Method for manufacturing metal organic structure

Abstract

To provide a method for manufacturing MOF by reaction of metal and an organic compound.SOLUTION: A method for manufacturing a metal organic structure includes obtaining a metal organic structure by carrying out mechanochemical treatment of an object including a metal that serves as a metal ion source, and an organic compound that serves as a cross-linking ligand. The mechanochemical treatment is carried out under conditions where at least a part of the metal is solid and at least a part of the organic compound is solid.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a metal-organic framework. [Background technology]

[0002] Metal-organic frameworks (MOFs) are known to have crystalline polymer structures with internal pores, which are formed by combining metal ions with bridging organic ligands that connect the metal ions.

[0003] Known methods for producing MOFs include the solution method, hydrothermal synthesis method, solvothermal method, microwave method, ultrasonic method, electrolytic synthesis method, etc. Other methods include methods for synthesizing MOFs by solid-state or semi-solid-state reactions, such as mixing using a ball mill or mortar, or shearing methods.

[0004] For example, Patent Document 1 discloses a method in which a metal plate selected from the group consisting of a pure metal plate, a metal oxide plate, and a metal nitride plate is prepared as a metal ion source, a ligand substance is dissolved in an alcohol-based solvent to prepare a ligand substance solution, the metal plate is introduced into the ligand substance solution, and the metal plate and the ligand substance are reacted to form a MOF membrane on the metal plate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-57439 Summary of the Invention [Problem to be solved by the invention]

[0006] MOF production methods that use a liquid phase such as a ligand substance solution require a long reaction time because the reaction continues until the metal is consumed. Furthermore, the MOF membrane production method disclosed in Patent Document 1 uses an alcohol-based solvent with a high water content of 0 to 12 mass %, making it less versatile.

[0007] Therefore, an object of the present invention is to provide a method for producing MOFs by reacting metals with organic compounds, which can reduce the amount of liquid phase such as solvents and allows for easy purification. [Means for solving the problem]

[0008] The present invention proposes a method for producing a metal organic framework, which comprises a step of mechanochemically treating an object containing a metal that serves as a metal ion source and an organic compound that serves as a bridging ligand to obtain a metal organic framework, wherein the mechanochemical treatment is carried out under conditions where at least a part of the metal is solid and at least a part of the organic compound is solid. [Effects of the Invention]

[0009] The present invention can provide a method for producing an MOF by reacting a metal with an organic compound, which can reduce the amount of liquid phase such as a solvent and facilitate purification. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an XRD pattern of the MOF of Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will now be described based on embodiments, although the present invention is not limited to the embodiments described below.

[0012] An embodiment of the present invention is a method for producing a metal-organic framework (MOF), comprising a step of mechanochemically treating an object containing a metal that serves as a metal ion source and an organic compound that serves as a bridging ligand to obtain a metal-organic framework (MOF), wherein the mechanochemical treatment is performed under conditions in which at least a portion of the metal is solid and at least a portion of the organic compound is solid.

[0013] When mechanical energy is applied to the metal and organic compound by mechanochemical treatment under conditions where at least a portion of the metal is solid and at least a portion of the organic compound is solid, metal ions are generated from the metal, and the metal ions react with ligands contained in the organic compound to obtain an MOF. Preferably, an MOF is obtained by reacting the solids of the metal and organic compound together by applying mechanical energy to the metal and organic compound by mechanochemical treatment.

[0014] Mechanochemical processing refers to the application of mechanical energy to a metal, at least a portion of which exists as a solid, and an organic compound containing a bridging ligand, at least a portion of which exists as a solid. The method of reacting solids using mechanochemical processing is also called a solid-phase method. Methods for applying mechanical energy to metals and organic compounds include, for example, stirring, grinding, and ultrasonic irradiation. A grinder such as a stirrer or a bead mill may be used as a device for applying mechanical energy to the solid raw material by stirring or grinding. Mechanochemical processing for stirring or grinding solid metals or organic compounds is also called mechanical milling. An ultrasonic device may be used as a device for applying mechanical energy to the solid raw material by ultrasonic irradiation.

[0015] By using mechanochemical treatment to react metals and organic compounds to form MOFs, the amount of liquid phase, such as solvent, can be reduced. Furthermore, since unreacted metals and other components can be easily removed, the resulting MOFs can be easily purified.

[0016] Mechanochemical treatment can be performed in a dry system where the target material does not contain liquid. When mechanochemical treatment is performed in a dry system, subsequent processes such as liquid separation and drying are not required. Therefore, processing of the separated liquid is also not required, making post-processing or purification of the resulting MOFs easier. When mechanochemical treatment is performed in a dry system, mechanical energy such as impact force or compression force is applied to the metal and organic compound to perform volumetric pulverization, and metal ions generated from the metal react with the organic compound to obtain MOFs.

[0017] The object to be subjected to mechanochemical treatment may further contain a liquid. The mechanochemical treatment can also be performed in a wet manner. When the mechanochemical treatment is performed in a wet manner, the object contains a liquid. When the object to be subjected to mechanochemical treatment contains a liquid, the metal and organic compound are more likely to be uniformly dispersed, mechanical energy can be applied evenly, and the reaction can be promoted. In addition, the dispersed metal and organic compound have good fluidity, which makes it easier for the metal and organic compound to come into contact with each other, and the reaction can be promoted. If the reaction between the metal and organic compound can be promoted, the reaction time can be shortened. The mechanochemical treatment may be performed on the metal and organic compound in a liquid.

