JP2017052714A - Porous polymer metal complex, gas adsorbent, gas separation device and gas storage device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porous polymer metal complex containing two kinds of similar ligand capable of use as a gas adsorbent and a gas separation device and a gas storage device using the same.SOLUTION: There are provided a porous polymer metal complex having a constitutional unit of [CuX](I), where X is an isophthalic acid ion substituted by a substituent having a chalcogen element at 5 position or a plurality of isophthalic acid ions containing the isophthalic acid ion substituted by a substituent having a chalcogen element at 5 position and n represents a state where a plurality of constitutional units consisting of [CuX]are aggregated, and a gas separation device and a gas storage device using the same.SELECTED DRAWING: Figure 4

Description

  The present invention relates to the use of a porous polymer metal complex and a porous polymer metal complex as a gas adsorbent, 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. .

  Oxygen gas is an industrial gas that is indispensable for industrial processes that use combustion, heating, and the like, such as iron making, chemistry, or bleaching, such as paper making, and is widely used. It is also important as a medical gas.

  For large-scale production of oxygen, cryogenic separation technology for extracting oxygen from air using the difference between the boiling points of oxygen and nitrogen has been established at extremely low temperatures. Not available for medium-scale. For small and medium scale oxygen production, PSA (Pressure Swing Adsorption) technology using zeolite, activated carbon or the like is widely used. However, it is a separation technology and material with a long history, and it is not partitioned to meet the need for smaller size and lower cost. (Non-patent documents 6 to 8)

  Porous polymer metal complex (PCP, Porous coordination Polymer) is a crystalline material having a network structure formed from metal ions and ligands. This material has many pores at the molecular level and is expected as a gas storage and separation material such as carbon dioxide and methane. On the other hand, this material has a low affinity with oxygen molecules, its application to oxygen separation is limited, performance has not reached a level where it can be put to practical use, and has a superior oxygen affinity and high porosity. Development of molecular metal complexes is expected, but it is not well understood how porous polymer metal complexes that selectively adsorb only oxygen in a wide temperature range can be produced. (Non-patent documents 9 to 12)

  Known as Kagome PCP, two-dimensional laminated PCP with a unique network structure synthesized from copper ions and isophthalic acid derivatives is known, and some of them have been reported to adsorb gas. Yes. Gas adsorption is greatly affected by the pore structure (shape and diameter) and the types of metal ions and ligands that make up the PCP, so which PCP is used to adsorb a specific gas. It is difficult to determine unambiguously whether or not it should be done, and material search is carried out by fumbling. (Patent Document 2, Non-Patent Documents 13 to 17)

On the other hand, there is a report example of oxygen-adsorbing PCP using the interaction between metal ions and oxygen molecules. (Non-patent document 12)
This is based on the common knowledge of complex chemistry that iron (II) ions and oxygen molecules have a strong interaction, but iron (II) ions are easily oxidized in the air, causing material deterioration. There are difficulties in practical use. Therefore, PCP that can adsorb oxygen by interaction with a ligand without depending on iron (II) ions is preferable, but such PCP is hardly known and design guidelines are not established.

JP 2000-109493 A Japanese Patent No. 5646789

Susumu Kitagawa, Integrated Metal Complex, Kodansha Scientific, 2001, pages 214-218 Long et al., Angew. Chem. Int. Ed. 2010, 49, 2-27 Suh et al. Inorganic Chemistry, Vol. 45, No. 21, 2006 Zhou et al., Inorganic Chemistry, Vol. 46, No. 4, 2007 1233 Rosi et al., J. AM. CHEM. SOC. 2010, 132, 38-39 Takebayashi et al., Toyo Soda Research Report Vol. 26, No. 1 (1982) 9 Haruna et al., Sumitomo Chemical 2005-II, 59 Hirano et al., Tosoh Res. & Tech. Rev. (2008) 52, 55 Farha et al., Angewandte Chem., Int. Ed., (2014) 14092 Kepert et al., J. Am. Chem. Soc., (2011) 10885 Kitagawa et al., Science, (2002) 298, 2358 Long et al., J. Am. Chem. Soc., (2011) 14814 Morris et al., Nature Commun. (2011) 304 Zaworotko et al., Chem. Commun. (2004) 2534 Zaworotko et al., Angew. Chem. Int. Ed. (2001) 2111 Zawarotko et al., Cryst. Growth. Des. (2003) 513 Burrows et al., Dalton Trans., (2008) 6788

