JPWO2015178205A1 - Metal organic structure and method for producing the same - Google Patents

Abstract

The present invention provides a metal organic structure which can exhibit sufficient ability to occlude and release hydrogen atoms and the like at room temperature and can be easily manufactured, and a method for manufacturing the metal organic structure. The present invention is a metal organic structure having a tubular structure, wherein the tubular structure is formed by a plurality of wall surfaces, and each wall surface has the following general formula (1) [Chemical Formula 1] (wherein R1 and R2 are the same) Or it is different and shows a nitrogen-containing heterocyclic group, R3 and R4 are the same or different, and -OH, -CHO, or R5COO- (R5 shows H or a C1-C3 alkyl group). M represents a transition metal, and n represents a natural number of 1 or more.) A one-dimensional monomer of a metal-organic compound represented by (1) is formed by two parallel one-dimensional dimers. This is a metal organic structure characterized by that.

Description

  The present invention relates to a metal organic structure and a method for producing the same.

  In recent years, in order to improve environmental problems such as carbon dioxide emissions accompanying energy production, petroleum alternative energy has been developed, and batteries such as fuel cells and secondary batteries have been actively developed. These batteries are particularly used as mobile power sources, and materials constituting such batteries are required to have an ability to occlude atoms such as hydrogen as a raw material for power generation.

  As a battery material exhibiting the ability to occlude atoms such as hydrogen, a metal organic structure having a three-dimensional network structure (hereinafter also referred to as “MOF”) having micropores has been proposed (see, for example, Non-Patent Document 1).

  However, the MOF used as a material constituting the conventional battery as described above is heavy and is not suitable for use as a mobile power source.

  In addition, since the conventional MOF has a three-dimensional network structure, it is difficult for atoms such as hydrogen to move, and since physical adsorption specific to low temperature is used, molecules such as hydrogen must be near the liquid nitrogen temperature (77 K). Occlusion and release cannot be performed sufficiently. For this reason, the conventional battery material has a problem that it cannot fully exhibit the ability to occlude or release hydrogen atoms or the like at room temperature.

  Furthermore, in order to produce the conventional MOF as described above, it is necessary to heat the metal inorganic precursor and the organic precursor, which are used as raw materials, and then perform the synthesis at room temperature and normal pressure. I can't. For this reason, there is a problem that mass production is difficult, the cost increases, and it cannot be easily manufactured.

  A metal organic structure that can exhibit sufficient ability to occlude and release hydrogen atoms and the like at room temperature and can be easily manufactured has not been developed yet.

N. L. Rosi et al., Science Vol. 300, 1127 (2003).

  An object of this invention is to provide the metal organic structure which can show sufficient occlusion and discharge | release capability of a hydrogen atom etc. at normal temperature, and can be manufactured easily, and its manufacturing method.

  As a result of intensive studies to achieve the above-mentioned object, the present inventor has a metal organic structure having a tubular structure, and a wall surface of the tubular structure is formed of a one-dimensional dimer of a specific metal organic compound, And the present invention has been completed by finding that the above-mentioned object can be achieved by a production method comprising mixing a specific compound and a nitrogen-containing heterocyclic compound.

That is, this invention relates to the manufacturing method of the following metal organic structure and metal organic structure.
1. A metal organic structure having a tubular structure,
The tubular structure is formed by a plurality of wall surfaces, and each wall surface has the following general formula (1)

(In the formula, R ¹ and R ² are the same or different and each represents a nitrogen-containing heterocyclic group; R ³ and R ⁴ are the same or different and represent —OH, —CHO, or R ⁵ COO— (R ⁵ Represents H or an alkyl group having 1 to 3 carbon atoms.) M represents a transition metal, and n represents a natural number of 1 or more.)
The one-dimensional monomer of the metal organic compound represented by is formed by two parallel one-dimensional dimers,
Metal organic structure characterized by the above.
2. Item 2. The metal organic structure according to Item 1, wherein the transition metal is at least one selected from the group consisting of Fe, Co, and Cu.
3. Item 3. The metal organic structure according to Item 1 or 2, wherein n is a natural number of 1 to 2.8 × 10 ⁶ .
4). Item 4. The metal organic structure according to any one of Items 1 to 3, which occludes and releases at least one selected from the group consisting of a hydrogen atom, an oxygen atom, a nitrogen atom, and a carbon atom.
5. It has a tubular structure formed by a plurality of wall surfaces, and each wall surface has the following general formula (1)

