Crystalline metal ring film and preparation method and application thereof

Abstract

The invention relates to the technical field of metal organic framework new materials, in particular to a crystalline metal ring film and a preparation method and application thereof.The crystalline metal ring film is formed by self-assembly of metal ligands and organic ligands through interface coordination, a film body of the crystalline metal ring film has crystallinity, pore channels formed by the metal ligands and the organic ligands are of an ordered structure, and the crystalline metal ring film can be used as a crystalline metal ring film. The molecular interaction of crystalline metal ring film molecules and chiral compounds and the transmission of chiral molecules are facilitated. Besides, the thickness of the crystalline metal ring film prepared through an interface coordination method is about 100 nm, the thickness of the mixed matrix film prepared through the preparation method provided by the prior art is about 43 microns, and the thickness of the mixed matrix film is obviously reduced compared with that of the mixed matrix film in the prior art. The crystalline metal ring membrane provided by the invention is coherent and defect-free in membrane body, the channel of the crystalline metal ring membrane greatly improves the transmission rate, and the crystalline metal ring membrane is expected to be applied to separation and / or detection of chiral compounds.

Description

Technical Field

[0001] The present invention relates to the technical field of new metal organic framework materials, and in particular to a crystalline metal ring film and a preparation method and application thereof. Background Art

[0002] Metal organic framework (MOF) is a type of crystalline porous material with a periodic network structure formed by the interconnection of inorganic metal centers and bridging organic ligands through self-assembly. As a crystalline porous material, MOF shows great potential in constructing high-performance molecular sieve membranes. High crystallinity means that the sieve membrane has periodic and uniform pores, thereby improving the sieving ability of the molecular sieve membrane; high crystallinity also represents a rigid skeleton structure, which will lead to poor film-forming ability, and defects and cracks between grains are prone to occur during membrane preparation and activation, affecting the continuity of film formation, and then affecting the selectivity of sieve membrane sieving; on the contrary, if the crystallinity of the sieve membrane is reduced, the rigidity of the skeleton structure is reduced, which is conducive to the optimization of the film-forming ability of the sieve membrane, but this optimization has to sacrifice the periodicity and uniformity of the sieving pores. Therefore, in order to obtain the best separation performance of MOF molecular sieve membranes, it is necessary to balance the structure between MOF membrane crystallization and film formation.

[0003] In addition, since the metal ring is a discrete structure rather than a framework structure, the method for constructing a metal ring membrane usually involves doping a polymer to obtain a mixed matrix metal ring membrane using the polymer as a matrix. The membrane prepared by this method itself is non-crystalline and has disordered channels, which limits the transport of molecules and affects the role of the metal ring molecules themselves. The polymer in the mixed matrix membrane is a dense structure, and the proportion of the metal ring in the membrane is small (usually less than 30%), so there are fewer pore channels formed by the metal ring in the membrane, which reduces the membrane transmission rate. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the first object of the present invention is to provide a method for preparing a crystalline metal ring film; the second object of the present invention is to provide a crystalline metal ring film; the third object of the present invention is to provide an application of the crystalline metal ring film.

[0005] In order to achieve the first purpose, the technical solution adopted by the present invention is: A method for preparing a crystalline metal ring film comprises the following steps: S100, preparing an organic ligand, the structural formula of the organic ligand is as follows: ; S200, preparing a metal ligand, the structural formula of the metal ligand is as follows: ; S300, dissolving the organic ligand obtained in step S100 and the metal ligand obtained in step S200 in a first organic solvent to obtain a mixed solution; In the mixed solution, the molar concentration of the organic ligand is 0.85-0.90 μmol / ml, and the molar concentration of the metal ligand is 0.75-1.00 μmol / ml; S400, preparing a crystalline metal ring film by an interface coordination method, the process is as follows: slowly pouring the mixed solution on the surface of a silver triflate (AgOTf) aqueous solution, reacting for 16 to 24 hours, and obtaining a crystalline metal ring film; The concentration of the AgOTf aqueous solution is 1.6-1.8 μmol / ml.

[0006] Further, in step S100, the organic ligand synthesis process is as follows: .

