rare earth complex

Abstract

To provide a new rare earth complex.SOLUTION: A rare earth complex contains one rare earth ion, and a plurality of ligands coordinated to the rare earth ion. At least one of the plurality of ligands is a diketone ligand. At least one of the plurality of ligands includes a chromophore that gives the rare earth complex a maximum absorption wavelength in a wavelength region of 400-600 nm.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to rare earth complexes.

Background Art

[0002] A rare earth complex is formed by a rare earth ion and a ligand coordinated to the rare earth ion. The use of rare earth complexes for various applications such as luminescent materials has been studied (for example, Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] One aspect of the present invention aims to provide a new rare earth complex.

Means for Solving the Problems

[0005] One aspect of the present invention relates to a rare earth complex including one rare earth ion and a plurality of ligands coordinated to the rare earth ion, wherein at least one of the plurality of ligands is a diketone ligand, and at least one of the plurality of ligands has a chromophore that gives a maximum absorption wavelength in the wavelength range of 400 to 600 nm to the rare earth complex.

[0006] Since at least one of the plurality of ligands of the rare earth complex of the present invention has a chromophore that gives a maximum absorption wavelength in the wavelength range of 400 to 600 nm, it is colored with visible light in a solid or in a solution and can exhibit fluorescence emission properties derived from the rare earth complex.

[0007] In the rare earth complex, the chromophore may have a pyromethene skeleton or a merocyanine skeleton. In this case, it is colored with visible light in a solid or in a solution, and the fluorescence emission properties of the rare earth complex become even more excellent.

[0008] At least one of the plurality of ligands in the rare earth complex may be a phosphine oxide ligand having a chromophore.

[0009] The phosphine oxide ligand having a chromophore may be a ligand represented by the following formula (III). In this case, it is colored with visible light in a solid or in a solution, and the fluorescence emission properties of the rare earth complex become even more excellent.

Chemical formula

Chemical formula

Chemical formula

[0010] In the rare earth complex, the rare earth ion may be a Eu ion or a Tb ion. In this case, the fluorescence emission property of the rare earth complex becomes even more excellent.

Advantages of the Invention

[0011] According to one aspect of the present invention, a new rare earth complex can be provided. The rare earth complex according to one aspect of the present invention can be colored with visible light in a solid or in a solution and can exhibit fluorescence emission properties.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments.

[0014] 〔Rare earth complex〕 One embodiment of the present invention is a rare earth complex including one rare earth ion and a plurality of ligands coordinated to the rare earth ion, wherein at least one of the plurality of ligands is a diketone ligand, and at least one of the plurality of ligands has a chromophore that gives a maximum absorption wavelength in the wavelength range of 400 to 600 nm to the rare earth complex.

[0015] Conventional rare earth complexes include those that are excited by light in the ultraviolet region and exhibit fluorescence in the visible region. However, usually these complexes do not show absorption in the visible region that does not include light in the ultraviolet region, so they are colorless or slightly yellowish. On the other hand, the rare earth complex according to this embodiment has absorption in the wavelength range of 400 to 600 nm also in the visible region, so that the rare earth complex itself exhibits a distinct color in the visible region. That is, it is possible to provide a rare earth complex colored in a wide wavelength range (wavelength range) from the ultraviolet region to the visible region. This property is considered useful, for example, for the use as a dye for coloring a target substance. Here, the target substance may be a liquid or a solid. If a rare earth complex excited only in the ultraviolet region and an organic dye having absorption in the visible region, at least two kinds of compounds are used in combination, there is a problem that it is difficult to ensure the dyeability to the target substance due to differences in solubility and the like. According to the rare earth complex according to this embodiment, since the rare earth complex alone can impart coloring and fluorescence emission properties to the target substance, it is easy to maintain the dyeability and the functional imparting becomes simpler.

[0016] The rare earth ion is a divalent to tetravalent rare earth ion, and may be a divalent or trivalent rare earth ion. The rare earth ion may be, for example, an ion of a lanthanum series element such as La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. From the viewpoint of further improving the fluorescence emission property, the rare earth ion may be a Eu ion or a Tb ion.

