Carbon dioxide capture agents, metal organic structures and compounds

Abstract

The present application provides a novel carbon dioxide capturing agent and the like capable of capturing carbon dioxide. The carbon dioxide capturing agent contains a metal organic structure, the metal organic structure is capable of capturing and releasing carbon dioxide, inside the metal organic structure, an isolated space is formed by the three-dimensional structure of the metal organic structure, the isolated space is a space capable of capturing carbon dioxide and a space not having a passageway through which carbon dioxide can pass in a normal state, the three-dimensional structure of the metal organic structure changes in the process of capturing carbon dioxide into the isolated space and the process of releasing carbon dioxide from the isolated space, but the three-dimensional structure of the metal organic structure when carbon dioxide has been captured into the isolated space is the same as the three-dimensional structure of the metal organic structure when carbon dioxide has not been captured into the isolated space.

Description

Technical Field

[0001] This invention relates to carbon dioxide scavengers, metal-organic structures that can be used in the carbon dioxide scavengers, and compounds that can be used as ligands in the metal-organic structures. Background Technology

[0002] In recent years, among the solutions for achieving a decarbonized society, there has been an urgent need to develop materials for recycling or storing carbon dioxide.

[0003] Porous network complexes (PCNs) composed of organic polydentate ligands and metal ions have attracted much attention as powerful carbon dioxide scavengers due to their high design potential.

[0004] To date, many PCNs have been reported to demonstrate carbon dioxide capture capabilities (e.g., see Non-Patent Literature 1 and 2).

[0005] Furthermore, gated MOFs are known as metal-organic frameworks (MOFs) capable of capturing gases. However, the volume of a gated MOF after capturing a gas is larger than its volume before capturing the gas. That is, the gated MOF undergoes a structural change such as volume expansion due to gas capture (see, for example, non-patent document 3). If the structural change of the MOF is large, the low durability of the MOF itself is considered a problem. In addition, if the volume expansion of the MOF is large, the low durability when the MOF is molded into a shaped body is considered a problem.

[0006] Existing technical documents

[0007] Non-patent literature

[0008] Non-patent literature 1: Zhong Li et al, ACS Sustainable Chem. Eng. 8, 41, 15378-15404 (2020).

[0009] Non-patent literature 2: Calogero Giancarlo Piscopo et al, ChemPlusChem 85, 538-547 (2020).

[0010] Non-patent literature 3: Isotope News, August 2017, No. 752, pp. 12-15. Summary of the Invention

[0011] The purpose of this invention is to provide novel carbon dioxide scavengers capable of capturing carbon dioxide, metal-organic structures that can be used in the aforementioned carbon dioxide scavengers, and compounds that can be used as ligands in the aforementioned metal-organic structures.

[0012] In order to solve the above-mentioned problems, the inventors conducted in-depth research and found that the above-mentioned problems could be solved, and completed the present invention with the following main points.

[0013] That is, the present invention includes the following key points.

[0014] [1] A carbon dioxide scavenger containing a metal-organic structure.

[0015] The aforementioned metal-organic structures can capture carbon dioxide and also release it.

[0016] Within the aforementioned metal-organic structure, isolated spaces are formed using its three-dimensional structure.

[0017] The aforementioned isolated space is a space capable of capturing carbon dioxide, and is a space that, under normal circumstances, does not have channels through which carbon dioxide can pass.

[0018] Although the three-dimensional structure of the metal-organic structure changes during the process of carbon dioxide being captured in the aforementioned isolated space and during the process of carbon dioxide being released from the aforementioned isolated space, the three-dimensional structure of the metal-organic structure when carbon dioxide has been captured in the aforementioned isolated space is the same as the three-dimensional structure of the metal-organic structure when carbon dioxide has not been captured in the aforementioned isolated space.

[0019] [2] According to the carbon dioxide scavenger described in [1], wherein the BET specific surface area of ​​the above-mentioned metal-organic structure in the specific surface area determination using N2 is 1 m². 2 / g or less.

[0020] [3] According to the carbon dioxide capture agent described in [1] or [2], wherein the above-mentioned metal-organic structure forms an interpenetrating structure with two interpenetrating frameworks.

[0021] [4] The carbon dioxide capture agent according to any one of [1] to [3], wherein the element constituting the isolated space in the metal-organic structure does not form a chemical bond with the carbon dioxide captured in the isolated space.

[0022] [5] The carbon dioxide capture agent according to any one of [1] to [4], wherein the above-mentioned metal-organic structure contains at least one of the elements of Group IIA to Group IVA as a constituent element.

[0023] [6] The carbon dioxide capture agent according to any one of [1] to [5], wherein the above-mentioned metal-organic structure contains a halogen element as a constituent element.

[0024] [7] The carbon dioxide scavenger according to any one of [1] to [6], wherein the above-mentioned organometallic structure contains a compound having a nitrogen-containing aromatic heterocycle as a ligand.

[0025] [8] According to the carbon dioxide scavenger described in [7], wherein the compound having a nitrogen-containing aromatic heterocycle is a compound represented by the following formula (1).

[0026]

[0027] (In the above formula (1),)

[0028] X 11 and X 13 For N and X 12 X 14 and X 15 For CR, or X 12 and X 14 For N and X 11 X 13 and X 15 For CR, or X 11 and X 15 For N and X 12 X 13 and X 14 It is CR.

[0029] X 21 and X 23 For N and X 22 X 24 and X 25 For CR, or X 22 and X 24 For N and X 21 X 23 and X 25 For CR, or X 21 and X 25 For N and X 22 X 23 and X 24 It is CR.

[0030] X 31 and X 33 For N and X 32 X 34 and X 35 For CR, or X 32 and X 34 For N and X 31 X 33 and X 35 For CR, or X 31 and X 35 For N and X 32 X 33and X 34 It is CR.

[0031] X 41 and X 43 For N and X 42 X 44 and X 45 For CR, or X 42 and X 44 For N and X 41 X 43 and X 45 For CR, or X 41 and X 45 For N and X 42 X 43 and X 44 It is CR.

[0032] R can be a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0033] R 1 ~R 6 Each of these can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0034] [9] The carbon dioxide capture agent according to [8], wherein the compound represented by the above formula (1) is the compound represented by the following formula (1-1).

[0035]

[0036] (In the above formula (1-1),

[0037] R can be a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0038] R 1 ~R 6 Each of these can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0039]

[10] The carbon dioxide capture agent according to any one of [1] to [9], wherein when the ligand is set as L, the composition of the above-mentioned metal-organic structure is represented by Cu4I4L.

[0040]

[11] A metal-organic structure comprising at least one of a group IIA to group IVA as a constituent element and a compound represented by the following formula (1) as a ligand.

[0041]

[0042] (In the above formula (1),)

[0043] X 11 and X 13 For N and X 12 X 14 and X 15 For CR, or X 12 and X 14 For N and X 11 X 13 and X 15 For CR, or X 11 and X 15 For N and X 12 X 13 and X 14 It is CR.

[0044] X 21 and X 23 For N and X 22 X 24 and X 25 For CR, or X 22 and X 24 For N and X 21 X 23 and X 25 For CR, or X 21 and X 25 For N and X 22 X 23 and X 24 It is CR.

[0045] X 31 and X 33 For N and X 32 X 34 and X 35 For CR, or X 32 and X 34 For N and X 31 X 33 and X 35 For CR, or X 31 and X 35 For N and X 32 X33 and X 34 It is CR.

[0046] X 41 and X 43 For N and X 42 X 44 and X 45 For CR, or X 42 and X 44 For N and X 41 X 43 and X 45 For CR, or X 41 and X 45 For N and X 42 X 43 and X 44 It is CR.

[0047] R can be a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0048] R 1 ~R 6 Each of these can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0049]

[12] According to the metal-organic structure described in

[11] , wherein the compound represented by the above formula (1) is the compound represented by the following formula (1-1).

[0050]

[0051] (In the above formula (1-1),

[0052] R can be a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0053] R 1 ~R 6 Each of these can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0054]

[13] The metal-organic structure according to

[11] or

[12] contains a halogen element as a constituent element.

[0055]

[14] The metal-organic structure according to any one of

[11] to

[13] , wherein when the above-mentioned ligand is set as L, the composition is represented by Cu4I4L.

[0056]

[15] The metal-organic structure according to any one of

[11] to

[14] , wherein the above-mentioned constituent elements contain copper,

[0057] The aforementioned ligand utilizes one of the two nitrogen atoms of the pyrimidine ring of the ligand to coordinate with the aforementioned copper.

[0058]

[16] The metal-organic structure according to any one of

[11] to

[15] , wherein the above-mentioned constituent elements contain copper and iodine,

[0059] In the above-mentioned organometallic structures, Cu4I4 exists in the cubane form.

[0060]

[17] The metal-organic structure according to any one of

[11] to

[16] , wherein the above-mentioned constituent elements contain copper and iodine,

[0061] In the aforementioned organometallic structures, Cu4I4 exists in the cubane form.

[0062] When the ligand is set to L, the composition is represented by Cu4I4L.

