Metal organic framework and method for producing same

Abstract

Provided are a metal-organic framework suitably used as a functional material, and a method for manufacturing same, the metal-organic framework containing a cluster (α) and a cluster (β) as constituent units respectively, wherein the cluster (α) contains a metal ion (Mα ion) and ligands (ligands Lα) that coordinate with the Mα ion, the cluster (β) contains a cubane-type structure containing a metal ion (Mβ ion) as an essential component, and at least one of the ligands Lα is a polydentate ligand (ligand Lα 1) that also coordinates with the Mβ ion.

Description

[Technical Field]

[0001] The present invention relates to a metal-organic framework and a method for producing the same. [Background technology]

[0002] Metal-organic frameworks (MOFs) are compounds that have a coordination network structure constructed by coordination bonds between metal ions and multidentate ligands, as well as covalent bonds within the multidentate ligands. Some MOCs have relatively large internal voids, and therefore, such MOCs are expected to be used as functional porous materials for gas adsorption, gas storage, and gas separation.

[0003] In recent years, in order to improve the selectivity of molecular incorporation into the voids or to impart new functions to the molecular chains that constitute the coordination network structure (hereinafter sometimes referred to as "metal-organic polymer chains"), in addition to the first metal ion that maintains the coordination network structure, a second metal ion has been introduced into the metal-organic polymer chain.

[0004] For example, Non-Patent Document 1 discloses [Zn2(bpdc)2L] (bpdc = biphenyldicarboxylate, L = (R,R)-(-)-1,2-cyclohexanediamino-N,N'-bis(3-tert-butyl-5-(4-pyridyl)salicylidene)Mn III It has been reported that a metal-organic framework (MnOF) (a metal-organic polymer chain incorporating an active site containing a manganese ion) is useful as a catalyst for the asymmetric epoxidation of 2,2-dimethyl-2H-chromene.

[0005] In connection with the present invention, it is known that low molecular weight complexes containing a cubane structure have interesting properties as magnetic materials. For example, Non-Patent Document 2 describes Dy 3+ (dysprosium ion) and OH -This paper describes the molecular structures of two types of low-molecular-weight complexes, each containing a cubane-type structure ([Dy(μ-OH) structure)) with a Dy-O-Dy ion as a component, as well as the magnetic properties of these low-molecular-weight complexes. Non-Patent Document 2 also describes that although the cubane-type structures of these low-molecular-weight complexes are similar, slight differences in the Dy-O-Dy angles significantly affect the magnetic properties of the low-molecular-weight complexes. Conventionally, compounds containing rare earth elements have been used as luminescent materials and the like. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2018 / 079831 [Non-patent literature]

[0007] [Non-Patent Document 1] Fundamentals of Materials Chemistry No. 7 "Fundamentals of Porous Coordination Polymers (PCPs) / Metal-Organic Frameworks (MOFs)" (Sigma-Aldrich Japan LLC) [Non-patent document 2] Inorg.Chem.,2010,49,7549 Summary of the Invention [Problem to be solved by the invention]

[0008] As described above, a metal-organic framework having a metal-organic polymer chain into which a functional metal ion has been introduced is extremely useful as a functional material such as a catalyst material, a magnetic material, or a light-emitting material. Furthermore, as described in Non-Patent Document 2, investigating the relationship between the molecular structure and function of functional materials and obtaining new knowledge is important for improving functional materials. However, in order to clarify the molecular structure of a low-molecular-weight complex, in addition to the synthesis process of the low-molecular-weight complex, a crystallization process for obtaining a sample for single-crystal X-ray crystal structure analysis is essential. On the other hand, in the case of metal-organic frameworks, the obtained metal-organic frameworks can usually be used as samples for single-crystal X-ray crystal structure analysis as they are, and therefore functional materials composed of metal-organic frameworks are suitable for further functionalization.

[0009] Under these circumstances, an object of the present invention is to provide a metal organic framework containing a cubane structure that is suitable for use as a functional material, and a method for producing the same. [Means for solving the problem]

[0010] The present inventors have discovered that an ionic solid, which is formed by the accumulation of anionic polynuclear metal complexes to form a crystal lattice and in which cationic species exist in the gaps of the crystal lattice, is useful as an ionic conductor, etc., because the cationic species have high mobility (Patent Document 1). As a result of further investigations, the present inventors have found that the molecular structure of a polynuclear metal complex containing a plurality of metal ions and having an appropriate size, such as this anionic polynuclear metal complex, is also suitable as a partial structure of a metal organic framework containing a cubane structure, and have thus completed the present invention.

[0011] Thus, according to the present invention, there are provided the following metal-organic frameworks (1) to (14) and a method for producing a metal-organic framework (15). [1] A metal organic framework containing cluster (α) and cluster (β) as structural units, wherein the cluster (α) is a metal ion (M α ions), and M α The ligand that coordinates to the ion (ligand L α ), and the cluster (β) contains a metal ion (M β ion) as an essential component, and the ligand L α At least one of the species is M β Multidentate ligands that also coordinate to ions (ligand L α 1 ) is a metal-organic framework. [2] Cluster (α) is M αAs the ion, a divalent or trivalent metal ion (M α 1 ions) and monovalent or divalent metal ions (M α 2 ions). [3] M α 1 ions are ions of one metal selected from the group consisting of metals of groups 8, 9, and 10 of the periodic table, Cr, and Mn, α 2 The metal organic structure according to [2], wherein the ion is an ion of one metal selected from the group consisting of metals of Groups 11 and 12 of the periodic table. [4] Ligand L α 1 is represented by the following formula (1):

[0012] [ka]

[0013] In formula (1), T 1 is M α The first atom coordinated to the ion (coordinating atom t 1 ) or coordinate atom t 1 represents a group containing T 2 is M α The second atom that coordinates to the ion (coordinating atom t 2 ) or coordinate atom t 2 represents a group containing T 3 is M β Atoms coordinated to the ion (coordinating atoms t 3 ) or coordinate atom t 3 and G represents a linking group. 1 -GT 2 is the coordinated atom t 1 and the coordinate atom t 2 M α It is an atomic group that forms a five- or six-membered chelate ring by coordinating with an ion. [5] Ligand L α 1 The metal organic structure according to any one of [1] to [4], wherein [6] The metal organic structure according to any one of [1] to [5], wherein the cluster (α) is represented by the following formula (2):

[0014] [ka]

[0015] In formula (2), M α 1 represents a divalent or trivalent metal ion capable of forming a complex having an octahedral molecular structure with a coordination number of 6, and M α 2 represents a monovalent or divalent metal ion capable of forming a complex having a tetrahedral molecular structure with a coordination number of 4; L α 1 is M β It represents a multidentate ligand that also coordinates to ions, and E is H - , O 2- , S 2- , Se 2- , Te 2- , F - , Cl - , Br - or I - m is 0 or 1, and n is (M α 1 Valence × 4) + (M α 2 Valence × 4) + (L α 1 This number is calculated by (valence of E × 12) + (valence of E × m). [7] The metal organic structure according to any one of [1] to [6], wherein the aggregate of clusters (α) is derived from an anion part of an ion-flow-type ionic solid, and the ion-flow-type ionic solid is formed by the accumulation of metal ions and anionic polynuclear metal complexes containing multidentate ligands to form a crystal lattice, and cationic species are present in the gaps of the crystal lattice. [8] M βThe metal organic structure according to any one of [1] to [7], wherein the ions are ions of a d-block transition metal or ions of an f-block transition metal. [9] M β The metal organic structure according to any one of [1] to [8], wherein the ions satisfy the following requirements 1 and 2: Requirement 1: The metal ion is a monovalent, divalent, or trivalent metal ion capable of forming a complex with a polyhedral molecular structure having a coordination number of four or more. Requirement 2: The ionic radius is 70 to 120 pm.

[10] The metal organic structure according to any one of [1] to [9], wherein the cubane structure in the cluster (β) is a tetranuclear complete cubane structure or a trinuclear incomplete cubane structure.

[11] The metal organic structure according to any one of [1] to

[10] , wherein the cubane structure in the cluster (β) further contains a hydroxide ion as a constituent element.

[12] The metal organic structure according to any one of [1] to

[11] , wherein the cluster (β) is represented by the following formula (3):

[0016] [ka]

[0017] In formula (3), M β represents a metal ion constituting a cubane structure, and L β represents a carboxylate ligand, p is an integer of 0 to 10, q is an integer of 0 to 10 (provided that p+q≧1), and r is (M β Valence × 4) + (-1 × 4) + (L β It is a number calculated by multiplying the valence of the element by q.

[13] Ligand L α 1 has a carboxylate group, and the ligand L α 1 carboxylate group and M β The metal organic structure according to any one of [1] to

[12] , wherein a coordinate bond is formed between the metal organic structure and an ion.