[0017] At least one of the plurality of ligands coordinated to the rare earth ion is a diketone ligand (β-diketone ligand). By having a diketone ligand, the rare earth complex can have good fluorescence emission property. Other ligands than the diketone ligand may be coordinated to the rare earth ion. The other ligand than the diketone ligand may be, for example, a phosphine oxide ligand.

[0018] At least one of the ligands has a chromophore that gives a maximum absorption wavelength in the wavelength range of 400 to 600 nm. The wavelength range may be, for example, 450 to 550 nm. That at least one of the ligands in the rare earth complex has the above chromophore is confirmed by measuring the absorbance of the rare earth complex and measuring the maximum absorption wavelength of the rare earth complex. The measurement of the absorbance of the rare earth complex can be measured under the conditions described in the examples below.

[0019] From the viewpoint of further improving the fluorescence emission property of the rare earth complex moiety, it is preferable that the absorption in the ultraviolet light region with a wavelength of less than 400 nm is small for the chromophore. The reason is that in the fluorescence process of the rare earth complex, first, the diketone ligand absorbs light in the ultraviolet light region of 300 to 400 nm and becomes an excited state. From here, energy transfer occurs to the rare earth metal center, and fluorescence of the rare earth complex is obtained. Therefore, it is required that the ligand having a chromophore does not affect the fluorescence of the rare earth complex. Therefore, it is preferable that the absorption at a wavelength of less than 400 nm is as small as possible.

[0020] The molar extinction coefficient at the maximum absorption wavelength in the wavelength range of 400 to 600 nm of the rare earth complex may be, for example, 1000 or more, or 5000 or more, and may be, for example, 200000 or less.

[0021] The ligand having a chromophore may be a compound having a coordination group that forms a coordination bond with a rare earth ion and a group containing a chromophore. The coordination group of the ligand having a chromophore may be, for example, a phosphine oxide group or a β-diketonato group. The ligand having a chromophore may be a monodentate or bidentate ligand. The number of groups containing a chromophore in one molecule may be, for example, 1 to 5, and may be 1. When a plurality of chromophores are contained in one molecule, the chromophores may be of the same kind or different kinds.

[0022] The chromophore may have at least one skeleton selected from the group consisting of a dye skeleton having a property that absorption of light with a wavelength of less than 400 nm is sufficiently small, for example, a pyromethene skeleton (for example, a boron dipyrromethene skeleton) and a merocyanine skeleton. Since the chromophore having the above-described skeleton has sufficiently small absorption of light with a wavelength of less than 400 nm necessary for excitation of the rare earth complex, the rare earth complex containing the above-described chromophore has sufficient coloring property and more excellent fluorescence emission property.

[0023] The ligand having a chromophore containing a pyromethene skeleton (boron dipyrromethene skeleton) may contain a group containing a chromophore represented by, for example, the following formula (I). When containing the chromophore represented by the following formula (I), the rare earth complex can have coloring property and more excellent fluorescence emission property.

Chemical formula

[0024] In formula (I), * represents a bond. n and m each independently represent an integer from 0 to 3. n and m may be 0 to 2, 0 to 1, or 0.

[0025] R 11 and R 12Each independently represents a monovalent organic group containing a second linking group, an alkyl group, a cyano group (-CN), a nitro group, a sulfo group, a hydroxy group (-OH), an amino group, a silyl group, a phosphonic acid group, a diazo group, a mercapto group, or a halogen atom. The second linking group may be at least one selected from the group consisting of a carbonyl group (-C(=O)-), an ester group (-COO-), an amide group (-NH-C(=O)-), an ether group (-O-), and a thioether group (-S-). R 11 and R 12 The number of carbon atoms of the alkyl group represented by may be, for example, 1 to 20, 1 to 15, 1 to 10, or 1 to 6. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. The halogen atom may be, for example, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. When m is 2 or more, a plurality of R 11 may be the same or different, and when n is 2 or more, a plurality of R 12 may be the same or different.

