Metal organic structure

Abstract

The purpose of the present invention is to provide an MOF having excellent desorption performance. The present invention is a metal-organic structure comprising a prescribed organic ligand and a prescribed metal ion, the metal-organic structure having a porosity of 20-75% and a ratio (maximum pore diameter L / minimum pore diameter S) of the maximum pore diameter L to the minimum pore diameter S as determined by steps (a1) to (a3) below of 1.06 or more. (a1) The crystal structure determined by X-ray crystal structure analysis is represented by a space filling model, and the presence or absence of the through-hole is observed under predetermined conditions to specify a through-hole (Pmax) in which the diameter of the inscribed circle is the largest. (a2) The maximum length of the inner diameter of the through-hole (Pmax) is found in a prescribed cross-section of the through-hole (Pmax), and the maximum diameter (L) of the through-hole (Pmax) is specified. And (a3) specifying the minimum aperture (S) within the cross section in which the maximum aperture (L) has been specified.

Description

Technical Field

[0001] The present invention relates to a metal-organic structure. Background Art

[0002] Metal-organic frameworks (MOFs), also known as porous coordination polymers, are materials that form porous structures through coordination bonds between metal ions and organic ligands, and are materials that have been expected to be used for gas adsorption / desorption or as catalysts, etc.

[0003] For example, in Patent Document 1, a metal-organic structure is disclosed, which is a metal-organic structure containing metal ions, a first ligand, a second ligand, and an optional third ligand. Among them, the metal ions are aluminum ions, the first and second ligands are organic compound ions composed of a heterocycle having two carboxyl groups, the angle formed by the heteroatom and the carboxyl group satisfies a specified condition, the third ligand is an organic compound ion having two carboxyl groups, and the presence ratios of the first to third ligands are within a specified range.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-176101 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] After a metal-organic structure (hereinafter sometimes referred to as MOF) adsorbs substances such as water, carbon dioxide, and hydrogen, it can be heated to a specified temperature to desorb and regenerate the adsorbed substances from the MOF and then used, but it is desired to efficiently desorb the adsorbed substances at this time.

[0009] Therefore, an object of the present invention is to provide an MOF having excellent desorption performance.

[0010] Means for Solving the Problems

[0011] The present invention for achieving the above problems is as follows.

[0012] [1] A metal-organic structure composed of an organic ligand and a metal ion, wherein

[0013] the porosity is 20 to 75%, and the ratio (maximum pore diameter L / minimum pore diameter S) of the maximum pore diameter L to the minimum pore diameter S determined by the following steps (a1) to (a3) is 1.06 or more,

[0014] The above organic ligand contains R(COO-)n At least one of the organic ligands represented by, wherein R is an aromatic hydrocarbon group or pyrrole, and it may have -OH, -NH 2 or a group of the functional group X of -SS-, n is 2 or more and 3 or less,

[0015] The metal ions are ions of at least one metal selected from the group consisting of Al, Ga, In, Ti, V, Cr, Mn, Fe, Co, Cu, Zr, and Hf.

[0016] (a1) The crystal structure determined by X-ray crystal structure analysis is represented by a space filling model, and the outer periphery of the through hole is represented without missing. The presence of the through hole is observed from all directions, and the through hole P with the largest inscribed circle diameter is identified. max .

[0017] (a2) In the through hole P max In each of the cross sections ab, bc and ca, find the cross section that is aligned with the through hole P. max The through hole P is cut by a line perpendicular to the central axis of max The maximum length of the inner diameter of the cross section ab, the cross section bc, and the cross section ca is the largest of the respective maximum lengths as the through hole P. max The maximum aperture L.

[0018] Here, the cross section ab is the through hole P in a plane parallel to the ab plane of the unit cell. max The cut surface is a through hole P max The surface cut in the through state, when there is a through hole P that can be cut in the through state max In the case of multiple cross sections, the through hole P max The section with the largest overlap is called section ab. In the above-mentioned specification of section ab, the section where section ab is replaced by section bc and the ab surface is replaced by the bc surface is section bc, and the section where section ab is replaced by section ca and the ab surface is replaced by the ca surface is section ca.

[0019] (a3) In the cross section where the maximum aperture L is determined, max The through hole P is cut by a line perpendicular to the central axis of max The minimum length of the inner diameter is taken as the minimum aperture S.

[0020] [2] The metal-organic structure according to [1], wherein the ratio of the maximum pore diameter L to the minimum pore diameter S (maximum pore diameter L / minimum pore diameter S) is 4.0 or less.

[0021] Effects of the Invention

[0022] According to the present invention, the desorption performance of the MOF can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is an example of observing the crystal structure of the MOF of Example 3 represented by a space-filling model from one direction.

[0024] Figure 2 is an example of observing the crystal structure of the MOF of Example 3 represented by a space-filling model from another direction.

