RU2716125C1 - Method of producing a coordinatively unsaturated metal-organic framework and a coordinatively unsaturated metal-organic framework - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: group of inventions relates to a method of producing a coordinatively unsaturated metal-organic framework and to a coordinatively unsaturated metal-organic framework. Method of producing a coordinatively unsaturated metal-organic framework includes steps of producing a precursor of a metal-organic framework, comprising a metal cluster and a polycarboxylic acid ion and a monocarboxylic acid ion, coordinated with the metal cluster, and enabling a precursor of a metal-organic framework and a metal salt having a Lewis acidity to coexist in a solvent for desorption of at least a portion of monocarboxylic acid ions which are coordinated with the metal cluster from the metal cluster. Besides, there is a coordinatively unsaturated metal-organic frame containing a metal cluster of type M₆O_8-x(OH)_x and carboxylic acid ions containing a polycarboxylic acid ion as a polydentate ligand and a monocarboxylic acid ion C_1-3 as a monodentate ligand, coordinated with metal cluster.

EFFECT: invention enables to obtain a metal-organic framework having high hygroscopicity under low moisture conditions and a method of making such a metal-organic framework.

12 cl, 14 dwg, 3 tbl

Description

FIELD OF TECHNOLOGY

[0001] The present description relates to a method for producing a coordination unsaturated metal-organic framework and to a coordination unsaturated metal-organic framework.

BACKGROUND

[0002] Metal-organic frameworks (IOC), which are porous compounds, are materials that are also called porous coordination polymers (PCPs). MOCs have a coordination framework structure having a large surface area, which is formed by the interaction of a metal and an organic ligand.

[0003] Since IOC can be used as a material for adsorption or separation of gas in sensors and catalysts, research and development regarding IOC is underway. In addition, IOCs can adsorb water vapor, and thus have been considered for use as a hygroscopic material in a chemical heat pump (adsorption heat pump) or in a humidity control system used for vehicles, residential buildings and industrial premises.

[0004] Non-Patent Document 1 describes an IOC (MOF-808) containing Zr ⁴⁺ as a metal ion, a trimesinic acid ion as a multidentate ligand, and formic acid ion as a monodentate ligand.

[0005] Non-Patent Document 2 describes an IOC containing a sulfate ion obtained by immersion of an IOC (MOF-808) that contains Zr ⁴⁺ as a metal ion, a trimesic acid ion as a polydentate ligand, and formic acid ion as a monodentate ligand, in sulfuric acid to replace the formic acid ion with a sulfate ion and its catalytic activity is revealed.

[0006] Non-Patent Document 3 describes an IOC containing Ti ⁴⁺ or Hf ⁴⁺ obtained by the reaction of an IOC (UiO-66) that contains Zr ⁴⁺ as a metal ion and a terephthalic acid ion as a multidentate ligand, with TiCpCl ₂ or HfCl ₄ to replace Zr ⁴⁺ with Ti ⁴⁺ or Hf ⁴⁺ .

[0007] Non-Patent Document 4 describes an IOC containing Zr ⁴⁺ as a metal ion, a trimesic acid ion as a multidentate ligand and formic acid ion, acetic acid ion or propionic acid ion as a monodentate ligand.

[LIST OF QUOTED MATERIALS]

[NON-PATENT DOCUMENT]

[0008]

[NPL 1] X. Furukawa et al., “Water Adsorption in Porous Metal-Organic Frames and Related Materials”, Journal of the American Chemical Society, 2014, 136, pp. 4369-4381 (N. Furukawa et al., " Water Adsorption in Porous Metal-Organic Frameworks and Related Materials ", J. Am. Chem. Soc. 2014, 136, pp 4369-4381)

[NPL 2] J. Giang et al., “Super Acidity in an Sulfate Metal-Organic Framework-808,” Journal of the American Chemical Society, 2014, 136, pp. 12844-12847 (J. Jiang et al., “Superacidity in Sulfated Metal -Organic Framework-808 ", J. Am. Chem. Soc. 2014, 136, pp 12844-12847)

[NPL 3] M. Kim et al., “Post-Synthetic Ligand and Cationic Exchange in Strong Metal-Organic Frames,” Journal of the American Chemical Society 2012, 134, pp. 18082-18088 (M. Kim et al., “Postsynthetic Ligand and Cation Exchange in Robust Metal-Organic Frameworks ", J. Am. Chem. Soc. 2012, 134, pp 18082-18088)

[NPL 4] W. Liang et al., “Pore Size Adjustment in the Zirconium-Tricarboxylate Metal-Organic Framework”, CrystEngComm, 2014, 16, pp. 6530-6533 (W. Liang et al., “Tuning Pore Size in a Zirconium -Tricarboxylate Metal-Organic Framework ", CrystEngComm. 2014, 16, pp 6530-6533)

SUMMARY OF THE INVENTION

[TECHNICAL PROBLEM]

[0009] The IOCs described in the above literature exhibit adsorption and desorption of water vapor in response to changes in relative humidity. However, these MOCs in conditions of low relative humidity have low hygroscopicity or, in some cases, do not show hygroscopicity. Thus, when used as a hygroscopic material for a chemical heat pump, the thermal power of these MOCs may be insufficient in some cases, and when used as a hygroscopic material for a humidity control system, the drying efficiency of these MOCs may be insufficient in some cases.

[0010] The present invention provides a method for efficiently producing a metal-organic framework that at least partially solves the above problems.

[THE SOLUTION OF THE PROBLEM]

[0011] As a result of a thorough study, the present inventors have presented the present disclosure below.

[0012]

<Aspect 1>

A method for producing a coordinately unsaturated metal-organic framework, comprising:

obtaining a precursor of a metal-organic framework containing a metal cluster and a polycarboxylic acid ion and a monocarboxylic acid ion that are coordinated with a metal cluster, and

enabling the precursor of the metal-organic carcass and the metal salt having a Lewis acidity to coexist in the solvent to desorb at least a portion of the monocarboxylic acid ion coordinated with the metal cluster from the metal cluster.

<Aspect 2>

The method in accordance with aspect 1, in which

the metal cluster is a metal cluster of the type M ₆ O _8-x (OH) _x , while

M represents an ion of an element of group IV or an ion of a rare earth element, wherein

the polycarboxylic acid ion and the monocarboxylic acid ion coordinated with the metal cluster are a polycarboxylic acid ion as a polydentate ligand and a C _1-3 monocarboxylic acid ion as a monodentate ligand, respectively, and wherein

less than six monocarboxylic acid ions are coordinated with each metal cluster.

<Aspect 3>

The method in accordance with aspect 2, in which M represents at least one of the group consisting of Zr ⁴⁺ , Hf ⁴⁺ and Ce ⁴⁺ .

<Aspect 4>

The method according to any one of aspects 1 to 3, wherein the monocarboxylic acid ion is at least one of the group consisting of formic acid ion, acetic acid ion and propionic acid ion.

<Aspect 5>

The method according to any one of aspects 1 to 4, wherein the metal salt having a Lewis acidity is a halide.

<Aspect 6>

Coordination-unsaturated metal-organic framework containing:

a metal cluster of type M ₆ O _8-x (OH) _x and carboxylic acid ions coordinated with the metal cluster,

in which M is a tetravalent ion of an element of group IV or an ion of a rare earth element,

wherein the carboxylic acid ions coordinated with the metal cluster contain a polycarboxylic acid ion as a polydentate ligand and a monocarboxylic acid ion as a monodentate ligand,

moreover, many metal clusters are connected to each other due to the ion of a polycarboxylic acid,

wherein the number of monocarboxylic acid ions coordinated with the metal cluster is 80% or less when the maximum number of monocarboxylic acid ions that can be coordinated with the metal cluster is 100%, and

moreover, the maximum number of monocarboxylic acid ions that can be coordinated with a metal cluster is six for each metal cluster.

<Aspect 7>

The coordination unsaturated metal-organic framework according to aspect 6, wherein the amount of monocarboxylic acid ions coordinated with the metal cluster is in the range of 5% to 80%.

<Aspect 8>

The coordination unsaturated metal-organic framework according to aspect 7, wherein M represents at least one of the group consisting of Zr ⁴⁺ , Hf ⁴⁺ and Ce ⁴⁺ .

<Aspect 9>

The coordination unsaturated metal-organic framework according to any one of aspects 6 to 8, wherein the monocarboxylic acid ion is a C _1-3 monocarboxylic acid ion.

