WO2013069721A1 - Metal complex, and adsorbent, absorbent and separator formed of same - Google Patents

Abstract

To provide a metal complex which has high water resistance. The above-mentioned problem is solved by a metal complex which is formed of a polyvalent carboxylic acid compound, at least one kind of metal ion that is selected from among ions of the metals in groups 2-13 of the periodic table, an organic ligand that is multidentately coordinatable to the metal ion, and an aliphatic monocarboxylic acid compound having 3-24 carbon atoms.

Description

Metal complex, adsorbent, occlusion material and separation material comprising the same

The present invention relates to a metal complex, and an adsorbent, an occlusion material and a separation material comprising the same. More specifically, it comprises a polyvalent carboxylic acid compound, at least one metal ion, an organic ligand capable of multidentate coordination with the metal ion, and an aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms. It relates to a metal complex. The metal complex of the present invention comprises an adsorbent for adsorbing a gas such as carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, a hydrocarbon having 1 to 4 carbon atoms, a rare gas, hydrogen sulfide, ammonia or organic vapor, It is preferable as a storage material for storing the gas and a separation material for separating the gas.

So far, various adsorbents have been developed in fields such as deodorization and exhaust gas treatment. Activated carbon is a representative example, and is widely used in various industries such as air purification, desulfurization, denitration, and removal of harmful substances by utilizing the excellent adsorption performance of activated carbon. In recent years, the demand for nitrogen has increased for semiconductor manufacturing processes, etc., and as a method for producing such nitrogen, a method of producing nitrogen from air by pressure swing adsorption method or temperature swing adsorption method using molecular sieve charcoal is used. Has been. Molecular sieve charcoal is also applied to various gas separation and purification such as hydrogen purification from methanol cracked gas.

When separating mixed gas by pressure swing adsorption method or temperature swing adsorption method, generally, molecular sieve charcoal or zeolite is used as the separation adsorbent, and separation is performed by the difference in the equilibrium adsorption amount or adsorption rate. . However, when separating the mixed gas based on the difference in the amount of equilibrium adsorption, the conventional adsorbents cannot selectively adsorb only the gas to be removed, so the separation factor becomes small, and the size of the apparatus is inevitable. . In addition, when separating the mixed gas based on the difference in adsorption speed, only the gas to be removed can be adsorbed depending on the type of gas, but it is necessary to perform adsorption and desorption alternately, and in this case, the apparatus still has to be large. I didn't get it.

On the other hand, polymer metal complexes have been developed as adsorbents that give better adsorption performance. The polymer metal complex has features such as (1) a large surface area and high porosity, (2) high designability, and (3) dynamic structural changes due to external stimuli. Expected characteristics.

However, in practical use, not only further improvement of adsorption performance, storage performance and separation performance but also improvement of durability against water contained in actual gas is required (for example, see Non-Patent Document 1).

After synthesizing a polymer metal complex consisting of 2-aminoterephthalic acid and a metal ion, an acid anhydride is reacted with the amino group at the 2-position of terephthalic acid constituting the polymer metal complex to form a polymer via an amide bond. It is known that water resistance is improved by introducing an alkyl chain into a metal complex (see Non-Patent Document 2). However, the method described in Non-Patent Document 2 requires two steps of a polymer metal complex production step and an alkyl chain introduction step, which complicates the production process. The particle size and morphology of the polymer metal complex are complicated. There is a problem that cannot be controlled. Non-Patent Document 2 does not mention any gas adsorption performance, occlusion performance, and separation performance of the metal complex.

Disclosed is a metal complex comprising terephthalic acid, at least one divalent metal selected from copper, rhodium, chromium, molybdenum, palladium, zinc and tungsten, and 4,4′-bipyridyl as an organic ligand. (See Patent Document 1). In Example 1, formic acid coexists when reacting copper ions with terephthalic acid, reacted at 40 ° C. for 3 days, and then reacted with 4,4′-bipyridyl for 2 days at room temperature. However, the use purpose of formic acid is not described, and no mention is made of the effect of monocarboxylic acid compounds other than formic acid on water resistance.

JP 2003-342260 A

Therefore, an object of the present invention is to provide a metal complex that can be used as a gas adsorbent, gas occlusion material or gas separation material having higher water resistance than conventional ones.

The present inventors have intensively studied, polyvalent carboxylic acid compounds, at least one metal ion, an organic ligand capable of multidentate coordination with the metal ion, and an aliphatic monocarboxylic acid having 3 to 24 carbon atoms. It has been found that the above object can be achieved by a metal complex comprising an acid compound, and the present invention has been achieved.

That is, according to the present invention, the following is provided.
(1) a polyvalent carboxylic acid compound, at least one metal ion selected from ions of metals belonging to Groups 2 to 13 of the periodic table, an organic ligand capable of multidentate coordination with the metal ion, A metal complex comprising an aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms.
(2) The metal complex according to (1), wherein the polyvalent carboxylic acid compound is a dicarboxylic acid compound.
(3) The multidentate organic ligand is 1,4-diazabicyclo [2.2.2] octane, pyrazine, 2,5-dimethylpyrazine, 4,4'-bipyridyl, 2,2'- Dimethyl-4,4′-bipyridine, 1,2-bis (4-pyridyl) ethyne, 1,4-bis (4-pyridyl) butadiyne, 1,4-bis (4-pyridyl) benzene, 3,6-di (4-pyridyl) -1,2,4,5-tetrazine, 2,2'-bi-1,6-naphthyridine, phenazine, diazapyrene, 2,6-di (4-pyridyl) -benzo [1,2- c: 4,5-c ′] dipyrrole-1,3,5,7 (2H, 6H) -tetron, 4,4′-bis (4-pyridyl) biphenylene, N, N′-di (4-pyridyl) -1,4,5,8-naphthalenetetracarboxydiimide, trans-1,2-bis ( 4-pyridyl) ethene, 4,4′-azopyridine, 1,2-bis (4-pyridyl) ethane, 4,4′-dipyridyl sulfide, 1,3-bis (4-pyridyl) propane, 1,2-bis The metal complex according to (1) or (2), which is at least one selected from (4-pyridyl) -glycol and N- (4-pyridyl) isonicotinamide.
(4) An adsorbent comprising the metal complex according to any one of (1) to (3).
(5) The adsorbent is carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbon having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia, sulfur oxide, nitrogen oxide, siloxane or organic vapor. The adsorbent according to (4), which is an adsorbent for adsorbing water.
(6) An occlusion material comprising the metal complex according to any one of (1) to (3).
(7) The occlusion material is an occlusion material for occluding carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbons having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia or organic vapor ( The occlusion material according to 6).
(8) A gas storage device including a pressure-resistant container that can be kept airtight and provided with a gas inlet / outlet, and provided with a gas storage space inside the pressure-resistant container, wherein the storage material according to (6) is provided in the gas storage space. Internal gas storage device.
(9) A gas vehicle provided with an internal combustion engine that obtains driving force from fuel gas supplied from the gas storage device according to (8).
(10) A separating material comprising the metal complex according to any one of (1) to (3).
(11) The separator is carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbon having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia, sulfur oxide, nitrogen oxide, siloxane, or organic vapor The separating material according to (10), which is a separating material for separating
(12) The separator is methane and carbon dioxide, hydrogen and carbon dioxide, nitrogen and carbon dioxide, ethylene and carbon dioxide, methane and ethane, ethane and ethylene, propane and propene, ethylene and acetylene, nitrogen and methane or air. The separation material according to (10), which is a separation material for separating methane.
(13) The separation method using the separation material according to (10), comprising a step of contacting the metal complex and the mixed gas in a pressure range of 0.01 to 10 MPa.
(14) The separation method according to (13), wherein the separation method is a pressure swing adsorption method.
(15) a polyvalent carboxylic acid compound, at least one metal ion selected from ions of metals belonging to Groups 2 to 13 of the periodic table, an organic ligand capable of multidentate coordination with the metal ion, The method for producing a metal complex according to any one of (1) to (3), wherein an aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms is reacted in a solvent to precipitate a metal complex.

According to the present invention, a polyvalent carboxylic acid compound, at least one metal ion selected from ions of metals belonging to Groups 2 to 13 of the periodic table, and an organic ligand capable of multidentate coordination with the metal ion, A metal complex comprising an aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms can be provided.

Since the metal complex of the present invention is excellent in the adsorption performance of various gases, carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbons having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia, sulfur oxidation It can be used as an adsorbent for adsorbing gases, nitrogen oxides, siloxanes or organic vapors.

In addition, since the metal complex of the present invention is excellent in the occlusion performance of various gases, carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbon having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia or It can also be used as a storage material for storing gases such as organic vapor.

Furthermore, since the metal complex of the present invention is excellent in the separation performance of various gases, carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbons having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia, It can also be used as a separating material for separating gases such as sulfur oxides, nitrogen oxides, siloxanes or organic vapors.

