A bridged polyviologen-based electrochromic material, its preparation method and application

Abstract

The present invention discloses a bridged polyviologen-based electrochromic material, its preparation method and application. The structural general formula of the electrochromic material is: #imgabs0# where M is formed by a direct bond, one or more heterocyclic bonds; X1 ‑ is selected from Cl ‑ , Br ‑ , I ‑ , PF6 ‑ , OTs ‑ , X2 ‑ is selected from Cl ‑ , Br ‑ , I ‑ , PF6 ‑ , OTs ‑ ; Y is selected from sulfur, oxygen, selenium; R1 is selected from an alkyl chain, an aryl group, an ester group, hydrogen; R2 is selected from an alkyl chain, an ester group, an aryl group, hydrogen; R3 is selected from hydrogen, an alkyl chain; m≥0. The present invention adopts a bridged polyviologen-based electrochromic material with the above structure, its preparation method and application. By synthesizing a heterocyclic bridged viologen polymer, on the one hand, the free diffusion of viologen-based electrochromic molecules inside the device is reduced, and on the other hand, the length of the conjugated chain is increased, making the viologen cation radical more stable and improving the bistable performance of the electrochromic material.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochromic materials, and particularly to a bridged polyviologen-based electrochromic material, a preparation method thereof, and an application thereof. Background Art

[0002] Electrochromic materials have great application potential in displays, smart windows, information storage, etc. Currently, the electrochromic materials commercially applied in aircraft windows and anti-glare rearview mirrors are mainly viologen-based. Since the structure of viologen compounds is easy to modify and has good redox stability, they have been widely studied. Electrochromic materials with memory effects can maintain their given redox state after the voltage is disconnected, and since they do not consume energy during the maintenance of optical properties, they contribute to reducing energy consumption. However, current viologen-based electrochromic materials have problems such as easy free diffusion in electrochromic devices and poor stability of radical cations, resulting in poor bistable performance of viologen-based electrochromic materials. Summary of the Invention

[0003] The purpose of the present invention is to provide a bridged polyviologen-based electrochromic material, a preparation method thereof, and an application thereof to solve the problem of poor bistable performance of the above-mentioned viologen-based electrochromic materials.

[0004] To achieve the above purpose, the first aspect of the present invention provides a bridged polyviologen-based electrochromic material, and the structural general formula of the electrochromic material is:

[0005]

[0006] wherein M is formed by a direct bond, one or more heterocyclic bonds; X 1 - is selected from Cl - 、Br - 、I - 、PF 6 - 、OTs - ,X 2 - is selected from Cl - 、Br - 、l - 、PF 6 - 、OTs - ;Y is selected from sulfur, oxygen, selenium; R 1 is selected from an alkyl chain, an aryl group, an ester group, hydrogen; R 2 is selected from an alkyl chain, an ester group, an aryl group, hydrogen; R 3 is selected from hydrogen, an alkyl chain; m≥0.

[0007] Preferably, the electrochromic material includes one of the following structures.

[0008]

[0009]

[0010] In a second aspect of the present invention, a preparation method of a bridged polyviologen-based electrochromic material is provided, including the following steps:

[0011] (1) Dissolve compound P1 in an organic solvent, then add compound P2, raise the temperature for reaction. After the reaction is completed, a solid precipitates from the reaction solution, filter to obtain intermediate 1;

[0012] (2) Dissolve intermediate 1 in an organic solvent, then add compound P3, raise the temperature for reaction. After the reaction is completed, a solid precipitates from the reaction solution, filter to obtain intermediate 2;

[0013] (3) Dissolve intermediate 2 in a solvent, after deoxygenation by nitrogen replacement, raise the temperature for polymerization reaction, cool the reaction solution to room temperature and freeze-dry to obtain the product;

[0014] Among them, the general chemical formulas of P1, P2, and P3 are respectively:

[0015] Preferably, in step (3), dissolve intermediate 2 in a solvent, then add compound P4, after deoxygenation by nitrogen replacement, raise the temperature for polymerization reaction, cool the reaction solution to room temperature and freeze-dry to obtain the product;

[0016] Among them, the general chemical formula of P4 is:

[0017] Preferably, the organic solvent in steps (1) and (2) includes one or more of N,N-dimethylformamide, chloroform, toluene, and dimethyl sulfoxide.

[0018] Preferably, the molar ratio of compound P1 to compound P2 in step (1) is 1-5:1.

[0019] Preferably, the molar ratio of intermediate 1 to compound P3 in step (2) is 1:1-6.

[0020] Preferably, the reaction temperature in steps (1) and (2) is 80-100 °C, and the reaction time is 12-48 h.

[0021] Preferably, in step (3), intermediate 2, K 2 S 2 O 8 、C 2 H4 After mixing with OS, it is dissolved in water. After performing three freeze - vacuumize - thaw cycles to displace oxygen with nitrogen in the solution system, it is stirred and reacted at 80 - 100 °C for 12 - 48 h. The reaction solution is cooled to room temperature and freeze - dried to obtain the product.

[0022] Preferably, in step (3), the molar ratio of intermediate 2 to compound P4 is 1:1 - 5.

[0023] Preferably, in step (3), intermediate 2, compound P4 and AIBA are dissolved in a mixed solvent of water and methanol. After performing three freeze - vacuumize - thaw cycles to displace oxygen with nitrogen in the solution system, the temperature is raised to 50 - 100 °C and reacted for 5 - 24 hours. After the reaction solution is cooled to room temperature, methanol is removed by rotary evaporation and water is removed by freeze - drying to obtain the product.

[0024] Therefore, the present invention adopts a bridged polyviologen - based electrochromic material with the above structure, its preparation method and application. By synthesizing heterocyclic - bridged viologen polymers, on the one hand, the free diffusion of viologen - based electrochromic molecules inside the device is reduced, and on the other hand, the length of the conjugated chain is increased, making the viologen cation radicals more stable and improving the bistable performance of the electrochromic material.

[0025] The technical solutions of the present invention will be further described in detail below with reference to the drawings and examples. Brief Description of the Drawings

[0026] Figure 1 Are the cyclic voltammograms of compounds E, H, I, J, where (a) compound E; (b) compound H; (c) compound I; (d) compound J;

[0027] Figure 2 Are the cyclic voltammograms of electrochromic devices prepared from compounds E, H, I, J, where (a) ECD (electrochromic device) based on compound E, (b) ECD based on compound H, (c) ECD based on compound I, (d) ECD based on compound J;

[0028] Figure 3 Are the ultraviolet absorption spectra of electrochromic devices prepared from compounds E, H, I, J, where (a) ECD (electrochromic device) based on compound E, (b) ECD based on compound H, (c) ECD based on compound I, (d) ECD based on compound J;

[0029] Figure 4Transmittance-time change curves of electrochromic devices prepared with compounds E, H, I, and J, where (a) ECD (electrochromic device) based on compound E, (b) ECD based on compound H, (c) ECD based on compound I, (d) ECD based on compound J;

[0030] Figure 5 Coloring efficiency diagrams of electrochromic devices prepared with compounds E, H, I, and J, where (a) ECD (electrochromic device) based on compound E, (b) ECD based on compound H, (c) ECD based on compound I, (d) ECD based on compound J;

[0031] Figure 6 Transmittance-time change curves of electrochromic devices prepared with compounds E, H, I, and J, where (a) ECD (electrochromic device) based on compound E, (b) ECD based on compound H, (c) ECD based on compound I, (d) ECD based on compound J. Detailed implementation mode

[0032] The present invention will be further described below. It should be noted that this embodiment is based on the present technical solution and gives detailed implementation methods and specific operation processes, but the present invention is not limited to this embodiment.

