JP2006328050A - Method for producing porous metal complex, porous metal complex, adsorbent, separation material, gas adsorbent, and hydrogen adsorbent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a porous metal complex by which a reaction time can be shortened and the yield can be increased. <P>SOLUTION: The method for producing the porous metal complex composed of a three-dimensional porous skeleton structure of the metal complex having a center metal and an organic ligand having a carboxy group comprises preparing a salt of the organic ligand as a metal salt of a monocarboxylic acid, preparing a salt of the center metal as the second metal salt, and reacting the metal salt of the monocarboxylic acid with the second metal salt. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a porous metal complex, a porous metal complex, an adsorbing material, a separating material, a gas adsorbing material, and a hydrogen adsorbing material.

  In recent years, development competition for solid polymer fuel cells to be installed in fuel cell vehicles has been actively developed. In order to put such a fuel cell vehicle into practical use, it is desired to develop an efficient hydrogen storage method using a hydrogen storage material that is low-cost, lightweight, and has a high storage density.

Therefore, a hydrogen storage material using a porous organometallic complex having a skeleton structure in which a two-dimensional lattice structure composed of metal ions and organic ligands is three-dimensionally stacked as a unit motif has been proposed (Patent Document 1, Patent). It is attracting attention as a gas adsorbent such as methane, nitrogen and hydrogen. In particular, it has been found that a porous organometallic complex using a monocarboxylic acid compound such as benzoic acid or toluic acid as an organic ligand is suitable as a gas storage material (Patent Document 3, Non-Patent Document). 1, refer to Non-Patent Document 2). The structure of an organometallic complex using a monocarboxylic acid compound changes flexibly according to the external environment such as pressure and temperature. Such a metal complex having a flexible skeleton structure has a selective adsorption property and is suitable as a gas storage material.
JP 2001-348361 A US Patent Application Publication No. 2003/0004364 JP 2003-342260 A Mori Kazuaki, Omura Tetsuki, Sato Tomohiko, “Gas Occlusion of Carboxylic Acid Metal Complexes and Their Applications”, Petrotech, Petroleum Institute of Japan, 2003, Vol. 26, No. 2, p. 105- 112 Ryotaro Matsuda, Susumu Kitagawa, “Structure and Function of a New Crystalline Porous Material“ Metal Complex Porous Material ””, Journal of the Crystallographic Society of Japan, 2004, Vol.46, No.1, p.53- 58

  However, the monocarboxylic acid compound serving as the organic ligand has low solubility in the solvent used to obtain the organometallic complex, and the amount of solvent required increases. The amount that can be synthesized at one time is limited, and increasing the amount requires a large amount of solvent. Monocarboxylic acid compounds have low reactivity with metal salts, and a long reaction time is required to obtain an organometallic complex. Increasing the reaction temperature to shorten the reaction time increases the number of side reactions, which may reduce the yield of the target organometallic complex. In a compound in which the intermediate is unstable, the yield is more markedly reduced, and there is a problem in terms of cost and mass productivity.

  The present invention has been made to solve the above problems, and the method for producing a porous metal complex according to the present invention is a three-dimensional metal complex comprising a central metal and an organic ligand having a carboxylate group. Method for preparing a porous metal complex having a porous skeleton structure, wherein a salt of an organic ligand is prepared as a monocarboxylic acid metal salt, a salt of a central metal is prepared as a second metal salt, Reacting an acid metal salt and a second metal salt.

  The porous metal complex according to the present invention is obtained by the method for producing a porous metal complex according to the present invention.

  The adsorbent according to the present invention includes the porous metal complex according to the present invention.

  The separating material according to the present invention includes the porous metal complex according to the present invention.

  The gas adsorbent according to the present invention includes the porous metal complex according to the present invention.

  The hydrogen adsorbent according to the present invention includes the porous metal complex according to the present invention.

  According to the present invention, the monocarboxylic acid metal salt is more easily dissociated than the monocarboxylic acid and has a higher solubility, so that the required amount of solvent can be reduced compared to the conventional case, and the reaction time can be shortened. Moreover, since the monocarboxylic acid metal salt is easily dissociated, the reactivity with the metal salt is high, the reaction temperature can be lowered, the productivity per unit time can be expected to increase, and the production cost can be reduced.

  According to the present invention, a flexible porous metal complex can be obtained efficiently and inexpensively.

  According to the present invention, since the porous metal complex according to the present invention is used, an inexpensive adsorbent, separation material, gas adsorbent and hydrogen adsorbent can be obtained efficiently.

  Hereinafter, a method for producing a porous metal complex, a porous metal complex, an adsorbing material, a separating material, a gas adsorbing material, and a hydrogen adsorbing material according to embodiments of the present invention will be described.

