JP5611606B2 - Rare earth complex, and fluorescent medium, light emitting element, security medium and lighting device using the same - Google Patents

Description

  The present invention relates to a rare earth complex having a high luminous intensity and a long life, and a fluorescent medium, a light emitting medium, a security medium, and a lighting device using the same.

  In recent years, the luminous intensity and lifetime of LED elements have been remarkably improved, and a wide range of market development is in progress, mainly for lighting applications. The light emitting diode elements (hereinafter referred to as LED elements) that use inorganic phosphors as light emitters, which are currently the mainstream, are dramatically improving their light emission efficiency. In particular, white LED elements will be used in the future for the efficiency of fluorescent lamps. It is a situation that is said to surpass. However, since an LED element using an inorganic phosphor has a difficulty in color rendering, an illuminating device that combines an organic phosphor with an LED has been proposed (for example, see Patent Document 1).

  However, the deterioration of the organic phosphor due to ultraviolet rays, the fluorescence spectrum changes depending on the concentration, the spectrum control is difficult, the fluorescence intensity is also concentration dependent, and concentration quenching occurs in the high concentration region, It has not yet been put to practical use as a lighting application due to the problem that the fluorescence spectrum changes depending on the type of polymer to be dispersed.

  In order to develop a combination of LED and organic phosphor in the general lighting market, further luminous intensity and long life are required. A characteristic that greatly affects durability is the stability of the ligand itself to photochemical reaction. Since the phosphor irradiated with light emitted from the LED is exposed to severe conditions with strong heat and light, radical (oxidation) degradation is likely to proceed.

  When a ligand undergoes a chemical change, the coordination ability is reduced and the ligand deviates from the central element, thereby degrading the fluorescence intensity or causing the deactivation of the ligand. .

  On the other hand, in order to realize a high luminous intensity, it is required that the solubility of the fluorescent complex in the resin is large. When the solubility is low and the phosphor is present in the form of particles in the resin, sufficient light intensity cannot be obtained due to light scattering. In order to improve the solubility of the fluorescent complex, the complex structure has also been studied.

  An effective technique for improving the durability of fluorescent complexes is binucleation. Dinucleation is a complex having a plurality of central ions in one molecule. However, although the binucleation improves the durability, the problem is that the solubility in the medium is significantly reduced due to the significant increase in molecular weight. There are currently no reported examples of binuclear complexes that sufficiently satisfy emission intensity and solubility.

  In addition, it is a general fact that a binuclear complex is insolubilized by an increase in molecular weight.

Japanese Patent Laid-Open No. 2007-1880

  The present invention has been made under the above circumstances, and an object thereof is to provide a rare earth complex having a high luminous intensity, a high solubility, and a long lifetime, and a light emitting element, a security medium, and a lighting device using the same.

In order to solve the above problems, a first aspect of the present invention is a rare earth complex comprising a plurality of rare earth ions, a phosphine oxide ligand, and a β-diketonato ligand, wherein the phosphine oxide ligand but have a molecular structure represented by the following formula (1), wherein the β- diketonate ligand 3 molecule is coordinated to the metal atom 1 atom, represented by the following formula (3), the same or different β- diketonate rare earth complex 2 molecule, the phosphine oxide ligand 1 molecules are coordinated, the rare earth metal atoms, Eu (III) or Tb (III) a rare earth complex characterized by der Rukoto .

（式中、Ｒ ^８ 及びＲ ^１１ は、水素原子、重水素原子、ハロゲン原子、置換されていてもよい炭素数１〜２０の飽和炭化水素基、置換されていてもよいアリール基、置換されていてもよいヘテロアリール基、又は置換されていてもよいアラルキル基を示し、Ｒ ^７ 、Ｒ ^９ 、Ｒ ^１０ 、及びＲ ^１２ は、それぞれ同一又は異なる、置換されていてもよい炭素数が１〜２０の飽和炭化水素基、炭素数１〜２０のペルフルオロアルキル基、置換されていてもよいアリール基、置換されていてもよいヘテロアリール基、又は置換されていてもよいアラルキル基を示し、Ｌｎ(III) ^１ 、及びＬｎ(III) ^２ は、３価の希土類金属イオンを示す。）
本発明の第２の態様は、上記希土類錯体をポリマーに溶解してなることを特徴とする蛍光媒体を提供する。 (Wherein, m, n, o are a 3 to 12 ^integer, R 1 to R ⁶ are the same or different, represents an aryl group which may have been substitution, adjacent on the same phosphorus atom R ¹ and R ² , R ³ and R ⁴ , or R ⁵ and R ⁶ may be bonded to form a ring.)

(In the formula, R ⁸ and R ¹¹ are a hydrogen atom, a deuterium atom, a halogen atom, an optionally substituted saturated hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aryl group, or a substituted group. An optionally substituted heteroaryl group or an optionally substituted aralkyl group, wherein R ⁷ , R ⁹ , R ¹⁰ , and R ¹² are the same or different and each have 1 to 20 carbon atoms that may be substituted; A saturated hydrocarbon group, a C 1-20 perfluoroalkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, or an optionally substituted aralkyl group, Ln (III ) ¹ and Ln (III) ² represent trivalent rare earth metal ions.)
According to a second aspect of the present invention, there is provided a fluorescent medium comprising the rare earth complex dissolved in a polymer.

  According to a third aspect of the present invention, there is provided a light emitting device comprising a fluorescent layer containing the rare earth complex.

  According to a fourth aspect of the present invention, there is provided a security medium, wherein a solution obtained by dissolving the rare earth complex in a polymer is printed on a substrate.

  According to a fifth aspect of the present invention, there is provided an illumination device comprising a light emitting layer containing the rare earth complex.

  According to the present invention, a rare earth complex having a high luminous intensity, a high solubility, and a long lifetime, and a light emitting element, a security medium, and a lighting device using the same are provided.

It is explanatory drawing of the structure of the LED element which concerns on one embodiment of this invention. It is explanatory drawing of the structure of the organic EL element which concerns on the other embodiment of this invention. It is a figure which shows a digital camera provided with the LED flash using the LED element which concerns on one embodiment of this invention. It is a figure which shows a mobile telephone provided with the LED flash using the LED element which concerns on one embodiment of this invention.

  Embodiments of the present invention will be described below.

  In the present specification, the terms “fluorescent rare earth complex”, “fluorescent complex”, and “fluorescent medium” are not necessarily limited to those that emit fluorescence in a strict sense, but also those that emit phosphorescence. It should be understood to mean a complex that emits light extensively.

  As a result of diligent investigations on fluorescent rare earth complexes having high luminous intensity, high solubility, and long lifetime that can be suitably used for lighting devices, the present inventors have obtained a plurality of rare earth ions and a predetermined phosphine oxide. The present inventors have found that a rare earth complex containing a ligand is excellent in emission intensity, durability, and solubility, and have led to the present invention.

Embodiment 1
The fluorescent rare earth complex according to the first embodiment of the present invention includes a plurality of rare earth ions and a phosphine oxide ligand, and the phosphine oxide ligand is represented by the following formula (1). It is what has.

(In the formula, m, n, and o are integers of 1 or more, and R ^{1 to} R ⁶ are the same or different, an optionally substituted saturated hydrocarbon group, an optionally substituted aryl group, An optionally substituted heteroaryl group or an optionally substituted aralkyl group, wherein adjacent R ¹ and R ² , or R ³ and R ⁴ , or R ⁵ and R ⁶ on the same phosphorus atom are bonded And may form a ring.)
The above phosphine oxide ligand and the β-diketonato ligand represented by the following formula (2) can be coordinated with a plurality of rare earth ions to form a fluorescent rare earth complex.

(In the formula, R ⁸ is a hydrogen atom, a deuterium atom, a halogen atom, an optionally substituted saturated hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aryl group, or optionally substituted. A heteroaryl group, or an optionally substituted aralkyl group, wherein R ⁷ and R ⁹ are the same or different, an optionally substituted saturated hydrocarbon group having 1 to 20 carbon atoms, and 1 to 20 carbon atoms; A perfluoroalkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, or an optionally substituted aralkyl group.
Further, two molecules of the same or different β-diketonato rare earth complexes represented by the following formula (3) in which three molecules of the β-diketonato ligand are coordinated to one metal atom are represented by the formula (1). One molecule of the phosphine oxide ligand represented can coordinate to form a fluorescent rare earth complex.

(In the formula, R ⁸ and R ¹¹ are a hydrogen atom, a deuterium atom, a halogen atom, an optionally substituted saturated hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aryl group, or a substituted group. An optionally substituted heteroaryl group or an optionally substituted aralkyl group, wherein R ⁷ , R ⁹ , R ¹⁰ , and R ¹² are the same or different and each have 1 to 20 carbon atoms that may be substituted; A saturated hydrocarbon group, a C 1-20 perfluoroalkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, or an optionally substituted aralkyl group, Ln (III ) ¹ and Ln (III) ² represent trivalent rare earth metal ions.)
As described above, the tetraphosphine tetraoxide ligand represented by the above formula (1) has a P═O bond in the structure, and is coordinated to the rare earth metal atom through this bond. This ligand forms a binuclear complex by coordinating with a plurality of rare earth metal atoms together with a β-diketonato ligand represented by the above formula (2). Since the formed binuclear complex has a flexible molecular structure, it also has excellent solubility characteristics.

  The emission intensity of the phosphor composed of such a rare earth complex largely depends on the type and combination of substituents connected to the β-diketonato ligand represented by the above formula (2). In the case of a europium complex, Among the two substituents of the β-diketonato ligand, the emission intensity is maximized when one is an aromatic group and the other is a perfluoroalkyl group.

  In addition, the solubility of such rare earth complexes is particularly excellent when the types or combinations of substituents of β-diketonato ligands connected to two rare earth ions sandwiching a tetraphosphine tetraoxide ligand are different. Yes.

In the rare earth complex according to the present embodiment, at least one of R ¹ to R ⁶ of the tetraphosphine tetraoxide ligand represented by the above formula (1) is a phenyl group substituted at the meta position or the para position. It can be. In this case, the saturation solubility is further improved, and particularly when the meta position is a phenyl group substituted with a perfluoroalkyl group, it is particularly useful for improving the solubility.

That is, the phosphine oxide ligand represented by the above formula (1) can be represented by the following formula (4).

