Binary hydroxamic acid compound, rare earth metal organic framework material and preparation method and application of binary hydroxamic acid compound and rare earth metal organic framework material

Abstract

The invention provides a binary hydroxamic acid compound, a rare earth metal organic framework material as well as a preparation method and application of the binary hydroxamic acid compound and the rare earth metal organic framework material. The binary hydroxamic acid compound disclosed by the invention has a structure as shown in a formula (II). The rare earth metal organic framework material comprises rare earth metal ions, a first ligand and a second ligand, wherein the first ligand and the second ligand are coordinated with the rare earth metal ions; wherein the first ligand comprises a binary hydroxamic acid compound, and the second ligand comprises monocarboxylic acid and / or dicarboxylic acid. The rare earth metal organic framework material disclosed by the invention has excellent gas adsorption and separation effects and relatively high stability. Formula (II).

Description

Technical Field

[0001] This invention relates to the field of metal-organic framework materials technology, specifically to a binary isohydroxamic acid compound, a rare earth metal-organic framework material, its preparation method, and its application. Background Technology

[0002] Metal-organic frameworks (MOFs) are a class of porous crystalline materials with periodic network structures formed by the self-assembly of metal ions / clusters and organic ligands. Due to their permanent porosity, ultra-high specific surface area, and modular designability, MOFs hold great promise for gas adsorption and separation. Rare-earth MOFs, in particular, often form porous frameworks due to the high coordination numbers and rich coordination modes of rare-earth metal ions. Ligand extension can modulate the pore size of the MOF without affecting its geometry, ensuring gas adsorption and separation. However, the high coordination numbers (7-9) and flexible coordination modes of rare-earth metal ions make network manipulation difficult, limiting their application. Most applications are limited to synthesizing rare-earth metal clusters to reduce their coordination numbers. While the formation of metal clusters improves network manipulation and achieves higher porosity, it often results in larger pores within the MOF material, leading to weak adsorption and separation capabilities for small gas molecules.

[0003] Hydroxamic acid (-CONHOH) ligands, similar to carboxylic acid (-COOH) ligands commonly used in MOF materials, can form strong coordination with metals. The imino group (-NH-) in hydroxamic acids often does not participate in the coordination of metal ions, thus providing additional adsorption sites compared to typical carboxylic acid ligands. While hydroxamic acids have been extensively studied in mineral flotation and biomedicine, there are relatively few reports on the formation of MOFs between rare earth metal ions and hydroxamic acid ligands in the field of metal-organic frameworks, particularly regarding the interaction between rare earth metal ions and hydroxamic acid ligands. This area of ​​research remains largely unexplored. Summary of the Invention

[0004] To address one of the aforementioned technical problems in the prior art, this invention provides a novel dihydroxyoxime acid compound that can be used as a ligand for rare earth metals in the preparation of MOF materials. This invention also provides a rare earth metal-organic framework material, which combines rare earth metal ions, represented by yttrium, with organic ligands containing two hydrooxime acid groups and mono / dicarboxylic acid ligands, resulting in materials with improved gas adsorption and separation capabilities. Furthermore, this invention provides methods for preparing the aforementioned dihydroxyoxime acid compound and rare earth metal-organic framework material, and their applications in the adsorption and / or separation of gases such as Xe, C2H2, CO2, and SF6.

[0005] In a first aspect, the present invention provides a dihydroxyoxime acid compound having the structure shown in formula (II): Equation (II) In equation (II), ring A represents C3~C 20 Monocycloalkyl or C5~C 20 Bridged cycloalkyl; R 2 Independently representing hydrogen atoms, hydroxyl groups, cyano groups, nitro groups, halogens, C1-C6 alkyl groups, C3-C8 cycloalkyl groups, C6-C6 cycloalkyl groups, and C6-C6 cycloalkyl groups. 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 Heteroaryloxy, C1-C6 haloalkyl, C6-C 10 Halogenated aryl, C1-C6 halogenated alkoxy, C1-C6 alkylthio, C6-C 10 aryl thiols, C3~C 10 heteroarylthio, C1~C6 alkylsulfinyl, C6~C 10 arylsulfinyl group, C3~C 10 heteroarylsulfinyl, C1~C6 alkylsulfonyl, C6~C 10 arylsulfonyl, C3~C 10 heteroarylsulfonyl, NR 5 R 6 R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, and a C6-C6 alkyl group. 10 aryl, C1-C6 alkyl carbonyl or C6-C 10 aryl carbonyl group; p represents R 2 The number of R, and p is any integer not exceeding the number of substituted sites in ring A minus 2; when p is greater than 1, each R 2 Same or different.

[0006] According to some embodiments of the present invention, ring A represents a C3-C8 monocycloalkyl group or a C5-C6 monocycloalkyl group. 12 Bridged cycloalkyl groups.

[0007] According to some embodiments of the present invention, ring A represents cyclobutyl, cyclopentyl, cyclohexyl, or C5~C6. 12 Bridged cycloalkyl groups.

[0008] According to some embodiments of the present invention, ring A represents a C3-C8 monocycloalkyl group or a C5-C6 monocycloalkyl group. 12Bridged cycloalkyl, such as cyclobutyl, cyclopentyl, cyclohexyl, bicyclo[2.2.2]octyl, bicyclo[1.1.1]pentyl or cubic alkyl.

[0009] According to some embodiments of the present invention, R 2 Independently representing hydrogen atom, hydroxyl group, cyano group, nitro group, fluorine, chlorine, bromine, C1~C6 alkyl group, C3~C8 cycloalkyl group, C6~C 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 heteroaryloxy, C1~C6 haloalkyl, C6~C 10 Halogenated aryl groups, C1-C6 halogenated alkoxy groups, or -NR 5 R 6 R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, or a C6-C6 alkyl group. 10 Aryl groups.

[0010] According to some embodiments of the present invention, R 2 Independently representing hydrogen, amino, hydroxyl, nitro, fluorine, chlorine, bromine, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, methoxy, ethoxy, propoxy, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cubic alkyl, epoxy, trifluoromethyl, trifluoromethyloxy, phenyl, phenoxy, furanyloxy, thiazolyloxy, pyridyloxy.

[0011] According to some embodiments of the present invention, R 2 It is hydrogen.

[0012] According to some embodiments of the present invention, p is 0, 1, 2, 3, 4, 5 or 6.

[0013] According to some embodiments of the present invention, p is 0.

[0014] According to some embodiments of the present invention, the dihydroxyoxime acid compound is selected from compounds of formula (A-4) or formula (A-5): Equation (A-4) Formula (A-5), In equation (A-4), t1 and t2 are independently 0, 1, 2 or 3; t3 is 1, 2 or 3.

[0015] In some embodiments, t1 in equation (A-4) is 0, 1, or 2. In some embodiments, t2 in equation (A-4) is 0, 1, or 2. In some embodiments, t3 in equation (A-4) is 1 or 2.

[0016] According to some embodiments of the present invention, the dihydroxyoxime acid compound is selected from the group consisting of: , , , , .

[0017] Secondly, the present invention provides a method for preparing a dihydroxyoxime acid compound, comprising the following steps: (1) Mix an alcoholic solution of an alkali metal hydroxide with an aqueous solution of hydroxylamine to obtain a mixture; or dissolve hydroxylamine hydrochloride and an alkali metal hydroxide in water to obtain a mixture; (2) The mixture is mixed with an alcoholic solution of the compound of formula (i) and reacted to obtain the corresponding dihydrooxime acid compound as shown in formula (A); Formula (i) Formula (A), In equations (i) and (A), ring Q represents C6~C 20 Monocyclic or polycyclic aryl, C3~C 20 Monocycloalkyl, C5~C 20 Bridged cycloalkyl; R a and R b Alkyl groups that are the same or different and independently represent C1 to C6; R independently represents a hydrogen atom, hydroxyl group, cyano group, nitro group, halogen, C1-C6 alkyl group, C3-C8 cycloalkyl group, C6-C6 cycloalkyl group, etc. 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 Heteroaryloxy, C1-C6 haloalkyl, C6-C 10 Halogenated aryl, C1-C6 halogenated alkoxy, C1-C6 alkylthio, C6-C 10 aryl thiols, C3~C 10 heteroarylthio, C1~C6 alkylsulfinyl, C6~C 10 arylsulfinyl group, C3~C 10 heteroarylsulfinyl, C1~C6 alkylsulfonyl, C6~C 10 arylsulfonyl, C3~C 10 heteroarylsulfonyl, NR 5 R 6 R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, and a C6-C6 alkyl group. 10aryl, C1-C6 alkyl carbonyl or C6-C 10 aryl carbonyl group; m represents the number of Rs, and m is any integer not exceeding the number of substituted sites in ring Q minus 2; when m is greater than 1, the Rs are either the same or different.