[0063] The aforementioned ligand utilizes one of the two nitrogen atoms of the pyrimidine ring of the ligand to coordinate with the aforementioned copper.

[0064]

[18] A carbon dioxide scavenger containing any one of the metal-organic structures described in

[11] to

[17] .

[0065]

[19] A compound represented by the following formula (1).

[0066]

[0067] (In the above formula (1),)

[0068] X 11 and X 13 For N and X 12 X 14 and X 15 For CR, or X 12 and X 14 For N and X 11 X 13 and X 15 For CR, or X 11 and X15 For N and X 12 X 13 and X 14 It is CR.

[0069] X 21 and X 23 For N and X 22 X 24 and X 25 For CR, or X 22 and X 24 For N and X 21 X 23 and X 25 For CR, or X 21 and X 25 For N and X 22 X 23 and X 24 It is CR.

[0070] X 31 and X 33 For N and X 32 X 34 and X 35 For CR, or X 32 and X 34 For N and X 31 X 33 and X 35 For CR, or X 31 and X 35 For N and X 32 X 33 and X 34 It is CR.

[0071] X 41 and X 43 For N and X 42 X 44 and X 45 For CR, or X 42 and X 44 For N and X 41 X 43 and X 45 For CR, or X 41 and X 45 For N and X 42 X 43 and X 44 It is CR.

[0072] R can be a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0073] R 1 ~R 6 Each of these can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0074]

[20] The compound according to

[19] is a compound represented by the following formula (1-1).

[0075]

[0076] (In the above formula (1-1),

[0077] R can be a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0078] R 1 ~R 6 Each of these can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0079] According to the present invention, novel carbon dioxide capture agents capable of capturing carbon dioxide, metal-organic structures that can be used in the aforementioned carbon dioxide capture agents, and compounds that can be used as ligands in the aforementioned metal-organic structures can be provided. Attached Figure Description

[0080] Figure 1 It is a schematic diagram of an interpenetrating structure in which two frames interpenetrate each other.

[0081] Figure 2 This is a schematic diagram of the cubane structure.

[0082] Figure 3 This is a schematic diagram of the three-dimensional structure of an example of the metal-organic structure of the present invention (without capturing carbon dioxide).

[0083] Figure 4 This is a schematic diagram of the three-dimensional structure of an example of the metal-organic structure of the present invention (with carbon dioxide capture).

[0084] Figure 5A The result is the single-crystal X-ray structure analysis of the pyrimidine ligand (Lp) (1).

[0085] Figure 5BThe result is the single-crystal X-ray structure analysis of the pyrimidine ligand (Lp) (2).

[0086] Figure 6 The results are obtained by FT-IR determination of the organometallic structure [Cu4I4Lp] and pyrimidine ligand (Lp) before solvent removal.

[0087] Figure 7A This is a diagram (Figure 1) showing the single crystal structure of the metal-organic structure [Cu4I4Lp] before solvent removal.

[0088] Figure 7B Figure 2 shows the single crystal structure of the metal-organic structure [Cu4I4Lp] before solvent removal.

[0089] Figure 8A This is another diagram (Figure 1) showing the single crystal structure of the metal-organic structure [Cu4I4Lp] before the solvent is removed.

[0090] Figure 8B This is another diagram (Figure 2) showing the single crystal structure of the metal-organic structure [Cu4I4Lp] before the solvent is removed.

[0091] Figure 8C This is another diagram (Figure 3) showing the single crystal structure of the metal-organic structure [Cu4I4Lp] before the solvent is removed.

[0092] Figure 9A This is another diagram (Figure 1) showing the single crystal structure of the metal-organic structure [Cu4I4Lp] before the solvent is removed.

[0093] Figure 9B This is another diagram (Figure 2) showing the single crystal structure of the metal-organic structure [Cu4I4Lp] before the solvent is removed.

[0094] Figure 10 These are the PXRD results of the organometallic structure [Cu4I4Lp] before solvent removal.

[0095] Figure 11 It is the adsorption isotherm of the metal-organic structure [Cu4I4Lp].

[0096] Figure 12 This is a diagram showing the single-crystal structure of the metal-organic structure [Cu4I4Lp] after the solvent has been removed.

[0097] Figure 13 This is a diagram showing the single-crystal structure of the metal-organic structure [Cu4I4Lp] after CO2 capture.

[0098] Figure 14These are the FT-IR measurements of the metal-organic structures [Cu4I4Lp] before solvent removal [III], after solvent removal [II], and after CO2 capture [I]. Detailed Implementation

[0099] (Carbon dioxide scavenging agent)

[0100] The carbon dioxide scavenger of the present invention contains a metal-organic structure. The carbon dioxide scavenger can be the metal-organic structure itself.

[0101] Metal-organic structures can capture carbon dioxide and also release it.

[0102] Inside the metal-organic structure, isolated spaces are formed by utilizing the three-dimensional structure of the metal-organic structure.

[0103] An isolated space is a space that can capture carbon dioxide and does not have a channel through which carbon dioxide can pass under normal conditions.

[0104] In metal-organic structures, the three-dimensional structure changes during the process of carbon dioxide being captured into the isolated space and during the process of carbon dioxide being released from the isolated space. However, the three-dimensional structure of the metal-organic structure when carbon dioxide has been captured into the isolated space is the same as the three-dimensional structure of the metal-organic structure when carbon dioxide has not been captured into the isolated space.

[0105] Here, "normal state" refers to the state of being placed in air at normal temperature (25°C) and normal pressure (1 atm).

[0106] A channel is a pathway for carbon dioxide to pass through between space and other spaces or the outside world.

[0107] Whether a pathway between a space and other spaces or the outside world can pass through a molecule can be determined by the molecule's kinetic diameter and the size of the pathway in terms of the molecule's probability of passage.

[0108] Here, the spatial size of the pathway, considered from the perspective of the possibility of molecular passage, can be determined by the positions of the atoms constituting the pathway and the van der Waals radii of those atoms. The space formed by reducing the van der Waals radius from the position of each atom within the space enclosed by the atoms constituting the pathway (called the passage space) is the pathway.

[0109] If a sphere with a diameter equivalent to the dynamic diameter of a molecule can pass through the passage space, then the molecule can pass through the passage.

[0110] It should be noted that the kinetic diameter of helium, the gas with the smallest kinetic diameter, is... If a sphere of a certain diameter cannot pass through the passageway, then all molecules cannot pass through the passageway.

[0111] The positions of the atoms that make up the pathway can be determined analytically using single-crystal X-ray structures.

[0112] Metal-organic structures are known to be porous coordination polymers (PCP).

[0113] Metal-organic structures have a framework. The framework is constructed by ligands bonded to metals or metal compounds that act as nodes via coordinate bonds, and consists of constituent elements and chemical bonds (mainly covalent and coordinate bonds).

[0114] The inventors have discovered a novel metal-organic structure in which the three-dimensional structure changes during the process of carbon dioxide being captured in an isolated space and during the process of carbon dioxide being released from the isolated space. However, the three-dimensional structure of the metal-organic structure when carbon dioxide has been captured in the isolated space is the same as the three-dimensional structure of the metal-organic structure when carbon dioxide has not been captured in the isolated space.

[0115] On the other hand, the novel metal-organic structure discovered by the inventors exhibits changes in its three-dimensional structure during the process of carbon dioxide being captured in the isolated space and during the process of carbon dioxide detaching from the isolated space. However, the three-dimensional structure of the metal-organic structure when carbon dioxide has already been captured in the isolated space is the same as the three-dimensional structure of the metal-organic structure when carbon dioxide has not been captured in the isolated space (hereinafter, this behavior of the metal-organic structure is sometimes referred to as "no change in three-dimensional structure before and after carbon dioxide capture"). Therefore, the aforementioned problems of gated MOFs are less likely to occur. This is very useful when using metal-organic structures.

[0116] Here, "the three-dimensional structure of metal-organic structures when carbon dioxide has been trapped in isolated space is the same as the three-dimensional structure of metal-organic structures when carbon dioxide has not been trapped in isolated space" refers to, for example, the lattice constant of the crystal structure of metal-organic structures when carbon dioxide has been trapped in isolated space. α1[°], β1[°], γ1[°]) and the lattice constants of the crystal structure of the metal-organic structure when carbon dioxide is not trapped in isolated space ( The variation rate of each of α2[°], β2[°], and γ2[°] is within ±10%. This variation rate is preferably within ±5%, more preferably within ±3%, and particularly preferably within ±1%.

[0117] Here, the rate of change of each lattice constant is determined as follows.

[0118] · Rate of change of a (%) = [(a1-a2) / a1] × 100

[0119] The rate of change of b (%) = [(b1-b2) / b1] × 100

[0120] The rate of change of c (%) = [(c1-c2) / c1] × 100

[0121] • Rate of change of α (%) = [(α1-α2) / α1] × 100

[0122] • Rate of change of β (%) = [(β1-β2) / β1] × 100

[0123] • Rate of change of γ (%) = [(γ1-γ2) / γ1] × 100

[0124] The lattice constant can be determined analytically using the X-ray structure of a single crystal.

