JP2012020956A - Metal complex and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal complex having excellent carbon dioxide-separating performance.SOLUTION: The metal complex comprises: at least one metal ion selected from metals that belong to Group II and Group VII to XII of the periodic table; a lewis-base anion; and an organic ligand capable of bidentate coordination to the metal ion, wherein the organic ligand is expressed by the general formula (I).

Description

  The present invention relates to a metal complex and a method for producing the same. More specifically, the present invention relates to a metal complex comprising at least one metal ion, a Lewis basic anion, and an organic ligand capable of bidentate coordination with the metal. The metal complex of the present invention 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 It is preferable as an adsorbent for adsorbing vapor and the like. The metal complex of the present invention includes 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 it is also preferable as a separating material for separating organic vapor, and is particularly preferable as a separating material such as methane and carbon dioxide, ethylene and carbon dioxide, hydrogen and carbon dioxide, nitrogen and carbon dioxide, methane and ethane, or air and methane.

  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.

  Examples of applying the dynamic structural change polymer metal complex to an occlusion material or separation material include (1) a metal complex having an interdigitated integrated structure (see Patent Document 1 and Patent Document 2), (2) two-dimensional Metal complex having lattice stacked type integrated structure (see Patent Document 3, Patent Document 4, Patent Document 5, Patent Document 6, Patent Document 7, and Patent Document 8), (3) Metal complex having interpenetrating type integrated structure (See Patent Document 9) and the like are known.

  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.

In Patent Document 6, a polymer metal complex having a unit structure of [X (CF ₃ SO ₃ ) ₂ L ₂ ] _n (wherein X is a divalent transition metal ion and L is an organic ligand). Is disclosed. However, what is described in the examples is a polymer metal complex composed of copper ion, trifluoromethanesulfonate ion, and 4,4′-bipyridyl. In gas adsorption and mixed gas separation, 4,4 ′ -No mention is made of the effect of organic ligands other than bipyridyl capable of bidentate coordination on adsorption performance and separation performance.

Patent Document 7 discloses a polymer metal complex having a unit structure of [NiY ₂ L ₂ ] _n (wherein Y is a counter ion and L is an organic ligand). However, what is described in the examples is a polymer metal complex composed of nickel ions, tetrafluoroborate ions and 1,4-bis (4-pyridyl) benzene, and in gas adsorption and mixed gas separation. No mention is made of the effect of bidentate organic ligands other than 1,4-bis (4-pyridyl) benzene on adsorption performance and separation performance.

In Patent Document 8, a polymer metal complex having a unit structure of [XY ₂ L ₂ ] _n (wherein X is a divalent transition metal ion, Y is a counter ion, and L is an organic ligand) It is disclosed. However, what is described in the examples is a polymer metal complex composed of copper ions, tetrafluoroborate ions, and 4,4′-bipyridyl, and other than copper ions in gas adsorption and mixed gas separation. No mention is made of the effects of organic ions capable of bidentate coordination other than metal ions and 4,4′-bipyridyl on the adsorption performance and separation performance.

  Gas storage organic metal having a three-dimensional structure composed of a divalent metal ion, an organic ligand capable of bidentate coordination having an atom capable of coordinating to the metal ion, and a halogenated divalent metal anion A complex is disclosed (see Patent Document 10). However, what is described in the examples is a polymer metal complex composed of copper ion, hexafluorosilicate ion and 4,4′-bipyridyl, copper ion, tetrafluoroborate ion and 1,4-bis (4 -Pyridyl) Polymer metal complex composed of benzene, Polymer metal complex composed of copper ion, hexafluorogermanate ion and 4,4'-bipyridyl, Copper ion, hexafluorotitanate ion and 4,4'-bipyridyl And a polymer metal complex composed of copper ion, hexafluorozirconate ion and 4,4′-bipyridyl, in the adsorption of gas and separation of mixed gas, Organic ligands capable of bidentate coordination other than 4,4'-bipyridyl and 1,4-bis (4-pyridyl) benzene adsorbed and separated It has not been any mention of the effect of.