[0033] Example 1

[0034] The synthesis route of electrochromic material compound A is as follows:

[0035]

[0036] The specific synthesis steps of compound A are as follows:

[0037] (1) Synthesis of 1-benzyl-[4,4'-bipyridine]-1-ammonium bromide

[0038] Dissolve 4,4'-bipyridine (20 g, 0.13 mol) in DMF (120 mL), then add benzyl bromide (5 mL, 0.04 mol), and stir at 90 °C for 24 h. A large amount of solid product precipitates from the reaction solution. Filter, wash the obtained filter cake with dichloromethane, and dry it in a vacuum drying oven to obtain 4.5 g of yellow solid product with a yield of 63%.

[0039] The nuclear magnetic resonance hydrogen spectrum data of the yellow solid product are as follows: 1 H NMR (400 MHz, DMSO-d 6)δ 9.40 (d, J = 6.6 Hz, 2H), 8.89 - 8.83 (m, 2H), 8.66 (d, J = 6.9 Hz, 2H), 8.05 - 7.99 (m, 2H), 7.61 (dd, J = 7.8, 1.8 Hz, 2H), 7.46 (d, J = 7.5 Hz, 3H), 5.94 (s, 2H).

[0040] The carbon NMR data of the yellow solid product are as follows: 13 C NMR (100 MHz, DMSO-d 6 )δ 152.72, 150.93, 145.30, 140.82, 134.35, 129.37, 129.21, 128.88, 125.88, 121.98, 62.69.

[0041] The proton NMR and carbon NMR spectra indicate that 1-benzyl-[4,4'-bipyridine]-1-ammonium bromide has been successfully synthesized.

[0042] (2) Synthesis of 1-benzyl-1'-(4-vinylbenzyl)-[4,4'-bipyridine]-1,1'-bromide-chloride-diammonium

[0043] Dissolve 1-benzyl-[4,4'-bipyridine]-1-ammonium bromide (4.4 g, 13.45 mmol) in acetonitrile (1.75 L), then add 4-vinylbenzyl chloride (11.27 mL, 67.25 mmol). Stir the mixture at 90 °C for 24 h. A large amount of solid product precipitates in the reaction solution. After filtration, wash the filter cake with acetonitrile and dry it in a vacuum drying oven to obtain 4.3 g of yellow solid product, with a yield of 67%.

[0044] The proton NMR data of the yellow solid product are as follows: 1 H NMR (400 MHz, DMSO-d 6 )δ 9.64 (t, J = 5.3 Hz, 4H), 8.81 (d, J = 6.3 Hz, 4H), 7.70 - 7.62 (m, 4H), 7.55 (d, J = 8.1 Hz, 2H), 7.48 - 7.40 (m, 3H), 6.74 (dd, J = 17.6, 10.9 Hz, 1H), 6.02 (d, J = 6.2 Hz, 4H), 5.88 (d, J = 17.6 Hz, 1H), 5.31 (d, J = 10.9 Hz, 1H).

[0045] The carbon NMR data of the yellow solid product are as follows: 13 C NMR (100 MHz, DMSO-d 6)δ149.12, 145.65, 138.25, 135.78, 134.22, 133.58, 129.49, 129.44, 129.23, 129.03, 127.21, 126.84, 115.80, 63.10, 62.84. HRMS(ESI): calcd for C 19 H 17 N 2 [M - Cl - Br - C 7 H 7 + : 273.1386; found, 273.1383.

[0046] The 1H NMR and 13C NMR spectra indicate that 1 - benzyl - 1′-(4 - vinylbenzyl)-[4,4′ - bipyridine]-1,1′ - dibromide - dichloride - diammonium has been successfully synthesized.

[0047] (3) Synthesis of poly(1 - benzyl - 1′-(4 - vinylbenzyl)-[4,4′ - bipyridine]-1,1′ - dibromide - dichloride - diammonium (Compound A))

[0048] 1 - benzyl - 1′-(4 - vinylbenzyl)-[4,4′ - bipyridine]-1,1′ - dibromide - dichloride - diammonium (384 mg, 0.8 mmol), K 2 S 2 O 8 、C 2 H 4 OS were mixed, 8 mL of water was added, and after the solution system was purged with nitrogen by three freeze - vacuum - thaw cycles to remove oxygen, the mixture was stirred at 85 °C for 12 h. The reaction solution was naturally cooled to room temperature, and water was removed by freeze - drying to obtain 350 mg of a dark red solid product, Compound A (yield 92% calculated based on the monomer).

[0049] Example 2

[0050] The synthetic route of the electrochromic material Compound B is as follows:

[0051]

[0052] The specific synthetic steps of Compound B are as follows:

[0053] (1) Synthesis of 1 - (3,5 - dimethoxybenzyl)-[4,4′ - bipyridine]-1 - ammonium bromide

[0054] ​4,4'-Bipyridine (4 g, 25.6 mmol) and 3,5-dimethoxybenzyl bromide (2.95 g, 12.8 mmol) were mixed and dissolved in toluene (240 mL). The temperature was raised to 110 °C and the reaction was carried out for 36 h. A large amount of solid precipitated in the reaction solution. It was filtered, and the filter cake was washed with toluene and dried in a vacuum drying oven to obtain 3.94 g of a yellow solid product with a yield of 79%.

[0055] The 1H NMR data of the yellow solid product are as follows: 1 H NMR (400 MHz, DMSO-d 6 ) δ 9.41 (d, J = 6.9 Hz, 2H), 8.89 - 8.83 (m, 2H), 8.64 (d, J = 7.0 Hz, 2H), 8.06 - 7.99 (m, 2H), 6.85 (d, J = 2.2 Hz, 2H), 6.55 (t, J = 2.2 Hz, 1H), 5.81 (s, 2H), 3.76 (s, 6H).

[0056] The 1H NMR data of the yellow solid product are as follows: 13 C NMR (100 MHz, DMSO-d 6 ) δ 160.95, 152.68, 150.85, 145.24, 140.92, 136.14, 125.80, 122.01, 107.17, 100.74, 62.73, 55.45.

[0057] The 1H NMR data and 13C NMR data indicate that 1-(3,5-dimethoxybenzyl)-[4,4'-bipyridine]-1-ammonium bromide has been successfully synthesized.

[0058] (2) Synthesis of 1-(3,5-dimethoxybenzyl)-1'-(4-vinylbenzyl)-[4,4'-bipyridine]-1,1'-bromide-chloride-diammonium

[0059] Compound 1-(3,5-dimethoxybenzyl)-[4,4'-bipyridine]-1-ammonium bromide (2.7 g, 6.97 mmol) was dissolved in acetonitrile (400 mL), and then 4-vinylbenzyl chloride (3.49 mL, 20.91 mmol) was added. The temperature was raised to 90 °C and the reaction was carried out for 24 h. A large amount of solid precipitated in the reaction solution. It was filtered, and the filter cake was washed with acetonitrile and dried in a vacuum drying oven to obtain 2.5 g of a yellow solid product with a yield of 66%.

[0060] The 1H NMR data, 13C NMR data and high-resolution mass spectrometry data of the yellow solid product are as follows:

[0061] 1 H NMR (400 MHz, DMSO-d 6)δ9.60 (dd, J = 8.8, 6.7 Hz, 4H), 8.78 (t, J = 6.8 Hz, 4H), 7.64 (d, J = 8.3 Hz, 2H), 7.56 (d, J = 8.2 Hz, 2H), 6.89 (d, J = 2.2 Hz, 2H), 6.75 (dd, J = 17.7, 11.0 Hz, 1H), 6.56 (t, J = 2.3 Hz, 1H), 5.98 (s, 2H), 5.92 (d, J = 1.0 Hz, 1H), 5.88 (s, 2H), 5.33 (dd, J = 10.8, 1.0 Hz, 1H), 3.76 (s, 6H).

[0062] 13 C NMR (100 MHz, DMSO-d 6 )δ160.95, 149.14, 149.08, 145.66, 138.24, 136.11, 135.79, 133.63, 129.45, 127.21, 127.13, 126.84, 115.78, 107.31, 100.81, 63.04, 62.80, 55.48.

[0063] HRMS (ESI): calcd for C 19 H 19 N 2 O 2 [M-Cl-Br-C 9 H 9 + : 307.1441; found, 307.1435.

