Porous polymers containing chalcogenide-containing viologens, methods of synthesis, and optoelectronic applications based thereon

Abstract

The application discloses a kind of porous polymer containing chalcogen-containing viologen and a synthesis method thereof, and photoelectric application based thereon, belongs to electrochromic device and visible light catalysis technical field.The polymer has unique spatial configuration, stable free radical state, extended excited state lifetime, narrow band gap width and enhanced visible light absorption capacity, special electron transfer and catalytic performance make it in photocatalytic cross-dehydrogenative coupling reaction Catalytic efficiency is as high as 82%, and in the process of visible light catalytic hydrogen production, it shows excellent hydrogen production efficiency.In addition, since the porous polymer is insoluble in any solvent, as a heterogeneous catalyst, it has good recycling characteristics, and can maintain high catalytic efficiency after multiple catalytic cycles, so it can be applied to electrochromic device, the porous polymer containing chalcogen-containing viologen in the application has wide application prospect in electrochromic device, visible light catalytic cross-dehydrogenative coupling and visible light catalytic hydrogen production.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrochromic devices and visible light catalysis, and particularly relates to a kind of porous polymer containing sulfur group element viologen, a synthesis method and photoelectric application based thereon. BACKGROUND

[0002] Viologen, as a classic redox species, has shown great application potential in many fields. In particular, in photocatalysis, electrocatalysis, electrochromism, photodynamic therapy, organic flow battery and host-guest chemistry, viologen has attracted much attention due to its unique properties. Among them, viologen containing main group elements is widely used in photocatalysis, electrochromism, photodynamic therapy and other fields due to its excellent visible light absorption capacity, narrower energy gap and stable free radical state.

[0003] However, the currently reported viologen containing main group elements is mostly used in homogeneous catalysis in photocatalysis, which has some problems, such as difficulty in recycling the catalyst after the reaction is completed, and toxicity of the soluble catalyst. Therefore, the further application of viologen containing main group elements in the field of photocatalysis is limited.

[0004] In order to solve these problems, heterogeneous photocatalysis technology emerges as the times require. Heterogeneous photocatalysis, also known as multiphase photocatalysis, refers to the process in which the photocatalyst and the reaction substrate are completely or partially in different phases. This technology has great potential in solar energy utilization and conversion, and therefore is increasingly favored. Exploring and improving new heterogeneous photocatalysts is a feasible strategy to further optimize the practical application effect of solar energy conversion. Compared with traditional inorganic semiconductor materials, organic photocatalysts have become an important part of promoting the development of new energy technology due to their light weight, strong structural adaptability and strong light utilization ability. Inspired by supramolecular chemistry, various two-dimensional / three-dimensional organic photocatalysts have been widely studied and reported, such as supramolecular organic frameworks (SOFs), metal-organic frameworks (MOFs), covalent organic frameworks (COFs) and other porous polymers. The emergence of these new organic photocatalysts provides new opportunities for the development of heterogeneous photocatalysis technology. In particular, RV2+ modified polycationic COFs / POPs materials have attracted much attention in heterogeneous photocatalysis due to their significant redox and free radical stability. Such materials not only have excellent catalytic performance, but also have good stability and recyclability, providing a new way to solve the problems of viologen containing main group elements in homogeneous catalysis. Therefore, exploring new heterogeneous photocatalysts based on viologen containing main group elements has important research value and practical application significance. SUMMARY

[0005] The existing main group element-containing viologen compound has weak absorption capacity in the visible light region, the free radical state is often not stable enough, and the catalyst is easily deactivated, the traditional external modification method has limited effect on improving the photoelectric performance of the main group element-containing viologen compound, and thus the technical status of the application of the main group element-containing viologen compound in the fields of photocatalysis and electrochromism is limited. The present application aims to provide a porous polymer containing a sulfur group element viologen, a synthesis method thereof and photoelectric applications based on the porous polymer.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions to achieve the above-mentioned purpose:

[0007] The present application provides a kind of porous polymer based on sulfur group element-containing viologen, the porous polymer based on sulfur group element-containing viologen includes the following two structural formulae:

[0008]

[0009] Wherein, E is any one of S, Se and Te;X is any one of Cl, Br, I, PF6.

