JP2009242385A - Rare earth metal complex and wavelength conversion material using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rare earth metal complex which excels in a luminescent quantum yield, is characteristics in a luminescent wavelength and can be produced from inexpensive raw materials, and its production method; and to provide a wavelength conversion material using the complex. <P>SOLUTION: The complex is characterized by comprising a ligand having at least three phosphine oxides in the same molecule, where the ligand is subjected to tridentate coordination with a central metal of a rare earth metal. The wavelength conversion material is characterized by containing the complex. The production method for the complex is characterized by subjecting the ligand having at least three phosphine oxides in the same molecule to tridentate coordination with the central metal at first, and thereafter another ligand is coordinated thereto. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rare earth metal complex having excellent wavelength conversion efficiency and having a characteristic in emission wavelength, a method for producing the same, and a wavelength conversion material using the rare earth metal complex.

  Rare earth metal complexes are expected to be used as light-emitting members for fluorescent probes, electronic materials, laser dyes, bioimaging, sensors, lighting, etc. because they exhibit very sharp narrow-band light emission. Inorganic phosphors are also known as narrow-band light-emitting materials, but phosphors made of rare earth metal complexes are less expensive to manufacture than inorganic phosphors and have high absorption efficiency of excitation light. It is difficult to escape. Furthermore, there are many advantages such as excellent solubility in organic solvents and dispersibility in a medium.

  In the strong light emitting rare earth metal complex, the selection of the ligand is very important. In these complexes, triphenylphosphine oxide is a frequently used ligand. However, a phosphine oxide bidentate ligand has been reported as an attempt to further improve emission quantum yield and durability (Patent Document 1). , 2).

  However, in these complexes, the spectral shape is distorted and the color purity is poor, and in the Eu complex having a high emission quantum yield, the maximum emission wavelength is about 610 nm, which is orangeish red. Had the problem of being insufficient. In addition, the phosphine oxide bidentate ligand has a disadvantage that the raw material is expensive.

Japanese Patent Laid-Open No. 2003-81986 JP 2005-15564 A

  The present invention provides a rare earth metal complex that is excellent in emission quantum yield, has a characteristic emission wavelength, and can be produced from an inexpensive raw material, a production method thereof, and a wavelength conversion material using the rare earth metal complex. It is for the purpose.

  As a result of intensive studies in view of the above circumstances, the present inventors have found that a rare earth metal complex in which a ligand having three or more phosphine oxides in the same molecule is tridentately coordinated with a rare earth metal that is a central metal. The present inventors have found that the emission wavelength is excellent and that the emission wavelength, which has been considered to be almost unique depending on the type of the central metal, can be increased. Usually, since the emission level of the rare earth metal complex is determined, it is extremely difficult to control the emission wavelength. However, with the rare earth metal complex of the present invention, the emission wavelength can be controlled regardless of the central metal. The emission wavelength can be increased.

  That is, the gist of the present invention is as follows.

[1] A rare earth metal complex, wherein a ligand having three or more phosphine oxides in the same molecule is tridentately coordinated with a rare earth metal as a central metal.

[2] The rare earth metal complex according to [1], wherein the structure of the ligand having three or more phosphine oxides in the same molecule is represented by the following general formula (I) or (II).

[In Formula (I),
A is any one of C, N, Si, and P. When A is C or Si, C or Si may further have a substituent.
X ₁ , Y ₁ and Z ₁ each independently have a direct bond, an alkylene group which may have a substituent, an arylene group which may have a substituent, or a substituent. Represents a suitable heterocyclic group, or a combination thereof,
R _{11 to} R ₁₆ each independently represents an arbitrary substituent. ]

[In Formula (II),
X ₂ and Y ₂ are each independently a direct bond, an alkylene group which may have a substituent, an arylene group which may have a substituent, or a heterocyclic group which may have a substituent. Or a combination of these,
R _{21 to} R ₂₅ each independently represent an arbitrary substituent. ]

[3] The rare earth metal complex according to [1] or [2], wherein the rare earth metal is any one of Eu, Tb, Er, Yb, Nd, and Sm.

[4] A wavelength conversion material comprising the rare earth metal complex according to any one of [1] to [3].

[5] Production of a rare earth metal complex characterized in that a ligand having three or more phosphine oxides in the same molecule is first tridentately coordinated to the central metal and then another ligand is coordinated. Method.

The rare earth metal complex of the present invention exhibits longer wavelength light emission than the conventional rare earth metal complex. That is, as described above, since the emission level of the rare earth metal complex is usually determined, the emission wavelength is extremely difficult to control. However, the rare earth metal complex of the present invention can be used as the central metal. However, the emission wavelength can also be controlled, and the emission wavelength can be increased. Accordingly, when the rare earth metal complex of the present invention is used as a phosphor for display, it emits light in a deeper red color and can reproduce a wide range of colors. Moreover, the rare earth metal complex of the present invention exhibits high-luminance emission comparable to that of conventional complexes when excited using a visible light source.
For this reason, the wavelength conversion material of the present invention using such a rare earth metal complex can be effectively used in a blue light emitting device and a light emitting method using a visible light emitting diode, In addition, high efficiency light emission by excitation of a visible light emitting diode can be achieved while ensuring high dispersibility in a medium and solubility in an organic solvent due to reduction in manufacturing cost and low specific gravity.

  Such a wavelength conversion material of the present invention can be used not only as a monochromatic light-emitting device, but also as a white light-emitting device using a combination of RGB. By using the light-emitting device, illumination and liquid crystal back-up can be performed. Applications to light, automotive headlights, general lighting, etc. can be expected.

  Moreover, since the wavelength conversion material of the present invention has high near-ultraviolet (NUV) absorption efficiency and does not leak NUV to the outside, when used for a liquid crystal backlight for NUVLED, it also helps protect the liquid crystal. Moreover, the wavelength conversion material of this invention can also be utilized as a NUV cut film and a sheet | seat. These can be combined with organic EL and used as a color conversion material for organic EL.

  In addition, since a ligand having three or more phosphine oxides in the same molecule used in the present invention can be produced through various synthetic routes using inexpensive starting materials, the conventional phosphine oxide bidentate is used. The industrial value of the rare earth metal complex of the present invention is also high in that it can be produced industrially advantageously at a lower cost than a ligand.

It is a chart which shows the emission spectrum by 465 nm excitation of the europium complex: Eu (hfa-H) ₃ (TP = O) of Example 1, and the europium complex of Comparative Example 1: Eu (hfa-H) ₃ (BIPHEPO). . Europium complex of Example 4: ORTEP diagram showing the single crystal structure of _{Eu (hfa-H) 3 (} HTrisO 3). 6 is an emission spectrum chart showing changes in the emission quantum yield of a europium complex by addition of nitrate ions, evaluated in Example 5. It is a chart which shows the difference in the emission spectrum of the europium complex by the kind of solvent evaluated in Example 7. FIG. It is a chart which shows the difference of the emission spectrum of the europium complex by the kind of solvent evaluated in Example 8. FIG. 10 is an ORTEP diagram showing the result of X-ray structural analysis of a single crystal of a europium complex in Example 9. FIG. 10 is a chart showing a microscopic emission spectrum of a single crystal of a europium complex in Example 9. (A) The figure is an ORTEP figure which shows the coordination structure of the europium complex obtained by recrystallizing in chloroform / hexane in Example 4, (b) The figure is recrystallized in acetone / water in Example 9. It is an ORTEP figure which shows the coordination structure of the europium complex obtained by doing. It is a chart which shows the change of the emission spectrum in Example 10 in presence of the hydrogen bonding molecule | numerator (acetone) of a europium complex. It is a chart which shows the change of the emission spectrum in Example 10 in presence of the hydrogen bond molecule | numerator (acetonitrile) of a europium complex. It is a chart which shows the change of the emission spectrum in Example 10 in the presence of the hydrogen bond molecule | numerator (methanol) of a europium complex. It is a chart which shows the change of the emission spectrum in Example 10 in the presence of the hydrogen bond molecule | numerator (pyridine) of a europium complex. It is a chart which shows the change of the emission spectrum in Example 10 in the presence of the hydrogen bonding molecule | numerator (DMSO) of a europium complex. It is a chart which shows the temperature dependence (in acetone) of the emission spectrum of the europium complex in Example 11. It is a chart which shows the temperature dependence (in dichloromethane / acetone) of the emission spectrum of the europium complex in Example 12.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.

1. Rare earth metal complex The rare earth metal complex of the present invention is a rare earth metal in which a ligand having three or more phosphine oxides in the same molecule (hereinafter sometimes referred to as “tridentate ligand”) is a central metal. It is characterized by tridentate coordination.
In the present invention, “may have a substituent” means that one or more substituents may be present.

1-1.3 Ligand Ligands Tridentate ligands have three or more phosphine oxides in the same molecule, and three of these phosphine oxides are tridentately coordinated with the rare earth metal that is the central metal. There is no particular limitation as long as it can be performed. Only one tridentate ligand may be coordinated to the central metal, or a plurality of tridentate ligands may be coordinated within a possible range depending on the type of the central metal. When a plurality of tridentate ligands are coordinated with the central metal, the plurality of tridentate ligands may be the same or different from each other.