  An object of the present invention is to provide a porous polymer metal complex and a gas adsorbent having excellent characteristics using the same. It is another object of the present invention to provide a gas storage device and a gas separation device that contain therein a gas adsorbent having the above characteristics.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained a so-called kagome structure obtained by a reaction between isophthalic acid substituted with a substituent having a chalcogen element at the 5-position and copper ion. It has been found that a porous polymer metal complex having an oxygen adsorbs only oxygen in a wide temperature range, and the present invention has been completed. In this specification, when the term “chalcogen element” is used, oxygen element is not included.

  That is, the present invention has a kagome structure, and includes a copper ion, an isophthalic acid ligand substituted with a substituent having a chalcogen element at the 5-position, or an isophthalic acid ion substituted with a substituent having a chalcogen element at the 5-position. A porous polymer metal complex containing a plurality of types of isophthalate ion ligands, and relates to the use of this material as a gas storage material and a gas storage device and a gas separation device containing this gas adsorbent inside. It is an invention.

That is, the present invention is as follows.
(1) [Cu ₂ X ₄ ] _n (I)
(Wherein X is an isophthalate ion substituted with a substituent having a chalcogen element at the 5-position or a plurality of types of isophthalate ions including an isophthalate ion substituted with a substituent having a chalcogen element at the 5-position. , Shows a state in which a large number of structural units composed of [Cu ₂ X ₄ ] are gathered.)
A porous polymer metal complex having the following structural unit:
(2) The structural unit has a paddle wheel structure in which two copper ions share four coordinate groups derived from each of the four isophthalate ions and coordinate to each other. The paddle wheel structure is connected by the isophthalate ion to form a kagome structure composed of a triangle and a hexagon, and further has a crystal structure in which the kagome structure is laminated (1) Porous polymer metal complex.
(3) The porous polymer metal complex according to (1) or (2), wherein the functional group contained in the substituent having the chalcogen element is thiol, sulfide, or disulfide.
(4) 5 mol% or more of the total mole number of X in the formula (I) [Cu ₂ X ₄ ] _n is an isophthalate ion substituted with a substituent having a chalcogen element at the 5-position. The porous polymer metal complex according to any one of (1) to (3).
(5) A gas adsorbent comprising the porous polymer metal complex according to any one of (1) to (4).
(6) A gas separation device using the adsorbent according to (5).
(7) A gas storage device using the adsorbent according to (6).

  The porous polymer metal complex of the present invention can absorb and release a large amount of oxygen gas and can selectively adsorb oxygen gas. Moreover, it becomes possible to manufacture an oxygen gas storage device and an oxygen gas separation device in which an oxygen gas storage material made of the porous polymer metal complex of the present invention is housed.

  If the porous polymer metal complex of the present invention is used, for example, as a pressure swing adsorption type (hereinafter abbreviated as “PSA type”) oxygen gas separator, very efficient oxygen gas separation is possible. In addition, the time required for pressure change can be shortened, contributing to energy saving. Furthermore, it can contribute to downsizing of the oxygen gas separation device, so it is possible to increase the cost competitiveness when selling high purity oxygen gas as a product. Even if it exists, since the cost which the installation which requires high purity oxygen gas requires can be reduced, it has the effect of reducing the manufacturing cost of a final product after all.

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

  When applied to an oxygen gas separation device or oxygen gas storage device, the container shape, container material, type of gas valve, etc. need not be specially used, and it is used for the oxygen gas separation device and oxygen 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 top view which cut out only one layer of the kagome structure of the crystal structure of the porous polymeric metal complex of this invention is shown. 1 shows an enlarged view of a so-called paddle wheel structure in which two copper ions in a porous polymer metal complex of the present invention share four carboxyl groups and coordinate to each other. The side view which cut out only two layers of the kagome structure of the crystal structure of the porous polymer metal complex of this invention is shown. The kagome structure of the crystal structure of the porous polymer metal complex obtained by analyzing the single crystal obtained in Example 1 is shown.