[0025] Figure 3 is an example of observing the crystal structure of the MOF of Example 3 represented by a space-filling model from yet another direction.

[0026] Figure 4 is a graph showing the maximum pore diameter L and the minimum pore diameter S of the through-hole P max DETAILED DESCRIPTION OF THE INVENTION

[0027] The MOF of the present invention is composed of an organic ligand and a metal ion, and has a porosity of 20 to 75%, and the ratio of the maximum pore diameter L to the minimum pore diameter S (maximum pore diameter L / minimum pore diameter S) determined by a specified step is 1.06 or more. If the porosity is above a specified value, the adsorbed substance is easily desorbed. In addition, if the maximum pore diameter L / minimum pore diameter S is above a specified value, the internal surface area of the MOF tends to increase, and substances such as water, carbon dioxide, and hydrogen are easily adsorbed.

[0028] 1. Porosity

[0029] The porosity of the MOF of the present invention is 20 to 75%, preferably 25% or more, more preferably 30% or more, further preferably 40% or more. In addition, it is preferably 70% or less, more preferably 65% or less, and further preferably 60% or less. In addition, from the viewpoint of increasing the desorption amount, the porosity can also be 30% or more and 45% or less.

[0030] Regarding the porosity, as shown in the following examples, the MOF of the present invention can be subjected to XRD (X-ray diffraction) measurement to obtain a cif (Crystallographic Information File) file, read it with software such as Mercury (The Cambridge Crystallographic Data Centre), and based on the obtained information, input the probe radius of the Void contact surface ​Approx.Grid Spacing: Thus, the porosity is obtained.

[0031] 2. Ratio of the maximum pore diameter L to the minimum pore diameter S (maximum pore diameter L / minimum pore diameter S)

[0032] The ratio of the maximum pore diameter L to the minimum pore diameter S is 1.06 or more, preferably 1.09 or more, more preferably 1.11 or more, further preferably 1.17 or more, most preferably 2.0 or more, and in addition, preferably 4.0 or less, more preferably 3.5 or less, further preferably 3.0 or less.

[0033] The ratio of the maximum pore diameter L to the minimum pore diameter S is determined by the following steps (a1) to (a3).

[0034] (a1) Represent the crystal structure determined by X-ray crystal structure analysis with a space-filling model, representing it without missing the outer periphery of the through-hole, observing the presence or absence of the through-hole from all directions, and specifying the through-hole P with the largest inscribed circle diameter. max .

[0035] Similar to the measurement of the above-mentioned porosity, if X-ray crystal structure analysis is performed by XRD measurement, a cif file is obtained, and the cif file is read into Mercury as described above, a single space-filling model (crystal structure) can be obtained.

[0036] After obtaining the space-filling model of the crystal structure, represent it without missing the outer periphery of the through-hole, and rotate the crystal structure to observe the presence or absence of the through-hole from all directions. Figures 1 to 3 Shows the case when the obtained crystal structure is rotated and the through-hole is observed from a specified direction. Figure 3 In, shows the inscribed circle 11 when observing the through-hole from the Figure 3 direction shown in. The inscribed circle is specified from all the through-holes observed from each direction, and the through-hole P with the largest inscribed circle diameter among all the observed through-holes is specified. max .

[0037] (a1) In order to observe all the observed through-holes without missing the outer periphery, first observe with 1 unit cell. In the case of a through-hole with a missing outer periphery, it is only necessary to observe a region 2×2×2 times the unit cell.

[0038] (a2) Next, observe the through-hole P max with the following specific cross-sections ab, cross-section bc, and cross-section ca.

[0039] The above-mentioned cross-section ab is the through-hole P in the plane parallel to the a-b plane of the unit cell. maxThe cut surface, and is a surface cut in a state where the through-hole P max penetrates. There may also be multiple surfaces parallel to the a-b plane of the unit cell and capable of cutting the through-hole P in a penetrating state max of the cross-section. In the case where there are multiple cross-sections, the cross-section with the largest overlap with the through-hole P max is called the cross-section ab.

[0040] The cross-section bc is the cross-section obtained by replacing the cross-section ab with the cross-section bc and replacing the a-b plane with the b-c plane in the above specification of the cross-section ab.

[0041] In addition, the cross-section ca is the cross-section obtained by replacing the cross-section ab with the cross-section ca and replacing the a-b plane with the c-a plane.

[0042] It should be noted that the observation regions in these cross-sections ab, bc, and ca follow the observation regions in step (a1).

[0043] After observing the through-hole P max with the cross-section ab, the cross-section bc, and the cross-section ca, find the maximum length among the inner diameters of the through-hole P max cut by a line orthogonal to the central axis of the through-hole P max and take the largest value among the maximum lengths of the cross-section ab, the cross-section bc, and the cross-section ca as the maximum aperture L of the through-hole P max .

[0044] (a3) Furthermore, in the cross-section where the above maximum aperture L is determined, take the minimum length among the inner diameters of the through-hole P max cut by a line orthogonal to the central axis of the through-hole P max as the minimum aperture S.