  Bidentate to the metal selected from copper ion, Lewis basic anion, 1,2-bis (4-pyridyl) ethane, 1,3-bis (4-pyridyl) propane and 4,4′-dipyridyl sulfide A polymer metal complex comprising an organic ligand capable of coordination is disclosed (see Patent Document 11). However, what is described in the examples is a polymer metal complex composed of copper ion, hexafluorophosphate ion and 1,2-bis (4-pyridyl) ethane, copper ion, hexafluorophosphate ion and tetrafluoro. Polymer metal complex composed of borate ion and 1,2-bis (4-pyridyl) ethane, Polymer metal complex composed of copper ion, tetrafluoroborate ion and 1,2-bis (4-pyridyl) ethane , A polymer metal complex composed of copper ion, hexafluorophosphate ion and 1,3-bis (4-pyridyl) propane, copper ion, tetrafluoroborate ion and 1,3-bis (4-pyridyl) propane Polymeric metal complex comprising copper ion, hexafluoroarsenic acid ion and 1,2-bis (4-pyridyl) ethane, copper ion Polymer metal complex comprising hexafluoroantimonate ion and 1,2-bis (4-pyridyl) ethane, copper ion, benzenesulfonate ion, tetrafluoroborate ion and 1,2-bis (4-pyridyl) ethane Is a polymer metal complex consisting of copper ion, hexafluorophosphate ion and 4-phenylpyridine, and other than trifluoromethanesulfonate ion and copper ion in gas adsorption and mixed gas separation No mention is made of the effect of metal ions on the adsorption performance and separation performance.

JP 2004-161675 A JP 2008-24784A JP 2003-275531 A JP 2003-278997 A JP 2004-74026 A JP 2005-232033 A JP 2005-232034 A JP-A-2005-232222 JP 2003-342260 A JP 2000-117100 A JP 2009-208028 A

Kazuhiro Uemura, Susumu Kitagawa, Future Materials, Volume 2, 44-51 (2002) Ryotaro Matsuda, Susumu Kitagawa, Petrotech, Vol. 26, 97-104 (2003)

  Accordingly, an object of the present invention is to provide an adsorbent having gas adsorbing properties superior to those of the prior art and a metal complex that can be used as a gas separating material having superior separation performance of a mixed gas as compared with the prior art.

  The present inventors have intensively studied and can achieve the above object with a metal complex comprising at least one metal, a Lewis basic anion, and an organic ligand capable of bidentate coordination with the metal. And found the present invention.

That is, according to the present invention, the following is provided.
(1) at least one metal ion selected from metals belonging to groups 2 and 7-12 of the periodic table, a Lewis basic anion, and the following general formula (I):

(Wherein X is the same or different and is a methylene group or a sulfur atom, and R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are the same or different and each represents a hydrogen atom, An alkyl group, alkoxy group, formyl group, acyloxy group, alkoxycarbonyl group, nitro group, cyano group, amino group, monoalkylamino group, dialkylamino group, acylamino group or halogen atom which may have a substituent , N is 1 or 2.) A metal complex composed of an organic ligand capable of bidentate coordination with the metal ion represented by the following formula:

(In the formula, M is at least one metal ion selected from metals belonging to Groups 2 and 7-12 of the periodic table. When M is a copper ion, A is a trifluoromethanesulfonate ion, When A is other than a copper ion, A is at least one anion selected from Lewis basic anions, and B is an organic ligand capable of bidentate coordination with the metal ion. Complex.
(2) The bidentate organic ligand is selected from 1,2-bis (4-pyridyl) ethane, 1,3-bis (4-pyridyl) propane, and 4,4′-dipyridyl sulfide. The metal complex according to (1), which is at least one kind.
(3) The metal complex according to (1) or (2), wherein the metal is at least one selected from manganese, iron, cobalt, nickel and copper.
(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 separating material according to (4), which is an adsorbing material for adsorbing organic vapor.
(6) A separating material comprising the metal complex according to any one of (1) to (3).
(7) 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 separating material according to (6), which is a separating material for separating organic vapor.
(8) The separation material according to (6), 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. Separation material.
(9) At least one metal ion selected from metals belonging to Group 2 and Groups 7-12 of the periodic table, a Lewis basic anion, and an organic ligand (I ) In a solvent to precipitate a metal complex. The method for producing a metal complex according to (1).

  The present invention can provide a metal complex comprising at least one metal ion, a Lewis basic anion, and an organic ligand (I) 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.