  Examples of such a tridentate ligand include compounds represented by the following general formula (I) or (II).

[In Formula (I),
A is any one of C, N, Si, and P. When A is C or Si, C or Si may further have a substituent.
X ₁ , Y ₁ and Z ₁ each independently have a direct bond, an alkylene group which may have a substituent, an arylene group which may have a substituent, or a substituent. Represents a suitable heterocyclic group, or a combination thereof,
R _{11 to} R ₁₆ each independently represents an arbitrary substituent. ]

[In Formula (II),
X ₂ and Y ₂ are each independently a direct bond, an alkylene group which may have a substituent, an arylene group which may have a substituent, or a heterocyclic group which may have a substituent. Or a combination of these,
R _{21 to} R ₂₅ each independently represent an arbitrary substituent. ]

1-1-1. About the compound represented by the general formula (I) <About A>
In general formula (I), A should just be an element which can connect three or more phosphine oxides, and is specifically C, N, Si, or P.
When A is C or Si, C or Si may further have a substituent.

  Examples of the substituent that C or Si may further include a deuterium atom; a linear or branched alkyl group such as methyl, ethyl, propyl, or butyl; a linear chain such as trifluoromethyl or pentafluoroethyl. A branched or branched fluoroalkyl group; a cycloalkyl group such as cyclohexyl; an ethynyl group; an arylethynyl group such as phenylethynyl, pyridylethynyl, thienylethynyl; an alkoxy group such as methoxy and ethoxy; an aryl group such as phenyl, naphthyl, and anthryl; Aralkyl groups such as benzyl and phenethyl; aryloxy groups such as phenoxy, naphthoxy and biphenyloxy; hydroxyl groups; allyl groups; acyl groups such as acetyl, propionyl, benzoyl, toluoyl and biphenylcarbonyl; acetoxy, propionyloxy and benzo Acyloxy groups such as ruoxy; alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl; aryloxycarbonyl groups such as phenoxycarbonyl; carboxyl group; carbamoyl group; amino group; dimethylamino, diethylamino, methylbenzylamino, diphenylamino, acetylmethylamino Substituted amino groups such as methylthio, ethylthio, phenylthio, benzylthio, etc .; mercapto groups; substituted sulfonyl groups such as ethylsulfonyl, phenylsulfonyl groups; cyano groups; nitro groups; halogens such as fluoro, chloro, bromo, and iodo Groups; furan, pyrrole, thiophene, oxazole, isoxazole, thiazole, imidazole, pyridine, benzofuran, benzothiophene, coumarin, benzopyran, Carbazole, xanthene, quinoline, triazine, dibenzofuran, dibenzothiophene, chroman, pyrazoline, pyrazone, and heterocyclic groups consisting of ring such chromone (flavone).

  Among these, those having a molecular weight of 350 or less are preferable from the viewpoints of solubility in various solvents and crystallinity without interfering with tridentate coordination, specifically, alkyl groups having 1 to 8 carbon atoms, An alkoxy group having 8 to 8 carbon atoms, preferably an aryl group having 6 to 10 carbon atoms, a heteroaryl group having 3 to 13 carbon atoms, a cycloalkyl group having 3 to 11 carbon atoms, and an aryloxy having 1 to 6 carbon atoms Group, aralkyl group having 7 to 22 carbon atoms, preferably 7 to 12 carbon atoms, ethynyl group and halogen group are preferable. In addition, a substituent is not limited to these. These substituents may further have a substituent. Further, examples of the substituent that may be included include the same as those described above.

<For _{X 1, Y 1, Z 1} >
In general formula (I), X ₁ , Y ₁ , and Z ₁ are each independently a direct bond, an alkylene group that may have a substituent, an arylene group that may have a substituent, or a substituent. It represents a heterocyclic group which may have, or a combination thereof. X ₁ , Y ₁ , and Z ₁ may be the same or different from each other, but it is preferable that the molecular lengths of X _{1 to} Z ₁ are not greatly different from each other in order that tridentate coordination is possible.

The alkylene group for X ₁ , Y ₁ and Z ₁ is preferably an alkylene group having 1 to 6 carbon atoms, and the alkylene group may be linear, branched or cyclic. Specifically, linear or branched having 1 to 6 carbon atoms such as methylene group, ethylene group, propylene group, isopropylene group, butylene group, iso-butylene group, sec-butylene group, tert-butylene group, hexylene group, etc. Cycloalkylene groups having 3 to 6 carbon atoms such as a chain-like alkylene group, cyclopropylene group, and cyclohexylene group.

Examples of the arylene group of X ₁ , Y ₁ , and Z ₁ include arylene groups having 6 to 18 carbon atoms, preferably 6 to 10 carbon atoms, such as a phenylene group, a naphthylene group, a biphenylene group, an anthracenylene group, and a phenanthrylene group. Of these, a phenylene group is preferred.

As the heterocyclic group for X ₁ , Y ₁ , and Z ₁ , those derived from a 5- to 6-membered monocyclic ring or a 2-6 condensed ring are preferable, and the hetero atom of the heterocyclic ring includes a nitrogen atom and an oxygen atom And sulfur atoms. These heterocyclic groups include those having a ketone structure on the ring. Specific examples of the heterocyclic ring constituting the heterocyclic group include 5-membered rings such as furan, pyrrole, thiophene, oxazole, isoxazole, thiazole, imidazole, and pyrazoline, 6-membered rings such as pyridine, pyran, and triazine, benzofuran, and benzothiophene. , Coumarin, benzopyran, carbazole, xanthene, quinoline, dibenzofuran, dibenzothiophene, chroman, chromone, etc., 5- or 6-membered 2-6 condensed rings.

Note that the alkylene group, arylene group, and heterocyclic group may further have a substituent.
Examples of such substituents include specific examples of substituents that may be present when A is C or Si.
Among the specific examples of the exemplified substituents, the alkylene group, arylene group and heterocyclic group may further have substituents that do not interfere with tridentate coordination, solubility in various solvents, and crystallinity. In view of the above, those having a molecular weight of 350 or less are preferable, specifically, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an aryl group having 6 to 14 carbon atoms, preferably an aryl having 6 to 10 carbon atoms. Group, heteroaryl group having 3 to 13 carbon atoms, cycloalkyl group having 3 to 11 carbon atoms, aryloxy group having 1 to 6 carbon atoms, aralkyl group having 7 to 22 carbon atoms, preferably 7 to 12 carbon atoms, ethynyl group, Halogen groups are preferred. In addition, a substituent is not limited to these. These substituents may further have a substituent. Further, examples of the substituent that may be included include the same as those described above.
Further, from the viewpoint of durability, a linear or branched fluoroalkyl group such as a fluoro group, a trifluoromethyl group, or a pentafluoroethyl group is particularly preferable.

X ₁ , Y ₁ , and Z ₁ may each be bridged or formed with a ring through each other or a substituent that each has.

<For _R 11 _{~R 16>}
In the general formula (I), R ₁₁ to ₁₆ each independently represent an arbitrary substituent.

R _{11 to} R ₁₆ are not particularly limited as long as they do not hinder tridentate coordination, and any substituent can be used. As an optional substituent, a deuterium atom; a linear or branched alkyl group such as methyl, ethyl, propyl, or butyl; a linear or branched fluoroalkyl group such as trifluoromethyl or pentafluoroethyl; A cycloalkyl group such as cyclohexyl; an ethynyl group; an arylethynyl group such as phenylethynyl, pyridylethynyl and thienylethynyl; an alkoxy group such as methoxy and ethoxy; an aryl group such as phenyl, naphthyl and anthryl; an aralkyl group such as benzyl and phenethyl; Aryloxy groups such as phenoxy, naphthoxy and biphenyloxy; hydroxyl groups; allyl groups; acyl groups such as acetyl, propionyl, benzoyl, toluoyl and biphenylcarbonyl; acyloxy groups such as acetoxy, propionyloxy and benzoyloxy An alkoxycarbonyl group such as methoxycarbonyl and ethoxycarbonyl; an aryloxycarbonyl group such as phenoxycarbonyl; a carboxyl group; a carbamoyl group; an amino group; a substituted amino group such as dimethylamino, diethylamino, methylbenzylamino, diphenylamino, and acetylmethylamino; Substituted thio groups such as methylthio, ethylthio, phenylthio, benzylthio; mercapto group; substituted sulfonyl groups such as ethylsulfonyl, phenylsulfonyl group; cyano group; nitro group; halogen groups such as fluoro, chloro, bromo, iodo; furan, pyrrole, Thiophene, oxazole, isoxazole, thiazole, imidazole, pyridine, benzofuran, benzothiophene, coumarin, benzopyran, carbazole, xanthene, key Phosphorus, triazine, dibenzofuran, dibenzothiophene, chroman, pyrazoline, pyrazone, and heterocyclic groups consisting of ring such chromone (flavone).