[0026] L 1 represents a divalent organic group containing a first linking group, an alkylene group, or a phenylene group. The first linking group may be at least one selected from the group consisting of a carbonyl group (-C(=O)-), an ester group (-COO-), an amide group (-NH-C(=O)-), an ether group (-O-), and a thioether group (-S-). L 1 may be, for example, an alkylene group containing a first linking group, an arylene group containing a first linking group (for example, a phenylene group), or a group consisting of a first linking group, an alkylene group, and an arylene group. The group represented by formula (I) may be bonded to the ligand via an ether group (-O-) or a thioether group (-S-).

[0027] The group represented by formula (I) may be, for example, a group represented by the following formula (Ia).

Chemical formula

[0028] In formula (Ia), m, n, R 11 , R 12 and * have the same meanings as described above. o represents an integer from 0 to 4. o may be 0 to 3, 0 to 2, 0 to 1, or 0. R 13 represents a monovalent organic group containing a fourth linking group, an alkyl group, a cyano group, a hydroxy group, a nitro group, a sulfo group, an amino group, a silyl group, a phosphonic acid group, a diazo group, a mercapto group, or a halogen atom. The fourth linking group may be at least one selected from the group consisting of a carbonyl group, an ester group, an amide group, an ether group, and a thioether group. R 13 Specific examples of the substituent represented by are the same as the above R 11 and R 12 may be the same.

[0029] L 2 represents an alkylene group or an arylene group. L 2 The number of carbon atoms of the alkylene group represented by may be, for example, 1 to 12, 1 to 10, or 1 to 6. L 2 The alkylene group represented by may be, for example, a methylene group (-CH2-), an ethylene group, a propylene group, a butylene group, a pentylene group, or a hexylene group. L 2 The arylene group represented by may be, for example, a phenylene group (-C6H4-), or a naphthylene group.

[0030] The group represented by formula (I) may be a group represented by the following formula (Ib) in which m, n, and o are 0 and L 2 is a methylene group.

Chemical formula

[0031] The ligand having a chromophore containing a merocyanine skeleton may contain, for example, a group containing a chromophore represented by the following formula (II). When containing the chromophore represented by the following formula (II), the rare earth complex can have coloring properties and more excellent fluorescence emission properties.

Chemical formula

[0032] In formula (II), p represents an integer from 0 to 4. p may be 0 to 3, 0 to 2, 0 to 1, or 0. * represents a bond.

[0033] R 21 represents a monovalent organic group containing a third bonding group, an alkyl group, a cyano group, a hydroxy group, a nitro group, a sulfo group, an amino group, a silyl group, a phosphonic acid group, a diazo group, a mercapto group, or a halogen atom. The third bonding group is at least one selected from the group consisting of a carbonyl group, an ester group, an amide group, an ether group, and a thioether group. When p is 2 or more, a plurality of R 21 may be the same or different. The details of the substituent represented by R 21 may be the same as those of the substituents represented by R 11 and R 12 .

[0034] R 22 ~R 25 each independently represents a C 1-12 alkyl group. The C 22 ~R 25 alkyl group represented by is an alkyl group having 1 to 12 carbon atoms. R 1-12 ~R 22 ~R 25 may be, for example, a C 1-12 alkyl group having 1 to 12 carbon atoms, a C 1-6 alkyl group having 1 to 10 carbon atoms, or a C 1-6 alkyl group having 1 to 6 carbon atoms. The C 1-12 alkyl group may be, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group.

[0035] L 3 represents an alkylene group or an arylene group. The details of the alkylene group and arylene group represented by L 3 may be as described above.

[0036] The group represented by formula (II) has p = 0 and R 22~R 25 is a methyl group, and L 3 is an n-propylene group (-CH2-CH2-CH2-), and may be a group represented by the following formula (IIa). In this case, the rare earth complex can have coloring properties and more excellent fluorescence emission properties.

Chemical formula

[0037] At least one of the plurality of ligands may be a phosphine oxide ligand having the above chromophore. That is, at least one of the plurality of ligands in the rare earth complex may be a phosphine oxide ligand having a chromophore, represented by the following formula (III). In this case, the rare earth complex can have coloring properties and more excellent fluorescence emission properties.

Chemical formula

[0038] Z 1 represents a group containing the above chromophore, for example, a group represented by the above formula (I) or (II).

