Sample forming material for x-ray structure analysis, and method for determining molecular structure of organic compound using said material

Abstract

Provided is a sample forming material for subjecting an organic compound to X-ray structure analysis.　A sample forming material for X-ray structure analysis according to the present disclosure contains a metal complex crystal that includes metal ions and compound [1], [2], or [3]. [1] A compound having a structure in which two or more benzene rings provided with coordinating functional groups are bonded via a linking group selected from urea bonds, azo groups, sulfonyl groups, imidazole groups, groups in which two or more of said groups are bonded via a hydrocarbon group, hydrocarbon groups, groups represented by formula (L1), groups represented by formula (L2), and groups represented by formula (L3); [2] a polycyclic aromatic hydrocarbon compound provided with a coordinating functional group; and [3] a compound having a structure in which two aromatic heterocyclic rings provided with coordinating functional groups are bonded via a linking group selected from single bonds, urea bonds, azo groups, sulfonyl groups, imidazole groups, and groups in which two or more of said groups are bonded via a hydrocarbon group.

Description

X-ray structural analysis sample forming material, and method for determining the molecular structure of organic compounds using the same.

[0001] This disclosure relates to a novel X-ray structural analysis sample forming material, a method for determining the molecular structure of an organic compound using the X-ray structural analysis sample forming material, and a method for determining the absolute configuration of a chiral organic compound using the X-ray structural analysis sample forming material. This application claims priority to Japanese Patent Application No. 2024-176593, filed in Japan on October 8, 2024, the contents of which are incorporated herein by reference.

[0002] One known method for determining the molecular structure of organic compounds is single-crystal X-ray diffraction, which involves subjecting a single crystal of the organic compound to X-ray diffraction. If a high-quality single crystal of the organic compound can be prepared, its molecular structure can be accurately determined using this method.

[0003] However, if the amount of organic compound is trace, it is difficult to determine the molecular structure using the above method because a sufficient amount of single crystal cannot be obtained. Furthermore, some organic compounds are difficult to crystallize, and the molecular structure of such compounds cannot be determined using the above method.

[0004] Therefore, the crystal sponge method was developed as a method for X-ray structural analysis of organic compounds without crystallization. In the crystal sponge method, a porous metal complex crystal [i.e., a metal complex crystal having regularly arranged pores (or vacancies)] is used as a host, and an organic compound whose molecular structure is to be determined is used as a guest molecule. An X-ray structural analysis sample is formed by soaking a solution containing the guest molecule into the host, thereby fixing the guest molecule within the pores of the host. The obtained X-ray structural analysis sample is then subjected to X-ray structural analysis to determine the molecular structure of the guest molecule.

[0005] As a host that can be used in the crystal sponge method, Patent Document 1 discloses a porous metal complex crystal obtained by coordinating 2,4,6-tris(4-pyridyl)-1,3,5-triazine to a zinc ion or cobalt ion.

[0006] International Publication No. 2014 / 038220

[0007] In the crystal sponge method, the success rate of determining molecular structure can be increased by optimizing the type of solvent used for soaking and soaking conditions such as soaking temperature, depending on the type of guest molecule, thereby increasing the percentage of guest molecules fixed within the pores of the host (fixation rate). However, the porous metal complex crystal described in Patent Document 1 has low solvent resistance and dissolves in medium-polar to highly polar solvents, limiting the types of solvents that can be used. Therefore, it is difficult to improve the fixation rate of guest molecules by optimizing the type of solvent, and the probability of determining the molecular structure of guest molecules is low. Furthermore, the probability of determining the absolute configuration of chiral guest molecules is also low.

[0008] Furthermore, the porous metal complex crystal described in Patent Document 1 has a hydrophobic environment within its pores, making it difficult to retain hydrophilic organic compounds within the pores. Therefore, the crystal sponge method using the porous metal complex crystal could not determine the molecular structure of hydrophilic organic compounds. Moreover, the porous metal complex crystal described in Patent Document 1 cannot maintain its crystal structure unless the pores are filled with a solvent. Therefore, the method of filling the pores with a gas containing a gaseous organic compound to fix the gaseous organic compound within the pores could not be employed with the porous metal complex crystal. For these reasons, a novel sample-forming material is needed.

[0009] Therefore, an object of this disclosure is to provide a novel sample-forming material for X-ray structural analysis of organic compounds. Another object of this disclosure is to provide a novel sample-forming material that can determine the molecular structure of an organic compound with high probability by X-ray structural analysis. Another object of this disclosure is to provide a novel sample-forming material that can determine the molecular structure of a hydrophilic organic compound by X-ray structural analysis. Another object of this disclosure is to provide a novel sample-forming material that can determine the absolute configuration of a chiral organic compound by X-ray structural analysis. Another object of this disclosure is to provide a method for determining the molecular structure of an organic compound using the sample-forming material. Another object of this disclosure is to provide a method for determining the absolute configuration of a chiral organic compound using the sample-forming material.

[0010] As a result of diligent research to solve the above problems, the present inventors have found that in the crystal sponge method, when a porous metal complex crystal composed of metal ions and specific organic ligands is used as a host, guest molecules, which are organic compounds, can be efficiently immobilized within the pores of the porous metal complex crystal, and the molecular structure of the immobilized organic compound can be determined with high probability. This disclosure is completed based on these findings.

[0011] In other words, the present disclosure provides a material for forming an X-ray structural analysis sample containing organic compounds in an orderly arrangement, and includes the following metal complex crystal for forming an X-ray structural analysis sample. Metal complex crystal: A metal complex crystal having a three-dimensional network structure with orderly arrangement of vacancies, composed of metal ions and organic ligands that coordinate to the metal ions, wherein the organic ligands include the compounds of [1], [2], or [3] below. [1] A compound having a structure in which two or more benzene rings having coordinating functional groups are linked via linking groups selected from urea bonds, azo groups, sulfonyl groups, imidazole groups, groups in which two or more of the above groups are linked via hydrocarbon groups, hydrocarbon groups, groups represented by the following formula (L1), groups represented by the following formula (L2), and groups represented by the following formula (L3). (In formulas (L1) to (L3), the bonds indicated by the wavy lines are bonded to the benzene ring. In formula (L1), R １∫ represents a coordinating functional group bonded to a benzene ring. m is an integer from 0 to 4. However, in a benzene ring bonded to a melamine group, the para position of the bond to the melamine group is a hydrogen atom.) [2] Polycyclic aromatic hydrocarbon compounds having a coordinating functional group [3] Compounds having a structure in which two aromatic heterocycles having coordinating functional groups are bonded via linking groups selected from single bonds, urea bonds, azo groups, sulfonyl groups, imidazole groups, and groups in which two or more of the above groups are bonded via hydrocarbon groups

[0012] This disclosure also provides an X-ray structural analysis sample forming material wherein the metal ion is selected from zinc ions, iron ions, cobalt ions, nickel ions, copper ions, silver ions, and europium ions.

[0013] This disclosure also provides an X-ray structural analysis sample forming material wherein the organic compound is an organic compound having a functional group selected from substituted or unsubstituted amino groups, carboxyl groups, active methylene groups, nitrile groups, ketone groups, aldehyde groups, ester groups, ether groups, amide groups, hydroxyl groups, halogen groups, and sulfonamide groups.

[0014] This disclosure also provides a method for determining the molecular structure of an organic compound (X), comprising the following steps 1 and 2. Step 1: The organic compound (X) is impregnated into the X-ray structural analysis sample forming material, and the organic compound (X) is fixed in the pores of the X-ray structural analysis sample forming material to obtain an X-ray structural analysis sample. Step 2: The obtained X-ray structural analysis sample is irradiated with X-rays to obtain diffraction data, and the obtained diffraction data is analyzed to determine the molecular structure of the organic compound (X).

[0015] This disclosure also provides a method for determining the molecular structure of an organic compound (X), wherein step 2 is a step of irradiating the obtained X-ray structural analysis sample with X-rays to obtain diffraction data, analyzing the obtained diffraction data to determine the absolute configuration of the organic compound (X) if the organic compound (X) is a chiral compound, and determining the molecular structure of the organic compound (X) if the organic compound (X) is an achiral compound.

[0016] This disclosure also provides a method for determining the absolute configuration of a chiral organic compound (Y), comprising the following steps A, B, and C. Step A: Optically separate a mixture of the chiral organic compound (Y) and its enantiomer to obtain the chiral organic compound (Y). Step B: Impregnate the X-ray structural analysis sample forming material with the chiral organic compound (Y), fix the chiral organic compound (Y) in the pores of the X-ray structural analysis sample forming material, and obtain an X-ray structural analysis sample. Step C: Irradiate the obtained X-ray structural analysis sample with X-rays to obtain diffraction data, and analyze the obtained diffraction data to determine the absolute configuration of the chiral organic compound (Y).

[0017] This disclosure also provides a method for determining the absolute configuration of a chiral organic compound (Y), wherein the optical separation in step A is performed using a chiral column.

[0018] This disclosure also provides a method for determining the absolute configuration of the chiral organic compound (Y), wherein the optical separation in step A is performed by a method selected from supercritical liquid chromatography using a chiral column, liquid chromatography using a chiral column, gas chromatography using a chiral column, pseudo-mobile bed chromatography using a chiral column, and capillary electrophoresis.

[0019] This disclosure also provides a method for determining the absolute configuration of a chiral organic compound (Y), wherein the optical separation in step A is performed by a method selected from liquid chromatography using a chiral column, gas chromatography using a chiral column, pseudo-mobile bed chromatography using a chiral column, and capillary electrophoresis.

[0020] The X-ray structural analysis sample forming material of this disclosure (hereinafter sometimes referred to as "sample forming material") includes a metal complex crystal having regularly aligned vacancies composed of the above-mentioned organic ligand [1], [2], or [3] having a functional group that readily interacts with guest molecules (organic compounds), and metal ions. Therefore, guest molecules can be incorporated into and immobilized in the vacancies of the metal complex crystal with a high probability. Furthermore, the vacancies of the metal complex crystal exhibit a hydrophilic environment. Therefore, hydrophilic organic compounds can be incorporated into and immobilized in the vacancies as guest molecules with a high probability. Moreover, since the metal complex crystal strongly interacts with guest molecules incorporated into the vacancies, when a chiral compound is incorporated as a guest molecule, the chirality of the guest molecule is easily transferred to the metal complex crystal. Therefore, by using the sample forming material containing the metal complex crystal, the absolute configuration of a chiral compound can be determined with a high probability. Furthermore, the metal complex crystal has excellent solvent resistance and can maintain its crystal structure in various solvents. Therefore, by selecting and using the optimal solvent to increase the fixation rate of guest molecules, the accuracy of determining the molecular structure of guest molecules can be further improved. Furthermore, the metal complex crystal exhibits excellent toughness and can maintain its crystal structure whether the pores are filled with a solvent or not (i.e., filled with gas). Therefore, not only can liquid guest molecules be impregnated into the pores of the sample-forming material (or solid guest molecules dissolved in a solvent) and fixed, but gaseous guest molecules can also be impregnated and fixed. Accordingly, by using the sample-forming material, it is possible to form an X-ray structural analysis sample in which solid, liquid, or gaseous guest molecules are fixed in the pores with a high probability.

[0021] By using the aforementioned sample-forming material, even if the amount of guest molecules is too small to form single crystals, or if the compound is one that cannot be formed into single crystals, the guest molecules can be fixed within the pores of the sample-forming material, thereby aligning them in an orderly manner. Then, by subjecting the guest molecules, which are orderedly aligned within the sample-forming material, to X-ray structural analysis, the molecular structure of the guest molecules can be determined, and if the guest molecules are chiral compounds, their absolute configuration can be determined.