  Among these, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, 6 to 14 carbon atoms, preferably an aryl group having 6 to 10 carbon atoms, a heteroaryl group having 3 to 13 carbon atoms, and a carbon number A cycloalkyl group having 3 to 11 carbon atoms, an aryloxy group having 1 to 6 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, preferably 7 to 12 carbon atoms, an ethynyl group, and a halogen group are preferable.

However, as R ₁₃ and R ₁₄ , a bulky substituent such as a t-butyl group may cause steric hindrance upon tridentate coordination, and therefore an alkyl not containing a tertiary carbon having 1 to 8 carbon atoms. Group, a substituent having a small volume such as an alkoxy group containing no tertiary carbon having 1 to 8 carbon atoms, or an aryl group having 6 to 14 carbon atoms, preferably 6 to 10 carbon atoms, or a heterogeneous group having 3 to 13 carbon atoms. Substitution with high planarity such as aryl group, cycloalkyl group having 3 to 11 carbon atoms, aryloxy group having 1 to 6 carbon atoms, 7 to 22 carbon atoms, preferably 7 to 12 aralkyl groups, ethynyl groups, and halogen groups Groups are preferred.

In addition, the arbitrary substituents as R < ₁₁ > -R < ₁₆ > are not limited to these. These substituents may further have a substituent. Examples of such substituents include specific examples of the above arbitrary substituents.

R ₁₁ and R ₁₂ , and R ₁₅ and R ₁₆ may each be bridged or formed with a ring through each other or a substituent that each has.

<Hydrogen bond formation>
Among the tridentate ligands represented by the general formula (I), the rare earth metal complex having a tridentate ligand in which A is C or Si having no substituent other than phosphine oxide, A hydrogen bond is formed between hydrogen bonding molecules existing in the environment, for example, acetone, acetonitrile, methanol, pyridine, DMSO (dimethyl sulfoxide) and the like. The formation of this hydrogen bond causes a twist in the coordination structure of the rare earth metal complex, and thus changes the shape of the emission spectrum. The twist of the coordination structure is assumed to vary depending on the type of hydrogen-bonding molecule, and therefore the shape of the emission spectrum is considered to change depending on the type of molecule present in the vicinity of the complex. Furthermore, it is considered that the emission spectrum shape changes depending on the concentration of hydrogen-bonding molecules present in the environment and the environmental temperature that contributes to the stability of hydrogen bonding. These characteristics suggest applicability to low temperature sensors and molecular recognition applications.

1-1-2. About the compound represented by the general formula (II) <About X ₂ and Y ₂ >
In general formula (II), X ₂ and Y ₂ each independently have a direct bond, an alkylene group which may have a substituent, an arylene group which may have a substituent, or a substituent. Represents an optionally substituted heterocyclic group, or a combination thereof. X ₂ and Y ₂ may be the same as or different from each other, but in order for tridentate coordination to be possible, it is important that the respective phosphine oxide groups are not too far apart, so that X ₂ and Y ₂ each It is preferable that the molecular lengths of these do not differ greatly. Preferably, the shortest number of atoms for bonding each phosphorus atom of X ₂ and Y ₂ is 0 to 6, and the difference between the numbers of X ₂ and Y ₂ is 0 to 4.

Specific examples and preferred examples of the alkylene group, arylene group, heterocyclic group of X ₂ and Y ₂ , and the substituent that these groups may have are X ₁ , Y ₁ and Z ₁ in the formula (I). It is similar to that.

X ₂ and Y ₂ may be bridged or ring-formed through the substituents or R ₂₃ possessed by themselves or each.

<For _R 21 _{~R 25>}
In formula _(II), represent any substituents R 21 _{to R 25} each independently.

Specific examples and preferred examples of the optional substituents of R _{21 to} R ₂₅ are the same as those of R _{11 to} R ₁₆ in the general formula (I).

R ₂₁ and R ₂₂ , R ₂₄ and R ₂₅ may be bridged or ring-formed through the substituents of each other or each.

1-1-3. Specific examples of the compound represented by the general formula (I) or (II) Specific examples of the tridentate ligand of the rare earth metal complex of the present invention are shown below. The tridentate used in the rare earth metal complex of the present invention is shown below. The ligand is not limited to these. In the following, Ph represents a phenyl group which may have a substituent, and Me represents a methyl group.

1-1-4. Method for synthesizing compound represented by formula (I) or (II) The compound represented by formula (I) can be synthesized by allowing hydrogen peroxide to act on the corresponding phosphine compound.

Moreover, the compound shown by general formula (II) is synthesize | combined according to the flow shown, for example. That is, a dihalide of X _{2 in} the general formula (II) and a dihalide of Y ₂ in the general formula (II) are prepared, and one of the halogens is phosphinated for each. Next, after the obtained phosphine compound is reacted with dihalogenated phosphine, the compound represented by the general formula (II) is obtained by allowing hydrogen peroxide water to act.

  As described above, the tridentate ligand used in the rare earth metal complex of the present invention is inexpensive as a starting material, and various synthetic variations are possible, which is superior to conventional phosphine oxide bidentate ligands. Yes.

1-1-5. Molecular Weight The tridentate ligand used in the rare earth metal complex of the present invention has a substituent and usually has a molecular weight of 160 to 2000, preferably 200 to 1000, including the substituent.

1-2. Central Metal The central metal of the rare earth metal complex of the present invention is not particularly limited as long as it is a rare earth metal, but is preferably Eu, Tb, Er, Yb, Nd, Sm, more preferably from the viewpoint of emission intensity. Eu, Tb or Sm, particularly preferably Eu.

1-3. Other ligands The rare earth metal complex of the present invention may have an arbitrary ligand in addition to the tridentate ligand.

  Such a ligand is not particularly limited as long as it does not interfere with the tridentate coordination of the tridentate ligand. Specific examples include β-diketone, water, halogen ion, nitrate ion, phenanthroline, bipyridine, pyridine, acetone, methanol, acetonitrile, dimethyl sulfoxide and the like. Among these, β-diketone, water, and nitrate ion are preferable from the viewpoint of light emission quantum yield. Among them, β-diketone, specifically hexafluoroacetylacetone (hfa), 1- (2-thenoyl) -4,4,4 -Trifluoro-1,3-butanedionate (TTA) is preferred.

1-4. Particularly Preferred Embodiment of Rare Earth Metal Complex of the Present Invention The rare earth metal complex of the present invention is particularly preferably one represented by the following general formula (I-1) or (II-1).

X ₁ , Y ₁ , Z ₁ and R _{11 to} R ₁₆ in the general formula (I-1) have the same meaning as in the general formula (I), and X ₂ , Y ₂ and R _{21 in the} general formula (II-1). to R ₂₅ has the same meaning as in the general formula (II).

In general formula (I-1) _{M 1} in the general formula (II-1) _{M 2} in represents a central metal as described in the section "1-2. Center metal", the general formula (I-1) Ln _1, Ln ₂ in the general formula (II-1) in is equivalent to other ligand described in the section "1-3. other ligands". n, m is any integer, _Ln 1 in a molecule, if Ln ₂ there is a plurality, the plurality of _Ln 1, Ln ₂ may be be the same or different.

1-5. Specific Examples of Rare Earth Metal Complexes of the Present Invention Specific examples of the rare earth metal complexes of the present invention are shown below, but the rare earth metal complexes of the present invention are not limited to these unless they exceed the gist. In the following, Ph represents a phenyl group which may have a substituent, and Me represents a methyl group.

1-6. Method for synthesizing rare earth metal complex of the present invention Among the rare earth metal complexes of the present invention, the rare earth metal complex in which a tridentate ligand and another ligand are coordinated to the rare earth metal is 3 or more in the same molecule. The phosphine oxide is tridentate by allowing a ligand having a phosphine oxide (tridentate ligand) and a rare earth metal salt to act in solution, and then other ligands such as β-diketones are formed. Manufactured by bonding. In the production of the rare earth metal complex of the present invention, if other ligands such as β-diketone are coordinated to the rare earth metal prior to the tridentate ligand, the tridentate phosphine oxide is later produced. It is very difficult to coordinate the tridentate. Therefore, the tridentate ligand is coordinated before other ligands.

  As the solvent used in this reaction, alcohols such as methanol, ethanol and isopropyl alcohol, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and dimethoxyethane, and organic solvents such as acetonitrile, dimethyl sulfoxide and dimethylformamide should be used. Can do. These may be used alone or in combination of two or more.

  The rare earth metal complex formed by the reaction between the rare earth metal and the ligand can be obtained by removing the reaction solvent from the reaction solution by distillation under reduced pressure, etc., but the reaction product complex must be purified by recrystallization, etc. Thus, impurities that inhibit light emission are removed, and a crystalline rare earth metal complex having high light emission efficiency can be obtained, which is preferable. Since the complex initially obtained by distilling off the solvent from the reaction solution may be amorphous and often contains impurities, the subsequent purification work is an important work to increase the luminous efficiency of the rare earth metal complex. is there. In addition, recrystallization for purifying the obtained crude product of the rare earth metal complex is hexane, chloroform, methylene chloride, acetone, acetonitrile, toluene, methanol, ethanol, ethyl acetate, dimethyl sulfoxide, N, N-dimethylformamide. It can carry out in accordance with a conventional method using 1 type, or 2 or more types of solvents, such as tetrahydrofuran and water. This recrystallization is usually performed about 1 to 3 times.