(In the formula, m, n, and o are integers of 1 or more, and R ^{13 to} R ¹⁸ each represent the same or different alkyl group, fluoroalkyl group, alkoxy group, or hydrogen atom.)
Further, two molecules of the same or different β-diketonato rare earth complexes represented by the above formula (3) in which three molecules of the β-diketonato ligand are coordinated to one metal atom are represented by the formula (1). One molecule of the phosphine oxide ligand represented can coordinate to form a fluorescent rare earth complex represented by the following formula (5).

  In the present embodiment, the rare earth ion can be appropriately selected so as to generate fluorescence having a wavelength according to the application, but is preferably a lanthanoid ion. More specifically, europium or terbium is preferable, and europium is particularly preferable for realizing a fluorescent rare earth complex having a large spectrum in the red region and excellent color rendering.

  Although the fluorescent rare earth complex according to the present embodiment described above is a binuclear complex, it is characterized in that both durability and emission intensity are compatible due to the flexibility of its molecular structure. What is used as a light-emitting medium by dissolving in a polymer contributes to an increase in light emission intensity by using it in the fluorescent layer of LED elements, and realizes a security medium that can produce clear pattern display by ink printing and ink-jet printing. And it contributes to the increase in emitted light intensity by using for the light emitting layer of an organic EL element.

  Hereinafter, each ligand which comprises the rare earth complex which concerns on this embodiment, its manufacturing method, the manufacturing method of a rare earth complex, etc. are demonstrated in detail.

A. Phosphine oxide ligand The phosphine oxide ligand represented by the above formula (1) will be described in detail below.

  In the above formula (1), the saturated hydrocarbon group of the saturated hydrocarbon group which may be substituted is not particularly limited, and for example, a linear or branched alkyl group having 1 to 20 carbon atoms, carbon Examples thereof include cycloalkyl groups of 3 to 12. Examples of the linear or branched alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, Examples include hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, icosyl group and the like.

  Examples of the cycloalkyl group having 3 to 12 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclododecyl group.

  Although it does not specifically limit as a substituent of the saturated hydrocarbon group which may be substituted, For example, a fluoroalkyl group, an alkoxy group, an aryloxy group, a siloxy group, a dialkylamino group etc. are mentioned. Examples of the fluoroalkyl group include a perfluoroalkyl group having 1 to 6 carbon atoms. Examples of the C 1-6 perfluoroalkyl group include a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and a tridecafluorohexyl group.

  As an alkoxy group, a C1-C6 alkoxy group is mentioned, for example. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, and a hexyloxy group. As an aryloxy group, a C6-C12 aryloxy group is mentioned, for example. Examples of the aryloxy group having 6 to 12 carbon atoms include a phenoxy group and a naphthyloxy group.

  Examples of the siloxy group include trimethylsiloxy, triethylsiloxy, triisopropylsiloxy, tert-butyldimethylsiloxy and the like. Examples of the dialkylamino group include dimethylamino and diethylamino.

  The substitution position of the substituent of the saturated hydrocarbon group which may be substituted and the number of substituents are not particularly limited. In particular, the saturated hydrocarbon group which may be substituted is preferably an optionally substituted saturated hydrocarbon group having 3 to 20 carbon atoms, and more preferably a saturated hydrocarbon group having 4 to 18 carbon atoms.

  The aryl group of the aryl group which may be substituted is not particularly limited, and examples thereof include an aryl group having 6 to 14 carbon atoms. Examples of the aryl group having 6 to 14 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, biphenylyl, anthryl and the like.

  The substituent of the aryl group which may be substituted is not particularly limited, and for example, an alkyl group having 1 to 6 carbon atoms, a perfluoroalkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 14 carbon atoms, Examples thereof include a 5- to 10-membered aromatic heterocyclic group, an alkoxy group, an aryloxy group, a siloxy group, and a dialkylamino group. Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl and the like.

  Examples of the C 1-6 perfluoroalkyl group include trifluoromethyl, pentafluoroethyl, heptafluoropropyl, tridecafluorohexyl and the like. Examples of the aryl group having 6 to 14 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, biphenylyl, 2-anthryl and the like.

  Examples of the 5- to 10-membered aromatic heterocyclic group include 2- or 3-thienyl, 2-, 3- or 4-pyridyl, 2-, 3-, 4-, 5- or 8-quinolyl, 1-, Examples include 3-, 4- or 5-isoquinolyl, 1-, 2- or 3-indolyl, 2-benzothiazolyl, 2-benzo [b] thienyl, benzo [b] furanyl and the like.

  For the C 1-6 perfluoroalkyl group, alkoxy group, aryloxy group, siloxy group and dialkylamino group, the alkoxy group, aryloxy group, siloxy group and dialkyl described as substituents of the saturated hydrocarbon group Same as amino group. The substitution position and the number of substituents of the substituent of the aryl group which may be substituted are not particularly limited.

  The heteroaryl group of the heteroaryl group which may be substituted is not particularly limited. For example, the heteroaryl group is a condensed ring containing 1 to 3 atoms selected from the group consisting of a sulfur atom, an oxygen atom and a nitrogen atom. There may be mentioned 5 to 14-membered aromatic heterocyclic groups. Aromatic heterocyclic groups include furyl, thienyl, pyrrolyl, pyrazolyl, imidazolyl, oxazolyl, isoxazolyl, isothiazolyl, thiazolyl, 1,2,3-oxadiazolyl, triazolyl, tetrazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolyl, Examples thereof include indazolyl, prynyl, quinolyl, isoquinolyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinolinyl, pteridinyl, carbazolyl, carbolinyl, phenanthridinyl and acridinyl.

  The substituent of the heteroaryl group which may be substituted is the same as the substituent described for the aryl group which may be substituted. The position of the substituent and the number of substituents in the optionally substituted heteroaryl group are not particularly limited.

  Examples of the aralkyl group of the aralkyl group which may be substituted include a benzyl group, a phenethyl group, and a phenylpropyl group. The substituent of the aralkyl group which may be substituted is the same as the substituent described for the aryl group which may be substituted. The position of the substituent of the aralkyl group which may be substituted and the number of substituents are not particularly limited.

Examples of the ring formed by combining R ¹ and R ² on the same phosphorus atom include a piperidine ring, a pyrrolidine ring, and a morpholine ring. m, n and o may each be an integer of 1 or more, preferably an integer of 3 to 12, more preferably an integer of 4 to 8.

B. Method for Producing Tetraphosphine Tetraoxide Ligand Tetraphosphine tetraoxide ligand represented by the above formula (1), in the presence of a catalyst, phosphine oxide represented by the following general formula (6), By reacting the phosphorus compound represented by the general formula (7) and / or the phosphorus compound represented by the following general formula (8), it can be produced simply and in high yield.

(In the formula, z is an integer of 2 or more.)

(Wherein R ¹ and R ² are the same or different, an optionally substituted saturated hydrocarbon group, an optionally substituted aryl group, an optionally substituted heteroaryl group, or an optionally substituted A aralkyl group may be bonded to form a ring.

(Wherein R ¹ and R ² are the same or different, an optionally substituted saturated hydrocarbon group, an optionally substituted aryl group, an optionally substituted heteroaryl group, or an optionally substituted A aralkyl group may be bonded to form a ring.
Although the manufacturing method of the phosphine oxide represented by the said General formula (6) is not specifically limited, The organometallic reagent prepared from the halide represented by following General formula (9), and the following general The method of manufacturing by making the phosphorus compound represented by Formula (10) react is preferable. This is because phosphine oxide can be produced with a high yield by such a method.

_{CH 2 = CH- (CH 2)} z-2 -X (9)
(In the formula, X represents a halogen atom, and z is an integer of 2 or more.)

(In the formula, Y ¹ , Y ² and Y ³ each represent the same or different halogen atom, alkoxy group or aryloxy group.)
That is, as a method for producing a tetraphosphine tetraoxide ligand according to the present embodiment, in particular, a series of processes shown in the following reaction formula (a series of processes through the following second step after the following first step). It is preferable to adopt. By adopting such a method, a tetraphosphine tetraoxide ligand represented by the following formula (1 ′) can be produced easily and in high yield while freely designing a molecule.

[Reaction Formula 1]

(Wherein z, X, Y ¹ , Y ² , Y ³ , R ¹ and R ² are the same as above)
Hereinafter, the production method of the tetraphosphine tetraoxide ligand according to the present embodiment will be specifically described with the method shown in the above reaction formula 1 as a representative example.

First Step In the first step, the organometallic reactant prepared from the halide represented by the above formula (9) is reacted with the phosphorus compound represented by the above formula (10), whereby the above formula ( The phosphine oxide represented by 6) is produced. For example, the phosphine oxide represented by the above formula (6) can be produced according to the following step (a) and step (b).

Step (a)
A step of adding a phosphorus compound represented by the above formula (10) to the organometallic reactant or obtaining a reaction solution by adding an organometallic reactant to the phosphorus compound Step (b)
After forming an organic layer and an aqueous layer by adding water to the reaction solution obtained in step (a) or adding the reaction solution obtained in step (a) to water, from this organic layer Obtaining phosphine oxide;

<Organic metal reactant>
The organometallic reactant can be prepared using a halide represented by the above formula (9).

  In general formula (9) and general formula (6), z should just be an integer greater than or equal to 2, Preferably it is an integer of 3-12, More preferably, it is an integer of 4-8. In the general formula (9), examples of the halogen atom represented by X include F, Cl, Br, and I. Among these, Cl and Br are particularly preferable from the viewpoints of reactivity and economy.

  A halide can be easily obtained by manufacturing according to a commercial item or a well-known method. Examples of organometallic reactants include Grignard reactants, organolithium reactants, and organozinc reactants. In particular, as the organometallic reactant, a Grignard reactant is preferred.

  The Grignard reactant can be easily prepared by a known method. For example, it can be prepared by reacting a halide and metallic magnesium in an aprotic solvent with stirring in an inert gas atmosphere.

  Examples of the inert gas include nitrogen gas and argon gas. These inert gases can be used alone or as a mixed gas of two or more.

  As the metal magnesium, any shape such as a cut shape, a foil shape, and a granular shape may be used.

Although the usage-amount of metallic magnesium is not specifically limited, About 0.2-5 mol is preferable with respect to 1 mol of halides, About 0.5-2 mol is more preferable, About 0.8-1.2 mol is further more preferable.

  Examples of the aprotic solvent include ether solvents, aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, amine solvents, and the like. In particular, an ether solvent is preferable.