<Aspect 10>

The coordination unsaturated metal-organic framework according to any one of aspects 6 to 9, wherein the monocarboxylic acid ion is at least one of the group consisting of formic acid ion, acetic acid ion and propionic acid ion.

<Aspect 11>

A coordinatively unsaturated metal-organic framework according to any one of aspects 6 to 10, further comprising a metal ion outside the cluster.

<Aspect 12>

The coordination unsaturated metal-organic framework according to aspect 11, wherein the metal ion outside the cluster is at least one of the group consisting of Li ⁺ , Mg ²⁺ , Al ³⁺ , Sc ³⁺ , Y ³⁺ , Ti ⁴⁺ , Zr ⁴⁺ and Hf ⁴⁺ .

[USEFUL EFFECTS OF THE INVENTION]

[0013] In accordance with the present disclosure, there is provided a method for efficiently producing a metal-organic carcass that can at least partially solve the problems indicated above, as well as a metal-organic carcass that at least partially solves the problems described above.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 is a view showing an example of a method according to the present invention for producing a coordinately unsaturated MOC.

FIG. 2 is a view showing an example of a metal cluster that can be used in the coordination unsaturated MOC according to the present invention.

FIG. 3 is a flowchart of a manufacturing method for comparative example A-1.

FIG. 4 is a flowchart of a production method for Example A-1.

FIG. 5 shows the ratio of the ligands constituting the IOC for comparative example A-1, example A-3, example A-4, and example A-5.

FIG. 6 shows isotherms of water vapor adsorption / desorption at 20 ° C. for Example A-3, Example A-4 and Example A-5.

FIG. 7 is a graph showing the residual amount of acetic acid ions and adsorption moisture for comparative example A-1 and examples A-1 to A-8.

FIG. 8 shows isotherms of water vapor adsorption / desorption at 20 ° C. for Example A-2, Example A-13, and Example A-14.

FIG. 9 shows isotherms of water vapor adsorption / desorption at 20 ° C. for Comparative Example B-1 and Example B-1.

FIG. 10 shows isotherms of water vapor adsorption / desorption at 20 ° C. for comparative example C-1 and example C-1.

FIG. 11 is a schematic view of a heat pump using a coordinately unsaturated IOC.

FIG. 12 is a schematic view of a humidity control system using coordinatively unsaturated IOCs.

FIG. 13 is a graph showing the residual amount of acetic acid ions and adsorption moisture in comparative examples A-1 and X-1 and in examples A-1 to A-8 and X-1 to X-4.

FIG. 14 shows isotherms of water vapor adsorption / desorption at 20 ° C. for Examples X-2 and X-4 and Comparative Example X-1.

DISCLOSURE OF OPTIONS FOR CARRYING OUT THE INVENTION

[0015] The present invention will be presented below with reference to the drawings. The aspects shown below are examples of the present invention. The present invention is not limited to the aspects presented below.

[0016]

<< A method for producing a coordinatively unsaturated metal-organic framework >>

The method according to the present invention for producing a coordinately unsaturated MOA comprises the preparation of a metal-organic precursor framework comprising a metal cluster and a polycarboxylic acid ion and a monocarboxylic acid ion that are coordinated with a metal cluster, and providing a metal-organic framework and a metal salt having a acidity for the precursor according to Lewis, the possibility for coexistence in a solvent for desorption of at least a portion of a monocarboxylic acid ion, which is coordinated with m metal cluster, from a metal cluster.

[0017] According to the method of the present invention, coordinatively unsaturated MOCs can be obtained.

[0018] FIG. 1 shows a specific example of the method according to the present invention, in which, due to the presence of a metal salt having a Lewis acidity, monocarboxylic acid ions are removed from one metal cluster constituting the MOC, as a result of which the MOC is in a coordinatively unsaturated state.

[0019] In the IOC precursor shown on the left side of FIG. 1, a trimesic acid ion, which is a tridentate polycarboxylic acid ligand, and an acetic acid ion, which is a monocarboxylic acid monodentate ligand, are coordinated for Zr ₆ O ₄ (OH) ₄ as a metal cluster. Polycarboxylic acid acts as an organic linker between adjacent metal clusters and forms a periodic periodic network.

[0020] In the example shown in FIG. 1, YCl ₃ , which is a metal salt having a Lewis acidity, can act on a monocarboxylic acid ion coordinated with a metal cluster to desorb a monocarboxylic acid ion from a metal cluster. As a result, a coordinately unsaturated MOC is formed having one or a plurality of coordinatively unsaturated centers (regions surrounded by dashed lines), as shown on the right side of FIG. 1, and a complex is formed from a monocarboxylic acid ion and a metal from a metal salt. This complex may remain in the coordinately unsaturated IOC in some cases.

[0021] Each constituent element of the method of the present invention will be described below.

[0022]

<Obtaining the precursor of the metal-organic framework>

In the method according to the present invention, a metal-organic carcass precursor (MOC precursor) is obtained containing a metal cluster and a polycarboxylic acid ion and a monocarboxylic acid ion coordinated with a metal cluster.

[0023] Such an IOC precursor can be obtained by known means. For example, an IOC precursor can be synthesized by mixing a source of metal ions, a polycarboxylic acid compound and a monocarboxylic acid compound, dissolving these components in a solvent, as necessary, and heating. For example, an IOC precursor can be synthesized by heating a solution containing a source of metal ions, a polycarboxylic acid compound, and a C _1-3 monocarboxylic acid compound.

[0024] The source of metal ions for the synthesis of the MOC precursor is not particularly limited, provided that the metal cluster forming the coordinately unsaturated MOC disclosed above can be formed with it. A compound containing metal forming a metal cluster, for example a metal halide, or the like, can be used as a source of metal ions. If the metal cluster contains an oxygen atom, a metal halide, hydroxy metal compound or metal oxide can be used as a source of metal ions.

[0025] The metal ion source may be at least one of the group consisting of a zirconium compound, a hafnium compound, and a cerium compound. In this case, for example, zirconium oxychloride octahydrate (ZrOCl ₂ ⋅ 8H ₂ O) or zirconium chloride (ZrCl ₄ ) can be used as a zirconium compound, and, for example, hafnium oxychloride octahydrate (HfOCl ₂ ⋅ 8H ₂ O) or hafnium chloride (HfCl ₄ ) can be used as a hafnium compound.

[0026] Polycarboxylic acids and monocarboxylic acids or their salts or anhydrides of these acids, corresponding to a polycarboxylic acid ion and a monocarboxylic acid ion, referred to with respect to the coordinately unsaturated IOC, can be used as a polycarboxylic acid compound and a monocarboxylic acid compound for the synthesis of an IOC precursor. Examples of the polycarboxylic acid salt and the monocarboxylic acid salt include a lithium salt, a sodium salt, a potassium salt or an ammonia salt of a polycarboxylic acid. Typically, polycarboxylic acid compounds are di-, tri- or tetrapolycarboxylic acid compounds.

[0027] The proportion of polycarboxylic acid ions relative to the total molar number of carboxylic acid ions in the IOC precursor may be 20 mol. % or more, 30 mol. % or more or 40 mol. % or more, and may be 95 mol. % or less, 90 mol%. % or less or 85 mol. % or less.

[0028] The proportion of monocarboxylic acid ions relative to the total molar number of carboxylic acid ions in the IOC precursor may be 5 mol. % or more, 10 mol. % or more or 15 mol. % or more, and may be 80 mol. % or less, 70 mol. % or less or 60 mol. % or less.

[0029] A mixture of a metal ion source, a polycarboxylic acid compound and a monocarboxylic acid compound may further comprise a compound to produce the above polydentate ligand other than polycarboxylic acid.

[0030] The solvent for forming the IOC precursor is not particularly limited as long as it is capable of dispersing or dissolving the above metal ion source, a polycarboxylic acid compound, a monocarboxylic acid compound and, if necessary, a compound to produce the described polydentate ligand more than polycarboxylic acid, and The IOC precursor can be synthesized during heating, which is disclosed below.

[0031] From the point of view of stimulating the synthesis of the IOC precursor, an amide is preferably used as a solvent. Amides decompose at high temperatures, gradually forming an amine base. The resulting amine base deprotonates the carboxyl groups of the polycarboxylic acid compound and the monocarboxylic acid compound and promotes the formation of polycarboxylic acid ions and monocarboxylic acid ions, which are coordinated with the metal cluster. Examples of the amide include N, N-dimethylformamide (DMF), N-N-diethylformamide (DEFA), and combinations thereof.