[0022] Therefore, the sample-forming material is extremely useful as a means of determining the molecular structure of solid, liquid, or gaseous organic compounds (especially hydrophilic organic compounds) as a guest molecule.

[0023] This is a schematic diagram showing the crystal structure of sample-forming material 1 obtained in the example. This is a stereomicrograph of sample-forming material 1 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 2 obtained in the example. This is a stereomicrograph of sample-forming material 2 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 3 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 4 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 5 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 6 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 7 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 8 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 9 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 10 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 11 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 12 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 13 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 14 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 15 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 16 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 17 obtained in the example. This is a schematic diagram showing the crystal structure of sample-forming material 18 obtained in the comparative example. This is a schematic diagram showing how the functional groups of the metal complex crystal and the guest molecule interact in structural analysis sample 1 obtained in the example. This is an enlarged view of a part of Figure 21. This is a schematic diagram showing how the functional groups of the metal complex crystal and the guest molecule interact in structural analysis sample 2 obtained in the example. This is an enlarged view of a part of Figure 23.

[0024] [X-ray structural analysis sample forming material] The X-ray structural analysis sample forming material of this disclosure is a material for forming a sample to be subjected to X-ray structural analysis, and is a host used in the crystal sponge method. The sample forming material is used to fix guest molecules, which are organic compounds, in an orderly and aligned state.

[0025] The sample-forming material contains at least the following metal complex crystals. The sample-forming material may contain components other than the following metal complex crystals, but the proportion of the following metal complex crystals in the total amount of the sample-forming material is, for example, 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more, particularly preferably 90% by weight or more, most preferably 95% by weight or more, and especially preferably 99% by weight or more. The sample-forming material may consist substantially only of the following metal complex crystals.

[0026] (Metal complex crystals) Metal complex crystals are metal complex crystals with a three-dimensional network structure having regularly arranged vacancies, composed of metal ions and organic ligands that coordinate to the metal ions, and are porous metal complex crystals.

[0027] From the viewpoint of improving the accuracy of determining the crystal structure by X-ray structural analysis, a crystal system with low symmetry, such as a monoclinic or triclinic system, is preferred for metal complex crystals. Therefore, it is preferable that metal complex crystals have a monoclinic or triclinic space group.

[0028] The aforementioned metal ions are not particularly limited as long as they can form a three-dimensional network structure through coordination bonding with organic ligands described later. Examples include metal ions from groups 8 to 12 of the periodic table, such as zinc ions, iron ions, cobalt ions, nickel ions, copper ions, and silver ions; and lanthanide metal ions, such as europium ions, lanthanum ions, cerium ions, neodymium ions, gadolinium ions, terbium ions, dysprosium ions, and ytterbium ions. Among these, at least one metal ion selected from zinc ions, cobalt ions, and europium ions is preferred because it yields a three-dimensional network structure metal complex crystal with large vacancies.

[0029] The organic ligand includes the compound described in [1] below, or the compound described in [2] below, or the compound described in [3] below. [1] A compound having a structure in which two or more benzene rings having coordinating functional groups are linked via a linking group (hereinafter sometimes referred to as "organic ligand 1"), wherein the linking group is selected from a urea bond, an azo group, a sulfonyl group, an imidazole group, a group in which two or more of the above groups are linked via a hydrocarbon group, a hydrocarbon group, a group represented by the following formula (L1), a group represented by the following formula (L2), and a group represented by the following formula (L3). (In formulas (L1) to (L3), the bonds indicated by the wavy lines are bonded to the benzene ring. In formula (L1), R １ represents a coordinating functional group bonded to a benzene ring. m is an integer from 0 to 4. However, in a benzene ring bonded to a melamine group, the para position of the bond to the melamine group is a hydrogen atom.) [2] A polycyclic aromatic hydrocarbon compound having a coordinating functional group (hereinafter sometimes referred to as "organic ligand 2") [3] A compound having a structure in which two aromatic heterocycles having coordinating functional groups are bonded via a linking group (hereinafter sometimes referred to as "organic ligand 3"), wherein the linking group is selected from a single bond, a urea bond, an azo group, a sulfonyl group, an imidazole group, or a group in which two or more of the above groups are bonded via a hydrocarbon group.

[0030] The aforementioned organic ligand may consist of only one selected from organic ligand 1, organic ligand 2, and organic ligand 3, or it may consist of one selected from organic ligand 1, organic ligand 2, and organic ligand 3 in combination with another organic ligand (hereinafter sometimes referred to as "organic ligand 4").

[0031] (Organic Ligand 1) Organic ligand 1 is a compound having a structure in which two or more (preferably two to four) benzene rings having coordinating functional groups are linked via a linking group. The linking group is a polarizing functional group, such as a urea bond, azo group, sulfonyl group, or imidazole group; a group in which two or more of the above groups are linked via a hydrocarbon group (i.e., a group in which two or more groups selected from a urea bond, azo group, sulfonyl group, and imidazole group are linked via a hydrocarbon group (preferably a divalent group)); the hydrocarbon group; a polarizing functional group represented by the above formula (L1); and a polarizing functional group represented by the above formula (L2); and a polarizing functional group represented by the above formula (L3).

[0032] The hydrocarbon groups constituting the linking groups are divalent hydrocarbon groups, such as linear or branched alkylene groups having 1 to 18 carbon atoms, including methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene; linear or branched alkenylene groups having 2 to 8 carbon atoms, including vinylene, propenylene, 1-butenylene, and 2-butenylene; and 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylidene, 1,2-cyclohexylene, and 1,3-cyclohexylene groups. Examples include cycloalkylene groups having 3 to 18 carbon atoms, such as 1,4-cyclohexylene and cyclohexyllidene; phenylene groups (e.g., o-phenylene, m-phenylene, and p-phenylene); phenylenebis(methylene) groups (e.g., 1,2-phenylenebis(methylene), 1,3-phenylenebis(methylene), and 1,4-phenylenebis(methylene)); biphenylene groups, naphthylene groups, binaphthylene groups, anthracenylene groups, phenanthrylene groups, and other arylene groups having 6 to 14 carbon atoms.

[0033] In the group represented by the above formula (L1), R １ R is a coordinating functional group that bonds to a benzene ring. １ Examples similar to those of R described later can be given. m represents the number of coordinating functional groups bonded to the benzene ring, and is an integer from 0 to 4 (preferably 1 to 3, more preferably 1 to 2). R １As the bonding position, in the benzene ring bonding to the melamine group, it may be either the ortho position or the meta position of the bonding position with the melamine group, but the meta position is preferred.

[0034] Examples of the organic ligand 1 include compounds represented by the following formulas (1-1) to (1-11). In the following formulas, R represents a coordinating functional group that is the same or different, and n represents an integer of 1 or more that is the same or different.

[0035] A heterocyclic ring that is aromatic or non-aromatic may be condensed with the benzene ring contained in the organic ligand 1.

[0036] The R is a coordinating functional group bonded to the benzene ring, for example, a carboxy group, a pyridinium group, an imidazole group, an amino group (-NH ２ ), a substituted amino group (-NHR', -NR' ２ ), an azo group (-N = NR'), a nitroso group (-N = O), a nitro group (-NO ２ ), a sulfo group (-SO ２ OH), a halogen atom, an oxo group, a hydroxyl group, a substituted oxy group (for example, a C １－４ alkoxy group), a cyano group, etc. The carboxy group etc. may form a salt.

[0037] The R' represents a hydrocarbon group. The hydrocarbon group includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group in which these are bonded. As the hydrocarbon group, an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an s-butyl group, a t-butyl group, etc. is preferred.

[0038] As the R, a carboxy group is preferred.

[0039] The n represents the number of coordinating functional groups bonded to the benzene ring, for example, an integer of 1 to 3, preferably 1 or 2, particularly preferably 1.

[0040] The bonding position of the coordinating functional group is preferably the meta or para position relative to the bonding position of the linking group that connects two or more benzene rings. In particular, the meta position is preferred when the linking group in organic ligand 1 is the group represented by the above formula (L1), and the para position is preferred when it is any other group.

[0041] (Organic ligand 2) Organic ligand 2 is a polycyclic aromatic hydrocarbon compound that possesses a coordinating functional group.

[0042] Examples of the aforementioned polycyclic aromatic hydrocarbon compounds include condensed polycyclic aromatic hydrocarbon compounds such as fluorene compounds, naphthalene compounds, anthracene compounds, and phenanthrene compounds; and linked polycyclic aromatic hydrocarbon compounds such as biphenyl compounds and terphenyl compounds.

[0043] Examples of organic ligand 2 include compounds represented by the following formulas (2-1) to (2-3). In the following formulas, R represents the same or different coordinating functional group, and n represents the same or different integer of 1 or more.

[0044]

[0045] The aforementioned R is a coordinating functional group, and examples similar to those of R in organic ligand 1 can be given. A carboxyl group is preferred as R.

[0046] The above n represents the number of coordinating functional groups, for example, 1 to 3, preferably 1 to 2, and particularly preferably 1.

[0047] When the compound represented by formula (2-1) has two coordinating functional groups, the preferred bonding positions of the two coordinating functional groups are positions 2 and 7, or positions 3 and 6. When the compound represented by formula (2-2) has two coordinating functional groups, the preferred bonding positions of the two coordinating functional groups are positions 2 and 6. When the compound represented by formula (2-3) has two coordinating functional groups, the preferred bonding positions of the two coordinating functional groups are positions 4 and 4'.

[0048] (Organic ligand 3) Organic ligand 3 is a compound having a structure in which two aromatic heterocycles equipped with coordinating functional groups are linked via a linking group. The linking group is selected from a single bond; a polarizing functional group, such as a urea bond, azo group, sulfonyl group, or imidazole group; or a group in which two or more of the polarizing functional groups are linked via a hydrocarbon group (i.e., a group in which two or more groups selected from urea bonds, azo groups, sulfonyl groups, and imidazole groups are linked via a hydrocarbon group (preferably a divalent group)).

[0049] Examples of hydrocarbon groups constituting the linking group include those similar to the hydrocarbon groups constituting the linking group of organic ligand 1.

[0050] Examples of organic ligand 3 include compounds represented by the following formulas (3-1) to (3-7). In the following formulas, ring Z represents an aromatic heterocycle, either identically or differently. In the following formulas, R represents a coordinating functional group, either identically or differently, and n represents an integer of 1 or more, either identically or differently.

[0051] Examples of the aromatic heterocycle include a 3- to 20-membered (preferably 3- to 10-membered, particularly preferably 4- to 6-membered) aromatic heterocycle (monocyclic ring) having carbon atoms and at least one heteroatom (for example, oxygen, sulfur, nitrogen, silicon, etc.) as atoms constituting the ring, and a fused ring of the aromatic heterocycle (monocyclic ring) and a non-aromatic heterocycle.

[0052] Examples of the aforementioned aromatic heterocycles (monocycles) include aromatic heterocycles containing an oxygen atom as a heteroatom, such as a furan ring; aromatic heterocycles containing a sulfur atom as a heteroatom, such as a thiophene ring; aromatic heterocycles containing a nitrogen atom as a heteroatom, such as a pyrrole ring, pyrazole ring, imidazole ring, imidazoline ring, triazole ring, tetrazole ring, pyridine ring, pyridazine ring, pyrimidine ring, and pyrazine ring; aromatic heterocycles containing an oxygen atom and a nitrogen atom as heteroatoms, such as an oxazole ring and isoxazole ring; aromatic heterocycles containing a sulfur atom and a nitrogen atom as heteroatoms, such as a thiazole ring; and aromatic heterocycles containing a silicon atom as a heteroatom, such as a silole ring.

