JP2014058481A - Metal complex, and adsorbent, occlusion material and separation material therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal complex having excellent gas absorption performance, gas occlusion performance and gas separation performance.SOLUTION: A metal complex contains a dicarboxylate ion (I) represented by the general formula (I), where Rand Rare as defined in the specification, A is a phenyl group or an ethenylene group which may have a substituent, at least one kind of metal ion selected from the metal ions of group 2 and group 7 to 12 in the periodic table, and an organic ligand having a point group of Dand a longitudinal length of 7.0 angstroms to 16.0 angstroms and capable of bidentate coordination to the metal ion having 2 heteroatoms.

Description

  The present invention relates to a metal complex, and an adsorbent, an occlusion material, and a separation material comprising the same. More specifically, the present invention relates to a metal complex comprising a specific dicarboxylate ion, at least one metal ion, and a specific organic ligand capable of bidentate coordination with the metal ion. The metal complex of the present invention occludes and adsorbs carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbons having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia, or organic vapor. Therefore, it is preferable as an occlusion material for separation 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 due to an external stimulus have been developed as adsorbents that give better adsorption performance. 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 present situation is that cost reduction by further downsizing of the apparatus is required, and in order to achieve this, further improvement in adsorption performance, storage performance and separation performance is required.

  An alkenylene dicarboxylic acid compound, at least one divalent metal selected from copper, rhodium, chromium, molybdenum, palladium, zinc and tungsten, and an organic ligand having a pKa of 4 or more capable of bidentate coordination with the metal There is disclosed a polymer metal complex comprising (see Patent Document 1). However, only triethylenediamine and 3,6-bis (4-pyridyl) -1,2,4,5-tetrazine are listed as organic ligands having a pKa of 4 or more. The effect of potential organic ligands on the structure of metal complexes and gas adsorption behavior is not clearly shown. In the examples, only the adsorption ability of a single component gas (methane) is shown, and no mention is made of the adsorption ability and separation ability of other gases.

JP 2001-348361 A

  Accordingly, an object of the present invention is to provide a metal complex that can be used as a gas adsorbent having a larger amount of adsorption than before, a gas occlusion material having a larger amount of occlusion than before, or a gas separation material exhibiting higher selectivity than the conventional one. There is.

  The present inventors have intensively studied, and by using a metal complex comprising a specific dicarboxylate ion, at least one metal ion, and a specific organic ligand capable of bidentate coordination with the metal ion, Has been found to achieve the present invention.

（式中、Ｒ^１及びＲ^２はそれぞれ同一または異なって、水素原子、ハロゲン原子または置換基を有していてもよいアルキル基、アルコキシ基、ホルミル基、アシロキシ基、アルコキシカルボニル基、ニトロ基、シアノ基、アミノ基、モノアルキルアミノ基、ジアルキルアミノ基若しくはアシルアミノ基であり、Ａは置換基を有していてもよいフェニレン基またはエテニレン基である。）
で表されるジカルボキシレートイオン（Ｉ）と、周期表の２族及び７〜１２族に属する金属のイオンから選択される少なくとも１種の金属イオンと、点群がＤ_∞ｈであり、かつ長軸方向の長さが７．０Å以上１６．０Å以下であり、かつヘテロ原子を２個有する該金属イオンに二座配位可能な有機配位子とからなる金属錯体。 That is, according to the present invention, the following is provided.
(1) The following general formula (I)

(Wherein R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom or an optionally substituted alkyl group, alkoxy group, formyl group, acyloxy group, alkoxycarbonyl group, nitro group, A cyano group, an amino group, a monoalkylamino group, a dialkylamino group, or an acylamino group, and A is an optionally substituted phenylene group or ethenylene group.)
A dicarboxylate ion (I) represented by: at least one metal ion selected from ions of metals belonging to Groups 2 and 7 to 12 of the periodic table, and a point group of D _∞h , and A metal complex comprising an organic ligand having a length in a major axis direction of from 7.0 to 16.0 and capable of bidentate coordination with the metal ion having two heteroatoms.

で表わされるフェニレン基、または下記一般式（III）

で表わされるエテニレン基
（式中、Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６、Ｒ^７及びＲ^８はそれぞれ同一または異なって、水素原子、ハロゲン原子または置換基を有していてもよいアルキル基、アルコキシ基、ホルミル基、アシロキシ基、アルコキシカルボニル基、ニトロ基、シアノ基、アミノ基、モノアルキルアミノ基、ジアルキルアミノ基若しくはアシルアミノ基である。）
であることを特徴とする（１）に記載の金属錯体。 (2) A is the following general formula (II)

Or a phenylene group represented by the following general formula (III)

(Wherein R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are the same or different and each represents a hydrogen atom, a halogen atom or an alkyl group which may have a substituent) , Alkoxy group, formyl group, acyloxy group, alkoxycarbonyl group, nitro group, cyano group, amino group, monoalkylamino group, dialkylamino group or acylamino group.)
(1) The metal complex according to (1).