(In the formula, R ¹ and R ² are the same or different and each represents a nitrogen-containing heterocyclic group; R ³ and R ⁴ are the same or different and represent —OH, —CHO, or R ⁵ COO— (R ⁵ Represents H or an alkyl group having 1 to 3 carbon atoms.) M represents a transition metal, and n represents a natural number of 1 or more.)
A one-dimensional monomer of a metal organic compound represented by the method for producing a metal-organic structure formed by two parallel one-dimensional dimers,
The following general formula (2)
M (R ⁶ ) ₂ · mH ₂ O (2)
(In the formula, M represents a transition metal, R ⁶ is the same as R ³ and R ⁴ , and m represents an integer of 2 to 4.)
And a step of mixing a nitrogen-containing heterocyclic compound with a compound represented by:
The manufacturing method characterized by the above-mentioned.
6). Item 6. The method according to Item 5, wherein the transition metal is at least one selected from the group consisting of Fe, Co, and Cu.
7). Item 5. The item 5 or 6, wherein the nitrogen-containing heterocyclic compound is at least one selected from the group consisting of pyridine, piperidine, piperazine, morpholine, pyrrolidine, pyrroline, imidazole, pyrazole, triazole, tetrazole and benzimidazole. Production method.
8). Item 8. The manufacturing method according to any one of Items 5 to 7, wherein the step is performed at room temperature.
9. Item 9. The method according to any one of Items 5 to 8, wherein the step is performed under normal pressure.
10. Item 5. The metal organic structure according to any one of Items 1 to 4, which is a gas storage material.
11. Item 5. A fuel cell or a secondary battery using the metal organic structure according to any one of Items 1 to 4.
12 Item 5. A gas sensor using the metal organic structure according to any one of Items 1 to 4.

  Since the metal organic structure of the present invention has voids inside and can store gaseous atoms such as hydrogen, oxygen and nitrogen in the voids, it is possible to store and release these gases. . In addition, unlike a metal organic structure having a conventional three-dimensional network structure, it has a tubular structure, so that the diffusion of gas atoms is fast, the speed of occlusion and release is high, and sufficient gas atoms at room temperature. The ability to occlude and release can be shown.

  Further, according to the production method of the present invention, the metal organic structure of the present invention can be produced by self-organization simply by mixing the raw material compound and the nitrogen-containing heterocyclic compound. It is possible to synthesize at normal temperature and normal pressure without the need to synthesize under. For this reason, mass production is possible, the cost can be kept low, and the metal organic structure of the present invention can be easily manufactured.

It is a schematic diagram which shows an example of the metal organic structure of this invention, and is the figure seen from b-axis direction. It is a schematic diagram which shows an example of the metal organic structure of this invention, and is the figure seen from c-axis direction. It is a schematic diagram which shows an example of the metal organic structure of this invention, and is the figure seen from the a-axis direction. It is a photograph which shows the single crystal of the metal organic structure obtained by the Example. It is a figure showing the measurement result which shows the relationship between elapsed time and hydrogen storage amount on condition of room temperature (296K) and 6.3MPa of the metal organic structure obtained by the Example. The small graph described in the graph is the measurement result before correction with a blank, the upper curve in the small graph shows the measurement result of the pressure cell and the sample, and the lower curve is the measurement result of the pressure cell. Is shown. It is a figure which shows the measurement result of the PCT characteristic in 296K of the metal organic structure obtained by the Example. It is a figure which shows the measurement result of the PCT characteristic in 258K of the metal organic structure obtained by the Example.

