JP5649480B2 - Metal complex, adsorbent, occlusion material and separation material comprising the same - Google Patents

Description

  The present invention relates to a metal complex and a method for producing the same, and an adsorbent, an occlusion material, and a separation material made of the metal complex. More specifically, the present invention relates to a metal complex comprising a specific dicarboxylic acid compound, at least one metal ion, and an organic ligand capable of bidentate coordination with the metal ion. The metal complex of the present invention is an adsorbent for adsorbing carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbons having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia, water vapor or organic vapor, It is preferable as an occlusion material for occlusion and a separation material for separation.

  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 that cause a dynamic structural change by an external stimulus have been developed as adsorbents that give better adsorption performance (see Non-Patent Document 1 and Non-Patent Document 2). When this new dynamic structure change polymer metal complex is used as a gas adsorbent, a unique phenomenon is observed in which gas adsorption does not adsorb up to a certain pressure, but gas adsorption starts when a certain pressure is exceeded. Yes. In addition, a phenomenon has been observed in which the adsorption start pressure varies depending on the type of gas.

  When this phenomenon is applied to, for example, an adsorbent in a pressure swing adsorption type gas separation apparatus, very efficient gas separation is possible. In addition, the pressure swing width can be narrowed, contributing to energy saving. Furthermore, since it can contribute to miniaturization of the gas separation device, it is possible to increase cost competitiveness when selling high-purity gas as a product, of course, even when high-purity gas is used inside its own factory Since the cost required for the equipment that requires high purity gas can be reduced, the manufacturing cost of the final product can be reduced.

  However, the current situation is that cost reduction by further downsizing of the apparatus is required, and further improvement in separation performance is required to achieve this.

  A polymer metal complex comprising a terephthalic acid derivative, a metal ion, and an organic ligand capable of bidentate coordination with the metal has been disclosed (see Patent Document 1). However, what is described in the examples is a polymer metal complex composed of terephthalic acid, copper ion, and pyrazine, and in the separation of the mixed gas, terephthalic acid has a substituent and an organic coordination capable of bidentate coordination. No mention is made of the effect of the child on the separation performance.

  A polymer metal complex comprising a terephthalic acid derivative, a metal ion, and an organic ligand capable of bidentate coordination with the metal has been disclosed (see Patent Document 2). However, what is described in the examples is a polymer metal complex composed of terephthalic acid, copper ions, and 1,4-diazabicyclo [2.2.2] octane, which terephthalic acid has in the separation of mixed gas No mention is made of the effects of substituents and bidentate organic ligands on the separation performance.

  A polymer metal complex composed of terephthalic acid, a metal ion, and 4,4'-bipyridyl has been disclosed (see Patent Document 3). However, no mention is made of the effect of the substituents of terephthalic acid and the organic ligands capable of bidentate coordination on the separation performance in the separation of the mixed gas.

  A polymer metal complex composed of terephthalic acid, cobalt ions, and trans-1,2-bis (4-pyridyl) ethene is known (see Non-Patent Document 3). However, no mention is made of the gas adsorption behavior, and no mention is made of the effect of the substituents of terephthalic acid on the separation performance in the separation of the mixed gas.

JP 2000-109485 A JP 2001-348361 A JP 2003-342260 A

Kazuhiro Uemura, Susumu Kitagawa, Future Materials, Volume 2, 44-51 (2002) Ryotaro Matsuda, Susumu Kitagawa, Petrotech, Vol. 26, 97-104 (2003) Xin-Hua Li, Sai-Zhen Yang, Hong-Ping Xiao, Crystal Growth & Design, Vol. 6, pp. 2392-2397 (2006)

  Accordingly, an object of the present invention is to provide a metal complex that can be used as a gas adsorbent having a large adsorption amount, a gas occlusion material having a large effective occlusion amount, or a gas separation material having excellent separation performance of a mixed gas.

  The present inventors have intensively studied and achieve the above object with a metal complex comprising a specific dicarboxylic acid compound, at least one metal ion, and an organic ligand capable of bidentate coordination with the metal ion. The present inventors have found that it is possible to achieve the present invention.

