JP2011051949A - Metal complex and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal complex having excellent gas separation performance. <P>SOLUTION: The metal complex comprises: a dicarboxylic acid compound represented by general formula (I); at least one metal selected from metals that belong to periods 4 and 5 of groups 6 to 11; and an organic ligand which can form a bidentate on the metal. In the formula (I), R<SP>1</SP>, R<SP>2</SP>and R<SP>3</SP>are each the same or different, and are a hydrogen atom, an alkyl group which may contain a substituent, or a halogen atom; X is a carbon atom or a nitrogen atom; and Y is a hydrogen atom, the alkyl group which may contain a substituent, an aryl group or the like, wherein Y does not exist when X is a nitrogen atom. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a metal complex, a method for producing the same, and a separating material comprising the metal complex. More specifically, from a specific dicarboxylic acid compound, at least one metal selected from metals belonging to the 4th to 5th periods of Groups 6 to 11, and an organic ligand capable of bidentate coordination with the metal To a metal complex and a separating material. 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 a separating material for separating steam, and particularly preferable as a separating material such as methane and carbon dioxide, hydrogen and carbon dioxide, nitrogen and carbon dioxide, 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. (For example, refer nonpatent literature 1). 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 Documents 2 and 3). 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. Moreover, the time required for the pressure change can be shortened, which contributes 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 structure-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 (2) a two-dimensional lattice stacking type. Metal complexes having an integrated structure (see Patent Document 2, Patent Document 3, Patent Document 4, Patent Document 5, Patent Document 6, and Patent Document 7), (3) Metal complexes having an interpenetrating structure (Patent Document 8) For example).

  However, since any polymer metal complex does not adsorb gas unless it exceeds a certain pressure, it cannot be adsorbed when the partial pressure of the gas to be adsorbed and removed in the mixed gas falls below a certain pressure, so that high purity can be achieved. However, it was difficult to reduce the size of the device.

  A polymer metal complex composed of 2,7-naphthalenedicarboxylic acid, zinc, and 4,4′-bipyridyl exhibits an I-type adsorption profile in the IUPAC classification, but in an adsorption test of a mixed gas of carbon dioxide, nitrogen, and oxygen. It is known to selectively adsorb carbon dioxide (see Non-Patent Document 4). However, no mention is made of the effect of the central metal on the separation performance in the separation of the mixed gas.

  A polymer metal complex comprising an isophthalic acid derivative, a 2,7-naphthalenedicarboxylic acid derivative, or a 4,4′-benzophenone dicarboxylic acid derivative, a metal ion, and an organic ligand capable of bidentate coordination with the metal ion Has an affinity for unsaturated organic molecules, and is known to be effective for the separation of unsaturated organic molecules (see Patent Document 9). However, no mention is made of the effect of the central metal on the separation performance in the separation of the mixed gas.

  A polymer metal complex composed of isophthalic acid and nickel or cadmium and 4,4'-bipyridyl is known (see Non-Patent Document 5). However, no mention is made of the gas adsorption behavior.

  A polymer metal complex composed of isophthalic acid, manganese, and 4,4'-bipyridyl is known (see Non-Patent Document 6). However, no mention is made of the gas adsorption behavior.

  A polymer metal complex composed of isophthalic acid, copper, and 4,4′-bipyridyl is known (see Non-Patent Document 7). However, no mention is made of the gas adsorption behavior.

  A polymer metal complex composed of isophthalic acid and zinc or cadmium and 4,4'-bipyridyl is known (see Non-Patent Document 8). However, no mention is made of the gas adsorption behavior.

  A polymer metal complex composed of isophthalic acid, zinc, and 4,4'-bipyridyl is known to adsorb methanol, ethanol, benzene, water, and carbon dioxide (see Non-Patent Document 9). However, nothing is mentioned about the separation performance of the mixed gas.