[0039] X 11 and X 12 are each independently an aromatic group, a heteroaromatic group, a C 1~12 alkyl group, a C 3~12 alkenyl group, a C 3~12 cycloalkyl group, a C 3~12 cycloalkenyl group, a C 3~12 alkynyl group, an aromatic oxy group, a heteroaromatic oxy group, a C 1~12 alkyloxy group, a C 3~12 alkenyloxy group, a C 3~12 cycloalkyloxy group, a C 3~12 cycloalkenyloxy group, or a C 3~12 alkynyl oxy group.

[0040] The aromatic group may be a phenyl group, a naphthyl group, a biphenyl group, etc. The heteroaromatic group may be a pyrrolyl group, a fulleryl group, an indolyl group, a thienyl group, etc. At least a part of the hydrogen atoms bonded to the aromatic group or the heteroaromatic group may be substituted with other groups, and may have at least one substituent selected from the group consisting of, for example, a hydroxy group, a nitro group, an amino group, a sulfo group, a cyano group, a silyl group, a phosphonic acid group, a diazo group, a mercapto group, and a halogen atom.

[0041] C 1~12 The alkyl group is an alkyl group having 1 to 12 carbon atoms. 1~12 Alkyl group (C n H 2n+1 : n = 1 to 12) may be linear or branched. 1~12 At least one hydrogen atom of the alkyl group may be substituted with another group or may not be substituted. 1~12 The alkyl group is, for example, a perfluoroalkyl group (C n F 2n+1 : n = 1 to 12) and perchloroalkyl groups (C n Cl 2n+1 : n = 1 to 12) or other linear or branched C 1~12 Examples of the alkyl group having a substituent include aralkyl groups such as a benzyl group and a phenethyl group, and perhalogenated aralkyl groups such as a perfluorobenzyl group.

[0042] C 3~12 The alkenyl group is an alkenyl group having 3 to 12 carbon atoms. 3~12 The alkenyl group may be linear or branched. 3~12 Examples of the alkenyl group include an allyl group and a butenyl group. 3~12 At least one hydrogen atom of the alkenyl group may be substituted with another group or may not be substituted. 3~12The alkenyl group is, for example, a perfluoroalkenyl group such as a perfluorovinyl group, a perfluoroallyl group, and a perfluorobutenyl group, and a perchloroalkenyl group, etc., a linear or branched C 3~12 A perhalogenated alkenyl group can be mentioned.

[0043] C 3~12 The cycloalkyl group is a cycloalkyl group having 3 to 12 carbon atoms. C 3~12 The alkenyl group may have a linear or branched structure. C 3~12 At least one hydrogen atom of the cycloalkyl group may or may not be substituted with another group. The C with a substituent 3~12 The cycloalkyl group is, for example, a perfluorocycloalkyl group (C n F 2n-1 : n = 3 to 12) and a perchlorocycloalkyl group (C n Cl 2n-1 : n = 3 to 12), etc. C 3~12 A perhalogenated cycloalkyl group can be mentioned.

[0044] C 3~12 The cycloalkenyl group is a cycloalkenyl group having 3 to 12 carbon atoms. C 3~12 Examples of the cycloalkenyl group include a cyclopentenyl group and a cyclohexenyl group, etc. C 3~12 At least one hydrogen atom of the cycloalkenyl group may or may not be substituted with another group. The C with a substituent 3~12 The cycloalkenyl group may be, for example, a perfluorocycloalkenyl group and a perchlorocycloalkenyl group, etc. C 3~12 A perhalogenated cycloalkenyl group.

[0045] C 3~12 The alkynyl group is an alkynyl group having 3 to 12 carbon atoms. C 3~12 At least one hydrogen atom of the alkynyl group may or may not be substituted with another group.

[0046] The aromatic oxy group is a group in which the above-mentioned aromatic group and an oxy group (-O-) are bonded. The heteroaromatic oxy group is a group in which the above-mentioned heteroaromatic group and an oxy group are bonded. C 1~12 The alkyloxy group is the above-mentioned C 1~12 a group in which an alkyl group and an oxy group are bonded. C 3~12 The alkenyloxy group is the above-mentioned C 3~12 a group in which an alkenyl group and an oxy group are bonded. C 3~12 The cycloalkyloxy group is the above-mentioned C 3~12 a group in which a cycloalkyl group and an oxy group are bonded. C 3~12 The cycloalkenyloxy group is the above-mentioned C 3~12 a group in which a cycloalkenyl group and an oxy group are bonded. C 3~12 The alkynyloxy group of C 3~12 is a group in which the above-mentioned alkynyl group and an oxy group are bonded.

