Diyne functionalized covalent organic framework material as well as preparation method and application thereof

Abstract

The invention relates to a diyne functionalized covalent organic framework material as well as a preparation method and application thereof, and the diyne functionalized covalent organic framework material is synthesized by taking 4, 4 ', 4', 4 ''-(pyrene-1, 3, 6, 8-tetrayl) tetraphenylamine and 5, 5 '-(butyl-1, 3-diyne-1, 4-diyl) diisophthalaldehyde as construction units and adopting a Schiff base reaction. The dialkynyl functionalized covalent organic framework material disclosed by the invention has good chemical stability and can be used as a carrier to controllably grow silver nanoparticles through metal coordination to obtain a composite material, and the composite material shows excellent catalytic activity and cycling stability in a 4-nitrophenol reduction reaction catalyzed by sodium borohydride; therefore, the method has important application potential in the fields of environmental restoration, green chemistry and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of covalent organic framework materials, and particularly relates to a diacetylene functionalized covalent organic framework material and a preparation method and application thereof. BACKGROUND

[0002] 4-nitrophenol is a chemical widely used in the fields of dyes, pesticides, medicines and the like. Due to the presence of a nitro functional group in the molecular structure, 4-nitrophenol exhibits long-term chemical stability and biological toxicity, is easy to be long-termly retained in water bodies and soil, and is enriched through a food chain, thereby posing a potential threat to an ecological system and human health. Traditional physical adsorption, high-temperature incineration and biodegradation methods cannot effectively and greenly realize degradation of 4-nitrophenol. Therefore, construction of a novel catalyst with high catalytic activity and structural stability becomes a research focus in the field of environmental remediation.

[0003] Covalent organic framework is a kind of crystalline porous polymer connected by strong covalent bonds between organic monomers. As a kind of novel crystalline porous material, covalent organic framework can be used as an ideal carrier for controllable growth of metal nanoparticles due to advantages such as a stable framework structure, flexible pore size adjustment and rich active sites. Therefore, uniform and stable silver nanoparticles can be prepared by using coordination between metal ions and functional units in covalent organic framework, a composite material with high catalytic activity and high stability can be constructed, and the composite material can be used for efficient catalysis of a 4-nitrophenol reduction reaction. SUMMARY

[0004] The technical problem to be solved by the application is to provide a diacetylene functionalized covalent organic framework material and a preparation method and application thereof, so as to overcome the deficiencies of environmental remediation composite materials in catalytic activity and stability in the prior art.

[0005] The application provides a diacetylene functionalized covalent organic framework material, and a structural general formula of the diacetylene functionalized covalent organic framework material is as follows: ; wherein R is independently selected from one of hydrogen, an alkyl group, an alkoxy group and a halogen atom.

[0006] The application further provides a preparation method of the diacetylene functionalized covalent organic framework material, and the preparation method comprises the following steps:

[0007] 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl) tetrakisphenylamine PTA is obtained through a Schiff base reaction with an aromatic aldehyde monomer; and a structural general formula of the aromatic aldehyde monomer is as follows: ; R is independently selected from one of hydrogen, an alkyl group, an alkoxy group and a halogen atom.

[0008] Preferably, the aromatic aldehyde monomer is 5,5'-(but-1,3-diyne-1,4-diyl)diphthaldehyde DTA.

[0009] Further, the preparation method of the 5,5'-(but-1,3-diyne-1,4-diyl)diphthaldehyde comprises:

[0010] 5-ethynylbenzene-1,3-dicarboxaldehyde, cuprous iodide, tetramethyl ethylenediamine and N, N-dimethylformamide are mixed, and then stirred to react, to obtain the product.

[0011] Further, the molar ratio of the 5-ethynylbenzene-1,3-dicarboxaldehyde and the cuprous iodide is 20-30:1.

[0012] Further, the molar ratio of the tetramethyl ethylenediamine and the N, N-dimethylformamide is 1000-1200:1.

[0013] Further, the temperature of the stirring reaction is 25-30 o C, and the time is 60-72 h.

[0014] Preferably, the molar ratio of the 4,4',4'',4'''-(pyrene-1,3,6,8- tetrayl)tetraphenylamine PTA and the aromatic aldehyde monomer in the Schiff base reaction system is 1:1.