That is, according to the present invention, the following is provided.
(1) The following general formula (I);

(Wherein R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group, a formyl group, an acyloxy group, an alkoxycarbonyl group, nitro A group, a cyano group, an amino group, a monoalkylamino group, a dialkylamino group, an acylamino group, or a halogen atom, or R ¹ and R ² , or R ³ and R ⁴ together have a substituent. May form an alkylene group or an alkenylene group (except when R ¹ , R ² , R ³ and R ⁴ are all hydrogen atoms). And at least one metal ion selected from ions of metals belonging to groups 2 and 7-12 of the periodic table, and the following general formula (II):

(In the formula, X is a methine group or a nitrogen atom, and the geometric isomers of double bonds formed by them are in the trans form, and R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent or a halogen atom.) An organic ligand capable of bidentate coordination with the metal ( II).
(2) The bidentate organic ligand (II) is bidentate organic ligand (II) is trans-1,2-bis (4-pyridyl) ethene or 4,4 The metal complex according to (1), which is at least one selected from '-azopyridine.
(3) The metal complex according to (1) or (2), wherein the metal ion is a zinc ion.
(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, water vapor or The adsorbent according to (4), which is an adsorbent for adsorbing organic vapor.
(6) An occlusion material comprising the metal complex according to any one of (1) to (3).
(7) The storage material is a storage material for storing carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbons having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia, water vapor or organic vapor. The storage material according to (6).
(8) A separating material comprising the metal complex according to any one of (1) to (3).
(9) 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, water vapor or The separation material according to (8), which is a separation material for separating organic vapor.
(10) The separator according to (4), wherein the separator is a separator for separating methane and carbon dioxide, ethylene and carbon dioxide, hydrogen and carbon dioxide, nitrogen and carbon dioxide, methane and ethane, or air and methane. Separation material.
(11) Dicarboxylic acid compound (I), at least one metal salt selected from salts of metals belonging to Groups 2 and 7-12 of the periodic table, and organic coordination capable of bidentate coordination with the metal The method for producing a metal complex according to (1), wherein the child (II) is reacted in a solvent to precipitate a metal complex.

  The present invention can provide a metal complex comprising a specific dicarboxylic acid compound, at least one metal ion, and an organic ligand capable of bidentate coordination with the metal ion.

  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 substances, nitrogen oxides, siloxanes, water vapor, organic vapors and the like.

  Moreover, since the metal complex of the present invention is excellent in the occlusion 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 storage material for storing water vapor or 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 sulfur oxides, nitrogen oxides, siloxanes, water vapor or organic vapors.

It is a schematic diagram of the structural change accompanying adsorption / desorption of the metal complex of this invention. 3 is a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 1. FIG. 4 is a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 2. FIG. 3 is a powder X-ray diffraction pattern of the metal complex obtained in Comparative Synthesis Example 1. FIG. 4 is a powder X-ray diffraction pattern of the metal complex obtained in Comparative Synthesis Example 2. FIG. 4 is a powder X-ray diffraction pattern of the metal complex obtained in Comparative Synthesis Example 3. FIG. 6 is a powder X-ray diffraction pattern of the metal complex obtained in Comparative Synthesis Example 4. FIG. It is the result of having measured the adsorption isotherm in 273K of a carbon dioxide by the capacitance method about the metal complex obtained by the synthesis example 1 and the synthesis example 2. FIG. It is the result of having measured the adsorption isotherm in 273K of a carbon dioxide by the capacity | capacitance method about the metal complex obtained by the comparative synthesis example 1, the comparative synthesis example 2, the comparative synthesis example 3, and the comparative synthesis example 4. FIG. It is the result of having measured the adsorption-desorption isotherm in 273K of a carbon dioxide by the capacitance method about the metal complex obtained by the synthesis example 1. FIG. It is the result of having measured the adsorption-desorption isotherm in 273K of a carbon dioxide by the capacitance method about the metal complex obtained by the synthesis example 2. FIG. It is the result of having measured the adsorption-desorption isotherm of carbon dioxide at 273K by the volume method for the metal complex obtained in Comparative Synthesis Example 1. It is the result of having measured the adsorption-desorption isotherm at 273K of a carbon dioxide by the capacitance method about the metal complex obtained by the comparative synthesis example 2. FIG. It is the result of having measured the adsorption-desorption isotherm in 273K of a carbon dioxide by the capacitance method about the metal complex obtained by the comparative synthesis example 3. FIG. It is the result of having measured the adsorption-desorption isotherm in 273K of a carbon dioxide by the capacitance method about the metal complex obtained by the comparative synthesis example 4. FIG. It is the result of measuring the adsorption-desorption isotherm of carbon dioxide and methane at 273 K by the volumetric method for the metal complex obtained in Synthesis Example 1. It is the result of measuring the adsorption-desorption isotherm of carbon dioxide and methane at 273 K by the volumetric method for the metal complex obtained in Synthesis Example 2. It is the result of measuring the adsorption / desorption isotherm of carbon dioxide and methane at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 1. It is the result of having measured the adsorption-desorption isotherm of carbon dioxide and methane at 273K by the volume method for the metal complex obtained in Comparative Synthesis Example 2. It is the result of having measured the adsorption-desorption isotherm of carbon dioxide and methane in 273K by the capacitance method about the metal complex obtained by the comparative synthesis example 3. FIG. It is the result of having measured the adsorption-desorption isotherm in 273K of a carbon dioxide and methane about the metal complex obtained by the comparative synthesis example 4 by the capacitance method. It is the result of measuring the adsorption-desorption isotherm of carbon dioxide and ethylene at 273 K by the volumetric method for the metal complex obtained in Synthesis Example 1. It is the result of having measured the adsorption-desorption isotherm of carbon dioxide and ethylene at 273 K by the capacitance method for the metal complex obtained in Comparative Synthesis Example 1. It is the result of measuring the adsorption / desorption isotherm of carbon dioxide and ethylene at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 2. It is the result of having measured the adsorption-desorption isotherm of carbon dioxide and ethylene at 273 K by the volume method for the metal complex obtained in Comparative Synthesis Example 3. It is the result of measuring the adsorption-desorption isotherm of carbon dioxide and nitrogen at 273 K by the volumetric method for the metal complex obtained in Synthesis Example 2. It is the result of measuring the adsorption-desorption isotherm of carbon dioxide and nitrogen at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 1. It is the result of having measured the adsorption-desorption isotherm of carbon dioxide and nitrogen at 273K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 4.

