Coumarin-linked conjugated porous polymers, methods of making and applications thereof

Abstract

This invention discloses a coumarin-linked conjugated porous polymer, its preparation method, and its applications. The preparation method includes: subjecting a homogeneous mixture containing o-hydroxybenzaldehyde monomer, phenylacetonitrile monomer, solvent, and catalyst to a Knauven-Gail condensation reaction to obtain the coumarin-linked conjugated porous polymer. The coumarin used in this invention to prepare the coumarin-linked conjugated porous polymer is a highly planar molecule. Its full conjugation extends the absorption wavelength to the visible light region and enhances π-electron excitation, thus exhibiting strong photosensitivity. The resulting series of coumarin-linked highly conjugated nanoarray conjugated porous polymers possess high porosity and a fully conjugated structure, making them highly efficient for applications in photocatalysis, fluorescence sensing, and optoelectronic devices.

Description

Technical Field

[0001] This invention relates to a coumarin-linked conjugated polymer, specifically to a coumarin-linked conjugated porous polymer and its preparation method and application, belonging to the field of conjugated porous polymer technology. Background Technology

[0002] Conjugated porous polymers are a class of organic polymer materials formed by the orderly assembly of organic molecular units through covalent bonds under the guidance of network chemistry. They exhibit regular nanopores and abundant active sites, showing outstanding potential in the field of photocatalysis. Currently, more research focuses on the design of monomer molecules, such as introducing photosensitive molecules or constructing electron donor-acceptor (DA) structures, while the bonding of conjugated porous polymers is also crucial to photocatalytic performance. Current bonding types include borate ester bonds, imine bonds, hydrazone bonds, carbon-carbon single bonds, carbon-carbon double bonds, and carbon-carbon triple bonds. However, incomplete conjugation leads to rapid recombination of photogenerated excitons, reducing light utilization and affecting photocatalytic reaction efficiency.

[0003] Coumarins, highly planar molecules found in legumes, possess a strong photosensitivity due to their planarity and conjugation, which extend absorption wavelengths into the visible light region and enhance π-electron excitation. They have been applied in fields such as fluorescence detection and organic photovoltaic cells. Introducing coumarin units into conjugated porous polymer frameworks as connectors can prepare nanoarray structures with high conjugation properties, promoting in-plane electron delocalization and the separation / transport of photogenerated electrons, thereby improving the solar energy conversion efficiency in photocatalytic reactions. However, the cyclization reaction of coumarin is irreversible, resulting in low polymer porosity and poor regularity. Therefore, designing and developing novel coumarin-linked conjugated porous polymers and efficient, scalable preparation methods is an urgent problem to be solved. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, the main objective of this invention is to provide a coumarin-linked conjugated porous polymer and its preparation method, thereby overcoming the shortcomings of the prior art.

[0005] Another object of the present invention is to provide the application of the coumarin-linked conjugated porous polymer.

[0006] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0007] This invention provides a method for preparing a coumarin-linked conjugated porous polymer, comprising: subjecting a homogeneous mixed reaction system containing o-hydroxybenzaldehyde monomer, phenylacetonitrile monomer, solvent and catalyst to a Knauvengel condensation reaction to obtain a coumarin-linked conjugated porous polymer.

[0008] In some embodiments, the temperature for heating the homogeneous mixed reaction system to carry out the Knauwengel condensation reaction is 80–220°C, and the time is 12–120 h.

[0009] This invention also provides a coumarin-linked conjugated porous polymer prepared by the aforementioned method, which has high porosity and a fully conjugated structure.

[0010] This invention also provides the application of the aforementioned coumarin-linked conjugated porous polymers in photocatalytic reactions.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] 1) The coumarin-linked conjugated porous polymer prepared by this invention has an excellent level of in-plane electron delocalization. Under photoexcitation conditions, more electrons transition to the excited state, generating a high concentration of photogenerated carriers, thus exhibiting excellent photoelectric effects.

[0013] 2) The method for preparing coumarin-linked conjugated porous polymers provided by the present invention can prepare a series of conjugated porous polymers with excellent photoelectric properties by selecting appropriate small molecule monomers and reaction conditions. These polymers can be widely used in fields such as photocatalytic hydrolysis to produce hydrogen, photocatalytic production of hydrogen peroxide, or photocatalytic degradation of pollutants.