[0032] The above monocarboxylic acid compound may be used as a solvent. In one embodiment, the combination of an amide compound and a monocarboxylic acid is used as a solvent.

[0033] Heating for the synthesis of the IOC precursor can be carried out under solvothermic conditions.

[0034] For example, an IOC precursor comprising a metal cluster and a polycarboxylic acid ion and a monocarboxylic acid ion coordinated with a metal cluster can be synthesized by loading a metal ion source, a polycarboxylic acid compound, a monocarboxylic acid compound and, if necessary, a solvent such as N, N-dimethylformamide (DMF) or N, N-diethylformamide (DEFA) in a pressure vessel, such as an autoclave, and heated at a temperature of 100 ° C or more, or 120 ° C or more, and 180 ° C or less or 150 ° C or me her, for 6 hours or more, or 24 hours or more, and 100 hours or less, or 72 hours or less.

[0035] The IOC precursor can be purified by filtration, washing or drying, if necessary, or a solution containing the synthesized IOC precursor can be used unchanged in subsequent processes. Washing may be carried out one or more times using a solvent, for example, DMF or acetone. Drying can be carried out by leaving the solution standing at room temperature or heating under normal or reduced pressure.

[0036]

<Desorption of a monocarboxylic acid ion>

Coordinatively unsaturated MOA can be obtained by providing the precursor of MOA and a metal salt having a Lewis acidity, the possibility of coexistence in a solvent for desorption of at least part of the monocarboxylic acid ions, which are coordinated with the metal cluster, from the metal cluster.

[0037]

(A metal salt having Lewis acidity)

Lewis acids are defined as receptors for electron pairs.

[0038] The metals included in the metal salt having a Lewis acidity act as Lewis acids for the desorption of monocarboxylic acid ions, which are Lewis bases, from a metal cluster. Since the desorption of ions of carboxylic acids by Lewis acid proceeds more favorably for ions of monocarboxylic acids, which are monodentate ligands, than for ions of polycarboxylic acids, which are polydentate ligands, it is possible to selectively desorb ions of monocarboxylic acids, while maintaining the crystal structure of MOCs for the generation of coordinately unsaturated centers at least in part of a metal cluster.

[0039] In the present disclosure, the Lewis acid is preferably aprotic.

[0040] The metal salt having a Lewis acidity is preferably a halide and more preferably is a chloride or bromide. In some cases, halogen ions derived from a halide may be included in the coordinately unsaturated IOC. Although such halogen ions, in particular, chlorine ions and bromine ions, can be coordinated with a metal cluster, since halogen ions are easily replaced by ligand with water molecules and are detached from the metal cluster, they do not significantly reduce the hygroscopic characteristics of the coordinately unsaturated MOC.

[0041] A metal salt having a Lewis acidity preferably contains a metal in which the number of electrons on the d-orbit of a metal ion having a stable oxidation state is 0 or 10. A metal salt containing such a metal acts as a Lewis acid and can promote the desorption of the monocarboxylic acid ion, which is the base, from the metal cluster.

[0042] Preferably, the metal salt having a Lewis acidity is one or more selected from the group consisting of LiCl, MgCl ₂ , AlCl ₃ , ScCl ₃ , YCl ₃ , ZrCl ₄ , HfCl ₄ , MgBr ₂ , and TiCl ₂ Cp ₂ . Cp is a cyclopentadienyl anion or derivative thereof, for example, pentamethylcyclopentadienyl anion (Cp *). When these metal salts are used, the desorption of monocarboxylic acid ions from the metal cluster is accelerated, as a result of which a coordinately unsaturated MOC having high hygroscopicity can be obtained.

[0043] The concentration of a metal salt having a Lewis acidity in a solvent can be, for example, 5 mmol / L or more, 10 mmol / L or more, 20 mmol / L or more, 30 mmol / L or more or 60 mmol / l or more, and may be 600 mmol / l or less, 500 mmol / l or less, 300 mmol / l or less, or 200 mmol / l or less.

[0044] The IOC precursor and a metal salt having a Lewis acidity may remain in a state of coexistence in the solvent. The IOC precursor can coexist in a solvent with a metal salt having a Lewis acidity by immersing the IOC precursor in a solution containing a metal salt having a Lewis acidity and a solvent.

[0045] The solvent is not particularly limited provided that it is possible to disperse or dissolve the MOC precursor and a metal salt having a Lewis acidity in it. For example, water, alcohols such as methanol, ethanol and isopropanol, amides such as N, N-dimethylformamide (DMF) and N, N-diethylformamide (DEPA), or combinations thereof can be used as a solvent.

[0046] The desorption of monocarboxylic acid ions from a metal cluster can occur at room temperature or can occur when heated. For example, a solution containing an IOC precursor, a metal salt having a Lewis acidity, and a solvent can be heated. The heating temperature may be 30 ° C or more, or 50 ° C or more, and may be 120 ° C or less, or 100 ° C or less. In addition, the heating time may be 6 hours or more, 24 hours or more, or 48 hours or more, and may be 100 hours or less, or 72 hours or less.

[0047] A coordinately unsaturated MOC can be obtained by desorption of at least a portion of the monocarboxylic acid ions from a metal cluster. The resulting coordinately unsaturated IOC can be purified by filtration, washing or drying, if necessary. Washing may be carried out one or more times using a solvent, for example, DMF or acetone. Drying can be done by leaving the IOC at room temperature or heating under normal or reduced pressure.

[0048]

<< Coordination unsaturated metal-organic framework >>

The coordinatively unsaturated metal-organic framework (coordinatively unsaturated MOC) according to the present invention contains a metal cluster and carboxylic acid ions coordinated with the metal cluster. At least a portion of the carboxylic acid ions are polycarboxylic acid ions that bind a plurality of metal clusters to each other, and at least a portion of the metal cluster contains coordination unsaturated centers. The coordinatively unsaturated IOC according to the present disclosure can be obtained by the aforementioned production method according to the present disclosure.

[0049] More specifically, the coordinatively unsaturated metal-organic framework according to the present invention comprises a metal cluster of type M ₆ O _8-x (OH) _x and carboxylic acid ions that are coordinated with a metal cluster in which

M represents an ion of an element of group IV or an ion of a rare earth element,

in which the carboxylic acid ions coordinated with the metal cluster are a polycarboxylic acid ion as a polydentate ligand and a monocarboxylic acid ion as a monodentate ligand in which

many metal clusters are connected to each other thanks to the polycarboxylic acid ion,

in which the number of monocarboxylic acid ions coordinated with the metal cluster is 80% or less, if the maximum number of monocarboxylic acid ions that can be coordinated with the metal cluster is 100%, and

the maximum number of monocarboxylic acid ions that can be coordinated with a metal cluster is six for each metal cluster.

[0050] The term “coordinatively unsaturated centers” of the coordinatively unsaturated MOC according to the present invention means coordination centers in which carboxylic acid ions containing monocarboxylic acid ions and polycarboxylic acid ions are not coordinated and other polyvalent ligands are not coordinated. Molecules, for example water (H ₂ O), or dimethylformamide (DMF) can be coordinated with coordinatively unsaturated centers, and these molecules can be obtained from a solvent.

[0051] It is believed that a fragment of an organic group, which is a hydrophobic fragment of a carboxylic acid ion, that is coordinated with a metal cluster, for example a methyl group in an acetic acid ion, reduces the hygroscopicity of MOC in low humidity conditions, since the methyl group is oriented on the pore surface of the MOC and shows hydrophobicity.

[0052] It is believed that the coordinately unsaturated MOCs of the present disclosure may exhibit high hygroscopicity even in low humidity conditions, since ligands having such hydrophobic centers are at least partially removed from the coordinatively unsaturated centers of the coordinatively unsaturated MOCs of the present disclosure. In addition, it is believed that by varying the number of coordinatively unsaturated centers in the coordinatively unsaturated MOC, it is possible to easily control the humidity that can be adsorbed.

[0053] Thus, the adsorption moisture of the coordination-unsaturated MOC according to the present invention can be 30% or less, 28% or less, 26% or less, 24% or less, 22% or less or 20% or less, and can be 10% or more, 12% or more, 16% or more, or 18% or more. It should be noted that in the present description adsorption humidity means the relative humidity during the adsorption of water vapor in an amount equal to half the maximum amount of adsorption of water vapor.

