Rare earth coordination polymers, methods for producing the same, phosphors using the same, security materials, light-emitting devices, image display devices, and radiation detectors.

Abstract

To provide rare-earth coordination polymers containing phosphine oxide ligands and diketone ligands, methods for producing the same, phosphors, security materials, light-emitting devices, image display devices, and radiation detectors using the same. [Solution] The rare earth coordination polymer of the present invention has a trivalent rare earth ion, a phosphine oxide ligand represented by formula (A), and a diketone ligand represented by formula (B), wherein one phosphine oxide ligand coordinates to two rare earth ions and bridges the two rare earth ions, and three diketone ligands coordinate to one rare earth ion.

Description

Technical Field

[0001] The present invention relates to a rare earth coordination polymer, a method for producing the same, a phosphor, a security material, a light-emitting device, an image display device, and a radiation detector using the same.

Background Art

[0002] Recently, rare earth compounds having organic ligands have been developed and are expected to be applied to various uses such as light-emitting devices, wavelength conversion materials, and security materials (for example, see Patent Document 1).

[0003] According to Patent Document 1, a rare earth compound which is a binuclear complex crystal containing two trivalent rare earth ions and two phosphine oxide ligands represented by the following formula, and in which the two rare earth ions are linked by the two phosphine oxide ligands coordinated to both of them, is developed and reported to function as a phosphor, a light-emitting device, a wavelength conversion material, and a security material.

[0004]

Chemical Formula

[0005] Here, C 1 、C 2 and C 3 represent carbon atoms, Ar represents a divalent monocyclic aromatic group or a condensed polycyclic aromatic group which may have substituents other than C 1 、C 2 and C 3 and may contain X 1 、X 1 represents a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms which may have substituents, an alkoxy group which may have substituents, an alkoxycarbonyl group which may have substituents, an alkanoyloxy group which may have substituents, an aryloxy group which may have substituents, an aryloxycarbonyl group which may have substituents, an arylcarbonyloxy group which may have substituents, a hydroxyl group, a carboxyl group or a cyano group, and R 1represents an aromatic group which may have substituents, or a linear or cyclic aliphatic group, and multiple Ar, X within the same molecule. 1 and R 1 These may be the same or different.

[0006] The rare earth compound of Patent Document 1 may further have a diketone ligand represented by the following formula.

[0007] [ka]

[0008] Here, R 2 R represents a hydrogen atom or a deuterium atom. 3 R represents a hydrocarbon group which may have substituents, 2 and R 3 They may be linked together to form a cyclic group. 2 They may be the same or different. 3 R may be an alkyl group or a halogenated alkyl group, and its carbon number may be 1 to 10. 3 This may be a fluoroalkyl group having 1 to 5 carbon atoms (for example, a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, or a perfluoropentyl group).

[0009] According to Patent Document 1, the rare earth compounds further containing the aforementioned diketone ligands have a high decomposition temperature exceeding 300°C and exhibit strong luminescence at high temperatures. However, for practical application, further thermal and light resistance is required, necessitating an increase in luminescence intensity at high temperatures. However, there are limitations to the thermal and light resistance of rare earth compounds, which are dinuclear complex crystals. Furthermore, the emergence of additional functions other than luminescence properties is also expected in rare earth compounds containing organic ligands. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] International Publication No. 2019 / 098286 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0011] The object of the present invention is to provide a rare-earth coordination polymer containing a phosphine oxide ligand and a diketone ligand, a method for producing the same, a phosphor using the same, a security material, a light-emitting device, an image display device, and a radiation detector. [Means for solving the problem]

[0012] The rare-earth coordination polymer according to the present invention comprises a trivalent rare-earth ion, a phosphine oxide ligand represented by formula (A), and a diketone ligand represented by formula (B). One phosphine oxide ligand coordinates to two of the rare-earth ions, bridging the two rare-earth ions, while three diketone ligands coordinate to one of the rare-earth ions, thereby solving the above problem. [ka] Here, in equation (A), C 1 , C 2 and C 3 represents a carbon atom, and Ar is C 1 , C 2 and C 3 Includes X 1 It represents a substituted or unsubstituted divalent monocyclic aromatic group or a fused polycyclic aromatic group other than X 1 R represents a halogen atom, a substituted or unsubstituted C1-C20 hydrocarbon group, a substituted or unsubstituted alkoxy group, an optionally substituted alkoxycarbonyl group, a substituted or unsubstituted alkanoyloxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted arylcarbonyloxy group, a hydroxyl group, a carboxyl group, or a cyano group. 1 This represents a substituted or unsubstituted aromatic group, or a linear or cyclic aliphatic group, and multiple Ar, X groups within the same molecule. 1and R 1 These may be the same or different. In equation (B), R 2 R represents a hydrogen atom or a deuterium atom. 3 and R 4 Each is selected from the group consisting of a monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 36 carbon atoms, and halogenated hydrocarbon groups thereof, R 3 and R 4 They are different from each other. The above rare-earth coordination polymer may have repeating units represented by formula (C). [ka] Here, M is the rare earth ion. The aforementioned R 3 and R 4 This may be selected from the group consisting of alkyl groups having 1 to 10 carbon atoms, aryl groups having 6 to 36 carbon atoms, and halogenated hydrocarbon groups thereof. The aforementioned R 3 The group is selected from -CF3, -(CF2)2-CF3, and -(C6H5), and the R 4 The group may be selected from the group consisting of -CF2-CF3, -C(CH3)3, -CHF2, and -CH2-CH3. The Ar may be a divalent aromatic group represented by formula (1), (2), or (3). [ka] Here, in equations (1) to (3), X 1 X in equation (A) 1 It is synonymous with multiple X 1 X can be the same or different. 2 X of the aromatic ring 1 This indicates a monovalent substituent bonded to a carbon atom other than the carbon atom to which it is bonded, n 1 n represents an integer between 0 and 2. 2 n represents an integer from 0 to 6, and n 3 This represents an integer from 0 to 9, and multiple X 2They may be the same or different, X 1 The atom adjacent to the bonded carbon atom and having a bond is the carbon atom C in formula (A). 1 That is the case. The rare earth ion may be an ion of at least one element selected from the group consisting of cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), terbium (Tb), dysprosium (Dy), gadolinium (Gd), erbium (Er), yttrium (Y), and ytterbium (Yb). The method for producing the above-mentioned rare-earth coordination polymer according to the present invention includes dissolving a phosphine oxide ligand represented by formula (A), a diketone ligand represented by formula (B), and an organic base in an organic solvent, dissolving a trivalent rare-earth salt in an alcohol, and mixing and refluxing the solution obtained by dissolving the phosphine oxide ligand, the diketone ligand, and the organic base in the organic solvent with the solution obtained by dissolving the trivalent rare-earth salt in the alcohol, thereby solving the above-mentioned problems. [ka] Here, in equation (A), C 1 , C 2 and C 3 represents a carbon atom, and Ar is C 1 , C 2 and C 3 Includes X 1 It represents a substituted or unsubstituted divalent monocyclic aromatic group or a fused polycyclic aromatic group other than X 1 R represents a halogen atom, a substituted or unsubstituted C1-C20 hydrocarbon group, a substituted or unsubstituted alkoxy group, an optionally substituted alkoxycarbonyl group, a substituted or unsubstituted alkanoyloxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted arylcarbonyloxy group, a hydroxyl group, a carboxyl group, or a cyano group. 1This represents a substituted or unsubstituted aromatic group, or a linear or cyclic aliphatic group, and multiple Ar, X groups within the same molecule. 1 and R 1 These may be the same or different. In equation (B), R 2 R represents a hydrogen atom or a deuterium atom. 3 and R 4 Each is selected from the group consisting of hydrocarbon groups having 1 to 10 carbon atoms, aromatic hydrocarbon groups having 6 to 36 carbon atoms, and halogenated hydrocarbon groups thereof, R 3 and R 4 They are different from each other. The trivalent rare earth salt may be selected from the group consisting of chlorides, sulfates, nitrates, and acetates of the trivalent rare earth ions. The organic base may be selected from the group consisting of triethylamine (TEA), trimethylamine, and ammonia, at least one of these. The phosphor according to the present invention contains the above-mentioned rare-earth coordination polymer, thereby solving the above-mentioned problems. The phosphor may emit fluorescence in response to light stimulation, radiation stimulation, or mechanical stimulation. The security material according to the present invention contains the above-mentioned rare-earth coordination polymer, thereby solving the above-mentioned problems. The light-emitting device according to the present invention comprises a light-emitting light source and a phosphor, wherein the phosphor includes the above-mentioned phosphor, thereby solving the above-mentioned problems. The image display device according to the present invention comprises an excitation source and a phosphor, the phosphor including the above-mentioned phosphor, thereby solving the above-mentioned problems. The radiation detector according to the present invention comprises a phosphor and a photoelectric converter, wherein the phosphor includes the above-mentioned phosphor, thereby solving the above-mentioned problems. [Effects of the Invention]

[0013] The rare-earth coordination polymer of the present invention comprises a trivalent rare-earth ion, a phosphine oxide ligand represented by formula (A) above, and a diketone ligand represented by formula (B) above, wherein one phosphine oxide ligand coordinates to two rare-earth ions, bridging the two rare-earth ions, and three diketone ligands coordinate to one rare-earth ion. The rare-earth coordination polymer of the present invention functions as a phosphor that emits fluorescence in response to light stimulation, radiation stimulation, or mechanical stimulation. The rare-earth coordination polymer of the present invention is a polymer in which rare-earth ions are linked by organic ligands and is crystallized, which can improve its resistance to heat and light. Such phosphors are applied to light-emitting devices, image display devices, radiation detectors and visualization devices, imaging devices, and security applications.

