Metal organic framework and method for producing the same

Abstract

The purpose of the present invention is to provide a metal-organic framework that exhibits an excellent adsorption performance for adsorption target substances. The present invention is a metal-organic framework that has a decomposition initiation temperature of at least 200°C and has a structure SM-x in which two or more metal ions are bonded to one oxygen atom in a structure Sx comprising at least one of O2-, OH2, OH-, OCH3 -, and OC2H5 -.

Description

metal organic framework

[0001] The present invention relates to a metal-organic framework.

[0002] Metal organic frameworks, also known as porous coordination polymers, are one type of material that form a porous structure through coordination bonds between metal ions and organic ligands, and are expected to be used for gas adsorption / desorption, catalysts, etc.

[0003] For example, Patent Document 1 discloses a metal organic framework including a metal ion, a first ligand, a second ligand, and an optional third ligand, in which the metal ion is an aluminum ion, the first and second ligands are organic compound ions composed of heterocycles having two carboxy groups, the angle formed between the heteroatom and the carboxy group satisfies a predetermined condition, the third ligand is an organic compound ion having two carboxy groups, and the abundance ratios of the first to third ligands are within a predetermined range.

[0004] Japanese Patent Application Laid-Open No. 2020-176101

[0005] It is desirable for a metal-organic framework (hereinafter sometimes referred to as MOF) to be able to adsorb a large amount of a target substance, but the adsorption performance of previously proposed MOFs still leaves room for improvement.

[0006] Therefore, an object of the present invention is to provide an MOF that has excellent adsorption performance for substances to be adsorbed (especially water).

[0007] The present invention, which has achieved the above object, is as follows: [1] O ２－ , O.H. ２ , O.H. － , OCH ３ － , and O.C. ２ H ５ － Structure S consisting of one or more of ｘ Structure S in which two or more metal ions are bound to one oxygen atom of Ｍ－ｘ [2] A metal organic framework having a decomposition starting temperature of 200° C. or higher.２ [3] The metal organic framework according to [1], wherein the ratio of O derived from the metal organic framework is 0.1 or more. ｘ and metal ions, and the metal ions are each formed into the structure S ｘ [4] The metal organic framework according to [1] or [2], wherein the metal organic framework has a cluster structure in which metal ions are bonded via oxygen atoms in the cluster structure, and there are three or four metal ions in one cluster structure. － ) ２ and R(COO － ) ｎ (R is an n-valent group, and n is an integer of 2 or more). [5] The metal organic structure according to any one of [1] to [4], wherein the metal ion is an ion of at least one metal selected from the group consisting of elements in periods 3 to 6 and groups 2 to 14 of the periodic table.

[0008] According to the present invention, a MOF with excellent water absorption performance can be provided.

[0009] The present invention ２－ , O.H. ２ , O.H. － , OCH ３ － , and O.C. ２ H ５ － Structure S consisting of one or more of ｘ Structure S in which two or more metal ions are bound to one oxygen atom of Ｍ－ｘ and has a decomposition starting temperature of 200°C or higher. ｘ is an oxygen atom that can coordinate to two or more metal ions and can serve as a ligand. ２－ , O.H. ２ , O.H. － , OCH ３ － , and O.C. ２ H ５ － In MOF, only the metal ion is bonded to the oxygen atom, and no other groups are bonded. Ｍ－ｘIt is believed that by having this property, it is possible to protect the structure formed by the bond between the metal ion and the organic ligand, which does not necessarily have sufficient water resistance, and thereby realize good water absorption performance. In addition, a high decomposition temperature, i.e., high thermal strength, can also be a factor in realizing excellent water absorption performance.

[0010] Structure S ｘ The fact that two or more metal ions are bound to one oxygen atom of the MOF means that the smallest repeating unit of the repeating structure in the MOF, for example, the structure S ｘ It can be determined by the smallest repeating unit in the repetition of bonds between the metal and the carbon.

[0011] Structure S ｘ Yes, O ２－ , O.H. ２ , O.H. － , and OCH ３ － It is preferable that the compound is one or more of the following: ２－ , O.H. ２ and OH － The MOF of the present invention comprises one or more of the following structures: Ｍ－ｘ and preferably has a plurality of structures S Ｍ－ｘ Structure S ｘ may be the same as or different from each other.

[0012] Structure S ｘ The number of metal ions bonded to one oxygen atom of the structure S is 2 or more, and usually 4 or less. ｘ The metal ion species bonded to one oxygen atom of the group may be the same or different.