FIG. 4 is a schematic diagram of a jungle gym skeleton formed by coordination of 4,4′-bipyridyl at the axial position of a metal ion in a paddle wheel skeleton composed of a carboxylate ion and a zinc ion of terephthalic acid. It is a schematic diagram of a three-dimensional structure in which the jungle gym skeleton is double interpenetrated. It is a conceptual diagram of the gas vehicle provided with the gas storage apparatus. 3 is a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 1. FIG. 4 is a SEM photograph of the metal complex obtained in Synthesis Example 1. 2 is a ¹ H NMR spectrum measured by dissolving the metal complex obtained in Synthesis Example 1 in deuterated aqueous ammonia. 4 is a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 2. FIG. 4 is a SEM photograph of the metal complex obtained in Synthesis Example 2. 3 is a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 3. FIG. 4 is a SEM photograph of the metal complex obtained in Synthesis Example 3. 6 is a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 4. FIG. 4 is a SEM photograph of the metal complex obtained in Synthesis Example 4. 3 is a powder X-ray diffraction pattern of the metal complex obtained in Comparative Synthesis Example 1. FIG. 3 is a SEM photograph of the metal complex obtained in Comparative Synthesis Example 1. 4 is a powder X-ray diffraction pattern of the metal complex obtained in Comparative Synthesis Example 2. FIG. It is the result of having measured the sedimentation rate to the water of the metal complex obtained by the synthesis example 1, the synthesis example 2, the synthesis example 3, the comparative synthesis example 1, and the comparative synthesis example 2. FIG. It is a photograph at the time of water contact angle measurement of the metal complex obtained in Synthesis Example 1. 6 is a photograph of the metal complex obtained in Synthesis Example 2 when measured with a water contact angle. It is a photograph at the time of water contact angle measurement of the metal complex obtained in Synthesis Example 3. It is a photograph at the time of water contact angle measurement of the metal complex obtained in Synthesis Example 4. It is a water resistance evaluation result of the metal complex obtained by the synthesis example 1, the synthesis example 3, and the comparative synthesis example 2. FIG. It is an adsorption isotherm of carbon dioxide at 273 K of the metal complexes obtained in Synthesis Example 1, Synthesis Example 2, Synthesis Example 3, Comparative Synthesis Example 1 and Comparative Synthesis Example 2. 4 is an adsorption isotherm of ethylene at 273 K of the metal complex obtained in Synthesis Example 4. 6 is an adsorption / desorption isotherm of methane at 273 K of the metal complex obtained in Synthesis Example 3. FIG. 2 is an adsorption / desorption isotherm of methane at 273 K of the metal complex obtained in Comparative Synthesis Example 1. FIG. 2 is an adsorption / desorption isotherm of carbon dioxide and methane at 273 K of the metal complex obtained in Synthesis Example 3. FIG. 2 is an adsorption and desorption isotherm of carbon dioxide and methane at 273 K of the metal complex obtained in Comparative Synthesis Example 1. FIG. 3 is an adsorption / desorption isotherm of carbon dioxide and nitrogen at 313 K of the metal complex obtained in Synthesis Example 3. FIG. 3 is an adsorption / desorption isotherm of ethane and methane at 298 K of the metal complex obtained in Synthesis Example 3. FIG. 6 is an adsorption / desorption isotherm of carbon dioxide and methane at 293 K of the metal complex obtained in Synthesis Example 3. FIG. For the metal complex obtained in Synthesis Example 3, a breakthrough curve at 293 K, 0.8 MPa, space velocity 6 min ⁻¹ was measured using a mixed gas of methane and carbon dioxide having a volume ratio of methane: carbon dioxide = 60: 40. It is the result.

In the measurement result of the powder X-ray diffraction pattern, the horizontal axis represents the diffraction angle (2θ) and the vertical axis represents the diffraction intensity (Intensity) indicated by cps (Counts per Second) (FIGS. 4, 7, 9, 11, 13, and 15). ).

In the measurement result of the adsorption / desorption isotherm, the horizontal axis is the equilibrium pressure (Pressure) expressed in MPa, and the vertical axis is the equilibrium adsorption amount (Amount Adsorbed) expressed in mL (STP) / g (FIG. 22-30). In the measurement results of the adsorption / desorption isotherm, the gas adsorption amount (ads.) At each pressure when the pressure is increased and the gas adsorption amount (des.) At each pressure when the pressure is reduced are plotted. STP (standard state, Standard Temperature and Pressure) indicates a state of a temperature of 273.15 K and a pressure of 1 bar (10 ⁵ Pa).

In the measurement result of the breakthrough curve, the horizontal axis is the gas flow time (Time [min]) in minutes, and the vertical axis is the ratio of outlet gas (Outlet Gas Ratio [%]) (FIG. 31).

The metal complex of the present invention includes a polyvalent carboxylic acid compound, at least one metal ion selected from ions of metals belonging to Groups 2 to 13 of the periodic table, and an organic configuration capable of multidentate coordination with the metal ion. It consists of a ligand and an aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms.

The polyvalent carboxylic acid compound used in the present invention is not particularly limited, and any of dicarboxylic acid compounds, tricarboxylic acid compounds, tetracarboxylic acid compounds and the like can be used. For example, succinic acid, 1,4-cyclohexanedicarboxylic acid, fumaric acid, muconic acid, 2,3-pyrazinedicarboxylic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2 , 7-Naphthalenedicarboxylic acid, 9,10-anthracene dicarboxylic acid, 4,4′-biphenyl dicarboxylic acid, 4,4′-stilbene dicarboxylic acid, 2,5-pyridinedicarboxylic acid, 3,5-pyridinedicarboxylic acid, 2, , 5-thiophene dicarboxylic acid, 2,2′-dithiophene dicarboxylic acid and the like; trimesic acid, trimellitic acid, biphenyl-3,4 ′, 5-tricarboxylic acid, 1,3,5-tris (4 -Carboxyphenyl) benzene, 1,3,5-tris (4'-carboxy [1,1'-biphenyl) ] -4-yl) benzene, tricarboxylic acid compounds such as 2,4,6-tris (4-carboxyphenyl) -s-triazine; pyromellitic acid, 3,3 ′, 5,5′-tetracarboxydiphenylmethane, [ 1,1 ′: 4 ′, 1 ″] terphenyl-3,3 ″, 5,5 ″ -tetracarboxylic acid, 1,2,4,5-tetrakis (4-carboxyphenyl) benzene and other tetra Carboxylic acid compounds and the like can be used, and among them, dicarboxylic acid compounds are preferable. The polyvalent carboxylic acid compound may be used alone, or two or more polyvalent carboxylic acid compounds may be mixed and used. The metal complex of the present invention may be a mixture of two or more metal complexes composed of a single polyvalent carboxylic acid compound (preferably a dicarboxylic acid compound). The polyvalent carboxylic acid compound may be used in the form of an acid anhydride or an alkali metal salt.

The polyvalent carboxylic acid compound may further have a substituent in addition to the carboxyl group. The polyvalent carboxylic acid having a substituent is preferably an aromatic polyvalent carboxylic acid, and the substituent is preferably bonded to the aromatic ring of the aromatic polyvalent carboxylic acid. For example, the terephthalic acid may be 2-nitroterephthalic acid. The number of substituents may be 1, 2 or 3. The substituent is not particularly limited. For example, the substituent may be linear or branched such as an alkyl group (methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group). Having an alkyl group having 1 to 5 carbon atoms), halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), alkoxy group (methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, Isobutoxy group, tert-butoxy group, etc.), amino group, monoalkylamino group (such as methylamino group), dialkylamino group (such as dimethylamino group), formyl group, epoxy group, acyloxy group (acetoxy group, n-propanoyl) Oxy group, n-butanoyloxy group, pivaloyloxy group, benzoyloxy group, etc.), alcohol Aryloxycarbonyl group (methoxycarbonyl group, ethoxycarbonyl group, etc. n- butoxycarbonyl group), a nitro group, a cyano group, a hydroxyl group, an acetyl group, and a trifluoromethyl group.

Examples of the metal ions belonging to groups 2 to 13 of the periodic table used in the present invention include magnesium ion, calcium ion, scandium ion, zirconium ion, vanadium ion, chromium ion, molybdenum ion, manganese ion, iron ion, and cobalt. Ions, nickel ions, copper ions, zinc ions, cadmium ions, aluminum ions and the like can be used, among which manganese ions, cobalt ions, nickel ions, copper ions and zinc ions are preferable, and copper ions are more preferable. The metal ion is preferably a single metal ion, but may be a mixed metal complex containing two or more kinds of metal ions. The metal complex of the present invention may be a mixture of two or more metal complexes composed of a single metal ion.