[0014] 3) The photocurrent of the coumarin-linked conjugated porous polymer prepared in this invention can reach 1–20 μA·cm⁻¹. 2 When ascorbic acid is used as a sacrificial agent and Pt as a co-catalyst, the hydrogen production from photocatalytic water splitting reaches as high as 521 mmol / h. -1 g -1 (2-10 mg coumarin linked to conjugated porous polymers) represents the highest level among current photocatalytic hydrogen production materials. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a synthetic route diagram of a coumarin-linked conjugated porous polymer in a typical embodiment of the present invention;

[0017] Figure 2 The infrared spectrum of the coumarin-linked conjugated porous polymer XDS-COF-1 prepared in Example 1 of this invention;

[0018] Figure 3 The X-ray diffraction pattern of the coumarin-linked conjugated porous polymer XDS-COF-1 prepared in Example 1 of this invention;

[0019] Figure 4 This is the solid-state carbon NMR spectrum of the coumarin-linked conjugated porous polymer XDS-COF-1 prepared in Example 1 of this invention;

[0020] Figure 5 The photocurrent-time spectrum of the coumarin-linked conjugated porous polymer XDS-COF-1 prepared in Example 1 of this invention is shown.

[0021] Figure 6 The photocatalytic hydrogen production performance of the coumarin-linked conjugated porous polymer XDS-COF-1 prepared in Example 1 of this invention;

[0022] Figure 7 Electrochemical impedance spectroscopy of the coumarin-linked conjugated porous polymer XDS-COF-1 prepared in Example 1 of this invention;

[0023] Figure 8 Thermogravimetric spectrum of coumarin-linked conjugated porous polymer XDS-COF-1 prepared in Example 1 of this invention;

[0024] Figure 9 This is a photocurrent test diagram of the im-COF conjugated porous polymer with imine bonds obtained in Comparative Example 1. Detailed Implementation

[0025] In view of the problems of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. Its main function is to provide an o-hydroxybenzaldehyde monomer suitable for coumarin-linked conjugated polymers. By selecting suitable phenylacetonitrile monomers and reaction conditions, a series of conjugated porous polymers with high photoelectric conversion activity can be synthesized as needed. The technical solution of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0026] Please see Figure 1 As shown, one aspect of the present invention provides a method for preparing a coumarin-linked conjugated porous polymer, comprising: thoroughly mixing an o-hydroxybenzaldehyde monomer, a phenylacetonitrile monomer, a catalyst, and a solvent to form a homogeneous mixed reaction system; evacuating the homogeneous mixed reaction system, sealing and heating it, and promoting the Knauvengay condensation reaction under high temperature to obtain the coumarin-linked conjugated porous polymer.

[0027] In some embodiments, the o-hydroxybenzaldehyde monomer used includes, but is not limited to, any one or a combination of two or more of the following structures:

[0028]

[0029]

[0030] The mechanism by which the o-hydroxybenzaldehyde monomer of the present invention is selected is that: such monomers contain hydroxyl groups, which can undergo intramolecular cyclization with nitrile groups to form fully conjugated coumarin units with cyclic lactone structures, which can promote in-plane electron delocalization, improve the separation ability of photogenerated electrons and holes, and thus improve light utilization and photocatalytic efficiency.

[0031] In some more specific embodiments, the o-hydroxybenzaldehyde monomer may specifically include, but is not limited to, 2,5-dihydroxy-terephthalaldehyde, 3,3′-dihydroxy-(1,1′-biphenyl)-4,4′-dicarboxaldehyde, 4,4′-(1,2-acetylenediyl)bis(2-hydroxy)benzaldehyde, 3,7-dihydroxynaphthalene-2,6-dicarboxaldehyde, 4,4′-dihydroxy-3,3′-glyoxal biphenyl, trialdehyde-phloroglucinol, 5′-(4-formyl-3-hydroxyphenyl)-3,3″-dihydroxy-(1,1′:3′,1″-terphenyl)-4,4″-dicarboxaldehyde, 4,4′,4″-(1,3,5-triazine-2,4,6-triyl)tris(2-hydroxybenzaldehyde), 4,4′,4″-(benzene-1,3,5-triyltris(acetylene-2,1) -diyl))tri(2-hydroxybenzaldehyde), 4,4′,4″-((1,3,5-triazine-2,4,6-triyl)tri(acetylene-2,1-diyl))tri(2-hydroxybenzaldehyde), 4,4′,4″,4″′-(pyrene-1,3,6,8-tetrayl)tetra(2-hydroxybenzaldehyde), 4,4′,4″,4″′-(pyrene-1,3,6,8-tetraalkyltetra( The following are any one or a combination of two or more of the following: acetylene-2,1-diyl)tetra(2-hydroxybenzaldehyde), 4,4′,4″,4″′-(porphyrin-5,10,15,20-tetrayl)tetra(2-hydroxybenzaldehyde), 4′,4″,4″″,4″″″′-(ethylene-1,1,2,2-tetrayl)tetra(3-hydroxy-(1″,1″-biphenyl)-4-carboxaldehyde).