(3) The metal complex according to (1) or (2), wherein the jungle gym skeleton has a structure in which a plurality of interpenetrations occur.
(4) The bidentate organic ligand is 4,4′-bipyridyl, 2,7-diazapyrene, 1,2-bis (4-pyridyl) ethyne, 1,4-bis (4-pyridyl) The metal complex according to any one of (1) to (3), which is at least one selected from butadiyne, 1,4-bis (4-pyridyl) benzene, and 4,4′-bis (4-pyridyl) biphenyl .
(5) An adsorbent comprising the metal complex according to any one of (1) to (4).
(6) 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 (5), which is an adsorbent for adsorbing water.
(7) An occlusion material comprising the metal complex according to any one of (1) to (4).
(8) The occlusion material is an occlusion material for occluding carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbon having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia or organic vapor ( The occlusion material according to 7).
(9) A gas storage device comprising 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 (7) is provided in the gas storage space. Internal gas storage device.
(10) A gas vehicle provided with an internal combustion engine that obtains driving force from the fuel gas supplied from the gas storage device according to (9).

(11) A separating material comprising the metal complex according to any one of (1) to (4).
(12) 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 separation material according to (11), which is a separation material for separating a mixed gas containing gas.
(13) The separation material separates methane and carbon dioxide, hydrogen and carbon dioxide, nitrogen and carbon dioxide, ethylene and carbon dioxide, methane and nitrogen, methane and ethane, ethane and ethylene, propane and propene, or air and methane. The separation material according to (11), which is a separation material for the purpose.
(14) The separation method using the separation material according to (11), including a step of contacting the metal complex and the mixed gas in a pressure range of 0.01 to 10 MPa.
(15) The separation method according to (14), wherein the separation method is a pressure swing adsorption method or a temperature swing adsorption method.
(16) Dicarboxylate ion (I), at least one metal ion selected from ions of metals belonging to Groups 2 and 7-12 of the periodic table, a point group of _D∞ , and a long length An axial length of 7.0 to 16.0 cm, and an organic ligand capable of bidentate coordination with the metal ion having two heteroatoms is reacted in a solvent and deposited ( The manufacturing method of the metal complex as described in 1).

According to the present invention, the specific dicarboxylate ion, at least one metal ion, the point group is _D∞h , the length in the major axis direction is 7.0 to 16.0 、, and hetero A metal complex comprising an organic ligand capable of bidentate coordination with the metal ion having two 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 substances, nitrogen oxides, siloxanes, organic vapors and the like.

  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, hydrocarbon having 1 to 4 carbon atoms, rare gas, hydrogen sulfide, ammonia or It can also be used as a storage material for storing organic vapors.

  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 or organic vapors.

It is a schematic diagram of a jungle gym skeleton formed by coordination of an organic ligand capable of bidentate coordination at the axial position of a metal ion in a paddle wheel skeleton composed of a dicarboxylate ion (I) and a metal ion. . FIG. 2 is a schematic diagram of a three-dimensional structure in which the jungle gym skeleton of FIG. 1 is double interpenetrated. It is a schematic diagram of the structural change accompanying adsorption / desorption of the metal complex of this invention. 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. 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. 2 is an adsorption isotherm of carbon dioxide at 273 K of the metal complexes obtained in Synthesis Example 1 and Comparative Synthesis Example 1. It is an adsorption isotherm of ethylene at 273 K of the metal complexes obtained in Synthesis Example 1 and Comparative Synthesis Example 2. It is an adsorption isotherm of methane at 273 K of the metal complexes obtained in Synthesis Example 1, Comparative Synthesis Example 1, Comparative Synthesis Example 2 and Comparative Synthesis Example 3. 2 is an adsorption / desorption isotherm of methane at 273 K of the metal complex obtained in Synthesis Example 1. 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 ethane and methane at 273 K of the metal complex obtained in Synthesis Example 1. FIG. 2 is an adsorption / desorption isotherm of ethane and methane at 273 K of the metal complex obtained in Comparative Synthesis Example 1. FIG.