1-7. Molecular Weight In the rare earth metal complex of the present invention, the total molecular weight of all ligands excluding the central metal is usually 500 to 5000, preferably 1000 to 3000 including the substituent when the ligand has a substituent. It is.

1-8. Performance The rare earth metal complex of the present invention thus obtained emits light having a wavelength of about 490 nm to 1500 nm depending on the type of the central metal by being excited using a light source having an emission maximum at a wavelength of 350 nm to 480 nm. For example, when the central metal is Eu or Sm, orange to red light, that is, usually 570 nm or more, preferably 580 nm or more, more preferably 585 nm or more, and usually 780 nm or less, preferably 700 nm or less, more preferably 680 nm or less. Emits light in the wavelength range of. When the central metal is Tb, it is green light, that is, usually in the wavelength range of 490 nm or more, preferably 500 nm or more, more preferably 505 nm or more, and usually 560 nm or less, preferably 555 nm or less, more preferably 550 nm or less. Emits light. When the central metal is Er, Yb, or Nd, near infrared light having a wavelength of about 900 nm to 1500 nm is emitted. The emission wavelength of the rare earth metal complex of the present invention is clearly longer than that of the conventional bidentate rare earth metal complex, and the shift width extends to several nm.

  The rare earth metal complex of the present invention has a high emission quantum yield, and the emission quantum yield is usually 4% or more, preferably 30% or more, and more preferably 50% or more. The higher the emission quantum yield, the better. There is no clear upper limit, but it is usually about 80% or less.

In addition, melting | fusing point and decomposition temperature are mentioned as a parameter | index which shows the heat resistance of the rare earth metal complex of this invention, and it can confirm easily with a differential scanning calorimeter (DSC) or a differential thermogravimetric analyzer (TG-DTA). .
Visible light-emitting diodes suitably used as an excitation light source are heated when used over time, but when the organic phosphor is melted or decomposed by the heat of the excitation light source, it leads to a decrease in luminous efficiency and color unevenness, Organic phosphors are required to have high heat resistance.
Therefore, when the rare earth metal complex of the present invention is used as an organic phosphor, the melting point is preferably 120 ° C. or higher, more preferably 150 ° C. or higher.
The decomposition temperature of the rare earth metal complex of the present invention is preferably 150 ° C. or more, more preferably 160 ° C. or more, at which the weight loss by 5% or more under nitrogen flow conditions.

1-9. Applications The rare earth metal complex of the present invention can be effectively used as various wavelength conversion materials used in lighting devices, display devices and the like.

2. Wavelength Conversion Material The wavelength conversion material of the present invention contains at least the rare earth metal complex of the present invention.
The rare earth metal complex of the present invention contained in the wavelength conversion material of the present invention may be one type or two or more types.
In addition, the wavelength conversion material of the present invention is a material other than the rare earth metal complex of the present invention, for example, various materials other than the rare earth metal complex of the present invention, as long as the emission quantum yield and durability of the rare earth metal complex of the present invention are not impaired. These organic and / or inorganic phosphors may be included.

  As the state of existence of the phosphor (the rare earth metal complex of the present invention and other phosphors blended as necessary) in the wavelength conversion material of the present invention, a known configuration can be arbitrarily applied. Usually, there are a solid solution state in which a phosphor is dissolved in a liquid medium, a dispersed state in which fine particles of the phosphor are dispersed in a liquid medium, and the like. In this case, the phosphor is fixed by the liquid medium and absorbs light from the light source to emit light.

2-1. Liquid medium The liquid medium used for the wavelength conversion material of the present invention is not particularly limited as long as the performance of the rare earth metal complex of the present invention is not impaired within the intended range. For example, there is no particular limitation as long as it exhibits a liquid property under the desired use conditions, suitably dissolves or disperses the rare earth metal complex of the present invention, and does not cause an undesirable reaction. Is optional.

  Examples of the inorganic liquid medium include a solution obtained by hydrolyzing a solution containing a metal alkoxide, a ceramic precursor polymer or a metal alkoxide by a sol-gel method, or a combination of these inorganic materials (for example, a siloxane bond). And inorganic materials).

  Examples of the organic liquid medium include thermoplastic resins, thermosetting resins, and photocurable resins. Specifically, for example, methacrylic resin such as polymethyl methacrylate; styryl resin such as polystyrene and styrene-acrylonitrile copolymer; polycarbonate resin; polyester resin; phenoxy resin; butyral resin; polyvinyl alcohol; ethyl cellulose, cellulose acetate, cellulose Cellulose resins such as acetate butyrate; epoxy resins; phenol resins; silicone resins such as addition reaction type silicone resins, condensation reaction type silicone resins, and modified silicone resins.

  When the phosphor is dispersed in a liquid medium, the amount of the liquid medium used is arbitrary as long as the effects of the present invention are not significantly impaired. The type of the liquid medium and the use of the wavelength conversion material (for the light emitting device to be applied) The weight ratio with respect to the phosphor (the rare earth metal complex of the present invention. When other phosphors are used in combination with the rare earth metal complex of the present invention), the weight ratio is usually 0.1 times or more. The range is preferably 3 times or more, more preferably 5 times or more, and usually 30 times or less, preferably 15 times or less. If the amount of the liquid medium is too small, the luminance may be lowered or the coating property may be deteriorated. If the amount is too large, the luminance may be decreased.

  The liquid medium mainly has a role as a binder and a sealing material in the wavelength conversion material of the present invention. The liquid medium may be used alone or in combination of two or more in any combination and ratio. For example, when a silicone resin or the like is used for the purpose of heat resistance or light resistance, other thermosetting resins such as an epoxy resin may be contained to the extent that the durability of the resin is not impaired. In this case, the content of the other thermosetting resin is usually 25% by weight or less, preferably 10% by weight or less based on the total amount of the liquid medium as the binder.

  The liquid medium may contain additives other than the phosphor. Examples of additives include color correction pigments, antioxidants, processing / oxidation and heat stabilizers such as phosphorus-based processing stabilizers, light-resistant stabilizers such as UV absorbers, and silane coupling agents. Can be mentioned.

2-2. Phosphors that can be used in combination The wavelength conversion material of the present invention includes, if necessary, a phosphor other than the rare earth metal complex of the present invention, for example, a rare earth metal complex other than the rare earth metal complex of the present invention, other organic phosphors and inorganic fluorescence. You may use a body etc. together.

  In the wavelength conversion material of the present invention, the presence / absence and type of phosphors (orange to red phosphors, green phosphors, blue phosphors, etc.) that can be used together as described below depend on the use of the wavelength conversion material. What is necessary is just to select suitably.

  For example, when the wavelength conversion material of the present invention is used for red light emission, among the rare earth metal complexes of the present invention, those whose central metals are Eu and Sm emit light in red. There is no problem even if only the metal complex is used, but the emission wavelength can be adjusted by using the rare earth metal complex of the present invention in combination with other orange or red phosphors.

  On the other hand, when the wavelength conversion material of the present invention is used for white light emission, the rare earth metal complex of the present invention and other phosphors that can be used together are appropriately combined so that desired white light can be obtained. Good.

  In addition, the rare earth metal complex of the present invention is mixed with other phosphors (here, mixing does not necessarily mean that phosphors are mixed with each other, but means that different phosphors are combined). .) Can be used. In addition, there is no restriction | limiting in particular in the kind of fluorescent substance to mix, and its ratio, A well-known fluorescent substance can be used.

  Specific examples of phosphors that can be used in combination with the rare earth metal complex of the present invention are listed below.

<Orange to red phosphor>
When an orange or red phosphor is used, any orange to red phosphor can be used as long as the effects of the present invention are not significantly impaired, but it emits light having a peak wavelength in the wavelength range of 380 nm to 450 nm. It is preferable to use one that absorbs at least part of light from the light source to emit light.

  As the orange to red phosphor, light having an emission peak wavelength in a wavelength range of usually 570 nm or more, preferably 580 nm or more, more preferably 585 nm or more, and usually 780 nm or less, preferably 700 nm or less, more preferably 680 nm or less. What emits is preferred.

  Examples of the red organic phosphor that can be used in the present invention include a red organic substance composed of a rare earth element ion complex having an anionic ligand such as β-diketonate, β-diketone, aromatic carboxylic acid, or Bronsted acid. Examples include phosphors.