The metal ion may be used in the form of a metal salt. Examples of the metal salt include magnesium salt, calcium salt, scandium salt, zirconium salt, vanadium salt, chromium salt, molybdenum salt, manganese salt, iron salt, cobalt salt, nickel salt, copper salt, zinc salt, cadmium salt, aluminum A salt or the like can be used, among which a manganese salt, a cobalt salt, a nickel salt, a copper salt and a zinc salt are preferable, and a copper salt is more preferable. The metal salt is preferably a single metal salt, but two or more metal salts may be mixed and used. Further, as these metal salts, organic acid salts such as acetates and formates, inorganic acid salts such as sulfates, nitrates, hydrochlorides, hydrobromides and carbonates can be used.

The multidentate organic ligand used in the present invention means a neutral ligand having at least two sites coordinated to a metal ion by an unshared electron pair. Examples of such an organic ligand capable of multidentate coordination include a bidentate ligand, a tridentate ligand, and a tetradentate ligand, and any of these may be used. Examples of the site coordinated to the metal ion by the lone pair include a nitrogen atom, an oxygen atom, a phosphorus atom, and a sulfur atom. The organic ligand capable of multidentate coordination is preferably a heteroaromatic ring compound, and more preferably a heteroaromatic ring compound having a nitrogen atom at a coordination site.
The multidentate organic ligand used in the present invention means a neutral ligand having at least two sites coordinated to a metal ion by an unshared electron pair. Examples of the site coordinated to the metal ion by the lone pair include a nitrogen atom, an oxygen atom, a phosphorus atom, and a sulfur atom. The organic ligand capable of multidentate coordination is preferably a heteroaromatic ring compound, and more preferably a heteroaromatic ring compound having a nitrogen atom at a coordination site.

Examples of the multidentate organic ligand include 1,4-diazabicyclo [2.2.2] octane, pyrazine, 2,5-dimethylpyrazine, 4,4′-bipyridyl, 2,2 ′. -Dimethyl-4,4'-bipyridine, 1,2-bis (4-pyridyl) ethyne, 1,4-bis (4-pyridyl) butadiyne, 1,4-bis (4-pyridyl) benzene, 3,6- Di (4-pyridyl) -1,2,4,5-tetrazine, 2,2'-bi-1,6-naphthyridine, phenazine, diazapyrene, 2,6-di (4-pyridyl) -benzo [1,2 -C: 4,5-c '] dipyrrole-1,3,5,7 (2H, 6H) -tetron, 4,4'-bis (4-pyridyl) biphenylene, N, N'-di (4-pyridyl) ) -1,4,5,8-naphthalenetetracarboxydiimide, Lance-1,2-bis (4-pyridyl) ethene, 4,4′-azopyridine, 1,2-bis (4-pyridyl) ethane, 4,4′-dipyridyl sulfide, 1,2-bis (4-pyridyl) Bidentate ligands such as propane, 1,2-bis (4-pyridyl) -glycol, N- (4-pyridyl) isonicotinamide, 2,4,6-tri (4-pyridyl) -1,3 , 5-triazine and other tetradentate ligands, and tetrakis (3-pyridyloxymethylene) methane, tetrakis (4-pyridyloxymethylene) methane and the like. The organic ligand capable of multidentate coordination may be used alone, or two or more organic ligands capable of multidentate coordination may be mixed and used. The metal complex of the present invention may be a mixture of two or more metal complexes composed of a single multidentate organic ligand.

As the organic ligand capable of multidentate coordination used in the present invention, an organic ligand capable of bidentate coordination having two sites coordinated to a metal ion by a lone pair is preferable. An organic ligand capable of bidentate coordination having a distance between sites coordinated to ions of 7.0 to 16.0 is more preferable. Here, the distance between the sites coordinated to the metal ion is half experience after performing conformational analysis with the molecular dynamics method MM3 using Scigress Explorer Professional Version 7.6.0.52 made by Fujitsu Limited. It is defined as the distance between two atoms at the farthest positions in the structural formula among the atoms coordinated to the metal ion in the most stable structure obtained by structural optimization by the mechanical molecular orbital method PM5.

Examples of the bidentate organic ligand having a distance between sites coordinated to metal ions of 7.0 to 16.0 mm include 4,4′-bipyridyl (7.061 Å), 4,4′-azopyridine (9.173Å), N- (4-pyridyl) isonicotinamide (9.342Å), trans-1,2-bis (4-pyridyl) ethene (9.386Å), 1,2 -Bis (4-pyridyl) ethyne (9.583Å), 1,4-bis (4-pyridyl) benzene (11.315Å), 3,6-di (4-pyridyl) -1,2,4,5- Tetrazine (11.204Å), 2,6-di (4-pyridyl) -benzo [1,2-c: 4,5-c ′] dipyrrole-1,3,5,7 (2H, 6H) -tetron ( 15.309Å), 4,4′-bis (4-pyridyl) biphenyle (15.570Å), N, N′-di (4-pyridyl) -1,4,5,8-naphthalenetetracarboxydiimide (15.533Å), etc. (numbers in parentheses are between nitrogen atoms in the compound) Represents distance). Among these, 4,4'-bipyridyl is particularly preferable.

Examples of the aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms used in the present invention include propionic acid (3 carbon atoms), butyric acid (4 carbon atoms), isobutyric acid (4 carbon atoms), valeric acid (carbon number). 5), pivalic acid (5 carbon atoms), caproic acid (6 carbon atoms), enanthic acid, cyclohexanecarboxylic acid (7 carbon atoms), caprylic acid (8 carbon atoms), octylic acid (8 carbon atoms), pelargonic acid ( 9 carbon atoms, capric acid (10 carbon atoms), lauric acid (12 carbon atoms), myristic acid (14 carbon atoms), pentadecylic acid (15 carbon atoms), palmitic acid (16 carbon atoms), margaric acid (carbon number) 17), stearic acid (18 carbon atoms), oleic acid (18 carbon atoms), linoleic acid (18 carbon atoms), α-linolenic acid (18 carbon atoms), tuberculostearic acid (19 carbon atoms), arachidic acid ( Charcoal Number 20), eicosapentaenoic acid (20 carbon atoms), behenic acid (22 carbon atoms), docosahexaenoic acid (22 carbon atoms), lignoceric acid (24 carbon atoms), or the like can be used. Among these, aliphatic monocarboxylic acid compounds having 5 to 20 carbon atoms are preferable, and pivalic acid, octylic acid, lauric acid, myristic acid, palmitic acid and stearic acid are particularly preferable. Formic acid (carbon number 1) and acetic acid (carbon number 2) having 2 or less carbon atoms do not exhibit sufficient water resistance. In addition, when the number of carbon atoms is 25 or more, the proportion of the portion (alkyl chain) that does not contribute to gas adsorption increases, so the adsorption amount per unit weight or unit volume decreases.

The proportion of the aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms is not particularly limited as long as the effects of the present invention are not impaired, but the composition ratio of the polyvalent carboxylic acid compound to the monocarboxylic acid compound is 100 Is preferably in the range of 1 to 5,000: 1, more preferably in the range of 250: 1 to 2,500: 1.

The composition ratio of the polycarboxylic acid compound and the monocarboxylic acid compound constituting the metal complex of the present invention is analyzed using gas chromatography, high performance liquid chromatography, or NMR after decomposing the metal complex into a uniform solution. However, the present invention is not limited to these.

The aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms may coexist from the initial stage of the reaction or may be added at the late stage of the reaction.

The metal complex of the present invention may further contain a monodentate organic ligand as long as the effects of the present invention are not impaired. The monodentate organic ligand means a neutral ligand having one site coordinated to a metal ion by an unshared electron pair. As the monodentate organic ligand, for example, furan, thiophene, pyridine, quinoline, isoquinoline, acridine, trimethylphosphine, triphenylphosphine, triphenylphosphite, methylisocyanide and the like can be used, and pyridine is particularly preferable. The monodentate organic ligand may have a hydrocarbon group having 1 to 23 carbon atoms as a substituent.

When the metal complex of the present invention contains the monodentate organic ligand, the ratio is not particularly limited as long as the effect of the present invention is not impaired, but the bidentate organic ligand and the monodentate organic ligand are not limited. The composition ratio with the ligand is preferably in the range of a molar ratio of 1: 5 to 1: 1,000, and more preferably in the range of 1:10 to 1: 100. The composition ratio can be determined by analysis using gas chromatography, high performance liquid chromatography, NMR, or the like, but is not limited thereto.

The metal complex includes a polyvalent carboxylic acid compound, at least one metal salt selected from salts of metals belonging to Groups 2 to 13 of the periodic table, and an organic ligand capable of multidentate coordination with the metal ion. Can be produced by reacting an aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms in a gas phase, a liquid phase or a solid phase, but for several hours to several days in a solvent under normal pressure. It is preferable to make it react and to precipitate a metal complex. For example, an aqueous solution or organic solvent solution of a metal salt and an aqueous solution or organic solvent solution containing a polyvalent carboxylic acid compound, an organic ligand capable of multidentate coordination, and an aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms Can be mixed and reacted under normal pressure to obtain the metal complex of the present invention.