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

Supervised by Atsushi Takeuchi, "The latest adsorption technology handbook" 1st edition, NTS, pages 84-163 (1999) Kazuhiro Uemura, Susumu Kitagawa, Future Materials, Volume 2, 44-51 (2002) Ryotaro Matsuda, Susumu Kitagawa, Petrotech, Vol. 26, 97-104 (2003) Hiroshi Nakagawa, Daisuke Tanaka, Satoru Shimomura, Susumu Kitagawa, Proceedings of the 61st Annual Meeting on Colloid and Interface Chemistry, P172 J. et al. Tao, X. -M. Chen, R.A. -B. Huang, L.H. -S. Zheng, Journal of Solid State Chemistry, 170, 130-134 (2003) C. Ma, C.I. Chen, Q.D. Liu, D.D. Liao, L.M. Li, L. Sun, New Journal of Chemistry, 27, 890-894 (2003) Y. -H. Wen, J.M. -K. Cheng, Y.C. -L. Feng, J.H. Zhang, Z .; -J. Li, Y. -G. Yao, Inorganica Chimica Acta, 358, 3347-3354 (2005) G. Tian, G. Zhu, Q.H. Fang, X. Guo, M.M. Xue, J. et al. Sun, S.M. Qiu, Journal of Molecular Structure, 787, 45-49 (2006) S. Horike, D.H. Tanaka, K .; Nakagawa, S .; Kitagawa, Chemical Communications, 3395-3397 (2007)

  Accordingly, an object of the present invention is to provide a metal complex that can be used as a gas separation material that exhibits a higher gas separation performance than conventional ones and requires less energy for desorption.

  The present inventors have intensively studied, a specific dicarboxylic acid compound, at least one metal selected from metals belonging to Groups 4 to 11 and 4 to 5 periods, and an organic capable of bidentate coordination with the metal. The present inventors have found that the above object can be achieved by a metal complex comprising a ligand, and have reached the present invention.

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

(Wherein R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom, an alkyl group or a halogen atom which may have a substituent, X represents a carbon atom or a nitrogen atom, and Y represents Hydrogen atom, optionally substituted alkyl group, aryl group, aralkyl group, alkoxy group, aryloxy group, aralkyloxy group, formyl group, acyloxy group, alkoxycarbonyl group, amino group, amide group, nitro group Or a halogen atom, and when X is a nitrogen atom, Y does not exist.) And a metal belonging to the 4th to 5th group of the 6th to 11th group (for example, chromium, At least one metal selected from molybdenum, manganese, iron, ruthenium, cobalt, rhodium, nickel, palladium and copper) and bidentate coordination with the metal Metal complex consisting of various organic ligands.
(2) The bidentate organic ligand is 1,4-diazabicyclo [2.2.2] octane, pyrazine, 2,5-dimethylpyrazine, 4,4'-bipyridyl, 2,2'- Dimethyl-4,4′-bipyridine, 1,2-bis (4-pyridyl) ethyne, 1,4-bis (4-pyridyl) butadiyne, 1,4-bis (4-pyridyl) benzene, 3,6-di (4-pyridyl) -1,2,4,5-tetrazine, 2,2′-bi-1,6-naphthyridine, phenazine, diazapyrene, trans-1,2-bis (4-pyridyl) ethene, 4,4 '-Azopyridine, 1,2-bis (4-pyridyl) ethane, 1,2-bis (4-pyridyl) -glycol and N- (4-pyridyl) isonicotinamide (1 ).
(3) The metal complex according to (1) or (2), wherein the metal is manganese, nickel, or copper.
(4) A separating material comprising the metal complex according to any one of (1) to (3).
(5) The separator is carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbon having 1 to 4 carbon atoms, noble gas, hydrogen sulfide, ammonia, sulfur oxide, nitrogen oxide, siloxane, water vapor or The separation material according to (4), which is a separation material for separating organic vapor.
(6) The separation material according to (5), wherein the separation material is a separation material for separating methane and carbon dioxide, hydrogen and carbon dioxide, nitrogen and carbon dioxide, or air and methane.
(7) Dicarboxylic acid compound (I) and at least one metal salt selected from metals belonging to groups 4 to 5 of Groups 6 to 11 (for example, chromium salt, molybdenum salt, manganese salt, iron salt, ruthenium) Salt, cobalt salt, rhodium salt, nickel salt, palladium salt and copper salt) and an organic ligand capable of bidentate coordination with the metal in a solvent, A method for producing a metal complex to be deposited.

  According to the present invention, two types of dicarboxylic acid compounds selected from specific dicarboxylic acid compounds, at least one metal selected from metals belonging to Groups 4 to 5 of Group 6-11, and bidentate to the metal A metal complex comprising an organic ligand capable of coordination can be provided.

  The metal complex used in the present invention can be used as a separation material that maintains high mixed gas separation performance and requires less energy for desorption in the separation of mixed gas.