The porous polymer metal complex of the present invention is a porous polymer metal complex having a so-called kagome structure represented by the following formula (I) and shown in FIG.
[Cu ₂ X ₄ ] _n (I)
(Wherein X is an isophthalate ion substituted with a substituent having a chalcogen element at the 5-position or a plurality of types of isophthalate ions including an isophthalate ion substituted with a substituent having a chalcogen element at the 5-position. , [Cu ₂ X ₄ ] represents a state in which a large number of structural units are gathered, and the size of n is not particularly limited.)

  FIG. 1 shows a top view in which only one layer of the kagome structure of the crystalline structure of the porous polymer metal complex of the present invention is cut out. It has a so-called paddle wheel structure (see FIG. 2) in which two copper ions share four carboxyl groups and coordinate to each other, and the paddle wheel is connected by an isophthalate ion, with the paddle wheel at the top. A so-called Kagome structure consisting of hexagons and triangles is formed. In this figure, four oxygen atoms of carboxylic acid are coordinated to one copper ion forming the paddle wheel structure, and one molecule of water is coordinated to the axial position of the copper ion.

  FIG. 2 shows an enlarged view of a so-called paddle wheel structure in which two copper ions share four carboxyl groups and coordinate to each other. This paddle wheel is connected by isophthalate ions to form a kagome structure as shown in FIG.

  FIG. 3 shows a side view in which only two layers of the kagome structure of the porous polymer metal complex in the porous polymer metal complex of the present invention are cut out. The kagome structure is a two-dimensional planar structure, and this two-dimensional planar structure is laminated on the porous polymer metal complex. In this figure, all are part of the molecular network structure cut out and are actually infinite lattices.

  The porous polymer metal complex of the present invention includes a plurality of kinds of copper ions and isophthalic acid ions substituted with a substituent having a chalcogen element at the 5-position or isophthalic acid ions substituted with a substituent having a chalcogen element at the 5-position. It has a so-called kagome network structure shown in FIG. 1 formed from isophthalate ions. What is important here is the topology of the network, and the individual bond angles of the Kagome network structure do not always have the same bond angles as in the figure because the porous polymer metal complex has flexibility. Also in the stacking mode of FIG. 3, the two-dimensional kagome network is stacked only by weak interactions such as hydrogen bonds and van der Waals forces. Are also regarded as the same porous polymer metal complex having the same function.

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 pores.
[Cu ₂ X ₄ ] _n (G) _m (II)
(Wherein X is an isophthalate ion substituted with a substituent having a chalcogen element at the 5-position or a plurality of types of isophthalate ions including an isophthalate ion substituted with a substituent having a chalcogen element at the 5-position. , [Cu ₂ X ₄ ] has a characteristic that many structural units are assembled, and the size of n is not particularly limited, G is an organic molecule such as water, alcohol or ether adsorbed in the pores M is an arbitrary number.)
It may change to a complex complex such as

  However, organic molecules such as water, alcohol, and ether in these complex complexes are only weakly bonded to the porous polymer metal complex, and are removed by pretreatment such as vacuum drying when used as a gas adsorbent. Returning to the original porous polymer metal complex represented by the formula (I). Therefore, even a porous polymer metal complex represented by the formula (II) can be regarded as essentially the same as the porous polymer metal complex of the present invention.

The copper ion in the porous polymer metal complex of the present invention has a so-called paddle wheel structure in which four carboxyl group oxygens are coordinated. Copper ions often have a six-coordinate structure, that is, the paddle wheel structure can receive two more coordinations in addition to the four oxygens of the carboxyl group. For example, the formula (III)
[Cu ₂ X ₄ Q _z ] _n (III)
(In the formula, X is the same as defined in formula (I). Q is a molecule coordinated to the copper ion forming the paddle wheel, and z is 1 or 2.)
It may change to a complex complex such as

  However, Q in these complex complexes is only weakly bonded to copper ions, and is removed by pretreatment such as drying under reduced pressure when used as a gas adsorbent, and is represented by the original formula (I). Return to the complex. Therefore, even a complex represented by the formula (III) can be regarded as essentially the same as the porous polymer metal complex of the present invention.

