JP2006341188A - Volatile organic compound adsorbent and hydrogen occlusion material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adsorbent which is capable of easily adsorbing, eliminating and continuously using a volatile organic compound and hydrogen, and to provide hydrogen occlusion material. <P>SOLUTION: The volatile organic compound adsorbent and hydrogen occlusion material are composed of an organic carboxylic acid metal complex constituted from a repeating unit represented by general formula [I], wherein M<SP>1</SP>and M<SP>2</SP>are a metal which takes bivalent value independently each other, R<SP>1a</SP>, R<SP>1b</SP>, R<SP>1c</SP>and R<SP>1d</SP>denote an organic group containing a conjugated system independently each other and R<SP>2</SP>, R<SP>3</SP>, R<SP>4</SP>and R<SP>5</SP>denote hydrogen atom, alkyl group having 1-4 carbon atoms and an alkenyl group having 1-4 carbon atoms independently each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a volatile organic compound adsorbent and a hydrogen storage material comprising a specific organic carboxylic acid metal complex.

  Conventionally, activated carbon, zeolite, or the like has been used as an adsorbent for adsorbing and removing vapors of organic solvents such as benzene and toluene (Patent Documents 1 and 2). Moreover, an alloy and its sintered body are used as a hydrogen storage material (patent documents 3 and 4).

  On the other hand, Patent Document 5 describes a carboxylic acid metal complex composed of benzoic acid, a metal, and an organic ligand capable of bidentate coordination with the metal, and the complex is useful as a methane gas occlusion material. It is described. Non-Patent Document 1 describes a crystal in which an organometallic complex composed of benzoic acid, rhodium, and pyrazine is connected one-dimensionally, and the metal complex adsorbs and desorbs carbon dioxide as a guest molecule. It is also described that the crystal structure changes during the process.

JP 2004-255336 A JP 2004-261780 A JP2003-1389 Japanese Patent Laid-Open No. 2003-3203 Japanese Unexamined Patent Publication No. 2000-309592 Satoshi Takamizawa et al., Angew. Chem. Int. Ed. 2003, 42, 4331-4334

  The object of the present invention is to easily adsorb and desorb organic solvent vapors such as benzene and toluene and harmful organic compounds such as formaldehyde, and can be used continuously without any particular reprocessing. Is to provide an adsorbent. Another object of the present invention is to provide a hydrogen storage material that easily adsorbs and desorbs hydrogen and has a large hydrogen storage amount per unit volume.

  As a result of diligent research, the inventors of the present application have found that an organic carboxylic acid metal complex having a specific structure easily adsorbs the vapor of an organic solvent, and easily desorbs even without performing a regeneration treatment. In addition, the present inventors have found that the organic carboxylic acid metal complex easily adsorbs and desorbs hydrogen and has a large hydrogen storage amount per unit volume, thereby completing the present invention.

  That is, the present invention provides a volatile organic compound adsorbent comprising an organic carboxylic acid metal complex composed of a repeating unit represented by the following general formula [I].

(However, M ¹ and M ² are independently divalent metals, R ^1a , R ^1b , R ^1c and R ^1d are independently of each other an organic group containing a conjugated system, R ² , R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkenyl group having 1 to 4 carbon atoms.

  Moreover, this invention provides the volatile organic compound density | concentration holding | maintenance agent which hold | maintains the density | concentration of the volatile organic compound in the air below the predetermined value consisting of the said organic carboxylic acid metal complex. Furthermore, the present invention provides a method for keeping the concentration of the volatile organic compound in the air below a predetermined value by placing the volatile organic compound adsorbent of the present invention in the air. Furthermore, the present invention provides a hydrogen storage material comprising the organic carboxylic acid metal complex. Furthermore, the present invention relates to a method of arranging metal atoms one-dimensionally one by one by adsorbing a metal vapor to an organic carboxylic acid metal complex, and a metal atom as a guest produced by the method in a channel structure. An organic carboxylate metal complex arranged one-dimensionally one atom at a time is provided.

