JP2016196417A - Porous polymer metal complex, gas adsorbent, and gas separation apparatus and gas storage apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porous polymer metal complex utilizable as a gas adsorbent capable of adsorbing oxygen and carbon monoxide selectively in a wide temperature region, and to provide a gas separation apparatus and a gas storage apparatus using the same.SOLUTION: A porous polymer metal complex has an aggregate structure expressed by [CuX](i). (In formula (i), X is a ligand of copper ion, and an isophthalic acid derivative having a functional group containing halogen other than fluorine on 5-position, and n shows an aggregation number of a metal complex comprising CuX, and n is not limited.)SELECTED DRAWING: Figure 4

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. Examples of the gas that is required to be separated or stored using such a gas adsorbent include oxygen and carbon monoxide.

  Since oxygen is used as an industrial gas in enormous amounts in steel and other industries, the development of an oxygen separation method is very important. For this purpose, so-called porous bodies having a large number of small pores are used as gas adsorbents, but most adsorbents that adsorb oxygen also adsorb gases other than oxygen, that is, nitrogen and the like. There are many things. In particular, since the interaction between the pores and various gases becomes strong at low temperatures, in principle, many porous bodies adsorb various gases. Therefore, it is not well understood how an adsorbent that selectively adsorbs (separates) only oxygen in a wide temperature range can be produced. Although oxygen separation using molecular sieve carbon and PSA (pressure swing adsorption) equipment has been put into practical use, there is a great need for miniaturization and high efficiency, and the development of a high-performance oxygen separator to meet this demand is important.

  Carbon monoxide is useful as a raw material for chemical products such as fuel, acetic acid and polycarbonate. A large amount of carbon monoxide is generated from the iron and steel industry during operations such as converters, and this is obtained as a mixed gas with nitrogen. However, carbon monoxide and nitrogen are very similar in physical properties and chemical properties, and the separation efficiency of carbon monoxide and nitrogen by a gas adsorbent using a porous material such as existing zeolite and activated carbon is low. For this reason, this technology is not widely used, and development of a gas adsorbent capable of selectively adsorbing carbon monoxide with high efficiency is desired.

  By the way, a porous polymer metal complex is a crystalline solid obtained from a metal ion and an organic ligand, and, like zeolite and activated carbon, has nano-scale fine pores to adsorb and separate gases. It is known that In view of this, a method in which a gas is occluded in a porous polymer metal complex has also been proposed (see Patent Document 1 and Non-Patent Document 1).

  However, the gas adsorbents conventionally proposed using these porous polymer metal complexes are not sufficiently satisfactory in terms of the amount of gas adsorption and workability, and have more excellent characteristics. Development of adsorbents is desired. Because of the combination of various metal ions and organic ligands and the diversity of skeletal structures, various gas adsorption characteristics are exhibited in addition to the porous polymer metal complexes disclosed in Patent Document 1 There is a possibility to do.

  A porous polymer metal complex having a kagome network structure obtained from isophthalic acid as a raw material is known. Many of these exhibit gas-adsorbing properties, and it is known that the substituent at the 5-position of isophthalic acid affects the gas-adsorbing properties. For example, Patent Document 2 describes that a porous polymer metal complex having a kagome network structure selectively adsorbs carbon dioxide (see Patent Document 2). However, what kind of substituents express what kind of gas-adsorbing property has not yet been examined sufficiently (see Patent Document 3 and Non-Patent Documents 6 to 11).

JP 2000-109493 A Japanese Patent No. 5646789 US Patent Application Publication No. 2002/0120165

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 Morris et al., Nature Commun., 2011, 304 Zaworotko et al., Chem. Commun., 2004, 2534 Zaworotko et al., Angew. Chem. Int. Ed. 2001, 2111 Zaworotko et al., Cryst. Growth Des. 2003, 513 Burrows et al., Dalton Trans., 2008, 6788 Sato et al., Science, 2014, 343, 167

  An object of the present invention is to provide a porous polymer metal complex capable of selectively adsorbing oxygen and carbon monoxide in a wide temperature range, 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 can obtain the reaction by reacting an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position with copper ions. The inventors have found that a porous polymer metal complex having a so-called kagome structure selectively adsorbs oxygen and carbon monoxide in a wide temperature range, and has completed the present invention.

  That is, the present invention relates to a porous polymer metal complex having an isophthalic acid derivative having a basic skeleton of a kagome structure and having a functional group containing a halogen element other than fluorine at the 5-position as a ligand of a copper ion, Furthermore, the present invention relates to the use of the present material as a gas adsorbent and a gas storage device and a gas separation device each containing the present gas adsorbent.

