A self-supporting molecular cage-based self-repairing extraction stationary phase and its preparation method and application

Abstract

The present invention discloses a self-supporting molecular cage-based self-repairing extraction stationary phase and its preparation method and application. A self-supporting molecular cage-based self-repairing extraction stationary phase comprises a tetrahedral metal-organic molecular cage MOC-Zr-S2 and a disulfide structural unit, which is obtained by polymerization of the molecular cage through intermolecular disulfide bonds, and the tetrahedral metal-organic molecular cage is obtained by coordination self-assembly of 4 tripod-type metal complex clusters and 6 linear aromatic dicarboxylic acid secondary structural units. The self-supporting molecular cage-based self-repairing extraction stationary phase proposed by the present invention not only has the characteristics of simple preparation method of conventional organic polymers, wide application range and good biocompatibility, but also can effectively overcome the "trade off" effect problem between the permeability and selectivity of traditional polymers by introducing nanoscale molecular cage units, and improve the selectivity of the stationary phase to the extraction target without reducing the permeability of the material.

Description

Technical Field

[0001] The present invention relates to the technical field of synthetic materials, and in particular to a self-supporting molecular cage-based self-repairing extraction stationary phase, a preparation method and an application thereof. Background Art

[0002] Extraction stationary phases are substances that separate target compounds from their matrix and coexisting interfering compounds. By selecting an appropriate extraction stationary phase and leveraging electrostatic, hydrophobic, hydrogen-bonding, and π-π interactions between the target compound and the stationary phase's modified groups, and exploiting competitive adsorption of the target compound between the extraction stationary phase and the matrix, as well as differential adsorption of the target compound and coexisting interfering compounds on the extraction stationary phase, the target compound can be selectively retained by the extraction stationary phase, achieving both purification and enrichment. The adsorbed target compound can then be released from the extraction stationary phase through methods such as solvent dissolution and thermal desorption, achieving separation, enrichment, and purification. Common extraction stationary phases are obtained by modifying solid supports such as silica gel, alumina, diatomaceous earth, and magnetic beads with specific groups. While these stationary phases are simple to prepare, they are often limited to specific scenarios due to the support format. In contrast, self-supporting extraction stationary phases, which do not require any support, have a wider range of applications. Organic polymer extraction stationary phases have the characteristics of a wide range of media materials, simple preparation methods, a wide applicable pH range, and good biocompatibility. They are increasingly widely used in fields such as sample pretreatment, separation, and purification. What is rare is that because this type of extraction stationary phase is obtained by polymerizing organic monomers, it can be made into various forms such as columns, rods, and membranes for independent use according to the requirements of the application scenario. However, traditional organic polymer extraction stationary phases have a "trade-off" effect between permeability and selectivity. Increasing selectivity will inevitably reduce permeability, and vice versa.

[0003] To improve stationary phase selectivity without compromising permeability, template-based methods have been used to prepare molecularly imprinted polymer (MIP) extraction stationary phases with highly selective binding to specific targets. However, this method requires the pre-production of large quantities of pure target compounds, making it unsuitable for targets where large quantities of pure compounds are difficult to obtain. In recent years, supramolecular-based polymer mixed-matrix extraction stationary phases, represented by metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), have garnered increasing attention due to their ability to combine the porosity and high selectivity of supramolecular materials with the high stability and processability of organic polymers. However, due to the poor compatibility of the added supramolecular powder with the polymer, the supramolecular material that provides separation activity tends to fall off, resulting in poor mechanical stability of the resulting mixed-matrix extraction stationary phase. As a key member of the supramolecular family, MOCs possess a regular shape, easily modifiable structure, a cavity of specific size, and easily tunable functionality. They have found widespread application in adsorption, separation, catalysis, and sensing. Their confined cavities provide a microenvironment distinct from the surrounding environment, enabling selective recognition and binding of specific guest molecules. More importantly, molecular cages, as discrete, three-dimensional oligomers at the nanoscale, exhibit excellent solubility and stability in conventional solvents, which lends them enhanced solution processability. Incorporating metal-organic molecular cages into polymer extraction stationary phases not only offers the advantages of traditional organic polymer extraction stationary phases but also offers selectivity for specific molecules, effectively resolving the trade-off between permeability and selectivity.