  FIG. 1 schematically shows a three-dimensional crystal structure 1 of rhodium (II) benzoate-pyrazine, which is an example of a porous metal complex. Here, two types of organic ligands and bridging ligands are used as the ligands for bonding between the central metals 2.

  The rhodium benzoate (II) -pyrazine 1 has a rhodium ion as a central metal 2 around which four benzoate ions are coordinated as an organic ligand 3. Each benzoate ion has one carboxylate group, and is coordinated to the rhodium ion through two oxygen atoms of the carboxylate group, whereby a ring (void) having two rhodium ions as four lattice points. A lattice-like two-dimensional structure in which is condensed is formed. Each organic ligand is bonded by a relatively weak bond such as π-π interaction or hydrogen bond, and this two-dimensional lattice structure is stacked as a unit motif, that is, a basic repeating pattern, and each two-dimensional lattice structure is cross-linked. A three-dimensional porous skeleton structure is formed by crosslinking with the pyrazine which is the ligand 4. In this structure, a plurality of one-dimensional channels are formed because each gap row of a plurality of two-dimensional structures is aligned in a row.

  A porous metal complex having such a structure is prepared by preparing a salt of an organic ligand having a carboxylate group as a monocarboxylic acid metal salt, and preparing a central metal salt as a second metal salt, Produced by reacting a metal salt and a second metal salt. In this case, since the compound that becomes the organic ligand is made into a metal salt, the compound is easily dissociated and the solubility in the solvent is increased. Can also be shortened. In addition, since the monocarboxylic acid metal salt and the second metal salt are easily dissociated, the reactivity is high, a reduction in the reaction temperature, an increase in productivity and yield per unit time can be expected, and the production cost can be reduced.

  Here, as an example of a method for producing a porous metal complex having a three-dimensional porous skeleton structure, the chemical reaction according to the embodiment of the present invention is shown in FIG. 2 (a), and the conventional example in FIG. 2 (b). Indicates a chemical reaction. As shown in FIG. 2B, in the conventional example, a monocarboxylic acid is used as a compound that becomes an organic ligand, and is reacted with a metal salt that becomes a central metal in a solvent. In this reaction, since the dissociation constant of monocarboxylic acid in the solvent is low and the solubility in the solvent is low, the reaction completion time is long and the reaction yield is low. On the other hand, when a monocarboxylic acid metal salt is used as a compound that becomes an organic ligand as shown in FIG. 2 (a), this compound is readily soluble in a solvent and easily ionized to react. move on. For this reason, the reaction is completed in a shorter time than the conventional example, and the reaction yield is higher than that of the conventional example. In this example, a two-dimensional lattice structure composed of a central metal and an organic ligand is laminated as a basic repeating pattern, and further crosslinked with an organic ligand to form a three-dimensional porous skeleton structure. .

  Next, when reacting the monocarboxylic acid metal salt and the second metal salt, an example in which a bridging ligand capable of bidentate coordination is added to the central metal, that is, as shown in FIG. As an example of preparing a porous metal complex (hereinafter often referred to as “porous cross-linked metal complex”) using two kinds of ligands, an organic ligand and a cross-linked ligand, as a bond between 3 (a) shows another example of the chemical reaction according to the embodiment of the present invention, and FIG. 3 (b) shows another conventional chemical reaction. As shown in FIG. 3B, in the conventional example, a monocarboxylic acid is used as a compound that becomes an organic ligand, and is reacted with a metal salt that becomes a central metal in a solvent. In this reaction, since the dissociation constant of the carboxylic acid in the solvent is low and the solubility is low, the reaction completion time is long and the reaction yield is low. Further, a two-step process is performed in which a monocarboxylic acid and a metal salt are reacted to form a metal complex having a two-dimensional lattice structure, and a compound serving as a bridging ligand is further added to the reaction solution to form a cross-linked metal complex. Take the synthesis method. For this reason, reaction time increases and reaction yield becomes still lower. On the other hand, as shown in FIG. 3 (a), when a monocarboxylic acid metal salt is used as a compound that becomes an organic ligand, in this reaction, from a copper ion and a benzoate ion that become a central metal, A unit motif consisting of the two-dimensional lattice structure is formed, and at the same time, pyrazine is bridged between the two-dimensional lattice structures by adding pyrazine as a bridging ligand capable of bidentate coordination to the central metal. An original porous skeletal structure is formed. In this reaction, the compound that becomes the organic ligand is made into a metal salt, so that the compound is easily dissociated and the solubility in the solvent is increased. Can be shortened. Moreover, since the first and second metal salts are easily dissociated, the reactivity is high, and a reduction in reaction temperature, an increase in productivity and yield per unit time can be expected, and the manufacturing cost can be reduced. In addition, since the monocarboxylic acid metal salt, the second metal salt, and the bridging ligand are reacted at the same time, the crosslinking reaction with the bridging ligand proceeds simultaneously with the formation of the metal complex having a two-dimensional lattice structure. Form. In this way, the synthesis process can be shortened to one stage, productivity and yield per unit time can be expected, and manufacturing costs can be reduced.

