Method for producing rare earth complex with coumarin skeleton

Abstract

To provide a method for producing a rare earth metal complex with high purity on an industrial scale.SOLUTION: A coumarinato compound with a specific structure represented by formula (4cm) is used to produce a rare earth complex. [CU is a coumarinato ligand. M3+ is a trivalent rare earth ion. L1 is a specific ligand. m1 is 1 or 2.]SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a rare earth complex having a coumarin skeleton. [Background technology]

[0002] Optoelectronics, such as optical communications and displays, and the light energy conversion industry, such as solar cells, are key technologies of the next generation, and various inorganic glass materials, ceramic materials, laser materials, organic low-molecular-weight luminescent materials, wavelength conversion materials, etc. are being created for use in these fields.

[0003] A wavelength conversion material is a material that absorbs light of a specific wavelength and emits light of a different wavelength, and can be used as an optical material by adding it to a resin material.

[0004] In recent years, rare earth complexes having β-diketonato and phosphine oxide ligands (Patent Documents 1 and 2) and rare earth complexes having phenanthroline ligands (Non-Patent Document 1) have been reported as such wavelength conversion materials. These rare earth complexes can absorb short-wavelength light such as ultraviolet light and emit longer-wavelength visible light, and therefore can be used in light-emitting devices that emit various colors of light when combined with semiconductor light-emitting elements such as light-emitting diodes (LEDs) (Patent Document 3).

[0005] The rare earth complexes include rare earth complexes having a coumarinato ligand (Non-Patent Document 2 and Patent Document 4). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] USSR Patent Invention No. 1453860 [Patent Document 2] JP 2003-81986 A [Patent Document 3] JP 2005-15564 A [Patent Document 4] International Publication No. 2023 / 282236 [Non-patent literature]

[0007] [Non-Patent Document 1] CrystEngComm,,vol.11,,pp.1197(2009) [Non-Patent Document 2] Inorganic Chemistry, Vol. 57, p. 908 (2018) Summary of the Invention [Problem to be solved by the invention]

[0008] However, when a rare earth complex having a specific coumarinato ligand is produced using a conventional production method, it can be synthesized with good purity in a small-scale reaction, but on a large scale, the reaction time takes time, which causes hydrolysis of the coumarinato ligand to progress and produces by-products that are difficult to remove, making it impossible to produce a rare earth complex with good purity. In addition, Patent Document 4 discloses a method for producing a rare earth complex having a coumarinato ligand, but does not provide a specific example of a method for producing a rare earth complex using a coumarinato compound having an organic cation as disclosed in this disclosure. The present disclosure aims to provide a method for producing a rare earth complex having a coumarinato ligand with good purity even on a large scale. [Means for solving the problem]

[0009] As a result of extensive research aimed at solving the above problems, the present inventors have found that a rare earth complex can be produced with high purity by carrying out a reaction using a coumarinato compound having an organic cation in a two-phase solvent of an organic solvent and water.

[0010] That is, the present invention is as described in the claims, and the gist of the present disclosure is as follows. [1] An enolate salt represented by the following formula (4cm) and L 1A method for producing a rare earth complex (1c), comprising reacting a nitrogen-containing ligand having two or more nitrogen atoms each having an unshared electron pair; or a phosphorus ligand represented by the following formula (3a) with a rare earth compound in the presence of an organic solvent and water:

[0011] [ka]

[0012] {CU is a coumarinato ligand represented by general formula (1cu).

[0013] [ka]

[0014] (In the formula, R A R represents a fluoroalkyl group having 1 to 4 carbon atoms. C1 , R C2 , R C3 and R C4 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms which may be substituted with one or more alkyloxy groups having 1 to 4 carbon atoms, an aryl group having 6 to 14 carbon atoms which may be substituted with one or more alkyloxy groups having 1 to 4 carbon atoms, a dialkylamino group having 2 to 8 carbon atoms, a diphenylamino group, a carbazol-9-yl group, a phenoxy group, or a thiophenoxy group. The diphenylamino group and the carbazol-9-yl group may be substituted with one or more fluorine atoms, cyano groups, or nitro groups. In addition, R C1 , R C2 , R C3 and R C4 Among these, two adjacent substituents may be bonded together with the benzene ring to form a 5-, 6-, or 7-membered ring. C A+ represents a monovalent organic cation. m 1 represents 1 or 2. L 1represents a nitrogen-containing ligand having two or more nitrogen atoms having an unshared electron pair or a phosphorus ligand represented by the following general formula (3a):

[0015] [ka]

[0016] [In the formula, X A each independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group represented by the following general formula (3c):

[0017] [ka]

[0018] (In the formula, X 1 each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an aryl group having 6 to 22 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, or a haloalkyloxy group having 1 to 6 carbon atoms, and the aryl group may be substituted with one or more substituents selected from the group consisting of a halogen atom, an alkyloxy group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, a haloalkyloxy group having 1 to 6 carbon atoms, a hydroxyl group, a cyano group, and a nitro group.)] M 3+ represents a trivalent rare earth metal ion. [2] The method for producing the rare earth complex (1c) according to [1], wherein the organic solvent is an aromatic hydrocarbon. [3] The method for producing a rare earth complex (1c) according to [1] or [2], wherein the volume ratio of the organic solvent to the water is 1:0.5 to 2.5. [4] A method for producing the rare earth complex (1c) according to any one of [1] to [3], wherein the enolate salt represented by formula (4cm) is used in an amount of 3.0 to 3.3 molar equivalents relative to the rare earth compound. [5] C A+The method for producing a rare earth complex (1c) according to any one of [1] to [4], wherein is imidazolium. [6] M 3+ The method for producing a rare earth complex (1c) according to any one of [1] to [5], wherein is a europium ion. [7]L 1 The method for producing the rare earth complex (1c) according to any one of [1] to [6], wherein is any one of tributylphosphine oxide, trioctylphosphine oxide, tricyclohexylphosphine oxide, triphenylphosphine oxide, tri(o-tolyl)phosphine oxide, tri(o-methoxyphenyl)phosphine oxide, and o-biphenyldiphenylphosphine oxide. [8] A method for producing a rare earth complex (1c), comprising the steps of: Step A: 4-hydroxycoumarin compound represented by the general formula (4cus)

[0019] [ka]

[0020] (In the formula, R C1 , R C2 , R C3 and R C4 Among these, two adjacent substituents may be bonded together with the benzene ring to form a 5-, 6-, or 7-membered ring. and an acid anhydride represented by formula (1ah)

[0021] [ka]

[0022] (In the formula, R A represents a fluoroalkyl group having 1 to 4 carbon atoms. in the presence of an organic base,

[0023] [ka]

[0024] (C A+ R represents a monovalent organic cation. A , R C1 , R C2 , R C3 and R C4 has the same meaning as above.) The process of obtaining the above. Step B: Reacting an enolate salt represented by formula (4cm) with L 1 A rare earth complex (1c), which is characterized by reacting a nitrogen-containing ligand represented by the following formula (3a) having two or more nitrogen atoms each having an unshared electron pair with a rare earth compound in the presence of an organic solvent and water:

[0025] [ka]

[0026] {CU is a coumarinato ligand represented by formula (1cu).

[0027] [ka]

[0028] (In the formula, R A , R C1 , R C2 , R C3 and R C4 has the same meaning as above.) C Ahas the same meaning as above. m 1 represents 1 or 2. L 1 represents a nitrogen-containing ligand having two or more nitrogen atoms having an unshared electron pair or a phosphorus ligand represented by the following formula (3a):

[0029] [ka]

[0030] [In the formula, X A each independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group represented by the following formula (3c):

[0031] [ka]

[0032] (In the formula, X 1 each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an aryl group having 6 to 22 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, or a haloalkyloxy group having 1 to 6 carbon atoms, and the aryl group may be substituted with one or more substituents selected from the group consisting of a halogen atom, an alkyloxy group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, a haloalkyloxy group having 1 to 6 carbon atoms, a hydroxyl group, a cyano group, and a nitro group. M 3+ represents a trivalent rare earth metal ion. The process of obtaining the above. [9] The method for producing the rare earth complex (1c) according to [8], wherein the organic solvent is an aromatic hydrocarbon.

[10] The method for producing a rare earth complex (1c) according to [8] or [9], wherein the volume ratio of the organic solvent to the water is 1:0.5 to 2.5.

[11] A method for producing the rare earth complex (1c) according to any one of [8] to

[10] , wherein the enolate salt represented by the general formula (4cm) is used in an amount of 3.0 to 3.3 molar equivalents relative to the rare earth compound.

[12] C A+ The method for producing a rare earth complex (1c) according to any one of [8] to

[11] , wherein is imidazolium.

[13] M 3+ The method for producing a rare earth complex (1c) according to any one of [8] to

[12] , wherein is a europium ion.

[14] L 1 The method for producing the rare earth complex (1c) according to any one of the above items [8] to

[13] , wherein is any one of tributylphosphine oxide, trioctylphosphine oxide, tricyclohexylphosphine oxide, triphenylphosphine oxide, tri(o-tolyl)phosphine oxide, tri(o-methoxyphenyl)phosphine oxide, and o-biphenyldiphenylphosphine oxide. Effect of the Invention

[0033] The present disclosure makes it possible to efficiently synthesize rare earth complexes with high purity. [Brief description of the drawings]

[0034] [Figure 1] 1 shows the UV-Vis and emission spectra of the rare earth complex (1c-204) of the present disclosure obtained in Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] The present disclosure will be described in detail below. However, the following description of the components is merely an example of an embodiment of the present disclosure, and the present disclosure is not limited to the contents thereof.

[0036] (Production method of rare earth complex (1c)) The method for producing the rare earth complex (1c) comprises reacting an enolate salt represented by the following formula (4cm) with L 1 and having two or more nitrogen atoms each having an unshared electron pair; or a phosphorus ligand represented by the following formula (3a); with a rare earth compound in the presence of an organic solvent and water.

[0037] [ka]

[0038] {CU is a coumarinato ligand represented by formula (1cu).