[0018] According to some embodiments of the present invention, the alcohols in steps (1) and (2) are independently C1-C4 alcohols, for example, methanol.

[0019] According to some embodiments of the present invention, the alkali metal hydroxide is at least one of sodium hydroxide and potassium hydroxide.

[0020] According to some embodiments of the present invention, the molar ratio of the compound of formula (i) to the alkali metal hydroxide is 1:(2-4), preferably 1:(2.5-3.5).

[0021] According to some embodiments of the present invention, the molar ratio of compound (i) to hydroxylamine is 1:(2-3).

[0022] According to some embodiments of the present invention, in step (2), the temperature of the reaction is 15-35°C.

[0023] According to some embodiments of the present invention, in step (2), the reaction time is 20-72 hours, preferably 20-30 hours.

[0024] According to some embodiments of the present invention, step (2) further includes: removing the alcohol solvent by vacuum distillation of the reaction solution obtained after the reaction to obtain the intermediate product.

[0025] According to some embodiments of the present invention, in step (3), the intermediate product is first dissolved in water and then mixed with the acid.

[0026] According to some embodiments of the present invention, the acid in step (3) is an inorganic acid or an organic acid, such as hydrochloric acid, sulfuric acid, acetic acid, etc.

[0027] According to some embodiments of the present invention, step (3) further includes washing the precipitate with water and vacuum drying.

[0028] According to some embodiments of the present invention, ring Q represents C6~C 12 Monocyclic or polycyclic aryl, C3-C8 monocyclic alkyl, C5-C 12 Bridged cycloalkyl groups.

[0029] According to some embodiments of the present invention, ring Q represents phenyl, naphthyl, biphenyl, cyclobutyl, cyclopentyl, cyclohexyl, C5~C 12Bridged cycloalkyl, such as bicyclo[2.2.2]octyl, bicyclo[1.1.1]pentyl or cubic alkyl, etc.

[0030] According to some embodiments of the present invention, R independently represents a hydrogen atom, hydroxyl group, cyano group, nitro group, fluorine group, chlorine group, bromine group, C1-C6 alkyl group, C3-C8 cycloalkyl group, C6-C6 ...3-C8 cycloalkyl group, C6-C6 cycloalkyl group, C3-C6 cycloalkyl group, C 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 heteroaryloxy, C1~C6 haloalkyl, C6~C 10 Halogenated aryl groups, C1-C6 halogenated alkoxy groups, or -NR 5 R 6 R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, or a C6-C6 alkyl group. 10 Aryl groups.

[0031] According to some embodiments of the present invention, R independently represents hydrogen, amino, hydroxyl, nitro, fluorine, chlorine, bromine, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, methoxy, ethoxy, propoxy, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cubic alkyl, epoxy, trifluoromethyl, trifluoromethyloxy, phenyl, phenoxy, furanyloxy, thiazolyloxy, pyridyloxy.

[0032] According to some embodiments of the present invention, R is hydrogen.

[0033] According to some embodiments of the present invention, m is 0, 1, 2, 3, 4, 5, or 6. According to some embodiments of the present invention, m is 0.

[0034] Thirdly, the present invention provides a rare earth metal-organic framework material comprising a rare earth metal ion and a first ligand and a second ligand coordinated with the rare earth metal ion; wherein the first ligand comprises a compound represented by formula (A), and the second ligand comprises a monocarboxylic acid and / or a dicarboxylic acid. Formula (A), In equation (A), ring Q represents C6~C 20 Monocyclic or polycyclic aryl, C3~C 20 Monocycloalkyl, C5~C 20 Bridged cycloalkyl; R independently represents a hydrogen atom, hydroxyl group, cyano group, nitro group, halogen, C1-C6 alkyl group, C3-C8 cycloalkyl group, C6-C6 cycloalkyl group, etc. 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C10 Heteroaryloxy, C1-C6 haloalkyl, C6-C 10 Halogenated aryl, C1-C6 halogenated alkoxy, C1-C6 alkylthio, C6-C 10 aryl thiols, C3~C 10 heteroarylthio, C1~C6 alkylsulfinyl, C6~C 10 arylsulfinyl group, C3~C 10 heteroarylsulfinyl, C1~C6 alkylsulfonyl, C6~C 10 arylsulfonyl, C3~C 10 heteroarylsulfonyl, NR 5 R 6 R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, and a C6-C6 alkyl group. 10 aryl, C1-C6 alkyl carbonyl or C6-C 10 aryl carbonyl group; m represents the number of Rs, and m is any integer not exceeding the number of substituted sites in ring Q minus 2; when m is greater than 1, the Rs are either the same or different.

[0035] According to some embodiments of the present invention, ring Q represents C6~C 12 Monocyclic or polycyclic aryl, C3-C8 monocyclic alkyl, C5-C 12 Bridged cycloalkyl groups.

[0036] According to some embodiments of the present invention, ring Q represents phenyl, naphthyl, biphenyl, cyclobutyl, cyclopentyl, cyclohexyl, C5~C 12 Bridged cycloalkyl groups.

[0037] According to some embodiments of the present invention, R independently represents a hydrogen atom, hydroxyl group, cyano group, nitro group, fluorine group, chlorine group, bromine group, C1-C6 alkyl group, C3-C8 cycloalkyl group, C6-C6 ...3-C8 cycloalkyl group, C6-C6 cycloalkyl group, C3-C6 cycloalkyl group, C 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 heteroaryloxy, C1~C6 haloalkyl, C6~C 10 Halogenated aryl groups, C1-C6 halogenated alkoxy groups, or -NR 5 R 6 R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, or a C6-C6 alkyl group. 10 Aryl groups.

[0038] According to some embodiments of the present invention, R independently represents hydrogen, amino, hydroxyl, nitro, fluorine, chlorine, bromine, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, methoxy, ethoxy, propoxy, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cubic alkyl, epoxy, trifluoromethyl, trifluoromethyloxy, phenyl, phenoxy, furanyloxy, thiazolyloxy, pyridyloxy.

[0039] According to some embodiments of the present invention, m is 0, 1, 2, 3, 4, 5 or 6.

[0040] According to some embodiments of the present invention, the first ligand is selected from compounds represented by formulas (A-1) to (A-5): Equation (A-1) Equation (A-2) Equation (A-3), Equation (A-4) Formula (A-5), In equations (A-1) to (A-3), the definitions of each R are the same as those in equation (A); in equation (A-4), t1 and t2 are independently 0, 1, 2 or 3; t3 is 1, 2 or 3.

[0041] In some embodiments, t1 in equation (A-4) is 0, 1, or 2. In some embodiments, t2 in equation (A-4) is 0, 1, or 2. In some embodiments, t3 in equation (A-4) is 1 or 2.

[0042] In some embodiments, the compound of formula (A-4) has the following structure: The definitions of each symbol are the same as in formula (A-4).

[0043] According to some embodiments of the present invention, the first ligand is selected from the group consisting of: .

[0044] According to some embodiments of the present invention, the second ligand is selected from formic acid, oxalic acid, and compounds shown in formulas (IV) and (V): , Among them, R 7 R 8 R 9 R 10 and R 11 Each of the following groups independently represents a hydrogen atom, halogen, cyano group, nitro group, hydroxyl group, C1-C6 alkyl group, C3-C8 cycloalkyl group, and C6-C6 cycloalkyl group. 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 Heteroaryloxy, C1-C6 haloalkyl, C6-C 10 Halogenated aryl, C1-C6 halogenated alkoxy, C1-C6 alkylthio, C6-C 10 aryl thiols, C3~C 10 Heteroaryl thiols, C1-C6 alkyl sulfinyls, C6-C 10 arylsulfinyl group, C3~C 10 Heteroarylsulfinyl, C1~C6 alkylsulfonyl, C6~C 10 arylsulfonyl, C3~C 10 heteroarylsulfonyl or -NR 12 R 13 R 12 and R 13 Each independently represents a hydrogen atom, a C1-C6 alkyl group, and a C6-C6 alkyl group. 10 aryl, C1-C6 alkyl carbonyl or C6-C 10 aryl carbonyl group.

