Crystalline metallo cyclic membrane, method for preparing the same and use thereof

Abstract

The present application relates to the technical field of metal organic framework new material, and particularly relates to a crystalline metal ring membrane, a preparation method and application thereof, the crystalline metal ring membrane is formed by interface coordination self-assembly of metal ligand and organic ligand, the membrane body has crystallinity, the channel formed by the metal ligand and the organic ligand is an ordered structure, which is conducive to the molecular interaction of the crystalline metal ring membrane molecule and the chiral compound and the transmission of the chiral molecule.In addition, the crystalline metal ring membrane prepared by the interface coordination method has a thickness of about 100 nm, and the mixed matrix membrane prepared by the preparation method provided by the prior art has a thickness of about 43 microns, which is obviously thinner than the thickness of the mixed matrix membrane in the prior art; the membrane body of the crystalline metal ring membrane provided by the present application is continuous and defect-free, and the channel greatly improves the transmission rate, and is expected to be applied to the separation and / or detection of chiral compounds.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new materials of metal organic frameworks, and particularly to a crystalline metal ring membrane, a preparation method and application thereof. BACKGROUND

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

[0003] In addition, since the metal ring is a discrete structure non-framework structure, the method for constructing the metal ring membrane usually dopes a polymer to obtain a hybrid matrix metal ring membrane with the polymer as a matrix. The membrane prepared by this method is non-crystalline itself, the channel is disordered, the transmission of the molecule is limited, and the role of the metal ring molecule itself is affected. The polymer in the hybrid matrix membrane is a dense structure, and the proportion of the metal ring in the membrane is small (usually less than 30%), so the pore channel formed by the metal ring in the membrane is small, and the transmission rate of the membrane is reduced. SUMMARY

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

[0005] To achieve the first object, the technical solution adopted by the present application is as follows:

[0006] A preparation method of a crystalline metal ring membrane, comprising the following steps:

[0007] S100, preparing an organic ligand, and the structure formula of the organic ligand is as follows:

[0008] ;

[0009] S200, preparing a metal ligand, the structural formula of which is shown as follows:

[0010] ;

[0011] 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;

[0012] 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.

[0013] S400, preparing a crystalline metal ring film by an interfacial coordination method, the process being as follows: slowly pouring the mixed solution on the surface layer of an aqueous silver triflate (AgOTf) solution, and reacting for 16-24 h to obtain the crystalline metal ring film.

[0014] In the aqueous AgOTf solution, the concentration is 1.6-1.8 μmol / ml.

[0015] Further, in step S100, the synthesis process of the organic ligand is as shown below:

[0016] .

[0017] Further, in step S200, the preparation process of the metal ligand is as follows: dissolving 4,4'-dibromobenzophenone and tetrakis(triethylphosphine) platinum in a second organic solvent, and reacting at 70-90℃ for 48-96 d to obtain the metal ligand.

[0018] Further, the second organic solvent is selected from toluene.

[0019] Further, in step S300, the first organic solvent is selected from ethyl acetate.

[0020] To achieve the second object, the technical scheme adopted by the present application is as follows:

[0021] A crystalline metal ring film, which is prepared from a metal ligand and an organic ligand by interfacial coordination self-assembly, and is prepared by the preparation method of the crystalline metal ring film according to any one of the above, and the structural formula of which is shown as follows:

[0022] .

[0023] To achieve the third object, the technical scheme adopted by the present application is as follows:

[0024] Use of a crystalline metal ring membrane, such as the crystalline metal ring membrane described above, the use comprising separation and / or detection of a chiral compound.

[0025] Further, the use comprises use of the crystalline metal ring membrane in a pervaporation separation device.

[0026] Further, the chiral compound comprises chiral isomers of phenylethanol.

[0027] Further, the chiral compound comprises chiral isomers of salbutamol.

[0028] The one or more technical solutions described above in the embodiments of the present application have at least one of the following technical effects:

[0029] The present application provides a preparation method of a crystalline metal ring membrane, the preparation method comprising interface coordination of a metal ligand and an organic ligand, and self-assembly of the crystalline metal ring membrane obtained by the interface coordination, the crystalline metal ring membrane having crystallinity, and the pore formed by the metal-organic framework having an ordered structure, which is conducive to molecular interaction of the crystalline metal ring membrane and the chiral compound and transmission of the chiral molecule; 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 body is continuous, and the channel greatly improves the transmission rate, and is expected to be applied to separation and / or detection of a chiral compound.

[0030] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0032] Figure 1 is a SEM image of a surface layer of the crystalline metal ring membrane provided in Embodiment 1 of the present application.

[0033] Figure 2 is a solid-state nuclear magnetic resonance image of the crystalline metal ring membrane and a solid powder of the crystalline metal ring membrane provided in Embodiment 1 of the present application.

[0034] Figure 3 is a TEM image of a surface layer of the crystalline metal ring membrane provided in Embodiment 1 of the present application.

[0035] Figure 4 is a SEM image of a longitudinal section of the crystalline metal ring membrane provided in Embodiment 1 of the present application.