[0032] Further, the o-hydroxybenzaldehyde monomer preferably includes any one or a combination of two or more of the following: 2,5-dihydroxyterephthalaldehyde, 3,3′-dihydroxy-(1,1′-biphenyl)-4,4′-dicarboxaldehyde, trialdehyde-resorcinol, 5′-(4-formyl-3-hydroxyphenyl)-3,3″-dihydroxy-(1,1′:3′,1″-terphenyl)-4,4″-dicarboxaldehyde, 4,4′,4″-(benzene-1,3,5-triyltris(acetylene-2,1-diyl))tris(2-hydroxybenzaldehyde), and 4,4′,4″,4″′-(pyrene-1,3,6,8-tetrayl)tetra(2-hydroxybenzaldehyde), but is not limited thereto.

[0033] In some embodiments, the styrene monomer used comprises any one or a combination of two or more of the following structures:

[0034]

[0035]

[0036] In some more specific embodiments, the phenylacetonitrile monomer includes, but is not limited to, terephthalonitrile, 4,4′-biphenylacetonitrile, 2,2′-((2,2′-bipyridine)-5,5′-wyl)acetonitrile, 2,2′-(acetylen-1,2-e-ylbis(4,1-phenylene))acetonitrile, 2,6-naphthaleneacetonitrile, 1,3,5-tris(4-cyanomethylbenzene)benzene, 2,2′,2′-(1,3,5-triazin-2,4,6-triyl)tris(phenyl-4,1-diyl)triacetonitrile, 2,2′,2″-(phenyl-1,3,5-tris(pyridine-5,2-wyl))triacetonitrile, 2,2′,2′-(phenyl-1,3,5-tris(pyridine-5,2-wyl))triacetonitrile, and 2,2′,2′-(phenyl-1,3,5-tris(pyridine-5,2-wyl))triacetonitrile. Any one or a combination of two or more of the following: (acetylene-2,1-diyl))tri(phenyl-4,1-diyl)triacetonitrile, 2,2′,2″,2″′-(pyrene-1,3,6,8-tetraalkyltetra(phenyl-4,1-diyl))tetraacetonitrile, 2,2′,2″,2″′-((pyrene-1,3,6,8-tetraalkyltetra(acetylene-2,1-diyl))tetra(phenyl-4,1-diyl)tetraacetonitrile, 2,2′,2″,2″′-(porphyrin-5,10,15,20-tetraalkyltetra(phenyl-4,1-diyl))tetraacetonitrile, and 2,2′,2″,2″′-(ethylene-1,1,2,2-tetraalkyltetra(phenyl-4,1-diyl))tetraacetonitrile.

[0037] In some embodiments, the catalyst may be any one or a combination of two or more of the following: 1,8-ediazobispiro[5.4.0]undecyl-7-ene (DBU), 4-dimethylaminopyridine (DMAP), potassium hydroxide, sodium hydroxide, potassium tert-butoxide, potassium acetate, cesium carbonate, ammonium acetate, sodium ethoxide, acetic acid, trifluoroacetic acid, p-toluenesulfonic acid, benzoic anhydride, benzoic acid, etc.

[0038] In some embodiments, the solvent may be any one or a combination of two or more of the following: o-dichlorobenzene, n-butanol, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, mesitylene, 1,4-dioxane, acetonitrile, ethanol, methanol, N-methylpyrrolidone, and water.

[0039] In some embodiments, the molar ratio of the o-hydroxybenzaldehyde monomer to the phenylacetonitrile monomer is 1:(0.5N3).

[0040] In some embodiments, the molar ratio of the o-hydroxybenzaldehyde monomer to the catalyst is 1:(1-3).

[0041] In some embodiments, the molar volume ratio of the o-hydroxybenzaldehyde monomer to the solvent is 1 mmol: (10 N 50) mL.

[0042] In some preferred embodiments, the preparation method specifically includes: mixing o-hydroxybenzaldehyde monomer, phenylacetonitrile monomer, and catalyst in a solvent to form a homogeneous mixed reaction system;

[0043] The homogeneous mixed reaction system is heated to carry out the Knauvengel condensation reaction, thereby obtaining a coumarin-linked conjugated porous polymer.

[0044] In some preferred embodiments, the preparation method further includes: first, subjecting the homogeneous mixed reaction system to a freeze-vacuum cycle 3 to 5 times, each time for 5 to 15 minutes, and then sealing the tube with a flame to heat the homogeneous mixed reaction system.

[0045] In some preferred embodiments, the temperature at which the homogeneous mixed reaction system is heated to carry out the Knauwengel condensation reaction is 80–220°C, and the heating time is 12–120 h.