[14] The metal-organic framework according to any one of [1] to

[13] , wherein the composition formula of the metal-organic framework is represented by the following formula (4):

[0018] [ka]

[0019] In formula (4), A represents a cation or an anion. β )4(OH)4(H2O) p (L β ) q} is a cation with valence r, and M β represents a metal ion constituting a cubane structure, and L β represents a carboxylate ligand, p is an integer of 0 to 10, and q is an integer of 0 to 10 (provided that p+q≧1). {(M α 1 )4(M α 2 )4(L α 1 ) 12 (E) m} is an n-valent anion, and M α 1 represents a divalent or trivalent metal ion capable of forming a complex having an octahedral molecular structure with a coordination number of 6, and M α 2 represents a monovalent or divalent metal ion capable of forming a complex having a tetrahedral molecular structure with a coordination number of 4; L α 1 is M β It represents a multidentate ligand that also coordinates to ions, and E is H - , O 2- , S 2- , Se 2- , Te 2- , F - , Cl - , Br - or I - m is 0 or 1. B represents a solvent molecule, and t is an integer of 20 to 100. y and z are each independently a number greater than 0 and equal to or less than 1, and x is a number that satisfies the relationship (valence of A × x) + (r × y) - (n × z) = 0.

[15] A method for producing a metal-organic framework having a cubane structure in a metal-organic polymer chain, the method comprising the step of bringing an ion-flow type ionic solid, in which metal ions and an anionic polynuclear metal complex containing a multidentate ligand are accumulated to form a crystal lattice, and cation species are present in the gaps of the crystal lattice, into contact with a solution containing ions of a d-block transition metal or ions of an f-block transition metal. [Effects of the Invention]

[0020] According to the present invention, there are provided a metal-organic framework containing a cubane structure that is suitable for use as a functional material, and a method for producing the same. [Brief explanation of the drawings]

[0021] [Figure 1] Figure 1 shows the molecular structure of cluster (α) [[Rh4Zn4(L-cys)12O]6-]. [Figure 2] FIG. 1 is a schematic diagram illustrating a cubane-type structure in cluster (β). [Figure 3] Figure 1 shows the molecular structure of cluster (β) [[Lu(OH)(HO)(OAc)]]. [Figure 4] FIG. 1 is a diagram showing the molecular structure of a metal-organic framework in which cluster (α) is [RhZn(L-cys)O] and cluster (β) is [Lu(OH)(HO)(OAc)]. [Figure 5] 1 shows powder X-ray diffraction patterns of the metal organic frameworks obtained in Examples 1 to 8. [Figure 6] FIG. 1 is a diagram showing a cubane structure in the metal-organic framework obtained in Examples 1 to 8. [Figure 7] FIG. 1 is a diagram showing the results of measuring the DC magnetic susceptibility of the metal organic frameworks obtained in Examples 2 to 8. [Figure 8] 12 is a graph showing the luminescence characteristics of the metal organic framework obtained in Example 12. [Figure 9]10 is a graph showing the magnetic refrigeration characteristics of the metal organic framework obtained in Example 8 (comparison of magnetic field change rates at 4 K). [Figure 10] 10 is a graph showing the magnetic refrigeration characteristics of the metal organic framework obtained in Example 8 (comparison based on the initial temperature at 2.2 T / min). DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, the present invention will be described in detail by dividing it into the sections of 1) a metal-organic framework and 2) a method for producing a metal-organic framework.

[0023] 1) Metal-organic framework The metal organic framework of the present invention is a metal organic framework containing a cluster (α) and a cluster (β) as constituent units, and the cluster (α) is a metal ion (M α ions), and M α The ligand that coordinates to the ion (ligand L α ), and the cluster (β) contains a metal ion (M β ion) as an essential component, and the ligand L α At least one of the species is M β Multidentate ligands that also coordinate to ions (ligand L α 1 ) is a metal organic framework.

[0024] As mentioned above, in this specification, some components of the present invention may be omitted. The omitted components are as follows: "M α "Ion" represents the metal ion in cluster (α). "Ligand L α " represents a ligand in cluster (α), and ligand L α Among them, M β Ligand L that also coordinates to ions α "Ligand L α 1 " is expressed as ". "M β"Ion" represents a metal ion that constitutes a cubane structure in cluster (β).

[0025] In the present invention, the term "cluster" refers to an atomic group formed by the accumulation of a plurality of metal ions and a plurality of ligands, which constitutes a structural unit of a metal organic framework. Furthermore, when explaining the present invention, the terms "cluster (α)" and "aggregate of clusters (α)" may be used. The former refers to a structural unit of the metal-organic framework (one cluster (α)), and the latter refers to an entity composed of all clusters (α) in the metal-organic framework (i.e., the "aggregate of clusters (α)" is a concept, and refers to what remains when elements other than cluster (α) are removed from the metal-organic framework). The same applies to "cluster (β)" and "aggregate of clusters (β)."

[0026] [Cluster (α)] The cluster (α) constituting the metal organic framework of the present invention is M α Ion and Ligand L α and the ligand L α At least one of the ligands L α 1 is.

[0027] M α Examples of ions include transition metal ions and metal ions of main group elements. Among these, M α The ions are preferably transition metal ions or ions of metals in Group 12 of the periodic table.

[0028] M included in cluster (α) α The number of ions is preferably 4 to 15, and more preferably 6 to 10. M included in cluster (α) α When the number of ions is small, the cluster (α) tends to be small, and the M contained in the cluster (α) αWhen the number of ions is large, the cluster (α) tends to become larger. Also, as the cluster (α) becomes larger, the distance between the centers of one cluster (α) and the neighboring cluster (α) tends to become longer. Therefore, an aggregate of clusters (α) consisting of large clusters (α) tends to have large spaces between the clusters (α).

[0029] From the viewpoint of accommodating the cluster (β) in the space generated between the clusters (α), it is preferable that the space generated between the clusters (α) is not too small. α 1 and M β From the viewpoint of forming coordinate bonds between ions, it is preferable that the space generated between the clusters (α) is not too large. M with 4 to 15 clusters (α) α By including ions, cluster (β) can be accommodated more stably in the space generated between clusters (α), and it becomes easier to obtain a more stable metal-organic framework having cluster (α) and cluster (β) as building blocks.

[0030] As will be described later, preferred examples of the molecular structure of cluster (α) include those similar to the molecular structure of anionic polynuclear metal complexes that constitute known ion-flux-type ionic solids (hereinafter, this anionic polynuclear metal complex may be referred to as "anionic polynuclear metal complex (α)." Examples of the anionic polynuclear metal complex (α) include the anionic heterometal complexes described in WO2018 / 079831 and WO2019 / 208753.). Since it is easy to obtain a cluster (α) with a molecular structure similar to that of the anionic polynuclear metal complex (α), the M contained in the cluster (α) α The number of ions is particularly preferably eight.

[0031] The phrase "the molecular structure of cluster (α) is similar to the molecular structure of anionic polynuclear metal complex (α)" means that the number of metal ions contained in cluster (α) and the anionic polynuclear metal complex (α) and the coordination type (chelate coordination, cross-linking coordination, etc.) of the ligands coordinated to these metal ions are the same, and the number of coordinating atoms coordinated to these metal ions is substantially the same (same except for the coordination of solvent molecules, etc.). Whether the molecular structures of two molecules are similar can be determined by single-crystal X-ray crystallography.

[0032] Cluster (α) is M α The ions may contain one type of metal ion or two or more types of metal ions. Since it is easy to obtain a cluster (α) with a molecular structure similar to that of the anionic polynuclear metal complex (α), M α It is preferable that the ions contain two types of metal ions.

[0033] When the cluster (α) contains two kinds of metal ions, the combination of the metal ions is preferably a divalent or trivalent metal ion (hereinafter referred to as M) that can form a complex having an octahedral molecular structure with a coordination number of 6. α 1 ions.) and monovalent or divalent metal ions (hereinafter referred to as M α 2 The combination of (Ions) is preferred. By using such a combination of metal ions, it becomes easier to obtain a cluster (α) having a molecular structure similar to that of the anionic polynuclear metal complex (α).

[0034] M α 1 The ionic radius of the ions is usually 60 to 90 pm, preferably 70 to 80 pm. M α 2 The ionic radius of the ions is usually 60 to 90 pm, preferably 70 to 75 pm. M α1 Ionic radius and M of ions α 2 When the ionic radius of the ion is within the above range, it becomes easier to obtain a cluster (α) having a molecular structure similar to that of the anionic polynuclear metal complex (α). In this specification, the ionic radii are values ​​that Shannon and Prewitt compiled based on actual measurements and that Shannon improved (Chemical Handbook, Basics, 5th Edition, II-887p, Table 16.35).

[0035] M α 1 The ions include ions of one metal selected from the group consisting of metals in groups 8, 9, and 10 of the periodic table, Cr, and Mn. Among these, the stable cluster (α) is easily formed, so M α 1 The ion is Rh 3+ , Ir 3+ , or Co 3+ is preferred, and Rh 3+ or Ir 3+ From the viewpoint of inexpensive raw materials, M α 1 The ions are Co 3+ is preferred.