[0010] The synthesis method of the above-mentioned one kind of porous polymer based on sulfur group element-containing viologen, characterized in that, it includes:

[0011] (1) preparation of sulfur group element-containing bridged 4,4'-bipyridine;

[0012] The structural formula of the sulfur group element-containing bridged 4,4'-bipyridine is as follows:

[0013] Wherein, E is S, Se or Te;

[0014] (2) step (1) sulfur group element-containing 4,4'-bipyridine and tetra (4- (bromomethyl) phenyl) methane or tetra (4- (bromoethynyl) phenyl) methane are prepared into porous polymer based on sulfur group element-containing viologen by S N 2 reaction.

[0015] The step (1) of preparing sulfur group element-containing bridged 4,4'-bipyridine includes:

[0016] Under the protection of inert gas, 3,3'-dibromo-4,4'-bipyridine is dissolved in pre-cooled tetrahydrofuran, fully stirred and uniformly mixed, sulfur group element chloride is added and fully reacted, the temperature is raised to room temperature to remove the solvent, and the organic phase is collected after washing and extraction, and then dried, filtered, concentrated and purified by silica gel column to obtain sulfur group element bridged 4,4'-bipyridine.

[0017] The sulfur group element chloride is any one of S2Cl2, SeCl2 and TeCl4.

[0018] The molar ratio of the 3,3'-dibromo-4,4'-bipyridine to the chalcogen chloride is 1:1-2; and the reaction conditions are -80°C to -90°C.

[0019] Said by S N 2. The reaction preparation of the porous polymer based on the sulfide-containing viologen includes: under the protection of inert gas, dissolving the sulfide-containing bridged 4,4'-bipyridine and tetrakis(4-(bromomethyl)phenyl)methane or tetrakis(4-(bromoethynyl)phenyl)methane in a solvent respectively, then slowly adding them into the reaction system, stirring the reaction, cooling to room temperature after the reaction, precipitating, collecting the precipitate, washing, filtering, and vacuum drying to obtain the porous polymer based on the sulfide-containing viologen.

[0020] The molar ratio of the chalcogen-containing bridged 4,4'-bipyridine to tetrakis(4-(bromomethyl)phenyl)methane or tetrakis(4-(bromoethynyl)phenyl)methane is 2:1, and the reaction solvent is any one of N-methylpyrrolidone, DMSO or DMF.

[0021] The reaction temperature is 100° C. to 150° C., and the reaction time is 6 to 8 days. The washing solvent is any one of dichloromethane, water and acetone.

[0022] The application of the above-mentioned porous polymer based on chalcogen-containing viologen in the preparation of electrochromic devices.

[0023] The above-mentioned type of porous polymer based on sulfur-containing viologen is applied in visible light-induced cross-dehydrogenation coupling reaction and visible light-induced hydrogen production.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The chalcogen-containing viologen porous polymer disclosed in the present invention is a class of organic porous polymers. By introducing a tetraphenylmethane structure, a regular tetrahedron (diamond structure) spatial configuration is formed. This structure not only stabilizes the electron cloud state of the viologen, but also enhances the overall stability of the material. The introduction of chalcogen elements further adjusts the electronic structure and optical properties of the material, giving it more superior performance. The polymer has the following properties: a more stable free radical state; a narrower band gap width, stronger visible light absorption; and a prolonged excited state lifetime.

[0026] The present invention discloses a method for synthesizing a porous polymer containing sulfur element viologen, in which the porous polymer containing sulfur element viologen is synthesized via an SN2 reaction. The method has clear steps, simple operation, high synthesis efficiency and yield. In order to compare the property differences between the monomer and the polymer, a regular tetrahedral model compound and a benzyl sulfur element viologen are also synthesized, providing strong support for subsequent performance research and application.

[0027] The application of the porous polymer containing sulfur family element viologen disclosed in the application has a wide application prospect in the field of photocatalysis, especially in visible light catalytic cross-dehydrogenative coupling reaction and visible light catalytic hydrogen production, and exhibits excellent electrochromic performance, and the color can be reversibly changed by adjusting the voltage, so that a new selection is provided for the preparation of electrochromic devices, and can be used in the fields of intelligent windows, displays, sensors and the like, and has wide application prospect and important research value. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 Reaction diagram of the porous polymer containing selenium viologen and model compound prepared in the application;

[0029] Figure 2 Thermogravimetric curve of the porous polymer containing selenium viologen and monomer; wherein Bn-SeV 2+ is the monomer, POP-SeV 2+ is the porous polymer containing selenium viologen;

[0030] Figure 3 Diffuse reflectance ultraviolet / visible absorption spectrum of the porous polymer containing selenium viologen and monomer; wherein Bn-SeV 2+ is the monomer, POP-SeV 2+ is the porous polymer containing selenium viologen