[0125] The inventors believe that, as a characteristic of metal-organic structures that do not undergo any changes in three-dimensional structure before and after capturing carbon dioxide, the important feature is the formation of an interpenetrating structure in which two frameworks interpenetrate each other.

[0126] A schematic diagram of the interpenetrating structure is shown below. Figure 1 (Christian S. Diercks, Omar M. Yaghi, Science 2017 Vol. 355, Issue 6328, eaal158). exist Figure 1 In the interpenetrating structure, the first frame F1 and the second frame F2 interpenetrate each other. In other words, the second frame F2 is embedded within the first frame F1. By forming such a structure (an interpenetrating structure of two interpenetrating frames), the relative positions of the two frames change, appropriately causing a change in the three-dimensional structure. On the other hand, since the two frames interpenetrate each other, the change in the relative positions of the two frames is limited. Therefore, the change in the three-dimensional structure is appropriately constrained. The inventors believe that this is an important reason why the three-dimensional structure of the metal-organic structure can be the same when carbon dioxide can pass through in an isolated space, and when carbon dioxide has been captured in the isolated space as it is when carbon dioxide has not been captured in the isolated space.

[0127] Furthermore, the inventors believe that the most important characteristic of a metal-organic structure that does not undergo any change in stereostructure before and after capturing carbon dioxide is the elasticity and flexibility of the ligand.

[0128] Because the structure of ligands is not rigid, there are non-rotatable but torsionable portions (bonds) throughout the ligand backbone, giving the ligands an elastic flexibility. This flexibility is believed to cause changes in the stereostructure of metal-organic structures. Furthermore, since this flexibility is elastic, if the factors causing the stereostructure change (e.g., pressure) are removed, the metal-organic structure can revert to a stable structure. The inventors believe this is an important reason why stereostructure changes that allow carbon dioxide to pass through in isolated spaces can occur, and why the stereostructure of a metal-organic structure when carbon dioxide has been trapped in isolated spaces can be the same as the stereostructure of a metal-organic structure when carbon dioxide has not been trapped in isolated spaces.

[0129] Twist (a change in angle of certain parts of a molecule relative to the rest) is thought to readily occur, for example, between carbon-carbon bonds in nitrogen-containing aromatic heterocycles and aromatic hydrocarbon rings in ligands. This carbon-carbon bond is extremely restrictive of rotation due to the physical proximity of hydrogens or substituents bonded to the nitrogen-containing aromatic heterocycle and those bonded to the aromatic hydrocarbon ring. Therefore, a twist originating from this carbon-carbon bond cannot rotate as freely as a carbon-carbon single bond in a straight-chain hydrocarbon group. Furthermore, a twist originating from this carbon-carbon bond, if the factors causing the steric change (e.g., pressure) are removed, will reduce the physical proximity of hydrogens or substituents bonded to the nitrogen-containing aromatic heterocycle and those bonded to the aromatic hydrocarbon ring, thus restoring it to its original state; therefore, it is elastic.

[0130] It should be noted that when an aromatic hydrocarbon ring and a nitrogen-containing aromatic heterocycle are bonded by carbon-carbon bonds, the state in which they are in the same plane is the highest energy state, i.e., the most unfavorable state. When a large substituent is present, it is impossible to overcome its energy barrier, and rotation is hindered. The angle between their faces varies depending on the presence and type of substituent. For example, in the case of the organometallic structure [Cu4I4Lp] shown in the embodiments of this specification, the angle between the face of the pyrimidine ring and the face of the methyl-substituted benzene ring is approximately 70°.

[0131] The BET specific surface area of ​​metal-organic structures, as measured using N2, is, for example, 1 m². 2 / g or less. In metal-organic structures with fine pores capable of capturing carbon dioxide or N2, the BET specific surface area measured using N2 is 1m². 2 / g and below refers to pores that are isolated spaces.

[0132] The BET specific surface area can be determined by measuring the adsorption isotherm using N2. The adsorption isotherm can be measured using a gas adsorption measuring device (e.g., the Microtrac BEL fully automated gas adsorption measuring device BELSORP MAX). Details of the measurement method are described in the examples.

[0133] In organometallic structures, for example, the elements constituting the isolated spaces do not form chemical bonds with the carbon dioxide already trapped within those spaces. The chemical bonds here are covalent, ionic, and hydrogen bonds.

[0134] Whether the elements constituting the isolated space form chemical bonds with the carbon dioxide that has been captured in the isolated space can be determined by the types of elements constituting the isolated space and the size of the isolated space.

[0135] The size of the isolated space can be determined by using the Mercury software at CCDC (Cambridge Crystallographic Data Centre) to calculate the results of single-crystal X-ray structure analysis.

[0136] The metal-organic structure contains at least one of Group IIA to Group IVA elements as constituent elements. Preferably, the Group IIA to Group IVA elements are Zr, Cd, Ti, Cu, Zn, Fe, Cr, Ni, Co, Mo, Hf, Mg, Al, or Si, and more preferably Cu, Zr, Zn, or Cd.

[0137] Organometallic structures can contain halogens as constituent elements, for example. Examples of halogens include fluorine, chlorine, bromine, and iodine.

[0138] The constituent elements mentioned here are not the elements that constitute ligands.

[0139] Organometallic structures contain compounds with nitrogen-containing aromatic heterocycles, for example, as ligands. Examples of nitrogen-containing aromatic heterocycles include pyridine rings and pyrimidine rings.

[0140] When the ligand is set to L, the composition of the metal-organic structure is preferably represented by Cu4I4L.

[0141] Compounds having nitrogen-containing aromatic heterocycles are preferably those represented by formula (1) as described later. Furthermore, compounds represented by formula (1) may be defined by the appendix as described later, regarding X. 11 ~X 15 X 21 ~X 25 X 31 ~X 35 and X 41 ~X 45 It can be X11 ~X 15 One of them is N, and the others are CR and X. 21 ~X 25 One of them is N, and the others are CR and X. 31 ~X 35 One of them is N, and the others are CR and X. 41 ~X 45 One of them is N and the others are CR. Additionally, regarding X... 11 ~X 15 X 21 ~X 25 X 31 ~X 35 and X 41 ~X 45 It can be X 13 X 23 X 33 and X 43 For N, the others are represented by CR. The R in CR has the same meaning as the R in the appendix of the compound represented by formula (1) described later.

[0142] As a metal-organic structure, the metal-organic structure of the present invention, which is described in detail below, is preferred.

[0143] (Metal-organic structures)

[0144] The metal-organic structure of the present invention contains at least one of the elements of group IIA to group IVA as constitutive elements, and a compound represented by the following formula (1) as a ligand.

[0145] In addition, metal-organic structures can contain halogens as constituent elements.

[0146] The constituent elements mentioned here are not the elements that constitute ligands.

[0147] The preferred elements as Group IIA to Group IVA are Zr, Cd, Ti, Cu, Zn, Fe, Cr, Ni, Co, Mo, Hf, Mg, Al, and Si, with Cu, Zn, and Cd being more preferred.

[0148] Examples of halogen elements include fluorine, chlorine, bromine, and iodine.

[0149] For example, when the ligand is set to L, the composition of the metal-organic structure of the present invention is represented by Cu4I4L.

[0150] For example, the ligand utilizes one of the two nitrogen atoms of the pyrimidine ring of the ligand to coordinate with copper.

[0151] Cu4I4 exists, for example, in the cubane form in the organometallic structure of the present invention.

[0152] A schematic diagram of the cubane structure is shown below. Figure 2 .

[0153] The cubane structure is cubic, with either Cu or I at each vertex, and the line segments between Cu and I forming edges. Cu and Cu are not adjacent to each other, and I and I are not adjacent to each other either. In other words, Cu and Cu exist only on the diagonal, and I and I also exist only on the diagonal.

[0154] Because Cu and I atoms are of different sizes, the actual structure is not cubic, but twisted. ∠Cu-I-Cu is approximately 60°, and ∠I-Cu-I is approximately 110°.

[0155] It should be noted that L in the figure represents the ligand.

[0156] For example, the tetragonal crystal system can be cited as the crystal system of the metal-organic structure of the present invention under normal conditions.

[0157] For example, I41 / a can be cited as the space group of the metal-organic structure of the present invention under normal conditions.

[0158] Here, a schematic diagram of the three-dimensional structure of an example of the metal-organic structure of the present invention is shown.

[0159] Figure 3 This is a schematic diagram of the three-dimensional structure of an example of the metal-organic structure of the present invention (without capturing carbon dioxide).

[0160] Figure 3 In the first frame L1a, represented by light gray spheres (atoms) and bars (bonds), and the second frame L2a, represented by dark gray spheres (atoms) and bars (bonds), interpenetrate with each other, forming an interpenetrating structure.

[0161] Figure 4 This is a schematic diagram of the three-dimensional structure of an example of the metal-organic structure of the present invention (with carbon dioxide capture).

[0162] Figure 4 In, with Figure 3 Similarly, the first frame L1a, represented by light gray spheres (atoms) and bars (bonds), interpenetrates with the second frame L2a, represented by dark gray spheres (atoms) and bars (bonds), forming an interpenetrating structure. Figure 4 In the isolated space formed by two frames, carbon dioxide, represented by the partial overlap of three spheres (corresponding to C and O respectively), was further captured.

