected depending on the material.

  The cathode of the organic EL device of the present invention supplies electrons to an electron injection layer, an electron transport layer, a light emitting layer, and the like. As a material of the cathode, metal, alloy, metal halide, metal oxide, electric conduction Or a mixture of these can be used. Specific examples of cathode materials include alkali metals (eg, Li, Na, K, etc.) and their fluorides or oxides, alkaline earth metals (eg, Mg, Ca, etc.) and their fluorides or oxides, gold Silver, lead, aluminum, sodium-potassium alloy or sodium-potassium mixed metal, lithium-aluminum alloy or lithium-aluminum mixed metal, magnesium-silver alloy or magnesium-silver mixed metal, or rare earth metals such as indium and ytterbium, etc. Can be mentioned. Among these, aluminum, lithium-aluminum alloy or lithium-aluminum mixed metal, magnesium-silver alloy or magnesium-silver mixed metal are preferable. The cathode may have a single layer structure of the material or a laminated structure of layers containing the material. For example, a laminated structure of aluminum / lithium fluoride and aluminum / lithium oxide is preferable. The film thickness of the cathode can be appropriately selected depending on the material.

  The hole injection layer and the hole transport layer of the organic EL device of the present invention have any one of a function of injecting holes from the anode, a function of transporting holes, and a function of blocking electrons injected from the cathode. If it is what. Specific examples include carbazole derivatives, triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, styrylanthracene derivatives. , Fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aromatic tertiary amine compounds, styrylamine compounds, aromatic dimethylidin compounds, porphyrin compounds, polysilane compounds, poly (N-vinylcarbazole) derivatives, aniline compounds Examples include copolymers, thiophene oligomers, conductive polymer oligomers such as polythiophene, organosilane derivatives, and metal complex compounds of the present invention. Further, the hole injection layer and the hole transport layer may have a single layer structure composed of one or more of the materials, or a multilayer structure composed of a plurality of layers having the same composition or different compositions. May be.

  The electron injection layer and the electron transport layer of the organic EL device of the present invention have any one of the function of injecting electrons from the cathode, the function of transporting electrons, and the function of blocking holes injected from the anode. If it is. Specific examples include triazole derivatives, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, fluorenone derivatives, anthraquinodimethane derivatives, anthrone derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, carbodiimide derivatives, fluorenylidenemethane derivatives. , Represented by metal complexes of aromatic ring tetracarboxylic anhydrides such as distyrylpyrazine derivatives, naphthalene and perylene, phthalocyanine derivatives, 8-quinolinol derivatives, metal phthalocyanines, benzoxazoles and benzothiazoles as ligands Examples include various metal complexes, organosilane derivatives, and metal complex compounds of the present invention. Further, the electron injection layer and the electron transport layer may have a single layer structure composed of one or more of the materials, or a multilayer structure composed of a plurality of layers having the same composition or different compositions. Good.

  The light emitting layer of the organic EL device of the present invention can inject holes from the anode or the hole injection layer when an electric field is applied, and can inject electrons from the cathode or the electron injection layer. And holes) by the force of an electric field, a field for recombination of electrons and holes, and a function to connect this to light emission. The light emitting layer of the organic EL device of the present invention preferably contains at least the metal complex compound of the present invention, and may contain a host material using the metal complex compound as a guest material. Examples of the host material include those having a carbazole skeleton, those having a diarylamine skeleton, those having a pyridine skeleton, those having a pyrazine skeleton, those having a triazine skeleton, and those having an arylsilane skeleton. It is preferable that T1 (the energy level of the lowest triplet excited state) of the host material is larger than the T1 level of the guest material. The host material may be a low molecular compound or a high molecular compound. Further, by co-evaporating the host material and a light emitting material such as the metal complex compound, a light emitting layer in which the light emitting material is doped in the host material can be formed.

In the organic EL device of the present invention, the method for forming each layer is not particularly limited, but a vacuum deposition method, an LB method, a resistance heating deposition method, an electron beam method, a sputtering method, a molecular lamination method, a coating method. Various methods such as a spin coating method, a casting method, a dip coating method, an ink jet method, and a printing method can be used. In the present invention, a coating method that is a coating method is preferable.
In the coating method, the metal complex compound of the present invention can be dissolved in a solvent to prepare a coating solution, and the coating solution can be applied on a desired layer (or electrode) and dried. The coating solution may contain a resin, and the resin can be dissolved in a solvent or dispersed. As the resin, a non-conjugated polymer (for example, polyvinyl carbazole) or a conjugated polymer (for example, a polyolefin-based polymer) can be used. More specifically, for example, polyvinyl chloride, polycarbonate, polystyrene, polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene oxide, polybutadiene, poly (N-vinylcarbazole), hydrocarbon resin, ketone resin, phenoxy resin. , Polyamide, ethyl cellulose, vinyl acetate, ABS resin, polyurethane, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin, silicon resin and the like.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
Example 1 (Synthesis of metal complex compound (1))
(1) Synthesis of 1,2-diphenyl-3,4-bis [(2,4,6-tri (t-butylphenyl) phosphinidene] -1-cyclobutene (DPCB-H)