  Examples of ether solvents include tetrahydrofuran (THF), diethyl ether, diisopropyl ether, dibutyl ether, t-butyl methyl ether, cyclopentyl methyl ether, 1,4-dioxane, 1,2-dimethoxyethane, diethylene glycol diethyl ether, diethylene glycol. Examples include dibutyl ether and anisole.

  Examples of the aliphatic hydrocarbon solvent include hexane, cyclohexane, heptane, octane, decalin and the like. Examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene, mesitylene and the like. Examples of the amine solvent include triethylamine and pyridine. The aprotic solvent can be used alone or as a mixed solvent in which two or more are mixed.

  Although the usage-amount of an aprotic solvent is not specifically limited, It is about 100-2000 ml normally with respect to 1 mol of halides (7), Preferably it is about 200-1000 ml.

  Stirring may be performed using, for example, a known stirring device such as a motor or a magnetic stirrer having a stirring blade attached to the rotating shaft. The reaction pressure is not particularly limited, and may usually be about normal pressure to about 100 kg / cm2. The reaction temperature may be appropriately set according to the type of halide, reaction scale, etc., but is preferably about −40 to 200 ° C., more preferably about −20 ° C. to 150 ° C. For example, when reacting at normal pressure, the range from −20 ° C. to the reflux temperature of the solvent is preferred. The reaction time may be appropriately set according to the reaction temperature and the like, but is preferably about 15 minutes to 48 hours, and more preferably about 1 hour to 24 hours.

  Organolithium reactants and organozinc reactants can also be easily prepared according to known methods. For example, the organolithium reactant can be prepared by reacting a halide and metallic lithium in an aprotic solvent with stirring in an inert gas atmosphere. In addition, the organozinc reactant is a method in which a halide and metallic zinc are reacted with stirring in an aprotic solvent under an inert gas atmosphere, or a Grignard reactant and / or organic under an inert gas atmosphere. It can be prepared by a method in which a lithium reactant and zinc chloride are reacted with stirring in an aprotic solvent.

<Phosphorus compound>
In the general formula (10), Y ¹ , Y ² and Y ³ each represent the same or different halogen atom, alkoxy group or aryloxy group. Examples of the halogen atom include F, Cl, Br, I and the like. The halogen atom is preferably Cl from the viewpoints of reactivity and economy. Examples of the alkoxy group include methoxy group, ethoxy group, isopropyloxy group, butoxy group and the like. Examples of the aryloxy group include a phenoxy group.

In particular, the phosphorus compound is preferably phosphorus oxychloride in which Y ¹ , Y ² and Y ^{3 in} the general formula (10) are chlorine atoms. A phosphorus compound can be easily obtained by manufacturing according to a commercial item or a well-known method.

<Preparation of reaction solution>
A reaction solution can be prepared by adding a phosphorus compound to the organometallic reactant or by adding an organometallic reactant to the phosphorus compound. In preparing the reaction solution, the phosphorus compound may be used as it is or in a state dissolved in a solvent. As the solvent, for example, an aprotic solvent can be used.

  In particular, in the step (a), it is preferable that a solution of the phosphorus compound is dropped into the organometallic reactant or the organometallic reactant is dropped into the solution of the phosphorus compound dissolved in the solvent. The concentration of the phosphorus compound in the solution is not particularly limited as long as the reaction between the organometallic reactant and the phosphorus compound proceeds favorably.

  The dropping speed is not particularly limited, but it is desirable to set the dropping solution so that the phosphorus compound solution is dropped usually over about 5 minutes to 12 hours, preferably over about 15 minutes to 6 hours. The dropwise addition is desirably performed under conditions where the temperature of the resulting reaction solution is usually about -20 to 150 ° C, preferably about 0 to 80 ° C.

  After completion of the dropwise addition, it may be further reacted as necessary, usually at about -20 to 150 ° C, preferably in the range of 0 ° C to the reflux temperature of the aprotic solvent.

  The reaction solution can be prepared by the above method.

  In step (b), water was added to the reaction solution obtained in step (a), or the reaction solution obtained in step (a) was added to water to form an organic layer and an aqueous layer. Thereafter, phosphine oxide (4) is obtained from the organic layer. Step (b) may be performed according to a known separation method using a known separation treatment apparatus. The amount of water added is not particularly limited as long as it is within a range in which the organic layer and the water layer can be suitably formed. Further, instead of water, an acidic aqueous solution such as dilute sulfuric acid, dilute hydrochloric acid or an acetic acid aqueous solution, a weak acidic aqueous solution such as an ammonium chloride aqueous solution, or a neutral aqueous solution such as a sodium chloride aqueous solution may be used.

  After separating the organic layer and the aqueous layer, if necessary, an organic solvent is added to the aqueous layer to separate the aqueous layer into an organic layer and an aqueous layer, and the organic layer is first separated. You may perform operation combined with the organic layer. Examples of the organic solvent include ether solvents, hydrocarbon solvents, ester solvents, and the like. Examples of the ether solvent include diethyl ether, diisopropyl ether, dibutyl ether, t-butyl methyl ether, cyclopentyl methyl ether, and the like.

  Examples of the hydrocarbon solvent include toluene, xylene, hexane, cyclohexane, heptane and the like. Examples of the ester solvent include ethyl acetate and butyl acetate.

  These organic solvents can be used individually by 1 type or in mixture of 2 or more types. The obtained organic layer may be dehydrated as necessary. For the dehydration treatment, for example, a known dehydrating agent such as magnesium sulfate or sodium sulfate may be used. By concentrating the obtained organic layer, phosphine oxide can be obtained. In addition, after concentrating an organic layer, you may refine | purify according to a well-known purification method as needed. Known purification methods include, for example, distillation, recrystallization, column chromatography and the like.

  The phosphine oxide can be obtained by the above method.

Second Step In the second step, the phosphine oxide obtained in the first step is reacted with the phosphorus compound represented by the formula (7) and / or the phosphorus compound represented by the formula (8) in the presence of a catalyst. To produce tetraphosphine tetraoxide.

  Examples of the catalyst include a radical initiator type catalyst, a transition metal complex catalyst, and a basic catalyst. These can be used alone or in combination of two or more. Among these, a radical initiator catalyst is particularly preferable. By using a radical initiator catalyst, the target tetraphosphine tetraoxide can be produced in a better yield.

  Examples of the radical initiator catalyst include azo compounds, organic peroxides, and trialkylboranes. Examples of the azo compound include 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, , 1′-azobis-1-cyclohexanecarbonitrile, dimethyl-2,2′-azobisisobutyrate (MAIB), 4,4′-azobis-4-cyanovaleric acid, 1,1′-azobis (1 -Acetoxy-1-phenylethane) and the like.

  Examples of organic peroxides include dibenzoyl peroxide (BPO), di (3-methylbenzoyl) peroxide, benzoyl (3-methylbenzoyl) peroxide, dilauroyl peroxide, diisobutyl peroxide, and t-butylperoxy-2- Ethylhexanoate (perbutyl-O), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butylperoxypivalate, t-butylperoxyneodecanoate, etc. It can be illustrated. Examples of the trialkylborane include trialkylboranes such as triethylborane and tributylborane. These radical initiator catalysts can be used singly or in combination of two or more.

  Examples of the transition metal complex catalyst include Fe complex, Ni complex, Pd complex and the like.

Examples of the Fe complex include [CpFe (CO) ₂ ] ₂ and Fe (CO) ₅ . Examples of the Ni complex include NiCl ₂ (PPh ₃ ) ₂ and NiBr ₂ (PPh ₃ ) ₂ . Examples of the Pd complex include PdCl ₂ (PPh ₃ ) ₂ , PdCl ₂ (PhCN) ₂ , PdCl ₂ (CH ₃ CN) _{2 and the} like. These transition metal complex catalysts can be used singly or in combination of two or more.

  Examples of the basic catalyst include sodium methoxide, sodium ethoxide, potassium-t-butoxide, isopropylmagnesium isoporoxide, t-butylmagnesium methoxide and the like. These basic catalysts can be used singly or in combination of two or more. In particular, as the catalyst, a radical initiator type catalyst is preferable, and an azo compound and an organic peroxide are preferable.

  Although the usage-amount of a catalyst is not limited, It is about 0.01-5 mol normally with respect to 1 mol of phosphine oxides, Preferably it is about 0.02-3 mol, More preferably, it is about 0.05-1 mol.

  The phosphorus compound represented by the formula (7) exists in an equilibrium state with the tautomeric phosphorus compound represented by the formula (8) as shown in the following reaction formula 2.

[Reaction Formula 2]

A phosphorus compound can be easily obtained by manufacturing according to a commercial item or a well-known method. For example, by the method described in R. Hays, J. Org. Chem., 1968, 33, 3691. That is, by reacting 1 mol of diethyl phosphite with 3 mol of Grignard reagent, R ¹ and R ² The same phosphorus compounds represented by the formula (7) can be produced. In addition, a phosphorus compound represented by the formula (7) in which R ¹ and R ² are different can be produced by the method described in GMKosolapoff, etal., J. Chem. Soc. (C), 1967, 1789. it can.

For ^{R 1} and ^{R 2} in general formula (7) and (8) in the same as ^{R 1} and ^{R 2} described in the general formula (1). In particular, each of R ¹ and R ² may be an optionally substituted saturated hydrocarbon group having 3 to 20 carbon atoms, an optionally substituted aryl group, an optionally substituted heteroaryl group, or a substituted group. Aralkyl groups which may be present are preferred. In particular, from the viewpoint of reactivity, an aryl group which may be substituted or a heteroaryl group which may be substituted is preferable.

  Although the usage-amount of the phosphorus compound represented by Formula (7) in a 2nd process (and / or the phosphorus compound represented by Formula (8)) is not limited, It is about 2-6 mol normally with respect to 1 mol of phosphine oxides. The amount is preferably about 2.5 to 4 mol, more preferably about 3 to 3.5 mol.

  The reaction of the phosphine oxide with the phosphorus compound represented by the formula (7) and / or the phosphorus compound represented by the formula (8) is performed in the presence of a catalyst, for example, without stirring or in a solvent while stirring.

  The solvent is not particularly limited as long as it can effectively exhibit the catalytic function. Examples include aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, alcohol solvents, ether solvents, ester solvents, amide solvents, sulfoxide solvents, and the like. Examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene, mesitylene and the like. Examples of the aliphatic hydrocarbon solvent include hexane, cyclohexane, heptane, octane, decalin and the like.