3 is a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 1. FIG. 4 is a powder X-ray diffraction pattern of the metal complex obtained in Synthesis Example 2. FIG. 3 is a powder X-ray diffraction pattern of the metal complex obtained in Comparative Synthesis Example 1. FIG. 4 is a powder X-ray diffraction pattern of the metal complex obtained in Comparative Synthesis Example 2. FIG. It is the result of having measured the adsorption rate of the carbon dioxide and methane in 273K and 0.1 MPa about the metal complex obtained by the synthesis example 1 and the comparative synthesis example 1. FIG. It is the result of measuring the adsorption / desorption isotherm of carbon dioxide and methane at 273 K by the volumetric method for the metal complex obtained in Synthesis Example 2. It is the result of having measured the adsorption-desorption isotherm of carbon dioxide and methane at 273 K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 2. It is the result of having measured the adsorption-desorption isotherm in the 273K, 283K, and 293K of a carbon dioxide by the capacitance method about the metal complex obtained by the synthesis example 1. FIG. It is the result of having measured the adsorption-desorption isotherm in the 273K, 283K, and 293K of a carbon dioxide by the capacitance method about the metal complex obtained by the comparative synthesis example 1. FIG. It is the result of having measured the adsorption-desorption isotherm in the 273K, 283K, and 293K of a carbon dioxide by the capacitance method about the metal complex obtained by the synthesis example 2. FIG. It is the result of measuring the adsorption / desorption isotherm of carbon dioxide at 273K, 283K, and 293K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 2.

  The metal complex used in the present invention includes a dicarboxylic acid compound (I), at least one metal selected from metals belonging to the 4th to 5th groups of Groups 6 to 11, and an organic compound capable of bidentate coordination with the metal. Consisting of a ligand.

  The metal complex includes a dicarboxylic acid compound (I), at least one metal salt selected from metals belonging to Groups 4 to 5 in Groups 6 to 11, and an organic ligand capable of bidentate coordination with the metal. Can be produced by reacting and precipitation in a solvent under normal pressure for several hours to several days. For example, it is obtained by mixing and reacting an aqueous solution or organic solvent solution of a metal salt with an organic solvent solution containing a dicarboxylic acid compound (I) and an organic ligand capable of bidentate coordination under normal pressure. Can do.

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

It is represented by In the formula, R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom, an optionally substituted alkyl group or a halogen atom, X represents a carbon atom or a nitrogen atom, and Y represents hydrogen. Atoms, optionally substituted alkyl groups, aryl groups, aralkyl groups, alkoxy groups, aryloxy groups, aralkyloxy groups, formyl groups, acyloxy groups, alkoxycarbonyl groups, amino groups, amide groups, nitro groups or When a halogen atom is shown and X is a nitrogen atom, Y does not exist.

As for R ¹ , R ² and R ³ , the alkyl group preferably has 1 to 5 carbon atoms. Examples of the alkyl group include a straight or branched alkyl group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and a pentyl group, and a halogen atom. Examples of are fluorine atom, chlorine atom, bromine atom and iodine atom. Examples of the substituent that the alkyl group may have include an alkoxy group (methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, tert-butoxy group, etc.), Amino group, 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) and the like. 1-3 are preferable and, as for the number of the substituents of an alkyl group, one is more preferable.

  Y is a hydrogen atom, an optionally substituted alkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, an aralkyloxy group, a formyl group, an acyloxy group, an alkoxycarbonyl group, an amino group, Amide group, nitro group or halogen atom may be mentioned.

  With respect to Y, the alkyl group preferably has 1 to 5 carbon atoms. Examples of the alkyl group include a straight chain 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. As an example of this, a phenyl group, an example of an aralkyl group, a benzyl group, an example of an alkoxy group, a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, Examples of the tert-butoxy group include an aryloxy group, a phenoxy group, an aralkyloxy group, a benzyloxy group, and an acyloxy group as an acetoxy group, n-propanoyloxy group, n- Butanoyloxy, pivaloyloxy and benzoyloxy groups are examples of alkoxycarbonyl groups Cicarbonyl group, ethoxycarbonyl group and n-butoxycarbonyl group are amino groups such as N, N-dimethylamino group and halogen atoms are fluorine atom, chlorine atom, bromine atom and iodine atom. , 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, 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) and the like. 1-3 are preferable and, as for the number of the substituents of an alkyl group, one is more preferable.