  Further, perylene pigments (for example, dibenzo {[f, f ′]-4,4 ′, 7,7′-tetraphenyl} diindeno [1,2,3-cd: 1 ′, 2 ′, 3′-lm) ] Perylene), anthraquinone pigments, lake pigments, azo pigments, quinacridone pigments, anthracene pigments, isoindoline pigments, isoindolinone pigments, phthalocyanine pigments, triphenylmethane basic dyes, indanthrone It is also possible to use a pigment, an indophenol pigment, a cyanine pigment, or a dioxazine pigment.

The orange or red inorganic phosphor that can be used in the present invention is composed of, for example, fractured particles having a red fracture surface, and emits light in a red region (Mg, Ca, Sr, Ba) ₂ Si ₅ N ₈ : Europium-activated alkaline earth silicon nitride phosphor expressed by Eu, composed of growth particles having a substantially spherical shape as a regular crystal growth shape, and emits light in a red region (Y, La, Gd, Lu) Examples include europium activated rare earth oxychalugenite-based phosphors represented by ₂ O ₂ S: Eu.

  Furthermore, an oxynitride and / or an acid containing at least one element selected from the group consisting of Ti, Zr, Hf, Nb, Ta, W, and Mo described in JP-A No. 2004-300247 A phosphor containing a sulfide and containing an oxynitride having an alpha sialon structure in which a part or all of the Al element is substituted with a Ga element can also be used. These are phosphors containing oxynitride and / or oxysulfide.

Other red phosphors include Eu-activated oxysulfide phosphors such as (La, Y) ₂ O ₂ S: Eu, Y (V, P) O ₄ : Eu, Y ₂ O ₃ : Eu, etc. Eu-activated oxide phosphor, (Ba, Mg) ₂ SiO ₄ : Eu, Mn, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, Mn-activated silicate phosphor such as Eu, Mn, Eu-activated tungstate phosphors such as LiW ₂ O ₈ : Eu, LiW ₂ O ₈ : Eu, Sm, Eu ₂ W ₂ O ₉ , Eu ₂ W ₂ O ₉ : Nb, Eu ₂ W ₂ O ₉ : Sm (Ca, Sr) S: Eu-activated sulfide phosphors such as Eu, YAlO ₃ : Eu-activated aluminate phosphors such as Eu, Ca ₂ Y ₈ (SiO ₄ ) ₆ O ₂ : Eu, LiY ₉ (SiO ₄ ) ₆ O ₂ : Eu, (Sr, Ba, Ca) ₃ SiO ₅ : Eu, Sr ₂ Ba-activated silicate phosphors such as BaSiO ₅ : Eu, (Y, Gd) ₃ Al ₅ O ₁₂ : Ce, (Tb, Gd) ₃ Al ₅ O ₁₂ : Ce-activated aluminate phosphors such as Ce, (Mg, Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Mg, Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Mg, Ca, Sr, Ba) AlSi (N, O) ₃ : Eu-activated oxide such as Eu, nitride or oxynitride phosphor, (Mg, Ca, Sr, Ba) AlSi (N, O) ₃ : Ce-activated oxide such as Ce , Nitride or oxynitride phosphor, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, Mn-activated halophosphate phosphor such as Eu, Mn, Ba ₃ MgSi ₂ O ₈ : Eu, Mn, (Ba, Sr, Ca, Mg) ₃ (Zn, Mg) Si ₂ O ₈ : E Eu, Mn activated silicate phosphors such as u and Mn, 3.5MgO · 0.5MgF ₂ · GeO ₂ : Mn activated germanate phosphors such as Mn, Eu activated acids such as Eu activated α sialon Nitride phosphor, (Gd, Y, Lu, La) ₂ O ₃ : Eu, Bi activated oxide phosphor such as Eu, Bi, (Gd, Y, Lu, La) ₂ O ₂ S: Eu, Bi Eu, Bi-activated oxysulfide phosphor such as (Gd, Y, Lu, La) VO ₄ : Eu, Bi-activated vanadate phosphor such as Eu, Bi, SrY ₂ S ₄ : Eu, Ce, etc. Eu activated Ce phosphors, Ce activated sulfide phosphors such as CaLa ₂ S ₄ : Ce, (Ba, Sr, Ca) MgP ₂ O ₇ : Eu, Mn, (Sr, Ca, Ba, Mg, Zn) ₂ P ₂ O ₇ : Eu, Mn-activated phosphate phosphor such as Eu, Mn, (Y, Lu) ₂ WO ₆ : Eu, Mo activated tungstate phosphor such as Eu, Mo, (Ba, Sr, Ca) _x Si _y N _z : Eu, Ce (where x, y, z are integers of 1 or more) To express. Eu, Ce-activated nitride phosphors such as (Ca, Sr, Ba, Mg) ₁₀ (PO ₄ ) ₆ (F, Cl, Br, OH): Eu, Mn-activated halophosphoric acid such as Eu, Mn Salt phosphors, ((Y, Lu, Gd, Tb) _1-xy Sc _x Ce _y ) ₂ (Ca, Mg) _1-r (Mg, Zn) _{2 + r} Si _z-q Ge _q O _{12 + δ and} other Ce It is also possible to use an activated silicate phosphor or the like.

Among these, as the red inorganic phosphor, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Ce, (Sr, Ba) ₃ SiO ₅ : Eu, (Ca, Sr) S: Eu , (La, Y) ₂ O ₂ S: Eu or Eu complex, more preferably (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Ce, (Sr, Ba) ₃ SiO ₅ : Eu, (Ca, Sr) S: Eu or (La, Y) ₂ O ₂ S: Eu, or It preferably has containing Eu _{(dibenzoylmethane)} 3 · 1,10-beta-diketone Eu complex or carboxylic acid Eu complex phenanthroline complex, _{etc., (Ca, Sr, Ba)} 2 Si 5 (N, O) ₈ : Eu, (Sr, Ca) AlSiN ₃ : Eu or (La, Y) ₂ O ₂ S: Eu is particularly preferable.

The orange phosphor is preferably (Sr, Ba) ₃ SiO ₅ : Eu.

  These orange to red phosphors may be used alone or in combination of two or more.

  When an orange or red phosphor is used in combination with the rare earth metal complex of the present invention, the blending ratio of these orange or red phosphor is usually 0 to 95% by weight with respect to the rare earth metal complex of the present invention. %, Preferably 0 to 75% by weight.

<Green phosphor>
When the green phosphor is used, any green phosphor can be used as long as the effects of the present invention are not significantly impaired. However, the green phosphor emits light having a peak wavelength in the wavelength range of 380 nm to 450 nm. It is preferable to use one that absorbs at least part of light and emits light.

  The green phosphor is usually 490 nm or more, preferably 500 nm or more, more preferably 505 nm or more, and usually 560 nm or less, preferably 550 nm or less, more preferably 545 nm or less, particularly preferably 540 nm or less in the emission peak wavelength. It is desirable to emit light having

  Examples of the green organic phosphor that can be used in the present invention include benzoxazinone-based, quinazolinone-based, coumarin-based, quinophthalone-based, naltalimide-based fluorescent dyes, terbium complexes, perylene-based green organic phosphors, and the like. Examples thereof include, but are not limited to, a yellow-green organic phosphor such as a pyridine-phthalimide condensed derivative disclosed in Kai 2002-34568.

Examples of the green inorganic phosphor that can be used in the present invention include (Mg, Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu that is composed of fractured particles having a fracture surface and emits light in the green region. Europium-activated alkaline earth silicon oxynitride-based phosphor expressed, and europium-activated expressed by (Ba, Ca, Sr) ₂ SiO ₄ : Eu that is composed of fractured particles having a fracture surface Examples include alkaline earth magnesium silicate phosphors.