[0045] Figure 4 is the cross-section 21 (any one of the cross-sections ab, bc, and ca) that determines the maximum aperture L25 of the through-hole P max 22. 23a and 23b are the outer periphery of the through-hole P max 22, and 24 is the central axis of the through-hole P max 22. In the cross-section 21 where the maximum aperture L25 is determined, the minimum length 26 among the inner diameters of the through-hole P max cut by a line orthogonal to the central axis 24 of the through-hole P max 22 is the minimum aperture S.

[0046] The value of the maximum aperture L / minimum aperture S determined in this way being 1.06 or more means that the shape of the through-hole is in a bent state, and it is considered that since the internal surface area of the through-hole becomes larger, it is easy to adsorb substances such as water, carbon dioxide, and hydrogen.

[0047] The values of the maximum pore diameter L and the minimum pore diameter S are not limited as long as the maximum pore diameter L / minimum pore diameter S is 1.06 or more. For example, the maximum pore diameter L is For example, the minimum pore diameter S is

[0048] The metal ions constituting the MOF are ions of at least one metal selected from the group consisting of Al, Ga, In, Ti, V, Cr, Mn, Fe, Co, Cu, Zr, and Hf. Preferably, they are ions of at least one metal selected from the group consisting of Al, Ga, In, Ti, V, Co, Zr, and Hf. More preferably, they are ions of at least one metal selected from the group consisting of Al, Ga, In, Ti, V, Zr, and Hf. Further preferably, they are ions of at least one metal selected from the group consisting of Al, In, and Ti. Particularly preferably, they are Al ions, or In and / or Ti ions.

[0049] The organic ligand constituting the MOF contains at least one of the following organic ligands. The organic ligand is a group represented by R(COO - ) n (carboxylate, corresponding English: carboxylate), where R is an aromatic hydrocarbon group or pyrrole, and it is a group that may have a functional group X of -OH, -NH 2 or -S-S-, and n is 2 or more and 3 or less.

[0050] The preferred range of the carbon number of the aromatic hydrocarbon group is successively 6 or more and 30 or less, 6 or more and 24 or less, 6 or more and 18 or less, 6 or more and 12 or less, 6 or more and 10 or less. Specifically, examples include groups obtained by removing n (preferably 2 or 3) hydrogen atoms from benzene or biphenyl, and it is a group that may contain the functional group X (especially -OH, -NH 2 or -S-S-).

[0051] R(COO - ) n is obtained by removing n protons from R(COOH) n .

[0052] As the above R(COOH) nSubstances in which n is 2, i.e., dicarboxylic acids, include 1,2-benzenedicarboxylic acid (phthalic acid), 1,3-benzenedicarboxylic acid (isophthalic acid), 1,4-benzenedicarboxylic acid (terephthalic acid), 2-aminoterephthalic acid, 2,5-dihydroxyterephthalic acid, 2,2'-dithiobisbenzoic acid, perylene-3,9-dicarboxylic acid, 4,4'-dihydroxybiphenyl-3,3'-dicarboxylic acid, 4,4'-diamino-1,1'-biphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 1,1'-binaphthalenedicarboxylic acid, phenylindanedicarboxylic acid, naphthalene-1,8-dicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,2,3-naphthalenedicarboxylic acid, anthracene-2,3-dicarboxylic acid, 2',3'-diphenyl-p-terphenyl-4,4''-dicarboxylic acid, 5-tert-butyl-1,3-benzenedicarboxylic acid, 5-hydroxy-1,3-benzenedicarboxylic acid, 2,5-dihydroxy-1,4-benzenedicarboxylic acid, 4,4'-dihydroxy-diphenylmethane-3,3'-dicarboxylic acid, 1H-pyrrole-2,5-dicarboxylic acid, 1-methylpyrrole-3,4-dicarboxylic acid, or 1-benzyl-1H-pyrrole-3,4-dicarboxylic acid, etc. The dicarboxylic acid is preferably at least one selected from the group consisting of isophthalic acid, 1H-pyrrole-2,5-dicarboxylic acid, terephthalic acid, 2-aminoterephthalic acid, 2,2'-dithiobisbenzoic acid, and 4,4'-dihydroxybiphenyl-3,3'-dicarboxylic acid.

[0053] As the above R(COOH) n Substances in which n is 3, i.e., tricarboxylic acids, include trimellitic acid, benzene-1,3,5-tricarboxylic acid (trimesic acid), biphenyl-3,4',5-tricarboxylic acid, 1,3,5-tris(4-carboxyphenyl)benzene, etc. Trimellitic acid, trimesic acid, or 1,3,5-tris(4-carboxyphenyl)benzene is preferred, and trimesic acid is particularly preferred.

[0054] The above R is preferably any one of the following (A-1) to (A-10).