  Examples of the dicarboxylic acid compound (I) include isophthalic acid, 3,5-pyridinedicarboxylic acid, 5-methoxyisophthalic acid, 5-fluoroisophthalic acid, 5-chloroisophthalic acid, 5-bromoisophthalic acid, 5-iodoisophthalic acid, 5-Nitroisophthalic acid or 5-formylisophthalic acid is preferred.

  The mixing ratio of the dicarboxylic acid compound (I) and the bidentate organic ligand is as follows: dicarboxylic acid compound (I): bidentate organic ligand = 1: 5 to 8: 1 mol. Within the range of the ratio, more preferably within the range of the molar ratio of 1: 3 to 6: 1. 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 organic ligand capable of bidentate coordination is preferably within the range of the molar ratio of metal salt: organic ligand capable of bidentate coordination = 3: 1 to 1: 3. A molar ratio in the range of 1: 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 dicarboxylic acid compound (I) is preferably from 0.01 to 5.0 mol / L, more preferably from 0.05 to 2.0 mol / L. Even if the reaction is performed at a concentration lower than this, the desired metal complex can be obtained, but this is not preferable because the yield decreases. If the concentration is higher than this, the solubility is lowered and the reaction does not proceed smoothly.

  The molar concentration of the bidentate organic ligand is preferably 0.01 to 5.0 mol / L, more preferably 0.05 to 2.0 mol / L. Even if the reaction is performed at a concentration lower than this, the desired metal complex can be obtained, but this is not preferable because the yield decreases. If the concentration is higher than this, the solubility is lowered and the reaction does not proceed smoothly.

  As the metal salt, a metal salt selected from chromium salt, molybdenum salt, manganese salt, iron salt, ruthenium salt, cobalt salt, rhodium salt, nickel salt, palladium salt and copper salt can be used, manganese salt, Nickel salts and copper salts are preferred, and manganese salts are more preferred. As these metal salts, organic acid salts such as acetates and formates, and inorganic acid salts such as sulfates, nitrates and carbonates can be used. The molar concentration of the metal salt is preferably 0.01 to 5.0 mol / L, more preferably 0.05 to 2.0 mol / L. Even if the reaction is performed at a concentration lower than this, the desired metal complex can be obtained, but this is not preferable because the yield decreases. Further, at a concentration higher than this, unreacted metal salt remains, and purification of the obtained metal complex becomes difficult.

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

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

  The separating material comprising the metal complex of the present invention obtained as described above is a two-dimensional chain in which a one-dimensional chain comprising a dicarboxylic acid compound (I) and a metal ion (for example, manganese ion) is linked by a bidentate ligand. A dimension sheet is formed. These two-dimensional sheets are accumulated to form a three-dimensional structure having pores (one-dimensional channels).

  Since the three-dimensional structure in the metal complex 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. In the present invention, by using a central metal having a strong cationic property, structural change is less likely to occur, and high mixed gas separation ability can be exhibited. In addition, the electrons of the ligand are attracted to the central metal having a strong cationic property, and the charge density on the pore surface is reduced, so that the heat of adsorption is reduced and the energy required for desorption is reduced. 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 can selectively adsorb various gases, carbon dioxide, hydrogen, carbon monoxide, oxygen, nitrogen, hydrocarbons having 1 to 4 carbon atoms (methane, ethane, ethylene, acetylene, etc.) ), Noble gases (such as helium, neon, argon, krypton, xenon), hydrogen sulfide, ammonia, sulfur oxides, nitrogen oxides, siloxanes (such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane), water vapor or organic vapors It is preferable as a separating material for separating the carbon dioxide, particularly carbon dioxide in methane, carbon dioxide in hydrogen, carbon dioxide in nitrogen or methane in air, etc., by pressure swing adsorption method or temperature swing adsorption method. Suitable for The organic vapor means a vaporized organic substance that is liquid at normal temperature and pressure. Examples of such organic substances include alcohols such as methanol and ethanol; amines such as trimethylamine; aldehydes such as acetaldehyde; aliphatic hydrocarbons having 5 to 16 carbon atoms; aromatic hydrocarbons such as benzene and toluene; acetone And ketones such as methyl ethyl ketone; halogenated hydrocarbons such as methyl chloride and chloroform.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. Analysis and evaluation in the following examples and comparative examples were performed as follows.

