A diacetylenic functionalized covalent organic framework material, and a preparation method and application thereof

Abstract

The present application relates to a kind of diacetylene functionalized covalent organic framework material and its preparation method and application, to 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl) tetraphenylamine, 5,5'- (but-1,3-diethynyl-1,4-diyl) diisophthalaldehyde as building unit, synthesis using Schiff base reaction.The diacetylene functionalized covalent organic framework material of the present application has good chemical stability, and can be used as carrier by metal coordination effect Controllable growth silver nanoparticles to obtain composite material, the composite material in sodium borohydride catalytic 4-nitrophenol reduction reaction has shown excellent catalytic activity and cycle stability, thus has important application potential in the field such as environmental remediation and green chemistry.

Description

Technical Field

[0001] This invention belongs to the field of covalent organic framework materials technology, and specifically relates to a diyne functionalized covalent organic framework material, its preparation method, and its application. Background Technology

[0002] 4-Nitrophenol, a chemical widely used in dyes, pesticides, and pharmaceuticals, exhibits long-term chemical stability and biotoxicity due to the presence of nitro functional groups in its molecular structure. It tends to persist in water and soil, accumulating through the food chain and posing a potential threat to ecosystems and human health. Traditional methods such as physical adsorption, high-temperature incineration, and biodegradation are ineffective and environmentally friendly in degrading 4-nitrophenol. Therefore, developing novel catalysts with both high catalytic activity and structural stability has become a key research focus in environmental remediation.

[0003] Covalent organic frameworks (COFs) are a class of crystalline porous polymers composed of organic monomers linked by strong covalent bonds. As a novel type of crystalline porous material, COFs, due to their stable framework structure, flexible pore size regulation, and abundant active sites, can serve as ideal supports for the controllable growth of metal nanoparticles. Therefore, by utilizing the coordination interactions between metal ions and functional units within COFs to prepare uniform and stable silver nanoparticles, composite materials with both high catalytic activity and high stability can be constructed and used for the efficient catalytic reduction of 4-nitrophenol. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a diyne functionalized covalent organic framework material, its preparation method and application, so as to overcome the shortcomings of existing environmental remediation composite materials in terms of catalytic activity and stability.

[0005] This invention provides a diyne-functionalized covalent organic framework material, the general structural formula of which is:

[0006] ; where R is independently selected from one of hydrogen, alkyl, alkoxy, and halogen atoms.

[0007] This invention also provides a method for preparing a diyne-functionalized covalent organic framework material, comprising the following steps:

[0008] The product is obtained by reacting 4,4',4'',4'''-(pyrene-1,3,6,8-tetramethyl)tetraphenylamine PTA with an aromatic aldehyde monomer via a Schiff base reaction; wherein the general structural formula of the aromatic aldehyde monomer is as follows: R is independently selected from one of hydrogen, alkyl, alkoxy, and halogen atoms.

[0009] Preferably, the aromatic aldehyde monomer is 5,5'-(but-1,3-diyne-1,4-diyl)di-m-phenylenedialdehyde (DTA).

[0010] Further, the preparation method of the 5,5'-(but-1,3-diyne-1,4-diyl)di-m-phenylenedialdehyde includes:

[0011] The mixture of 5-ethynyl-isophthalaldehyde, cuprous iodide, tetramethylethylenediamine, and N,N-dimethylformamide, followed by stirring and reaction, yields the final product.

[0012] Furthermore, the molar ratio of 5-ethynyl-isophthalaldehyde to cuprous iodide is 20~30:1.

[0013] Furthermore, the molar ratio of tetramethylethylenediamine to N,N-dimethylformamide is 1000~1200:1.

[0014] Furthermore, the temperature of the stirring reaction is 25-30°C. o C, the time is 60~72 hours.

[0015] Preferably, the molar ratio of 4,4',4'',4'''-(pyrene-1,3,6,8-tetramethyl)tetraphenylamine PTA to aromatic aldehyde monomers in the Schiff base reaction system is 1:1.

[0016] Preferably, the Schiff base reaction system further includes a solvent and an acid catalyst.

[0017] Preferably, the solvent is 1,4-dioxane and mesitylene or benzyl alcohol and mesitylene; the acid catalyst is an acetic acid solution.

[0018] Furthermore, the volume ratio of the 1,4-dioxane, mesitylene, and acetic acid solution is 2:8:1; the volume ratio of the benzyl alcohol, mesitylene, and acetic acid solution is 2:8:1.