[0163] <Compounds represented by formula (1)>

[0164] The compound represented by formula (1) is also the subject of this invention.

[0165]

[0166] (In the above formula (1),)

[0167] X 11 and X 13 For N and X 12 X 14 and X 15 For CR, or X 12 and X 14 For N and X 11 X 13 and X 15 For CR, or X 11 and X 15 For N and X 12 X 13 and X 14 It is CR.

[0168] X 21 and X 23 For N and X 22 X 24 and X 25 For CR, or X 22 and X 24 For N and X 21 X 23 and X 25 For CR, or X 21 and X 25 For N and X 22 X 23 and X 24 It is CR.

[0169] X 31 and X 33 For N and X 32 X 34 and X 35 For CR, or X 32 and X 34 For N and X 31 X 33 and X 35 For CR, or X 31 and X 35 For N and X 32 X 33 and X 34 It is CR.

[0170] X 41 and X 43 For N and X 42 X 44 and X 45 For CR, or X 42 and X44 For N and X 41 X 43 and X 45 For CR, or X 41 and X 45 For N and X 42 X 43 and X 44 It is CR.

[0171] R can be a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0172] R 1 ~R 6 Each of these can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted by a halogen atom, an alkoxy group that can be substituted by a halogen atom, or an aryl group (which can be substituted by a halogen atom, an alkyl group that can be substituted by a halogen atom, or an alkoxy group that can be substituted by a halogen atom).

[0173] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine.

[0174] The alkyl group in alkyl and alkoxy groups can be straight-chain, branched, or cyclic. The number of carbon atoms in straight-chain and branched alkyl groups is preferably 1 to 30, more preferably 1 to 12, and particularly preferably 1 to 4. Furthermore, the number of carbon atoms in cyclic alkyl groups is preferably 3 to 30, more preferably 3 to 12, and particularly preferably 3 to 10.

[0175] It should be noted that R 1 ~R 6 When the alkyl or alkoxy group is used, from the perspective of imparting appropriate steric hindrance to the benzene ring, the alkyl group is preferably linear.

[0176] Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, 3,7-dimethyloctyl, and n-dodecyl. Among these, methyl, ethyl, n-propyl, isopropyl, and n-butyl are preferred.

[0177] There is no particular limitation on the number of halogen atoms in an alkyl group that is replaced by a halogen atom.

[0178] Examples of alkyl groups that are substituted with halogen atoms include trifluoromethyl, pentafluoroethyl, perfluorobutyl, perfluorohexyl, and perfluorooctyl.

[0179] Examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, n-pentoxy, n-hexoxy, cyclohexoxy, n-heptoxy, n-octoxy, 2-ethylhexoxy, n-nonoxy, n-decoxy, 3,7-dimethyloctoxy, and dodecyloxy. Among these, methoxy, ethoxy, n-propoxy, isopropoxy, and n-butoxy are preferred.

[0180] There is no particular limitation on the number of halogen atoms in the alkoxy group that is replaced by a halogen atom.

[0181] Examples of alkoxy groups that are substituted with halogen atoms include trifluoromethoxy, pentafluoroethoxy, perfluorobutoxy, perfluorohexyloxy, perfluorooctoxy, methoxymethoxy, and 2-methoxyethoxy.

[0182] R and R 1 ~R 6 The aryl group can be unsubstituted. The aryl group can be substituted with a halogen atom. The aryl group can be substituted with an alkyl group that can be substituted with a halogen atom. The aryl group can be substituted with an alkoxy group that can be substituted with a halogen atom.

[0183] Examples of (unsubstituted) aryl groups include phenyl, 1-naphthyl, 2-naphthyl, 1-anthrayl, 2-anthrayl, 9-anthrayl, etc.

[0184] Aryl groups that are substituted with halogen atoms include, for example, pentafluorophenyl.

[0185] Aryl groups that can be substituted with alkyl groups that can be replaced by halogen atoms include, for example, C1-C12 alkylphenyl groups (“C1-C12” means having 1 to 12 carbon atoms. The same applies below).

[0186] Aryl groups that are substituted with alkoxy groups that can be replaced by halogen atoms include, for example, C1-C12 alkoxyphenyl groups.

[0187] An aryl group is a group of atoms obtained by removing one hydrogen atom from an aromatic hydrocarbon. Such aromatic hydrocarbons include aromatic hydrocarbons with fused rings, and aromatic hydrocarbons formed by the direct or intermediate bonding of two or more groups selected from an isolated benzene ring and / or a fused ring, such as vinylidene groups.

[0188] As R, hydrogen atom, halogen atom, alkyl group with 1 to 3 carbon atoms that can be replaced by halogen atom, alkoxy group with 1 to 3 carbon atoms that can be replaced by halogen atom, and hydrogen atom are more preferred.

[0189] As R 1 ~R 6Preferably, it contains hydrogen atoms, halogen atoms, alkyl groups with 1 to 3 carbon atoms that can be substituted by halogen atoms, alkoxy groups with 1 to 3 carbon atoms that can be substituted by halogen atoms, and more preferably alkyl groups with 1 to 3 carbon atoms that can be substituted by halogen atoms.

[0190] As X 11 ~X 15 X 21 ~X 25 X 31 ~X 35 and X 41 ~X 45 For example, the following combinations can be cited.

[0191] (i): X 11 X 13 X 21 X 23 X 31 X 33 X 41 and X 43 For N, and X 12 X 14 X 15 X 22 X 24 X 25 X 32 X 34 X 35 X 42 X 44 and X 45 For CR combinations.

[0192] (ii): X 12 X 14 X 22 X 24 X 32 X 34 X 42 and X 44 For N, and X 11 X 13 X 15 X 21 X 23 X 25 X 31 X 33 X 35 X 41 X 43 and X 45 For CR combinations.

[0193] (iii): X 11 X 15 X 21 X25 X 31 X 35 X 41 and X 45 For N, and X 12 X 13 X 14 X 22 X 23 X 24 X 32 X 33 X 34 X 42 X 43 and X 44 For CR combinations.

[0194] Among these, from the perspective of easily obtaining regular three-dimensional structures, the combination of (ii) is preferred.

[0195] That is, the compound represented by the above formula (1) is preferably the compound represented by the following formula (1-1).

[0196]

[0197] (In the above formula (1-1),

[0198] R can be a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0199] R 1 ~R 6 Each of these can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group (which can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom).

[0200] <<Method for manufacturing the compound represented by formula (1)>>

[0201] There are no particular limitations on the method of manufacturing the compound represented by formula (1). For example, a method of manufacturing it according to the synthetic reaction of the following scheme can be cited.

[0202]

[0203] (In formula (1A), Y) 1 ~Y 4 It is a halogen atom.

[0204] In equations (1A) and (1C), R 1 ~R6 R in equation (1) 1 ~R 6 The meaning is the same.

[0205] In equations (1B) and (1C), X 1 ~X 5 X in equation (1) 11 ~X 15 X 21 ~X 25 X 31 ~X 35 and X 41 ~X 45 (The meaning is the same.)

[0206] The synthetic reaction described above is the so-called Suzuki-Miyaura coupling reaction.

[0207] Examples of palladium catalysts used in the reaction include, for instance, [1,1'-bis(diphenylphosphine)ferrocene]palladium(II) dichloride (PdCl2(dppf)), tetra(triphenylphosphine)palladium (Pd(PPh3)4), bis(triphenylphosphine)palladium(Pd(PPh3)2Cl2), bis(benzylacetone)palladium (Pd(dba)2), tri(benzylacetone)dipalladium (Pd2(dba)3), bis(tri-tert-butylphosphine)palladium (Pd(Pt-Bu3)2), palladium acetate (Pd(OAc)2), and chloro[(tri-tert-butylphosphine)-2-(2-aminobiphenyl)]palladium(II) ((tBu3P)PdG2). These catalysts can be used with suitable ligands known to the public. The amount of catalyst used can be the so-called catalyst amount, which is preferably 20 mol% or less, and particularly preferably 10 mol% or less, relative to the compound represented by formula (1B). In addition, when using ligands, the amount used can be the so-called catalyst amount, which is preferably 20 mol% or less, and particularly preferably 10 mol% or less, relative to the compound represented by formula (1B).

[0208] In addition, bases can also be used in the above synthesis reactions. Examples of bases include hydroxides, alkoxides, fluoride salts, carbonates, phosphates, and fluoride salts.

[0209] Examples of hydroxides include sodium hydroxide, potassium hydroxide, and cesium hydroxide.

[0210] Examples of alkoxides include sodium tert-butoxide and potassium tert-butoxide.

[0211] Examples of fluoride salts include lithium fluoride, potassium fluoride, and cesium fluoride.

[0212] Examples of carbonates include lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0213] Examples of phosphates include, for instance, potassium phosphate.

[0214] Examples of amines include trimethylamine, triethylamine, diisopropylamine, n-butylamine, and diisopropylethylamine.

