Preparation method and application of chiral aldehyde amine condensation covalent organic framework material

Abstract

The invention discloses a preparation method and application of a chiral aldehyde amine condensation covalent organic framework material, through an ultrasonic chemical synthesis method, the synthesis cost and energy consumption are remarkably reduced, the reaction time is shortened, and the chiral transmission efficiency and the crystallinity of the material are greatly improved; the synthesis method disclosed by the invention not only has the characteristics of high efficiency and environmental protection, but also provides a brand new technical means for preparing a high-performance chiral two-dimensional COF material with a controllable structure; according to the preparation method, the preparation of the chiral two-dimensional COF material is more efficient and stable, and the chiral two-dimensional COF material has high repeatability and controllability, is suitable for being widely applied to various technical fields needing high-chiral materials, and further promotes the development of the chiral materials in scientific research and industrial application.

Description

Technical Field

[0001] The invention belongs to the technical field of covalent organic framework materials, and specifically relates to a preparation method and application of a chiral aldehyde-amine condensation covalent organic framework material. Background Art

[0002] Covalent organic frameworks are a class of ordered porous structures formed by organic molecules through covalent bonds, with high specific surface area, good chemical stability and excellent optoelectronic properties. Due to their unique properties, COFs have broad application potential in many fields such as gas storage, separation, catalysis and sensors. Chirality is crucial in the fields of chemistry and biology because many biomolecules have specific chiral forms, which play a key role in drug activity, metabolism and biocompatibility.

[0003] Chiral covalent organic frameworks (COFs) have shown excellent performance in the application field of chiral materials. For example, in chromatographic separation technology, they provide more significant advantages over traditional chiral polymer stationary phases. They have precise and regular pore structures, which not only provide consistent and predictable separation effects, but also have higher efficiency in loading and mass transfer rate due to their low density, high specific surface area and high porosity. In addition, the chemical and thermal stability of COFs enables them to maintain stable performance over a wide temperature range and in different chemical environments, which is crucial for the long-term operation of chromatographic stationary phases. The diversity of building blocks and functional tunability of COFs allow their pore size and chemical properties to be customized by changing monomers or synthesis conditions to meet various chiral separation requirements. The easy post-modification feature further enhances the chiral recognition ability of COFs, giving them potential advantages in the recognition and separation efficiency of chiral molecules. Therefore, chiral COFs, due to their unique structure and properties, show broader prospects in the application of chiral stationary phases than ordinary chiral polymers.

[0004] In the field of synthesis of chiral covalent organic frameworks (COFs), hydrothermal synthesis is currently the mainstream technology. However, this method has multiple limitations, mainly including the following problems: (1) Harsh synthesis conditions: Traditional solvothermal methods usually require high temperature and high pressure conditions (120~200℃), long synthesis time (2~7 days), and the use of toxic organic solvents. The operation process is complicated and there are certain safety risks; (2) Low chiral transfer efficiency: Although there is a method of inducing chiral COFs by directly adding chiral molecules through hydrothermal method, this method often leads to uneven distribution of chiral induction rate and low chiral transfer efficiency; (3) Difficulty in reaction control: The existing methods are relatively complex in controlling reaction conditions, and it is difficult to achieve efficient chiral induction and stable product consistency, which limits the promotion of materials in practical applications. Although the hydrothermal method achieves chiral induction, its chiral transfer efficiency is not high, and the control of reaction conditions is relatively complex, making it difficult to achieve efficient chiral induction and product consistency.

[0005] How to develop an economical and environmentally friendly synthesis strategy to achieve efficient synthesis of COFs with high chiral activity is an urgent problem to be solved. This strategy needs to reduce the synthesis cost while ensuring chiral purity, reduce the impact on the environment, and improve the green level of the reaction. In addition, the new synthesis method should also have good crystallinity and reaction controllability to ensure the stability and selectivity of the resulting COFs materials, which is crucial for their performance in applications such as chiral separation and asymmetric catalysis. At the same time, this method should also be universal and applicable to the synthesis of a variety of COFs to meet the needs of different application scenarios. In short, the development of such a synthesis method will greatly promote the industrialization of chiral COFs and have a far-reaching impact on the fields of chemistry and biology. Summary of the invention

[0006] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0007] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0008] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a chiral aldehyde-amine condensation covalent organic framework material.