  The metal complex of the present invention comprises a dicarboxylic acid compound (I), at least one metal ion selected from ions of metals belonging to Groups 2 and 7 to 12 of the periodic table, and bidentate coordination to the metal ion. It consists of possible organic ligands (II).

  As ions of metals belonging to Groups 2 and 7-12 of the periodic table, magnesium ions, calcium ions, manganese ions, iron ions, ruthenium ions, cobalt ions, rhodium ions, nickel ions, palladium ions, copper ions, zinc ions Alternatively, cadmium ion is preferable, magnesium ion, manganese ion, cobalt ion, nickel ion, copper ion, zinc ion or cadmium ion is more preferable, and zinc ion is particularly preferable. The metal ion is preferably a single metal ion, but may be a mixed metal complex containing two or more metal ions. Moreover, the metal complex of this invention can also mix and use 2 or more types of metal complexes which consist of a single metal ion.

  The metal complex includes a dicarboxylic acid compound (I), at least one metal salt selected from salts of metals belonging to Groups 2 and 7 to 12 of the periodic table, and an organic configuration capable of bidentate coordination with the metal. The ligand (II) can be produced by reacting and reacting in a solvent for several hours to several days under normal pressure. For example, an aqueous solution or an organic solvent solution of a metal salt and an organic solvent solution containing a dicarboxylic acid compound (I) and an organic ligand (II) capable of bidentate coordination are mixed and reacted under normal pressure. Can be obtained.

  The dicarboxylic acid compound (I) used in the present invention is represented by the following general formula (I):

It is represented by In the formula, R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, an alkoxy group, a formyl group, an acyloxy group, an alkoxycarbonyl group or a nitro group. , A cyano group, an amino group, a monoalkylamino group, a dialkylamino group, an acylamino group, or a halogen atom, or R ¹ and R ² and / or R ³ and R ⁴ together have a substituent. May form an alkylene group or an alkenylene group (except when R ¹ , R ² , R ³ and R ⁴ are all hydrogen atoms).