[0064] The 1H NMR data and 13C NMR data indicate that 1-(3,5-dimethoxybenzyl)-1'-(4-vinylbenzyl)-[4,4'-bipyridine]-1,1'-bromide-chloride-diammonium has been successfully synthesized.

[0065] (3) Synthesis of poly(1-(3,5-dimethoxybenzyl)-1'-(4-vinylbenzyl)-[4,4'-bipyridine]-1,1'-bromide-chloride-diammonium (Compound B))

[0066] 1-(3,5-Dimethoxybenzyl)-1'-(4-vinylbenzyl)-[4,4'-bipyridine]-1,1'-bromide-chloride-diammonium (432 mg, 0.8 mmol), K 2 S 2 O 8 、C 2 H 4 ​After mixing with OS, 5 mL of water was added. After carrying out 3 freeze - vacuumize - thaw cycles to displace oxygen with nitrogen in the solution system, the mixture was stirred and reacted at 85 °C for 12 h. The reaction solution was naturally cooled to room temperature, and water was removed by freeze - drying to obtain 400 mg of a dark red solid product, compound B (calculated based on the monomer, yield 92%).

[0067] Example 3

[0068] The synthetic route of electrochromic material compound C is as follows:

[0069]

[0070] The specific synthesis steps of compound C are as follows:

[0071] (1) The preparation method of 1 - benzyl - 1′-(4 - vinylbenzyl)-[4,4′ - bipyridine]-1,1′ - bromide - chloride - diammonium is the same as that in Example 1.

[0072] (2) Synthesis of poly(1 - benzyl - 1′-(4 - vinylbenzyl)-[4,4′ - bipyridine]-1,1′ - bromide - chloride - diammonium - co - methyl methacrylate) (compound C)

[0073] 1 - benzyl - 1′-(4 - vinylbenzyl)-[4,4′ - bipyridine]-1,1′ - bromide - chloride - diammonium (2.4 g, 5 mmol), AIBA (200 mg, 0.74 mmol) and MMA (1.01 mL, 10 mmol) were dissolved in a mixed solvent of water and methanol (40 mL, v∶v = 1:1). After carrying out 3 freeze - vacuumize - thaw cycles to displace oxygen with nitrogen in the solution system, the mixture was stirred and reacted at 70 °C for 5 h. The reaction solution was naturally cooled to room temperature, methanol was removed by rotary evaporation, and then water was removed by freeze - drying to obtain 3.1 g of a dark red solid product, compound C, with a yield of 91%. 1 The characteristic absorption peaks disappeared in 1H NMR, and the target product was successfully prepared.

[0074] Example 4

[0075] The synthetic route of electrochromic material compound D is as follows:

[0076]

[0077] The specific synthesis steps of compound D are as follows:

[0078] (1) The preparation process of 1-(3,5 - dimethoxybenzyl)-1′-(4 - vinylbenzyl)-[4,4′ - bipyridine]-1,1′ - bromide - chloride - diammonium is the same as that in Example 2.

[0079] (2) 1-(3,5-dimethoxybenzyl)-1′-(4-vinylbenzyl)-[4,4′-bipyridine]-1,1′-bromide-chloride-diammonium (1.7 g, 3.1 mmol), AIBA (126 mg, 0.46 mmol) and MMA (0.64 mL, 6.2 mmol) were dissolved in a mixed solvent of water and methanol (25 mL, v:v = 1:1). After the solution system was purged with nitrogen by three freeze-pump-thaw cycles to remove oxygen, the reaction was stirred at 70 °C for 5 h and then cooled to room temperature. After removing methanol by rotary evaporation and water by freeze-drying, 2.2 g of a dark red solid product, compound D, was obtained with a yield of 94%. 1 The characteristic absorption peaks disappeared on 1H NMR, and the target product was successfully prepared.

[0080] Example 5

[0081] The synthetic route of the electrochromic material compound E is as follows:

[0082]

[0083] The specific synthesis steps of compound E are as follows:

[0084] (1) Synthesis of 2,5-bis(pyridin-4-yl)thiophene

[0085] 4-Pyridineboronic acid (50 g, 0.4 mol), 2,5-dibromothiophene (40 g, 0.17 mol), potassium carbonate (112 g, 0.98 mol) and tetrakis(triphenylphosphine)palladium (7.72 g, 6.6 mmol) were added to a round-bottom flask, and a mixed solvent of toluene, ethanol and deionized water (1.2 L, v:v:v = 3:2:1) was added. After three degassing cycles, the reaction mixture was heated to 88 °C and stirred under a nitrogen atmosphere for 72 h. After the reaction was complete, the reaction solution was cooled to room temperature, filtered, and the organic phase was separated by a separatory funnel. The organic phase was concentrated to dryness. The residue was dissolved in dichloromethane (400 mL), washed with water (3 × 200 mL), and the organic phase was concentrated to dryness and then purified by flash silica gel column chromatography (dichloromethane:ethyl acetate, v:v = 5:1) to obtain 26 g of a light yellow solid with a yield of 65%.

[0086] The 1H NMR data and 13C NMR data of the light yellow solid are as follows:

[0087] 1 1H NMR (400 MHz, CDCl 3 -d) δ 8.68 - 8.59 (m, 4H), 7.52 (s, 2H), 7.51 - 7.47 (m, 4H).

[0088] 13¹³C NMR (100 MHz, CDCl 3 -d) δ 150.64, 142.61, 140.69, 126.56, 121.45, 119.75.

[0089] The proton nuclear magnetic resonance data and carbon nuclear magnetic resonance data indicate that 2,5-bis(pyridin-4-yl)thiophene has been successfully synthesized.

[0090] (2) Synthesis of 1-benzyl-4-(5-(pyridin-4-yl)thiophen-2-yl)pyridin-1-ium bromide

[0091] Dissolve 2,5-bis(pyridin-4-yl)thiophene (11.78 g, 49.4 mmol) in chloroform (400 mL), add benzyl bromide (1.96 mL, 16.46 mmol), and react at 90 °C for 2 hours. A large amount of yellow solid precipitates in the reaction solution. After cooling the reaction to room temperature, filter, wash the filter cake with chloroform, and dry it in a vacuum drying oven to obtain 5 g of yellow solid product with a yield of 74%.

[0092] The proton nuclear magnetic resonance data and carbon nuclear magnetic resonance data of the yellow solid product are as follows:

[0093] 1 ¹H NMR (400 MHz, DMSO-d 6 ) δ 9.18 - 9.11 (m, 2H), 8.72 - 8.66 (m, 2H), 8.47 - 8.41 (m, 2H), 8.36 (d, J = 4.1 Hz, 1H), 8.09 (d, J = 4.1 Hz, 1H), 7.80 - 7.74 (m, 2H), 7.55 (d, J = 6.4 Hz, 2H), 7.50 - 7.42 (m, 3H), 5.80 (s, 2H).

[0094] 13 ¹³C NMR (100 MHz, DMSO-d 6 ) δ 150.73, 147.65, 147.34, 144.88, 139.07, 137.86, 134.52, 133.79, 129.26, 129.20, 129.04, 128.71, 122.84, 119.81, 62.18.

[0095] The proton nuclear magnetic resonance data and carbon nuclear magnetic resonance data indicate that 1-benzyl-4-(5-(pyridin-4-yl)thiophen-2-yl)pyridin-1-ium bromide has been successfully synthesized.

[0096] (3) Synthesis of 1-benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)thiophen-2-yl)pyridin-1,1′-bromide-chloride-diammonium

[0097] After dissolving 1-benzyl-4-(5-(pyridin-4-yl)thiophen-2-yl)pyridin-1-ium bromide (4.7 g, 11.18 mmol) in dimethyl sulfoxide (70 mL), 4-vinylbenzyl chloride (4.86 mL, 34.44 mmol) was added. The temperature was raised to 90 °C and the reaction was carried out for 64 hours. After cooling the reaction solution to room temperature, it was poured into ethyl acetate and stirred. A large amount of yellow solid was precipitated. After the filter cake was washed with dichloromethane, it was dried under vacuum to obtain 5.6 g of a yellow solid product with a yield of 87%.