The metal complex of the present invention comprises a specific dicarboxylate ion (I), at least one metal ion selected from ions of metals belonging to Groups 2 and 7-12 of the periodic table, and a point group of D _{∞ h,} and and the length of the major axis direction is less 16.0Å than 7.0 Å, and consists with the metal ions in a bidentate coordination acceptable organic ligand having two hetero atoms.

The dicarboxylate ion (I) used in the metal complex of the present invention is represented by the following general formula (I).

In formula (I), R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom or an optionally substituted alkyl group, alkoxy group, formyl group, acyloxy group, alkoxycarbonyl group, nitro Group, cyano group, amino group, monoalkylamino group, dialkylamino group or acylamino group.

Examples of the alkyl group constituting R ¹ and R ² include a straight chain 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. Examples of branched alkyl groups include alkoxy groups such as methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, and tert-butoxy group. Examples of the acetoxy group, n-propanoyloxy group, n-butanoyloxy group, pivaloyloxy group, and benzoyloxy group are alkoxycarbonyl groups. Examples of amino groups are methylamino groups, examples of dialkylamino groups are Dimethylamino group. Examples of the acylamino group include an acetylamino group, examples of the halogen atom, fluorine atom, chlorine atom, bromine atom, iodine atom, and the like, respectively. The alkyl group or alkoxy group preferably has 1 to 5 carbon atoms.

  In formula (I), A is a phenylene group or an ethenylene group which may have a substituent. The phenylene group is a divalent group obtained by removing two hydrogen atoms from a benzene ring, and the bonding position may be any of o-position, m-position and p-position. The ethenylene group is a divalent group obtained by removing two hydrogen atoms from ethylene, and may be either a cis type or a trans type.

で表わされるフェニレン基、または下記一般式（III）

で表わされるエテニレン基が好ましく用いられる。一般式（III）で表されるエテニレン基は、シス型及びトランス型のいずれの結合様式であってもよいことを示している。前記式中、Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６、Ｒ^７及びＲ^８はそれぞれ同一または異なって、水素原子、ハロゲン原子または置換基を有していてもよいアルキル基、アルコキシ基、ホルミル基、アシロキシ基、アルコキシカルボニル基、ニトロ基、シアノ基、アミノ基、モノアルキルアミノ基、ジアルキルアミノ基若しくはアシルアミノ基である。Ｒ^３〜Ｒ^８を構成する置換基の例としては、前記Ｒ^１及びＲ^２で例示したものと同じものが挙げられる。 As A, the following general formula (II)

Or a phenylene group represented by the following general formula (III)

An ethenylene group represented by the formula is preferably used. The ethenylene group represented by the general formula (III) indicates that it may be in any of a cis type or a trans type. In the above formula, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are the same or different and each is a hydrogen atom, a halogen atom or an optionally substituted alkyl group, alkoxy group, formyl A group, an acyloxy group, an alkoxycarbonyl group, a nitro group, a cyano group, an amino group, a monoalkylamino group, a dialkylamino group or an acylamino group. Examples of the substituent group constituting R ³ to R ⁸ are it may be the same as those exemplified for the R ¹ and R ^2.

Examples of the substituent that each R ^{1 to} R ⁸ may further 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). The number of substituents that each R ^{1 to} R ⁸ may further have is preferably 1 to 3, and more preferably 1.

  The dicarboxylate ion (I) used in the metal complex of the present invention has a three-dimensional structure excellent in gas adsorbing ability, occlusion ability, and separation ability because the π-electron conjugate length between the carboxylate groups is an appropriate length. Can be formed.

  As the dicarboxylate ion (I), a muconate anion (1,3-butadiene-1,4-dicarboxylate anion) which may have a substituent or a substituent represented by the following chemical formula An optional 4-carboxycinnamic acid anion can be used, and among them, 4-carboxycinnamic acid anion is preferable.

  The dicarboxylate ion (I) may be generated from an acid anhydride or an alkali metal salt as well as the corresponding dicarboxylic acid compound.

  The metal complex of the present invention may contain only one type of dicarboxylate ion (I), or may contain two or more types of dicarboxylate ion (I). The metal complex of the present invention can be used by mixing two or more metal complexes containing a single dicarboxylate ion (I).

  Examples of ions of metals belonging to Groups 2 and 7-12 of the periodic table used in the metal complex of the present invention include, for example, magnesium ion, calcium ion, manganese ion, iron ion, cobalt ion, nickel ion, copper ion, and zinc ion. Cadmium ions, etc. can be used. 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 ion may be used in the form of a metal salt. Examples of salts of metals belonging to Groups 2 and 7-12 of the periodic table used for the production of metal complexes include, for example, magnesium salts, calcium salts, manganese salts, iron salts, cobalt salts, nickel salts, copper salts, zinc salts, Cadmium salts can be 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 organic ligand capable of bidentate coordination used in the metal complex of the present invention has a point group of _D∞h , a length in the major axis direction of from 7.0 to 16.0 and a heteroatom. Have two. Here, the organic ligand capable of bidentate coordination means a neutral ligand having two sites coordinated to a metal ion by an unshared electron pair.