Among the substituents that can constitute R ¹ , R ² , R ³ and R ⁴ , the alkyl group or alkoxy group preferably has 1 to 5 carbon atoms. Examples of the alkyl group include a linear or branched alkyl group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and a pentyl group, and an alkoxy group. Examples of methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, tert-butoxy group, and examples of acyloxy group include acetoxy group, n-propanoyloxy group , N-butanoyloxy group, pivaloyloxy group, benzoyloxy group, examples of alkoxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, n-butoxycarbonyl group, examples of monoalkylamino group include methylamino group However, as an example of a dialkylamino group, a dimethylamino group is acyl Examples of amino group, an acetylamino group, examples of the halogen atom, fluorine atom, chlorine atom, bromine atom, iodine atom, and the like, respectively. Examples of the substituent that the alkyl group may have include an 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-propanoyloxy group, n-butanoyl) Oxy group, pivaloyloxy group, benzoyloxy group, etc.), alkoxycarbonyl group (methoxycarbonyl group, ethoxycarbonyl group, n-butoxycarbonyl group, etc.), carboxylic acid anhydride group (—CO—O—CO—R group) (R Is an alkyl group having 1 to 5 carbon atoms). 1-3 are preferable and, as for the number of the substituents of an alkyl group, one is more preferable.

The alkylene group preferably has 2 carbon atoms. When the alkylene group has 2 carbon atoms, R ¹ and R ² and / or R ³ and R ⁴ together with the carbon atom to which they are bonded form a 4-membered ring (cyclobutene ring). Examples of such dicarboxylic acid compound (I) include dihydrocyclobuta [1,2-b] terephthalic acid which may have a substituent.

The alkenylene group preferably has 4 carbon atoms. When the alkenylene group has 4 carbon atoms, R ¹ and R ² and / or R ³ and R ⁴ together with the carbon atom to which they are bonded form a 6-membered ring (benzene). Examples of such dicarboxylic acid compound (I) include 1,4-naphthalenedicarboxylic acid which may have a substituent and 9,10-anthracene dicarboxylic acid which may have a substituent. .

  Examples of the substituent that the alkylene group or the alkenylene group may have include an alkoxy group (methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, tert. -Butoxy group etc.), amino group, monoalkylamino group (methylamino group etc.), dialkylamino group (dimethylamino group etc.), formyl group, epoxy group, acyloxy group (acetoxy group, n-propanoyloxy group, n -Butanoyloxy group, pivaloyloxy group, benzoyloxy group, etc.), alkoxycarbonyl group (methoxycarbonyl group, ethoxycarbonyl group, n-butoxycarbonyl group, etc.), carboxylic anhydride group (-CO-O-CO-R group) (R is an alkyl group having 1 to 5 carbon atoms).

  As the dicarboxylic acid compound (I), 2-methylterephthalic acid, 2-methoxyterephthalic acid, 2-nitroterephthalic acid, dihydrocyclobuta [1,2-b] terephthalic acid, 1,4-naphthalenedicarboxylic acid or 9, 10-anthracene dicarboxylic acid can be used. Among them, 2-methylterephthalic acid, 2-methoxyterephthalic acid or 2-nitroterephthalic acid is preferable, and 2-methylterephthalic acid is more preferable.

  As salts of metals belonging to Groups 2 and 7-12 of the periodic table used for the production of metal complexes, magnesium salts, calcium salts, manganese salts, iron salts, ruthenium salts, cobalt salts, rhodium salts, nickel salts, palladium salts A copper salt, a zinc salt or a cadmium salt can be used, and a magnesium salt, a manganese salt, a cobalt salt, a nickel salt, a copper salt, a zinc salt or a cadmium salt is preferable, and a zinc 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, carbonates, hydrochlorides and hydrobromides can be used.

  The organic ligand (II) capable of bidentate coordination used in the present invention has the following general formula (II):

It is represented by In the formula, X is a methine group (CH) or a nitrogen atom (N), and the geometric isomer of the double bond formed by them is a trans type, and R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, or a halogen atom.

Of the substituents that can constitute R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² , the alkyl group preferably has 1 to 5 carbon atoms. Examples of the alkyl group include a straight or branched alkyl group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and a pentyl group, and a halogen atom. Examples of are fluorine atom, chlorine atom, bromine atom and iodine atom. Examples of the substituent that the alkyl group may have include an 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-propanoyloxy group, n-butanoyloxy) Group, pivaloyloxy group, benzoyloxy group, etc.), alkoxycarbonyl group (methoxycarbonyl group, ethoxycarbonyl group, n-butoxycarbonyl group, etc.), carboxylic acid anhydride group (—CO—O—CO—R group) (R is And an alkyl group having 1 to 5 carbon atoms). 1-3 are preferable and, as for the number of the substituents of an alkyl group, one is more preferable.