[0098] The 1H NMR, 13C NMR and mass spectrometry data of the yellow solid product are as follows:

[0099] 1 H NMR (400 MHz, DMSO-d 6 ) δ 9.26 (dd, J = 6.8, 4.2 Hz, 4H), 8.55 - 8.49 (m, 4H), 8.47 (s, 2H), 7.59 (d, J = 2.1 Hz, 1H), 7.57 (d, J = 3.6 Hz, 4H), 7.52 - 7.35 (m, 4H), 6.75 (dd, J = 17.7, 10.9 Hz, 1H), 5.93 - 5.87 (m, 1H), 5.85 (d, J = 6.9 Hz, 4H), 5.32 (dd, J = 10.9, 0.9 Hz, 1H).

[0100] 13 C NMR (100 MHz, DMSO-d 6 ) δ 146.93, 145.22, 142.62, 138.06, 135.82, 134.46, 133.95, 133.84, 129.29, 129.23, 129.18, 128.81, 126.81, 123.59, 115.65, 62.35, 62.09.

[0101] HRMS (ESI): calcd for C 21 H 17 N 2 S [M - Br - Cl - C 9 H 9 + : 329.1107; found, 329.1109.

[0102] The 1H NMR, 13C NMR and mass spectrometry data indicate that 1-benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)thiophen-2-yl)pyridine-1,1′-bromide-chloride-diammonium has been successfully synthesized.

[0103] ​(4) Synthesis of poly(1-benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)thiophen-2-yl)pyridine-1,1′-bromide-chloride-diammonium-co-methyl methacrylate) (Compound E)

[0104] Dissolve 1-benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)thiophen-2-yl)pyridine-1,1′-bromide-chloride-diammonium (4 g, 7 mmol), AIBA (129 mg, 0.47 mmol) and methyl methacrylate (1.3 mL, 14 mmol) in a mixed solvent of water and methanol (100 mL, v:v = 1:1). After subjecting the solution system to three freeze-pump-thaw cycles to displace nitrogen and remove oxygen, heat the solution to 70 °C and react for 20 hours. After the reaction solution is cooled to room temperature, rotary evaporate to remove methanol and freeze-dry to remove water to obtain 5.1 g of yellow solid product Compound E, with a yield of 96%.

[0105] Example 6

[0106] The synthetic route of electrochromic material Compound F is as follows:

[0107]

[0108] The specific synthesis steps of Compound F are as follows:

[0109] (1) The preparation method of 1-benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)thiophen-2-yl)pyridine-1,1′-bromide-chloride-diammonium is the same as that in Example 5.

[0110] (2) Dissolve 1-benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)thiophen-2-yl)pyridine-1,1′-bromide-chloride-diammonium (112.4 mg, 0.2 mmol), acrylamide (14.2 mg, 0.2 mmol), K 2 S 2 O 8 in water (3 mL). After subjecting the solution system to three freeze-pump-thaw cycles to displace nitrogen and remove oxygen, heat the solution to 85 °C and react for 18 hours. After the reaction solution is cooled to room temperature, freeze-dry to remove water. Obtain 100 mg of yellow solid product Compound F, with a yield of 89%.

[0111] Example 7

[0112] The synthetic route of electrochromic material Compound G is as follows:

[0113]

[0114] The specific synthesis steps of compound G are as follows:

[0115] (1) The preparation method of 1-benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)thiophen-2-yl)pyridine-1,1′-bromide-chloride-diammonium is the same as that in Example 5.

[0116] (2) 1-benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)thiophen-2-yl)pyridine-1,1′-bromide-chloride-diammonium (125 mg, 0.22 mmol), N-isopropylacrylamide (112.5 mg, 0.99 mmol), AIBN (125 mg, 0.76 mmol) were dissolved in DMSO (7 mL). After deoxygenating the solution system by three freeze-pump-thaw cycles to displace nitrogen, the temperature was raised to 80 °C and the reaction was carried out for 14 hours. After the reaction solution was cooled to room temperature, it was poured into ethyl acetate and stirred vigorously, then filtered to obtain 110 mg of yellow solid product compound G, with a yield of 88%.

[0117] Example 8

[0118] The synthesis route of electrochromic material compound H is as follows:

[0119]

[0120] The specific synthesis steps of compound H are as follows:

[0121] (1) The preparation method of 2,5-bis(pyridin-4-yl)thiophene is the same as that in Example 5.

[0122] (2) Synthesis of 1-(3,5-dimethoxybenzyl)-4-(5-(pyridin-4-yl)thiophen-2-yl)pyridin-1-ammonium bromide

[0123] 2,5-bis(pyridin-4-yl)thiophene (5.5 g, 23 mmol) and 3,5-dimethoxybenzyl bromide (2.65 g, 11.5 mmol) were mixed and dissolved in toluene (200 mL). After the temperature was raised to 110 °C, the reaction was carried out for 24 hours. A large amount of yellow solid precipitated in the reaction solution. After the reaction solution was cooled to room temperature, it was filtered, and the filter cake was washed with toluene and dried in a vacuum drying oven to obtain 4.8 g of yellow solid product, with a yield of 89%.

[0124] The 1H NMR and 13C NMR data of the yellow solid product are as follows:

[0125] 1 H NMR(400MHz, DMSO-d 6)δ 9.15 (d, J = 6.5 Hz, 2H), 8.69 (d, J = 5.2 Hz, 2H), 8.42 (d, J = 6.6 Hz, 2H), 8.36 (d, J = 4.1 Hz, 1H), 8.09 (d, J = 4.1 Hz, 1H), 7.81 - 7.74 (m, 2H), 6.78 (d, J = 2.3 Hz, 2H), 6.55 (s, 1H), 5.68 (s, 2H), 3.76 (s, 6H).

[0126] 13 C NMR (100 MHz, DMSO-d 6 )δ 160.96, 150.43, 147.60, 147.16, 144.82, 139.38, 138.03, 136.33, 133.75, 129.17, 128.86, 128.17, 125.28, 122.78, 119.91, 107.02, 100.66, 62.21, 55.43.

[0127] The 1H NMR and 13C NMR data indicate that 1-(3,5-dimethoxybenzyl)-4-(5-(pyridin-4-yl)thiophen-2-yl)pyridin-1-ium bromide has been successfully synthesized.

[0128] (3) Synthesis of 1-(3,5-di-methoxybenzyl)-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)thiophen-2-yl)pyridin-1,1′-bromide-chloride-diammonium

[0129] 1-(3,5-Dimethoxybenzyl)-4-(5-(pyridin-4-yl)thiophen-2-yl)pyridin-1-ium bromide (4.7 g, 10 mmol) was dissolved in acetonitrile (500 mL), and then 4-vinylbenzyl chloride (4.7 mL, 30 mmol) was added. The temperature was raised to 90 °C and the reaction was carried out for 40 hours. After the reaction solution was cooled to room temperature, it was poured into ether. A large amount of yellow solid was precipitated, filtered, and dried under vacuum to obtain 5.6 g of yellow solid product with a yield of 67%.

[0130] The 1H NMR, 13C NMR, and MS data of the yellow solid product are as follows:

[0131] 1 1H NMR (400 MHz, DMSO-d 6)δ 9.26 (t, J = 6.8 Hz, 4H), 8.51 (dd, J = 7.1, 5.8 Hz, 4H), 8.47 (s, 2H), 7.56 (s, 4H), 6.81 (d, J = 2.3 Hz, 2H), 6.75 (dd, J = 17.7, 11.0 Hz, 1H), 6.55 (t, J = 2.3 Hz, 1H), 5.91 (d, J = 1.0 Hz, 1H), 5.84 (s, 2H), 5.74 (s, 2H), 5.32 (dd, J = 10.9, 1.0 Hz, 1H), 3.76 (s, 6H).