[0018] When the object to be mechanochemically treated contains a liquid, the liquid preferably accounts for more than 0% by mass and 99% by mass or less of the total mass of the organic compound and the liquid. When the object to be mechanochemically treated contains a liquid, the liquid preferably accounts for more than 0% by mass and 99% by mass or less of the total mass of the organic compound and the liquid, thereby improving the dispersibility and fluidity of the metal and the organic compound and promoting the reaction between the metal and the organic compound. When the object to be mechanochemically treated contains a liquid, the liquid preferably accounts for more than 0.1% by mass and 90% by mass or less of the total mass of the organic compound and the liquid, more preferably for more than 30% by mass and 80% by mass or less, and even more preferably for more than 40% by mass and 70% by mass or less.

[0019] The mechanochemical treatment may be performed in a combination of dry and wet processes. For example, after a mechanochemical treatment is performed in a dry process where the object does not contain liquid, a liquid may be added to the object and a further mechanochemical treatment may be performed in a wet process.

[0020] When the object of the mechanochemical treatment contains a liquid and the mechanochemical treatment is carried out in a container provided in a mixer or grinder described below, the volume of the liquid may be in the range of 1% by volume to 50% by volume of the container. When the mechanochemical treatment is carried out in a container provided in a mixer or grinder described below, a metal that serves as a metal ion source and an organic compound react in the container. When mechanochemical treatment is carried out in a container provided in a stirrer or pulverizer (described later), and the volume of the liquid in the object is smaller than the volume of the metal that serves as the metal ion source, the dispersibility of the metal and the organic compound in the container can be improved, and the reaction between the metal and the organic compound can be promoted. When mechanochemical treatment is carried out in a container provided in a stirrer or pulverizer (described later), and the volume of the liquid is smaller than the volume of the metal that serves as the metal ion source, the volume of the liquid is preferably in the range of 0.5% to 18% by volume, more preferably in the range of 1% to 15% by volume, and even more preferably in the range of 2% to 10% by volume, relative to the 100% by volume of the container provided in the stirrer or pulverizer. When the mechanochemical treatment is carried out in a container provided in a stirrer or pulverizer described below, and the volume of the liquid is greater than the volume of the metal that serves as the metal ion source, the fluidity of the metal and the organic compound in the liquid in the container can be increased, thereby promoting the reaction between the metal and the organic compound. When the mechanochemical treatment is carried out in a container provided in a stirrer or pulverizer described below, and the volume of the liquid is greater than the volume of the metal that serves as the metal ion source, the volume of the liquid is preferably in the range of 20% by volume to 55% by volume, and more preferably in the range of 25% by volume to 50% by volume, relative to 100% by volume of the volume of the container provided in the stirrer or pulverizer.

[0021] When the object to be mechanochemically treated contains a liquid, the liquid may be at least one selected from the group consisting of water and organic solvents. Examples of the liquid contained in the object to be mechanochemically treated include protic polar solvents such as water, methanol, ethanol, 1-propanol, 2-propanol, n-butanol, and acetic acid; aprotic polar solvents such as N,N'-dimethylformamide, acetonitrile, acetone, dimethyl sulfoxide, and tetrahydrofuran; and nonpolar solvents such as dioxane and hexane. One type of liquid may be used alone, or two or more types may be used in combination. For example, a mixed liquid may be used in which water and ethanol are mixed in a volume ratio (water:ethanol) ranging from 1:9 to 9:1.

[0022] The mechanochemical treatment is preferably carried out by contacting the metal with the organic compound multiple times, which promotes the reaction between the metal ions generated from the metal and the organic compound, resulting in the production of MOFs.

[0023] The mechanochemical treatment may be carried out using a stirrer, kneader, or pulverizer, and is preferably carried out using a stirrer or pulverizer. A stirrer, kneader, or pulverizer may be used in the mechanochemical treatment, which involves contacting a metal with an organic compound multiple times. Examples of the stirrer, kneader, or pulverizer used in the mechanochemical treatment include media-agitating mills such as bead mills, ball mills, and attritors; container-driven mills such as rotary mills, vibration mills, and planetary mills; high-speed rotary pulverizers such as pin mills and hammer mills; paint shakers, disc mills, rotor mills, jet mills, roller mills, ring mills, mortars, automatic mortars, stamp mills, automatic pulverizers, cutter mills, roll crushers, hammer crushers, jaw crushers, and twin-screw kneaders.

[0024] When a media-agitating mill such as a bead mill, a ball mill, or an attritor is used for the mechanochemical treatment, a metal that serves as a metal ion source may be used as a medium.

[0025] When a metal is used as a medium, the metal particles are preferably spherical, cylindrical, or polyhedral. By using a metal as a medium, mechanical energy can be applied to the metal and an organic compound by mechanochemical treatment, generating metal ions from the metal and promoting the reaction between the metal and the organic compound to obtain MOFs. When the metal particles are spherical, the spherical shape also includes spheres with protruding portions, known as shot-shaped particles. When the metal particles are cylindrical, the cylindrical shape also includes wires such as rods. When the metal particles are polyhedral, the polyhedral shape also includes, for example, plate-like and block-like shapes. By using a metal serving as a metal ion source as a medium for mechanochemical treatment, mechanical energy can be applied to the metal and the organic compound serving as a bridging ligand without using a medium. As a result, impurities can be prevented from being mixed into the produced MOFs due to damage to the medium, and the resulting MOFs can be easily purified.