  The monocarboxylic acid metal salt is preferably made of an alkali metal or alkaline earth metal salt. When the monocarboxylic acid metal salt is an alkali metal or alkaline earth metal salt, it easily dissociates into a carboxylate group and a metal ion in a solvent as compared with the deprotonation of the monocarboxylic acid. For this reason, the monocarboxylic acid metal salt is more easily dissociated than the monocarboxylic acid and has a higher solubility, so that the amount of solvent required is smaller than that of the conventional one, and the reaction time can be shortened. Moreover, since the monocarboxylic acid metal salt is easily dissociated, the reactivity with the metal salt is high, the reaction temperature can be lowered, the productivity per unit time can be expected to increase, and the production cost can be reduced. When two types of ligands, an organic ligand and a bridging ligand, are used, the first and second metal salts are easy to dissociate and are highly reactive. Even if the synthesis process is shortened to one step, Increase in productivity and yield per unit time can be expected, and the manufacturing cost can be reduced.

This monocarboxylic acid metal salt has the following general formula (I)
XOOC-R (I)
(Wherein R represents an alkyl group, an alkynyl group, an alkenyl group, or an aryl group. X represents an alkali metal or an alkaline earth metal). In this case, the alkyl group, alkynyl group, alkenyl group or aryl group may have a substituent.

  In the above general formula (I), X preferably contains Na (sodium) or K (potassium). When X is Na or K, a porous metal complex can be obtained efficiently and inexpensively as compared with the conventional case. R preferably contains an aryl group, and the aryl group may have a substituent.

This R is represented by the following general formulas (II) to (XII)

It is preferable that the substituent represented by any one of these is included. In the general formulas (II) to (XII), a carboxylate group is bonded to a position *, and an oxygen atom of the carboxylate group is coordinated to the central metal to form a two-dimensional lattice structure.

  The second metal salt preferably includes a metal selected from a metal group including a divalent to tetravalent metal. In particular, the second metal salt preferably includes a divalent metal. In this case, since the second metal salt is dissociated by the solvent and the metal is ionized, the reaction with the monocarboxylic acid metal salt is promoted. For this reason, compared with the past, reaction time can also be shortened, reaction temperature can be lowered, and yield can be increased. In addition, it is more preferable that this 2nd metal salt contains the metal selected from the metal group containing Cu, Zn, Mo, Ru, Cr, Ni, and Rh. Moreover, it is preferable that a 2nd metal salt contains the metal salt selected from the metal salt group containing nitrate, a sulfate, acetate, carbonate, and a formate.

  The preparation of the monocarboxylic acid metal salt includes dissolving the monocarboxylic acid metal salt in a first solvent to obtain a first solution, and the preparation of the second metal salt includes converting the second metal salt to the second metal salt. And the reaction comprises mixing the first and second solutions. By mixing the first and second solutions, the monocarboxylic acid metal salt is dissociated and the second metal salt is dissociated to generate metal ions, thereby forming a metal complex. In addition, any one of the preparation of the monocarboxylic acid metal salt, the preparation of the second metal salt, and the reaction may include irradiating the first or second solution with ultrasonic waves. In this case, the reaction between the monocarboxylic acid metal salt and the second metal salt or the reaction between the monocarboxylic acid metal salt and the bridging ligand is promoted.

  In addition, one of the first and second solvents is from a solvent group including N, N′-dimethylformamide, N, N′-diethylformamide, water, alcohols, tetrahydrofuran, benzene, toluene, hexane, acetone, and acetonitrile. It is preferred to include a selected solvent. As the alcohol, methanol, ethanol, propanol or the like can be used. These solvents dissolve the monocarboxylic acid metal salt and the second metal salt, but do not dissolve the target metal complex, so that the target product can be obtained efficiently. Among these, one of the first and second solvents preferably includes a solvent selected from a solvent group including N, N′-dimethylformamide, N, N′-diethylformamide, water, and alcohols. Further, the first and second solvents may be the same solvent.

  The reaction comprises obtaining a metal salt selected from the group of metal salts including sodium nitrate, sodium sulfate, sodium acetate, sodium carbonate, sodium formate, potassium nitrate, potassium sulfate, potassium acetate, potassium carbonate and potassium formate as a by-product. It is preferable to include. Since these by-products have a high reaction rate, the reaction between the monocarboxylic acid metal salt and the second metal salt, or the reaction between the monocarboxylic acid metal salt, the bridging ligand, and the second metal salt is promoted. . For this reason, it becomes possible to decrease the reaction time, decrease the reaction temperature, and increase the reaction yield. The produced porous metal complex preferably has a pH of 8 to 10. When the pH is in the range of 8 to 10, the monocarboxylic acid metal salt and the second metal salt are easily dissociated in the solvent, so that the solubility in the solvent is increased and the reaction is promoted.