[0053] Examples of fused rings of aromatic heterocycles (monocycles) and non-aromatic heterocycles include indole rings, isoindole rings, benzofuran rings, benzimidazole rings, purine rings, benzotriazole rings, quinoline rings, isoquinoline rings, quinazoline rings, and carbazole rings.

[0054] Among the 3- to 20-membered aromatic heterocycles, 3- to 6-membered aromatic heterocycles are preferred, 4- to 6-membered aromatic heterocycles are particularly preferred, and 5- or 6-membered aromatic heterocycles are most preferred.

[0055] As for aromatic heterocycles with 3 to 20 members, aromatic heterocycles containing a nitrogen atom or a sulfur atom as a heteroatom are preferred.

[0056] As for 3- to 20-membered aromatic heterocycles, 5- or 6-membered aromatic heterocycles containing a nitrogen atom or a sulfur atom as a heteroatom are particularly preferred.

[0057] The aforementioned aromatic heterocycle may have an aromatic or non-aromatic hydrocarbon ring fused to it.

[0058] The aforementioned R is a coordinating functional group, and examples similar to R in organic ligand 1 can be given. Among these, a carboxyl group is preferred.

[0059] The above n represents the number of coordinating functional groups bonded to the aromatic heterocycle, for example, 1 to 3, preferably 1 to 2, and particularly preferably 1.

[0060] The bonding position of the coordinating functional group is preferably the meta or para position relative to the bonding position of the linking group that connects the two aromatic heterocycles, with the para position being particularly preferred.

[0061] (Organic Ligand 4) Organic ligand 4 is an organic ligand different from organic ligands 1 to 3. Examples of organic ligand 4 include bidentate ligands such as triazole and benzotriazole; compounds having a structure in which two benzene rings or aromatic heterocycles are linked via polarizing functional groups such as amide groups [or groups in which two amide groups are linked via hydrocarbon groups (preferably divalent groups)]; and compounds having a structure in which two benzene rings or aromatic heterocycles are linked via azo groups [or groups in which two azo groups are linked via hydrocarbon groups (preferably divalent groups)], or tetradinylene groups [or groups in which two tetradinylene groups are linked via hydrocarbon groups (preferably divalent groups)].

[0062] Examples of aromatic heterocycles in organic ligand 4 are similar to those in organic ligand 3. Examples of hydrocarbon groups in organic ligand 4 are similar to those that constitute the linking group in organic ligand 1.

[0063] Examples of organic ligand 4 include compounds represented by the following formulas (4-1) to (4-8). In the following formulas, ring Z may be the same or different aromatic heterocycle. Examples of aromatic heterocycles in ring Z are the same as those described above. Compounds represented by the following formula (4-2) include compounds in which two N-phenylamide groups are bonded to the ortho, meta, or para position of the benzene ring. Compounds represented by the following formula (4-5) include compounds in which two ring Z-containing amide groups are bonded to the ortho, meta, or para position of the benzene ring.

[0064] The compounds represented by formulas (4-3) to (4-8) are preferably those represented by the following formulas (4-3-1) to (4-8-1). The compounds represented by the following formulas (4-3-1) to (4-8-1) include compounds in which a linking group is bonded to the nitrogen atom of the pyridine ring at the ortho, meta, or para position, respectively.

[0065] When the metal complex crystal contains a combination of organic ligand 1 and organic ligand 4, the content ratio of organic ligand 1 to organic ligand 4 [organic ligand 1 / organic ligand 4; molar ratio] is, for example, 80 / 20 to 20 / 80, preferably 75 / 25 to 40 / 60, particularly preferably 75 / 25 to 45 / 55, and most preferably 70 / 30 to 45 / 55.

[0066] When the metal complex crystal contains a combination of organic ligand 2 and organic ligand 4, the content ratio of organic ligand 2 to organic ligand 4 [organic ligand 2 / organic ligand 4; molar ratio] is, for example, 80 / 20 to 20 / 80, preferably 75 / 25 to 40 / 60, particularly preferably 75 / 25 to 45 / 55, and most preferably 70 / 30 to 45 / 55.

[0067] When the metal complex crystal contains a combination of organic ligand 3 and organic ligand 4, the content ratio of organic ligand 3 to organic ligand 4 [organic ligand 3 / organic ligand 4; molar ratio] is, for example, 80 / 20 to 20 / 80, preferably 75 / 25 to 40 / 60, particularly preferably 75 / 25 to 45 / 55, and most preferably 70 / 30 to 45 / 55.

[0068] As for the organic ligands constituting the metal complex crystal, organic ligands having polarizing functional groups are preferred, in that they can efficiently interact with the reactive functional groups of guest molecules incorporated into the vacancies and efficiently fix the guest molecules in the vacancies, and in particular, organic ligands having polarizing functional groups that bond so as to protrude into the vacancies are preferred. Specifically, the organic ligands preferably include organic ligand 1, and a combination of organic ligand 1 and organic ligand 4 is preferred.

[0069] Furthermore, as organic ligand 1, a compound having a structure in which two benzene rings having coordinating functional groups are linked via a linking group selected from a urea bond, an azo group, a sulfonyl group, a group represented by formula (L1), and a group represented by formula (L2) is preferred, and a compound having a structure in which two benzene rings having carboxyl groups (especially one carboxyl group) are linked via a linking group selected from a urea bond, an azo group, a sulfonyl group, and a group represented by formula (L1) is particularly preferred.

[0070] The ratio of metal ions to organic ligand 1 (or organic ligand 2, or organic ligand 3, or organic ligand 4) [metal ion / organic ligand 1 (or organic ligand 2, or organic ligand 3, or organic ligand 4); molar ratio] is, for example, 30 / 70 to 70 / 30, preferably 40 / 60 to 60 / 40, and particularly preferably 45 / 55 to 55 / 45.

[0071] Furthermore, the content ratio of metal ions to organic ligands (total amount if two or more are included) [metal ion / organic ligand; molar ratio] is, for example, 20 / 80 to 80 / 20, preferably 25 / 75 to 60 / 40, and particularly preferably 30 / 70 to 55 / 45.

[0072] The metal complex crystal may contain other ligands in addition to the organic ligand mentioned above. Other ligands include, for example, F － , Cl － , Br － , I － SCN － NO ３ － , ClO ４ － BF ４ － SbF ４ － , PF ６ － AsF ６ － ,CH ３ COO － Examples of anions include the following.

[0073] As the aforementioned anion, NO is obtained in the sense that a three-dimensional network structure metal complex crystal with large vacancies can be obtained. ３ － F － , Cl － , Br － , and I － Anions selected from the following are preferred.

[0074] In the total amount of ligands constituting the metal complex crystal, the proportion of the total content of the organic ligands (particularly organic ligand 1, organic ligand 2, organic ligand 3, and organic ligand 4) is, for example, 30% by weight or more, preferably 45% by weight or more, more preferably 60% by weight or more, even more preferably 75% by weight or more, and most preferably 90% by weight or more. The upper limit of the above proportion is 100% by weight.

[0075] The metal complex crystal has a three-dimensional network structure with regularly arranged vacancies. These vacancies are located inside the metal complex crystal and are spaces partitioned by a network structure composed of metal ions and ligands. These vacancies are spaces that communicate with the outside of the metal complex crystal.

[0076] Preferably, the aforementioned voids are arranged in a regular, three-dimensional manner without disorder, as can be confirmed by X-ray structural analysis.

[0077] The shape of the pores is not particularly limited, but it is preferable that each pore has a certain shape and size, to the extent that it can be confirmed by X-ray structural analysis.

[0078] The shape of the aforementioned pore has variability, which changes depending on the shape of the guest molecule incorporated into the pore.

[0079] The size of the vacancies within a single unit cell is preferably such that they have a volume capable of containing one to several guest molecules (for example, one to six).

[0080] The size of a vacancy correlates with the diameter of the inscribed circle of the vacancy (hereinafter sometimes simply referred to as the "vacancy inscribed circle") on the plane parallel to the crystal plane that is closest to perpendicular to the direction in which the vacancy extends (hereinafter sometimes referred to as the "parallel plane"). A larger inscribed circle results in a larger vacancy, and a smaller inscribed circle results in a smaller vacancy.

[0081] The aforementioned "direction in which the vacancy extends" can be determined by the following method. First, select a suitable crystal plane 1 (one of the six crystal planes connecting the four lattice points included in one unit cell) that crosses the target vacancy. Then, represent the atoms constituting the metal complex crystal that are present on crystal plane 1 using van der Waals radii to draw a cross-sectional view of the vacancy with crystal plane 1 as the cutting plane. Similarly, draw a cross-sectional view of the vacancy with crystal plane 2, which is shifted by one unit cell from crystal plane 1, as the cutting plane. Next, connect the centers of the cross-sectional shapes of the vacancies on each crystal plane with a straight line in the three-dimensional view. The direction of the resulting straight line is the direction in which the vacancy extends.

[0082] Furthermore, the "diameter of the inscribed circle of the void" can be determined by the following method. First, draw a cross-sectional view of the void using the method described above. Next, draw an inscribed circle on the cross-sectional view and measure its diameter. Then, convert the obtained measurement to the actual scale to determine the actual diameter of the inscribed circle of the void. Furthermore, by gradually moving the parallel planes within a single unit cell, drawing cross-sectional views of the void on each parallel plane, and measuring the diameter of the inscribed circle, the diameter of the narrowest part and the diameter of the widest part of the inscribed circle can be determined.

[0083] The diameter of the inscribed circle of the void is, for example, 8 to 12 Å, preferably 9 to 12 Å.

[0084] Furthermore, if the shape of the void differs significantly from a perfect circle, it is preferable to predict the size of the void from the minor and major axes of the inscribed ellipse of the void on the parallel plane.

[0085] The major axis of the inscribed ellipse of the void is preferably 10 to 15 Å, and more preferably 10 to 12 Å. The minor axis of the inscribed ellipse of the void is preferably 8 to 15 Å, and more preferably 8 to 11 Å.

[0086] The cell volume (volume per unit cell) of the metal complex crystal is, for example, 3000 or more, preferably 5000 or more, particularly preferably 7000 or more, most preferably 8000 or more, and especially preferably 10000 or more. The upper limit of the cell volume is, for example, 35000. The upper limit may also be 30000, 25000, or 20000.

[0087] Furthermore, when the metal complex crystal is irradiated with X-rays, it is preferable that the X-rays reflected by the atoms in the metal complex crystal form a substantially circular (preferably perfectly circular) reflection spot, as this allows for the determination of the molecular structure of the guest molecule with a high probability. It is particularly preferable that the reflection spot is formed in the range of low to high X-ray irradiation angles (especially when the X-ray irradiation angle is 100 degrees or higher).

[0088] Since the metal complex crystal contains one selected from organic ligands 1 to 3 as a component (particularly when it contains one of the organic ligands 1 to 3 that has a polarizing functional group, and the polarizing functional group has a structure that protrudes into the vacancy), it can easily and strongly interact with the reactive functional group of a guest molecule incorporated into the vacancy, and can immobilize the guest molecule in the vacancy with a high probability. Therefore, by using a sample-forming material containing the metal complex crystal, the molecular structure of the guest molecule can be determined with a high probability.

[0089] Furthermore, since the metal complex crystal contains one selected from organic ligands 1 to 3 as a component (especially when it contains one of the organic ligands 1 to 3 that has a polarizing functional group, and the polarizing functional group has a structure that protrudes into the vacancy), it can easily and strongly interact with the reactive functional group of a guest molecule incorporated into the vacancy, and if the guest molecule has chirality, the chirality of the guest molecule is easily transferred. Therefore, by using a sample-forming material containing the metal complex crystal, the absolute configuration of a chiral guest molecule can be determined with high probability.