  Examples of the bidentate organic ligand (II) include trans-1,2-bis (4-pyridyl) ethene or 4,4′-azopyridine. -Bis (4-pyridyl) ethene is preferred. Here, an organic ligand capable of bidentate coordination means a neutral ligand having two or more sites coordinated to a metal ion by an unshared electron pair.

  The mixing ratio of the dicarboxylic acid compound (I) to the bidentate organic ligand (II) when producing the metal complex is as follows: dicarboxylic acid compound (I): bidentate organic ligand (II) = 1: 5-8: 1 is preferable, and a molar ratio of 1: 3-6: 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.

  The mixing ratio of the metal salt to the bidentate organic ligand (II) when producing the metal complex is as follows: metal salt: bidentate organic ligand (II) = 3: 1 to 1 : Within the range of the molar ratio of 3: 3, and more preferably within the range of the molar ratio of 2: 1 to 1: 2. 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 dicarboxylic acid compound (I) in the mixed solution for producing the metal complex is preferably 0.005 to 5.0 mol / L, and more preferably 0.01 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 0.005 to 5.0 mol / L, and more preferably 0.01 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 bidentate organic ligand (II) in the mixed solution for producing the metal complex is preferably 0.001 to 5.0 mol / L, and preferably 0.005 to 2.0 mol / L. More preferred. 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 a solvent used for producing 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.

  A metal complex having good crystallinity has high purity and good adsorption performance. 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 obtained as described above is an organic ligand capable of bidentate coordination to the axial position of the metal ion in the skeleton composed of the carboxylate ion and the metal ion of the dicarboxylic acid compound (I) ( II) has a three-dimensional structure in which the jungle gym skeleton formed by coordination is doubly interpenetrated.

  In this specification, the “jungle gym skeleton” means an organic ligand capable of bidentate coordination at the axial position of the metal ion in the skeleton composed of the carboxylate ion and metal ion of the dicarboxylic acid compound (I). It is defined as a jungle gym-like three-dimensional structure formed by connecting two-dimensional lattice-like sheets composed of dicarboxylic acid compound (I) and metal ions.

  In the present specification, the “structure in which the jungle gym skeleton is double-interpenetrated” is defined as a three-dimensional integrated structure in which two jungle gym skeletons penetrate each other so as to fill the pores of each other. The fact that the metal complex has “a structure in which the jungle gym skeleton is double interpenetrated” can be confirmed by, for example, single crystal X-ray structure analysis, powder X-ray crystal structure analysis, or the like.

  Since the three-dimensional structure in the metal complex of the present invention can be changed in the synthesized crystal, the structure and size of the pores change with the change. The conditions for changing the structure depend on the type of substance to be adsorbed, the adsorption pressure, and the adsorption temperature. That is, in addition to the difference in the interaction between the pore surface and the substance (the strength of the interaction is proportional to the magnitude of the Lennard-Jones potential of the substance), the degree of structural change differs depending on the adsorbing substance, so high gas adsorption performance High gas storage performance and high selectivity are exhibited. FIG. 1 shows a schematic diagram of the structural change accompanying adsorption / desorption. In the present invention, the steric repulsion between jungle gym skeletons is controlled using the dicarboxylic acid compound represented by the general formula (I) and the bidentate organic ligand represented by the general formula (II). Thus, high gas adsorption performance, high gas storage performance and high gas separation performance are exhibited. After the adsorbed substance is desorbed, it returns to its original structure, so the pore size also returns.

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

Since the metal complex of the present invention is excellent in the adsorption performance of various gases, carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, C 1-4 hydrocarbon (methane, ethane, ethylene, acetylene, etc.), Noble gas (such as helium, neon, argon, krypton, xenon), hydrogen sulfide, ammonia, sulfur oxide, nitrogen oxide, siloxane (such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane), water vapor or organic vapor It is preferable as an adsorbent for adsorbing. The organic vapor means a vaporized organic substance that is liquid at normal temperature and pressure. Examples of such organic substances include alcohols such as methanol and ethanol; amines such as trimethylamine; aldehydes such as acetaldehyde; aliphatic hydrocarbons having 5 to 16 carbon atoms; aromatic hydrocarbons such as benzene and toluene; acetone And ketones such as methyl ethyl ketone; halogenated hydrocarbons such as methyl chloride and chloroform.