[0014] The rare-earth coordination polymer of the present invention is advantageous because it can be obtained by mixing readily available raw materials and refluxing them, thus eliminating the need for expensive equipment. [Brief explanation of the drawing]

[0015] [Figure 1] Flowchart showing the process for manufacturing the rare earth coordination polymer of the present invention. [Figure 2] Schematic diagram showing the light-emitting device of the present invention [Figure 3] Schematic diagram showing a different light-emitting device of the present invention. [Figure 4] Schematic diagram showing the image display device of the present invention [Figure 5] Schematic diagram showing an image display device according to the present invention. [Figure 6] Schematic diagram showing an image display device according to the present invention. [Figure 7] Schematic diagram showing the radiation detector of the present invention [Figure 8] Schematic diagram showing the non-destructive testing apparatus of the present invention [Figure 9] Schematic diagram showing a positron emission tomography (PET) scanner. [Figure 10] Schematic diagram showing the radiation visualization device of the present invention [Figure 11] Schematic diagram showing the authenticity determination system of the present invention. [Figure 12] Figure showing the crystal structure of the sample in Example 1. [Figure 13] Figure showing the crystal structure of the sample in Example 10. [Figure 14] Figure showing the crystal structure of the sample in Example 11. [Figure 15] Figure showing the crystal structure of the sample in Example 13. [Figure 16] Figure showing the thermogravimetric differential thermal curves of the samples in Example 1 and Example 15. [Figure 17] Figure showing the excitation emission spectrum of the sample in Example 1. [Figure 18] Figure showing the excitation emission spectrum of the sample in Example 2. [Figure 19] Figure showing the excitation emission spectrum of the sample in Example 3. [Figure 20] Figure showing the excitation emission spectrum of the sample in Example 4. [Figure 21] Figure showing the excitation emission spectrum of the sample in Example 5. [Figure 22] This figure shows the excitation wavelength dependence of the internal quantum efficiency, external quantum efficiency, and absorption rate of the emission of light emitted by the sample in Example 1 upon photoexcitation (light stimulation). [Figure 23] This figure shows the temperature dependence of the emission integral intensity upon photoexcitation (photostimulation) of the samples in Example 1 and Example 15. [Figure 24] Figure showing the emission spectrum of the sample in Example 1 due to mechanical stimulation. [Figure 25] Figures showing the emission spectra when the samples of Example 1, Example 2, and Example 3 were irradiated with X-rays. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described below with reference to the drawings. Similar elements will be given the same numbers, and their descriptions will be omitted.

[0017] (Embodiment 1) Embodiment 1 describes the rare-earth coordination polymer of the present invention and a method for producing the same.

[0018] The rare-earth coordination polymer of the present invention comprises a trivalent rare-earth ion, a phosphine oxide ligand represented by formula (A), and a diketone ligand represented by formula (B).

[0019] [ka]

[0020] Furthermore, one of the phosphine oxide ligands in formula (A) coordinates to two rare earth ions, bridging them together. In addition, three diketone ligands in formula (B) coordinate to one rare earth ion.

[0021] Here, in equation (A), C 1 , C 2 and C 3 represents a carbon atom. Ar is C 1 , C 2 and C 3 Includes X 1 It represents a substituted or unsubstituted divalent monocyclic aromatic group or a fused polycyclic aromatic group other than X 1 R represents a halogen atom, a substituted or unsubstituted C1-C20 hydrocarbon group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted alkanoyloxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted arylcarbonyloxy group, a hydroxyl group, a carboxyl group, or a cyano group. 1 This indicates a substituted or unsubstituted aromatic group, or a linear or cyclic aliphatic group. Multiple Ar, X groups within the same molecule. 1 and R 1 These may be the same or different.

[0022] In equation (B), R 2 R represents a hydrogen atom or a deuterium atom. 3 and R 4R is selected from the group consisting of monovalent aliphatic hydrocarbon groups having 1 to 10 carbon atoms, monovalent aromatic hydrocarbon groups having 6 to 36 carbon atoms, and halogenated hydrocarbon groups thereof. 3 and R 4 They are different from each other. 3 and R 4 Because these elements are different from each other, the oxygen configuration around the coordinating rare-earth ions becomes asymmetrical, which can improve luminescence efficiency.

[0023] The inventors of this application have found that the above configuration results in a rare-earth coordination polymer. Details will be explained below.

[0024] The rare-earth coordination polymer of the present invention may have a repeating unit represented by the following formula (C). Here, formula (C) represents a repeating unit of the rare-earth coordination polymer that includes a trivalent rare-earth ion M(III), a phosphine oxide ligand represented by formula (A), and a diketone ligand represented by formula (B). Such a repeating unit can be determined by performing the single-crystal structure analysis shown in the examples.

[0025] [ka]

[0026] The two coordinating sites of one phosphine oxide ligand in formula (C) coordinate to two different trivalent rare earth ions M(III), thereby bridging these two rare earth ions. Another phosphine oxide ligand then coordinates to the rare earth ions to which the phosphine oxide ligand has coordinated, successively bridging the rare earth ions and thereby forming a rare earth coordination polymer. The rare earth ion M(III) in formula (C) is further coordinated to a diketone ligand represented by formula (B). Thus, the rare earth coordination polymer of the present invention has a structure in which multiple trivalent rare earth ions M(III) are linked via coordination bonds by ligands.

[0027] The trivalent rare earth ions are not particularly limited and can be appropriately selected depending on the desired emission color of the rare earth coordination polymer. Preferably, at least one rare earth ion is selected from the group consisting of cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), terbium (Tb), dysprosium (Dy), gadolinium (Gd), erbium (Er), yttrium (Y), and ytterbium (Yb).

[0028] For example, the rare-earth coordination polymer of the present invention emits five narrow-linewidth red light in the range of 575 nm to 700 nm when the rare-earth ion is Eu, four or more narrow-linewidth green light in the range of 470 nm to 650 nm when the rare-earth ion is Tb, and broad-linewidth bluish-white light in the range of 400 nm to 630 nm when the rare-earth ion is Gd. When the rare-earth ion is Sm, it emits four or more narrow-linewidth orange to red light in the range of 500 nm to 800 nm. When the rare-earth ion is Yb, it emits near-infrared light in the range of 900 nm to 1100 nm. In particular, from the viewpoint of obtaining high emission intensity, at least one rare-earth ion is selected from the group consisting of Eu, Tb, Gd, and Sm, and these can be arbitrarily mixed.

[0029] The amount of trivalent rare earth ions contained in the rare earth coordination polymer may be 0.1 to 30% by mass, based on the mass of the rare earth coordination polymer. Within this range, the luminescence intensity is excellent. More preferably, the amount of rare earth ions is 1 to 20% by mass.

[0030] The rare earth ions contained in the rare earth coordination polymer may be of one kind or any combination of two or more kinds. When the rare earth coordination polymer of the present invention contains two or more kinds of rare earth ions, by adjusting the ratio (molar ratio) of the rare earth ions contained in the rare earth coordination polymer, it is possible to obtain luminescence of an intermediate color that is difficult to obtain with a polymer containing a single rare earth ion. Thereby, the emission color can be adjusted more finely. The rare earth coordination polymer containing two or more kinds of rare earth ions exhibits luminescence of different colors depending on differences in excitation light irradiation or stress stimulation, differences in excitation wavelength, differences in temperature, etc. Therefore, by using two or more kinds of rare earth ions, various additional properties can be imparted to the rare earth complex polymer. Note that even when two or more kinds of rare earth ions are contained, the total amount of rare earth ions only needs to satisfy the above-mentioned range.

[0031] X 1 When X 1 is a halogen atom, X 1 is preferably selected from the group consisting of a fluorine atom, a bromine atom, and a chlorine atom. X

[0032] X 1 When X 1 is a hydrocarbon group, X

[0033] X 1 When X 1 is an alkoxy group, an alkoxycarbonyl group, or an alkanoyloxy group, X

[0034] X 1When it is an aryloxy group, an aryloxycarbonyl group, or an arylcarbonyloxy group, the aryl group is preferably a phenyl group. This stabilizes the structure.