[0015] Preferably, the Schiff base reaction system further comprises a solvent and an acid catalyst.

[0016] Preferably, the solvent is 1,4-dioxane and mesitylene or benzyl alcohol and mesitylene; and the acid catalyst is an acetic acid solution.

[0017] Further, the volume ratio of the 1,4-dioxane, the mesitylene and the acetic acid solution is 2:8:1; and the volume ratio of the benzyl alcohol, the mesitylene and the acetic acid solution is 2:8:1.

[0018] Preferably, the temperature of the Schiff base reaction system is 120-140 o C, and the reaction time is 3-5 d.

[0019] The application further provides an application of the diacetylene functionalized covalent organic framework material in catalyzing a 4-nitrophenol reduction reaction.

[0020] Preferably, the diacetylene functionalized covalent organic framework material is used as a carrier, and a composite material is obtained by controllable growth of silver nanoparticles through metal coordination.

[0021] Further, the preparation method of the composite material comprises the following steps: sequentially stirring silver nitrate, methanol and diacetylene functionalized covalent organic framework material at room temperature; then, collecting the generated solid by centrifugation, and washing with excess methanol and vacuum drying to obtain the composite material.

[0022] Further, the mass ratio of the silver nitrate and the diacetylene functionalized covalent organic framework material is 1-2:1.

[0023] Advantages

[0024] (1) The diacetylene functionalized covalent organic framework material is synthesized by Schiff base reaction in the application, has good chemical stability, can resist common organic solvents and maintain the complete framework structure.

[0025] (2) The diacetylene unit is introduced as a functional unit in the application, and the coordination between the diacetylene unit and silver ions is utilized to prepare uniform and stable silver nanoparticles, which provides a theoretical guidance and experimental example for functional oriented covalent organic framework material design.

[0026] (3) The diacetylene functionalized covalent organic framework material loaded with silver nanoparticles in the application exhibits excellent catalytic activity and cycle stability in the reduction reaction of 4-nitrophenol catalyzed by sodium borohydride, and thus has important application potential in the fields of environmental remediation and green chemistry. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The nuclear magnetic resonance hydrogen spectrum of 5,5'-(but-1,3-diyn-1,4-diyl) dibenzil synthesized in Example 1.

[0028] Figure 2 The synthesis route diagram of 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-diyn-1,4-diyl) dibenzil (DTA) and 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl) tetrakisbenzeneamine (PTA).

[0029] Figure 3 The Fourier transform infrared spectrum of the COF-DP material synthesized in Example 2 and the corresponding monomers DTA and PTA.

[0030] Figure 4 The Fourier transform infrared spectrum of the COF-BP material synthesized in Example 3 and the corresponding monomers BTA and PTA.

[0031] Figure 5Powder X-ray diffraction pattern of the COF-DP material synthesized in Example 2.

[0032] Figure 6 Powder X-ray diffraction pattern of the COF-BP material synthesized in Example 3.

[0033] Figure 7 Nitrogen adsorption-desorption curve and BET specific surface area of the COF-DP material synthesized in Example 2.

[0034] Figure 8 Nitrogen adsorption-desorption curve and BET specific surface area of the COF-BP material synthesized in Example 3.

[0035] Figure 9 Solid-state nuclear magnetic resonance carbon spectrum of the diacetylenic functionalized covalent organic framework material synthesized in Examples 2, 3.

[0036] Figure 10 Powder X-ray diffraction pattern of the AgNPs@COF-DP material synthesized in Example 4.

[0037] Figure 11 Powder X-ray diffraction pattern of the AgNPs@COF-BP material synthesized in Example 5.

[0038] Figure 12 Transmission electron microscopy images of the AgNPs@COF-DP and AgNPs@COF-BP materials synthesized in Examples 4, 5.

[0039] Figure 13 UV-Vis absorption spectrum of the AgNPs@COF-DP material catalyzing the reduction reaction of p-nitrophenol in Example 6.

[0040] Figure 14 UV-Vis absorption spectrum of the AgNPs@COF-BP material catalyzing the reduction reaction of p-nitrophenol in Example 6.

[0041] Figure 15 Conversion rate comparison chart of the AgNPs@COF-DP material catalyzing the reduction reaction of p-nitrophenol after 9 cycles in Example 7.