[0054] The hygroscopicity of the coordination unsaturated MOC will be disclosed with reference to FIG. 1, an example of a method for producing a coordinately unsaturated MOC according to the present disclosure is shown.

[0055] In the IOC shown on the left side of FIG. 1, as an example of a conventional IOC, a trimesic acid ion, which is a tridentate ligand polycarboxylic acid, and an acetic acid ion, which is a monodentate ligand monocarboxylic acid ion, are coordinated with Zr ₆ O ₄ (OH) ₄ as a metal cluster. Polycarboxylic acid acts as an organic linker between adjacent metal clusters, which allows the formation of a periodic periodic structure.

[0056] In the coordinatively unsaturated MOC shown on the right side in FIG. 1, as an example of a coordinately unsaturated MOC according to the present invention, a part of a metal cluster contains one or a plurality of coordinatively unsaturated centers (regions surrounded by a dashed line). Since these coordinatively unsaturated centers contribute to the hydrophilization of the pore surface of coordinately unsaturated MOCs, it is believed that water adsorption into the pores of coordinatively unsaturated MOCs is stimulated compared to MOCs in which there are no coordinatively unsaturated centers.

[0057] Since the pore diameters of conventional MOCs are several times larger than those of water molecules, and water molecules are adsorbed in the pores as a result of the interaction of water molecules with the pore surface and the interaction between water molecules, it is believed that hydrophilization of the pore surface has a significant effect on improving hygroscopicity. In addition, it is also believed that hygroscopicity can be controlled by changing the number of coordinatively unsaturated centers in the coordinately unsaturated MOC.

[0058] The coordination unsaturated MOA according to the present invention can be used, depending on the application, in the form of a powder or in the form of granules or tablets. In addition, when forming the coordination unsaturated MOC according to the present invention, a polymeric binder or the like can be used.

[0059] Each constituent element included in the coordinately unsaturated IOC according to the present disclosure will be disclosed below.

[0060]

<Metal cluster>

In the coordinately unsaturated MOC according to the present invention, the metal cluster determines the vertex shape in the periodic structure of the coordinatively unsaturated MOC. As a metal cluster, any metal cluster capable of forming an MOC can be used.

[0061] For example, a metal cluster of type M ₆ O _8-x (OH) _x can be used as the metal cluster of the coordination unsaturated MOC according to the present invention.

[0062] This metal cluster has the structure shown in FIG. 2, where M is a tetravalent element of the periodic table of group IV or a rare earth ion, for example, Zr ⁴⁺ , Hf ⁴⁺ , and Ce ⁴⁺ , in particular Zr ⁴⁺ , and its saturated coordination number is 12. Examples of MOC, containing this metal cluster include MOF-808, UiO-66, and MOF-801. In addition, examples of ligands for this metal cluster include trimesic acid, formic acid, terephthalic acid and fumaric acid.

[0063] For example, if the coordination-unsaturated MOC metal cluster of the present invention is a metal cluster of type M ₆ O ₈ - _x (OH) _x , then the carboxylic acid ions coordinated with the metal cluster include a polycarboxylic acid ion as a polydentate ligand and C _1-3 monocarboxylic acid ion as a monodentate ligand and less than 6, 5 or less, or 4 or less monocarboxylic acid ions can be coordinated with the metal cluster.

[0064] It should be noted that in the case of a metal cluster of type M ₆ O _8-x (OH) _{x, the} maximum number of monocarboxylic acid ions that can be coordinated with the metal cluster is six for each metal cluster.

[0065] Thus, in the present disclosure, it is preferable that the number of monocarboxylic acid ions coordinated with a metal cluster is 80% or less if the maximum number of monocarboxylic acid ions that can be coordinated with a metal cluster of type M ₆ O _8-x ( OH) _x is 100%, more preferably in the range of 5 to 80%. In addition, the number of monocarboxylic acid ions coordinated with this metal cluster can be 7% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more , 40% or more, 45% or more, or 50% or more, and may be 95% or less, 90% or less, 85% or less, 80% or less, 78% or less, or 75% or less .

[0066]

<Polycarboxylic acid ion>

Polycarboxylic acid ions function as an organic linker, coordinating their carboxylate group with a metal cluster and linking many metal clusters to each other. This forms the periodic structure of the coordinately unsaturated IOC. Any arbitrary polycarboxylic acid with which MOC can be formed can be used, and typically polycarboxylic acid ions are ions of di-, tri- or tetrapolycarboxylic acids.

[0067] Examples of divalent carboxylic acid ions include substituted or unsubstituted isophthalic acid ions, substituted or unsubstituted terephthalic acid ions, oxalate ions, fumarate ions, malonate ions, trans, trans-muconic acid ions, cis ions, cis-muconic acid, 2-6-naphthalenedicarboxylic acid ions, 9,10-anthracene dicarboxylic acid ions, 2,2'-diamino-4,4'-stilbendicarboxylic acid ions, 2,2'-dinitro-4,4'-stilbendicarboxylic acid ions, and ions 2,3-pyrazindicarboxylic acid.

[0068] Substituted or unsubstituted isophthalic acid ions may be represented by formula 1.

[0069]

[Formula 1]

[0070] In formula 1, each R is an independent substituent other than a carboxylate group, and n is an integer from 0 to 4. R is not particularly limited provided that the above ions can function as an organic linker to form an MOC. Examples thereof include hydroxy groups, nitro groups, fluoro groups, chloro groups, bromo groups, iodine groups, cyano groups, methyl groups, ethyl groups, tert-butyl groups and ethynyl groups. Preferably, R has no positive charge that neutralizes the negative charge of the carboxylate ion. Examples of R having a positive charge include ammonium groups such as a trimethyl ammonium group (-N (CH ₃ ) ₃ ⁺ ) or a triethyl ammonium group (-N (C ₂ H ₅ ) ₃ ⁺ ).

[0071] Specific examples of isophthalic acid ions represented by Formula 1 include isophthalate ions (m-BDC ^2- ), 5-hydroxyisophthalate, 5-nitroisophthalate ions, 5-tert-butyl isophthalate ions, 5-ethynyl isophthalate ions, ions 5-chlorisophthalate, 5-bromisophthalate ions, 5-cyanisophthalate ions, and 4,6-dimethylisophthalate ions. The substituted or unsubstituted isophthalic acid ion represented by Formula 1 is preferably an isophthalic acid ion (m-BDC ^2- ).

[0072] Substituted or unsubstituted terephthalic acid ions can be represented by formula 2.

[0073]

[Formula 2]

[0074] In formula 2, each R is an independent substituent other than a carboxylate group, and n is an integer from 0 to 4. R is not particularly limited provided that the above ions can function as an organic linker to form an MOC. Examples thereof include hydroxy groups, nitro groups, fluoro groups, chloro groups, bromo groups, iodine groups, cyano groups, methyl groups, ethyl groups, tert-butyl groups and ethynyl groups. Preferably, R has no positive charge that neutralizes the negative charge of the carboxylate ion. Examples of R having a positive charge include ammonium groups such as a trimethyl ammonium group (-N (CH ₃ ) ₃ ⁺ ) or a triethyl ammonium group (-N (C ₂ H ₅ ) ₃ ⁺ ).

[0075] Specific examples of substituted or unsubstituted terephthalic acid ions represented by Formula 2 include terephthalic acid ions (p-BDC ^2- ), 2-aminoterephthalic acid ions, 2,5-diaminoterephthalic acid ions, 2-hydroxyterephthalic acid ions, and 2,5-dihydroxyterephthalic acid ions. The substituted or unsubstituted terephthalic acid ions represented by Formula 2 are preferably terephthalic acid ion (p-BDC ^2- ).

[0076] Examples of trivalent carboxylic acid ions include substituted or unsubstituted trimesic acid ions, 1,3,5-tris (4-carboxyphenyl) benzene ions, 1,3,5-triscarboxyphenylethynylbenzene ions, 4.4 ', 4' ions '-c-triazine-2,4,6-triyl-tribenzoic acid, 1,3,5-tris (4'-carboxy [1,1'-biphenyl] -4-yl) benzene ions, diphenyl-3- ions 4'-5-tricarboxylic acid; and 4.4 ', 4' '- (1,3,5-triazine-2,4,6-triyl triimino) trisbenzoic acid ions.

[0077] Substituted or unsubstituted trimesinic acid ions can be represented by formula 3.