  The porous metal complex produced by this method for producing a porous metal complex includes a central metal and an organic ligand having a carboxylate group, and the organic ligand is coordinated around the central metal. Each organic ligand has one carboxylate group, and a ring (void) having the central metal as a lattice point is condensed by coordinating to the central metal via two oxygen atoms of the carboxylate group. A lattice-like two-dimensional structure is formed. Each organic ligand is bonded by a relatively weak bond such as π-π interaction or hydrogen bond, and this two-dimensional lattice structure is stacked as a unit motif, that is, a basic repeating pattern, and the unit of each two-dimensional lattice structure A three-dimensional porous skeleton structure is formed by laminating the motif in the three-dimensional direction or cross-linking with another organic compound. In this structure, each gap row of a plurality of two-dimensional structures is aligned in a row, so that a plurality of one-dimensional channels are formed. Further, in the reaction, when a bridging ligand capable of bidentate coordination is added to the central metal, a porous crosslinked metal complex is formed. This porous cross-linked metal complex has an organic ligand having a central metal and a carboxylate group, and a cross-linking ligand capable of bidentate coordination with the central metal, and the organic ligand and the cross-linked coordination around the central metal. Child is coordinated. Each organic ligand has one carboxylate group, and a ring (void) having the central metal as a lattice point is condensed by coordinating to the central metal via two oxygen atoms of each carboxylate group. A lattice-like two-dimensional structure is formed. This two-dimensional lattice structure is laminated as a unit motif, that is, a basic repeating pattern, and each two-dimensional lattice structure is further crosslinked with a bridging ligand to form a three-dimensional porous skeleton structure. In this structure, each gap row of a plurality of two-dimensional structures is aligned in a row, so that a plurality of one-dimensional channels are formed.

  In this porous metal complex, a three-dimensional porous skeleton structure in which unit motifs of a two-dimensional lattice structure are stacked is a skeleton part that defines voids, and the pore diameter of each void is 0.3 to 2.0 [nm. ]. A gas or liquid molecule smaller than the pore diameter can be taken into the skeleton structure. In addition, since the organic ligand is bonded by a relatively weak bond, the bond is shifted according to an external environment such as pressure and heat, so that the skeleton structure forms a flexible structure having flexibility. The void can be deformed by deforming the skeletal structure by heat or pressure from the outside. Moreover, this porous metal complex contains the said by-product as a residue. When the by-product is included as a residue, it indicates that the starting materials are a monocarboxylic acid metal salt and a second metal salt.

  According to the production method described above, in the production method of the porous metal complex according to the embodiment of the present invention, the monocarboxylic acid metal salt is more easily dissociated than the monocarboxylic acid and has higher solubility, so that it is necessary compared to the conventional case. The amount of solvent is small and the reaction time can be shortened. Moreover, since the monocarboxylic acid metal salt is easily dissociated, the reactivity with the metal salt is high, the reaction temperature can be lowered, the productivity per unit time can be expected to increase, and the production cost can be reduced. When using two types of ligands, organic ligands and bridging ligands, the monocarboxylic acid metal salt and the second metal salt are easy to dissociate and are highly reactive, shortening the synthesis process to one step. Even so, an increase in productivity and yield per unit time can be expected, and the manufacturing cost can be reduced. Thus, a porous metal complex can be obtained efficiently and inexpensively by this production method. Moreover, when an adsorbent, a separating material, a gas adsorbent and a hydrogen adsorbent are produced using the porous metal complex obtained by this production method, it can be obtained efficiently and inexpensively compared to the conventional case.

  Hereinafter, although the manufacturing method of the porous metal complex which concerns on embodiment of this invention is demonstrated more concretely by Example 1- Example 12 and Comparative Example 1- Comparative Example 2, the scope of the present invention is limited to these. Is not to be done.

1. Sample Preparation Example 1 Synthesis of Copper Benzoate-Pyrazine Sodium benzoate was used as the monocarboxylic acid derivative and copper acetate was used as the second metal salt. First, 2.10 [g] sodium benzoate and 2.60 [g] copper acetate monohydrate were dissolved in a water / methanol solution and stirred and allowed to stand at room temperature for 18 [hours]. The precipitated solid was collected by suction filtration to obtain crude crystals. The crude crystals were dissolved in acetone, pyrazine was added, and the mixture was stirred at room temperature for 6 hours, followed by suction filtration. Then, vacuum drying was performed at 100 [° C.] for 2 [hours] to obtain the target product, copper benzoate-pyrazine benzoate.