[0031] Figure 4 Electron paramagnetic resonance spectrum of the porous polymer containing selenium viologen, monomer and model compound; wherein Bn-SeV 2+ is the monomer, TBn-SeV 2+ is the model compound, POP-SeV 2+ is the porous polymer containing selenium viologen;

[0032] Figure 5 Comparison diagram of the fluorescence quantum yield and fluorescence lifetime of the porous polymer containing selenium viologen and monomer compound; wherein Bn-SeV 2+ is the monomer, POP-SeV 2+ is the porous polymer containing selenium viologen;

[0033] Figure 6 Two-dimensional transient absorption spectrum of the tetrahedral model compound containing selenium viologen;

[0034] Figure 7UV-Vis absorption spectra and device color change results after the cut-off voltage of the electrochromic device based on selenium-containing viologen porous polymer and model compound of the present application; wherein TBn-SeV 2+ is a model compound, POP-SeV 2+ is a selenium-containing viologen porous polymer;

[0035] Figure 8 Effect comparison of photocatalytic cross-dehydrogenative coupling of different systems of the present application; wherein Bn-SeV 2+ is a monomer, POP-SeV 2+ is a selenium-containing viologen porous polymer;

[0036] Figure 9 Effect comparison of photocatalytic cross-dehydrogenative coupling of selenium-containing viologen porous polymer of the present application after multiple cycles;

[0037] Figure 10 Photocatalytic hydrogen production curve of selenium-containing viologen porous polymer of the present application over time;

[0038] Figure 11 Effect diagram of photocatalytic hydrogen production of selenium-containing viologen porous polymer of the present application after multiple cycles;

[0039] Figure 12 Effect diagram of photocatalytic hydrogen production of selenium-containing viologen porous polymer of the present application after photocatalytic cross-dehydrogenative coupling reaction;

[0040] Figure 13 Visible light catalytic mechanism of selenium-containing viologen porous polymer of the present application. DETAILED DESCRIPTION

[0041] In order for those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0042] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, unless the context clearly indicates otherwise. It will be further understood that the use of relational terms such as first and second, and the like are used solely to distinguish one from another entity without necessarily implying a relationship or order between these entities. Much of the detail of the embodiments described in this detailed description are merely for the purposes of illustration and are not intended to exhaustively describe all embodiments of the present application. The detailed description is also not to be taken as limiting the scope of the application as it is to be defined by the claims.

[0043] The application will be described in further detail below with reference to the drawings in which:

[0044] Example 1

[0045] The selenium-containing viologen porous polymer and model compound prepared in the present application, as shown in the accompanying drawings, is prepared by the following reaction equation steps, specifically including the following steps: Figure 1

[0046] Preparation of chalcogen-bridged 4,4'-bipyridine (compound 2)

[0047] (a) The specific steps of the reaction: 628 mg of 3,3'-dibromo-4,4'-bipyridine (compound 1) is dissolved in tetrahydrofuran (60 mL) under argon protection, and after being stirred uniformly, 4.2 mmol of n-butyllithium is added at -85°C, and after 1 hour of reaction, SeCl2(2.1 mmol) is added, and after sufficient reaction, the temperature is raised to room temperature to remove the solvent, and after washing and extraction, the organic phase is collected, and then dried, filtered, concentrated, and purified by silica gel column to prepare selenium-bridged 4,4'-bipyridine.

[0048]

[0049] Specific steps for preparing compound 3 using compound 2

[0050] (b) The specific steps of the reaction: 0.7 mmol of compound 2 is dissolved in 30 mL of dichloromethane at 60°C, and methyl iodide (142 mg, 1 mmol) is added, and after sufficient reaction, it is washed with dichloromethane to obtain compound 3.

[0051]

[0052] Preparation of compound 6 tetra(4-(bromomethyl)phenyl)methane

[0053] ​(d) Specific procedure for the reaction: 320 mg of 5 (1.00 mmol) and 1.10 g of titanium bromide (3.00 mmol) were placed in 5 mL of dry dichloromethane under argon protection, then 1.08 g of bromomethyl methyl ether (8.00 mmol) was added dropwise at 0°C, and heated to reflux for 48 hours. After the reaction was completed, 5 mL of water was added dropwise to the reaction system, the liquid was separated, the aqueous phase was extracted with dichloromethane for 3-5 times, the organic phase was collected, washed with water and saturated brine for 3-5 times, then dried over anhydrous magnesium sulfate. Then the solvent was removed under reduced pressure, and purified by silica gel chromatography column (PE:DCM = 1:2) to obtain white solid 6.