[0090] Furthermore, the metal complex crystal exhibits excellent durability and can maintain its crystalline structure not only in solution but also in an air atmosphere. Therefore, the metal complex crystal can incorporate and fix organic compounds that are volatile and dispersed in the gas phase after being gasified into the pores of the metal complex crystal. Consequently, the metal complex crystal can also be used to permeate and fix odor components in a gaseous state and determine their molecular structure, demonstrating its excellent versatility.

[0091] [Method for manufacturing X-ray structural analysis sample forming material] The X-ray structural analysis sample forming material can be manufactured using the following method for manufacturing metal complex crystals.

[0092] (Method for producing metal complex crystals) Metal complex crystals can be produced, for example, by reacting the aforementioned organic ligand with a salt of a metal ion and a counterion (=metal salt) in the presence of a solvent.

[0093] For example, F － , Cl － , Br － , I － SCN － NO ３ － , ClO ４ － BF ４ － SbF ４ － , PF ６ － AsF ６ － ,CH ３ COO － Examples of anions include the following.

[0094] The amount of metal salt used is, for example, 0.2 to 3 moles, preferably 0.5 to 2 moles, and particularly preferably 0.8 to 1.5 moles, per mole of the organic ligand (organic ligand 1, or organic ligand 2, or organic ligand 3, or organic ligand 4).

[0095] Furthermore, the amount of metal salt used is, for example, 0.2 to 3 moles, preferably 0.5 to 3 moles, particularly preferably 0.8 to 3 moles, and most preferably 1 to 2.5 moles, per mole of the organic ligand (total amount if two or more types are included).

[0096] Examples of the aforementioned solvents include water; benzene; benzene derivatives in which at least one hydrogen atom bonded to the benzene ring is substituted with a halogen atom, alkyl group, haloalkyl group, alkoxy group, cyano group, nitro group, substituted oxycarbonyl group, etc., such as toluene, xylene, ethylbenzene, trifluoromethylbenzene (or trifluorotoluene), chlorobenzene, anisole, benzonitrile, nitrobenzene, and ethyl benzoate; aliphatic hydrocarbons such as hexane, heptane, and octane; alicyclic hydrocarbons such as cyclohexane; haloalkanes such as carbon tetrachloride, chloroform, dichloromethane, and 1,2-dichloroethane; ketones such as acetone and methyl ethyl ketone; esters such as methyl acetate, ethyl acetate, isopropyl acetate, and butyl acetate; amides such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), and N-methylpyrrolidone; nitriles such as acetonitrile and propionitrile; linear or cyclic ethers such as diethyl ether, dibutyl ether, dimethoxyethane, dioxane, and tetrahydrofuran; and organic acids such as acetic acid. These can be used individually or in combination of two or more types.

[0097] The temperature of the reaction is, for example, 80 to 130°C.

[0098] The reaction time is, for example, 12 to 48 hours.

[0099] The reaction atmosphere is not particularly limited as long as it does not inhibit the reaction, and may be any of the following: an air atmosphere, a nitrogen atmosphere, an argon atmosphere, etc.

[0100] After this reaction is complete, the resulting reaction product can be separated and purified by conventional precipitation, washing, and filtration methods.

[0101] As the sample forming material, it is preferable to select and use metal complex crystals obtained by the above-mentioned method for producing metal complex crystals that have excellent transparency and a clear external shape (for example, needle-shaped, block-shaped, or flaky), in order to improve the accuracy of determining the molecular structure.

[0102] The size of the sample-forming material is, for example, if the sample-forming material is needle-shaped or block-shaped, a length of 10 μm or more, preferably 10 to 200 μm, and particularly preferably 10 to 100 μm. If the sample-forming material is too small, the measurement time tends to be prolonged, and if the sample-forming material is too large, it becomes difficult to sufficiently penetrate the guest molecule, and the determination rate of the molecular structure tends to decrease.

[0103] [Method for Determining the Molecular Structure of Organic Compound (X)] The method for determining the molecular structure of organic compound (X) according to this disclosure includes the following steps 1 and 2. Step 1: The organic compound (X) is impregnated into the X-ray structural analysis sample forming material, and the organic compound (X) is fixed in the pores of the X-ray structural analysis sample forming material to obtain an X-ray structural analysis sample. Step 2: The obtained X-ray structural analysis sample is irradiated with X-rays to obtain diffraction data, and the obtained diffraction data is analyzed to determine the molecular structure of organic compound (X).

[0104] The aforementioned sample-forming material corresponds to the host in the crystalline sponge method, and the organic compound (X) corresponds to the guest molecule in the crystalline sponge method.

[0105] The organic compound (X) is, for example, a compound having a functional group (which may be referred to herein as a "reactive functional group") that interacts with an organic ligand (preferably a polarizing functional group possessed by the organic ligand) that constitutes the sample forming material (or the metal complex crystal).

[0106] Examples of reactive functional groups include groups with an electronegativity of, for example, 1.0 to 4.0 (preferably 1.6 to 3.6, and particularly preferably 2.0 to 3.4).

[0107] Examples of reactive functional groups include substituted or unsubstituted amino groups, carboxyl groups, active methylene groups, nitrile groups, ketone groups, aldehyde groups, ester groups, ether groups, amide groups, hydroxyl groups, halogen groups, and sulfonamide groups.

[0108] The molecular weight of the organic compound (X) is, for example, 15 to 1000. The upper limit of the molecular weight may be 800 or 600. The lower limit of the molecular weight is preferably 30, particularly preferably 50, most preferably 100, and especially preferably 150.

[0109] The organic compound (X) may be a hydrophilic compound or a hydrophobic compound. The logP (octanol / water partition coefficient) value of the organic compound (X) is, for example, -5.0 to 4.5. In terms of improving the determination rate of the molecular structure, the lower limit of logP is preferably -4.6, particularly preferably -2.0, and most preferably -1.0, and the upper limit of logP is preferably 4.0, more preferably 3.5, even more preferably 3.0, particularly preferably 2.0, most preferably 1.5, and especially preferably 1.0.

[0110] The logP value of an organic compound (X) can be determined using commercially available software (for example, "EPI suite," software jointly developed by the U.S. EPA (The Estimations Programs Interface for Windows) and Syracuse).

[0111] (Step 1) Step 1 is a step in which an organic compound (X) is impregnated (soaked) into the sample forming material to incorporate and fix the organic compound (X) into the pores of the sample forming material, thereby obtaining an X-ray structural analysis sample in which the organic compound (X) is fixed in the pores of the sample forming material.

[0112] The amount of the sample-forming material used is, for example, 0.1 to 50 mg (preferably 0.5 to 15 mg, particularly preferably 1 to 3 mg).

[0113] The method for impregnating the sample-forming material with an organic compound (X) and fixing the organic compound (X) into the pores of the sample-forming material can be appropriately selected depending on the state of the organic compound (X) (solid, liquid, or gas). If the organic compound (X) is a solid or gas, for example, the sample-forming material is placed in a container such as a test tube, a solution of the organic compound (X) dissolved in an inert solvent (a so-called soaking solution) is added thereto, and the mixture is left to stand at -20 to 100°C for 0.25 to 24 hours. If the organic compound (X) is a liquid, for example, the sample-forming material is placed in a container such as a test tube, the organic compound (X) is added thereto, and the mixture is left to stand at -20 to 100°C for 0.25 to 24 hours.

[0114] A soaking solution may be added to the sample-forming material and allowed to stand, after which the permeated solution may be concentrated. By performing this concentration treatment, the fixation rate of the organic compound (X) into the pores can be increased, thereby improving the determination rate of the molecular structure.

[0115] Examples of inert solvents used in the soaking solution include alcohols such as methanol, ethanol, and isopropyl alcohol; and linear or cyclic ethers such as tetrahydrofuran (THF), dimethoxyethane, and dioxane. These can be used individually or in combination of two or more. The sample forming material has excellent solvent resistance, allowing the use of various solvents as inert solvents and providing excellent handling.

[0116] When the organic compound (X) is a solid or a gas, the concentration of the organic compound (X) in the solution obtained by dissolving the organic compound (X) in an inert solvent is, for example, 0.001 to 50 μg / μL, preferably 0.01 to 5 μg / μL, and more preferably 0.1 to 1 μg / μL.

[0117] The metal complex crystals contained in the sample-forming material have excellent toughness, so they can maintain their crystal structure when the pores of the metal complex crystals are filled with an inert solvent, and they can also maintain their crystal structure even when the pores are filled with air and not with an inert solvent.

[0118] Therefore, when the organic compound (X) is a gas, its molecular structure can be easily determined by X-ray structural analysis even while it is still in a gaseous state.

[0119] One method for impregnating the sample-forming material with an organic compound (X) in a gaseous state and fixing the organic compound (X) into the pores of the sample-forming material is to fill a sealed container, such as a test tube with a cap, with an inert gas (e.g., helium gas, nitrogen gas, etc.), seal the sample-forming material and the gaseous organic compound (X) inside, and leave it standing at -20 to 100°C for 0.25 to 24 hours.

[0120] The gaseous organic compound (X) may be subjected to separation and purification treatments such as gas chromatography before being sealed in a container such as a test tube.

[0121] The type of sample forming material used in step 1 and / or the type of inert solvent used in the soaking solution are preferably selected appropriately according to the reactive functional groups, molecular weight, logP, etc., of the organic compound (X).

[0122] As the sample-forming material, it is preferable to select and use a sample-forming material that comprises one organic ligand 1 to 3 that readily interacts with the organic compound (X) (preferably one of the organic ligands 1 to 3 that readily interacts with the organic compound (X) and has a polarizing functional group, and particularly preferably one of the organic ligands 1 to 3 that readily interacts with the organic compound (X) and has a polarizing functional group that protrudes into the pore) as a component, in that it readily interacts with the organic compound (X) incorporated into the pore of the sample-forming material and can fix the organic compound (X) in the pore with a high probability.

[0123] Furthermore, it is preferable to select and use an inert solvent for the soaking solution that promotes the incorporation of the organic compound (X) into the pores of the sample forming material and improves the fixation rate of the organic compound (X) incorporated into the pores.

[0124] The optimal combination of organic compound (X) and sample-forming material, or the optimal combination of organic compound (X), sample-forming material, and inert solvent used in the soaking solution, can be determined, for example, by performing atomic-level simulations.

[0125] For example, the aforementioned atomic-level simulation can utilize density functional theory (DFT), which analyzes electronic states based on density functional theory. Alternatively, the atomic-level simulation may be combined with AI technologies such as deep learning. Combining the atomic-level simulation with AI technologies such as deep learning can improve the simulation speed.

[0126] For the aforementioned atomic-level simulations, commercially available products such as "Matlantis®" manufactured by Preferred Computational Chemistry, Inc. can be used.

[0127] Through this process, an X-ray structural analysis sample is obtained in which the organic compound (X) is immobilized in the vacancies of the metal complex crystal.

[0128] (Step 2) Step 2 is a step in which the sample for structural analysis obtained in the previous step (i.e., the metal complex crystal in which the organic compound (X) is immobilized in the pores) is irradiated with X-rays, and the obtained diffraction data is analyzed to determine the molecular structure of the organic compound (X).

[0129] According to the method for determining the molecular structure of an organic compound (X) described herein, even if the amount of organic compound (X) obtained is too small to obtain a single crystal, or even if the organic compound (X) is a compound that cannot be crystallized into a single crystal, the molecular structure can be easily determined by X-ray structural analysis without going through the crystallization process.