(1) Measurement of powder X-ray diffraction pattern Using an X-ray diffractometer, a range of diffraction angle (2θ) = 5 to 50 ° was scanned at a scanning speed of 1 ° / min, and measured by a symmetric reflection method. Details of the measurement conditions are shown below.
<Analysis conditions>
Apparatus: RINT2400 manufactured by Rigaku Corporation
X-ray source: CuKα (λ = 1.5418Å) 40 kV 200 mA
Goniometer: Vertical goniometer Detector: Scintillation counter Step width: 0.02 °
Slit: Divergent slit = 0.5 °
Receiving slit = 0.15mm
Scattering slit = 0.5 °

(2) Measurement of gas adsorption rate at 0.1 MPa Prepare a glass 10 mL two-necked flask equipped with a three-way cock and a septum, and connect a 100-mL syringe to one of the three-way cocks via another three-way cock with a tube. did. For measurement, put the sample in a two-necked flask, dry at 373 K, 4.0 × 10 ⁻³ Pa for 3 hours, remove adsorbed water, etc., then close the three-way cock attached to the flask, and then three-way on the syringe side 100 mL of the mixed gas was introduced into the syringe through the cock, and finally, the three-way cock attached to the flask was opened to adsorb the mixed gas to the sample. At this time, the adsorption amount was calculated from the decrease in the scale of the syringe (the dead volume was measured in advance using helium).

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

(4) Measurement of adsorption heat The adsorption / desorption isotherm was measured at 273K, 283K, and 293K by a volumetric method using a high-precision gas / vapor adsorption amount measuring apparatus, and the adsorption heat was calculated from the Clapeyron-Clauus equation. At this time, prior to the measurement, the sample was dried at 373 K and 10 Pa for 8 hours to remove adsorbed water and the like. Details of the measurement conditions are shown below.
<Analysis conditions>
Device: Nippon Bell Co., Ltd. BELSORP-18PLUS
Equilibrium waiting time: 500 seconds

Synthesis example 1:
Under a nitrogen atmosphere, manganese nitrate hexahydrate 4.82 g (17 mmol), isophthalic acid 2.80 g (17 mmol) and 4,4′-bipyridyl 2.65 g (17 mmol) were dissolved in 200 mL of N, N-dimethylformamide. Stir at 393 K for 24 hours. After suction filtration, it was washed with ethanol three times and dried at 373 K and 50 Pa for 8 hours to obtain 5.67 g (yield 90%) 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, manganese nitrate hexahydrate (4.82 g, 17 mmol), 3,5-pyridinedicarboxylic acid (2.80 g, 17 mmol), and 4,4′-bipyridyl (2.65 g, 17 mmol) were mixed with N, N-dimethylformamide. Dissolve in 200 mL and stir at 393 K for 24 hours. After suction filtration, it was washed with ethanol three times and dried at 373 K and 50 Pa for 8 hours to obtain 4.86 g (yield 76%) of the target metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

Comparative synthesis example 1:
Under a nitrogen atmosphere, 5.00 g (17 mmol) of zinc nitrate hexahydrate, 2.80 g (17 mmol) of isophthalic acid and 2.65 g (17 mmol) of 4,4′-bipyridyl were dissolved in 200 mL of N, N-dimethylformamide, Stir at 393 K for 24 hours. After suction filtration, it was dried at 373 K and 50 Pa for 8 hours to obtain 6.35 g (yield 98%) of the desired 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, 5.00 g (17 mmol) of zinc nitrate hexahydrate, 2.80 g (17 mmol) of 3,5-pyridinedicarboxylic acid and 2.65 g (17 mmol) of 4,4′-bipyridyl were added to N, N-dimethylformamide. Dissolve in 200 mL and stir at 393 K for 24 hours. After suction filtration, it was washed with ethanol three times and dried at 373 K and 50 Pa for 8 hours to obtain 5.17 g (yield 79%) of the target metal complex. The powder X-ray diffraction pattern of the obtained metal complex is shown in FIG.

Example 1:
FIG. 5 shows the results of measuring the adsorption rates of methane and carbon dioxide at 273 K and 0.1 MPa for the metal complex obtained in Synthesis Example 1. Further, Table 1 shows the ratio of the adsorption amount of methane and carbon dioxide 10 minutes after the start of adsorption.

Comparative Example 1:
FIG. 5 shows the results of measuring the adsorption rates of methane and carbon dioxide at 273 K and 0.1 MPa for the metal complex obtained in Comparative Synthesis Example 1. Further, Table 1 shows the ratio of the adsorption amount of methane and carbon dioxide 10 minutes after the start of adsorption.