[0026] The maximum length of the metal particles is preferably in the range of 1 μm to 100 mm, more preferably 10 μm to 50 mm, and even more preferably 1 mm to 30 mm. When the maximum length of the metal particles is in the range of 1 μm to 100 mm, the contact area between the metal serving as a metal ion source and the organic compound is increased, and the mechanical energy applied to the metal during mechanochemical treatment promotes the reaction between the metal and the organic compound, resulting in the production of MOFs. When the maximum length of the metal is in the range of 1 μm or more, the metal particles can move sufficiently within the object to be mechanochemically treated, allowing sufficient mechanical energy to be applied to the object, further promoting the reaction between the metal and the organic compound. When the maximum length of the metal particles is in the range of 100 mm or less, the contact area between the metal and the organic compound during mechanochemical treatment is sufficient, further promoting the reaction. In addition, the application of large amounts of energy to the metal can cause cracks or chips in the metal, preventing impurities from being mixed into the MOF and making purification difficult. The maximum length of the metal can be measured, for example, using image analysis or a vernier caliper. If the metal particles are spherical, the maximum length of the metal particles may be the diameter of one metal particle.

[0027] The mass of each metal particle (or particles) can be adjusted depending on the volume of the vessel used for the reaction. The mass of each solid metal particle is preferably in the range of 0.10 g to 100 g, more preferably 0.15 g to 10 g, and even more preferably 0.18 g to 1 g. For example, when a 50 mL reaction vessel is used, the mass of each solid metal can be set within this range. When the mass of each solid metal is 0.10 g or more, it exhibits high reactivity with organic compounds. Even when used as a medium for mechanochemical treatment using a stirrer or grinder, mechanical energy is easily applied to the metal and organic compound, promoting the reaction with the organic compound and producing an MOF. When the mass of each metal is 100 g or less, it is easy to handle and is therefore suitable for the reaction of the present invention. The total amount of metal added to the vessel used for the reaction also depends on the volume of the reaction vessel. For example, when a reaction vessel with a volume of 50 mL is used, the total amount of metal added to the vessel is preferably in the range of 10 g to 1000 g, more preferably in the range of 10 g to 100 g, and even more preferably in the range of 10 g to 50 g, so that the mechanical energy of the mechanochemical treatment is easily applied to the organic compound and the metal. The total amount of metal added to the vessel used for the reaction refers to the total mass of multiple metal particles.

[0028] The Mohs hardness of the metal is preferably in the range of 1 to 10, more preferably in the range of 1 to 8, and even more preferably in the range of 2 to 5. When the Mohs hardness of the metal is in the range of 1 to 10, metal ions are easily generated when mechanical energy is applied by mechanochemical treatment, and the reaction with the organic compound is promoted, allowing MOFs to be obtained. When the Mohs hardness of the metal is in the range of 1 to 10, even when used as a medium for mechanochemical treatment using a stirrer or grinder, cracking and chipping of the metal are suppressed, and impurities in the resulting MOF can be reduced.

[0029] When a metal is used as the medium, the metal may be a resin or ceramic material whose surface has been metal-plated. The preferred shape, maximum length, mass, and Mohs hardness of the material are the same as those described above.

[0030] The metal is a metal ion donor that provides metal ions during the process of producing the resulting MOF. The metal ions bond with ligands provided by the organic compound to form three-dimensional secondary building units (SBUs), also known as metal clusters, and the SBUs are further bonded with ligands to form the MOF. In this specification, "homogeneous MOFs" refer to MOFs with the same SBUs and ligands.

[0031] The metal preferably includes at least one selected from the group consisting of alkali metals, alkaline earth metals, transition metals including rare earth metals, and Group 13 metals. To prevent impurities from being mixed in, the metal is preferably an elemental metal. Specific examples of the metal include Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Ir, Al, Ga, In, and Tl. For example, MOF called MOF-303 contains Al as a metal. MOF called HKUST-1 contains Cu. MOF called MIL-100(Fe) contains Fe. The MOF designated MOF-5 contains Zn, the MOF designated UiO-66 contains Zr, and the MOF designated MOF-74 contains Mg as a divalent metal ion. 2+ , Mn 2+ , Fe 2+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ and Cd 2+ The compound contains at least one selected from the group consisting of:

[0032] The metal serving as the metal ion source preferably accounts for 30% by mass or more and 99.9% by mass or less, more preferably 50% by mass or more and 99.5% by mass or less, and even more preferably 70% by mass or more and 99% by mass or less, based on the total mass of the metal and the organic compound serving as the bridging ligand. The organic compound serving as the bridging ligand is preferably in the form of a powder, as described below. The organic compound serving as the bridging ligand may also be in the form of a powder. The metal serving as the metal ion source preferably accounts for 30% by mass or more and 99.9% by mass or less, based on the total mass of the metal and the organic compound serving as the powder bridging ligand. When the metal serving as the metal ion source accounts for 30% by mass or more and 99.9% by mass or less, based on the total mass of the metal and the organic compound serving as the bridging ligand in the form of a powder, mechanical energy is applied by the mechanochemical treatment to generate metal ions, which readily react with the bridging ligand, enabling the production of an MOF.