[0019] Preferably, the Schiff base reaction system is held at a temperature of 120-140°C. o C, the reaction time is 3~5 days.

[0020] This invention also provides the application of diyne-functionalized covalent organic framework materials in the catalytic reduction reaction of 4-nitrophenol.

[0021] Preferably, the composite material is obtained by controllably growing silver nanoparticles through metal coordination using the diyne-functionalized covalent organic framework material as a carrier.

[0022] Furthermore, the preparation method of the composite material includes the following steps: silver nitrate, methanol and diyne functionalized covalent organic framework material are continuously stirred at room temperature; then, the generated solid is collected by centrifugation, washed with excess methanol and vacuum dried to obtain the composite material.

[0023] Furthermore, the mass ratio of the silver nitrate and diyne-functionalized covalent organic framework material is 1-2:1.

[0024] Beneficial effects

[0025] (1) The present invention synthesizes a diyne-functionalized covalent organic framework material by Schiff base reaction, which has good chemical stability and can withstand common organic solvents while maintaining the complete framework structure.

[0026] (2) This invention introduces a diyne unit as a functional unit and uses the coordination effect between the diyne unit and silver ions to prepare uniform and stable silver nanoparticles, providing theoretical guidance and experimental examples for the design of function-oriented covalent organic framework materials.

[0027] (3) The diyne functionalized covalent organic framework material loaded with silver nanoparticles in this invention exhibits excellent catalytic activity and cycle stability in the sodium borohydride-catalyzed reduction reaction of 4-nitrophenol, and therefore has important application potential in environmental remediation and green chemistry. Attached Figure Description

[0028] Figure 1 The 1H NMR spectrum of 5,5'-(but-1,3-diyne-1,4-diyl)di-m-phenylenedialdehyde synthesized in Example 1.

[0029] Figure 2 This is a schematic diagram of the synthesis routes for the COF-DP material synthesized in Example 2 and the COF-BP material synthesized in Example 3; the monomers involved are [1,1'-biphenyl]-3,3',5,5'-tetracarboxaldehyde (BTA), 5,5'-(but-1,3-diyne-1,4-diyl)di-m-phenylenedialdehyde (DTA) and 4,4',4'',4'''-(pyrene-1,3,6,8-tetramethyl)tetraphenylamine (PTA).

[0030] Figure 3 The Fourier transform infrared spectra of the COF-DP material synthesized in Example 2 and its corresponding monomers DTA and PTA are shown.

[0031] Figure 4 The Fourier transform infrared spectra of the COF-BP material synthesized in Example 3 and its corresponding monomers BTA and PTA are shown.

[0032] Figure 5The image shows the powder X-ray diffraction pattern of the COF-DP material synthesized in Example 2.

[0033] Figure 6 The image shows the powder X-ray diffraction pattern of the COF-BP material synthesized in Example 3.

[0034] Figure 7 The nitrogen adsorption-desorption curve and BET specific surface area of ​​the COF-DP material synthesized in Example 2 are shown.

[0035] Figure 8 The nitrogen adsorption-desorption curve and BET specific surface area of ​​the COF-BP material synthesized in Example 3 are shown.

[0036] Figure 9 The solid-state carbon NMR spectra of the diyne functionalized covalent organic framework materials synthesized in Examples 2 and 3 are shown.

[0037] Figure 10 The powder X-ray diffraction pattern of the AgNPs@COF-DP material synthesized in Example 4 is shown.

[0038] Figure 11 The powder X-ray diffraction pattern of the AgNPs@COF-BP material synthesized in Example 5 is shown.

[0039] Figure 12 Transmission electron microscopy (TEM) images of the AgNPs@COF-DP and AgNPs@COF-BP materials synthesized in Examples 4 and 5.

[0040] Figure 13 The image shows the UV-Vis absorption spectrum of the reduction reaction of p-nitrophenol catalyzed by the AgNPs@COF-DP material in Example 6.

[0041] Figure 14 The image shows the UV-Vis absorption spectrum of the reduction reaction of p-nitrophenol catalyzed by the AgNPs@COF-BP material in Example 6.

[0042] Figure 15 This is a comparison chart of the conversion rates of the AgNPs@COF-DP material catalyzing the reduction of p-nitrophenol after 9 cycles in Example 7.