[0045] In some implementations, R 7 R 8 R 9 R 10 and R 11 Each of the following can be independently represented: hydrogen atom, halogen, cyano group, nitro group, hydroxyl group, C1-C6 alkyl group, C6-C6 alkyl group. 10 aryl, C1-C6 haloalkyl or -NR 12 R 13 R 12 and R 13 Each can be used independently to represent a hydrogen atom or a C1-C6 alkyl group.

[0046] In some implementations, R 7 R 8 R 9 R 10 and R 11Each of these can be independently represented as a hydrogen atom, fluorine, cyano, nitro, amino, hydroxyl, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, phenyl, or trifluoromethyl.

[0047] In some embodiments, the second ligand is selected from the group consisting of: .

[0048] According to some embodiments of the present invention, the second ligand is selected from formic acid, acetic acid, propionic acid and butyric acid.

[0049] According to some embodiments of the present invention, the rare earth metal is selected from at least one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium.

[0050] According to some embodiments of the present invention, the rare earth metal is selected from at least one of scandium and yttrium.

[0051] Fourthly, the present invention provides a method for preparing a rare earth metal-organic framework material as described in the third aspect, comprising the following steps: (1) Mix the first solution containing the first ligand with the second solution containing the rare earth metal ions to obtain a mixed solution; (2) The mixture is mixed with the second ligand or its salt and heated to react, thereby obtaining the rare earth metal-organic framework material.

[0052] According to some embodiments of the present invention, the molar ratio of the first ligand to the rare earth metal ion is 1:(0.8~1.5), for example, 0.8:1, 0.9:1, 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, etc.

[0053] According to some embodiments of the present invention, the molar ratio of the second ligand or its salt to the rare earth metal ion is (15~25):1, for example, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 21:1, 22:1, 23:1, 24:1, 25:1, etc.

[0054] According to some embodiments of the present invention, the reaction temperature is 60~110°C, for example 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, etc., preferably 90~110°C.

[0055] According to some embodiments of the present invention, step (1) further includes the step of ultrasonic treatment of the mixture.

[0056] According to some embodiments of the present invention, the solvent in the first solution and the second solution includes one or more of water, amides, and ketones. In some embodiments, the solvent in the first solution and the second solution includes N,N-dimethylformamide.

[0057] It should be noted that, since some of the first ligand compounds are unstable in acid, in the preparation method of the rare earth metal-organic framework material of the present invention, in step (2), the second ligand can also be selected in the form of its corresponding carboxylate (e.g., alkali metal salt, sodium carboxylate).

[0058] Fifthly, the present invention provides the application of diisohydroxyoxime acid compounds as described in the first aspect, or diisohydroxyoxime acid compounds prepared by the preparation method described in the second aspect, or rare earth metal-organic framework materials as described in the third aspect, or rare earth metal-organic framework materials prepared by the preparation method described in the fourth aspect, in gas adsorption and / or separation.

[0059] According to some embodiments of the present invention, the gas includes one or two or more of Xe, Kr, CO2, N2, CH4, SF6, CF4, and C2H2.

[0060] According to some embodiments of the present invention, the gas contains a mixture of Xe and Kr, or a mixture of CO2 and N2, or a mixture of CO2 and CH4, or a mixture of SF6 and CF4, or a mixture of CO2 and C2H2, or a mixture of CO2, N2 and CH4.

[0061] According to some embodiments of the present invention, the gas is a mixture of CO2 and N2.

[0062] According to some embodiments of the present invention, the gas is a mixture of CO2 and CH4.

[0063] According to some embodiments of the present invention, the gas is a mixture of CO2 and C2H2.

[0064] According to some embodiments of the present invention, the gas is a mixture of CO2, N2 and CH4.

[0065] According to some embodiments of the present invention, the gas is a mixture of SF6 and CF4.

[0066] According to some embodiments of the present invention, the gas is a mixture of Xe and Kr.

[0067] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention provides a new class of dihydroxyoxime acid compounds, which, when used as rare earth metal ligands, can be used to prepare MOF materials with good thermal / chemical stability and strong adsorption and separation capabilities for gases such as Xe, C2H2, CO2, and SF6.

[0068] 2. Zirconium-based MOFs have a two-dimensional layered structure, are not resistant to acids and alkalis, have poor stability, and the macropores they form have poor adsorption and separation capabilities for small molecules. The rare earth metal-organic framework material provided by this invention uses rare earth metals that are octetably coordinated, while transition metals such as zinc, cobalt, and zirconium are typically hexatetably coordinated. This octetically coordinated mode gives the MOF material of this application better thermal / chemical stability. In addition, isohydroxamic acid ligands have good coordination ability and, compared with mono- or dicarboxylic acid ligands, have advantages such as ligand modifiability and abundant binding sites, resulting in better adsorption and separation capabilities.

[0069] 3. The rare earth metal-organic framework material provided by this invention has a gating effect and ultra-microporous structure that are rare in other binary ligand-metal-organic frameworks at room temperature. It has specific adsorption properties for strongly polar gases and gases with large kinetic diameters. For example, it only adsorbs CO2 with strong polarity and hardly adsorbs N2 and CH4 with weak polarity. It only adsorbs SF6 with large kinetic diameter and not CF4 with small kinetic diameter. In the adsorption of C2H2 and CO2 mixture, it preferentially adsorbs acetylene.

[0070] 4. The carboxylic acid ligands in the rare earth metal-organic framework materials of the present invention not only serve as part of the metal-organic framework, but also as an important part of regulating the chemical environment inside the material pores. Different monocarboxylic acids (such as formic acid, acetic acid, propionic acid, etc.) affect the environment inside the pores, causing the material to exhibit "S"-shaped flexible adsorption and conventional rigid adsorption in adsorbing Xe, resulting in MOFs with different adsorption and separation capabilities.

[0071] 5. The method for preparing dihydroxamic acid compounds provided by the present invention, by optimizing the operating conditions, eliminates the need for ice baths and heating of raw materials compared with existing methods, allowing the raw materials to be directly mixed and reacted at room temperature. The method is simple, the conditions are mild, and it is conducive to the scale-up synthesis of materials. Attached Figure Description

[0072] Figure 1 The hydrogen nuclear magnetic resonance spectrum of compound 2 synthesized in the preparation example of this application is shown.

[0073] Figure 2 The hydrogen nuclear magnetic resonance spectrum of compound 3 synthesized in the preparation example of this application is shown.

[0074] Figure 3 The 1H NMR spectrum of compound 4 synthesized in the preparation example of this application is shown.

[0075] Figure 4 The 1H NMR spectrum of compound 5 synthesized in the preparation example of this application is shown.

[0076] Figure 5 The 1H NMR spectrum of compound 6 synthesized in the preparation example of this application is shown.

[0077] Figure 6 This is a schematic diagram of the crystal structure of rare earth metal-organic framework material 1-1 in Example 1-1.

[0078] Figure 7 This is a schematic diagram of the crystal structure of rare earth metal-organic framework materials 1-7 in Examples 1-7.

[0079] Figure 8 The Xe / Kr adsorption isotherm (298 K) for the rare earth metal-organic framework material in Comparative Example 2 is shown.

[0080] Figure 9 The adsorption isotherms (298K) of Xe on the rare earth metal-organic framework materials of Examples 1-1, 1-2, and 1-3 are shown.

[0081] Figure 10 The PXRD spectra of the rare earth metal-organic framework materials in Examples 1-1, 1-2, 1-3, and 1-4 are shown.

[0082] Figure 11 The PXRD spectra of the rare earth metal-organic framework materials in Examples 1-1, 2-1, 2-2, 2-3, 2-4, 2-5, 2-6, and 2-7 are shown.

[0083] Figure 12 The adsorption isotherm (298K) of the rare earth metal-organic framework material 1-1 in Example 1-1 for CO2, CH4, and N2.

[0084] Figure 13 The adsorption isotherms (298K) of rare earth metal-organic framework materials 1-2 for SF6 and CF4 in Examples 1-2 are shown.

[0085] Figure 14 The adsorption isotherms (298K) of rare earth metal-organic framework materials 1-10 for C2H2 and CO2 in Examples 1-10 are shown.

[0086] Figure 15 The adsorption isotherms (298 K) of Xe by the rare earth metal-organic framework materials in Examples 1-1, 2-1, 2-3, 2-4, 2-5, 2-6, and 2-7 are shown.

[0087] Figure 16 The PXRD spectra of rare earth metal-organic framework material 1-1 in Example 1-1 under different pH conditions are shown. Detailed Implementation

[0088] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way.