[0033] When the mechanochemical treatment is carried out in a container provided in a mixer or grinder, the volume of the metal serving as the metal ion source is preferably in the range of 1% to 20% by volume, more preferably 3% to 15% by volume, and even more preferably 5% to 12% by volume, relative to the volume of the container. When the volume of the metal serving as the metal ion source is in the range of 1% to 20% by volume, relative to the volume of the container, mechanical energy is easily applied to the metal serving as the metal ion source and the organic compound in the container, promoting the reaction between the metal and the organic compound and producing an MOF.

[0034] The metal to be used as the metal ion source may be pretreated before undergoing mechanochemical treatment. For example, the pretreatment of the metal to be used as the metal ion source may involve acid washing, followed by washing with deionized water and drying before use. When metal particles are used as the metal to be used as the metal ion source, pretreatment may involve sieving the particles to a specific size. Sieving may be performed after the metal has been acid washed. For acid washing, for example, hydrochloric acid with a concentration in the range of 1% by mass to 5% by mass, e.g., 2% by mass, may be used.

[0035] The organic compound serving as a bridging ligand of the MOF is preferably selected from the group consisting of, for example, a carboxylic acid compound, an amine compound, and a heterocyclic compound. The organic compound serving as a ligand preferably includes at least one organic compound selected from the group consisting of isophthalic acid, 2-methylimidazole, 2,5-dihydroxyterephthalic acid, 4,4'-dioxide-3,3'-biphenyldicarboxylate, fumaric acid, 1,3,5-tris(4-carboxyphenyl)benzene, 4,4'-biphenyldicarboxylic acid, oxalic acid, 1,2,4-triazole, 3,5-pyrazoledicarboxylic acid, 1,4-benzenedicarboxylic acid (also referred to as "bdc"), 1,3,5-benzenetricarboxylic acid (also referred to as "btc"), 2,5-dioxidobenzene-1,4-dicarboxylic acid (also referred to as "dobdc"), and 2,5-dihydroquiterephthalic acid. The organic compound serving as a bridging ligand is preferably an organic compound serving as a multidentate ligand. The bridging ligands act as organic linkers, which bond with metal ions generated from the metals by mechanochemical processing to form secondary structural units, also known as metal clusters, which then link adjacent secondary structural units to form MOFs. The organic compounds that serve as bridging ligands can be monodentate, bidentate, or tridentate.

[0036] The organic compound serving as a bridging ligand of the MOF is preferably in the form of a powder, which facilitates the application of mechanical energy to at least a part of the metal that is solid and at least a part of the metal that is solid by mechanochemical treatment.

[0037] When the organic compound is a powder, the average particle size of the organic compound is preferably in the range of 0.001 μm to 1000 μm, more preferably 0.01 μm to 1000 μm, and even more preferably 0.1 μm to 100 μm. When the organic compound is a powder and the average particle size of the powder organic compound is in the range of 0.001 μm to 1000 μm, mechanical energy from the mechanochemical treatment is easily applied to the metal, at least a portion of which exists as a solid, and the organic compound, at least a portion of which exists as a solid, promoting the reaction between the metal ions generated from the metal and the organic compound, making it easier to obtain an MOF. The average particle size of the organic compound can be measured, for example, by laser scattering diffraction or image analysis using a microscope.

[0038] When the organic compound is in powder form, the organic compound is preferably present in a range of 0.1% to 10% by mass, more preferably 0.5% to 7% by mass, and even more preferably 1% to 5% by mass, based on the total 100% by mass of the metal ion source and the organic compound serving as a bridging ligand. When the organic compound is present in a range of 0.1% to 10% by mass, based on the total 100% by mass of the metal ion source and the organic compound serving as a bridging ligand, the mechanical energy generated by the mechanochemical treatment can be easily applied, promoting the reaction between the metal ions generated from the metal and the organic compound to obtain an MOF. When the organic compound is in powder and / or liquid form, the organic compound may be present in a range of 0.1% to 70% by mass, 0.5% to 50% by mass, or 1% to 30% by mass, based on the total 100% by mass of the metal ion source and the organic compound serving as a bridging ligand.

[0039] When mechanochemical treatment is performed using a stirrer or a grinder, only the metal and organic compound serving as the metal ion source may be placed in the vessel where mechanochemical treatment is performed, or only the metal, organic compound, and the above-mentioned liquid serving as the metal ion source may be placed in the vessel where mechanochemical treatment is performed. When only the metal, organic compound, and, if necessary, liquid serving as the metal ion source are placed in the vessel where mechanochemical treatment is performed, the metal serving as the metal ion source also functions as a medium, and metal ions generated from the metal react with the organic compound to produce MOFs.

[0040] It is preferable to perform the mechanochemical treatment without using metals or metal compounds other than the metal ion source. By using the metal ion source as a medium in the mechanochemical treatment, MOFs can be easily purified without being contaminated with other metals or foreign matter such as damaged media.