The point group of the organic ligand capable of bidentate coordination can be determined according to the method described in Reference Document 1 below.
Reference 1: Masao Nakazaki, Molecular symmetry and group theory, 39-40 (1973, Tokyo Chemical Doujin)

For example, 4,4′-bipyridyl, 1,2-bis (4-pyridyl) ethyne, 1,4-bis (4-pyridyl) benzene, and 4,4′-bis (4-pyridyl) biphenyl are symmetrical straight lines. Since it is a molecule and has a symmetric _center , the point group is D _∞h . In addition, 1,2-bis (4-pyridyl) ethene has a two-fold rotation axis and a plane of symmetry perpendicular to the axis, so the point group is C _2h .

When the point group of the organic ligand capable of bidentate coordination is other than D _∞h , useless voids are generated due to low symmetry, and the amount of adsorption decreases.

  The length in the major axis direction of the organic ligand capable of bidentate coordination in this specification was determined using conformational analysis by molecular dynamics method MM3 using Scigress Explorer Professional Version 7.6.0.52 manufactured by Fujitsu Limited. After that, in the most stable structure obtained by optimizing the structure by the semi-empirical molecular orbital method PM5, among the atoms coordinated to the metal ion, the two atoms at the most distant positions in the structural formula Is defined as the distance.

  For example, the distance between nitrogen atoms of triethylenediamine (1,4-diazabicyclo [2.2.2] octane) is 2.609Å, the distance between nitrogen atoms of pyrazine is 2.810Å, and the nitrogen atoms of 4,4'-bipyridyl are between The distance is 7.061Å, the distance between nitrogen atoms of 1,2-bis (4-pyridyl) ethyne is 9.583Å, the distance between nitrogen atoms of 1,4-bis (4-pyridyl) benzene is 11.315Å, 4, The distance between nitrogen atoms of 4′-bis (4-pyridyl) biphenyl is 15.570.

  When the length in the major axis direction of the bidentate organic ligand is less than 7.0 mm, the distance between metal ions becomes too short, and a three-dimensional structure in which the jungle gym skeleton is interpenetrated multiple times is formed. It is not possible to obtain a metal complex having excellent gas adsorbing ability, occlusion ability and separation ability. On the other hand, when the length in the major axis direction exceeds 16.0 mm, the distance between metal ions becomes too long, and a metal complex cannot be stably obtained.

  Examples of the hetero atom of the organic ligand capable of bidentate coordination in the present specification include a nitrogen atom, an oxygen atom, a phosphorus atom, and a sulfur atom.

  For example, 4,4′-bipyridyl has two heteroatoms, 1,2-bis (4-pyridyl) ethyne has two heteroatoms, and 1,4-bis (4-pyridyl) benzene has The number of heteroatoms is 2, and the number of heteroatoms possessed by 3,6-di (4-pyridyl) -1,2,4,5-tetrazine is 6.

  If the organic ligand capable of bidentate coordination has one heteroatom, bidentate coordination with the metal ion is not possible, and a three-dimensional structure of the desired metal complex is constructed. I can't. On the other hand, when the organic ligand capable of bidentate coordination has 3 or more hetero atoms, the charge density on the ligand constituting the pore wall increases, and the mutual relationship between the gas molecule and the pore wall increases. Since the effect is increased, the selectivity is lowered.

  Examples of the bidentate organic ligand include 4,4′-bipyridyl, 2,7-diazapyrene, 1,2-bis (4-pyridyl) ethyne, and 1,4-bis (4-pyridyl). Butadiyne, 1,4-bis (4-pyridyl) benzene, 4,4′-bis (4-pyridyl) biphenyl and the like can be used, and among these, 4,4′-bipyridyl is preferable.

  The metal complex of the present invention may contain only one kind of an organic ligand capable of bidentate coordination, or may contain two or more kinds of organic ligands capable of bidentate coordination. The metal complex of the present invention may be used by mixing two or more metal complexes containing an organic ligand capable of single bidentate coordination.