Example 2 Synthesis of copper naphthoate-pyrazine Sodium naphthoate synthesized by ion exchange of naphthoic acid as a monocarboxylic acid derivative and copper acetate as a second metal salt were used. Sodium naphthoate 2.60 [g] and copper acetate monohydrate 2.60 [g] were dissolved in a water / methanol solution, stirred and allowed to stand at room temperature for 26 [hours]. The precipitated solid was collected by suction filtration to obtain crude crystals. The crude crystals were dissolved in acetone, pyrazine was added, and the mixture was stirred at room temperature for 10 [hour], followed by suction filtration. Then, vacuum drying was performed at 100 [° C.] for 2 [hours] to obtain the target product, copper naphthoate-pyrazine.

Example 3 Synthesis of copper benzoate-pyrazine Potassium benzoate was used as the monocarboxylic acid derivative, and copper acetate was used as the second metal salt. Potassium benzoate 2.42 [g] and copper acetate monohydrate 2.60 [g] were dissolved in a water / methanol solution, stirred and allowed to stand at room temperature for 26 [hours]. The precipitated solid was collected by suction filtration to obtain crude crystals. The crude crystals were dissolved in acetone, pyrazine was added, and the mixture was stirred at room temperature for 10 [hour], followed by suction filtration. Then, vacuum drying was performed at 100 [° C.] for 2 [hours] to obtain the target product, copper benzoate-pyrazine benzoate.

Example 4 Synthesis of rhodium benzoate-pyrazine Sodium benzoate was used as the monocarboxylic acid derivative, and rhodium acetate dihydrate was used as the second metal salt. Sodium benzoate 2.10 [g] and rhodium acetate dihydrate 2.60 [g] were dissolved in a water / methanol solution, stirred and allowed to stand at room temperature for 26 [hours]. The precipitated solid was collected by suction filtration to obtain crude crystals. The crude crystals were dissolved in acetone, pyrazine was added, and the mixture was stirred at room temperature for 10 [hour], followed by suction filtration. Then, vacuum drying was performed at 100 [° C.] for 2 [hours] to obtain the target product, rhodium benzoate-pyrazine.

Example 5 Synthesis of Copper Benzoate Sodium benzoate was used as the monocarboxylic acid derivative, and copper acetate was used as the second metal salt. First, sodium benzoate 2.88 [g] and copper acetate monohydrate 2.00 [g] were dissolved in a water / methanol solution and stirred, and then allowed to stand at room temperature for 18 [hours]. The precipitated solid was collected by suction filtration, and then vacuum-dried at 80 [° C.] for 2 [hours] to obtain the target product, copper benzoate.

Example 6 Synthesis of copper naphthoate Sodium naphthoate synthesized by ion exchange of naphthoic acid as a monocarboxylic acid derivative and copper acetate as a second metal salt were used. Sodium naphthoate 3.88 [g] and copper acetate monohydrate 2.00 [g] were dissolved in a water / methanol solution, stirred and allowed to stand at room temperature for 24 [hours]. The precipitated solid was collected by suction filtration, and then vacuum-dried at 80 [° C.] for 2 [hours] to obtain the target product, copper naphthoate.

Example 7 Synthesis of copper benzoate Potassium benzoate was used as the monocarboxylic acid derivative, and copper acetate was used as the second metal salt. Potassium benzoate 3.20 [g] and copper acetate monohydrate 2.00 [g] were dissolved in a water / methanol solution, stirred and allowed to stand at room temperature for 24 [hours]. The precipitated solid was collected by suction filtration, and then vacuum-dried at 80 [° C.] for 2 [hours] to obtain the target product, copper benzoate.

Example 8 Synthesis of rhodium benzoate Sodium benzoate was used as the monocarboxylic acid derivative, and rhodium acetate dihydrate was used as the second metal salt. Sodium benzoate 2.88 [g] and rhodium acetate dihydrate 4.78 [g] were dissolved in a water / methanol solution, stirred and allowed to stand at room temperature for 24 [hours]. The precipitated solid was collected by suction filtration, and then vacuum-dried at 80 [° C.] for 2 [hours] to obtain the target product, rhodium benzoate.

Example 9 Synthesis of copper benzoate-pyrazine Sodium benzoate was used as the monocarboxylic acid derivative, and copper acetate was used as the second metal salt. First, sodium benzoate 2.88 [g], pyrazine 0.40 [g] and copper acetate monohydrate 2.00 [g] were dissolved in a water / methanol solution and stirred for 18 hours at room temperature. I left it alone. The precipitated solid was collected by suction filtration, and then vacuum-dried at 80 [° C.] for 2 [hours] to obtain the target product, copper benzoate-pyrazine.