[0047] X 11 and X 12 The above-mentioned groups represented by are such that one or more of -COO- and -CO- may be inserted between the C-C single bonds at any position thereof.

[0048] X 11 and X 12 may each independently be an aromatic group and may be a phenyl group.

[0049] The ligand having a chromophore may specifically be a compound represented by the following formula (A-1) or (A-2). In this case, the rare earth complex can have coloring properties and more excellent fluorescence emission properties.

Chemical formula

Chemical formula

[0050] The rare earth complex according to this embodiment may be, for example, a complex represented by the following formula (IV). [Chemical formula]

[0051] In the formula, Ln represents a rare earth element, n1 represents an integer from 2 to 4, n2 represents an integer from 2 to 4, and n3 represents an integer from 0 to 2.

[0052] X 21 , X 22 and X 23 each independently represents an aromatic group, a heteroaromatic group, a C 1~12 alkyl group, a C 3~12 alkenyl group, a C 3~12 cycloalkyl group, a C 3~12 cycloalkenyl group, a C 3~12 alkynyl group, an aromatic oxy group, a heteroaromatic oxy group, a C 1~12 alkyloxy group, a C 3~12 alkenyloxy group, a C 3~12 cycloalkyloxy group, a C 3~12 cycloalkenyloxy group, a C 3~12 alkynyl oxy group, or a group containing a chromophore.

[0053] Y 1 and Y 2 each independently represents an aromatic group, a heteroaromatic group, a C 1~12 alkyl group, a C 3~12 alkenyl group, a C 3~12 cycloalkyl group, a C 3~12 cycloalkenyl group, a C 3~12 alkynyl group, or a group containing a chromophore. Examples of the heteroaromatic group include a thiophenyl group.

[0054] X 21 , X 22 , X 23 , Y 1 and Y 2 represented by C 1~12 alkyl group, a C 3~12 alkenyl group, a C 3~12 cycloalkyl group, and a C 3~12In the cycloalkenyl group, some or all of the hydrogen atoms may be substituted with halogen atoms, for example, fluorine atoms or chlorine atoms.

[0055] X 21 , X 22 , X 23 , Y 1 and Y 2 Specific examples of the substituent represented by the formula (I) may be as described above.

[0056] Y 3 represents a hydrogen atom or a deuterium atom.

[0057] If n3 is 0, then Y 1 and Y 2 At least one of the groups is a group containing a chromophore. When n3 is 1 to 2, X 21 , X 22 , X 23 , Y 1 and Y 2 At least one of or any one of the groups is a group containing a chromophore.

[0058] [Method for producing rare earth complex] The rare earth complex can be produced by a method including a step of reacting a complex precursor containing a rare earth ion with a ligand having a chromophore to coordinate the ligand having a chromophore to the rare earth ion. The reaction may be carried out while heating. Specific examples of reaction conditions may be as described in the examples below.

[0059] The ligand having a chromophore can be produced according to a conventional synthesis method, and examples of the synthesis method of the ligand having a chromophore will be shown in the examples described later.

[0060] For example, a ligand compound having a chromophore (compound B) represented by formula (B) can be synthesized according to the following reaction scheme. [ka]

[0061] Compound B can be obtained by a method including a step of reacting Compound (Compound 1) represented by Formula (1), ethyl cyanoacetate, Compound (Compound 2) represented by Formula (2), and a base to obtain Compound (Compound 3) represented by Formula (3), and a step of reacting Compound 3, Compound (Compound 4) represented by Formula (4), and acetic anhydride to obtain Compound B.

[0062] In the formula, X 31 and X 32 are the same as X 21 and X 22 in Formula (IV). q is the same as p in Formula (II). R 31 ~R 35 are the same as R 21 ~R 25 in Formula (II). R 36 represents a hydrocarbon group such as an alkyl group. R 31 may be, for example, a methyl group or an ethyl group.