[0036] M α 2 The ions include ions of one metal selected from the group consisting of metals in Groups 11 and 12 of the periodic table. Among these, Zn is the most suitable because it is the most stable cluster (α). 2+ , Cu + or Ag + is preferred, and Zn 2+ is more preferred.

[0037] M α 1 Ion and M α 2 Preferred combinations of ions (M α 1 Ion / Mα 2 ions) are (Rh 3+ / Zn 2+ ), (Rh 3+ / Cu + ), (Rh 3+ / Ag + ), (Ir 3+ / Zn 2+ ), (Co 3+ / Ag + ), (Co 3+ / Zn 2+ ) are mentioned.

[0038] Since it is easy to obtain a cluster (α) with a molecular structure similar to that of the anionic polynuclear metal complex (α), the cluster (α) is α 1 Contains four ions, M α 2 It is preferred to include four ions.

[0039] Ligand L α is M α There are no particular limitations as long as it can be coordinated to an ion. Ligand L α may be an electrically neutral ligand or an anionic ligand. In addition, the ligand L α has an asymmetric center, the ligand L α may consist of one kind of optical isomer or a mixture of plural kinds of optical isomers.

[0040] Examples of electrically neutral ligands include acyclic amines such as diethylamine and triethylamine; nitrogen-containing heterocycles such as pyrrole, pyridine, and imidazole; ethers such as tetrahydrofuran and diethyl ether; ketones such as acetone; phosphines such as triphenylphosphine; nitriles such as acetonitrile; and water molecules.

[0041] Examples of anionic ligands include hydride ions, hydroxide ions, oxide ions, sulfide ions, selenide ions, telluride ions, fluoride ions, chloride ions, bromide ions, iodide ions, cyanide ions, alkoxo ions such as methoxo ions, aryloxo ions such as phenoxo ions, and carboxylate ions such as acetate ions.

[0042] Ligand L α The ligand may be a multidentate ligand having one or more of the coordinating groups of these ligands. Examples of such multidentate ligands include diamines such as ethylenediamine, β-diketones such as acetylacetonate ion, picolinic acid ion, and amino acid ligands such as glycinate ion. Cluster (α) is a ligand L α One kind may be contained, or two or more kinds may be contained.

[0043] Ligand L contained in cluster (α) α The number is usually 5 to 30, preferably 8 to 20, more preferably 10 to 15, and particularly preferably 12 or 13. Ligand L contained in cluster (α) α When the number of ligands L contained in cluster (α) is small, cluster (α) tends to be small. α The larger the number of clusters, the larger the cluster (α) tends to be. As explained above, the size of the cluster (α) tends to affect the formation and stabilization of the cluster (β). Ligand L with 5 to 30 clusters (α) α By including the cluster (α) and the cluster (β), it becomes easier to obtain a stable metal-organic framework having the cluster (α) and the cluster (β) as building blocks.

[0044] Ligand L α At least one of the species is M β Multidentate ligands that also coordinate to ions (ligand L α 1 ) Ligand L α1 M α Ion and M β Ligand L coordinates with both metal ions and easily forms a stable metal organic framework. α 1 is preferably a di- to pentadentate ligand, more preferably a tridentate or tetradentate ligand. In particular, it is easy to obtain a cluster (α) with a molecular structure similar to that of the anionic polynuclear metal complex (α), so the ligand L α 1 is particularly preferably a tridentate ligand.

[0045] Ligand L α 1 Examples of the compound include those represented by the following formula (1).

[0046] [ka]

[0047] In formula (1), T 1 is M α The first atom coordinated to the ion (coordinating atom t 1 ) or coordinate atom t 1 represents a group containing T 2 is M α The second atom that coordinates to the ion (coordinating atom t 2 ) or coordinate atom t 2 represents a group containing T 3 is M β Atoms coordinated to the ion (coordinating atoms t 3 ) or coordinate atom t 3 and G represents a linking group. 1 -GT 2 is the coordinated atom t 1 and the coordinate atom t 2 M α It is an atomic group that forms a five- or six-membered chelate ring by coordinating with an ion.

[0048] T 1 is the coordinated atom t 1 If the coordinated atom t 1usually forms part of an anionic group together with the atoms in G. Similarly, T 2 is the coordinated atom t 2 If T 3 is the coordinated atom t 3 Even if the coordinated atom t 2 , coordinating atom t 3 usually forms part of an anionic group together with the atoms in G. Examples of such coordinating atoms include an oxygen atom constituting an alcoholate group and a sulfur atom constituting a thiolate group.

[0049] T 1 is the coordinated atom t 1 When T is a group containing 1 is usually an anionic group or an electrically neutral group, or a group that forms part of a coordinating structure together with the atoms in G. Similarly, T 2 is the coordinated atom t 2 In the case of a group containing T 3 is the coordinated atom t 3 In the case of a group containing 2 , T 3 is usually an anionic group or an electrically neutral group, or a group that forms part of a coordinating structure together with the atoms in G. T 1 , T 2 , T 3 (hereinafter referred to as “T 1 When T is an anionic group, 1 Examples of the alkyl group include a carboxylate group (the coordinating atom is an oxygen atom). T 1 etc. are electrically neutral groups, T 1 Examples of the group include an amino group (where the coordinating atom is a nitrogen atom) and a phosphino group (where the coordinating atom is a phosphorus atom). T 1 When the group T is a group that forms a part of a coordinating structure together with the atoms in G, 1 Examples of the alkyl groups include an alkoxy group (where the coordinating atom is an oxygen atom) that forms an ether structure, and an alkylthio group (where the coordinating atom is a sulfur atom) that forms a thioether structure.

[0050] The atoms constituting G include a hydrogen atom, a carbon atom, an oxygen atom, and a nitrogen atom. The number of atoms constituting G (excluding hydrogen atoms) is usually 2 to 15, preferably 2 to 10, and more preferably 2 to 5.

[0051] T 1 is preferably a coordinating atom that forms part of an anionic group together with the atom in G, and more preferably a sulfur atom that forms a thiolate group. T 2 is preferably an electrically neutral group, more preferably an amino group. T 3 is preferably an anionic group, more preferably a carboxylate group. T 1 , T 2 , T 3 When each of the groups is the above, it becomes easier to obtain a cluster (α) having a molecular structure similar to that of the anionic polynuclear metal complex (α).

[0052] Ligand L α 1 Examples of such ligands include amino acid ligands (as used herein, "amino acid ligands" includes not only those in which an amino acid with an overall charge of 0 functions as a ligand, but also those in which a protonated or deprotonated amino acid functions as a ligand). Ligand L α 1 When is an amino acid ligand, it is possible to efficiently form a cluster (α) having a molecular structure similar to that of the anionic polynuclear metal complex (α).

[0053] The amino acid ligand may be one represented by the following formula (5).

[0054] [ka]

[0055] In equation (5), R is T1 represents an amino acid side chain having 1 , r 2 , r 3 Each of —N(r 1 )(r 2 ) is T in Eq. (1) 2 (t 2 is a nitrogen atom), and -C(O)O - is T in Eq. (1). 3 (t 3 is an oxygen atom).

[0056] r 1 , r 2 , r 3 Examples of the alkyl group having 1 to 5 carbon atoms represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, a t-butyl group, and an isobutyl group. Since it is easy to obtain a cluster (α) with a molecular structure similar to that of the anionic polynuclear metal complex (α), 1 , r 2 , r 3 is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom.

[0057] Examples of the amino acid ligand include the following: 1 , r 2 , r 3 represents the same meaning as above.

[0058] [ka]

[0059] [ka]

[0060] [ka]

[0061] The ligands represented by formulas (5-1) to (5-5) are T 1 is a ligand that has a negative charge and can form a five-membered chelate ring. The ligands represented by formulas (5-6) and (5-7) are T 1 is a ligand that has a negative charge and can form a six-membered chelate ring. The ligand represented by formula (5-8) is T 1 is an electrically neutral ligand that can form a six-membered chelate ring.

[0062] Among these, ligands represented by formulas (5-1) to (5-7) are preferred because they are easy to obtain a cluster (α) with a molecular structure similar to that of the anionic polynuclear metal complex (α), and ligands represented by formulas (5-3), (5-4), and (5-6) are more preferred because they form a stable five- or six-membered ring together with the metal. An example of formula (5-3) is cysteine, an example of formula (5-4) is penicillamine, and an example of formula (5-6) is homocysteine.

[0063] Cluster (α) is a ligand L α 1 One kind may be contained, or two or more kinds may be contained. Ligand L contained in cluster (α) α 1 The number of is usually 8 to 24, preferably 8 to 16, and more preferably 12.

