JP6452357B2 - Coordination polymer complex containing fluorine, gas adsorbent, gas separation device and gas storage device using the same - Google Patents

Description

  The present invention relates to use as a porous polymer metal complex and a gas adsorbing material, and a gas separation device and a gas storage device using the same.

  The gas adsorbent has a characteristic of storing a large amount of gas at a low pressure as compared with pressurized storage and liquefied storage. For this reason, in recent years, development of a gas storage device and a gas separation device using a gas adsorbent has been active. As the gas adsorbent, activated carbon, zeolite and the like are known. Recently, a method of occluding gas in a porous polymer metal complex has also been proposed (see Patent Document 1 and Non-Patent Document 1).

  Porous polymer metal complexes are crystalline solids obtained from metal ions and organic ligands, and exhibit various gas adsorption properties due to the variety of metal ions, combinations of organic ligands and the variety of skeletal structures. It has potential. However, these conventionally proposed gas adsorbents are not sufficiently satisfactory in terms of the amount of gas adsorption and workability, and the development of gas adsorbents with better characteristics is desired. .

  One of the characteristics of the porous polymer metal complex is its network structure. There are known porous polymer metal complexes having various structures such as a one-dimensional chain aggregate, a two-dimensional square lattice laminate, and a jungle gym-shaped three-dimensional structure (Non-patent Document 2). These various porous polymer metal complexes exhibit various physical properties derived from the network structure, the metal ions constituting the network, the chemical properties of the ligand, and the physical shape.

  PCP (Porous Coordination Polymer; hereinafter referred to as “porous polymer metal complex” may also be referred to as “PCP” in this specification) is a so-called two-dimensional laminate in which the network structure spreads in a plane and is laminated. A type of PCP is known. It is known that a part of such a laminated PCP has a so-called gate phenomenon due to a shift between layers during gas adsorption, resulting in excellent gas storage and separation characteristics. (Non-patent document 3; Patent document 2). Many PCPs synthesized using nitrogen-containing ligands such as pyrazine and 4,4'-bipyridine are known. On the other hand, there are few examples of the two-dimensional PCP which consists of a carboxylic acid type ligand which does not contain a nitrogen atom (nonpatent literatures 4-6).

  A group of PCPs called kagome-type PCPs, which are synthesized from copper ions and isophthalic acids, do not contain nitrogen-containing ligands, but the types of substituents are limited, and metal ions are also copper ions, ruthenium. Limited to ions. In general, it is not known what kind of metal ion, what kind of ligand, and what kind of synthesis conditions should be combined (Non-Patent Documents 7 to 9, Patent Document 3).

  In order to control the gas adsorption characteristics of the porous body, attempts have been made to introduce fluorine atoms into the ligand (Non-Patent Documents 10 to 13). Sliding properties and water repellency are known as general effects on fluorine materials, but in the case of the porous polymer metal complex introduced with fluorine as described above, the hydrogen adsorption characteristics by fluorine atoms are improved. Is stated. These do not coincide with the physical properties caused by the above-mentioned fluorine atoms, and the principle by which the introduction of fluorine atoms improves the hydrogen adsorption characteristics is not described in detail. That is, the introduction of fluorine atoms is a porous polymer. It is not clear how it affects the gas adsorption properties of metal complexes.

  It has been suggested that the strength of interlayer interaction is an important factor in the gate phenomenon of interlayer displacement in the two-dimensional stacked PCP (Non-patent Document 3). However, it is not known what kind of atoms are arranged to cause the gate phenomenon. Since the interaction between fluorine atoms is weak, it is speculated that the introduction of fluorine atoms between layers will weaken the interlayer interaction. It is not known if the introduction of fluorine atoms will cause a gate phenomenon, and will exhibit better gas separation performance.

JP 2000-109493 A Japanese Patent No. 4398749 JP 2012-228667 A

Susumu Kitagawa, Integrated Metal Complex, Kodansha Scientific, 2001, pages 214-218 Robson et al., Angew. Chem. Int. Ed. 1998, 37, 1460 ± 1494 Koushiro et al., Int. J. Mol. Sci. 2010, 11, 3803 Yaghi et al., J. Am. Chem. Soc., Vol. 118, No. 38, 1996, 9096 Zhao et al., Inorganic Chemistry, Vol. 45, No. 21, 2006 8677 Roseinsky et al., Chem. Commun (2007) 1532-1534) Kitagawa et al., Chem. Commun., 2005, 865-867 Morris et al., Nature Chem., 2011, 3, 304 Zaworotko et al., Chem. Commun., 2004, 2534-2535 Omary et al., J. Am. Chem. Soc., 2007,129, 15454 Omary et al., Angew. Chem. Int. Ed. 2009, 48, 2500 Li et al., J. Am. Chem. Soc., 2004, 126, 1308 Ferey et al., J. Am. Chem. Soc., 2010, 132, 1127-1136