[0013] The MOF of the present invention preferably has a cluster structure, which is a cluster structure consisting of a metal ion and a structure S ｘ and the metal ions are structured as S ｘ MOF refers to a structure in which metal ions and organic ligands (OCH) are bonded together via oxygen atoms in the metal ions. ３ － and O.C. ２ H ５ －When the MOF of the present invention has a cluster structure, the cluster structures are bonded to each other via organic ligands.

[0014] If the MOF has a cluster structure, the structure S ｘ O ２－ , O.H. ２ , and O-H － In one cluster structure, the total number of the groups is preferably 2 or more and 15 or less, more preferably 2 or more and 8 or less, and even more preferably 4 or more and 8 or less. ｘ O ２－ , O.H. ２ , and O-H － When the total number of the hydroxyl groups is within the above range, a cluster structure is easily formed and the basic skeleton of the MOF is stabilized. As a result, the water absorption performance of the MOF is easily improved.

[0015] When the MOF has a cluster structure, the number of metal ions in one cluster structure is preferably 2 or more, more preferably 3 or more, and is preferably 10 or less, more preferably 8 or less. The number of metal ions in one cluster structure is particularly preferably 3 or 4, which particularly improves water absorption performance.

[0016] The structure S ｘ OH ２ The ratio of OH to O derived from the organic ligand is preferably 0.1 or more. By doing so, the water absorption performance can be improved. ２ The ratio of O derived from the fluorine atom is preferably 0.12 or more, more preferably 0.14 or more, and may be 0.20 or less.

[0017] The structure S ｘ O ２－ The ratio of O derived from the structure S to O derived from the organic ligands of the MOF may be 0.2 or more and 0.4 or less. ｘ OH － The ratio of O derived from the fluorine atom is preferably 0.1 or more, more preferably 0.15 or more, and is preferably 0.25 or less.

[0018] The MOF of the present invention has a cluster structure, in which one cluster structure contains three or four metal ions, and the number of OH groups is 1 to 4 relative to the O groups derived from the organic ligands. ２ It is particularly preferred that the ratio of O originating from the fluorine atom is 0.14 or more.

[0019] The decomposition onset temperature of the MOF of the present invention is 200°C or higher, more preferably higher than 200°C, even more preferably 250°C or higher, still more preferably 270°C or higher, and is preferably 500°C or lower, more preferably 400°C or lower, and even more preferably 350°C or lower.

[0020] The metal ions constituting the MOF of the present invention are preferably ions of at least one metal selected from elements in periods 3 to 6 and groups 2 to 14 of the periodic table. In this specification, the term "metal" is used to include metalloids such as Si and Ge. The metal ions constituting the MOF are more preferably ions of at least one metal selected from the group consisting of Mg, Al, Ga, In, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, and Hf, even more preferably ions of at least one metal selected from the group consisting of Al, Ti, Cu, In, and Mg, and particularly preferably ions of at least one metal selected from the group consisting of Cu, In, and Mg.

[0021] The organic ligands that make up MOF are oxalate ions (COO － ) ２ and R(COO － ) ｎ(R is an n-valent group, n is an integer of 2 or more). R is preferably an aliphatic chain hydrocarbon group, an aliphatic cyclic hydrocarbon group, an aliphatic heterocyclic hydrocarbon group (a group in which one or more carbon atoms of an aliphatic cyclic hydrocarbon group are replaced with heteroatoms), an aromatic hydrocarbon group, or an aromatic heterocyclic hydrocarbon group (a group in which one or more carbon atoms of an aromatic hydrocarbon group are replaced with heteroatoms). The aliphatic chain hydrocarbon group may be linear or branched, and may be a saturated or unsaturated hydrocarbon group. The heteroatom in the aliphatic heterocyclic hydrocarbon group or aromatic heterocyclic hydrocarbon group is preferably nitrogen. n is preferably 2 or more and 4 or less, more preferably 2 or more and 3 or less, and most preferably 2.

[0022] The above-mentioned aliphatic chain hydrocarbon group, aliphatic cyclic hydrocarbon group, aliphatic heterocyclic hydrocarbon group, aromatic hydrocarbon group, and aromatic heterocyclic hydrocarbon group may further include a carboxylic acid anhydride group, —OH, —OR １ , -NH ２ , -NHR １ , -N(R １ ) ２ , —CN, a halogeno group, —C(═S)SH, —C(═O)SH and tautomers thereof, —SO ３ The R may contain one or more functional groups X selected from the group consisting of H. １ Each of the groups represents an alkyl group having 1 or 2 carbon atoms. The functional group X is, for example, —OH or —NH ２ is preferred, and —NH ２ is more preferred.