[0007] Furthermore, in step S200, the preparation process of the metal ligand is as follows: 4,4'-dibromobenzophenone and tetrakis(triethylphosphine)platinum are dissolved in a second organic solvent, reacted at 70-90°C for 48-96 days to obtain the metal ligand.

[0008] Furthermore, the second organic solvent is selected from toluene.

[0009] Furthermore, in step S300, the first organic solvent is selected from ethyl acetate.

[0010] In order to achieve the second purpose, the technical solution adopted by the present invention is: A crystalline metal ring membrane, which is self-assembled by metal ligands and organic ligands through interface coordination, is prepared by any of the above-mentioned methods for preparing crystalline metal ring membranes, and has a structural formula as shown below: .

[0011] In order to achieve the third purpose, the technical solution adopted by the present invention is: An application of a crystalline metal ring membrane, such as the above crystalline metal ring membrane, includes separation and / or detection of chiral compounds.

[0012] Furthermore, the application includes applying the crystalline metal ring membrane to a permeation separation device.

[0013] Furthermore, the chiral compound includes chiral isomer phenylethanol.

[0014] Furthermore, the chiral compound includes chiral isomer salbutamol.

[0015] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: The present invention provides a method for preparing a crystalline metal ring membrane. The preparation method uses interface coordination between metal ligands and organic ligands to self-assemble the obtained crystalline metal ring membrane. The crystalline metal ring membrane has crystallinity, and the pores formed by the metal-organic framework are of an ordered structure, which is conducive to the molecular interaction between the crystalline metal ring membrane molecules and chiral compounds and the transmission of chiral molecules. In addition, the crystalline metal ring membrane prepared by the interface coordination method is two orders of magnitude thinner than the mixed matrix membrane in the prior art. The crystalline metal ring membrane has a coherent membrane body and its channels greatly improve the transmission rate, which is expected to be applied to the separation and / or detection of chiral compounds.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a SEM image of the surface layer of the crystalline metal ring film provided in Example 1 of the present invention.

[0019] Figure 2 It is the solid-state nuclear magnetic resonance image of the crystalline metal ring film and the crystalline metal ring film solid powder provided in Example 1 of the present invention.

[0020] Figure 3 This is a TEM image of the surface layer of the crystalline metal ring film provided in Example 1 of the present invention.

[0021] Figure 4 This is a SEM image of the longitudinal section of the crystalline metal ring membrane provided in Example 1 of the present invention.

[0022] Figure 5 1 is a curve relationship diagram of the permeation amount and transmission time of the phenylethanol enantiomer in the crystalline metal ring membrane provided in Example 1 of the present invention.

[0023] Figure 6 It is a SEM picture of the longitudinal section of the mixed matrix metal ring membrane obtained according to the prior art.

[0024] Figure 7The figure is a graph showing the relationship between the permeation amount and the transmission time of the phenylethanol enantiomers in the mixed matrix metallocyclic membrane obtained according to the prior art.

[0025] Figure 8 It is a schematic diagram of the osmotic separation device in Example 2 and Example 3 of the present invention.

[0026] Fig. 9 This is an HPLC chromatogram before and after separation of 1-phenylethanol enantiomers by the crystalline metal ring membrane provided in Example 2 of the present invention.

[0027] Fig.10 This is an HPLC chromatogram before and after separation of chiral enantiomers of salbutamol by the crystalline metal ring membrane provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0029] A method for preparing a crystalline metal ring film comprises the following steps: S100, preparing an organic ligand, the structural formula of the organic ligand is as follows: ; S200, preparing a metal ligand, the structural formula of the metal ligand is as follows: ; S300, dissolving the organic ligand obtained in step S100 and the metal ligand obtained in step S200 in a first organic solvent to obtain a mixed solution; In the mixed solution, the molar concentration of the organic ligand is 0.85-0.90 μmol / ml, and the molar concentration of the metal ligand is 0.75-1.00 μmol / ml; S400, preparing a crystalline metal ring film by an interface coordination method, the process is as follows: slowly pouring the mixed solution on the surface of the AgOTf aqueous solution, reacting for 16 to 24 hours, and obtaining a crystalline metal ring film; The concentration of the AgOTf aqueous solution is 1.6-1.8 μmol / ml.