[0009] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing a chiral aldehyde-amine condensation covalent organic framework material, characterized in that: comprising: Introducing chirality: dissolving the organic monomer 1 and the chiral inducing agent in an acetic acid aqueous solution and subjecting the mixture to ultrasonic treatment to obtain a mixed solution; Introducing a second organic monomer and prolonging the ultrasonic treatment: adding organic monomer 2 to the mixed solution and ultrasonically treating for 40 to 120 minutes; Product separation and purification: After the ultrasonic treatment, the reaction mixture was separated by filtration; The organic monomer 1 includes but is not limited to one or more of triformylbenzene, terephthalaldehyde, 2,5-dihydroxyterephthalaldehyde, and 4,4'-biphenyldicarboxaldehyde; the organic monomer 2 includes but is not limited to one or more of 1,3,5-tris(4-aminophenyl)benzene, 2,4,6-tris(4-aminophenyl)-1,3,5-triazine, and benzidine.

[0010] As a preferred embodiment of the preparation method of the present invention, the concentration of the acetic acid aqueous solution is 6-12 mol / L.

[0011] As a preferred embodiment of the preparation method of the present invention, the diameter of the ultrasonic probe for introducing chirality into the ultrasonic treatment is 2-10 mm.

[0012] As a preferred embodiment of the preparation method of the present invention, the chiral inducing agent is one or more of (R)-(+)-α-methylbenzylamine, (S)-(+)-α-methylbenzylamine, (R)-(+)-1-(1-naphthyl)ethylamine, (S)-(+)-1-(1-naphthyl)ethylamine, L-tryptophan, D-tryptophan, L-lysine, D-lysine, (R)-2-(1-aminoethyl)phenol, and (S)-2-(1-aminoethyl)phenol.

[0013] As a preferred embodiment of the preparation method of the present invention, the molar ratio of the organic monomer 1 to the chiral inducing agent is 1:1-5.

[0014] As a preferred embodiment of the preparation method of the present invention, the ratio of the aldehyde group and the amino substance used for the reaction in the organic monomer is 1:1.

[0015] As a preferred embodiment of the preparation method of the present invention, the diameter of the ultrasonic probe for introducing chirality into the ultrasonic treatment is 6 mm.

[0016] As a preferred embodiment of the preparation method of the present invention, in the introduction of chirality, ultrasonic treatment is performed at a power of 30-70% for 10-30 minutes.

[0017] As a preferred embodiment of the preparation method of the present invention, during the prolonged ultrasonic treatment, the ultrasonic frequency is maintained at 40 kHz and the power is 30-70%.

[0018] Beneficial effects of the present invention: 1. The present invention innovatively utilizes ultrasonic energy to make the reactants mix more evenly, thereby achieving uniform induction of the COF material skeleton by the chiral auxiliary agent; during the reaction process, the ultrasound accelerates the uniform dispersion of the material, so that the chiral auxiliary agent can evenly induce the chiral structure of the entire material without being embedded in the final product. This process significantly improves the chiral induction rate and the consistency of the material, and solves the problem of uneven chirality in the prior art.

[0019] 2. The present invention greatly improves the synthesis efficiency of covalent organic framework (COFs) materials by utilizing the high energy efficiency characteristics of ultrasound. In traditional synthesis methods, such as the solvothermal method, a long-term (e.g., 2-7 days) heating reaction is usually required under high temperature and high pressure conditions, and toxic organic solvents are often required. These conditions not only limit the batch synthesis of COFs, but also bring safety and environmental risks. In contrast, the ultrasonic synthesis method is carried out in an aqueous phase system, does not require the participation of organic solvents, and can be operated in room temperature air, which makes the synthesis process greener and more environmentally friendly. The ultrasonic synthesis of the present invention can significantly shorten the reaction time to less than 1 hour, which not only greatly improves the efficiency of material preparation, but also greatly reduces energy consumption.