[0078]

[Formula 3]

[0079] In formula 3, each R is an independent substituent other than a carboxylate group, and n is an integer from 0 to 3. R is not specifically limited provided that the above ions can function as an organic linker to form an MOC. Examples thereof include hydroxy groups, nitro groups, fluoro groups, chloro groups, bromo groups, iodine groups, cyano groups, methyl groups, ethyl groups, tert-butyl groups and ethynyl groups.

[0080] Specific examples of substituted or unsubstituted trimesic acid ions represented by formula 3 include trimesic acid ions (BTC ^3- ), 2-hydroxy-1,3,5-benzenetricarboxylic acid ions, 2-nitro-1,3 ions , 5-benzene-tricarboxylic acid, 2-chloro-1,3,5-benzene-tricarboxylic acid ions, 2-bromo-1,3,5-benzene-tricarboxylic acid ions, and 2-methyl-1,3,5-benzene-tricarboxylic acid ions. The substituted or unsubstituted trimesic acid ions represented by formula 1 are preferably trimesic acid ion (BTC ^3- ).

[0081] Examples of tetravalent carboxylic acid ions include [1,1 ': 4', 1 ""] terphenyl-3,3 ", 5,5" -tetracarboxylic acids, 3,3 ', 5, 5'-tetracarboxydiphenylmethane, 1,2,4,5-tetrakis (4-carboxyphenyl) benzene ions, and diphenyl-3,3 ', 5,5'-tetracarboxylic acid ions.

[0082] The polycarboxylic acid ion is preferably at least one of the group consisting of substituted or unsubstituted isophthalic acid ions, substituted or unsubstituted terephthalic acid ions, and substituted or unsubstituted trimesinic acid ions. Using the aforementioned polycarboxylic acid ion, a net periodic structure having pores suitable for adsorption of water vapor can be imparted to a coordinately unsaturated IOC. Polycarboxylic acid ions can be a combination of divalent carboxylic acid ions and trivalent carboxylic acid ions.

[0083] The proportion of polycarboxylic acid ions may be 20 mol%. or more, 30 mol%. or more, or 40 mol%. or more, and may be 95 mol%. or less, 90 mol%. or less or 85 mol%. or less using the total molar number of carboxylic acid ions as a reference level.

[0084]

<Monocarboxylic acid ion>

The coordinately unsaturated MOC may include a monocarboxylic acid ion coordinated with a metal cluster. A monocarboxylic acid ion functions as a monodentate ligand, inhibits the coordination of a polydentate ligand, for example, a polycarboxylic acid ion, with a metal cluster and can be used to control the periodic structure and crystalline form (morphology) of coordinatively unsaturated IOC.

[0085] A monocarboxylic acid ion is not particularly limited provided that coordinatively unsaturated IOC can form with it. Since a monocarboxylic acid ion is preferred for the formation of a periodic structure of coordination unsaturated MOC, the monocarboxylic acid ion is preferably a C _1-3 monocarboxylic acid ion. Monocarboxylic acid C _1-3 preferably represents at least one of the group consisting of formic acid ions, acetic acid ions and propionic acid ions, and more preferably at least one of the group consisting of formic acid ions and acetic acid ions.

[0086] The proportion of monocarboxylic acid ions may be 5 mol%. or more, 10 mol%. or more or 15 mol%. or more, and may be 80 mol%. or less, 70 mol%. or less or 60 mol%. or less with respect to the total molar number of carboxylic acid ions.

[0087]

<Polydentate ligands other than polycarboxylic acids>

The coordinatively unsaturated MOC may include a polydentate ligand other than polycarboxylic acid, for example, a polydentate ligand donor nitrogen. Examples of such polydentate ligands as donor nitrogen include imidazole ions, 2-methylimidazole ions (mIM), 4,4'-bipyridyl, ethylenediamine, 1,4-diazabicyclo [2.2.2] octane (DABCO), pyrazine, 1, 2-bis (4-pyridyl) ethane, and 1,2-bis (4-pyridyl) ethylene. Like polycarboxylic acid ions, these polydentate ligands, other than carboxylic acid ligands, can function as an organic linker, linking many metal clusters to each other. In the present disclosure, a ligand containing both two or more carboxylate groups and a nitrogen atom having a donor property is classified as a polycarboxylic acid ion.

[0088] The proportion of a multidentate ligand other than polycarboxylic acid may be 40 mol%. or less, 30 mol%. or less or 20 mol%. or less relative to the total molar number of ligands coordinated with the metal cluster. In addition, the coordinately unsaturated MOC may not include a polydentate ligand other than polycarboxylic acid.

[0089]

<Metal ion not included in the metal cluster (metal ion outside the cluster)>

The coordination unsaturated MOC of the present invention may include a metal ion that is not included in a metal cluster. In the present disclosure, a metal ion that is not included in a metal cluster is referred to as a “metal ion outside the cluster”. As will be described below, the coordinatively unsaturated MOA according to the present invention can be obtained by allowing the metal-organic carcass precursor and a metal solvent having Lewis acidity to coexist in the solvent, and allowing the desorption of monocarboxylic acid ions that are coordinated with the metal cluster . Thus, the coordinately unsaturated MOC according to the present invention may include metal ions derived from a metal salt used as metal ions outside the cluster in some cases.

[0090] Although this is not related to any particular theory, it is believed that metal ions outside the cluster form a complex with monocarboxylic acid ions desorbed from the metal cluster and balance the charge of the entire coordination unsaturated MOC, which is the result of the presence of such a complex, for example, in the pores of coordinatively unsaturated IOC.

[0091] The metal ions outside the cluster may be at least one of the group consisting of Li ⁺ , Mg ²⁺ , Al ³⁺ , Sc ³⁺ , Y ³⁺ , Ti ⁴⁺ , Zr ⁴⁺ and Hf ⁴⁺ .

[0092]

<< Chemical heat pump >>

The coordination unsaturated metal-organic framework according to the present invention can be used, for example, as a hygroscopic material in a chemical heat pump. The chemical heat pump in this case contains a water storage tank for storing water, in which water is stored as a working substance, a unit for storing hygroscopic material and a channel for the flow of water vapor, which circulates water vapor between the water store and the unit for storing hygroscopic material. In such a chemical heat pump, the water storage can be used both as an evaporator and as a condenser, or the water storage can be used as an evaporator, and water vapor can be condensed by a separate condenser. Such a chemical heat pump can be used for air conditioning and heating of vehicles, residential buildings and industrial premises.

[0093] An aspect will be disclosed in which the water storage is used as an evaporator and condenser in such a chemical heat pump. As shown, for example, on the left side of FIG. 11 (a), heat is supplied externally to the water (H ₂ O liquid) in the water storage 10 to evaporate water in the water storage tank, resulting in water vapor (vaporous H ₂ O). This step is also called the step of transferring cold from the water storage to the outside, by evaporating water into the water storage to form water vapor. At this time, in such a chemical heat pump, as shown on the right side of FIG. 11 (a), the water vapor generated by the water storage 10 enters the hygroscopic material storage part 20 through the water vapor channel 30, reacts with the hygroscopic material, and supplies adsorption heat to the outside. In other words, in such a heat pump, heat can be transferred from the side of the water storage 10 to the side of the storage part 20 for absorbent material.

[0094] Furthermore, in such a chemical heat pump, in a regeneration step, the reaction of which is shown in FIG. 11 (a), this reaction can be carried out again, as shown on the right side of FIG. 11 (b), heat is supplied externally to the hygroscopic material storage portion 20, and water is desorbed from the hygroscopic material to form water vapor. This step may also be referred to as a step in which cold is supplied outward from the hygroscopic material storage portion 20 by desorption of water from the hygroscopic material in the hygroscopic material storage portion 20. At this time, in such a chemical heat pump, as shown on the left side of FIG. 11 (b), water vapor generated in the hygroscopic material storage portion 20 is supplied to the water storage 10 and condenses, whereby the latent heat of condensation is supplied to the outside.

[0095]

<< Humidity Control System >>

The coordination unsaturated metal-organic framework according to the present invention can be used, for example, as a hygroscopic material in a humidity control system. The humidity control system in this case comprises a part for storing absorbent material, an air supply channel for supplying air containing water vapor to the part for storing absorbent material, and a channel for discharging air supplied to the part for storing absorbent material from the part for storing absorbent material . Such a humidity control system can be used to drain or control the humidity of vehicles, houses and industrial premises.