[0004] Currently reported methods for preparing polymeric molecular cages can be categorized by the type of bond formed during polymerization: irreversible covalent bonds and dynamic covalent bonds. The former include addition reactions between carbon-carbon double bonds, "thiol-ene" click reactions between carbon-carbon double bonds and thiol groups, and condensation reactions between acyl chlorides and amino groups, resulting in carbon-carbon single bonds, sulfides, and amides. The latter involves condensation reactions between aldehyde groups and free amino groups, resulting in imines. Compared to irreversible covalent bonds, which are difficult to break once formed, dynamic covalent bonds can break and regenerate under certain conditions. The resulting polymeric molecular cages can self-repair under external stimuli, thereby extending the material's service life. However, current imine-based polymeric molecular cages can only achieve self-repair through the additional introduction of acid or free amine / ammonia, and cannot be achieved independently in situ. They must then undergo a cumbersome washing and impurity removal process, and the amount of repair reagent introduced is difficult to control, making practical applications difficult. Self-repairing polymeric molecular cage materials that do not require the additional introduction of repair reagents remain to be developed. Summary of the Invention

[0005] The present invention provides a self-supporting molecular cage-based self-repairing extraction stationary phase, and its preparation method and application. The self-supporting molecular cage-based self-repairing extraction stationary phase proposed in the present invention not only has the characteristics of simple preparation method of conventional organic polymers, wide application range and good biocompatibility, but also can effectively overcome the "trade off" effect problem between the permeability and selectivity of traditional polymers by introducing nanoscale molecular cage units, and improve the selectivity of the stationary phase to the extraction target without reducing the permeability of the material.

[0006] The purpose of the present invention is to propose a self-supporting molecular cage-based self-repairing extraction stationary phase, comprising a tetrahedral metal-organic molecular cage MOC-Zr-S2 and a disulfide structural unit, wherein the tetrahedral metal-organic molecular cage MOC-Zr-S2 comprises four tripod-type metal complex clusters and six linear aromatic dicarboxylic acid secondary structural units; the tripod-type metal complex cluster is located at the vertices of the tetrahedron, and its general structural formula is Cp3Zr3μ3-O(μ2-OH )3, wherein Cp is cyclopentadiene and / or its n-butyl substituted derivative; the linear aromatic dicarboxylic acid is located at the edge of the tetrahedron and is a disulfide substituted derivative of 1,1'biphenyl-3,3'-diamino-4,4'-dicarboxylic acid, which is obtained by forming an amide bond between the 3- and 3'-amino groups of 1,1'biphenyl-3,3'-diamino-4,4'-dicarboxylic acid and the thioctic acid; the tripod-type metal complex cluster is connected to the linear aromatic dicarboxylic acid through a Zr-O coordination bond.

[0007] The second purpose of the present invention is to protect the preparation method of the self-supporting molecular cage-based self-repairing extraction stationary phase, which is obtained by polymerization of tetrahedral metal-organic molecular cage MOC-Zr-S2 through intermolecular disulfide bonds.

[0008] Preferably, the preparation method specifically comprises the following steps:

[0009] (1) 1,1'-biphenyl-3,3'-diamino-4,4'-dicarboxylic acid, bis(cyclopentadienyl)zirconium dichloride or / and bis(n-butylcyclopentadienyl)zirconium dichloride are dissolved in a mixed solvent of N,N-diethylformamide and water, and a molecular cage precursor MOC-Zr-NH2 containing a primary amine is obtained under heating conditions;

[0010] (2) dissolving the molecular cage precursor MOC-Zr-NH2 and diisopropylethylamine in pre-deoxygenated N,N-dimethylformamide to obtain solution A;