  The present invention is to provide a novel porous polymer metal complex having a two-dimensional laminated structure synthesized with a ligand containing a fluorine atom and a gas adsorbent having excellent characteristics using the same. . Another object of the present invention is to provide a gas storage device and a gas separation device that contain a gas adsorbent having the above-mentioned characteristics.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have converted an isophthalic acid type ligand having a perfluoroalkyl group having 1-10 carbon atoms at the 5-position to a transition metal ion. In the reaction, a small amount of a fluorine-containing aromatic compound can be present to synthesize a two-dimensional stacked PCP in which perfluoroalkyl groups are aggregated between layers, and this PCP has a unique gas adsorption ability. As a result, the present invention has been completed.

  That is, the present invention provides a two-dimensional structure in which perfluoroalkyl groups are obtained by reacting an isophthalic acid type ligand having a perfluoroalkyl group having 1-10 carbon atoms at the 5-position with a transition metal ion. The invention relates to a gas storage device and a gas separation device that are laminated porous polymer metal complexes, use the material as a gas storage material, and store the gas adsorbent therein.

That is, the present invention is as follows.
(1) The following formula (1)
[MX] _n (1)
(In the formula, M is a divalent transition metal ion selected from cobalt ion, copper ion, zinc ion and nickel ion, and X is the following formula:
(In the formula, Rf is a perfluoroalkyl group having 1 to 10 carbon atoms.)
Is an isophthalic acid derivative (ligand) having a perfluoroalkyl group having 1 to 10 carbon atoms represented by n indicates a characteristic that a large number of structural units composed of [MX] are gathered, and the size of n is not particularly limited. )
A porous polymer metal complex represented by the formula (1) and containing a fluorine atom and having a two-dimensional laminated network structure.

  (2) A layered structure network composed of a square lattice composed of transition metal ions and isophthalic acid derivative ligands is formed, and the layered structure network is laminated, and the 5-position par of the isophthalic acid derivative is interposed between these layers. The porous polymer metal complex according to (1), wherein a fluoroalkyl group protrudes and there is a portion where the perfluoroalkyl group is aggregated.

  (3) A total of four carboxyl groups of each of the four isophthalic acid type ligands coordinate to two transition metal ions, and one of the carboxyl groups has two oxygen atoms. Both coordinate to the same transition metal ion, and two of the carboxyl groups each have two oxygen atoms coordinate to different transition metal ions, and the remaining one of the carboxyl groups Has a coordination structure in which one oxygen atom is coordinated to one transition metal ion and the other oxygen atom is coordinated to two transition metal ions, (1) Or the porous polymeric metal complex as described in (2).

( 4 ) The perfluoroalkyl group is CF ₃ , C ₂ F ₅ , n-C ₃ F ₇ , n-C ₄ F ₉ , n-C ₅ F ₁₁ , n-C ₈ F ₁₇ , n-C _10. selected from F _21, porous polymer metal complex according to (1) to (3).

( 5 ) A gas adsorbent comprising the porous polymer metal complex according to any one of (1) to (4) above.

( 6 ) A gas separation apparatus using the gas adsorbent according to ( 5 ) above.

( 7 ) A gas storage device using the gas adsorbent described in ( 5 ) above.

  The porous polymer metal complex of the present invention is capable of adsorbing and releasing a large amount of gas and selectively adsorbing gas. In addition, it is possible to manufacture a gas storage device and a gas separation device in which a gas adsorbing material comprising the porous polymer metal complex of the present invention is housed.

  When the porous polymer metal complex of the present invention is used, for example, as a gas separation device of a pressure swing adsorption method (hereinafter abbreviated as “PSA method”), very efficient gas separation is possible. In addition, the time required for pressure change can be shortened, contributing to energy saving. Furthermore, since it can contribute to the miniaturization of the gas separation device, it is possible to increase the cost competitiveness when selling high-purity gas as a product. 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.

  Another application of the porous polymer metal complex of the present invention is a gas storage device. When the gas adsorbent of the present invention is applied to a gas storage device (business gas tank, consumer gas tank, vehicle fuel tank, etc.), it is possible to dramatically reduce the pressure during transportation and storage. . As an effect resulting from the ability to reduce the gas pressure during transportation or storage, firstly, improvement in the degree of freedom of shape can be mentioned. In the conventional gas storage device, the gas adsorption amount cannot be maintained high unless the pressure during storage is maintained. However, in the gas storage device of the present invention, a sufficient gas adsorption amount can be maintained even if the pressure is lowered.