[0039] [ka]

[0040] (In the formula, R A R represents a fluoroalkyl group having 1 to 4 carbon atoms. C1 , R C2 , R C3 and R C4 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms which may be substituted with one or more alkyloxy groups having 1 to 4 carbon atoms, an aryl group having 6 to 14 carbon atoms which may be substituted with one or more alkyloxy groups having 1 to 4 carbon atoms, a dialkylamino group having 2 to 8 carbon atoms, a diphenylamino group, a carbazol-9-yl group, a phenoxy group, or a thiophenoxy group. The diphenylamino group and the carbazol-9-yl group may be substituted with one or more fluorine atoms, cyano groups, or nitro groups. In addition, R C1 , R C2 , R C3 and RC4 Among these, two adjacent substituents may be bonded together with the benzene ring to form a 5-, 6-, or 7-membered ring. m 1 represents 1 or 2. C A+ represents a monovalent organic cation. L 1 represents a nitrogen-containing ligand having two or more nitrogen atoms having an unshared electron pair or a phosphorus ligand represented by the following formula (3a):

[0041] [ka]

[0042] [In the formula, X A each independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group represented by the following formula (3c):

[0043] [ka]

[0044] (In the formula, X 1 each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an aryl group having 6 to 22 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms, an aryloxy group having 5 to 14 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, or a haloalkyloxy group having 1 to 6 carbon atoms, and the aryl group may be substituted with one or more substituents selected from the group consisting of a halogen atom, an alkyloxy group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, a haloalkyloxy group having 1 to 6 carbon atoms, a hydroxyl group, a cyano group, and a nitro group. M 3+ represents a trivalent rare earth metal ion. R AThe fluoroalkyl group having 1 to 4 carbon atoms represented by the formula (I) may be any of a linear, branched, or cyclic haloalkyl group, and specific examples thereof include a trifluoromethyl group, a difluoromethyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a 2,2,3,3-tetrafluoropropyl group, a 3,3,3 -trifluoropropyl group, 1,1-difluoropropyl group, perfluoropropan-2-yl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 3,3,4,4,4-pentafluorobutyl group, 4,4,4-trifluorobutyl group, 1,1,1,2,3,3,4,4,4-nonaorobutan-2-yl group, 1,1,1-trifluorobutan-2-yl group, 4,4,4-trifluorobutan-2-yl group can be exemplified. In terms of the ease of availability of raw materials, trifluoromethyl group, difluoromethyl group, 2,2,2-trifluoroethyl group, or perfluoropropyl group is preferred, and trifluoromethyl group is more preferred.

[0045] R C1 , R C2 , R C3 and R C4 Examples of the halogen atom represented by the formula (1) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. A chlorine atom or a bromine atom is preferred in terms of the ease of availability of the raw materials.

[0046] R C1 , R C2 , R C3 and R C4 The alkyl group having 1 to 4 carbon atoms represented by the formula (I) may be any of a linear, branched, or cyclic alkyl group, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, a 1-methylpropyl group, a 2-methylpropyl group, a cyclopropyl group, a 2-methylcyclopropyl group, and a cyclobutyl group.

[0047] R C1 , R C2 , R C3and R C4 The alkyloxy group having 1 to 4 carbon atoms represented by the formula (I) may be linear, branched, or cyclic. Specific examples of the alkyloxy group include a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a butyloxy group, a 1-methylpropyloxy group, a 2-methylpropyloxy group, a cyclopropyloxy group, a 2-methylcyclopropyloxy group, a tert-butyloxy group, and a cyclobutyloxy group.

[0048] R C1 , R C2 , R C3 and R C4 The alkenyl group having 2 to 4 carbon atoms represented by the formula (I) may be either a linear or branched alkenyl group, and specific examples thereof include a vinyl group, a 1-propenyl group, an allyl group, a 2-propenyl group, a 1-butenyl group, a 2-butenyl group, a 2-methylallyl group, and a butadiene-1-yl group.

[0049] R C1 , R C2 , R C3 and R C4 The alkenyl group having 2 to 4 carbon atoms represented by the formula (I) may be substituted with one or more alkyloxy groups having 1 to 4 carbon atoms, and the alkyloxy group having 1 to 4 carbon atoms is preferably R C1 , R C2 , R C3 and R C4 Examples of the alkyloxy group include those having 1 to 4 carbon atoms represented by the following formula:

[0050] R C1 , R C2 , R C3 and R C4Specific examples of the aryl group having 6 to 14 carbon atoms represented by the formula (I) include a phenyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 2,3-dimethylphenyl group, a 2,4-dimethylphenyl group, a 2,5-dimethylphenyl group, a 2,6-dimethylphenyl group, a 3,4-dimethylphenyl group, a 3,5-dimethylphenyl group, a 2,3,4-trimethylphenyl group, a 2,3,5-trimethylphenyl group, a 2,3,6-trimethylphenyl group, a 2,4,5-trimethylphenyl group, a 2,5,6-trimethylphenyl group, a 2,6,7-trimethylphenyl group, a 2,7,8-trimethylphenyl group, a 2,8,9-trimethylphenyl group, a 2,9,10-trimethylphenyl group, a 2,10,11-trimethylphenyl group, a 2,11,12-trimethylphenyl group, a 2,12,13-trimethylphenyl group, a 2,13,14-trimethylphenyl group, a 2,14,15-trimethylphenyl group, a 2,15,16-trimethylphenyl group, a 2,16,17-trimethylphenyl group, a 2,17,18-trimethylphenyl group, a 2,18,19-trimethylphenyl group, a 2,19,11-trimethylphenyl group, a 2,19,12-trimethylphenyl group, a 2,19,13-trimethylphenyl group, a 2,19,14-trimethylphenyl group, a 2,19,15-trimethylphenyl group, a 2,19,16-trimethylphenyl group, a 2,19,17-trimethylphenyl group, a 2,19,18-trimethylphenyl group, a 2,19,19-trimethylphenyl group, a 2,19,19 Methylphenyl group, 2,4,6-trimethylphenyl group, 3,4,5-trimethylphenyl group, 2,3,4,5-tetramethylphenyl group, 2,3,4,6-tetramethylphenyl group, 2,3,5,6-tetramethylphenyl group, 2-ethylphenyl group, 3-ethylphenyl group, 4-ethylphenyl group, 2,3-diethylphenyl group, 2,4-diethylphenyl group, 2,5-diethylphenyl group, 2,6-diethylphenyl group, 3,4-diethylphenyl group, 3,5-di Examples of the alkyl group include an ethylphenyl group, a 2-propylphenyl group, a 3-propylphenyl group, a 4-propylphenyl group, a 2-isopropylphenyl group, a 3-isopropylphenyl group, a 4-isopropylphenyl group, a 2-cyclopropylphenyl group, a 3-cyclopropylphenyl group, a 4-cyclopropylphenyl group, a 2-butylphenyl group, a 3-butylphenyl group, a 4-butylphenyl group, a 2-(1-methylpropyl)phenyl group, a 3-(1-methylpropyl)phenyl group, a 4-(1-methylpropyl)phenyl group, a 2-(2-methylpropyl)phenyl group, a 3-(2-methylpropyl)phenyl group, a 4-(2-methylpropyl)phenyl group, a 2-cyclobutylphenyl group, a 3-cyclobutylphenyl group, a 4-cyclobutylphenyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-biphenylyl group, a 3-biphenylyl group, a 4-biphenylyl group, a 9-anthryl group, a 2-phenanthrenyl group, a 3-phenanthrenyl group, and a 9-phenanthrenyl group.

[0051] R C1 , R C2 , R C3 and R C4The aryl group having 6 to 14 carbon atoms represented by the formula (I) may be substituted with one or more alkyloxy groups having 1 to 4 carbon atoms, and the alkyloxy group having 1 to 4 carbon atoms is preferably R C1 , R C2 , R C3 and R C4 Examples of the alkyloxy group include those having 1 to 4 carbon atoms represented by the following formula:

[0052] R C1 , R C2 , R C3 and R C4 Specific examples of the dialkylamino group having 2 to 8 carbon atoms represented by the formula (I) include a dimethylamino group, a diethylamino group, a dipropylamino group, a diisopropylamino group, a dibutylamino group, a bis(2-methylpropyl)amino group, a bis(3-cyclopropyl)amino group, a dicyclopropylamino group, a di(tert-butyl)amino group, and a dicyclobutylamino group.

[0053] R C1 , R C2 , R C3 and R C4 When any one or more of the above is a diphenylamino group, the diphenylamino group may be substituted with one or more fluorine atoms; cyano groups; or nitro groups. Specific examples include a diphenylamino group, a bis(4-fluorophenyl)amino group, a bis(3-fluorophenyl)amino group, a bis(2-fluorophenyl)amino group, a bis(2,3-difluorophenyl)amino group, a bis(3,5-difluorophenyl)amino group, a bis(2,4-difluorophenyl)amino group, a bis(2,6-difluorophenyl)amino group, a bis(3,4,5-trifluorophenyl)amino group, a bis(2,4,6-trifluorophenyl)amino group, a bis(perfluorophenyl)amino group, a bis(4-cyanophenyl)amino group, a bis(3,5-dicyanophenyl)amino group, and a bis(4-nitrophenyl)amino group.

[0054] R C1 , R C2 , R C3 and R C4When any one or more of the above is a carbazol-9-yl group, the carbazol-9-yl group may be substituted with one or more fluorine atoms; cyano groups; or nitro groups. Specific examples of the carbazol-9-yl group include a carbazoyl-9-yl group, a 3,6-difluorocarbazoyl-9-yl group, a 3,6-dicyanocarbazoyl-9-yl group, and a 3,6-dinitrocarbazoyl-9-yl group.

[0055] R C1 , R C2 , R C3 and R C4 Among these, two adjacent substituents may form a 5-, 6-, or 7-membered ring together with the benzene ring to which they are bonded. Specific examples of such a ring include a butadiene-1,4-diyl group, a methylenedioxy group, and an ethylenedioxy group.

[0056] R C1 , R C2 , R C3 and R C4 is preferably a hydrogen atom, a chlorine atom, a bromine atom, or a methoxy group, and more preferably a hydrogen atom, in terms of easy availability of raw materials.