[0132] 13 C NMR (100 MHz, DMSO-d 6 )δ 160.93, 146.90, 145.18, 142.64, 138.06, 136.30, 135.82, 133.94, 133.83, 129.23, 126.81, 123.57, 123.51, 115.64, 107.13, 100.70, 62.32, 62.07, 55.45.

[0133] HRMS (ESI): calcd for C 23 H 21 N 2 O 2 S [M - Br - Cl - C 9 H 9 + : 389.1318; found, 389.1306.

[0134] The above data prove that 1-(3,5-dimethoxybenzyl)-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)thiophen-2-yl)pyridine-1,1'-bromide-chloride-diammonium has been successfully synthesized.

[0135] (4) Synthesis of poly(1-(3,5-dimethoxybenzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)thiophen-2-yl)pyridine-1,1'-bromide-chloride-diammonium-co-methyl methacrylate) (PSV-2-MMA)

[0136] ​Dissolve -benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)thiophen-2-yl)pyridine-1,1′-bromide-chloride-diammonium (4 g, 6.45 mmol), AIBA (129 mg, 0.47 mmol) and methyl methacrylate (1.3 mL, 14 mmol) in a mixed solvent of water and methanol (100 mL, v:v = 1:1). After performing three freeze-pump-thaw cycles to displace nitrogen in the solution system to remove radon, the temperature is raised to 70 °C and the reaction is carried out for 18 hours. After the reaction solution is cooled to room temperature, methanol is removed by rotary evaporation, and water is removed by freeze-drying. 5.0 g of a yellow solid product, compound H, is obtained with a yield of 92%.

[0137] Example 9

[0138] The synthetic route of the electrochromic material compound I is as follows:

[0139]

[0140] The specific synthesis steps of compound I are as follows:

[0141] (1) Synthesis of 2,5-bis(pyridin-4-yl)furan

[0142] Add 4-pyridineboronic acid (19.5 g, 159 mmol), 2,5-dibromofuran (15 g, 66 mmol), potassium carbonate (45 g, 0.33 mol) and tetrakis(triphenylphosphine)palladium (7.05 g, 6.09 mmol) into a round-bottom flask, add a mixed solvent of toluene, ethanol and deionized water (450 mL, v:v:v = 3:2:1). After three degassing cycles, heat the reaction mixture to 88 °C and stir for 72 hours under a nitrogen atmosphere. After the reaction is complete, cool the reaction solution to room temperature, filter, separate the organic phase with a separatory funnel, and concentrate the organic phase to dryness. The residue is dissolved in dichloromethane (150 mL), washed with water (3 × 80 mL), and after concentrating the organic phase to dryness, 11.5 g of a light yellow solid is obtained by flash silica gel column chromatography (dichloromethane:acetone, v:v = 20:1) with a yield of 78%.

[0143] The 1H NMR and 13C NMR data of the light yellow solid are as follows:

[0144] 1 H NMR (400 MHz, CDCl 3 -d) δ 8.69 - 8.63 (m, 4H), 7.63 - 7.57 (m, 4H), 7.01 (s, 2H).

[0145] 13 C NMR (100 MHz, DMSO-d 6)δ 151.65, 150.53, 150.31, 136.02, 121.23, 117.75, 112.23.

[0146] The 1H NMR and 13C NMR data indicate that 2,5-bis(pyridin-4-yl)furan has been successfully synthesized.

[0147] (2) Synthesis of 1-benzyl-4-(5-(pyridin-4-yl)furan-2-yl)pyridin-1-ium bromide

[0148] 2,5-Bis(pyridin-4-yl)furan (6.5 g, 29.2 mmol) was dissolved in DMF (200 mL), then benzyl bromide (1.15 mL, 9.73 mmol) was added. After heating to 90 °C, the reaction was carried out for 2 h. After cooling the reaction to room temperature, it was poured into ether and stirred, and a large amount of yellow solid precipitated. It was filtered, and the filter cake was washed with dichloromethane and dried in a vacuum drying oven to obtain 3.9 g of yellow solid product with a yield of 73%.

[0149] The 1H NMR and 13C NMR of the yellow solid product are as follows:

[0150] 1 H NMR (400 MHz, DMSO-d 6 ) δ 9.19 (d, J = 7.1 Hz, 2H), 8.75 - 8.69 (m, 2H), 8.53 (d, J = 7.0 Hz, 2H), 8.03 (d, J = 3.8 Hz, 1H), 7.99 - 7.92 (m, 2H), 7.68 (d, J = 3.8 Hz, 1H), 7.54 (d, J = 1.6 Hz, 2H), 7.50 - 7.41 (m, 3H).

[0151] 13 C NMR (100 MHz, DMSO-d 6 ) δ 150.73, 147.65, 147.34, 144.88, 139.07, 137.86, 134.52, 133.79, 129.26, 129.20, 129.04, 128.71, 122.84, 119.81, 62.18.

[0152] The above data indicate that 1-benzyl-4-(5-(pyridin-4-yl)furan-2-yl)pyridin-1-ium bromide has been successfully synthesized.

[0153] (3) Synthesis of 1-benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)furan-2-yl)pyridin-1,1′-bromide-chloride-diammonium

[0154] After dissolving 1-benzyl-4-(5-(pyridin-4-yl)thiophen-2-yl)pyridin-1-ium bromide (3.68 g, 9.36 mmol) in acetonitrile (1.2 L), 4-vinylbenzyl chloride (4.84 mL, 28 mmol) was added. The temperature was raised to 90 °C and the reaction was carried out for 72 hours. After cooling the reaction solution to room temperature, it was poured into diethyl ether. A large amount of yellow solid precipitated out. After filtration and vacuum drying, 2.6 g of yellow solid product was obtained with a yield of 51%.

[0155] The 1H NMR, 13C NMR and mass spectrometry data of the yellow solid product are as follows:

[0156] 1 H NMR (400 MHz, DMSO-d 6 ) δ 9.35 (dd, J = 6.9, 3.0 Hz, 4H), 8.75 - 8.66 (m, 4H), 8.15 (s, 2H), 7.61 - 7.53 (m, 6H), 7.50 - 7.39 (m, 4H), 6.75 (dd, J = 17.7, 10.9 Hz, 1H), 5.89 (d, J = 16.0 Hz, 4H), 5.84 (s, 1H), 5.32 (d, J = 10.9 Hz, 1H).

[0157] 13 C NMR (100 MHz, DMSO-d 6 ) δ 151.86, 145.26, 142.16, 138.02, 135.84, 134.58, 133.97, 129.26, 129.18, 129.11, 128.70, 126.80, 122.15, 119.73, 115.63, 62.43, 62.17.

[0158] HRMS (ESI): calcd for C 21 H 17 N 2 O[M - Br - Cl - C 9 H 9 + : 313.1335; found, 313.1339.

[0159] The above data indicate that 1-benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)furan-2-yl)pyridin-1,1'-bromide-chloride-diammonium has been successfully synthesized.

[0160] (4) Synthesis of poly(1-benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)furan-2-yl)pyridin-1,1'-bromide-chloride-diammonium-co-methyl methacrylate) (Compound I)​

[0161] 1-Benzyl-4-(5-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)furan-2-yl)pyridin-1,1'-bromide-chloride-diammonium (2 g, 3.66 mmol), AIBA (129 mg, 1.4 mmol), and methyl methacrylate were dissolved in a mixed solvent of water and methanol (30 mL, v:v = 1:1). After subjecting the solution system to three freeze-pump-thaw cycles to displace and remove oxygen with nitrogen, the temperature was raised to 70 °C and the reaction was carried out for 15 hours. After the reaction solution was cooled to room temperature, methanol was removed by rotary evaporation and water was removed by freeze-drying. 2.6 g of yellow solid product Compound I was obtained with a yield of 94%.

[0162] Example 10

[0163] The synthetic route of electrochromic material Compound J is as follows:

[0164]

[0165] The specific synthesis steps of Compound J are as follows:

[0166] (1) The preparation method of 2,5-bis(pyridin-4-yl)furan is the same as that in Example 9.