[0011] (3) dissolving lipoic acid and (ethyl 2-oxime-cyanoacetate)-N,N-dimethyl-morpholinyl uronium hexafluorophosphate in pre-deoxygenated N,N-dimethylformamide, and reacting at room temperature for 1 to 2 hours in a nitrogen or argon atmosphere to obtain solution B; or dissolving lipoyl chloride in pre-deoxygenated N,N-dimethylformamide to obtain solution C;

[0012] (4) adding solution B or solution C to solution A, stirring the mixture at room temperature in a nitrogen or argon atmosphere, then adding ethanol to precipitate a solid, collecting the solid, washing it, and drying it to obtain a disulfide group-modified molecular cage MOC-Zr-S2;

[0013] (5) dissolving the disulfide group-modified molecular cage MOC-Zr-S2 in N,N-dimethylformamide to obtain a casting solution, which is then injected into a mold to undergo a redox reaction of the disulfide compound to generate a polymer;

[0014] (6) The polymer is separated from the mold, soaked in acetone, taken out, and dried to obtain a self-supporting molecular cage-based self-repairing extraction stationary phase.

[0015] In step (1), the molar ratio of 1,1'-biphenyl-3,3'-diamino-4,4'-dicarboxylic acid and bis(n-butylcyclopentadienyl)zirconium dichloride is 1:1, or the molar ratio of 1,1'-biphenyl-3,3'-diamino-4,4'-dicarboxylic acid and bis(cyclopentadienyl)zirconium dichloride is 1:1, the volume ratio of N,N-diethylformamide and water in the mixed solvent is 40:1, the molar ratio of 1,1'-biphenyl-3,3'-diamino-4,4'-dicarboxylic acid and N,N-diethylformamide is 1:360, and the heating temperature is 60°C to 80°C.

[0016] Further preferably, in steps (2)-(3), the molar ratio of the molecular cage precursor MOC-Zr-NH2, diisopropylethylamine, thioctic acid, (ethyl 2-oxime-cyanoacetate)-N,N-dimethyl-morpholinyl urea hexafluorophosphate, thioctic acid chloride, and N,N-dimethylformamide is 1:24-48:12-24:24-48:12-24:4000-8000, N,N-dimethylformamide refers to the sum of the molar ratios of N,N-dimethylformamide in steps (2) and (3), and the molar ratio of N,N-dimethylformamide in steps (2) and (3) is 1:1; the reaction time in step (4) is 18-36 h, and the drying time is 8-12 h.

[0017] Further preferably, the molar ratio of the molecular cage MOC-Zr-S2 and N,N-dimethylformamide in step (5) is 1:3000-6000; the mold is a hollow capillary / column or a planar fixture with an empty interlayer; and the redox reaction conditions are selected from one or more of ultraviolet light, heating and ultrasonic treatment.

[0018] Further preferably, the specific conditions of the ultraviolet light are: ultraviolet light wavelength 240-380nm, light power density 20-50mW / cm 2 , illumination time 0.5 ~ 2h; the specific conditions of the heating are: heating temperature 60 ℃ ~ 80 ℃, heating time 1 ~ 3h; the specific conditions of the ultrasonic treatment are: ultrasonic power density 0.5 ~ 2W / cm 2 , frequency 20~80kHz, ultrasonic treatment time 0.5~1h.

[0019] More preferably, the soaking time in acetone in step (6) is 2 to 8 hours.

[0020] The third object of the present invention is to provide a self-repairing method for the self-supporting molecular cage-based self-repairing extraction stationary phase, comprising the following steps:

[0021] (1) re-infiltrating the self-supporting molecular cage-based self-repairing extraction stationary phase to be repaired with N,N-dimethylformamide;

[0022] (2) treating the self-supporting molecular cage-based self-repairing extraction stationary phase to be repaired soaked in N,N-dimethylformamide, wherein the treatment method is selected from one or more of ultraviolet light treatment, heating and ultrasonic treatment;

[0023] (3) The treated self-supporting molecular cage-based self-repairing extraction stationary phase is soaked in acetone, taken out, and dried with supercritical carbon dioxide.