[0057] m 1 represents 1 or 2. L 1 When m is a nitrogen-containing ligand having two or more nitrogen atoms with unshared electron pairs, 1 is preferably 1, and L 1 When is a phosphorus ligand represented by formula (3a), m 1 It is preferred that the number is 2.

[0058] C A+Specific examples of the monovalent organic cation represented by the formula (1) include tertiary ammonium ions such as triethylammonium, trimethylammonium, and diisopropylethylammonium, secondary ammonium ions such as diethylammonium, diisopropylammonium, and piperidinium, pyridinium ions such as pyridinium and 2,6-dimethylpyridinium, imidazolium ions such as imidazolium and N-methylimidazolium, and ammonium ions. In terms of high yield and purity of the rare earth complex (1c), triethylammonium, diisopropylethylammonium, pyridinium, imidazolium, ammonium, pyridinium, and piperidinium are preferred, and imidazolium is more preferred in terms of ease of synthesis of the raw material enolate salt (4cm).

[0059] The enolate salt (4cm) can be isomerized to form structures of enolate salt (4cmi) to enolate salt (4cmiii). The production method of the present disclosure includes all of the enolate salts described above, but for convenience, these isomers are referred to as the enolate salt (4cm) in this specification.

[0060] [ka]

[0061] (In the formula, R A , R C1 , R C2 , R C3 , R C4 and C A+ is R in the above formula (1cu). A , R C1 , R C2 , R C3 , R C4 and C A+ It has the same meaning as

[0062] L in formula (1c) 1represents a nitrogen-containing ligand having two or more nitrogen atoms having an unshared electron pair. In the rare earth complex (1c), when the nitrogen-containing ligand is coordinated, the unshared electron pair of the nitrogen atom in the nitrogen-containing ligand is M 3+Specific examples of the nitrogen-containing ligand include 1,10-phenanthroline, 2-methyl-1,10-phenanthroline, 5-methyl-1,10-phenanthroline, 5,6-dimethyl-1,10-phenanthroline, 2,9-dimethyl-1,10-phenanthroline, 4,7-dimethyl-1,10-phenanthroline, 3,4,7,8-tetramethyl-1,10-phenanthroline, 2,4,7,9-tetramethyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 5-chloro-1,10-phenanthroline, and the like. 2-chloro-1,10-phenanthroline, 2,9-dichloro-1,10-phenanthroline, 4,7-dichloro-1,10-phenanthroline, 5-bromo-1,10-phenanthroline, 2-bromo-1,10-phenanthroline, 3-bromo-1,10-phenanthroline, 3,8-dibromo-1,10-phenanthroline, 4,7-dibromo-1,10-phenanthroline, 3,5,6,8-tetrabromo-1,10-phenanthroline, 5-hydroxy-1,10-phenanthroline, 4,7-dihydroxy-1,10-phenanthroline, Phenanthroline, 4,7-diphenyl-1,10-phenanthroline, 2,9-diphenyl-1,10-phenanthroline, 5-amino-1,10-phenanthroline, 5,6-diamino-1,10-phenanthroline, 5-nitro-1,10-phenanthroline, 1,10-phenanthroline-5,6-dione, 2,2'-bipyridine, 2,2'-bipyridine-d8, 2,2'-bipyridine-6-carbonitrile, 5,5'-dimethyl-2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine, 6,6'-dimethyl-2,2'- Bipyridine, 4,4'-diamino-2,2'-bipyridine, 2,2'-bipyridyl-1,1'-dioxide, 2,2'-bipyridine-5,5'-diol, 6,6'-dicyano-2,2'-bipyridine, 4,4'-bis(dihydroxymethyl)-2,2'-bipyridine, 4,4'-dinonyl-2,2'-bipyridine, 4,4'-di(tert-butyl)-2,2'-bipyridine, 4,4'-dimethoxy-2,2'-bipyridine, 2,2':6'2''-terpyridine, 6-bromo-2,2'-bipyridine, 4-bromo-2,2'-bipyridine, 4,4'-Dibromo-2,2'-bipyridine, 5,5'-dibromo-2,2'-bipyridine, 4,4'-diphenyl-2,2'-bipyridine, 5,5'-dimethyl-2,2'-bipyridine, 4,4',5,5'-tetramethyl-2,2'-bipyridine, 4,4'-bis(1,1-dimethylethyl)-2,2'-bipyridine, 4,4'-bis(dimethylamino)-2,2'-bipyridine, 4,4'-difluoro-2,2'-bipyridine, 5,5'-difluoro-2,2'-bipyridine, 4,4'-bis(trifluoromethyl)-2,2'-bipyridine, 5,5'-bis(trifluoromethyl)-2,2'-bipyridine, dimethyl-2,2'-bipyridine-4,4'-dicarboxylate, dimethyl Examples of the diethyl-2,2'-bipyridine-5,5'-dicarboxylate include diethyl-2,2'-bipyridine-4,4'-dicarboxylate, diethyl-2,2'-bipyridine-5,5'-dicarboxylate, dipyrido[3,2-a:2',3'-c]phenazine, 2,2'-biquinoline, 4,5-diazafluoren-9-one, and N,N-diethyl-4-{[4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazin-2-yl]}aniline. 1,10-phenanthroline or 2,2'-bipyridine is preferred because the raw materials are readily available.

[0063] X in formula (3a) AThe alkyl group having 1 to 10 carbon atoms represented by the formula (I) may be any of linear, branched, and cyclic alkyl groups, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 2,2-dimethylpropyl group, a 3-cyclopropylpropyl group, a cyclopropyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-(1,1-dimethylethyl) group, a cyclobutyl group, a pentyl group, a 2-methylpentyl group, a 1-methylbutyl group, a 1,2-dimethylbutyl group, a 1-ethylpropyl group, a cyclopentyl group, a 5-dimethylcyclopropyl ... Examples include a cyclopentyl group, a 3-ethylcyclopentyl group, a hexyl group, a cyclohexyl group, a 4-ethylcyclohexyl group, a 4-propylcyclohexyl group, a 4,4-dimethylcyclohexyl group, a 2,6-dimethylcyclohexyl group, a 3,5-dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecanyl group, a bicyclo[2.2.1]heptan-2-yl group, a bicyclo[2.2.2]octan-2-yl group, an adamantan-2-yl group, a bicyclo[2.2.1]heptan-2-yl group, and an adamantan-1-yl group.

[0064] X A represents an aryl group represented by formula (3c), X in formula (3c) 1 The halogen atom represented by the formula R C1 and R C4 Examples of the substituents include those exemplified as the halogen atom represented by the following formula:

[0065] X in formula (3c) 1 Examples of the alkyl group having 1 to 4 carbon atoms represented by the formula: C2 and R C3 Examples of the alkyl group having 1 to 4 carbon atoms and represented by the following formula can be mentioned.

[0066] X in formula (3c) 1 The alkyloxy group having 1 to 4 carbon atoms represented by the formula: C2 and R C3 Examples of the alkyloxy group having 1 to 4 carbon atoms include those exemplified as the alkyloxy group represented by the following formula:

[0067] X in formula (3c) 1 Specific examples of the heteroaryl group having 3 to 20 carbon atoms represented by the formula (I) include a triazinyl group, a furanyl group, a thienyl group, a pyrrolinyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, a pyridyl group, a quinolinyl group, an isoquinolinyl group, a pyrazinyl group, a pyrimidyl group, a pyridazinyl group, a triazinyl group, a naphthyridinyl group, a cinnolinyl group, a phthalazinyl group, a quinoxalinyl group, a quinazolinyl group, a dibenzofuranyl group, a dibenzothienyl group, a carbazolyl group, a di-tert-butylcarbazolyl group, a carbolinyl group, a benzimidazolyl group, an imidazopyridyl group, a benzoxazolyl group, a benzothiazolyl group, and a phenanthrolinyl group.

[0068] X in formula (3c) 1Specific examples of the aryloxy group having 6 to 14 carbon atoms represented by the formula (I) include an indenyloxy group, a phenyloxy group, a 2-methylphenyloxy group, a 3-methylphenyloxy group, a 4-methylphenyloxy group, a 2,3-dimethylphenyloxy group, a 2,4-dimethylphenyloxy group, a 2,5-dimethylphenyloxy group, a 2,6-dimethylphenyloxy group, a 3,4-dimethylphenyloxy group, a 3,5-dimethylphenyloxy group, a 2,3,4-trimethylphenyloxy group, a 2,3,5-trimethylphenyloxy group, a 2,3,6-trimethylphenyloxy group, a 2 ,4,5-trimethylphenyloxy group, 2,4,6-trimethylphenyloxy group, 3,4,5-trimethylphenyloxy group, 2,3,4,5-tetramethylphenyloxy group, 2,3,4,6-tetramethylphenyloxy group, 2,3,5,6-tetramethylphenyloxy group, 2-ethylphenyloxy group, 3-ethylphenyloxy group, 4-ethylphenyloxy group, 2,3-diethylphenyloxy group, 2,4-diethylphenyloxy group, 2,5-diethylphenyloxy group, 2,6-diethylphenyloxy group, 3,4-diethylphenyloxy group, 3,5-diethylphenyloxy group, 2-propylphenyloxy group, 3-propylphenyloxy group, 4-propylphenyloxy group, 2-isopropylphenyloxy group, 3-isopropylphenyloxy group, 4-isopropylphenyloxy group, 2-cyclopropylphenyloxy group, 3-cyclopropylphenyloxy group, 4-cyclopropylphenyloxy group, 2-butylphenyloxy group, 3-butylphenyloxy group, 4-butylphenyloxy group, 2-(1-methylpropyl)phenyloxy group, 3-(1-methylpropyl)phenyloxy group Examples of the aryloxy group include a 4-(1-methylpropyl)phenyloxy group, a 2-(2-methylpropyl)phenyloxy group, a 3-(2-methylpropyl)phenyloxy group, a 4-(2-methylpropyl)phenyloxy group, a 2-cyclobutylphenyloxy group, a 3-cyclobutylphenyloxy group, a 4-cyclobutylphenyloxy group, a (biphenyl-2-yl)oxy group, a (biphenyl-3-yl)oxy group, a (biphenyl-4-yl)oxy group, a (phenanthren-9-yl)oxy group, and an (anthracen-9-yl)oxy group.