[0054]

[0055] Preparation of compound 6b (tetra(4-(bromoethynyl)phenyl)methane)

[0056] Compound 6 (3.50 g, 5.50 mmol) and triphenylphosphine (462 mg, 1.76 mmol) were placed in a 250 mL round-bottom flask. Diisopropyl amine (100 mL) was added, and the solution was purged with nitrogen for 30 min. Then bis(triphenylphosphine)palladium dichloride (618 mg, 0.88 mmol), copper iodide (168 mg, 0.88 mmol) and trimethylsilyl acetylene (6.2 mL, 44.0 mmol) were added. Cooled to -78°C, and refluxed under nitrogen for 24 h. After removing the volatile substances in vacuum, the residue was redissolved in chloroform (100 mL), filtered, the filter paper was washed with 50 mL of chloroform, then the combined filtrate was washed with distilled water (2×25 mL) and aqueous sodium chloride (25 mL), dried over anhydrous magnesium sulfate, and evaporated to dryness under vacuum. The crude product was subjected to flash column chromatography on silica gel, using pure n-hexane and n-hexane / ethyl acetate (4:1) as eluent, to obtain intermediate compound 6'.

[0057] Compound 6 (3.50 g, 5.50 mmol) and triphenylphosphine (462 mg, 1.76 mmol) were placed in a 250 mL round-bottom flask. Diisopropyl amine (100 mL) was added, and the solution was purged with nitrogen for 30 min. Then bis(triphenylphosphine)palladium dichloride (618 mg, 0.88 mmol), copper iodide (168 mg, 0.88 mmol) and trimethylsilyl acetylene (6.2 mL, 44.0 mmol) were added. Cooled to -78°C, and refluxed under nitrogen for 24 h. After removing the volatile substances in vacuum, the residue was redissolved in chloroform (100 mL), filtered, the filter paper was washed with 50 mL of chloroform, then the combined filtrate was washed with distilled water (2×25 mL) and aqueous sodium chloride (25 mL), dried over anhydrous magnesium sulfate, and evaporated to dryness under vacuum. The crude product was subjected to flash column chromatography on silica gel, using pure n-hexane and n-hexane / ethyl acetate (4:1) as eluent, to obtain intermediate compound 6'.

[0058]

[0059] 1. Preparation of selenium-containing porphyrin 7a

[0060] Under argon, 200 mg of selenium-containing dipyrrin (0.86 mmol) and 300 mg of compound 6 tetra(4-(bromomethyl)phenyl)methane (0.43 mmol) were placed in 10 mL of dry N-methylpyrrolidone, and the reaction system was reacted at 110°C for 7d, and then slowly cooled to room temperature; the precipitate was collected by filtration under reduced pressure, and washed with dichloromethane and water several times, and then dried in vacuum to obtain a light yellow solid 7a.

[0061] The reaction equation is as follows:

[0062]

[0063] 2. Preparation of selenium-containing porphyrin orthotetrahedral model compound 8a

[0064] Under argon, 180 mg of compound 3 monomethylated selenium-containing dipyrrin (0.48 mmol) and 80 mg of compound 6 tetra(4-(bromomethyl)phenyl)methane (0.11 mmol) were placed in 5 mL of dry DMF, and the reaction system was reacted at 100°C for 20h, and then slowly cooled to room temperature; the precipitate was collected by filtration under reduced pressure, and washed with dichloromethane and acetone several times, and then dried in vacuum to obtain a yellow-brown solid 8a.

[0065] The reaction equation is as follows:

[0066]

[0067] 3. Preparation of selenium-containing porphyrin 7b

[0068] Under argon, 200 mg of compound 2 selenium-containing dipyrrin (0.86 mmol) and 340 mg of compound 6b (0.43 mmol) were placed in 10 mL of dry N-methylpyrrolidone, and the reaction system was reacted at 110°C for 7d, and then slowly cooled to room temperature; the precipitate was collected by filtration under reduced pressure, and washed with dichloromethane and water several times, and then dried in vacuum to obtain a light yellow solid 7b.

[0069] The reaction equation is as follows:

[0070]

[0071] 4. Preparation of selenium-containing porphyrin orthotetrahedral model compound 8b

[0072] Under argon atmosphere, 180 mg of selenium-containing viologen monomethylated (0.48 mmol) and 80 mg of compound 6b (0.11 mmol) were placed in 5 mL of dry DMF to obtain a reaction system, which was reacted at 100°C for 20 h, and then slowly cooled to room temperature; the precipitate was collected by filtration under reduced pressure, washed with dichloromethane and acetone several times, and then dried under vacuum to obtain a yellow-brown solid 8b.