  Examples of alcohol solvents include methanol, ethanol, propanol, isopropanol, butanol, t-butanol, octanol and the like. Examples of ether solvents include THF, 1,4-dioxane, diisopropyl ether, dibutyl ether, t-butyl methyl ether, 1,2-dimethoxyethane, and the like. Examples of ester solvents include ethyl acetate and butyl acetate. Examples of the amide solvent include dimethylformamide and diethylformamide. Examples of the sulfoxide solvent include dimethyl sulfoxide. These solvents can be used singly or as a mixed solvent of two or more.

  When reacting in a solvent, from the viewpoint of reaction efficiency, the phosphine oxide, the phosphorus compound represented by the formula (7) (and / or the phosphorus compound represented by the formula (8)) and the catalyst are completely dissolved in the solvent. It is preferable. At this time, phosphine oxide or the like may be dissolved while being reacted.

The reaction of the phosphine oxide with the phosphorus compound represented by the formula (7) and / or the phosphorus compound represented by the formula (8) may be carried out in any of a batch type or a continuous type. The reaction pressure is not particularly limited, and may usually be about normal pressure to about 100 kg / cm ² . The reaction temperature may be appropriately set according to the type of the catalyst and the like, but is usually about -20 ° C to 200 ° C, preferably about 0 ° C to 150 ° C. For example, when reacting at normal pressure, the range of 0 ° C. to the reflux temperature of the solvent is preferred. The reaction time is not particularly limited and may be appropriately set according to the reaction temperature and the degree of progress of the reaction, but is usually about 15 minutes to 72 hours, preferably about 1 hour to 36 hours.

  You may refine | purify by a well-known purification method as needed after reaction. As a known purification method, the method exemplified in the above step (b) can be employed.

  As described above, the tetraphosphine tetraoxide ligand according to this embodiment can be obtained through the first step and the second step.

C. Rare earth metal atom The rare earth metal atom in the present embodiment can be appropriately selected so as to generate fluorescence having a wavelength according to the application, but is preferably a lanthanoid metal atom. More specifically, europium or terbium is preferable, and europium is particularly preferable for realizing a fluorescent rare earth complex having a large red region spectrum and excellent color rendering.

D. β-diketonato ligand The β-diketonato ligand is preferably a β-diketonato ligand represented by the following general formula (2).

(In the formula, R ⁸ is a hydrogen atom, a deuterium atom, a halogen atom, an optionally substituted saturated hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aryl group, or optionally substituted. A heteroaryl group, or an optionally substituted aralkyl group, wherein R ⁷ and R ⁹ are the same or different, an optionally substituted saturated hydrocarbon group having 1 to 20 carbon atoms, 20 perfluoroalkyl groups, an optionally substituted aryl group, an optionally substituted heteroaryl group, or an optionally substituted aralkyl group.
Regarding R ⁸ , examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. With respect to R ⁷ , R ⁸ , and R ⁹ , the saturated hydrocarbon group of a saturated hydrocarbon having 1 to 20 carbon atoms that may be substituted is not particularly limited, and for example, a straight chain having 1 to 20 carbon atoms or Examples thereof include a branched alkyl group and a cycloalkyl group having 3 to 12 carbon atoms. Examples of the linear or branched alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, Examples include a hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, icosyl group and the like.

  Examples of the cycloalkyl group having 3 to 12 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclododecyl group. Although it does not specifically limit as a substituent of the saturated hydrocarbon group which may be substituted, For example, a fluoroalkyl group, an alkoxy group, an aryloxy group, a siloxy group, a dialkylamino group etc. are mentioned. As a fluoroalkyl group, a C1-C6 perfluoroalkyl group is mentioned, for example. Examples of the C 1-6 perfluoroalkyl group include a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and a tridecafluorohexyl group.

  As an alkoxy group, a C1-C6 alkoxy group is mentioned, for example. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, and a hexyloxy group. As an aryloxy group, a C1-C12 aryloxy group is mentioned, for example. Examples of the aryloxy group having 6 to 12 carbon atoms include a phenoxy group and a naphthyloxy group. Examples of the siloxy group include trimethylsiloxy, triethylsiloxy, triisopropylsiloxy, tert-butyldimethylsiloxy and the like. Examples of the dialkylamino group include dimethylamino and diethylamino.

  The number of substituents of the saturated hydrocarbon group that may be substituted is not particularly limited.

Regarding R ⁷ , R ⁸ , and R ⁹ , the aryl group of the aryl group which may be substituted is not particularly limited, and examples thereof include an aryl group having 6 to 14 carbon atoms. Examples of the aryl group having 6 to 14 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, biphenylyl, anthryl and the like. The substituent of the aryl group which may be substituted is not particularly limited, and for example, an alkyl group having 1 to 6 carbon atoms, a perfluoroalkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 14 carbon atoms, Examples thereof include a 5- to 10-membered aromatic heterocyclic group, an alkoxy group, an aryloxy group, a siloxy group, and a dialkylamino group.

  Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl and the like. Examples of the C1-6 perfluoroalkyl group include trifluoromethyl, pentafluoroethyl, heptafluoropropyl, tridecafluorohexyl and the like. Examples of the aryl group having 6 to 14 carbon atoms include phenyl, 1-naphthyl, 2-naphthyl, biphenylyl, 2-anthryl and the like.

  Examples of the 5- to 10-membered aromatic heterocyclic group include 2- or 3-thienyl, 2-, 3- or 4-pyridyl, 2-, 3-, 4-, 5- or 8-quinolyl, 1-, Examples include 3-, 4- or 5-isoquinolyl, 1-, 2- or 3-indolyl, 2-benzothiazolyl, 2-benzo [b] thienyl, benzo [b] furanyl and the like. The alkoxy group, aryloxy group, siloxy group and dialkylamino group are the same as the alkoxy group, aryloxy group, siloxy group and dialkylamino group described as the substituent of the saturated hydrocarbon group.

  The substitution position and number of substituents of the aryl group which may be substituted are not particularly limited.

With respect to R ⁷ , R ⁸ and R ⁹ , the heteroaryl group of the optionally substituted heteroaryl group is not particularly limited, and for example, an atom selected from the group consisting of a sulfur atom, an oxygen atom and a nitrogen atom A 5- to 14-membered aromatic heterocyclic group optionally containing 1 to 3 rings is exemplified. Examples of the aromatic heterocyclic group include furyl, thienyl, pyrrolyl, pyrazolyl, imidazolyl, oxazolyl, isoxazolyl, isothiazolyl, thiazolyl, 1,2,3-oxadiazolyl, triazolyl, tetrazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolyl , Indazolyl, purinyl, quinolyl, isoquinolyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinolinyl, pteridinyl, carbazolyl, carbolinyl, phenanthridinyl, acridinyl and the like.

  The substituent of the heteroaryl group which may be substituted is the same as the substituent described for the aryl group which may be substituted.

Regarding R ⁷ , R ⁸ , and R ⁹ , examples of the aralkyl group of the aralkyl group that may be substituted include a benzyl group, a phenethyl group, and a phenylpropyl group. The substituent of the aralkyl group which may be substituted is the same as the substituent described for the aryl group which may be substituted. The position of the substituent of the aralkyl group which may be substituted and the number of substituents are not particularly limited.

Regarding R ⁷ , R ⁸ , and R ⁹ , the C 1-20 perfluoroalkyl group may be linear, branched, or cyclic. For example, trifluoromethyl, pentafluoroethyl, heptafluoropropyl, pentafluorocyclopropyl, heptafluoroisopropyl, nonafluorobutyl, nonafluoroisobutyl, heptafluorocyclobutyl, undecafluoropentyl, undecafluoroisopentyl, nonafluorocyclopentyl , Tridecafluorohexyl, tridecafluoroisohexyl, undecafluorocyclohexyl, pentadecafluoroheptyl, heptadecafluorooctyl, nonadecafluorononyl, henicosafluorodecyl, tricosafluoroundecyl, pentacosafluorododecyl, hepta Examples include a cosafluorotridecyl group.

In particular, as the β-diketonato ligand, R ⁷ and R ⁹ may be the same or different from each other and may be substituted with a C 1-20 saturated hydrocarbon group, an optionally substituted aryl group, a substituted Preferred is a heteroaryl group, a perfluoroalkyl group having 1 to 20 carbon atoms, and a β-diketonato ligand in which R ⁸ is a hydrogen atom, a deuterium atom or a halogen atom, and R ⁷ and R ⁹ There mutually same or different substituted carbon atoms and optionally 1 to 20 saturated hydrocarbon group, an aryl group which may be substituted, a pair fluoroalkyl group having 1 to 20 carbon atoms, R ⁸ is hydrogen A β-diketonato ligand which is an atom or a deuterium atom is more preferable.

E. Production method of β-diketonato rare earth complex β-diketonato rare earth complex is a known route below, CSSSpringer, etal., InorgChem., 1967,6,
1105., RESievers, etal., Advan. Chemser., 1968, 71, 141.

In addition, said (beta) -diketone can be manufactured using the following well-known route | root, Claisen condensation reaction, etc.

F. Method for producing rare earth complex having tetraphosphine tetraoxide ligand and β-diketonato ligand As a method for producing rare earth complex having tetraphosphine tetraoxide ligand and β-diketonato ligand,
(1) A method of reacting at least one kind selected from rare earth metal ions and rare earth metal salts, β-diketone, base, and tetraphosphine tetraoxide in a solvent, (2) β-diketonato rare earth complex and tetraphosphine tetra The method of making an oxide react in a solvent is mentioned.

  In the case of the method (1), the rare earth metal ions include the ions of the rare earth metal atoms described above. Examples of rare earth metal salts include rare earth metal halides, rare earth metal nitrates, rare earth metal carboxylates, rare earth metal alkoxides, rare earth metal aryloxides, and the like. Although there is no restriction | limiting in particular as (beta) -diketone, General formula (2 ') can be used.

  As the base, sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide and the like can be used. Examples of the solvent include DMF, DMSO, methanol, ethanol water, and the like.

  The method (2) is preferable because a β-diketonato rare earth complex containing a tetraphosphine tetraoxide ligand having a clear composition can be synthesized with high yield. As the β-diketonato rare earth complex, commercially available products or those synthesized by the above-mentioned method can be used.