  When applied to a gas separation device or gas storage device, there is no need to use a special device for the shape of the container, the material of the container, the type of gas valve, etc., and those used in the gas separation device and gas storage device Can be used. However, the improvement of various devices is not excluded, and any device is included in the technical scope of the present invention as long as the porous polymer metal complex of the present invention is used. .

The chain structure which the layer which forms the laminated network structure of the porous polymer metal complex of this invention comprises is shown. The structure of the layer which forms the laminated network structure of the porous polymer metal complex of this invention is shown. It is the figure which looked at the laminated structure of the laminated network structure of the porous polymer metal complex of this invention from the side surface. It is a figure which shows the coupling | bonding of the transition metal ion and ligand of the porous polymeric metal complex of invention.

The present invention provides the following formula (1):
[MX] _n (1)
(In the formula, M is a divalent transition metal ion, X is an isophthalic acid derivative (ligand) having a perfluoroalkyl group having 1 to 10 carbon atoms in the 5-position. N is composed of [MX]. (It shows the characteristic that many structural units are gathered, and the size of n is not particularly limited.)
And a porous polymer metal complex containing a fluorine atom and having a two-dimensional laminated network structure. In the porous polymer metal complex of the present invention, a layered structure network composed of a square lattice composed of a divalent transition metal ion and an isophthalic acid derivative ligand is formed, and the layered structure network is laminated. In between, there is a portion where the perfluoroalkyl group at the 5-position of the isophthalic acid derivative protrudes and the perfluoroalkyl group is aggregated.

  The PCP of the present invention has a two-dimensional laminated network. As shown in FIG. 1 showing the one-dimensional bond and FIG. 2 showing the two-dimensional bond, each layer forming the stacked structure is formed from a square lattice composed of a divalent transition metal ion and a ligand. A perfluoroalkyl group substituted at the 5-position of the isophthalic acid type ligand protrudes from the layer in the vertical direction of the layer. However, in FIGS. 1 and 2, for the sake of clarity, hydrogen atoms are omitted, divalent transition metal ions M are shown in black, oxygen atoms are shown in dark gray, and carbon atoms and fluorine atoms are shown in white or light gray. . The fluorine atom is present in the perfluoroalkyl group at the 5-position of isophthalic acid. As a result, as shown in FIG. 3 in which the laminated structure is viewed from the side, there is a portion where there is a lot of fluorine in which perfluoroalkyl groups are aggregated between the layers. In FIG. 3, the divalent transition metal ion, the oxygen atom, and the carbon atom are the same color as in FIGS. 1 and 2, but the fluorine atom in FIG. Change the brightness). The divalent transition metal ion is coordinated with DMF as a solvent used in the synthesis.

  In each figure, the compounds synthesized in the examples are measured with a single crystal X-ray diffractometer, and the obtained electron density data is illustrated with dedicated software. In actual materials, there are crystal lattice defects and molecular thermal vibrations, resulting in defects in the data derived from them. For this reason, the aromatic ring is distorted and functional groups (especially alkyl groups) disappear on the drawing. Etc. can occur. However, even if this is the case, under the mild synthesis conditions of the present invention, it is considered that the aromatic ring is not distorted, the functional group disappears, etc., and the defect is only a measurement problem. The compound may be considered to be composed of a ligand used as a raw material. Further, as described later, the porous polymer metal complex of the present invention may contain a solvent or water molecule in the complex molecule (crystal), but the structure of the porous polymer metal complex of the present invention is clear. is there.

  As shown in FIG. 4, the bond between the divalent transition metal ion and the ligand is such that each of the four isophthalic acid type ligands corresponds to two divalent transition metal ions (M). A total of four carboxyl groups (C1-C4) are coordinated to cancel the charge. One of four carboxyl groups (C1-C4) (C1) is coordinated to a divalent transition metal ion in which both two oxygen atoms are the same, and two of the four carboxyl groups (C2, In C3), the oxygen atom is coordinated to a separate divalent transition metal ion, and the last one of the four carboxyl groups (C4) is one oxygen in the two oxygen atoms. It has a complex coordination structure in which atoms are coordinated to one divalent transition metal ion and another oxygen atom is coordinated to two divalent transition metal ions. However, to which divalent transition metal ion is coordinated can vary depending on the definition of the coordinate bond distance, the above description is only a description of a certain bond distance, and the bond distance definition is changed. They may appear to be different coordination forms, but they are substantially the same.