[0064] Cluster (α) may optionally contain a hydride ion (H - ), oxide ions (O 2- ), sulfide ions (S 2- ), selenide ion (Se 2- ), telluride ion (Te 2- ), fluoride ion (F - ), chloride ions (Cl - ), bromide ion (Br - ), and iodide ion (I - It is preferable that the compound contains a ligand (hereinafter, sometimes referred to as "ligand E") selected from the group consisting of

[0065] The ligand E is a relatively small anion. α Coordination to the ion may make the cluster (α) more stable. As the ligand E, an oxide ion, a sulfide ion, a chloride ion, or a bromide ion is preferred, and an oxide ion or a sulfide ion is more preferred, since this effect can be easily obtained.

[0066] An example of the cluster (α) is one represented by the following formula (2).

[0067] [ka]

[0068] In formula (2), M α 1 represents a divalent or trivalent metal ion capable of forming a complex having an octahedral molecular structure with a coordination number of 6, and M α 2 represents a monovalent or divalent metal ion capable of forming a complex having a tetrahedral molecular structure with a coordination number of 4; L α 1 is M β It represents a multidentate ligand that also coordinates to ions, and E is H - , O 2- , S 2- , Se 2- , Te 2- , F - , Cl - , Br - or I - m is 0 or 1, and n is (M α 1 Valence × 4) + (M α 2 Valence × 4) + (L α 1 This number is calculated by (valence of E × 12) + (valence of E × m).

[0069] M of cluster (α) represented by equation (2) α 1 , M α2 , L α 1 and E are as explained above. n is usually an integer of 4 to 14, and preferably an integer of 6 to 8.

[0070] The molecular structure of the cluster (α) represented by formula (2) may be similar to the molecular structure of the anionic polynuclear metal complex (α) (for example, the molecular structure shown in Figure 2 of WO2019 / 208753).

[0071] An example of the molecular structure of cluster (α) represented by formula (2) is [Rh4Zn4(L-cys) 12 O] 6- The molecular structure of (L-cys represents a ligand derived from L-cysteine; the same applies below) is shown in Figure 1. Figure 1(a) shows the metal-organic framework [Lu 0.33 [Lu4(OH)4(H2O)7(OAc)3][Rh4Zn4(L-cys) 12 From the results of crystal structure analysis of [RhZn(L-cys)], the cluster (α) part ([RhZn(L-cys) 12 O] 6- ) only. Figure 1(b) shows the structure of [Rh4Zn4(L-cys) 12 O] 6- is a schematic representation of the above. Figure 1(c) shows one [Rh4Zn4(L-cys) 12 O] 6- and this cluster (α) forms a coordinate bond with [Lu4(OH)4(H2O)7(OAc)3] 5+ This is a diagram showing the relationship between the cubane structure in the

[0072] As shown in Figure 1(a)-(c), [Rh4Zn4(L-cys) 12 O] 6- The carboxylate oxygen atom of the L-cysteine-derived ligand (L-cys) is not coordinated to the Rh or Zn ion, but is [Lu4(OH)4(H2O)7(OAc)3] 5+It can form coordinate bonds with the Lu ions in

[0073] The aggregate of clusters (α) constituting the metal organic framework of the present invention is formed by regularly arranging clusters (α). The aggregate of clusters (α) is preferably derived from the anion portion of the ion-flux type ionic solid.

[0074] The term "ionic solid" refers to a solid that contains cationic and anionic species as essential components. "Ion flow type ionic solid" refers to an ionic solid that has ion fluidity. Examples of ion flow type ionic solids include those in which anionic polynuclear metal complexes are accumulated to form a crystal lattice, and cationic species are present in the gaps of the crystal lattice. "Cation species are present in the gaps of the crystal lattice" refers to a state in which the anionic polynuclear metal complexes are bound to specific positions that form the crystal lattice, while the cationic species are present in free positions in the gaps of the crystal lattice. Because of this structure, this ion flow type ionic solid has cation exchange ability.

[0075] The metal ions that constitute the anionic polynuclear metal complexes include M α Examples of ions include those described above. The polydentate ligands constituting the anionic polynuclear metal complexes include the ligand L 1 Examples of the above include those similar to those described above.

[0076] Known complexes can be used as the anionic polynuclear metal complex, including, for example, the anionic heterometallic complexes described in WO2018 / 079831 and WO2019 / 208753.

[0077] Examples of cationic species that constitute the ion flow type ionic solid include metal ions. Specific examples of cation species include Li + , Na + , K. + , Rb+ , Cs + , Be 2+ , Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ , Ra 2+ Among these, Na is preferred because it can be used to more efficiently obtain the metal organic framework of the present invention. + , K. + , Rb + , Cs + , Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ is preferred, Na + or K + is more preferred.

[0078] As the ion flow type ionic solid, for example, the ionic solids described in WO2018 / 079831 and WO2019 / 208753 can be suitably used.

[0079] By using the anion part of the ion flow type ionic solid as the aggregate of cluster (α), it is possible to efficiently form the metal-organic polymer chain of the metal organic framework.

[0080] [Cluster (β)] The cluster (β) constituting the metal organic framework of the present invention is a metal ion (M β It contains a cubane structure that has cations as an essential component.

[0081] M β The ions include ions of d-block transition metals or ions of f-block transition metals. Specific examples of d-block transition metal ions include Sc 3+ , Co 2+ , Ni 2+ , Cu + , Y 3+ etc. Specific examples of f-block transition metal ions include La 3+ , Ce 3+ , Pr 3+, Nd 3+ , Pm 3+ , Sm 3+ ,EU 3+ , Gd 3+ , Tb 3+ , Dy 3+ , Ho 3+ , Er 3+ , Tm 3+ , Yb 3+ , Lu 3+ etc. Among these, when the metal organic framework of the present invention is used as a light-emitting material, Tb 3+ is preferable, and when used as a magnetic refrigeration material, Gd 3+ is preferred.

[0082] Since it is easy to obtain a more stable metal-organic framework with cluster (α) and cluster (β) as building blocks, M β The ions preferably satisfy the following requirements 1 and 2. Requirement 1: The metal ion is a monovalent, divalent, or trivalent metal ion capable of forming a complex with a polyhedral molecular structure having a coordination number of four or more. Requirement 2: The ionic radius is 70 to 120 pm.

[0083] M β When the ions satisfy requirement 1, a more stable cubane structure is more likely to be formed. M β When the ions satisfy requirement 2, clusters (β) of an appropriate size are formed, and a more stable metal-organic framework can be obtained.

[0084] M included in cluster (β) β The number of ions is usually three or four. The cluster (β) may have a metal ion that does not form a cubane structure. The total number of metal ions contained in the cluster (β) is preferably 3 to 10, more preferably 3 to 6.

[0085] As mentioned above, cluster (β) occupies the space between clusters (α). Cluster (β) also has M β Ion and Ligand L α 1 By forming a coordinate bond with the metal-organic polymer, the metal-organic framework becomes a part of the metal-organic polymer chain. When the cluster (β) contains 3 to 10 metal ions, it becomes easier to obtain a stable metal organic framework having the cluster (α) and the cluster (β) as building blocks.

[0086] The cubane structure in cluster (β) includes a tetranuclear complete cubane structure and a trinuclear incomplete cubane structure. A schematic diagram of a tetranuclear complete cubane structure is shown in Figure 2(a). Among the eight vertices of the hexahedron, M β A complete cubane structure is formed when a metal ion occupies the position indicated by and the remaining vertices are occupied by monoatomic bridging ligands (ligands that bridge two or more metal ions, such as hydroxide ions or oxide ions, with one atom). Although the hexahedron shown in FIG. 2(a) is a cube, the tetranuclear complete cubane structure may be expressed by a hexahedron other than a cube.

[0087] A schematic diagram of a trinuclear incomplete cubane structure is shown in Figure 2(b). The trinuclear incomplete cubane structure is formed by removing one metal ion and the monoatomic bridging ligand that was coordinated to that metal ion from a tetranuclear complete cubane structure.

[0088] The single-atom bridging ligand that constitutes the cubane structure in cluster (β) is a hydroxide ion (OH - ), oxide ions (O 2- ), alkoxo ions (RO - , R represents an alkyl group.), sulfide ions (S 2- Among these, hydroxide ions are preferred.

[0089] As the cubane structure, a tetranuclear complete cubane structure is preferred because the cluster (β) is more stabilized. M β When the ions satisfy the following requirements 1' and 2', a cluster (β) having a tetranuclear complete cubane structure is easily formed. Requirement 1': The metal ion is a divalent or trivalent metal ion capable of forming a complex having a polyhedral molecular structure with a coordination number of 5 to 8. Requirement 2': The ionic radius is 75 to 115 pm.