[0055] [Chemical formula 1]

[0056]

[0057] In the above (A-1) to (A-10), at least one of the hydrogen atoms bonded to the carbon atom may also be replaced by -OH or -NH 2 substituted, and -X- represents -S-S- or a single bond.

[0058] As the organic ligand constituting the MOF of the present invention, it may further contain the above R(COO - ) nOrganic ligands with different carboxylate groups are represented. As such organic ligands, at least one selected from the group consisting of urea, pyrazine, oxazole, isoxazole, thiazole, imidazole, pyrazole, 1,2,3-thiadiazole, pyridazine, pyrimidine, purine, pteridine, 2,2'-bipyridine and 4,4'-bipyridine can be cited, and 4,4'-bipyridine is particularly preferred.

[0059] The molar ratio of the metal ion to the organic ligand (in the case of multiple kinds, the total amount) (metal ion / organic ligand) is preferably 0.1 or more, more preferably 0.3 or more, further preferably 0.5 or more, particularly preferably 0.9 or more. In addition, it is preferably 5 or less, more preferably 4 or less, further preferably 3 or less, particularly preferably 2.5 or less. This molar ratio is particularly preferably 0.9 or more and 4 or less, and most preferably 0.9 or more and 2.5 or less.

[0060] Next, the manufacturing method of the MOF of the present invention will be described. The MOF of the present invention can be obtained by reacting a metal compound containing a metal ion constituting the MOF with one or more organic compounds serving as organic ligands constituting the MOF in a solvent. In addition, it is also preferable to mix an inorganic compound serving as an inorganic ligand with the above metal compound or organic compound in the solvent as needed.

[0061] Specifically, it is preferable to prepare a solution A obtained by first completely dissolving either a metal compound containing a metal ion or an organic compound serving as an organic ligand in a solvent, and then dropwise adding the other (at this time, it is also preferable to dropwise add a solution B obtained by dissolving the other in a solvent). In addition, it is also preferable to prepare a solution X obtained by completely dissolving both a metal compound containing a metal ion and an organic compound serving as an organic ligand in a solvent, and then dropwise adding a metal compound or an organic compound different from the metal compound and the organic compound in the solution X, or dropwise adding a solution Y obtained by completely dissolving a metal compound or an organic compound different from the metal compound and the organic compound in the solution X in a solvent. The temperature of the dropwise addition is preferably room temperature (specifically, about 20 to 30 °C). In addition, it is preferably added dropwise such that the amount of the added metal compound or organic compound is 1.0 mmol / minute or less. The dropping rate is preferably 0.8 mmol / minute or less, and in addition, it can also be 0.01 mmol / minute or more, preferably 0.1 mmol / minute or more, more preferably 0.3 mmol / minute or more. It is particularly preferred to dropwise add a metal compound or a solution obtained by dissolving a metal compound in a solvent in a solution obtained by dissolving an organic compound in a solvent, and at this time, it is further preferred to add dropwise at the above dropping rate.

[0062] The metal compound containing the metal ions that constitute the MOF is preferably a sulfate, nitrate, acetate, chloride, bromide, or alkoxide of a metal.

[0063] The organic compound that becomes the organic ligand constituting the MOF preferably contains one or more selected from the group consisting of polycarboxylic acids represented by R(COOH). n R and n have the same meanings as R and n in the carboxylate represented by the above R(COO - ) n For all including the preferred embodiments, the explanations of R and n above can be referred to for the R and n in the carboxylate represented by the above.

[0064] The organic compound that becomes the organic ligand preferably contains a dicarboxylic acid or a tricarboxylic acid. Specific examples thereof can be referred to the dicarboxylic acids or tricarboxylic acids described in the carboxylate represented by R(COO - ) n including the preferred range.

[0065] As the organic compound that becomes the organic ligand, in addition to one or more selected from the group consisting of polycarboxylic acids represented by R(COOH), it is preferably further used at least one selected from the group consisting of urea, pyrazine, oxazole, isoxazole, thiazole, imidazole, pyrazole, 1,2,3-thiadiazole, pyridazine, pyrimidine, purine, pteridine, 2,2'-bipyridine, and 4,4'-bipyridine. In addition, the above inorganic compound that becomes the inorganic ligand is preferably an alkali metal hydroxide or an alkali metal azide. In addition, OH n may be included in the MOF due to solvents such as solvents for dissolving metal compounds or organic compounds, moisture in the air, etc., O - , or an inorganic ligand of OH 2- , or OH 2 .

[0066] The solvent for dissolving the metal compound containing metal ions or the organic compound that becomes the organic ligand is preferably water; alcohol solvents such as methanol and ethanol; amide solvents such as dimethylformamide, etc. One kind can be used alone, or two or more kinds can be mixed and used.