[0130] Furthermore, according to the method for determining the molecular structure of organic compound (X), if organic compound (X) is an achiral compound, the molecular structure of organic compound (X) can be determined with a high probability, and if organic compound (X) is a chiral compound, the chirality of organic compound (X) is transferred to the X-ray structural analysis sample with a high probability, so the absolute configuration of organic compound (X) can be determined with a high probability along with the molecular structure.

[0131] Therefore, step 2 may also be a step in which the obtained X-ray structural analysis sample is irradiated with X-rays to obtain diffraction data, the obtained diffraction data is analyzed to determine the absolute configuration of the organic compound (X) if it is a chiral compound, and to determine the molecular structure of the organic compound (X) if it is an achiral compound.

[0132] The method for determining the molecular structure of organic compound (X) described herein makes it possible to easily and reliably determine trace amounts of impurities in pharmaceuticals, odor-causing substances (including fragrances, e.g., fragrances), food additives, trace components in plants and animals, and the like.

[0133] [Method for Determining the Absolute Configuration of a Chiral Organic Compound (Y)] The method for determining the absolute configuration of a chiral organic compound (Y) according to this disclosure includes the following steps A, B, and C. Step A: Obtain the chiral organic compound (Y) by optically separating a mixture of the chiral organic compound (Y) and its enantiomer. Step B: Permeate the chiral organic compound (Y) into the X-ray structural analysis sample forming material and fix the chiral organic compound (Y) in the pores of the X-ray structural analysis sample forming material to obtain an X-ray structural analysis sample. Step C: Irradiate the obtained X-ray structural analysis sample with X-rays to obtain diffraction data, and analyze the obtained diffraction data to determine the absolute configuration of the chiral organic compound (Y).

[0134] Organic compound (Y) is a chiral organic compound and corresponds to the chiral compound among the guest molecules (or organic compound (X)) mentioned above.

[0135] (Step A) Step A is a step in which a mixture of a chiral organic compound (Y) and its enantiomer is optically separated to obtain the chiral organic compound (Y).

[0136] The mixture comprises a pair of optical isomers, a chiral organic compound (Y) and its enantiomer (hereinafter sometimes referred to as "organic compound (Y')"). There are no particular restrictions on the mixing ratio of organic compound (Y) and organic compound (Y'). When the mixture is an equal mixture of organic compound (Y) and organic compound (Y'), the mixture is a racemate.

[0137] The optical separation method for the aforementioned mixture is not particularly limited as long as it can separate optical isomers, but it is preferable to employ at least one method selected from methods such as separation using a chiral column or separation by capillary electrophoresis.

[0138] Examples of the chiral columns include columns having a stationary phase modified with a cellulose carbamate derivative or an amylose carbamate derivative on silica gel. For example, Daicel Corporation's products "CHIRALCEL OD" and "CHIRALPAK AD" can be suitably used.

[0139] Methods for separation using chiral columns include supercritical liquid chromatography (SFC), liquid chromatography (HPLC), gas chromatography (GC), and pseudo-mobile bed chromatography (SMB), depending on the type of mobile phase.

[0140] In SFC, at least one solvent selected from alcohols (e.g., methanol, ethanol) and nitriles (e.g., acetonitrile) can be used as the mobile phase.

[0141] In HPLC, at least one solvent selected from alcohol-based solvents (e.g., methanol, ethanol, isopropanol, etc.), hydrocarbon-based solvents (e.g., hexane), nitrile-based solvents (e.g., acetonitrile), ester-based solvents (e.g., ethyl acetate), water, etc. can be used as the mobile phase.

[0142] In GC, an inert gas (for example, at least one inert gas selected from helium, nitrogen, etc.) can be used as the mobile phase.

[0143] In SMB, at least one solvent selected from alcohol-based solvents (e.g., methanol, ethanol, isopropanol, etc.), hydrocarbon-based solvents (e.g., hexane), nitrile-based solvents (e.g., acetonitrile), ester-based solvents (e.g., ethyl acetate), water, etc. can be used as the mobile phase.

[0144] Generally, the higher the optical purity of the chiral organic compound (Y) obtained by optically separating a mixture of a chiral organic compound (Y) and its enantiomer organic compound (Y'), the more reliable the determination of the absolute configuration of the chiral organic compound (Y) in step C. However, increasing the optical purity of the chiral organic compound (Y) is time-consuming and costly. For example, in the case of the porous metal complex crystal described in Patent Document 1, reliable results could not be obtained unless the optical purity (or enantiomer excess) of the chiral guest molecule was 60% ee or higher, so it was necessary to perform the optical separation process with high precision. However, the X-ray structural analysis sample forming material of this disclosure contains organic ligands with excellent reactivity with guest molecules as constituent elements, so it can incorporate and fix guest molecules with a high probability. Therefore, even if the optical purity of the chiral guest molecule is lower than in the conventional method (for example, if the optical purity of the chiral guest molecule is 45% ee or higher), the absolute configuration can be determined with high reliability. Therefore, by using the X-ray structural analysis sample forming material of this disclosure, the absolute configuration of chiral guest molecules can be determined even with low accuracy in optical separation processing, thereby reducing the effort and cost associated with optical separation processing.

[0145] (Step B) Step B is a step in which the chiral organic compound (Y) obtained in Step A is impregnated into the sample forming material, and the chiral organic compound (Y) is fixed in the pores of the sample forming material to obtain an X-ray structural analysis sample.

[0146] This process can be carried out in the same manner as in process 1 above.

[0147] (Step C) Step C is a process in which the X-ray structural analysis sample obtained in Step B is irradiated with X-rays to obtain diffraction data, and the obtained diffraction data is analyzed to determine the absolute configuration of the chiral organic compound (Y).

[0148] This process can be carried out in the same manner as in process 2 above.

[0149] According to the method for determining the absolute configuration of a chiral organic compound (Y) described herein, even if the amount of organic compound (Y) obtained is too small to obtain a single crystal, or even if the organic compound (Y) is a compound that cannot be crystallized into a single crystal, the absolute configuration can be easily determined by X-ray structural analysis without going through the crystallization process.

[0150] Therefore, according to the method for determining the absolute configuration of a chiral organic compound (Y) as disclosed herein, trace amounts of chiral organic compounds contained in pharmaceuticals, odor-causing substances (e.g., fragrances), food additives, plants, and animals can be easily and with high accuracy.

[0151] The configurations and combinations thereof described herein are examples only, and can be added, omitted, replaced, and modified as appropriate, without departing from the spirit of this disclosure. Furthermore, each aspect disclosed herein can be combined with any other features disclosed herein. Moreover, this disclosure is not limited by its embodiments.

[0152] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0153] X-ray structural analysis was performed using the following automated X-ray diffractometer: Automated X-ray diffractometer: "XtaLABSynergy Custom", manufactured by Rigaku Corporation. Radiation source: Cu-Kα rays (wavelength 0.83 Å). Output: 50 mA, 24 kV.

[0154] Example 1 (Preparation of Sample-Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 120°C for 36 hours. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain transparent block-shaped single crystal particles. These were designated as Sample-Forming Material 1. Sample-Forming Material 1 contains DMF within its pores.

[0155] Metal salt: Zn (NO ３ ) ３ 6H ２O (119 mg, 0.4 mmol) Organic ligands: 4,4'-Bibenzoic acid-2,2'-sulfone (129 mg, 0.4 mmol) represented by the following formula (1-5-1) and 4,4'-Bipyridyl (31 mg, 0.2 mmol) represented by the following formula (4-3-1a), compound represented by formula (1-5-1) / compound represented by formula (4-3-1a) (molar ratio) = 2 / 1 Solvent: DMF (15 mL)

[0156] X-ray structural analysis was performed on sample-forming material 1. A schematic diagram of sample-forming material 1 is shown in Figure 1. The results of the X-ray structural analysis confirmed that sample-forming material 1 has a three-dimensional network structure and that sulfonyl groups protrude into the vacancies. It was also found that the inscribed ellipse of the vacancies contained in sample-forming material 1 has a major axis of 11.8 Å, a minor axis of 7.7 Å, and a cell volume of 5931. Furthermore, when sample-forming material 1 was irradiated with X-rays (irradiation angle: 133 degrees), the resulting reflection spot was a perfect circle. A stereomicroscope image of the obtained sample-forming material 1 is shown in Figure 2.

[0157] Example 2 (Preparation of Sample-Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 110°C for 24 hours. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain red block-shaped single crystal particles. This was designated as Sample-Forming Material 2. Sample-Forming Material 2 contains DMF within its pores.

[0158] Metal salt: Zn (NO ３ ) ３ 6H ２ O (59 mg, 0.2 mmol) Organic ligand: Azobenzene-4,4'-dicarboxylic Acid (54 mg, 0.2 mmol) represented by the following formula (1-3-1) and N,N'-bis(pyridin-3-yl)benzene-1,4-dicarboxamide (63.6 mg, 0.2 mmol) represented by the following formula (4-5-1a), compound represented by formula (1-3-1) / compound represented by formula (4-5-1a) (molar ratio) = 1 / 1 Solvent: DMA (5 mL)

[0159] X-ray structural analysis was performed on sample-forming material 2. A schematic diagram of sample-forming material 2 is shown in Figure 3. The results of the X-ray structural analysis confirmed that sample-forming material 2 has a three-dimensional network structure and that amide groups protrude into the pores. It was also found that the inscribed ellipse of the pores contained in sample-forming material 2 has a major axis of 10.1 Å, a minor axis of 8.8 Å, and a cell volume of 3065. Furthermore, when sample-forming material 2 was irradiated with X-rays (irradiation angle: 133 degrees), the resulting reflection spot was a perfect circle. Finally, a stereomicroscope image of the obtained sample-forming material 2 is shown in Figure 4.

[0160] Example 3 (Preparation of Sample Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 110°C for 24 hours. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain transparent block-shaped single crystal particles. This was designated as sample forming material 3. X-ray structural analysis was performed on sample forming material 3. A schematic diagram of sample forming material 3 is shown in Figure 5. The results of the X-ray structural analysis showed that the urea group protruded into the vacancies. In addition, the inscribed ellipse of the vacancies contained in sample forming material 3 had a major axis of 18.1 Å, a minor axis of 14.9 Å, and a cell volume of 13009.

[0161] Metal salt: Eu(NO ３ ) ３ 6H ２ O (22.3 mg, 0.05 mmol) Organic ligand: Compound represented by the following formula (1-1-1) (19.4 mg, 0.05 mmol) Solvent: DMF / H ２ O / EtOH (3mL / 0.5mL / 0.5mL) mixture

[0162] Example 4 (Preparation of Sample Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 85°C for 24 hours. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain transparent block-shaped single crystal particles. This was designated as sample forming material 4. X-ray structural analysis was performed on sample forming material 4. A schematic diagram of sample forming material 4 is shown in Figure 6. The results of the X-ray structural analysis showed that the urea group protruded into the vacancies. In addition, the inscribed ellipse of the vacancies contained in sample forming material 4 had a major axis of 20.8 Å, a minor axis of 12.2 Å, and a cell volume of 14464.

[0163] Metal salt: Eu(NO ３ ) ３ 6H ２ O (22.3 mg, 0.05 mmol) Organic ligand: Compound represented by the following formula (1-1-2) (15 mg, 0.05 mmol) Solvent: DMF / H ２ O (3mL / 0.5mL) mixed solution

[0164] Example 5 (Preparation of Sample Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 100°C for 24 hours. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain transparent block-shaped single crystal particles. These were designated as sample forming material 5. X-ray structural analysis was performed on sample forming material 5. A schematic diagram of sample forming material 5 is shown in Figure 7. As a result of the X-ray structural analysis, the inscribed ellipse of the vacancies contained in sample forming material 5 had a major axis of 19.4 Å, a minor axis of 10.5 Å, and a cell volume of 12270.