  Hereinafter, the metal organic structure of the present invention and the production method thereof will be described in detail.

  The metal organic structure of the present invention has a tubular structure, and the tubular structure is formed by a plurality of wall surfaces. Each wall surface is composed of a one-dimensional monomer of the metal organic compound represented by the general formula (1). It is formed by two parallel one-dimensional dimers.

  FIG. 1 is a schematic view showing a metal organic structure of the present invention, and is a view of the metal organic structure of the present invention viewed from the b-axis direction. As shown in FIG. 1, the metal organic structure 1 of the present invention has a b-axis in which two one-dimensional monomers 2 of the chain metal organic compound represented by the general formula (1) face each other in parallel. A one-dimensional dimer 3 is formed in a direction (from the front to the back of the page). In FIG. 1, the one-dimensional dimer 3 is shown surrounded by a dotted line.

  In FIG. 1, the one-dimensional dimer 3 shown surrounded by the dotted line constitutes the wall surface of the metal organic structure, and a plurality of (four in FIG. 1) wall surfaces gather to surround the space 4 to form a tubular shape. Forming a structure. In FIG. 1, the tubular structure is continuous in the b-axis direction (from the front to the back of the page). Note that the tubular structure is not limited to a single tube, and a plurality of tubes may be bundled as shown in FIG. In FIG. 1, there are as many tubes as there are spaces 4, and the tubes are bundled.

  2 and 3 are schematic views showing the metal organic structure of the present invention. FIG. 2 is a view of the metal organic structure of the present invention as seen from the c-axis direction, and FIG. 3 is a view as seen from the a-axis direction.

  The metal organic structure of the present invention having the above-described structure has voids inside, and can store gas atoms such as hydrogen, oxygen, nitrogen, etc. in the voids, so that these gases are stored and released. It is possible. In addition, unlike a metal organic structure having a conventional three-dimensional network structure, it has a tubular structure, so that the diffusion of gas atoms is fast, the speed of occlusion and release is high, and sufficient gas atoms at room temperature. The ability to occlude and release can be shown.

  Moreover, the manufacturing method of the metal organic structure of this invention has the process of mixing the compound represented with the said General formula (2), and a nitrogen-containing heterocyclic compound. According to the production method of the present invention, the metal organic structure of the present invention can be produced simply by mixing the compound represented by the general formula (2) and the nitrogen-containing heterocyclic compound. The reason why the metal organic structure of the present invention can be produced simply by mixing the compound represented by the general formula (2) and the nitrogen-containing heterocyclic compound is not clear, but the following general formula (3)

(In the formula, R ¹ and R ² are the same or different and each represents a nitrogen-containing heterocyclic group; R ³ and R ⁴ are the same or different and represent —OH, —CHO, or R ⁵ COO— (R ⁵ Represents H or an alkyl group having 1 to 3 carbon atoms), and M represents a transition metal.) The metal organic compound simple substance represented by A linear one-dimensional monomer of the metal organic compound represented by the general formula (1) is formed, and the two one-dimensional monomers are arranged in parallel to face each other to form a one-dimensional dimer. It is considered that the metal organic structure of the present invention can be produced by arranging a plurality of one-dimensional dimers so as to surround a space and forming a wall surface of a tubular structure.

  That is, according to the production method of the present invention, the metal organic structure of the present invention is produced by self-organization only by mixing the compound represented by the general formula (2) and the nitrogen-containing heterocyclic compound. Therefore, it is not necessary to synthesize at high temperature and high pressure, and it is possible to synthesize at normal temperature and normal pressure. For this reason, mass production is possible, the cost can be kept low, and the metal organic structure of the present invention can be easily manufactured.

1. Metal Organic Structure The metal organic structure of the present invention has a tubular structure, and the tubular structure is formed by a plurality of wall surfaces, and each wall surface has the following general formula (1)

Is formed by two one-dimensional dimers facing each other in parallel.