[0023] Examples of the aromatic heterocyclic hydrocarbon group include pyrazole, imidazole, thiazole, oxazole, pyridine, pyrimidine, pyridazine, pyrazine, and triazine, with pyrazole being particularly preferred.

[0024] The R is preferably at least one of an unsaturated linear hydrocarbon group, an aromatic hydrocarbon group, and a hydrocarbon group having an aromatic ring containing a nitrogen atom, and may have the above-mentioned functional group X. The R is preferably an aromatic hydrocarbon group, and may have the above-mentioned functional group X (particularly, -NH ２ ) is more preferably a group having the formula:

[0025] The number of carbon atoms in R is preferably 1 or more, more preferably 2 or more, and is preferably 30 or less. The number of carbon atoms in R is further preferably 6 or more, 10 or more, 15 or more, and 20 or more, in that order, and the upper limit may be 28 or less, 24 or less, 18 or less, 12 or less, or 10 or less.

[0026] In particular, the organic ligands constituting the MOF are oxalate ions (COO － ) ２ and R(COO － ) ２ Specifically, examples include a carboxylate in which two protons have been eliminated from two carboxyl groups (—COOH) of a dicarboxylic acid, or a carboxylate in which three protons have been eliminated from three carboxyl groups of a tricarboxylic acid.