[0165] Metal salt: EuCl ３ 6H ２ O (36.6 mg, 0.1 mmol) Organic ligand: Compound represented by the following formula (3-1-2) (38.1 mg, 0.15 mmol) Solvent: DMF (2 mL)

[0166] Example 6 (Preparation of Sample Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 100°C for 24 hours. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain transparent block-shaped single crystal particles. These were designated as sample forming material 6. X-ray structural analysis was performed on sample forming material 6. A schematic diagram of sample forming material 6 is shown in Figure 8. The results of the X-ray structural analysis showed that the urea group protruded into the vacancies. Furthermore, the inscribed ellipse of the vacancies contained in sample forming material 6 had a major axis of 11.8 Å, a minor axis of 12.3 Å, and a cell volume of 9012.

[0167] Metal salt: Zn (NO ３ ) ２ 6H ２ O (30.0 mg, 0.1 mmol) Organic ligand: Compound represented by formula (1-1-2) above (30 mg, 0.1 mmol) and compound represented by formula (4-3-1a) above (15.6 mg, 0.1 mmol), compound represented by formula (1-1-2) above / compound represented by formula (4-3-1a) above (molar ratio) = 1 / 1 Solvent: DMF (2 mL)

[0168] Example 7 (Preparation of Sample Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 100°C for 24 hours. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain transparent block-shaped single crystal particles. These were designated as sample forming material 7. X-ray structural analysis was performed on sample forming material 7. A schematic diagram of sample forming material 7 is shown in Figure 9. As a result of the X-ray structural analysis, the inscribed ellipse of the vacancies contained in sample forming material 7 had a major axis of 12.6 Å, a minor axis of 12.0 Å, and a cell volume of 12152.

[0169] Metal salt: Zn (NO ３ ) ２ 6H ２ O (30.0 mg, 0.1 mmol) Organic ligand: Compound represented by the following formula (2-1-1) (25 mg, 0.1 mmol) and compound represented by the above formula (4-3-1a) (15.6 mg, 0.1 mmol), compound represented by the following formula (2-1-1) / compound represented by the above formula (4-3-1a) (molar ratio) = 1 / 1 Solvent: DMF (2 mL)

[0170] Example 8 (Preparation of Sample Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 85°C for 3 days. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain transparent block-shaped single crystal particles. These were designated as sample forming material 8. X-ray structural analysis was performed on sample forming material 8. A schematic diagram of sample forming material 8 is shown in Figure 10. As a result of the X-ray structural analysis, the inscribed ellipse of the vacancies contained in sample forming material 8 had a major axis of 14.2 Å, a minor axis of 10.8 Å, and a cell volume of 12270.

[0171] Metal salt: Zn (NO ３ ) ２ 6H ２ O (30.0 mg, 0.1 mmol) Organic ligand: Compound represented by the following formula (1-7-1) (17.4 mg, 0.05 mmol) and benzotriazole represented by the following formula (BTA) (5.9 mg, 0.05 mmol), compound / benzotriazole (molar ratio) = 1 / 1 Solvent: DMF (3 mL)

[0172] Example 9 (Preparation of Sample Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 65°C for 3 days. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain transparent block-shaped single crystal particles. These were designated as sample forming material 9. X-ray structural analysis was performed on sample forming material 9. A schematic diagram of sample forming material 9 is shown in Figure 11. The results of the X-ray structural analysis showed that secondary amino groups protruded into the pores. The cell volume of sample forming material 9 was 16886.

[0173] Metal salt: EuCl ３ 6H ２ O (18.3 mg, 0.05 mmol) Organic ligand: Compound represented by the following formula (1-8-1) (18.7 mg, 0.025 mmol) Solvent: DMF (2 mL)

[0174] Example 10 (Preparation of Sample Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 80°C for 24 hours. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain yellow block-shaped single crystal particles. This was designated as sample forming material 10. X-ray structural analysis was performed on sample forming material 10. A schematic diagram of sample forming material 10 is shown in Figure 12. The results of the X-ray structural analysis showed that the amide group protruded into the vacancy. In addition, the inscribed ellipse of the vacancy contained in sample forming material 10 had a major axis of 14.4 Å, a minor axis of 8.4 Å, and a cell volume of 9320.

[0175] Metal salt: Zn (NO ３ ) ２ 6H ２ O (22.3 mg, 0.05 mmol) Organic ligand: Compound represented by the above formula (2-1-1) (25.4 mg, 0.1 mmol) and compound represented by the following formula (4-6-1a) (21 mg, 0.05 mmol), compound represented by the above formula (2-1-1) / compound represented by the following formula (4-6-1a) (molar ratio) = 2 / 1 Solvent: DMF (10 mL)

[0176] Example 11 (Preparation of Sample Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 80°C for 48 hours. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain yellow block-shaped single crystal particles. These were used as sample forming material 11. X-ray structural analysis was performed on sample forming material 11. A schematic diagram of sample forming material 11 is shown in Figure 13. As a result of the X-ray structural analysis, the inscribed ellipse of the vacancies contained in sample forming material 11 had a major axis of 12.8 Å, a minor axis of 12.4 Å, and a cell volume of 9391.

[0177] Metal salt: Zn (NO ３ ) ２ 6H ２ O (30 mg, 0.1 mmol) Organic ligand: Compound represented by formula (2-1-1) above (25.4 mg, 0.1 mmol) and compound represented by formula (4-6-1a) above (21 mg, 0.05 mmol), molar ratio of compound represented by formula (2-1-1) above / compound represented by formula (4-6-1a) above = 2 / 1 Solvent: DMF (10 mL)

[0178] Example 12 (Production of Sample-Forming Material) A metal salt, an organic ligand, and a solvent were added to a glass test tube and stored at 80°C for 48 hours. Thereafter, the crystals deposited in the glass test tube were washed with DMF to obtain yellow block-shaped single crystal particles. This was designated as sample-forming material 12. X-ray structural analysis of sample-forming material 12 was performed. A schematic diagram of sample-forming material 12 is shown in FIG. 14. As a result of the X-ray structural analysis, the inscribed ellipse of the pores contained in sample-forming material 12 had a major axis of 14.6 Å, a minor axis of 14.1 Å, and a cell volume of 6126.

[0179] Metal salt: Zn(NO ３ ) ２ ・6H ２ O (30 mg, 0.1 mmol) Organic ligand: Compound represented by the following formula (1-9-1) (26.8 mg, 0.1 mmol) and compound represented by the above formula (4-6-1a) (21 mg, 0.05 mmol), compound represented by the following formula (1-9-1) / compound represented by the above formula (4-6-1a) (molar ratio) = 2 / 1 Solvent: DMF (10 mL)

[0180] Example 13 (Production of Sample-Forming Material) A metal salt, an organic ligand, and a solvent were added to a glass test tube and stored at 80°C for two days. Thereafter, the crystals deposited in the glass test tube were washed with DMF to obtain yellow block-shaped single crystal particles. This was designated as sample-forming material 13. X-ray structural analysis of sample-forming material 13 was performed. A schematic diagram of sample-forming material 13 is shown in FIG. 15. As a result of the X-ray structural analysis, the inscribed ellipse of the pores contained in sample-forming material 13 had a major axis of 12.0 Å, a minor axis of 10.8 Å, and a cell volume of 3705.

[0181] Metal salt: Zn(NO ３ ) ２ ・6H ２ O (30 mg, 0.1 mmol) Organic ligand: Compound represented by the following formula (2-2-1) (11 mg, 0.1 mmol) and compound represented by the above formula (4-6-1a) (11 mg, 0.025 mmol), compound represented by the following formula (2-2-1) / compound represented by the above formula (4-6-1a) (molar ratio) = 4 / 1 Solvent: DMF (10 mL)

[0182] Example 14 (Production of sample-forming material) A glass test tube was charged with the following metal salt, organic ligand, and solvent, and stored at 110 °C for 3 days. Thereafter, the crystals deposited in the glass test tube were washed with DMF to obtain red block-shaped single crystal particles. This was designated as sample-forming material 14. X-ray structural analysis of sample-forming material 14 was performed. A schematic diagram of sample-forming material 14 is shown in Fig. 16. As a result of the X-ray structural analysis, the inscribed ellipse of the pores contained in sample-forming material 14 had a major axis of 10.5 Å, a minor axis of 9.53 Å, and a cell volume of 6861.

[0183] Metal salt: Zn(NO ３ ) ２ ·6H ２ O (30 mg, 0.1 mmol) Organic ligand: The compound represented by the following formula (1-10-1) (29.8 mg, 0.1 mmol) and the compound represented by the following formula (4-7-1) (18.4 mg, 0.1 mmol), the compound represented by the following formula (1-10-1) / the compound represented by the following formula (4-7-1) (molar ratio) = 1 / 1 Solvent: DMF (10 mL)

[0184] Example 15 (Production of sample-forming material) A glass test tube was charged with the following metal salt, organic ligand, and solvent, and stored at 100 °C for 3 days. Thereafter, the crystals deposited in the glass test tube were washed with DMF to obtain red block-shaped single crystal particles. This was designated as sample-forming material 15. X-ray structural analysis of sample-forming material 15 was performed. A schematic diagram of sample-forming material 15 is shown in Fig. 17. As a result of the X-ray structural analysis, the inscribed ellipse of the pores contained in sample-forming material 15 had a major axis of 13.9 Å, a minor axis of 11.1 Å, and a cell volume of 5771.

[0185] Metal salt: In(NO ３ ) ３ ·4.5H ２ O (0.020 g, 0.052 mmol) Organic ligand: The compound represented by the following formula (1-11-1) (0.013 mg, 0.034 mmol) Solvent: DMF / H ２A solution prepared by adding two drops of hydrochloric acid to a mixture of O / EtOH / acetic acid (2 mL / 0.5 mL / 0.5 mL / 0.3 mL).

[0186] Example 16 (Preparation of Sample Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 80°C for 3 days. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain transparent block-shaped single crystal particles. These were used as sample forming material 16. X-ray structural analysis was performed on sample forming material 16. A schematic diagram of sample forming material 16 is shown in Figure 18. As a result of the X-ray structural analysis, the inscribed ellipse of the vacancies contained in sample forming material 16 had a major axis of 13.1 Å, a minor axis of 10.0 Å, and a cell volume of 3124.

[0187] Metal salt: Zn (NO ３ ) ２ 6H ２ O (30 mg, 0.1 mmol) Organic ligand: Compound represented by the following formula (2-3-1) (12.1 mg, 0.05 mmol) and compound represented by the above formula (4-3-1a) (7.8 mg, 0.05 mmol), compound represented by the following formula (2-3-1) / compound represented by the above formula (4-3-1a) (molar ratio) = 1 / 1 Solvent: DMF (4 mL)

[0188] Example 17 (Preparation of Sample Forming Material) The following metal salt, organic ligand, and solvent were added to a glass test tube and stored at 100°C for one day. After that, the crystals precipitated in the glass test tube were washed with DMF to obtain red block-shaped single crystal particles. These were used as sample forming material 17. X-ray structural analysis was performed on sample forming material 17. A schematic diagram of sample forming material 17 is shown in Figure 19. As a result of the X-ray structural analysis, the inscribed ellipse of the vacancies contained in sample forming material 17 had a major axis of 11.3 Å, a minor axis of 10.9 Å, and a cell volume of 15349.