[0041] The temperature inside the container or environment during mechanochemical treatment may be room temperature, specifically, preferably in the range of 10°C to 40°C, more preferably in the range of 12°C to 35°C, and even more preferably in the range of 15°C to 30°C. If the object to be mechanochemically treated contains a liquid, the liquid may be heated to a temperature close to its boiling point before being added to the object. For example, if the object to be mechanochemically treated contains a liquid and the liquid is water, the water may be boiled at 100°C and then added to the object. If the liquid is water, it is estimated that if it is boiled at 100°C and then added to the object, the temperature of the object will be close to 90°C in parts.

[0042] The atmosphere inside the container or the environment during the mechanochemical treatment may be air or an inert atmosphere. The inert atmosphere refers to an atmosphere containing an inert gas such as nitrogen, argon, or helium, and may also be a mixed gas atmosphere containing hydrogen and nitrogen. The inert gas atmosphere may contain more than 0% by volume and not more than 20% by volume of oxygen.

[0043] The pressure inside the container or environment when performing mechanochemical treatment may be atmospheric pressure (0.101 MPa), may be greater than 0.101 MPa but not greater than 1 MPa, or may be reduced pressure lower than atmospheric pressure (0.101 MPa), and is preferably 0.00001 MPa (10 Pa) or greater, and more preferably 0.0001 MPa (100 Pa) or greater.

[0044] The time for mechanochemical treatment is preferably 10 minutes to 96 hours, more preferably 1.5 hours to 90 hours. The time for mechanochemical treatment varies depending on the type of agitator or grinder used and the size of the container in which the metal and organic compound react. For example, when mechanochemical treatment is performed using a paint shaker, the time is preferably 1 hour to 5 hours, and more preferably 1.5 hours to 3 hours. Furthermore, when mechanochemical treatment is performed using a media-agitating mill such as a bead mill or ball mill, the time is preferably 10 hours to 96 hours, more preferably 15 hours to 90 hours, and may be 85 hours or less, or may be 80 hours or less. The time for mechanochemical treatment does not need to be such that mechanical energy is continuously applied to the metal and organic compound; for example, mechanochemical treatment may be performed intermittently every 10 minutes. When mechanochemical treatment is performed intermittently, the total time is preferably 10 minutes to 96 hours. When the mechanochemical treatment is carried out using a stirrer or a pulverizer, the time during which the stirrer or the pulverizer is driven may be the time for the mechanochemical treatment.

[0045] The crystal structure of the MOF obtained by mechanochemical processing can be confirmed by, for example, X-ray diffraction (XRD) measurement, observing the XRD pattern, and comparing it with the X-ray diffraction pattern registered in the ICDD (JCPDS). X-ray diffraction measurements can be performed using a horizontal-type high-power X-ray diffractometer (e.g., RINT-TTR III, manufactured by Rigaku Corporation). For example, a Cu Kα (0.6 kW, 40 kV, 15 mA) X-ray source can be used.

[0046] The embodiments of the present invention encompass the following technical ideas. [1] A method for producing a metal-organic framework by mechanochemically treating an object containing a metal as a metal ion source and an organic compound as a bridging ligand, A method for producing a metal organic framework, wherein the mechanochemical treatment is carried out under conditions in which at least a part of the metal is solid and at least a part of the organic compound is solid. [2] The method for producing a metal-organic framework according to [1], wherein the metal-organic framework is obtained by a solid-state reaction between the metal and the organic compound. [3] The method for producing a metal organic framework according to [1] or [2], wherein the object further contains a liquid. [4] The method for producing a metal organic framework according to [3], wherein the liquid is in a range of more than 0 mass % to 99 mass % or less with respect to the total mass of the organic compound and the liquid. [5] The method for producing a metal organic framework according to [1] or [2], wherein the mechanochemical treatment is performed on the metal and the organic compound in a liquid. [6] The method for producing a metal-organic framework according to any one of [1] to [5], wherein the metal and the organic compound are brought into contact with each other multiple times. [7] The method for producing a metal organic framework according to any one of [1] to [6], wherein the metal is in the form of spherical, cylindrical, or polyhedral metal particles. [8] The method for producing a metal organic framework according to [7], wherein the maximum length of the metal particles is in the range of 1 μm or more and 100 mm or less. [9] The method for producing a metal organic framework according to [7] or [8], wherein the mass of each of the metal particles is within the range of 0.10 g or more and 100 g or less.

[10] The method for producing a metal organic framework according to any one of [1] to [9], wherein the metal has a Mohs hardness in the range of 1 or more and 10 or less.