[0089] The rare earth metal-organic framework material provided by this invention is composed of three components: rare earth metal ions, a first ligand having two isohydroxamic acid groups, and a second ligand selected from monocarboxylic acids / diacarboxylic acids. It should be noted that "combination" refers to chemical bonds such as coordination bonds between rare earth metal ions and ligands containing isohydroxamic acid groups, and coordination bonds between rare earth metal ions and monocarboxylic acids / diacarboxylic acids.

[0090] Based on their composition, metal-organic framework materials are referred to as M-L1-L2, where M refers to rare earth metal ions, L1 refers to the first ligand with two isohydroxamic acid groups (with or without substituents), and L2 refers to the second ligand selected from monocarboxylic acids / diacarboxylic acids.

[0091] The first ligand with two isohydroxamic acid groups used in this invention is required to have two isohydroxamic acid groups in the molecule, and the isohydroxamic acid groups cannot be substituted, and can combine with rare earth metal ions to form MOF molecules.

[0092] In one specific embodiment, L1 refers to the first ligand having two isohydroxamic acid groups selected from at least one of the compounds represented by formulas (I) to (III) below.

[0093] In formula (II), A represents any monocyclic alkyl or bridged alkyl group that can simultaneously have two isohydroxamic acid groups; In equations (I) to (III), R 1 R 2 R 3 and R 4 Each of the following can be independently represented: hydrogen atom, hydroxyl group, C1-C6 alkyl group, C3-C8 cycloalkyl group, C6-C6 cycloalkyl group, etc. 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 Heteroaryloxy groups, halogenated groups, C1-C6 halogenated alkyl groups, C6-C6 halogenated alkyl groups 10 Halogenated aryl, C1-C6 halogenated alkoxy, C1-C6 alkylthio, C6-C 10 aryl thiols, C3~C 10 Heteroaryl thiols, C1-C6 alkyl sulfinyls, C6-C 10arylsulfinyl, heteroarylsulfinyl, C1~C6 alkylsulfonyl, C6~C 10 arylsulfonyl, C3~C 10 heteroarylsulfonyl, cyano, nitro or -NR 5 R 6 The group represented, R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, and a C6-C6 alkyl group. 10 aryl, C1-C6 alkyl carbonyl or C6-C 10 aryl carbonyl group; n represents R 1 The number of elements, where n represents 0 or any integer from 1 to 4; when n is an integer greater than 2, each R 1 They can be the same as or different from each other; p represents R 2 The number of substitutable sites, and p represents "any integer not exceeding the number of substitutable sites of the corresponding bridge alkane - 2"; r represents R 3 The number of elements, where r represents 0 or any integer from 1 to 4; when r is an integer greater than 2, each R 3 They can be the same as or different from each other; s represents R 4 The number of R, where s represents 0 or any integer from 1 to 4; when s is an integer greater than 2, each R 4 They can be the same as or different from each other.

[0094] As a C1~C6 alkyl group, it can be straight-chain or branched, and examples include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, 2-methyln-butyl, isohexyl, etc.

[0095] Examples of C3-C8 cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cubic alkyl. C6~C 10 The aryl group can be any type of monocyclic or polycyclic aryl group. In a polycyclic aryl group, as long as at least one ring is an aromatic ring, the remaining rings can be any type of saturated alicyclic, unsaturated alicyclic, or aromatic ring. Specifically, examples include phenyl, 1-naphthyl, 2-naphthyl, azulel, indene, indanel, and naphthanel.

[0096] As a 3- to 6-membered heterocyclic group, it is a group containing 1 to 4 heteroatoms selected from nitrogen, oxygen, and sulfur atoms as ring structural atoms. The heterocyclic group can be any type of monocyclic or polycyclic. For polycyclic heterocyclic groups, at least one ring needs to be a heterocyclic ring, and the remaining ring can be any type of hydrocarbon ring, including saturated alicyclic, unsaturated alicyclic, or aromatic rings. Examples of 3- to 6-membered heterocyclic groups include 3- to 6-membered saturated heterocyclic groups, 5- to 6-membered heteroaryl groups, and 5- to 6-membered partially unsaturated heterocyclic groups.

[0097] Examples of 3- to 6-membered saturated heterocyclic groups include aziridinyl, epoxy, pyrrolyl, tetrahydrofuranyl, thiazolyl, piperidinyl, piperazinyl, morpholinyl, dioxopentyl, and dioxohexyl. Examples of five-membered heteroaryl groups include pyrrolyl, furanyl, thiophene, imidazolyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, triazolyl, oxadiazolyl, thiadiazolyl, tetrazolyl, dihydroindolyl, isoindololinyl, indolazinyl, benzimidazolyl, and carbazoleyl.

[0098] Examples of six-membered heteroaryl groups include pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, quinolinyl, isoquinolinyl, quinoxalinyl, cinolinyl, quinazolinyl, phthalazinyl, acridineyl, azathaneyl, and phenazinyl.

[0099] Examples of C1-C6 alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, and tert-butoxy.

[0100] As C6~C 10 The aryloxy groups can include phenoxy, 1-naphthoxy, 2-naphthoxy, azurooxy, indoxy, indaminozoxy, tetrahydronaphthoxy, etc.

[0101] Examples of heteroaryloxy groups include furanyloxy, thiazolyloxy, and pyridinyloxy.

[0102] Examples of halogenated groups include fluorine, chlorine, bromine, and iodine groups.

[0103] Examples of C1-C6 alkyl halogens include fluoromethyl, difluoromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, pentafluoroethyl, 3,3,3-trifluoropropyl, 2,2,3,3,3-pentafluoropropyl, perfluoropropyl, 2,2,2-trifluoro-1-trifluoromethylethyl, perfluoroisopropyl, 4-fluorobutyl, 2,2,3,3,4,4,4-heptafluorobutyl, perfluorobutyl, perfluoropentyl, perfluorohexyl, chloromethyl, bromomethyl, dichloromethyl, dibromomethyl, trichloromethyl, tribromomethyl, 1-chloroethyl, 2,2,2-trichloroethyl, 4-chlorobutyl, perchlorohexyl, 2,4,6-trichlorohexyl, etc.

[0104] As C6~C10 Examples of halogenated aryl groups include 4-chlorophenyl, 3,5-dichlorophenyl, 2,4,6-trichlorophenyl, and 2,3,4,5,6-pentafluorophenyl.

[0105] Examples of C1-C6 haloalkoxy groups include trifluoromethoxy, 2,2,2-trifluoroethoxy, pentafluoroethoxy, 3,3,3-trifluoropropoxy, 2,2,3,3,3-pentafluoropropoxy, perfluoropropoxy, 2,2,2-trifluoro-1-trifluoromethylethoxy, perfluoroisopropoxy, 4-fluorobutoxy, 2,2,3,3,4,4,4-heptafluorobutoxy, perfluorobutoxy, perfluoropentoxy, perfluorohexyloxy, 2,2,2-trichloroethoxy, 4-chlorobutoxy, perchlorohexyloxy, and 2,4,6-trichlorohexyloxy.

[0106] Examples of C1-C6 alkyl thio groups include methyl thio, ethyl thio, n-propyl thio, isopropyl thio, n-butyl thio, isobutyl thio, sec-butyl thio, and tert-butyl thio.

[0107] As C6~C 10 Aryl thio groups can include phenyl thio, 1-naphthyl thio, 2-naphthyl thio, azulel thio, indene thio, indene thio, tetrahydronaphthyl thio, etc.

[0108] Examples of heteroaryl thio groups include furanyl thio, thiazolyl thio, and pyridyl thio.

[0109] Examples of C1-C6 alkyl sulfinyl groups include methyl sulfinyl, ethyl sulfinyl, and tert-butyl sulfinyl.

[0110] As C6~C 10 Aryl sulfinyl groups can include phenyl sulfinyl, 1-naphthyl sulfinyl, 2-naphthyl sulfinyl, azuleyl sulfinyl, indyl sulfinyl, indumyl sulfinyl, tetrahydronaphthyl sulfinyl, etc.

[0111] Examples of heteroarylsulfinyl groups include furanylsulfinyl, thiazolylsulfinyl, and pyridylsulfinyl.

[0112] Examples of C1-C6 alkyl sulfonyl groups include methyl sulfonyl, ethyl sulfonyl, and tert-butyl sulfonyl.

[0113] As C6~C 10 Arylsulfonyl groups can include phenylsulfonyl, 1-naphthylsulfonyl, 2-naphthylsulfonyl, azuleylsulfonyl, indolesulfonyl, indolesulfonyl, tetrahydronaphthylsulfonyl, etc.