[0043] Figure 16 This is a schematic diagram of the structure of the diyne-functionalized covalent organic framework material of the present invention. Detailed Implementation

[0044] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0045] Raw material sources: 5-acetylene-m-phenylenedialdehyde (Henan Pusai Chemical Products Co., Ltd.), 4,4',4'',4'''-(pyrene-1,3,6,8-tetramethyl)tetraphenylamine (Shanghai Mairui Biochemical Technology Co., Ltd.), [1,1'-biphenyl]-3,3',5,5'-tetracarboxaldehyde (Shanghai Mairui Biochemical Technology Co., Ltd.).

[0046] Example 1

[0047] 5-ethynyl-isophthalaldehyde (300.0 mg, 1.90 mmol), cuprous iodide (22.0 mg, 0.09 mmol), tetramethylethylenediamine (57 μL, 0.35 mmol), and N,N-dimethylformamide (30 mL, 389 mmol) were placed in a Schlenk flask (100 mL). After three cycles of freezing-vacuuming-thawing to remove gas, the mixture was stirred at room temperature for 3 days. After the reaction was complete, the mixture was collected by filtration and extracted with dichloromethane. The organic phase was dried over anhydrous magnesium sulfate and filtered. The crude product was purified by silica gel column chromatography to give 282.3 mg of 5,5'-(but-1,3-diyne-1,4-diyl)isophthalaldehyde as a pale yellow powder, with a yield of 94%.

[0048] The 1H NMR spectrum of 5,5'-(but-1,3-diyne-1,4-diyl)di-m-phenylenedialdehyde obtained in this embodiment is as follows: Figure 1 As shown.

[0049] Example 2

[0050] The 5,5'-(butyr-1,3-diyne-1,4-diyl)di-m-phenylenedialdehyde (10.0 mg, 0.032 mmol) obtained in Example 1, along with 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetraphenylamine (18.0 mg, 0.032 mmol), benzyl alcohol (0.2 mL), and mesitylene (0.8 mL), were added to an ampoule (2 mL). The mixture was sonicated to form a homogeneous dispersion. Then, 9 M HOAc (0.1 mL) was added, and the mixture was sonicated again for 10 min. The ampoule was then evacuated and backfilled with nitrogen three times. The ampoule was then sealed under vacuum and placed at 120°C. oThe reaction was carried out in a constant temperature oven at C for 5 days. After the reaction was completed, the mixture was cooled to room temperature, filtered through a sintered glass funnel, washed successively with tetrahydrofuran and n-hexane, and then vacuum dried for 12 h to obtain a bright yellow powdered COF-DP material (17.6 mg), with a yield of 68.5%.

[0051] The synthesis route of the COF-DP material obtained in this embodiment is as follows: Figure 2 As shown, the infrared spectrum is as follows Figure 3 As shown, the PXRD spectrum is as follows Figure 5 As shown, the nitrogen adsorption-desorption curves are as follows: Figure 7 As shown, the solid-state carbon NMR spectrum is as follows: Figure 9 As shown, the general structural formula is as follows Figure 16 As shown in the figure, the prepared COF-DP material has a crystalline framework, regularly arranged pores, and a large specific surface area.

[0052] Example 3

[0053] [1,1'-Biphenyl]-3,3',5,5'-Tetracarboxaldehyde (10.0 mg, 0.038 mmol), 4,4',4'',4'''-(Pyrene-1,3,6,8-Tetrayl)tetraphenylamine (21.3 mg, 0.038 mmol), 1,4-dioxane (0.2 mL), and mesitylene (0.8 mL) were added to an ampoule (2 mL). The mixture was sonicated to form a homogeneous dispersion. Then, 9 M HOAc (0.1 mL) was added, and the mixture was sonicated again for 10 min. The ampoule was evacuated and backfilled with nitrogen three times. The ampoule was then sealed under vacuum and placed at 120°C. o The reaction was carried out in a constant temperature oven at C for 5 days. After the reaction was completed, the mixture was cooled to room temperature, filtered through a sintered glass funnel, washed successively with tetrahydrofuran and n-hexane, and then dried under vacuum for 12 h to obtain a yellowish-brown powdered COF-BP material (20.8 mg), with a yield of 72.9%.

[0054] The synthesis route of the COF-BP material obtained in this embodiment is as follows: Figure 2 As shown, the infrared spectrum is as follows Figure 4 As shown, the PXRD spectrum is as follows Figure 6 As shown, the nitrogen adsorption-desorption curves are as follows: Figure 8 As shown, the solid-state carbon NMR spectrum is as follows: Figure 9 As shown in the figure, the prepared COF-BP material has a crystalline framework, regularly arranged pores, and a large specific surface area.