[0063] Compound 1 can be produced according to a conventional synthesis method. An example of the synthesis method of Compound 1 is as described in the Examples below.

[0064] The reaction for obtaining Compound 3 is usually carried out in the presence of a base. The base may be, for example, piperidine, pyridine, triethylamine, and / or hexamethyleneimine. The reaction for obtaining Compound 3 may be carried out in the presence of a solvent. Examples of the solvent include ethanol, dichloromethane, tetrachloroethane, carbon tetrachloride, diethyl ether, tetrahydrofuran, benzene, toluene, etc. The reaction for obtaining Compound 3 may be carried out while heating. After the reaction is completed, post-treatment may be carried out by a conventional method. Specific examples of the reaction conditions are as described in the Examples below.

[0065] Compound 3 is useful as a precursor compound of Compound B. Another embodiment of the present invention is a compound represented by formula (3). In the compound represented by formula (3), from the viewpoint of easily obtaining a ligand capable of forming a rare earth complex having sufficient coloring property and more excellent fluorescence emission property, R 35 may be a C 1-10 alkyl group, and may be a C 1-6 alkyl group, and may be a methyl group. L 4 may be an alkylene group from the viewpoint of easily obtaining a ligand capable of forming a rare earth complex having sufficient coloring property and more excellent fluorescence emission property, and may be, for example, an n-propylene group. The compound represented by formula (3) may specifically be a compound represented by the following formula (3-1). In this case, a ligand capable of forming a rare earth complex having sufficient coloring property and more excellent fluorescence emission property can be easily obtained.

Chemical formula

[0066] 〔Resin composition〕 Another embodiment of the present invention is a resin composition containing the above rare earth complex and a resin.

[0067] Examples of the resin include polymethyl (meth) acrylate, polycarbonate, polystyrene, polyurethane, polycarbonate, polyether, polyamide, polyester, polyvinyl chloride, silicone, epoxy resin, fluororesin, polyethylene, polypropylene, etc. The resin may be a copolymer obtained by combining various monomers or a mixture of a plurality of resins.

[0068] The shape of the resin may be film-like, sheet-like, fibrous, woven fabric, paper, particulate, pellet-like, or liquid.

[0069] The rare earth complex can be incorporated into the resin composition by the following methods. For example, a method of impregnating and drying an object in the form of a film, fiber, or particle in a solution containing the rare earth complex, or a method of dissolving the rare earth complex and the resin in an organic solvent and applying and drying them on a substrate using various coating techniques, or a method of adding a dye solution to a resin fine particle dispersion and dyeing, or a method of directly adding the rare earth complex during the melt-kneading of resin pellets, etc. A plurality of methods can be selected.

[0070] The content of the rare earth complex in the resin composition is appropriately selected according to the purpose of the resin composition. For example, the content of the rare earth complex in the resin composition may be 0.001 parts by mass or more, or 0.01 parts by mass or more, and may be 0.5 parts by mass or less, or 0.4 parts by mass or less, based on 1 part by mass of the resin.

[0071] The content of the resin can be appropriately adjusted according to the use, required properties, etc. of the resin composition. The content of the resin in the resin composition may be 50% by mass or more, or 60% by mass or more, and may be 99.9% by mass or less, or 99% by mass or less, based on the total mass of the resin composition.

[0072] The resin composition may contain an inorganic substance inside and / or within the resin. Examples of candidates for the inorganic substance include ceramic fillers such as silica, alumina, silicon nitride, boron nitride, etc., or metal particles such as iron, nickel, cobalt, etc.

[0073] The resin composition may further contain other components. Examples of other components include additives such as antioxidants, ultraviolet absorbers, light stabilizers, flame retardants, lubricants, plasticizers, antistatic agents, thixotropic agents, surfactants, thickeners, inorganic fillers, pigments, etc.

[0074] The resin composition can be produced by a method including a step of mixing the resin and the rare earth complex.