[0067] When preparing solution A, solution B, or solution X obtained by completely dissolving a metal compound containing metal ions, the ratio of the metal compound to the solvent (metal compound / solvent) in these solutions is preferably 0.01 mol / L or more, more preferably 0.1 mol / L or more, further preferably 0.18 mol / L or more, and preferably 1 mol / L or less, more preferably 0.7 mol / L or less, further preferably 0.5 mol / L or less, and particularly preferably 0.370 mol / L or less. This ratio is particularly preferably 0.18 mol / L or more and 0.5 mol / L or less, and most preferably 0.18 mol / L or more and 0.370 mol / L or less.

[0068] When preparing solution A, solution B, or solution X obtained by completely dissolving an organic compound that serves as an organic ligand, the ratio of the organic compound to the solvent (organic compound / solvent) in these solutions is preferably 0.01 mol / L or more, more preferably 0.1 mol / L or more, further preferably 0.2 mol / L or more, and preferably 1.5 mol / L or less, more preferably 1 mol / L or less, further preferably 0.7 mol / L or less.

[0069] In addition, when an inorganic compound that serves as an inorganic ligand is contained in solution A, solution B, or solution X, the ratio of the inorganic compound to the solvent (inorganic compound / solvent) in these solutions is preferably 0.05 mol / L or more and preferably 1 mol / L or less.

[0070] Regarding the molar ratio of the metal compound containing metal ions to the organic compound that serves as an organic ligand, the ratio of the molar amount of the metal atoms in the metal compound to the molar amount of the organic compound only needs to be adjusted so as to be equal to the molar ratio of the above-mentioned metal ions to the organic ligand.

[0071] After the above-mentioned dropping is completed, it is important to perform at least any one of refluxing, stirring, and standing at a temperature of room temperature (e.g., 25 °C) to 200 °C for about 5 minutes to 100 hours. More specifically, when the temperature is from room temperature to less than 100 °C, it is important to react the metal compound with the organic compound for 72 hours or more, when the temperature is 100 °C or more and less than 130 °C, for 20 hours or more, and when the temperature is 130 °C or more and 200 °C or less, for 15 hours or more. By separating the obtained reaction product from the solvent by centrifugation or filtration, etc., and performing washing and drying, the target MOF can be obtained.

[0072] This application claims priority based on Japanese Patent Application No. 2022-174075 filed on October 31, 2022 and Japanese Patent Application No. 2022-174076 filed on October 31, 2022. The entire contents of the specifications of Japanese Patent Application No. 2022-174075 filed on October 31, 2022 and Japanese Patent Application No. 2022-174076 filed on October 31, 2022 are incorporated herein by reference.

[0073] Example

[0074] Hereinafter, the present invention will be described more specifically by way of examples. The present invention is not limited to the following examples, and of course, it can be appropriately modified and implemented within the scope suitable for the above-mentioned and hereinafter-mentioned gists, and they are all included in the technical scope of the present invention.

[0075] Example 1

[0076] In a 20 mL eggplant-shaped flask, 3.233 mmol of isophthalic acid and 2.5 mL of dimethylformamide (DMF) were mixed at 25 °C and completely dissolved to obtain Solution A. Additionally, a solution B was prepared by mixing 3.693 mmol of Al 2 (SO 4 ) 3 ·nH 2 O (n = 14 - 18) with 10 mL of ion-exchanged water and completely dissolving it. Solution B was added dropwise to Solution A at 25 °C over 5 minutes. In Solution A, the ratio of isophthalic acid to the solvent was 1.29 mol / L. In Solution B, the ratio of Al 2 (SO 4 ) 3 ·nH 2 O to the solvent was 0.369 mol / L, and the dropping rate of Al 2 (SO 4 ) 3 ·nH 2 O was 0.739 mmol / minute. Subsequently, the mixture was refluxed at 125 °C for 24 hours to obtain a suspension. It was decanted, and the precipitated solid was centrifugally washed three times with 10 mL of water. The obtained filter cake was dried in a vacuum drying oven at 80 °C for 24 hours, 100 °C for 24 hours + 120 °C for 48 hours to obtain 0.66 g of the product (yield 99%).

[0077] Example 2

[0078] In a 100 mL eggplant-shaped flask, 5.169 mmol of 1H-pyrrole-2,5-dicarboxylic acid, 13.5 mL of ion-exchanged water, and 10.42 mmol of sodium hydroxide were mixed at 25 °C and completely dissolved to obtain solution A. Additionally, a solution B was prepared by mixing 2.555 mmol of Al 2 (SO 4 ) 3 ·nH 2 O (n = 14 - 18) with 13.35 mL of ion-exchanged water and completely dissolving it. Solution B was added dropwise to solution A at 25 °C over 5 minutes. In solution A, the ratio of 1H-pyrrole-2,5-dicarboxylic acid to the solvent was 0.383 mol / L. In solution B, the ratio of Al 2 (SO 4 ) 3 ·nH 2 O to the solvent was 0.191 mol / L, and the dropping rate of Al 2 (SO 4 ) 3 ·nH 2 O was 0.511 mmol / minute. Subsequently, the mixture was refluxed at 100 °C for 24 hours to obtain a suspension. It was decanted, and the precipitated solid was filtered and washed 3 times with 20 ml of water and 3 times with 20 ml of ethanol. The obtained filter cake was dried in a vacuum drying oven at 60 °C for 24 hours to obtain 0.88 g of the product (yield 87%).