[0020] 3. The present invention achieves precise control of chiral two-dimensional COF materials, ensuring high crystallinity and high purity products. At the same time, the method has wide adaptability, is compatible with a variety of different organic monomers and chiral additives, and is suitable for the development of a variety of functional chiral materials.

[0021] 4. The present invention uses ultrasonic waves to carry out reactions at room temperature and normal pressure, without the need for high temperature, high pressure or toxic or hazardous solvents, which greatly simplifies the operating process, reduces equipment and environmental requirements, and improves experimental safety and environmental friendliness.

[0022] 5. The method of the present invention is not only suitable for laboratory-scale material preparation, but also has the potential for large-scale industrial application due to its simple operation, strong controllability and high efficiency. In the fields of catalysis, gas separation, drug delivery and chiral separation, chiral two-dimensional COF materials have shown broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them: Figure 1COF in Comparative Example 1 of the present invention TFP+DAB 、R-MBA-COF TFP+DAB , and R-NEA- COF TFP+DAB Fourier transform infrared spectrum.

[0024] Figure 2 COF in Comparative Example 1 of the present invention TFP+DAB 、R-MBA-COF TFP+DAB , and R-NEA- COF TFP+DAB Powder X-ray diffraction pattern of .

[0025] Figure 3 The S-MBA-COF in Comparative Example 1 of the present invention TFP+DAB 、R-MBA-COF TFP+DAB 、S-NEA- COF TFP+DAB , and R-NEA-COF TFP+DAB Circular dichroism spectrum.

[0026] Figure 4 COF in Comparative Example 1 of the present invention TFP+DAB 、R-MBA-COF TFP+DAB and R-NEA-COF TFP+DAB Thermogravimetric analysis spectrum.

[0027] Figure 5 COF in Comparative Example 1 of the present invention TFP+DAB 、R-MBA-COF TFP+DAB and R-NEA-COF TFP+DAB Scanning electron microscope image of .

[0028] Figure 6 1-L-alanine-COF in Comparative Example 2 of the present invention DMTA+TAPB 、5-L-alanine-COF DMTA+TAPB and COF DMTA+TAPB Powder X-ray diffraction pattern of .

[0029] Figure 7 5 min-S-MBA-COF in Comparative Example 5 of the present invention TFP+DAB 、10 min-S-MBA-COF TFP+DAB 、30 min-S-MBA-COF TFP+DAB , and 60 min-S-MBA-COF TFP+DAB Powder X-ray diffraction pattern of .

[0030] Figure 8 5 min-S-MBA-COF in Comparative Example 5 of the present invention TFP+DAB 、10 min-S-MBA-COFTFP+DAB 、30 min-S-MBA-COF TFP+DAB , and 60 min-S-MBA-COF TFP+DAB Fourier transform infrared spectrum. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0032] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0033] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0034] Raw materials and reagents used in the present invention: The raw materials and reagents used in the present invention are commercially available, including acetic acid, triformylbenzene (TFP), terephthalaldehyde (TPA), 2,5-dihydroxyterephthalaldehyde (DHTA), 2,5-dimethoxybenzene-1,4-dicarboxaldehyde (DMTA), 4,4'-biphenyldicarboxaldehyde (BDCA), (R)-(+)-α-methylbenzylamine (R-MBA), (S)-(+)-α-methylbenzylamine (S-MBA), (R)-(+)-1-(1-naphthyl)ethylamine (R-NEA), (S)-(+)-1-(1-naphthyl)ethylamine (S-NEA), (R)-(+)-α-methylbenzylamine (R-MBA), (S)-(+)-α-methylbenzylamine (S-MBA), (R)-(+)-1-(1-naphthyl)ethylamine (R-NEA), (S)-(+)-1-(1-naphthyl)ethylamine (S-NEA), L-alanine (L-alanine), p-phenylenediamine (DAB), 1,3,5-tris(4-aminophenyl)benzene (TAPB), 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAPT), benzidine (BD), etc.