  In addition to the above, the metal complex of the present invention may further contain a monocarboxylic acid compound. Examples of the monocarboxylic acid compound include formic acid; acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, cyclohexanecarboxylic acid, caprylic acid, octylic acid, pelargonic acid, capric acid, lauric acid, Aliphatic acids such as myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, tuberculostearic acid, arachidic acid, behenic acid, lignoceric acid, α-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, linoleic acid and oleic acid Monocarboxylic acids; aromatic monocarboxylic acids such as benzoic acid; heteroaromatic monocarboxylic acids such as nicotinic acid and isonicotinic acid can be used, among which formic acid, acetic acid, octylic acid, lauric acid, myristic acid, Palmitic acid and stearic acid are preferred.

  The monocarboxylic acid compound may be used in the form of an acid anhydride or an alkali metal salt, or may be used as a counter anion of a raw metal salt. In addition, the monocarboxylic acid compound may coexist from the initial stage of the reaction or may be added at the late stage of the reaction.

  When the metal complex of the present invention contains the monocarboxylic acid compound, the ratio 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 and the monocarboxylic acid compound is , Preferably in the range of 100: 1 to 5,000: 1, and more preferably in the range of 250: 1 to 2,500: 1. The composition ratio can be determined by analysis using gas chromatography, high performance liquid chromatography, NMR, or the like.

  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.

  The metal complex of the present invention comprises a dicarboxylate ion (I), at least one metal salt selected from salts of metals belonging to Groups 2 and 7 to 12 of the periodic table, and bidentate to the metal ion. It can be produced by reacting a potential organic ligand in the gas phase, liquid phase, or solid phase, but it can be produced by reacting in a solvent at normal pressure for several hours to several days and depositing it. Is preferred. For example, an aqueous solution or organic solution of the metal salt, an aqueous solution or organic solution containing an alkenylene dicarboxylic acid compound, and an aqueous solution or organic solution containing an organic ligand capable of bidentate coordination are mixed under normal pressure. Thus, the metal complex of the present invention can be obtained.

  The mixing ratio of the dicarboxylate ion (I) to the bidentate organic ligand when producing the metal complex is as follows: dicarboxylate ion (I): bidentate organic ligand = 1 : Preferably in the range of 5-8: 1 molar ratio, more preferably in the range of 1: 3-6: 1 molar ratio. 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 and the bidentate organic ligand when producing the metal complex is as follows: metal salt: bidentate organic ligand = 3: 1 to 1: 3 molar ratio Within the range, the molar ratio of 2: 1 to 1: 2 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.

  The molar concentration of the dicarboxylate ion (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 in the mixed solution for producing the metal complex is preferably 0.001 to 5.0 mol / L, and more preferably 0.005 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.

  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.

  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 used as the adsorbent, occlusion material, or separation material of the present invention, it is necessary to vacuum dry the previously obtained metal complex to remove the solvent in the pores.

  In the metal complex of the present invention obtained as described above, an organic ligand capable of bidentate coordination is arranged at the axial position of the metal ion in the paddle wheel skeleton composed of the dicarboxylate ion (I) and the metal ion. The jungle gym skeleton formed at the same position has a three-dimensional structure with double interpenetration. A schematic diagram of a jungle gym skeleton composed of 4-carboxycinnamic acid anion, zinc ion and 1,4-bis (4-pyridyl) benzene is shown in FIG. 1, and a schematic diagram of a three-dimensional structure in which the jungle gym skeleton is interpenetrated in triplicate. Is shown in FIG.

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

  In the present specification, “a structure in which multiple jungle gym skeletons interpenetrate” is defined as a three-dimensional integrated structure in which a plurality of jungle gym skeletons penetrate each other so as to fill the pores.

  It can be confirmed by, for example, crystal X-ray analysis or powder X-ray crystal structure analysis that the metal complex has “a structure in which the jungle gym skeleton has multiple interpenetrations”.

  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 varies depending on the adsorbed substance, and thus high selectivity is achieved. To express. FIG. 3 shows a schematic diagram of the structural change accompanying the adsorption / desorption. In the present invention, by using dicarboxylate ion (I) to control the strength of interaction between the pore surface and gas molecules and the pore diameter, high gas adsorption performance, high gas storage performance, and high gas separation performance. Is expressed. After the adsorbed substance is desorbed, it returns to its original structure, so the pore size also returns.

  Although the said adsorption mechanism is presumption, even if it does not follow the said mechanism, if the requirements prescribed | regulated by this invention are satisfied, it will be included in the technical scope of this 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, hydrocarbon having 1 to 4 carbon atoms (methane, ethane, ethylene, acetylene, propane, Propene, methylacetylene, propadiene, butane, 1-butene, isobutene, butadiene, etc.), noble gases (such as helium, neon, argon, krypton, xenon), hydrogen sulfide, ammonia, sulfur oxide, nitrogen oxide, siloxane (hexa) Methylcyclotrisiloxane, octamethylcyclotetrasiloxane, etc.), water vapor, organic vapor, etc. are preferred as adsorbents. 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; 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 usage form of the adsorbent 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.