2,4,6-Tri-t-butylbromobenzene (3.58 g, 11.0 mmol) and anhydrous tetrahydrofuran (THF) (20 ml) were added to a 50 ml flask, cooled to −78 ° C., and n-butyllithium (7.4 ml, 1.6 M). Hexane solution, 12.0 mmol) was added. After stirring at −78 ° C. for 30 minutes, an anhydrous THF solution (5.0 ml) of dichloro (phenylethynyl) phosphine (2.17 g, 11.0 mmol) was added. The reaction mixture was stirred at −78 ° C. for 30 minutes and then at room temperature for 12 hours. The solvent was removed under reduced pressure, the residue was dissolved in anhydrous hexane (40 ml), the inorganic salt was removed by filtration and concentrated. The residue was dissolved in anhydrous THF (40 ml), zinc dust (1.5 g, 22.9 mmol) was added, and the mixture was stirred for 12 hours while protected from light. The reaction mixture was filtered through celite and concentrated. The residue was crystallized from hexane to give yellow crystalline 1,2-diphenyl-3,4-bis [(2,4,6-tri (t-butylphenyl) phosphinidene] -1-cyclobutene (DPCB-H) ( 1.92 g, was confirmed to be the desired product by 46% yield). ¹ H-NMR and ³¹ P ^[1 H] -NMR measurement. shows the measurement results below.
¹ H-NMR (CDCl ₃ , room temperature): δ 1.37 (s, 18H, t-Bu), 1.54 (s, 36H, t-Bu), 6.51 (d, ³ J _HH = 8.7Hz, 4H, o-Ph ), 6.78 (t, ³ J _HH = 7.5Hz, 4H, m-Ph), 6.97 (t, ³ J _HH = 7.5Hz, 2H, p-Ph), 7.34 (s, 4H, m-Ar).
³¹ P [ ¹ H] -NMR (CDCl ₃ , room temperature): δ 171.8 (s).

(2) Synthesis of metal complex compound (1)

10 ml of THF was added to [Ir (ppy) ₂ (μ-Cl)] ₂ (83.7 mg, 0.078 mmol) and silver triflate (44.0 mg, 0.157 mmol), and the mixture was stirred at room temperature for 1 hour. After confirming the precipitation of silver chloride, DPCB-H (118 mg, 0.156 mmol) was added and stirred at room temperature for 24 hours. After removing silver chloride by Celite filtration, the solvent was distilled off with a vacuum pump and washed with diethyl ether. Recrystallization from methylene chloride and diethyl ether gave compound (1) red crystals (63 mg, 0.044 mmol) in a yield of 28.7%. [Ir (ppy) ₂ (μ-Cl)] ₂ was prepared with reference to the method described in J. Am. Chem. Soc. 106, 6647 (1984). The obtained compound (1) was measured for mass spectrometry, ¹ H-NMR, ³¹ P [ ¹ H] -NMR, and melting point (mp), and the results are shown below.
Compound (1) (C ₇₅ H ₈₄ F ₃ IrN ₂ O ₃ P ₂ S): calcd. C 64.13, H 6.03, N 1.99; found C 64.48, H 5.99, N 2.04.
¹ H-NMR (300.1 MHz, CDCl ₃ , 20 ° C): δ = 0.78 (s, 18H), 1.27 (s, 18H), 1.73 (s, 18H), 5.76 (dd, J _HH = 7.7, 2.9Hz, 2H), 6.44 (d, J _HH = 7.7Hz, 4H), 6.74 (t, J _HH = 7.7Hz, 2H), 6.82 (t, J _HH = 7.2Hz, 2H), 6.91 (t, J _HH = 7.9 Hz, 4H), 7.13 (d, J _HH = 2.6Hz, 2H), 7.15 (d, J _HH = 8.1Hz, 2H), 7.44 (d, J _HH = 6.8Hz, 2H), 7.46 (s, 2H) , 7.54 (t, J _HH = 6.1Hz, 2H), 7.99 (d, J _HH = 7.1Hz, 2H), 8.20 (t, J _HH = 7.5Hz, 2H), 9.93 (d, J _HH = 4.9Hz, 2H)
³¹ P [ ¹ H] -NMR (121.5 MHz, CDCl ₃ , 20 ° C.): δ = 119.7 ppm (s)
mp: 256 ℃
Further, when the absorption and emission spectra of the obtained compound (1) were measured, the absorption λ _max = 360 nm (ε = 37000), the emission λ _max = 516 nm (excitation wavelength 475 nm), and the fluorescence quantum yield was 0.3%. Met.