  The tubular structure of the metal organic structure of the present invention is formed by arranging a plurality of wall surfaces in parallel surrounding a space. The tubular structure may be configured by a single tube, but a plurality of tubes may be configured as a bundle as shown in FIG.

  The number of wall surfaces forming the tubular structure is not particularly limited as long as the tubular structure can be formed, but is preferably 3 or more. When the wall surface is 3 or more, a stable tubular structure can be formed. The number of wall surfaces of the tubular structure is more preferably 4. Note that the number of wall surfaces of the tubular structure varies depending on the type of transition metal M, which will be described later, and the number of wall surfaces is 4 when M is Fe, Co, or Cu.

  In the tubular structure, the wall surface preferably has a structure in which the one-dimensional dimer is arranged in parallel surrounding the space. The tubular structure is not limited to a form in which the one-dimensional dimer is arranged in parallel strictly and surrounds the space, and may be substantially parallel. The term “substantially parallel” includes, for example, a form in which a plurality of one-dimensional dimers are aligned with a shift in the range of 0 to 10 ° in the length direction.

In the general formula (1), R ¹ and R ² are the same or different and represent a nitrogen-containing heterocyclic group. The nitrogen-containing heterocyclic group is not particularly limited, and examples thereof include a 5- to 7-membered nitrogen-containing heterocyclic monocycle or a condensed ring thereof, and may further have another heteroatom, It may have a substituent. Moreover, the nitrogen-containing heterocyclic group may have aromaticity.

  Specific examples of the nitrogen-containing heterocyclic compound forming the nitrogen-containing heterocyclic group include pyridine, piperidine, piperazine, morpholine, pyrrolidine, pyrroline, imidazole, pyrazole, triazole, tetrazole, and benzimidazole. Of these, nitrogen-containing heterocyclic compounds containing only nitrogen atoms as heteroatoms such as pyridine, piperidine, piperazine, and imidazole are preferred, and nitrogen-containing heterocyclic groups having aromaticity such as pyridine and imidazole are preferred. More preferred is pyridine, still more preferred.

  Examples of the substituent that the nitrogen-containing heterocyclic group may have include, for example, a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, an aralkyl group, an aryl group, F, Cl, Br, and the like. These can be used in combination. Moreover, the substitution position of these substituents and the number of substituents are not particularly limited.

In the general formula (1), R ³ and R ⁴ are the same or different and represent —OH, —CHO, or R ⁵ COO—. R ³ and R ⁴ are the same or different and are preferably R ⁵ COO—. The R ⁵ COO— is specifically a group represented by the following general formula (4).

R ⁵ represents H or an alkyl group having 1 to 3 carbon atoms. R ⁵ is preferably H. When R ⁵ is H, voids of the formed metal organic structure are increased, and the amount of occluded gas is increased. When R ⁵ is an alkyl group, R ⁵ is preferably an alkyl group having 1 to 2 carbon atoms. By setting the number of carbon atoms of R ⁵ to 1 or 2, a one-dimensional space is more easily formed, and voids of the formed metal organic structure are increased, and the amount of gas occlusion is further increased.

It is preferable that R ¹ , R ² , R ³ and R ⁴ are formed only from elements having a large Clarke number because they can be easily applied in fields where occlusion of atoms such as hydrogen is required. Examples of the element having a large Clark number include oxygen, hydrogen, carbon, nitrogen and the like. The number of Clarks of the elements forming R ^{1 to} R ⁴ is preferably 0.02 or more, and more preferably 0.03 or more. When an element having a large Clark number is used as an element forming R ^{1 to} R ⁴ , and a transition metal having a large Clark number is used as a transition metal as M in the general formula (1) as described later, the present invention The metal organic structure can be composed of atoms having a large Clarke number, and can be more easily applied in fields where atoms such as hydrogen are required to be occluded.