  According to the present invention, a novel volatile organic compound vapor adsorbent and hydrogen storage material comprising an organic carboxylic acid metal complex having a specific structure are provided. In the organic solvent vapor adsorbent of the present invention, when the concentration of the organic solvent vapor increases to a predetermined value or more, the crystal structure of the organic carboxylic acid metal complex changes and the adsorption amount increases rapidly. Can be maintained below the concentration at which the amount of adsorption increases rapidly (hereinafter referred to as “critical concentration”). Furthermore, since the adsorption and desorption of organic solvent vapor is rapid and reversible, when the organic solvent vapor concentration in the air falls below the critical concentration due to ventilation or the like, the organic solvent vapor adsorbed on the adsorbent is absorbed. Quickly desorbs. Therefore, the adsorbent continuously maintains the ability as an adsorbent without performing a special regeneration process such as a heat treatment. The hydrogen storage material of the present invention is suitable for storing hydrogen because it easily adsorbs and desorbs hydrogen and has a large hydrogen storage amount per unit volume.

As described above, the organic carboxylic acid metal complex used in the present invention is composed of a repeating unit having a structure represented by the above general formula [I]. In the general formula [I], coordinate bonds exist between M ¹ and O, between M ² and O, between M ¹ and M ² and between M ² and N. The repeating number of the repeating unit represented by the general formula [I] is not particularly limited, but is usually 10 to 10 ⁸ , preferably 10 ² to 10 ⁷ . As is clear from the general formula [I], among the four oxygen atoms bonded to M ¹ in the general formula [I], the upper right oxygen atom is the carbon atom bonded to R ^1b. The oxygen atom in the lower right is bonded to the carbon atom to which R ^1c is bonded. Similarly, of the four oxygen atoms bonded to M ² , the upper left oxygen atom is bonded to the carbon atom bonded to R ^1a , and the lower left oxygen atom is bonded to R ^1d . It is bonded to a carbon atom.

In the general formula [I], M ¹ and M ² may be a transition metal or a typical metal independently of each other. Preferable examples of M ¹ and M ² include manganese, iron, cobalt, nickel, copper, zinc, ruthenium, rhodium, chromium, molybdenum, palladium and tungsten. Among these, copper and rhodium are particularly preferable. M ¹ and M ² are preferably the same type of metal atom.

In the general formula [I], R ^1a , R ^1b , R ^1c and R ^1d (hereinafter R ^1a , R ^1b , R ^1c and R ^1d may be collectively referred to as “R ¹ ”) are conjugated An organic group containing a system, that is, an organic group containing, for example, a benzene ring, a naphthalene ring, an anthracene ring, a hetero ring thereof, or the like, an optionally substituted phenyl group is preferable, and an unsubstituted phenyl group is particularly preferable. When the phenyl group is substituted, examples of the substituent include an alkyl group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 4 carbon atoms, a hydroxyl group, an amino group, a cyano group, and an alkyl having 1 to 4 carbon atoms. An amino group, an alkoxyl group having 1 to 4 carbon atoms, a halogen atom, and an optionally substituted phenyl group (substituents are the same as described above (excluding substituted phenyl groups)) can be exemplified. 1-5. In the present specification, the “alkyl group” includes both a linear alkyl group and a branched alkyl group unless otherwise specified. The same applies to “alkenyl group” and “alkoxyl group”. R ^1a , R ^1b , R ^1c and R ^1d are preferably the same type of organic group.

In general formula [I], R ² , R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 1 to 4 carbon atoms. Preferable examples of R ² , R ³ , R ⁴ and R ⁵ include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an allyl group and the like, and R ² , R ³ , R ⁴ and R Of those, 2 to 4 of ⁵ are preferably hydrogen atoms.

The repeating units represented by the above general formula [I] are connected one-dimensionally, and they gather to constitute a molecular crystal. At this time, since the conjugated system of R ¹ approaches, a π-π bond is generated, and the crystal structure is stabilized. The molecular crystal is preferably a single crystal. If it is a single crystal, not only can the amount of organic solvent vapor or hydrogen adsorbed per unit volume be increased, but also physical properties can be made uniform, and complexes having predetermined physical properties can be produced with good reproducibility. Have advantages. Furthermore, a huge single crystal having a long side length of 0.8 mm or more can be produced by the method described later, and if such a large single crystal is used, the amount of vapor adsorbed per unit apparent volume and hydrogen storage This is advantageous because the amount can be further increased.