[0167] (2) Synthesis of 1-(3,5-dimethoxybenzyl)-4-(5-(pyridin-4-yl)furan-2-yl)pyridin-1-ammonium bromide

[0168] 2,5-Bis(pyridin-4-yl)furan (4.5 g, 23 mmol) and 3,5-dimethoxybenzyl bromide (1.65 g, 6.75 mmol) were mixed and dissolved in chloroform (60 mL). After the temperature was raised to 60 °C, the reaction was carried out for 30 hours. A large amount of yellow solid precipitated in the reaction solution. After the reaction was cooled to room temperature, it was filtered, and the filter cake was washed with chloroform and dried in a vacuum drying oven to obtain 2.9 g of yellow solid product with a yield of 96%.

[0169] The 1H NMR and 13C NMR data of the yellow solid product are as follows:

[0170] 1 H NMR (400 MHz, DMSO-d 6 ) δ 9.21 (d, J = 6.9 Hz, 2H), 8.77 - 8.67 (m, 2H), 8.52 (d, J = 6.7 Hz, 2H), 8.03 (d, J = 3.8 Hz, 1H), 7.99 - 7.95 (m, 2H), 7.70 (d, J = 3.8 Hz, 1H), 6.78 (t, J = 2.1 Hz, 2H), 6.55 (d, J = 2.3 Hz, 1H), 5.69 (d, J = 1.9 Hz, 2H), 3.76 (s, 6H).

[0171] 13 C NMR (100 MHz, DMSO-d 6 ) δ 160.95, 155.23, 150.22, 148.99, 144.87, 142.63, 136.47, 135.47, 121.02, 119.74, 118.54, 113.61, 106.86, 100.63, 62.25, 55.43.

[0172] The above data indicate that 1-(3,5-dimethoxybenzyl)-4-(5-(pyridin-4-yl)furan-2-yl)pyridin-1-ium bromide has been successfully synthesized.

[0173] (3) Synthesis of 1-(3,5-dimethoxybenzyl)-4-(5-(1-(4-vinylbenzyl)furan-1-ium-4-yl)furan-2-yl)pyridin-1,1′-bromide-chloride-diammonium

[0174] 1-(3,5-Dimethoxybenzyl)-4-(5-(pyridin-4-yl)furan-2-yl)pyridin-1-ium bromide (2.79 g, 6.18 mmol) was dissolved in DMSO (35 mL), and then 4-vinylbenzyl chloride (4.88 mL, 30.9 mmol) was added. The temperature was raised to 80 °C and the reaction was carried out for 80 hours. After the reaction solution was cooled to room temperature, it was poured into ethyl acetate. A large amount of yellow solid was precipitated, filtered, and dried in vacuo to obtain 3.6 g of yellow solid product with a yield of 97%.

[0175] The 1H NMR, 13C NMR and mass spectrum data of the yellow solid product are as follows:

[0176] 1H NMR (400 MHz, DMSO-d 6 ) δ 9.35 (t, J = 6.9 Hz, 4H), 8.70 (dd, J = 6.8, 5.1 Hz, 4H), 8.14 (s, 2H), 7.56 (s, 4H), 6.81 (d, J = 2.2 Hz, 2H), 6.75 (dd, J = 17.6, 10.9 Hz, 1H), 6.55 (t, J = 2.3 Hz, 1H), 5.89 (d, J = 17.8 Hz, 1H), 5.85 (s, 2H), 5.75 (s, 2H), 5.32 (d, J = 11.0 Hz, 1H), 3.76 (s, 6H).

[0177] 13 13C NMR (100 MHz, DMSO-d 6)δ 160.92, 151.87, 151.82, 145.23, 142.13, 138.00, 136.45, 135.83, 133.97, 129.10, 126.78, 122.12, 122.06, 119.70, 115.61, 106.98, 100.68, 62.38, 62.13, 55.45.

[0178] HRMS(ESI): calcd for C 23 H 21 N 2 O 3 [M - Br - Cl - C 9 H 9 + : 373.1547; found, 373.1547.

[0179] The above data indicate that 1-(3,5 - dimethoxybenzyl)-4-(5-(1-(4 - vinylbenzyl)furan - 1 - ylium - 4 - yl)furan - 2 - yl)pyridinium - 1,1′ - bromide - chloride - diammonium has been successfully synthesized.

[0180] (3) Synthesis of poly(1-(3,5 - dimethoxybenzyl - 4-(5-(1-(4 - vinylbenzyl)pyridinium - 1 - ylium - 4 - yl)furan - 2 - yl)pyridinium - 1,1′ - bromide - chloride - diammonium - co - methyl methacrylate) (Compound J)

[0181] Dissolve - benzyl - 4-(5-(1-(4 - vinylbenzyl)pyridinium - 1 - ylium - 4 - yl)furan - 2 - yl)pyridinium - 1,1′ - bromide - chloride - diammonium (3.5 g, 5.78 mmol), AIBA (231 mg, 0.85 mmol) and methyl methacrylate (1.2 mL, 11.5 mmol) in a mixed solvent of water and methanol (46 mL, v:v = 1:1). After subjecting the solution system to 3 freeze - vacuum - thaw cycles to displace nitrogen and remove oxygen, heat the mixture to 70 °C and react for 10 hours. After the reaction solution is cooled to room temperature, rotary evaporate to remove methanol and freeze - dry to remove water. Obtain 4.6 g of yellow solid product Compound J with a yield of 92%.

[0182] Example 11

[0183] The synthetic route of electrochromic material Compound K is as follows:

[0184]

[0185] The specific synthesis steps of Compound K are as follows:

[0186] ​(1) Synthesis of 5,7-bis(pyridin-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxine

[0187] 4-Pyridineboronic acid (639.6 mg, 5.2 mmol), 2,5-dibromo-3,4-ethylenedioxythiophene (596 mg, 2 mmol), potassium carbonate (2.22 g, 16 mmol), and tetrakis(triphenylphosphine)palladium(0) (234 mg, 0.2 mmol) were added to a round-bottom flask, and a mixed solvent of toluene, dioxane, and deionized water (15 mL, v:v:v = 2:2:1) was added. After three degassing cycles, the reaction mixture was heated to 85 °C and stirred under a nitrogen atmosphere for 72 hours. After the reaction was complete, the reaction solution was cooled to room temperature, filtered, and the organic phase was separated by a separatory funnel. The organic phase was concentrated to dryness. The residue was dissolved in dichloromethane (100 mL), washed with water (3 × 50 mL), and the organic phase was concentrated to dryness and then purified by flash silica gel column chromatography (petroleum ether:ethyl acetate, v:v = 1:1) to obtain 200 mg of a light yellow solid with a yield of 34%.

[0188] The 1H NMR data are as follows:

[0189] 1 H NMR (400 MHz, DMSO-d 6 ) δ 8.66 - 8.50 (m, 4H), 7.74 - 7.57 (m, 4H), 4.50 (s, 4H).

[0190] (2) Synthesis of 1-benzyl-4-(7-(pyridin-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)pyridin-1-ium bromide

[0191] 5,7-Bis(pyridin-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxine (1.08 g, 3.65 mmol) and benzyl bromide (499.16 mg, 2.92 mmol) were mixed and dissolved in chloroform (40 mL). After heating to 60 °C, the reaction was carried out for 12 hours. After the reaction was complete, the reaction solution was cooled to room temperature, and the organic phase was concentrated to dryness and then purified by flash silica gel column chromatography (dichloromethane:methanol, v:v = 15:1) to obtain 740 mg of a light yellow solid with a yield of 54%.

[0192] The 1H NMR data are as follows:

[0193] 1H NMR (400 MHz, DMSO-d6) δ 9.09 - 8.95 (m, 2H), 8.71 - 8.63 (m, 2H), 8.30 - 8.19 (m, 2H), 7.77 - 7.69 (m, 2H), 7.56 - 7.50 (m, 2H), 7.49 - 7.43 (m, 3H), 5.79 (s, 2H), 4.64 - 4.59 (m, 2H), 4.55 (dt, J = 6.5, 2.0 Hz, 2H).