That is, the embodiments of the present invention are as follows.
(1) [CuX] _n (i)
(In formula (i), X is a copper ion ligand and is an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position. N is a constituent unit of a metal complex composed of CuX. Indicates the number of sets, and n is not limited.)
A porous polymer metal complex having an aggregate structure represented by:
(2) The aggregate structure has a paddle wheel structure in which copper ions are coordinated with four carboxyl groups in the isophthalic acid derivative, and two units are coordinated up and down. The porous polymer metal complex according to the above (1), which has a crystal structure in which a kagome structure composed of a six-membered ring and a three-membered ring formed by connecting with an isophthalic acid derivative is laminated.
(3) The porosity as described in (1) or (2) above, wherein the halogen element of the functional group containing a halogen element other than fluorine is one or more selected from the group consisting of chlorine, bromine and iodine Polymer metal complex.
(4) The porous polymer metal complex according to the above (3), wherein the halogen element of the functional group containing a halogen element other than fluorine is iodine.
(5) The functional group containing a halogen element other than fluorine is a linear or branched alkyl group or alkoxy group in which the halogen element is substituted with hydrogen, or any one of (1) to (4) above Porous polymer metal complex.
(6) The porous polymer metal complex according to (5) above, wherein the number of carbon atoms in the alkyl group or alkoxy group is in the range of 1 to 10.
(7) The porous polymer metal complex according to any one of (1) to (6), wherein the functional group containing a halogen element other than fluorine contains 1 to 21 halogen atoms.
(8) [CuX] _n (iv)
(In the formula (iv), X is a copper ion ligand, and an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position, and isophthalic acid and an isophthalic acid derivative having a substituent at the 5-position The proportion of isophthalic acid derivatives having a functional group containing a halogen element other than fluorine at the 5-position when the total number of moles of X is 100 mol%, including one or more selected from the group consisting of Is 5 mol% or more, n represents the number of aggregates of structural units of the metal complex composed of CuX, and n is not limited.)
A porous polymer metal complex having an aggregate structure represented by:
(9) The isophthalic acid derivative having a substituent at the 5-position is selected from an isophthalic acid derivative having an alkyl group at the 5-position, an isophthalic acid derivative having an alkoxy group at the 5-position, and an isophthalic acid derivative having an amino group Or the porous polymeric metal complex as described in said (8) which is 2 or more types.
(10) A gas adsorbent comprising the porous polymer metal complex according to any one of (1) to (9).
(11) A gas separation device using the adsorbent according to (10).
(12) A gas storage device using the adsorbent according to (10).

  The porous polymer metal complex of the present invention can store and release a large amount of gas with respect to oxygen and carbon monoxide, and can perform selective gas adsorption. In addition, it is possible to manufacture a gas storage device and a gas separation device in which the gas adsorbent 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 fact that the gas pressure during transportation and storage can be reduced, an improvement in the degree of freedom in shape is first 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 a gas storage device, the container shape, the material of the container, the type of the gas valve, etc. need not be specially used, and are used in the gas separation device or the 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 basic skeleton of the kagome structure which the porous polymer metal complex which concerns on this embodiment has is shown. In FIG. 1, copper ions are shown in black, carbon atoms are shown in gray, and oxygen atoms are shown in white. The illustration of hydrogen atoms is omitted. FIG. 1 shows an enlarged view of a so-called paddle wheel structure in which two units in which copper ions are coordinated with four carboxyl groups in an isophthalic acid derivative are coordinated up and down. As in FIG. 1, copper ions are shown in black, carbon atoms are shown in gray, and oxygen atoms are shown in white. The illustration of hydrogen atoms is omitted. The side view which cut out only two layers of the basic skeleton of the kagome structure which the porous polymer metal complex shown in FIG. 1 has is shown. In FIG. 3, copper ions are shown in black, carbon atoms are shown in gray, and oxygen atoms and hydrogen atoms are shown in white. The kagome structure (only one layer) of the porous polymer metal complex obtained by analyzing the single crystal obtained in Example 1 is shown. In FIG. 4, the circled atoms are iodine. The diffraction pattern obtained by measuring the powder obtained in Example 1 with a powder X-ray apparatus is shown.

The porous polymer metal complex according to this embodiment is a compound represented by the following formula (i) and having a basic skeleton having a so-called kagome structure shown in FIG. That is, all of the isophthalic acid derivatives coordinated to the copper ion have a functional group containing halogen.
[CuX] _n (i)
(In formula (i), X is a copper ion ligand and is an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position. N is a constituent unit of a metal complex composed of CuX. Indicating the number of aggregates, n is not particularly limited, but is an integer greater than or equal to 1. From the viewpoint of the stability of the material comprising the porous polymer metal complex, n is preferably greater than or equal to 50 and excellent adsorption From the viewpoint of characteristics, n is preferably 100 or more.)