  Further, 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 separator for separating sulfur oxides, nitrogen oxides, siloxanes, water vapor or organic vapors, and in particular, methane and carbon dioxide, ethylene and carbon dioxide, hydrogen and carbon dioxide, nitrogen and carbon dioxide. It can be used as a separating material such as carbon, methane and ethane or air and methane.

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 Synthesis Example 3. FIG. 6 is a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 4. FIG. 6 is a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 5. 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 195K of ethylene by the capacitance method about the metal complex obtained by the synthesis example 1, the comparative synthesis example 1, and the comparative synthesis example 2. FIG. It is the result of having measured the adsorption-desorption isotherm in 195K of a carbon dioxide and methane about the metal complex obtained by the synthesis example 1 by the capacitance method. It is the result of having measured the adsorption-desorption isotherm of carbon dioxide and methane in 195K 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 in 195K of a carbon dioxide and methane about the metal complex obtained by the synthesis example 3 by the capacitance method. It is the result of having measured the adsorption-desorption isotherm in 195K of a carbon dioxide and methane about the metal complex obtained by the comparative synthesis example 3 by the capacitance method. It is the result of having measured the adsorption-desorption isotherm in 195K of a carbon dioxide and ethylene about the metal complex obtained by the synthesis example 4 by the capacitance method. It is the result of having measured the adsorption-desorption isotherm in 195K of a carbon dioxide and ethylene about the metal complex obtained by the synthesis example 5 by the capacitance method. It is the result of having measured the adsorption-desorption isotherm of carbon dioxide and ethylene in 195K by the capacitance method about the metal complex obtained by the comparative synthesis example 4.

  The metal complex of the present invention comprises at least one metal ion selected from metals belonging to Groups 2 and 7-12 of the periodic table, a Lewis basic anion, and an organic coordination capable of bidentate coordination with the metal. It consists of a child (I).

  The metal complex of the present invention comprises at least one metal ion selected from metals belonging to Groups 2 and 7-12 of the periodic table, a Lewis basic anion, and an organic coordination capable of bidentate coordination with the metal. The child (I) can be produced by reacting and precipitating for a few hours to several days in a solvent under normal pressure. For example, an aqueous solution or organic solvent solution of a metal salt and an organic solvent solution containing a Lewis basic anion and an organic ligand capable of bidentate coordination are mixed and reacted under normal pressure to react with the metal of the present invention. A complex can be obtained.

  Examples of salts of metals belonging to Groups 2 and 7-12 of the periodic table used in the present invention include magnesium salts, calcium salts, manganese salts, iron salts, ruthenium salts, cobalt salts, rhodium salts, nickel salts, palladium salts, Copper salts, zinc salts and cadmium salts can be used, with manganese salts, iron salts, cobalt salts, nickel salts and copper salts being preferred, and cobalt salts and nickel salts being more preferred. 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.

  Examples of Lewis basic anions used in the present invention include tetrafluoroborate ion, hexafluorophosphate ion, hexafluoroarsenate ion, hexafluoroantimonate ion, formate ion, acetate ion, trifluoroacetate ion, trifluoromethanesulfone. Acid ions and benzenesulfonate ions can be used, and tetrafluoroborate ions, hexafluorophosphate ions, hexafluoroarsenate ions, hexafluoroantimonate ions, and trifluoromethanesulfonate ions are preferable. Two or more kinds of anions may be mixed and used. Here, the Lewis basic anion means an anion which is chemically stable and hardly exhibits reducibility or nucleophilicity.

  The Lewis basic anion used in the present invention may be a metal salt counter anion or may be used in the form of an alkali metal salt.

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

It is represented by In the formula, X is the same or different and is a methylene group (CH ₂ ) or a sulfur atom (S), and R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are the same. Alternatively, a hydrogen atom, an optionally substituted alkyl group, an alkoxy group, a formyl group, an acyloxy group, an alkoxycarbonyl group, a nitro group, a cyano group, an amino group, a monoalkylamino group, a dialkylamino group, an acylamino group A group or a halogen atom, and n is 1 or 2.

Among the substituents that can constitute R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ , 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 are examples of alkoxycarbonyl group, methoxycarbonyl group, ethoxycarbonyl group, n-butoxycarbonyl group are examples of monoalkylamino group, methylamino Examples of the dialkylamino group include a dimethylamino group Examples of amino group, 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.