  Further, since the metal complex of the present invention is excellent in the occlusion performance of various gases, carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, C 1-4 hydrocarbons (methane, ethane, ethylene, acetylene, etc. ), Noble gases (helium, neon, argon, krypton, xenon, etc.), hydrogen sulfide, ammonia, water vapor, organic vapor, etc. The organic vapor means a vaporized organic substance that is liquid at normal temperature and pressure. Examples of such organic substances include alcohols such as methanol and ethanol; amines such as trimethylamine; aldehydes such as acetaldehyde; aliphatic hydrocarbons having 5 to 16 carbon atoms; aromatic hydrocarbons such as benzene and toluene; acetone And ketones such as methyl ethyl ketone; halogenated hydrocarbons such as methyl chloride and chloroform.

  Furthermore, since the metal complex of the present invention can selectively adsorb various gases, carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, C 1-4 hydrocarbons (methane, ethane, ethylene, Acetylene), noble gases (such as helium, neon, argon, krypton, xenon), hydrogen sulfide, ammonia, sulfur oxides, nitrogen oxides, siloxanes (such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane), water vapor or It is also preferable as a separating material for separating organic vapors, and in particular, carbon dioxide in methane, carbon dioxide in ethylene, carbon dioxide in hydrogen, carbon dioxide in nitrogen, ethane in methane or methane in air Is suitable for separation by a pressure swing adsorption method or a temperature swing adsorption method. The organic vapor means a vaporized organic substance that is liquid at normal temperature and pressure. Examples of such organic substances include alcohols such as methanol and ethanol; amines such as trimethylamine; aldehydes such as acetaldehyde; aliphatic hydrocarbons having 5 to 16 carbon atoms; aromatic hydrocarbons such as benzene and toluene; acetone And ketones such as methyl ethyl ketone; halogenated hydrocarbons such as methyl chloride and chloroform.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. 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, a 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: RINT2400 manufactured by Rigaku Corporation
X-ray source: CuKα (λ = 1.5418Å) 40 kV 200 mA
Goniometer: Vertical goniometer Detector: Scintillation counter Step width: 0.02 °
Slit: Divergent slit = 0.5 °
Receiving slit = 0.15mm
Scattering slit = 0.5 °

(2) Measurement of adsorption / desorption isotherm The measurement was performed by a volume method using a high-pressure gas adsorption amount measuring device. At this time, prior to the measurement, the sample was dried at 373 K and 50 Pa for 10 hours to remove adsorbed water and the like. Details of the analysis conditions are shown below.
<Analysis conditions>
Apparatus: BELSORP-HP manufactured by Nippon Bell Co., Ltd.
Equilibrium waiting time: 500 seconds

<Synthesis Example 1>
Under a nitrogen atmosphere, zinc nitrate hexahydrate 2.81 g (9.5 mmol), 2-methylterephthalic acid 1.70 g (9.5 mmol) and trans-1,2-bis (4-pyridyl) ethene 0.862 g ( 4.7 mmol) was dissolved in 800 mL of a mixed solvent of N, N-dimethylformamide and ethanol having a volume ratio of N, N-dimethylformamide: ethanol = 1: 1 and stirred at 393 K for 24 hours. The precipitated 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 2.91g (yield 92%). The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

<Synthesis Example 2>
In a nitrogen atmosphere, 4.40 g (15 mmol) of zinc nitrate hexahydrate, 3.12 g (15 mmol) of 2-nitroterephthalic acid and 1.36 g (7.4 mmol) of 4,4′-azopyridine were mixed with N, N-dimethylformamide. It was dissolved in 600 mL and stirred at 393 K for 24 hours. The precipitated metal complex was collected by suction filtration, and then washed with ethanol three times. Then, it dried at 373K and 50 Pa for 8 hours, and obtained the target metal complex 3.24g (yield 60%). The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

<Comparative Synthesis Example 1>
Under a nitrogen atmosphere, zinc nitrate hexahydrate 2.81 g (9.5 mmol), terephthalic acid 1.57 g (9.5 mmol) and trans-1,2-bis (4-pyridyl) ethene 0.862 g (4.7 mmol) ) Was dissolved in 800 mL of a mixed solvent of N, N-dimethylformamide and ethanol consisting of N, N-dimethylformamide: ethanol = 1: 1 in a volume ratio and stirred at 363 K for 48 hours. The precipitated 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 2.89g (yield 95%). The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