[0046] In some more specific preferred embodiments, the preparation method of the coumarin-linked conjugated porous polymer may specifically include: adding o-hydroxybenzaldehyde monomer, phenylacetonitrile monomer, catalyst, and solvent into a quartz glass tube to form a homogeneous mixed reaction system, freezing and vacuuming the quartz glass tube three times, sealing it after each freezing and vacuuming cycle of 5 to 15 minutes, and then heating the homogeneous mixed reaction system.

[0047] Another aspect of the present invention provides a coumarin-linked conjugated porous polymer material with good stability, abundant active sites, high photoelectric activity, and full conjugation, prepared by the aforementioned method. It has high porosity and a fully conjugated structure, and exhibits excellent photoelectric conversion performance.

[0048] Furthermore, the specific surface area of ​​the coumarin-linked conjugated porous polymer is 50–2200 m². 2 / g, with a pore size distribution of 1–5 nm.

[0049] The coumarin-linked conjugated porous polymer prepared by this invention has an excellent level of in-plane electron delocalization. Under photoexcitation conditions, more electrons transition to the excited state, generating a high concentration of photogenerated carriers, thus exhibiting excellent photoelectric effects.

[0050] Another aspect of this invention provides applications of the coumarin-linked conjugated porous polymers. Specifically, the coumarin used in the preparation of the coumarin-linked conjugated porous polymers is a highly planar molecule whose full conjugation extends the absorption wavelength to the visible light region and enhances π-electron excitation, thereby exhibiting strong photosensitivity. The resulting series of coumarin-linked, highly conjugated nanoarray conjugated porous polymers can be efficiently applied in photocatalysis, fluorescence sensing, optoelectronic devices, and other fields.

[0051] Specifically, the photocatalytic reaction may include any one of the following, but is not limited to: photocatalytic hydrolysis (e.g., hydrogen production), carbon dioxide reduction, photocatalytic hydrogen peroxide production, and biomass degradation reaction (e.g., photocatalytic pollutant degradation reaction).

[0052] The method for preparing coumarin-linked conjugated porous polymers provided by this invention can produce a series of conjugated porous polymers with excellent photoelectric properties by selecting appropriate small molecule monomers and reaction conditions. These polymers can be widely used in fields such as photocatalytic hydrolysis to produce hydrogen, photocatalytic production of hydrogen peroxide, or photocatalytic degradation of pollutants.

[0053] Furthermore, the photocurrent of the coumarin-linked conjugated porous polymer can reach 1–20 μA·cm⁻¹. 2 When ascorbic acid is used as a sacrificial agent and Pt as a co-catalyst, the hydrogen production from photocatalytic water splitting reaches as high as 521 mmol / h. -1 g -1 (2-10 mg coumarin linked to conjugated porous polymers) represents the highest level among current photocatalytic hydrogen production materials.

[0054] In summary, the coumarin monomers in the coumarin-linked conjugated porous polymer prepared by this invention have excellent in-plane electron delocalization levels. Under photoexcitation conditions, more electrons transition to the excited state, generating a high concentration of photogenerated carriers. Therefore, it has excellent photoelectric effects and can be widely used in photocatalytic water splitting to produce hydrogen, photocatalytic hydrogen peroxide production, or photocatalytic degradation of pollutants.

[0055] The technical solution of the present invention will be further described in detail below with reference to several preferred embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. It should be noted that the following embodiments are intended to facilitate the understanding of the present invention, and do not constitute any limitation thereof. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise specified, the experimental materials used in the embodiments below can be purchased from conventional biochemical reagent companies.

[0056] Example 1

[0057] The preparation of the coumarin-linked conjugated porous polymer in this embodiment includes the following steps:

[0058] (1) Sealing reaction: 4,4′,4″-(benzene-1,3,5-triyltris(acetylene-2,1-diyl))tris(2-hydroxybenzaldehyde) (0.03 mmol), terephthalonitrile (0.045 mmol), o-dichlorobenzene (0.3 mL), n-butanol (0.7 mL) and 3 mol L were added to a quartz glass tube. -1 DBU (0.03 mmol) was mixed thoroughly, and the mixture was vacuumed for 15 minutes to seal the quartz glass tube. The quartz glass tube was then heated at 120°C for 3 days.

[0059] (2) Post-reaction treatment: After the reaction was completed, the product was washed with N,N-dimethylformamide, methanol, acetone and tetrahydrofuran solvent, and dried under vacuum to obtain a coumarin-linked conjugated porous polymer (labeled as XDS-COF-1).