  As long as the adsorbent of the present invention is within a range not impairing the effects of the present invention, cellulose acetate, polyamide, polyester, polycarbonate, polysulfone, polyethersulfone, polyolefin, polytetrafluoroethylene derivative, paper, etc. You may combine with natural or synthetic fiber, or inorganic fiber, such as glass or an alumina.

  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, hydrocarbons having 1 to 4 carbon atoms (methane, ethane, ethylene, acetylene, To store propane, propene, methylacetylene, propadiene, butane, 1-butene, isobutene, butadiene, etc.), noble gases (such as helium, neon, argon, krypton, xenon), hydrogen sulfide, ammonia, water vapor, or organic vapor. It is also preferable as an occlusion material. 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; 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 usage form of the occlusion 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.

  As long as the occlusion material of the present invention is within the range not impairing the effects of the present invention, as necessary, cellulose acetate, polyamide, polyester, polycarbonate, polysulfone, polyethersulfone, polyolefin, polytetrafluoroethylene derivative, paper, etc. You may combine with natural or synthetic fiber, or inorganic fiber, such as glass or an alumina.

  The metal complex of the present invention can also be used in a gas storage device taking advantage of its occlusion 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, and a gas storage space is provided inside the pressure-resistant container, and the gas storage space is provided with an occlusion material made of the metal complex of the present invention. 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 installing the occlusion material 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.

  An example of the gas vehicle provided with the gas storage device of the present invention described above is shown in FIG. 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 under such a high temperature range (about 298 to 333 K), the storage material of the present invention can keep its adsorption capacity high, and is useful.

  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 (methane, ethane, ethylene, acetylene, Propane, propene, methylacetylene, propadiene, butane, 1-butene, isobutene, butadiene, etc.), noble gases (such as helium, neon, argon, krypton, xenon), hydrogen sulfide, ammonia, sulfur oxide, nitrogen oxide, siloxane (Hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, etc.), preferable as a separating material for separating water vapor or organic vapor, etc., especially carbon dioxide in methane, carbon dioxide in hydrogen, carbon dioxide in nitrogen , Carbon dioxide in ethylene, nitrogen in methane, ethane in methane, in ethane Ethylene, methane propene or air in propane, are suitable for separating the pressure swing adsorption or temperature swing adsorption. 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; 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 usage form of the separating 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.

  As long as the separating material of the present invention is within a range not impairing the effects of the present invention, cellulose acetate, polyamide, polyester, polycarbonate, polysulfone, polyethersulfone, polyolefin, polytetrafluoroethylene derivative, paper, etc. You may combine with natural or synthetic fiber, or inorganic fiber, such as glass or an alumina.

  The separation method includes a step of bringing the gas into contact with the metal complex of the present invention under conditions that allow the gas to 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 pressure range for bringing the metal complex of the present invention into contact with the mixed gas is preferably 0.01 to 10 MPa, and more preferably 0.1 to 3.5 MPa. Further, the temperature is preferably 195K to 343K, 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, and 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 273 to 473K, and more preferably 273 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.

  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: 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) Measurement of adsorption isotherm or adsorption / desorption isotherm A gas adsorption amount was measured by a volume method using a high-pressure gas adsorption amount apparatus, and an adsorption isotherm was created (based on JIS Z8831-2). 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>
In a nitrogen atmosphere, 2.81 g (9.5 mmol) of zinc nitrate hexahydrate, 1.82 g (9.5 mmol) of 4-carboxycinnamic acid and 0.734 g (4.7 mmol) of 4,4′-bipyridyl were used. Were 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 393 K for 24 hours. The precipitated metal complex was collected 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 2.56g (yield 90%). FIG. 5 shows a powder X-ray diffraction pattern of the obtained metal complex.

<Comparative Synthesis Example 1>
Under a nitrogen atmosphere, 2.81 g (9.5 mmol) of zinc nitrate hexahydrate, 1.57 g (9.5 mmol) of terephthalic acid, and 0.739 g (4.7 mmol) of 4,4′-bipyridyl in a volume ratio of N, It was dissolved in 800 mL of a mixed solvent of N, N-dimethylformamide and ethanol consisting of N-dimethylformamide: ethanol = 1: 1 and stirred at 363 K for 48 hours. Subsequently, the deposited 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 2.75 g (yield 95%) of the target metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

<Comparative Synthesis Example 2>
Under a nitrogen atmosphere, zinc nitrate hexahydrate 2.81 g (9.5 mmol), 4,4′-biphenyldicarboxylic acid 2.29 g (9.5 mmol) and 4,4′-bipyridyl 0.75 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 24 hours. The precipitated 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 3.24g (yield 89%). FIG. 7 shows a powder X-ray diffraction pattern of the obtained metal complex.