[0042] Figure 16 Structural schematic diagram of the diacetylenic functionalized covalent organic framework material of the present application. DETAILED DESCRIPTION

[0043] The application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate the application and not used to limit the scope of the application. Furthermore, it should be understood that after reading the content of the application, those skilled in the art can make various modifications or changes to the application, and these equivalent forms also fall within the scope defined by the appended claims.

[0044] Raw material sources: 5-ethynylisophthalaldehyde (Hengnan Puyi Chemical Product Co., Ltd.), 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl) tetrabenzenamine (Shanghai Maierer Biotech Co., Ltd.), [1,1'-biphenyl]-3,3',5,5'-tetraformaldehyde (Shanghai Maierer Biotech Co., Ltd.).

[0045] Example 1

[0046] 5-ethynylisophthalaldehyde (300.0 mg, 1.90 mmol), cuprous iodide (22.0 mg, 0.09 mmol), tetramethyl ethylenediamine (57 μL, 0.35 mmol), N, N-dimethylformamide (30 mL, 389 mmol) were placed in a Schlenk flask (100 mL). After three cycles of freeze-pump-thaw degassing, the reaction was stirred at room temperature for 3 days. After the reaction was completed, the mixture was filtered and extracted with dichloromethane. The organic phase was dried over anhydrous magnesium sulfate, filtered, and the crude product was purified by silica gel column chromatography to obtain 5,5'-(but-1,3-diyn-1,4-diyl) diisophthalaldehyde (282.3 mg) as a light yellow powder, with a yield of 94%.

[0047] The nuclear magnetic resonance hydrogen spectrum of 5,5'-(but-1,3-diyn-1,4-diyl) diisophthalaldehyde obtained in this example is shown in Figure 1 .

[0048] Example 2

[0049] 5,5'-(but-1,3-diyn-1,4-diyl) diisophthalaldehyde (10.0 mg, 0.032 mmol) obtained in Example 1, 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl) tetrabenzenamine (18.0 mg, 0.032 mmol), benzyl alcohol (0.2 mL), and mesitylene (0.8 mL) were added to an ampoule (2 mL), and the mixture was ultrasonically treated to form a uniform dispersion system, followed by the addition of 9 M HOAc (0.1 mL) and ultrasonic dispersion for 10 min again. The ampoule was sealed in a vacuum environment and placed in a 120 oC The reaction was carried out in a constant temperature oven for 5 days. After the reaction was completed, it was cooled to room temperature, filtered under suction in a sand core funnel, washed with tetrahydrofuran and n-hexane in turn, and then vacuum dried for 12 h to obtain COF-DP material (17.6 mg) in the form of bright yellow powder, with a yield of 68.5%.

[0050] The synthetic route of the COF-DP material obtained in this example is shown in Figure 2 , the infrared spectrum is shown in Figure 3 , the PXRD spectrum is shown in Figure 5 , the nitrogen adsorption-desorption curve is shown in Figure 7 , the solid-state carbon nuclear magnetic resonance spectrum is shown in Figure 9 , and the general structure is shown in Figure 16 . From the above results, it can be seen that the prepared COF-DP material has a crystalline skeleton, regularly arranged channels and a large specific surface area.

[0051] Example 3

[0052] [1,1'-Biphenyl]-3,3',5,5'-tetracarboxaldehyde (10.0 mg, 0.038 mmol) and 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl) tetrakisbenzenamine (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 ultrasonically treated to form a uniform dispersion system, then 9 M HOAc (0.1 mL) was added, and the mixture was ultrasonically dispersed for 10 min again. The ampoule was sealed under vacuum and placed in a 120 o C The reaction was carried out in a constant temperature oven for 5 days. After the reaction was completed, it was cooled to room temperature, filtered under suction in a sand core funnel, washed with tetrahydrofuran and n-hexane in turn, and then vacuum dried for 12 h to obtain COF-BP material (20.8 mg) in the form of yellow-brown powder, with a yield of 72.9%.