[0090] Cluster (β) may contain ligands other than the monoatomic bridging ligands that constitute the cubane structure. Ligands other than the single-atom bridging ligands that constitute the cubane structure include the ligand L α (excluding the above-mentioned single atom bridging ligands). M β When the coordination number of the ion is large (for example, the coordination number is 7 or 8), a more stable cluster (β) is likely to be obtained, and therefore, cluster (β) preferably has a carboxylate ligand. Examples of the carboxylate ligand include acetate ions, propionate ions, and benzoate ions. The carboxylate ligand has an M of 2 or more. β It may also function as a bridging ligand that bridges between ions.

[0091] An example of the cluster (β) is one represented by the following formula (3).

[0092] [ka]

[0093] In formula (3), M β represents a metal ion constituting a cubane structure, and L 2 represents a carboxylate ligand, p is an integer of 0 to 10, q is an integer of 0 to 10 (provided that p+q≧1), and r is (M βValence × 4) + (-1 × 4) + (L 2 It is a number calculated by multiplying the valence of the element by q.

[0094] M of cluster (β) represented by equation (3) β , and L 2 are as explained above. r is usually an integer of 4 to 6.

[0095] An example of the molecular structure of cluster (β) represented by formula (3) is [Lu4(OH)4(H2O)7(OAc)3] 5+ The molecular structure of is shown in Figure 3. Figure 3(a) shows the metal-organic framework (Lu 0.33 [Lu4(OH)4(H2O)7(OAc)3][Rh4Zn4(L-cys) 12 From the crystal structure analysis of the cluster (β) part ([Lu4(OH)4(H2O)7(OAc)3] 5+ ) only. Figure 3(b) shows [Lu4(OH)4(H2O)7(OAc)3] 5+ is a schematic representation of the above.

[0096] As shown in Figure 3(a) and (b), [Lu4(OH)4(H2O)7(OAc)3] 5+ has a tetranuclear full cubane structure consisting of four Lu ions and four hydroxo ions, with acetate ions acting as bridging ligands between two Lu ions. Although not shown in Figure 3, one [Lu4(OH)4(H2O)7(OAc)3] 5+ Around it are three [Rh4Zn4(L-cys) 12 O] 6- The carboxylate group of the cysteine ​​ligand contained in these bridges two Lu ions, just like the acetate ion mentioned above [Fig. 1(c)].

[0097] [Metal-organic structure] The metal organic framework of the present invention contains the cluster (α) and the cluster (β) as structural units, and the ligand L in the cluster (α) α 1 The metal ions (M β It is also coordinated to the cation.

[0098] Ligand L α 1 But, M α Ion and M β By bridging the ions, a stable metal-organic framework is formed. Ligand L α 1 has a carboxylate group, the ligand L α 1 The carboxylate group of M β It is preferably coordinated to the ion. β When the coordinating group that coordinates with the ion is a carboxylate group, a more stable metal organic framework is more easily formed.

[0099] As mentioned above, the size of the cluster (α) usually affects the size of the space between the clusters (α), and the size of the space between the clusters (α) also affects the stability of the cluster (β). Therefore, the metal ions (M α ion) and ligand L α It is preferable to stabilize the cluster (β) by adjusting the number and type of the clusters and optimizing the size of the cluster (α).

[0100] When the cluster (α) is formally represented as a single sphere, taking into account the spread of the atoms constituting the cluster (α), the diameter of such a sphere (hereinafter sometimes referred to as "sphere (α)") is usually 1.0 to 3.0 nm, preferably 1.2 to 2.0 nm. The diameter of the sphere (α) can be calculated based on the results of single crystal X-ray crystal structure analysis. For example, if cluster (α) has the molecular structure shown in Figure 1, the atom located farthest from the center of cluster (α) is the oxygen atom of a carboxylate group, and therefore the longest distance between an oxygen atom of one carboxylate group and an oxygen atom of another carboxylate group can be assumed to be the diameter of sphere (α). Specifically, with regard to the metal organic framework obtained in the examples described below, [Rh4Zn4(L-cys) 12 O] 6- The diameter of the sphere (α) corresponding to [Ir4Zn4(L-cys) 12 O] 6- The diameter of the corresponding sphere (α) is 1.550 nm.

[0101] Diameter of the sphere (α) and M β The ratio of the ion radius (sphere (α) / M β ion] is usually 14.0 to 19.0, preferably 14.2 to 18.5, and more preferably 14.6 to 17.3. β When the value of the ion radius ratio is within the above range, a more stable metal organic framework can be easily obtained.

[0102] As described above, the metal ions (M α ion) and ligand L α The size of the cluster (α) can be changed by adjusting the number and type of For example, the anionic heterometallic complex [[Rh4Ag4(L-cys) 12 ] 8- The diameter of the sphere (α) was calculated to be 1.567 nm. Therefore, the cluster (α) derived from this anionic heterometallic complex has a larger M β It is expected to be suitable for stabilizing metal-organic frameworks containing ions.

[0103] The composition formula representing the metal organic framework is represented by the following formula (4).

[0104] [ka]

[0105] In formula (4), A represents a cation or an anion. β )4(OH)4(H2O) p (L β ) q} is a cation with valence r, and M β represents a metal ion constituting a cubane structure, and L β represents a carboxylate ligand, p is an integer of 0 to 10, and q is an integer of 0 to 10 (provided that p+q≧1). {(M α 1 )4(M α 2 )4(L α 1 ) 12 (E) m} is an n-valent anion, and M α 1 represents a divalent or trivalent metal ion capable of forming a complex having an octahedral molecular structure with a coordination number of 6, and M α 2 represents a monovalent or divalent metal ion capable of forming a complex having a tetrahedral molecular structure with a coordination number of 4; L α 1 is M β It represents a multidentate ligand that also coordinates to ions, and E is H - , O 2- , S 2- , Se 2- , Te 2- , F - , Cl - , Br - or I - m is 0 or 1. B represents a solvent molecule, and t is an integer of 20 to 100. y and z are each independently a number greater than 0 and equal to or less than 1, and x is a number that satisfies the relationship (valence of A × x) + (r × y) - (n × z) = 0.

[0106] {(M β )4(OH)4(H2O) p (Lβ ) q} and {(M α 1 )4(M α 2 )4(L α 1 ) 12 (E) m} is as explained above. When A is a cation, such A is Li + , Na + , K. + , Rb + , Cs + , Be 2+ , Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ , Ra 2+ , Co 2+ , Ni 2+ ,Sc. 3+ , Y 3+ , La 3+ , Ce 3+ , Pr 3+ , Nd 3+ , Pm 3+ , Sm 3+ ,EU 3+ , Gd 3+ , Tb 3+ , Dy 3+ , Ho 3+ , Er 3+ , Tm 3+ , Yb 3+ , Lu 3+ etc. When A is an anion, such A may be O 2- , S 2- , Se 2- , Te 2- , F - , Cl - , Br - , I - , O.H. - , OAc - (acetate ion), etc. B is a solvent molecule used in the synthesis. Examples of B include water, alcohols such as methanol and ethanol, ketones such as acetone, ethers such as diethyl ether and tetrahydrofuran, nitriles such as acetonitrile, and halogenated hydrocarbons such as chloroform.

[0107] As an example of the molecular structure of the metal organic framework having the composition formula represented by formula (4), the cluster (α) is [Rh4Zn4(L-cys) 12 O] 6- and cluster (β) is [Lu4(OH)4(H2O)7(OAc)3] 5+ The molecular structure of the metal-organic framework is shown in Figure 4.

[0108] FIG. 4(a) is a diagram showing the packing structure of a crystal of a metal-organic framework. Figure 4(b) is a schematic diagram of a metal-organic framework crystal. [Rh4Zn4(L-cys) 12 O] 6- is represented by a pink sphere, and [Lu4(OH)4(H2O)7(OAc)3] 5+ is represented by an orange sphere. Figure 4(c) shows one [Rh4Zn4(L-cys) 12 O] 6- and the three surrounding [Lu4(OH)4(H2O)7(OAc)3] 5+ This is a diagram showing how coordinate bonds are formed. Figure 4(d) shows one [Lu4(OH)4(H2O)7(OAc)3] 5+ and the three surrounding [Rh4Zn4(L-cys) 12 O] 6- This is a diagram showing how coordinate bonds are formed.

[0109] As shown in Figure 4(a)-(d), this metal-organic framework is [Lu4(OH)4(H2O)7(OAc)3] 5+ and [Rh4Zn4(L-cys) 12 O] 6- The metal-organic polymer chain is formed by a coordinate bond between the metal and the organic compound.

[0110] The metal organic framework of the present invention has a metal ion (M β It has a cubane structure with cations as essential components. Therefore, the metal organic framework of the present invention can be suitably used as a magnetic material such as a magnetic refrigeration material, a light-emitting material, a catalytic material, or other functional material.