  Four such complex SBUs are bridged between each other by four isophthalic acid type ligands to form a square minimum unit lattice in which SBUs are arranged at the four corners, which becomes a continuum. Thus, a planar square lattice network is formed (FIG. 2). Furthermore, a laminated body is formed by laminating these planes. At this time, the perfluoroalkyl group substituted with the isophthalic acid type ligand forms an agglomerated portion between the layers (FIG. 3). In FIG. 3, solvent molecules, water molecules, and the like enter between the layers of the planar square lattice network, but these molecules are easily removed by light heating.

Since the porous polymer metal complex of the present invention is a porous body, when it comes into contact with organic molecules such as water, alcohol or ether, it contains water or an organic solvent in the pore.
[MX] _n (G) m (2)
(In the formula, M is a divalent transition metal ion, X is an isophthalic acid derivative ligand having a perfluoroalkyl group having 1 to 10 carbon atoms at the 5-position. G was used for the synthesis as described later. Solvent molecules and water molecules in the air, usually called guest molecules, where n is a characteristic that many structural units composed of [MX] are assembled, and the size of n is not particularly limited. May be 0.2 to 6 with respect to the divalent transition metal ion 1).

  However, the guest molecule represented by G in these complex complexes is only weakly bonded to the porous polymer metal complex, and is removed by pretreatment such as vacuum drying when used as a gas adsorbent. Return to the complex represented by the original formula (1). Therefore, even a complex represented by the formula (2) can be regarded as essentially the same as the porous polymer metal complex of the present invention.

The porous polymer metal complex of the present invention is coordinated with divalent transition metal ions by solvent molecules used in the synthesis as described later and water molecules in the air.
[MXLz] _n (3)
(In the formula, M is a divalent transition metal ion, X is an isophthalic acid derivative ligand having a perfluoroalkyl group having 1 to 10 carbon atoms in the 5-position. L is used in the synthesis as described below. Solvent molecules and water molecules in the air, where n is a characteristic that a large number of structural units consisting of [MX] are assembled, and the size of n is not particularly limited, z is a divalent transition metal 1 or 2 with respect to ion 1).

  However, the coordinating molecule represented by L in these complex complexes is only weakly bonded to the divalent transition metal ion, and is used before drying under reduced pressure when used as a gas adsorbent. It is removed by the treatment and returns to the complex represented by the original formula (1). Therefore, even a complex represented by the formula (3) can be regarded as essentially the same as the porous polymer metal complex of the present invention.

  In the novel porous polymer metal complex containing the fluorine of the present invention and having a two-dimensional laminated network structure, the metal ion is a divalent transition metal ion. A divalent transition metal ion is preferable because it stably forms the above coordination structure. Specific examples of divalent transition metal ions include cobalt ions, nickel ions, zinc ions, and copper ions. From the viewpoint of chemical stability of the obtained porous polymer metal complex, copper ions and cobalt ions are preferable, and from the viewpoint of oxygen adsorption, cobalt ions are more preferable.

The isophthalic acid type ligand having a perfluoroalkyl group at the 5-position used in the porous polymer metal complex of the present invention has a linear or branched carbon number of 1 to 10 as the 5-position perfluoroalkyl group. Any of the perfluoroalkyl groups may be used, and CF ₃ , C ₂ F ₅ , n-C ₃ F ₇ , n-C ₄ F ₉ , n-C ₅ F ₁₁ , n- C ₈ F ₁₇ and n-C ₁₀ F ₂₁ groups are preferred. As a method for introducing a perfluoroalkyl group into the benzene ring, for example, Shibasaki et al., Chem. Asian J. 2006, 1, 314-321 can be referred to.

  In the present invention, the compound represented by the formula (1) uses a divalent transition metal ion source, an isophthalic acid derivative having a perfluoroalkyl group having 1 to 10 carbon atoms at the 5-position, It can be produced by dissolving in a solvent and mixing in a solution state and allowing an aromatic compound having a fluorine atom to coexist.

  A transition metal salt can be used as a source of divalent transition metal ions in the production method of the present invention. The cobalt salt may be any salt containing divalent cobalt ions, and is highly soluble in a solvent, and therefore, cobalt nitrate, cobalt acetate, cobalt sulfate, cobalt formate, cobalt chloride, bromide. Cobalt nitrate and cobalt sulfate are particularly preferable because cobalt is preferable and reactivity is high.

  Other transition metal salts used in the production method of the present invention, such as copper salts, zinc salts and nickel salts, may be salts containing divalent copper ions, zinc ions and nickel ions as well as cobalt salts. Nitrate, acetate, sulfate, formate, chloride, and bromide are preferable in terms of high solubility in a solvent, and nitrate and sulfate are particularly preferable in terms of high reactivity. .