Other green phosphors include Eu-activated aluminate phosphors such as Sr ₄ Al ₁₄ O ₂₅ : Eu, (Ba, Sr, Ca) Al ₂ O ₄ : Eu, and (Sr, Ba) Al _2. Si ₂ O ₈ : Eu, (Ba, Mg) ₂ SiO ₄ : Eu, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ba, Sr, Ca) ₂ (Mg, Zn) Si ₂ O ₇ : Eu, (Ba, Ca, Sr, Mg) ₉ (Sc, Y, Lu, Gd) ₂ (Si, Ge) ₆ O ₂₄ : Eu-activated silicate phosphor such as Eu, Y ₂ SiO ₅ : Ce, Ce, Tb-activated silicate phosphors such as Tb, Sr ₂ P ₂ O ₇ —Sr ₂ B ₂ O ₅ : Eu-activated borate phosphate phosphors such as Eu, Sr ₂ Si ₃ O ₈ -2SrCl ₂ : Eu-activated halo silicate phosphor such as _Eu, Zn 2 _SiO 4: M such as Mn Activated silicate _{phosphors, CeMgAl 11 O 19: Tb,} Y 3 Al 5 O 12: Tb -activated aluminate phosphors such as _{Tb, Ca 2 Y 8 (SiO} 4) 6 O 2: Tb, La 3 Ga ₅ SiO ₁₄ : Tb-activated silicate phosphor such as Tb, (Sr, Ba, Ca) Ga ₂ S ₄ : Eu, Tb, Sm-activated thiogallate phosphor such as Eu, Tb, Sm, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, (Y, Ga, Tb, La, Sm, Pr, Lu) ₃ (Al, Ga) ₅ O ₁₂ : Ce-activated aluminate phosphor such as Ce, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, Ca ₃ (Sc, Mg, Na, Li) ₂ Si ₃ O ₁₂ : Ce activated silicate phosphor such as Ce, Ce activated oxide phosphor such as CaSc ₂ O ₄ : Ce, Eu-activated oxynitride phosphors such as Eu-activated β sialon BaMgAl ₁₀ O _17: Eu, Eu such as Mn, Mn-activated aluminate phosphor, SrAl ₂ O _4: Eu-activated aluminate phosphor such as _{Eu, (La, Gd, Y} ) 2 O 2 S: Tb-activated oxysulfide phosphors such as Tb, LaPO ₄ : Ce, Tb-activated Ce, Tb-activated phosphate phosphors, ZnS: Cu, ZnS: Cu, Al, ZnS: Cu, Au, Al, etc. sulfide _{phosphor, (Y, Ga, Lu,} Sc, La) BO 3: Ce, Tb, Na 2 Gd 2 B 2 O 7: Ce, Tb, (Ba, Sr) 2 (Ca, Mg, Zn) B ₂ O ₆ : Ce, Tb activated borate phosphor such as K, Ce, Tb, etc., Ca ₈ Mg (SiO ₄ ) ₄ Cl ₂ : Eu, Mn activated halosilicate phosphor such as Eu, Mn, (Sr , Ca, Ba) (Al, Ga, in) 2 S 4: Eu Tsukekatsuchi such as Eu Aluminate phosphor or thiogallate _{phosphor, (Ca, Sr) 8 (} Mg, Zn) (SiO 4) 4 Cl 2: Eu, Eu such as Mn, Mn-activated halo silicate _phosphor, M 3 _Si 6 _{O 9} N ₄ : Eu, M ₃ Si ₆ O ₁₂ N ₂ : Eu (where M represents an alkaline earth metal element). It is also possible to use Eu-activated oxynitride phosphors such as

  These green phosphors may be used alone or in combination of two or more.

<Blue phosphor>
In the case of using a blue phosphor, any blue phosphor can be used as long as the effect of the present invention is not significantly impaired, but from a light source that emits light having a peak wavelength in a wavelength range of 380 nm to 450 nm. It is preferable to use one that absorbs at least part of light and emits light.

  The blue phosphor usually emits light having an emission peak wavelength in a wavelength range of 420 nm or more, preferably 430 nm or more, more preferably 440 nm or more, and usually 490 nm or less, preferably 480 nm or less, more preferably 470 nm or less. Is desirable.

  Examples of blue organic phosphors that can be used in the present invention include naphthalimide, benzoxazole, styryl, coumarin, pyrazone, and triazole fluorescences disclosed in, for example, JP-A-2005-276785. Examples thereof include organic phosphors such as dyes and thulium complexes, and 1,4-bis (2-methylstyryl) benzene.

The blue inorganic phosphor that can be used in the present invention is represented by, for example, BaMgAl ₁₀ O ₁₇ : Eu composed of grown particles having a substantially hexagonal shape as a regular crystal growth shape and emitting light in a blue region. Europium-activated barium magnesium aluminate-based phosphor, composed of growing particles having a substantially spherical shape as a regular crystal growth shape, emits light in the blue region (Ca, Sr, Ba) ₅ (PO ₄ ) ₃ Cl: Eu The europium-activated calcium halophosphate phosphor represented by formula (1) is composed of growth particles having a substantially cubic shape as a regular crystal growth shape, and emits light in a blue region (Ca, Sr, Ba) ₂ B ₅ O ₉ Cl: Europium-activated alkaline earth chloroborate phosphor represented by Eu, composed of fractured particles having a fracture surface Europium-activated alkaline earth aluminate-based fluorescence represented by (Sr, Ca, Ba) Al ₂ O ₄ : Eu or (Sr, Ca, Ba) ₄ Al ₁₄ O ₂₅ : Eu Examples include the body.

In addition, as the blue phosphor, Sn-activated phosphate phosphors such as Sr ₂ P ₂ O ₇ : Sn, (Sr, Ca, Ba) Al ₂ O ₄ : Eu or (Sr, Ca, Ba) ₄ Al ₁₄ O ₂₅ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, Tb, Sm, BaAl ₈ O ₁₃ : with Eu, etc. Active aluminate phosphor, Ce-activated thiogallate phosphor such as SrGa ₂ S ₄ : Ce, CaGa ₂ S ₄ : Ce, Eu, Mn such as (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, Mn Active aluminate phosphor, Sr ₅ (PO ₄ ) ₃ Cl: Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, (Ba, Sr, Ca) ₅ (PO ₄ ) ₃ ( Cl, F, Br, OH): Eu-activated halophosphate phosphor such as Eu, Mn, Sb, etc., BaAl ₂ Si ₂ O ₈ : Eu, (Sr, Ba) ₃ MgSi ₂ O ₈ : with Eu such as Eu Activated silicate phosphor, Eu-activated phosphate phosphor such as Sr ₂ P ₂ O ₇ : Eu, sulfide phosphor such as ZnS: Ag, ZnS: Ag, Al, and Ce such as Y ₂ SiO ₅ : Ce Activated silicate phosphor, tungstate phosphor such as CaWO ₄ , (Ba, Sr, Ca) BPO ₅ : Eu, Mn, (Sr, Ca) ₁₀ (PO ₄ ) ₆ .nB ₂ O ₃ : Eu, 2SrO · 0.84P ₂ O ₅ · 0.16B ₂ O ₃ : Eu, Mn activated boric acid phosphor phosphor such as Eu, Sr ₂ Si ₃ O ₈ · 2SrCl ₂ : Eu activated halosilicate such as Eu Phosphor, SrSi ₉ Al ₁₉ ON ₃₁ : Eu, EuSi ₉ Eu ₁₉ activated oxynitride phosphor such as Al ₁₉ ON ₃₁ , La _1-x Ce _x Al (Si _6-z Alz) (N _10-z O _z ) (where x and y are each 0 ≦ x ≦ 1, 0 ≦ z ≦ 6.), La _1-xy Ce _x Ca _y Al (Si _6-z Al _z ) (N _10-z O _z ) (where x , Y, and z are numbers satisfying 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, and 0 ≦ z ≦ 6, respectively. is there.

Among the above examples, as the blue inorganic phosphor, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu Alternatively, (Ba, Ca, Mg, Sr) ₂ SiO ₄ : Eu is preferably included, and (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ More preferably, (Cl, F) ₂ : Eu or (Ba, Ca, Sr) ₃ MgSi ₂ O ₈ : Eu is included, and BaMgAl ₁₀ O ₁₇ : Eu, Sr ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu or Ba ₃ MgSi ₂ O ₈ : Eu is more preferable. Of these, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu or (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu is particularly preferable for illumination and display applications.

  These blue phosphors may be used alone or in a combination of two or more.

<Yellow phosphor>
In the case of using a yellow phosphor, any yellow phosphor can be used as long as the effect of the present invention is not significantly impaired, but from a light source that emits light having a peak wavelength in a wavelength range of 380 nm to 450 nm. It is preferable to use one that absorbs at least part of light and emits light.

  The yellow phosphor usually emits light having an emission peak wavelength in a wavelength range of 530 nm or more, preferably 540 nm or more, more preferably 550 nm or more, and usually 620 nm or less, preferably 600 nm or less, more preferably 580 nm or less. Is desirable.

  Examples of yellow organic phosphors that can be used in the present invention include brilliant sulfoflavine FF (Color Index Number 56205), basic Yellow HG (Color Index Number 160460), eosine (Color Index Number 4560). A fluorescent dye or the like can be used.

  Examples of the yellow inorganic phosphor that can be used in the present invention include those having the same emission characteristics as the above-described yellow organic phosphor, such as various oxides, nitrides, oxynitrides, sulfides, acids Examples thereof include phosphors such as sulfides.

In particular, RE ₃ M ₅ O ₁₂ : Ce (where RE represents at least one element selected from the group consisting of Y, Tb, Gd, Lu, and Sm, and M represents Al, Ga, and Sc. And M ^a ₃ M ^b ₂ M ^c ₃ O ₁₂ : Ce (where M ^a is a divalent metal element and M ^b is a trivalent metal element) , ^{M c} is garnet phosphor having a garnet structure represented by the representative) like a tetravalent metallic ^{_{element, AE 2 M d O 4:}} . Eu ( where, AE is, Ba, Sr, Ca, Mg , And at least one element selected from the group consisting of Zn and M ^d represents Si and / or Ge.), Etc., and constituent elements of the phosphors of these systems Oxynitridation by substituting part of oxygen in nitrogen with nitrogen System phosphors, AEAlSiN _3: Ce (here, AE is, Ba, Sr, Ca, represents at least one element selected from the group consisting of Mg and Zn.) Nitride phosphor having CaAlSiN ₃ structures such as And phosphors activated by Ce such as a body.