  In FIG. 1, the top view which cut out only one layer of the basic skeleton of the kagome structure which the porous polymer metal complex which concerns on this embodiment has is shown. The copper ion has a so-called paddle wheel structure (see FIG. 2) in which two units coordinated with four carboxyl groups in the isophthalic acid derivative are coordinated up and down, and the paddle wheel structure is formed by an isophthalic acid derivative. A so-called kagome structure is formed which is connected to form a hexagon (six-membered ring) and a triangle (three-membered ring) having a paddle wheel structure as a vertex. This figure shows a kagome structure in which the 5-position of the isophthalic acid derivative has an alkyl group, but even if the 5-position has a functional group containing a halogen element other than fluorine, the paddle wheel structure has an isophthalic structure. The basic skeleton of the kagome structure formed by linking with an acid derivative is not changed.

  FIG. 2 shows an enlarged view of the paddle wheel structure shown in FIG. In this figure, four oxygen atoms of the carboxyl group are coordinated to one copper ion forming the paddle wheel structure, and one molecule of water is coordinated. This paddle wheel structure is connected by an isophthalic acid derivative 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 of FIG. 1 are cut out. The kagome structure is a two-dimensional planar structure, and the porous polymer metal complex has a structure in which the two-dimensional planar structure is laminated. In FIG. 3, the space between the six-membered ring or the three-membered ring is a space, which is a pore in the porous polymer metal complex. Various gases are adsorbed in the pores. 1 to 3 are all cut out of a part of the molecular network structure, and are actually infinite lattices.

  The porous polymer metal complex according to the present embodiment includes the so-called kagome network structure shown in FIG. 1 formed from a copper ion and an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position. have. What is important here is the topology of the network, and the individual bond angles do not always have the same bond angles as in the figure because the porous polymer metal complex has flexibility. Also in the laminated state of FIG. 3, the two-dimensional kagome network structure is laminated only by weak interactions such as hydrogen bonds and van der Waals forces. It is regarded as the same compound having the same function.

Since the porous polymer metal complex according to the present embodiment is a porous body, water or an organic solvent is contained in the pores when contacted with organic molecules such as water, alcohol or ether, and is represented by the following formula (ii), for example. May change to a complex complex.
[CuX] _n (G) _m (ii)
(In the formula (ii), X is a copper ion ligand and is an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position. N is a constituent unit of a metal complex composed of CuX. Indicating the number of aggregates, n is not particularly limited, but is an integer greater than or equal to 1. From the viewpoint of the stability of the material comprising the porous polymer metal complex, n is preferably greater than or equal to 50 and excellent adsorption From the viewpoint of characteristics, n is preferably 100 or more, G is an organic molecule such as water, alcohol or ether adsorbed in the pores, and m is an arbitrary number.)

  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 pretreated by drying under reduced pressure when used as a gas adsorbent. It is removed and it returns to the complex represented by the original formula (i). Therefore, even a complex represented by the formula (ii) can be regarded as essentially the same as the porous polymer metal complex according to the present embodiment.

Moreover, the copper ion in the porous polymer metal complex according to the present embodiment has a structure called a so-called paddle wheel in which four oxygen atoms of the carboxyl group in the isophthalic acid derivative 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 oxygen atoms of the carboxyl group. For example, in the following formula (iii) It may change to the complex complex represented.
[CuXQ _z ] _n (iii)
(In the formula (iii), X is a copper ion ligand and is an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position. N is a structural unit of a metal complex composed of CuX. Indicating the number of aggregates, n is not particularly limited, but is an integer greater than or equal to 1. From the viewpoint of the stability of the material comprising the porous polymer metal complex, n is preferably greater than or equal to 50 and excellent adsorption (From the viewpoint of characteristics, n is preferably 100 or more. Q is a molecule coordinated to a copper ion forming a paddle wheel structure, and z is 1 or 2.)

  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 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 according to the present embodiment.

  Hereinafter, an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position will be described.

  In the present embodiment, examples of the functional group containing halogen include a linear or branched alkyl group and an alkoxy group in which a halogen element other than fluorine is substituted for hydrogen. The number of carbon atoms in these groups is preferably in the range of 1 to 10 in terms of easy formation of a kagome structure, and in the range of 3 to 8 in terms of excellent gas adsorbability.

  Examples of the halogen include one or two or more selected from the group consisting of chlorine, bromine, and iodine, and one or two selected from bromine and iodine are particularly high in gas selectivity. Iodine is particularly preferable in that a kagome structure is easily formed.