The above-mentioned organic carboxylic acid metal complex includes a metal salt (when M ¹ and M ² are different, two kinds of metal salts, the same shall apply hereinafter) and an organic carboxylic acid (R ¹ -COOH (R ¹ is as defined above, R ^1a , R ^1b , R ^1c and R ^1d can be produced by slowly reacting a plurality of types of organic carboxylic acids (hereinafter the same)) with a substituted pyrazine in a solvent. By this method, a single crystal of the organic carboxylic acid metal complex of the present invention can be produced. Alternatively, it can also be produced by reacting a metal salt of an organic carboxylic acid (R ¹ -COOH (R ¹ is as defined above)) with a substituted pyrazine in a solvent. As the solvent, methanol and acetonitrile are preferable. As the metal salt, acetate, formate, sulfate, nitrate and carbonate are preferable, and acetate is particularly preferable. The reaction temperature is not particularly limited and can be about 0 ° C. to 70 ° C., but good results can be obtained at room temperature. The reaction time is not particularly limited, but good results are usually obtained in about 3 hours to 1 week. The ratio of the metal salt to be reacted and the organic carboxylic acid is not particularly limited, but the molar ratio is usually about 1: 2 to 1: 8, and the ratio of the metal salt to the substituted pyrazine is usually 1: 0.5 in molar ratio. ˜1: 10 or so. In addition, the preferable example of a manufacturing method is described in detail in the following Example.

  Further, a solution containing an organic carboxylic acid having a conjugate system with a metal salt capable of taking the divalent or a solution of a metal salt capable of taking the divalent of the organic carboxylic acid having a conjugated system is used as an upper layer, and the solvent of the solution Two layers are formed with a solvent not mixed with the lower layer, and pyrazine or a substituted pyrazine vapor from a solution of pyrazine or a substituted pyrazine is introduced and reacted, and the organic carboxylic acid metal complex is simply formed at the interface of the two layers. By generating crystals, it is possible to produce huge single crystals having a long side length of 0.8 mm or more. This method is also specifically described in the examples below.

  The organic carboxylic acid metal complex forms a molecular crystal, and the molecular crystal has pores (channel structure) or regularly arranged voids extending one-dimensionally inside the crystal. A gas can be adsorbed and desorbed as a guest in the crystal internal space. The volatile organic compound adsorbent of the present invention comprises the above-described organic carboxylic acid metal complex. As specifically shown in the following examples, in the volatile organic compound adsorbent of the present invention, when the concentration of the organic solvent vapor increases to a specific value or more, the crystal structure of the organic carboxylic acid metal complex changes and the adsorbed amount. Increases rapidly. For this reason, the density | concentration of the organic solvent vapor | steam in the air can be maintained below the density | concentration (critical density | concentration) from which this adsorption amount becomes large rapidly. That is, by placing the volatile organic compound adsorbent of the present invention in the air, the organic solvent vapor concentration in the air can be maintained below the critical concentration. That is, the volatile organic compound adsorbent of the present invention can be used as an organic solvent vapor concentration maintaining agent. Furthermore, since the adsorption and desorption of organic solvent vapor is rapid and reversible, when the organic solvent vapor concentration in the air falls below the critical concentration due to ventilation or the like, the organic solvent vapor adsorbed on the adsorbent is absorbed. Quickly desorbs. Therefore, the adsorbent continuously maintains the ability as an adsorbent without performing a special regeneration process such as a heat treatment. This is a very advantageous feature compared to conventional adsorbents using activated carbon, zeolite, or the like that require regeneration treatment such as heat treatment as the adsorption proceeds. Furthermore, since adsorption of organic solvent vapor hardly occurs below the critical concentration, there is no deterioration in adsorption capacity due to accumulation of organic solvent vapor. For this reason, the adsorbent of the present invention can be used permanently while maintaining its ability.