[0215] From the viewpoint of efficiently obtaining the target substance, the alkali is preferably a carbonate or phosphate, and more preferably potassium carbonate or cesium carbonate.

[0216] The amount of the above-mentioned base used is preferably 1 to 20 mol, more preferably 2 to 10 mol, relative to 1 mol of formula (1B).

[0217] As for the solvents used in the above-mentioned synthetic reactions, there are no particular limitations as long as they do not have an adverse effect on the reaction. Specific examples include aliphatic hydrocarbons, halogenated aliphatic hydrocarbons, aromatic hydrocarbons, ethers, amides, lactams, lactones, alcohols, urea derivatives, sulfoxides, and water.

[0218] Examples of aliphatic hydrocarbons include pentane, n-hexane, n-octane, n-decane, and decahydronaphthalene.

[0219] Examples of halogenated aliphatic hydrocarbons include chloroform, dichloromethane, dichloroethane, and carbon tetrachloride.

[0220] Examples of aromatic hydrocarbons include benzene, nitrobenzene, toluene, o-xylene, m-xylene, p-xylene, and mesitylene.

[0221] Examples of ethers include, for example, diethyl ether, diisopropyl ether, tert-butyl methyl ether, tetrahydrofuran (THF), and diethyl ether. Alkane, 1,2-dimethoxyethane, 1,2-diethoxyethane, etc.

[0222] Examples of amides include, for example, N,N-dimethylformamide (DMF) and N,N-dimethylacetamide.

[0223] Examples of lactams include, for example, N-methylpyrrolidone.

[0224] Examples of lactones include, for example, γ-butyrolactone.

[0225] Examples of alcohols include methanol, ethanol, and propanol.

[0226] Examples of urea derivatives include N,N-dimethylimidazolinone and tetramethylurea.

[0227] Examples of sulfoxides include, for example, dimethyl sulfoxide, sulfolane, and nitrile (acetonitrile, propionitrile, butyronitrile).

[0228] These can be used individually or in combination with two or more.

[0229] Regarding the amounts of the compound represented by formula (1A) and the compound represented by formula (1B), from the perspective of efficiently carrying out the cyclization reaction, the amount of the compound represented by formula (1B) is preferably 4 to 10 mol, more preferably 4.2 to 10 mol, relative to 1 mol of the compound represented by formula (1A).

[0230] The reaction temperature of the above synthesis reaction can be appropriately set within the range of the melting point to boiling point of the solvent, taking into account the type and amount of the raw material compounds and catalysts used. It is usually around 0 to 200°C, and preferably 20 to 100°C.

[0231] In addition, the reaction time of the above synthesis reaction varies depending on the raw material compounds used, the reaction temperature, etc., so it cannot be generalized and is usually about 1 to 72 hours.

[0232] The above synthesis reaction is preferably carried out in a reaction vessel under conditions where nitrogen is flowing through it.

[0233] <Methods for Manufacturing Metal-Organic Structures>

[0234] There are no particular limitations on the manufacturing method of metal-organic structures. Methods known as MOF preparation methods can be used, such as one-pot synthesis (e.g., self-assembly, solvothermal, microwave radiation, ionothermal, high-throughput synthesis, etc.), stepwise synthesis (e.g., precursor complex method, complex ligand method, in-situ stepwise synthesis, post-synthesis modification method, etc.), sonochemical synthesis, mechanochemical synthesis, etc.

[0235] Among these, the solvothermal method is preferred from the perspective of obtaining stable thermodynamic products.

[0236] The fabrication of metal-organic structures using the solvothermal method can be carried out, for example, by referring to the literature (Shi-Bin Ren, et al. CrystEngComm, 2009, 11, 1834-1836).

[0237] The following is an example of a method for manufacturing a metal-organic structure containing a compound represented by formula (1), copper, and iodine using a solvothermal method.

[0238] In the solvothermal method, for example, a mixture of the compound represented by formula (1), cuprous iodide (I), potassium iodide, and a solvent is heated. It should be noted that potassium iodide is used to improve the solubility of CuI in the solvent. Therefore, depending on the type of solvent and the type of ligand, potassium iodide may not be used.

[0239] The ratio of compound (L) represented by formula (1) to cuprous iodide (I) (CuI) when manufacturing metal-organic structures is not particularly limited, but is preferably 1:4 to 1:10 in molar ratio (L:CuI), and more preferably 1:4 to 1:6.

[0240] The amount of potassium iodide used in the manufacture of metal-organic structures is not particularly limited, but is preferably 10 to 100 moles relative to 1 mole of cuprous iodide (I), and more preferably 30 to 80 moles.

[0241] In the fabrication of metal-organic structures, modifiers may be used to promote crystallization as needed. Examples of modifiers include triphenylphosphine and pyridine. Hydrochloride, isoquinoline, etc.

[0242] The amount of the regulator used in the manufacture of metal-organic structures is not particularly limited, but is preferably 0.5 to 10 equivalents, more preferably 1 to 5 equivalents, relative to the compound represented by formula (1).

[0243] Examples of solvents include, but are not limited to, N,N-dimethylformamide (DMF), N,N-diethylformamide (DEF), acetonitrile, formic acid, acetic acid, methanol, ethanol, water, and mixtures of two or more of these solvents.

[0244] Among these, a mixed solvent of acetonitrile, ethanol and water is preferred.

[0245] There is no particular limit to the amount of solvent used when manufacturing metal-organic structures.

[0246] During heating, the raw material solution can be placed in any sealed container, or it can be heated while the raw material solution is being refluxed.

[0247] There is no particular limitation on the heating temperature. For example, from the viewpoint of improving reactivity, it can be above 100°C or above 120°C. In addition, from the viewpoint of preventing vapor leakage during the reaction, it can be below 150°C.

[0248] There is no particular limitation on the heating time, which can be adjusted appropriately according to the heating temperature. For example, from the viewpoint of complete reaction, the heating time can be more than 6 hours, more than 10 hours, more than 12 hours, more than 18 hours, more than 24 hours, more than 30 hours, more than 36 hours, more than 42 hours, more than 48 hours, more than 54 hours, or more than 60 hours. Alternatively, it can be less than 96 hours, less than 84 hours, less than 72 hours, less than 60 hours, less than 48 hours, less than 24 hours, less than 12 hours, or less than 10 hours.

[0249] In addition, after the reaction is complete, the obtained product can be appropriately post-processed.

[0250] As a post-processing step, the obtained product can be filtered, for example. Additionally, if necessary, a poor solvent can be added to the filter block obtained from filtration, and the mixture can be dispersed at room temperature or appropriately heated before filtration again. Here, the poor solvent can be a solvent that is not easily soluble in the target organometallic structure, such as water, acetonitrile, hexane, ethanol, dimethylformamide, etc. Furthermore, the heating temperature can be, for example, 40°C or higher, 50°C or higher, 60°C or higher, 70°C or higher, or 80°C or higher, or 100°C or lower, 90°C or lower, or 80°C or lower. The heating time can be, for example, 1 hour or more, 2 hours or more, 6 hours or more, 10 hours or more, or 12 hours or more, or 24 hours or less, or 16 hours or less.

[0251] Furthermore, the target metal-organic structure is obtained by appropriately drying the filter block obtained from filtration or re-filtration. Drying can be carried out under normal pressure or under reduced pressure; from the viewpoint of improving efficiency, drying under reduced pressure is preferred. The drying temperature can be, for example, 20°C or higher, 25°C or higher, 40°C or higher, 50°C or higher, or 60°C or higher, or 100°C or lower, 90°C or lower, 80°C or lower, or 60°C or lower. The drying time can be, for example, 1 hour or more, 2 hours or more, 6 hours or more, 10 hours or more, or 12 hours or more, or 24 hours or less or 16 hours or less.

[0252] <Uses>

[0253] There are no particular limitations on the use of metal-organic structures, but carbon dioxide capture agents are preferred from the perspective of excellent carbon dioxide capture performance.

[0254] In addition, carbon dioxide capture agents can be used in carbon dioxide storage systems that are capable of storing carbon dioxide.

[0255] Example

[0256] The following examples illustrate the present invention in detail, but the present invention is not limited to these examples.

[0257] <NMR Measurement Conditions>

[0258] 1 H-NMR spectrum (400MHz) and 13 C-NMR spectroscopy (400 MHz) was performed using a JEOL JNM-ECA400II. The sample was dissolved in deuterated chloroform (CDCl3) with added tetramethylsilane (TMS). Chemical shifts were determined using TMS as a reference (δ 0.0 ppm).

[0259] <Conditions for Single-Crystal X-ray Structure Analysis>

[0260] Single-crystal X-ray diffraction data for crystals of pyrimidine ligands (Lp) and crystals of the metal-organic structure [Cu4I4Lp] containing solvent (MeCN: acetonitrile) in fine pores were determined using Rigaku's VariMax with Saturn X-ray structure analysis system. The single crystals were cooled by nitrogen blowing at 123 K using a Rigaku GNNP cryogenic cooling system. The irradiation X-rays were MoKα rays extracted using a graphite monochromator. The detector was a two-dimensional CCD detector. The measured diffraction data were analyzed using Rigaku's software CrysAlisPro.