[0114] Examples of heteroarylsulfonyl groups include furanylsulfonyl, thiazolylsulfonyl, and pyridylsulfonyl.

[0115] NR 5 R 6 In the represented groups, R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, and a C6-C6 alkyl group. 10 aryl, C1-C6 alkyl carbonyl or C6-C 10 aryl carbonyl group.

[0116] As C1~C6 alkyl and C6~C 10 The aryl group can be listed as having the same properties as the R group mentioned above. 1 R 2 R 3 and R 4 The groups are the same as those shown in the examples.

[0117] Examples of C1-C6 alkyl carbonyl groups include acetyl, n-propionyl, isopropionyl, n-butyryl, isobutyryl, neopentanoyl, and n-pentanoyl.

[0118] As C6~C 10 Aryl carbonyl groups can be exemplified by benzoyl, 1-naphthyl carbonyl, 2-naphthyl carbonyl, etc.

[0119] As NR 5 R 6 The groups represented can include amino, methylamino, dimethylamino, ethyl-isopropylamino, aniline, diphenylamino, acetamino, benzoylamino, etc.

[0120] The benzene ring in formula (I) of the present invention can be extended to a fused-ring aromatic hydrocarbon represented by a naphthalene ring, in which case (R 1 ) n In this context, 'n' represents the R on a polycyclic aromatic hydrocarbon. 1 The number of , but the number of n is not particularly restricted at this time, only required to be "any integer not exceeding the number of substituted sites of the corresponding fused-ring aromatic hydrocarbon - 2".

[0121] Specifically, the following compounds can be listed as compounds represented by formula (I): .

[0122] Specifically, the following compounds can be listed as compounds represented by formula (II): .

[0123] Specifically, the following compounds can be listed as compounds represented by formula (III): .

[0124] The monocarboxylic acid / diacarboxylic acid ligand L2 used in this invention is not particularly limited, as long as it can bind to rare earth metal ions.

[0125] In one specific embodiment of the present invention, L2 refers to the monocarboxylic acid / diacarboxylic acid ligand for binding with rare earth metal ions, selected from at least one of formic acid (HCOOH), oxalic acid (HOOCCOOH), and compounds represented by formulas (IV) to (V).

[0126] In equations (IV) to (V), R 7 R 8 R 9 R 10 and R 11 Each of the following can be independently represented: hydrogen atom, hydroxyl group, C1-C6 alkyl group, C3-C8 cycloalkyl group, C6-C6 cycloalkyl group, etc. 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy groups, heteroaryloxy groups, halogenated groups, C1-C6 alkyl halogenated groups, C6-C6 alkyl halogenated groups 10 Halogenated aryl, C1-C6 halogenated alkoxy, C1-C6 alkylthio, C6-C 10 aryl thiols, C3~C 10 Heteroaryl thiols, C1-C6 alkyl sulfinyls, C6-C 10 arylsulfinyl group, C3~C 10 Heteroarylsulfinyl, C1~C6 alkylsulfonyl, C6~C 10 arylsulfonyl, C3~C 10 heteroarylsulfonyl, cyano, nitro or -NR 12 R 13 R 12 and R 13 Each independently represents a hydrogen atom, a C1-C6 alkyl group, and a C6-C6 alkyl group. 10 aryl, C1-C6 alkyl carbonyl or C6-C 10 aryl carbonyl group.

[0127] The above R 7 R 8 R 9R 10 and R 11 Examples of the above R can be listed. 1 R 2 R 3 and R 4 Since the groups shown in the examples are the same, they will not be described in detail again.

[0128] Specifically, the following compounds can be listed as compounds represented by formula (IV): .

[0129] Specifically, the following compounds can be listed as compounds represented by formula (V): .

[0130] Theoretically, any rare earth metal ions used in this invention (lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium) are acceptable, with no particular restrictions. However, considering the separation performance of the prepared MOF, ions of at least one metal from scandium and yttrium are preferred.

[0131] The manufacturing method of the rare earth metal-organic framework material of the present invention can be achieved by the following two methods: solvent diffusion method or hydrothermal method.

[0132] As one specific implementation method, the preparation method of rare earth metal-organic framework materials includes the following steps: A first solution containing the first ligand having two isohydroxamic acid groups is mixed with a second solution containing the rare earth metal ions to obtain a mixture. The mixture is mixed with the second ligand selected from monocarboxylic acids and dicarboxylic acids and heated to react, thereby obtaining the rare earth metal-organic framework material.

[0133] Rare earth metal ions can be supplied in the form of various salts, but considering factors such as the purity of the salt and the binding ability of the metal ions to ligands containing isohydroxamic acid groups, nitrates corresponding to rare earth metals are preferred. Specifically, examples include yttrium(III) hexahydrate (Y(NO3)3·6H2O) and scandium(III) hexahydrate (Sc(NO3)3·6H2O).

[0134] The molar ratio of rare earth metal ion M, first ligand L1 with two isohydroxamic acid groups, and monocarboxylic acid / dicarboxylic acid ligand L2 varies to some extent depending on the organic ligands used, but generally follows the ratio of M: L1 = 1:1. In addition, the amount of monocarboxylic acid / dicarboxylic acid L2 is basically only required to be in excess (in actual experiments, it is often added in a 20-fold amount relative to M).

[0135] In the second solution, the concentration of the rare earth metal ions is preferably in the range of 0.1 to 1 mol / L.

[0136] In the first solution, the concentration of the first ligand L1 having two isohydroxamic acid groups is preferably in the range of 0.1 to 1 mol / L.

[0137] The concentration of the second ligand L2 in the reaction solution is preferably 5~20 mol / L.

[0138] As a solvent used in the synthesis, one or more selected from N,N-dimethylformamide (hereinafter sometimes referred to as "DMF"), acetone, and water can be used. Among these, N,N-dimethylformamide alone is preferred.

[0139] The preferred heating temperature for the reaction solution is in the range of 60~110℃.

[0140] After the reaction is complete, the material needs to be replaced with acetone again for about 3 days as a solvent.

[0141] Before conducting adsorption separation tests on the materials, they need to be vacuum activated at a temperature of 100-120℃.

[0142] The following embodiments and accompanying drawings are provided to aid in understanding the present invention. However, it should be understood that these embodiments and drawings are for illustrative purposes only and do not constitute any limitation. The actual scope of protection of the present invention is set forth in the claims. It should be understood that any modifications and changes can be made without departing from the spirit of the present invention.

[0143] Preparation Example 1: Synthesis of Compounds 1, 4, and 7 Sodium hydroxide (75.7 mmol) was dissolved in methanol (100 mL), and hydroxylamine solution (50 wt% aqueous solution, 5 mL) was added dropwise to the solution. A methanol solution (150 mL) of bicyclo[2.2.2]octane-1,4-dicarboxylic acid dimethyl ester (25.2 mmol) was added, and the mixture was stirred at room temperature for 24 hours. The solution was subjected to vacuum distillation to remove most of the methanol. The intermediate was dissolved in water, and dilute hydrochloric acid (1 mmol / L) was added to the system until a precipitate formed. The precipitate was filtered, washed thoroughly with water, and dried under vacuum for 6 hours to obtain 3.63 g (20.1 mmol) of bicyclo[2.2.2]octane-1,4-dimethylisohydroxyxamic acid (Table 1, compound number 4), with a yield of 72.6%. The 1H NMR spectrum of compound 4 is shown below. Figure 3 As shown.

[0144] Using the same synthetic method as compound 4, the starting material "bicyclo[2.2.2]octane-1,4-dicarboxylic acid dimethyl ester" was replaced with an equimolar amount of "dimethyl terephthalate" to obtain compound 1 in Table 1, with a yield of 83%.

[0145] Using the same synthetic method as compound 4, the starting material "bicyclo[2.2.2]octane-1,4-dicarboxylic acid dimethyl ester" was replaced with an equimolar amount of "trimethyl pyromellitic acid" to obtain compound 7 in Table 1, with a yield of 45%.

[0146] For comparison, the synthesis of compound 1 was reproduced using the literature synthesis method: hydroxylamine hydrochloride (4.88 g, 75.7 mmol) and sodium hydroxide were dissolved in 75 mL of methanol under ice bath conditions at 0 °C and stirred for 30 min. Then, 150 mL of dimethyl terephthalate in methanol was added to the system, and the mixture was stirred at 25 °C for approximately 24 h. The solution was then subjected to vacuum distillation to remove most of the methanol. The intermediate was dissolved in water, and dilute hydrochloric acid (1 mmol / L) was added to the system until a precipitate formed. The precipitate was filtered, thoroughly washed with water, and dried under vacuum for 6 hours to obtain compound 1, with a yield of approximately 81.0%.