[0060] The infrared spectral characterization results of the coumarin-linked conjugated porous polymer XDS-COF-1 obtained in this embodiment are as follows: Figure 2 As shown, 1726cm -1 The infrared vibrational peaks indicate the formation of carbonyl groups in coumarin. The X-ray diffraction pattern of XDS-COF-1 is shown below. Figure 3 As shown in the figure, this material has good crystallinity. Figure 4The solid-state carbon NMR spectrum of XDS-COF-1 shows that the peak positions are consistent with the theoretical structure, proving the successful preparation of carbon-carbon XDS-COF-1. Figure 5 Photocurrent testing showed that XDS-COF-1 has good photoelectric response, with a photocurrent reaching 7 μA·cm⁻¹. 2 When ascorbic acid is used as a sacrificial agent and Pt as a co-catalyst, the hydrogen production from photocatalytic water splitting reaches as high as 521 mmol g. -1 h -1 (2-10 mg coumarin linked to conjugated porous polymer) Figure 6 Electrochemical impedance spectroscopy (EIS) is shown below. Figure 7 As shown, the thermogravimetric spectrum is as follows: Figure 8 As shown.

[0061] Example 2

[0062] The preparation of the coumarin-linked conjugated porous polymer in this embodiment includes the following steps:

[0063] (1) Sealing reaction: Trialdehyde phloroglucinol (0.03 mmol), terephthalonitrile (0.015 mmol), o-dichlorobenzene (0.5 mL), n-butanol (0.5 mL) and 3 mol L were added to a quartz glass tube. -1 DBU (0.045 mmol) was mixed thoroughly, and the mixture was vacuumed for 15 minutes to seal the quartz glass tube. The quartz glass tube was then heated at 150°C for 3 days.

[0064] (2) Post-reaction treatment: After the reaction was completed, the product was washed with N,N-dimethylformamide, methanol, acetone and tetrahydrofuran solvent, and dried under vacuum to obtain a coumarin-linked conjugated porous polymer (labeled as XDS-COF-2).

[0065] Example 3

[0066] The preparation of the coumarin-linked conjugated porous polymer in this embodiment includes the following steps:

[0067] (1) Sealing reaction: 4,4′,4″-(benzene-1,3,5-triyltri(acetylene-2,1-diyl))tri(2-hydroxybenzaldehyde) (0.03 mmol), 1,3,5-tris(4-cyanomethylbenzene)benzene (0.09 mmol), mesitylene (0.7 mL), dioxane (0.3 mL) and cesium carbonate (0.045 mmol) were added to a quartz glass tube, mixed thoroughly, and the quartz glass tube was sealed under vacuum for 30 minutes. Then the quartz glass tube was heated at 110 °C for 48 h.

[0068] (2) Post-reaction treatment: After the reaction was completed, the product was washed with N,N-dimethylformamide, methanol, acetone and tetrahydrofuran solvent, and dried under vacuum to obtain a coumarin-linked conjugated porous polymer (labeled as XDS-COF-3).

[0069] Example 4

[0070] The preparation of the coumarin-linked conjugated porous polymer in this embodiment includes the following steps:

[0071] (1) Sealing reaction: Add trialdehyde phloroglucinol (0.03 mmol), 1,3,5-tris(4-cyanomethylbenzene)benzene (0.015 mmol), o-dichlorobenzene (0.5 mL), mesitylene (0.5 mL) and potassium hydroxide (0.09 mmol) to a quartz glass tube, mix well, evacuate for 15 minutes and then seal the quartz glass tube, and then heat the quartz glass tube at 100℃ for 3 days.

[0072] (2) Post-reaction treatment: After the reaction was completed, the product was washed with N,N-dimethylformamide, methanol, acetone and tetrahydrofuran solvent, and dried under vacuum to obtain a coumarin-linked conjugated porous polymer (labeled as XDS-COF-4).

[0073] Example 5

[0074] The preparation of the coumarin-linked conjugated porous polymer in this embodiment includes the following steps:

[0075] (1) Sealing reaction: 5′-(4-formyl-3-hydroxyphenyl)-3,3″-dihydroxy-[1,1′:3′,1″-terphenyl]-4,4″-dicarboxaldehyde (0.03mmol), terephthalonitrile (0.045mmol), o-dichlorobenzene (0.1mL), n-butanol (0.9mL) and potassium tert-butoxide (0.03mmol) were added to a quartz glass tube, mixed evenly, and vacuumed for 2 minutes to seal the quartz glass tube. Then the quartz glass tube was heated at 120℃ for 3 days.

[0076] (2) Post-reaction treatment: After the reaction was completed, the product was washed with N,N-dimethylformamide, methanol, acetone and tetrahydrofuran solvent, and dried under vacuum to obtain a coumarin-linked conjugated porous polymer (labeled as XDS-COF-5).