[0030] Preferably, in step S200, the preparation process of the metal ligand is as follows: 4,4'-dibromobenzophenone and tetrakis(triethylphosphine)platinum are dissolved in a second organic solvent, reacted at 70-90°C for 48-96 days to obtain the metal ligand.

[0031] In the following examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all available from commercial sources unless otherwise specified.

[0032] Example 1 The synthetic route of organic ligands is as follows: ; The specific process is as follows: (300 mg) was dissolved in ethyl acetate (5 ml), and then 4M hydrochloric acid (10 ml) was added dropwise to the solution, and stirred at room temperature for 2 h. The reaction system was washed with saturated sodium bicarbonate solution and dichloromethane, the organic layer was collected and the solvent was removed by vacuum, the residue was dissolved in dichloromethane (10 ml), 3,5-bis(trifluoromethyl)phenylisothiocyanate (275 mg) was added dropwise in an ice-water bath, and stirred at room temperature for 5 hours. After the reaction was completed, the solvent was removed by decompression to obtain an organic ligand .

[0033] Preparation of metal ligands The process is as follows: Under nitrogen atmosphere, 4,4'-dibromobenzophenone (512 mg) and tetrakis(triethylphosphine)platinum (2464 mg) were dissolved in toluene solvent and reacted at 70°C for 3 days to obtain the metal ligand. .

[0034] The reaction process of the crystalline metal ring film is as follows: ; The preparation process is as follows: the organic ligand (8.8 μmol) and metal ligand (8.8 μmol) prepared above are dissolved in ethyl acetate solution (about 10 mL) to obtain ethyl acetate solution of organic ligand and metal ligand, AgOTf (16 μmol) is dissolved in about 10 mL of water, and the ethyl acetate solution is slowly poured on the surface of the aqueous solution at the interface to carry out coordination reaction for about 16 hours to obtain a crystalline metal ring film, and the scanning electron microscopy (SEM) scanning results are as follows: Figure 1 As shown, the results indicate that the crystalline metal ring film prepared by the interface coordination method is coherent and defect-free.

[0035] Solid-state NMR of crystalline metal ring film and crystalline metal ring film solid powder, such as Figure 2As shown, the nuclear magnetic resonance signal peaks of the crystalline metal ring film and the solid powder of the crystalline metal ring film are consistent, indicating that the crystalline metal ring film is successfully prepared.

[0036] The transmission electron microscopy (TEM) scanning results of the crystalline metal ring film are as follows: Figure 3 As shown, the lattice stripes in the figure illustrate that according to the preparation method of the crystalline metal ring film provided by the present invention, the obtained metal ring film is crystalline.

[0037] According to the method for preparing the crystalline metal ring film provided by the present invention, the thickness of the obtained crystalline metal ring film at the interface coordination is about 100 nm. Figure 4 As shown; the curve relationship between the permeation amount and transmission time of the chiral enantiomer of phenylethanol in the crystalline metal ring membrane, as shown Figure 5 As shown; According to the prior art, the preparation method disclosed in the patent (CN15894569A), the prepared mixed matrix metal ring membrane has a thickness as shown Figure 6 As shown, it is about 43μm; the curve relationship between the permeation amount and transmission time of the chiral enantiomer of phenylethanol in the mixed matrix metal ring membrane is as follows: Figure 7 As shown; from Figures 4 to 7 It can be seen that the crystalline metal ring membrane obtained by interface coordination is significantly thinner than the mixed matrix membrane prepared according to the prior art, and its channel greatly improves the transmission rate.

[0038] Example 2 Application of crystalline metallocyclic membrane to separation of chiral compound 1-phenylethanol.