As the organic ligand (I) capable of bidentate coordination, for example, 1,2-bis (4-pyridyl) ethane (X═CH ₂ , n = 1), 1,3-bis (4-pyridyl) Propane (X═CH ₂ , n = 2) and 4,4′-dipyridyl sulfide (X═S, n = 1) are preferred. Here, an organic ligand capable of bidentate coordination means a neutral ligand having two or more atoms coordinated to a metal by an unshared electron pair.

  The mixing ratio of the Lewis basic anion to the bidentate organic ligand (I) when producing the metal complex is as follows: Lewis basic anion: bidentate organic ligand (I) = 1 : Preferably in the range of 5-5: 1 molar ratio, more preferably in the range of 1: 3-3: 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.

  When the metal complex is produced, the mixing ratio of the metal salt and the organic ligand (I) capable of bidentate coordination is as follows: metal salt: organic ligand capable of bidentate coordination (I) = 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 metal salt in the solvent 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 Lewis basic anion in the solvent 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.

  The molar concentration of the organic ligand (I) capable of bidentate coordination in the solvent for producing the metal complex is preferably 0.001 to 5.0 mol / L, more preferably 0.005 to 2.0 mol / L. preferable. 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.

  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 degree of structural change differs depending on the substance to be adsorbed, so that high selectivity is expressed. In the present invention, the interaction between the metal ion and its counter anion, the basic anion, is controlled, that is, the metal ion and the organic ligand capable of bidentate coordination represented by the general formula (I) By controlling the charge density on the surface of the pores composed of a one-dimensional chain structure consisting of the above, high gas separation performance is 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 and triethylamine; aldehydes such as acetaldehyde; aliphatic hydrocarbons having 5 to 16 carbon atoms; aromatic hydrocarbons such as benzene and toluene. Ketones such as acetone and methyl ethyl ketone; halogenated hydrocarbons such as methyl chloride, methylene chloride and chloroform;

  In addition, since the metal complex of the present invention can selectively adsorb various gases, carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, C 1-4 hydrocarbon (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 3 ° / min, and measured by a symmetric reflection method. Details of the analysis conditions are shown below.
<Analysis conditions>
Equipment: NEW D8 ADVANCE manufactured by Bruker AXS Co., Ltd.
X-ray source: CuKα (λ = 1.5418Å) 40 kV 40 mA
Goniometer: Horizontal goniometer Detector: LynxEye
Step width: 0.02 °
Slit: Divergent slit = 0.6mm
Receiving slit = 1.5 °
Scattering slit = 0.6mm

(2) Measurement of adsorption / desorption isotherm Measurement was performed by a volumetric method using a gas adsorption amount measuring device. At this time, prior to measurement, the sample was dried at 373 K and 2 Pa for 12 hours to remove adsorbed water and the like. Details of the analysis conditions are shown below.
<Analysis conditions>
Apparatus: BELSORP-max manufactured by Nippon Bell Co., Ltd.
Equilibrium waiting time: 300 seconds

<Synthesis Example 1>
Under a nitrogen atmosphere, 0.290 g (0.85 mmol) of cobalt tetrafluoroborate hexahydrate was dissolved in 20 mL of acetonitrile and stirred at 353 K for 30 minutes. Subsequently, 20 mL of acetonitrile solution of 0.380 g (2.1 mmol) of 1,2-bis (4-pyridyl) ethane was dropped over 30 minutes. Thereafter, the mixture was stirred at 353 K for 3 hours. The precipitated metal complex was collected by suction filtration and then washed three times with acetonitrile to obtain 0.218 g (yield 37%) of the target metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

<Synthesis Example 2>
Under a nitrogen atmosphere, 0.299 g (1.0 mmol) of cobalt nitrate hexahydrate and 0.365 g (2.0 mmol) of 1,2-bis (4-pyridyl) ethane in a volume ratio of water: ethanol = 1: 4 The resultant was dissolved in 25 mL of a mixed solvent of water and ethanol, and stirred at 353 K for 30 minutes. Subsequently, 10 mL of an aqueous solution of 0.850 g (5.1 mmol) of sodium hexafluorophosphate was added dropwise over 10 minutes. Then, it stirred at 353K for 1 hour. The deposited metal complex was collected by suction filtration, and then washed with water three times and then with ethanol three times to obtain 0.346 g (43% yield) of the target metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