[0055] Example 4

[0056] Silver nitrate (22 mg, 0.13 mmol), methanol (10 mL), and COF-DP (20 mg) obtained in Example 2 were placed in a 25 mL round-bottom flask and stirred continuously at room temperature for 24 hours. Subsequently, the solid generated was collected by centrifugation, washed with excess methanol, and dried under vacuum for 6 h to obtain a dark brown AgNPs@COF-DP composite material.

[0057] The transmission electron microscope (TEM) image of the AgNPs@COF-DP material obtained in this embodiment is as follows: Figure 12 As shown, the silver nanoparticles supported on the COF-DP material containing diyne units are small in size and uniformly distributed.

[0058] Example 5

[0059] Silver nitrate (22 mg, 0.13 mmol), methanol (10 mL), and COF-BP (20 mg) obtained in Example 3 were placed in a 25 mL round-bottom flask and stirred continuously at room temperature for 24 hours. Subsequently, the solid generated was collected by centrifugation, washed with excess methanol, and dried under vacuum for 6 h to obtain an orange-red AgNPs@COF-BP composite material.

[0060] The transmission electron microscope (TEM) image of the AgNPs@COF-BP material obtained in this embodiment is as follows: Figure 12 As shown, the silver nanoparticles loaded in the COF-BP material without diyne units are large in size and unevenly distributed.

[0061] Example 6

[0062] 4-Nitrophenol aqueous solution (0.18 mmol / L, 20 mL) and sodium borohydride aqueous solution (0.36 mol / L, 12 mL) were placed in a 50 mL round-bottom flask. 5 mg of catalyst (AgNPs@COF-DP or AgNPs@COF-BP) was added with stirring, and the reaction progress was monitored by UV-Vis spectroscopy.

[0063] The UV-Vis spectra of the AgNPs@COF-DP and AgNPs@COF-BP materials catalyzing the reduction of 4-nitrophenol in this embodiment are as follows: Figure 13 and Figure 14 As shown, the AgNPs@COF-DP material containing diyne units exhibits superior catalytic performance.

[0064] Example 7

[0065] 4-Nitrophenol aqueous solution (0.18 mmol / L, 20 mL) and sodium borohydride aqueous solution (0.36 mol / L, 12 mL) were placed in a 50 mL round-bottom flask. AgNPs@COF-DP material (5 mg) was added as a catalyst while stirring. After the reaction was completed, the catalyst was separated by centrifugation for the next reaction, and the catalytic reaction progress was monitored by UV-Vis spectroscopy.

[0066] like Figure 15 As shown, the AgNPs@COF-DP material maintains excellent catalytic activity and stability after 9 catalytic cycles, demonstrating that this composite material has broad application prospects in the field of catalysis and can be applied to fields such as green chemistry and environmental remediation.

Claims

1. A diacetylenic functionalized covalent organic framework material, characterized by: The diacetylene functionalized covalent organic framework material has a general structural formula: ; wherein R is independently selected from one of hydrogen, alkyl, alkoxy, and halogen.

2. A method for preparing a diacetylene functionalized covalent organic framework material, comprising the following steps: 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetraphenylamine PTA is obtained by Schiff base reaction with aromatic aldehyde monomers; wherein, The structural general formula of the aromatic aldehyde monomer is ; R is independently selected from one of hydrogen, alkyl, alkoxy, halogen atom.

3. The method of claim 2, wherein: The aromatic aldehyde monomer is 5,5'-(but-1,3-diyn-1,4-diyl)diphthaldehyde DTA.

4. The method of claim 2, wherein: The molar ratio of 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetraphenylamine PTA to the aromatic aldehyde monomer in the Schiff base reaction system is 1:

1.

5. The method of claim 2, wherein: The Schiff base reaction system further comprises a solvent and an acid catalyst.

6. The method of claim 5, wherein: The solvent is 1,4-dioxane and mesitylene or benzyl alcohol and mesitylene; and the acid catalyst is an acetic acid solution.

7. The method of claim 2, wherein: The temperature of the Schiff base reaction system is 120~140 o C, and the reaction time is 3~5 d.

8. Use of the diacetylene functionalized covalent organic framework material according to claim 1 in catalyzing a 4-nitrophenol reduction reaction.

9. Use according to claim 8, characterized in that: The diacetylene functionalized covalent organic framework material is used as a carrier to controllably grow silver nanoparticles through metal coordination to obtain a composite material.

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