[11] The method for producing a metal organic framework according to any one of [1] to

[10] , wherein the organic compound is in the form of a powder. [Example]

[0047] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0048] Example 1 The metal used was copper (Cu) spherical balls (80 pieces, 5 mm in diameter, each copper ball weighing 0.58 g). The copper material was pure copper. The Mohs hardness of the copper balls was 4. The copper balls were used so that they accounted for 99% by mass of the total mass of the copper balls and the organic compound described below. When the internal volume of the container of the ball mill in which the mechanochemical treatment is performed is taken as 100% by volume, the volume ratio of the copper (Cu) balls is 10% by volume. 0.50 g of powder of 1,3,5-benzenetricarboxylic acid (hereinafter also referred to as "BTC") was used as the organic compound to be used as the bridging ligand. The powder of the organic compound to be used as the bridging ligand was used so that it accounted for 1 mass % of the total mass of the copper balls and the organic compound. The liquid was added to the object containing the copper ball and BTC. The liquid used was N,N'-dimethylformamide (DMF). The liquid was added so that its mass was 79% when the total mass of the liquid and BTC was 100% by mass. Furthermore, when the internal volume of the ball mill container used for the mechanochemical treatment is taken as 100% by volume, the volume ratio of the liquid is 4% by volume. The amount of liquid added is 2.0 mL. The mechanochemical treatment was carried out using a ball mill with a container capacity of 50 mL. The target copper balls, BTC, and liquid were placed in a ball mill container, and the container was rotated at 133 rpm in an air atmosphere (0.101 MPa) at 20°C for 72 hours to perform mechanochemical treatment, yielding MOF (HKUST-1).

[0049] Example 2 The metal used was zinc (Zn) spherical shot balls with a protruding portion (120 balls, 4 mm diameter, 0.24 g each). The zinc was pure zinc. The Mohs hardness of zinc was 2. The zinc shot balls were used so that they accounted for 97% by mass of the total mass of the zinc shot balls and the organic compound described below. When the internal volume of the container of the ball mill in which the mechanochemical treatment is carried out is taken as 100% by volume, the volume ratio of the zinc shot balls is 8% by volume. 1.00 g of 2-methylimidazole (hereinafter also referred to as "2MeIm") powder was used as the organic compound serving as the bridging ligand. The powder of the organic compound serving as the bridging ligand was used in an amount of 3 mass % relative to the total mass of the zinc shot balls and the organic compound. The liquid was added to a target containing zinc shot-type balls and 2MeIm. The liquid used was water (H2O). The liquid was added so that its content was 50% by mass when the total mass of the liquid and 2MeIm was taken as 100% by mass. Furthermore, when the internal volume of the ball mill container used for the mechanochemical treatment is taken as 100% by volume, the volume ratio of the liquid is 2% by volume. The amount of liquid added is 1.0 mL. The mechanochemical treatment was carried out using a ball mill with a container capacity of 50 mL. The target zinc shot balls, 2MeIm, and liquid were placed in a ball mill container, and the container was rotated at 133 rpm in an air atmosphere (0.101 MPa) at 20°C for 24 hours to perform mechanochemical treatment, thereby obtaining MOF (ZIF-8).

[0050] Example 3 The metal used was iron (Fe) rod-shaped wire (2 mm x 3 mm (maximum length 2 mm or 3 mm), 150 pieces, each iron rod-shaped wire weighing 0.18 g). The iron material was pure iron. The Mohs hardness of iron was 5. The iron wire was used so that it accounted for 99 mass% of the total mass of the iron wire and the organic compound described below. When the internal volume of the container of the ball mill in which the mechanochemical treatment is performed is taken as 100% by volume, the volume ratio of the iron wire is 8% by volume. 0.25 g of BTC powder is used as the organic compound that serves as the bridging ligand. A liquid was added to the object containing the iron wire and BTC. The powder of the organic compound acting as a bridging ligand was added so that it was 1% by mass of the total mass of the iron wire and the organic compound. The liquid used was a mixture of 0.4 mL of water (H2O) and 0.1 mL of ethanol (EtOH). The liquid was added in an amount of 0.5 mL so that the total mass of the liquid and BTC was 66 mass % when the total mass of the liquid and BTC was 100 mass %. The mechanochemical treatment was carried out using a ball mill with a container capacity of 50 mL. Furthermore, when the internal volume of the container of the ball mill in which the mechanochemical treatment is carried out is taken as 100% by volume, the volume ratio of the liquid is 1% by volume. The target iron wire, BTC, and liquid were placed in the ball mill container, and the container was rotated at 133 rpm in an air atmosphere (0.101 MPa) at 20°C for 24 hours to perform mechanochemical treatment, yielding MOF (Fe(BTC)).

[0051] Example 4 The metal used was nickel (Ni) spherical balls (diameter 5 mm, 60 pieces, each nickel ball weighing 0.58 g). The nickel material was pure nickel. Nickel has a Mohs hardness of 5. The nickel balls were used so that they accounted for 99% by mass of the total mass of the nickel balls and the organic compound described below. When the internal volume of the container of the ball mill in which the mechanochemical treatment is carried out is taken as 100% by volume, the volume ratio of the nickel balls is 8% by volume. 0.50 g of BTC powder was used as the organic compound that would serve as a bridging ligand. The powder of the organic compound that would serve as a bridging ligand was used so that it accounted for 1 mass % of the total mass of the nickel balls and the organic compound. A liquid was added to the object containing the nickel balls and BTC. The liquid used was a mixture of 0.8 mL of water (H2O) and 0.2 mL of ethanol (EtOH). The liquid was added so that its content was 66% by mass when the total mass of the liquid and BTC was taken as 100% by mass. The mechanochemical treatment was carried out using a ball mill with a container capacity of 50 mL. Furthermore, when the internal volume of the ball mill container used for the mechanochemical treatment is taken as 100% by volume, the volume ratio of the liquid is 2% by volume. The amount of liquid added is 1.0 mL. The target nickel balls, BTC, and liquid were placed in a ball mill container, and mechanochemical treatment was carried out for 16 hours at 133 rpm in an air atmosphere (0.101 MPa) at 20°C to obtain MOF(Ni(BTC)). Note that the mechanochemical treatment was carried out in a dry state for 13 hours, followed by the addition of ethanol and a wet state for 3 hours.