  The charge molar ratio of tetraphosphine tetraoxide and β-diketonato rare earth complex is not particularly limited, but it is preferable to react 1 to 3 mol of β-diketonato rare earth complex with respect to 1 mol of tetraphosphine tetraoxide. More preferably, the β-diketonato rare earth complex is 1.5 to 2.5 moles per mole of tetraphosphine tetraoxide, and most preferably 2 moles of the β-diketonato rare earth complex per mole of tetraphosphine tetraoxide. .

  Examples of the solvent include halogen solvents such as chloroform and dichloromethane; ketone solvents such as acetone and methyl isobutyl ketone; aromatic solvents such as toluene, xylene and nitrobenzene; alcohols such as methanol, ethanol, propanol, isopropanol and octanol. System solvent; water and the like. These solvents can be used singly or as a mixed solvent of two or more. Of these solvents, halogen solvents and aromatic solvents are particularly preferable.

The reaction format may be either batch type or continuous type. The reaction pressure is not particularly limited, and may usually be about normal pressure to about 100 kg / cm ² . The reaction temperature may be appropriately set, but is usually about -20 to 200 ° C, preferably 20 to 150 ° C. For example, when reacting at normal pressure, the range of 20 ° C. to the reflux temperature of the solvent is preferred. The reaction time is not particularly limited and may be appropriately set according to the reaction temperature and the like, but is usually about 15 minutes to 24 hours, preferably about 30 minutes to 12 hours.

  You may refine | purify by a well-known purification method as needed after reaction. Examples of known purification methods include recrystallization and column chromatography.

Embodiment 2
The second embodiment of the present invention is a fluorescent medium including the rare earth complex according to the first embodiment of the present invention described above. That is, the rare earth complex according to the first embodiment has a feature of high saturation solubility in a medium such as a solvent or a polymer. For this reason, for example, by dissolving in a polymer, it is possible to realize a fluorescent medium that is colorless and transparent under indoor light and emits strong light under ultraviolet light or near ultraviolet light.

  Such a fluorescent medium can be used for various ornaments and security methods. In particular, in the security method, by creating a fluorescent medium in which a rare earth complex is dissolved in a polymer, etc., and applying it to a security card to create a barcode, etc., it is completely colorless under visible light, It can be a security medium that emits strong light by ultraviolet rays. According to such a security method, it is difficult to know even the presence of a barcode under visible light, so higher security can be realized.

Embodiment 3
The third embodiment of the present invention is a near-ultraviolet red LED element including the fluorescent medium according to the second embodiment of the present invention. Since the fluorescent medium according to the second embodiment obtained by dissolving the rare earth complex according to the first embodiment in a polymer or the like is excellent in durability and light emission intensity, a light emitting element such as an LED element or an organic EL element. Can be applied to. An example of such a light emitting element is a near ultraviolet light emitting red LED element, and a cross-sectional view thereof is as shown in FIG.

  In the red LED element shown in FIG. 1, a fluorescent layer 5 in which a fluorescent rare earth complex 3 according to this embodiment is dispersed in a matrix polymer 4 is disposed on an LED chip 2 accommodated in a container 1. . With such a configuration, the fluorescent rare earth complex 3 emits light by the light from the LED chip 2. Furthermore, a white LED can also be configured in combination with another fluorescent layer.

  In such a light emitting element, it is preferable to use a fluorine-based resin as a resin constituting the fluorescent layer. This is because there are few C—H bonds and O—H bonds contained in the resin. Accordingly, a resin having a high fluorination rate is more preferable, but it is appropriately selected according to conditions such as solubility or dispersibility of the fluorescent rare earth complex and other components used. As resin which can be used, Cefral Coat FG700X, A402B, A610X manufactured by Central Glass Co., Ltd., Lumiflon manufactured by Asahi Glass Co., Ltd., ZEONOR manufactured by Nippon Zeon Co., Ltd., KYNAR, KYNARFLEX manufactured by Nihon Paint Co., Ltd., and Duflon manufactured by Nippon Paint Co., Ltd. Dyneon THV 220, 310, and 415 (each trade name).

In addition to the fluorescent rare earth complex according to the present embodiment, the fluorescent layer includes a YAG phosphor, an alkaline earth metal silicate phosphor, an alkaline earth metal phosphate phosphor, a halophosphate phosphor, BAM: Eu, Mn, BAM: Eu, ZnS, SrGa ₂ S ₄ : Eu, Oxynitride: Eu, SrAlO ₄ : Eu, Alkaline earth apatite: Eu, Ca apatite: Eu, Mn, CaS: Ce, Y2SiO ₅ : Tb, Sr ₂ P ₂ O ₇ : Eu, Mn, SrAl ₂ O ₄ : Eu, and the like can be used, and some of them can be combined to realize white light emission.

Embodiment 4
The fourth embodiment of the present invention is an organic electroluminescence device using the rare earth complex according to the first embodiment of the present invention described above. In this case, the rare earth complex is used as a dopant in the light emitting layer. Here, the host material of the light emitting layer is not particularly limited, but is preferably at least one selected from the group consisting of aromatic amine derivatives, carbazole derivatives, and thiophene oligomers and polymers.

  An example of the configuration of the organic electroluminescence element according to this embodiment is, for example, shown in FIG. That is, the organic electroluminescence element shown in FIG. 2 is configured by laminating the anode 12, the light emitting layer 13, the electron transport layer 14, and the cathode 15 on the glass substrate 11. In addition to these layers, a hole transport layer, a hole injection layer, a hole blocking layer, and the like can be appropriately disposed in the organic electroluminescence element.

  The anode 16 of the organic electroluminescence element according to this embodiment can be formed of, for example, gold, copper iodide, bell oxide, indium tin oxide (ITO), or the like. The cathode 15 can be formed of a metal of Group 1 or 2 of the periodic table such as sodium, lithium, magnesium, or calcium, or a metal of Group 3 of the periodic table such as gallium or indium.

  The light emitting layer 13 can be configured by dispersing the rare earth complex according to the first embodiment of the present invention as a dopant in a hole transport material. Examples of the hole transport material include arylamine derivatives, carbazole derivatives, thiophene oligomers or polymers, and copper phthalocyanine. As a dopant, in addition to the rare earth complex according to the first embodiment, in addition to Alq3 as an Al oxine complex, a perylene compound, a naphthalene compound, a coumarin compound, an oxadiazole compound, an aldazine compound, a bisbenzo A xazoline compound, a bisstyryl compound, a pyrazine compound, a CPD compound, an In oxine complex, a Zn complex, a Fe oxine complex, or a Ga imine complex can also be used.

  The electron transport layer 14 can be composed of an electron transport material such as a metal chelate compound containing Alq3, benzoxador, benzothiazole, tris (8-hydroxyquinolinol) bismuth, and a perylene compound.

  Further, the material used for the hole blocking layer needs to be a material having a high ionization potential and a low hole mobility, and includes a triazole compound and a derivative thereof.

  The LED element and the organic EL element described above can be used for a lighting device, but can also be applied to a flash device using a short light emission lifetime. In particular, LED light-emitting elements are useful as flashes for camera-equipped mobile phones because they use elements that consume less electrical energy.

  FIG. 3 and FIG. 4 are conceptual diagrams of a camera and a camera-equipped mobile phone that include the LED light emitting device according to the third embodiment of the present invention as a flash. The camera shown in FIG. 3 includes a flash 20, a lens 21, and a shutter button 22 as in a normal camera. The camera-equipped mobile phone shown in FIG. 4 includes a flash 30, a lens 31, and a shutter button (not shown), as in a normal camera-equipped mobile phone. The difference from the conventional camera and camera-equipped mobile phone is that the flashes 20 and 30 are LED light emitting devices according to the third embodiment of the present invention, which have excellent color rendering properties and a long lifetime.

  Examples of the present invention are shown below, but the present invention is not limited to these examples.

  Prior to the description of the examples, production examples of tetraphosphine tetraoxide ligands and β-diketonato rare earth complexes used in the examples will be described.

Production Example 1
<Synthesis of tetraphosphine tetraoxide ligand (1-A)>
Under a nitrogen atmosphere, 3.3 g (0.136 mol) of magnesium and 5 g of THF were charged into a 200 mL capacity four-necked flask equipped with a stirrer, a thermometer and a cooler, and 4-bromo-1-butene was added while stirring. A solution prepared by dissolving 0 g (0.133 mol) in 50.0 g of THF was added by about 1/30 of the total amount and heated to 65 ° C. Thereafter, the remaining solution was dropped at 65 ° C. to 70 ° C. over 1 hour, followed by stirring for 3 hours under heating to reflux to prepare a Grignard reactant. The obtained Grignard reactant was transferred to a 100 ml dropping funnel under a nitrogen atmosphere.

  Next, under a nitrogen atmosphere, a solution prepared by dissolving 6.4 g (0.042 mol) of phosphorus oxychloride in 25.0 g of THF in a 200 mL four-necked flask equipped with a separately prepared stirrer, thermometer, and cooler. The internal temperature was cooled to 5 ° C. While maintaining the internal temperature of the flask in the range of 5 to 25 ° C., the Grignard reactant is added dropwise over 1 hour and stirred at 25 ° C. for 2 hours, thereby containing tris (3-butenyl) phosphine oxide. A reaction solution was obtained.

  Next, 90 g of water and 0.4 g of sulfuric acid were added to a four-necked flask having a capacity of 300 mL equipped with a stirrer, a thermometer, and a cooler, and the mixed solution was added dropwise while stirring. Then, the solvent in the flask was concentrated at normal pressure by heating the flask until the internal temperature reached 90 ° C.

  Then, after adding toluene 100g to the said flask and isolate | separating into an organic layer and an aqueous layer, the organic layer was further wash | cleaned with 5% sodium hydrogen carbonate solution, it was made to dry with magnesium sulfate, and the organic layer was concentrate | evaporated under reduced pressure.

6.7 g (0.031 mol) of tris (3-butenyl) phosphine oxide was obtained by subjecting the obtained concentrate to distillation under reduced pressure (pressure 267 Pa, oven temperature 170 to 180 ° C.) using a Kugelrohr distillation apparatus. The yield was 75%.