  M represents a transition metal. It does not specifically limit as said transition metal, The element of 3A, 4A, 5A, 6A, 7A, 8, 1B, 2B group of a periodic table can be used. Among these, Fe, Co, Cu, and Cr are preferably used, Fe, Co, and Cu are more preferably used, Fe and Cu are further preferably used, and Cu is particularly preferably used. The transition metals may be used alone or in combination of two or more.

  As M, a transition metal having a large Clarke number is preferably used because it can be easily applied in a field where storage of atoms such as hydrogen is required. Examples of the transition metal having a large Clark number include Fe and Cu. The number of Clarks of the transition metal is preferably 0.008 or more, more preferably 0.01 or more, further preferably 0.02 or more, particularly preferably 1.90 or more, and most preferably 4.50 or more. When a transition metal having a large Clark number is used and the nitrogen-containing heterocyclic group is formed only with an element having a large Clark number, the metal organic structure of the present invention may be composed of atoms having a large Clark number. It can be applied more easily in a field where storage of atoms such as hydrogen is required.

In the general formula (1), n represents a natural number of 1 or more. n is preferably an integer of 1～2.8X10 ^6, and more preferably 1.4 × 10 ⁶ ～2.8X10 natural number of ^6. When n is in the above range, single crystal growth is facilitated, and the ability to occlude hydrogen atoms and the like in the metal organic structure and the ability to release hydrogen atoms and the like are further improved.

  The one-dimensional monomer of the metal organic compound represented by the general formula (1) is represented by the following general formula (3).

It is formed by aligning n organic metal compound molecules represented by the formula in a chain. In the general formula (3), M, R ¹ , R ² , R ³ and R ⁴ are the same as those in the general formula (1).

Although the reason why the molecules of the metal organic compound represented by the general formula (3) are aligned in a chain is not clear, the following general formula (2) is obtained by the production method of the present invention described later.
M (R ⁶ ) ₂ · mH ₂ O (2)
(In the formula, M represents a transition metal, R ⁶ is the same as R ³ and R ⁴ , and m represents an integer of 2 to 4.)
Is mixed with a nitrogen-containing heterocyclic compound to form a molecule of the metal organic compound represented by the general formula (3), and the molecule is chained by self-assembly. It is thought that they are aligned in series. At this time, the compound represented by the above general formula (3) is a compound of R ¹ or R ² which is a nitrogen-containing heterocyclic group, which is an adjacent R of a metal organic compound molecule represented by the above general formula (3). It is considered that self-organization occurs due to π-π stacking of π electrons between ¹ or R ² , hydrogen bonding, and intermolecular force.

  Each wall surface of the tubular structure is formed by a one-dimensional dimer in which two one-dimensional monomers of the metal organic compound represented by the general formula (1) face each other in parallel. Although the reason why two one-dimensional monomers of the metal organic compound represented by the general formula (1) are oriented in parallel is not clear, it is represented by the general formula (1) by self-organization. After the one-dimensional monomer of the metal organic compound is formed, two one-dimensional monomers of the metal organic compound represented by the above general formula (1) are parallelly opposed by self-assembly. Orient.

  The one-dimensional dimer is not limited to a form in which the one-dimensional monomers face each other strictly in parallel, and may be substantially parallel. The term “substantially parallel” includes, for example, a form in which chain-like one-dimensional monomers are opposed to each other with a shift of 0 to 10 ° in the length direction.

The metal organic structure is formed as a needle-like single crystal. The length of the single crystal is not particularly limited, and is preferably about 3 to 5 mm, and more preferably about 4 to 5 mm. The upper limit of the cross-sectional area of the single crystal is preferably about ² 3X0.3Mm, and more preferably about ² 2.5X0.3Mm.

  Since the metal organic structure of the present invention has the above-described configuration, it has an excellent ability to occlude gaseous atoms, and can sufficiently occlude gaseous atoms even at room temperature. The upper limit of the occlusion amount of gaseous atoms at normal temperature of the metal organic structure of the present invention is not particularly limited, and is preferably about 3.9% by mass with the metal organic structure being 100% by mass. In addition, in this specification, normal temperature means room temperature, and is specifically the temperature of 10-30 degreeC.