[0039] The crystalline metallocyclic membrane was used to separate the chiral compound 1-phenylethanol. The process is as follows: The crystalline metal ring membrane is fixed in the middle through the permeation separation device, such as Figure 8 As shown, an ethanol solution of the racemic enantiomer of 1-phenylethanol (concentration of 10 mmol / L) was added to one side of the crystalline metal ring membrane, and a pure ethanol solution was added to the other side of the crystalline metal ring membrane. After 4 hours of osmotic transmission, the solution on the osmotic side was taken out, and the separation effect was detected by high performance liquid chromatography (HPLC); Liquid chromatography separation conditions: volume ratio of n-hexane:isopropanol 95:5, flow rate 0.5 mL / min, OD-H chiral column; The HPLC spectrum of the crystalline metallocyclic membrane before and after separation of the chiral enantiomers of 1-phenylethanol provided by the present invention is as follows: Fig. 9 As shown, the results indicate that the crystalline metal ring membrane has a good separation effect on the enantiomers of the chiral compound 1-phenol.

[0040] Example 3 Application of crystalline metallocyclic membrane to separation of chiral compound salbutamol.

[0041] Crystalline metallocyclic membranes were used to separate the chiral compound salbutamol. The process was as follows: The crystalline metal ring membrane is fixed in the middle through the permeation separation device, such as Figure 8 As shown, an ethanol solution of racemic enantiomer of salbutamol (concentration of 10 mmol / L) was added to one side of the crystalline metal ring membrane, and a pure ethanol solution was added to the other side of the crystalline metal ring membrane. After 4 hours of osmotic transmission, the solution on the osmotic side was taken out, and the separation effect was detected by HPLC; Liquid chromatography separation conditions: volume ratio of n-hexane:isopropanol 95:5, flow rate 0.5 mL / min, OD-H chiral column; The HPLC analysis of the crystalline metallocyclic membrane provided by the present invention before and after separation of the enantiomers of salbutamol is as follows: Fig.10 As shown, the results indicate that the crystalline metal ring membrane has a good separation effect on the chiral enantiomers of salbutamol.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a crystalline metal ring film, characterized in that: The steps include: S100, preparing an organic ligand, the structural formula of the organic ligand is as follows: ； S200, preparing a metal ligand, the structural formula of the metal ligand is as follows: ； S300, dissolving the organic ligand obtained in step S100 and the metal ligand obtained in step S200 in a first organic solvent to obtain a mixed solution; In the mixed solution, the molar concentration of the organic ligand is 0.85-0.90 μmol / ml, and the molar concentration of the metal ligand is 0.75-1.00 μmol / ml; S400, preparing a crystalline metal ring film by an interface coordination method, the process is as follows: slowly pouring the mixed solution on the surface of the silver trifluoromethanesulfonate aqueous solution, reacting for 16 to 24 hours, and obtaining a crystalline metal ring film; The concentration of the silver trifluoromethanesulfonate aqueous solution is 1.6-1.8 μmol / ml.

2. The method for preparing the crystalline metal ring film according to claim 1, characterized in that: In step S100, the organic ligand synthesis process is as follows: 。 3. The method for preparing the crystalline metal ring film according to claim 1, characterized in that: In step S200, the preparation process of the metal ligand is as follows: 4,4'-dibromobenzophenone and tetrakis(triethylphosphine)platinum are dissolved in a second organic solvent, reacted at 70-90°C for 48-96 days to obtain the metal ligand.

4. The method for preparing the crystalline metal ring film according to claim 3, characterized in that: The second organic solvent is selected from toluene.

5. The method for preparing the crystalline metal ring film according to claim 1, characterized in that: In step S300, the first organic solvent is selected from ethyl acetate.

6. A crystalline metal ring film, characterized in that: It is self-assembled by metal ligands and organic ligands through interface coordination, and is prepared by the preparation method of the crystalline metal ring membrane according to any one of claims 1 to 5, and its structural formula is as follows: 。 7. An application of a crystalline metal ring film, characterized in that: The crystalline metal ring membrane according to claim 6, wherein the application includes separation and / or detection of chiral compounds.

8. The use of the crystalline metal ring film as claimed in claim 7, characterized in that: The application includes using the crystalline metal ring membrane in a permeation separation device.

9. The use of the crystalline metal ring film as claimed in claim 7, characterized in that: The chiral compound includes chiral isomer phenylethanol.

10. The use of the crystalline metal ring film according to claim 7, characterized in that: The chiral compound includes chiral isomers of salbutamol.

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