The mixing ratio of the metal salt and the polyvalent carboxylic acid compound when producing the metal complex is preferably within the range of the molar ratio of metal salt: polyvalent carboxylic acid compound = 1: 5 to 8: 1, and 1: 3 to 6 A molar ratio in the range of 1 is more preferable. Even if the reaction is carried out in a range other than this, the desired metal complex can be obtained, but this is not preferable because the yield is lowered and the side reaction is also increased.

When the metal complex is produced, the mixing ratio of the metal salt and the organic ligand capable of multidentate coordination is such that the molar ratio of metal salt: organic ligand capable of multidentate coordination is 1: 3 to 3: 1. Within the range, a molar ratio within the range of 1: 2 to 2: 1 is more preferable. In other ranges, the yield of the target metal complex decreases, and purification of the metal complex obtained by leaving unreacted raw materials becomes difficult.

When the metal complex is produced, the mixing ratio of the polyvalent carboxylic acid compound and the aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms is as follows: polyvalent carboxylic acid compound: monocarboxylic acid compound = 1: 5 to 1: 1,000. Is preferably within the range of the molar ratio of 1:10 to 1: 100. In other ranges, the yield of the target metal complex decreases, and purification of the metal complex obtained by leaving unreacted raw materials becomes difficult.

The molar concentration of the polyvalent carboxylic acid compound in the mixed solution for producing the metal complex is preferably 0.01 to 5.0 mol / L, and more preferably 0.05 to 2.0 mol / L. Even if the reaction is performed at a concentration lower than this, the desired metal complex can be obtained, but this is not preferable because the yield decreases. If the concentration is higher than this, the solubility is lowered and the reaction does not proceed smoothly.

The molar concentration of the metal salt in the mixed solution for producing the metal complex is preferably 0.01 to 5.0 mol / L, and more preferably 0.05 to 2.0 mol / L. Even if the reaction is performed at a concentration lower than this, the desired metal complex can be obtained, but this is not preferable because the yield decreases. Further, at a concentration higher than this, unreacted metal salt remains, and purification of the obtained metal complex becomes difficult.

The molar concentration of the organic ligand capable of multidentate coordination in the mixed solution for producing the metal complex is preferably 0.005 to 2.5 mol / L, and more preferably 0.025 to 1.0 mol / L. Even if the reaction is performed at a concentration lower than this, the desired metal complex can be obtained, but this is not preferable because the yield decreases. If the concentration is higher than this, the solubility is lowered and the reaction does not proceed smoothly.

As the solvent used for the production of the metal complex, an organic solvent, water, or a mixed solvent thereof can be used. Specifically, methanol, ethanol, propanol, diethyl ether, dimethoxyethane, tetrahydrofuran, hexane, cyclohexane, heptane, benzene, toluene, methylene chloride, chloroform, acetone, ethyl acetate, acetonitrile, N, N-dimethylformamide, water or These mixed solvents can be used. The reaction temperature is preferably 253 to 423K.

The completion of the reaction can be confirmed by quantifying the remaining amount of the raw material by gas chromatography or high performance liquid chromatography. After completion of the reaction, the obtained mixed solution is subjected to suction filtration to collect a precipitate, washed with an organic solvent, and then vacuum dried at about 373 K for several hours to obtain the metal complex of the present invention.

The metal complex of the present invention does not adsorb gas when the solvent is adsorbed. Therefore, when the metal complex of the present invention is used as an adsorbent, occlusion material, or separation material, it is necessary to vacuum-dry the metal complex obtained in advance to remove the solvent in the pores. Usually, vacuum drying may be performed at a temperature at which the metal complex is not decomposed (for example, 293 K to 523 K or less), but the temperature is preferably lower (for example, 293 K to 393 K or less). This operation can be replaced by cleaning with supercritical carbon dioxide, and is more effective.

The metal complex of the present invention has a one-dimensional, two-dimensional, or three-dimensional integrated structure depending on the polyvalent carboxylic acid compound used, the metal ion, and the type of organic ligand that can be multidentately coordinated with the metal ion.

The particle size and morphology of the metal complex of the present invention can be controlled by the type and amount of the aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms to be used.

As an example, a metal complex having terephthalic acid as a polyvalent carboxylic acid compound, zinc ion as a metal ion, and 4,4'-bipyridyl as an organic ligand capable of multidentate coordination will be described in detail. The metal complex has a double jungle gym skeleton formed by coordination of 4,4'-bipyridyl at the axial position of the metal ion in the paddle wheel skeleton composed of the carboxylate ion and metal ion of terephthalic acid. It has an intrusive three-dimensional structure. A schematic diagram of a jungle gym skeleton is shown in FIG. 1, and a schematic diagram of a three-dimensional structure in which the jungle gym skeleton is double-interpenetrated is shown in FIG.

The above “jungle gym skeleton” is an organic compound capable of multidentate coordination such as 4,4′-bipyridyl at the axial position of a metal ion in a paddle wheel skeleton composed of a polyvalent carboxylic acid compound such as terephthalic acid and a metal ion. It means a jungle gym-like three-dimensional structure formed by linking ligands and connecting two-dimensional lattice-like sheets composed of polyvalent carboxylic acid compounds and metal ions. “A structure in which multiple jungle gym skeletons interpenetrate” is a three-dimensional integrated structure in which a plurality of jungle gym skeletons penetrate each other so as to fill the pores.

The fact that the metal complex has a structure in which the jungle gym skeleton is interpenetrated can be confirmed by, for example, single crystal X-ray structure analysis, powder X-ray crystal structure analysis, but is not limited thereto.

When the polyvalent carboxylic acid compound is reacted with the metal ion, the reaction of the metal ion with the polyvalent carboxylic acid compound and the metal ion with the aliphatic group are allowed to coexist with an aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms. The reaction with the monocarboxylic acid compound will compete. Aliphatic monocarboxylic acid compounds can be regarded as terminators in crystal growth reactions, while the reaction between metal ions and aliphatic monocarboxylic acid compounds is reversible, so the crystal nucleation rate and crystal growth rate are controlled. Is done. As a result, particle size and morphology can be controlled.

When the aliphatic monocarboxylic acid compound is coordinated, there is only one coordination site of the monocarboxylic acid compound, so the crystal growth at the coordination site is stopped, and the particle size and morphology are also controlled. Considering this crystal growth mechanism, since the aliphatic monocarboxylic acid compound is unevenly distributed at the end of the crystal growth, that is, the crystal surface, the alkyl chain derived from the aliphatic monocarboxylic acid compound is exposed on the crystal surface of the metal complex. And since the approach of water to a metal ion is inhibited by the hydrophobic effect and steric effect of the alkyl chain, the decomposition reaction of the metal complex accompanied by the dissociation of the coordination bond is suppressed, and the water resistance is improved.

The uneven distribution of the aliphatic monocarboxylic acid compound on the crystal surface of the metal complex can be confirmed, for example, by time-of-flight secondary ion mass spectrometry.

Although the above water resistance improvement mechanism is estimated, even if it does not follow the above mechanism, it is included in the technical scope of the present invention as long as it satisfies the requirements defined in the present invention.

The water repellency of the metal complex of the present invention can be evaluated by measuring the water contact angle. The metal complex of the present invention preferably has a water contact angle of 90 ° or more, and more preferably 150 ° or more.

The hydrophobicity of the metal complex of the present invention can be evaluated by measuring the sedimentation rate when the metal complex is floated on the water surface. For example, when a powdered metal complex is floated on the surface of water and the sedimentation rate is measured, if the metal complex is hydrophobic, it repels water and agglomerates to form a lump, so it sinks faster due to an increase in its own weight. On the other hand, if the metal complex is hydrophilic, aggregation does not occur, so the particle size of the metal complex remains small and the sedimentation rate is slow. In other words, the faster the sedimentation rate, the more hydrophobic the metal complex is, and it is expected to exhibit high water resistance.

Furthermore, the water resistance of the metal complex of the present invention can be evaluated by exposing the metal complex to water vapor and measuring the amount of adsorption with time. In other words, even when the metal complex is placed under high humidity, if there is no significant change in the adsorption amount or adsorption rate retention rate of the metal complex, it means that the metal complex has water resistance.

The metal complex of the present invention is excellent in adsorption performance, occlusion performance, and separation performance of various gases. Therefore, the metal complex of the present invention is useful as an adsorbent, a storage material, and a separation material for various gases, and these are also included in the scope of the present invention.

Examples of the adsorbent, occlusion material, and separation material of the present invention include carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, and hydrocarbons having 1 to 4 carbon atoms (methane, ethane, ethylene, acetylene, propane, propene, methyl Acetylene, propadiene, butane, 1-butene, isobutene, 1-butyne, 2-butyne, 1,3-butadiene, methylallene, etc.), noble gases (such as helium, neon, argon, krypton, xenon), hydrogen sulfide, ammonia , Sulfur oxides, nitrogen oxides, siloxanes (hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, etc.), water vapor or organic vapor can be suitably used to adsorb, occlude, and separate gases. In the separation material of the present invention, in particular, carbon dioxide in methane, carbon dioxide in hydrogen, carbon dioxide in nitrogen, carbon dioxide in ethylene, ethane in methane, ethane in ethylene, and propene in propane It is suitable for separating acetylene in ethylene, methane in nitrogen, methane in air, or the like by a pressure swing adsorption method or a temperature swing adsorption method.