[0024] The tetrahedral metal-organic molecular cage proposed in this invention is constructed through coordination self-assembly from four tripod-type metal complex clusters and six linear aromatic dicarboxylic acid secondary building blocks. The cage's inherent confined hydrophobic cavity enables selective recognition and binding of specific targets. Under external stimulation, the self-supporting molecular cage-based extraction stationary phase can self-repair the material structure by cleaving and regenerating disulfide bonds.

[0025] Preferably, the specific conditions of the ultraviolet light irradiation in step (2) are: ultraviolet light wavelength 240-380nm, light power density 20-50mW / cm 2 , illumination time 0.5~2h; specific conditions for heating are: heating temperature 60℃~80℃, heating time 1~3h; specific conditions for ultrasonic treatment are: ultrasonic power density 0.5~2W / cm2 , frequency is 20~80kHz, and ultrasonic treatment time is 0.5~1h.

[0026] The zirconium-based metal-organic molecular cage proposed in the present invention contains a strong Zr-O coordination bond, which ensures that the molecular cage structure is not easily destroyed during the ligand post-modification process. The biphenyl linear ligand not only induces the formation of a tetrahedral structure of the cage molecule, but also regulates the shape and size of the cavity inside the molecular cage, making it able to accommodate larger guest molecules. The post-modified disulfide group on the ligand can undergo polymerization reaction when exposed to ultraviolet light, heating, and ultrasonic treatment, and a self-supporting polymer can be formed in situ without the need to introduce additional monomer molecules. At the same time, the disulfide bond, as a type of dynamic covalent bond, can be broken again and new disulfide bonds can be generated under conditions such as ultraviolet light, heating, and ultrasonic treatment, thereby achieving in situ self-repair of the material. The self-supporting molecular cage-based self-repairing extraction stationary phase thus obtained not only has the characteristics of simple preparation methods of conventional organic polymers, a wide range of applications, and good biocompatibility, but also can effectively overcome the "trade-off" effect problem between the permeability and selectivity of traditional polymers, and improves the selectivity of the stationary phase for the extraction target without reducing the permeability of the material. It is expected to be promoted and applied in the fields of sample pretreatment, separation, and purification.

[0027] The present invention also protects the application of the self-supporting molecular cage-based self-repairing extraction stationary phase in the field of sample pre-treatment, separation or purification.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The self-supporting molecular cage-based self-repairing extraction stationary phase described in the present invention not only has the advantages of simple preparation methods, wide application range and good biocompatibility of conventional organic polymers, but also effectively overcomes the "trade-off effect" problem between the permeability and selectivity of traditional polymers by introducing nanoscale molecular cage units, thereby improving the selectivity of the stationary phase for the extraction target without reducing the permeability of the material;

[0030] (2) The self-supporting molecular cage-based self-repairing extraction stationary phase of the present invention utilizes the disulfide groups on the cage molecular ligands to undergo polymerization reaction under conditions such as ultraviolet light, heating, and ultrasonic treatment, and can form a self-supporting polymer in situ without the need to introduce additional monomer molecules;

[0031] (3) The self-supporting molecular cage-based self-repairing extraction stationary phase of the present invention utilizes the dynamic covalent bond properties of disulfide bonds, which can be broken again and new disulfide bonds can be generated under conditions such as ultraviolet light, heating, and ultrasonic treatment. Without the need to introduce additional self-repairing reagents, the material can be self-repaired in situ. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Fourier transform infrared spectra of the molecular cage before (left) and after (right) modification with disulfide groups in Example 1;

[0033] Figure 2 This is a picture of the thin film self-supporting molecular cage-based self-repairing extraction stationary phase obtained in Example 3. DETAILED DESCRIPTION

[0034] The present invention will be described in further detail below with reference to the examples. These examples are intended to illustrate the present invention only and are not intended to limit the scope of the present invention. The experimental methods in the following examples, for which specific conditions are not specified, are generally based on conventional conditions in the art or the conditions recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are deemed to be raw materials and reagents that can be obtained through commercial channels such as conventional markets. Any non-substantial changes and substitutions made by those skilled in the art on the basis of the present invention fall within the scope of protection claimed in the present invention.