[0079] Example 3

[0080] In a 50 mL pressure-resistant container made of SUS-304 (including a Teflon (registered trademark) inner cylinder tube), 3.000 mmol of 2-aminoterephthalic acid was completely dissolved in 25 mL of a mixture of dimethylformamide (DMF) and MeOH at a volume ratio of 1 / 1 to obtain solution A. At 25 °C, 1.518 mmol of Ti[OCH(CH 3 ) 2 4 was added dropwise thereto over 20 minutes, and a stirrer tip was placed and stirred for 5 minutes. In solution A, the ratio of 2-aminoterephthalic acid to the solvent was 0.12 mol / L, and the dropping rate of Ti[OCH(CH 3 ) 2 4 was 0.0759 mmol / minute. Subsequently, the mixture was allowed to stand at 150 °C for 16 hours. The obtained precipitated solid was washed and filtered 3 times with 10 mL of DMF. The obtained filter cake was dried under reduced pressure in a vacuum drying oven at 120 °C for 24 hours and then at 150 °C for 24 hours to obtain 0.62 g of the product (yield 89.4%).​​

[0081] Example 4

[0082] In a 50 mL round-bottom flask, 5 mL of DMF was added to 2.496 mmol of terephthalic acid, and a magnetic stir bar was added and stirred until completely dissolved to obtain Solution A. Separately, 5 mL of dimethylformamide (DMF) was added to 2.654 mmol of indium(III) nitrate hydrate, and then 2 mL of ethanol was added. A magnetic stir bar was added and stirred until completely dissolved to prepare Solution B. Solution B was added dropwise to Solution A over 20 minutes and stirred for 20 minutes. In Solution A, the ratio of terephthalic acid to the solvent was 0.499 mol / L, and in Solution B, the ratio of indium(III) nitrate hydrate to the solvent was 0.379 mol / L. The dropping rate of indium(III) nitrate hydrate was 0.133 mmol / minute. Then, it was allowed to stand at 120 °C for 48 hours. The resulting precipitate solid was washed and filtered three times with 30 mL of DMF, and the obtained filter cake was dried under reduced pressure in a vacuum drying oven at 120 °C for 24 hours to obtain 0.49 g of the product (yield 89.1%).

[0083] Example 5

[0084] In a 1 L eggplant-shaped flask, 3.05 mmol of cobalt(II) chloride hexahydrate, 10.42 mmol of 2,2'-dithiobenzoic acid, 10.40 mmol of sodium azide, and 150 mL of DMF were mixed at 25 °C and stirred until completely dissolved to obtain Solution A. Separately, a solution B was prepared by mixing 3.08 mmol of benzene tricarboxylic acid, 3.10 mmol of 4,4'-bipyridine, and 150 mL of ethanol and stirring until completely dissolved. Solution B was added dropwise to Solution A over 3 hours at 25 °C. In Solution A, the ratio of cobalt(II) chloride hexahydrate to the solvent was 0.0203 mol / L, and the ratio of 2,2'-dithiobenzoic acid to the solvent was 0.0695 mol / L. In Solution B, the total ratio of benzene tricarboxylic acid and 4,4'-bipyridine to the solvent was 0.0412 mol / L. In addition, the dropping rate of the total amount of benzene tricarboxylic acid and 4,4'-bipyridine was 0.0343 mmol / minute. Then, it was stirred at 25 °C for 4 days to obtain a suspension. The resulting precipitate solid was washed and filtered three times with 30 mL of DMF, and the obtained filter cake was dried under reduced pressure in a vacuum drying oven at 120 °C for 24 hours to obtain 1.16 g of the product (yield 90.0%).

[0085] Example 6

[0086] In a 100 mL pressure-resistant container made of SUS-304 (including a Teflon (registered trademark) inner cylinder tube), 7.483 mmol of terephthalic acid was completely dissolved in 25 mL of a mixture of dimethylformamide (DMF) and MeOH in a volume ratio of 9 / 1 to obtain Solution A. Solution A was added dropwise to 4.523 mmol of Ti[OCH(CH 3 ) 2 4 over 30 minutes at 25 °C and mixed, and a magnetic stirrer was added and stirred for 5 minutes. In Solution A, the ratio of terephthalic acid to the solvent was 0.299 mol / L, and the dropping rate of terephthalic acid was 0.249 mmol / minute. Thereafter, it was allowed to stand at 150 °C for 16 hours. The resulting precipitate solid was washed and filtered 3 times with 10 mL of DMF, and the obtained filter cake was dried under reduced pressure in a vacuum drying oven at 120 °C for 24 hours and 150 °C for 24 hours to obtain 0.35 g of the product (yield 24.6%).