  The porous polymer metal complex represented by the formula (I) of the present invention is a copper salt, isophthalic acid substituted by a substituent having a chalcogen element at the 5-position, or isophthalate substituted by a substituent having a chalcogen element at the 5-position. It can be produced by dissolving a plurality of types of isophthalic acid containing acid ions in a solvent and mixing them in a solution state. As a solvent for dissolving the copper salt, good results can be obtained by using a proton solvent such as water or alcohol. Protonic solvents such as water and alcohol dissolve copper salts well and stabilize copper salts by coordinating and hydrogen bonding to copper ions and counter ions, thereby suppressing rapid reaction with ligands. In order to suppress side reactions.

  Examples of the alcohol 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 preferred because they are inexpensive and have high solubility of copper salts. These alcohols may be used alone or in combination.

  It is also preferable to use a mixture of the above alcohols and an organic solvent other than alcohol or water as a solvent. The mixing ratio is in an arbitrary range of 1:99 to 100: 0 (volume ratio). The mixing ratio of alcohols is preferably 30% or more from the viewpoint of improving the solubility of copper salts and isophthalic acids.

  As the organic solvent other than the alcohol that can be used, a highly polar solvent is preferable because of its excellent solubility, specifically, dialkylformamide such as tetrahydrofuran, acetonitrile, dioxane, acetone, dimethylformamide, diethylformamide, and dimethylacetamide. And dialkylacetamide such as diethylacetamide, dimethylsulfoxide and the like.

  The copper salt used in the production of the porous polymer metal complex of the present invention may be a salt containing a divalent copper ion, and is highly soluble in the solvent used. Copper nitrate, copper acetate, copper sulfate, copper formate, copper fumarate, copper chloride, copper bromide are preferred, and copper nitrate, copper fluoride, copper sulfate are particularly preferred in terms of high reactivity. .

Next, isophthalic acid substituted with a substituent having a chalcogen element at the 5-position will be described. Examples of the substituent having a chalcogen element include a substituent containing a sulfur atom. Specifically, it is a functional group containing an SH group, for example, 5-hydroxythioisophthalic acid in which an SH group is directly substituted with isophthalic acid, an alkyl group in which an SH group is substituted, such as a hydroxythiomethyl group (HS-CH ₂ -), hydroxy thioethyl group (HS-CH ₂ -CH ₂ -) and the like are isophthalic acids substituted. Examples of the alkyl group include straight-chain and branched-chain alkyl groups. The alkyl group contains 1 to 10 carbon atoms, and 1 to 6 carbon atoms from the viewpoint of ease of PCP synthesis. It is.

Another substituent containing a sulfur atom is a sulfide group containing an alkyl group, specifically a methylthio group (CH ₃ —S—), a methylthiomethyl group (CH ₃ —S—CH ₂ —), methylthioethyl group _{(CH 3 -S-CH 2 -CH} 2 -) and the like.

Another substituent containing a sulfur atom is a disulfide group containing an alkyl group, specifically, a CH ₃ —SS— group, a CH ₃ —SS—CH ₂ — group, a CH ₃ — S—S—CH ₂ —CH ₂ group may be mentioned.

Another substituent having a chalcogen element is a substituent containing a selenium (Se) atom. Specifically, it is a functional group containing a SeH group, such as SeH group, HSe—CH ₂ —, HSe—CH ₂ —CH ₂ — and the like. Examples of the alkyl group contained include linear and branched alkyl groups. The alkyl group contains 1 to 10 carbon atoms, and the number of carbon atoms is 1 from the viewpoint of ease of PCP synthesis. ~ 6.

Further, the substituent containing another Se atom is a CH ₂ —Se—CH ₂ group containing an alkyl group, specifically, CH ₃ —Se—, CH ₃ —Se—CH ₂ —, CH ₃ —. Se-CH ₂ -CH ₂ - and the like.