<Synthesis Example 3>
Under a nitrogen atmosphere, 3.62 g (10 mmol) of copper trifluoromethanesulfonate was dissolved in 200 mL of water and stirred at 298 K for 30 minutes. Subsequently, 200 mL of an acetone solution of 3.69 g (20 mmol) of 1,2-bis (4-pyridyl) ethane was added dropwise over 1 hour. Then, it stirred at 298K for 1 hour. The precipitated metal complex was collected by suction filtration and then washed with acetone three times to obtain 6.73 g (yield 83%) of the target metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

<Synthesis Example 4>
Under a nitrogen atmosphere, 0.290 g (1.0 mmol) of nickel nitrate hexahydrate and 0.380 g (2.1 mmol) of 1,2-bis (4-pyridyl) ethane in a volume ratio of water: ethanol = 1: 4 The resultant was dissolved in 25 mL of a mixed solvent of water and ethanol, and stirred at 353 K for 30 minutes. Subsequently, 10 mL of an aqueous solution of sodium tetrafluoroborate 0.550 g (5.0 mmol) was added dropwise over 10 minutes. Then, it stirred at 353K for 1 hour. The precipitated metal complex was collected by suction filtration, and then washed with water three times and then with ethanol three times to obtain 0.289 g (yield 44%) of the target metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

<Synthesis Example 5>
Under a nitrogen atmosphere, 0.290 g (1.0 mmol) of nickel nitrate hexahydrate and 0.390 g (2.1 mmol) of 1,2-bis (4-pyridyl) ethane in a volume ratio of water: ethanol = 1: 4 The resultant was dissolved in 25 mL of a mixed solvent of water and ethanol, and stirred at 353 K for 30 minutes. Subsequently, 10 mL of an aqueous solution of 0.850 g (5.1 mmol) of sodium tetrafluorophosphate was added dropwise over 10 minutes. Then, it stirred at 353K for 1 hour. The precipitated metal complex was collected by suction filtration, and then washed with water three times and then with ethanol three times to obtain 0.679 g (yield 80%) of the target metal complex. FIG. 5 shows a powder X-ray diffraction pattern of the obtained metal complex.

<Comparative Synthesis Example 1>
Under a nitrogen atmosphere, 3.45 g (10 mmol) of copper hexafluoroborate hexahydrate was dissolved in 200 mL of water and stirred at 298 K for 30 minutes. Subsequently, 200 mL of an acetone solution of 3.69 g (20 mmol) of 1,2-bis (4-pyridyl) ethane was added dropwise over 1 hour. Then, it stirred at 298K for 1 hour. The deposited metal complex was collected by suction filtration and then washed with acetone three times to obtain 5.99 g (yield 83%) of the target metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

<Comparative Synthesis Example 2>
In a nitrogen atmosphere, 3.45 g (10 mmol) of copper hexafluoroborate hexahydrate and 3.68 g (20 mmol) of potassium hexafluorophosphate were dissolved in 200 mL of water, stirred at 298 K for 30 minutes, and then insoluble by suction filtration. The thing was removed. Subsequently, 200 mL of an acetone solution of 3.69 g (20 mmol) of 1,2-bis (4-pyridyl) ethane was added dropwise to the filtrate over 1 hour. Then, it stirred at 298K for 1 hour. The deposited metal complex was collected by suction filtration and then washed with acetone three times to obtain 6.71 g (yield 80%) of the target metal complex. FIG. 7 shows a powder X-ray diffraction pattern of the obtained metal complex.

<Comparative Synthesis Example 3>
Under nitrogen atmosphere, 1.55 g (4.5 mmol) of copper hexafluoroborate hexahydrate was dissolved in 100 mL of water and stirred at 353 K for 1 hour. Subsequently, 100 mL of an acetone solution of 2.20 g (10 mmol) of 4,4′-dipyridyl disulfide was added dropwise over 30 minutes. Thereafter, the mixture was stirred at 353 K for 3 hours. The precipitated metal complex was collected by suction filtration, and then washed with water three times and then with acetone three times to obtain 2.93 g (yield 82%) of the desired metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

<Comparative Synthesis Example 4>
Under nitrogen atmosphere, 1.55 g (4.5 mmol) of copper hexafluoroborate hexahydrate was dissolved in 100 mL of water and stirred at 353 K for 1 hour. Subsequently, 100 mL of an acetone solution of 1.99 g (10 mmol) of 1,3-bis (4-pyridyl) propane was added dropwise over 60 minutes. Thereafter, the mixture was stirred at 353 K for 3 hours. The precipitated metal complex was collected by suction filtration, and then washed with water three times and then with acetone three times to obtain 2.40 g (yield 63%) of the target metal complex. 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, an adsorption isotherm of ethylene at 195 K was measured. The results are shown in FIG.