[0077] Example 6

[0078] The preparation of the coumarin-linked conjugated porous polymer in this embodiment includes the following steps:

[0079] (1) Sealing reaction: 5′-(4-formyl-3-hydroxyphenyl)-3,3″-dihydroxy-[1,1′:3′,1″-terphenyl]-4,4″-dicarboxaldehyde (0.03 mmol), 1,3,5-tris(4-cyanomethylbenzene)benzene (0.09 mmol), N,N-dimethylformamide (0.4 mL), methanol (0.6 mL), and 3 mol L were added to a quartz glass tube. -1 DBU (0.03 mmol) was mixed thoroughly, and the mixture was evacuated for 15 minutes to seal the quartz glass tube. The quartz glass tube was then heated at 120°C for 48 hours.

[0080] (2) Post-reaction treatment: After the reaction was completed, the product was washed with N,N-dimethylformamide, methanol, acetone and tetrahydrofuran solvent, and dried under vacuum to obtain a coumarin-linked conjugated porous polymer (labeled as XDS-COF-6).

[0081] Example 7

[0082] The preparation of the coumarin-linked conjugated porous polymer in this embodiment includes the following steps:

[0083] (1) Sealing reaction: 2,2′,2″-(benzene-1,3,5-tris(pyridin-5,2-diyl))triacetonitrile (0.03 mmol), 2,5-dihydroxyterephthalaldehyde (0.045 mmol), N,N-dimethylacetamide (0.4 mL), acetonitrile (0.6 mL) and potassium acetate (0.09 mmol) were added to a quartz glass tube, mixed evenly, and vacuumed for 30 minutes to seal the quartz glass tube. Then the quartz glass tube was heated at 150 °C for 3 days.

[0084] (2) Post-reaction treatment: After the reaction was completed, the product was washed with N,N-dimethylformamide, methanol, acetone and tetrahydrofuran solvent, and dried under vacuum to obtain a coumarin-linked conjugated porous polymer (labeled as XDS-COF-7).

[0085] Example 8

[0086] The preparation of the coumarin-linked conjugated porous polymer in this embodiment includes the following steps:

[0087] (1) Sealing reaction: 2,2′,2″-(benzene-1,3,5-tris(pyridine-5,2-diyl))triacetonitrile (0.07 mmol), 3,3'-dihydroxy-[1,1′-biphenyl]-4,4'-dicarboxaldehyde (0.045 mmol), mesitylene (0.7 mL), and trifluoroacetic acid (0.09 mmol) were added to a quartz glass tube, mixed thoroughly, and the quartz glass tube was sealed under vacuum for 15 minutes. Then the quartz glass tube was heated at 220 °C for 12 h.

[0088] (2) Post-reaction treatment: After the reaction was completed, the product was washed with N,N-dimethylformamide, methanol, acetone and tetrahydrofuran solvent, and dried under vacuum to obtain a coumarin-linked conjugated porous polymer (labeled as XDS-COF-8).

[0089] Example 9

[0090] The preparation of the coumarin-linked conjugated porous polymer in this embodiment includes the following steps:

[0091] (1) Sealing reaction: 3,3′-dihydroxy-[1,1′-biphenyl]-4,4′-dicarboxaldehyde (0.045 mmol), 1,3,5-tris(4-cyanomethylbenzene)benzene (0.03 mmol), dioxane (2.25 mL), and p-toluenesulfonic acid (0.09 mmol) were added to a quartz glass tube, mixed evenly, and the quartz glass tube was sealed by vacuuming for 15 minutes. Then the quartz glass tube was heated at 80 °C for 120 h.

[0092] (2) Post-reaction treatment: After the reaction was completed, the product was washed with N,N-dimethylformamide, methanol, acetone and tetrahydrofuran solvent, and dried under vacuum to obtain a coumarin-linked conjugated porous polymer (labeled as XDS-COF-9).

[0093] Tests showed that the properties of the coumarin-linked conjugated porous polymers obtained in Examples 2-9 were basically similar to those in Example 1, all exhibiting excellent photoelectrocatalytic activity.

[0094] Comparative Example 1

[0095] The preparation process of this comparative example is basically the same as that of Example 1, except that the methyl monomer used is replaced with an amino monomer (p-phenylenediamine) to construct an imine-linked conjugated polymer im-COF.

[0096] (1) Sealing reaction: Add 0.03 mmol of 4,4′,4″-(benzene-1,3,5-triyltris(acetylene-2,1-diyl))tris(2-hydroxybenzaldehyde), 0.06 mmol of p-phenylenediamine, 1 mL of o-dichlorobenzene, and 3 mol L- to a quartz glass tube. 1 DBU (0.09 mmol) was mixed thoroughly, and the mixture was vacuumed for 15 minutes to seal the quartz glass tube. The quartz glass tube was then heated at 120°C for 3 days.