[0035] Two Ar's within the same molecule may be the same or different, but are preferably the same. The monocyclic aromatic group as Ar can be an aromatic hydrocarbon group or an aromatic heterocyclic group. Examples of the monocyclic aromatic group include residues derived by removing two hydrogen atoms from benzene, furan, pyrrole, or thiophene. The condensed polycyclic aromatic group as Ar can be a condensed polycyclic aromatic hydrocarbon group or a condensed polycyclic aromatic heterocyclic group. Examples of the condensed polycyclic aromatic group include residues derived by removing two hydrogen atoms from pyrene, coronene, triphenylene, naphthalene, or phenanthrene.

[0036] Ar may preferably be a divalent aromatic group represented by formulas (1) to (3).

[0037]

Chemical formula

[0038] In formulas (1) to (3), X 1 is synonymous with X in formula (A), and multiple X's 1 may be the same or different. X 1 is a monovalent substituent bonded to a carbon atom other than the carbon atom to which X of the aromatic ring 2 is bonded, n 1 represents an integer from 0 to 2, n 1 represents an integer from 0 to 6, n 2 represents an integer from 0 to 9. Multiple X's 3 may be the same or different. X 2 is, for example, a hydrocarbon group having 1 to 20 carbon atoms, a hydroxyl group, a nitro group, an amino group, a sulfo group, a cyano group, a silyl group, a phosphonic acid group, a diazo group, or a mercapto group. X 2 and X 1 and X 2The substituents may be the same. In these formulas, X 1 A carbon atom adjacent to a carbon atom to which is bonded and having a bond is the carbon atom C in formula (A). 1 It corresponds to this.

[0039] R 1 If R is an aromatic group, 1 The group is preferably an aromatic group having 6 to 10 carbon atoms, and more preferably selected from the group consisting of phenyl, naphthyl, cyclohexane, thiophene, and furan. This stabilizes the structure.

[0040] R 1 If R is a linear or cyclic aliphatic group, 1 Preferably, the aliphatic group has 1 to 20 carbon atoms, and more preferably, the linear aliphatic group is selected from the group consisting of methylene, ethylene, propylene, and difluoromethylene, and the cyclic aliphatic group is selected from the group consisting of cyclopentyl, cyclohexyl, norbornyl, and adamantyl. This stabilizes the structure.

[0041] If substituents are present, they may be, for example, bromine atoms, fluorine atoms, nitrile groups, hydroxyl groups, C1-C10 alkyl groups, alkoxy groups, carboxyl groups, or carbonyl groups.

[0042] R 3 and R 4 In this, the monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms may be linear, branched, or non-aromatic cyclic, and may have unsaturated bonds in its structure. The monovalent aliphatic hydrocarbon group includes alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, and n-pentyl groups; alkenyl groups such as vinyl, allyl, butenyl, butadienyl, and pentenyl groups; alkynyl groups such as ethynyl, propagyl, and butynyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; cycloalkenyl groups such as cyclohexenyl and methylcyclohexenyl groups; and cycloalkynyl groups such as cyclohexynyl groups.

[0043] R 3 and R 4 In this context, monovalent aromatic hydrocarbon groups with 6 to 36 carbon atoms are aromatic hydrocarbon groups consisting of a monocyclic or fused ring. Examples include residues obtained from benzene rings, naphthalene rings, indene rings, anthracene rings, etc.

[0044] R 3 and R 4 In this context, a halogenated hydrocarbon group is a hydrocarbon group in which some or all of the hydrogen atoms of the monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms and the monovalent aromatic hydrocarbon group having 6 to 36 carbon atoms are replaced with halogen elements such as fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).

[0045] R 3 and R 4 Preferably, the group is selected from the group consisting of alkyl groups having 1 to 10 carbon atoms, aryl groups having 6 to 36 carbon atoms, and halogenated hydrocarbon groups thereof.

[0046] The linear or branched alkyl group having 1 to 10 carbon atoms is preferably selected from the group consisting of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups, and more preferably selected from the group consisting of methyl, ethyl, and propyl groups. This stabilizes the structure and provides excellent luminescence efficiency.

[0047] The aryl group having 6 to 36 carbon atoms is preferably selected from the group consisting of phenyl, naphthyl, anthryl, phenanthryl, biphenyl, pyrenyl, pentaphenyl, and tetraphenylethylene groups. Among these, the phenyl group provides structural stability and excellent luminescence efficiency.

[0048] R 3 and R 4 If R is an alkyl halogen with 1 to 10 carbon atoms, 3and R 4 This refers to a group in which some or all of the hydrogen atoms of the aforementioned C1-C10 alkyl group or C6-C36 aryl group are substituted with halogen atoms. Preferably, the halogen atom is a fluorine atom. This stabilizes the structure and provides excellent luminescence efficiency.

[0049] R 3 and R 4 They just need to be different from each other, for example, R 3 and R 4 However, all of them may be alkyl groups as described above, or all of them may be halogenated alkyl groups as described above, R 3 R is the alkyl group mentioned above, 4 This could be the aforementioned alkyl halogenated compound, or vice versa.

[0050] Particularly preferred, R 3 It is selected from the group consisting of -CF3, -(CF2)2-CF3, and -(C6H5), R 4 The group is selected from the group consisting of -CF2-CF3, -C(CH3)3, -CHF2, and -CH2-CH3, or vice versa. This results in a particularly stable structure and excellent luminescence efficiency.

[0051] Furthermore, in the rare earth coordination polymer of the present invention, as long as it has repeating units represented by formula (C), all repeating units may be the same, or they may be a combination of different repeating units. That is, one or more rare earth ions may be arbitrarily selected according to the desired properties, or different R values ​​may be used between the repeating units. 1 , R 3 , R 4 , C 1 ~C 3 While you may choose one option, from the standpoint of the manufacturing method described later, it is preferable to have the same option.

[0052] The rare-earth coordination polymer of the present invention functions as a phosphor that emits fluorescence in response to external stimuli. External stimuli include photostimuli from vacuum ultraviolet light, ultraviolet light, or visible light with wavelengths of 100 nm to less than 500 nm; radiation stimuli from alpha rays, beta rays, electron beams, X-rays, or gamma rays; or mechanical stimuli such as the application of pressure or grinding. These are collectively called phosphors because they emit fluorescence, but the emission of fluorescence in response to radiation stimuli is sometimes called scintillation, and such materials are sometimes called scintillators.

[0053] The emission color varies depending on the rare earth ion, but as mentioned above, when the rare earth ion is Eu, it emits red light in the range of 575 nm to 750 nm; when the rare earth ion is Tb, it emits green light in the range of 470 nm to 650 nm; and when the rare earth ion is Gd, it emits bluish-white light in the range of 400 nm to 630 nm. The rare earth coordination polymer of the present invention forms polymer chains through coordination bonds between the rare earth and the organic ligand, and the chains form intermolecular bonds at various sites. Therefore, it has superior thermal resistance compared to mononuclear complex crystals, and even when used in light-emitting devices, there is little decrease in brightness.

[0054] The rare-earth coordination polymer of the present invention may be a powder with an average particle size of 2 nm to 100 μm. This allows it to function as a phosphor with high luminescence efficiency and high brightness. In this specification, the average particle size is determined by measuring the particle size of 100 randomly selected particles in an image observed by an electron microscope using image analysis software, and taking the average value. In this specification, Image J (ver. 1.54d; open-source, public domain image processing software) was used as the image analysis software.

[0055] In the rare-earth coordination polymer of the present invention, preferably, the Ar atoms of the phosphine oxide ligand represented by formula (A) are linked to each other in a twisted direction. This stabilizes the structure. In the rare-earth coordination polymer of the present invention, preferably, three diketone ligands that coordinate to one rare-earth ion are coordinated outward from the main chain direction of the polymer. This results in excellent luminescence efficiency.

[0056] For example, in the case of the phosphine oxide ligand represented by formula (4) and the diketone ligand represented by formula (5), the rare-earth coordination polymer of the present invention has an orthorhombic crystal structure, belongs to the space group of Pna21 (space group 33 in the International Tables for Crystalography), and has lattice constants a = 22.1045(5) Å, b = 13.8111(3) Å, and c = 19.4392(4) Å.

[0057] [ka]

[0058] The present invention may be used as a composition in which the rare earth coordination polymer is dispersed in a liquid medium. Any liquid medium can be selected according to the purpose, as long as it exhibits liquid properties under the desired usage conditions, adequately disperses the rare earth coordination polymer of the present invention, and does not cause undesirable reactions.