[0035] Experimental methods used in the present invention: Preparation method of chiral aldehyde-amine condensation covalent organic framework material: 1. Introducing chirality (through the combination of aldehyde monomers and chiral molecules) The organic monomer 1 and the chiral inducing agent were weighed in proportion and added to a 40 ml reaction vial, followed by a 6 mol / L to 12 mol / L acetic acid aqueous solution as the reaction solvent. Ultrasonic treatment was performed using a 6 mm micro-tip probe, which was driven by a 650 W JY92-IIN intelligent ultrasonic crusher and operated in continuous mode at a frequency of 40 kHz for 10 minutes, with the power set to 50%; 2. Introducing the second organic monomer and extending the ultrasonic treatment A second organic monomer was added to the reaction mixture, and ultrasonic treatment was continued for 60 minutes. The reaction conditions were adjusted to further ensure high crystallinity and chiral purity of the material. 3. Product separation and purification After the ultrasonic treatment, the reaction mixture was separated by filtration. First, acetone and methanol were used to wash to remove the byproducts and unreacted precursors attached to the surface. Second, in order to further remove the precursor residues and impurities in the pores of the COFs material, tetrahydrofuran was used for 24 hours of Soxhlet extraction. After washing and Soxhlet extraction, n-hexane was used for 24 hours to further remove possible residual small molecules. Finally, the residual solvent and small molecules were removed by freeze drying to ensure the integrity of the material structure.

[0036] Example 1 1. Chiral two-dimensional covalent organic framework materials (R-NEA-COF TFP+DAB ) preparation method: Weigh 2,4,6-triformylphloroglucinol (210 mg, 1 mmol) and R-NEA (171 mg, 1 mmol) into a 10 ml glass bottle, and add 6 mol / L acetic acid aqueous solution (4 ml); The mixture was sonicated using a 6 mm microtip probe, and a 650 W JY92-IIN intelligent ultrasonic disruptor was set to drive the probe at 60% power in a continuous mode at 20 kHz for 10 min; p-phenylenediamine (162 mg, 1.5 mmol) was added to the mixed solution, and ultrasonic treatment was continued for 60 min; The yellow powder obtained after the reaction was filtered through a 0.22 μm nylon membrane to collect the solid, washed with acetone and methanol in turn, then subjected to Soxhlet extraction with tetrahydrofuran, and finally dried under vacuum to obtain the chiral two-dimensional covalent organic framework material R-NEA-COF TFP+DAB product.

[0037] Example 2 1. Chiral two-dimensional covalent organic framework materials (R-MBA-COF TFP+DAB ) preparation method: Weigh 2,4,6-triformylphloroglucinol (210 mg, 1 mmol) and R-MBA (119 mg, 1 mmol) into a 10 ml glass bottle, and add 6 mol / L acetic acid aqueous solution (4 ml); The mixture was sonicated using a 6 mm microtip probe, and a 650 W JY92-IIN intelligent ultrasonic disruptor was set to drive the probe at 60% power in a continuous mode at 20 kHz for 10 min; p-phenylenediamine (162 mg, 1.5 mmol) was added to the mixed solution, and ultrasonic treatment was continued for 60 min; The yellow powder obtained after the reaction was filtered through a 0.22 μm nylon membrane to collect the solid, washed with acetone and methanol in turn, then subjected to Soxhlet extraction with tetrahydrofuran, and finally dried under vacuum to obtain the chiral two-dimensional covalent organic framework material R-MBA-COF TFP+DAB product.

[0038] Comparative Example 1 1. Two-dimensional covalent organic framework materials (COF TFP+DAB ) preparation method: Weigh 2,4,6-triformylphloroglucinol (210 mg, 1 mmol) and p-phenylenediamine (162 mg, 1.5 mmol) into a 10 ml glass bottle, and add 6 mol / L acetic acid aqueous solution (4 ml); The mixture was sonicated using a 6 mm microtip probe, and a 650 W JY92-IIN intelligent ultrasonic disruptor was set to drive the probe at 60% power in a continuous mode at 20 kHz for 60 min; The yellow powder obtained after the reaction was filtered through a 0.22 μm nylon membrane to collect the solid, washed with acetone and methanol in turn, then subjected to Soxhlet extraction with tetrahydrofuran, and finally dried under vacuum to obtain a two-dimensional covalent organic framework material COF TFP+DAB product.