Example 2 (Synthesis of metal complex compound (2))
(1) Synthesis of 1,2-bis (p-methoxyphenyl) -3,4-bis [(2,4,6-tri-t-butylphenyl) phosphinidene] -1-cyclobutene (DPCB-OMe) 1, dichloro (p-methoxyphenylethynyl) phosphine was used instead of dichloro (phenylethynyl) phosphine, and 1,2-bis (p-methoxyphenyl) -3,4-bis [(2,4,6-tri -t-Butylphenyl) phosphinidene] -1-cyclobutene (DPCB-OMe) was obtained as yellow crystals (52% yield). It was confirmed to be the target product by ¹ H-NMR and ³¹ P [ ¹ H] -NMR measurement. The measurement results are shown below.
¹ H-NMR (CDCl ₃ , room temperature): δ 1.39 (s, 18H, pt-Bu), 1.55 (s, 36H, ot-Bu), 3.67 (s, 6H, OCH ₃ ), 6.31 (d, ³ J _HH = 9.0Hz, 4H, o-Ph), 6.43 (d, ³ J _HH = 9.0Hz, 4H, m-Ph), 7.37 (s, 4H, PAr).
³¹ P [ ¹ H] -NMR (CDCl ₃ , room temperature): δ 162.2 (s)

(2) Synthesis of metal complex compound (2)

[Ir (ppy) ₂ (μ-Cl)] ₂ (34.0 mg, 0.0317 mmol) and silver triflate (15.9 mg, 0.0569 mmol) were added with 4 ml of THF and stirred at room temperature for 1 hour. After confirming the precipitation of silver chloride, DPCB-OMe (50.9 mg, 0.0624 mmol) was added and stirred at room temperature for 24 hours. After removing silver chloride by Celite filtration, the solvent was distilled off with a vacuum pump and washed with diethyl ether. Recrystallization from methylene chloride and diethyl ether gave compound (2) red crystals (16 mg, 0.107 mmol) in a yield of 17.9%. With respect to the obtained compound (2), the results of mass spectrometry, ¹ H-NMR, ³¹ P-NMR and melting point (mp) are shown below.
Compound (2) (C ₇₇ H ₈₈ F ₃ IrN ₂ O ₅ P ₂ S): calcd. C 63.14, H 6.06, N 1.91; found C 63.15, H 6.01, N 1.67.
¹ H-NMR (300.1 MHz, CDCl ₃ , 20 ° C): δ = 0.79 (s, 18H), 1.30 (s, 18H), 1.72 (s, 18H), 3.72 (s, 6H), 5.76 (d, J _HH = 5.1Hz, 2H), 6.34 (d, J _HH = 9.0Hz, 4H), 6.42 (d, J _HH = 9.0Hz, 4H), 6.73 (t, J _HH = 6.9Hz, 2H), 6.82 (t , J _HH = 7.5Hz, 2H), 7.19 (s, 2H), 7.44 (d, J _HH = 7.5Hz, 2H), 7.50 (t, J _HH = 6.0Hz, 2H), 7.47 (s, 2H), 7.97 (d, J _HH = 7.7Hz, 2H), 8.15 (t, J _HH = 7.4Hz, 2H), 9.94 (d, J _HH = 5.1Hz, 2H)
³¹ P-NMR (121.5 MHz, CDCl ₃ , 20 ° C): δ = 110.8 ppm (s)
mp: 197 ℃
Further, when the absorption and emission spectra of the obtained compound (2) were measured, the absorption λ _max = 382 nm (ε = 38000) and the emission λ _max = 503 nm (excitation wavelength 466 nm).