[0194] (3) Synthesis of 1-Benzyl-4-(7-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)pyridin-1-ium chloride

[0195] 1-Benzyl-4-(7-(pyridin-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)pyridin-1-ium bromide (700 mg, 1.50 mmol) was dissolved in DMSO (18 mL), and then 4-vinylbenzyl chloride (687 mg, 4.51 mmol) was added. The temperature was raised to 90 °C and the reaction was carried out for 24 h. After cooling the reaction solution to room temperature, it was poured into ethyl acetate. A large amount of yellow solid was precipitated, filtered, and dried under vacuum to obtain 900 mg of yellow solid product with a yield of 97%.

[0196] The 1H NMR data are as follows:

[0197] 1 1H NMR (400 MHz, DMSO-d 6 ) δ 9.24 - 9.10 (m, 4H), 8.34 (dd, J = 7.2, 2.3 Hz, 4H), 7.61 - 7.50 (m, 6H), 7.50 - 7.39 (m, 3H), 6.76 (dd, J = 17.6, 11.0 Hz, 1H), 5.92 (d, J = 1.0 Hz, 1H), 5.90 - 5.80 (m, 4H), 5.35 - 5.29 (m, 1H), 4.65 (s, 4H).

[0198] (4) Synthesis of poly(1-benzyl-4-(7-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)pyridin-1-ium chloride-co-methyl methacrylate) (Compound K)

[0199] Dissolve 1-benzyl-4-(7-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxan-5-yl)pyridin-1-ium chloride (300 mg, 0.49 mmol), AIBA (19.80 mg, 0.073 mmol) and methyl methacrylate (97.19 mg, 0.97 mmol) in a mixed solvent of water and methanol (6 mL, v:v = 1:1). After performing 3 freeze-pump-thaw cycles to displace nitrogen and remove oxygen from the solution system, heat the solution to 70 °C and react for 24 hours. After the reaction solution is cooled to room temperature, rotary evaporate to remove methanol and freeze-dry to remove water. Obtain 280 mg of a yellow solid product K with a yield of 76%.

[0200] Example 12

[0201] The synthetic route of the electrochromic material compound L is as follows:

[0202]

[0203] The specific synthetic route steps of compound L are as follows:

[0204] (1) Synthesis of 1-(3,5-dimethoxybenzyl)-4-(7-(pyridin-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxan-5-yl)pyridin-1-ium bromide

[0205] Mix 5,7-bis(pyridin-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxane (270 mg, 0.91 mmol) and 3,5-dimethoxybenzyl bromide (210.74 mg, 0.91 mmol), add chloroform (8 mL) to dissolve, and heat to 60 °C and react for 12 hours. After the reaction is complete, cool the reaction solution to room temperature, concentrate the organic phase to dryness, and obtain 270 mg of a light yellow solid by flash silica gel column chromatography (dichloromethane:methanol, v:v = 20:1) with a yield of 56%.

[0206] The 1H NMR data are as follows:

[0207] 1 H NMR (400 MHz, Chloroform-d) δ 9.35 (d, J = 6.7 Hz, 2H), 8.66 (d, J = 5.4 Hz, 2H), 8.07 (d, J = 6.5 Hz, 2H), 7.67 - 7.57 (m, 2H), 6.86 (d, J = 2.2 Hz, 2H), 6.40 (t, J = 2.2 Hz, 1H), 6.01 (s, 2H), 4.59 - 4.52 (m, 2H), 4.50 - 4.44 (m, 2H), 3.79 (s, 6H), 3.49 (s, 1H).

[0208] (2) Synthesis of 1-(3,5-dimethoxybenzyl)-4-(7-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxan-5-yl)pyridin-1-ium chloride

[0209] After dissolving 1-(3,5-dimethoxybenzyl)-4-(7-(pyridin-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxan-5-yl)pyridin-1-ium bromide (200 mg, 0.38 mmol) in DMSO (5 mL), 4-vinylbenzyl chloride (173.28 mg, 1.14 mmol) was added. The temperature was raised to 90 °C and the reaction was carried out for 24 hours. After cooling the reaction solution to room temperature, it was poured into ethyl acetate. A large amount of yellow solid was precipitated, filtered, and dried in vacuo to obtain 190 mg of yellow solid product with a yield of 73%.

[0210] The proton nuclear magnetic resonance spectrum data are as follows:

[0211] 1 H NMR (400 MHz, DMSO-d 6 ) δ 9.13 (t, J = 5.8 Hz, 4H), 8.39 - 8.26 (m, 4H), 7.62 - 7.45 (m, 4H), 6.84 - 6.70 (m, 3H), 6.56 (t, J = 2.2 Hz, 1H), 5.90 (dd, J = 17.6, 1.0 Hz, 1H), 5.82 (s, 2H), 5.71 (s, 2H), 5.33 (dd, J = 10.9, 0.9 Hz, 1H), 4.64 (s, 4H), 3.76 (s, 6H).

[0212] (3) Synthesis of poly(1-(3,5-dimethoxybenzyl)-4-(7-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxan-5-yl)pyridin-1-ium chloride-co-methyl methacrylate) (Compound L)

[0213] Dissolve 1-(3,5-dimethoxybenzyl)-4-(7-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)-2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)pyridin-1-ium chloride (200 mg, 0.29 mmol), AIBA (12 mg, 0.04 mmol) and methyl methacrylate (59 mg, 0.59 mmol) in a mixed solvent of water and methanol (6 mL, v:v = 1:1). After deoxygenating the solution system by subjecting it to 3 freeze-pump-thaw cycles to displace nitrogen, the temperature is raised to 70 °C and the reaction is carried out for 24 hours. After the reaction solution is cooled to room temperature, methanol is removed by rotary evaporation and water is removed by freeze-drying. 180 mg of a yellow solid product L is obtained, with a yield of 77%.

[0214] Example 13

[0215] The synthetic route of the electrochromic material compound M is as follows:

[0216]

[0217] The specific synthesis steps of compound M are as follows:

[0218] (1) Synthesis of 5,5′-bis(pyridin-4-yl)-2,2′-bithiophene

[0219] Add 4-bromopyridine (1.738 g, 11 mmol), 5,5′-bis(tributylstannyl)-2,2′-bithiophene (3.73 g, 5 mmol), potassium carbonate (2.22 g, 16 mol) and tetrakis(triphenylphosphine)palladium (234 mg, 0.2 mmol) to a round-bottom flask, add toluene solvent (50 mL). After undergoing three degassing cycles, heat the reaction mixture to 100 °C and stir for 24 hours under a nitrogen atmosphere. After the reaction is complete, cool the reaction solution to room temperature, filter, and obtain 1 g of a light yellow solid, with a yield of 63%.

[0220] The 1H NMR data are as follows:

[0221] 1 H NMR (400 MHz, Chloroform-d) δ 8.73 - 8.44 (m, 4H), 7.49 - 7.41 (m, 6H), 7.24 (s, 2H).

[0222] (2) Synthesis of 1-benzyl-4-(5′-(pyridin-4-yl)-[2,2′-bithiophene]-5-yl)pyridin-1-ium bromide

[0223] After mixing 5,5'-bis(pyridin-4-yl)-2,2'-bithiophene (200 mg, 0.62 mmol) and benzyl bromide (84.97 mg, 0.50 mmol), chloroform (20 mL) was added to dissolve them. After heating to 60 °C, the reaction was carried out for 12 hours. After the reaction was complete, the reaction solution was cooled to room temperature. The organic phase was concentrated to dryness and then purified by flash silica gel column chromatography (dichloromethane:methanol, v:v = 15:1) to obtain 120 mg of a light yellow solid with a yield of 49%.