  Subsequently, 1.83 g (8.62 mmol) of tris (3-butenyl) phosphine oxide and 5.23 g of diphenylphosphine oxide were placed in a four-necked flask having a capacity of 100 mL equipped with a stirrer, a thermometer, and a condenser under a nitrogen atmosphere. (25.9 mmol), AIBN 0.71 g (4.3 mmol), and toluene 20 g were added, and the flask was heated to an internal temperature of 75 ° C. and stirred at the same temperature for 24 hours. The flask was then cooled to 30 ° C. with stirring, concentrated under reduced pressure, purified by silica gel column chromatography (eluent: hexane, ethyl acetate), and 3.64 g of tetraphosphine tetraoxide (1-A) (4. 45 mmol) was obtained. The yield was 52%. The spectral data of the compounds are shown in Tables 1 to 3 below together with the description of the production process.

Production Example 2
<Synthesis of tetraphosphine tetraoxide ligand (1-B to 1-G)>
In the same manner as in Production Example 1, tetraphosphine tetraoxide (1-B to 1-G) in which the number of carbon chains and the substituent of the aryl group were changed was synthesized. The results are shown in Tables 1 to 3 below.

Production Example 3
<Synthesis of β-diketonato rare earth complex (2-A)>
Under a nitrogen atmosphere, in a four-necked flask with a capacity of 300 mL equipped with a stirrer, a thermometer and a condenser, 25.0 g (0.147 mol) of 2-acetonaphthone and 40.0 g (0.175 mol) of methylheptafluoroprobutylate Then, 110 g of diethyl ether was charged and stirred to dissolve the raw materials. Subsequently, 15.9 g (0.294 mol) of sodium methoxide was added and stirred at room temperature for 40 hours.

  Next, 80 g of water was added to a 500 mL four-necked flask equipped with a separately prepared stirrer, thermometer and cooler, and the reaction solution was added dropwise with stirring, followed by stirring for 15 minutes. The organic layer and the aqueous layer were separated, the organic layer was dried over magnesium sulfate, and the organic layer was concentrated under reduced pressure. The resulting concentrate was purified by silica gel column chromatography (eluent: hexane, ethyl acetate), and 4,4,5,5,6,6,6-heptafluoro-1- (2), which is a β-diketone compound. -Naphthyl) -1,3-hexadione (42.2 g) was obtained. The yield was 78%. The spectrum data is shown below.

¹ H-NMR (CDCl ₃ , TMS, 600 MHz, ppm) δ: 8.54 (s, 1 H), 7.99 (d, J = 8.1 Hz, 1 H), 7.95 (s, 2 H),
7.91 (d, J = 8.1Hz), 7.65 (dd, J = 7.3, 7.3Hz, 1H), 7.61 (dd, J = 7.3, 7.3Hz, 1H).
IR (KBr, cm ^-1 ) 3064,1602,1589,134,1271,1230,1195,1126.
MS (EI) m / Z = 366 (M).
Next, the 4,4,5,5,6,6,6-heptafluoro-1 (2-naphthyl) obtained above was added to a 300 mL four-necked flask equipped with a stirrer, a thermometer and a condenser. -1,3-hexadione 25.7 g (0.070 mol) and methanol 150 g were charged and stirred to dissolve the raw materials. Subsequently, 17.6 g (0.070 mol) of 4M aqueous sodium hydroxide solution was added dropwise with stirring, and the mixture was stirred at room temperature for 2 hours.

  Thereafter, europium nitrate pentahydrate 10.0 g (0.023 mol) and methanol 40 g were charged into a 500 mL four-necked flask equipped with a stirrer, a thermometer, and a cooler separately prepared and stirred. Subsequently, the reaction solution was added dropwise over 15 minutes with stirring, and the mixture was stirred at room temperature for 1 hour.

  Next, 3000 g of water was charged into a 3 L four-necked flask equipped with a separately prepared stirrer, thermometer and cooler, and the reaction solution was added dropwise over 1 hour with stirring, followed by stirring at room temperature for 3 hours. . The resulting precipitate was filtered, washed with water, and dried under reduced pressure to give β-diketonato rare earth complex (2-A), that is, tris (4,4,5,5,6,6,6-heptafluoro-1 26.4 g of (2-naphthyl) -1,3-hexadionato) europium (III) were obtained. The yield was 91%. The spectrum data is shown below.

IR (KBr, cm- ¹ ) 3060,1610,1593,1569,1525,1458,1344,1284,1234,1199,1182,1114.
Example 1
<Synthesis of Complex Composed of Tetraphosphine Tetraoxide Ligand (1-A) and β-Diketonato Rare Earth Complex (2-A), Measurement of Saturation Solubility, Luminous Intensity, and Durability of the Complex>
Under a nitrogen atmosphere, tetraphosphine tetraoxide (1-A) 0.41 g (0.50 mmol), β-diketonato rare earth complex (2-A) was added to a 100 mL four-necked flask equipped with a stirrer, a thermometer and a condenser. ) 1.25 g (1.00 mmol) and 30 g of chloroform were charged, heated with stirring, and reacted for 4 hours under heating to reflux. The mixture was cooled to 30 ° C. with stirring, transferred to an eggplant type flask, and concentrated under reduced pressure with an evaporator. Then, it dried under reduced pressure with the vacuum pump.

  By the above method, a rare earth complex in which one tetraphosphine tetraoxide ligand is coordinated to two Eu atoms as shown in the following formula (11) was synthesized (yield 1.65 g, yield). 99%). The saturation solubility at room temperature of the obtained fluorine-based solvent VertrelXF (Mitsui DuPont) of the complex was measured and compared with the compound of Comparative Example 1 described later. The relative values of the saturation solubility are shown in Table 4 below. In addition, the fluorescence spectrum at room temperature in the same solvent was measured, and the emission intensity at the maximum emission wavelength was compared with the compound of Comparative Example 1. The relative values of the emission intensity are shown in Table 4 below.

In addition, it is dispersed in a fluoropolymer (Cefal 220: manufactured by Central Glass Co., Ltd.), left in an atmosphere at a temperature of 85 ° C. and a humidity of 85%, and the time until the initial emission intensity reaches 70% is used as a measure of durability. Compared with. The relative values of durability are shown in Table 4 below.

Example 2
In the same manner as in Example 1, using tetraphosphine oxide ligand (1-B) and β-diketonato rare earth complex (2-A), two Eu atoms as shown in the following formula (12) A rare earth complex in which one tetraphosphine tetraoxide ligand is coordinated was synthesized. Table 4 below shows the measurement results of the saturation solubility, fluorescence intensity, and durability of the obtained complex.

Example 3
Tris (1,1,1,2,2,3,3-heptafluoro-7, tetraphosphine tetraoxide ligand (1-C), β-diketonato rare earth complex in the same manner as in Example 1 7-dimethyl-4,6-octanedionate) europium (III) (manufactured by Aldrich), tetraphosphine tetraoxide ligand for two Eu atoms as shown in the following formula (13) A rare earth complex with a single coordination was synthesized. Table 4 below shows the measurement results of the saturation solubility, fluorescence intensity, and durability of the obtained complex.

Example 4
Tris (1,1,1,2,2,3,3-heptafluoro-7, tetraphosphine tetraoxide ligand (1-D) and β-diketonato rare earth complex were prepared in the same manner as in Example 1. 7-dimethyl-4,6-octanedionate) europium (III) (manufactured by Aldrich), tetraphosphine tetraoxide ligand for two Eu atoms as shown in the following formula (14) A rare earth complex with a single coordination was synthesized. The saturated solubility, fluorescence intensity, and durability results of the obtained complex are shown in Table 4 below.

Example 5
Using the tetraphosphine tetraoxide ligand (1-C) and the β-diketonato rare earth complex (2-A) in the same manner as in Example 1, two Eu atoms as shown in the following formula (15) are used. We synthesized a rare earth complex in which one tetraphosphine tetraoxide ligand was coordinated. The saturated solubility, fluorescence intensity, and durability results of the obtained complex are shown in Table 4 below.

Example 6
Using the tetraphosphine tetraoxide ligand (1-D) and the β-diketonato rare earth complex (2-A) in the same manner as in Example 1, two Eu atoms as shown in the following formula (16) are used. We synthesized a rare earth complex in which one tetraphosphine tetraoxide ligand was coordinated. The saturated solubility, fluorescence intensity, and durability results of the obtained complex are shown in Table 4 below.

Example 7
In the same manner as in Example 1, tris (1,1,1,2,2,3,3-heptafluoro-7, tetraphosphine tetraoxide ligand (1-E), β-diketonato rare earth complex, 7-dimethyl-4,6-octanedionate) europium (III) (manufactured by Aldrich), tetraphosphine tetraoxide ligand for two Eu atoms as shown in the following formula (17) A rare earth complex with a single coordination was synthesized. The saturated solubility, fluorescence intensity, and durability results of the obtained complex are shown in Table 4 below.

Example 8
Using the tetraphosphine tetraoxide ligand (1-E) and the β-diketonato rare earth complex (2-A) in the same manner as in Example 1, two Eu atoms as shown in the following formula (18) are used. We synthesized a rare earth complex in which one tetraphosphine tetraoxide ligand was coordinated. Table 4 shows the saturation solubility, fluorescence intensity, and durability results of the obtained complex.

Example 9
In the same manner as in Example 1, tris (1,1,1,2,2,3,3-heptafluoro-7, tetraphosphinetetraoxide ligand (1-F), β-diketonato rare earth complex, 7-dimethyl-4,6-octanedionate) europium (III) (manufactured by Aldrich) using tetraphosphine tetraoxide ligand for two Eu atoms as shown in the following formula (19) A rare earth complex with a single coordination was synthesized. The saturated solubility, fluorescence intensity, and durability results of the obtained complex are shown in Table 4 below.

Example 10
Using the tetraphosphine tetraoxide ligand (1-F) and β-diketonato rare earth complex (2-A) in the same manner as in Example 1, two Eu atoms as shown in the following formula (20) are used. We synthesized a rare earth complex in which one tetraphosphine tetraoxide ligand was coordinated. The saturated solubility, fluorescence intensity, and durability results of the obtained complex are shown in Table 4 below.

Example 11
In the same manner as in Example 1, tris (1,1,1,2,2,3,3-heptafluoro-7, tetraphosphine tetraoxide ligand (1-G), β-diketonato rare earth complex, 7-dimethyl-4,6-octanedionate) europium (III) (manufactured by Aldrich), tetraphosphine tetraoxide ligand for two Eu atoms as shown in the following formula (21) A rare earth complex with a single coordination was synthesized. The saturated solubility, fluorescence intensity, and durability results of the obtained complex are shown in Table 4 below.