[0069] X in formula (3c) 1The haloalkyl group having 1 to 6 carbon atoms represented by the formula (I) may be any of linear, branched, or cyclic haloalkyl groups, and specific examples thereof include a trifluoromethyl group, a difluoromethyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a 2,2,3,3-tetrafluoropropyl group, a 3,3,3-trifluoropropyl group, a 1,1-difluoropropyl group, a perfluoropropan-2-yl group, a 2,2,2-trifluoropropyl ... 1-(trifluoromethyl)ethyl group, perfluorobutyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 3,3,4,4,4-pentafluorobutyl group, 4,4,4-trifluorobutyl group, 1,1,1,2,3,3,4,4,4-nonaorobutan-2-yl group, 1,1,1-trifluorobutan-2-yl group, 4,4,4-trifluorobutan-2-yl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, 3,3,4,4,5,5,5-heptafluoropentyl group, 4,4,5,5, 5-Pentafluoropentyl group, 5,5,5-trifluoropentyl group, perfluoropentan-2-yl group, 1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethyl)pentan-2-yl group, 1,1,2,3,3,4,4,4-octafluoro-2-(trifluoromethyl)butyl group, 1,1,2,2,3,4,4,4-octafluoro-3-(trifluoromethyl)butyl group, 1,1,3,3,3-pentafluoro-2,2-bis(trifluoromethyl)propyl group, 1,1,1,2,3,3,4,4,4-nonafluoro -1-(trifluoromethyl)butan-2-yl group, perfluorocyclopentyl group, perfluorohexyl group, 1,1,1,2,3,3,4,4,5,5,6,6,6-decafluorohexan-2-yl group, 1,1,2,3,3,4,4,5,5,5,5-decafluoro-2-(trifluoromethyl)pentyl group, 1,1,2,2,3,4,4,5,5,5,5-decafluoro-3-(trifluoromethyl)pentyl group, 1,1,2,2,3,3,4,5,5,5-decafluoro-4-(trifluoromethyl)pentyl group,Examples of the 5,5,5-dodecafluoro-1-(trifluoromethyl)pentan-2-yl group include a 1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethyl)pentan-2-yl group, a 1,1,1,2,2,4,4,5,5,5-decafluoro-3-(trifluoromethyl)pentan-2-yl group, a 1,1,3,3,4,4,4-heptafluoro-2,2-bis(trifluoromethyl)butyl group, a 1,2,2,3,4,4,4-heptafluoro-2,3-bis(trifluoromethyl)butyl group, a 1,1,2,2,4,4,4-heptafluoro-3,3-bis(trifluoromethyl)butyl group, a perfluorocyclohexyl group, a perfluorocyclopentylmethyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group, a 2-chloroethyl group, and a 3-bromopropyl group. ,

[0070] X in formula (3c) 1 The haloalkyloxy group having 1 to 6 carbon atoms represented by the formula (I) may be any of a linear, branched, or cyclic haloalkyloxy group, and specific examples thereof include a trifluoromethyloxy group, a difluoromethyloxy group, a perfluoroethyloxy group, a 2,2,2-trifluoroethyloxy group, a 1,1-difluoroethyloxy group, a 2,2-difluoroethyloxy group, a perfluoropropyloxy group, a 2,2,3,3,3-pentafluoropropyloxy group, a 2,2,3,3-tetrafluoropropyloxy group, a 3,3,3-trifluoropropyloxy group, a 5,5-difluoropropyloxy group, a 6,5-difluoropropyloxy group, a 7,5-difluoropropyloxy group, a 8,5-difluoropropyloxy group, a 9,5-difluoropropyloxy group, a 10,5-difluoropropyloxy group, a 11,5-difluoropropyloxy group, a 12,5-difluoropropyloxy group, a 13,5-difluoropropyloxy group, a 14,5-difluoropropyloxy group, a 15,5-difluoropropyloxy group, a 16,5-difluoropropyloxy group, a 17,5-difluoropropyloxy group, a 18,5-difluoropropyloxy group, a 21,5-difluoropropyloxy group, a 22,5-difluoropropyloxy group, a 23,5-difluoropropyloxy group, a 25,5-difluoropropyloxy group, a 26,5-difluoropropyloxy group, a 27,5-difluoropropyloxy group, a 28,5-difluoropropyloxy group, a 29,5-difluoropropyloxy group, a 30,5-difluoropropyloxy group, a 31,5-difluoropropyloxy group, a 32,5-difluoropropyloxy group, a 33,5-difluoropropyloxy group, a 34,5-difluoropropyloxy group, a 35, Examples of such aryloxy groups include an aryloxy group, a 1,1-difluoropropyloxy group, a 1,1,1,2,3,3,3-heptafluoropropan-2-yloxy group, a 2,2,2-trifluoro-1-(trifluoromethyl)ethyloxy group, a perfluoropentyloxy group, a perfluorocyclopentyloxy group, a perfluorohexyloxy group, a perfluorocyclohexyloxy group, a chloromethyloxy group, a bromomethyloxy group, an iodomethyloxy group, a 2-chloroethyloxy group, a 3-bromopropyloxy group, and a 3-iodopropyloxy group.

[0071] X in formula (3c) 1is an aryl group having 6 to 22 carbon atoms, the aryl group having 6 to 22 carbon atoms may be substituted with one or more substituents selected from the group consisting of a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkyloxy group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, a haloalkyloxy group having 1 to 6 carbon atoms, a hydroxyl group, a cyano group, and a nitro group, and specific examples thereof include a phenyl group, a deuterated phenyl group, a 1-naphthyl group, a 2-naphthyl group, a deuterated naphthyl group, 2-methylphenyl group, 4-methylphenyl group, 2,5-dimethylphenyl group, 2,4,6-trimethylphenyl group, 4-ethylphenyl group, 4-propylphenyl group, 2,4,6-triisopropylphenyl group, 4-tert-butylphenyl group, 1-methylnaphthalen-2-yl group, 2-methylnaphthalen-1-yl group, 4-methylnaphthalen-1-yl group, 4-methylnaphthalen-2-yl group, 2-trifluoromethylphenyl group, 3-( trifluoromethyl)phenyl group, 4-trifluoromethylphenyl group, 3,5-bis(trifluoromethyl)phenyl group, 1-(trifluoromethyl)naphthalen-2-yl group, 2-(trifluoromethyl)naphthalen-1-yl group, 4-(trifluoromethyl)naphthalen-2-yl group, 4-(trifluoromethyl)naphthalen-1-yl group, 4-methoxyphenyl group, 4-(isopropyloxy)phenyl group, 1-methoxynaphthalen-2-yl group, 2-methoxynaphthalen-1-yl group, 4-methoxynaphthalen-2-yl group, 4-trifluoromethoxyphenyl group, 1-(trifluoromethyloxy)naphthalen-2-yl group, 2-(trifluoromethyloxy)naphthalen-1-yl group, 2-fluorophenyl group, 3-fluorophenyl group, 4-fluorophenyl group, 2-chlorophenyl group, 3-chlorophenyl group, 4-chlorophenyl group, 3,5-dichlorophenyl group, 2,Examples of the alkyl group include a 6-dichlorophenyl group, a 2-bromophenyl group, a 3-bromophenyl group, a 4-bromophenyl group, a 1-bromonaphthalene-2-yl group, a 2-bromonaphthalene-1-yl group, a 4-bromonaphthalene-2-yl group, a 6-bromonaphthalene-2-yl group, a 2-cyanophenyl group, a 3-cyanophenyl group, a 4-cyanophenyl group, a 1-cyanonaphthalene-2-yl group, a 2-cyanonaphthalene-1-yl group, a 4-cyanonaphthalene-2-yl group, a 6-cyanonaphthalene-2-yl group, a 2-nitrophenyl group, a 3-nitrophenyl group, and a 4-nitrophenyl group.

[0072] Therefore, the phosphorus ligand represented by formula (3a) is more specifically triphenylphosphine oxide, cyclohexyldiphenylphosphine oxide, tri(p-tolyl)phosphine oxide, triphenylphosphine oxide-d 15 , tributylphosphine oxide, tri(tert-butyl)phosphine oxide, trioctylphosphine oxide, tricyclohexylphosphine oxide, dicyclohexylphenylphosphine oxide, dicyclohexyl(o-tolyl)phosphine oxide, 2-biphenylyldicyclohexylphosphine oxide, tripentylphosphine oxide, 2-biphenylyldiphenylphosphine oxide, tri(o-tolyl)phosphine oxide, and tris(2-methoxyphenyl)phosphine oxide can be exemplified. In terms of easy availability of raw materials, triphenylphosphine oxide, tributylphosphine oxide, trioctylphosphine oxide, tricyclohexylphosphine oxide, tri(o-tolyl)phosphine oxide, or tris(2-methoxyphenyl)phosphine oxide is preferred, and trioctylphosphine oxide or tricyclohexylphosphine oxide is more preferred.

[0073] In the manufacturing method, m 1 is an integer of 1 or 2. m 1 It is preferred that the number is 2.

[0074] In the manufacturing method, M 3+ Specific examples of the trivalent rare earth metal ion represented by the formula (1) include scandium ion, yttrium ion, lanthanum ion, cerium ion, praseodymium ion, neodymium ion, promethium ion, samarium ion, europium ion, gadolinium ion, terbium ion, dysprosium ion, holmium ion, erbium ion, thulium ion, ytterbium ion, and lutetium ion. In terms of having optical properties suitable for use as an optical functional material, europium ion and terbium ion are preferred, and europium ion is more preferred.

[0075] CU is preferably any one of the coumarinato ligands (1cu-1) to (1cu-3) represented by the following formulas.

[0076] [ka]

[0077] (In the formula, R A has the same meaning as above. C5 and R C6 each independently represents a hydrogen atom, a chlorine atom, a bromine atom, a methyl group, a methoxy group, a 4-methoxyphenyl group, a 4-diphenylaminophenyl group, a dimethylamino group, or a diethylamino group.