[0224] The 1H NMR data are as follows:

[0225] 1 H NMR(400MHz, DMSO-d 6 ) δ 9.17 - 9.02 (m, 2H), 8.68 - 8.58 (m, 2H), 8.43 - 8.34 (m, 2H), 8.30 (d, J = 4.1 Hz, 1H), 7.91 (d, J = 4.0 Hz, 1H), 7.75 (d, J = 4.1 Hz, 1H), 7.72 - 7.68 (m, 3H), 7.59 - 7.53 (m, 2H), 7.50 - 7.40 (m, 3H), 5.77 (d, J = 7.6 Hz, 2H).

[0226] (3) Synthesis of 1-benzyl-4-(5'-(1-(4-vinylbenzyl)pyridin-1-ium-4-yl)-[2,2'-bithiophene]-5-yl)pyridin-1-ium chloride

[0227] 1-Benzyl-4-(5'-(pyridin-4-yl)-[2,2'-bithiophene]-5-yl)pyridin-1-ium bromide (418 mg, 0.85 mmol) was dissolved in DMSO (20 mL), and then 4-vinylbenzyl chloride (390 mg, 2.55 mmol) was added. The temperature was raised to 90 °C and the reaction was carried out for 24 hours. After the reaction solution was cooled to room temperature, it was poured into ethyl acetate. A large amount of yellow solid precipitated. After filtration and vacuum drying, 520 mg of a yellow solid product was obtained with a yield of 95%.

[0228] The 1H NMR data are as follows:

[0229] 1 H NMR(400MHz, DMSO-d 6)δ 9.24 - 9.08 (m, 4H), 8.42 (dt, J = 7.0, 1.7 Hz, 4H), 8.35 (dd, J = 4.4, 1.3 Hz, 2H), 7.88 (d, J = 4.1 Hz, 2H), 7.56 (s, 6H), 7.52 - 7.39 (m, 3H), 6.76 (dd, J = 17.7, 10.9 Hz, 1H), 5.90 (dd, J = 17.7, 1.0 Hz, 1H), 5.81 (d, J = 6.8 Hz, 4H), 5.33 (dd, J = 11.0, 1.0 Hz, 1H).

[0230] (4) Synthesis of poly(1 - benzyl - 4 - (5′-(1-(4 - vinylbenzyl)pyridin - 1 - ium - 4 - yl)-[2,2′ - bithiophene]-5 - yl)pyridin - 1 - ammonium chloride - co - methyl methacrylate) (Compound M)

[0231] Dissolve 1 - benzyl - 4 - (5′-(1-(4 - vinylbenzyl)pyridin - 1 - ium - 4 - yl)-[2,2′ - bithiophene]-5 - yl)pyridin - 1 - ammonium chloride (200 mg, 0.31 mmol), AIBA (12 mg, 0.05 mmol) and methyl methacrylate (62 mg, 0.62 mmol) in a mixed solvent of water and methanol (6 mL, v:v = 1:1). After performing 3 freeze - vacuum - thaw cycles to displace nitrogen from the solution system for deoxygenation, the temperature is raised to 70 °C and the reaction is carried out for 24 hours. After the reaction solution is cooled to room temperature, methanol is removed by rotary evaporation and water is removed by freeze - drying. 180 mg of yellow solid product Compound M is obtained, with a yield of 73%.

[0232] Comparative Example 1

[0233] The difference from Example 8 is that 4 - vinylbenzyl chloride in step (3) is replaced by 3 - chloropropene.

[0234] Test Example 1

[0235] Electrochemical property tests were carried out on Compound E prepared in Example 5, Compound H prepared in Example 8, Compound I prepared in Example 9, and Compound J prepared in Example 10.

[0236] First, test the electrochemical properties of Compound E, Compound H, Compound I, and Compound J. The test conditions for the cyclic voltammetry curve are: in an N - methylpyrrolidone solution of 0.1 mM TBAPF6, the scan rate is 100 mV / s, showing a stable redox reaction as Figure 1 shown. Then assemble into a solid - state electrochromic device and test the electrochemical performance of the electrochromic device. The voltage scan range is - 1.8 V to 0.2 V, showing as Figure 2The stable redox reaction shown. Then, the spectral properties of the electrochromic device were tested, and the operating voltage (-1.3V) of the electrochromic device was as Figure 3 shown. Figure 4 The response time is shown as Figure 5 shown, and the coloring efficiency is shown as Figure 6 shown. The bistable performance is shown as

[0237] The results of the response time, coloring efficiency, and bistable performance of the electrochromic devices prepared from Compound E, Compound H, Compound I, and Compound J are shown in Table 1.

[0238] Table 1 Test Results of Electrochemical Performance

[0239]

[0240] Test Example 2

[0241] The bistable performance of Examples 1 to 13 and Comparative Example 1 was tested, and the test results are shown in Table 2.

[0242] Table 2 Test Results of Bistable Performance of Examples 1 to 13 and Comparative Example 1

[0243]

[0244]

[0245] Therefore, the present invention adopts a bridged polyviologen-based electrochromic material with the above structure, its preparation method and application. By synthesizing a heterocyclic-bridged viologen polymer, on the one hand, the free diffusion of viologen-based electrochromic molecules inside the device is reduced, and on the other hand, the length of the conjugated chain is increased, making the viologen cation radical more stable and improving the bistable performance of its use as an electrochromic material.

[0246] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. An electrochromic material based on bridged polyviologen, characterized in that: The general structural formula of electrochromic materials is: Where M is X1 - Selected from Br - , X2 - Selected from Cl - ; R1 is selected from phenyl; R2 is selected from -COO-CH3; R3 is selected from methyl; m>0.

2. The method for preparing a bridged polyviologen electrochromic material according to claim 1, characterized in that: The following steps are involved: (1) Compound P1 is dissolved in an organic solvent, and then compound P2 is added and the temperature is raised to react. After the reaction is completed, a solid is precipitated from the reaction solution and filtered to obtain intermediate 1; (2) Dissolving the intermediate 1 in an organic solvent, then adding compound P3, heating the mixture to react, and after the reaction is completed, solid precipitates from the reaction solution, which is filtered to obtain the intermediate 2; (3) Dissolving the intermediate 2 in a solvent, then adding the compound P4, removing oxygen by nitrogen exchange, heating to carry out a polymerization reaction, cooling the reaction solution to room temperature and freeze-drying to obtain a product; The chemical structural formulas of P1, P2, P3 and P4 are:

3. The method for preparing a bridged polyviologen electrochromic material according to claim 2, characterized in that: The organic solvent in step (1) and step (2) includes one or more of N,N-dimethylformamide, chloroform, toluene, and dimethyl sulfoxide.

4. The method for preparing a bridged polyviologen electrochromic material according to claim 2, characterized in that: In step (1), the molar ratio of compound P1 to compound P2 is 1 to 5:

1.

5. The method for preparing a bridged polyviologen electrochromic material according to claim 2, characterized in that: The molar ratio of intermediate 1 to compound P3 in step (2) is 1:1-6.

6. The method for preparing a bridged polyviologen electrochromic material according to claim 2, characterized in that: The reaction temperature in step (1) and step (2) is 80-100° C., and the reaction time is 12-48 hours.

7. The method for preparing a bridged polyviologen electrochromic material according to claim 2, characterized in that: In step (3), intermediate 2, K2S2O8 and C2H4OS are mixed and dissolved in water. After three freeze-vacuum-thaw cycles, the solution system is replaced with nitrogen and deoxygenated. The mixture is stirred at 80-100°C for 12-48h, and the reaction solution is cooled to room temperature and freeze-dried to obtain the product.

8. The method for preparing a bridged polyviologen electrochromic material according to claim 2, characterized in that: In step (3), the molar ratio of intermediate 2 to compound P4 is 1:1-5.

9. A method for preparing electrochromic materials based on bridged polyviologens according to claim 8, characterized in that: In step (3), intermediate 2, compound P4 and AIBA are dissolved in a mixed solvent of water and methanol, and the solution system is deoxygenated by nitrogen replacement after three freeze-vacuum-thaw cycles, and then the temperature is raised to 50-100° C. for reaction for 5-24 hours. After the reaction solution is cooled to room temperature, the methanol is removed by rotary evaporation, and the water is removed by freeze drying to obtain the product.

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