[0059] The rare earth coordination polymer of the present invention disperses well in liquid media such as methanol and acetone, as well as in halogenated liquids such as chloroform and dichloromethane, long-chain alcohols such as diethylene glycol, nonanol, and octanol, ethers such as diethylene glycol monoethyl ether and triethylene glycol dimethyl ether, and benzene-based liquid media such as xylene.

[0060] When using the present invention as a composition in which the rare earth coordination polymer is dispersed in a liquid medium, selecting a liquid medium with a viscosity of 1 to 40 mPa·s results in excellent applicability by brush application and ejection by inkjet printing. Naturally, the above-mentioned liquid media may be combined as appropriate to achieve the desired viscosity.

[0061] The rare-earth coordination polymer of the present invention can also be mixed with various plastic materials to form a resin molded article. Such plastic materials may include, for example, polyacrylic resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, urea resin, fluororesin, polyester resin, polyamide resin, polyacetal resin, polycarbonate resin, polyarylate resin, polysulfone resin, polyphenylene sulfoid resin, polyethersulfone resin, polyallylsulfone resin, polytetrafluoroethylene resin, phenolic resin, unsaturated polyester resin, epoxy resin, polyimide resin, polyamideimide resin, silicone resin, etc., and these may be combined. Polyacrylic resins such as polymethyl methacrylate (PMMA), which are transparent in the visible range, are also advantageous for inkjet inks and human body phantoms.

[0062] The composition and resin molded articles obtained by dispersing the rare-earth coordination polymer of the present invention in a liquid medium exhibit high thermal and light resistance. In particular, in liquid media and plastic materials, the rare-earth coordination polymer of the present invention, which is a fluorescent substance, exists as clumps and, while being colorless and transparent, has a high ability to visualize radiation such as X-rays.

[0063] The resin molded article can be produced by mixing a composition in which the rare earth coordination polymer of the present invention described above is dispersed in a liquid medium with the plastic material described above and then molding it.

[0064] Furthermore, the composition containing the rare earth coordination polymer of the present invention may contain other optional components in addition to the rare earth coordination polymer and liquid medium of the present invention, depending on its application. Examples of such components include diffusing agents, thickeners, bulking agents, and buffering agents. Specifically, these may be silica-based fine powders such as Aerosil, alumina, and the like.

[0065] From the perspective of being organic polymers, it is preferable to combine the rare earth coordination polymer of the present invention with a plastic material, but it may also be mixed with inorganic glass instead of a plastic material.

[0066] The present invention describes a method for producing rare earth coordination polymers. Figure 1 is a flowchart showing the process for producing the rare earth coordination polymer of the present invention.

[0067] Step S110: Dissolve the phosphine oxide ligand represented by formula (A), the diketone ligand represented by formula (B), and the organic base in an organic solvent. Step S120: Dissolve the trivalent rare earth salt in alcohol. Step S130: Mix the solution obtained in step S110 with the solution obtained in step S120 and reflux. The rare-earth coordination polymer of the present invention can be produced by the steps S110 to S130 described above. Each step will be described in detail.

[0068] [ka]

[0069] In equations (A) and (B), C 1 , C 2 , C 3 Ar, R 1 , R 2 , R 3 , R 4 , and, X 1 As explained above, the explanation will be omitted.

[0070] In step S110, the molar ratio of the phosphine oxide ligand, the diketone ligand, and the organic base (phosphine oxide ligand: diketone ligand: organic base) is preferably 0.5-1.5:2.5-3.5:2.5-3.5. This promotes polymerization. More preferably, the molar ratio is 0.8-1.2:2.8-3.2:2.8-3.2.

[0071] In step S110, the organic solvent is not particularly limited as long as it can dissolve the phosphine oxide ligand, diketone ligand, and organic base, but examples include dichloromethane, chloroform, tetrahydrofuran, dioxane, diethyl ether, and diisopropyl ether.

[0072] In step S110, the organic base is not particularly limited, but may be at least one from the group consisting of triethylamine (TEA), trimethylamine, and ammonia, for example.

[0073] In step S110, preferably, the phosphine oxide ligand and the diketone ligand are dissolved in an organic solvent, and then the organic base is slowly added thereto, and the mixture is stirred at room temperature (20°C to 25°C) for 1 to 10 minutes.

[0074] In step S120, the trivalent rare earth salt can be a chloride, sulfate, nitrate, or acetate of a trivalent rare earth ion. The rare earth salt is preferably added in solution form.

[0075] In step S120, the amount of trivalent rare earth salt added may be the same as the number of moles of phosphine oxide ligand in step S110. If two or more rare earth salts are used as the trivalent rare earth salt, the total number of moles should be the same as the number of moles of phosphine oxide ligand.

[0076] Trivalent rare earth ions are ions of at least one element selected from the group consisting of cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), terbium (Tb), dysprosium (Dy), gadolinium (Gd), erbium (Er), yttrium (Y), and ytterbium (Yb).

[0077] In step S120, the alcohol is not particularly limited as long as it dissolves the rare earth salt and can be mixed with the organic solvent mentioned above, but examples include methanol, ethanol, 2-propanol, 1-propanolmethanol, etc.

[0078] In step S130, the solution obtained in step S110 reacts with the solution obtained in step S120 to obtain the rare-earth coordination polymer of the present invention as a white powder. The reflux conditions vary depending on the selected organic solvent and alcohol, but for example, if chloroform is selected as the organic solvent and ethanol as the alcohol, reflux can be performed in a temperature range of 60°C to 80°C. There are no particular restrictions on the reflux time, but exemplary it may be in the range of 1 hour to 24 hours.

[0079] In step S130, mixing is preferably carried out by slowly adding the solution from step S120 dropwise to the solution from step S110. This promotes the reaction.

[0080] After step S130, the white powder may be removed by filtration. Alternatively, the solvent in the filtrate may be removed and recrystallized with alcohol or the like. This improves purity and yield.

[0081] In Figure 1, the solution was prepared in the order of step S110 and then step S120, but the solution may also be prepared in the order of step S120 and then step S110, and then step S130 may be performed.

[0082] In this way, the rare earth coordination polymer of the present invention can be obtained as a powder, but the particle size may be adjusted by grinding, classification, etc., as needed. Furthermore, depending on the application, the powder may be mixed with the above-mentioned liquid medium and, if necessary, with other arbitrary components to prepare a composition.

[0083] (Embodiment 2) As described above, the rare-earth coordination polymer of the present invention functions as a phosphor. Embodiment 2 describes various applications using a phosphor containing the rare-earth coordination polymer of the present invention (hereinafter simply referred to as the phosphor of the present invention).

[0084] (1) Light-emitting device The phosphor of the present invention is excited by irradiation with ultraviolet to visible light and emits other visible light, thus enabling the provision of a light-emitting device using the phosphor of the present invention. The light-emitting device of the present invention comprises at least a light-emitting light source and a phosphor, and the phosphor is configured to include the phosphor of the present invention as described above.

[0085] Figure 2 is a schematic diagram showing the light-emitting device of the present invention.

[0086] Figure 2 shows a bullet-shaped light-emitting diode lamp as a specific example of the light-emitting device 1. The light-emitting diode lamp, as a light-emitting device, comprises a light-emitting light source 4 and a phosphor 7 of the present invention which contains at least the rare-earth coordination polymer of the present invention as a phosphor, thereby emitting fluorescence. The phosphor 7 of the present invention contains the rare-earth coordination polymer of the present invention as described in Embodiment 1, so its description is omitted.

[0087] In the light-emitting device 1 shown in Figure 2, the light-emitting light source 4 is placed in a recess 2a for element mounting on the lead wire 2. The lead wire 2 and the lower electrode 4a of the light-emitting light source 4 are electrically connected, and the upper electrode 4b of the light-emitting light source 4 and the lead wire 3 are electrically connected by a bonding wire 5. The light-emitting light source 4 is covered with a first resin 6 in which the phosphor 7 of the present invention is dispersed, and the entire element is sealed with a second resin 8. The second resin 8 is generally cylindrical in shape, with its tip having a lens-shaped curved surface, and is commonly referred to as bullet-shaped. Figure 2 shows a specific example of the configuration, but it is just one example, and those skilled in the art can easily modify it within the usual range. The first resin 6 in which the phosphor 7 of the present invention is dispersed may be a molded resin body.

[0088] The light-emitting source 4 applied to the light-emitting device 1 is not particularly limited in wavelength as long as it can excite the phosphor 7 of the present invention, but examples include LED light-emitting devices, laser diode (LD) light-emitting devices, organic EL (OLED) light-emitting devices, fluorescent lamps, and semiconductor lasers. In the case of an LED light-emitting device, the phosphor of the present invention can be used to manufacture the device by known methods as described in Japanese Patent Application Publication No. 5-152609, Japanese Patent Application Publication No. 7-99345, and Japanese Patent Publication No. 2927279. In this case, the light-emitting element or light-emitting source is preferably one that emits light with a wavelength of 330 to 500 nm, and among these, an ultraviolet (or violet) LED light-emitting element with a wavelength of 330 to 420 nm or a blue LED light-emitting element with a wavelength of 420 to 450 nm is preferred. These LED light-emitting elements may be made of nitride semiconductors such as GaN or InGaN, and by adjusting the composition, they can become light-emitting sources that emit light with a predetermined wavelength.