As the isophthalic acid derivative having a perfluoroalkyl group at the 5-position used for the production of the porous polymer metal complex of the present invention, the isophthalic acid type ligand having a perfluoroalkyl group at the 5-position may be used. it can.

  The mixing ratio of the divalent transition metal salt used in the reaction of the present invention and the ligand (isophthalic acid salt having a perfluoroalkyl group at the 5-position) is such that the ratio of metal: ligand is 1: 5-5. The molar ratio is preferably 1: 1, and more preferably within the range of 1: 3 to 3: 3. In other ranges, the yield of the target product decreases, and unreacted raw materials remain, making it difficult to take out the target product.

  Good results can be obtained by using a mixed solvent of a proton solvent such as alcohols and an amide solvent such as dimethylformamide as the solvent. Protonic solvents such as alcohols and amide solvents such as dimethylamide and dimethylacetamide dissolve 2 divalent transition metal salts well, and further by coordination or hydrogen bonding to divalent transition metal ions or counter ions. Side reactions are suppressed by stabilizing valent transition metal salts and suppressing rapid reactions with ligands. Examples of alcohols include aliphatic monohydric alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-butanol, and aliphatic dihydric alcohols such as ethylene glycol. Methanol, ethanol, 1-propanol, 2-propanol, and ethylene glycol are preferable because they are inexpensive and have high solubility of the divalent transition metal salt. Moreover, these alcohols may be used alone or in combination. Examples of amide solvents include dimethylformamide, diethylformamide, dibutylformamide, dimethylacetamide and the like. Dimethylformamide and diethylformamide are preferred in that the solubility of the divalent transition metal salt is high.

  The mixing ratio of the alcohol and the amino solvent is arbitrary from 1:99 to 99: 1 (volume ratio). From the viewpoint that the solubility of both the ligand and the transition metal salt is enhanced and the generation of by-products can be suppressed, the mixing ratio is 90:10 to 10:90 (volume ratio), and the reaction can be accelerated. : 20-20: 80 (volume ratio) is preferable.

  It is also preferable to use a mixed organic solvent mixed with the above-mentioned alcohol or amide solvent as a solvent. From the viewpoint of improving the solubility of the divalent transition metal salt and the ligand, the mixing ratio of the mixed solvent composed of the alcohol and the amide solvent with respect to another organic solvent is preferably 30% or more.

  In order to synthesize the two-dimensional stacked PCP having a perfluoroalkyl group of the present invention, it is important that an aromatic compound having a fluorine atom coexists in the reaction. The fluorine atom must be directly bonded to the carbon atom that forms the aromatic ring. The ring may be monocyclic or multicyclic. The ring may be substituted with a low-polarity alkyl group other than a fluorine atom, but it is preferable that an oxygen-containing functional group such as a highly polar hydroxyl group or a nitrogen-containing functional group such as an amino group is not included. The number of fluorine atoms is preferably 1 or more and 6 or less per aromatic ring, and preferably 1 or more and 4 or less in that the yield of the target compound is improved. Specifically, monofluorobenzene, 1,2-difluorobenzene, 1,3-difluorobenzene, 1,2,3-trifluorobenzene, 1,3,5-trifluorobenzene, hexafluorobenzene, 4- Examples thereof include fluorotoluene, 1-fluoronaphthalene and perfluoronaphthalene. Monofluorobenzene, 1,2-difluorobenzene, 1,3-difluorobenzene, 1,2,3-trifluorobenzene, and 1,3,5-trifluorobenzene are preferable in that they can be obtained at low cost.

  The addition amount of the aromatic compound having a fluorine atom is 0.001 mol or more and 200 mol or less with respect to 1 mol of the divalent transition metal salt used in the reaction. More than 20 mol and less than 20 mol. From the viewpoint of reducing impurities, the amount is 0.008 mol or more and 0.2 mol or less.

  The aromatic compound having an added fluorine atom only contributes to the formation of the network structure as an additive, and is not included in the network structure itself. However, it may be incorporated as a guest molecule in the pores, or may be included as an impurity in the target powder after the reaction is complete, but this is because aromatic compounds having added fluorine atoms are in many solvents. Since the target PCP is soluble and insoluble in most solvents, aromatic compounds having fluorine atoms added by washing the solid product obtained after the reaction with the solvent are removed or recovered from the target PCP. It is possible to do.