[0073] The reaction equation is as follows:

[0074]

[0075] 5. Preparation of selenium-containing viologen porous polymer monomer 4

[0076] Under argon atmosphere, 100 mg of selenium-containing bipyridine (0.43 mmol) was placed in 5 mL of benzyl bromide to obtain a reaction system, which was reacted at 60°C for 12 h, and then cooled to room temperature, the precipitate was collected by filtration under reduced pressure, washed with dichloromethane several times, and dried under vacuum to obtain a light yellow solid compound 4.

[0077]

[0078] The physical properties and structural analysis of some selenium-containing viologen porous polymers prepared in the present application are as follows:

[0079] Yield, nuclear magnetic resonance, mass spectrum of selenium-containing viologen porous polymer, monomer and model compound

[0080] Compound 4, yellow powder, yield: 46%, 1 H NMR (400 MHz, DMSO-d6): δ 10.31 (s, 2H), 9.58 (d, J = 6.6 Hz, 2H), 9.48 (d, J = 6.5 Hz, 2H), 7.67-7.61 (m, 4H), 7.52-7.43 (m, 6H), 6.10 (s, 4H). 13 C NMR (100 MHz, DMSO-d6): δ 146.10, 145.53, 144.19, 140.26, 133.92, 129.67, 129.45, 129.38, 124.40, 64.22. HRMS (ESI+) m / z: calculated for C 24 H 20 N2Se 2+ ,208.03904, found,208.03884.

[0081] Compound 8a, yellow powder, yield: 33%, 1H NMR (400 MHz, DMSO-d6): δ 10.44 (s, 4H), 10.16 (s, 4H), 9.57 (d, J = 4.9 Hz, 4H), 9.52-9.35 (m, 8H), 9.30 (d, J = 5.3 Hz, 4H), 7.58 (d, J = 6.4 Hz, 8H), 7.37 (d, J = 6.0 Hz, 8H), 6.06 (s, 8H), 4.58 (s, 12H). 13 C NMR (101 MHz, DMSO-d6): 147.64, 147.03, 146.53, 145.57, 144.34, 143.91, 141.32, 140.67, 132.02, 131.48, 129.57, 124.74, 124.07, 64.75, 63.98, 49.63. HRMS (ESI+) m / z: [M+NH4] + calculated for C 73 H 60 N8Se4I 7+ , 231.61449, found, 231.64761.

[0082] Compound 7a, yellow powder, 13 C CP / MAS NMR: δ 64.5 (-CH2), 131.1 (benzene ring), 146.1 (pyridine ring).

[0083] Example 2

[0084] (1) Electrochromic device based on the selenium-containing viologen porous polymer

[0085] Preparation of an electrochromic device using the selenium-containing viologen porous polymer prepared in Example 1: two pieces of ITO conductive film were pasted together with double-sided tape to form a device substrate with a cavity of 50 μm-100 μm in thickness, the selenium-containing viologen porous polymer was dissolved or dispersed in DMSO, and then injected into the cavity of the above-prepared device substrate, and sealed to obtain an electrochromic device.

[0086] (2) Photocatalytic cross-dehydrogenative coupling reaction based on the selenium-containing viologen porous polymer

[0087] Photocatalytic cross-dehydrogenative coupling application using the selenium-containing viologen porous polymer prepared in Example 1: 20.9 mg (0.1 mmol) of N-phenyl-tetrahydroisoquinoline, (1 mmol, 10 eq) nitromethane and the selenium-containing viologen porous polymer (SeV 2+The mixture of the molecule (2mmol%) and 2mL of methanol was stirred with a magnetic stirrer, the solvent was removed by rotary evaporation, and the target product was purified by column chromatography on silica gel with petroleum ether / ethyl acetate (10:1) as the eluent.

[0088] (3) Photocatalytic hydrogen production based on the selenium-containing viologen porous polymer

[0089] The selenium-containing viologen porous polymer prepared in Example 1 was used for photocatalytic hydrogen production: selenium-containing viologen porous polymer 7a (2mg), PVP-Pt (4mg) and EDTA (160mg) were placed in 5mL of deionized water, argon was bubbled for 30min, irradiated under a xenon lamp (λ>400nm) with a light power of 100mW, and then the content of hydrogen was detected by gas chromatography.

[0090] The test results are shown in Table 1. Figure 2 Table 1 Figure 13 .