Another Se-containing substituent is a CH ₂ —Se—Se—CH ₂ group containing an alkyl group, specifically a CH ₃ —Se—Se— group, a CH ₃ —Se—Se—CH group. ₂ - _{group, CH 3 -Se-Se-CH} 2 -CH 2 group can be mentioned.

Another substituent having a chalcogen element is a substituent containing a tellurium (Te) atom. Specifically, it is a functional group containing a TeH group, and examples thereof include a TeH group, HTe—CH ₂ —, HTe—CH ₂ —CH ₂ — and the like. Examples of the alkyl group contained include linear and branched alkyl groups. The alkyl group contains 1 to 10 carbon atoms, and the number of carbon atoms is 1 from the viewpoint of ease of PCP synthesis. ~ 6.

Examples of the substituent containing a different Te atoms are CH ₂ -Te-CH ₂ groups containing an alkyl group, in particular _{CH 3 -Te-, CH 3 -Te-} CH 2 -, CH 3 - Te-CH ₂ -CH ₂ - and the like.

Examples of the substituent containing a different Te is CH ₂ -Te-Te-CH ₂ groups containing an alkyl group, in particular CH ₃ -Se-Se- group, CH ₃ -Se-Se-CH ₂ - _{group, CH 3 -Te-Te-CH} 2 -CH 2 group can be mentioned.

  In the porous polymer metal complex having the kagome structure of the present invention and containing an isophthalic acid ligand substituted with a substituent having a chalcogen element at the 5-position, a mixture of plural types of isophthalic acids is used as a raw material, A so-called solid solution type porous polymer metal complex is synthesized, which synthesizes a porous polymer metal complex containing a plurality of types of isophthalic acids used. At this time, at least one kind of a plurality of types of isophthalic acids used in combination needs to be isophthalic acids substituted with a substituent having a chalcogen element at the 5-position, and the content thereof is 5% or more, preferably 20% or more.

  This solid solution type porous polymer metal complex is also the porous polymer metal complex of the present invention having the so-called kagome structure represented by the above formula (I) and shown in FIGS.

  Combining copper ions with isophthalate ions and two or more types of isophthalate ions having a substituent at the 5-position forms a solid solution type porous polymer metal complex having the so-called kagome structure shown in FIGS. Make sure you do. The solid solution type porous polymer metal complex of the present invention is a substituent having a chalcogen element at the 5-position as an isophthalate ion and an isophthalate ion having a substituent at the 5-position in the solid-solution type porous polymer metal complex. It contains 5 mol% or more of isophthalate ions substituted. The plural types of isophthalic acids used by mixing may be isophthalic acids substituted by a substituent having a chalcogen element at the 5-position. At this time, there is no mutual penetration of the kagome structure.

  In the isophthalate ion used in the solid solution type porous polymer metal complex of the present invention and the isophthalate ion having a substituent having a chalcogen element at the 5-position, the substituent at the 5-position may be a halogen atom, substituted or unsubstituted Alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryl group, aralkyl group, substituted or unsubstituted amino group, nitro group, amide group, formyl group, carbonyl group, ester group, azide group, carboxyl It is a group selected from a group, a sulfo group, a hydroxyl group and the like. The alkyl group is preferably an alkyl group having 1 to 12 carbon atoms, particularly 1 to 6 carbon atoms such as a methyl group and an ethyl group. Examples of the substituent of the substituted alkyl group include a hydroxy group and an amino group. The alkoxy group is preferably an alkoxy group having 1 to 12 carbon atoms, particularly 1 to 6 carbon atoms, particularly a methoxy group, an ethoxy group or a benzyloxy group. Examples of the substituent for the substituted alkoxy group include a hydroxy group, an amino group, and a dimethylamino group. As the aryl group, a phenyl group and a parahydroxyphenyl group are preferable. Examples of the substituted aryl group include a parahydroxyphenyl group and a paradimethylaminophenyl group. As the aralkyl group, a phenyl group in which any one or more of a benzyl group, o-, m-, and p- is substituted with a methyl group and / or an ethyl group is preferable. An unsubstituted or substituted amino group is preferable, and specifically, an amino group, a methylamino group, a dimethylamino group, an ethylamino group, a diethylamino group, a phenylamino group, and a diphenylamino group are more preferable.