[0052] Example 5 MOF (HKUST-1) was obtained in the same manner as in Example 1, except that a mixed liquid of 0.8 mL of water (H2O) and 0.2 mL of ethanol (EtOH) was used as the liquid. The liquid was added in an amount of 1.0 mL so that the total mass of the liquid and BTC was 62 mass % when the total mass of the liquid and BTC was 100 mass %. Furthermore, when the internal volume of the container of the ball mill in which the mechanochemical treatment is carried out is taken as 100% by volume, the volume ratio of the liquid is 2% by volume.

[0053] Example 6 MOF (HKUST-1) was obtained in the same manner as in Example 1, except that acetonitrile was used as the liquid. The liquid was added in an amount of 1.0 mL so that the total mass of the liquid and BTC was 61% by mass, assuming that the total mass of the liquid and BTC was 100% by mass. Furthermore, when the internal volume of the container of the ball mill in which the mechanochemical treatment is carried out is taken as 100% by volume, the volume ratio of the liquid is 2% by volume.

[0054] Example 7 MOF (HKUST-1) was obtained in the same manner as in Example 1, except that acetic acid was used as the liquid. The liquid was added in an amount of 3.0 mL so that the total mass of the liquid and BTC was 86% by mass, assuming that the total mass of the liquid and BTC was 100% by mass. Furthermore, when the internal volume of the container of the ball mill in which the mechanochemical treatment is carried out is taken as 100% by volume, the volume ratio of the liquid is 6% by volume.

[0055] Example 8 MOF (ZIF-8) was obtained in the same manner as in Example 2, except that hexane was used as the liquid. The liquid was added in an amount of 1.0 mL so that the total mass of the liquid and 2MeIm was 57% by mass, assuming that the total mass of the liquid and 2MeIm was 100% by mass. Furthermore, when the internal volume of the container of the ball mill in which the mechanochemical treatment is carried out is taken as 100% by volume, the volume ratio of the liquid is 2% by volume.

[0056] Example 9 MOF (ZIF-8) was obtained in the same manner as in Example 2, except that a paint shaker was used for the mechanochemical treatment. The internal volume of the paint shaker container was 50 mL. The mechanochemical treatment was carried out for 10 minutes using a paint shaker at 1110 cycles / min, followed by a 1-minute rest period. This process was repeated 10 times, for a total of 100 minutes.

[0057] Example 10 The metal used was spherical magnesium (Mg) balls (200 pieces, 5 mm in diameter, 0.24 g each). The magnesium material was pure magnesium. The Mohs hardness of magnesium is 2. The magnesium balls were used so that they accounted for 96% by mass of the total mass of the magnesium balls and the organic compound described below. When the internal volume of the container of the ball mill in which the mechanochemical treatment is performed is taken as 100% by volume, the volume ratio of the magnesium balls is 17% by volume. 1.00 g of 2,5-dihydroxyterephthalic acid (hereinafter also referred to as "DHTA") powder was used as the organic compound to be used as the bridging ligand. The powder of the organic compound to be used as the bridging ligand was used so that it accounted for 4 mass % of the total mass of the magnesium balls and the organic compound. The liquid was added to the object containing the magnesium ball and DHTA. The liquid used was water (H2O). The liquid was added so that its content was 83% by mass when the total mass of the liquid and DHTA was taken as 100% by mass. Furthermore, when the internal volume of the container of the ball mill in which the mechanochemical treatment is carried out is taken as 100% by volume, the volume ratio of the liquid is 10% by volume. The amount of the liquid added is 5.0 mL. The mechanochemical treatment was carried out using a ball mill with a container capacity of 50 mL. The target magnesium balls, DHTA, and liquid, as well as 0.005 mol of NaOH as an additive, were placed in a ball mill container, and the container was rotated at 133 rpm in an air atmosphere (0.101 MPa) at 20°C for 24 hours to obtain MOF (MOF-74-Mg).

[0058] Example 11 The metal used was spherical aluminum (Al) balls (diameter 5 mm, 160 pieces, each aluminum ball weighing 0.19 g). The aluminum material was pure aluminum. The Mohs hardness of aluminum was 2.5. The aluminum balls were used so that their weight was 83% by mass of the total mass of the aluminum balls and the organic compound described below. When the internal volume of the container of the ball mill in which the mechanochemical treatment is carried out is taken as 100% by volume, the volume ratio of the aluminum balls is 20% by volume. 1.00 g of 3,5-pyrazoledicarboxylic acid (hereinafter also referred to as "PZDC") powder was used as the organic compound to be used as the bridging ligand. The powder of the organic compound to be used as the bridging ligand was used so that it accounted for 4 mass % of the total mass of the aluminum balls and the organic compound. The liquid was added to the object containing the aluminum ball and PZDC. The liquid used was water (H2O). The liquid was added so that its content was 83% by mass when the total mass of the liquid and PZDC was taken as 100% by mass. Furthermore, when the internal volume of the container of the ball mill in which the mechanochemical treatment is carried out is taken as 100% by volume, the volume ratio of the liquid is 10% by volume. The amount of the liquid added is 5.0 mL. The mechanochemical treatment was carried out using a ball mill with a container capacity of 50 mL. The aluminum balls, PZDC, and liquid were placed in a ball mill container and heated to 90°C for 1 hour. Then, mechanochemical treatment was performed for 30 minutes at 133 rpm in an air atmosphere (0.101 MPa) at 20°C. This heating and mechanical treatment process was repeated 12 times to obtain MOF (MOF-303).