[0189] Metal salt: Zn (NO ３ ) ２ 6H ２O (30 mg, 0.1 mmol) Organic ligand: Compound represented by the above formula (1-10-1) (29.8 mg, 0.1 mmol) and compound represented by the following formula (4-8-1a) (23.6 mg, 0.1 mmol), compound represented by the above formula (1-10-1) / compound represented by the following formula (4-8-1a) (molar ratio) = 1 / 1 Solvent: DMF / EtOH (2.5 mL / 2.5 mL) mixture

[0190] Comparative Example 1 (Preparation of Sample Forming Material) First, 2,4,6-tris(4-pyridyl)-1,3,5-triazine (31.3 mg, 0.1 mmol) and CHCl2 were added to a 50 mL vial. ３ 21 mL of [unclear] and 1.7 mL of methanol were added, and sonication was performed to completely dissolve them. 4.5 mL of the resulting solution was placed in a screw-cap test tube. Next, zinc chloride (20.5 mg, 0.15 mmol) and 5 mL of methanol were added to a 10 mL vial, and sonication was performed to dissolve them. 1 mL of the resulting solution was added to the screw-cap test tube. The lid of the screw-cap test tube was then closed, and it was left to stand at room temperature for 3 days. This yielded transparent, needle-shaped or block-shaped single crystal particles with a length of 10 to 200 μm. These were designated as the sample-forming material 18. X-ray structural analysis was performed on the sample-forming material 18. A schematic diagram of the sample-forming material 18 is shown in Figure 20. The results of the X-ray structural analysis showed that the inscribed ellipses of the pores contained in the sample-forming material 18 had a major axis of 20.3 Å and a minor axis of 16.2 Å.

[0191] The solvent resistance of sample-forming materials 1 to 18 obtained in the examples and comparative examples of solvent resistance evaluation was evaluated using the following method. Specifically, one single crystal particle of the sample-forming material was placed in a microvial, 1 μL of the solvent listed in the table below was added, and the material was left to stand at room temperature (25°C) under normal pressure for 10 days. After standing, the presence or absence of the crystal structure was visually observed. Then, the solvent resistance was evaluated according to the following criteria. <Evaluation Criteria> Good solvent resistance (○): The crystal structure could be maintained, and the metal complex skeleton could be observed by X-ray measurement. Poor solvent resistance (×): The crystal structure could not be maintained.

[0192]

[0193] Example 18 DL-ethyl mandelate was optically resolved under the following conditions to obtain an n-hexane / isopropanol solution of L-(+)-ethyl mandelate. Subsequently, the n-hexane in the obtained solution was removed by centrifugal evaporator. This yielded an isopropanol solution of L-(+)-ethyl mandelate (optical purity: 99% ee, LogP value = 0.550). This was used as the soaking solution. <Optical Resolution Conditions> Apparatus: HPLC, Agilent Technologies, Agilent 1100 series system Chiral column: Product name "CHIRALPAK IC", Daicel Corporation Eluent: n-hexane / isopropanol = 90 / 10 (v / v) Eluent flow rate: 1.0 mL / min Column temperature: 25°C Detector: G1315B DAD UV 254 nm

[0194] The sample-forming material 1 obtained in Example 1 was added to a microvial with a septum cap and washed three times with isopropanol solvent. Then, 50 μL of the soaking solution was added to the microvial, the cap was closed, and soaking was performed at 50°C for three days. The sample-forming material 1 after soaking was used as structural analysis sample 1. The obtained structural analysis sample 1 was mounted on an X-ray structural analyzer and crystal structure analysis was performed. A schematic diagram of the crystal structure of structural analysis sample 1 is shown in Figure 21, and Figure 22 shows that the oxygen atoms constituting the sulfonyl group of the sample-forming material 1 and the hydrogen atoms bonded to the carbon atoms directly connected to the ester group among the carbon atoms constituting the ethyl group of the guest molecule L-(+)-ethyl mandelate are interacting.

[0195] Example 19 A structural analysis sample 2 was obtained in the same manner as in Example 18, except that the sample forming material 2 obtained in Example 2 was used instead of the sample forming material 1 obtained in Example 1. The crystal structure of the obtained structural analysis sample 2 was then analyzed. A schematic diagram of the crystal structure of structural analysis sample 2 is shown in Figure 23, and Figure 24 shows that the oxygen atoms constituting the amide group of the sample forming material 2 interact with the hydrogen atoms constituting the hydroxyl group of the guest molecule, L-(+)-ethyl mandelate.

[0196] In summary, the configuration and variations thereof of this disclosure are described below. [Appendix 1] A material for forming an X-ray structural analysis sample containing organic compounds in an orderly arrangement, comprising the following metal complex crystal. Metal complex crystal: A metal complex crystal having a three-dimensional network structure with orderly arrangement of vacancies, composed of metal ions and organic ligands coordinating to the metal ions, wherein the organic ligands include the compounds of [1], [2], or [3] below. [1] A compound having a structure in which two or more (preferably 2 to 4) benzene rings having coordinating functional groups are linked via a urea bond, an azo group, a sulfonyl group, an imidazole group, a group in which two or more of the above groups are linked via a hydrocarbon group, a hydrocarbon group, a group represented by the following formula (L1), a group represented by the following formula (L2), and a linking group selected from the following formula (L3). (In formulas (L1) to (L3), the bonds indicated by the wavy lines are bonded to the benzene ring. In formula (L1), R １∫ represents a coordinating functional group bonded to a benzene ring. m is an integer from 0 to 4. However, in a benzene ring bonded to a melamine group, the para position of the bonded position to the melamine group is a hydrogen atom.) [2] A polycyclic aromatic hydrocarbon compound having a coordinating functional group [3] A compound having a structure in which two aromatic heterocycles having coordinating functional groups are bonded via linking groups selected from single bonds, urea bonds, azo groups, sulfonyl groups, imidazole groups, and groups in which two or more of the above groups are bonded via hydrocarbon groups [Note 2] The X-ray structural analysis sample forming material as described in [Note 1], wherein the metal ion is a metal ion selected from zinc ions, iron ions, cobalt ions, nickel ions, copper ions, silver ions, and europium ions. [Note 3] The X-ray structural analysis sample forming material according to [Note 1] or [Note 2], wherein the organic compound is an organic compound having a functional group selected from substituted or unsubstituted amino groups, carboxyl groups, active methylene groups, nitrile groups, ketone groups, aldehyde groups, ester groups, ether groups, amide groups, hydroxyl groups, halogen groups, and sulfonamide groups. [Note 4] The X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 3], wherein the proportion of the metal complex crystal in the total amount of the sample forming material is 50% by weight or more (preferably 60% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more, particularly preferably 90% by weight or more, most preferably 95% by weight or more, and especially preferably 99% by weight or more).

[0197] [Note 5] The X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 4], wherein the hydrocarbon group comprises one or more divalent hydrocarbon groups selected from the group consisting of a linear or branched alkylene group having 1 to 18 carbon atoms, a linear or branched alkenylene group having 2 to 8 carbon atoms, a cycloalkylene group having 3 to 18 carbon atoms, and an arylene group having 6 to 14 carbon atoms, in the compound of [1] above. [Note 6] The X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 5], wherein the coordinating functional group comprises a carboxyl group, in the compound of [1] above. [Note 7] The X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 6], wherein the number of coordinating functional groups bonded to the benzene ring in the compound of [1] above is 1 to 3 (preferably 1 to 2, particularly preferably 1), in the compound of [1] above. [Note 8] In the compound of [1], the bonding position of the coordinating functional group is meta or para relative to the bonding position of a linking group that links two or more benzene rings (preferably meta if the linking group in the compound of [1] is a group represented by the above formula (L1), and para if it is any other group), the X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 7].

[0198] [Note 9] An X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 8], wherein the compound in [2] comprises one or more compounds selected from the group consisting of fluorene compounds, naphthalene compounds, anthracene compounds, phenanthrene compounds, biphenyl compounds, and terphenyl compounds, in which the polycyclic aromatic hydrocarbon compound is. [Note 10] An X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 9], wherein the compound in [2] comprises a carboxyl group as the coordinating functional group. [Note 11] An X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 10], wherein the compound in [2] comprises 1 to 3 (preferably 1 to 2, particularly preferably 1) coordinating functional groups bonded to the polycyclic aromatic hydrocarbon compound.

[0199] [Note 12] The X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 11], wherein the hydrocarbon group comprises one or more divalent hydrocarbon groups selected from the group consisting of a linear or branched alkylene group having 1 to 18 carbon atoms, a linear or branched alkenylene group having 2 to 8 carbon atoms, a cycloalkylene group having 3 to 18 carbon atoms, and an arylene group having 6 to 14 carbon atoms, in the compound of [3] above, wherein the aromatic heterocycle comprises a 3 to 20-membered (preferably 3 to 10-membered, particularly preferably 4 to 6-membered) aromatic heterocycle having carbon atoms and at least one heteroatom among the atoms constituting the ring, in the compound of [3] above, wherein the X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 12], wherein the aromatic heterocycle comprises a 3 to 20-membered (preferably 3 to 10-membered, particularly preferably 4 to 6-membered) aromatic heterocycle having carbon atoms and at least one heteroatom among the atoms constituting the ring, in the compound of [3] above, wherein the aromatic heterocycle is comprised of one or more divalent hydrocarbon groups selected from the group consisting of a linear or branched alkylene group having 1 to 18 carbon atoms, a linear or branched alkenylene group having 2 to 8 carbon atoms, a cycloalkylene group having 3 to 18 carbon atoms, and a arrine group having 6 to 14 carbon atoms, in the compound of [3] above, wherein the X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 12], wherein the aromatic heterocycle has 3 to 20 members (preferably 3 to 10 members, particularly preferably 4 to 6 members), in the compound of [3] above, a linear or branched alkylene group having 1 to 18 carbon atoms, a linear or branched alkenylene group having 2 to 8 carbon atoms, a cycloalkylene [Note 14] The X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 13], wherein the compound in [3] contains a carboxyl group. [Note 15] The X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 14], wherein the compound in [3] has 1 to 3 (preferably 1 to 2, particularly preferably 1) coordinating functional groups bonded to the polycyclic aromatic hydrocarbon compound. [Note 16] The X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 15], wherein the compound in [3] has a bond position of the coordinating functional group that is meta or para (preferably para) relative to the bond position of the linking group that connects the two aromatic heterocycles.

[0200] [Note 17] An X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 16], wherein the content ratio (molar ratio) of the metal ion to the compound of [1] is 30 / 70 to 70 / 30 (preferably 40 / 60 to 60 / 40, particularly preferably 45 / 55 to 55 / 45). [Note 18] An X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 17], wherein the content ratio (molar ratio) of the metal ion to the compound of [2] is 30 / 70 to 70 / 30 (preferably 40 / 60 to 60 / 40, particularly preferably 45 / 55 to 55 / 45). [Note 19] An X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 18], wherein the content ratio (molar ratio) of the metal ion to the compound of [3] is 30 / 70 to 70 / 30 (preferably 40 / 60 to 60 / 40, particularly preferably 45 / 55 to 55 / 45).