[0027] Examples of the dicarboxylic acids include oxalic acid, succinic acid, fumaric acid, tartaric acid, 1,4-butanedicarboxylic acid, 1,4-butenedicarboxylic acid, 4-oxopyran-2,6-dicarboxylic acid, 1,6-hexanedicarboxylic acid, decanedicarboxylic acid, 1,8-heptadecanedicarboxylic acid, 1,9-heptadecanedicarboxylic acid, heptadecanedicarboxylic acid, acetylenedicarboxylic acid, 1,2-benzenedicarboxylic acid (phthalic acid), 1,3-benzenedicarboxylic acid (isophthalic acid), 2,3-pyridinedicarboxylic acid, and 1,3-butadiene-1,4-dicarboxylic acid. Carboxylic acid, 1,4-benzenedicarboxylic acid (terephthalic acid), 2-aminoterephthalic acid, 2,5-dihydroxyterephthalic acid, imidazole-2,4-dicarboxylic acid, 3,5-pyrazoledicarboxylic acid, 2-methylquinoline-3,4-dicarboxylic acid, quinoline-2,4-dicarboxylic acid, quinoxaline-2,3-dicarboxylic acid, 6-chloroquinoxaline-2,3-dicarboxylic acid, 4,4'-diaminodiphenylmethane-3,3'-dicarboxylic acid, quinoline-3,4-dicarboxylic acid, 7-chloro-4-hydroxyquinoline-2,8-dicarboxylic acid Carboxylic acid, diimidedicarboxylic acid, pyridine-2,6-dicarboxylic acid, 2-methylimidazole-4,5-dicarboxylic acid, thiophene-3,4-dicarboxylic acid, 2-isopropylimidazole-4,5-dicarboxylic acid, tetrahydropyran-4,4-dicarboxylic acid, perylene-3,9-dicarboxylic acid, perylenedicarboxylic acid, Pluriol E200-dicarboxylic acid, 3,6-dioxaoctanedicarboxylic acid, 3,5-cyclohexadiene-1,2-dicarboxylic acid, octanedicarboxylic acid, pentane-3,3-carboxylic acid, 4,4'-dicarboxylic acid Amino-1,1'-biphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, benzidine-3,3'-dicarboxylic acid, 1,4-bis(phenylamino)benzene-2,5-dicarboxylic acid, 1,1'-binaphthyl dicarboxylic acid, 7-chloro-8-methylquinoline-2,3-dicarboxylic acid, 1-anilinoanthraquinone-2,4'-dicarboxylic acid, polytetrahydrofuran 250-dicarboxylic acid, 1,4-bis(carboxymethyl)piperazine-2,3-dicarboxylic acid, 7-chloroquinoline-3,8-dicarboxylic acid, 1-(4-carboxy)phenyl-3-(4-chloro)phenylpyrazoline-4,5-dicarboxylic acid, 1,4,5,6,7,7-hexachloro-5-norbornene-2,3-dicarboxylic acid, phenylindanedicarboxylic acid, 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, naphthalene-1,8-dicarboxylic acid, 2-benzoylbenzene-1,3-dicarboxylic acid, 1,3-dibenzyl-2-oxoimidazolidine-4,5-cis-dicarboxylic acid, 2,2'-biquinoline -4,4'-dicarboxylic acid, pyridine-3,4-dicarboxylic acid, 3,6,9-trioxaundecanedicarboxylic acid, hydroxybenzophenonedicarboxylic acid, Pluriol E300-dicarboxylic acid, Pluriol E400-dicarboxylic acid, Pluriol E600-dicarboxylic acid, pyrazole-3,4-dicarboxylic acid, 2,3-pyrazinedicarboxylic acid, 5,6-dimethyl-2,3-pyrazinedicarboxylic acid, bis(4-aminophenyl)etherdiimide-dicarboxylic acid, 4,4'-diaminodiphenylmethanediimide-dicarboxylic acid, bis(4-aminophenyl) 1) sulfondiimide-dicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,3-adamantanedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 8-methoxy-2,3-naphthalenedicarboxylic acid, 8-nitro-2,3-naphthalenedicarboxylic acid, 8-sulfo-2,3-naphthalenedicarboxylic acid, anthracene-2,3-dicarboxylic acid, 2',3'-diphenyl-p-terphenyl-4,4''-dicarboxylic acid, (diphenyl ether)-4,4'-dicarboxylic acid, imidazole- 4,5-dicarboxylic acid, 4(1H)-oxothiochromene-2,8-dicarboxylic acid, 5-tert-butyl-1,3-benzenedicarboxylic acid, 7,8-quinolinedicarboxylic acid, 4,5-imidazoledicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, hexatriacontanedicarboxylic acid, tetradecanedicarboxylic acid, 1,7-heptanedicarboxylic acid, 5-hydroxy-1,3-benzenedicarboxylic acid, 2,5-dihydroxy-1,4-benzenedicarboxylic acid, pyrazine-2,3-dicarboxylic acid, furan-2,5-dicarboxylic acid, 1-nonene-6,9-dicarboxylic acid, eicosene dicarboxylic acid, 4,4'-dihydroxy-diphenylmethane-3,3'-dicarboxylic acid, 1-amino-4-methyl-9,10-dioxo-9,10-dihydroanthracene-2,3-dicarboxylic acid, 2,5-pyridinedicarboxylic acid, cyclohexene-2,3-dicarboxylic acid, 2,9-dichlorofluorubin-4,11-dicarboxylic acid, 7-chloro-3-methylquinoline-6,8-dicarboxylic acid, 2,4-dichlorobenzophenone-2',5'-dicarboxylic acid, 1,3-benzenedicarboxylic acid, 2 ,6-pyridinedicarboxylic acid, 1-methylpyrrole-3,4-dicarboxylic acid, 1-benzyl-1H-pyrrole-3,4-dicarboxylic acid, anthraquinone-1,5-dicarboxylic acid, 3,5-pyrazoledicarboxylic acid, 2-nitrobenzene-1,4-dicarboxylic acid, heptane-1,7-dicarboxylic acid, cyclobutane-1,1-dicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 5,6-dehydronorbornane-2,3-dicarboxylic acid, 5-ethyl-2,3-pyridinedicarboxylic acid, or camphordicarboxylic acid. The dicarboxylic acid is preferably at least one selected from the group consisting of terephthalic acid and 2-aminoterephthalic acid.

[0028] Examples of the tricarboxylic acid include tricarballylic acid, aconitic acid, trimellitic acid, trimesic acid, biphenyl-3,4',5-tricarboxylic acid, and 1,3,5-tris(4-carboxyphenyl)benzene, with 1,3,5-tris(4-carboxyphenyl)benzene being preferred.

[0029] As the organic ligand constituting the MOF of the present invention, oxalate ions (COO － ) ２ and the above-mentioned R(COO － ) ｎ and examples of such organic ligands include at least one selected from the group consisting of urea, pyrazine, oxazole, isoxazole, thiazole, imidazole, pyrazole, 1,2,3-thiadiazole, pyridazine, pyrimidine, purine, and pteridine.