[0111] Magnetic refrigeration materials are substances that exhibit the magnetic refrigeration effect. The magnetic refrigeration effect is a cooling method that utilizes the change in entropy caused by a magnetic field. In other words, when a magnetic field is applied to a magnetic refrigeration material, the magnetic moments caused by unpaired electrons in atoms (ions) are regularly aligned in the direction of the magnetic field lines, and the decrease in entropy is released as heat. On the other hand, when the magnetic field is removed from the magnetic refrigeration material, the direction of the magnetic moments becomes irregular, and entropy increases, causing the temperature of the magnetic refrigeration material to decrease in an adiabatic state. By utilizing this cycle, the surrounding area can be cooled efficiently.

[0112] in general, 4 When He is used as a refrigerant, extremely low temperatures of about 2 K can be achieved. The metal organic framework of the present invention is suitable for use as a magnetic refrigeration material under such cryogenic conditions. That is, the cluster (β) constituting the metal organic framework of the present invention contains a cubane structure, but when metal ions having unpaired electrons form the cubane structure, spin-spin interactions are unlikely to occur. Therefore, in the metal organic framework of the present invention, magnetic entropy change due to magnetic field manipulation is large mainly in the temperature range of about 2 K or less, making it suitable as a magnetic refrigeration material under the above-mentioned cryogenic conditions. Furthermore, in the metal-organic framework of the present invention, the cubane structure is stabilized and is regularly aggregated, which is also thought to have a favorable effect on the magnetic refrigeration effect.

[0113] When the metal organic framework of the present invention is used as a magnetic refrigeration material, the metal ions contained in the cubane structure are Gd 3+ The ion is preferred. 3+ Ions have a large spin quantum number and a high maximum spin degree of freedom, which means that they are highly responsive to magnetic fields and have a large magnetic entropy change, making it easier to obtain magnetic refrigeration materials with greater cooling capacity.

[0114] 2) Method for manufacturing metal-organic structures The method for producing a metal organic framework of the present invention is a method for producing a metal organic framework having a cubane structure in a metal-organic polymer chain, and comprises a step of bringing an ion-flow type ionic solid, in which metal ions and anionic polynuclear metal complexes containing multidentate ligands are accumulated to form a crystal lattice and cationic species are present in the gaps of the crystal lattice, into contact with a solution containing ions of a d-block transition metal or ions of an f-block transition metal.

[0115] Examples of the ion flow type ionic solid include those similar to those previously mentioned in the description of the metal organic framework invention. Examples of ions of d-block transition metals and ions of f-block transition metals include those similar to those previously described in the description of the metal organic framework invention.

[0116] A solution containing ions of a d-block transition metal or ions of an f-block transition metal can be prepared by dissolving a salt of an ion of a d-block transition metal or a salt of an ion of an f-block transition metal in a suitable solvent. The anions contained in these salts are F - , Cl - , Br - , I - , OAc - , NO3 - , SO4 2- etc.

[0117] The solvent of the solution containing metal ions for forming a cubane structure is not particularly limited as long as it does not dissolve the ion-flowing ionic solid or the metal-organic framework of the present invention. A mixed solvent may be used to adjust the solubility of the ion-flowing ionic solid or the metal-organic framework. Specific examples of the solvent to be used include water; alcohols such as methanol, ethanol, propyl alcohol, and isopropyl alcohol; and mixed solvents of water and alcohols.

[0118] In the step of contacting the ion flow type ionic solid with the solution containing metal ions for forming a cubane structure, the contacting procedure, contact time and contact temperature are not particularly limited. For example, the metal organic framework of the present invention can be obtained by immersing an ion-flow type ionic solid in a solution containing metal ions for forming a cubane structure and leaving it to stand at around room temperature (for example, 5 to 25°C) for one day to one month, preferably about one week. [Example]

[0119] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0120] [Synthesis example 1] K6[Rh4Zn4(L-cys) 12 Synthesis of [O]·47.5HO According to the method described in Example 1 of WO2019 / 208753, K6[Rh4Zn4(L-cys) 12 O]·47.5HO (hereinafter referred to as "ion-flowing ionic solid (1)"). The ion flow type ionic solid (1) was a yellow solid.

[0121] [Synthesis example 2] K6[Ir4Zn4(L-cys) 12 Synthesis of [O]·40H2O K6[Ir4Zn4(L-cys)3] was prepared in the same manner as in Synthesis Example 1, except that Δ-H3[Ir(L-cys)3] was used instead of Δ-H3[Rh(L-cys)3].12 O]·40H2O (hereinafter referred to as "ion-flowing ionic solid (2)").

[0122] [Synthesis Example 3] K8[Rh4Ag4(L-cys) 12 Synthesis of ]·nH2O In Example 1 of WO2018 / 079831, except that potassium hydroxide was used instead of lithium hydroxide, K8[Rh4Ag4(L-cys) 12 ]·nH2O (hereinafter referred to as "ion-flowing ionic solid (3)").

[0123] Ion fluidity solids other than these can also be produced by referring to, for example, WO2019 / 208753 and WO2018 / 079831.

[0124] The metal organic frameworks obtained in the following examples were each subjected to the following analyses. [X-ray fluorescence analysis] The measurement sample was introduced into a polytetrafluoroethylene sample cell covered with a Mylar film, and subjected to X-ray fluorescence analysis under vacuum using an energy dispersive X-ray fluorescence analyzer (Shimadzu Corporation, EDX-7000). From the obtained intensities of Ln, Zn, and K, the number of lanthanoid atoms relative to the number of zinc atoms (Ln / Zn) and the number of potassium atoms relative to the number of zinc atoms (K / Zn) were calculated. Since the number of zinc atoms contained in the cluster (α) of the metal-organic framework synthesized in the examples is 4, if Ln / Zn is a value around 1, the metal-organic framework is expected to have a tetranuclear cubane structure equivalent to that of the cluster (α). Furthermore, the K / Zn value indicates the extent to which a structure similar to the ion-flux type ionic solid of the starting material remains. In addition, for the "metal organic framework having a cubane structure" obtained in the examples described below, fluorescent X-ray analysis was performed on the product in all examples, and the analysis results were used to determine the composition.

[0125] [Powder X-ray diffraction] A powder sample was introduced into a capillary tube, which was then sealed. The capillary tube was rotated and irradiated with X-rays to obtain a powder X-ray diffraction pattern. The measurement was performed using a powder X-ray diffractometer equipped at SPring-8 BL02B2 (λ=1.0 Å, detector: MYTHEN microstrip X-ray detector, manufactured by Dectris). If a sharp diffraction pattern is observed, it is clear that the solid has crystallinity. In particular, with regard to the metal organic frameworks obtained in the examples, when the peak originating from the (111) plane, which appears around 2θ=4°, is smaller than the peak originating from the (200) plane, which appears around 2θ=5°, it suggests that a cubane structure is formed. The measurement results for the metal organic frameworks obtained in Examples 1 to 8 are shown in FIG.

[0126] [Single-crystal X-ray crystallography] The metal-organic framework was subjected to single-crystal X-ray crystallography under a nitrogen gas flow adjusted to a temperature of 100K. The measurement equipment used was a single crystal X-ray diffractometer (λ=0.62997 Å, detector: MX225HS, Rayonic) installed at BL-2D of the Pohang Accelerator Laboratory (PAL, Pohang, Korea). The cubane structure in the metal organic framework obtained in Examples 1 to 8 is shown in FIG. It should be noted that, with regard to the "metal organic frameworks having a cubane structure" obtained in the following examples, those obtained in examples other than Examples 1 to 8 were also subjected to single crystal X-ray crystal structure analysis to confirm their structures.

[0127] Example 1 100 mg of the ion-flowing ionic solid (1) was immersed in 20 mL of a 0.02 M lutetium acetate (Lu(OAc)3) solution (water / ethanol (v / v = 1 / 3)) and allowed to stand. After one week, the supernatant was removed by decantation, and the remaining yellow solid was immersed in 20 mL of a 0.1 M lutetium acetate aqueous solution and allowed to stand for another week. The solid was then collected by filtration and dried to give a yield of 100 mg (90%). The results of X-ray fluorescence analysis, powder X-ray diffraction, and single-crystal X-ray crystal structure analysis showed that the obtained solid was a metal-organic framework with a cubane structure [Lu 0.33 [{Lu4(OH)4(H2O)7(OAc)3}{Rh4Zn4(L-cys) 12 O}·nH2O).