[0201] [Note 20] The X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 19], wherein the organic ligand further comprises the compound of [4] below. [4] A compound having a structure in which a bidentate ligand (e.g., triazole, benzotriazole), two benzene rings or aromatic heterocycles are linked via an amide group [or a group in which two amide groups are linked via a hydrocarbon group (preferably a divalent group)], or a compound having a structure in which two benzene rings or aromatic heterocycles are linked via an azo group [or a group in which two azo groups are linked via a hydrocarbon group (preferably a divalent group)] or a tetrazinylene group [or a group in which two tetrazinylene groups are linked via a hydrocarbon group (preferably a divalent group)]. [Note 21] The X-ray structural analysis sample forming material according to [Note 20], wherein the content ratio (molar ratio) of the metal ion to the compound in [4] is 30 / 70 to 70 / 30 (preferably 40 / 60 to 60 / 40, particularly preferably 45 / 55 to 55 / 45). [Note 22] The X-ray structural analysis sample forming material according to [Note 20] or [Note 21], wherein the organic ligand comprises the compound of [1] and the compound of [4], and the content ratio (molar ratio) of the compound of [1] to the compound of [4] is 80 / 20 to 20 / 80 (preferably 75 / 25 to 40 / 60, particularly preferably 75 / 25 to 45 / 55, most preferably 70 / 30 to 45 / 55). [Note 23] The X-ray structural analysis sample forming material according to [Note 20] or [Note 21], wherein the organic ligand comprises the compound of [2] and the compound of [4], and the content ratio (molar ratio) of the compound of [2] to the compound of [4] is 80 / 20 to 20 / 80 (preferably 75 / 25 to 40 / 60, particularly preferably 75 / 25 to 45 / 55, most preferably 70 / 30 to 45 / 55). [Note 24] The X-ray structural analysis sample forming material according to [Note 20] or [Note 21], wherein the organic ligand comprises the compound of [3] and the compound of [4], and the content ratio (molar ratio) of the compound of [3] to the compound of [4] is 80 / 20 to 20 / 80 (preferably 75 / 25 to 40 / 60, particularly preferably 75 / 25 to 45 / 55, most preferably 70 / 30 to 45 / 55).[Note 25] The X-ray structural analysis sample forming material according to any one of [Note 1] to [Note 24], wherein the content ratio (molar ratio) of the metal ion to the organic ligand is 20 / 80 to 80 / 20 (preferably 25 / 75 to 60 / 40, particularly preferably 30 / 70 to 55 / 45).

[0202] [Appendix 26] A method for determining the molecular structure of an organic compound (X), comprising the following steps 1 and 2. Step 1: The organic compound (X) is impregnated into an X-ray structural analysis sample forming material described in any one of [Appendix 1] to [Appendix 25], and the organic compound (X) is fixed in the pores of the X-ray structural analysis sample forming material to obtain an X-ray structural analysis sample. Step 2: The obtained X-ray structural analysis sample is irradiated with X-rays to obtain diffraction data, and the obtained diffraction data is analyzed to determine the molecular structure of the organic compound (X). [Appendix 27] The method for determining the molecular structure of an organic compound (X) as described in [Appendix 26], wherein step 2 is a step of irradiating the obtained X-ray structural analysis sample with X-rays to obtain diffraction data, analyzing the obtained diffraction data to determine the absolute configuration of the organic compound (X) if the organic compound (X) is a chiral compound, and determining the molecular structure of the organic compound (X) if the organic compound (X) is an achiral compound. [Note 28] The method for determining the molecular structure of an organic compound (X) according to [Note 26] or [Note 27], wherein the organic compound (X) is a compound having a reactive functional group which is a functional group that interacts with the organic ligand (preferably a polarizing functional group possessed by the organic ligand) constituting the X-ray structural analysis sample forming material (or the metal complex crystal). [Note 29] The method for determining the molecular structure of an organic compound (X) according to [Note 28], wherein the reactive functional group comprises a group having an electronegativity of 1.0 to 4.0 (preferably 1.6 to 3.6, particularly preferably 2.0 to 3.4). [Note 30] The method for determining the molecular structure of an organic compound (X) according to [Note 28] or [Note 29], wherein the reactive functional group comprises at least one group selected from the group consisting of substituted or unsubstituted amino groups, carboxyl groups, active methylene groups, nitrile groups, ketone groups, aldehyde groups, ester groups, ether groups, amide groups, hydroxyl groups, halogen groups, and sulfonamide groups. [Note 31] A method for determining the molecular structure of an organic compound (X) according to any one of [Note 26] to [Note 30], wherein the molecular weight of the organic compound (X) is 15 to 1000 (preferably 30 to 1000, more preferably 50 to 800, even more preferably 100 to 800, and even more preferably 150 to 600).[Note 32] A method for determining the molecular structure of an organic compound (X) according to any one of [Note 26] to [Note 31], wherein the logP (octanol / water partition coefficient) value of the organic compound (X) is -5.0 to 4.5 (preferably -4.6 to 4.0, more preferably -2.0 to 3.5, even more preferably -1.0 to 3.0, even more preferably -1.0 to 2.0, even more preferably -1.0 to 1.5, and even more preferably -1.0 to 1.0).

[0203] [Note 33] A method for determining the absolute configuration of a chiral organic compound (Y), comprising the following steps A, B, and C. Step A: Obtain the chiral organic compound (Y) by optically separating a mixture of the chiral organic compound (Y) and its enantiomer. Step B: Permeate an X-ray structural analysis sample forming material described in any one of [Note 1] to [Note 25] with the chiral organic compound (Y), fix the chiral organic compound (Y) in the pores of the X-ray structural analysis sample forming material, and obtain an X-ray structural analysis sample. Step C: Irradiate the obtained X-ray structural analysis sample with X-rays to obtain diffraction data, and analyze the obtained diffraction data to determine the absolute configuration of the chiral organic compound (Y). [Note 34] The method for determining the absolute configuration of a chiral organic compound (Y) as described in [Note 33], wherein the optical separation in step A is performed using a chiral column. [Note 35] The method for determining the absolute configuration of a chiral organic compound (Y) as described in [Note 33], wherein the optical separation in step A is performed by a method selected from supercritical liquid chromatography using a chiral column, liquid chromatography using a chiral column, gas chromatography using a chiral column, pseudo-mobile bed chromatography using a chiral column, and capillary electrophoresis. [Note 36] The method for determining the absolute configuration of a chiral organic compound (Y) as described in [Note 33], wherein the optical separation in step A is performed by a method selected from liquid chromatography using a chiral column, gas chromatography using a chiral column, pseudo-mobile bed chromatography using a chiral column, and capillary electrophoresis. [Note 37] The method for determining the absolute configuration of a chiral organic compound (Y) according to any one of [Notes 33] to [Note 36], wherein the organic compound (Y) is a compound having a reactive functional group which is a functional group that interacts with the organic ligand (preferably a polarizing functional group possessed by the organic ligand) constituting the X-ray structural analysis sample forming material (or the metal complex crystal). [Note 38] The method for determining the absolute configuration of a chiral organic compound (Y) according to [Note 37], wherein the reactive functional group includes a group having an electronegativity of 1.0 to 4.0 (preferably 1.6 to 3.6, particularly preferably 2.0 to 3.4).[Note 39] The method for determining the absolute configuration of a chiral organic compound (Y) according to [Note 37] or [Note 38], wherein the reactive functional group comprises at least one group selected from the group consisting of substituted or unsubstituted amino groups, carboxyl groups, active methylene groups, nitrile groups, ketone groups, aldehyde groups, ester groups, ether groups, amide groups, hydroxyl groups, halogen groups, and sulfonamide groups. [Note 40] The method for determining the absolute configuration of a chiral organic compound (Y) according to any one of [Note 33] to [Note 39], wherein the molecular weight of the organic compound (Y) is 15 to 1000 (preferably 30 to 1000, more preferably 50 to 800, even more preferably 100 to 800, and even more preferably 150 to 600). [Note 41] The method for determining the absolute configuration of a chiral organic compound (Y) according to any one of [Note 33] to [Note 40], wherein the logP (octanol / water partition coefficient) value of the organic compound (Y) is -5.0 to 4.5 (preferably -4.6 to 4.0, more preferably -2.0 to 3.5, even more preferably -1.0 to 3.0, even more preferably -1.0 to 2.0, even more preferably -1.0 to 1.5, and even more preferably -1.0 to 1.0).

Claims

1. A material for forming an X-ray structural analysis sample containing organic compounds in an orderly arrangement, comprising the following metal complex crystals: Metal complex crystal: A metal complex crystal having a three-dimensional network structure with orderly arrangement of vacancies, composed of metal ions and organic ligands that coordinate to the metal ions, wherein the organic ligands include the compounds of [1], [2], or [3] below. [1] A compound having a structure in which two or more benzene rings equipped with coordinating functional groups are linked via linking groups selected from urea bonds, azo groups, sulfonyl groups, imidazole groups, groups in which two or more of the above groups are linked via hydrocarbon groups, hydrocarbon groups, groups represented by the following formula (L1), groups represented by the following formula (L2), and groups represented by the following formula (L3). (In formulas (L1) to (L3), the bonds indicated by the wavy lines are bonded to the benzene ring. In formula (L1), R １ ∫ represents a coordinating functional group bonded to a benzene ring. m is an integer from 0 to 4. However, in a benzene ring bonded to a melamine group, the para position of the bond to the melamine group is a hydrogen atom.) [2] Polycyclic aromatic hydrocarbon compounds having a coordinating functional group [3] Compounds having a structure in which two aromatic heterocycles having coordinating functional groups are bonded via linking groups selected from single bonds, urea bonds, azo groups, sulfonyl groups, imidazole groups, and groups in which two or more of the above groups are bonded via hydrocarbon groups 2. The X-ray structural analysis sample forming material according to claim 1, wherein the metal ion is a metal ion selected from zinc ions, iron ions, cobalt ions, nickel ions, copper ions, silver ions, and europium ions.

3. The X-ray structural analysis sample forming material according to claim 1 or 2, wherein the organic compound is an organic compound having a functional group selected from a substituted or unsubstituted amino group, a carboxyl group, an active methylene group, a nitrile group, a ketone group, an aldehyde group, an ester group, an ether group, an amide group, a hydroxyl group, a halogen group, and a sulfonamide group.

4. A method for determining the molecular structure of an organic compound (X), comprising the following steps 1 and 2. Step 1: The organic compound (X) is impregnated into an X-ray structural analysis sample forming material according to claim 1 or 2, and the organic compound (X) is fixed in the pores of the X-ray structural analysis sample forming material to obtain an X-ray structural analysis sample. Step 2: The obtained X-ray structural analysis sample is irradiated with X-rays to obtain diffraction data, and the obtained diffraction data is analyzed to determine the molecular structure of the organic compound (X).

5. The method for determining the molecular structure of an organic compound (X) according to claim 4, wherein step 2 is a step of irradiating the obtained X-ray structural analysis sample with X-rays to obtain diffraction data, analyzing the obtained diffraction data to determine the absolute configuration of the organic compound (X) if the organic compound (X) is a chiral compound, and determining the molecular structure of the organic compound (X) if the organic compound (X) is an achiral compound.

6. A method for determining the absolute configuration of a chiral organic compound (Y), comprising the following steps A, B, and C: Step A: Optically separate a mixture of the chiral organic compound (Y) and its enantiomer to obtain the chiral organic compound (Y). Step B: Impregnate the X-ray structural analysis sample forming material described in claim 1 or 2 with the chiral organic compound (Y), fix the chiral organic compound (Y) in the pores of the X-ray structural analysis sample forming material, and obtain an X-ray structural analysis sample. Step C: Irradiate the obtained X-ray structural analysis sample with X-rays to obtain diffraction data, and analyze the obtained diffraction data to determine the absolute configuration of the chiral organic compound (Y).

7. The method for determining the absolute configuration of a chiral organic compound (Y) according to claim 6, wherein the optical separation in step A is performed using a chiral column.

8. The method for determining the absolute configuration of a chiral organic compound (Y) according to claim 6, wherein the optical separation in step A is performed by a method selected from supercritical liquid chromatography using a chiral column, liquid chromatography using a chiral column, gas chromatography using a chiral column, pseudo-mobile bed chromatography using a chiral column, and capillary electrophoresis.

9. The method for determining the absolute configuration of a chiral organic compound (Y) according to claim 6, wherein the optical separation in step A is performed by a method selected from liquid chromatography using a chiral column, gas chromatography using a chiral column, pseudo-mobile bed chromatography using a chiral column, and capillary electrophoresis.

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