Example 12
In the same manner as in Example 1, using tetraphosphine tetraoxide ligand (1-G) and β-diketonato rare earth complex (2-A), two Eu atoms as shown in the following formula (22) are used. We synthesized a rare earth complex in which one tetraphosphine tetraoxide ligand was coordinated. The saturated solubility, fluorescence intensity, and durability results of the obtained complex are shown in Table 4 below.

Comparative Example 1
In the same manner as in Example 1, the number of oxygen atoms of phosphine oxide coordinated to Eu atoms was combined to obtain tris (1,1,1,2,2,3,3-heptafluoro-7 as a β-diketonato rare earth complex. , 7-dimethyl-4,6-octanedionate) Europium (III) (made by Aldrich) is reacted with 2 mol of triphenylphosphine oxide (made by Aldrich) instead of tetraphosphine tetraoxide. A rare earth complex as shown in the following formula (23) was obtained.

Example 13
Tris (2,2,6,6-tetramethyl-3,5-heptanedionate) terbium as a tetraphosphine oxide ligand (1-A) and a β-diketonato rare earth complex in the same manner as in Example 1. Using (III) (Aldrich), a rare earth complex in which one tetraphosphine tetraoxide ligand is coordinated to two Tb atoms as shown in the following formula (24) was synthesized. . The saturated solubility, fluorescence intensity, and durability results of the obtained complex are shown in Table 4 below.

The saturated solubility, fluorescence intensity, and durability of the obtained complex are compared with the compound of Comparative Example 2 in the same manner as in Example 1, and are shown in Table 4 below as relative values.

Example 14
Tris (2,2,6,6-tetramethyl-3,5-heptanedionate) terbium as a tetraphosphine oxide ligand (1-B) and a β-diketonato rare earth complex in the same manner as in Example 1. Using (III) (Aldrich), a rare earth complex in which one tetraphosphine tetraoxide ligand is coordinated to two Tb atoms as shown in the following formula (25) was synthesized. . The saturated solubility, fluorescence intensity, and durability results of the obtained complex are shown in Table 4 below.

Comparative Example 2
As in Example 1, triphenylphosphine oxide as the phosphine oxide ligand, tris (1,1,1,5,5,5-hexafluoro-2,4-pentanedionate as the β-diketonato rare earth complex ) Terbium (III) (Aldrich) was used to obtain a rare earth complex as shown in the following formula (26).

The results of Examples 1 to 14 and Comparative Examples 1 and 2 are shown in Table 4 below.

  * 1: Relative value at room temperature in fluorinated solvent Vertrel XF (Mitsui DuPont). Examples 1 to 12 are based on the value of Comparative Example 1, and Examples 13 and 14 are based on the value of Comparative Example 2.

  * 2: Relative intensity at the maximum emission wavelength at room temperature in the fluorinated solvent Vertrel XF.

  * 3: Relative value of the time required to reach 70% of the initial emission intensity when dispersed in a fluoropolymer and left in an atmosphere of 85 ° C. and 85% humidity.

  From Table 4 above, the following can be understood.

  Although the saturation solubility of the rare earth complexes obtained in Examples 1 to 14 is greatly improved as a whole as compared with the rare earth complexes obtained in Comparative Examples 1 and 2, the following tendencies are shown in the examples. There is. That is, compared to the rare earth complexes according to Examples 1 and 2 in which the phosphine oxide is represented by unsubstituted Formulas (11) and (12), Example 3 represented by Formulas (13) to (22) The rare earth complex according to No. 12 shows an improvement effect by substitution. Among them, rare earth complexes having a phosphine oxide ligand having a trifluoromethyl group introduced therein (formulas (13), (15), (17), (18), (19), (20), (21), (21 22)) tends to have a large effect of improving the saturation solubility.

  Regarding the emission intensity, the rare earth complexes obtained in Examples 1 to 14 are remarkably improved as compared with the rare earth complexes obtained in Comparative Examples 1 and 2, but the following tendencies among the examples are as follows. . That is, in the rare earth complexes having a naphthyl group in the β-diketone ligand (formulas (11), (12), (15), (16), (18), (20), (22)), the substituent is The emission intensity is higher than that of rare earth complexes (formulas (13), (14), (17), (19), (21)) consisting only of a fattic substituent.

  As for durability, compared with the rare earth complexes obtained in Comparative Examples 1 and 2, the rare earth complexes obtained in Examples 1 to 14 are observed to be improved by dinucleation. There is a tendency. That is, the dominant factor of durability is a substituent connected to the β diketone, and the rare earth complex (formulas (13), (14), (17), (19), (21)) is more durable than rare earth complexes having a naphthyl group in the β-diketone ligand (formulas (11), (12), (15), (16), (18), (20), (22)) Excellent in properties.

Example 15
A fluorescent layer made of a fluorescent polymer in which 20 wt% of the europium complex synthesized in Example 1 is dissolved in Cephral 220 (manufactured by Central Glass Co., Ltd.), which is a fluorine-based polymer, is placed on an LED chip having an emission center wavelength of 402 nm. An LED element having the structure shown in FIG.

  When a current of 20 mA was passed through this LED element, a luminous intensity of about 300 mcd was obtained, and no decrease in luminous intensity was observed even after 200 hours of continuous lighting.

Example 16
A fluorescent layer made of a fluorescent polymer in which 20 wt% of the europium complex synthesized in Example 2 is dissolved in cephalal 220 (manufactured by Central Glass Co., Ltd.), which is a fluorine-based polymer, is disposed on an LED chip having an emission center wavelength of 402 nm. An LED element having the structure shown in FIG.

  When a current of 20 mA was passed through the LED element, a luminous intensity of about 280 mcd was obtained, and no decrease in luminous intensity was observed even after 200 hours of continuous lighting.

Example 17
A fluorescent layer composed of a fluorescent polymer obtained by dissolving 20 wt% of the terbium complex synthesized in Example 3 in Cefluor 220 (manufactured by Central Glass Co., Ltd.), which is a fluorine-based polymer, is disposed on an LED chip having an emission center wavelength of 385 nm. An LED element having the structure shown in FIG.

  When a current of 20 mA was passed through this LED element, a luminous intensity of about 220 mcd was obtained, and no decrease in luminous intensity was observed even after 200 hours of continuous lighting.

Example 18
A fluorescent layer composed of a fluorescent polymer obtained by dissolving 20 wt% of the terbium complex synthesized in Example 3 in Cefluor 220 (manufactured by Central Glass Co., Ltd.), which is a fluorine-based polymer, is disposed on an LED chip having an emission center wavelength of 385 nm. An LED element having the structure shown in FIG.

  When a current of 20 mA was passed through this LED element, a luminous intensity of about 200 mcd was obtained, and no decrease in luminous intensity was observed even after 200 hours of continuous lighting.

Comparative Example 3
An LED element similar to that of Example 15 was prototyped except that the compound synthesized in Comparative Example 1 was used as the europium complex. When a current of 20 mA was passed through this LED element, only a small luminous intensity of 120 mcd was obtained, and no decrease in luminous intensity was observed even after 200 hours of continuous lighting.

Comparative Example 4
An LED element similar to that of Example 15 was prototyped except that the compound synthesized in Comparative Example 2 was used as the terbium complex. When a current of 20 mA was passed through the LED element, only a very small luminous intensity of 114 mcd was obtained.

Example 19
The light-emitting layer has a structure represented by the formula (10) in which the phosphor represented by the formula (3) synthesized in Example 1 is a guest, the compound represented by the formula (9) is a host, and the electron transport layer is represented by the formula (10). An electroluminescence element was produced. By applying a voltage of 12 V between the electrodes, a luminance (brightness) of 200 cd / m 2 was obtained.

Comparative Example 5
An electroluminescent device identical to that of Example 8 was made experimentally except that the guest material of the fluorescent layer was changed to the compound shown in Comparative Example 1 Formula (7). The luminance under the same conditions was as weak as 100 cd / m2.

Example 20
A thin film was formed by dissolving 20 wt% of the phosphor represented by formula (3) in Cefral 220 (Central Glass Co., Ltd.). Although it was not visible under room light, a maximum emission of 300 lm / m ² could be obtained by UV irradiation with a UV lamp.

（式中、ｍ、ｎ、ｏは、１以上の整数であり、Ｒ ^１ 〜Ｒ ^６ は、それぞれ同一又は異なる、置換されていてもよい飽和炭化水素基、置換されていてもよいアリール基、置換されていてもよいヘテロアリール基、又は置換されていてもよいアラルキル基を示し、同一リン原子上の隣り合うＲ ^１ 及びＲ ^２ 、またはＲ ^３ 及びＲ ^４ 、またはＲ ^５ 及びＲ ^６ が結合して環を形成していてもよい。）
［２］
複数の希土類イオンに、前記ホスフィンオキシド配位子と、下記式（２）により表されるβ−ジケトナト配位子とが配位していることを特徴とする項１に記載の希土類錯体。

（式中、Ｒ ^８ は、水素原子、重水素原子、ハロゲン原子、置換されていてもよい炭素数１〜２０の飽和炭化水素基、置換されていてもよいアリール基、置換されていてもよいヘテロアリール基、又は置換されていてもよいアラルキル基を示し、Ｒ ^７ 及びＲ ^９ は、それぞれ同一又は異なる、置換されていてもよい炭素数が１〜２０の飽和炭化水素基、炭素数１〜２０のペルフルオロアルキル基、置換されていてもよいアリール基、置換されていてもよいヘテロアリール基、又は置換されていてもよいアラルキル基を示す。）
［３］
金属原子１原子に対して前記β−ジケトナト配位子３分子が配位した下記式（３）により表される、同一又は異なるβ−ジケトナト希土類錯体２分子に、前記ホスフィンオキシド配位子１分子が配位していることを特徴とする項１又は２に記載の希土類錯体。