[0078] R C5 and R C6 is preferably a hydrogen atom, a bromine atom, a methoxy group, a methyl group, a dimethylamino group, or a diethylamino group in that the raw materials are readily available, and more preferably a hydrogen atom in that synthesis is easy.

[0079] L 1 When is a phosphorus ligand represented by formula (3a) (hereinafter referred to as phosphorus ligand (3a)), the phosphorus ligand (3a) can be obtained, for example, by the method described in Chemical Reviews, Vol. 60, pp. 243-260, 1960. Alternatively, a commercially available product may be used.

[0080] Specific examples of the phosphorus ligand (3a) include any of the following formulae (3a-1) to (3a-16), although the present invention is not limited thereto.

[0081] [ka]

[0082] L 1 Specific examples of the nitrogen-containing ligand having two or more nitrogen atoms having an unshared electron pair represented by the formula (I) include 1,10-phenanthroline, 4,7-dimethyl-1,10-phenanthroline, 3,4,7,8-tetramethyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline, 2,9-diphenyl Examples include 1,10-phenanthroline, 2,2'-bipyridine, 5,5'-dimethyl-2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine-d8, 6,6'-dimethyl-2,2'-bipyridine, 4,4'-diphenyl-2,2'-bipyridine, 5,5'-diphenyl-2,2'-bipyridine, and 4,4',5,5'-tetramethyl-2,2'-bipyridine.

[0083] L 1 As the nitrogen-containing ligand having two or more nitrogen atoms having an unshared electron pair, which is represented by the following formula (I), a commercially available product may be used.

[0084] The enolate salt (4cm) can be obtained by reacting the enol (4c) with a base, or by the method described in Example 1. The enolate salt (4cm) may contain a salt by-produced during the synthesis of the enolate salt (4cm).

[0085] [ka]

[0086] (In the formula, R A , R C2 , R C3 and C A+ is R in the above formula (1cu). A , R C1 , R C2 , R C3 , R C4 and C A+ It has the same meaning as The enol (4c) can be obtained, for example, by the method described in The Journal of Organic Chemistry, Vol. 75, pp. 2741-2744, 2010; Journal of the American Chemical Society, Vol. 66, pp. 1220-1222, 1944; Tetrahedron, Vol. 74, pp. 2762-2768, 2018; The Journal of Organic Chemistry, Vol. 80, pp. 10643-10650, 2015. Commercially available products may also be used.

[0087] Examples of rare earth compounds include europium compounds such as halide salts or hydrates thereof, such as europium fluoride (III), europium chloride (III), europium bromide (III), and europium iodide (III); organic acid salts or hydrates thereof, such as europium oxalate (III), europium acetate (III), europium trifluoroacetate (III), and europium trifluoromethanesulfonate (III); metal alkoxides such as tris[N,N-bis(trimethylsilyl)amide]europium(III), europium(III) trimethoxide, europium(III) triethoxide, and europium(III) tri(isopropoxide); and inorganic acid salts or hydrates thereof, such as europium(III) phosphate, europium(III) sulfate, and europium(III) nitrate. Among these, in terms of good reaction yields, inorganic acid salts such as europium(III) chloride and europium(III) nitrate, or hydrates thereof; or organic acid salts such as europium(III) oxalate, europium(III) acetate, europium(III) trifluoroacetate; and europium(III) trifluoromethanesulfonate, or hydrates thereof; are preferred, with europium(III) acetate; europium(III) chloride; or europium(III) nitrate or hydrates thereof being more preferred.

[0088] The rare earth compound used in the production method of the present disclosure may be a commercially available product.

[0089] From the viewpoint of a good yield of the rare earth complex (1c), it is preferable to carry out the reaction in the presence of an organic solvent and water. There is no particular limitation on the type of organic solvent that can be used as long as it does not inhibit the reaction. Examples of organic solvents that can be used include aromatic hydrocarbons such as benzene, toluene, and xylene; hydrocarbons such as hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, heptane, and octane; halogenated hydrocarbons such as dichloromethane, chloroform, and chlorobenzene; alcohols such as methanol, ethanol, propanol, and isopropyl alcohol; esters such as methyl acetate, ethyl acetate, butyl acetate, and isoamyl acetate; glycol ethers such as ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, and ethylene glycol monobutyl ether; ethers such as diethyl ether, tert-butyl methyl ether, glyme, diglyme, triglyme, tetrahydrofuran, and cyclopentyl methyl ether; or ketones such as tert-butyl methyl ketone, isobutyl methyl ketone, ethyl butyl ketone, dipropyl ketone, diisobutyl ketone, cyclohexanone, and acetone. These solvents may be used alone or in combination in any ratio. In view of the high purity of the obtained rare earth complex (1c), aromatic hydrocarbons such as benzene, toluene, and xylene are preferred as the organic solvent, and toluene is more preferred in view of the industrially efficient production.

[0090] The mixing volume ratio of the organic solvent and water is preferably 0.1 to 10 mL of water, more preferably 0.5 to 5 mL of water, and even more preferably 0.25 to 2.5 mL of water, per 1 mL of organic solvent.

[0091] The molar ratio of the rare earth compound and the enolate salt (4cm) will be described. It is preferable to use 1.0 to 5.0 moles of the enolate salt (4cm) relative to 1 mole of the rare earth compound, more preferably 3.0 to 4.0 moles of the enolate salt (4cm), and even more preferably 3.0 to 3.3 moles of the enolate salt (4cm).

[0092] L 1In the case where the nitrogen-containing ligand has two or more nitrogen atoms each having an unshared electron pair, the molar ratio of the rare earth compound and the nitrogen-containing ligand will be described below. It is preferable to use 0.5 to 2.5 moles of the nitrogen-containing ligand per mole of the rare earth compound, more preferably 1.0 to 1.5 moles of the nitrogen-containing ligand, and even more preferably 1.0 mole of the nitrogen-containing ligand.

[0093] L 1 When the rare earth compound is a phosphorus ligand (3a), the molar ratio of the rare earth compound and the phosphorus ligand (3a) will be described below. It is preferable to use 0.5 to 5.0 moles of the phosphorus ligand (3a) relative to 1 mole of the rare earth compound, more preferably 1.0 to 3.0 moles of the phosphorus ligand (3a), and further preferably 2.0 moles of the phosphorus ligand (3a).

[0094] m 1 When L is 2, two different L 1 may be added simultaneously or separately.

[0095] The reaction temperature is not particularly limited, and general conditions used by those skilled in the art when producing metal complexes can be used. As a specific example, rare earth complex (1c) can be produced in good yield at a reaction temperature of -80°C to 120°C.

[0096] The reaction time is not particularly limited, and general conditions for those skilled in the art to produce metal complexes can be used. As a specific example, the rare earth complex (1c) can be produced in good yield by appropriately selecting the reaction time from 1 minute to 120 hours.

[0097] The rare earth complex (1c) produced by the production method of the present disclosure can be purified by a purification method generally used by those skilled in the art for purifying metal complexes, which can be appropriately selected and used. Specific purification methods include one or more methods selected from the group consisting of filtration, extraction, centrifugation, decantation, distillation, sublimation, crystallization, precipitation, and column chromatography.

[0098] The rare earth complex (1c) produced by the production method of the present disclosure may contain a crystallization solvent used in the purification by reprecipitation or recrystallization.

[0099] The production method of the present disclosure also includes a production method of a rare earth complex (1c) comprising steps A and B below. Step A: A 4-hydroxycoumarin compound represented by the formula (4cus) (hereinafter also referred to as a 4-hydroxycoumarin compound (4cus))

[0100] [ka]

[0101] (In the formula, R C1 , R C2 , R C3 and R C4 has the same meaning as above.) and an acid anhydride represented by formula (1ah) (hereinafter also referred to as acid anhydride (1ah)).

[0102] [ka]

[0103] (In the formula, R A has the same meaning as above.) in the presence of an organic base to obtain an enolate salt represented by formula (4cm):

[0104] [ka]

[0105] (In the formula, C A+ , R A , R C1 , R C2 , R C3 and R C4 has the same meaning as above.) The process of obtaining the above. Step B: Reacting an enolate salt represented by formula (4cm) with L 1 a phosphorus ligand represented by the following formula (3a): or a nitrogen-containing compound having two or more nitrogen atoms each having an unshared electron pair is reacted with a rare earth compound in the presence of an organic solvent and water,

[0106] [ka]

[0107] (In the formula, C A+ , R A , R C1 , R C2 , R C3 , R C4 , C.U., M. 3+ , m 1 , and L 1 has the same meaning as above.) The process of obtaining the above.

[0108] In step B, C A+ , R A , R C1 , R C2 , R C3 , R C4 , C.U., M. 3+ , m 1 , and L 1 The definitions and specific examples shown in are based on the C A+ , R A , R C2 , R C3 , C.U., M. 3+ , m 1 , and L 1 is the same as:

[0109] In step A, the 4-hydroxycoumarin compound (4cus) and the acid anhydride (1ah) can be commercially available products.

[0110] The molar ratio of the 4-hydroxycoumarin compound (4cus) and the acid anhydride (1ah) in the step A will be described. It is preferable to use 1.0 to 5.0 moles of the acid anhydride (1ah) relative to 1 mole of the 4-hydroxycoumarin compound (4cus), more preferably 1.0 to 2.5 moles of the acid anhydride (1ah), and further preferably 1.0 to 1.5 moles of the acid anhydride (1ah).

[0111] Examples of the organic base used in step A include trimethylamine, triethylamine, diethylamine, pyridine, quinoline, piperidine, pyrrolidine, and imidazole. The base is preferably imidazole in terms of a good yield of the enolate salt (4cm). The equivalent amount of the base is preferably 2.0 to 10 mol, more preferably 2.0 to 6.0 mol, and even more preferably 2.0 to 5.0 mol, per mol of the 4-hydroxycoumarin compound (4cus).