  In the method of the present invention, a base can be added as a reaction accelerator. The base is presumed to accelerate the reaction by converting the carboxyl group of the ligand into an anion. Examples of the base include lithium hydroxide, sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide and the like as inorganic bases. Examples of the organic base include triethylamine, diethylisopropylamine, pyridine, 2,6-lutidine and the like. Lithium hydroxide, sodium carbonate, sodium hydroxide, and pyridine are preferred because of their high reaction acceleration. The addition amount is preferably 0.1 to 6.0 mol in terms of the effect of accelerating the reaction with respect to the total moles of isophthalic acid used, and more preferably 0.5 to less in terms of side reactions. 4.0 moles.

  In the method of the present invention, an organic acid can be added as a reaction control agent. It is considered that the organic acid controls the proper progress of the reaction by controlling the dissociation of the carboxyl group of the ligand as an acid. Aliphatic organic acids include monovalent acids such as acetic acid and propionic acid, divalent acids such as oxalic acid and malonic acid, and bicyclo [2,2,2] -octane-1,4-dicarboxylic acid. A cyclic carboxylic acid is mentioned. Examples of the aromatic organic acid include monovalent acids such as benzoic acid and 4-methylbenzoic acid. Of these, acetic acid, benzoic acid, and bicyclo [2,2,2] -octane-1,4-dicarboxylic acid, which have high solubility and are not highly coordinated to the divalent transition metal ion, are preferable. The amount added is preferably 0.1 to 12.0 mol in terms of the effect of the reaction with respect to the total mol of the ligand used, and more preferably 0.5 in terms of few side reactions. To 8.0 moles.

  In the reaction of the divalent transition metal salt solution and the ligand, in addition to the method of adding the solvent after the divalent transition metal salt and the ligand are charged into the container, the divalent transition metal salt, These solutions may be mixed after preparing the ligands separately as solutions.

  When the divalent transition metal salt and the ligand are mixed as respective solutions, the concentration of the solution is preferably 10 μmol / L to 4 mol / L, and 100 μmol / L to 2 mol / L for the divalent transition metal salt solution. It is more preferable that The organic solution of the ligand is preferably 10 μmol / L to 3 mol / L, and more preferably 100 μmol / L to 2 mol / L. Even if the reaction is carried out at a concentration lower than this, the desired product can be obtained, but this is not preferable because the production efficiency is lowered. Further, at a concentration higher than this, the adsorptive capacity may be lowered.

  The solution may be mixed by adding the ligand solution to the divalent transition metal salt solution or vice versa. Moreover, after laminating | stacking a bivalent transition metal salt solution and a ligand solution, you may mix by the method by natural diffusion. As a mixing method, it is not always necessary to use a solution, for example, a method in which a solid ligand is added to a divalent transition metal salt solution and a solvent is simultaneously added, or a divalent transition metal salt is charged into a reaction vessel. After that, various methods can be used so long as the reaction finally takes place in a solvent, such as injecting a solid or solution of the ligand and further injecting a solution for dissolving the divalent transition metal salt. A method is possible. However, the method of dropping and mixing the divalent transition metal salt solution and the ligand solution is industrially the most convenient and preferable.

  In any method, in order to form a two-dimensional square lattice stacked network structure, the reaction between the ligand and the metal ion is kept at an appropriate rate by preparing the reaction solution and then allowing it to stand. It is preferable. Here, the standing temperature is preferably −20 ° C. to 180 ° C., and −20 ° C. to 150 ° C. in that generation of by-products can be suppressed. The standing time is preferably 1 hour to 3 months, and more preferably 4 hours to 2 months in that there are few by-products.

  The reaction can be carried out using an ordinary glass-lined SUS reaction vessel and a mechanical stirrer. After completion of the reaction, the target substance and raw material can be separated by filtration and drying to produce a target substance with high purity.

  Whether the porous polymer metal complex obtained by the above reaction has the desired two-dimensional square lattice laminated network structure is analyzed by analyzing the reflection obtained by single crystal X-ray crystal analysis. It can be confirmed with. The gas adsorption ability of the porous polymer metal complex obtained by the above reaction can be measured using a commercially available gas adsorption apparatus.

  The porous polymer metal complex of the present invention is a porous material containing plural kinds of ligands used by mixing phthalic acid derivative ligands having side chains containing plural kinds of fluorine atoms as raw materials. It was confirmed that it is possible to form a so-called solid solution type porous polymer metal complex that synthesizes a polymer metal complex.

  The porous polymer metal complex of the present invention has a two-dimensional laminated network structure, and perfluoroalkyl groups protrude from the two-dimensional network structure above and below (between the layers) of this layer. Due to the influence of the fluorine atoms existing between the layers, the network structure in the laminated state is easily slippery compared to the laminated PCP having no fluorine agglomerated part, and therefore, a unique gas adsorption characteristic can be developed. It is done. However, the present invention is not bound by theory, and the characteristics of the porous polymer metal complex of the present invention are not limited by this theory.