[0091] The thermogravimetric curves of the selenium-containing viologen porous polymer compound 7a and the monomer compound 4 are shown in Figure 1. Figure 2 As can be seen from the data, the monomer starts to lose weight significantly at a lower temperature compared to the selenium-containing viologen porous polymer 7a, and the porous polymer maintains the integrity of the structure at a higher temperature due to its complex crosslinked network structure, thereby delaying the occurrence of mass loss, which indicates that the thermal stability of the system is improved after the formation of the polymer. Figure 2 The diffuse reflectance ultraviolet-visible absorption spectra of the selenium-containing viologen porous polymer compound 7a and the monomer compound 4 are shown in Figure 2.

[0092] As can be seen from the data, the formation of the tetrahedral structure leads to a red shift of the maximum absorption wavelength of the selenium-containing viologen porous polymer, and the energy gap is significantly reduced, indicating that the electrons in the selenium-containing viologen porous polymer are more likely to transition from the valence band to the conduction band, thereby increasing the conductivity of the material or making it exhibit more obvious semiconductor properties, providing a basis for its application in the fields of photoelectric materials and photocatalysts. Figure 3 Figure 3 The electron paramagnetic resonance spectra of the selenium-containing viologen porous polymer compound 7a, the compound 4 and the model compound 8a are shown in Figure 3. As can be seen from the data, the signal in the EPR spectrum of the selenium-containing viologen porous polymer has changed significantly compared to the monomer and the model compound, which indicates that the free radical generation ability of the polymer system has been enhanced, indicating that the free radical generation ability of the system is enhanced after the formation of the selenium-containing viologen porous polymer.

[0093] Figure 4 The electron paramagnetic resonance spectra of the selenium-containing viologen porous polymer compound 7a, the compound 4 and the model compound 8a are shown in Figure 3. Figure 4 As can be seen from the data, the signal in the EPR spectrum of the selenium-containing viologen porous polymer has changed significantly compared to the monomer and the model compound, which indicates that the free radical generation ability of the polymer system has been enhanced, indicating that the free radical generation ability of the system is enhanced after the formation of the selenium-containing viologen porous polymer.

[0094] The electron paramagnetic resonance spectra of the selenium-containing viologen porous polymer compound 7a, the compound 4 and the model compound 8a are shown in Figure 3. Figure 5 ​The fluorescence quantum yield and fluorescence lifetime comparison of the selenium-containing viologen porous polymer compound 7a and the monomer compound 4 of the present invention are two important parameters for measuring the fluorescence performance of the material. They reflect the efficiency of the material in converting the absorbed light energy into fluorescence emission and the duration of the fluorescence emission state. Figure 5 The data shows that compared with monomeric compounds, selenium-containing violetogen porous polymers have excellent performance in fluorescence quantum yield and fluorescence lifetime. The unique porous structure not only improves the interaction between molecules and the efficiency of energy transfer, but also prolongs the fluorescence lifetime by reducing non-radiative transitions and fluorescence quenching. This shows that after the formation of selenium-containing violetogen porous polymers, the fluorescence lifetime of the system is extended and the quantum yield is increased.

[0095] Attachment Figure 6 The two-dimensional transient absorption spectrum of the tetrahedral model compound 8a containing selenium viologen of the present invention is shown in FIG. Figure 6 The data show that under visible light excitation, the selenium-containing violet tetrahedral model compound 8a exhibits an obvious charge separation state, and the lifetime of the charge separation state is longer than that of the monomer, which is beneficial for its application in photocatalysis.

[0096] Attachment Figure 7 The color change and absorption spectrum of the electrochromic device based on the selenium-containing viologen porous polymer compound 7a and the model compound 8a of the present invention are shown in FIG. Figure 7 The data shows that when a voltage of -0.8 V is applied, the electrochromic device based on the selenium-containing viologen porous polymer compound 7a turns green, and the absorption at 650 nm in the absorption spectrum gradually increases, which has excellent application potential in the field of electrochromism.