  As a use mode of the volatile organic compound adsorbent of the present invention, a molecular crystal of an organic carboxylate metal complex, preferably a single crystal, may be left in a room or the like in a container having air circulation holes. Further, it may be mixed as an adsorbent component in a composition that generates an organic solvent vapor, such as paint or building material. Or what filled the adsorbent of this invention into the air permeable bag etc. may be embedded in the inside of a wall, under the floor, etc. In the present specification and claims, the phrase “keep the volatile organic compound adsorbent in the air” is used in a sense encompassing any of these embodiments.

  The volatile organic compound adsorbed by the volatile organic compound adsorbent of the present invention is an organic compound that is liquid at room temperature or an organic compound solution that is liquid at room temperature, and vapor of the organic compound is emitted into the air at room temperature. This means that it is not particularly limited as long as it is a volatile organic compound, but an organic solvent vapor and an aldehyde vapor such as formaldehyde are preferred. Here, the organic solvent is not particularly limited as long as it is an organic solvent, but aliphatic organic solvents such as alkanes such as hexane, heptane, and octane and derivatives thereof (halides), and aromatic solvents such as benzene, toluene, and xylene. An organic solvent can be mentioned as a preferred example. Since these organic solvents and aldehydes are part of the causative substances of sick house, the adsorbent of the present invention is also useful for preventing sick house. Formaldehyde is a gas at normal temperature, but concentrated aqueous solutions and formalin that are liquid at normal temperature are widely used, and formaldehyde vaporizes as vapor at normal temperature from these solutions. Included in “organic compounds”.

  The critical concentration varies depending on the type of organic carboxylic acid metal complex used and the type of organic solvent, but is usually about 1 mmHg to 10 mmHg. The critical concentration is the concentration of the organic solvent vapor in the air in contact with the adsorbent of the present invention. Therefore, when the adsorbent of the present invention is mixed with paint or building material, or when used independently as an adsorbent. However, if an adsorbent is placed near the wall or floor where organic solvent vapor is generated, the concentration of the organic solvent vapor at that location will be maintained below the critical concentration, so air that is far away from the wall or floor The concentration of the organic solvent vapor can be kept lower than the critical concentration.

  In addition, the above-described organic carboxylic acid metal complex easily adsorbs hydrogen and desorbs easily, and further, hydrogen diffuses quickly and reaches an adsorption equilibrium state in a short time. As specifically shown in the following examples, the crystal structure of the organic carboxylic acid metal complex realizes a stable adsorption structure of hydrogen, and hydrogen aggregates are formed in a fine space in the crystal at a high density. Therefore, the organic carboxylic acid metal complex can be advantageously used as a hydrogen storage material.

  The hydrogen storage material of this invention can be used similarly to the hydrogen storage material which consists of a conventional alloy. For example, the hydrogen storage material of the present invention can be filled in a sealed container, the hydrogen gas can be stored at a high pressure, and the hydrogen gas can be taken out from the container when the hydrogen gas is used. The extracted hydrogen gas can be used as fuel for a hydrogen engine.

  By adsorbing metal vapor to the crystal of the organic carboxylic acid metal complex, metal atoms can be arranged one-dimensionally one by one along the channel structure in the crystal. Such a line of metal atoms is the thinnest metal line that is theoretically conceivable, and each metal atom is arranged within a distance where free electron circulation occurs, and thus a current can flow. Therefore, such a metal wire can be used as the finest wiring, and is useful as a fine wiring of quantum semiconductors and various nanotech devices that are currently under development.

  Hereinafter, the present invention will be described more specifically based on examples. However, the present invention is not limited to the following examples.