The preparation method of the porous polymer metal complex has various conditions and cannot be uniquely determined, but here, it will be described based on examples.
For powder X-ray diffraction measurement, a powder X-ray apparatus DISCOVER D8 with GADDS manufactured by Bruker AX Co., Ltd. was used.

Example 1
Cobalt nitrate trihydrate 0.01 mmol, 5-pentafluoroethylisophthalic acid (isophthalic acid having C ₂ F ₅ group at 5-position) 0.01 mmol, monofluorobenzene 0.001 mmol, ethanol 1 mL, dimethylformamide 1 mL was put into a glass test tube having a diameter of 5 mm, covered, and heated in an oil bath at 120 ° C. for 3 days. After coating the obtained single crystal with Palaton so as not to be exposed to the atmosphere, a single crystal measuring device manufactured by Rigaku Co., Ltd. (single crystal structure analysis device VariMax for ultrafine crystal, MoK line (λ = 0.70109Å) )) (Irradiation time 8 seconds, d = 45 mm, 2θ = −20, temperature = −180 ° C.), and the obtained diffraction image is analyzed with analysis software, analysis software “CrystalStructure” manufactured by Rigaku Corporation. The basic structure is the same as the one shown in FIGS. 1 to 4 except for the perfluorocarbon group, and a perfluoroalkyl group protrudes between the layers. (A = 10.9, b = 16.25, c = 23.29; α = 90, β = 100.8, γ = 90; space group = P2).

  That is, the substance obtained in Example 1 is formed with a layered structure network composed of a square lattice composed of cobalt ions and an isophthalic acid derivative ligand (5-pentafluoroethylisophthalic acid). A porous polymer metal complex, which is laminated, has a perfluoroalkyl group at the 5-position of the isophthalic acid derivative protruding between the layers, and a portion where the perfluoroalkyl group is aggregated, and two For each divalent transition metal ion, four carboxyl groups of the four isophthalic acid type ligands are coordinated in total, and one of the carboxyl groups has the same two oxygen atoms. And two of the carboxyl groups coordinate oxygen atoms to different transition metal ions, and the rest of the carboxyl groups. Number of carboxyl groups, the one oxygen atom is one metal ion, one more oxygen atoms are coordinated to two metal ions, it had a coordination structure.

Example 2
Cobalt nitrate trihydrate 0.01 mmol, 5-Henicosafluorodecylisophthalic acid (isophthalic acid having a C ₁₀ F ₂₁ group at the 5-position) 0.01 mmol, monofluorobenzene 0.001 mmol, ethanol 1 mL, dimethyl 1 mL of formamide was placed in a glass test tube having a diameter of 5 mm, covered, and heated in an oil bath at 80 ° C. for 3 days. From the obtained single crystal, it was confirmed by X-ray diffraction analysis that it was the same two-dimensional laminated network structure as in Example 1. (A = 10.278 (8), b = 17.301 (13), c = 28.014 (2); α = 90, β = 90.731, γ = 90; space group = P2 ₁ ).

Example 3
Copper nitrate trihydrate 0.01 mmol, 5-trifluoromethylisophthalic acid (isophthalic acid having a CF ₃ group at the 5-position) 0.01 mmol, pentafluorobenzene 0.001 mmol, methanol 1 mL, dimethylformamide 1 mL The sample was put in a glass test tube having a diameter of 5 mm, covered, and heated in an oil bath at 80 ° C. for 3 days. From the obtained single crystal, the X-ray diffraction analysis revealed that it was the same two-dimensional laminated network structure as in Example 1. (A = 1.79, b = 16.33, c = 24.192; α = 90, β = 103.1, γ = 90; space group = P2).

Example 4
0.01 mmol of zinc nitrate trihydrate, 0.01 mmol of 5-undecafluoropentylisophthalic acid (isophthalic acid having a C ₅ F ₁₁ group at the 5-position), 1,3,5-trifluorobenzene 0.001 Mole, 1 mL of ethanol and 1 mL of dimethylformamide were placed in a glass test tube having a diameter of 5 mm, capped, and heated in an oil bath at 80 ° C. for 3 days. From the obtained single crystal, the X-ray diffraction analysis revealed that it was the same two-dimensional laminated network structure as in Example 1. (A = 9.722 (6), b = 18.824 (8), c = 27.399 (7); α = 90, β = 90.634, γ = 90; space group = P2 ₁ ).