  Examples of the number of halogen atoms substituted include a perhalogenalkyl group or a perhalogenalkoxy group in which halogen is substituted on all carbons, and a monohalogenalkyl group or a monohalogenalkoxy group in which only one halogen is substituted on carbon. The In the present embodiment, the number of halogen atoms contained in the functional group containing halogen is preferably in the range of 1 to 21.

  In the case of a monohalogenalkyl or monohalogenalkoxy group, a monohalogenalkyl group or monohalogenalkoxy group in which a halogen is substituted at the terminal is particularly preferred in order to ensure flexibility of the alkyl group or alkoxy group.

  In the porous polymer metal complex having the basic skeleton having the above-mentioned kagome structure and containing an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position as a ligand, a plurality of types of isophthalic acid are used as raw materials. Alternatively, a so-called solid solution type porous polymer metal complex is formed by synthesizing a porous polymer metal complex containing multiple types of isophthalic acid used by mixing isophthalic acid derivatives (hereinafter also referred to as isophthalic acids). It has been confirmed that it is possible. At this time, at least one of the plural types of isophthalic acids to be used in combination needs to be an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position. The total content is 5% or more, preferably 20% or more.

Specifically, this solid solution type porous polymer metal complex is a compound having a so-called kagome structure represented by the following formula (iv) and shown in FIGS.
[CuX] _n (iv)
(In the formula, X is a copper ion ligand, and is composed of an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position, and isophthalic acid and an isophthalic acid derivative having a substituent at the 5-position. When the total number of moles of X is 100 mole%, the proportion of isophthalic acid derivatives having a functional group containing a halogen element other than fluorine at the 5-position is 5 moles % Is not less than 20 mol%, and n is the number of aggregates of constituent units of the metal complex composed of CuX, and n is not particularly limited, but is an integer of 1 or more. N is preferably 50 or more from the viewpoint of the stability of the material comprising the complex, and n is preferably 100 or more from the viewpoint of excellent adsorption characteristics.

  Combining copper ions with two or more selected from the group consisting of isophthalic acid and an isophthalic acid derivative having a substituent at the 5-position results in a solid solution type having the so-called kagome structure shown in FIGS. It has been confirmed that a porous polymer metal complex is formed. The solid solution type porous polymer metal complex according to the present embodiment has a functional group containing a halogen element other than fluorine at the 5-position when the total number of moles of isophthalic acids as a ligand is 100 mol%. An isophthalic acid derivative is contained in an amount of 5 mol% or more, preferably 20 mol% or more. When a mixture of a plurality of types of isophthalic acids is used, a plurality of isophthalic acid derivatives having a functional group containing a halogen element other than fluorine at the 5-position may be included. At this time, there is no mutual penetration of the kagome structure.

In the isophthalic acid derivative having a substituent at the 5-position used in the solid solution type porous polymer metal complex represented by the formula (iv), the substituent at the 5-position may be a substituted or unsubstituted alkyl group, a 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 group, sulfo group, hydroxyl group Etc. are exemplified.
As the alkyl group, an alkyl group having 1 to 12 carbon atoms such as a methyl group or an ethyl group is preferable, and an alkyl group having 1 to 6 carbon atoms is particularly preferable. Examples of the substituent of the substituted alkyl group include a hydroxy group and an amino group.
As the alkoxy group, an alkoxy group having 1 to 12, particularly 1 to 6 carbon atoms is preferable, and a methoxy group, an ethoxy group, and a benzyloxy group are particularly preferable. 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.
The aralkyl group is preferably a benzyl group, a phenyl group in which one or more of o, m, and p- are substituted with a methyl group and / or an ethyl group. An unsubstituted functional 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.

  X is an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position, isophthalic acid, and one or more selected from the group consisting of an amino group, an alkyl group and an alkoxy group at the 5-position. The combination with the isophthalic acid derivative having is preferable.

  In the case of this solid solution type porous polymer metal complex, X is composed of two or more kinds of isophthalic acids, but can be, for example, three kinds or four kinds. 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 of the six-membered rings constituting the Kagome network stochastically and the characteristics are easily improved.

[Method for producing porous polymer metal complex]
The compound represented by the above formula (i) is obtained by dissolving a copper salt and an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position, and mixing and reacting them in a solution state. Can be manufactured. In addition, the compound represented by the above formula (vi) contains, as a solvent, a copper salt and isophthalic acids containing 5 mol% or more of an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position. It can be manufactured by dissolving and mixing in a solution state and reacting.

  As a solvent for dissolving the copper salt, good results can be obtained by using a proton solvent such as water or alcohol. Proton solvent dissolves copper salt well, and also stabilizes copper salt by coordinating bond or hydrogen bond to copper ion or counter ion, thereby suppressing side reaction by suppressing rapid reaction with ligand. Suppress. 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.