Organic vapor means vaporized organic substance that is liquid at room temperature and pressure. Examples of such organic substances include alcohols such as methanol and ethanol; amines such as trimethylamine; aldehydes such as acetaldehyde; pentane, isoprene, hexane, cyclohexane, heptane, methylcyclohexane, octane, 1-octene, cyclooctane, C5-C16 aliphatic hydrocarbons such as cyclooctene, 1,5-cyclooctadiene, 4-vinyl-1-cyclohexene, 1,5,9-cyclododecatriene; aromatics such as benzene, toluene and xylene Hydrocarbons; ketones such as acetone and methyl ethyl ketone; esters such as methyl acetate and ethyl acetate; halogenated hydrocarbons such as methyl chloride and chloroform.

The adsorbent, occlusion material, and separation material of the present invention are cellulose acetate, polyamide, polyester, polycarbonate, polysulfone, polyethersulfone, polyolefin, polytetrafluoro, if necessary, as long as the effects of the present invention are not impaired. They may be combined with natural or synthetic fibers such as ethylene derivatives or paper, or inorganic fibers such as glass or alumina.

The usage form of the adsorbent, occlusion material and separation material in the present invention is not particularly limited. For example, the metal complex may be used as a powder, pellets, films, sheets, plates, pipes, tubes, rods, granules, various deformed shapes, fibers, hollow fibers, woven fabrics, knitted fabrics, non-woven fabrics, etc. You may shape | mold and use.

There is no particular limitation on the method for producing the pellet containing the adsorbent, occlusion material or separation material of the present invention, and any of the conventionally known pelletization methods can be adopted, but the density of the pellet can be increased. A tableting method is preferred.

The method for producing a sheet containing the adsorbent, occlusion material or separation material of the present invention is not particularly limited, and any conventionally known sheeting method can be adopted, but the density of the sheet can be further increased. Wet paper making is preferred. The wet papermaking method is a manufacturing method in which raw materials are dispersed in water, filtered through a net, and dried.

As an example of the heteromorphic shape, a honeycomb shape can be given. Any of the conventionally known processing methods can be adopted as a method for forming a sheet containing the adsorbent, occlusion material or separation material of the present invention into a honeycomb shape. In addition, in the present invention, the honeycomb shape refers to a continuous hollow column body such as a square, sinusoidal, or roll-shaped hollow polygonal column or a cylinder in addition to a hexagonal cross section. For example, in order to make a sheet containing the adsorbent, occlusion material or separation material of the present invention into a sinusoidal honeycomb shape, the sheet is first shaped into a waveform through a shaping roll, and one side of the corrugated sheet or Join flat sheets on both sides. This is laminated to form a sinusoidal honeycomb filter. Here, it is normal to attach and fix an adhesive at the top of the corrugation, but when the corrugated sheets are laminated, the flat sheet between them is necessarily fixed, so it is not always necessary to apply the adhesive Absent. In addition, when attaching an adhesive agent, it is necessary to use what does not impair the adsorption capacity of the sheet. As the adhesive, for example, corn starch, vinyl acetate resin, acrylic resin, or the like can be used. In order to improve the gas adsorption performance, it is preferable to reduce the adhesion pitch of the corrugated sheet and reduce the peak height. The pitch is preferably 0.5 to 8 mm, and the peak height is preferably 0.4 to 5 mm.

The metal complex of the present invention or the storage material of the present invention can also be used in a gas storage device taking advantage of its storage performance. As an example of a gas storage device, a pressure-resistant container that can be kept airtight and has a gas inlet / outlet is provided. There is a gas storage device. By press-fitting a desired gas into the gas storage device, the gas can be adsorbed and stored in the internal storage material. When taking out the gas from the gas storage device, the gas can be desorbed by opening the pressure valve and reducing the internal pressure in the pressure vessel. When the occlusion material is installed in the gas storage space, the metal complex of the present invention may be embedded in powder form, but from the viewpoint of handleability, etc., a pellet shaped product obtained by molding the metal complex of the present invention is used. May be.

FIG. 3 shows an example of a gas vehicle equipped with the above-described gas storage device of the present invention. The gas storage device can store fuel gas in the gas storage space 3, and can be suitably used as the fuel tank 1 of a gas vehicle or the like. This gas vehicle includes the gas storage device in which the metal complex of the present invention is incorporated as a fuel tank 1, obtains natural gas stored in the tank from the fuel tank 1, and generates a combustion oxygen-containing gas (for example, air) ) And an engine as an internal combustion engine that obtains a driving force by combustion. The fuel tank 1 includes a pressure vessel 2 and includes a pair of outlets 5 and 6 as inlets and outlets through which gas to be stored can enter and exit the container 2. A pair of valves 7 constituting an airtight holding mechanism that can be maintained in a pressure state are provided at each of the entrances and exits. Natural gas as fuel is filled into the fuel tank 1 in a pressurized state at a gas station. The fuel tank 1 includes a storage material 4 made of the metal complex of the present invention, and the storage material 4 adsorbs natural gas (such as a gas containing methane as a main component) at room temperature and under pressure. . Then, when the valve 7 on the outlet side is opened, the gas in the adsorbed state is desorbed from the occlusion material 4 and sent to the engine side for combustion to obtain travel driving force.

Since the fuel tank 1 includes the metal complex of the present invention, the gas compression ratio can be increased with respect to the apparent pressure as compared with the fuel tank not filled with the occlusion material. As a result, the thickness of the tank can be reduced and the weight of the entire gas storage device can be reduced, which is useful for gas vehicles and the like. Further, the fuel tank 1 is normally in a normal temperature state, and is not particularly cooled. The temperature of the fuel tank 1 is relatively high, for example, in summer, when the temperature rises. Even in such a high temperature range (about 298 to 333 K), the occlusion material of the present invention can keep its adsorption capacity high and is useful.

The separation method includes a step of bringing the gas into contact with the metal complex of the present invention or the separation material of the present invention under conditions where the gas can be adsorbed to the metal complex. The adsorption pressure and the adsorption temperature, which are conditions under which the gas can be adsorbed on the metal complex, can be appropriately set according to the type of substance to be adsorbed. For example, the adsorption pressure is preferably from 0.01 to 10 MPa, more preferably from 0.1 to 3.5 MPa. Further, the adsorption temperature is preferably 195K to 343K, and more preferably 273 to 313K.

The separation method can be a pressure swing adsorption method or a temperature swing adsorption method. When the separation method is a pressure swing adsorption method, the separation method further includes a step of increasing the pressure from the adsorption pressure to a pressure at which gas can be desorbed from the metal complex. The desorption pressure can be appropriately set according to the type of substance to be adsorbed. For example, the desorption pressure is preferably 0.005 to 2 MPa, more preferably 0.01 to 0.1 MPa. When the separation method is a temperature swing adsorption method, the separation method further includes a step of raising the temperature from the adsorption temperature to a temperature at which the gas can be desorbed from the metal complex. The desorption temperature can be appropriately set according to the type of substance to be adsorbed. For example, the desorption temperature is preferably 303 to 473K, and more preferably 313 to 373K.

When the separation method is a pressure swing adsorption method or a temperature swing adsorption method, the step of bringing the gas into contact with the metal complex and the step of changing the pressure to a temperature or a temperature at which the gas can be desorbed from the metal complex are repeated as appropriate. Can do.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. Analysis and evaluation in the following examples and comparative examples were performed as follows.