[0036] Figure 5 is a curve of the permeation amount and the transmission time of the phenylethanol enantiomer in the crystalline metal ring membrane provided by the embodiment 1 of the present application.

[0037] Figure 6 is a SEM image of the longitudinal section of the mixed matrix metal ring membrane obtained according to the prior art.

[0038] Figure 7 is a curve of the permeation amount and the transmission time of the phenylethanol enantiomer in the mixed matrix metal ring membrane obtained according to the prior art.

[0039] Figure 8 is a schematic diagram of the permeation separation device in the embodiment 2 and the embodiment 3 of the present application.

[0040] Figure 9 is an HPLC chromatogram before and after the separation of the 1-phenylethanol enantiomer by the crystalline metal ring membrane provided by the embodiment 2 of the present application.

[0041] Figure 10 is an HPLC chromatogram before and after the separation of the salbutamol chiral enantiomer by the crystalline metal ring membrane provided by the embodiment 3 of the present application. DETAILED DESCRIPTION

[0042] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application. The following embodiments are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0043] A preparation method of a crystalline metal ring membrane, comprising the following steps:

[0044] S100, preparing an organic ligand, and the structural formula of the organic ligand is as follows:

[0045]

[0046] S200, preparing a metal ligand, and the structural formula of the metal ligand is as follows:

[0047]

[0048] S300, dissolving the organic ligand obtained in the step S100 and the metal ligand obtained in the step S200 in a first organic solvent to obtain a mixed solution;

[0049] ​​The molar concentration of the organic ligand in the mixed solution is 0.85-0.90 μmol / ml, and the molar concentration of the metal ligand is 0.75-1.00 μmol / ml.

[0050] S400, the crystalline metal ring membrane is prepared by the interface coordination method, and the process is as follows: the mixed solution is slowly poured on the surface layer of the AgOTf aqueous solution, and reacted for 16-24 h to obtain the crystalline metal ring membrane.

[0051] The concentration of the AgOTf aqueous solution is 1.6-1.8 μmol / ml.

[0052] Preferably, in step S200, the metal ligand is prepared as follows: 4,4'-dibromobenzophenone and tetrakis(triethylphosphine) platinum are dissolved in a second organic solvent, reacted at 70-90°C for 48-96 d to obtain the metal ligand.

[0053] In the following examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are commercially available unless otherwise specified.

[0054] Example 1

[0055] The synthesis route of the organic ligand is as follows:

[0056] ;

[0057] The specific process is as follows: compound (300 mg) is dissolved in ethyl acetate (5 ml), then 4M hydrochloric acid (10 ml) is added dropwise to the solution, stirred at room temperature for 2 h, the reaction system is washed with saturated sodium bicarbonate solution and dichloromethane, the organic layer is collected and the solvent is removed by vacuum, the residue is dissolved in dichloromethane (10 ml), 3,5-di(trifluoromethyl)phenyl isothiocyanate (275 mg) is added dropwise in an ice water bath, and stirred at room temperature for 5 hours, after the reaction is completed, the solvent is removed by reduced pressure to obtain the organic ligand .

[0058] The metal ligand is prepared as follows: 4,4'-dibromobenzophenone (512 mg) and tetrakis(triethylphosphine) platinum (2464 mg) are dissolved in toluene solvent under a nitrogen atmosphere, reacted at 70°C for 3 days to obtain the metal ligand .

[0059] The reaction process of the crystalline metal ring membrane is as follows: ;

[0060] The preparation process is as follows: the above prepared organic ligand (8.8 μmol) and metal ligand (8.8 μmol) are dissolved in ethyl acetate solution (about 10 mL) to obtain an ethyl acetate solution of the organic ligand and the metal ligand, AgOTf (16 μmol) is dissolved in about 10 mL of water, the ethyl acetate solution is slowly poured onto the surface of the water solution at the interface, and the coordination reaction is carried out for about 16 h to obtain a crystalline metal ring membrane, and the scanning electron microscopy (SEM) scanning result is as shown in Figure 1 The result shows that the crystalline metal ring membrane prepared by the interface coordination method has a continuous and defect-free membrane body.

[0061] The solid-state nuclear magnetic resonance of the crystalline metal ring membrane and the solid powder of the crystalline metal ring membrane is as shown in Figure 2 The nuclear magnetic resonance signal peaks of the crystalline metal ring membrane and the solid powder of the crystalline metal ring membrane are consistent, indicating that the crystalline metal ring membrane is successfully prepared.

[0062] The transmission electron microscopy (TEM) scanning result of the crystalline metal ring membrane is as shown in Figure 3 The lattice fringes in the figure show that the metal ring membrane prepared by the preparation method of the crystalline metal ring membrane provided by the application is in a crystalline state.