Example 3 (Synthesis of metal complex compound (3))
(1) Synthesis of 1,2-bis (p-trifluoromethylphenyl) -3,4-bis [(2,4,6-tri-t-butylphenyl) phosphinidene] -1-cyclobutene (DPCB-CF3) In Example 1, dichloro (p-trifluoromethylphenylethynyl) phosphine was used in place of dichloro (phenylethynyl) phosphine and 1,2-bis (p-trifluoromethylphenyl) -3,4-bis [(2 , 4,6-Tri-t-butylphenyl) phosphinidene] -1-cyclobutene (DPCB-CF3) was obtained as yellow crystals (yield 54%). It was confirmed to be the target product by ¹ H-NMR and ³¹ P [ ¹ H] -NMR measurement. The measurement results are shown below.
¹ H-NMR (CDCl ₃ , room temperature): δ 1.36 (s, 18H, pt-Bu), 1.54 (s, 36H, ot-Bu), 6.57 (d, ³ J _HH = 8.1Hz, 4H, o-Ph ), 7.06 (d, ³ J _HH = 8.1 Hz, 4H, m-Ph), 7.43 (s, 4H, PAr).
³¹ P [ ¹ H] -NMR (CDCl ₃ , room temperature): δ 181.0 (s)

(2) Synthesis of metal complex compound (3)

4 ml of methylene chloride was added to [Ir (ppy) ₂ (μ-Cl)] ₂ (29.9 mg, 0.0278 mmol) and silver triflate (15.4 mg, 0.0552 mmol), and the mixture was stirred at room temperature for 1 hour. After confirming the precipitation of silver chloride, DPCB-CF3 (54.7 mg, 0.0613 mmol) was added and stirred at room temperature for 24 hours. After removing silver chloride by Celite filtration, the solvent was distilled off with a vacuum pump and washed with pentane to obtain a yellow powder (28.5 mg, 0.0182 mmol) of Compound (3) in a yield of 33.0%. About the obtained compound (3), the result of having measured ¹ H-NMR and ³¹ P-NMR is shown below.
¹ H-NMR (300.1 MHz, CDCl ₃ , 20 ° C): δ = 0.77 (s, 18H), 1.26 (s, 18H), 1.75 (s, 18H), 5.75 (d, J _HH = 7.3Hz, 2H) , 6.55 (d, J _HH = 8.2Hz, 4H), 6.76 (t, J _HH = 7.0Hz, 2H), 6.85 (t, J _HH = 7.1Hz, 2H), 7.13 (s, 2H), 7.20 (d , J _HH = 8.6Hz, 4H), 7.47 (d, J _HH = 7.0Hz, 2H), 7.50 (s, 2H), 7.60 (t, J _HH = 5.9Hz, 2H), 8.01 (d, J _HH = 7.5Hz, 2H), 8.22 (t, J _HH = 7.7Hz, 2H), 9.88 (d, J _HH = 5.5Hz, 2H)
³¹ P-NMR (121.5 MHz, CDCl ₃ , 20 ° C): δ = 130.6 ppm (s)
Further, when the absorption and emission spectra of the obtained compound (3) were measured, the absorption λ _max = 356 nm (ε = 29000) and the emission λ _max = 498 nm (excitation wavelength: 465 nm).

Example 4 (Synthesis of metal complex compound (15))

[Ir (ppy) ₂ (μ-Cl)] ₂ (49.9 mg, 0.0465 mmol) and silver triflate (27.5 mg, 0.0985 mmol) were added with 5 ml of methylene chloride and stirred at room temperature for 1 hour. After confirming the precipitation of silver chloride, (E) -2- (1- (2,4,6-tri-t-butylphenyl) -2-phosphaethenylpyridine (35.6 mg, 0.0968 mmol) was added at room temperature. After stirring for 24 hours, the silver chloride was removed by celite filtration, the solution was concentrated to a saturated solution with a vacuum pump, and diethyl ether was gently added to form two layers. An ocherous powder (42.7 mg, 0.0410 mmol) was obtained in a yield of 45.0%, and the results of ¹ H-NMR and ³¹ P-NMR measurements of the obtained compound (15) are shown below.
¹ H-NMR (300.1 MHz, CDCl ₃ , 20 ° C): δ = 0.86 (s, 9H), 1.32 (s, 9H), 1.66 (s, 9H), 5.64 (t, J _HH = 7.1Hz, 1H) , 6.30 (d, J _HH = 7.7Hz, 1H), 6.79 (t, J _HH = 6.9Hz, 1H), 6.87 (t, J _HH = 7.1Hz, 1H), 6.92-6.98 (m, 2H), 7.07 (t, J _HH = 7.5Hz, 1H), 7.13-7.20 (m, 2H), 7.42 (s, 1H), 7.50 (s, 1H), 7.51 (d, J _HH = 8.4Hz, 1H), 7.61- 7.66 (m, 2H), 7.88 (m, 1H), 8.04 (d, J _HH = 5.7Hz, 1H), 8.55 (d, J _HP = 22.3Hz, 1H), 9.07 (d, J _HH = 6.2Hz, 1H)
³¹ P-NMR (121.5 MHz, CDCl ₃ , 20 ° C): δ = 244.2 ppm (s)
Further, when the absorption and emission spectra of the obtained compound (15) were measured, the absorption λ _max = 382 nm (ε = 9300) and the emission λ _max = 499 nm (excitation wavelength 466 nm).