[0030] The molar ratio of metal ions to organic ligands (total amount when multiple types are used) (metal ions / organic ligands) is preferably 0.1 or more, more preferably 0.5 or more, and even more preferably 1.0 or more, and is preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less.

[0031] The BET specific surface area of ​​MOF is 200 cm ２ / g or more, and ２ / g or more is more preferable, and 1000 cm ２ The upper limit of the BET specific surface area is not particularly limited, but is, for example, 2000 cm ２ / g or less.

[0032] Next, a method for producing the MOF of the present invention will be described. The MOF of the present invention can be obtained by reacting a metal compound containing metal ions constituting the MOF with one or more organic compounds that serve as organic ligands constituting the MOF in a solvent.

[0033] The metal compound containing the metal ion that constitutes the MOF is preferably a metal sulfate, acetate, nitrate, halide (particularly chloride), or alkoxide, more preferably a nitrate, chloride, or alkoxide, and even more preferably a nitrate.

[0034] The organic compounds that form the organic ligands of the MOF are oxalic acid and R(COOH). ｎ Preferably, R and n are one or more selected from the group consisting of polycarboxylic acids represented by the above R(COO － ) ｎ The above descriptions of R and n, including preferred embodiments, can all be referred to.

[0035] The organic compound preferably contains at least one selected from the group consisting of tricarboxylic acids and dicarboxylic acids, and specific examples thereof include R(COO － ) ｎ The tricarboxylic acids and dicarboxylic acids described above for the carboxylates represented by the formula (I) can be referenced, including their preferred ranges.

[0036] The organic compounds that serve as organic ligands include oxalic acid and R(COOH). ｎ In addition to one or more selected from the group consisting of polycarboxylic acids represented by the following formula (I), it is preferable to use at least one selected from the group consisting of urea, pyrazine, oxazole, isoxazole, thiazole, imidazole, pyrazole, 1,2,3-thiadiazole, pyridazine, pyrimidine, purine, and pteridine.

[0037] The solvent is not particularly limited as long as it can dissolve the metal compound and the organic compound that will become the organic ligand, and an appropriate solvent can be selected from water and organic solvents. The solvent is preferably water; an alcohol solvent such as methanol; or an amide solvent such as dimethylformamide or dimethylacetamide, and more preferably contains at least an amide solvent. The structure S of the MOF of the present invention is ｘ It is believed that this is due to these solvents or moisture in the air during the manufacturing process.

[0038] The ratio of the metal compound to the solvent (metal compound / solvent) is preferably 0.01 mol / L or more, more preferably 0.03 mol / L or more, even more preferably 0.05 mol / L or more, and is preferably 1 mol / L or less, more preferably 0.5 mol / L or less, even more preferably 0.2 mol / L or less.

[0039] The ratio of the organic compound serving as the organic ligand to the solvent (organic compound / solvent) is preferably 0.005 mol / L or more, more preferably 0.01 mol / L or more, and even more preferably 0.02 mol / L or more, and is preferably 3 mol / L or less, more preferably 1 mol / L or less, and even more preferably 0.1 mol / L or less.

[0040] The molar ratio of the metal compound to the organic compound may be adjusted so that the ratio of the molar amount of metal atoms in the metal compound to the molar amount of the organic compound is equal to the molar ratio of metal ions to organic ligands in the MOF.

[0041] In order to obtain the MOF of the present invention, it is particularly necessary to (i) appropriately adjust the mixing conditions for the metal compound and the organic compound that will serve as the organic ligand. In addition to requirement (i), it is also preferable to appropriately adjust at least one of (ii) the stirring or standing temperature after mixing the metal compound and the organic compound that will serve as the organic ligand, and (iii) the post-treatment conditions for the reaction product of the metal compound and the organic compound that will serve as the organic ligand.

[0042] In the mixing of the metal compound and the organic compound serving as the organic ligand in (i) above, it is important to completely dissolve the metal compound and the organic compound. Specifically, when mixing the metal compound and the organic compound all at once, ultrasonic treatment for at least 2 minutes is required after mixing. Furthermore, when either the metal compound or the organic compound is first completely dissolved in a solvent and then the other is added, stirring for at least 5 minutes is required thereafter. For example, stirring using a stirrer or ultrasonic treatment may be performed.

[0043] The stirring temperature after mixing the metal compound (ii) and the organic compound that will become the organic ligand may be any temperature higher than room temperature, and the subsequent standing conditions are preferably 100°C to 200°C and about 10 hours to 6 days.