[0039] R-NEA-COF prepared in Examples 1-2 and Comparative Example 1 TFP+DAB 、R-MBA-COF TFP+DAB , and COF TFP+DAB The physical and chemical properties were characterized and analyzed. Figure 1-5 shown.

[0040] Figure 1 R-NEA-COF is shown TFP+DAB 、R-MBA-COF TFP+DAB , and COF TFP+DABFourier transform infrared spectrum of C=C stretching vibration peak (1579 cm -1 ) and the vibration peak of CH-NH (1253 cm -1 ) demonstrated the synthesis of chiral covalent organic framework materials.

[0041] Figure 2 For R-NEA-COF TFP+DAB 、R-MBA-COF TFP+DAB , and COF TFP+DAB The powder X-ray diffraction pattern of the present invention shows that the diffraction peak at about 5° belongs to the (110) crystal plane of AA stacking. This shows that the two-dimensional covalent organic framework material prepared by the present invention has strong crystallinity.

[0042] Figure 3 It is S-MBA-COF TFP+DAB , R-MBA-COF TFP+DAB , S-NEA-COF TFP+DAB , and R-NEA-COF TFP+DAB Circular dichroism spectrum.

[0043] from Figure 3 It can be clearly seen that the chiral covalent organic framework (COF) prepared by the present invention exhibits excellent chiral properties. According to CD data, the (R / S)-MBA-COF TFP+DAB g lum The value is 0.718, (R / S)-NEA-COF TFP+DAB g lum The value is 0.089; its circular dichroism (CD) signal intensity can reach up to 160. In comparison, the chiral signal in previous studies usually does not exceed 50 (Xing Han et al. Chiral induction in covalentorganic frameworks, Nat. Commun. 9, 1294(2018)). This significant improvement shows that the product of the present invention has obvious advantages in terms of chiral characteristics.

[0044] Figure 4 For R-NEA-COF TFP+DAB 、R-MBA-COF TFP+DAB , and COF TFP+DAB Thermogravimetric analysis spectra of these materials show excellent thermal stability, which further verifies that the materials synthesized in the present invention are indeed two-dimensional covalent organic framework materials.

[0045] Figure 5 For R-NEA-COF TFP+DAB 、R-MBA-COFTFP+DAB , and COF TFP+DAB Scanning electron microscope image. The COF material synthesized by ultrasound-assisted method is rod-shaped, and the π-π interaction between layers accelerates its crystallization process.

[0046] Example 3 1. Optimization of the ratio of chiral inducing agent: Chiral two-dimensional covalent organic framework material (1-L-alanine-COF DMTA+TAPB ) preparation method: Weigh 2,5-dimethoxybenzene-1,4-dicarbaldehyde (112.8 mg, 0.58 mmol) and L-alanine (51.75 mg, 0.58 mmol) into a 10 ml glass bottle, add 6 mol / L acetic acid aqueous solution (8 ml); The mixture was sonicated using a 6 mm microtip probe, and a 650 W JY92-IIN intelligent ultrasonic disruptor was set to drive the probe at 60% power in a continuous mode at 20 kHz for 10 min; 1,3,5-tri(4-aminophenyl)benzene (92.8 mg, 0.39 mmol) was added to the mixed solution, and ultrasonic treatment was continued for 60 min; The yellow powder obtained after the reaction was filtered through a 0.22 μm nylon membrane to collect the solid, washed with acetone and methanol in turn, then subjected to Soxhlet extraction with tetrahydrofuran, and finally dried under vacuum to obtain a chiral two-dimensional covalent organic framework material L-alanine-COF DMTA+TAPB product.

[0047] Example 4 1. Chiral two-dimensional covalent organic framework material (5-L-alanine-COF DMTA+TAPB ) preparation method: Weigh 2,5-dimethoxybenzene-1,4-dicarbaldehyde (112.8 mg, 0.58 mmol) and L-alanine (258.75 mg, 2.9 mmol) into a 10 ml glass bottle, and add 6 mol / L acetic acid aqueous solution (8 ml); The mixture was sonicated using a 6 mm microtip probe, and a 650 W JY92-IIN intelligent ultrasonic disruptor was set to drive the probe at 60% power in a continuous mode at 20 kHz for 10 min; 1,3,5-tri(4-aminophenyl)benzene (92.8 mg, 0.39 mmol) was added to the mixed solution, and ultrasonic treatment was continued for 60 min; The yellow powder obtained after the reaction was filtered through a 0.22 μm nylon membrane to collect the solid, washed with acetone and methanol in turn, then subjected to Soxhlet extraction with tetrahydrofuran, and finally dried under vacuum to obtain a chiral two-dimensional covalent organic framework material L-alanine-COF DMTA+TAPB product.