[0089] In this light-emitting device 1, when electricity flows to the light source 4 via the lead wire 2, the light source 4 emits light having a peak in the wavelength range of, for example, 300 nm to less than 450 nm. The phosphor 7 of the present invention is excited by the ultraviolet light or blue light emitted by the light source 4 and emits blue to red fluorescence. In this way, the light-emitting device 1 of the present invention operates. As for the phosphor of the present invention, if the rare earth ion is Eu, it emits red light; if the rare earth ion is Tb, it emits green light; and if the rare earth ion is Gd, it emits blue light.

[0090] Examples of light-emitting devices of the present invention include white light-emitting diodes containing the phosphor of the present invention, lighting fixtures containing multiple such white light-emitting diodes, and backlights for liquid crystal panels.

[0091] In such a light-emitting device, if the rare earth ions of the phosphor 7 of the present invention include Eu, Tb, and Gd, the light-emitting source 4 emits light having a peak in the wavelength range of 300 nm to less than 450 nm, thereby exciting the phosphor 7 of the present invention, which emits red, green, and blue light, and when these are mixed, white light can be emitted.

[0092] Since the phosphor 7 of the present invention is composed of a rare-earth coordination polymer, its emission spectrum differs from that of phosphors composed of inorganic materials in that it has fewer subpeaks or the emission of subpeaks is small. Therefore, by using a combination of phosphors containing the rare-earth coordination polymer of the present invention, it is possible to construct an emission line white spectrum similar to that of a mercury-excited phosphor.

[0093] Figure 3 is a schematic diagram showing another light-emitting device of the present invention.

[0094] Figure 3 shows a chip-type light-emitting diode lamp for substrate mounting as a specific example of the light-emitting device 11. The light-emitting diode lamp, as the light-emitting device 11, comprises a light-emitting light source 14 and a phosphor 17 of the present invention, thereby emitting fluorescence.

[0095] In the light-emitting device 11 shown in Figure 3, a light-emitting source 14 is mounted on a lead wire 12 fixed to a substrate 19. The lead wire 12 and the lower electrode 14a of the light-emitting source 14 are electrically connected, and the upper electrode 14b of the light-emitting source 14 and the lead wire 13 are electrically connected by a bonding wire 15. The light-emitting source 14 is coated with a first resin 16 in which the phosphor 17 of the present invention is dispersed, and the entire element is sealed with a second resin 18. A wall member 20 with a hole in the center is fixed to the substrate 19. Figure 3 shows a specific example of the configuration, but it is just one example, and those skilled in the art can easily modify it within the usual range.

[0096] Here, the light-emitting light source 14 and the phosphor 17 of the present invention are the same as the light-emitting light source 4 and the phosphor 7 of the present invention described in Figure 2, respectively, so their descriptions are omitted. Also, components similar to those in Figure 2 are given the same names and their descriptions are omitted. Here again, the first resin 16 in which the phosphor 17 of the present invention is dispersed may be a resin molded body.

[0097] In such a light-emitting device 11, when electricity flows to the light source 14 via the lead wire 12, the light source 14 emits ultraviolet or visible light having a peak in the wavelength range of, for example, 300 nm to less than 450 nm. The phosphor 17 of the present invention is excited by the light emitted by the light source 14 and emits fluorescence. In this way, the light-emitting device 11 of the present invention operates.

[0098] (2) Image display device The phosphor of the present invention emits fluorescence when excited by irradiation with vacuum ultraviolet light or an electron beam, thus enabling the provision of an image display device using the phosphor of the present invention. The image display device of the present invention comprises at least an excitation source and a phosphor, and the phosphor is configured to include the phosphor of the present invention as described above.

[0099] Figure 4 is a schematic diagram illustrating the image display device of the present invention.

[0100] Composition 31 containing the phosphor of the present invention whose rare earth ion is Eu, composition 32 containing the phosphor of the present invention whose rare earth ion is Tb, and composition 33 containing the phosphor of the present invention whose rare earth ion is Gd are coated on the inner surfaces of cells 34-36, which are arranged on a glass substrate 44 via electrodes 37-39 and a dielectric layer 41. When current is applied to electrodes 37-40, vacuum ultraviolet light is generated in the cells by Xe discharge, which excites the phosphors and emits red, green, and blue visible light. This light is observed from the outside via the protective layer 43, dielectric layer 42, and glass substrate 45, and the system functions as an image display device for a plasma display panel.

[0101] Figure 5 is a schematic diagram showing another image display device of the present invention.

[0102] A composition 56 containing the phosphor of the present invention, in which the rare earth ion is Eu, is coated on the inner surface of the anode 53. By applying a voltage between the cathode 52 and the gate 54, electrons 57 are emitted from the emitter 55. The electrons 57 are accelerated by the voltage between the anode 53 and the cathode 52 and collide with the composition 56, causing the phosphor to emit light. The whole is protected by glass 51. The figure shows one light-emitting cell consisting of one emitter and one phosphor composition, but in reality, an image display device for a field emission display panel is constructed by arranging many cells of various colors, including red, green, and blue cells. The phosphor of the present invention can also be used for the green and blue cells.

[0103] Figure 6 is a schematic diagram showing another image display device of the present invention.

[0104] A phosphor sheet 620 containing the phosphor of the present invention, in which the rare earth ion is Gd, Eu, or Tb, is placed on a phosphor excitation LED 610 that emits light in the range of 360 nm to 480 nm. A commonly used liquid crystal layer 630 is placed on the phosphor sheet 620. This enables the realization of a liquid crystal display with good color reproduction. In addition to commonly used surface-mount LEDs, miniLEDs, microLEDs, and organic LEDs (OLEDs) can also be used for the LED 610. Furthermore, blue LEDs may be used as part of the LED 610.

[0105] In addition to the plasma display panels (PDPs) and field emission displays (FEDs) mentioned above, other image display devices include fluorescent display tubes (VFDs), cathode ray tubes (CRTs), and liquid crystal displays (LCDs). The phosphor of the present invention has been confirmed to emit light when excited by vacuum ultraviolet light in the range of 100 to 190 nm, ultraviolet light in the range of 190 to 380 nm, electron beams, etc. By combining these excitation sources with the phosphor of the present invention, the above-mentioned image display devices can be constructed.

[0106] (3) Scintillator The phosphor of the present invention functions as a scintillator because it is excited by irradiation with radiation and emits fluorescence, and a radiation detector using the phosphor of the present invention can be provided. The radiation detector of the present invention comprises at least a phosphor and a photoelectric converter, and the phosphor is configured to include the phosphor of the present invention as described above.

[0107] Figure 7 is a schematic diagram showing the radiation detector of the present invention.

[0108] The radiation detector 700 of the present invention comprises a resin molded body 710 containing the phosphor of the present invention and a photoelectric converter 720. The resin molded body 710 may be molded containing the phosphor of the present invention, a liquid medium, and a plastic material, as described above. Since the phosphor of the present invention is made of an organic material, it is a well-known Bi4Ge3O 12 It can be supplied at a lower cost compared to scintillator single crystals such as (BGO), Ce:Gd2SiO5 (Ce:GSO), and Ce:Lu2SiO5 (Ce:LSO).

[0109] The photoelectric converter 720 can employ a photomultiplier tube (PMT), silicon photomultiplier (SiPM), CCD or photodetector (PD), avalanche photodiode (APD), multipixel photon counter (MPPC), etc., and is appropriately selected according to the wavelength of fluorescence from the resin molded body 710.

[0110] When radiation R is irradiated onto the resin molded body 710 of the radiation detector 700 of the present invention, the resin molded body 710 emits fluorescence S, the photoelectric converter 720 detects the fluorescence S, converts it into an electrical signal, and enables the detection or non-detection of radiation by the change in the electrical signal.

[0111] Furthermore, a non-destructive testing device can be provided using the radiation detector 700. Figure 8 is a schematic diagram showing the non-destructive testing apparatus of the present invention.

[0112] By irradiating the object 820 with radiation R from the radiation source 810 and detecting the radiation R that has passed through the object 820 with the radiation detector 700, the device can also be used as a radiation measuring device or resource exploration device, which are non-destructive testing devices equipped with the radiation detector 700.

[0113] For the single-life phosphors among the phosphors of the present invention, the above-described radiation detector 700 can be applied to imaging devices such as positron emission tomography (PET) systems and SPECT (Single Photon Emission Computed Tomography) systems.