[0044] Regarding the post-treatment conditions for the reaction product of the metal compound and the organic compound serving as the organic ligand in (iii), it is preferable to wash the reaction product three or more times with the solvent used in the reaction of the metal compound and the organic compound, etc. In this case, it is particularly preferable that the solvent contains an amide solvent such as dimethylformamide or dimethylacetamide.

[0045] The MOF of the present invention is suitable for use in the adsorption and removal of, for example, gases and organic molecules. Examples of gases include carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbons having 1 to 4 carbon atoms, rare gases, hydrogen sulfide, ammonia, sulfur oxides, nitrogen oxides, and siloxanes. Examples of organic molecules include hydrocarbons having 5 to 8 carbon atoms, alcohols having 1 to 8 carbon atoms, aldehydes having 1 to 8 carbon atoms, carboxylic acids having 1 to 8 carbon atoms, ketones having 1 to 8 carbon atoms, amines having 1 to 8 carbon atoms, esters having 1 to 8 carbon atoms, and amides having 1 to 8 carbon atoms. The organic molecules may contain an aromatic ring.

[0046] This application claims the benefit of priority based on Japanese Patent Application No. 2022-042377, filed on March 17, 2022. The entire contents of the specification of Japanese Patent Application No. 2022-042377, filed on March 17, 2022, are incorporated herein by reference.

[0047] The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples, and can of course be practiced with appropriate modifications within the scope of the above and below-described aims, all of which are included in the technical scope of the present invention.

[0048] Example 1: In a 50 mL SUS-304 pressure vessel (including a Teflon (registered trademark) inner cylinder), 3.000 mmol of 2-aminoterephthalic acid was dissolved in 25 mL of a 1 / 1 (volume ratio) mixture of dimethylformamide (DMF) and MeOH. 1.518 mmol of Ti[OCH(CH3)2]4 was added to the solution at 25°C, and the mixture was stirred for 5 minutes using a stirrer. The mixture was then allowed to stand at 150°C for 16 hours. The resulting precipitated solid was washed three times with 10 mL of DMF and filtered. The resulting filter cake was dried under reduced pressure in a vacuum oven at 120°C for 24 hours and 150°C for 24 hours, yielding 0.62 g of the product (yield: 89.4%).

[0049] Example 2: In a 50 mL SUS-304 pressure vessel (including a Teflon inner tube), 0.348 mmol of In(NO3)3.5H2O, 0.955 mmol of Mg(NO3)2.6H2O, 0.518 mmol of 1,3,5-tris(4-carboxyphenyl)benzene, 2.5 mL of H2O, and 13.5 mL of DMF were mixed with stirring at room temperature and sonicated for 3 minutes to dissolve. The mixture was then allowed to stand at 100°C for 5 days. The resulting precipitated solid was washed three times with 10 mL of dimethylacetamide (DMA) and filtered. The resulting filter cake was dried at room temperature for 3 days, yielding 0.24 g of the product (yield: 90%).

[0050] Example 3: In a 100 mL SUS-304 pressure vessel (including a Teflon inner tube), 0.864 mmol of Cu(NO3)3.3H2O, 0.351 mmol of In(NO3)3.5H2O, 0.513 mmol of 1,3,5-tris(4-carboxyphenyl)benzene, 2.5 mL of H2O, and 13.5 mL of DMF were mixed with stirring at room temperature and sonicated for 2 minutes to dissolve. The mixture was then allowed to stand at 100°C for 5 days. The resulting precipitated solid was washed three times with 30 mL of DMA and filtered. The resulting filter cake was dried under reduced pressure in a vacuum oven at 120°C for 24 hours, yielding 0.39 g of the product (yield: 84.9%).

[0051] Example 4: In a 100 mL SUS-304 pressure vessel (including a Teflon (registered trademark) inner tube), 5.1 mmol of AlCl, 2.089 mmol of terephthalic acid, and 60 mL of DMF were mixed and dissolved by ultrasonication at room temperature for 5 minutes. The mixture was then allowed to stand at 110°C for 20 hours. The resulting precipitated solid was washed and filtered three times with 30 mL of DMF, and the resulting filter cake was dried under reduced pressure in a vacuum drying oven at 60°C for 30 minutes and 150°C for 12 hours, yielding 0.38 g of the product (yield: 90%).