[0128] Example 2 A metal organic framework having a cubane structure [Yb 0.33 [{Yb4(OH)4(H2O)7(OAc)3}{Rh4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0129] Example 3 A metal organic framework having a cubane structure [Tm 0.33 [{Tm4(OH)4(H2O)7(OAc)3}{Rh4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0130] Example 4 A metal organic framework having a cubane structure [Er(OAc)3] was prepared in the same manner as in Example 1, except that an erbium acetate [Er(OAc)3] solution [water / ethanol (v / v=1 / 3)] was used instead of the lutetium acetate solution in Example 1.0.33 [{Er4(OH)4(H2O)7(OAc)3}{Rh4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0131] Example 5 A metal organic framework having a cubane structure [Ho(OAc)3] was prepared in the same manner as in Example 1, except that a holmium acetate [Ho(OAc)3] solution [water / ethanol (v / v=1 / 3)] was used instead of the lutetium acetate solution in Example 1. 0.33 [{Ho4(OH)4(H2O)7(OAc)3}{Rh4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0132] Example 6 A metal organic framework having a cubane structure [Dy(OAc)3] was prepared in the same manner as in Example 1, except that a dysprosium acetate [Dy(OAc)3] solution [water / ethanol (v / v=1 / 3)] was used instead of the lutetium acetate solution in Example 1. 0.33 [{Dy4(OH)4(H2O)7(OAc)3}{Rh4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0133] Example 7 A metal organic framework having a cubane structure [Tb 0.33 [{Tb4(OH)4(H2O)7(OAc)3}{Rh4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0134] Example 8 A metal organic framework having a cubane structure [Gd 0.33 [{Gd4(OH)4(H2O)7(OAc)3}{Rh4Zn4(L-cys)12 O}·nH2O] was obtained.

[0135] Example 9 100 mg of the ion-flow ionic solid (1) was immersed in 20 mL of 0.1 M cobalt acetate (Co(OAc)2) solution (water / ethanol (v / v = 1 / 3)) and allowed to stand. After one week, the supernatant was removed by decantation, and the remaining pink solid was immersed in a water / ethanol mixed solvent (v / v = 1 / 3) and allowed to stand for another week. The solid was then collected by filtration and dried, yield 100 mg (90%). X-ray fluorescence analysis, powder X-ray diffraction, and single-crystal X-ray crystal structure analysis revealed that the obtained solid was a metal-organic framework with a cubane structure [Co[{Co4(OH)4(H2O)9}{Rh4Zn4(L-cys) 12 O}·nH2O).

[0136] Example 10 A metal organic framework having a cubane structure [Ni[{Ni(OH)(HO)}{RhZn(L-cys)]] was prepared in the same manner as in Example 9, except that a nickel acetate [Ni(OAc)] solution [water / ethanol (v / v=1 / 3)] was used instead of the cobalt acetate solution in Example 9. 12 O}·nH2O] was obtained.

[0137] Example 11 A metal organic framework having a cubane structure [Cu[{Cu(OH)(HO)}{RhZn(L-cys)]] was prepared in the same manner as in Example 9, except that a copper acetate [Cu(OAc)] solution [water / ethanol (v / v=1 / 3)] was used instead of the cobalt acetate solution in Example 9. 12 O}·nH2O] was obtained.

[0138] Example 12 A metal organic framework having a cubane structure [[{Tb(OH)(OAc)}{IrZn(L-cys)]] was prepared in the same manner as in Example 7, except that the ion flow-type ionic solid (2) was used instead of the ion flow-type ionic solid (1) in Example 7. 12 O}·nH2O] was obtained.

[0139] Example 13 A metal organic framework having a cubane structure [Lu 0.33 [{Lu4(OH)4(H2O)7(OAc)3}{Ir4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0140] Example 14 A metal organic framework having a cubane structure [Yb 0.33 [{Yb4(OH)4(H2O)7(OAc)3}{Ir4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0141] Example 15 A metal organic framework having a cubane structure [Tm 0.33 [{Tm4(OH)4(H2O)7(OAc)3}{Ir4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0142] Example 16 A metal organic framework having a cubane structure [Er(OAc)3] was prepared in the same manner as in Example 13, except that an erbium acetate [Er(OAc)3] solution [water / ethanol (v / v=1 / 3)] was used instead of the lutetium acetate solution in Example 13. 0.33 [{Er4(OH)4(H2O)7(OAc)3}{Ir4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0143] Example 17 A metal organic framework having a cubane structure [Ho(OAc)3] was prepared in the same manner as in Example 13, except that a holmium acetate [Ho(OAc)3] solution [water / ethanol (v / v=1 / 3)] was used instead of the lutetium acetate solution in Example 13. 0.33 [{Ho4(OH)4(H2O)7(OAc)3}{Ir4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0144] Example 18 A metal organic framework having a cubane structure [Dy(OAc)3] was prepared in the same manner as in Example 13, except that a dysprosium acetate [Dy(OAc)3] solution [water / ethanol (v / v=1 / 3)] was used instead of the lutetium acetate solution in Example 13. 0.33 [{Dy4(OH)4(H2O)7(OAc)3}{Ir4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0145] Example 19 A metal organic framework having a cubane structure [Gd 0.33 [{Gd4(OH)4(H2O)7(OAc)3}{Ir4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0146] Example 20 A metal organic framework having a cubane structure [Yb 0.33 [{Yb4(OH)4(H2O)7(OPr)3}{Rh4Zn4(L-cys) 12 O}·nH2O] was obtained.

[0147] Example 21 A metal organic framework having a cubane structure [Lu[{Lu(OH)(HO)(OAc)}{RhAg(L-cys)]] was prepared in the same manner as in Example 1, except that the ion flow-type ionic solid (3) was used instead of the ion flow-type ionic solid (1) in Example 1. 12}].nH2O] was obtained.

[0148] Example 22 A metal organic framework having a cubane structure [Yb[{Yb(OH)(HO)(OAc)}{RhAg(L-cys)]] was prepared in the same manner as in Example 21, except that an ytterbium acetate [Yb(OAc)] solution [water / ethanol (v / v=1 / 3)] was used instead of the lutetium acetate solution in Example 21. 12}].nH2O] was obtained.

[0149] Example 23 A metal-organic framework having a cubane structure [Tm[{Tm(OH)(HO)(OAc)}{RhAg(L-cys)]] was prepared in the same manner as in Example 21, except that a thulium acetate [Tm(OAc)] solution [water / ethanol (v / v=1 / 3)] was used instead of the lutetium acetate solution in Example 21. 12}].nH2O] was obtained.

[0150] Example 24 A metal organic framework having a cubane structure [Er[{Er(OH)(HO)(OAc)}{RhAg(L-cys)]] was prepared in the same manner as in Example 21, except that an erbium acetate [Er(OAc)] solution [water / ethanol (v / v=1 / 3)] was used instead of the lutetium acetate solution in Example 21. 12}].nH2O] was obtained.

[0151] [Magnetic susceptibility measurement] Using the metal organic frameworks obtained in Examples 2 to 8 as measurement samples, DC magnetic susceptibility measurements were carried out under conditions of a magnetic field of 0.1 T and a temperature range of 2 to 300 K. The measurement device used was MPMS-2 (manufactured by Quantum Design). The measurement results are shown in Figure 7.

[0152] [Light Emitting Characteristics] The metal organic framework [[{Tb(OH)(OAc)}{IrZn(L-cys) 12 The luminescence properties were investigated using the solid sample [O}]·nH2O]. The measurement was carried out at room temperature (25°C) using a fluorescence spectrophotometer, FP-8500 (manufactured by JASCO Corporation). The emission spectrum was measured at an excitation wavelength of 350 nm, and the excitation spectrum was measured at an emission wavelength of 544 nm. The measurement results are shown in Figure 8. In Figure 8, the spectrum in the range of 420 to 750 nm (red line) is the emission spectrum, and the spectrum in the range of 250 to 480 nm (black line) is the excitation spectrum. The sharp signals in the emission spectrum are all Tb 3+ This is attributed to ion-derived emission (489 nm: 5 D4 → 7 F6, 544nm: 5 D4 → 7 F5, 584nm: 5 D4 → 7 F4, 620nm: 5 D4 → 7 F3).

[0153] The metal organic framework [Gd 0.33 [{Gd4(OH)4(H2O)7(OAc)3}{Rh4Zn4(L-cys) 12 The magnetic refrigeration effect was investigated using a solid sample of [H2O}·nH2O] as follows. To prevent temperature changes due to eddy currents in the metal, a thermal bath was constructed using two 10 kΩ ruthenium oxide resistance thermometers (one for the sample and one for the reference) mounted on a 2 cm diameter insulating Bakelite cell stage. A 136.9 μg solid sample was placed in the sample resistance thermometer that constituted the thermal bath. This thermal bath was placed in a superconducting magnet (8 T, Cryogenics, UK) set to temperatures ranging from 2.0 to 10.0 K. A magnetic field was applied from 0 to 5 T at a rate of 2.2 T / min, resulting in a temperature increase of 2.33 K. Furthermore, after confirming that the sample had cooled to 4.0 K while maintaining the applied 5 T, a temperature decrease of 2.76 K was observed when the magnetic field was reduced from 5 T to 0 T at a rate of 2.2 T / min. Furthermore, when the magnetic field sweep rate was increased to 3.54 T / min, the temperature drop increased to a maximum of 3.26 K, and the sample temperature reached 0.74 K, which is below 1 K. Figures 9 and 10 show the changes in magnetic field and temperature. In this way, by using the metal organic framework of the present invention, 3 By applying a magnetic field, it is possible to create extremely low temperatures below 1 K without using He etc. This temperature change indicates the existence of a magnetic refrigeration effect originating from Gd ions in the sample, which have a large magnetic moment due to their cubane structure but are paramagnetic without forming order.