<Comparative Synthesis Example 3>
In a nitrogen atmosphere, 12.6 g (43 mmol) of zinc nitrate hexahydrate, 4.93 g (43 mmol) of fumaric acid and 3.32 g (21 mmol) of 4,4′-bipyridyl were dissolved in 500 mL of N, N-dimethylformamide. Stir 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 373K and 50 Pa for 8 hours, and obtained the target metal complex 6.93g (yield 63%). The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

<Example 1>
For the metal complex obtained in Synthesis Example 1, the amount of carbon dioxide adsorbed at 273 K was measured by the volumetric method, and an adsorption isotherm was created. The results are shown in FIG.

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

  From FIG. 9, the metal complex obtained in Synthesis Example 1 that satisfies the constituent requirements of the present invention adsorbs carbon dioxide as the pressure increases, and the amount of adsorption is the metal obtained in Comparative Synthesis Example 1 that does not satisfy the constituent requirements of the present invention. Since it is more than the complex, it is clear that the metal complex of the present invention is excellent as an adsorbent for carbon dioxide.

<Example 2>
For the metal complex obtained in Synthesis Example 1, the amount of ethylene adsorbed at 273 K was measured by the volumetric method, and an adsorption isotherm was created. The results are shown in FIG.

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

  From FIG. 10, the metal complex obtained in Synthesis Example 1 that satisfies the constituent requirements of the present invention adsorbs ethylene as the pressure increases, and the amount of adsorption is the metal complex obtained in Comparative Synthesis Example 2 that does not satisfy the constituent requirements of the present invention. Therefore, it is clear that the metal complex of the present invention is excellent as an adsorbent for ethylene.

<Example 3>
For the metal complex obtained in Synthesis Example 1, the amount of methane adsorbed at 273 K was measured by the volumetric method, and an adsorption isotherm was created. The results are shown in FIG.

<Comparative Example 3>
For the metal complex obtained in Comparative Synthesis Example 1, the amount of methane adsorbed at 273 K was measured by the volumetric method, and an adsorption isotherm was created. The results are shown in FIG.

<Comparative Example 4>
For the metal complex obtained in Comparative Synthesis Example 2, the amount of methane adsorbed at 273 K was measured by the volumetric method, and an adsorption isotherm was prepared. The results are shown in FIG.

<Comparative Example 5>
For the metal complex obtained in Comparative Synthesis Example 3, the amount of methane adsorbed at 273K was measured by the volumetric method, and an adsorption isotherm was created. The results are shown in FIG.

  From FIG. 11, the metal complex obtained in Synthesis Example 1 that satisfies the constituent requirements of the present invention adsorbs methane as the pressure increases, and the amount of adsorption thereof is Comparative Synthetic Example 1 and Comparative Synthetic Example 2 that do not satisfy the constituent requirements of the present invention. As compared with the metal complex obtained in Comparative Synthesis Example 3, it is clear that the metal complex of the present invention is excellent as an adsorbent for methane.

<Example 4>
For the metal complex obtained in Synthesis Example 1, the adsorption / desorption amount of methane at 273K was measured by the volumetric method, and an adsorption / desorption isotherm was prepared. 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 273K was measured by the volumetric method, and an adsorption / desorption isotherm was prepared. The results are shown in FIG.

  From the comparison between FIG. 12 and FIG. 13, the metal complex obtained in Synthesis Example 1 that satisfies the constituent requirements of the present invention adsorbs methane as the pressure increases, releases methane as the pressure decreases, and stores it. Since the amount is larger than that of the metal complex obtained in Comparative Synthesis Example 1 that does not satisfy the constituent requirements of the present invention, it is clear that the metal complex of the present invention is excellent as a methane occlusion material. Application to tanks can be expected.

<Example 5>
For the metal complex obtained in Synthesis Example 1, the adsorption and desorption amounts of ethane and methane at 273 K were measured by the volumetric method, and adsorption and desorption isotherms were created. The results are shown in FIG.

<Comparative Example 7>
For the metal complex obtained in Comparative Synthesis Example 3, the adsorption and desorption amount of ethane and methane at 273 K was measured by the volume method, and an adsorption and desorption isotherm was created. The results are shown in FIG.