[0112] In the step A, it is preferable to carry out the reaction in a solvent, since the yield of the enolate salt (4cm) is good. The type of organic solvent that can be used is not particularly limited as long as it does not inhibit the reaction. Examples of organic solvents that can be used include halogenated hydrocarbons such as dichloromethane, chloroform, and chlorobenzene; alcohols such as methanol, ethanol, propanol, and isopropyl alcohol; esters such as methyl acetate, ethyl acetate, butyl acetate, and isoamyl acetate; glycol ethers such as ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, and ethylene glycol monobutyl ether; ethers such as diethyl ether, tert-butyl methyl ether, glyme, diglyme, triglyme, tetrahydrofuran, and cyclopentyl methyl ether; ketones such as tert-butyl methyl ketone, isobutyl methyl ketone, ethyl butyl ketone, dipropyl ketone, diisobutyl ketone, cyclohexanone, and acetone; hydrocarbons such as hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, heptane, and octane; or aromatic hydrocarbons such as benzene, toluene, and xylene. These solvents may be used alone or in combination in any ratio. Tetrahydrofuran, toluene, ethyl acetate, dichloromethane, or chloroform is preferred in terms of the purity of the enolate salt (4cm) obtained, and tetrahydrofuran is more preferred in terms of industrially efficient production.

[0113] The reaction temperature in step A is not particularly limited, and general conditions used by those skilled in the art for production can be used. As a specific example, the enolate salt (4cm) can be produced in good yield at a reaction temperature of -80°C to 120°C.

[0114] The reaction time in step A is not particularly limited, and general conditions used by those skilled in the art for production can be used. As a specific example, the enolate salt (4cm) can be produced in good yield by appropriately selecting the reaction time from 1 minute to 120 hours.

[0115] In process B, L 1When is a phosphorus ligand (3a), it can be obtained by the method exemplified in the explanation of the above production method. In addition, a commercially available product can also be used.

[0116] In process B, L 1 When is a phosphorus ligand (3a), examples of the phosphorus ligand (3a) used include the same ones as those exemplified in the above description of the production method.

[0117] In process B, L 1 When the nitrogen-containing ligand has two or more nitrogen atoms each having an unshared electron pair, examples of the nitrogen-containing ligand to be used include those similar to those exemplified above.

[0118] In step B, the enolate salt (4cm) may contain an organic salt represented by formula (1by) (hereinafter also referred to as organic salt (1by)) which is produced as a by-product during the synthesis of the enolate salt (4cm).

[0119] [ka]

[0120] (In the formula, C A+ , R A , R C1 , R C2 , R C2 and R C4 has the same meaning as above.)

[0121] In step B, it is preferable to carry out the reaction in the presence of an organic solvent and water, since the yield of the rare earth complex (1c) is good. The type of organic solvent that can be used is not particularly limited as long as it does not inhibit the reaction. Examples of organic solvents that can be used include aromatic hydrocarbons such as benzene, toluene, and xylene; hydrocarbons such as hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, heptane, and octane; halogenated hydrocarbons such as dichloromethane, chloroform, and chlorobenzene; alcohols such as methanol, ethanol, propanol, and isopropyl alcohol; esters such as methyl acetate, ethyl acetate, butyl acetate, and isoamyl acetate; glycol ethers such as ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, and ethylene glycol monobutyl ether; ethers such as diethyl ether, tert-butyl methyl ether, glyme, diglyme, triglyme, tetrahydrofuran, and cyclopentyl methyl ether; or ketones such as tert-butyl methyl ketone, isobutyl methyl ketone, ethyl butyl ketone, dipropyl ketone, diisobutyl ketone, cyclohexanone, and acetone. These solvents may be used alone or in combination in any ratio. Aromatic hydrocarbons such as benzene, toluene, and xylene are preferred in terms of the purity of the resulting rare earth complex (1c), and toluene is more preferred in terms of industrially efficient production.

[0122] The molar ratio of the rare earth compound and the enolate salt (4cm) in step B will be described. It is preferable to use 1.0 to 5.0 moles of the enolate salt (4cm), more preferably 3.0 to 4.0 moles of the enolate salt (4cm), and even more preferably 3.0 to 3.3 moles of the enolate salt (4cm), relative to 1 mole of the rare earth compound.

[0123] In process B, L 1In the case where the nitrogen-containing ligand has two or more nitrogen atoms each having an unshared electron pair, the molar ratio of the rare earth compound and the nitrogen-containing ligand will be described below. It is preferable to use 0.5 to 2.5 moles of the nitrogen-containing ligand per mole of the rare earth compound, more preferably 1.0 to 1.5 moles of the nitrogen-containing ligand, and even more preferably 1.0 mole of the nitrogen-containing ligand.

[0124] In process B, L 1 When the rare earth compound is a phosphorus ligand (3a), the molar ratio of the rare earth compound and the phosphorus ligand (3a) will be described below. It is preferable to use 0.5 to 5.0 moles of the phosphorus ligand (3a) relative to 1 mole of the rare earth compound, more preferably 1.0 to 3.0 moles of the phosphorus ligand (3a), and further preferably 2.0 moles of the phosphorus ligand (3a).

[0125] m in process B 1 When L is 2, two different L 1 may be added simultaneously or separately.

[0126] In step B, the reaction temperature is not particularly limited, and general conditions used by those skilled in the art when producing a metal complex can be used. As a specific example, the rare earth complex (1c) can be produced in good yield at a reaction temperature of -80°C to 120°C.

[0127] In step B, the reaction time is not particularly limited, and general conditions used by those skilled in the art when producing metal complexes can be used. As a specific example, the rare earth complex (1c) can be produced in good yield by appropriately selecting the reaction time from 1 minute to 120 hours.

[0128] The rare earth complex (1c) produced in step B can be purified by appropriately selecting and using a general purification method used by those skilled in the art when purifying metal complexes. Specific purification methods include filtration, extraction, centrifugation, decantation, distillation, sublimation, crystallization, precipitation, and column chromatography.

[0129] The rare earth complex (1c) produced by the production method of the present invention may contain a crystallization solvent used in the purification by reprecipitation or recrystallization.

[0130] In steps A and B, CU is preferably any one of the coumarinato ligands (1cu-1) to (1cu-3) represented by the following formulas.

[0131] [ka]

[0132] (In the formula, R A has the same meaning as above. C5 and R C6 each independently represents a hydrogen atom, a chlorine atom, a bromine atom, a methyl group, a methoxy group, a 4-methoxyphenyl group, a 4-diphenylaminophenyl group, a dimethylamino group, or a diethylamino group. R C5 and R C6 is preferably a hydrogen atom, a bromine atom, a methoxy group, a methyl group, a dimethylamino group, or a diethylamino group in that the raw materials are readily available, and more preferably a hydrogen atom in that synthesis is easy.

[0133] Specifically, the rare earth complex (1c) produced by the production method of the present invention can be represented by the following formulae (1c-1) to (1c-207), in which Me represents a methyl group.

[0134]

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[0135]

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[0136]

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[0137]

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[0138]

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[0139]

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[0140]

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[0141]

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[0142]

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[0143]

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[0144]

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[0145]

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[0146] Among the above formulas (1c-1) to (1c-207), in terms of ease of availability of raw materials, the following are preferred: formulas (1c-1) to (1c-8), (1c-10) to (1c-13), (1c-16) to (1c-23), (1c-25), (1c-28), (1c-31) to (1c-33), (1c-35) to (1c-41), (1c-47) to (1c-48), (1c-50) to (1c-58), (1c-61), (1c-64) to (1c-68), (1c-70) to (1c-89), (1c-91) to (1c-92), (1c-94) to (1c-108), (1c-111) to (1c-207) The compounds represented by the formulae (1c-145), (1c-148), (1c-150) to (1c-152), (1c-157) to (1c-160), (1c-163) to (1c-181), (1c-184) to (1c-185) or (1c-190) to (1c-207) are preferred, and in terms of ease of synthesis, the compounds represented by the formulae (1c-1), (1c-3), (1c-6) to (1c-8), (1c-10) to (1c-13), (1c-16) to (1c-23), (1c-25), (1c-28), (1c-31) to (1c-33), (1c-36), (1c-38), (1c-5 2)~(1c-58), (1c-64)~(1c-65), (1c-67)~(1c-68), (1c-70)~(1c-84), (1 c-91), (1c-92), (1c-94)~(1c-95), (1c-97), (1c-99)~(1c-100), (1c-10 2), (1c-107), (1c-112), (1c-115)~(1c-117), (1c-133)~(1c-145), (1c- 148), (1c-150), (1c-157)~(1c-160), (1c-167)~(1c-181), (1c-184)~(1 In terms of good yield, the compounds represented by formula (1c-1), (1c-8), (1c-11), (1c-19), (1c-21), (1c-23), (1c-52), (1c-54), (1c-64), (1c-65), (1c-73), (1c-75), (1c-77) to (1c-78), (1c-80) to (1c-81), (1c-99) to (1c-100), (1c-102), (1c-107), (1c-191), (1c-203) or (1c-204) are even more preferred.

[0147] In a more preferred embodiment, the rare earth complex (1c) that can be produced by the production method of the present disclosure is a rare earth complex represented by formula (1ci) (hereinafter, also referred to as rare earth complex (1ci)). Specifically, rare earth complexes represented by the following formulas (1ci-1) to (1ci-207) can be exemplified.