<Comparative Example 1>
For the metal complex obtained in Comparative Synthesis Example 1, an adsorption isotherm of ethylene at 195 K was measured. The results are shown in FIG.

<Comparative example 2>
For the metal complex obtained in Comparative Synthesis Example 2, an ethylene adsorption isotherm at 195K was measured. The results are shown in FIG.

  From FIG. 10, it is clear that the metal complex of the present invention is excellent as an ethylene adsorbent because it has a large amount of ethylene adsorbed in a low pressure region.

<Example 2>
For the metal complex obtained in Synthesis Example 1, the adsorption / desorption isotherm of carbon dioxide and methane at 195 K was measured. The results are shown in FIG.

<Example 3>
For the metal complex obtained in Synthesis Example 2, the adsorption and desorption isotherm of carbon dioxide and methane at 195 K was measured. The results are shown in FIG.

<Example 4>
For the metal complex obtained in Synthesis Example 3, the adsorption / desorption isotherm of carbon dioxide and methane at 195 K was measured. The results are shown in FIG.

<Comparative Example 3>
For the metal complex obtained in Comparative Synthesis Example 3, the adsorption / desorption isotherm of carbon dioxide and methane at 195 K was measured. The results are shown in FIG.

  From comparison between FIGS. 11, 12 and 13 and FIG. 14, it is clear that the metal complex of the present invention selectively adsorbs carbon dioxide, and thus is excellent as a separator for methane and carbon dioxide.

<Example 5>
For the metal complex obtained in Synthesis Example 4, the adsorption and desorption isotherm of carbon dioxide and ethylene at 195 K was measured. The results are shown in FIG.

<Example 6>
For the metal complex obtained in Synthesis Example 5, the adsorption and desorption isotherm of carbon dioxide and ethylene at 195 K was measured. The results are shown in FIG.

<Comparative example 4>
For the metal complex obtained in Comparative Synthesis Example 4, the adsorption / desorption isotherm of carbon dioxide and ethylene at 195 K was measured. The results are shown in FIG.

  From the comparison of FIGS. 15, 16, and 17, the metal complex of the present invention has an adsorption amount of carbon dioxide of three times or more than the adsorption amount of ethylene and selectively adsorbs carbon dioxide. It is clear that it is excellent as a material.

Claims (9)

At least one metal ion selected from metals belonging to Groups 2 and 7-12 of the periodic table, a Lewis basic anion, and the following general formula (I);

(Wherein X is the same or different and is a methylene group or a sulfur atom, and R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are the same or different and each represents a hydrogen atom, An alkyl group, alkoxy group, formyl group, acyloxy group, alkoxycarbonyl group, nitro group, cyano group, amino group, monoalkylamino group, dialkylamino group, acylamino group or halogen atom which may have a substituent , N is 1 or 2.) A metal complex composed of an organic ligand capable of bidentate coordination with the metal ion represented by the following formula:

(In the formula, M is at least one metal ion selected from metals belonging to Groups 2 and 7-12 of the periodic table. When M is a copper ion, A is a trifluoromethanesulfonate ion, When A is other than a copper ion, A is at least one anion selected from Lewis basic anions, and B is an organic ligand capable of bidentate coordination with the metal ion. Complex.   The bidentate organic ligand is at least one selected from 1,2-bis (4-pyridyl) ethane, 1,3-bis (4-pyridyl) propane and 4,4′-dipyridyl sulfide. The metal complex according to claim 1, wherein   The metal complex according to claim 1 or 2, wherein the metal is at least one selected from manganese, iron, cobalt, nickel, and copper.   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 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 6, which is a separation material for separation. The separation material according to claim 6, 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. At least one metal ion selected from metals belonging to Groups 2 and 7-12 of the periodic table, a Lewis basic anion, and an organic ligand (I) capable of bidentate coordination with the metal ion The method for producing a metal complex according to claim 1, wherein the metal complex is precipitated by reacting in a solvent.

Images