In addition, as yellow phosphors, sulfide-based fluorescence such as CaGa ₂ S ₄ : Eu, (Ca, Sr) Ga ₂ S ₄ : Eu, (Ca, Sr) (Ga, Al) ₂ S ₄ : Eu, etc. Body, Cax (Si, Al) ₁₂ (O, N) ₁₆ : phosphor activated by Eu such as oxynitride-based phosphor having a SiAlON structure such as Eu, (M _1-a-b Eu _a Mn _b ) ₂ (BO ₃ ) _1-p (PO ₄ ) _p X (where M represents one or more elements selected from the group consisting of Ca, Sr, and Ba, and X represents F, Cl, and Br) Represents one or more elements selected from the group consisting of: a, b, and p are 0.001 ≦ a ≦ 0.3, 0 ≦ b ≦ 0.3, and 0 ≦ p ≦ 0.2, respectively. Eu-activated or Eu / Mn co-activated halogenated borate phosphor etc. Possible it is.

  These yellow phosphors may be used alone or in combination of two or more.

2-3. Applications The wavelength conversion material of the present invention can be used as various illumination devices and display devices such as illumination lamps, backlights for liquid crystal panels, and ultra-thin illumination.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

[Example 1]

<Synthesis of bis (o-diphenylphosphinophenyl) phenylphosphine (TP)>
In a 200 mL four-necked flask, o-bromophenyldiphenylphosphine (3 g, 9.55 mmol) was added, and after Ar gas substitution, dry ether (90 mL) was added. Further, a 1.6M hexane solution of n-BuLi (6 mL, 9.64 mmol) was added dropwise at -80 ° C. After stirring at −80 ° C. for 30 minutes, dichlorophenylphosphine (855 mg, 4.77 mmol) was added, and the mixture was returned to room temperature and stirred for 3 hours. Water (about 30 mL) was added to quench the reaction system, and the resulting white solid was collected by filtration. The obtained solid was dissolved in chloroform (about 100 mL), transferred to a separatory funnel, and washed with water three times. The organic layer was dried over magnesium sulfate, the solvent was evaporated, and the resulting solid was recrystallized from chloroform / hexane to give colorless crystals (1.45 g, 48%).

¹ H NMR (500 MHz, CDCl ₃ ): δ 8.84 (m, 2H), 7.08-7.20 (m, 31H)
³¹ P NMR (200 MHz, CDCl ₃ ): δ-14.02 (d, J = 140 Hz), -14.10 (d, J = 140 Hz), -17.41 (d, J = 140 Hz), -18.25 (d, J = 140 Hz)

<Synthesis of tridentate phosphine oxide (TP = O)>
TP (1.45 g, 2.30 mmol) and dichloromethane (50 mL) were added to a 100 mL flask, cooled to 0 ° C. in an ice bath, and 30 wt% H ₂ O ₂ aqueous solution (7.8 mL, 69 mmol) was added dropwise thereto. did. After stirring for 4 hours in an ice bath, water (about 10 mL) was added to complete the reaction. The organic layer was further washed three times with water, dried over magnesium sulfate, and the solvent was evaporated to give a white solid. This was further recrystallized from chloroform / hexane to obtain colorless crystals (1.40 g, yield 90%).

¹ H NMR (500 MHz, CDCl ₃ ): δ 7.98 (m, 2H), 7.25-7.60 (m, 31H)
³¹ P NMR (200 MHz, CDCl ₃ ): δ 34.90, 34.86, 32.21, 32.17

<Synthesis of Europium Complex (Eu (hfa-H) ₃ (TP═O))>
In a 25 mL flask, TP═O (164 mg, 0.24 mmol), (Eu (hfa-H) ₃ (H ₂ O) ₂ (217 mg, 0.27 mmol), and methanol (10 mL) were placed, and the oil bath was filled with 11 The resulting reaction solution was dried up, and chloroform / hexane was added to the residue, and the mixture was stirred for 1 hour at room temperature and filtered and allowed to stand to collect colorless crystals to obtain the desired product (90 mg). .

¹⁹ F NMR (acetone-d ₆ ): δ-79.36
³¹ P NMR (acetone-d ₆ ): δ 0.55, -29.03, -68.37
Anal.Calcd for C ₅₇ H ₃₆ EuF ₁₈ O ₉ P ₃ : C = 47.16%, H = 2.50%
Found: C = 47.28%, H = 2.55%

The obtained europium complex was measured for the emission spectrum in acetone d ₆ (heavy acetone) based on the following evaluation method. The emission peak wavelength was 615 nm and the emission quantum yield (φ _f ) was 59%. It was. As shown in FIG. 1, the emission spectrum of this europium complex has a very sharp spectral shape that is symmetrical.

<Evaluation of emission spectrum shape>
The emission spectrum was measured using a spectrophotometer (Hitachi F4500 type).
Excitation emission (PL) spectrum: Hitachi F4500 spectrophotometer, wavelength increment 0.2 nm, integration time Auto, excitation wavelength: 465 nm, excitation side slit 2.5 nm, fluorescence side slit The measurement was performed at room temperature using a liquid sample measurement cell under the condition of 1 nm.
<Evaluation of luminescence quantum yield>
Emission spectrum is normalized by ⁵ Do → ⁷ F ₁ emission, Eu (hfa-H) ₃ (TPPO) ₂ is φ _f = 65%, (Table 1; Y. Hasegawa et al. Thin Solid Films 2376-2381 (2008) 516).

[Example 2]

  By using 2-bromo-5-fluorophenyldiphenylphosphine instead of o-bromophenyldiphenylphosphine, a tridentate phosphine oxide coordinated europium complex represented by the above structural formula was synthesized in the same manner as in Example 1. .

¹⁹ F NMR (acetone-d ₆ ): δ-78.27, -106.6
³¹ P NMR (acetone-d ₆ ): δ 1.39, -28.30, -66.82
Anal.Calcd for C ₅₇ H ₃₆ EuF ₁₈ O ₉ P ₃ : C = 46.02%, H = 2.30%
Found: C = 45.64%, H = 2.07%

When the emission spectrum of this europium complex was measured in acetone d ₆ under the same conditions as in Example 1, an emission peak wavelength of 616 nm was confirmed. The light emission quantum yield (φ _f ) was 67%.

[Example 3]

  By using 2-bromo-5-methoxyphenyldiphenylphosphine instead of o-bromophenyldiphenylphosphine, a tridentate phosphine oxide coordinated europium complex represented by the above structural formula was synthesized in the same manner as in Example 1. .

¹⁹ F NMR (acetone-d ₆ ): δ-79.26
³¹ P NMR (acetone-d ₆ ): δ-97.22
Anal.Calcd for C ₅₇ H ₃₆ EuF ₁₈ O ₉ P ₃ : C = 46.87%, H = 2.67%
Found: C = 47.21%, H = 2.65%

When the emission spectrum of this europium complex was measured in acetone d ₆ under the same conditions as in Example 1, an emission peak wavelength of 615 nm was confirmed. Further, the emission quantum yield (φ _f ) was 69%.

[Comparative Example 1]
When Eu (hfa-H) ₃ (BIPHEPO) having a phosphine oxide bidentate ligand having the following structure was measured in acetone d ₆ under the same conditions as in Example 1, the emission peak wavelength was The light emission quantum yield (φ _f ) was 60% at 610.0 nm.
As shown in FIG. 1, the emission spectrum of this europium complex is not bilaterally symmetric and has an irregular shape with a shoulder on the right side.

[Example 4]

In a 50 mL flask, methylidyne tris (diphenylphosphine oxide) (HTrisO ₃ ) (302 mg, 4.9 × 10 ⁻⁴ mol) and EuCl ₃ · 6H ₂ O (577 mg, 1.6 × 10 ⁻³ mol), and acetonitrile (15 mL) was added and stirred at room temperature for 5 hours. Hfa-H ₂ (0.67 mL, 4.7 × 10 ⁻³ mol) was added to the resulting cloudy solution, and ethanol (3 mL) was further added to completely dissolve the insoluble components. After stirring for 16 hours at room temperature, the solvent was evaporated. Toluene (20 mL) was added to the obtained white solid and stirred for 1 hour, followed by filtration to recover soluble components. After evaporation of the solvent, recrystallization was further performed with chloroform / hexane to obtain transparent granular crystals.
The resulting granular crystals, IR, NMR, ESI-Mass analysis, a result of performing the X-ray structure analysis, the following results are obtained, tridentate phosphine oxides of the crystal structure showing the following structural formula and in FIG. 2 (HTrisO ₃ It was confirmed that a coordinated europium complex was synthesized.