[0154] [Reference example 1] K6[Co4Zn4(L-cys) 12 Synthesis of [O]·nHO According to the method described in Example 2 of WO2018 / 079831, K6[Co4Zn4(L-cys) 12 O]·nH2O was synthesized.

[0155] [Reference example 2] K8[Co4Ag4(L-cys) 12 Synthesis of ]·nH2O According to the method described in Example 3 of WO2018 / 079831, K8[Co4Ag4(L-cys)] 12 ]·nH2O was synthesized.

[0156] [Reference example 3] Na8[Rh4Cu4(L-cys) 12 Synthesis of ]·nH2O The target compound was synthesized according to the method described in Chem. Commun., 2021, 57, 5386-5389. That is, a 1:1 mixture of Δ-H3[Rh(L-cys)3] and CuCl was treated with aqueous sodium hydroxide and subjected to the specified procedure to obtain Na8[Rh4Cu4(L-cys) 12 ]·nH2O was synthesized.

[0157] [Reference example 4] Na8[Rh4Cu4(L-cys) 12 Synthesis of [O]·nHO The same procedure as in Reference Example 3 was carried out except that CuCl was used instead of CuCl to obtain Na[RhCu(L-cys)]. 12 O]·nH2O was synthesized.

[0158] [Reference example 5] Na6[Ir4Cu4(L-cys) 12 Synthesis of ]·nH2O The same procedure as in Reference Example 3 was carried out except that Δ-H3[Ir(L-cys)3] was used instead of Δ-H3[Rh(L-cys)3] in Reference Example 3, to obtain Na6[Ir4Cu4(L-cys) 12 ]·nH2O was synthesized.

[0159] [Reference example 6] K6[Rh4Hg4(L-cys) 12 Synthesis of [O]·nHO The same procedure as in Example 1 of WO2019 / 208753 was carried out, except that Hg(ClO) was used instead of ZnBr, to obtain K[RhHg(L-cys)]. 12 O]·nH2O was synthesized.

[0160] The compounds obtained in Reference Examples 1 to 6 were subjected to X-ray fluorescence analysis and single-crystal X-ray crystal structure analysis, and it was confirmed that these compounds contained anionic polynuclear metal complexes having the same structure as the constituent components of the ion-flux-type ionic solids (1) to (3). Furthermore, exchangeable cationic species existed in the spaces between these anionic polynuclear metal complexes. Furthermore, the spacing between these anionic polynuclear metal complexes was large enough to allow the formation of cubane-containing clusters. Therefore, by using the compounds obtained in Reference Examples 1 to 6 instead of the ion flow type ionic solids (1) to (3) in the same manner as in Examples 1 to 24, it was possible to obtain clusters (α) derived from the compounds obtained in Reference Examples 1 to 6 and metal ions (M β The metal organic framework of the present invention can be efficiently synthesized by using the above-mentioned method.

Claims

1. A metal organic framework containing cluster (α) and cluster (β) as structural units, Cluster (α) is a metal ion (M α ions), and M α The ligand coordinated to the ion (ligand L α ) Cluster (β) is a metal ion (M β ions) as essential components, Ligand L α At least one of β Multidentate ligands that also coordinate to ions (ligand L α １ ) and Cluster (α) is M α The ions are selected from the group consisting of metals in Groups 8, 9, and 10 of the periodic table, Cr, and Mn, and are divalent or trivalent metal ions (M α １ and a monovalent or divalent metal ion (M ion) which is an ion of a metal selected from the group consisting of metals of Groups 11 and 12 of the periodic table and which is capable of forming a complex having a tetrahedral molecular structure with a coordination number of 4. α ２ ions), Ligand L α １ is a multidentate ligand represented by the following formula (5-3), (5-4) or (5-6), 【Chemistry 1】 [each of r 1 , r 2 , and r 3 independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. In the formula, the sulfur atom and nitrogen atom are coordinated to the M α ion, and the oxygen atom is coordinated to the M β ion.] M β the ions are metal ions selected from the group consisting of ions of d-block transition metals and ions of f-block transition metals; The cluster (α) is represented by the following formula (2): 【Chemistry 2】 [M α １ is the M α １ represents an ion, M α ２ is the M α ２ represents an ion, and L α １ is the ligand L α １ E represents H － , O ２－ , S ２－ , Se ２－ , Te ２－ , F － , Cl － ,Br － or I － m is 0 or 1, and n is (M α １ Valence × 4) + (M α ２ Valence × 4) + (L α １ The number is calculated by (valence of E × 12) + (valence of E × m). A metal organic framework, wherein the cluster (β) is represented by the following formula (3): 【Transformation 3】 [M β is the M β represents an ion, and L β represents a carboxylate ligand, p is an integer of 0 to 10, q is an integer of 0 to 10 (provided that p+q≧1), and r is (M β Valence × 4) + (-1 × 4) + (L β The number is calculated by multiplying the valence of the element by q.

2. Said M α １ The ion is Rh ３＋ , Ir ３＋ and Co ３＋ is a metal ion selected from the group consisting of Said M α ２ The ions are Zn ２＋ , Ag ＋ , Cu ＋ and Hg ２＋ The metal organic framework according to claim 1, wherein the metal ion is selected from the group consisting of:

3. The ligand L α １ The metal organic framework according to claim 1 or 2, wherein is a ligand selected from the group consisting of cysteine, penicillamine, and homocysteine.

4. The aggregate of clusters (α) is derived from the anion portion of an ion flow-type ionic solid, The ion-flow type ionic solid is an anionic polynuclear metal complex represented by the formula (2) (wherein the ligand L α １ The oxygen atom of M β The metal organic structure according to any one of claims 1 to 3, wherein the cationic species are not coordinated to the cations (which are not coordinated to the cations) and are accumulated to form a crystal lattice, and cationic species are present in the gaps of the crystal lattice.

5. M β The metal organic framework according to any one of claims 1 to 4, wherein the ions satisfy the following requirements 1 and 2: Requirement 1: The metal ion is a monovalent, divalent, or trivalent metal ion capable of forming a complex having a polyhedral molecular structure with a coordination number of four or more. Requirement 2: The ionic radius is 70 to 120 pm.

6. Said M β The ions are Co ２＋ , Ni ２＋ , Cu ＋ , Gd ３＋ , Tb ３＋ , Dy ３＋ , Ho ３＋ , Er ３＋ , Tm ３＋ , Yb ３＋ and Lu ３＋ The metal organic structure according to any one of claims 1 to 5, wherein the metal ion is selected from the group consisting of:

7. Said L β The metal organic structure according to any one of claims 1 to 6, wherein is a ligand selected from the group consisting of acetate ions, propionate ions, and benzoate ions.

8. The metal organic structure according to any one of claims 1 to 7, wherein the cubane structure in the cluster (β) is a tetranuclear complete cubane structure or a trinuclear incomplete cubane structure.

9. The metal organic framework according to any one of claims 1 to 8, wherein the cubane structure in the cluster (β) further contains a hydroxide ion as a constituent element.

10. The metal organic framework according to any one of claims 1 to 9, wherein the composition formula of the metal organic framework is represented by the following formula (4): 【Chemistry 4】 In formula (4), A represents a cation or an anion. β ) ４ (OH) ４ (H ２ O) ｐ (L β ) ｑ } is a cation with a valence of r, and M β is the M β represents an ion, and L β represents a carboxylate ligand, p is an integer of 0 to 10, and q is an integer of 0 to 10 (provided that p+q≧1). α １ ) ４ (M α ２ ) ４ (L α １ ) １２ (E) ｍ } is an n-valent anion, and M α １ is the M α １ represents an ion, M α ２ is the M α ２ represents an ion, and L α １ is the ligand L α １ and E represents H － , O ２－ , S ２－ , Se ２－ , Te ２－ , F － , Cl － ,Br － or I － m is 0 or 1. B represents a solvent molecule, and t is an integer of 20 to 100. y and z are each independently a number greater than 0 and equal to or less than 1, and x is a number that satisfies the relationship (valence of A × x) + (r × y) - (n × z) = 0.

11. A method for producing the metal organic framework according to claim 1, The anionic polynuclear metal complex represented by the formula (2) (wherein the ligand L α １ The oxygen atom of M β ions) accumulate to form a crystal lattice, and cationic species exist in the gaps of the crystal lattice. A method for producing a metal-organic framework having a cubane structure in a metal-organic polymer chain, comprising a step of contacting a metal-organic polymer with a solution containing ions of a d-block transition metal or ions of an f-block transition metal.

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