[0048] Comparative Example 2 1. Two-dimensional covalent organic framework materials (COF DMTA+TAPB ) preparation method: Weigh 2,5-dimethoxybenzene-1,4-dicarbaldehyde (112.8 mg, 0.58 mmol) and 1,3,5-tris(4-aminophenyl)benzene (92.8 mg, 0.39 mmol) into a 10 ml glass bottle, and add 6 mol / L acetic acid aqueous solution (8 ml); The mixture was sonicated using a 6 mm microtip probe, and a 650 W JY92-IIN intelligent ultrasonic disruptor was set to drive the probe at 60% power in a continuous mode at 20 kHz for 60 min; The yellow powder obtained after the reaction was filtered through a 0.22 μm nylon membrane to collect the solid, washed with acetone and methanol in turn, then subjected to Soxhlet extraction with tetrahydrofuran, and finally dried under vacuum to obtain a two-dimensional covalent organic framework material COF TFP+DAB product.

[0049] 1-L-alanine-COF prepared in Examples 3-4 and Comparative Example 2 DMTA+TAPB 、5-L-alanine-COF DMTA+TAPB and COF DMTA+TAPB The physical and chemical properties were characterized and analyzed. Figure 6 shown.

[0050] Figure 6 1-L-alanine-COF is shown DMTA+TAPB 、5-L-alanine-COF DMTA+TAPB and COF DMTA+TAPB The powder X-ray diffraction pattern of the image shows that the diffraction peak at about 5° belongs to the (110) crystal plane of AA stacking. By comparing the crystallinity of products with different proportions of chiral inducers, it can be found that when the molar ratio of the chiral inducer to the organic monomer 1 is 1:1, the product with the best crystallinity is obtained.

[0051] Example 5 1. Chiral two-dimensional covalent organic framework materials (60 min-S-MBA-COF TFP+DAB ) preparation method: Weigh 2,4,6-triformylphloroglucinol (210 mg, 1 mmol) and S-MBA (119 mg, 1 mmol) into a 10 ml glass bottle, and add 6 mol / L acetic acid aqueous solution (4 ml); The mixture was sonicated using a 6 mm microtip probe, and a 650 W JY92-IIN intelligent ultrasonic disruptor was set to drive the probe at 60% power in a continuous mode at 20 kHz for 10 min; p-phenylenediamine (162 mg, 1.5 mmol) was added to the mixed solution, and ultrasonic treatment was continued for 60 min; The yellow powder obtained after the reaction was filtered through a 0.22 μm nylon membrane to collect the solid, washed with acetone and methanol in turn, then subjected to Soxhlet extraction with tetrahydrofuran, and finally dried under vacuum to obtain the chiral two-dimensional covalent organic framework material 60min-S-MBA-COF TFP+DAB product.

[0052] Comparative Example 3 1. Chiral two-dimensional covalent organic framework materials (5 min-S-MBA-COF TFP+DAB ) preparation method: Weigh 2,4,6-triformylphloroglucinol (210 mg, 1 mmol) and S-MBA (119 mg, 1 mmol) into a 10 ml glass bottle, and add 6 mol / L acetic acid aqueous solution (4 ml); The mixture was sonicated using a 6 mm microtip probe, and a 650 W JY92-IIN intelligent ultrasonic disruptor was set to drive the probe at 60% power in a continuous mode at 20 kHz for 10 min; p-phenylenediamine (162 mg, 1.5 mmol) was added to the mixed solution, and ultrasonic treatment was continued for 5 min; The yellow powder obtained after the reaction was filtered through a 0.22 μm nylon membrane to collect the solid, washed with acetone and methanol in sequence, then subjected to Soxhlet extraction with tetrahydrofuran, and finally dried under vacuum to obtain the chiral two-dimensional covalent organic framework material 5min-S-MBA-COF TFP+DAB product.