Example 10 Synthesis of Naphthoic Acid Copper-Pyrazine Sodium naphthoate synthesized by ion exchange of naphthoic acid as a monocarboxylic acid derivative and copper acetate as a second metal salt were used. Sodium naphthoate 3.85 [g], pyrazine 0.40 [g] and copper acetate monohydrate 2.00 [g] were dissolved in a water / methanol solution, stirred and allowed to stand at room temperature for 20 [hours]. . The precipitated solid was collected by suction filtration, and then vacuum-dried at 80 [° C.] for 2 [hours] to obtain the target product, copper naphthoate-pyrazine.

Example 11 Synthesis of copper benzoate-pyrazine Potassium benzoate was used as the monocarboxylic acid derivative, and copper acetate was used as the second metal salt. Potassium benzoate 3.20 [g], pyrazine 0.40 [g] and copper acetate monohydrate 2.00 [g] were dissolved in a water / methanol solution and stirred and allowed to stand at room temperature for 20 [hours]. . The precipitated solid was collected by suction filtration, and then vacuum-dried at 80 [° C.] for 2 [hours] to obtain the target product, copper benzoate-pyrazine.

Example 12 Synthesis of rhodium benzoate-pyrazine Sodium benzoate was used as the monocarboxylic acid derivative, and rhodium acetate dihydrate was used as the second metal salt. Sodium benzoate 2.88 [g], pyrazine 0.40 [g] and rhodium acetate dihydrate 4.78 [g] were dissolved in a water / methanol solution, stirred and allowed to stand at room temperature for 20 [hours]. . The precipitated solid was collected by suction filtration, and then vacuum-dried at 80 [° C.] for 2 [hours] to obtain the target product, rhodium benzoate-pyrazine.

Comparative Example 1 Synthesis of Copper Benzoate-Pyrazine Benzoic acid was used as the monocarboxylic acid. First, 1.00 [g] benzoic acid and 0.50 [g] copper acetate monohydrate were dissolved in diethylene glycol methyl ester and allowed to stand at room temperature for 36 [hours] after stirring. The precipitated solid was collected by suction filtration to obtain crude crystals. The crude crystals were dissolved in acetone, pyrazine was added, and the mixture was stirred at room temperature for 10 [hour], followed by suction filtration. Then, vacuum drying was performed at 100 [° C.] for 2 [hours] to obtain the target product, copper benzoate-pyrazine benzoate.

Comparative Example 2 Synthesis of rhodium benzoate-pyrazine Benzoic acid was used as a monocarboxylic acid. First, 1.00 [g] benzoic acid and 0.50 [g] rhodium acetate dihydrate were dissolved in diethylene glycol methyl ester, and allowed to stand at room temperature for 48 [hours] after stirring. The precipitated solid was collected by suction filtration to obtain crude crystals. The crude crystals were dissolved in acetone, pyrazine was added, and the mixture was stirred at room temperature for 10 [hour], followed by suction filtration. Then, vacuum drying was performed at 100 [° C.] for 2 [hours] to obtain the target product, rhodium benzoate-pyrazine.

2. Measurement of gas storage capacity The samples obtained in Example 1 and Example 2 were measured for gas storage capacity. The measurement method followed the hydrogen storage / release measurement test of JIS H7201. After weighing the sample and placing it in a pressure-resistant sample tube for measurement and evacuating it at 200 [° C.] for 3 [hours] to release the gas remaining in the sample tube and obtaining the origin where hydrogen is not occluded Measurements were made. The measurement temperature was 25 [° C.]. Thereafter, the pressure was reduced to atmospheric pressure, and the amount of hydrogen released was confirmed.

3. Confirmation of crystal structure To confirm the crystal structure of the synthesized sample, an X-ray diffractometer (MXP 18VAHF) manufactured by Max Science was used, and measurement was performed at a voltage of 40 [kV], a current of 300 [mA], and an X-ray wavelength of CuKα. .

4). Confirmation of composition The composition of the synthesized sample was confirmed by elemental analysis. JPI-5S-65-2004 was used for confirmation of carbon, hydrogen, and nitrogen, and inductively coupled plasma emission spectroscopy was used for confirmation of metal elements.

Table 1 shows the metal complexes, organic ligands, second metal salts, bridging ligands, reaction completion times, and reaction yields synthesized in Examples 1 to 12, Comparative Examples 1 and 2. Table 2 shows the hydrogen storage capacity of the samples obtained in Example 1 and Example 2.