  In this specification, the occlusion amount of gaseous atoms is a value measured by a capacity method using a PCT characteristic measuring device manufactured by Suzuki Shokan Co., Ltd. in accordance with JIS H7201.

  The gas atoms occluded in the metal organic structure of the present invention are not particularly limited, and examples thereof include a hydrogen atom, an oxygen atom, a nitrogen atom, and a carbon atom. Among these, a hydrogen atom is preferable because it is useful for a fuel cell or the like.

  Since the metal organic structure of the present invention can occlude and release gas atoms, it can be used as a gas occlusion material. In particular, it is useful as a gas storage material for fuel cells or secondary batteries. Moreover, the metal organic structure of the present invention can also be used as a gas sensor.

2. Manufacturing Method The manufacturing method of the present invention has an annular structure formed by a plurality of wall surfaces, and each wall surface has the following general formula (1).

(In the formula, R ¹ and R ² are the same or different and each represents a nitrogen-containing heterocyclic group; R ³ and R ⁴ are the same or different and represent —OH, —CHO, or R ⁵ COO— (R ⁵ Represents H or an alkyl group having 1 to 3 carbon atoms), M represents a transition metal, and n represents a natural number of 1 or more.)
A metal organic compound represented by the following general formula (2), wherein the one-dimensional monomer of the metal-organic compound is formed of two parallel one-dimensional dimers.
M (R ⁶ ) ₂ · mH ₂ O (2)
And a step of mixing a nitrogen-containing heterocyclic compound.

In the general formula (2), M represents a transition metal and is the same as M described in the metal organic structure of the present invention. R ⁶ is the same as R ³ and R ⁴ described in the metal organic structure of the present invention.

  In the said General formula (2), m represents the integer of 2-4. The m is preferably 4.

  The nitrogen-containing heterocyclic compound is not particularly limited as long as it is a heterocyclic compound containing one or more nitrogen atoms, and examples thereof include a 5- to 7-membered nitrogen-containing heterocyclic compound or a condensed ring compound thereof. Further, it may have another hetero atom or may have a substituent. Moreover, the nitrogen-containing heterocyclic compound may have aromaticity.

  Specific examples of the nitrogen-containing heterocyclic compound include pyridine, piperidine, piperazine, morpholine, pyrrolidine, pyrroline, imidazole, pyrazole, triazole, tetrazole, and benzimidazole. Of these, nitrogen-containing heterocyclic compounds containing only nitrogen atoms as heteroatoms such as pyridine, piperidine, piperazine, and imidazole are preferable, and nitrogen-containing heterocyclic compounds having weak basicity such as pyridine and imidazole are more preferable. Pyridine is more preferable.

  Examples of the substituent that the nitrogen-containing heterocyclic compound may have include, for example, a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, an aralkyl group, an aryl group, F, Cl, Br, and the like. These can be used in combination. Moreover, the substitution position of these substituents and the number of substituents are not particularly limited.

  The manufacturing method of this invention has the process of mixing the compound represented with the said General formula (2), and a nitrogen-containing heterocyclic compound. In the production method of the present invention, the metal organic structure of the present invention can be obtained by self-assembly only by mixing the compound represented by the general formula (2) and the nitrogen-containing heterocyclic compound. It is possible to synthesize at normal temperature and normal pressure without requiring synthesis at high temperature and high pressure.

  In addition, normal temperature means room temperature as mentioned above, and is specifically the temperature of 10-30 degreeC. Further, in the present specification, the normal pressure generally means atmospheric pressure, and is a gas pressure of about 1 atm.