[0096] In this humidity control system, as shown, for example, in FIG. 12 (a), air containing a relatively large amount of water vapor is supplied externally to the hygroscopic material storage portion 25 through the air supply passage 32, and at least a portion of the water vapor in the air in the hygroscopic material storage portion 25 is adsorbed and removed hygroscopic material. At this time, in part 25 for storing the hygroscopic material, adsorption heat is released as a result of adsorption of water vapor by the hygroscopic material. Thereafter, at least a portion of the water vapor in the hygroscopic material storage portion 25 is removed, and air having a relatively small amount of water vapor is discharged from the hygroscopic material storage portion through the air discharge passage 34. “Relatively small amount” and “relatively large amount” of water vapor have relative values, and thus, air having a relatively small amount of water vapor means air having less water vapor compared to air having a relatively large amount of water vapor.

[0097] Furthermore, in this humidity control system, in a regeneration step in which the reaction shown in FIG. 12 (a), as shown in FIG. 12 (b), air containing a relatively small amount of water vapor is supplied externally to the hygroscopic material storage portion 25 through the air supply passage 32, while heat is supplied externally to the hygroscopic material storage portion 25, and as a result, at least a portion of the water vapor that has been adsorbed by the absorbent material in the absorbent storage portion 25 is discharged into the air. Thereafter, water vapor is added to the hygroscopic material storage part 25, and air having a relatively high water vapor content is discharged from the hygroscopic material storage part through the air discharge passage 34. This regeneration step may also be carried out as a humidification step. It should be noted that at this stage of regeneration it is also possible to reverse the air flow, that is, to introduce air from the channel 34 to release air and to exhaust air from the channel 32 for air supply. Similarly to the aforementioned, “relatively small amount” and “relatively large amount” of water vapor have relative values.

EXAMPLES

[0098]

<< Synthesis of a metal-organic framework (IOC) >>

The metal-organic scaffolds (IOC) of the examples and comparative examples were synthesized using the reagents shown in table 1.

[0099]

[Table 1]

[0100]

<Comparative Example A-1 (Preparation of Zr-BTC / m-BDC (A))>

The product was obtained using the following steps: (1) through (3). In FIG. 3 shows a flowchart of a production method for comparative example A-1.

[0101] (1) 387 mg (120 mmol) of zirconium oxychloride octahydrate (ZrOCl ₂ ⋅ 8H ₂ O), 76 mg (36 mmol) of trimesic acid (H ₃ BTC), 7 mg (4 mmol) of isophthalic acid (mH ₂ BDC ), 20 ml of acetic acid and 20 ml of N, N-dimethylformamide (DMF) were added to a 100 ml PTFE container (HUT-100, manufactured by Sanai-Kagaku Co.).

[0102] (2) The PTFE container was loaded into a pressure-resistant stainless steel outer cylinder (HUS-100, manufactured by Sanai-Kagaku Co.) and heated for 48 hours at a temperature of 130 ° C.

[0103] (3) The product was filtered, washed three times using 10 ml of DMF, and washed three times using 10 ml of acetone, and then heated to 60 ° C overnight until the pressure dropped to less than 10 ^{- 1} Pa, and dried to give the product (Zr-BTC / m-BDC (A)) as a white powder. The resulting product is a metal-organic framework having a structure in which an acetic acid ion as a monodentate ligand and a trimesinic acid ion and an isophthalic acid ion as polydentate ligands are coordinated with a zirconium ion.

[0104]

<Comparative example X-1 (Preparation (Zr-BTC / m-BDC (A); immersion in DEPA (30 ° C))>

The product for comparative example X-1 is obtained through the following steps (1) to (3).

[0105] (1) 187 mg of Zr-BTC / m-BDC (A) (approximately 0.8 mmol relative to Zr) as an IOC precursor, and 40 ml of N, N-dimethylformamide (DMF) as a solvent were added to a 110-volume vial ml

[0106] (2) A 110 ml vial was heated for 48 hours at a temperature of 30 ° C.

[0107] (3) The product was filtered, washed three times in 10 ml of DMF and washed three times in 10 ml of acetone, and then heated at 60 ° C overnight until the pressure dropped to 10 ^-1 Pa or less , and dried to obtain a product.

[0108]

<Example A-1>

The product for example A-1 was obtained through the following steps (1) to (3). The resulting product is a coordinately unsaturated MOA in which a portion of the acetic acid ions as a ligand was desorbed. In FIG. 4 shows a flowchart of a production method for Example A-1.

[0109] (1) 187 mg of Zr-BTC / m-BDC (A) (approximately 0.8 mmol relative to Zr) as a precursor of IOC, 107 mg (0.8 mmol) of aluminum chloride (AlCl ₃ ) and 40 ml of N, N-dimethylformamide (DMF) as a solvent was added to a 110 ml vial.

[0110] (2) A 110 ml vial was heated for 48 hours at a temperature of 30 ° C.

[0111] (3) The product was filtered, washed three times in 10 ml of DMF and washed three times in 10 ml of acetone, and then heated at 60 ° C. overnight until the pressure dropped to less than 10 ^-1 Pa , and dried to obtain a product.

[0112]

<Example A-2>

The product was obtained in the same manner as in Example A-1, except that 121 mg (0.8 mmol) of scandium chloride (ScCl ₃ ) was added instead of the aluminum chloride in step (1) of Example A-1.

[0113]

<Example A-3>

The product was obtained in the same manner as in Example A-1, except that 156 mg (0.8 mmol) of yttrium chloride (YCl ₃ ) was added instead of aluminum chloride in step (1) of Example A-1.

[0114]

<Example A-4>

The product was obtained in the same manner as in Example A-1, except that 469 mg (2.4 mmol) of yttrium chloride (YCl ₃ ) was added instead of aluminum chloride in step (1) of Example A-1.

[0115]

<Example A-5>

The product was obtained in the same manner as in Example A-1, except that 1562 mg (8 mmol) of yttrium chloride (YCl ₃ ) was added instead of aluminum chloride in step (1) of Example A-1.

[0116]

<Example A-6>

The product was obtained in the same manner as in Example A-2, except that the heating temperature in step (2) of Example A-2 was changed to 80 ° C.

[0117]

<Example A-7>

The product was obtained in the same manner as in Example A-3, except that the heating temperature in step (2) of Example A-3 was changed to 80 ° C.

[0118]

<Example A-8>

The product was obtained in the same manner as in Example A-4, except that the heating temperature in step (2) of Example A-4 was changed to 80 ° C.

[0119]

<Example A-9>

The product was obtained in the same manner as in Example A-2, except that the solvent in step (1) of Example A-2 was changed from DMF to water.

[0120]

<Example A-10>

The product was obtained in the same manner as in Example A-3, except that the solvent in step (1) of Example A-3 was changed from DMF to water.

[0121]

<Example A-11>

The product was obtained in the same manner as in Example A-4, except that the solvent in step (1) of Example A-4 was changed from DMF to water.

[0122]

<Example A-12>

The product was obtained in the same manner as in Example A-1, except that 34 mg (0.8 mmol) of lithium chloride (LiCl) was added instead of aluminum chloride in step (1) of Example A-1.

[0123]

<Example A-13>

The product was obtained in the same manner as in Example A-1, except that 76 mg (0.8 mmol) of magnesium chloride (MgCl ₂ ) was added instead of aluminum chloride in step (1) of Example A-1.

[0124]

<Example A-14>

The product was obtained in the same manner as in Example A-1, except that 256 mg (0.8 mmol) of hafnium chloride (HfCl ₄ ) was added instead of aluminum chloride in step (1) of Example A-1.

[0125]

<Comparative example B-1 (Preparation of Zr-BTC (F)>

The product for comparative example B-1 was obtained through the following steps (1) to (3).

[0126] (1) 387 mg (120 mmol) of zirconium oxychloride octahydrate (ZrOCl ₂ ⋅ 8H ₂ O), 84 mg (40 mmol) of trimesic acid (H ₃ BTC), 20 ml of formic acid and 20 ml of N, N-dimethylformamide (DMF) was added to a 100 ml PTFE container (HUT-100, manufactured by Sanai-Kagaku Co.).

[0127] (2) The PTFE container was loaded into a pressure-resistant external stainless steel cylinder (HUS-100, manufactured by Sanai-Kagaku Co.) and heated for 48 hours at a temperature of 130 ° C.

[0128] (3) The product was filtered, washed three times using 10 ml of DMF, and washed three times using 10 ml of acetone, and then was heated to 60 ° C. overnight until the pressure decreased to below 10 ^-1 Pa, and dried to obtain the product Zr-BTC (F) in the form of a white powder.