<Comparative Synthesis Example 2>
In a nitrogen atmosphere, zinc nitrate hexahydrate 2.81 g (9.5 mmol), 2-methylterephthalic acid 1.70 g (9.5 mmol) and 4,4′-bipyridyl 0.739 g (4.7 mmol) Was dissolved in 800 mL of a mixed solvent of N, N-dimethylformamide and ethanol consisting of N, N-dimethylformamide: ethanol = 1: 1 and stirred at 363 K for 48 hours. The precipitated 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 objective metal complex 2.72g (yield 89%). FIG. 5 shows a powder X-ray diffraction pattern of the obtained metal complex.

<Comparative Synthesis Example 3>
Under a nitrogen atmosphere, zinc nitrate hexahydrate 2.81 g (9.5 mmol), 2-methylterephthalic acid 1.70 g (9.5 mmol) and 1,2-bis (4-pyridyl) ethyne 0.852 g (4. 7 mmol) was dissolved in 800 mL of a mixed solvent of N, N-dimethylformamide and ethanol having a volume ratio of N, N-dimethylformamide: ethanol = 1: 1 and stirred at 363 K for 48 hours. The precipitated 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 2.99g (yield 95%). The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

<Comparative Synthesis Example 4>
In a nitrogen atmosphere, 2.81 g (9.5 mmol) of zinc nitrate hexahydrate, 2.00 g (9.5 mmol) of 2-nitroterephthalic acid, and 0.739 g (4.7 mmol) of 4,4′-bipyridyl were used. Was dissolved in 800 mL of a mixed solvent of N, N-dimethylformamide and ethanol consisting of N, N-dimethylformamide: ethanol = 1: 1 and stirred at 363 K for 24 hours. The precipitated metal complex was recovered by suction filtration, and then washed with methanol three times. Then, it dried at 373K and 50Pa for 8 hours, and obtained the target metal complex 2.89g (yield 87%). FIG. 7 shows a powder X-ray diffraction pattern of the obtained metal complex.

<Example 1>
FIG. 8 shows the results of measuring the adsorption isotherm of carbon dioxide at 273 K by the volumetric method for the metal complex obtained in Synthesis Example 1.

<Example 2>
FIG. 8 shows the results of measuring the adsorption isotherm of carbon dioxide at 273 K by the capacity method for the metal complex obtained in Synthesis Example 2.

<Comparative Example 1>
FIG. 9 shows the results of measuring the adsorption isotherm of carbon dioxide at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 1.

<Comparative example 2>
FIG. 9 shows the results of measuring the adsorption isotherm of carbon dioxide at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 2.

<Comparative Example 3>
FIG. 9 shows the results of measuring the adsorption isotherm of carbon dioxide at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 3.

<Comparative example 4>
FIG. 9 shows the results of measuring the adsorption isotherm of carbon dioxide at 273 K by the capacity method for the metal complex obtained in Comparative Synthesis Example 4.

  From the comparison between FIG. 8 and FIG. 9, it is clear that the metal complex of the present invention is excellent as a carbon dioxide adsorbent because it has a large amount of carbon dioxide adsorption.

<Example 3>
FIG. 10 shows the results of measuring the adsorption / desorption isotherm of carbon dioxide at 273 K by the capacity method for the metal complex obtained in Synthesis Example 1.

<Example 4>
FIG. 11 shows the results of measuring the adsorption / desorption isotherm of carbon dioxide at 273 K by the volumetric method for the metal complex obtained in Synthesis Example 2.

<Comparative Example 5>
FIG. 12 shows the results of measuring the adsorption / desorption isotherm of carbon dioxide at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 1.

<Comparative Example 6>
FIG. 13 shows the results of measuring the adsorption / desorption isotherm of carbon dioxide at 273 K by the capacity method for the metal complex obtained in Comparative Synthesis Example 2.

<Comparative Example 7>
FIG. 14 shows the results of measuring the adsorption / desorption isotherm of carbon dioxide at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 3.

<Comparative Example 8>
FIG. 15 shows the results of measuring the adsorption / desorption isotherm of carbon dioxide at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 4.

  From the comparison of FIGS. 10 and 11 and FIGS. 12 to 15, it is clear that the metal complex of the present invention is excellent as a carbon dioxide occlusion material because it has a large amount of occlusion of carbon dioxide.