(1) Measurement of powder X-ray diffraction pattern Using an X-ray diffractometer, the range of diffraction angle (2θ) = 5 to 50 ° was scanned at a scanning speed of 1 ° / min and measured by a symmetric reflection method. Details of the analysis conditions are shown below.
<Analysis conditions>
Apparatus: SmartLab, manufactured by Rigaku Corporation
X-ray source: CuKα (λ = 1.5418Å) 45 kV 200 mA
Goniometer: Horizontal goniometer Detector: D / teX Ultra
Step width: 0.02 °
Slit: Divergent slit = 2/3 °
Receiving slit = 0.3mm
Scattering slit = 2/3 °

(2) Determination of aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms The metal complex was dissolved in deuterated ammonia water to obtain a uniform solution, ¹ H NMR measurement was performed, and calculation was performed from the integral ratio of the obtained spectrum. Details of the analysis conditions are described below.
<Analysis conditions>
Apparatus: Advance600 manufactured by Bruker BioSpin Corporation
Resonance frequency: 600 MHz
Solvent: Heavy ammonia water Reference substance: Sodium 3- (trimethylsilyl) propanoate-d4
Temperature: 298K
Flip angle: 30 °
Pulse repetition time: 5.5 seconds Integration count: 2,000 times

(3) SEM observation It observed about the metal complex after an electroconductive process using the scanning electron microscope. Details of the analysis conditions are shown below.
<Analysis conditions>
Equipment: Hitachi High-Technologies Corporation S-3000N
Filament: Tungsten hairpin acceleration voltage: 10.0 kV
Magnification: 3,000 times

(4) Sedimentation rate measurement Using a high-precision surface tension meter, the time-dependent change (sedimentation rate) of the sedimentation weight of the metal complex dispersed on the water surface was measured. Details of the analysis conditions are shown below.
<Analysis conditions>
Apparatus: DY-700 manufactured by Kyowa Interface Science Co., Ltd.
Measurement mode: Paper penetration measurement

(5) Water contact angle measurement The water contact angle was measured using a contact angle meter (based on JIS R3257). At this time, prior to the measurement, the sample was filled without applying force to the powder X-ray diffraction sample holder, and the upper surface of the sample was smoothed with a glass plate. Details of the analysis conditions are shown below.
<Analysis conditions>
Apparatus: DM-700 manufactured by Kyowa Interface Science Co., Ltd.
Liquid volume: 3μL
Waiting time after landing: 0.1 seconds Analysis method: θ / 2 method

(6) Measurement of adsorption isotherm or adsorption / desorption isotherm The gas adsorption / desorption amount was measured by a volume method using a high-pressure gas adsorption amount measuring device, and an adsorption isotherm or adsorption / desorption isotherm was created (JIS Z8831- 2). At this time, the sample was dried at 373 K and 0.5 Pa for 5 hours prior to measurement to remove adsorbed water and the like. Details of the analysis conditions are shown below.
<Analysis conditions>
Equipment: BELSORP-HP manufactured by Nippon Bell Co., Ltd.
Equilibrium waiting time: 500 seconds

(7) Water vapor exposure test A water vapor exposure test was performed on the metal complexes obtained in the synthesis examples and comparative synthesis examples using a low temperature and temperature and humidity chamber PL-2KP manufactured by Espec Co., Ltd., and used as an index for water resistance evaluation. Sampling was carried out 8 hours, 24 hours and 48 hours after the start of exposure to water vapor, and the amount of carbon dioxide adsorbed at 273 K was measured by the volumetric method, and an adsorption isotherm was prepared in the same manner as above.
<Water vapor exposure conditions>
Temperature: 353K
Relative humidity: 80%

<Synthesis Example 1>
Under a nitrogen atmosphere, 5.86 g (23 mmol) of copper sulfate pentahydrate, 3.90 g (23 mmol) of terephthalic acid, and 71.9 g (704 mmol) of pivalic acid were dissolved in 4,000 mL of methanol and stirred at 313 K for 21 hours. The precipitated metal complex was recovered by suction filtration, and then washed with methanol three times to isolate the intermediate. Next, the isolated intermediate was dispersed in 2,000 mL of methanol under a nitrogen atmosphere, 1.83 g (12 mmol) of 4,4′-bipyridyl was added, and the mixture was stirred at 313 K for 3 hours. At this time, the reaction solution remained suspended. The metal complex was recovered by suction filtration, and then washed with methanol three times. Then, it dried at 373 K and 50 Pa for 8 hours, and obtained the target metal complex 0.817g (yield 11%). The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG. As a result of the powder X-ray crystal structure analysis, it was found that the obtained metal complex had a structure in which the jungle gym skeleton was double interpenetrated. The powder X-ray crystal structure analysis results are shown below. Moreover, the SEM photograph of the obtained metal complex is shown in FIG.
Triclinic (P-1)
a = 7.887355Å
b = 8.994070cm
c = 10.79101mm
α = 67.14528 °
β = 80.73986 °
γ = 79.331579 °
R _wp = 2.30%
R _I = 4.96%

10 mg of the obtained metal complex was dissolved in 700 mg of heavy ammonia water (containing 0.4 wt% of sodium 3- (trimethylsilyl) propanoate-d4 as a reference substance), and ¹ H NMR measurement was performed. The obtained spectrum is shown in FIG. As a result of analyzing the spectrum, when the integral value of the peak of 7.925 ppm (s, 4H) attributed to protons at the 2nd, 3rd, 5th and 6th positions of terephthalic acid was set to 1,000, pivalic acid Since the integrated value of the peak at 1.122 ppm (s, 9H) attributed to the proton of tert-butyl group was 3.345, the molar ratio of terephthalic acid and pivalic acid contained in the metal complex was terephthalic acid. : Pivalic acid was found to be 673: 1. In FIG. 6, the broad signal around 3.9 ppm is due to water.

<Synthesis Example 2>
Under a nitrogen atmosphere, 5.86 g (23 mmol) of copper sulfate pentahydrate, 3.90 g (23 mmol) of terephthalic acid, and 101 g (704 mmol) of octylic acid were dissolved in 4,000 mL of methanol and stirred at 313 K for 43 hours. The precipitated metal complex was recovered by suction filtration, and then washed with methanol three times to isolate the intermediate. Next, the isolated intermediate was dispersed in 2,000 mL of methanol under a nitrogen atmosphere, 1.83 g (12 mmol) of 4,4′-bipyridyl was added, and the mixture was stirred at 313 K for 5 hours. At this time, the reaction solution remained suspended. The metal complex was recovered by suction filtration, and then washed with methanol three times. Then, it dried at 373K and 50 Pa for 8 hours, and obtained the target metal complex 1.12g (yield 16%). FIG. 7 shows a powder X-ray diffraction pattern of the obtained metal complex. From comparison between FIG. 4 and FIG. 7, it is clear that the obtained metal complex has the same structure as the metal complex obtained in Synthesis Example 1. Moreover, the SEM photograph of the obtained metal complex is shown in FIG.

Using the same method as in Synthesis Example 1, the integrated value of the peak at 7.925 ppm (s, 4H) attributed to protons at the 2nd, 3rd, 5th and 6th positions of terephthalic acid, Included in the resulting metal complex from the ratio of the combined value of the 0.742 ppm (s, 3H) peak attributed to the chain and side chain protons to the 0.871 ppm (s, 3H) peak. As a result of calculating the molar ratio of terephthalic acid to octylic acid, it was found that terephthalic acid: octylic acid = 252: 1.

<Synthesis Example 3>
Under a nitrogen atmosphere, 2.93 g (12 mmol) of copper sulfate pentahydrate, 1.95 g (12 mmol) of terephthalic acid and 74.6 g (370 mmol) of lauric acid were dissolved in 2,000 mL of methanol and stirred at 313 K for 18 hours. The precipitated metal complex was recovered by suction filtration, and then washed with methanol three times to isolate the intermediate. Next, the isolated intermediate was dispersed in 1,800 mL of methanol under a nitrogen atmosphere, 0.937 g (6.0 mmol) of 4,4′-bipyridyl was added, and the mixture was stirred at 298 K for 7 hours. At this time, the reaction solution remained suspended. The metal complex was recovered by suction filtration, and then washed with methanol three times. Then, it dried at 373 K and 50 Pa for 8 hours, and obtained the target metal complex 0.400g (yield 11%). The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG. From comparison between FIG. 4 and FIG. 9, it is clear that the obtained metal complex has the same structure as the metal complex obtained in Synthesis Example 1. Moreover, the SEM photograph of the obtained metal complex is shown in FIG.

Using the same method as in Synthesis Example 1, the integrated value of the peak of 7.925 ppm (s, 4H) attributed to protons at the 2nd, 3rd, 5th and 6th positions of terephthalic acid and the carboxyl of lauric acid As a result of calculating the molar ratio of terephthalic acid and lauric acid contained in the obtained metal complex from the ratio of the integrated value of the peak of 2.169 ppm (s, 2H) attributed to the methylene group proton at the α group, It was found that acid: lauric acid = 687: 1.

<Synthesis Example 4>
Under a nitrogen atmosphere, 5.86 g (23 mmol) of copper sulfate pentahydrate, 3.90 g (23 mmol) of terephthalic acid, and 141 g (704 mmol) of lauric acid were dissolved in 4,000 mL of methanol and stirred at 313 K for 18 hours. The precipitated metal complex was recovered by suction filtration, and then washed with methanol three times to isolate the intermediate. Next, the isolated intermediate was dispersed in 2,000 mL of methanol under a nitrogen atmosphere, 2.14 g (12 mmol) of 1,2-bis (4-pyridyl) ethene was added, and the mixture was stirred at 313 K for 4 hours. At this time, the reaction solution remained suspended. The metal complex was recovered by suction filtration, and then washed with methanol three times. Then, it dried at 373 K and 50 Pa for 8 hours, and obtained the target metal complex 1.06g (yield 14%). The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG. Moreover, the SEM photograph of the obtained metal complex is shown in FIG.

Using the same method as in Synthesis Example 1, the integrated value of the peak of 7.922 ppm (s, 4H) attributed to the 2nd, 3rd, 5th and 6th position protons of terephthalic acid and the carboxyl of lauric acid As a result of calculating the molar ratio of terephthalic acid and lauric acid contained in the obtained metal complex from the ratio of the integrated value of the peak of 1.919 ppm (s, 2H) attributed to the methylene group proton at the group α-position, It was found that acid: lauric acid = 439: 1.