  The reaction of Example 9 and Comparative Example 1 will be described using FIG. 3 described above. FIG. 3A shows the chemical reaction in Example 9, and FIG. 3B shows the chemical reaction in Comparative Example 1. As shown in FIG. 3B, in Comparative Example 1, benzoic acid, which is a monocarboxylic acid, is used as the carboxylic acid and reacted with copper acetate monohydrate in diethylene glycol methyl ester. In this reaction, since the dissociation constant of benzoic acid in diethylene glycol methyl ester is low and the solubility is low, the reaction completion time is as long as 46 [hours] as shown in Table 1, and then the reaction product of benzoic acid and copper acetate. And pyrazine, which is a bridging ligand, are reacted with each other, and the reaction yield is as low as 48 [%]. On the other hand, Example 9 uses sodium benzoate, which is a monocarboxylic acid derivative. Sodium benzoate is readily soluble in a water / methanol solution and easily ionizes to promote the reaction. Moreover, since sodium benzoate, copper acetate and pyrazine which is a bridging ligand are reacted at the same time, the synthesis process can be shortened to one step, the reaction time is as short as 18 [hours], and the reaction yield is also 85 [ %] Was high.

  In FIG. 4, the relationship between the reaction rate and reaction yield in Example 1, Example 9, and Comparative Example 1 is shown. Here, the reaction rate indicates the reciprocal of the reaction time, and the reaction rate increases as it goes to the right. When Example 1 using a metal salt as a carboxylic acid derivative was compared with Comparative Example 1 using a monocarboxylic acid, the reaction rate of Example 1 was 1.9 times that of Comparative Example 1, and the reaction yield was It was 1.7 times. In addition, when Example 9 and Comparative Example 1 in which a metal salt was used as a carboxylic acid derivative and sodium benzoate, copper acetate, and pyrazine as a bridging ligand were reacted at the same time, the reaction rate of Example 9 was compared. Is 2.6 times that of Comparative Example 1 and the reaction yield is 1.8 times. By reacting pyrazine with sodium benzoate and copper acetate at the same time, the reaction rate is faster than Example 1, and the reaction yield is Improved. As described above, when a monocarboxylic acid metal salt is used as the monocarboxylic acid derivative and the cross-linking ligand is reacted simultaneously with the reaction of the monocarboxylic acid metal salt, the reaction time is longer than when the monocarboxylic acid is used. Was short, and it was found that the yield could be increased.

  In both Example 3 using potassium benzoate as the carboxylic acid derivative and Example 4 using rhodium acetate as the second metal salt, the yield was higher than that in Comparative Example 1, and the monocarboxylic acid derivative was mono The effect by using carboxylic acid metal salt was seen. When naphthoic acid was used as a carboxylic acid derivative, the values obtained in Example 2 and Comparative Example 2 were compared, and Example 2 was 1.33 times in both reaction time and yield compared to Comparative Example 2. The effect was higher due to the use of naphthoic acid metal salt. In Examples 5 to 8 in which no bridging ligand was used, the reaction time was short and the reaction yield was high due to the use of the monocarboxylic acid metal salt as the carboxylic acid derivative. In Example 9 to Example 12 in which the bridging ligand was reacted with the monocarboxylic acid metal salt and the second metal salt at the same time, the reaction time was shorter than in Examples 1 to 4. Thus, the reaction yield was high.

  The hydrogen storage capacity of Example 1 is 0.51 [wt%] at 10 [MPa] and 0.86 [wt%] at 35 [MPa], and the hydrogen storage capacity of Example 2 is 0 at 10 [MPa]. It was 0.98 [wt%] at 53 [wt%] and 35 [MPa]. Thus, it was found that the samples obtained in Example 1 and Example 2 have a high hydrogen storage capacity.

  From the results of Examples 1 to 12, Comparative Example 1 and Comparative Example 2, in the method for producing a porous metal complex according to the embodiment of the present invention, the monocarboxylic acid metal salt is a solvent compared to the monocarboxylic acid. It was found that the reaction time can be shortened and the yield can be increased as compared with the conventional method because it is easily dissociated in the medium and has high solubility. Further, it was found that when the bridging ligand was reacted simultaneously with the monocarboxylic acid metal salt and the second metal salt, the reaction time was further shortened and the yield could be increased. .

  Although the present embodiment has been described above, it should not be understood that the description and the drawings, which form part of the disclosure of the above embodiment, limit the present invention. From this disclosure, various alternative embodiments, examples, and operational techniques will be apparent to those skilled in the art.

It is a schematic diagram which shows the three-dimensional structure of a porous metal complex. (A) It is a figure which shows an example of the chemical reaction which concerns on embodiment of this invention. (B) It is a figure which shows the chemical reaction in a prior art example. (A) It is a figure which shows the chemical reaction of the other example which concerns on embodiment of this invention. (B) A chemical reaction in another conventional example is shown. It is a graph which shows the relationship between the reaction rate and reaction yield in manufacture of a porous metal complex.