  In the case of this solid solution type porous polymer metal complex, X in the formulas (I), (II), and (III) is two or more types, but can be, for example, three types or four types. Although there is no upper limit, in general, it is preferable to have up to six types in which one type of substituent can be substituted for each hexagon forming the Kagome network stochastically and the characteristics are easily improved.

  In the method for producing a porous polymer metal complex of the present invention, a base can be added as a reaction accelerator. Examples of the base that can be used as the reaction accelerator 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 preferable in terms of high reaction acceleration. The amount added is preferably 0.1 to 6.0 moles in terms of the effect of accelerating the reaction relative to the total number of moles of isophthalic acid used, and more preferably in terms of few side reactions. Is 0.5 to 4.0 moles.

  In reacting the copper salt solution with the isophthalic acid described above, after the copper salt and isophthalic acid are charged in a container, the copper salt and the isophthalic acid are separately prepared as a solution, in addition to the method of adding a solvent, These solutions may be mixed. The solution may be mixed by adding an isophthalic acid solution to the copper salt solution or vice versa. In addition, the mixing method is not necessarily performed in a solution. For example, a method of adding solid isophthalic acid into a copper salt solution and simultaneously adding a solvent, or after charging a reaction vessel with a copper salt, isophthalic acid solids Alternatively, various methods are possible as long as the reaction finally occurs in a solvent, such as injecting a solution and further injecting a solution for dissolving the copper salt. However, a method of dropping and mixing a copper salt solution and an isophthalic acid solution is industrially the most convenient and preferable.

  The concentration of the solution is 40 mmol / L to 4 mol / L, preferably 80 mmol / L to 2 mol / L for the copper salt solution, and 40 mmol / L to 3 mol / L, preferably 80 mmol / L to 1 for the organic solution of isophthalic acids. 0.8 mol / L. Even if the reaction is carried out at a concentration lower than these lower limit concentrations, the desired product can be obtained, but this is not preferable because the production efficiency is lowered. On the other hand, a concentration higher than this is not preferable because the gas adsorption ability is lowered.

  The reaction temperature is -20 to 180 ° C, preferably 25 to 140 ° C. If it is carried out at a lower temperature, the solubility of the raw material is lowered, which is not preferable. Although it is possible to carry out the reaction at a higher temperature by using an autoclave or the like, the yield does not improve for the energy cost such as heating, so there is no substantial meaning at a temperature higher than 180 ° C. .

  The mixing ratio of the copper salt and isophthalic acid used in the synthesis reaction is in the range of 3: 1 to 1: 5, preferably 1.5: 1 to 1: 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.

  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 the raw material are separated by filtration and drying to produce a target substance with high purity.

  Whether the porous polymer metal complex obtained by the above synthesis reaction has a kagome structure can be confirmed by analyzing the reflection obtained by single crystal X-ray crystal analysis. It can also be confirmed by a reflection pattern of powder X-ray analysis. Whether the porous polymer metal complex obtained by the above reaction is porous can be confirmed by thermogravimetric analysis (TG). For example, in a nitrogen atmosphere (flow rate = 50 mL / min), the rate of temperature increase is 5 ° C / min. it can. 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.

[Combination of adsorbents]
The gas adsorbent (hereinafter referred to as adsorbent (A)) containing the porous polymer metal complex of the present invention may be used alone as an adsorbent, or may be used in combination with another adsorbent.

  The preparation method of the porous polymer metal complex has various conditions and cannot be determined uniquely. Here, one condition will be described as an example.