[0035] Example 1

[0036] The preparation method of tetrahedral metal-organic molecular cage MOC-Zr-S2 is as follows:

[0037] (1) 27.2 mg (0.1 mmol) of 1,1'-biphenyl-3,3'-diamino-4,4'-dicarboxylic acid and 40.4 mg (0.1 mmol) of bis(n-butylcyclopentadienyl)zirconium dichloride were dissolved in a mixed solvent of 8 mL of N,N-diethylformamide and 200 μL of water, and the molecular cage precursor MOC-Zr-NH2 containing primary amine was obtained under heating conditions;

[0038] (2) 44.4 mg (0.01 mmol) of molecular cage precursor MOC-Zr-NH2 and 42 μL (0.24 mmol) of diisopropylethylamine were dissolved in 4 mL of pre-deoxygenated N,N-dimethylformamide to obtain solution A;

[0039] (3) Dissolve 24.8 mg (0.12 mmol) of lipoic acid and 102.8 mg (0.24 mmol) of (ethyl 2-oximinocyanoacetate)-N,N-dimethyl-morpholinyl uronium hexafluorophosphate in 4 mL of pre-deoxygenated N,N-dimethylformamide and react at room temperature for 1.5 h under nitrogen or argon atmosphere to obtain solution B;

[0040] (4) Solution B was added to solution A, and the mixture was stirred at room temperature for 24 h in a nitrogen or argon atmosphere. Then, ethanol was added to precipitate the solid. The solid was collected and washed with dichloromethane, and then vacuum-dried at room temperature for 12 h to obtain the disulfide group-modified molecular cage MOC-Zr-S2.

[0041] The structure of the tetrahedral metal-organic molecular cage MOC-Zr-S2 in Example 1 was characterized. Figure 1 The Fourier transform infrared spectra of the molecular cage before and after disulfide group modification are shown in Figure 1. As can be seen from the figure, the molecular cage modified with disulfide groups retains the coordinated hydroxyl OH stretching vibration absorption peak (3600~3000cm) of the initial molecular cage precursor MOC-Zr-NH2. -1 ), the CH stretching vibration absorption peak of cyclopentadiene ligand (2985~2815cm -1 ) and the C=O stretching vibration absorption peak of the carboxyl group (1610~1430cm -1 Comparing the spectra before and after modification, it can be seen that the molecular cage modified with disulfide groups has a new C=O stretching vibration absorption peak of the amide carbonyl group (1657cm -1 , amide I peak), CNH bending vibration absorption peak (1543cm -1 , amide II peak) and CS stretching vibration absorption peak (1183 cm -1 ), and due to the introduction of lipoyl, the CH stretching vibration absorption peak intensity of methylene is enhanced (2911cm -1 ), and the methylene shear vibration absorption peak (1412 cm -1 ) and out-of-plane rocking vibration absorption peak (1267cm -1 ) appears, and the original NH symmetric and antisymmetric vibration absorption peaks of the primary amine group (3078 cm -1 and 3187cm -1 The above results indicate that the lipoyl group was successfully modified into the molecular cage structure by forming an amide bond with the aromatic primary amine on the cage ligand, thus proving the acquisition of the target metal-organic molecular cage MOC-Zr-S2.