  As the solvent, it is also preferable to use a mixture of the above alcohols and an organic solvent other than alcohol or water. The mixing ratio is arbitrary in the range of alcohols: organic solvent other than alcohol or water = 1: 100 to 100: 0 (volume ratio). The mixing ratio of alcohols is preferably 30% or more from the viewpoint of improving the solubility of the copper salt and the ligand.

  As the organic solvent to be used, a highly polar solvent is preferable in terms of excellent solubility. Specifically, dialkylformamide such as tetrahydrofuran, acetonitrile, dioxane, acetone, dimethylformamide, and diethylformamide, and dialkyl such as dimethylacetamide and diethylacetamide are used. Examples include acetamide and dimethyl sulfoxide.

  As the copper salt, any salt containing divalent copper ions may be used, and in terms of high solubility in a solvent, copper nitrate, copper borofluoride, copper acetate, copper sulfate, copper formate, Copper fumarate, copper chloride, and copper bromide are preferred, and copper nitrate, copper borofluoride, copper sulfate, and copper chloride are particularly preferred in terms of high reactivity.

  In addition, regarding isophthalic acid derivatives having a functional group containing a halogen element other than fluorine at the 5-position, for example, isophthalic acid derivatives having a monohalogenated alkyloxy substituent are chloro-substituted by condensation of α-bromo-ω-chloroalkane and phenol. The bromine-substituted product and iodine-substituted product can be obtained by reacting with sodium bromide, sodium iodide and the like, respectively. An isophthalic acid derivative having a perhalogenated alkyl group or a perhalogenated alkoxy group can be obtained by allowing a halogenating agent such as N-bromosuccinimide to act on an isophthalic acid derivative having an alkyl group or an alkoxy group.

  In the reaction in the method for producing the porous polymer metal complex, it is important that a trace amount of halogen salts is allowed to coexist in the reaction system. As the kind of halogen in the halogen salt, one or two or more selected from the group consisting of chlorine, bromine and iodine are preferable, and one or two selected from chlorine and bromine are preferable in that they are effective in a trace amount. As the counter ion of the halogen ion, sodium ion, potassium ion, rubidium ion and the like are preferable, but sodium ion and potassium ion are preferable because they are effective in a small amount. The addition amount of the halogen salt is preferably 0.0001 mol% to 0.01 mol% with respect to 100 mol% of the ligand, and 0.0005 mol% to 0.005 mol% from the viewpoint of improving the yield. Is more preferable. The coexistence of such a trace amount of halogen salts has a functional group containing a halogen element other than fluorine when an isophthalic acid derivative having a functional group containing a halogen element other than fluorine is used as the ligand at the 5-position. This has the effect of preventing the yield loss that is likely to occur when no isophthalic acid derivative is used. Specifically, when an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position is used in the reaction, an isophthalic acid derivative having a transition metal ion and a functional group containing a halogen element other than fluorine at the 5-position The reaction is hindered due to the interaction with the halogen atom of the compound to form a cluster, but when a small amount of halogen salt is present, this is an isophthalate having a transition metal ion and a functional group containing a halogen element other than fluorine at the 5-position. It is presumed that the reaction is promoted by suppressing the interaction with the acid derivative. However, the technical scope of the present invention is not limited based on such estimation.

  Furthermore, in the method for producing a porous polymer metal complex according to the present embodiment, it is possible to add a base as a reaction accelerator different from the above halogen salts. 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. As the addition amount, when the total mole of isophthalic acid to be used is 1 mol, it is preferably 10 to 600 mol% in that the acceleration effect of the reaction is remarkable, and more preferably 50 to 400 in terms of few side reactions. Mol%.

  In the reaction of the copper salt solution and the isophthalic acid as the ligand, the copper salt and the ligand are separately separated from each other in addition to the method of adding the solvent after the copper salt and the ligand are loaded into the container. These solutions may be mixed after preparing as a solution. The solution may be mixed by adding the ligand solution to the copper salt solution or vice versa. The mixing method is not necessarily performed in a solution. For example, a solid ligand is charged into a copper salt solution and a solvent is simultaneously added. Various methods are possible as long as the reaction finally occurs substantially in a solvent, such as a method of injecting a solid or a solution and then injecting a solution for dissolving a copper salt. However, the method of dropping and mixing the copper salt solution and the ligand solution is industrially the most convenient and preferable.

  The concentration of the copper salt solution is 40 mmol / L to 4 mol / L, preferably 80 mmol / L to 2 mol / L, and the concentration of the organic solution of the ligand is 40 mmol / L to 3 mol / L, preferably 80 mmol / L to 1 0.8 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. On the other hand, a concentration higher than this is not preferable because the adsorption ability is lowered.