[0114] Figure 9 is a schematic diagram of a positron emission tomography (PET) scanner.

[0115] The PET scanner 900 is equipped with multiple radiation detectors 700 arranged in a roughly circular shape. The multiple radiation detectors 700 are positioned to surround the subject 910. When a radioactive substance 920 is administered to the subject 910, for example, by utilizing the fact that the radioactive substance 920 concentrates more in cancer cells, the radiation detectors 700 detect the radiation R emitted from the radioactive substance 920, making it possible to identify the location and size of cancer cells. Examples of other types of PET include two-dimensional PET, three-dimensional PET, and time-of-flight (TOF) PET.

[0116] Figure 10 is a schematic diagram showing the radiation visualization device of the present invention.

[0117] The radiation visualization device of the present invention comprises a radiation source 810, a human body model 1010 containing the rare-earth coordination polymer of the present invention, and an imaging camera 1020. The human body model 1010 contains the phosphor, liquid medium, and plastic material of the present invention and is molded into the shape of a human body. The imaging camera 1020 is not particularly limited as long as it is a camera that images fluorescence in two dimensions, but as an example, it may be a multi-pixel photon counter (MPPC). Figure 10 shows only one imaging camera 1020, but multiple imaging cameras 1020 may be installed, or the human body model 1010 may be rotatable 360° around a rotation center.

[0118] Using the radiation visualization device of the present invention, when radiation R from a radiation source 810 irradiates a human body model (human phantom) 1010, the human body model 1010 emits fluorescence 1030 along the location and path of the radiation R. The imaging camera 1020 captures the fluorescence 1030, and by performing three-dimensional image analysis with an external computer (not shown), the precise irradiation location and dose of radiation R on the human body model 1010 can be calculated. Using the radiation visualization device of the present invention, physicians can estimate appropriate irradiation paths and doses for each patient in advance of treatment during radiation therapy.

[0119] (4) Security The phosphor of the present invention emits fluorescence when excited by optical or mechanical stimuli, and therefore functions as a security material that can be used to prevent counterfeiting or to provide encrypted information. This allows for the provision of a genuineness determination system using the phosphor of the present invention.

[0120] Figure 11 is a schematic diagram illustrating the authenticity determination system of the present invention.

[0121] A printed image 1120 printed with ordinary ink and a printed image 1130 printed with ink containing the rare-earth coordination polymer of the present invention are printed on printing paper 1110. Under normal natural light 1140, only the printed image 1120 is visible. When phosphor excitation light 1160 from a phosphor excitation source 1150 is irradiated onto this, the printed image 1130 emits light due to the ink containing the rare-earth coordination polymer of the present invention. In contrast, if the print is copied using a normal copier or is forged, the printed image 1130 is not observed, making it possible to determine authenticity. The ink containing the rare-earth coordination polymer of the present invention may be a composition in which the rare-earth coordination polymer of the present invention described above is dispersed in a liquid medium.

[0122] Figure 11 shows an example where an excitation source is irradiated, but since the rare-earth coordination polymer of the present invention fluoresces not only in response to optical stimuli but also to mechanical stimuli, for example, pressure, tensile stress, vibration, or impact may be applied to the printing paper 1110. [Examples]

[0123] The present invention will be further described in detail by the following embodiments, but these are disclosed solely to facilitate understanding of the present invention, and the present invention is not limited to these embodiments.

[0124] [Raw materials] The phosphine oxide ligand Fdpbp, represented by formula (4), was synthesized according to Patent Document 1. The obtained Fdpbp was a white powder, similar to that obtained in Patent Document 1, and its identity as the phosphine oxide ligand represented by formula (4) was confirmed by NMR.

[0125] Diketone ligands (5) to (14) were purchased from Tokyo Chemical Industry Co., Ltd. and Sigma-Aldrich Co., Ltd. The diketone ligand in equation (5) is the same as the diketone ligand in equation (B), where R 2 H is R 3 is -CF3, R 4 Since is -CF2CF3, the diketone ligand of equation (6) is, in the diketone ligand of equation (B), R 2 H is R 3 is -CF3, R 4 Since is -CF3, the diketone ligand of equation (7) is, in the diketone ligand of equation (B), R 2 H is R 3 is -CH3, and R 4 Since is -(CH2)-(CH)(CH3)2, the diketone ligand of equation (8) is, in the diketone ligand of equation (B), R 2 is -CH3, and R 3 is -CH3, and R 4 Since it is -(CH2)4-CH3, the diketone ligand of formula (9) is, in the diketone ligand of formula (B), R 2 H is R 3 is -CF3, R 4 Since is -C4H4O, the diketone ligand of formula (10) is, in the diketone ligand of formula (B), R 2 H is R3 is -(CF2)2-CF3, and R 4 Since is -C-(CH3)3, the diketone ligand of formula (11) is, in the diketone ligand of formula (B), R 2 H is R 3 is -CF3, R 4 Since is -C-(CH3)3, the diketone ligand of formula (12) is, in the diketone ligand of formula (B), R 2 H is R 3 It is -C6H5, and R 4 Since is -CHF2, the diketone ligand of formula (13) is, in the diketone ligand of formula (B), R 2 H is R 3 is -CF3, R 4 Since it is -(CH2)-CH3, the diketone ligand of formula (14) is, in the diketone ligand of formula (B), R 2 H is R 3 is -CF3, R 4 It is -C4H4S.

[0126] [ka]

[0127] [Example 1] In Example 1, rare earth compounds were prepared using the phosphine oxide ligands and diketone ligands shown in Table 1, according to the method shown in Figure 1.

[0128] Fdpbp, a phosphine oxide ligand represented by formula (A), ofhd (formula (5)), a diketone ligand represented by formula (B), and triethylamine (TEA), an organic base, were dissolved in chloroform as an organic solvent (step S110 in Figure 1). Specifically, chloroform (20 mL) was placed in a round-bottom flask, and Fdpbp (349.6 mg, 0.5 mmol) and ofhd (278.6 μL, 1.5 mmol) were added and dissolved. Then, TEA (207.9 μL, 1.5 mmol) was slowly added dropwise, and the mixture was stirred at room temperature for 5 minutes.

[0129] Next, europium(III) chloride hexahydrate (183.2 mg, 0.5 mmol) was dissolved in methanol (20 mL) as the alcohol (Step S120 in Figure 1).

[0130] Next, the solution obtained in step S110 and the solution obtained in step S120 were mixed and refluxed (step S130 in Figure 1). Specifically, the solution obtained in step S120 was slowly added dropwise to the solution obtained in step S110, and the mixture was heated under reflux at 65°C for 12 hours.

[0131] The reaction solution was filtered by suction to obtain a white powder. The remaining solution was then recrystallized with methanol after removing the solvent, yielding a similar white powder. This powder was then ground in a mortar and pestle to obtain a powder with an average particle size of 25 μm. The yield of the white powder was 55%. The white powder was then used with the sample from Example 1 or [Eu(ofhd)3Fdpbp]. n It is called that.

[0132] The infrared absorption spectrum of the sample in Example 1 was measured using the FT-IR method. The sample in Example 1 was measured using an infrared spectrometer (IRSprit-X, manufactured by Shimadzu Corporation).

[0133] Single-crystal structure analysis was performed on the sample from Example 1. X-ray diffraction measurements were taken of the sample from Example 1 using a single-crystal X-ray diffractometer with a rotating cathode for MoKα rays (XtaLAB Synergy-S, Rigaku Corporation) under conditions of X-ray source output of 50kV and 50mA. The crystal structure was determined from these results using single-crystal structure analysis software (CrysAlisPro, Rigaku Corporation).

[0134] Thermogravimetric and differential thermal analysis was performed on the sample from Example 1 using a thermogravimetric differential thermal analyzer (Shimadzu Corporation, DTG-60). The excitation emission spectrum of the sample from Example 1 was measured using a fluorescence spectrophotometer (JASCO Corporation, FP-8750). In addition, the integrated emission intensity was investigated when the temperature of the sample from Example 1 was varied from 25°C to 225°C.

[0135] The luminescence observed when mechanical stimulation was applied to the sample in Example 1 was investigated. Specifically, the sample in Example 1 was placed in a sample holder, a metal rod was launched from a solenoid-type launching device (manufactured by Thermal Block Co., Ltd.), and the luminescence emitted when it struck the sample in Example 1 was captured with a CCD camera, integrated, and the emission spectrum was obtained.

[0136] The emission of X-rays from the sample in Example 1 was investigated. Specifically, the sample in Example 1 was placed in a quartz container, and the emission of X-rays from an X-ray irradiation device (80 keV, tungsten) onto the sample in Example 1 was captured with a CCD camera, integrated, and the emission spectrum was obtained.