[0261] Single-crystal X-ray diffraction data of (i) metal-organic structure [Cu4I4Lp] crystals with solvent removed from the pores and (ii) metal-organic structure [Cu4I4Lp] crystals with CO2 trapped were determined in BL-5A of the Institute for Research on the Structure of Matter (IMSS) at the High Energy Accelerator Research Institute (KEK). The single crystals were cooled to 90 K using a Rigaku cryocooler and irradiated with synchrotron radiation. The diffraction pattern was detected using a Decrisris Pilatus 3S6M microscope. The measured diffraction data were integrated using XDS software. After the crystals that had captured CO2 were removed from the CO2 atmosphere and exposed to air, they were immediately immersed in oil for analysis.

[0262] <Gas Adsorption Measurement Conditions>

[0263] The adsorption-desorption isotherms related to the capture and desorption of nitrogen (77 K and 298 K) and carbon dioxide (273 K and 298 K) were determined using the Microtrac BEL fully automated gas adsorption assay apparatus BELSORP MAX. The sample was ground in a mortar, and approximately 60 mg was placed in a glass assay container and attached to the apparatus. The container was evacuated using a rotary pump and a turbomolecular pump, and the solvent within the pores was removed by heating at 473 K for 12 hours at below 1 kPa.

[0264] The adsorption capacity (gas capture amount) was determined directly using a constant-volume gas adsorption method without removing the container from the apparatus. This method involves introducing a certain volume of gas into the measuring container and calculating the adsorption capacity (gas capture amount) by detecting the pressure change of the gas. Adsorption isotherms were created by gradually increasing the amount of gas, and desorption isotherms related to gas removal were obtained by reducing the pressure through vacuum. After heating at 473 K for 2 hours below 1 kPa, the measuring container was removed from the apparatus, and the mass of the sample (adsorbate) after solvent removal was determined by weighing using a precision balance. The measuring temperature was maintained by filling a Dewar flask with liquid nitrogen at 77 K and circulating antifreeze filled with water in an open cooling circulator at 273 K or 298 K. The experimental results were analyzed using the BELMASTER analytical program. TM .

[0265] <Infrared Absorption Spectroscopy>

[0266] The infrared absorption spectrum was measured using a Thermo Fisher Scientific Fourier transform infrared spectrophotometer (Nicolet). TM iS TM The procedure was performed using a liquid nitrogen-cooled MCT-A detector and diffuse reflectance method. The sample was diluted with potassium bromide (KBr), and KBr was used as the background.

[0267] <X-ray Powder Diffraction (PXRD) Measurement>

[0268] X-ray powder diffraction measurements were performed using Rigaku's fully automated, multi-functional X-ray diffractometer, SmartLab. The powder sample was irradiated with CuK characteristic X-rays at room temperature. The diffraction pattern was detected while the sample was rotated using a D / teX Ultra(1D) detector.

[0269] <Elemental Analysis>

[0270] Elemental analysis was performed using Elementar's macroscopic organic elemental analysis apparatus, the vario MICRO cube.

[0271] (Example 1)

[0272] The synthesis of pyrimidine ligands (Lp) was carried out based on the following synthetic scheme.

[0273]

[0274] <Synthesis of 2,2',4,4',6,6'-hexamethyl-1,1'-biphenyl>

[0275] In a three-necked flask, 59 g (0.090 mol) of ferric(III) hexahydrate was added to 100 mL (0.18 mol) of mesitylene and stirred for 4 hours under a nitrogen atmosphere. The resulting reaction solution was quenched in ice water and transferred to a separatory funnel. The organic layer was removed, washed twice with water, and dried with sodium sulfate. It was then transferred to a 100 mL flask, and the mesitylene was distilled off under reduced pressure. If the residue after distillation was cooled with ice water, crystals precipitated. The crystals were collected by filtration, washed with acetone, and a pale yellow powder was obtained. The yield was 12%.

[0276] 1 H NMR (JEOL 400MHz CDCl3, TMS reference): δ 6.93 (s, 4H, Ha), 2.31 (s, 6H, Hb), 1.85 (s, 12H, Hc)

[0277]

[0278] <Synthesis of 3,3',5,5'-Tetraiodo-2,2',4,4',6,6'-Hexamethyl-1,1'-Biphenyl>

[0279] In a 300 mL flask containing 2,2',4,4',6,6'-hexamethyl-1,1'-biphenyl (2.0 g, 8.5 mmol), iodine (3.5 g, 13.6 mmol), and periodic acid (1.6 g, 6.8 mmol), a mixed solvent of acetic acid (120 mL), water (24 mL), and sulfuric acid (3.6 mL) was added, and the mixture was heated under reflux at 90 °C for 3 days. The resulting mixture was poured into water, and the solid precipitate was collected by vacuum filtration and washed with water. The pink solid was dissolved in chloroform (100 mL), and the solution was washed with a saturated sodium thiosulfate aqueous solution. Iodine was removed by separation. The organic layer was dried over magnesium sulfate, and the orange solid was obtained by vacuum drying. The solid was washed with ethyl acetate, and the target substance was obtained as a white powder by vacuum filtration. The yield was 71%.

[0280] 1 H NMR (JEOL 400MHz CDCl3, TMS reference): δ 3.03 (s, 6H, Ha), 2.03 (s, 12H, Hb)

[0281]

[0282] <Synthesis of (5,5',5”,5”'-(2,2',4,4',6,6'-hexamethyl-[1,1'-biphenyl]-3,3',5,5'-tetramethyl)tetrapyrimidine (synthesis of pyrimidine ligand (Lp)>

[0283] Add 3,3',5,5'-tetraiodo-2,2',4,4',6,6'-hexamethyl-1,1'-biphenyl (0.52 g, 0.70 mmol), 5-pyrimidineboronic acid (0.41 g, 3.3 mmol), tetra(triphenylphosphine)palladium (0.24 g, 0.22 mmol), and potassium carbonate (2.84 g, 21 mmol) to a 50 mL Schlenk tube. Repeat the process of vacuuming and nitrogen flow three times, replacing nitrogen in the reaction.

[0284] Degassed toluene (30 mL), ethanol (20 mL), and distilled water (10 mL) were added under nitrogen bubbling, and the mixture was heated to reflux at 80 °C for 2 days under nitrogen flow. The solvent was removed by drying under reduced pressure, allowing the solid to dissolve in chloroform and distilled water. The organic layer was separated by liquid-liquid chromatography and washed with saturated brine. The organic layer was dried over magnesium sulfate and then dried under reduced pressure to obtain the crude product. The crude product was dissolved in a small amount of chloroform and purified by silica gel column chromatography using ethyl acetate / triethylamine = 100 / 1 (v / v) as the developing solvent. The target analyte was obtained as a white powder in 69% yield.

[0285] 1 H NMR (JEOL 400MHz CDCl3, TMS reference): δ 9.25 (s, 4H, Ha), 8.64 (s, 8H, Hb), 1.75 (s, 6H, Hc), 1.72 (s, 12H, Hd).

[0286]

[0287] 13 C NMR (JEOL 400MHz CDCl3, TMS reference): δ 157.8 (A), 157.3 (B), 133.6–138.7 (CG), 20.0 (H), 18.9 (I)

[0288]

[0289] Elemental analysis calculated value [C 34 H 30 N8·0.25CH3COOC2H5]: C, 73.40; H, 5.63; N, 19.56.

[0290] Found: C, 73.40; H, 5.54; N, 19.34.

[0291] <Single Crystal X-ray Structure Analysis>

[0292] The pyrimidine ligand (Lp) was dissolved in chloroform in a vial, covered with Kimwipe lint-free paper, and allowed to evaporate the chloroform for half a day, thereby obtaining a single crystal of the pyrimidine ligand (Lp).

[0293] The single crystal structure was successfully resolved by diffraction using a miniature single-crystal X-ray structure resolution apparatus (Rigaku VariMax with Saturn). The results are shown in Table 1 below.

[0294] [Table 1]

[0295]

[0296] The X-ray structure analysis results of the single crystal were plotted. Figure 5A and Figure 5B As shown in the image. Figure 5A For unit lattice, Figure 5B It has the structure of a single molecule.

[0297] The single-crystal structure confirmed the presence of the target compound. Furthermore, the dihedral angles of the two central aromatic rings were measured, yielding 92.15°, indicating they are approximately orthogonal. This confirms the presence of a ligand with d-symmetry.

[0298] (Example 2)

[0299] <Synthesis of the organometallic structure [Cu4I4Lp]>

[0300] In a PTFE sample decomposition vessel containing pyrimidine ligand (Lp) (11 mg, 0.020 mmol), cuprous iodide (I) (19 mg, 0.10 mmol), potassium iodide (0.83 g, 5.0 mmol), and triphenylphosphine (5.2 mg, 0.020 mmol), acetonitrile (5.4 mL), distilled water (3.6 mL), and ethanol (1 mL) were added sequentially, and the mixture was heated in an oven at 140 °C for 64 hours. After heating, the mixture was slowly cooled in the oven for at least half a day before being removed. The precipitate was removed by filtration and washed with dimethylformamide, water, and acetonitrile to obtain yellow prismatic crystals. The solid in this state was a mixture. The solid was immersed in a liquid consisting of 4 mL of dichloromethane and 3 mL of dibromomethane, and only the precipitated crystals were removed to obtain the pure organometallic structure [Cu4I4Lp]. The yield, based on the ligand, was 58%.