[0129]

<Example B-1>

The product was obtained in the same manner as in Example A-14, except that in step (1) of Example A-14, 182 mg (0.8 mmol relative to Zr) Zr-BTC (F) was used instead of Zr-BTC / m-BDC (A), the amount of N, N-dimethylformamide (DMF) was changed to 80 ml and the amount of hafnium chloride (HfCl ₄ ) was changed to 769 mg (2.4 mmol).

[0130]

<Comparative example C-1 (Preparation of Zr-p-BDC (A))>

The product of comparative example C-1 was obtained by the following steps (1) to (3).

[0131] (1) 387 mg (120 mmol) of zirconium oxychloride octahydrate (ZrOCl ₂ ⋅ 8H ₂ O), 199 mg (120 mmol) of terephthalic acid (p-H ₂ BTC), 10 ml of acetic acid and 30 ml of N, N -dimethylformamide (DMF) was added to a 100 ml PTFE container (HUT-100, manufactured by Sanai-Kagaku Co.).

[0132] (2) The PTFE container was loaded into a pressure-resistant external stainless steel cylinder (HUS-100, manufactured by Sanai-Kagaku Co.) and heated for 48 hours at a temperature of 130 ° C.

[0133] (3) The product was filtered, washed three times using 10 ml of DMF, and washed three times using 10 ml of acetone, and then heated to 60 ° C. overnight until the pressure decreased to below 10 ^-1 Pa, and dried to obtain the product Zr-p-BDC (A) as a white powder.

[0134]

<Comparative example C-2>

The product was obtained in the same manner as in Example A-1, except that in step (1) of Example A-1, 222 mg (approximately 0.8 mmol relative to Zr) of Zr-p-BDC (A) were used instead Zr-BTC / m-BDC (A) and aluminum chloride were not used.

[0135]

<Example C-1>

The product was obtained in the same manner as in Example A-3, except that in step (1) of Example A-3, 222 mg (approximately 0.8 mmol relative to Zr) of Zr-p-BDC (A) were used instead Zr-BTC / m-BDC (A).

[0136]

<Example X-1>

The product was obtained in the same manner as in Example A-1, except that 4.69 g (24.0 mmol) of yttrium chloride (YCl ₃ ) was added instead of aluminum chloride in step (1) of Example A-1.

[0137]

<Example X-2>

The product was obtained in the same manner as in Example A-1, except that 2.56 g (8.0 mmol) of hafnium chloride (HfCl ₄ ) was added instead of aluminum chloride in step (1) of Example A-1.

[0138]

<Example X-3>

The product was obtained in the same manner as in Example X-2, except that in step (1) of Example X-2, N, N-diethylformamide (DEPA) was used as a solvent instead of N, N-dimethylformamide (DMF) .

[0139]

<Example X-4>

The product was obtained in the same manner as in Example A-1, except that 7.69 g (24.0 mmol) of hafnium chloride (HfCl ₄ ) was added instead of aluminum chloride in step (1) of Example A-1.

[0140] The synthesis conditions of the obtained MOC are shown in table 2.

[Table 2-1]

[Table 2-2]

[0141]

<analysis>

(Measurement ¹ H-NMR (IOC Composition Analysis))

After decomposition of the products, the spectrum of proton magnetic resonance, ¹ H-NMR, of a solution was measured to obtain the ratio of ligands in the IOC based on the total ratio. The separation conditions, measuring device and measurement conditions are indicated below.

Условия разложения: 1 мл бисульфата (D₂SO₄) добавляют к приблизительно 10 мг продукта (МОК) и перемешивают

Decomposition conditions: 1 ml of bisulfate (D ₂ SO ₄ ) is added to approximately 10 mg of the product (IOC) and mixed

Измерительное устройство: JNM-AL400 (Изготовитель: JEOL)

Measuring device: JNM-AL400 (Manufacturer: JEOL)

Условия измерения: Спектр ¹H-NMR раствора измеряют с использованием тетраметилсилана (ТМС) в качестве внутренней базовой линии

Measurement conditions: Spectrum ^{1 of an} H-NMR solution is measured using tetramethylsilane (TMS) as an internal baseline

Расчет состава: С использованием (M₆O₄(OH)₄)(BTC)_a(BDC)_b(OAc)_c(OH)_d(DMF)_e(H₂O)_f (М is Zr) значения от а до f были определены таким образом, чтобы удовлетворять следующим трем уравнениям, посредством чего координационное число и заряд уравновешиваются, и чтобы удовлетворять соотношению а, b, с и е, полученному из спектра ¹H-NMR.

Composition calculation: Using (M ₆ O ₄ (OH) ₄ ) (BTC) _a (BDC) _b (OAc) _c (OH) _d (DMF) _e (H ₂ O) _f (M is Zr) values from a to f were determined so as to satisfy the following three equations, whereby the coordination number and charge are balanced, and to satisfy the relationship a, b, c and e obtained from the ¹ H-NMR spectrum.

6 = 3a + 2b

12 = 3a + 2b + c + d

24 = 6a + 4b + 2c + d + e + f

[0142] The ratio of ligands constituting Zr-BTC / m-BDC (A) (comparative example A-1) before immersion in a solution (Lewis acid solution) of a metal salt having a Lewis acidity and the ratio of ligands constituting Zr-BTC / m-BDC (A) (Example A-3: 20 mmol ⋅ ^-1 ; Example A-4: 60 mmol ^{-1 -1} ; and Example A-5: 200 mmol ^{-1 -1} ) after immersion in solutions having different concentrations of YCl ₃ (a metal salt having a Lewis acidity) are shown in FIG. 5.

[0143] From FIG. 5 it should be understood that if the concentration of YCl ₃ increases, then the ratio of acetic acid ions in the IOC decreases. In addition, as shown in table 2, from the IOC compositions obtained by formulas 1 to 3, it can be understood that, since the content of trimesic acid ions and isophthalic acid ions (a and b) did not change significantly, and only the content (c) the amount of acetic acid ions decreased, acetic acid ions (monocarboxylic acid ions) in the MOC were selectively desorbed as a result of immersion in a Lewis acid solution.

[0144]

(Measurements by inductively coupled plasma atomic emission spectroscopy ICP-AE (Analysis of impurities obtained from a metal salt having a Lewis acidity))

After decomposition, the products are diluted with ultrapure water for the quantitative analysis of metal elements obtained from a metal salt having a Lewis acidity. Decomposition conditions and measuring device are indicated below.

Условия разложения: азотную кислоту (HNO₃) и серную кислоту (H₂SO₄) добавляют в продукт и нагревают

Decomposition conditions: nitric acid (HNO ₃ ) and sulfuric acid (H ₂ SO ₄ ) are added to the product and heated

Измерительное устройство: SPS5100 (Изготовитель: SII Nanotechnology Со.)

Measuring device: SPS5100 (Manufacturer: SII Nanotechnology Co.)

[0145] The types and contents of impurity metals contained in the products after immersion in a Lewis acid solution are shown in Table 3. From Table 3 it can be understood that although their content depends on the washing stage, the metal elements obtained from a metal salt having acidity according to Lewis, remain in the product.

[0146]

(Measurement of adsorption / desorption of water vapor / (Evaluation of the characteristics of adsorption / desorption of water vapor))

After pretreatment, the adsorption / desorption isotherms of the water vapor of the products are measured and the adsorption values of water vapor are determined at a relative humidity of 0 to 40%. The pre-treatment device, pre-treatment conditions, measuring device and measurement conditions are indicated below.

Устройство предварительной обработки: BELPREP-vacII (Изготовитель: MicrotracBEL Corp.)

Pretreatment Unit: BELPREP-vacII (Manufacturer: MicrotracBEL Corp.)