Example 5
Nickel nitrate trihydrate 0.01 mmol, 5-nonafluorobutylisophthalic acid (isophthalic acid having a C ₄ F ₉ group at the 5-position) 0.01 mmol, monofluorobenzene 0.001 mmol, ethanol 1 mL, dimethylformamide 1 mL was put into a glass test tube having a diameter of 5 mm, covered, and heated in an oil bath at 80 ° C. for 3 days. From the obtained single crystal, X-ray diffraction analysis revealed that it had the same two-dimensional laminated network structure as in Example 1. (A = 11.585 (7), b = 19.041 (6), c = 27.264 (5); α = 90, β = 94.613, γ = 90; space group = P2).

Comparative Example 1
In the same manner as in Example 1, 0.01 mmol of cobalt nitrate trihydrate, 0.01 mmol of 5-pentafluoroethylisophthalic acid (isophthalic acid having a C ₂ F ₅ group at the 5-position), 1 mL of ethanol, dimethyl Synthesis was performed using 1 mL of formamide, but without adding a fluorine-containing aromatic compound. When the obtained powder was measured with a powder X-ray apparatus, it was different from the powder pattern simulation result from the single crystal X-ray data obtained in Example 1, and it was found that a two-dimensional laminated structure was not obtained. It was.

<Results of gas adsorption>
The adsorptivity of carbon dioxide, oxygen, nitrogen and carbon monoxide of the obtained gas adsorbent was evaluated using a BET automatic adsorption device (Bell Mini II manufactured by Bell Japan Co., Ltd.) (measurement temperature: carbon dioxide is 195K and 273K And 77K for oxygen and nitrogen and 273K for carbon monoxide). Prior to the measurement, the sample was vacuum-dried at 423 K for 6 hours to remove solvent molecules that may remain in a trace amount.

  Table 1 shows gas adsorption characteristic absorption of the porous polymer metal complexes obtained in Examples 1 to 5. All of them adsorbed carbon dioxide well and were found to be usable as gas storage materials. The thing containing a fluorine atom has the outstanding characteristic that the adsorption amount of a carbon dioxide and oxygen gas adsorption amount in 273K are especially large, and these are considered the thing in which the characteristic of the fluorine atom was reflected. . Moreover, the adsorptivity of carbon monoxide was also good. In addition, all show a gate phenomenon, which is considered to be an effect of a perfluoroalkyl group existing between layers.

  In the porous polymer metal complex of the present invention, a large number of micropores formed by alignment of ligands are present in the substance. Taking advantage of this porosity, specific adsorption of gas having affinity for fluorine atoms such as carbon dioxide and especially oxygen is possible, and it can be suitably used for separation and storage of these gases.

Claims (7)

Following formula (1)
[MX] _n (1)
(In the formula, M is a divalent transition metal ion selected from cobalt ion, copper ion, zinc ion and nickel ion, and X is the following formula:
(In the formula, Rf is a perfluoroalkyl group having 1 to 10 carbon atoms.)
Is an isophthalic acid derivative (ligand) having a perfluoroalkyl group having 1 to 10 carbon atoms represented by n indicates a characteristic that a large number of structural units composed of [MX] are gathered, and the size of n is not particularly limited. )
A porous polymer metal complex represented by the formula (1) and containing a fluorine atom and having a two-dimensional laminated network structure.   A layered structure network composed of a square lattice composed of transition metal ions and an isophthalic acid derivative ligand is formed, the layered structure network is laminated, and the perfluoroalkyl group at the 5-position of the isophthalic acid derivative is interposed between these layers. The porous polymer metal complex according to claim 1, wherein a portion where the perfluoroalkyl group is aggregated is present.   A total of four carboxyl groups of each of the four isophthalic acid type ligands coordinate to two divalent transition metal ions, and one of the carboxyl groups has two oxygen atoms. Both of them coordinate to the same transition metal ion, and two of the carboxyl groups each have two oxygen atoms coordinate to different transition metal ions, and the remaining one of the carboxyl groups 1 or 2 has a coordination structure in which one oxygen atom is coordinated to one transition metal ion and the other oxygen atom is coordinated to two transition metal ions. 2. The porous polymer metal complex according to 2. The perfluoroalkyl group is CF _Three , C ₂ F _Five , N-C _Three F ₇ , N-C _Four F ₉ , N-C _Five F ₁₁ , N-C ₈ F ₁₇ , N-C _Ten F _{twenty one} The porous polymer metal complex according to claim 1, which is selected from the group consisting of: A gas adsorbent comprising the porous polymer metal complex according to claim 1. A gas separation device using the gas adsorbent according to claim 5. A gas storage device using the gas adsorbent according to claim 5.