<Comparative Synthesis Example 1>
Under a nitrogen atmosphere, 5.86 g (24 mmol) of copper sulfate pentahydrate, 3.90 g (24 mmol) of terephthalic acid and 44.7 g (775 mmol) of acetic acid were dissolved in 4,000 mL of methanol and stirred at 313 K for 6 hours. The precipitated metal complex was collected by suction filtration and then washed with methanol three times. Next, the recovered metal complex was dispersed in 2,000 mL of methanol under a nitrogen atmosphere, 1.84 g (12 mmol) of 4,4′-bipyridyl was added, and the mixture was stirred at 298 K for 3 hours. At this time, the reaction solution remained suspended. The metal complex was recovered by suction filtration, and then washed with methanol three times. Then, it dried at 373 K and 50 Pa for 8 hours, and obtained the target metal complex 0.992g (yield 14%). FIG. 13 shows a powder X-ray diffraction pattern of the obtained metal complex. Moreover, the SEM photograph of the obtained metal complex is shown in FIG.

<Comparative Synthesis Example 2>
Under a nitrogen atmosphere, 5.86 g (23 mmol) of copper sulfate pentahydrate, 3.90 g (23 mmol) of terephthalic acid and 32.4 g (704 mmol) of formic acid were dissolved in 3,750 mL of methanol and stirred at 313 K for 24 hours. The precipitated metal complex was recovered by suction filtration, and then washed with methanol three times to isolate the intermediate. Next, the isolated intermediate was dispersed in 2,000 mL of methanol under a nitrogen atmosphere, 1.83 g (12 mmol) of 4,4′-bipyridyl was added, and the mixture was stirred at 298 K for 3 hours. At this time, the reaction solution remained suspended. The metal complex was recovered by suction filtration, and then washed with methanol three times. Then, it dried at 373 K and 50 Pa for 8 hours, and obtained 1.79 g (yield 12%) of the target metal complex. FIG. 15 shows a powder X-ray diffraction pattern of the obtained metal complex.

<Comparative Synthesis Example 3>
In a nitrogen atmosphere, 5.86 g (23 mmol) of copper sulfate pentahydrate, 3.90 g (23 mmol) of terephthalic acid and 85.9 g (704 mmol) of benzoic acid were dissolved in 3,750 mL of methanol and stirred at 313 K for 24 hours. The solution remained homogeneous and the target metal complex could not be obtained.

The metal complexes obtained in Synthesis Examples 1 to 4 and Comparative Synthesis Examples 1 to 3 are summarized in Table 1.

<Example 1>
The metal complex obtained in Synthesis Example 1 was dispersed in water, and the sedimentation rate was measured. The results are shown in FIG.

<Example 2>
The metal complex obtained in Synthesis Example 2 was dispersed in water, and the sedimentation rate was measured. The results are shown in FIG.

<Example 3>
The metal complex obtained in Synthesis Example 3 was dispersed in water, and the sedimentation rate was measured. The results are shown in FIG.

<Comparative Example 1>
The metal complex obtained in Comparative Synthesis Example 1 was dispersed in water, and the sedimentation rate was measured. The results are shown in FIG.

<Comparative example 2>
The metal complex obtained in Comparative Synthesis Example 2 was dispersed in water, and the sedimentation rate was measured. The results are shown in FIG.

From FIG. 16, the metal complexes obtained in Synthesis Example 1, Synthesis Example 2 and Synthesis Example 3 that satisfy the constituent requirements of the present invention are the metals obtained in Comparative Synthesis Example 1 and Comparative Synthetic Example 2 that do not satisfy the constituent requirements of the present invention. It is clear that the metal complex of the present invention is hydrophobic because the sedimentation rate is faster than that of the complex.
≪Figure 16≫

<Example 4>
For the metal complex obtained in Synthesis Example 1, an attempt was made to measure the water contact angle, but the water repellency was high and the contact angle could not be measured. A photograph at the time of measurement is shown in FIG.

<Example 5>
For the metal complex obtained in Synthesis Example 2, an attempt was made to measure the water contact angle, but the water repellency was high and the contact angle could not be measured. A photograph at the time of measurement is shown in FIG.

<Example 6>
With respect to the metal complex obtained in Synthesis Example 3, an attempt was made to measure the water contact angle, but the water repellency was high and the contact angle could not be measured. A photograph at the time of measurement is shown in FIG.

<Example 7>
The metal complex obtained in Synthesis Example 4 was tried to measure the water contact angle, but the water repellency was high and the contact angle could not be measured. A photograph at the time of measurement is shown in FIG.

From FIG. 17 to FIG. 20, it is clear that the metal complexes obtained in Synthesis Example 1, Synthesis Example 2, Synthesis Example 3 and Synthesis Example 4 that satisfy the constituent requirements of the present invention have a water contact angle of 150 ° or more. It is clear that the metal complex of the present invention has super water repellency.

<Example 8>
The metal complex obtained in Synthesis Example 1 was subjected to a water vapor exposure test. The equilibrium adsorption amount of carbon dioxide at 0.92 MPa is calculated from the obtained adsorption isotherm, and the result of plotting the change in retention rate is shown in FIG. 21 (Example 8).

<Example 9>
The metal complex obtained in Synthesis Example 3 was subjected to a water vapor exposure test. The equilibrium adsorption amount of carbon dioxide at 0.92 MPa is calculated from the obtained adsorption isotherm, and the result of plotting the change in the retention is shown in FIG. 21 (Example 9).

<Comparative Example 3>
The metal complex obtained in Comparative Synthesis Example 2 was subjected to a water vapor exposure test. The equilibrium adsorption amount of carbon dioxide at 0.92 MPa is calculated from the obtained adsorption isotherm, and the result of plotting the change in the retention is shown in FIG. 21 (Comparative Example 3).

From FIG. 21, the metal complexes obtained in Synthesis Example 1 and Synthesis Example 3 that satisfy the constituent requirements of the present invention are in equilibrium adsorption of carbon dioxide as compared with the metal complex obtained in Comparative Synthesis Example 2 that does not satisfy the constituent requirements of the present invention. Since the amount retention is high and the decrease in retention over time is small, it is clear that the metal complex of the present invention is excellent in water resistance.

<Example 10>
About the metal complex obtained by the synthesis example 1, the adsorption amount of the carbon dioxide in 273K was measured by the capacitance method, and the adsorption isotherm was created. The results are shown in FIG. 22 (Example 10).

<Example 11>
About the metal complex obtained by the synthesis example 2, the adsorption amount of the carbon dioxide in 273K was measured by the capacitance method, and the adsorption isotherm was created. The results are shown in FIG. 22 (Example 11).

<Example 12>
About the metal complex obtained by the synthesis example 3, the adsorption amount of the carbon dioxide in 273K was measured by the capacitance method, and the adsorption isotherm was created. The results are shown in FIG. 22 (Example 12).

<Comparative Example 4>
About the metal complex obtained by the comparative synthesis example 1, the adsorption amount of the carbon dioxide in 273K was measured by the capacitance method, and the adsorption isotherm was created. The results are shown in FIG. 22 (Comparative Example 4).

<Comparative Example 5>
For the metal complex obtained in Comparative Synthesis Example 2, the amount of carbon dioxide adsorbed at 273K was measured by the volumetric method, and an adsorption isotherm was prepared. The results are shown in FIG. 22 (Comparative Example 5).

FIG. 22 shows that the metal complex obtained in Synthesis Example 1, Synthesis Example 2 and Synthesis Example 3 and the metal complex obtained in Comparative Synthesis Example 1 and Comparative Synthesis Example 2 have the same carbon dioxide adsorption performance.

From the results of Examples 1 to 12 and Comparative Examples 1 to 5, Synthesis Example 1, Synthesis Example 2, Synthesis Example 3 and Synthesis satisfying the constituent requirements of the present invention and having an aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms The metal complex obtained in Example 4 has the same level of carbon dioxide adsorption performance as the metal complexes obtained in Comparative Synthesis Example 1 and Comparative Synthesis Example 2 that do not have an aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms. It is clear that the water resistance is improved while maintaining the above. The reason why such a difference has occurred is not necessarily clear, but as a result of the monocarboxylic acid compound constituting the metal complex of the present invention being unevenly distributed on the crystal surface and imparting hydrophobicity by the monocarboxylic acid compound, super repellent properties are obtained. It is considered that water was exhibited, diffusion of water vapor into the pores was suppressed, and excellent water resistance was developed.

<Example 13>
For the metal complex obtained in Synthesis Example 4, the adsorption amount of ethylene at 273 K was measured by a volumetric method, and an adsorption isotherm was created. The results are shown in FIG.

FIG. 23 clearly shows that the metal complex obtained in Synthesis Example 4 adsorbs ethylene as the pressure increases, so that the metal complex of the present invention can be used as an adsorbent for ethylene.