[0042] Example 2

[0043] An embodiment of the self-supporting molecular cage-based self-repairing extraction stationary phase of the present invention, and a method for preparing a capillary self-supporting molecular cage-based self-repairing extraction stationary phase, are as follows:

[0044] (1) 20 mg (0.003 mmol) of the disulfide group-modified molecular cage MOC-Zr-S2 prepared in Example 1 was dissolved in 1 mL of N,N-dimethylformamide to obtain a casting solution. An appropriate amount of the casting solution was then injected into a hollow quartz capillary, both ends were sealed by sintering, and a light source with a wavelength of 365 nm and a power density of 50 mW / cm was used at a distance of 2 cm from the capillary. 2 The ultraviolet light was irradiated vertically on the tube wall for 0.5h, and the redox reaction of the disulfide compound occurred to generate a polymer;

[0045] (2) The capillary is broken, the polymer is separated from it, and the polymer is taken out after being soaked in acetone for 3 hours. The capillary is dried with supercritical carbon dioxide to obtain a capillary self-supporting molecular cage-based self-repairing extraction stationary phase.

[0046] Example 3

[0047] An embodiment of the self-supporting molecular cage-based self-repairing extraction stationary phase of the present invention, and a method for preparing a thin film self-supporting molecular cage-based self-repairing extraction stationary phase, are as follows:

[0048] (1) 20 mg (0.003 mmol) of the disulfide-modified molecular cage MOC-Zr-S2 prepared in Example 1 was dissolved in 1 mL of N,N-dimethylformamide to obtain a casting solution. An appropriate amount of the casting solution was then injected into a flat fixture with an empty interlayer, placed in a forced air drying oven, and heated at 80°C for 2 h to cause a redox reaction of the disulfide compound to generate a polymer.

[0049] (2) The polymer was taken out from the fixture, soaked in acetone for 3 hours, and then dried with supercritical carbon dioxide to obtain a thin film self-supporting molecular cage-based self-repairing extraction stationary phase.

[0050] like Figure 2 As shown, the obtained self-supporting molecular cage-based self-repairing extraction stationary phase film is brown-red and transparent, about 0.2 mm thick, and has a certain elasticity.

[0051] Example 4

[0052] An embodiment of the self-supporting molecular cage-based self-repairing extraction stationary phase of the present invention and a method for preparing a self-supporting molecular cage-based self-repairing extraction stationary phase monolithic column are as follows:

[0053] (1) 20 mg (0.003 mmol) of the disulfide group-modified molecular cage MOC-Zr-S2 prepared in Example 1 was dissolved in 1 mL of N,N-dimethylformamide to obtain a casting solution, which was then injected into an empty solid phase extraction column. After end-capping, the column was placed vertically in an ultrasonic cleaner and the power density was 2 W / cm 2 , ultrasonic treatment at a frequency of 60 kHz for 0.5 h to cause redox reaction of disulfide compounds to generate polymers;

[0054] (2) The solid phase extraction monolithic column was taken out from the ultrasonic cleaner, and the polymer phase was soaked in acetone for 3 h. After removing the acetone, the monolithic column was dried with supercritical carbon dioxide to obtain a self-supporting molecular cage-based self-repairing extraction stationary phase monolithic column.

[0055] Example 5

[0056] The same as Example 1, except that: in steps (2)-(3), the molar ratio of the molecular cage precursor MOC-Zr-NH2, diisopropylethylamine, thioctic acid, (2-oxime-ethyl cyanoacetate)-N,N-dimethyl-morpholinoura hexafluorophosphate, and N,N-dimethylformamide is 1:48:24:48:8000, and the reaction time is 2 h; in step (4), the reaction time is 18 h, and the drying time is 8 h.

[0057] Example 6

[0058] The same as Example 1, except that: in steps (2)-(3), the molar ratio of the molecular cage precursor MOC-Zr-NH2, diisopropylethylamine, thioctic acid, (2-oxime-ethyl cyanoacetate)-N,N-dimethyl-morpholinoura hexafluorophosphate, and N,N-dimethylformamide is 1:24:12:24:4000, and the reaction time is 1 hour; in step (4), the reaction time is 36 hours, and the drying time is 12 hours.