[0097] (2) Post-reaction treatment: After the reaction is completed, the product is washed with ethanol, acetone and tetrahydrofuran solvent, and then dried under vacuum to obtain im-COF.

[0098] Compared with the conjugated porous polymer XDS-COF-1 obtained in Example 1, the im-COF obtained in this comparative example has a smaller photocurrent (imine bond-linked conjugated porous polymer im-COF). Figure 9 Therefore, the coumarin XDS-COF-1 conjugated porous polymer designed in this invention exhibits superior photoelectric activity.

[0099] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the foregoing embodiments. For example, the o-hydroxybenzaldehyde monomer in Examples 1-9 was replaced with 4,4′-(1,2-acetylenidediyl)bis(2-hydroxy)benzaldehyde, 3,7-dihydroxynaphthalene-2,6-dicarboxaldehyde, 4,4'-dihydroxy-3,3'-glyoxal biphenyl, 4,4′,4″-(1,3,5-triazine-2,4,6-triyl)tris(2-hydroxybenzaldehyde), and 4,4′,4″-((1,3,5-triazine-2,4,6-triyl)tris(acetylenide-2,1-diyl))tris(2-hydroxybenzaldehyde). The following monomers were tested: formaldehyde, 4,4′, 4″, 4″′-(pyrene-1,3,6,8-tetrayl)tetra(2-hydroxybenzaldehyde), 4,4′, 4″, 4″′-(pyrene-1,3,6,8-tetraalkyltetra(acetylene-2,1-diyl))tetra(2-hydroxybenzaldehyde), 4,4′, 4″, 4″′-(porphyrin-5,10,15,20-tetrayl)tetra(2-hydroxybenzaldehyde), and 4′, 4″, 4″″, 4″″″′-(ethylene-1,1,2,2-tetrayl)tetra(3-hydroxy-(1″,1″-biphenyl)-4-formaldehyde), etc., with the phenylacetonitrile monomer in Examples 1-9 replaced by 4,4′-biphenyl. Diacetonitrile, 2,2′-((2,2′-bipyridine)-5,5′-diyl)diacetonitrile, 2,2′-(acetylen-1,2-diylbis(4,1-phenylene))diacetonitrile, 2,6-naphthalenediacetonitrile, 2,2′,2′-(1,3,5-triazine-2,4,6-triyl)tris(benzene-4,1-diyl)triacetonitrile, 2,2′,2′-(benzene-1,3,5-tris(acetylene-2,1-diyl))tris(benzene-4,1-diyl)triacetonitrile, 2,2′,2″,2″′-(pyrene-1,3,6,8-tetraalkyltetra(benzene-4,1-diyl))tetraacetonitrile, 2,2′,2″,2″′-((pyrene- Experiments were conducted using 1,3,6,8-tetraalkyltetra(acetylene-2,1-diyl))tetra(benzene-4,1-diyl)tetraacetonitrile, 2,2′,2″,2″′-(porphyrin-5,10,15,20-tetraalkyltetra(benzene-4,1-diyl))tetraacetonitrile, 2,2′,2″,2″′-(ethylene-1,1,2,2-tetraalkyltetra(benzene-4,1-diyl))tetraacetonitrile, etc., and the catalysts in Examples 1-9 were replaced with 4-dimethylaminopyridine (DMAP), sodium hydroxide, potassium tert-butoxide, potassium acetate, ammonium acetate, sodium ethoxide, acetic acid, trifluoroacetic acid, p-toluenesulfonic acid, etc., and all yielded relatively ideal results.

[0100] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a coumarin-linked conjugated porous polymer, characterized in that, include: A coumarin-linked conjugated porous polymer was obtained by subjecting a homogeneous mixture of o-hydroxybenzaldehyde monomer, phenylacetonitrile monomer, solvent and catalyst to a Knauwengel condensation reaction.

2. The preparation method according to claim 1, characterized in that, The o-hydroxybenzaldehyde monomer includes any one or a combination of two or more of the following structures:

3. The preparation method according to claim 1, characterized in that: The o-hydroxybenzaldehyde monomers include 2,5-dihydroxyterephthalaldehyde, 3,3′-dihydroxy-(1,1′-biphenyl)-4,4′-dicarboxaldehyde, 4,4′-(1,2-acetylenide)bis(2-hydroxy)benzaldehyde, 3,7-dihydroxynaphthalene-2,6-dicarboxaldehyde, 4,4′-dihydroxy-3,3′-glyoxal biphenyl, trialdehyde phloroglucinol, 5′-(4-formyl-3-hydroxyphenyl)-3,3″-dihydroxy-(1,1′:3′,1″-terphenyl)-4,4″-dicarboxaldehyde, 4,4′,4″-(1,3,5-triazine-2,4,6-triyl)tris(2-hydroxybenzaldehyde), and 4,4′,4″-(benzene-1,3,5-triyltris(acetylenide-2,1-diyl))tris(2-hydroxybenzaldehyde). The following are all of the following: 4,4′,4″-((1,3,5-triazine-2,4,6-triyl)tri(acetylene-2,1-diyl))tri(2-hydroxybenzaldehyde), 4,4′,4″,4″′-(pyrene-1,3,6,8-tetrayl)tetra(2-hydroxybenzaldehyde), 4,4′,4″,4″′-(pyrene-1,3,6,8-tetraalkyltetra(acetylene-2,1-diyl))tetra(2-hydroxybenzaldehyde), 4,4′,4″,4″′-(porphyrin-5,10,15,20-tetrayl)tetra(2-hydroxybenzaldehyde), and 4′,4″,4″″,4″″″-(ethylene-1,1,2,2-tetrayl)tetra(3-hydroxy-(1″,1″-biphenyl)-4-carboxaldehyde).

4. The preparation method according to claim 3, characterized in that: The o-hydroxybenzaldehyde monomer includes any one or a combination of two or more of the following: 2,5-dihydroxyterephthalaldehyde, 3,3′-dihydroxy-(1,1′-biphenyl)-4,4′-dicarboxaldehyde, trialdehyde-phloroglucinol, 5′-(4-formyl-3-hydroxyphenyl)-3,3"-dihydroxy-(1,1′:3′,1″-terphenyl)-4,4"-dicarboxaldehyde, 4,4′,4″-(benzene-1,3,5-triyltri(acetylene-2,1-diyl))tri(2-hydroxybenzaldehyde), and 4,4′,4″,4″′-(pyrene-1,3,6,8-tetrayl)tetra(2-hydroxybenzaldehyde).

5. The preparation method according to claim 1, characterized in that, The phenylacetonitrile monomer comprises any one or a combination of two or more of the following structures:

6. The preparation method according to claim 1, characterized in that: The catalyst comprises any one or a combination of two or more of 1,8-diazobisspirocyclic [5.4.0]undecyl-7-ene, 4-dimethylaminopyridine, potassium hydroxide, sodium hydroxide, potassium tert-butoxide, potassium acetate, cesium carbonate, ammonium acetate, sodium ethoxide, acetic acid, trifluoroacetic acid, p-toluenesulfonic acid, benzoic anhydride, and benzoic acid. And / or, the solvent includes any one or a combination of two or more of o-dichlorobenzene, n-butanol, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, mesitylene, 1,4-dioxane, acetonitrile, ethanol, methanol, N-methylpyrrolidone, and water.

7. The preparation method according to claim 1, characterized in that: The molar ratio of the o-hydroxybenzaldehyde monomer to the phenylacetonitrile monomer is 1:(0.5N3); and / or, the molar ratio of the o-hydroxybenzaldehyde monomer to the catalyst is 1:(1N3); and / or, the molar volume ratio of the o-hydroxybenzaldehyde monomer to the solvent is 1mmol:(10-50)mL.

8. The preparation method according to claim 1, characterized in that, include: The o-hydroxybenzaldehyde monomer, phenylacetonitrile monomer, and catalyst are mixed evenly in a solvent to form a homogeneous mixed reaction system. The homogeneous mixed reaction system was heated to carry out the Knauwengel condensation reaction to obtain a coumarin-linked conjugated porous polymer. Preferably, the preparation method further includes: first, subjecting the homogeneous mixed reaction system to a freeze-vacuum cycle 3 to 5 times, each time for 15 minutes at 5N, and then sealing the tube with a flame to heat the homogeneous mixed reaction system; And / or, the temperature for heating the homogeneous mixed reaction system to carry out the Krono-Vernger condensation reaction is 80–220°C, and the time is 12–120 h.

9. A coumarin-linked conjugated porous polymer prepared by any one of claims 1-8, having high porosity and a fully conjugated structure; preferably, the specific surface area of ​​the coumarin-linked conjugated porous polymer is 50-2200 m². 2 / g, with a pore size distribution of 1–5 nm.

10. The application of the coumarin-linked conjugated porous polymer of claim 9 in photocatalytic reactions, fluorescence sensing, or optoelectronic devices; preferably, the photocatalytic reaction includes photocatalytic hydrolysis to produce hydrogen, carbon dioxide reduction, photocatalytic production of hydrogen peroxide, or photocatalytic degradation of pollutants.

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