[0052] Comparative Example 1 In a 100 mL SUS-304 pressure vessel (including a Teflon (registered trademark) inner tube), 20 mL of tetrahydrofuran (THF) and 1.556 mmol of 2,5-dihydroxyterephthalic acid were mixed to obtain a mixture A. Separately, 3.028 mmol of [Zn(NO ３ ) ２ ]・6H ２ Mixture B was obtained by mixing 0 with 6 ml of an aqueous NaOH solution (1 M) and 10 ml of ion-exchanged water. Mixture B was added to mixture A, and the mixture was allowed to stand at 110°C for 3 days. The resulting precipitated solid was washed three times with 30 ml of THF and filtered. The resulting filter cake was dried in a vacuum drying oven at 80°C for 24 hours to obtain 0.16 g of the product (yield: 32.9%).

[0053] Comparative Example 2 In a 100 mL SUS-304 pressure vessel (including a Teflon (registered trademark) inner tube), 40 mL of N-methylpyrrolidone (NMP) and 3.839 mmol of 2,5-dihydroxyterephthalic acid were mixed to obtain a mixture A. Separately, 7.605 mmol of Mn(CH ３ COO) ２ ・4H ２ Mixture B was obtained by mixing 0 and 5 ml of ion-exchanged water. Mixture B was added to mixture A, and the mixture was allowed to stand at 110°C for 24 hours. The resulting precipitated solid was washed three times with 30 ml of ion-exchanged water and filtered, and the resulting filter cake was dried in a vacuum drying oven at 100°C for 24 hours to obtain 0.66 g of the product (yield: 55.1%).

[0054] The substances obtained in the examples and comparative examples were evaluated by the following methods.

[0055] (1) Measurement of decomposition onset temperature The obtained MOF was pretreated by holding it for 12 hours in an air atmosphere conditioned at 25°C and a relative humidity of 50%, and then heated at a temperature increase rate of 5°C / min under a nitrogen flow until it reached 500°C. The point at which decomposition behavior was observed in DTA measurement specified in the general rules for thermal analysis of JIS K0129 within this range (25 to 500°C) was defined as the decomposition onset temperature.

[0056] (2) Evaluation of MOF structure After XRD (X-ray diffraction) measurement under the following conditions, a cif (Crystallo- graphic Information File) file was obtained and applied to software called Mercury (The Cambridge Crystallographic Data Centre). From the obtained image, the O in one cluster structure was identified. ２－ , O.H. ２ , and OH - The number of metal ions in one cluster structure, the number of metal ions in each structure S ｘ The number of metal ions bonded to the oxygen atoms of each structure S ｘ The ratio of O derived from the organic ligand to O derived from the organic ligand was calculated. Apparatus: SmartLab manufactured by Rigaku Corporation Radiation source: Cu Measurement range: 2θ = 3 to 40° Step size: 0.01° Scanning speed: 3° / min Measurement temperature: room temperature (25°C)

[0057] (3) Evaluation of Water Absorbency The product materials (MOFs) obtained in the Examples and Comparative Examples were left for 12 hours in an air atmosphere conditioned at a temperature of 25°C and a relative humidity of 50%, and then the mass W １ Then, the mass W １ The MOF for which the mass W was determined was heated at a rate of 5°C / min under a nitrogen flow and left at 200°C for 1 hour. ２ The value calculated by the following formula (1) was taken as the water absorption rate A. Water absorption rate A = (W １ -W ２ ) / W ２ …(1)