  From the comparison between FIG. 14 and FIG. 15, the metal complex obtained in Synthesis Example 1 that satisfies the constituent requirements of the present invention selectively adsorbs methane, and the amount of adsorption does not satisfy the constituent requirements of the present invention. Since it is more than the metal complex obtained in Example 3, it is clear that the metal complex of the present invention is excellent as a separator for methane and ethane.

From the results of Examples 1 to 5 and Comparative Examples 1 to 7, the metal complex obtained in Synthesis Example 1 that satisfies the constituent requirements of the present invention is the metal obtained in Comparative Synthesis Examples 1 to 3 that does not satisfy the constituent requirements of the present invention. It is clear that it is excellent as an adsorbent, occlusion material, or separation material for various gases as compared with a complex. The reason why such a difference occurs is not necessarily clear, but it is selected from dicarboxylate ions (I) constituting the metal complex of the present invention and ions of metals belonging to Groups 2 and 7-12 of the periodic table. _Bidentate to at least one metal ion and the metal ion having a point cloud of _D∞h and a length in the major axis direction of 7.0 to 16.0 cm and having two heteroatoms The optimal combination with the positionable organic ligands, and the interaction between the gas molecules and the pore surface is increased, resulting in excellent gas adsorption performance, excellent gas storage performance and excellent gas separation performance. it is conceivable that.

DESCRIPTION OF SYMBOLS 1 Fuel tank as gas storage device 2 Pressure-resistant container 3 Gas storage space 4 Occlusion material 5 Outlet 6 Inlet 7 Valve

Claims (16)

The following general formula (I)

(Wherein R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom or an optionally substituted alkyl group, alkoxy group, formyl group, acyloxy group, alkoxycarbonyl group, nitro group, A cyano group, an amino group, a monoalkylamino group, a dialkylamino group, or an acylamino group, and A is an optionally substituted phenylene group or ethenylene group.)
A dicarboxylate ion (I) represented by: at least one metal ion selected from ions of metals belonging to Groups 2 and 7 to 12 of the periodic table, and a point group of D _∞h , and A metal complex comprising an organic ligand having a length in a major axis direction of from 7.0 to 16.0 and capable of bidentate coordination with the metal ion having two heteroatoms. A is the following general formula (II)

Or a phenylene group represented by the following general formula (III)

(Wherein R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are the same or different and each represents a hydrogen atom, a halogen atom or an alkyl group which may have a substituent) , Alkoxy group, formyl group, acyloxy group, alkoxycarbonyl group, nitro group, cyano group, amino group, monoalkylamino group, dialkylamino group or acylamino group.)
The metal complex according to claim 1, wherein   The metal complex according to claim 1 or 2, wherein the jungle gym skeleton has a structure in which a plurality of interpenetrations are present.   The bidentate organic ligand is 4,4′-bipyridyl, 2,7-diazapyrene, 1,2-bis (4-pyridyl) ethyne, 1,4-bis (4-pyridyl) butadiyne, The metal complex according to claim 1, which is at least one selected from 1,4-bis (4-pyridyl) benzene and 4,4′-bis (4-pyridyl) biphenyl.   An adsorbent comprising the metal complex according to claim 1.   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 5, which is an adsorbent for the purpose.   The occlusion material which consists of a metal complex in any one of Claims 1-4.   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 storage material described.   A gas storage device comprising a pressure-resistant container capable of being kept airtight and having a gas inlet and outlet, and having a gas storage space inside the pressure-resistant container, wherein the gas storage space includes the storage material according to claim 7. Some gas storage devices.   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 9.   The separating material which consists of a metal complex in any one of Claims 1-4.   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 11, which is a separation material for the purpose.   Separation material for separating methane and carbon dioxide, hydrogen and carbon dioxide, nitrogen and carbon dioxide, ethylene and carbon dioxide, methane and nitrogen, methane and ethane, ethane and ethylene, propane and propene, or air and methane. The separation material according to claim 11, which is a material.   The separation method using the separation material according to claim 11, comprising a step of bringing the metal complex into contact with the mixed gas in a pressure range of 0.01 to 10 MPa.   The separation method according to claim 14, wherein the separation method is a pressure swing adsorption method or a temperature swing adsorption method. A dicarboxylate ion (I), at least one metal ion selected from ions of metals belonging to Groups 2 and 7-12 of the periodic table, a point group of _D∞h , and a long axis direction The metal ligand having a length of 7.0 to 16.0 and having 2 heteroatoms is reacted with an organic ligand capable of bidentate coordination with a metal ion, and precipitated. The manufacturing method of the metal complex of description.

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