Examples 1 to 6 Production and properties of copper complex Copper acetate (II) monohydrate, 80 mg (2.4 × 10 ⁻⁴ mol) and benzoic acid 117.2 mg (8.4 · 10 ⁻⁴ mol) were dissolved in 80 ml of methanol to prepare a blue solution. did. After filtration, pyrazine: 8.0 mg (Example 1), 2-methylpyrazine: 0.3 ml (Example 2), 2,3-dimethylpyrazine: 0.3 ml (Example 3), 2-ethylpyrazine: 0.3 ml (implementation) Example 4), 2,3-diethylpyrazine: 0.3 ml (Example 5) or 2-propylpyrazine: 0.3 ml (Example 6) was added and allowed to react slowly at room temperature for 24 hours. A blue single crystal was formed. Pyrazine complex (Example 1): 12.2 mg (58.6%), 2-methylpyrazine complex (Example 2): 11.7 mg (57.4%), 2,3-dimethylpyrazine complex (Example 3): 16.0 mg (74.2 %), 2-ethylpyrazine complex (Example 4) (19.2%), 2,3-diethylpyrazine complex (Example 5) (13.2%), 2-propylpyrazine complex (Example 6) (39.3%). Identification was performed by single crystal X-ray structural analysis and elemental analysis. The number of repeating units represented by the general formula [I] was about 10 ⁴ to 4 × 10 ⁵ calculated from the size of the produced crystal (about 10 ⁷ per 1 cm of crystal).

  The results of elemental analysis and X-ray structure analysis are shown in Table 1 below.

  The physical property data of each obtained single crystal is shown in Table 2-1 and Table 2-2 below.

Examples 7 to 12 Production and properties of rhodium complex 80 mg (1.0 × 10 ⁻⁴ mol) of synthesized rhodium benzoate was dissolved in 80 ml of acetonitrile to obtain a red-purple solution. After filtration, pyrazine: 8.0 mg (Example 7), 2-methylpyrazine: 0.3 ml (Example 8), 2,3-dimethylpyrazine: 0.3 ml (Example 9), 2-ethylpyrazine: 0.3 ml (implementation) Example 10), 2,3-diethylpyrazine: 0.3 ml (Example 11) or 2-propylpyrazine: 0.3 ml (Example 12) was added and allowed to react slowly at room temperature for 24 hours. Brown microcrystals were formed. Pyrazine complex (Example 7): 12.9 mg (67.2%), 2-methylpyrazine complex (Example 8): 11.9 mg (60.7%), 2,3-dimethylpyrazine complex (Example 9): 16.3 mg (81.7 %), 2-ethylpyrazine complex (Example 10) (42.6%), 2,3-diethylpyrazine complex (Example 11) (85.5%), 2-propylpyrazine complex (Example 12) (14.6%). Identification was performed by single crystal X-ray structural analysis and elemental analysis. The number of repeating units represented by the general formula [I] was about 10 ^{4 to} 5 × 10 ⁵ calculated from the size of the produced crystal (about 10 ⁷ per 1 cm of crystal).

  The results of elemental analysis and X-ray structure analysis are shown in Table 3 below.

  The physical property data of each obtained single crystal is shown together in the following Tables 4-1 and 4-2.

Example 13 Adsorption and Desorption of Organic Solvent Vapor Vapor when adsorbing and desorbing n-hexane or benzene at an isothermal temperature of 10 ° C or 20 ° C for the organic carboxylate metal complexes produced in Example 1 and Example 2. The adsorption amount of was measured.

  The results are shown in FIGS. In the figure, a) shows the result for n-hexane, and b) shows the result for benzene. Moreover, the results at 10 ° C for the circle and the results at 20 ° C for the square are shown. Further, black indicates the adsorption amount in the adsorption process, and white indicates the adsorption amount in the desorption process.

  Characteristic reversible adsorption / desorption ability was observed, and both complexes showed almost the same adsorption behavior. This indicates that it can function as an adsorbent widely for organic molecules having various shapes and properties due to the flexibility of the pore structure. Further, the adsorption curve showed a behavior in which the pressure required for the adsorption shifted to the high pressure side as the temperature rose to 20 ° C. rather than 10 ° C. This suggests a thermodynamic correlation between adsorption behavior and adsorbent temperature.