[0075] The resin composition can be used, for example, in the dyeing of plastic raw materials, coating and film-forming materials such as paints, printing inks, and paint materials, writing instruments such as paints and pens, toys, resins for 3D printers, agricultural films, display plates for safety, disaster prevention, and crime prevention products, fluorescent labeling agents for biomolecules such as proteins and nucleic acids, labeling agents for immunoassay methods, etc.

Examples

[0076] Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to the following examples. In the following description, "TTA" is an abbreviation for thenoyltrifluoroacetone, and "TOPO" is an abbreviation for trioctylphosphine oxide.

[0077] <Synthesis of Ligand 1> Synthesis Example 1-1: Synthesis of (3-aminopropyl)diphenylphosphine oxide

Chemical formula

[0078] 10 mL of dry benzene and 5 mL of chloroform were added to 3.8 mol of 3-chloropropylamine hydrochloride. Then, 8.3 mmol of a triethylamine solution (dissolved in 3.3 mL of dry benzene and 1.7 mL of chloroform) was added. After stirring for 20 minutes, it was cooled to 2 - 4°C, and 3.8 mmol of a diphenylchlorophosphine solution (dissolved in 6.6 mL of dry benzene and 3.4 mL of chloroform) was added. After stirring for 1 hour, the temperature was raised to reflux, and stirring was continued for another 1 hour. The temperature was lowered to room temperature, and the solvent was distilled off. The residue was dissolved in 50 mL of chloroform and extracted with 100 mL of distilled water. The organic layer was removed, an aqueous sodium hydroxide solution was added until pH = 10, and extraction was performed with 100 mL of chloroform. Chloroform was distilled off to obtain the compound represented by the above formula (1-1) as the target product. The yield was 75%.

[0079] Synthesis Example 1-2: Synthesis of 1-(3-diphenylphosphoryl)propyl)-6-hydroxy-4-methyl-2-oxo-1,2-dihydropyridine-3-carbonitrile

Chemical formula

[0080] To 1 mmol of the compound represented by the above formula (1-1), 1 mmol of ethyl cyanoacetate and 5 mL of ethanol were added, and the mixture was stirred at room temperature for 6 hours. Then, 1.1 mmol of ethyl acetoacetate and 0.1 mL of piperidine were added, and the mixture was stirred at 110 °C. After cooling to room temperature, the solvent was distilled off, and 10 mL of 10% hydrochloric acid was added. The resulting precipitate was collected by filtration, washed with distilled water and hexane, and dried to obtain the compound represented by the above formula (1-2) as the target product. The yield was 65%.

[0081] Synthesis Example 1-3: Synthesis of (Z)-5-(2-((E)-3,3-dimethylindolin-2-ylidene)ethylidene)-1-(3-(diphenylphosphoryl)propyl)-4-methyl-2,6-dioxo-1,2,5,6-tetrahydropyridine-3-carbonitrile

Chemical formula

[0082] To 1 mmol of the compound represented by the above formula (1-2), 1.05 mmol of 2-(1,3,3-trimethylindolin-2-ylidene)acetaldehyde and 3 mL of acetic anhydride were added, and the mixture was refluxed for 15 minutes. After collecting the resulting precipitate by filtration, it was washed with hexane and dried to obtain the compound represented by the above formula (1-3). The yield was 82%. 31 P-NMR: 32.4 ppm (solvent: chloroform)

[0083] The fact that the compound represented by the above formula (1-3) was obtained was confirmed by X-ray crystal structure analysis. The results of the X-ray crystal structure analysis are shown in Figure 1. The measurement was performed using D8 VENTURE, and the analysis was performed using VESTA.

[0084] <Synthesis of rare earth complexes of examples> Synthesis Examples 1-4: Synthesis of Eu complexes of examples

Chemical formula

[0085] To 1 mmol of the compound represented by the above formula (1-3), 1 mmol of Eu(TTA)3·2H2O and 10 mL of isopropanol were added, and the mixture was refluxed at 80 °C for 4 hours. The solvent was distilled off to obtain the Eu complex of the example, which was the target product. The yield was 87%. 31 P-NMR: -93.1 ppm (solvent: chloroform), nanoESI-MS: 1414.1064 (C 59 H 46 O9N3F9PS3Eu+Na + , theoretical value: 1414.1095)