[0148] [ka]

[0149] [ka]

[0150] [ka]

[0151] [ka]

[0152] [ka]

[0153]

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[0154]

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[0156]

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[0157]

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[0158]

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[0159]

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[0160] Among the above formulas (1ci-1) to (1ci-207), the formulas (1ci-1) to (1ci-8), (1ci-10) to (1ci-13), (1ci-16) to (1ci-23), (1ci-25), (1ci-28), (1ci-31) to (1ci-33), (1ci-35) to (1ci-41), (1ci-47) to (1ci-48), (1ci-50) to (1ci-58), (1ci-61), (1ci-64) to (1ci-68), (1ci-70) to (1ci-89), (1ci-91) to (1ci-92), (1ci The compounds represented by the formulae (1ci-1), (1ci-3), (1ci-6) to (1ci-8), (1ci-10) to (1ci-13), (1ci-16) to (1ci-23), (1ci-25), (1ci-26), (1ci-27), (1ci-29), (1ci-30), (1ci-31), (1ci-32), (1ci-33), (1ci-34), (1ci-35), (1ci-36), (1ci-37), (1ci-38), (1ci-39), (1ci-40), (1ci-41), (1ci-42), (1ci-43), (1ci-44), (1ci-45), (1ci-46), (1ci-47), (1ci-48), (1ci-49), (1ci-50), (1ci-51), (1ci-52), (1ci-53), (1ci-54), (1ci-55), (1ci-56), (1ci-57), (1ci-58), (1ci-59), (1ci-60), (1ci-63) to (1ci-181), (1ci-184) to (1ci-185), or (1ci-190) to (1ci-207) are preferred, and in terms of ease of synthesis, the compounds represented by the formulae (1ci-1), (1ci-3), (1ci-6) to (1ci-8), (1ci-10) to (1ci-13), (1ci-16) to (1ci-23), (1ci-25), (1ci-59), (1ci-60), (1ci-61), (1ci-62), (1ci-63), (1ci-64), (1ci-65), (1ci-66), (1ci-67), (1ci-68), (1ci i-28), (1ci-31)~(1ci-33), (1ci-36), (1ci-38), (1ci-52)~(1ci-58), (1ci-64)~(1ci-65), (1ci-67)~(1ci-68), (1ci-70)~(1ci-84), (1ci-91), ( 1ci-92), (1ci-94)~(1ci-95), (1ci-97), (1ci-99)~(1ci-100), (1ci-102), (1ci-107), (1ci-112), (1ci-115)~(1ci-117), (1ci-133)~(1ci-145), The compounds represented by the formulae (1ci-148), (1ci-150), (1ci-157) to (1ci-160), (1ci-167) to (1ci-181), (1ci-184) to (1ci-185) or (1ci-190) to (1ci-207) are more preferred, and in terms of good yield, the compounds represented by the formulae (1ci-1), (1ci-8), (1ci-11), (1ci-19), (1ci-21), (1ci-23), (1ci-52), (1ci-54), (1ci-64), (1ci-65), (1ci-73), (1ci-75), (1ci-77) to (1ci-78),(1ci-80) to (1ci-81), (1ci-99) to (1ci-100), (1ci-102), (1ci-107), (1ci-191), (1ci-203) or (1ci-204) are more preferred.

[0161] In the rare earth complex (1c) produced by the production method of the present disclosure, the coumarinato ligand (1cu) has one or two oxygen atoms, M 3+ In addition, due to the structure of the tautomer of the coumarinato ligand (1cu), the following rare earth complexes (1ci) to (1cviii) are coordinated. The rare earth complex (1c) of the present disclosure includes all of the rare earth complexes (1ci) to (1cviii), but for convenience, these isomers are referred to as rare earth complex (1c) in this specification.

[0162] In addition, the rare earth complex (1c) is preferably a rare earth complex (1ci) or a rare earth complex (1cii) in terms of having suitable optical properties as an optical functional material. The rare earth complex (1ci) can undergo tautomerization to form a rare earth complex (1cii), but the rare earth complex (1ci) includes the rare earth complex (1cii), and when describing the coordination structure in this specification, the rare earth complex (1cii) is conveniently written as the rare earth complex (1ci).

[0163] [ka]

[0164] (In the formula, R A , R C1 , R C2 , R C3 , R C4 , L 1 , and m 1 R in the formula (1c) and the formula (1cu) A , R C1 , RC2 , R C3 , R C4 , L 1 , and m 1 M represents a trivalent rare earth ion. EXAMPLES

[0165] The present disclosure will be described below with reference to examples, comparative examples, and evaluation examples. However, the present disclosure is not limited thereto.

[0166] The following analytical method was used to identify the rare earth complex (1c).

[0167] 1 H-NMR, 19 F-NMR and 31 For the measurement of each P-NMR spectrum, BRUKER's ULTRASHIELD PLUS AVANCE III (400 MHz, 376 MHz, and 162 MHz) and ASCEND AVANCE III HD (400 MHz, 376 MHz, and 162 MHz) were used. 1 H-NMR was measured using deuterated chloroform (CDCl3) or deuterated acetone (Acetone-d6) as a measurement solvent and tetramethylsilane (TMS) as an internal standard. 19 F-NMR was measured using deuterated chloroform (CDCl3), deuterated acetone (Acetone-d6), deuterated acetonitrile (CD3CN) or deuterated dimethyl sulfoxide (DMSO-d6) as the measurement solvent. 31 P-NMR was measured using deuterated chloroform (CDCl3) or deuterated acetone (Acetone-d6).

[0168] Mass spectrometry was performed using a Waters2695-MicromassZQ4000 (Waters Corporation).

[0169] The excitation and emission spectra were measured using a spectrophotometer (JASCO Corporation, FP-6500).

[0170] The UV-Vis spectrum was measured using an ultraviolet-visible-near infrared spectrophotometer (V-670, manufactured by JASCO Corporation).

[0171] The emission quantum yield was measured using an absolute PL quantum yield measurement apparatus (manufactured by Hamamatsu Photonics, C9920-03 and C11347-01).

[0172] The reagents used were commercially available. Example 1

[0173] [ka]

[0174] Tetrahydrofuran (790mL) was added to 4-hydroxycoumarin (79.9g, 493mmol) and imidazole (101g, 1.48mol), and a solution of trifluoroacetic anhydride (69.0mL, 493mmol) in tetrahydrofuran (196mL) was added dropwise while stirring under ice cooling. After stirring the reaction solution at room temperature for 4 hours, the solvent was distilled off under reduced pressure, and the concentrate was washed three times with ethyl acetate and dried under reduced pressure to obtain a mixture of 4-hydroxy-3-(2,2,2-trifluoroethane-1-on-1-yl)-2H-chromene-2-onatoimidazolium and trifluoroacetate imidazolium (molar ratio = 1:0.41) as a white solid (yield 125g, purity 81.4%, yield 63%). 1 H-NMR(400MHz,Acetone-d6)δ(ppm):9.72(brs,3.0H),8.98(dd,J=1.3,1.3Hz,1.4H),8.08(ddd,J=7.9,1.7,0.4Hz,1H),7.7 1(d,J=1.3Hz,2.8H),7.56(ddd,J=8.3,7.2,1.7Hz,1H),7.22(ddd,J=7.9,7.2,1.1Hz,1H),7.16(ddd,J=8.3,1.1,0.4Hz,1H). 19 F-NMR (376MHz, Acetone-d6) δ (ppm): -73.5 (s, 3F), -75.8 (s, 1.2F).

[0175] Europium(III) acetate hydrate (42.1g, 99.7mmol as 5.2 hydrate) was added with 498mL of water and 498mL of toluene and stirred at room temperature for 10 minutes, then trioctylphosphine oxide (77.1g, 199mmol) was added and stirred at room temperature for another hour. The mixture of 4-hydroxy-3-(2,2,2-trifluoroethane-1-one-1-yl)-2H-chromene-2-onatoimidazolium and trifluoroacetate imidazolium obtained above (120g, molar ratio = 1:0.41, 4-hydroxy-3-(2,2,2-trifluoroethane-1-one-1-yl)-2H-chromene-2-onatoimidazolium 299mmol) was added to the reaction mixture and stirred at room temperature for 2 hours. The mixture was separated and the organic layer was washed twice with 500mL of water. The solution was concentrated under reduced pressure to give tris[4-hydroxy-3-(2,2,2-trifluoroethan-1-one-1-yl)-2H-chromen-2-onato]bis(trioctylphosphine oxide)europium(III) (1c-204) as a colorless oil (yield 164 g, 97%). 1 H-NMR(400MHz,Acetone-d6)δ(ppm):7.12(brs,3H),6.90(brs,3H),6.45ppm(brs,3H),6.21ppm( brs, 3H), 1.43ppm(brs, 12H), 1.07-1.31ppm(m, 60H), 0.78-0.90ppm(m, 18H), 0.55ppm(brs, 12H). 19 F-NMR(376MHz,Acetone-d6)δ(ppm):-72.2(s,9F). 31 P-NMR (162MHz, Acetone-d6) δ (ppm): -64.4 (s, 2P).

[0176] A PMMA film containing 1.0 wt% of the synthesized rare earth complex was used as a sample for evaluating the emission spectrum measurement of the rare earth complex of the present disclosure obtained above. The PMMA film containing 1.0 wt% rare earth complex was prepared by dissolving 4.5 mg of rare earth complex and 445 mg of PMMA pellets (G-1000, product of Kuraray Co., Ltd.) in 2 mL of chloroform, bar coating the obtained PMMA solution on a white glass plate, and air drying. A sample for measuring the UV-Vis spectrum of the rare earth complex obtained in Example 1 was prepared by dissolving the rare earth complex obtained above in chloroform for spectroscopic analysis at 1.0 x 10 ―5 It was prepared by dissolving it at a concentration of 1 mol / L and filling it into a 1 cm quartz cell for spectroscopic analysis.

[0177] The measurement results of the UV-Vis spectrum and emission spectrum (excitation light 350 nm) of the rare earth complex obtained in Example 1 are shown in FIG. Comparative Example 1

[0178] [ka]

[0179] Tetrahydrofuran (768mL) was added to 4-hydroxycoumarin (74.9g, 462mmol) and imidazole (157g, 2.31mol), and then a mixture of trifluoroacetic anhydride (129mL, 924mmol) and tetrahydrofuran (156mL) was added dropwise over 1 hour in an ice bath. The mixture was then stirred at room temperature for 4 hours, the resulting white solid was filtered off, and the solvent was distilled off under reduced pressure. 220mL of ethyl acetate was added and stirred, and the resulting precipitate was filtered off. 931mL of toluene and 665mL of 2M hydrochloric acid were added to this and stirred, and the aqueous layer was removed. This was washed twice with 665mL of water, and the solvent was distilled off under reduced pressure to obtain a white solid of 4-hydroxy-3-(2,2,2-trifluoroethan-1-one-1-yl)-2H-chromen-2-one (yield 61.3g, 51%). 1H-NMR(400MHz,CDCl3)δ(ppm):15.04(brs,1H),8.11(dd,J=8.1,1.6Hz,1H),7.80(ddd, J=8.5,7.3,1.6Hz,1H),7.41(ddd,J=8.1,7.3,1.0Hz,1H),7.36(dd,J=8.5,1.0Hz,1H). 19 F-NMR(376MHz, CDCl3)δ(ppm):-74.6(s,3F).