[0301] Elemental analysis calculated value {Cu4I4[C]} 34 H 30N8(Lp)]·2.21(CH3CN)·1.17(C2H5OH)}: C, 33.53; H, 3.01; N, 9.75. Found: C, 33.53; H, 2.76; N, 9.75.

[0302] <Characteristics before solvent (acetonitrile) removal>

[0303] Acetonitrile was present in the pores of the newly synthesized metal-organic structure [Cu4I4Lp]. In this state, FT-IR, single-crystal X-ray diffraction, PXRD, and adsorption isotherm measurements were performed.

[0304] <<FT-IR Measurement>>

[0305] Using an FT-IR spectrophotometer (Nicolet) TM iS TM The solid crystals of the organometallic structure [Cu4I4Lp] were determined by 50FT-IR. The results are presented together with those for the pyrimidine ligand (Lp). Figure 6 It should be noted that this result is before the solvent (acetonitrile) is removed from the crystals.

[0306] A comparison of the IR spectra of the pyrimidine ligand (Lp) and the organometallic structure [Cu4I4Lp] showed that the network structure exhibited a high IR spectrum at 2200 cm⁻¹. -1 A new peak ([A]) was observed nearby. This is thought to be caused by the stretching motion of the C≡N bond, and is inferred to originate from acetonitrile entering the isolated space (pore).

[0307] <<Single Crystal X-ray Structure Analysis>>

[0308] The single crystal obtained by the above method was determined using a miniature single-crystal X-ray structure analyzer (Rigaku VariMax with Saturn), and the crystal structure was successfully resolved by diffraction. Details of the results are shown in Table 2. It should be noted that these results are before removing the solvent (acetonitrile) from the crystal.

[0309] [Table 2]

[0310]

[0311] The single-crystal X-ray structure analysis results of the obtained metal-organic structure [Cu4I4Lp] are shown in... Figures 7A-7B , Figures 8A to 8C and Figures 9A-9B .

[0312] The metal-organic linker [Cu4I4Lp], acting as a metal connector, is cubane-type. Both the cubane-type linker and ligand exhibit a four-coordinate diamond structure, resulting in a three-dimensional diamond structure overall. Additionally, disordered acetonitrile acts as a solvent within the fine pores. The packing structure is as follows... Figures 8A to 8C As shown, but without the solvent, it can be inferred that micropores exist at locations where the solvent is present. Furthermore, this structure forms an interpenetrating structure with two interpenetrating frames.

[0313] When calculating the size of the pores using CCDC's Mercury algorithm, the pores are at a size of... The spatial porosity is 12%. Furthermore, the pathway between this space and other spaces has a kinetic diameter similar to that of gaseous helium. The size is such that a sphere of a comparable diameter cannot pass through. Therefore, it can be considered that in the obtained metal-organic structure [Cu4I4Lp], there are no pathways for matter to pass through between the micropores and other micropores, or between the micropores and the outside. That is, the micropores of the obtained metal-organic structure [Cu4I4Lp] are isolated spaces. This is thought to be due to the large volume structure of the ligands and the interpenetrating structure of the two frameworks.

[0314] <<PXRD>>

[0315] X-ray powder diffraction (PXRD) measurements were performed on the metal-organic structure [Cu4I4Lp]. The results are presented below. Figure 10 It should be noted that this result is before the solvent (acetonitrile) is removed from the crystals.

[0316] PXRD pattern as Figure 10 As shown, the results are almost identical to simulations of the single-crystal structure obtained from Mercury using CCDC. No other peaks were observed, thus confirming the presence of a single-crystal structure.

[0317] <<Gas Adsorption Isotherms>>

[0318] Determine the adsorption isotherms related to gas capture in the metal-organic structure [Cu4I4Lp]. The results are presented below. Figure 11 It should be noted that this result is obtained after removing the solvent (acetonitrile) from the crystals. It should also be noted that the solvent was removed through the procedures performed during the gas adsorption assay (using a rotary pump and a turbomolecular pump to evacuate the container and heat at 473 K for 12 hours at below 1 kPa).

[0319] Based on the adsorption isotherm, it was observed that the metal-organic structure [Cu4I4Lp] did not capture nitrogen, but specifically captured CO2. Furthermore, a hysteresis phenomenon was observed in the capture and release of CO2.

[0320] Because the pores are only mediated by a kinetic diameter similar to that of gaseous helium. Since a sphere of comparable diameter cannot pass through the isolated space connected to the outside, it can generally be understood that nitrogen molecules with a kinetic diameter exceeding that of gaseous helium will not be captured. On the other hand, the capture and release of CO2 indicates that CO2 causes a change in the stereostructure of the metal-organic structure [Cu4I4Lp], creating a channel through which CO2 can pass.

[0321] <Characteristics after removing solvent (acetonitrile)>

[0322] After removing acetonitrile from the pores of the metal-organic structure [Cu4I4Lp], single-crystal X-ray structural analysis and FT-IR measurements were performed. It should be noted that the FT-IR results are interpreted using the characterization of the CO2-captured regions described later.

[0323] <<Methods for Removing Solvents>>

[0324] In the adsorption isotherm using BELSORP MAX, by heating at 200 °C for more than 12 h below 1 kPa, the powdered metal-organic structure [Cu4I4Lp] was confirmed to exhibit adsorption properties that capture gases, i.e., remove the solvent.

[0325] Therefore, to remove the solvent in the single-crystal state, one spatula of the metal-organic structure [Cu4I4Lp] single crystal was placed into a 10 mL ampoule, and the ampoule was evacuated for 1 hour using a rotary pump. The ampoule was then sealed under vacuum and heated in an oven at 240°C for 14 hours.

[0326] <<Single Crystal X-ray Structure Analysis>>

[0327] Measurements were taken at the BL-5A of the Experimental Facility for Radioactive Light (PF) at the Institute for the Science of the Structure of Matter (IMSS), High Energy Accelerator Research Organization (KEK). The ampoule was carried in a sealed container and immediately immersed in oil after being opened. Therefore, measurements were performed in air. Detailed results are shown in Table 3. It should be noted that these results are after removing the solvent (acetonitrile) from the crystals.

[0328] [Table 3]

[0329]

[0330] The crystal X-ray structure analysis results of the metal-organic structure [Cu4I4Lp] without acetonitrile are shown in the figure. Figure 12 .

[0331] Single-crystal X-ray structural analysis confirmed that the single crystal retained almost no solvent after vacuum heating. Furthermore, the point group of the crystal structure remained unchanged after solvent removal, and the lattice size also showed almost no change, thus confirming that the structure was maintained.

[0332] <Characteristics after CO2 capture>

[0333] After CO2 was adsorbed onto the metal-organic structure [Cu4I4Lp], single-crystal X-ray structure analysis and FT-IR determination were performed.

[0334] <<Methods for capturing CO2>>

[0335] CO2 capture was performed using BELSORP MAX. Two scraper-sized single crystals, with the solvent removed by vacuum heating, were added to the BELSORP assay vessel. Heating was performed at 200°C for 12 hours below 1 kPa, following the same procedure as for adsorption isotherm determination. After heating, the vessel was evacuated and CO2 was purged. The vessel was left to stand for one day with CO2 filling. The single crystals were then removed from the vessel and transferred to a 5 mL vial. CO2 was injected into the vial using a commercially available CO2 nebulizer, and the vial was immediately capped, thus preserving the crystals under high CO2 concentration.

[0336] <<Single Crystal X-ray Structure Analysis>>

[0337] Measurements were taken in BL-5A at the Institute for the Science of the Structure of Matter (IMSS), High Energy Accelerator Research Institute (KEK), at the Experimental Facility for Radioactive Light (PF). Measurements were performed one day after the crystal was transferred from the BELSORP measurement vessel to a vial. The single crystal was removed from the vessel and immediately immersed in oil before measurement. Detailed analysis results are shown in Table 4. It should be noted that these results are after CO2 capture.

[0338] [Table 4]

[0339]

[0340] The results of single-crystal X-ray structure analysis are shown in Figure 13 .

[0341] A linear electron density distribution, not observed after solvent removal, was detected in the corresponding pores. This distribution can be interpreted as CO2, indicating that CO2 was captured within the pores. Since the measurement was performed in air, it is assumed that the structure can capture CO2 even in the absence of a CO2 atmosphere.

[0342] <<FT-IR Measurement>>

[0343] The FT-IR spectrum of the metal-organic structure [Cu4I4Lp] after capturing CO2 is shown in... Figure 14 ([I]).