[0147] For comparison, the synthesis of compound 7 was reproduced using the literature synthesis method: hydroxylamine hydrochloride (5.0 g, 19.8 mmol) and sodium hydroxide were dissolved in 75 mL of methanol under ice bath conditions at 0 °C and stirred for 30 min. Then, 150 mL of dimethyl terephthalate in methanol was added to the system, and the mixture was stirred at 40 °C for approximately 48 h. The solution was then subjected to vacuum distillation to remove most of the methanol. The intermediate was dissolved in water, and dilute hydrochloric acid (1 mmol / L) was added to the system until a precipitate formed. The precipitate was filtered, thoroughly washed with water, and dried under vacuum for 6 hours to obtain compound 1, with a yield of approximately 49%.

[0148] It can be seen that this application can achieve comparable yields to existing synthetic methods under milder conditions (without an ice bath).

[0149] Preparation Example 2: Synthesis of compounds 2, 3, 5, 8, and 9 Bicyclo[1.1.1]pentane-1,3-dicarboxylic acid (1 mmol), O-(7-azabenzotriazole)-N,N,N,N-tetramethylurea hexafluorophosphate (HATU) (2.2 mmol), and O-triphenylmethylhydroxylamine (2.4 mmol) were dissolved in 100 mL of N,N-dimethylformamide (DMF). 6 mL of N,N-diisopropylethylamine (DIPEA) was added dropwise to the solution, and the mixture was stirred at room temperature for 24 hours. Water, ethyl acetate, and saturated brine were added sequentially, and the mixture was separated. The organic layer obtained by ethyl acetate extraction was dried over anhydrous sodium sulfate and then filtered. The filtrate was distilled under reduced pressure to obtain a colorless, transparent solid. The solid was dissolved in 50 mL of dichloromethane, and 2 mL of trifluoroacetic acid solution was added dropwise to the solution. After approximately 30 min of reaction, a precipitate appeared in the solution. The precipitate was filtered, washed thoroughly with dichloromethane, and dried under vacuum for 6 hours to obtain 0.14 g (0.76 mmol) of bicyclo[1.1.1]pentane-1,3-dimethylisohydroxamic acid (Table 1, compound number 5), with a yield of 23.5%.

[0150] Using the same synthetic method as compound 5, the starting material "bicyclo[1.1.1]pentane-1,3-dicarboxylic acid" was replaced with an equimolar amount of "trans-1,4-cyclohexanedicarboxylic acid" to obtain compound 2 in Table 1, with a yield of 63.1%.

[0151] Using the same synthetic method as compound 5, the starting material "bicyclo[1.1.1]pentane-1,3-dicarboxylic acid" was replaced with an equal molar amount of "cuboalkyl-1,4-dicarboxylic acid" to obtain compound 3 in Table 1, with a yield of 75.4%.

[0152] Using the same synthetic method as compound 5, the starting material "bicyclo[1.1.1]pentane-1,3-dicarboxylic acid" was replaced with an equimolar amount of "2,6-naphthalenedicarboxylic acid" to obtain compound 8 in Table 1, with a yield of 37.2%.

[0153] Using the same synthetic method as compound 5, the starting material "bicyclo[1.1.1]pentane-1,3-dicarboxylic acid" was replaced with an equal molar amount of "biphenyl dicarboxylic acid" to obtain compound 9 in Table 1, with a yield of 40.3%.

[0154] The proton NMR spectra of compounds 2, 3, and 5 are shown below. Figure 1 , Figure 2 and Figure 4 As shown.

[0155] Preparation Example 3: Synthesis of Compound 6

[0156] Hydroxylamine hydrochloride (25.9 mmol) and sodium hydroxide (51.5 mmol) were dissolved in 13 mL of deionized water. Then, dimethyl 2-aminoterephthalate (8.6 mmol) was dissolved in 15 mL of anhydrous ethanol, and the mixture was stirred at room temperature for 72 hours. The pH was then adjusted to 6 with 30% acetic acid, resulting in a precipitate. The precipitate was filtered, thoroughly washed with deionized water, and dried under vacuum for 6 hours to obtain 1.6 g (7.74 mmol) of dimethylhydroxamic acid 2-aminoterephthalate (Table 1, compound number 6), with a yield of 43.4%. The 1H NMR spectrum of compound 6 is shown below. Figure 5 As shown.

[0157] Table 1

[0158] Example 1-1 Compound 1 (0.5 mmol) was dissolved in 50 mL of DMF, and then placed in a preheated 100 °C oven and heated for about 1 hour to ensure complete dissolution. After returning to room temperature, 10 mL of DMF solution containing 0.5 mmol of yttrium nitrate hexahydrate was added. The system was then sonicated, and formic acid (4 mL) was added dropwise. The system was then quickly placed in an oven for reaction (reaction conditions: 100 °C, 8 hours). After the reaction was complete, the product was filtered through an organic filter membrane and washed with DMF. After vacuum drying at 120 °C for 24 hours, a white powdery metal-organic framework material 1-1 was obtained.

[0159] Examples 1-2 to Examples 1-11 As shown in Table 2, compounds 1, 2, 3, 4, 5, and 6 obtained in the above preparation example were used as organic ligands L1 and co-prepared with the second ligand L2 to prepare metal-organic framework materials. The reaction was carried out under the reaction conditions (temperature and heating time) shown in Table 2. Otherwise, the same operation as in Example 1 was performed to obtain metal-organic framework materials 1-2 to 1-11.

[0160] Table 2

[0161] A schematic diagram of the crystal structure of the rare earth metal-organic framework material 1-1 obtained in Example 1-1 is shown below. Figure 6 As shown; schematic diagrams of the crystal structures of rare earth metal-organic framework materials 1-7 obtained in Examples 1-7 are shown below. Figure 7 As shown.

[0162] The PXRD spectra of the rare earth metal-organic framework materials prepared in Examples 1-1 to 1-4 are as follows: Figure 10 As shown.

[0163] Examples 1-12

[0164] Compound 1 (0.1 mmol) was dissolved in 2 mL of DMF and then sonicated for approximately 1 hour to ensure complete dissolution. Cerium nitrate hexahydrate (0.5 mmol) and formic acid (0.5 mL) were then added, and the mixture was placed in an oven for reaction (reaction conditions: 80 °C, 12 hours). After the reaction was complete, the product was filtered through an organic filter membrane and then washed with DMF. Colorless and transparent metal-organic framework materials 1-12 were obtained.

[0165] Examples 1-13

[0166] Compound 1 (0.1 mmol) was dissolved in 2 mL of DMF and then sonicated for approximately 1 hour to ensure complete dissolution. Cerium nitrate hexahydrate (0.5 mmol) and acetic acid (0.5 mL) were then added, and the mixture was placed in an oven for reaction (reaction conditions: 80 °C, 12 hours). After the reaction was complete, the product was filtered through an organic filter membrane and then washed with DMF. Colorless and transparent metal-organic framework materials 1-13 were obtained.

[0167] Examples 2-1 to 2-7

[0168] As shown in Table 3, metal-organic framework materials were prepared by using different rare earth nitrates, compound 1 obtained in the above preparation example as organic ligand L1, and formic acid as second ligand L2. The reaction was carried out under the reaction conditions (temperature and heating time) shown in Table 3. Otherwise, the same operation as in Example 1-1 was performed to obtain metal-organic framework materials 2-1 to 2-7.

[0169] Table 3

[0170] The PXRD patterns of the metal-organic framework materials in Examples 1-1, 2-1 to 2-7 are as follows: Figure 11 As shown, the peak shapes of the metal-organic framework materials in Examples 2-1 to 2-7 are basically the same as those of the metal-organic framework material 1-1 obtained in Example 1-1, indicating that, in addition to yttrium, different rare earth metal salts and the diisohydroxamic acid ligand compounds and carboxylic acid ligand compounds of this application can also be used to synthesize rare earth metal-organic framework materials.

[0171] Comparative Example 1

[0172] The only difference from Example 1-1 is that the ligand "formic acid" is not added, resulting in metal-organic framework material D1.

[0173] Comparative Example 2

[0174] Following the methods described in existing literature, a metal-organic framework material, named Y-BDC, was synthesized under hydrothermal conditions using yttrium nitrate and terephthalic acid ligands.