[0097] Attachment Figure 8 The comparison diagram of the effects of different catalytic systems in the cross dehydrogenation coupling reaction of the present invention is shown in the attached figure. Figure 8As can be seen from the data, the catalytic efficiency of the selenium-containing viologen porous polymer compound 7a can reach 82%, which is significantly higher than that of its monomer form. The porous structure of the polymer provides abundant adsorption sites and reaction channels for the reactant molecules, promoting the enrichment and contact of the reactant on the catalyst surface, thereby accelerating the reaction rate. The selenium-containing viologen in the polymer acts as an active center and promotes the progress of the key step in the CDC reaction through its unique redox properties. The interaction between the polymer chains further stabilizes the reaction intermediates, reduces the reaction energy barrier, and improves the catalytic efficiency. This indicates the advantage of the polymer structure in improving the catalytic performance, and also proves that the catalyst and light are essential for the catalytic process. In the CDC reaction catalyzed by the selenium-containing viologen porous polymer, light further improves the catalytic efficiency through synergistic effect with the catalyst. As an important method for constructing carbon-carbon and carbon-heteroatom bonds, CDC reaction has important significance in the synthesis of complex organic molecules. The selenium-containing viologen porous polymer, as a highly efficient and recyclable catalyst, is expected to replace traditional transition metal catalysts and realize a more green and economical organic synthesis process.

[0098] attached Figure 9 For the effect comparison of the selenium-containing viologen porous polymer compound 7a after multiple cycles in the photocatalytic cross-dehydrogenative coupling reaction, this is important data for evaluating the stability and reusability of the catalyst, as shown in the attached Figure 9 As can be seen from the data, even after multiple cycles of catalytic process, the selenium-containing viologen porous polymer can still maintain high catalytic efficiency, which indicates that the catalyst has excellent stability. This stability is due to the protection of the active center by the porous structure, which prevents the loss or deactivation of the active center during the reaction process. In addition, the interaction between the polymer chains may also enhance the overall structural stability of the catalyst, allowing it to maintain catalytic activity in multiple cycles. This means that the catalyst can be recycled and reused in the same catalytic reaction, thereby reducing production costs and waste generation. This is of great significance for realizing green chemistry and sustainable development.

[0099] attached Figure 10 For the photocatalytic hydrogen production curve of the selenium-containing viologen porous polymer 7a over time, as shown in the attached Figure 10 As can be seen from the data, the hydrogen production gradually increases over time, which indicates that the selenium-containing viologen porous polymer can effectively catalyze the decomposition of water molecules into hydrogen gas under continuous light. The fastest hydrogen production rate is within the first 6 hours, indicating that the catalyst has high activity and stability, and exhibits excellent performance in photocatalytic hydrogen production, providing a broad prospect for its application in the field of renewable energy.

[0100] attached Figure 11The photocatalytic hydrogen production effect of the porous polymer 7a containing selenium violet in the present invention is shown in FIG. The stability of the catalyst during multiple cycles is one of the key factors for its widespread promotion in practical applications. Figure 11 The data shows that the selenium-containing violet porous polymer maintains its highly effective catalytic effect after multiple cycles. After four cycles, the catalyst's catalytic effect barely decreased, demonstrating excellent catalytic performance. This fully demonstrates the catalyst's catalytic stability and reusability over multiple cycles. These excellent properties not only provide strong support for the catalyst's application in photocatalytic hydrogen production reactions, but also lay a solid foundation for its promotion and application in other related fields.

[0101] Attachment Figure 12 The effect diagram of the photocatalytic cross-dehydrogenation coupling reaction of the selenium-containing viologen porous polymer 7a of the present invention and the subsequent photocatalytic hydrogen production is shown in FIG. Figure 12 The data show that after one, two, and three cross-dehydrogenation coupling reactions, the catalyst can continue to produce hydrogen through photocatalysis, demonstrating that the selenium-containing violet porous polymer of the present invention can be reused in multiple catalytic reactions. The catalyst can not only be reused in CDC reactions, but also be switched between different types of catalytic reactions without significantly affecting its catalytic effect. This characteristic gives the catalyst a wide range of application prospects in industrial production, significantly reducing production costs and waste generation, and providing broad prospects for its application in chemical synthesis, drug synthesis, energy conversion, and other fields.

[0102] Attachment Figure 13 The photocatalytic mechanism of the selenium-containing viologen porous polymer 7a of the present invention is as follows: Figure 13 The results show that the photocatalytic mechanism of the selenium-containing viologen porous polymer of the present invention is:

[0103] Photoexcitation process: When the selenium-containing viologen porous polymer of the present invention is irradiated with visible light, the energy of these photons is absorbed by the polymer, causing its electrons to transition from the ground state to the excited state. This is the initial step of the photocatalytic reaction, which enables the polymer to have the energy and activity required for subsequent chemical reactions.

[0104] Free radical generation: When a polymer is excited to an excited state, the electron distribution inside it changes, forming free radicals. Free radicals are highly reactive molecules or atomic groups that have unpaired electrons and are therefore able to participate in a variety of chemical reactions.