Условия предварительной обработки: Нагревание в течение 6 часов при 130°С, в условиях вакуума, при давлении менее 10^-2 Па

Pretreatment conditions: Heating for 6 hours at 130 ° C, under vacuum, at a pressure of less than 10 ^-2 Pa

Измерительное устройство: BELSORP-max (Изготовитель: Microtrac-Bel Corporation)

Measuring device: BELSORP-max (Manufacturer: Microtrac-Bel Corporation)

Условия измерения: Количество адсорбции водяного пара измеряют при температуре 20°С при относительной влажности в диапазоне от 0 до 85%

Measurement conditions: The amount of adsorption of water vapor is measured at a temperature of 20 ° C at a relative humidity in the range from 0 to 85%

[0147] The differences in adsorption moisture and the difference in adsorption humidity before and after immersion in a Lewis acid solution for examples and comparative examples are shown in Table 3. It should be noted that the difference in adsorption humidity before and after immersion in a Lewis acid solution was obtained from the difference in the adsorption moisture content of IOC (examples A-1 to A-14, B-1, C-1 and X-1 to X-4), as well as IOC of other comparative examples (comparative examples X-1 and C-2) after immersion in a solution of Lewis acid relative to the adsorption moisture of the IOC before immersion in a solution of Lewis acid (adsorption moisture for comparative examples A-1, B-1 and C-1), and these data are presented in table 3 as moisture differences. From table 3 it can be understood that after immersion in a solution of Lewis acid, the adsorption moisture of the MOC significantly decreased (from 2.3% to 14.5%).

[0148]

[Table 3-1]

[Table 3-2]

[0149] Water vapor adsorption / desorption isotherms at 20 ° C. for Comparative Example A-1, Example A-3, Example A-4 and Example A-5 are shown in FIG. 6. On the water vapor adsorption curves of Example A-3 (residual amount of acetic acid ions: 48%), Example A-4 (residual amount of acetic acid ions: 37%) and Example A-5 (residual amount of acetic acid ions: 29 %), the rise front is biased toward low humidity (left side in FIG. 6) compared with comparative example A-1 (residual amount of acetic acid ions: 90%). In addition, the smaller the residual amount of acetic acid ions, the greater the shift in the adsorption curve of water vapor.

[0150] It should be noted that the residual amount of acetic acid ions (%) shown in Table 3 was determined by dividing the “c” value, which is the “(OAc)” coefficient in the IOC, by six using the value for cases when six ions of monocarboxylic acid are coordinated with a metal cluster, as 100%.

[0151] The relative humidity during water vapor adsorption in an amount equal to half the maximum amount of water vapor adsorption was used as adsorption humidity and is shown in FIG. 7 together with the residual amount of acetic acid ions. It is understood that in Examples A-1 to A-8, the residual amount of acetic acid ions was reduced compared to Comparative Example A-1, and the adsorption humidity decreased accordingly. In addition, there was a strong correlation between the residual amount of acetic acid ions (%) and adsorption moisture (%).

[0152] In addition, the humidity at which the amount of adsorbed water vapor in comparative examples A-1 and X-1 and examples A-1 to A-8 and X-1 to X-4 reached half the value of 40% humidity, were taken as adsorption moisture and are shown in FIG. 13 together with residual amounts of acetic acid ions. It is clear that in examples A-1 to A-8 and X-1 to X-4, the residual amount of acetic acid ions was reduced in comparison with comparative examples A-1 and X-1, and the adsorption humidity decreased accordingly. In addition, there was a strong correlation between the residual amount of acetic acid ions (%) and adsorption moisture (%).

[0153] From the above results, it can be understood that, by controlling the residual amount of monocarboxylic acid ions (acetic acid ions) in the coordinately unsaturated MOC, the adsorption moisture of the coordinately unsaturated MOC can be controlled.

[0154] Water vapor adsorption / desorption isotherms at 20 ° C for comparative example A-1, example A-2, example A-13 and example A-14 are shown in FIG. 8. In the water vapor adsorption curves for Example A-2 (ScCl ₃ ), Example A-13 (MgCl ₂ ), and Example A-14 (HfCl ₄ ), the rise front shifted toward low relative humidity (left side in FIG. 8) compared with comparative example A-1 (in which immersion in a solution of Lewis acid was not carried out).

[0155] Water vapor adsorption / desorption isotherms at 20 ° C for comparative example B-1 and example B-1 are shown in FIG. 9, and water vapor adsorption / desorption isotherms at 20 ° C. for comparative example C-1 and example C-1 are shown in FIG. 10. Even when the MOC was obtained from Zr-BTC (F) or Zr-p-BDC (A), immersed in a HfCl ₄ / DMF solution, the front of rise of the water vapor adsorption curve is shifted toward lower humidity (left sides of FIG. 9 and Fig. 10).

[0156] Water vapor adsorption / desorption isotherms at 20 ° C. for Examples X-2 and X-4 and Comparative Example X-1 are shown in FIG. 14. On the curves of water vapor adsorption for examples X-2 and X-4, the front of growth is shifted toward low humidity (the left side of Fig. 14) in comparison with comparative example X-1. It should be noted that in example X-4 it can be seen that the value of water vapor adsorption has decreased. This is believed to be the result of the fact that the concentration of the metal salt having a Lewis acidity was too high (e.g. 600 mmol / L or more), as a result of which the polycarboxylic acid ions that were coordinated with the metal cluster were desorbed.

[0157] As can be understood from the results given above, according to the present invention, coordinatively unsaturated centers can be generated using various types of metal salts having Lewis acidity in different MOCs, and the adsorption humidity of the coordinatively unsaturated MOCs can be controlled based on the strength and amount of salt a metal having a Lewis acidity.

Claims (24)

1. A method of obtaining a coordinatively unsaturated metal-organic framework, containing: obtaining a precursor of a metal-organic framework containing a metal cluster and a polycarboxylic acid ion and a monocarboxylic acid ion that are coordinated with a metal cluster, and enabling the precursor of the metal-organic carcass and the metal salt having a Lewis acidity to coexist in the solvent to desorb at least a portion of the monocarboxylic acid ion coordinated with the metal cluster from the metal cluster. 2. The method of claim 1, wherein the metal cluster is a metal cluster of the type M ₆ O _8-x (OH) _x , while M represents an ion of an element of group IV or an ion of a rare earth element, wherein the polycarboxylic acid ion and the monocarboxylic acid ion coordinated with the metal cluster are a polycarboxylic acid ion as a polydentate ligand and a C _1-3 monocarboxylic acid ion as a monodentate ligand, respectively, and wherein less than six monocarboxylic acid ions are coordinated with each metal cluster. 3. The method according to p. 2, in which M represents at least one of the group consisting of Zr ⁴⁺ , Hf ⁴⁺ and Ce ⁴⁺ . 4. The method according to any one of paragraphs. 1-3, in which the monocarboxylic acid ion is at least one of the group consisting of formic acid ion, acetic acid ion and propionic acid ion. 5. The method according to any one of paragraphs. 1-4, in which the metal salt having a Lewis acidity is a halide. 6. Coordination-unsaturated metal-organic framework containing: a metal cluster of type M ₆ O _8-x (OH) _x and carboxylic acid ions coordinated with the metal cluster, in which M is a tetravalent ion of an element of group IV or an ion of a rare earth element, wherein the carboxylic acid ions coordinated with the metal cluster contain a polycarboxylic acid ion as a polydentate ligand and a monocarboxylic acid ion as a monodentate ligand, moreover, many metal clusters are connected to each other due to the ion of a polycarboxylic acid, wherein the number of monocarboxylic acid ions coordinated with the metal cluster is 80% or less when the maximum number of monocarboxylic acid ions that can be coordinated with the metal cluster is 100%, and moreover, the maximum number of monocarboxylic acid ions that can be coordinated with a metal cluster is six for each metal cluster. 7. Coordination-unsaturated metal-organic framework according to claim 6, in which the amount of monocarboxylic acid ions coordinated with the metal cluster is in the range from 5 to 80%. 8. Coordination-unsaturated metal-organic framework according to claim 7, in which M represents at least one of the group consisting of Zr ⁴⁺ , Hf ⁴⁺ and Ce ⁴⁺ . 9. Coordination-unsaturated metal-organic framework according to any one of paragraphs. 6-8, in which the monocarboxylic acid ion is a monocarboxylic acid ion With _1-3 . 10. Coordination-unsaturated metal-organic framework according to any one of paragraphs. 6-9, in which the monocarboxylic acid ion is at least one of the group consisting of formic acid ion, acetic acid ion and propionic acid ion. 11. Coordination-unsaturated metal-organic framework according to any one of paragraphs. 6-10, further comprising a metal ion outside the cluster. 12. The coordination unsaturated metal-organic framework according to claim 11, wherein the metal ion outside the cluster is at least one of the group consisting of Li ⁺ , Mg ²⁺ , Al ³⁺ , Sc ³⁺ , Y ³⁺ , Ti ⁴⁺ , Zr ⁴⁺ and Hf ⁴⁺ .

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