<Example 5>
FIG. 16 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide and methane at 273 K by the capacity method for the metal complex obtained in Synthesis Example 1.

<Example 6>
FIG. 17 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide and methane at 273 K by the capacity method for the metal complex obtained in Synthesis Example 2.

<Comparative Example 9>
FIG. 18 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide and methane at 273 K by the capacity method for the metal complex obtained in Comparative Synthesis Example 1.

<Comparative Example 10>
FIG. 19 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide and methane at 273 K by the capacity method for the metal complex obtained in Comparative Synthesis Example 2.

<Comparative Example 11>
FIG. 20 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide and methane at 273 K by the capacity method for the metal complex obtained in Comparative Synthesis Example 3.

<Comparative Example 12>
FIG. 21 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide and methane at 273 K by the capacity method for the metal complex obtained in Comparative Synthesis Example 4.

  16 and FIG. 17 and FIGS. 18 to 21 show that the metal complex of the present invention selectively adsorbs carbon dioxide and has a large amount of adsorbed carbon dioxide, and thus is excellent as a separator for methane and carbon dioxide. Obviously.

<Example 7>
FIG. 22 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide and ethylene at 273 K by the capacity method for the metal complex obtained in Synthesis Example 1.

<Comparative Example 13>
FIG. 23 shows the results of measuring the adsorption / desorption isotherm of carbon dioxide and ethylene at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 1.

<Comparative example 14>
FIG. 24 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide and ethylene at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 2.

<Comparative Example 15>
FIG. 25 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide and ethylene at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 3.

  From the comparison between FIG. 22 and FIG. 23 to FIG. 25, the metal complex of the present invention selectively adsorbs carbon dioxide and has a large amount of carbon dioxide adsorption. it is obvious.

<Example 8>
FIG. 26 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide and nitrogen at 273 K by the volumetric method for the metal complex obtained in Synthesis Example 2.

<Comparative Example 16>
FIG. 27 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide and nitrogen at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 1.

<Comparative Example 17>
FIG. 28 shows the results of measuring the adsorption / desorption isotherm of carbon dioxide and nitrogen at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 4.

  From comparison between FIG. 26, FIG. 27 and FIG. 28, the metal complex of the present invention selectively adsorbs carbon dioxide and has a large amount of adsorbed carbon dioxide, so that it is excellent as a separator for nitrogen and carbon dioxide. it is obvious.

Claims (11)

A dicarboxylic acid compound (I) selected from the group consisting of 2-methylterephthalic acid and 2-nitroterephthalic acid;
At least one metal ion selected from ions of metals belonging to Groups 2 and 7-12 of the periodic table, and the following general formula (II):
(Wherein, X is a methine group or a nitrogen atom, and the geometric isomers of the double bonds formed by them are in the trans form, and R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² are the same or different and each represents a hydrogen atom, an alkyl group which may have a substituent, or a halogen atom.) An organic ligand capable of bidentate coordination with the metal ion A metal complex comprising (II).   The bidentate organic ligand (II) is at least one selected from trans-1,2-bis (4-pyridyl) ethene or 4,4'-azopyridine. Metal complex.   The metal complex according to claim 1 or 2, wherein the metal ion is a zinc ion. The adsorbent which consists of a metal complex in any one of Claims 1-3. 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, water vapor or organic vapor. The adsorbent according to claim 4 , which is an adsorbent for adsorbing.   The occlusion material which consists of a metal complex in any one of Claims 1-3. 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, water vapor or organic vapor. 6. The occlusion material according to 6 .   The separating material which consists of a metal complex in any one of Claims 1-3.   The separation material 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, water vapor or organic vapor. The separation material according to claim 8, which is a separation material for separation.   The separation material according to claim 8, wherein the separation material is a separation material for separating methane and carbon dioxide, ethylene and carbon dioxide, hydrogen and carbon dioxide, nitrogen and carbon dioxide, methane and ethane, or air and methane. Dicarboxylic acid compound (I) selected from the group consisting of 2-methylterephthalic acid and 2-nitroterephthalic acid, and at least one metal selected from salts of metals belonging to Groups 2 and 7-12 of the periodic table The method for producing a metal complex according to claim 1, wherein the salt and the organic ligand (II) capable of bidentate coordination with the metal are reacted in a solvent to precipitate the metal complex.