上記化合物（Ｃ）をInorg.Chem.,27,3464(1988) 記載の方法を参照して合成した。化合物（Ｃ）の吸収及び発光スペクトルを測定したところ、発光のλ_max =565nm（励起波長280nm)であった。 Comparative Example 1

The compound (C) was synthesized with reference to the method described in Inorg. Chem., 27, 3464 (1988). When the absorption and emission spectra of the compound (C) were measured, the emission λ _{max was} 565 nm (excitation wavelength: 280 nm).

From the above examples and comparative examples, the bidentate chelate ligand containing the sp ² type P atom in which the nitrogen atom of the nitrogen atom bidentate chelate ligand is changed to a phosphorus atom shortens the emission wavelength of the complex. It turns out that there is an effect.

As described above in detail, the organic EL device using the novel metal complex compound of the present invention emits blue light, has high luminous efficiency, has a long life, and is used as a phosphorescent organic EL material for various colors including blue. It can be used and can be applied to various display elements, displays, backlights, illumination light sources, signs, signboards, interiors, and the like, and is particularly suitable as a display element for color displays.

Claims (9)

A metal complex compound having a partial structure represented by the following general formula (I).

[In the formula, the ring structure A is an aromatic ring residue having 6 to 20 carbon atoms which may have a substituent,
Ring structure B represents a ring structure having 5 to 20 carbon atoms including at least one carbon-nitrogen double bond, and may have a substituent,
X is an optionally substituted phosphorus (P) atom or nitrogen (N) atom, M is a group 7, 8 or 9 atom of the periodic table;
Z is an alkane residue having 2 to 10 carbon atoms, a cycloalkane residue having 4 to 20 carbon atoms, or a cycloalkene residue having 4 to 20 carbon atoms bonded to P and X by a double bond, respectively. And may be bonded to a substituent of P and / or X to form a ring.
Ring structure A and ring structure B are connected to each other by a carbon atom, the bond between M and ring structure A is a covalent bond, and the bond between M and ring structure B, P, and X is a π bond, and at least one P The atoms are sp ² type P atoms. ] The metal complex compound according to claim 1, which has a partial structure represented by the following general formula (II) or (III).

[In the general formulas (II) and (III), R ^{1 to} R ¹² and R ¹ ′ to R ⁶ ′ are each independently a hydrogen atom or a C 1-12 which may have a substituent. An alkyl group, an aromatic ring group having 6 to 20 carbon atoms which may have a substituent, a halogen atom, a cyano group or a nitro group is represented. In addition, adjacent ones of R ^{5 to} R ¹² may be bonded to each other to form a ring. ] The metal complex compound according to claim 1, which has a partial structure represented by the following general formula (II ') or (III').

[In the general formulas (II) and (III), R ^{1 to} R ¹² and R ¹ ′ to R ⁶ ′ are each independently a hydrogen atom or a C 1-12 which may have a substituent. An alkyl group, an aromatic ring group having 6 to 20 carbon atoms which may have a substituent, a halogen atom, a cyano group or a nitro group is represented. In addition, adjacent ones of R ^{5 to} R ¹² may be bonded to each other to form a ring.
L represents a valence-1 anion containing any one of Group 13 to 16 elements of the Periodic Table. ] In the general formula (I)

The structure represented by

The metal complex compound according to claim 1, which has a structure represented by any one of the following: In the general formula (I)

The structure represented by

The metal complex compound according to claim 1, which has a structure represented by any one of the following:   In the organic electroluminescent element by which the organic thin film layer which consists of a single layer or multiple layers which has at least a light emitting layer between a pair of electrodes is clamped, at least 1 layer of this organic thin film layer is in any one of Claims 1-5. An organic electroluminescence device that contains a metal complex compound of 1 and emits light when a voltage is applied between both electrodes.   The organic electroluminescent element of Claim 7 in which the said light emitting layer contains the metal complex compound in any one of Claims 1-5.   The organic electroluminescence device according to claim 6 or 7, which emits blue phosphorescence. The organic electroluminescence device according to claim 6, wherein the layer containing the metal complex compound is formed by coating.