[0105] Electron transfer process: The generated free radicals then transfer electrons to the catalytic substrate. This is the core step in the photocatalytic reaction and determines the reaction rate and the type of product. In the system of selenium violet-containing porous polymer, electrons are quickly transferred to the catalytic substrate and PVP-Pt through the polymer chain or pore structure.

[0106] The role of PVP-Pt: PVP-Pt as a kind of co-catalyst, when the free radical state of polymer transmits electrons to PVP-Pt, PVP-Pt can further promote the transmission and conversion of electrons, and accelerate the progress of catalytic reaction;

[0107] The completion of catalytic process: in the process of electron transmission and conversion, the catalytic substrate undergoes redox reaction to generate the required product, thereby completing the whole catalytic process.

[0108] The above is only to illustrate the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of technical scheme falls within the protection scope of the claims of the present application.

Claims

1. A porous polymer based on sulfide-containing viologen, characterized in that: The porous polymer based on chalcogen-containing viologen includes the following two structural formulas: Wherein, E is any one of S, Se and Te; X is any one of Cl, Br, I and PF6.

2. The method for synthesizing a porous polymer based on chalcogen-containing viologen according to claim 1, characterized in that: include: (1) Preparation of chalcogen-containing bridged 4,4'-bipyridine; The structural formula of the chalcogen-bridged 4,4'-bipyridine is as follows: Wherein, E is S, Se or Te; (2) Step (1) 4,4'-bipyridine containing a sulfur element and tetrakis(4-(bromomethyl)phenyl)methane or tetrakis(4-(bromoethynyl)phenyl)methane are reacted by S N 2. Preparation of porous polymers based on sulfide-containing viologen.

3. The method for synthesizing a porous polymer based on chalcogen-containing viologen according to claim 2, characterized in that: The step (1) of preparing the chalcogen-containing bridged 4,4'-bipyridine comprises: Under inert gas protection, 3,3'-dibromo-4,4'-bipyridine is dissolved in pre-cooled tetrahydrofuran and thoroughly stirred. Chalcogen chloride is then added and reacted fully. The mixture is then heated to room temperature to remove the solvent. The organic phase is collected after washing and extraction, and then dried, filtered, concentrated, and purified on a silica gel column to obtain chalcogen-bridged 4,4'-bipyridine.

4. The method for synthesizing a porous polymer based on chalcogen-containing viologen according to claim 3, characterized in that: The chalcogenide chloride is any one of S2Cl2, SeCl2 and TeCl4.

5. The method for synthesizing a porous polymer based on chalcogen-containing viologen according to claim 3, characterized in that: The molar ratio of the 3,3'-dibromo-4,4'-bipyridine to the chalcogen chloride is 1:1-2; and the reaction conditions are -80°C to -90°C.

6. The method for synthesizing a porous polymer based on chalcogen-containing viologen according to claim 2, characterized in that: The method for preparing a porous polymer based on chalcogen-containing viologen by an SN2 reaction includes: dissolving chalcogen-containing viologen-bridged 4,4'-bipyridine and tetrakis(4-(bromomethyl)phenyl)methane or tetrakis(4-(bromoethynyl)phenyl)methane in a solvent under the protection of an inert gas, then slowly adding the mixture to a reaction system, stirring the reaction, cooling the mixture to room temperature after the reaction, precipitating the mixture, collecting the precipitate, washing the mixture, filtering the mixture, and vacuum drying the mixture to obtain a porous polymer based on chalcogen-containing viologen.

7. The method for synthesizing a porous polymer based on chalcogen-containing viologen according to claim 6, characterized in that: The molar ratio of the chalcogen-containing bridged 4,4'-bipyridine to tetrakis(4-(bromomethyl)phenyl)methane or tetrakis(4-(bromoethynyl)phenyl)methane is 2:1, and the reaction solvent is any one of N-methylpyrrolidone, DMSO or DMF.

8. The method for synthesizing a porous polymer based on chalcogen-containing viologen according to claim 6, characterized in that: The reaction temperature is 100° C. to 150° C., and the reaction time is 6 to 8 days. The washing adopts any one of the solvents of dichloromethane, water and acetone.

9. Use of the porous polymer based on chalcogen-containing viologen according to claim 1 in the preparation of electrochromic devices.

10. Use of the porous polymer based on chalcogen-containing viologen according to claim 1 in visible light-induced cross-dehydrogenation coupling reaction and visible light-induced hydrogen production.

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