[0053] Comparative Example 4 1. Chiral two-dimensional covalent organic framework materials (10 min-S-MBA-COF TFP+DAB ) preparation method: Weigh 2,4,6-triformylphloroglucinol (210 mg, 1 mmol) and S-MBA (119 mg, 1 mmol) into a 10 ml glass bottle, and add 6 mol / L acetic acid aqueous solution (4 ml); The mixture was sonicated using a 6 mm microtip probe, and a 650 W JY92-IIN intelligent ultrasonic disruptor was set to drive the probe at 60% power in a continuous mode at 20 kHz for 10 min; p-phenylenediamine (162 mg, 1.5 mmol) was added to the mixed solution, and ultrasonic treatment was continued for 10 min; The yellow powder obtained after the reaction was filtered through a 0.22 μm nylon membrane to collect the solid, washed with acetone and methanol in turn, then subjected to Soxhlet extraction with tetrahydrofuran, and finally dried under vacuum to obtain the chiral two-dimensional covalent organic framework material 10min-S-MBA-COF TFP+DAB product.

[0054] Comparative Example 5 1. Chiral two-dimensional covalent organic framework materials (30 min-S-MBA-COF TFP+DAB ) preparation method: Weigh 2,4,6-triformylphloroglucinol (210 mg, 1 mmol) and S-MBA (119 mg, 1 mmol) into a 10 ml glass bottle, and add 6 mol / L acetic acid aqueous solution (4 ml); The mixture was sonicated using a 6 mm microtip probe, and a 650 W JY92-IIN intelligent ultrasonic disruptor was set to drive the probe at 60% power in a continuous mode at 20 kHz for 10 min; p-phenylenediamine (162 mg, 1.5 mmol) was added to the mixed solution, and ultrasonic treatment was continued for 30 min; The yellow powder obtained after the reaction was filtered through a 0.22 μm nylon membrane to collect the solid, washed with acetone and methanol in turn, then subjected to Soxhlet extraction with tetrahydrofuran, and finally dried under vacuum to obtain the chiral two-dimensional covalent organic framework material 30min-S-MBA-COF TFP+DAB product.

[0055] 5 min-S-MBA-COF prepared in Examples 1-2 and Comparative Example 1 TFP+DAB 、10 min-S-MBA-COF TFP+DAB 、30 min-S-MBA-COF TFP+DAB , and 60 min-S-MBA-COF TFP+DAB The physical and chemical properties were characterized and analyzed. Figure 7-8 shown.

[0056] Figure 7 5 min-S-MBA-COF TFP+DAB 、10 min-S-MBA-COF TFP+DAB 、30 min-S-MBA-COF TFP+DAB , and 60 min-S-MBA-COF TFP+DAB The powder X-ray diffraction pattern of the product shows that the diffraction peak at about 5° belongs to the (110) crystal plane of AA stacking. Comparing the crystallinity of different reaction times, it can be found that the product obtained at 60 min has the best crystallinity.

[0057] Figure 8 5 min-S-MBA-COF is shown TFP+DAB 、10 min-S-MBA-COF TFP+DAB 、30 min-S-MBA-COF TFP+DAB , and 60 min-S-MBA-COF TFP+DAB Fourier transform infrared spectrum. It can be found that when the reaction time is 5 min, 1513 cm -1 The peaks that appeared indicated that a large amount of p-phenylenediamine precursor still remained in the product.

[0058] In summary, the present invention is based on the chiral auxiliary induction method. By temporarily introducing chiral auxiliary during the synthesis process, a covalent organic framework (COF) material with "structural chirality" is successfully constructed. Different from the traditional practice of directly using chiral precursors or post-modification to achieve chiral functions, the chiral auxiliary in this method only exists as an induction factor during the reaction process and is not embedded in the final framework structure. This unique induction strategy not only overcomes the problem of uneven chirality distribution or decreased framework stability caused by embedding chiral molecules into the framework, but also significantly improves the transmission efficiency of chiral information.