[0175] Source of literature: Chem. Commun. , 2021, 57, 6121. The synthesis method used was the synthesis method of Y-UiO-66.

[0176] Test Example 1: Gas Adsorption Effect Test

[0177] (1-1) Test on the adsorption effect of metal-organic framework materials on xenon and krypton The testing method is as follows: Using the metal-organic framework (MOF) samples prepared above as adsorbents, the single-component static adsorption isotherms of Xe and Kr prepared by the rare-earth MOFs in the comparative and example studies were determined using a 3Flex gas adsorption analyzer. The test temperature was 298 K, the test pressure was 0-1 bar, and approximately 100 mg of sample was used for each analysis. Before analysis, the samples were degassed and activated for 24 h under high vacuum (< 6 mmHg) at 100 °C. The results are shown in Table 4.

[0178] Table 4

[0179] The Xe / Kr adsorption isotherm (298 K) of the metal-organic framework material Y-BDC in Comparative Example 2 is as follows: Figure 8 As shown.

[0180] The adsorption isotherms (298K) of Xe by the metal-organic framework materials in Examples 1-1, 1-2, and 1-3 are as follows: Figure 9 As shown. From Figure 9 It can be seen that different monocarboxylic acids (formic acid, acetic acid, propionic acid) affect the internal environment of the metal-organic framework material pores, resulting in "S"-shaped flexible adsorption and conventional rigid adsorption in Xe adsorption, and its adsorption and separation capacity is also affected.

[0181] Furthermore, this application can use monoamino acids to further adjust the chemical environment within the material's pores, thereby providing materials with specific adsorption capabilities for different adsorption and separation tasks.

[0182] The adsorption isotherms (298 K) of Xe on the metal-organic framework materials prepared in Examples 2-1, 2-3 to 2-7 are as follows: Figure 15 As shown, metal-organic framework materials synthesized from different rare earth metals all exhibit a certain adsorption effect on Xe, and the gate pressure decreases as the atomic radius decreases.

[0183] (1-2) Adsorption effect test of metal-organic framework materials on CO2, CH4 and N2 Using the same method as the xenon and krypton adsorption experiments described above, the adsorption effects of the metal-organic framework materials prepared in Examples 1-1 on CO2, CH4, and N2 were tested. The adsorption isotherm (298 K) is as follows: Figure 12 As shown, this material can adsorb only CO2 with strong polarity and hardly adsorb N2 and CH4 with weak polarity, which is consistent with the test results of Xe / Kr and has a gating effect rarely seen in other binary ligand-metal-organic framework materials.

[0184] (1-3) Adsorption effect test of metal-organic framework materials on SF6 and CF4 Using the same method as the xenon and krypton adsorption experiments described above, the adsorption effects of the metal-organic framework materials prepared in Examples 1-2 on SF6 and CF4 were tested. The adsorption isotherm (298 K) is as follows: Figure 13 As shown, this material adsorbs only SF6 with a large kinetic diameter but not CF4 with a small kinetic diameter, exhibiting a gating effect rarely seen in other binary ligand-metal-organic frameworks.

[0185] (1-4) Adsorption effect test of metal-organic framework materials on C2H2 and CO2 Using the same method as the xenon and krypton adsorption experiments described above, the adsorption effects of the metal-organic framework materials prepared in Examples 1-10 on C2H2 and CO2 were tested. The adsorption isotherm (298K) is as follows: Figure 14 As shown, the material preferentially adsorbs acetylene, with a maximum adsorption capacity of 77.6 cm⁻¹. 3 / g, exhibits adsorption selectivity for C2H2 / CO2.

[0186] Test Example 2: Stability Test

[0187] Test method: The rare earth metal-organic framework material 1-1 prepared in Example 1-1 was immersed in sodium hydroxide solution (pH=13), aqueous solution (pH=7), and hydrochloric acid (pH=1) for one week, and then PXRD analysis was performed.

[0188] The results are as follows Figure 16 As shown, this material exhibits good stability under both alkaline and neutral conditions.

[0189] The rare earth metal-organic framework materials prepared in other embodiments of this application also exhibit good stability under alkaline or neutral conditions.

[0190] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A dihydroxyoxime acid compound having the structure shown in formula (II): Equation (II) In equation (II), ring A represents C3~C 20 Monocycloalkyl or C5~C 20 Bridged cycloalkyl; R 2 Independently representing hydrogen atoms, hydroxyl groups, cyano groups, nitro groups, halogens, C1-C6 alkyl groups, C3-C8 cycloalkyl groups, C6-C6 cycloalkyl groups, and C6-C6 cycloalkyl groups. 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 Heteroaryloxy, C1-C6 haloalkyl, C6-C 10 Halogenated aryl, C1-C6 halogenated alkoxy, C1-C6 alkylthio, C6-C 10 aryl thiols, C3~C 10 heteroarylthio, C1~C6 alkylsulfinyl, C6~C 10 arylsulfinyl group, C3~C 10 heteroarylsulfinyl, C1~C6 alkylsulfonyl, C6~C 10 arylsulfonyl, C3~C 10 heteroarylsulfonyl, NR 5 R 6 R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, and a C6-C6 alkyl group. 10 aryl, C1-C6 alkyl carbonyl or C6-C 10 aryl carbonyl group; p represents R 2 The number of R, and p is any integer not exceeding the number of substituted sites in ring A minus 2; when p is greater than 1, each R 2 Same or different.

2. The dihydroxyoxime acid compound according to claim 1, characterized in that, Ring A represents a C3-C8 monocycloalkyl group or a C5-C6 monocycloalkyl group. 12 Bridged cycloalkyl, preferably cyclobutyl, cyclopentyl, cyclohexyl, bicyclo[2.2.2]octyl, bicyclo[1.1.1]pentyl or cubic alkyl; and / or R 2 Independently representing hydrogen atom, hydroxyl group, cyano group, nitro group, fluorine, chlorine, bromine, C1~C6 alkyl group, C3~C8 cycloalkyl group, C6~C 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 heteroaryloxy, C1~C6 haloalkyl, C6~C 10 Halogenated aryl groups, C1-C6 halogenated alkoxy groups, or -NR 5 R 6 R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, or a C6-C6 alkyl group. 10 aryl; preferably, R 2 Independently representing hydrogen, amino, hydroxyl, nitro, fluorine, chlorine, bromine, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, methoxy, ethoxy, propoxy, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cuboalkyl, epoxy, trifluoromethyl, trifluoromethyloxy, phenyl, phenoxy, furanyloxy, thiazolyloxy, or pyridyloxy; and / or p can be 0, 1, 2, 3, 4, 5, or 6.

3. The diisohydroxamic acid compound according to claim 1 or 2, characterized in that, The compound is selected from the compounds shown in formula (A-4) or formula (A-5): Equation (A-4) Formula (A-5), In equation (A-4), t1 and t2 are independently 0, 1, 2 or 3, preferably independently 0, 1 or 2; t3 is 1, 2 or 3, preferably 1 or 2; Preferably, the dihydroxyoxime acid compound is selected from the group consisting of: ， ， ， ， 。 4. A method for preparing a dihydroxyoxime acid compound, comprising the following steps: (1) Mix an alcoholic solution of an alkali metal hydroxide with an aqueous solution of hydroxylamine to obtain a mixture; or dissolve hydroxylamine hydrochloride and an alkali metal hydroxide in water to obtain a mixture; (2) The mixture is mixed with an alcoholic solution of the compound of formula (i) and reacted to obtain an intermediate product; (3) The intermediate product is mixed with an acid, preferably hydrochloric acid, until a precipitate is formed to obtain the corresponding dihydroxamic acid compound as shown in formula (A); Formula (i), Formula (A), In equations (i) and (A), ring Q represents C6~C 20 Monocyclic or polycyclic aryl, C3~C 20 Monocycloalkyl, C5~C 20 Bridged cycloalkyl; R a and R b Alkyl groups that are the same or different and independently represent C1 to C6; R independently represents a hydrogen atom, hydroxyl group, cyano group, nitro group, halogen, C1-C6 alkyl group, C3-C8 cycloalkyl group, C6-C6 cycloalkyl group, etc. 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 Heteroaryloxy, C1-C6 haloalkyl, C6-C 10 Halogenated aryl, C1-C6 halogenated alkoxy, C1-C6 alkylthio, C6-C 10 aryl thiols, C3~C 10 heteroarylthio, C1~C6 alkylsulfinyl, C6~C 10 arylsulfinyl group, C3~C 10 heteroarylsulfinyl, C1~C6 alkylsulfonyl, C6~C 10 arylsulfonyl, C3~C 10 heteroarylsulfonyl, NR 5 R 6 R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, and a C6-C6 alkyl group. 10 aryl, C1-C6 alkyl carbonyl or C6-C 10 aryl carbonyl group; m represents the number of R, and m is any integer not exceeding the number of substituted sites in ring Q minus 2; when m is greater than 1, all R are either the same or different; Preferably, the alcohols in steps (1) and (2) are independently C1-C4 alcohols, and more preferably, they are both methanol; Preferably, the alkali metal hydroxide is at least one of sodium hydroxide and potassium hydroxide; Preferably, the molar ratio of the compound of formula (i) to the alkali metal hydroxide is 1:(2-4), more preferably 1:(2.5-3.5). Preferably, the molar ratio of the compound of formula (i) to hydroxylamine is 1:(2-3); Preferably, in step (2), the reaction temperature is 15-35°C and the reaction time is 20-72 hours, preferably 20-30 hours.