[0087] Comparative Example 1

[0088] Formic acid (2.69 mol), acetic anhydride (1.08 mol), and Ti(OCH(CH 3 ) 2 ) 4 (0.067 mol) were added to a 500 mL eggplant-shaped flask, stirred at 25 °C for 30 minutes, then heated to 120 °C and refluxed for 12 hours. While heating the resulting turbid reaction solution to 50 °C, it was washed with acetone (100 ml × 3 times) to obtain 12.03 g of white solid A (yield: 74.8%).

[0089] In a 500 mL pressure-resistant container made of SUS-304 (including a Teflon (registered trademark) inner cylinder tube), 0.23 mmol of white solid A was dissolved in a liquid mixture of acetic anhydride (10 mL) and acetic acid (10 mL). After adding 55.2 mmol of 5-aminoisophthalic acid all at once, 1 mL of methanol was added at 25 °C and mixed, and a magnetic stirrer was added and stirred for 5 minutes. Thereafter, it was allowed to stand at 180 °C for 48 hours. The resulting precipitate solid was washed and filtered 3 times with 30 mL of acetone, and the obtained filter cake was dried by air drying for 24 hours to obtain 0.20 g of the product (yield 47.9%).

[0090] Comparative Example 2

[0091] In a 50 mL eggplant-shaped flask, 2.54 mmol of 2,5-thiophenedicarboxylic acid and 4 mL of DMF were mixed at 25 °C and completely dissolved to obtain Solution A. Separately, a solution of Al 2 (SO 4 )​3 ·nH 2 Solution B was obtained by mixing 5.64 mmol of O (n = 14 - 18) with 16 ml of ion-exchanged water and completely dissolving it. Solution B was added to Solution A at one time at 25°C. Thereafter, while stirring at 135°C for 24 hours, reflux was carried out to obtain a suspension. The obtained precipitate solid was washed and filtered 3 times with 30 mL of DMF and washed and filtered 3 times with 30 mL of methanol. The obtained filter cake was dried under reduced pressure in a vacuum drying oven at 80°C for 24 hours to obtain 0.65 g of the product substance (yield 48.2%).

[0092] Comparative Example 3

[0093] In a 100 mL pressure-resistant container made of SUS-304 (including a Teflon (registered trademark) inner cylinder tube), 5.1 mmol of AlCl 3 was mixed all at once with 2.089 mmol of terephthalic acid and 60 ml of DMF, and ultrasonic waves were applied for 5 minutes at room temperature to dissolve. Thereafter, it was allowed to stand at 110°C for 20 hours. The obtained precipitate solid was washed and filtered 3 times with 30 mL of DMF. The obtained filter cake was dried under reduced pressure in a vacuum drying oven at 60°C for 30 minutes and at 150°C for 12 hours to obtain 0.38 g of the product substance (yield 90%).

[0094] Comparative Example 4

[0095] In a 50 mL eggplant-shaped flask, 5.04 mmol of 2,5-furandicarboxylic acid, 10.59 mmol of NaOH, and 15 mL of ion-exchanged water were mixed and completely dissolved to obtain Solution A. Solution B obtained by mixing 5.04 mmol of AlCl 3 ·6H 2 O with 10 mL of ion-exchanged water and completely dissolving it was added dropwise to Solution A at 25°C over 30 minutes. In Solution A, the ratio of 2,5-furandicarboxylic acid to the solvent was 0.336 mol / L, and in Solution B, the ratio of AlCl 3 ·6H 2 O to the solvent was 0.504 mol / L, and the dropping rate of AlCl 3 ·6H 2 O was 0.168 mmol / minute. Thereafter, reflux was carried out at 25°C for 18 hours to obtain a suspension. The obtained precipitate solid was washed 3 times by centrifugation with 50 mL of water. The obtained cake was dried in a vacuum drying oven at 80°C for 24 hours to obtain the product substance.

[0096] The substances obtained in the examples and comparative examples were evaluated by the following method.

[0097] (1) Measurement of porosity

[0098] The substances generated in the examples and comparative examples were subjected to XRD measurement under the following conditions to obtain a cif file. The cif file was read into software such as Mercury, and the probe radius input as Void contact surface was entered into the obtained data. Approx.Grid Spacing: Calculate the porosity.

[0099] Apparatus: SmartLab manufactured by Rigaku

[0100] X-ray source: Cu

[0101] Measurement range: 2θ = 3 - 40°

[0102] Step size: 0.01°

[0103] Scanning speed: 3° / min

[0104] Measurement temperature: Room temperature (25°C)

[0105] (2) Measurement of the maximum pore size L and the minimum pore size S

[0106] From the drawing of Mercury obtained during the measurement of the above porosity, a crystal structure including pore size and pore shape was obtained, and the maximum pore size L and the minimum pore size S were determined according to the above steps (a1) - (a3).