（式中、Ｒ ^８ 及びＲ ^１１ は、水素原子、重水素原子、ハロゲン原子、置換されていてもよい炭素数１〜２０の飽和炭化水素基、置換されていてもよいアリール基、置換されていてもよいヘテロアリール基、又は置換されていてもよいアラルキル基を示し、Ｒ ^７ 、Ｒ ^９ 、Ｒ ^１０ 、及びＲ ^１２ は、それぞれ同一又は異なる、置換されていてもよい炭素数が１〜２０の飽和炭化水素基、炭素数１〜２０のペルフルオロアルキル基、置換されていてもよいアリール基、置換されていてもよいヘテロアリール基、又は置換されていてもよいアラルキル基を示し、Ｌｎ(III) ^１ 、及びＬｎ(III) ^２ は、３価の希土類金属イオンを示す。）
［４］
前記希土類金属原子が、Ｅｕ(III)又はＴｂ(III)である項１〜３のいずれかに記載の希土類錯体。
［５］
前記式（１）において、Ｒ ^１ ないしＲ ^６ は、置換されていてもよいアリール基を示し、ｍ、ｎ、ｏは、３〜１２の整数を示すことを特徴とする項１〜４のいずれかに記載の希土類錯体。
［６］
前記式（１）において、Ｒ ^１ ないしＲ ^６ の少なくとも一つは、メタ位またはパラ位が置換されているフェニル基であることを特徴とする項１〜５のいずれかに記載の希土類錯体。
［７］
前記ホスフィンオキシド配位子が、式（４）により表されることを特徴とする項６に記載の希土類錯体。

（式中、ｍ、ｎ、ｏは、１以上の整数であり、Ｒ ^１３ 〜Ｒ ^１８ は、それぞれ同一又は異なる、アルキル基、フルオロアルキル基、アルコキシ基、または水素原子を表す。）
［８］
前記式（２）及び式（３）において、Ｒ ^７ とＲ ^９ の組合せ、及びＲ ^１０ とＲ ^１２ の組合せが互いに異なることを特徴とする項３〜７のいずれかに記載の希土類錯体。
［９］
前記式（２）及び式（３）において、Ｒ ^７ とＲ ^９ の組合せ、及びＲ ^１０ とＲ ^１２ の組合せは、一方が置換されていてもよいアリール基であり、他方がペルフルオロアルキル基であり、前記希土類金属はユーロピウムであることを特徴とする項３〜８のいずれかに記載の希土類錯体。
［１０］
前記式（２）及び（３）において、Ｒ ^７ 、Ｒ ^９ 、Ｒ ^１０ 及びＲ ^１２ がいずれも電子供与性基であり、前記希土類金属はテルビウムであることを特徴とする項３〜８のいずれかに記載の希土類錯体。
［１１］
項１〜１０のいずれかに記載の希土類錯体をポリマーに溶解してなることを特徴とする蛍光媒体。
［１２］
項１〜１０のいずれかに記載の希土類錯体を含む蛍光層を具備することを特徴とする発光素子。
［１３］
項１〜１０のいずれかに記載の希土類錯体をポリマーに溶解した溶液を基体に印刷してなることを特徴とするセキュリティー媒体。
［１４］
項１〜１０のいずれかに記載の希土類錯体を含む発光層を具備することを特徴とする照明装置。 Comparative Example 5
A thin film similar to Example 10 was formed using the phosphor represented by formula (7). Although there was no visibility under room light, slight light emission was confirmed by ultraviolet irradiation.
The invention described in the original claims is appended below.
[1]
A rare earth complex comprising a plurality of rare earth ions and a phosphine oxide ligand, wherein the phosphine oxide ligand has a molecular structure represented by the following formula (1).

(In the formula, m, n, and o are integers of 1 or more, and R ^{1 to} R ⁶ are the same or different, an optionally substituted saturated hydrocarbon group, an optionally substituted aryl group, An optionally substituted heteroaryl group or an optionally substituted aralkyl group, wherein adjacent R ¹ and R ² , or R ³ and R ⁴ , or R ⁵ and R ⁶ on the same phosphorus atom are bonded And may form a ring.)
[2]
Item 2. The rare earth complex according to item 1, wherein the phosphine oxide ligand and a β-diketonato ligand represented by the following formula (2) are coordinated to a plurality of rare earth ions.

(In the formula, R ⁸ is a hydrogen atom, a deuterium atom, a halogen atom, an optionally substituted saturated hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aryl group, or optionally substituted. A heteroaryl group, or an optionally substituted aralkyl group, wherein R ⁷ and R ⁹ are the same or different, an optionally substituted saturated hydrocarbon group having 1 to 20 carbon atoms, 20 perfluoroalkyl groups, an optionally substituted aryl group, an optionally substituted heteroaryl group, or an optionally substituted aralkyl group.
[3]
One molecule of the phosphine oxide ligand is added to two molecules of the same or different β-diketonato rare earth complexes represented by the following formula (3) in which three molecules of the β-diketonato ligand are coordinated to one metal atom. Item 3. The rare earth complex according to Item 1 or 2, wherein is coordinated.

(In the formula, R ⁸ and R ¹¹ are a hydrogen atom, a deuterium atom, a halogen atom, an optionally substituted saturated hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aryl group, or a substituted group. An optionally substituted heteroaryl group or an optionally substituted aralkyl group, wherein R ⁷ , R ⁹ , R ¹⁰ , and R ¹² are the same or different and each have 1 to 20 carbon atoms that may be substituted; A saturated hydrocarbon group, a C 1-20 perfluoroalkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, or an optionally substituted aralkyl group, Ln (III ) ¹ and Ln (III) ² represent trivalent rare earth metal ions.)
[4]
Item 4. The rare earth complex according to any one of Items 1 to 3, wherein the rare earth metal atom is Eu (III) or Tb (III).
[5]
In the formula (1), R ¹ to R ^{6 each} represents an optionally substituted aryl group, and m, n, and o each represent an integer of 3 to 12, The rare earth complex according to any one of the above.
[6]
Item ^6. The rare earth complex according to any one of Items 1 to 5, wherein in the formula (1), at least one of R ¹ to R ⁶ is a phenyl group substituted at a meta position or a para position.
[7]
Item 7. The rare earth complex according to Item 6, wherein the phosphine oxide ligand is represented by Formula (4).

(In the formula, m, n, and o are integers of 1 or more, and R ^{13 to} R ¹⁸ each represent the same or different alkyl group, fluoroalkyl group, alkoxy group, or hydrogen atom.)
[8]
Item 8. The rare earth complex according to any one of Items 3 to 7, wherein in the formulas (2) and (3), the combination of R ⁷ and R ^{9 and} the combination of R ¹⁰ and R ¹² are different from each other.
[9]
In the formulas (2) and (3), one of the combination of R ⁷ and R ^{9 and} the combination of R ¹⁰ and R ¹² is an aryl group which may be substituted, and the other is a perfluoroalkyl group. Item 9. The rare earth complex according to any one of Items 3 to 8, wherein the rare earth metal is europium.
[10]
Any one of Items 3 to 8, wherein in the formulas (2) and (3), R ⁷ , R ⁹ , R ¹⁰ and R ¹² are all electron donating groups, and the rare earth metal is terbium. The rare earth complex according to any one of the above.
[11]
Item 11. A fluorescent medium comprising the rare earth complex according to any one of Items 1 to 10 dissolved in a polymer.
[12]
Item 11. A light emitting device comprising a fluorescent layer containing the rare earth complex according to any one of Items 1 to 10.
[13]
Item 11. A security medium obtained by printing on a substrate a solution in which the rare earth complex according to any one of Items 1 to 10 is dissolved in a polymer.
[14]
Item 10. A lighting device comprising a light emitting layer containing the rare earth complex according to any one of Items 1 to 10.

  DESCRIPTION OF SYMBOLS 1 ... Fluorescence layer, 2 ... Near ultraviolet light emission LED chip, 3 ... Europium complex, 4 ... Matrix polymer, 11 ... Glass substrate, 12 ... ITO electrode (anode), 13 * ..Light emitting layer, 14... Electron transport layer, 15.

Claims (10)

A rare earth complex comprising a plurality of rare earth ions, a phosphine oxide ligand, and a β-diketonato ligand,
The phosphine oxide ligand, have a molecular structure represented by the following formula (1),
To the same or different β-diketonato rare earth complex represented by the following formula (3) in which three molecules of the β-diketonato ligand are coordinated to one metal atom, the phosphine oxide ligand 1 The molecule is coordinated,
The rare earth metal atoms, Eu (III) or Tb (III) a rare earth complex characterized by der Rukoto.

(Wherein, m, n, o are a 3 to 12 ^integer, R 1 to R ⁶ are the same or different, represents an aryl group which may have been substitution, adjacent on the same phosphorus atom R ¹ and R ² , R ³ and R ⁴ , or R ⁵ and R ⁶ may be bonded to form a ring.)

(In the formula, R ⁸ and R ¹¹ are a hydrogen atom, a deuterium atom, a halogen atom, an optionally substituted saturated hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aryl group, or a substituted group. An optionally substituted heteroaryl group or an optionally substituted aralkyl group, wherein R ⁷ , R ⁹ , R ¹⁰ , and R ¹² are the same or different and each have 1 to 20 carbon atoms that may be substituted; A saturated hydrocarbon group, a C 1-20 perfluoroalkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, or an optionally substituted aralkyl group, Ln (III ) ¹ and Ln (III) ² represent trivalent rare earth metal ions.) 2. The rare earth complex according to claim 1, wherein in the formula (1), at least one of R ¹ to R ⁶ is a phenyl group substituted at a meta position or a para position. The rare earth complex according to claim 2 , wherein the phosphine oxide ligand is represented by the following formula (4).

(In the formula, m, n, and o are integers of 3 to 12 , and R ^{13 to} R ¹⁸ each represent the same or different alkyl group, fluoroalkyl group, alkoxy group, or hydrogen atom.) Prior following formula (3), the combination of ^{R 7} and ^{R 9,} and ^{R 10} and a rare earth complex according to claim 1, the combination of ^{R 12} is different from each other. Prior following formula (3), the combination of the combination of R ⁷ and R ^9, and R ¹⁰ and R ¹² are, one is an aryl group which may be substituted and the other is a perfluoroalkyl group, the rare earth metal The rare earth complex according to any one of claims 1 to 4 , wherein is a europium. In the formula (3), the rare earth complex according to claim 1, wherein the pre-Symbol rare earth metal is terbium. Fluorescent medium characterized by a rare earth complex according to claim 1 obtained by dissolving the polymer. Emitting element characterized by comprising a fluorescent layer containing a rare earth complex according to any one of claims 1 to 6. A security medium, wherein a solution obtained by dissolving the rare earth complex according to any one of claims 1 to 6 in a polymer is printed on a substrate. Lighting apparatus characterized by comprising a light emitting layer containing a rare earth complex according to any one of claims 1 to 6.

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