[0344] In addition, the FT-IR spectrum of the metal-organic structure [Cu4I4Lp] without acetonitrile and without CO2 capture is shown in... Figure 14 ([II]). The FT-IR spectrum was obtained by pounding a vacuum-heated metal-organic structure [Cu4I4Lp] single crystal into powder using a mortar, diluting it with KBr, and measuring it in air at room temperature.

[0345] In addition, Figure 6 The FT-IR spectrum before solvent (acetonitrile) removal is also shown. Figure 14 ([III]).

[0346] [I]: After capturing CO2

[0347] [II]: After vacuum heating

[0348] [III]: Before removing the solvent (acetonitrile)

[0349] The wavenumber of 2200 cm⁻¹ was confirmed before the removal of the solvent (acetonitrile) ([III]). -1 ~2300cm -1 Peak [A] disappeared after vacuum heating ([II]). It is believed that the peak originated from the solvent acetonitrile, indicating that the solvent in the pores was completely removed by vacuum heating. Based on this fact, the results are consistent with the analysis of the single-crystal X-ray crystal structure.

[0350] [A]: C≡N vibration (acetonitrile)

[0351] [B]: Asymmetric vibration of C=O(CO2)

[0352] Additionally, after capturing CO2, at 2300cm -1 ~2400cm -1 A new peak [B] appears (refer to [I]). This peak is believed to originate from CO2, indicating that the structure captures CO2, both in the structure and in the air. Furthermore, when the single crystal was placed in air for one week, the height of the CO2 peak gradually decreased but still persisted. This suggests that the structure continues to capture CO2 in the air.

Claims

1. A carbon dioxide scavenging agent containing a metal-organic structure. The metal-organic structure forms an interpenetrating structure with two interpenetrating frameworks. The metal-organic structure can capture carbon dioxide and also release it. Within the metal-organic structure, isolated spaces are formed by the three-dimensional structure of the metal-organic structure. The isolated space is a space capable of capturing carbon dioxide, and is a space that does not have channels through which carbon dioxide can pass under normal conditions. Although the three-dimensional structure of the metal-organic structure changes during the process of carbon dioxide being captured into the isolated space and during the process of carbon dioxide detaching from the isolated space, the three-dimensional structure of the metal-organic structure when carbon dioxide has been captured into the isolated space is the same as the three-dimensional structure of the metal-organic structure when carbon dioxide has not been captured into the isolated space. The metal-organic structure contains copper and iodine as constituent elements, and Cu4I4 exists in the cubane form in the metal-organic structure. The metal-organic structure contains a compound represented by the following formula (1) as a ligand. In the above formula (1), X 11 and X 13 For N and X 12 X 14 and X 15 For CR, or X 12 and X 14 For N and X 11 X 13 and X 15 For CR, or X 11 and X 15 For N and X 12 X 13 and X 14 For CR, X 21 and X 23 For N and X 22 X 24 and X 25 For CR, or X 22 and X 24 For N and X 21 X 23 and X 25 For CR, or X 21 and X 25 For N and X 22 X 23 and X 24 For CR, X 31 and X 33 For N and X 32 X 34 and X 35 For CR, or X 32 and X 34 For N and X 31 X 33 and X 35 For CR, or X 31 and X 35 For N and X 32 X 33 and X 34 For CR, X 41 and X 43 For N and X 42 X 44 and X 45 For CR, or X 42 and X 44 For N and X 41 X 43 and X 45 For CR, or X 41 and X 45 For N and X 42 X 43 and X 44 For CR, R can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group that can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom. R 1 ~R 6 Each of the following is independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted by a halogen atom, an alkoxy group that can be substituted by a halogen atom, or an aryl group that can be substituted by a halogen atom, an alkyl group that can be substituted by a halogen atom, or an alkoxy group that can be substituted by a halogen atom.

2. The carbon dioxide scavenging agent according to claim 1, wherein, The BET surface area of ​​the metal-organic structure measured using N2 was 1 m². 2 / g or less.

3. The carbon dioxide scavenging agent according to claim 1, wherein, In the metal-organic structure, the elements constituting the isolated space do not form chemical bonds with the carbon dioxide trapped in the isolated space.

4. The carbon dioxide scavenging agent according to claim 1, wherein, The compound represented by formula (1) is the compound represented by formula (1-1) below. In the above formula (1-1), R can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group that can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom. R 1 ~R 6 Each of the following is independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted by a halogen atom, an alkoxy group that can be substituted by a halogen atom, or an aryl group that can be substituted by a halogen atom, an alkyl group that can be substituted by a halogen atom, or an alkoxy group that can be substituted by a halogen atom.

5. The carbon dioxide scavenging agent according to claim 1, wherein, When the ligand is set to L, the composition of the metal-organic structure is represented by Cu4I4L.

6. A metal-organic structure comprising at least one of Group IIA to Group IVA elements as constitutive elements, and a compound represented by the following formula (1) as a ligand. The constituent elements include copper and iodine. In the aforementioned organometallic structure, Cu4I4 exists in the cubane form. In the above formula (1), X 11 and X 13 For N and X 12 X 14 and X 15 For CR, or X 12 and X 14 For N and X 11 X 13 and X 15 For CR, or X 11 and X 15 For N and X 12 X 13 and X 14 For CR, X 21 and X 23 For N and X 22 X 24 and X 25 For CR, or X 22 and X 24 For N and X 21 X 23 and X 25 For CR, or X 21 and X 25 For N and X 22 X 23 and X 24 For CR, X 31 and X 33 For N and X 32 X 34 and X 35 For CR, or X 32 and X 34 For N and X 31 X 33 and X 35 For CR, or X 31 and X 35 For N and X 32 X 33 and X 34 For CR, X 41 and X 43 For N and X 42 X 44 and X 45 For CR, or X 42 and X 44 For N and X 41 X 43 and X 45 For CR, or X 41 and X 45 For N and X 42 X 43 and X 44 For CR, R can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group that can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom. R 1 ~R 6 Each of the following is independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted by a halogen atom, an alkoxy group that can be substituted by a halogen atom, or an aryl group that can be substituted by a halogen atom, an alkyl group that can be substituted by a halogen atom, or an alkoxy group that can be substituted by a halogen atom.

7. The metal-organic structure according to claim 6, wherein, The compound represented by formula (1) is the compound represented by formula (1-1) below. In the aforementioned formula (1-1), R can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group that can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom. R 1 ~R 6 Each of the following is independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted by a halogen atom, an alkoxy group that can be substituted by a halogen atom, or an aryl group that can be substituted by a halogen atom, an alkyl group that can be substituted by a halogen atom, or an alkoxy group that can be substituted by a halogen atom.

8. The metal-organic structure according to claim 6, wherein, When the ligand is set to L, the composition is represented by Cu4I4L.

9. The metal-organic structure according to claim 6, wherein, The ligand is coordinated to the copper using one of the two nitrogen atoms of the pyrimidine ring of the ligand.

10. The metal-organic structure according to claim 6, wherein, When the ligand is set to L, the composition is represented by Cu4I4L. The ligand is coordinated to the copper using one of the two nitrogen atoms of the pyrimidine ring of the ligand.

11. A carbon dioxide scavenger comprising the metal-organic structure according to any one of claims 6 to 10.

12. A compound represented by the following formula (1), In the above formula (1), X 11 and X 13 For N and X 12 X 14 and X 15 For CR, or X 12 and X 14 For N and X 11 X 13 and X 15 For CR, or X 11 and X 15 For N and X 12 X 13 and X 14 For CR, X 21 and X 23 For N and X 22 X 24 and X 25 For CR, or X 22 and X 24 For N and X 21 X 23 and X 25 For CR, or X 21 and X 25 For N and X 22 X 23 and X 24 For CR, X 31 and X 33 For N and X 32 X 34 and X 35 For CR, or X 32 and X 34 For N and X 31 X 33 and X 35 For CR, or X 31 and X 35 For N and X 32 X 33 and X 34 For CR, X 41 and X 43 For N and X 42 X 44 and X 45 For CR, or X 42 and X 44 For N and X 41 X 43 and X 45 For CR, or X 41 and X 45 For N and X 42 X 43 and X 44 For CR, R can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group that can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom. R 1 ~R 6 Each of the following is independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted by a halogen atom, an alkoxy group that can be substituted by a halogen atom, or an aryl group that can be substituted by a halogen atom, an alkyl group that can be substituted by a halogen atom, or an alkoxy group that can be substituted by a halogen atom.

13. The compound according to claim 12, wherein it is a compound represented by the following formula (1-1), In the aforementioned formula (1-1), R can be independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted with a halogen atom, an alkoxy group that can be substituted with a halogen atom, or an aryl group that can be substituted with a halogen atom, an alkyl group that can be substituted with a halogen atom, or an alkoxy group that can be substituted with a halogen atom. R 1 ~R 6 Each of the following is independently a hydrogen atom, a halogen atom, an alkyl group that can be substituted by a halogen atom, an alkoxy group that can be substituted by a halogen atom, or an aryl group that can be substituted by a halogen atom, an alkyl group that can be substituted by a halogen atom, or an alkoxy group that can be substituted by a halogen atom.

Images