[0137] [Examples 2-14] In Examples 2-14, rare earth compounds were prepared using the phosphine oxide ligands and diketone ligands shown in Table 1, following the same procedure as in Example 1. The same molar amounts of phosphine oxide ligands, diketone ligands, and rare earth salts were used as in Example 1. No reaction occurred in Examples 7 and 8, so no further action was taken. The resulting samples were referred to as the samples for Examples 2-6 and 9-14, respectively, and were evaluated in the same manner as in Example 1. The samples for Examples 2-5 were respectively analyzed using [Tb(ofhd)3Fdpbp] n [Gd(ofhd)3Fdpbp] n [Sm(ofhd)3Fdpbp] n [Yb(ofhd)3Fdpbp] n It is sometimes called that.

[0138] [Example 15] In Example 15, similar to Patent Document 1, Fdpbp (349.6 mg, 0.5 mmol) was placed in a round-bottom flask and dissolved in heated chloroform (20 mL). In a separate container, the previously synthesized Eu(hfa)3(H2O)2 (406.8 mg, 0.5 mmol) was dissolved in methanol (20 mL). The methanol solution was added dropwise to the chloroform solution of Fdpbp and heated under reflux for 12 hours. A colorless, transparent powder was obtained by recrystallization from the reaction mixture. The sample thus obtained was called the sample of Example 15 and was evaluated in the same manner as in Example 1. The sample of Example 15 is sometimes referred to as Eu(hfa)3(Fdpbp)2.

[0139] [Example 16] In Example 16, an attempt was made to perform the same procedure as in Example 15, as described in Patent Document 1, but Eu(ofhd)3(H2O)2 could not be synthesized, so no further operations were performed. This suggests that the method of the present invention shown in Figure 1 is effective.

[0140] [Table 1]

[0141] The results of Examples 1 through 16 will be summarized and explained. According to the infrared absorption spectrum (KBr) of the sample in Example 1, the absorption spectrum is 1656 cm⁻¹. -1 (st,C=O),1255cm -1 A peak was observed at (st,P=O). This indicates that different ligands were bound to each component.

[0142] Figure 12 shows the crystal structure of the sample from Example 1. Figure 13 shows the crystal structure of the sample from Example 10. Figure 14 shows the crystal structure of the sample from Example 11. Figure 15 shows the crystal structure of the sample from Example 13.

[0143] X-ray diffraction results showed that in the samples of Example 1, Example 10, Example 11, and Example 13, two Eu ions are bridged by the tetrafluorophenylene group of the phosphine oxide ligand Fdpbp, and three diketone ligands are coordinated to the Eu ions. More specifically, in the samples of Example 1, Example 10, Example 11, and Example 13, the tetrafluorophenylene groups of the phosphine oxide ligand Fdpbp bound to the Eu ions are linked in alternating twisted directions, forming a stable structure. Furthermore, as shown in Figures 12 to 15, the three diketone ligands coordinated to the Eu ions are coordinated outward from the main chain direction. Although not shown, the samples of Example 2 to Example 5 had similar crystal structures. From this, it was shown that the samples of Example 1 to Example 5 and Example 10 to Example 13 are polymers having repeating units as shown in formula (C).

[0144] [Table 2]

[0145] [Table 3]

[0146] [Table 4]

[0147] [Table 5]

[0148] Tables 2 to 5 show the crystal structure parameters of the samples in Examples 1, 10, 11, and 13. The samples in Examples 1 to 5 and 11 all had an orthorhombic crystal structure and belonged to the space group Pna21 (space group 33 in the International Tables for Crystallography). The sample in Example 10 had an orthorhombic crystal structure and belonged to the space group P21 / n (space group 14 in the International Tables for Crystallography). The sample in Example 13 had an orthorhombic crystal structure and belonged to the space group P21 / n (space group 14 in the International Tables for Crystallography).

[0149] On the other hand, the sample in Example 15, as shown in Patent Document 1, had two tetrafluorophenylene groups of the phosphine oxide ligand Fdpbp bonded to two Eu ions linked in an alternatingly twisted orientation. Each Eu ion had three diketone ligands coordinated to it, and it was a dinuclear complex crystal rather than a polymer.

[0150] Furthermore, no reaction occurred in Examples 7, 8, and 16, and none of the samples in Examples 6, 9, and 14 were converted into coordination polymers. This indicates that rare earth coordination polymers can be obtained by the method of the present invention shown in Figure 1, using only the phosphine oxide ligand represented by formula (A) and the diketone ligand represented by formula (B).

[0151] Figure 16 shows the thermogravimetric differential thermal curves for the samples in Example 1 and Example 15.

[0152] According to Figure 16, the sample in Example 1 began to decompose at 345°C, while the sample in Example 15 began to decompose at 325°C. This indicates that the polymerized sample in Example 1 has superior heat resistance compared to the sample in Example 15, which is a dinuclear complex crystal.

[0153] Figure 17 shows the excitation emission spectrum of the sample from Example 1. Figure 18 shows the excitation emission spectrum of the sample from Example 2. Figure 19 shows the excitation emission spectrum of the sample from Example 3. Figure 20 shows the excitation emission spectrum of the sample from Example 4. Figure 21 shows the excitation emission spectrum of the sample from Example 5.

[0154] Figures 17 to 21 show the results measured at 25°C under atmospheric conditions. Figure 17 shows that the sample in Example 1 was efficiently excited by ultraviolet light in the 300 nm to 420 nm range, emitting red light based on trivalent Eu with an emission peak at 618 nm, demonstrating its function as a photostimulated red phosphor. As shown in Table 6, the samples in Examples 10 to 13 were also most efficiently excited by ultraviolet light in the 360 ​​nm range, emitting red light based on trivalent Eu with an emission peak at 611 nm to 615 nm.

[0155] As shown in Figure 18, the sample from Example 2 was efficiently excited by ultraviolet light in the 300 nm to 450 nm range, emitting green light based on trivalent Tb with an emission peak at 544 nm, demonstrating its function as a photostimulated green phosphor.

[0156] As shown in Figure 19, the sample of Example 3 was efficiently excited by ultraviolet light in the 300 nm to 400 nm range, emitting bluish-white light based on singlet and triplet emission of an organic ligand with an emission peak at 460 nm, demonstrating its function as a photostimulated bluish-white phosphor. For example, a compound obtained by mixing the samples of Example 1 and Example 2 can exhibit yellow light composed of two narrow-line spectra. Adding the sample of Example 3 to this mixture can produce a pseudo-white light.

[0157] As shown in Figure 20, the sample of Example 4 was efficiently excited by ultraviolet light in the 300 nm to 500 nm range, emitting red light based on trivalent Sm with an emission peak at 644 nm, demonstrating its function as a photostimulated red phosphor.

[0158] As shown in Figure 21, the sample of Example 5 was efficiently excited by ultraviolet light in the 300 nm to 500 nm range, emitting near-infrared light based on trivalent Yb with an emission peak at 970 nm, demonstrating its function as a photostimulated near-infrared photophosphor.

[0159] As shown in Figures 17 to 21, the emission spectra of rare-earth coordination polymers differ from those of phosphors made of inorganic materials in that they have fewer subpeaks or weaker subpeak emission. Therefore, it is suggested that by using phosphors containing the rare-earth coordination polymer of the present invention in combination, it is possible to construct an emission line white spectrum similar to that of mercury-excited phosphors.

[0160] Figure 22 shows the excitation wavelength dependence of the internal quantum efficiency, external quantum efficiency, and absorption rate of the light emission induced by photoexcitation (light stimulation) of the sample in Example 1.

[0161] According to Figure 22, the sample in Example 1 has an internal quantum efficiency of 50% or more in the excitation range of 330 nm to 440 nm, and the light absorption efficiency is also 80% or more in the range of 330 nm to 360 nm, so the optimal excitation wavelength is 360 nm. As shown in Figure 12, the diketone ligand R 3 and R 4 It is presumed that the difference in these factors leads to an asymmetrical oxygen arrangement around the rare earth ions, thus improving the luminescence efficiency of the rare earth ions.

[0162] Figure 23 shows the temperature dependence of the luminescence integral intensity upon photoexcitation (photostimulation) of the samples in Example 1 and Example 15.

[0163] According to Figure 23, the emission quenching temperature I of the sample in Example 1 under atmospheric conditions 1 / 2 The temperature of the sample in Example 1 was 175°C, while that of the sample in Example 15 was 160°C. From this, it was found that the sample in Example 1, which is a rare-earth coordination polymer, showed less decrease in luminescence intensity at high temperatures and had superior heat resistance compared to the sample in Example 15, which is a dinuclear complex crystal. Since the rare-earth coordination polymer of the present invention is a phosphor with excellent heat resistance, it is suggested that it is effective in light-emitting devices.