  What is characteristic of the adsorption behavior is that adsorption jumps are observed in all cases. (This pressure is hereinafter referred to as critical pressure.) Almost no adsorption is observed in the low pressure part, and the adsorption jump is observed only when the critical pressure is reached. This is due to the bulk phase transition of the solid sample. The jump of the adsorption line is due to the α-β phase transition induced by vapor adsorption, and the flat portion of the adsorption enthalpy is due to the two-phase coexistence state of the α-β phase. The adsorption curve transitions between the adsorption lines of the α-β phase through a two-phase coexistence state in a very narrow pressure region. In hexane and benzene, no adsorption in the low pressure part is observed until the critical pressure is reached. This is because the α phase pore structure is relatively thin and bent with respect to the guest molecular structure, so that diffusion is difficult. Since this material is a crystal and the phase transition is induced by guest adsorption, it exhibits a specific adsorption / desorption behavior depending on the distribution of guest molecules in the crystal. This material, which is a crystal with a small surface area compared to the volume of the solid, has a vapor pressure (concentration) sensing function in which adsorption is hardly observed up to the critical pressure, and sudden adsorption starts at the critical pressure. This is considered to be a phenomenon caused by the flexibility of the pore structure and the phase transition phenomenon. Thus, the flexibility of the pore structure of this crystal material and the phase transition phenomenon revealed the adsorption characteristics with high vapor concentration selectivity and reversibility.

Example 14 Synthesis of copper (II) benzoate pyrazine adduct giant single crystal 501.4 equivalents of 21.4 g (176 mmol) of benzoic acid were dissolved in 350 mg (3.50 mmol) of copper (II) acetate monohydrate, In a Teflon (registered trademark) container, it was poured on 50 ml of Fluorinert (trade name, manufactured by 3M, FC77). In a state where the upper layer methanol solution and the lower layer florinate (trade name) were separated into two layers, pyrazine dissolved in ethylene glycol and suppressed in vapor pressure was introduced into the solution by vapor diffusion and reacted at 20 ° C. Vapor diffusion was performed by supporting a test tube containing an ethylene glycol solution of pyrazine with care not to contact the reaction solution, sealing the entire system, and slowly dissolving pyrazine vapor into the reaction solution. . Crystal growth occurred in the florinate-methanol bilayer interface, and after 1 month, the target product was isolated as a single crystal by filtration and then air-dried. Blue plate-like single crystal 360 mg (yield 60%). When calculated from the size of the produced crystal (about 10 ⁷ per 1 cm of crystal), the number of repeating units was about 5 × 10 ⁶ to 10 ⁷ .

Example 15 Synthesis of rhodium (II) benzoate pyrazine adduct giant single crystal Rhodium (II) benzoate (20 mg, 3.50 mmol) was dissolved in acetonitrile (40 ml) and Florinate (trade name, manufactured by 3M) in a Teflon (registered trademark) container. , FC77) poured over 5ml. Pyrazine dissolved in ethylene glycol and suppressed in vapor pressure is introduced into the solution by vapor diffusion in the same manner as in Example 1 while being separated into two layers of the upper acetonitrile solution and the lower fluorinate, and slowly reacted at 15 ° C. I let you. Crystals grew in the interface between the two layers of fluorinate-methanol, and after 1 month, the target product was isolated as a single crystal by filtration. Red plate-like single crystal 360 mg (70% yield). When calculated from the generated crystal size, the number of repeating units was about 10 ^{6 to} 7 × 10 ⁶ .

Example 16 Occlusion of Hydrogen Gas Adsorption of hydrogen when hydrogen gas was adsorbed and desorbed at an isothermal temperature of 77K with respect to the organic carboxylic acid metal complexes produced in Example 1, Example 7, Example 2 and Example 8. The amount was measured.

  The results are shown in FIG. In the figure, a), b), c), and d) show the results for the organic carboxylic acid metal complexes produced in Example 1, Example 7, Example 2, and Example 8, respectively. Further, the black circles indicate the adsorption amount in the adsorption process, and the white circles indicate the adsorption amount in the desorption process.

  As shown in FIG. 3, a large amount of hydrogen can be stored in the organic carboxylic acid metal complex. Moreover, as a result of observation, the diffusion was fast and the adsorption equilibrium state was reached in a short time.

  Furthermore, the occlusion state of hydrogen was examined by X-ray analysis of the crystal in a state where hydrogen was adsorbed on rhodium pyrazine benzoate produced in Example 7. The results are schematically shown in FIG. Table 5 below shows the crystallographic parameters of the crystal in a state where hydrogen is adsorbed.