Example 1
After adding 50 μL of pyridine to 30 mL of an aqueous solution of 120 mg of copper acetate monohydrate, 30 mL of a methanol solution of 150 mg of 5- (methylthiosulfanyl) isophthalic acid was added dropwise. After the mixture was stirred at room temperature for 14 hours, 180 mg of a green hexagonal plate single crystal was obtained. After a single crystal having a diameter of about 250 microns was coated with Palaton so as not to be exposed to the atmosphere, a single crystal measuring device manufactured by Rigaku Co., Ltd. 71069Å)) (irradiation time 16 seconds, d = 45 mm, 2θ = −20, temperature = −180 ° C.), and the obtained diffraction image was analyzed using analysis software “hermit crab XG2009” As shown in FIG. 4, it was confirmed that it has a kagome structure (a = 18.3863 (11), b = 18.3863 (11), c = 6.6169 (6); α = 90, β = 90, γ = 120; space group = P-3m1)).

Comparative Examples 1 and 2
In the same manner as in Example 1, porous polymer metal complexes of Comparative Examples 1 and 2 were obtained using isophthalic acid having an —OMe substituent and an —OH substituent at the 5-position. When the diffraction image obtained by the single crystal structure analyzer for ultrafine crystals was analyzed in the same manner as in Example 1, these porous polymer metal complexes were found to be kagome-structured porous polymer metal complexes. confirmed.

<Measurement of gas adsorption characteristics>
Various gas adsorption characteristics of the obtained gas adsorbent were measured at various temperatures using a BET automatic adsorption device (Bell Mini II manufactured by Nippon Bell Co., Ltd.). Prior to the measurement, the sample was vacuum-dried at 393 K for 6 hours to remove solvent molecules that may remain in a trace amount.

Examples 2-5
In the same manner as in Example 1, porous polymer metal complexes having various kagome structures in which a substituent containing a chalcogen element was substituted at the 5-position of isophthalic acid shown in Table 1 were synthesized. In any case, as a result of the powder X-ray analysis, the same reflection pattern as in Example 1 was shown, so that it was confirmed to have a kagome structure.

  Tables 1 and 2 show the amounts of adsorption of oxygen gas and nitrogen gas at various temperatures. In all of Tables 1 and 2, the adsorption amount is an adsorption amount at a relative pressure of 0.95, and the relative pressure is a value obtained by dividing the pressure at the time of adsorption by the boiling point of the gas at the temperature. .

  At any temperature, the porous polymer metal complex using isophthalic acid substituted with a substituent containing a chalcogen element at the 5-position of the present invention adsorbs only a large amount of oxygen gas, and the adsorption amount of nitrogen gas is Remarkably less. Compared with the porous polymer metal complex using the isophthalic acid which has the substituent which does not have a chalcogen element in 5-position of the comparative examples 1 and 2, the effect is clear.

  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. Oxygen gas can be selectively adsorbed, separated, and stored by making use of this porosity and the affinity between the chalcogen element and oxygen.

Claims (7)

[Cu ₂ X ₄ ] _n (I)
(Wherein X is an isophthalate ion substituted with a substituent having a chalcogen element at the 5-position or a plurality of types of isophthalate ions including an isophthalate ion substituted with a substituent having a chalcogen element at the 5-position. , Shows a state in which a large number of structural units composed of [Cu ₂ X ₄ ] are gathered.)
A porous polymer metal complex having the following structural unit:   The structural unit has a paddle wheel structure in which two copper ions share and coordinate with each other four carboxyl groups derived from each of the four isophthalate ions. 2. The porous structure according to claim 1, wherein a wheel structure is connected by the isophthalate ion to form a kagome structure composed of a triangle and a hexagon, and further has a crystal structure in which the kagome structure is laminated. Molecular metal complex.   The porous polymer metal complex according to claim 1, wherein the functional group contained in the substituent having the chalcogen element is thiol, sulfide, or disulfide. 5 or more mol% of the total number of moles of X in the formula (I) [Cu ₂ X ₄ ] _n is an isophthalate ion substituted with a substituent having a chalcogen element at the 5-position. The porous polymer metal complex according to any one of 1 to 3.   A gas adsorbent comprising the porous polymer metal complex according to any one of claims 1 to 4.   A gas separation device using the adsorbent according to claim 5.   A gas storage device using the adsorbent according to claim 6.