[0059] Comparative Example 1 The same procedure as in Example 2 was repeated, except that the metal, organic compound, and liquid were allowed to stand in a single container at 20°C for 110 hours without mechanochemical treatment. No MOF was obtained.

[0060] Comparative Example 2 The same procedure as in Example 3 was repeated, except that the metal, organic compound, and liquid were allowed to stand in a single container at 20°C for 40 hours without mechanochemical treatment. No MOF was obtained.

[0061] Comparative Example 3 The procedure was the same as in Example 4, except that the metal, organic compound, and liquid were allowed to stand in a single container at 20°C for 4 hours without mechanochemical treatment, and then 15 mL of ethanol (EtOH) was added and the mixture was allowed to stand at room temperature for 22 hours. No MOF was obtained.

[0062] Comparative Example 4 The same procedure as in Example 11 was repeated, except that the total amount of aluminum (Al) spherical balls used as the metal was 14.1 g, the amount of liquid (HO) added was 25 mL, and no mechanochemical treatment was performed. The metal, organic compound, and liquid were allowed to stand in one container at 90°C for 3 hours, and then at 20°C for 21 hours. An MOF could not be obtained.

[0063] Metals, organic compounds, and MOFs were evaluated in one of the following ways. The results are shown in the table. In the table, the symbol "-" indicates that there is no applicable item.

[0064] X-ray diffraction patterns of MOFs X-ray diffraction (XRD) measurements were performed on each MOF. A MiniFlex 600-C X-ray diffractometer manufactured by Rigaku Corporation was used. The X-ray source used was Cu Kα (0.15406 nm, 40 kV, 15 mA, output 0.6 kW). The scan rate was 10° / sec, and the scan step was 0.02°. The measurement results were used to determine whether MOFs were obtained. The results were graded as follows: "A" if a single phase of each MOF was confirmed; "B" if X-ray peaks of substances other than MOFs were observed in addition to the X-ray peaks of each MOF; and "C" if no X-ray peaks of each MOF were observed (i.e., MOFs were not obtained). Figure 1 shows the X-ray diffraction pattern of the MOF (HKUST-1) produced by the method of Example 1.

[0065] [Table 1]

[0066] [Table 2]

[0067] As shown in Tables 1 and 2, MOFs could be obtained by mechanochemical treatment of metals and organic compounds. MOFs could also be obtained by mechanochemical treatment when liquids of metals and organic compounds were added.

[0068] As shown in Figure 1, the MOF (HKUST-1) obtained by mechanochemically treating a metal and an organic compound using the production method of Example 1 had peak positions that matched the X-ray diffraction pattern registered with the ICDD.

[0069] [Table 3]

[0070] As shown in Table 3, MOFs could not be obtained by simply leaving metals and organic compounds to stand without mechanochemical treatment. [Industrial Applicability]

[0071] The MOFs produced by the production method of the present disclosure can be suitably used for adsorption and separation of gases and ions, gas separation, filters, reaction fields for polymer synthesis and the like, various sensors, particularly sensors for gas detection, and the like.

Claims

1. a metal serving as a metal ion source; and an organic compound serving as a bridging ligand, by mechanochemical treatment to obtain a metal organic framework, A method for producing a metal organic framework, wherein the mechanochemical treatment is carried out under conditions in which at least a part of the metal is solid and at least a part of the organic compound is solid.

2. The method for producing a metal-organic framework according to claim 1 , wherein the metal-organic framework is obtained by a solid-state reaction between the metal and the organic compound.

3. The method for producing a metal-organic framework according to claim 1 , wherein the object further comprises a liquid.

4. 4. The method for producing a metal organic framework according to claim 3, wherein the liquid is present in an amount in the range of more than 0 mass % to 99 mass % or less with respect to the total mass of the organic compound and the liquid.

5. The method for producing a metal-organic framework according to claim 1 , wherein the mechanochemical treatment is performed on the metal and the organic compound in a liquid.

6. The method for producing a metal-organic framework according to claim 1 , wherein the metal and the organic compound are contacted multiple times.

7. 3. The method for producing a metal organic framework according to claim 1 or 2, wherein the metal is in the form of spherical, cylindrical, or polyhedral metal particles.

8. 8. The method for producing a metal organic framework according to claim 7, wherein the maximum length of the metal particles is in the range of 1 μm or more and 100 mm or less.

9. 8. The method for producing a metal organic framework according to claim 7, wherein the mass of each of the metal particles is in the range of 0.10 g or more and 100 g or less.

10. 3. The method for producing a metal organic framework according to claim 1 or 2, wherein the metal has a Mohs hardness in the range of 1 or more and 10 or less.

11. The method for producing a metal organic framework according to claim 1 or 2, wherein the organic compound is in the form of a powder.

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