[0164] Figure 24 shows the emission spectrum of the sample from Example 1 induced by mechanical stimulation.

[0165] As shown in Figure 24, the sample in Example 1 emitted red light based on trivalent Eu with an emission peak at 618 nm upon impact with a metal rod, demonstrating its function as a red phosphor responsive to mechanical stimulation. As shown in Table 6, the samples in Examples 2-5 and 10-13 were also confirmed to emit fluorescence upon mechanical stimulation. Furthermore, their fluorescence was identical to that responsive to light stimulation.

[0166] On the other hand, the complex samples of Examples 6, 9, 14, and 15 did not fluoresce when mechanically stimulated. This suggests that the rare-earth coordination polymer of the present invention functions as a fluorescent material responsive to mechanical stimulation and can be used as a security material for mechanically stimulated markers and inks.

[0167] Figure 25 shows the emission spectra when the samples of Example 1, Example 2, and Example 3 were irradiated with X-rays.

[0168] As shown in Figure 25, the samples of Examples 1 to 3, which are rare-earth coordination polymers, emitted fluorescence upon X-ray irradiation and were shown to function as scintillators. The fluorescence was the same as that induced by photostimulation and mechanical stimulation. As shown in Table 6, the samples of Examples 4 to 5 and Examples 10 to 13, which are rare-earth coordination polymers, also emitted fluorescence upon X-ray irradiation. This suggests that the rare-earth coordination polymers of the present invention function as scintillators upon radiation irradiation and can be used in radiation detectors, non-destructive testing equipment using them, and imaging devices. Resin molded products obtained by dissolving these in plastic materials also exhibit similar fluorescence, and therefore can be used in X-ray visualization human phantom applications where the X-ray irradiation path can be visualized.

[0169] [Table 6] [Industrial applicability]

[0170] The rare earth coordination polymer of the present invention functions as a phosphor that emits fluorescence by light stimulation, radiation stimulation, or mechanical stimulation. Further, since it is polymerized, its heat and light resistance can be improved. Such a phosphor is applied to a light-emitting device, an image display device, a radiation detector, a radiation visualization device, an imaging device, and a security material.

Explanation of Symbols

[0171] 1, 11 Light-emitting device 2, 3, 12, 13 Lead wire 4, 14 Light-emitting light source 5, 15 Bonding wire 6, 16 First resin 7, 17 Phosphor 8, 18 Second resin 19 Substrate 20 Wall member 31, 32, 33, 56 Composition 34, 35, 36 Cell 37, 38, 39, 40 Electrode 41, 42 Dielectric layer 43 Protective layer 44, 45 Glass substrate 51 Glass 52 Cathode 53 Anode 54 Gate 55 Emitter 57 Electron 100 Particle 610 LED 620 Phosphor sheet 630 Liquid crystal layer 700 Radiation detector 710 Resin molded body 720 Photoelectric converter 810 Radiation source 820 Measurement object 900 PET device 910 Subject 920 Radiation substance 1010 Phantom 1020 Imaging camera 1030 Fluorescence 1110 Printing paper 1120, 1130 printed image 1140 natural light 1150 Phosphor excitation source 1160 Phosphor excitation light

Claims

1. Trivalent rare earth ions, A phosphine oxide ligand represented by formula (A), The diketone ligand represented by formula (B) and It has, One phosphine oxide ligand coordinates to two of the rare earth ions, bridging the two rare earth ions together. The aforementioned diketone ligand is a rare-earth coordination polymer in which three ligands are coordinated to one of the aforementioned rare-earth ions. 【Chemistry 1】 Here, in formula (A), C １ , C ２ and C ３ represent carbon atoms, Ar represents a divalent monocyclic aromatic group or a condensed polycyclic aromatic group containing C １ , C ２ and C ３ and excluding a substituted or unsubstituted divalent monocyclic aromatic group or a condensed polycyclic aromatic group other than X １ , X １ represents a halogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group, an alkoxycarbonyl group which may have a substituent, a substituted or unsubstituted alkanoyloxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted arylcarbonyloxy group, a hydroxyl group, a carboxyl group, or a cyano group, R １ represents a substituted or unsubstituted aromatic group, or a linear or cyclic aliphatic group, and a plurality of Ar, X １ and R １ in the same molecule may be the same or different from each other. In equation (B), R ２ R represents a hydrogen atom or a deuterium atom. ３ and R ４ Each is selected from the group consisting of a monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 36 carbon atoms, and halogenated hydrocarbon groups thereof, R ３ and R ４ They are different from each other.

2. The rare earth coordination polymer according to claim 1, having a repeating unit represented by formula (C). 【Chemistry 2】 Here, M is the rare earth ion.

3. The aforementioned R ３ and R ４ The rare earth coordination polymer according to claim 1 or 2, wherein the group consists of alkyl groups having 1 to 10 carbon atoms, aryl groups having 6 to 36 carbon atoms, and halogenated hydrocarbon groups thereof.

4. The aforementioned R ３ -CF ３ , - (CF ２ ) ２ -CF ３ , and, -(C ６ H ５ Selected from the group consisting of, The aforementioned R ４ -CF ２ -CF ３ , -C(CH ３ ) ３ ,-CHF ２ , and, -CH ２ -CH ３ A rare earth coordination polymer according to claim 3, selected from the group consisting of the following.

5. The rare earth coordination polymer according to any one of claims 1 to 4, wherein the Ar is a divalent aromatic group represented by formula (1), (2), or (3). 【Transformation 3】 Here, in equations (1) to (3), X １ X in equation (A) １ It is synonymous with multiple X １ They may be the same or different, X ２ X of the aromatic ring １ This indicates a monovalent substituent bonded to a carbon atom other than the carbon atom to which it is bonded, n １ n represents an integer between 0 and 2. ２ n represents an integer from 0 to 6. ３ This represents an integer from 0 to 9, and multiple X ２ They may be the same or different, X １ The atom adjacent to the bonded carbon atom and having a bond is the carbon atom C in formula (A). １ That is the case.

6. The rare earth coordination polymer according to any one of claims 1 to 5, wherein the rare earth ion is an ion of at least one element selected from the group consisting of cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), terbium (Tb), dysprosium (Dy), gadolinium (Gd), erbium (Er), yttrium (Y), and ytterbium (Yb).

7. Dissolving a phosphine oxide ligand represented by formula (A), a diketone ligand represented by formula (B), and an organic base in an organic solvent, Dissolving trivalent rare earth salts in alcohol, The solution obtained by dissolving the phosphine oxide ligand, the diketone ligand, and the organic base in the organic solvent is mixed with the solution obtained by dissolving the trivalent rare earth salt in the alcohol and refluxed. A method for producing a rare earth coordination polymer according to any one of claims 1 to 6, comprising: 【Chemistry 4】 Here, in equation (A), C １ , C ２ and C ３ represents a carbon atom, and Ar is C １ , C ２ and C ３ Includes X １ It represents a substituted or unsubstituted divalent monocyclic aromatic group or a fused polycyclic aromatic group other than X １ R represents a halogen atom, a substituted or unsubstituted C1-C20 hydrocarbon group, a substituted or unsubstituted alkoxy group, an optionally substituted alkoxycarbonyl group, a substituted or unsubstituted alkanoyloxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted arylcarbonyloxy group, a hydroxyl group, a carboxyl group, or a cyano group. １ This represents a substituted or unsubstituted aromatic group, or a linear or cyclic aliphatic group, and multiple Ar, X groups within the same molecule. １ and R １ These may be the same or different. In equation (B), R ２ R represents a hydrogen atom or a deuterium atom. ３ and R ４ Each is selected from the group consisting of hydrocarbon groups having 1 to 10 carbon atoms, aromatic hydrocarbon groups having 6 to 36 carbon atoms, and halogenated hydrocarbon groups thereof, R ３ and R ４ They are different from each other.

8. The method according to claim 7, wherein the trivalent rare earth salt is selected from the group consisting of chlorides, sulfates, nitrates, and acetates of the trivalent rare earth ion.

9. The method according to claim 7 or 8, wherein the organic base is selected from the group consisting of triethylamine (TEA), trimethylamine, and ammonia.

10. A phosphor comprising a rare earth coordination polymer according to any one of claims 1 to 6.

11. The phosphor according to claim 10, wherein the phosphor emits fluorescence upon light stimulation, radiation stimulation, or mechanical stimulation.

12. A security material comprising a rare earth coordination polymer according to any one of claims 1 to 6.

13. A light-emitting device comprising a light-emitting light source and a phosphor, A light-emitting device comprising the phosphor described in claim 10 or 11.

14. An image display device comprising an excitation source and a phosphor, The image display device comprises the phosphor described in claim 10 or 11.

15. A radiation detector comprising a phosphor and a photoelectric converter, A radiation detector comprising the phosphor described in claim 10 or 11.

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