[0180] Ethanol (343 mL) was added to europium(III) acetate hydrate (29.0 g, 68.7 mmol as pentadecahydrate) and trioctylphosphine oxide (53.2 g, 206 mmol) and stirred at room temperature for 2 hours. 4-Hydroxy-3-(2,2,2-trifluoroethan-1-one-1-yl)-2H-chromen-2-one (53.2 g, 206 mmol) obtained above was added to the reaction mixture and stirred at room temperature for 3 hours. The reaction solution was concentrated under reduced pressure, and then 520 mL of toluene was added and washed three times with 324 mL of water. The toluene solution was concentrated under reduced pressure to obtain tris[4-hydroxy-3-(2,2,2-trifluoroethan-1-one-1-yl)-2H-chromen-2-onato]bis(trioctylphosphine oxide)europium(III) (1c-204) as a colorless oil (yield: 113 g, yield: 97%). 1 H-NMR reveals that it contains 5.7 mol% of 4-hydroxycoumarin as an impurity. 1 H-NMR(400MHz,Acetone-d6)δ(ppm):7.89(dd,7.9,1.7Hz,0.057H),7.64(ddd,8.4,7.4 ,1.7Hz,0.057H),7.35(ddd,7.9,7.4,1.0Hz,0.057H),7.30(dd,8.4,1.0Hz,0.057H),7 .12(brs,3H),6.90(brs,3H),6.45ppm(brs,3H),6.21ppm(brs,3H),5.68(s,0.057H),1 .43ppm(brs,12H),1.07-1.31ppm(m,60H),0.78-0.90ppm(m,18H),0.60ppm(brs,12H). 19F-NMR(376MHz,Acetone-d6)δ(ppm):-72.2(s,9F). 31 P-NMR (162MHz, Acetone-d6) δ (ppm): -64.4 (s, 2P). Comparative Example 2

[0181] [ka]

[0182] Ethanol (19mL) was added to europium(III) acetate hydrate (1.57g, 3.71mmol as 5.2 hydrate) and trioctylphosphine oxide (2.87g, 7.41mmol) and stirred at room temperature for 2 hours. A mixture of 4-hydroxy-3-(2,2,2-trifluoroethane-1-one-1-yl)-2H-chromene-2-onatoimidazolium and trifluoroacetate imidazolium (5.65g, molar ratio = 1:1.0, 4-hydroxy-3-(2,2,2-trifluoroethane-1-one-1-yl)-2H-chromene-2-onatoimidazolium 11.1mmol) was added to the reaction mixture and stirred at room temperature for 3 hours. After distilling off the reaction solvent under reduced pressure, 28mL of toluene was added and the resulting precipitate was filtered off. This toluene solution was washed three times with water, and the solvent was then removed by distillation under reduced pressure. The residue was dried in vacuum at 80° C. for 13 hours to obtain a colorless oil. 1 H-NMR revealed that the product was not the target compound, tris[4-hydroxy-3-(2,2,2-trifluoroethan-1-one-1-yl)-2H-chromen-2-onato]bis(trioctylphosphine oxide)europium(III).

[0183] [Table 1] [Industrial Applicability]

[0184] According to the present disclosure, rare earth complexes can be efficiently produced with high purity.

Claims

1. An enolate salt represented by the following formula (4cm) and L １ a nitrogen-containing ligand having two or more nitrogen atoms having an unshared electron pair, or a phosphorus ligand represented by the following formula (3a): 【Chemistry 1】 {CU is a coumarinato ligand represented by formula (1cu). 【Chemistry 2】 (In the formula, R Ａ R represents a fluoroalkyl group having 1 to 4 carbon atoms. Ｃ１ , R Ｃ２ , R Ｃ３ and R Ｃ４ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms which may be substituted with one or more alkyloxy groups having 1 to 4 carbon atoms, an aryl group having 6 to 14 carbon atoms which may be substituted with one or more alkyloxy groups having 1 to 4 carbon atoms, a dialkylamino group having 2 to 8 carbon atoms, a diphenylamino group, a carbazol-9-yl group, a phenoxy group, or a thiophenoxy group. The diphenylamino group and the carbazol-9-yl group may be substituted with one or more fluorine atoms, cyano groups, or nitro groups. In addition, R Ｃ１ , R Ｃ２ , R Ｃ３ and R Ｃ４ Among these, two adjacent substituents may be bonded together with the benzene ring to form a 5-, 6-, or 7-membered ring. C Ａ＋ represents a monovalent organic cation. m １ represents 1 or 2. L １ represents a nitrogen-containing ligand having two or more nitrogen atoms having an unshared electron pair or a phosphorus ligand represented by the following formula (3a): 【Chemistry 3】 [In the formula, X Ａ each independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group represented by the following formula (3c): 【Chemistry 4】 (In the formula, X １ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an aryl group having 6 to 22 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, or a haloalkyloxy group having 1 to 6 carbon atoms, and the aryl group may be substituted with one or more substituents selected from the group consisting of a halogen atom, an alkyloxy group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, a haloalkyloxy group having 1 to 6 carbon atoms, a hydroxyl group, a cyano group, and a nitro group. M ３＋ represents a trivalent rare earth metal ion.

2. 2. The method for producing a rare earth complex (1c) according to claim 1, characterized in that the organic solvent is an aromatic hydrocarbon.

3. 2. The method for producing a rare earth complex (1c) according to claim 1, characterized in that the volume ratio of the organic solvent to the water is 1:0.5 to 2.

5.

4. The method for producing a rare earth complex (1c) according to claim 1, characterized in that the enolate salt represented by the formula (4cm) is used in an amount of 3.0 to 3.3 molar equivalents relative to the rare earth compound.

5. C Ａ＋ The method for producing the rare earth complex (1c) according to claim 1, characterized in that is imidazolium.

6. M ３＋ The method for producing the rare earth complex (1c) according to claim 1, characterized in that is a europium ion.

7. L １ The method for producing a rare earth complex (1c) according to claim 1, characterized in that is any one of tributylphosphine oxide, trioctylphosphine oxide, tricyclohexylphosphine oxide, triphenylphosphine oxide, tri(o-tolyl)phosphine oxide, tri(o-methoxyphenyl)phosphine oxide, and o-biphenyldiphenylphosphine oxide.

8. A method for producing a rare earth complex (1c), comprising the steps of: Step A: 4-hydroxycoumarin compound represented by formula (4cus) 【Chemistry 5】 (In the formula, R Ｃ１ , R Ｃ２ , R Ｃ３ and R Ｃ４ each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms which may be substituted with one or more alkyloxy groups having 1 to 4 carbon atoms, an aryl group having 6 to 14 carbon atoms which may be substituted with one or more alkyloxy groups having 1 to 4 carbon atoms, a dialkylamino group having 2 to 8 carbon atoms, a diphenylamino group, a carbazol-9-yl group, a phenoxy group or a thiophenoxy group. The diphenylamino group and the carbazol-9-yl group may be substituted with one or more fluorine atoms, cyano groups or nitro groups. In addition, R Ｃ１ , R Ｃ２ , R Ｃ３ and R Ｃ４ Among these, two adjacent substituents may be bonded together with the benzene ring to form a 5-, 6-, or 7-membered ring. and an acid anhydride represented by formula (1ah) 【Chemistry 6】 (In the formula, R Ａ represents a fluoroalkyl group having 1 to 4 carbon atoms. and an enolate salt represented by formula (4cm), which is reacted in the presence of an organic base. 【Chemistry 7】 (C Ａ＋ R represents a monovalent organic cation. Ａ , R Ｃ１ , R Ｃ２ , R Ｃ３ and R Ｃ４ represents the same meaning as above.) The process of obtaining the above. Step B: Reacting an enolate salt represented by formula (4cm) with L １ a rare earth complex (1c), which is characterized by reacting a nitrogen-containing ligand represented by the following formula (3a) having two or more nitrogen atoms each having an unshared electron pair with a rare earth compound in the presence of an organic solvent and water: 【Chemistry 8】 {CU is a coumarinato ligand represented by formula (1cu). 【Chemistry 9】 (In the formula, R Ａ , R Ｃ１ , R Ｃ２ , R Ｃ３ and R Ｃ４ represents the same meaning as above.) C Ａ＋ has the same meaning as above. m １ represents 1 or 2. L １ represents a nitrogen-containing ligand having two or more nitrogen atoms having an unshared electron pair or a phosphorus ligand represented by the following formula (3a): 【Chemistry 10】 [In the formula, X Ａ each independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group represented by the following formula (3c): 【Chemistry 11】 (In the formula, X １ each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an aryl group having 6 to 22 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms, an aryloxy group having 6 to 14 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, or a haloalkyloxy group having 1 to 6 carbon atoms, and the aryl group may be substituted with one or more substituents selected from the group consisting of a halogen atom, an alkyloxy group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, a haloalkyloxy group having 1 to 6 carbon atoms, a hydroxyl group, a cyano group, and a nitro group. M ３＋ represents a trivalent rare earth metal ion. The process of obtaining the above.

9. The method for producing a rare earth complex (1c) according to claim 8, characterized in that the organic solvent is an aromatic hydrocarbon.

10. 9. The method for producing a rare earth complex (1c) according to claim 8, characterized in that the volume ratio of the organic solvent to the water is 1:0.5 to 2.

5.

11. The method for producing a rare earth complex (1c) according to claim 8, characterized in that the enolate salt represented by the formula (4cm) is used in an amount of 3.0 to 3.3 molar equivalents relative to the rare earth compound.

12. C Ａ The method for producing a rare earth complex (1c) according to claim 8, characterized in that is imidazolium.

13. M ３＋ The method for producing a rare earth complex (1c) according to claim 8, characterized in that is a europium ion.

14. L １ The method for producing a rare earth complex (1c) according to claim 8, characterized in that is any one of tributylphosphine oxide, trioctylphosphine oxide, tricyclohexylphosphine oxide, triphenylphosphine oxide, tri(o-tolyl)phosphine oxide, tri(o-methoxyphenyl)phosphine oxide, and o-biphenyldiphenylphosphine oxide.

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