[0059] Example 7

[0060] Same as Example 1, except that:

[0061] (3) dissolving lipoyl chloride in pre-deoxygenated N,N-dimethylformamide to obtain solution C;

[0062] (4) adding solution B or solution C to solution A, stirring the mixture at room temperature in a nitrogen or argon atmosphere, then adding ethanol to precipitate a solid, collecting the solid, washing it, and drying it to obtain a disulfide group-modified molecular cage MOC-Zr-S2;

[0063] In steps (2)-(3), the molar ratio of the molecular cage precursor MOC-Zr-NH2, diisopropylethylamine, thioctic acid chloride, and N,N-dimethylformamide is 1:48:24:8000, and the reaction time is 2 h; in step (4), the reaction time is 18 h, and the drying time is 8 h.

[0064] Example 8

[0065] The same as Example 7, except that: in steps (2)-(3), the molar ratio of the molecular cage precursor MOC-Zr-NH2, diisopropylethylamine, thioctic acid chloride, and N,N-dimethylformamide is 1:24:12:4000, and the reaction time is 1 hour; in step (4), the reaction time is 36 hours, and the drying time is 12 hours.

[0066] Example 9

[0067] An embodiment of the self-supporting molecular cage-based self-repairing extraction stationary phase of the present invention, a self-repairing method of a thin film self-supporting molecular cage-based self-repairing extraction stationary phase, is as follows:

[0068] (1) The self-supporting molecular cage-based self-repairing extraction stationary phase film is spread flat on a flat-bottomed container again, and a small amount of N,N-dimethylformamide is added to completely soak the stationary phase to be repaired;

[0069] (2) Place the self-supporting molecular cage-based self-repairing extraction stationary phase film to be repaired in N,N-dimethylformamide in an ultrasonic cleaning instrument with a power density of 2W / cm 2 , ultrasonic treatment at a frequency of 60 kHz for 0.5 h to break the old disulfide bonds and generate new disulfide bonds;

[0070] (3) The repaired self-supporting molecular cage-based self-repairing extraction stationary phase was taken out, soaked in acetone for 3 hours, and then dried with supercritical carbon dioxide.

[0071] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. Persons skilled in the art will appreciate that improvements and modifications may be made without departing from the spirit and scope of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A self-supporting molecular cage-based self-repairing extraction stationary phase, characterized in that: The invention comprises a tetrahedral metal-organic molecular cage MOC-Zr-S2 and a disulfide structural unit. The tetrahedral metal-organic molecular cage MOC-Zr-S2 comprises four tripod-type metal complex clusters and six linear aromatic dicarboxylic acid secondary structural units. The tripod-type metal complex cluster is located at the vertices of the tetrahedron, and its general structural formula is Cp3Zr3 μ 3-O( μ 2-OH)3, wherein Cp is cyclopentadiene and / or its n-butyl substituted derivative; the linear aromatic dicarboxylic acid is located at the edge of the tetrahedron and is a disulfide substituted derivative of 1,1'-biphenyl-3,3'-diamino-4,4'-dicarboxylic acid, which is obtained by forming an amide bond between the 3- and 3'-amino groups of 1,1'-biphenyl-3,3'-diamino-4,4'-dicarboxylic acid and the thioctic acid; the tripod-type metal complex cluster is connected to the linear aromatic dicarboxylic acid through a Zr-O coordination bond.

2. The method for preparing the self-supporting molecular cage-based self-repairing extraction stationary phase according to claim 1, characterized in that: It is obtained by tetrahedral metal-organic molecular cage MOC-Zr-S2 through intermolecular disulfide bond polymerization.