  The reaction temperature is -20 to 180 ° C, preferably 25 to 140 ° C. If it is performed at a lower temperature than this, 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 using an autoclave or the like, there is no substantial meaning because the yield does not improve for the energy cost such as heating.

  The mixing ratio of the copper salt and the organic ligand used in the reaction of the present invention is a molar ratio: copper salt: organic ligand = 3: 1 to 1: 5, preferably 1.5: 1 to 1: Within the range of 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 can be separated by filtration and drying to produce a target substance with high purity.

  The porous polymer metal complex obtained by the above production method is usually in the form of fine powder. Therefore, there is a problem such as powder scattering, and it is preferable to form a pellet or the like for processing in measuring characteristics or the like. In the case of a porous polymer metal complex containing, as a ligand, an isophthalic acid derivative having a functional group containing a halogen element other than fluorine as a ligand, the powder is easily molded and the molded product after molding is not easily broken. In the case of a porous polymer metal complex containing an isophthalic acid derivative having a functional group containing fluorine as a ligand, the molded powder may be molded due to the low affinity of fluorine. Since the later molded body tends to be fragile, it is not preferable.

Whether the porous polymer metal complex obtained by the above 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 the 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), it can be confirmed whether the weight loss from the temperature range of room temperature to 200 ° C. is 3 to 50% by measuring the heating rate = 5 ° C./min.
Whether or not the porous polymer metal complex represented by the formula (iv) obtained by the above reaction contains a mixture of two or more kinds of ligands is determined by infrared spectroscopy or porous polymer metal. By allowing EDTA or the like to act on the complex in solution or decomposing-inducing to an ester with methanol-sulfuric acid, etc., and then measuring the recovered ligand or ligand ester by proton nuclear magnetic resonance (NMR) I can confirm.
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 according to this embodiment (hereinafter also referred to as adsorbent (A)) may be used alone as an adsorbent, or may be used in combination with another adsorbent. When combined and used, as another adsorbent, a gas having very excellent adsorption characteristics when used in combination with an adsorbent (B) that exhibits a behavior in which the adsorption isotherm and desorption isotherm relating to gas coincide. It can be an adsorbent.

  Here, the adsorbent (B) is a material in which the gas pressure-gas adsorption amount curve during adsorption substantially matches the gas pressure-gas adsorption amount curve during desorption. The adsorbent (B) is not particularly limited as long as it has such characteristics, and a physical adsorbent, a chemical adsorbent, and a physicochemical adsorbent formed by combining these can be used.

  A physical adsorbent refers to an adsorbent that adsorbs molecules to be adsorbed using weak force such as interaction between molecules. Examples of the physical adsorbent include activated carbon, silica gel, activated alumina, zeolite, clay, super adsorbent fiber, and metal complex. A chemical adsorbent refers to an adsorbent that adsorbs molecules to be adsorbed by chemical bonds. Examples of the chemical adsorbent include calcium carbonate, calcium sulfate, potassium permanganate, sodium carbonate, potassium carbonate, sodium phosphate, and activated metal. The physicochemical adsorbent refers to an adsorbent that has an adsorption mechanism for both the physical adsorbent and the chemical adsorbent. Two or more of these may be used in combination. However, the technical scope of the present invention is not limited to these specific examples. The shape of the adsorbent (B) is not particularly limited, but generally, a powdery material having an average particle size of 500 to 5000 μm is used.

As the adsorbent (B), activated carbon is preferable in consideration of production cost and gas adsorption performance. Activated carbon is relatively inexpensive and has a large amount of gas adsorption per mass. In addition, activated carbon has poor cycle characteristics related to gas adsorption and desorption, and when adsorption and desorption is repeated, the amount of gas adsorption tends to be remarkably reduced. For this reason, conventionally, it has been difficult to use the gas storage device or the gas separation device despite the large amount of gas adsorption per mass. In this regard, when used as the adsorbent (B) of the present invention, the excellent gas adsorption performance of the activated carbon can be sufficiently extracted. Moreover, since the activated carbon has a tendency that the amount of adsorption increases as the specific surface area increases, the specific surface area of the activated carbon is preferably 1000 m ² / g or more.

  Moreover, it is preferable that the structure of the adsorbent (B) to be used is appropriately controlled according to the gas to be adsorbed. For example, the pores contained in the activated carbon can be classified into super micropores (up to 0.8 nm), micropores (0.8 to 2 nm), mesopores (2 to 50 nm), and macropores (50 nm to) depending on the size of the pores. . Gases that are easily adsorbed differ depending on the size of the pores, and methane gas is easily adsorbed to micropores. Therefore, when it is desired to adsorb methane gas, the pore distribution of the activated carbon may be controlled so that the proportion of micropores is increased.