  From FIG. 5 and Table 1, it is clear that the metal complex of the present invention is excellent as a separator for methane and carbon dioxide because it has a high carbon dioxide selective adsorption ability.

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

Comparative Example 2:
FIG. 7 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide and methane at 273 K by the capacity method for the metal complex obtained in Comparative Synthesis Example 2.

  6 and 7, it is clear that the metal complex of the present invention is excellent as a separator for methane and carbon dioxide because it selectively adsorbs carbon dioxide.

Example 3:
FIG. 8 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide at 273K, 283K, and 293K by the capacitance method for the metal complex obtained in Synthesis Example 1.

Comparative Example 3:
FIG. 9 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide at 273K, 283K, and 293K by the capacitance method for the metal complex obtained in Comparative Synthesis Example 1.

  The heat of adsorption of carbon dioxide calculated using the pressure value when the carbon dioxide adsorption amount in FIG. 8 is 13.6 mL is 29.3 kcal / mol, and the pressure when the carbon dioxide adsorption amount in FIG. 9 is 19.4 mL. The adsorption heat of carbon dioxide calculated using the value is 35.5 kcal / mol. Since the metal complex of the present invention has a small heat of adsorption of carbon dioxide, it is clear that the energy required for desorption of carbon dioxide is small.

Example 4:
FIG. 10 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide at 273K, 283K, and 293K by the capacitance method for the metal complex obtained in Synthesis Example 2.

Comparative Example 4:
FIG. 11 shows the results of measuring the adsorption and desorption isotherms of carbon dioxide at 273K, 283K and 293K by the volumetric method for the metal complex obtained in Comparative Synthesis Example 2.

  The adsorption heat of carbon dioxide calculated using the pressure value when the adsorption amount of carbon dioxide in FIG. 10 is 7.8 mL is 21.3 kcal / mol, and the pressure when the adsorption amount of carbon dioxide in FIG. 11 is 8.8 mL. The adsorption heat of carbon dioxide calculated using the value is 33.2 kcal / mol. Since the metal complex of the present invention has a small heat of adsorption of carbon dioxide, it is clear that the energy required for desorption of carbon dioxide is small.

Claims (7)

The following general formula (I);

(Wherein R ¹ , R ² and R ³ are the same or different and each represents a hydrogen atom, an alkyl group or a halogen atom which may have a substituent, X represents a carbon atom or a nitrogen atom, and Y represents Hydrogen atom, optionally substituted alkyl group, aryl group, aralkyl group, alkoxy group, aryloxy group, aralkyloxy group, formyl group, acyloxy group, alkoxycarbonyl group, amino group, amide group, nitro group Or a halogen atom, and when X is a nitrogen atom, Y does not exist.) And at least selected from metals belonging to Groups 4 to 5 in Groups 6 to 11 A metal complex comprising one kind of metal and an organic ligand capable of bidentate coordination with the metal.   The organic ligand capable of bidentate coordination is 1,4-diazabicyclo [2.2.2] octane, pyrazine, 2,5-dimethylpyrazine, 4,4′-bipyridyl, 2,2′-dimethyl-4. , 4′-bipyridine, 1,2-bis (4-pyridyl) ethyne, 1,4-bis (4-pyridyl) butadiyne, 1,4-bis (4-pyridyl) benzene, 3,6-di (4- Pyridyl) -1,2,4,5-tetrazine, 2,2'-bi-1,6-naphthyridine, phenazine, diazapyrene, trans-1,2-bis (4-pyridyl) ethene, 4,4'-azopyridine The at least one selected from 1,2-bis (4-pyridyl) ethane, 1,2-bis (4-pyridyl) -glycol and N- (4-pyridyl) isonicotinamide. Metal complexes.   The metal complex according to claim 1 or 2, wherein the metal is manganese, nickel or copper.   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 4, which is a separation material for separation.   The separation material according to claim 4, wherein the separation material is a separation material for separating methane and carbon dioxide, hydrogen and carbon dioxide, nitrogen and carbon dioxide, or air and methane.   In a solvent, a dicarboxylic acid compound (I), at least one metal salt selected from metals belonging to Groups 4 to 5 in Groups 4 to 5 and an organic ligand capable of bidentate coordination with the metal A method for producing a metal complex that is reacted with and precipitated.

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