[0063] According to the preparation method of the crystalline metal ring membrane provided by the application, the thickness of the crystalline metal ring membrane prepared by the interface coordination is about 100 nm, as shown in Figure 4 The curve relationship between the permeation amount and the transmission time of the chiral enantiomers of phenethyl alcohol in the crystalline metal ring membrane is as shown in Figure 5 According to the preparation method disclosed in the prior art patent (CN15894569A), the mixed matrix metal ring membrane prepared has a thickness of about 43 μm, as shown in Figure 6 The curve relationship between the permeation amount and the transmission time of the chiral enantiomers of phenethyl alcohol in the mixed matrix metal ring membrane is as shown in Figure 7

[0064] From Figures 4 to 7 It can be seen that the crystalline metal ring membrane obtained by the interface coordination is significantly thinned compared with the thickness of the mixed matrix membrane prepared according to the prior art, and the channel greatly improves the transmission rate.

[0065] Example 2: Application of the crystalline metal ring membrane to the separation of the chiral compound 1-phenethyl alcohol.

[0066] The application of the crystalline metal ring membrane to the separation of the chiral compound 1-phenethyl alcohol is as follows:

[0067] ​The crystalline metal ring membrane is fixed in the middle through a penetration separation device, as shown in the figure, an ethanol solution (concentration of 10 mmol / L) of 1-phenyl ethanol racemic enantiomers is added to one side of the crystalline metal ring membrane, and a pure ethanol solution is added to the other side of the crystalline metal ring membrane, the solution on the penetration side is taken out after penetration transmission for 4 hours, and the separation effect is detected by high performance liquid chromatography (HPLC); Figure 8

[0068] The liquid chromatography separation condition is that the volume ratio of n-hexane to isopropyl alcohol is 95:5, the flow rate is 0.5 mL / min, and the OD-H chiral column is used;

[0069] The HPLC chromatograms of the crystalline metal ring membrane before and after separating 1-phenyl ethanol chiral enantiomers are as shown in the figure, Figure 9 The results show that the crystalline metal ring membrane has a good separation effect on the chiral compound 1-phenyl alcohol enantiomers.

[0070] Example 3: Application of the crystalline metal ring membrane to separation of a chiral compound salbutamol.

[0071] The crystalline metal ring membrane is applied to separation of a chiral compound salbutamol, and the process is as follows:

[0072] The crystalline metal ring membrane is fixed in the middle through a penetration separation device, as shown in the figure, Figure 8 An ethanol solution (concentration of 10 mmol / L) of salbutamol racemic enantiomers is added to one side of the crystalline metal ring membrane, and a pure ethanol solution is added to the other side of the crystalline metal ring membrane, the solution on the penetration side is taken out after penetration transmission for 4 hours, and the separation effect is detected by HPLC;

[0073] The liquid chromatography separation condition is that the volume ratio of n-hexane to isopropyl alcohol is 95:5, the flow rate is 0.5 mL / min, and the OD-H chiral column is used;

[0074] The HPLC of the crystalline metal ring membrane before and after separating salbutamol enantiomers is as shown in the figure, Figure 10 The results show that the crystalline metal ring membrane has a good separation effect on the chiral compound salbutamol.

[0075] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.​

Claims

1. A method of preparing a crystalline metallo cyclic membrane, characterized by, The method 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 membrane by an interfacial coordination method, the process is as follows: slowly pouring the mixed solution on the surface layer of an aqueous silver trifluoromethanesulfonate solution, and reacting for 16-24 hours to obtain the crystalline metal ring membrane. The concentration of the aqueous silver trifluoromethanesulfonate solution is 1.6-1.8 μmol / ml.

2. The method of claim 1, wherein the crystalline metallo cyclic film is prepared by a process comprising: In step S100, the synthesis process of the organic ligand is as follows: 。 3. The method of claim 1, wherein the crystalline metallo cyclic film is prepared by a process comprising: In step S200, the preparation process of the metal ligand is as follows: dissolving 4,4'-dibromobenzophenone and tetrakis(triethylphosphine) platinum in a second organic solvent, reacting at 70-90 °C for 48-96 days to obtain the metal ligand.

4. The method of claim 3, wherein the crystalline metallo cyclic membrane is prepared by the steps of: The second organic solvent is selected from toluene.

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

6. A crystalline metallo cyclic membrane characterized by, The crystalline metal ring membrane is formed by self-assembly of the metal ligand and the organic ligand by interfacial coordination, and is prepared by the method for preparing the crystalline metal ring membrane according to any one of claims 1-5, and the structural formula is as follows: 。 7. Use of a crystalline metallo cyclic membrane, characterized in that The crystalline metal ring membrane according to claim 6, wherein the application comprises separation and / or detection of chiral compounds.

8. Use of a crystalline metallo cyclic membrane according to claim 7, characterized in that, The application comprises applying the crystalline metal ring membrane to a pervaporation separation device.

9. Use of a crystalline metallo cyclic membrane according to claim 7, wherein the membrane is used in a process for the separation of a gas mixture. The chiral compounds comprise chiral isomers of phenethyl alcohol.

10. Use of a crystalline metallo cyclic membrane according to claim 7, characterized in that, The chiral compounds comprise chiral isomers of salbutamol.

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