[0053] The synthetic route of the COF-BP material obtained in this example is shown in Figure 2 , the infrared spectrum is shown in Figure 4 , the PXRD spectrum is shown in Figure 6 , the nitrogen adsorption-desorption curve is shown in Figure 8 , the solid-state carbon nuclear magnetic resonance spectrum is shown in Figure 10 , and the general structure is shown in Figure 16 . From the above results, it can be seen that the prepared COF-BP material has a crystalline skeleton, regularly arranged channels and a large specific surface area.

[0054] Example 4

[0055] Silver nitrate (22 mg, 0.13 mmol), methanol (10 mL) and COF-DP (20 mg) obtained from Example 2 were sequentially placed in a 25 mL round-bottom flask, and the mixture was continuously stirred at room temperature for 24 h. Subsequently, the generated solid was collected by centrifugation and washed with excess methanol and then dried under vacuum for 6 h to obtain a dark brown AgNPs@COF-DP composite material.

[0056] The transmission electron microscopy of the AgNPs@COF-DP material obtained in this example is shown in FIG. 2, which shows that the silver nanoparticles loaded by the COF-DP material containing a diacetylenic unit are small in size and uniformly distributed. Figure 12

[0057] Example 5

[0058] Silver nitrate (22 mg, 0.13 mmol), methanol (10 mL) and COF-BP (20 mg) obtained from Example 3 were sequentially placed in a 25 mL round-bottom flask, and the mixture was continuously stirred at room temperature for 24 h. Subsequently, the generated solid was collected by centrifugation and washed with excess methanol and then dried under vacuum for 6 h to obtain an orange-red AgNPs@COF-BP composite material.

[0059] The transmission electron microscopy of the AgNPs@COF-BP material obtained in this example is shown in FIG. 4, which shows that the silver nanoparticles loaded by the COF-BP material not containing a diacetylenic unit are large in size and not uniformly distributed. Figure 12

[0060] Example 6

[0061] A 4-nitrophenol aqueous solution (0.18 mmol / L, 20 mL) and a sodium borohydride aqueous solution (0.36 mol / L, 12 mL) were sequentially placed in a 50 mL round-bottom flask, 5 mg of a catalyst (AgNPs@COF-DP or AgNPs@COF-BP) was added under stirring, and the reaction process was monitored by ultraviolet-visible spectroscopy.

[0062] The ultraviolet-visible spectra of the AgNPs@COF-DP and AgNPs@COF-BP materials obtained in this example for catalyzing the reduction reaction of 4-nitrophenol are shown in FIGS. 6 and 7, respectively, which shows that the AgNPs@COF-DP material containing a diacetylenic unit has a more excellent catalytic effect. Figure 13 Figure 14

[0063] Example 7

[0064] ​​​​A 4-nitrophenol aqueous solution (0.18 mmol / L, 20 mL) and a sodium borohydride aqueous solution (0.36 mol / L, 12 mL) were placed in a 50 mL round-bottom flask, and AgNPs@COF-DP material (5 mg) was added as a catalyst under stirring. After the reaction was completed, the catalyst was separated by centrifugation for the next reaction, and the progress of the catalytic reaction was monitored by UV-visible spectroscopy.

[0065] like Figure 15 As shown in the figure, the AgNPs@COF-DP material still maintains excellent catalytic activity and stability after 9 catalytic cycles, which proves that the composite material has broad application prospects in the field of catalysis and can be applied to green chemistry and environmental remediation.

Claims

1. A diyne-functionalized covalent organic framework material, characterized by: The general structural formula of the diyne functionalized covalent organic framework material is: ; wherein R is independently selected from one of hydrogen, alkyl, alkoxy and halogen atoms.

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

3. The preparation method according to claim 2, wherein: The aromatic aldehyde monomer is 5,5'-(butane-1,3-diyne-1,4-diyl) diisophthalaldehyde DTA.

4. The preparation method according to 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 preparation method according to claim 2, wherein: The Schiff base reaction system also includes a solvent and an acid catalyst.

6. The preparation method according to claim 5, characterized in that: The solvent is 1,4-dioxane and mesitylene or benzyl alcohol and mesitylene; and the acid catalyst is acetic acid solution.

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

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

9. The use according to claim 8, characterized in that: The diyne functionalized covalent organic framework material is used as a carrier, and silver nanoparticles are controllably grown through metal coordination to obtain a composite material.

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