5. A rare earth metal-organic framework material, comprising a rare earth metal ion and a first ligand and a second ligand coordinated with the rare earth metal ion; wherein, The first ligand comprises a diisohydroxamic acid compound as shown in formula (A), and the second ligand comprises a monocarboxylic acid and / or a dicarboxylic acid; Formula (A) In equation (A), ring Q represents C6~C 20 Monocyclic or polycyclic aryl, C3~C 20 Monocycloalkyl, C5~C 20 Bridged cycloalkyl; R independently represents a hydrogen atom, hydroxyl group, cyano group, nitro group, halogen, C1-C6 alkyl group, C3-C8 cycloalkyl group, C6-C6 cycloalkyl group, etc. 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 Heteroaryloxy, C1-C6 haloalkyl, C6-C 10 Halogenated aryl, C1-C6 halogenated alkoxy, C1-C6 alkylthio, C6-C 10 aryl thiols, C3~C 10 heteroarylthio, C1~C6 alkylsulfinyl, C6~C 10 arylsulfinyl group, C3~C 10 heteroarylsulfinyl, C1~C6 alkylsulfonyl, C6~C 10 arylsulfonyl, C3~C 10 heteroarylsulfonyl, NR 5 R 6 R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, and a C6-C6 alkyl group. 10 aryl, C1-C6 alkyl carbonyl or C6-C 10 aryl carbonyl group; m represents the number of Rs, and m is any integer not exceeding the number of substituted sites in ring Q minus 2; when m is greater than 1, the Rs are either the same or different.

6. The rare earth metal-organic framework material according to claim 5, characterized in that, The rare earth metal is selected from at least one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium, preferably at least one of scandium and yttrium; and / or In equation (A), ring Q represents C6~C 12 Monocyclic or polycyclic aryl, C3-C8 monocyclic alkyl, C5-C 12 Bridged cycloalkyl groups; preferably phenyl, naphthyl, biphenyl, cyclobutyl, cyclopentyl, cyclohexyl, C5~C 12 Bridged cycloalkyl groups; and / or In formula (A), R independently represents a hydrogen atom, hydroxyl group, cyano group, nitro group, fluorine group, chlorine group, bromine group, C1-C6 alkyl group, C3-C8 cycloalkyl group, C6-C6 cycloalkyl group, C6-C6 cycloalkyl group, C6-C6 cycloalkyl group, C3-C8 cycloalkyl group, C6-C6 cycloalkyl group, C3 ... 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 heteroaryloxy, C1~C6 haloalkyl, C6~C 10 Halogenated aryl groups, C1-C6 halogenated alkoxy groups, or -NR 5 R 6 R 5 and R 6 Each independently represents a hydrogen atom, a C1-C6 alkyl group, or a C6-C6 alkyl group. 10 The aryl group; preferably, R independently represents hydrogen, amino, hydroxyl, nitro, fluorine, chlorine, bromine, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, methoxy, ethoxy, propoxy, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cuboalkyl, epoxy, trifluoromethyl, trifluoromethyloxy, phenyl, phenoxy, furanyloxy, thiazolyloxy, pyridyloxy; and / or In formula (A), m is 0, 1, 2, 3, 4, 5 or 6.

7. The rare earth metal-organic framework material according to claim 5 or 6, characterized in that, The first ligand is selected from the compounds shown in formulas (A-1) to (A-5): Equation (A-1) Equation (A-2) Equation (A-3), Equation (A-4) Formula (A-5), In equations (A-1) to (A-3), the definition of each R is the same as that in equation (A); in equation (A-4), t1 and t2 are independently 0, 1, 2 or 3, preferably independently 0, 1 or 2; t3 is 1, 2 or 3, preferably 1 or 2; Preferably, the first ligand is selected from the group consisting of: ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， 。 8. The rare earth metal-organic framework material according to any one of claims 5 to 7, characterized in that, The second ligand is selected from formic acid, oxalic acid, and compounds shown in formulas (IV) and (V): ， ， Among them, R 7 R 8 R 9 R 10 and R 11 Each of the following groups independently represents a hydrogen atom, halogen, cyano group, nitro group, hydroxyl group, C1-C6 alkyl group, C3-C8 cycloalkyl group, and C6-C6 cycloalkyl group. 10 aryl, 3-6 membered heterocyclic, C1-C6 alkoxy, C6-C 10 aryloxy group, C3~C 10 Heteroaryloxy, C1-C6 haloalkyl, C6-C 10 Halogenated aryl, C1-C6 halogenated alkoxy, C1-C6 alkylthio, C6-C 10 aryl thiols, C3~C 10 Heteroaryl thiols, C1-C6 alkyl sulfinyls, C6-C 10 arylsulfinyl group, C3~C 10 Heteroarylsulfinyl, C1~C6 alkylsulfonyl, C6~C 10 arylsulfonyl, C3~C 10 heteroarylsulfonyl or -NR 12 R 13 R 12 and R 13 Each independently represents a hydrogen atom, a C1-C6 alkyl group, and a C6-C6 alkyl group. 10 aryl, C1-C6 alkyl carbonyl or C6-C 10 aryl carbonyl group; Preferably, R 7 R 8 R 9 R 10 and R 11 Each of the following can be independently represented: hydrogen atom, halogen, cyano group, nitro group, hydroxyl group, C1-C6 alkyl group, C6-C6 alkyl group. 10 aryl, C1-C6 haloalkyl or -NR 12 R 13 R 12 and R 13 Each can be used independently to represent a hydrogen atom or a C1-C6 alkyl group; Preferably, R 7 R 8 R 9 R 10 and R 11 Each of these can be independently represented as a hydrogen atom, fluorine, cyano, nitro, amino, hydroxyl, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, phenyl, or trifluoromethyl. Preferably, the second ligand is selected from the group consisting of: ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ， ； Preferably, the second ligand is selected from formic acid, acetic acid, propionic acid, and butyric acid.

9. A method for preparing a rare earth metal-organic framework material as described in any one of claims 5 to 7, comprising the following steps: (1) Mix the first solution containing the first ligand with the second solution containing the rare earth metal ions to obtain a mixed solution; (2) The mixture is mixed with the second ligand or its salt and heated to react, thereby obtaining the rare earth metal-organic framework material; Preferably, the molar ratio of the first ligand to the rare earth metal ion is 1:(0.8~1.5). Preferably, the molar ratio of the second ligand or its salt to the rare earth metal ion is (15~25):1; Preferably, the reaction temperature is 60~110℃, more preferably 90~110℃; Preferably, step (1) further includes the step of ultrasonic treatment of the mixture; Preferably, the solvent in the first solution and the second solution includes one or more of water, amides, and ketones, and more preferably includes N,N-dimethylformamide.

10. The application of the diisohydroxamic acid compound as described in any one of claims 1 to 4, or the diisohydroxamic acid compound obtained by the preparation method as described in claim 5, or the rare earth metal-organic framework material as described in any one of claims 6 to 8, or the rare earth metal-organic framework material obtained by the preparation method as described in claim 9, in gas adsorption and / or separation; Preferably, the gas includes one or two or more of Xe, Kr, CO2, N2, CH4, SF6, CF4, and C2H2; Preferably, the gas contains a mixture of Xe and Kr, or a mixture of CO2 and N2, or a mixture of CO2 and CH4, or a mixture of SF6 and CF4, or a mixture of CO2 and C2H2, or a mixture of CO2, N2 and CH4.

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