[0086] <Synthesis of ligand 2> Synthesis Example 2-1: Synthesis of 4-(5,5-difluoro-5H-4l4,5l4-dipyrrolo[1,2-c:2’,1’-f][1,3,2]diazaborinin-10-yl)benzyldiphenylphosphinate

Chemical formula

[0087] <Synthesis of rare earth complexes of comparative examples> Comparative Synthesis Example: Synthesis of Eu(TTA)3·(TOPO)2

Chemical formula

[0088] 1 mmol of Eu(TTA)3·2H2O and 2 mmol of TOPO (trioctylphosphine oxide) were added to 10 mL of ethanol and stirred at room temperature. The solvent was distilled off to obtain the target product. Recrystallization was performed using ethanol and distilled water for purification. Thus, the Eu complex (Eu(TTA)3·(TOPO)2) of the comparative example was obtained. The yield was 78%. 31 P-NMR: -49.8 ppm (solvent: chloroform), nanoESI-MS: 1611.6082 (C 72 H 114 O8F9P2S3Eu+Na + , theoretical value: 1611.6117)

[0089] Evaluation 0.35 mmol of the Eu complex was dissolved in 10 mL of chloroform and diluted 1000-fold to obtain a measurement sample.

[0090] For the measurement of the absorption wavelength, a Jasco V-650 spectrophotometer was used to measure the absorbance. For the measurement of the excitation wavelength and the fluorescence wavelength, a Hitachi High-Tech F-7000 and a long-pass filter: LPF-39 were used to measure the photoluminescence intensity (PL Intensity). A square cell (□10 mm, made of quartz) was used for the measurement. For the measurement of the excitation wavelength, 615 nm was set as the monitor wavelength. For the measurement of the fluorescence wavelength, 350 nm was set as the excitation wavelength.

[0091] The measurement results of the absorption wavelength, excitation wavelength, and fluorescence wavelength of the Eu complex of the example (the Eu complex represented by the above formula (1-4)) are shown in FIGS. 2 to 4. The measurement results of the absorption wavelength, excitation wavelength, and fluorescence wavelength of the Eu complex of the comparative example are shown in FIGS. 5 to 7.

[0092] <Preparation and Evaluation of Colored Resin Composition> 8.0 g of chloroform was dissolved with 2.0 g of a general-purpose polystyrene resin and 0.050 g of the compound represented by the formula (1-4) to prepare a resin solution. The resin solution was applied onto a glass plate using a bar coater, and the solvent was air-dried to form a colored resin film with a film thickness of 10 μm. Absorption wavelength and fluorescence wavelength measurements were performed on this film. For the absorption wavelength measurement, a Jasco V-650 spectrophotometer was used. For the fluorescence wavelength measurement, an Otsuka Electronics MCPD9800 was used, and the excitation wavelength was set to 365 nm. The results of the absorption wavelength measurement and the fluorescence wavelength measurement are shown in FIGS. 8 to 9, respectively.

Claims

**Claim 1** A rare earth complex comprising one rare earth ion and a plurality of ligands coordinated to the rare earth ion, wherein at least one of the plurality of ligands is a diketone ligand, at least one of the plurality of ligands is a phosphine oxide ligand having a chromophore that gives the rare earth complex a maximum absorption wavelength in the wavelength range of 400 to 600 nm, the phosphine oxide ligand having the chromophore is a ligand represented by the following formula (III). 【Chemical 1】 [In the formula, X11 and X12 each independently represent an aromatic group, a heteroaromatic group, a C1-12 alkyl group, a C3-12 alkenyl group, a C3-12 cycloalkyl group, a C3-12 cycloalkenyl group, a C3-12 alkynyl group, an aromatic oxy group, a heteroaromatic oxy group, a C1-12 alkyloxy group, a C3-12 alkenyloxy group, a C3-12 cycloalkyloxy group, a C3-12 cycloalkenyloxy group, or a C3-12 alkynyloxy group, Z1 represents a group represented by the following formula (Ib) or (IIa). [Chemical 2] 【Chemical Formula 3】 **Claim 2** The rare earth complex according to claim 1, wherein the rare earth ion is a Eu ion or a Tb ion.

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