[0107] (3) Measurement of the desorption amount

[0108] Using a thermogravimetric - differential thermal simultaneous measurement (TG - DTA: Thermogravimetry - Differential Thermal Analysis) apparatus manufactured by Rigaku, the desorption amount of water in the MOF pretreated under the following conditions was measured.

[0109] Pretreatment conditions: Keep in an air atmosphere with a humidity of 25°C and a relative pressure of 0.5 for 12 hours.

[0110] Desorption amount: After the above pretreatment, the temperature was raised at a heating rate of 5°C / min under a nitrogen flow, and held at 50°C for 30 minutes. Measure the weight reduction amount W in this interval (25 - 50°C). 25-50 , and divide this W 25-50 by the weight of the sample after the above pretreatment as the desorption amount (mass%).

[0111] The results are shown in Table 1. It should be noted that in Comparative Example 1, since the holes observed in the cross-sectional observation in step (a2) did not become through-holes, “closed” is described in the column of maximum pore diameter L / minimum pore diameter S.

[0112]

[0113] In Examples 1 to 6, crystalline MOFs with a porosity of 20 to 75% and a maximum pore diameter L / minimum pore diameter S of 1.06 or more were obtained. In contrast, the MOFs of Comparative Examples 1 to 3 did not satisfy at least one of the requirements of the maximum pore diameter L / minimum pore diameter and the porosity. In addition, in Comparative Example 4, since the reflux conditions after dropping and adding Solution B to Solution A were not appropriate, a crystalline substance could not be confirmed by measurement using XRD.

[0114] Industrial applicability

[0115] The MOF of the present invention can be suitably used, for example, for the adsorption and removal of gases and organic molecules. Examples of the gas include water (water vapor), carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbons having 1 to 4 carbon atoms, noble gases, hydrogen sulfide, ammonia, sulfur oxides, nitrogen oxides, siloxanes, etc. Examples of the organic molecule 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, amides having 1 to 8 carbon atoms, etc. It should be noted that the above organic molecules may also contain an aromatic ring.

[0116] Explanation of reference numerals

[0117] 11 inscribed circle

[0118] 21 cross-section

[0119] 22 through-hole P max

[0120] 23a, 23b through-hole P max periphery of

[0121] 24 through-hole P max central axis of

[0122] 25 maximum pore diameter L

[0123] 26 minimum pore diameter S

Claims

1. A metal-organic structure which is a metal-organic structure composed of an organic ligand and metal ions, wherein, the porosity is 20 to 75%, and the ratio of the maximum pore diameter L to the minimum pore diameter S (maximum pore diameter L / minimum pore diameter S) determined by the following steps (a1) to (a3) is 1.06 or more, The organic ligand contains at least one of the organic ligands represented by R(COO-), n wherein R is an aromatic hydrocarbon group or pyrrole, and it may have a functional group X such as -OH, -NH 2 or -S-S-, n is 2 or more and 3 or less. the metal ions are ions of at least one metal selected from the group consisting of Al, Ga, In, Ti, V, Cr, Mn, Fe, Co, Cu, Zr, and Hf, (a1) The crystal structure determined by X-ray crystal structure analysis is represented by a space-filling model, and the outer periphery of the through-hole is represented without omission. The presence or absence of the through-hole is observed from all directions, and the through-hole P with the largest inscribed circle diameter is specified. max , (a2) within the through-hole P max In each of the cross-sections ab, bc, and ca of the through-hole P max find the maximum length of the inner diameter of the through-hole P cut by a line orthogonal to the central axis of the through-hole P max and take the maximum of the maximum lengths of the cross-sections ab, bc, and ca respectively as the maximum aperture L of the through-hole P max ; Among them, the so-called cross-section ab is a through-hole P in a plane parallel to the a-b plane of the unit cell max of the cut surface, and is a surface cut in a state where the through-hole P max passes through. In the case where there are multiple cross-sections that can cut the through-hole P in a state where it passes through max , the cross-section with the largest overlap with the through-hole P max is called the cross-section ab; moreover, in the specification of the cross-section ab, the cross-section obtained by replacing the cross-section ab with the cross-section bc and replacing the a-b plane with the b-c plane is the cross-section bc, and the cross-section obtained by replacing the cross-section ab with the cross-section ca and replacing the a-b plane with the c-a plane is the cross-section ca; (a3)Within the cross-section where the maximum aperture L is determined, the minimum inner diameter length of the through-hole P cut along a line orthogonal to the central axis of the through-hole P max is taken as the minimum aperture S. max ​ 2. The metal-organic structure according to claim 1, wherein, the ratio of the maximum pore diameter L to the minimum pore diameter S (maximum pore diameter L / minimum pore diameter S) is 4.0 or less.

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