[0058] (4) Measurement of BET specific surface area Since the adsorption occupied area of ​​nitrogen molecules is known in advance, the amount of gas molecules adsorbed only on the sample surface was measured, and the surface area of ​​the sample was measured using the BET adsorption isotherm. Pretreatment conditions: From the results of the TG-DTA measurement described above, the temperature at which the water contained in the sample could be removed was confirmed, and the sample was heated under reduced pressure overnight. Apparatus: BELSORP-mini manufactured by Microtrac-Bell Pretreatment conditions: (1) A glass rod for reducing the volume (for standard sample tubes) was placed in the standard sample tube, and the tube was plugged with a quick seal. This sample tube set was prepared for the number of samples to be measured (up to a maximum of three samples per measurement), connected to a pretreatment device (BELPREP VAC II), and after evacuating the air from the sample tube, N ２ Gas (purity 99.999% or higher) is introduced up to atmospheric pressure. (2) Afterwards, the sample tube is removed from the pretreatment machine and its weight is measured three times using a precision balance (displaying four or more decimal places) to obtain the average (W1). When using a precision balance, an ionizer is used to eliminate the effects of static electricity. (3) Approximately 50 mg of the sample to be measured is weighed out onto a piece of wrapping paper and the sample is placed directly into the spherical part at the bottom of the standard sample tube using a long-legged funnel. (4) The glass rod is returned to the sample tube, and after sealing it with a quick seal, the total weight is measured once to provisionally confirm the amount of sample added. (5) The sample tube containing the sample is connected to the pretreatment machine and the sample tube is evacuated. (6) Once the pressure inside the sample tube has reached a sufficiently low level, heating begins (vacuum drawing continues). Measurement conditions: (1) After pretreatment (vacuum heating) is complete, the sample tube is allowed to cool while kept under reduced pressure, and after it has reached room temperature, N２ The gas is introduced up to atmospheric pressure and then removed from the device. (2) The weight of the sample tube containing the pre-treated sample is measured three times using a precision balance, and the average (W2) is obtained. The weight of the sample is calculated by subtracting W2 from W1. (3) The sample weight and N at liquid nitrogen temperature are entered into the measurement software. ２ Enter the gas information (such as the second virial coefficient), enter the relative pressure you want to measure, and press the measurement start button. Then, follow the software's instructions to set up a Dewar vessel filled with liquid nitrogen and a sample tube, and then perform the measurement.

[0059] The results are shown in Table 1. In Table 1, the organic ligands are shown as the names of the carboxylic acids before the protons are released from the carboxyl groups. In Table 1, the number of nuclei in the cluster structure indicates the number of metal ions in one cluster structure.

[0060]

Claims

1. O ２－ , O.H. ２ , O.H. － , OCH ３ － , and O.C. ２ H ５ － Structure S consisting of one or more of ｘ Structure S in which two or more metal ions are bound to one oxygen atom of Ｍ－ｘ and a decomposition starting temperature of 200°C or higher.

2. The OH relative to O derived from the organic ligand of the metal organic framework ２ The metal organic structure according to claim 1, wherein the ratio of O derived from the metal organic structure is 0.1 or more.

3. The metal organic framework is Structure S ｘ and metal ions, and the metal ions are each formed into the structure S ｘ It has a cluster structure in which the atoms are bonded together via oxygen atoms in the 3. The metal organic framework according to claim 1, wherein one cluster structure contains three or four metal ions.

4. The organic ligand of the metal organic framework is an oxalate ion (COO － ) ２ and R(COO － ) ｎ 3. The metal organic structure according to claim 1, comprising at least one selected from the group consisting of carboxylates represented by the formula (I), wherein R is an n-valent group, and n is an integer of 2 or more.

5. The metal organic structure according to claim 1, wherein the organic ligand of the metal organic structure comprises at least one selected from the group consisting of carboxylates represented by R(COO − ) n (R is an n-valent group, and n is an integer of 2 or more).

6. 3. The metal organic structure according to claim 1, wherein the metal ion is an ion of at least one metal selected from elements in periods 3 to 6 and groups 2 to 14 of the periodic table.

7. A metal organic framework obtained by mixing a metal compound containing a metal ion constituting the metal organic framework with one or more organic compounds serving as organic ligands constituting the metal organic framework, and reacting the mixture in a solvent, In the mixing, when the metal compound and the organic compound are mixed into the solvent all at once, ultrasonic treatment is carried out for 2 minutes or more after mixing, and when either the metal compound or the organic compound is first completely dissolved in the solvent and then the other is added, a metal organic framework is subsequently stirred for 5 minutes or more.

8. The metal organic structure according to claim 7, wherein the stirring temperature after mixing the metal compound and the organic compound is room temperature or higher, and the mixture is then left to stand at 100 to 200°C for 10 hours to 6 days.

9. A method for producing a metal organic framework, comprising: The method includes a step of mixing a metal compound containing a metal ion constituting the metal organic framework with one or more organic compounds that become organic ligands constituting the metal organic framework, and reacting the mixture in a solvent, In the mixing, when the metal compound and the organic compound are mixed into the solvent all at once, ultrasonic treatment is carried out for 2 minutes or more after the mixing, and when either the metal compound or the organic compound is first completely dissolved in the solvent and then the other is added, a stirring operation is carried out for 5 minutes or more thereafter.

10. The method of claim 9, wherein the stirring temperature after mixing the metal compound and the organic compound is room temperature or higher, and the mixture is then left to stand at 100 to 200°C for 10 hours to 6 days.