  When combining the adsorbent (A) and the adsorbent (B) according to the present embodiment, the adsorbent (A) is combined by covering the adsorbent (B). Preferably, it is preferable to completely cover the adsorbent (B) so that it does not come into contact with outside air without cracks and incomplete coating. However, even if there are some cracks or the like, the adsorbent (B) obstructs free gas adsorption, and the adsorbent (B) covered with the adsorbent (A) is related to gas adsorption. Any gas adsorption characteristic similar to A) is included in the technical scope of the present invention. Preferably, the adsorbent (B) is covered with 5 to 50% by volume of the adsorbent (A) with respect to the adsorbent (B). Further, the thickness of the adsorbent (A) covering the adsorbent (B) needs to be determined according to the type of the adsorbent (A), but if the thickness of the adsorbent (A) is too thin, the adsorbent (B ) May not be able to fully control the gas adsorption characteristics. On the other hand, if the thickness of the adsorbent (A) is too thick, gas adsorption to the adsorbent (B) is difficult to occur, and the gas adsorption amount as a whole may be reduced. Considering these, it is preferable that the average thickness of the adsorbent (A) is 10 to 100 μm. The thickness of the adsorbent (A) can be controlled by adjusting the amount of adsorbent (A) used. The thickness of the adsorbent (A) can be calculated from a cross-sectional photograph taken using an electron microscope.

  As a method of combining the adsorbent (A) and the adsorbent (B), (1) the adsorbent (B) that does not dissolve in the solution is added to the solution in which the adsorbent (A) is dissolved. Then, the method of adhering the adsorbent (A) to the surface of the adsorbent (B) by crystal growth of the adsorbent (A), (2) preparing the slurry containing the adsorbent (A), and adsorbing the slurry A method of attaching the adsorbent (A) to the surface of the adsorbent (B) by coating the surface of the material (B) and drying can be used.

  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
Water (2 mL) in which 0.02 mmol of copper chloride dihydrate as a copper salt and 0.001 micromol of sodium chloride as a halogen salt were dissolved was placed in a container, and 5- 5- A methanol (2 mL) solution in which 0.03-mmol of (3-iodo-n-propyloxy) isophthalic acid derivative was dissolved was layered by slowly adding it so that the two liquids would not mix. After standing for a week, a light blue hexagonal plate-like single crystal was obtained. After coating a single crystal having a diameter of about 210 microns 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, MoKα ray (λ = 0.71069Å) )) (Irradiation time 12 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 = 18.615, b = 18.615, c = 15.970; α = 90, β = 90, γ = 120; space group = P321)).

  Further, 1 mmol of copper chloride dihydrate as a copper salt, 0.05 μmol of sodium chloride as a halogen salt, and 5- (3-iodo-n-propyloxy) isophthalic acid derivative 1 as a ligand Then, 2 mmol of pyridine as a reaction accelerator was added, and the vessel was sealed and heated at 120 ° C. for 1 hour. After cooling, it was filtered and washed with methanol to obtain 129 mg of a blue powder. As a result of measuring this powder with a powder X-ray apparatus DISCOVER D8 with GADDS manufactured by Bruker AX Co., Ltd. (CuKα (λ = 1.54Å), 2θ = 4-40, measured at room temperature), the reflection pattern shown in FIG. This was the same as the single crystal powder simulation pattern described above. That is, it was confirmed that a porous polymer metal complex having a kagome structure can be synthesized by the above two kinds of the present methods and can be analyzed by single crystal X-ray diffraction and powder X-ray diffraction methods.

(Comparative Example 1)
In the same manner as in Example 1, instead of the 5- (3-iodo-n-propyloxy) isophthalic acid derivative, an isophthalic acid derivative having a substituent not having a halogen element at the 5-position of isophthalic acid was used. A porous polymer metal complex with structure was synthesized.

<Results of gas adsorption>
Various gas adsorption characteristics of the obtained gas adsorbent were measured at various temperatures. A BET automatic adsorption device (Bell Mini II manufactured by Nippon Bell Co., Ltd.) was used. 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 to 7)
In the same manner as in Example 1, a porous polymer metal complex having various kagome structures was synthesized using an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position of isophthalic acid shown in Table 1. did. In any case, as a result of powder X-ray analysis, a reflection pattern similar to the above was shown, so that it was confirmed to have a kagome structure.