  The production method of the present invention includes a step of mixing the compound represented by the general formula (2) and the nitrogen-containing heterocyclic compound because the metal organic structure is produced by self-assembly. Heating and pressurization are not particularly required, but heating and pressurization may be performed for the purpose of promoting the formation of the metal organic structure. It does not specifically limit as heating temperature, For example, the temperature of 30-300 degreeC is mentioned. Moreover, it does not specifically limit as a pressure of pressurization, For example, the pressure of 1-140 atmospheres is mentioned.

In the above step, the molar ratio (m1) :( m2) between the number of moles of the compound represented by the general formula (2) (m1) and the number of moles of the nitrogen-containing heterocyclic compound (m2) is ( ⁴ × 10 ⁻⁴ ): (0.65) to ( ⁴ × 10 ⁻⁴ ): (1.2), preferably ( ⁴ × 10 ⁻⁴ ): (0.9) to ( ⁴ × 10 ⁻⁴ ): (1.2) It is more preferable. When the molar ratio (m1) :( m2) is in the above-described range, a good-quality crystal is easily grown and the crystal is easily grown as a solid.

  In the above step, the metal organic structure of the present invention can be obtained by mixing and leaving the compound represented by the general formula (2) and the nitrogen-containing heterocyclic compound. The standing time is not particularly limited, but is preferably 24 to 48 hours, and more preferably 36 to 48 hours. By setting the standing time within the above range, the metal organic structure is more sufficiently formed and solidified more sufficiently as a crystal.

  The metal organic structure of the present invention is manufactured by the steps described above.

  The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the examples.

Example 1
<Preparation of a single crystal of Cu (HCO ₂ ) ₂ .4H ₂ O>
As a raw material, _{Cu (HCO 2) 2 · 4H} 2 O to 2g, and distilled water 100ml mixing, by leaving about one month at room temperature to obtain a _{Cu (HCO 2) 2 · 4H} 2 O in the single crystal .

<Manufacture of metal organic structure>
In a beaker, 0.1 g ( ⁴ × 10 ⁻⁴ mol) of a single crystal of Cu (HCO ₂ ) ₂ .4H ₂ O obtained as described above and C ₅ H ₅ N (1 mol) as a nitrogen-containing heterocyclic compound were contained. The mixture was prepared by mixing at room temperature and normal pressure.

The obtained mixed liquid was allowed to stand in a draft chamber at room temperature and normal pressure for 48 hours. At the bottom of the beaker, a needle-like single crystal of the metal organic structure shown in FIG. 4 was formed. The single crystal had a length of 2 to 4 mm and a cross section of 1.5 × 0.2 to 2.0 × 0.2 mm ² . Among the obtained single crystals, the volume of the 4 mm length was length × width (cross section) × length (cross section) = 4 × 2 × 0.2 mm ³ .

  The crystal structure of the obtained single crystal was determined by performing a single crystal structure analysis using X-rays. The results are shown in Tables 1 and 2.

  From Tables 1 and 2, it was found that the crystal structure of the single crystal obtained in Example 1 had the configuration of the metal organic structure of the present invention.

<Measurement of hydrogenation rate>
Using a PCT characteristic measuring device manufactured by Suzuki Shokan Co., Ltd., the hydrogen storage amount of the obtained metal organic structure for each elapsed time is measured under a temperature condition of room temperature (296K) and a pressure condition of 6.3 MPa. Thus, the hydrogenation rate was evaluated. The results are shown in FIG. Moreover, the average value of the hydrogen storage amount of each elapsed time was measured under a pressure condition of 6.3 MPa and a temperature condition of 257K.

<PCT characteristic measurement>
Using a PCT characteristic measuring apparatus manufactured by Suzuki Shokan Co., Ltd., PCT characteristics were measured under a temperature condition of room temperature (296K) while applying a hydrogen pressure up to an upper limit of 7 MPa, and cycle characteristics were also evaluated. The results are shown in FIG. In addition, under the same pressure condition, the temperature condition was set to 258K, and the PCT characteristic and the cycle characteristic were evaluated. The results are shown in FIG.