IR (neat): 1649,1483,1252,1200,1137,1097cm ^-1
19 F NMR (CDCl ₃ ): -79.4, -80.0
³¹ P NMR (CDCl ₃ ): 9.17
ESI-Mass: 1183.0 [Eu (hfa-H) ₂ (HTrisO ₃ ) ⁺ ]
Elemental analysis: C = 34.46%, H = 1.62%
Calculated value (C ₅₂ H ₃₄ EuF ₁₈ O ₉ P ₃ · 5CHCl ₃ ): C = 34.46%, H = 1.98%

<Crystal data>

When the emission spectrum of this europium complex was measured in acetone d ₆ under the same conditions as in Example 1, an emission peak wavelength of 618 nm was confirmed. The emission quantum yield (φ _f ) was 35%.

  As described above, from the results of the maximum emission wavelengths of the rare earth metal complexes evaluated in Examples 1 to 4 and Comparative Example 1, the rare earth metal complex of the present invention is clearly compared to Comparative Example 1 while the central metal is the same. It was found that the maximum emission wavelength is on the long wavelength side.

[Example 5]
To 1mM acetone _{d 6} solution of the synthesized (HTrisO ₃₎ coordination europium complex in Example 4, tetrabutylammonium nitrate ^(TBA + · NO ₃ ^-) while adding, emission evaluation conditions as in Example 1 When the spectrum was evaluated, the emission quantum yield was improved as shown in FIG. 3, and the equilibrium was reached when the nitrate ion concentration reached 15 mM. The equilibrium value of the luminescence quantum yield was 50%.
When this solution was evaluated by NMR, it was considered that a clear splitting broadening was observed at the CF ₃ site, and a part of the hfa site was substituted with nitrate ions, so that the emission quantum yield was improved.

[Example 6]
A tridentate phosphine oxide (HTrisO ₃ ) coordinated samarium complex having the following structural formula was synthesized in the same manner as in Example 4 using SmCl ₃ · 6H ₂ O instead of EuCl ₃ · 6H ₂ O.
IR (neat); 1649,1558,1523,1506,1473,1441,1253,1198,1138,1112,1093,799,791,769,732,697,686,660cm ^-1
19 F NMR (CDCl ₃ ): -76.0, -76.1
³¹ P NMR (CDCl ₃ ): 40.78
ESI-Mass: 1182.0 [Sm (hfa-H) ₂ (HTrisO ₃ ) ⁺ ]
Elemental analysis: C = 39.74%, H = 2.05%
Calculated value (C ₅₂ H ₃₄ F ₁₈ O ₉ P ₃ Sm · 2CHCl ₃ ): C = 39.87%, H = 2.23%

When the emission spectrum of this samarium complex was measured in acetone d ₆ under the same conditions as in Example 1, an emission peak wavelength of 645 nm was confirmed. The light emission quantum yield (φ _f ) was 4.7%.

[Example 7]
The emission spectrum was observed under the same conditions as in Example 1 when the (HTrisO ₃ ) coordinated europium complex synthesized in Example 4 was dissolved in CDCl ₃ and dissolved in acetone d _6. did. The results are shown in FIG.
From FIG. 4, a clear difference in spectral shape was observed depending on the type of solvent.

[Example 8]
Under the same conditions as in Example 1, the Eu (hfa-H) ₃ (TP═O) complex synthesized in Example 1 was dissolved in CDCl ₃ and dissolved in heavy acetone. The result of observation of the emission spectrum is shown in FIG.
From FIG. 5, no difference in spectral shape depending on the type of solvent was observed.

[Example 9]
A single crystal (transparent granular crystal) of (HTrisO ₃ ) coordinated europium complex was obtained in the same manner as in Example 4 except that the recrystallization solvent was acetone / water. As a result of X-ray structural analysis of the obtained crystal, the structure shown in FIG. 6 was clarified. The microscopic emission spectrum of the crystal (measured with a CCD camera) was as shown in FIG.

From FIG. 6, it is clear that the acetone molecule is hydrogen bonded to the center CH of the tridentate ligand HTrisO ₃ .

Furthermore, when compared with the crystals obtained by recrystallization with chloroform / hexane in Example 4 (see FIG. 8A), a difference is observed in the coordination structure. That is, in the crystal in which acetone is hydrogen-bonded (acetone / water crystal), it can be seen that the hfa site coordinated in the vertical direction is twisted (see the part X in FIG. 8B). The emission spectrum of the acetone / water crystal having this coordination structure has a single sharp peak at 616.5 nm as shown in FIG.
From this result, it was estimated that the difference in emission spectrum shape depending on the type of solvent was due to the twist of the coordination structure due to the binding of acetone.

[Example 10]
Whether the change in the emission spectrum shape observed in Examples 7 and 9 is observed even in the presence of hydrogen-bonding molecules other than acetone, the following conditions were used for acetone, acetonitrile, methanol, pyridine, and DMSO. Went.

<Drip experiment of hydrogen bonding molecule>
Into a 1 cm cell, acetone, acetonitrile, methanol, pyridine or DMSO as a hydrogen-bonding molecule was dropped into 2 ml of a 1 mM dichloromethane solution of the (HTrisO ₃ ) coordinated europium complex synthesized in Example 4 in the following addition amount. However, the emission wavelength was observed according to the conditions described in Example 1 (however, the excitation wavelength was 380 nm).
Acetone: 0 to 250 μL
Acetonitrile: 0-200 μL
Methanol: 0-200 μL
Pyridine: 0-300 μL
DMSO: 0 to 400 μL
Changes in emission spectrum when each hydrogen bonding molecule is dropped are shown in FIGS. 9 to 13, the peak position of the emission intensity increases as the amount of hydrogen bonding molecules added increases.

  As a result of the study by the present inventors, the change in the emission spectrum shape is not limited to the presence of acetone molecules, but is a hydrogen bonding molecule such as acetonitrile, methanol, pyridine, DMSO (dimethyl sulfoxide), etc. Similar spectral shape changes were observed. Moreover, it was found that the change in the spectrum shape also shows different aspects for each compound, reflecting the strength of hydrogen bonding (DMSO> methanol to pyridine> acetone> acetonitrile). From the above, among the rare earth metal complexes having a tridentate ligand represented by the general formula (I) of the present invention, those in which A is C or Si having no substituent other than phosphine oxide are used for molecular recognition. Is also expected to be promising.

[Example 11]
The (HTrisO ₃ ) coordinated europium complex synthesized in Example 4 was dissolved in acetone, and the temperature change of the emission spectrum of the acetone solution was observed in the range of 183K to 300K. Specifically, a fluorescence quartz cell (1 × 1 cm) was cooled using a liquid nitrogen cryostat (Optistat DN manufactured by Oxford Instruments), and an emission spectrum was observed in the same procedure as in Example 1. The results are shown in FIG.

[Example 12]
The (HTrisO ₃ ) coordinated europium complex synthesized in Example 4 was dissolved in dichloromethane, and a small amount (10 wt%) of acetone was added to the dichloromethane solution. Observed. Specifically, a fluorescence quartz cell (1 × 1 cm) was cooled using a liquid nitrogen cryostat (Optistat DN manufactured by Oxford Instruments), and an emission spectrum was observed in the same procedure as in Example 1. The results are shown in FIG.

  In both FIG. 14 and FIG. 15, the shoulder on the low wavelength side clearly observed at 300K becomes smaller under low temperature conditions, the ratio of the main peak on the high wavelength side increases, and the peak shape becomes steeper. understood. This is because the hydrogen bond between the acetone molecule and the tridentate ligand confirmed in Example 9 exists more stably at a low temperature, so that the emission spectrum reflecting the twist of the coordination structure is shifted to the higher wavelength side. Is estimated to be observed more clearly.

  From the above, among the rare earth metal complexes having a tridentate ligand represented by the general formula (I) of the present invention, those in which A is C or Si having no substituent other than phosphine oxide are used as a low temperature sensor. Is also expected to be promising.

Claims (5)

  A rare earth metal complex, wherein a ligand having three or more phosphine oxides in the same molecule is tridentately coordinated with a rare earth metal that is a central metal. The rare earth metal complex according to claim 1, wherein the structure of the ligand having three or more phosphine oxides in the same molecule is represented by the following general formula (I) or (II).

[In Formula (I),
A is any one of C, N, Si, and P. When A is C or Si, C or Si may further have a substituent.
X ₁ , Y ₁ and Z ₁ each independently have a direct bond, an alkylene group which may have a substituent, an arylene group which may have a substituent, or a substituent. Represents a suitable heterocyclic group, or a combination thereof,
R _{11 to} R ₁₆ each independently represents an arbitrary substituent. ]

[In Formula (II),
X ₂ and Y ₂ are each independently a direct bond, an alkylene group which may have a substituent, an arylene group which may have a substituent, or a heterocyclic group which may have a substituent. Or a combination of these,
R _{21 to} R ₂₅ each independently represent an arbitrary substituent. ]   The rare earth metal complex according to claim 1 or 2, wherein the rare earth metal is any one of Eu, Tb, Er, Yb, Nd, and Sm.   A wavelength conversion material comprising the rare earth metal complex according to any one of claims 1 to 3.   A method for producing a rare earth metal complex, wherein a ligand having three or more phosphine oxides in the same molecule is first tridentately coordinated with a central metal and then another ligand is coordinated.

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