<Example 14>
For the metal complex obtained in Synthesis Example 3, the adsorption / desorption amount of methane at 273K was measured by the volumetric method, and an adsorption / desorption isotherm was created. The results are shown in FIG.

<Comparative Example 6>
For the metal complex obtained in Comparative Synthesis Example 1, the adsorption / desorption amount of methane at 273 K was measured by the volume method, and an adsorption / desorption isotherm was prepared. The results are shown in FIG.

24 and FIG. 25, it can be seen that the methane occlusion performance of the metal complex obtained in Synthesis Example 3 and the metal complex obtained in Comparative Synthesis Example 1 is equivalent.

From the results of Examples 3 and 14 and Comparative Examples 1 and 6, the metal complex obtained in Synthesis Example 3 that satisfies the constituent requirements of the present invention is a comparative synthesis that does not have an aliphatic monocarboxylic acid compound having 3 to 24 carbon atoms. Compared to the metal complex obtained in Example 1, it is clear that the water resistance is improved while maintaining the same level of methane storage performance.

From FIG. 24, the metal complex obtained in Synthesis Example 3 that satisfies the constituent requirements of the present invention adsorbs methane as the pressure increases, and 95% of the methane adsorbed as the pressure decreases without reducing the pressure to 0.1 MPa or less. Since the above is desorbed, it is clear that the effective storage amount of methane is large, and application to a fuel storage tank of a gas vehicle can be expected.

<Example 15>
For the metal complex obtained in Synthesis Example 3, the adsorption and desorption amounts of carbon dioxide and methane at 273 K were measured by a volumetric method, and an adsorption and desorption isotherm was created. The results are shown in FIG.

<Comparative Example 7>
For the metal complex obtained in Comparative Synthesis Example 1, the adsorption and desorption amounts of carbon dioxide and methane at 273 K were measured by a volumetric method, and an adsorption and desorption isotherm was created. The results are shown in FIG.

FIG. 26 and FIG. 27 show that the separation performance of carbon dioxide and methane of the metal complex obtained in Synthesis Example 3 and that of the metal complex obtained in Comparative Synthesis Example 1 are equivalent.

From FIG. 26, the metal complex obtained in Synthesis Example 3 that satisfies the constituent requirements of the present invention selectively adsorbs carbon dioxide with increasing pressure in the pressure range of 0 to 0.6 MPa, and carbon dioxide with decreasing pressure. It is clear that the metal complex of the present invention can be used as a separator for methane and carbon dioxide.

<Example 16>
For the metal complex obtained in Synthesis Example 3, the adsorption and desorption amounts of carbon dioxide and nitrogen at 313 K were measured by the volume method, and an adsorption and desorption isotherm was created. The results are shown in FIG.

From FIG. 28, the metal complex obtained in Synthesis Example 3 that satisfies the constituent requirements of the present invention selectively adsorbs carbon dioxide with increasing pressure in the pressure range of 0 to 1.0 MPa, and carbon dioxide with decreasing pressure. It is clear that the metal complex of the present invention can be used as a separator for nitrogen and carbon dioxide.

<Example 17>
For the metal complex obtained in Synthesis Example 3, the adsorption and desorption amounts of ethane and methane at 298 K were measured by the volume method, and an adsorption and desorption isotherm was created. The results are shown in FIG.

From FIG. 29, the metal complex obtained in Synthesis Example 3 that satisfies the constituent requirements of the present invention selectively adsorbs ethane as the pressure increases in the pressure range of 0 to 1.0 MPa, and releases ethane as the pressure decreases. Therefore, it is clear that the metal complex of the present invention can be used as a separator for methane and ethane.

<Example 18>
For the metal complex obtained in Synthesis Example 3, the adsorption and desorption amounts of carbon dioxide and methane at 293K were measured by the volume method, and adsorption and desorption isotherms were created. The results are shown in FIG.

FIG. 26 and FIG. 30 show that the adsorption start pressure of the metal complex obtained in Synthesis Example 3 that satisfies the constituent requirements of the present invention depends on the temperature and can be controlled. By utilizing this feature, it is understood that the degree of separation can be improved in the temperature swing adsorption method as compared with the case of using a conventional separation material.

For the metal complex obtained in Synthesis Example 3, a breakthrough curve was measured at 293 K, 0.8 MPa, and a space velocity of 6 min ⁻¹ using a mixed gas of methane and carbon dioxide having a volume ratio of methane: carbon dioxide = 60: 40. The gas separation performance was evaluated. The results are shown in FIG.

FIG. 31 shows that the metal complex obtained in Synthesis Example 1 that satisfies the constituent requirements of the present invention can preferentially adsorb carbon dioxide and concentrate methane to 99.5% or more. It is clear that the metal complex of the present invention can be used as a separator for methane and carbon dioxide because the breakthrough time of carbon dioxide (time until carbon dioxide is detected in the outlet gas) is long and only methane can be taken out during that time. . From FIG. 30, it is clear that the metal complex of the present invention releases carbon dioxide adsorbed as the pressure decreases, so that it can be used as a separation material used in the pressure swing adsorption method.

1 Gas storage device (fuel tank)
2 pressure vessel 3 gas storage space 4 occlusion material 5 outlet 6 inlet 7 valve

Claims (15)

1. A polyvalent carboxylic acid compound, at least one metal ion selected from ions of metals belonging to Groups 2 to 13 of the periodic table, an organic ligand capable of multidentate coordination with the metal ion, and a carbon number of 3 A metal complex comprising 24 to 24 aliphatic monocarboxylic acid compounds.
2. The metal complex according to claim 1, wherein the polyvalent carboxylic acid compound is a dicarboxylic acid compound.
3. The multidentate organic ligand is 1,4-diazabicyclo [2.2.2] octane, pyrazine, 2,5-dimethylpyrazine, 4,4′-bipyridyl, 2,2′-dimethyl-4. , 4′-bipyridine, 1,2-bis (4-pyridyl) ethyne, 1,4-bis (4-pyridyl) butadiyne, 1,4-bis (4-pyridyl) benzene, 3,6-di (4- Pyridyl) -1,2,4,5-tetrazine, 2,2′-bi-1,6-naphthyridine, phenazine, diazapyrene, 2,6-di (4-pyridyl) -benzo [1,2-c: 4 , 5-c ′] dipyrrole-1,3,5,7 (2H, 6H) -tetron, 4,4′-bis (4-pyridyl) biphenylene, N, N′-di (4-pyridyl) -1, 4,5,8-naphthalenetetracarboxydiimide, trans-1,2- Su (4-pyridyl) ethene, 4,4′-azopyridine, 1,2-bis (4-pyridyl) ethane, 4,4′-dipyridyl sulfide, 1,3-bis (4-pyridyl) propane, 1,2 The metal complex according to claim 1 or 2, which is at least one selected from -bis (4-pyridyl) -glycol and N- (4-pyridyl) isonicotinamide.
4. An adsorbent comprising the metal complex according to any one of claims 1 to 3.
5. The adsorbent adsorbs carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbon having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia, sulfur oxide, nitrogen oxide, siloxane or organic vapor. The adsorbent according to claim 4, which is an adsorbent for the purpose.
6. An occlusion material comprising the metal complex according to any one of claims 1 to 3.
7. The storage material according to claim 6, wherein the storage material is a storage material for storing carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbon having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia or organic vapor. The storage material described.
8. A gas storage device comprising a pressure-resistant container capable of being hermetically sealed and having a gas inlet / outlet, and having a gas storage space inside the pressure-resistant container, wherein the gas storage space includes the storage material according to claim 6. Some gas storage devices.
9. A gas vehicle provided with an internal combustion engine that obtains driving force from fuel gas supplied from the gas storage device according to claim 8.
10. A separation material comprising the metal complex according to any one of claims 1 to 3.
11. The separation material separates carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbon having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia, sulfur oxide, nitrogen oxide, siloxane, or organic vapor. The separation material according to claim 10, which is a separation material for the purpose.
12. The separation material separates methane and carbon dioxide, hydrogen and carbon dioxide, nitrogen and carbon dioxide, ethylene and carbon dioxide, methane and ethane, ethane and ethylene, propane and propene, ethylene and acetylene, nitrogen and methane or air and methane. The separation material according to claim 10, wherein the separation material is a separation material.
13. 11. The separation method using a separation material according to claim 10, comprising a step of contacting the metal complex and the mixed gas in a pressure range of 0.01 to 10 MPa.
14. The separation method according to claim 13, wherein the separation method is a pressure swing adsorption method.
15. A polyvalent carboxylic acid compound, at least one metal ion selected from ions of metals belonging to Groups 2 to 13 of the periodic table, an organic ligand capable of multidentate coordination with the metal ion, and a carbon number of 3 The method for producing a metal complex according to any one of claims 1 to 3, wherein the metal complex is precipitated by reacting with an aliphatic monocarboxylic acid compound of ~ 24 in a solvent.

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