[0059] In traditional methods, the use of chiral precursors may be limited by the availability and cost of raw materials; although post-modification methods can expand the chiral functions of existing materials, they often require additional steps, which may affect the crystallinity and stability of COF. The chiral auxiliary induction method, with its low cost, simplified operation process and efficient induction ability, provides a green, environmentally friendly and economical solution for the construction of high-crystallinity, high-purity chiral COF.

[0060] The present invention focuses on constructing "structural chirality", which is significantly different from the traditional method of directly imparting chiral functions to materials by introducing chiral molecules. Through the induction of chiral auxiliary agents, the originally non-chiral precursors can be connected by covalent bonds to form regular and stable chiral framework materials without retaining chiral molecules in the final material.

[0061] This method not only enhances the application potential of chiral COF in the fields of chiral separation and catalysis, but also demonstrates significant advantages of greenness, low energy consumption and high efficiency in the synthesis process, providing new ideas for the further development of chiral materials.

[0062] 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 preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the present invention.

Claims

1. A method for preparing a chiral aldehyde-amine condensation covalent organic framework material, characterized in that: include, Introducing chirality: dissolving the organic monomer 1 and the chiral inducing agent in an acetic acid aqueous solution and subjecting the mixture to ultrasonic treatment to obtain a mixed solution; Introducing a second organic monomer and prolonging the ultrasonic treatment: adding organic monomer 2 to the mixed solution and ultrasonically treating for 40 to 120 minutes; Product separation and purification: After the ultrasonic treatment, the reaction mixture was separated by filtration; Wherein, the organic monomer 1 includes but is not limited to one or more of triformylbenzene, terephthalaldehyde, 2,5-dihydroxyterephthalaldehyde and 4,4'-biphenyldicarboxaldehyde; the organic monomer 2 includes but is not limited to one or more of 1,3,5-tris(4-aminophenyl)benzene, 2,4,6-tris(4-aminophenyl)-1,3,5-triazine and benzidine.

2. The method for preparing a chiral aldehyde-amine condensation covalent organic framework material according to claim 1, characterized in that: The concentration of the acetic acid aqueous solution is 6-12 mol / L.

3. The method for preparing the chiral aldehyde-amine condensation covalent organic framework material according to claim 1, characterized in that: The diameter of the ultrasonic probe for introducing chiral ultrasonic treatment is 2-10 mm.

4. The method for preparing the chiral aldehyde-amine condensation covalent organic framework material according to claim 1, characterized in that: The chiral inducing agent is one or more of (R)-(+)-α-methylbenzylamine, (S)-(+)-α-methylbenzylamine, (R)-(+)-1-(1-naphthyl)ethylamine, (S)-(+)-1-(1-naphthyl)ethylamine, L-tryptophan, D-tryptophan, L-lysine, D-lysine, (R)-2-(1-aminoethyl)phenol and (S)-2-(1-aminoethyl)phenol.

5. The method for preparing the chiral aldehyde-amine condensation covalent organic framework material according to claim 1, characterized in that: The molar ratio of the organic monomer 1 to the chiral inducing agent is 1:1-5.

6. The method for preparing a chiral aldehyde-amine condensation covalent organic framework material according to claim 1, characterized in that: The ratio of the aldehyde group and the amino group used for the reaction in the organic monomer is 1:

1.

7. The method for preparing a chiral aldehyde-amine condensation covalent organic framework material according to any one of claims 1 or 3, characterized in that: The diameter of the ultrasonic probe used for the chiral ultrasonic treatment is 6 mm.

8. The method for preparing a chiral aldehyde-amine condensation covalent organic framework material according to claim 1, characterized in that: During the introduction of chirality, ultrasonic treatment was performed at 30-70% power for 10-30 min.

9. The method for preparing a chiral aldehyde-amine condensation covalent organic framework material according to claim 1, characterized in that: During the extended ultrasonic treatment, the ultrasonic frequency was maintained at 40 kHz and the power was 30-70%.

10. A chiral aldehyde-amine condensation covalent organic framework material prepared by the preparation method according to any one of claims 1 to 9.

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