<Result>
From the measurement result of FIG. 5, the metal organic structure of Example 1 has a high hydrogen storage amount immediately after the start of the test. Thereby, it turned out that the metal organic structure of Example 1 has a high hydrogenation rate. In addition, the average value of the hydrogen storage amount during the test was 3.8 wt%, and it was found that a high hydrogen storage amount was exhibited at a pressure of 6.3 MPa and normal temperature (296 K). Moreover, the average value of the hydrogen storage amount at a pressure of 6.3 MPa and 257 K was 2.7 wt%, and it was found that a high hydrogen storage amount was exhibited even under low temperature conditions.

  From the measurement result of FIG. 6, under the temperature condition of room temperature (296K), the hydrogen occlusion amount increased by pressurization, and the hydrogen occlusion amount decreased by pressure reduction. From the results of the PCT characteristics and the cycle characteristics, it is found that the metal organic structure of Example 1 is useful as a gas storage material because it can absorb hydrogen by pressurization at room temperature (296K) and release it by decompression. It was.

  Further, from the measurement results of FIG. 7, the metal organic structure of Example 1 can store hydrogen under pressure and release it under reduced pressure as in the case of room temperature (298K) under the temperature condition of 258K. As useful.

Claims (12)

A metal organic structure having a tubular structure,
The tubular structure is formed by a plurality of wall surfaces, and each wall surface has the following general formula (1)

(In the formula, R ¹ and R ² are the same or different and each represents a nitrogen-containing heterocyclic group; R ³ and R ⁴ are the same or different and represent —OH, —CHO, or R ⁵ COO— (R ⁵ Represents H or an alkyl group having 1 to 3 carbon atoms.) M represents a transition metal, and n represents a natural number of 1 or more.)
The one-dimensional monomer of the metal organic compound represented by is formed by two parallel one-dimensional dimers,
Metal organic structure characterized by the above.   The metal organic structure according to claim 1, wherein the transition metal is at least one selected from the group consisting of Fe, Co, and Cu. The metal organic structure according to claim 1, wherein n is a natural number of 1 to 2.8 × 10 ⁶ .   The metal organic structure according to claim 1, wherein at least one selected from the group consisting of a hydrogen atom, an oxygen atom, a nitrogen atom, and a carbon atom is occluded and released. It has a tubular structure formed by a plurality of wall surfaces, and each wall surface has the following general formula (1)

(In the formula, R ¹ and R ² are the same or different and each represents a nitrogen-containing heterocyclic group; R ³ and R ⁴ are the same or different and represent —OH, —CHO, or R ⁵ COO— (R ⁵ Represents H or an alkyl group having 1 to 3 carbon atoms.) M represents a transition metal, and n represents a natural number of 1 or more.)
A one-dimensional monomer of a metal organic compound represented by the method for producing a metal-organic structure formed by two parallel one-dimensional dimers,
The following general formula (2)
M (R ⁶ ) ₂ · mH ₂ O (2)
(In the formula, M represents a transition metal, R ⁶ is the same as R ³ and R ⁴ , and m represents an integer of 2 to 4.)
And a step of mixing a nitrogen-containing heterocyclic compound with a compound represented by:
The manufacturing method characterized by the above-mentioned.   The manufacturing method according to claim 5, wherein the transition metal is at least one selected from the group consisting of Fe, Co, and Cu.   The nitrogen-containing heterocyclic compound is at least one selected from the group consisting of pyridine, piperidine, piperazine, morpholine, pyrrolidine, pyrroline, imidazole, pyrazole, triazole, tetrazole and benzimidazole. Manufacturing method.   The said process is a manufacturing method in any one of Claims 5-7 performed under normal temperature.   The said process is a manufacturing method in any one of Claims 5-8 performed under a normal pressure.   The metal organic structure according to any one of claims 1 to 4, which is a gas storage material.   A fuel cell or a secondary battery using the metal organic structure according to claim 1.   The gas sensor using the metal organic structure in any one of Claims 1-4.

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