  Tables 1 and 2 show the amounts of adsorption of various gases at various temperatures. In all of Tables 1 to 4, 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 synthesized using an isophthalic acid derivative having a halogen-containing functional group other than fluorine at the 5-position has a larger amount of adsorption of oxygen gas than other gases. . Further, it can be seen that the adsorption ratio of carbon monoxide and nitrogen (carbon monoxide adsorption amount / nitrogen adsorption amount at 273 K) is large, which is advantageous for the separation of carbon monoxide and nitrogen, which is usually difficult to separate. Compared with the porous polymer metal complex synthesized using isophthalic acid whose functional group at the 5-position does not contain a halogen atom, as shown in Comparative Example 1, the effect is clear.

(Examples 8 to 11 and Comparative Examples 2 to 4)
In the same manner as in Example 1, in addition to the 5- (3-iodo-n-propyloxy) isophthalic acid derivative (ligand A), the results obtained when isophthalic acid (ligand B) was used as a raw material were mixed. Examples 8 to 11 and Comparative Examples 2 to 4 are shown. In addition, from the analysis by single crystal X-ray diffraction and powder X-ray diffraction method, it was confirmed that the kagome structure was not in an interpenetrating state.

  The same effect as in Example 1 was obtained when 5- (3-iodo-n-propyloxy) isophthalic acid derivative was mixed and used at a ratio of 5 mol% or more. In particular, it was confirmed that the amount of oxygen adsorbed at 77K was remarkably increased.

(Examples 12 to 14)
The material obtained in Examples 1, 3 and 5 (porous polymer metal complex powder) was placed in a KBr tablet former used in infrared spectroscopy, and a plate-like body having a diameter of about 5 mm and a thickness of about 1 mm. Molded into. This material was subjected to carbon dioxide measurement (195K), but the shape of the plate was maintained after the measurement.

(Comparative Example 5)
Material synthesized using 5- (3-fluoro-n-propyloxy) isophthalic acid derivative instead of 5- (3-iodo-n-propyloxy) isophthalic acid derivative of Example 1 (porous polymer metal) The complex powder was molded and measured in the same manner as in Examples 12-14. After the measurement, the material was broken into a powder.

  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. Utilizing this porosity, oxygen, carbon monoxide can be selectively adsorbed, separated and stored.

Claims (12)

[CuX] _n (i)
(In formula (i), X is a copper ion ligand and is an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position. N is a constituent unit of a metal complex composed of CuX. Indicates the number of sets, and n is not limited.)
A porous polymer metal complex having an aggregate structure represented by:   The aggregate structure has a paddle wheel structure in which a unit in which copper ions are coordinated to four carboxyl groups in the isophthalic acid derivative is coordinated up and down, and the paddle wheel structure is the isophthalic acid derivative. 2. The porous polymer metal complex according to claim 1, wherein the porous polymer metal complex has a crystal structure in which a kagome structure composed of a six-membered ring and a three-membered ring formed by connecting with each other is laminated.   3. The highly porous material according to claim 1, wherein the halogen element of the functional group containing a halogen element other than fluorine is one or more selected from the group consisting of chlorine, bromine and iodine. Molecular metal complex.   The porous polymer metal complex according to claim 3, wherein the halogen element of the functional group containing a halogen element other than fluorine is iodine.   5. The functional group containing a halogen element other than fluorine is a linear or branched alkyl group or alkoxy group in which the halogen element substitutes hydrogen, 5. Porous polymer metal complex.   6. The porous polymer metal complex according to claim 5, wherein the number of carbon atoms in the alkyl group or alkoxy group is in the range of 1 to 10.   The porous polymer metal complex according to any one of claims 1 to 6, wherein the functional group containing a halogen element other than fluorine contains 1 to 21 halogen atoms. [CuX] _n (iv)
(In the formula (iv), X is a copper ion ligand, and an isophthalic acid derivative having a functional group containing a halogen element other than fluorine at the 5-position, and isophthalic acid and an isophthalic acid derivative having a substituent at the 5-position The proportion of isophthalic acid derivatives having a functional group containing a halogen element other than fluorine at the 5-position when the total number of moles of X is 100 mol%, including one or more selected from the group consisting of Is 5 mol% or more, n represents the number of aggregates of structural units of the metal complex composed of CuX, and n is not limited.)
A porous polymer metal complex having an aggregate structure represented by:   The isophthalic acid derivative having a substituent at the 5-position is selected from an isophthalic acid derivative having an alkyl group at the 5-position, an isophthalic acid derivative having an alkoxy group at the 5-position, and an isophthalic acid derivative having an amino group at the 5-position Or the porous polymeric metal complex of Claim 8 characterized by the above-mentioned.   A gas adsorbent comprising the porous polymer metal complex according to any one of claims 1 to 9.   A gas separation apparatus using the gas adsorbent according to claim 10.   A gas storage device using the gas adsorbent according to claim 10.