3. The preparation method according to claim 2, characterized in that The specific steps include: (1) 1,1'-biphenyl-3,3'-diamino-4,4'-dicarboxylic acid, bis(cyclopentadienyl)zirconium dichloride or / and bis(n-butylcyclopentadienyl)zirconium dichloride are dissolved in a mixed solvent of N,N-diethylformamide and water, and a molecular cage precursor MOC-Zr-NH2 containing a primary amine is obtained under heating conditions; (2) Dissolve the molecular cage precursor MOC-Zr-NH2 and diisopropylethylamine in pre-deoxygenated N,N-dimethylformamide to obtain solution A; (3) Dissolve lipoic acid and (2-hydroxy-ethyl cyanoacetate)-N,N-dimethyl-morpholinyl uronium hexafluorophosphate in pre-deoxygenated N,N-dimethylformamide, and react at room temperature for 1-2 h in a nitrogen or argon atmosphere to obtain solution B; or dissolve lipoyl chloride in pre-deoxygenated N,N-dimethylformamide to obtain solution C; (4) Add solution B or solution C to solution A, stir and react at room temperature in a nitrogen or argon atmosphere, then add ethanol to precipitate the solid, collect the solid, wash it, and dry it to obtain the disulfide group-modified molecular cage MOC-Zr-S2; (5) The disulfide group-modified molecular cage MOC-Zr-S2 is dissolved in N,N-dimethylformamide to obtain a casting solution, which is then injected into a mold to undergo a redox reaction of the disulfide compound to generate a polymer; (6) Separating the polymer from the mold, soaking it in acetone, taking it out, and drying it to obtain a self-supporting molecular cage-based self-repairing extraction stationary phase.

4. The preparation method according to claim 3, characterized in that In steps (2)-(3), the molar ratio of the molecular cage precursor MOC-Zr-NH2, diisopropylethylamine, thioctic acid, (2-oxime-ethyl cyanoacetate)-N,N-dimethyl-morpholinyl uronium hexafluorophosphate, and N,N-dimethylformamide is 1:24~48:12~24:24~48:4000~8000, and the molar ratio of the molecular cage precursor MOC-Zr-NH2, diisopropylethylamine, thioctic acid chloride, and N,N-dimethylformamide is 1:24~48:12~24:4000~8000; in step (4), the reaction time is 18~36 h, and the drying time is 8~12 h.

5. The preparation method according to claim 3, characterized in that The molar ratio of the molecular cage MOC-Zr-S2 and N,N-dimethylformamide in step (5) is 1:3000-6000; the mold is a hollow capillary / column or a flat fixture with an empty interlayer; and the redox reaction conditions are selected from one or more of ultraviolet light, heating, and ultrasonic treatment.

6. The preparation method according to claim 5, characterized in that The specific conditions of the ultraviolet light are: ultraviolet light wavelength 240~380nm, light power density 20~50mW / cm 2 , illumination time 0.5~2 h; the specific conditions of the heating are: heating temperature 60℃~80℃, heating time 1~3 h; the specific conditions of the ultrasonic treatment are: ultrasonic power density 0.5~2 W / cm 2 , frequency 20~80 kHz, ultrasonic treatment time 0.5~1 h.

7. The preparation method according to claim 3, characterized in that The soaking time in acetone in step (6) is 2 to 8 hours.

8. The self-repairing method of the self-supporting molecular cage-based self-repairing extraction stationary phase according to claim 1, characterized in that: The steps include: (1) The self-supporting molecular cage-based self-repairing extraction stationary phase to be repaired is re-infiltrated with N,N-dimethylformamide; (2) treating the self-supporting molecular cage-based self-repairing extraction stationary phase to be repaired soaked in N,N-dimethylformamide by one or more treatment methods selected from ultraviolet light, heating, and ultrasonic treatment; (3) The treated self-supporting molecular cage-based self-repairing extraction stationary phase is soaked in acetone, taken out, and dried with supercritical carbon dioxide.

9. The self-repairing method according to claim 8, characterized in that: The specific conditions of the ultraviolet light irradiation in step (2) are: ultraviolet light wavelength 240~380 nm, light power density 20~50 mW / cm 2 , illumination time 0.5~2 h; specific heating conditions are: heating temperature 60℃~80℃, heating time 1~3 h; specific ultrasonic treatment conditions are: ultrasonic power density 0.5~2 W / cm 2 , frequency is 20~80 kHz, and ultrasonic treatment time is 0.5~1 h.

10. Use of the self-supporting molecular cage-based self-repairing extraction stationary phase according to claim 1 in the field of sample pretreatment, separation or purification.

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