Example 17 Adsorption of mercury vapor The rhodium pyrazine benzoate single crystal (crystal size 0.40 x 0.25 x 0.04 mm ³ ) produced in Example 7 was placed in a glass sealed container together with mercury and evacuated with an oil rotary pump. The vessel was heated to 1500C and the crystals were exposed to mercury vapor (vapor pressure 2.8mmHg). Seven days later, it was cooled with water to room temperature, and the crystals were taken out in the air. The crystal remained in a single crystal state, and an inclusion crystal of mercury atoms was obtained. 100% recovery

  The resulting inclusion crystal of mercury atoms was subjected to X-ray analysis. The state of the crystal is schematically shown in FIG. In the figure, black circles are mercury atoms. The crystallographic parameters of the inclusion crystal of mercury atoms are shown in Table 6 below.

The isothermal vapor | steam adsorption curve of the organic carboxylic acid metal complex manufactured in Example 1 of this invention is shown. The isothermal vapor | steam adsorption curve of the organic carboxylic acid metal complex manufactured in Example 7 of this invention is shown. The hydrogen adsorption curve at the time of making the organic carboxylic acid metal complex manufactured in Example 1, Example 7, Example 2, and Example 8 of this invention occlude hydrogen gas is shown. It is a figure which shows typically the crystal structure of the crystal body of the state which made hydrogen adsorb | suck to the rhodium benzoate pyrazine manufactured in Example 7. FIG. It is a figure which shows typically the crystal structure of the state which made the mercury vapor | steam adsorb | suck to the rhodium benzoate pyrazine single crystal manufactured in Example 7. FIG.

Claims (13)

A volatile organic compound adsorbent comprising an organic carboxylate metal complex composed of a repeating unit represented by the general formula [I].

(However, M ¹ and M ² are independently divalent metals, R ^1a , R ^1b , R ^1c and R ^1d are independently of each other an organic group containing a conjugated system, R ² , R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkenyl group having 1 to 4 carbon atoms. The volatile organic compound adsorbent according to claim ¹ , wherein R ^1a , R ^1b , R ^1c and R ^1d are independently substituted phenyl groups. The M ¹ and M ² are each independently at least one selected from the group consisting of manganese, iron, cobalt, nickel, copper, zinc, ruthenium, rhodium, chromium, molybdenum, palladium and tungsten. The volatile organic compound adsorbent described. The organic carboxylic acid according to any one of claims 1 to 3, wherein M ¹ and M ² are the same type of metal, and R ^1a , R ^1b , R ^1c and R ^1d are the same type of organic group. Metal complex. R ^1a , R ^1b , R ^1c and R ^1d are phenyl groups, R ² , R ³ , R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, M ¹ and M The volatile organic compound adsorbent according to claim 1, wherein ² is copper or rhodium.   The volatile organic compound adsorbent according to any one of claims 1 to 5, wherein the organic carboxylic acid metal complex is in a single crystal form.   The volatile organic compound adsorbent according to any one of claims 1 to 6, wherein the volatile organic compound is an organic solvent vapor or aldehydes.   The volatile organic compound adsorbent according to claim 7, wherein the volatile organic compound is a vapor of an aliphatic or aromatic organic solvent.   The volatile organic compound density | concentration maintenance agent which maintains the density | concentration of the volatile organic compound in the air below the predetermined value which consists of an organic carboxylic acid metal complex of any one of Claim 1 thru | or 6.   A method for maintaining the concentration of the organic solvent vapor in the air below a predetermined value by placing the volatile organic compound adsorbent according to any one of claims 1 to 6 in the air.   A hydrogen storage material comprising the organic carboxylic acid metal complex according to any one of claims 1 to 6.   A method of arranging metal atoms one-dimensionally one by one by adsorbing a metal vapor to the organic carboxylic acid metal complex according to claim 1. An organic carboxylic acid metal complex produced by the method according to claim 12, wherein metal atoms as guests are one-dimensionally arranged in the channel structure one by one.

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