Explanation of symbols

1 Three-dimensional crystal structure of rhodium benzoate (II) -pyrazine 2 Central metal 3 Organic ligand 4 Bridged ligand

Claims (28)

A method for producing a porous metal complex comprising a three-dimensional porous skeleton structure of a metal complex comprising a central metal and an organic ligand having a carboxylate group,
Preparing a salt of the organic ligand as a monocarboxylic acid metal salt;
Preparing the central metal salt as a second metal salt;
A method for producing a porous metal complex comprising reacting the monocarboxylic acid metal salt and the second metal salt.   The method for producing a porous metal complex according to claim 1, wherein a bridging ligand capable of bidentate coordination is added to the central metal in the reaction.   The method for producing a porous metal complex according to claim 1 or 2, wherein the monocarboxylic acid metal salt contains an alkali metal or alkaline earth metal salt. The monocarboxylic acid metal salt has the following general formula (I)
XOOC-R (I)
(Wherein R represents an alkyl group, an alkynyl group, an alkenyl group, or an aryl group, and X represents an alkali metal or an alkaline earth metal). A method for producing the porous metal complex according to 1.   The said alkyl group, alkynyl group, alkenyl group, or aryl group has a substituent, The manufacturing method of the porous metal complex of Claim 4 characterized by the above-mentioned.   The said X contains Na or K, The manufacturing method of the porous metal complex of Claim 4 or Claim 5 characterized by the above-mentioned.   The said R contains an aryl group, The manufacturing method of the porous metal complex as described in any one of Claim 4 thru | or 6 characterized by the above-mentioned.   The method for producing a porous metal complex according to claim 7, wherein the aryl group has a substituent. R represents the following general formulas (II) to (XII)

The manufacturing method of the porous metal complex as described in any one of Claims 4 thru | or 8 characterized by including the substituent represented by any one of these.   3. The method for producing a porous metal complex according to claim 1, wherein the second metal salt includes a metal selected from a metal group including a divalent to tetravalent metal.   The method for producing a porous metal complex according to claim 10, wherein the second metal salt contains a divalent metal.   The method for producing a porous metal complex according to claim 11, wherein the second metal salt includes a metal selected from a metal group including Cu, Zn, Mo, Ru, Cr, Ni, and Rh.   The second metal salt includes a metal salt selected from a metal salt group including nitrate, sulfate, acetate, carbonate, and formate. A method for producing a porous metal complex according to Item. The preparation of the monocarboxylic acid metal salt includes dissolving the monocarboxylic acid metal salt in a first solvent to obtain a first solution;
The preparation of the second metal salt includes dissolving the second metal salt in a second solvent to obtain a second solution;
The method for producing a porous metal complex according to claim 1 or 2, wherein the reaction includes mixing the first and second solutions.   Any one of the preparation of the monocarboxylic acid metal salt, the preparation of the second metal salt, and the reaction includes irradiating the first or second solution with ultrasonic waves. Item 15. A method for producing a porous metal complex according to Item 14.   One of the first and second solvents is selected from a solvent group comprising N, N′-dimethylformamide, N, N′-diethylformamide, water, alcohols, tetrahydrofuran, benzene, toluene, hexane, acetone and acetonitrile. The method for producing a porous metal complex according to claim 14, comprising a solvent that has been prepared.   The one of the first and second solvents includes a solvent selected from the group of solvents including N, N'-dimethylformamide, N, N'-diethylformamide, water, and alcohols. 16. A method for producing a porous metal complex according to 16.   The reaction obtains as a by-product a metal salt selected from a group of metal salts including sodium nitrate, sodium sulfate, sodium acetate, sodium carbonate, sodium formate, potassium nitrate, potassium sulfate, potassium acetate, potassium carbonate and potassium formate. The manufacturing method of the porous metal complex as described in any one of Claims 1 thru | or 17 characterized by the above-mentioned.   The method for producing a porous metal complex according to any one of claims 1 to 18, wherein the porous metal complex has a pH of 8 to 10.   A porous metal complex obtained by the method for producing a porous metal complex according to any one of claims 1 to 19.   The porous metal complex according to claim 20, wherein the porous metal complex contains the by-product according to claim 18 as a residue.   The porous metal complex according to claim 20 or 21, wherein the porous metal complex has a gas or a liquid taken into the skeleton structure.   The porous metal complex according to any one of claims 20 to 22, wherein the skeleton structure has flexibility.   24. The porous metal complex according to claim 23, wherein the skeleton structure includes a skeleton part that defines a void, and the void can be deformed by deforming the skeleton part from the outside by heat or pressure. .   An adsorbent comprising the porous metal complex according to any one of claims 20 to 24.   A separator comprising the porous metal complex according to any one of claims 20 to 24.   A gas adsorbent comprising the porous metal complex according to any one of claims 20 to 24.   A hydrogen adsorbent comprising the porous metal complex according to any one of claims 20 to 24.

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