A triphenylamine phenyl conjugated dithiophene ethylene derivative, its preparation and application

Abstract

This invention belongs to the field of new materials technology, and more specifically, relates to a triphenylamine phenyl conjugated modified dithienylethylene derivative, its preparation and application. The dithienylethylene derivative has structural units as shown in formula (I): wherein R1 and R2 are each independently -H, C1-C4 alkyl, or C6-C... 24 The invention designs a triphenylamine phenyl-modified dithienylethylene molecular switch, which red-shifts the absorption wavelength to the visible light region, allowing the ring-closing reaction to be regulated by visible light. At the same time, the ring-opening reaction itself regulates the wavelength in the visible light region, realizing the full visible light regulation of the dithienylethylene molecular switch photoisomerization reaction, and possessing both high visible light responsiveness and on / off ratio.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology, and more specifically, relates to a triphenylamine phenyl conjugated modified dithiophene ethylene derivative, its preparation and application. Background Technology

[0002] Photochromic materials refer to compounds that undergo reversible photoisomerization reactions after being irradiated with light of a specific wavelength, resulting in significant changes in their absorption spectrum, color, and other properties due to structural alterations. Among numerous photochromic molecules, dithiophene ethylene (DTE) derivatives have become a research hotspot due to their excellent thermal stability, fatigue resistance, and rapid photoresponse, showing promising development prospects in high-density optical storage fields such as information storage and anti-counterfeiting. The ring-opening reaction of DTE can generally be achieved under visible light, but its ring-closing reaction mostly relies on ultraviolet light. Ultraviolet light, compared to visible light, has a shorter wavelength and lower penetration, and its high energy results in phototoxicity, easily causing photobleaching, material damage, and reduced fatigue resistance. In contrast, visible light, with its lower energy consumption and higher penetration, is more suitable for practical applications of photosensitive materials. Therefore, developing novel visible light-driven DTE molecular switches is of great significance.

[0003] Currently, various strategies exist for realizing visible light-driven DTE molecular switching, such as extending π-conjugation, triplet energy transfer, two-photon absorption, upconversion nanoparticles, and intramolecular proton transfer. According to existing reports, most of these novel strategies, such as upconversion and multiphoton absorption, rely on complex instruments and structures; extending π-conjugation is the simplest and most direct strategy. However, extending π-conjugation usually reduces photochromic efficiency or even eliminates the photo-switching capability. [J.Org.Chem.2001,66,11,3913-3923] Irie et al. synthesized six dithienylethylene-bridged bisporphyrin compounds, of which only two molecules maintained reversible photo-switching performance. However, their quantum yields were much lower than those of dithienylethylene molecules without linking groups, indicating that extending π-conjugation actually inhibited the photoreactivity. [J.Am.Chem.Soc.2014,136,17145-17154] Subsequently, Irie's group synthesized 10 molecules based on the dithiophene ethylene skeleton based on the strategy of extending π conjugation, but only one molecule could maintain bidirectional switching capability, while the others were either unresponsive to light or could only switch unidirectionally. [DyesPigments.202(2022)110298] Wang Sheng et al. synthesized a novel visible light-controllable photochromic dithiophene ethylene derivative, but the photoisomerization conversion rate under 420 nm visible light was only 10%. CN112409324A developed a series of molecules with high photoisomerization conversion rates, but they had low molar absorptivity and poor photosensitivity. To address these problems, this invention designs and develops new molecules to obtain visible light-responsive molecular switches with better performance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a triphenylamine phenyl conjugated modified dithiophene ethylene derivative, its preparation and application, in order to solve the technical problems of existing DTE molecular switches, such as the need for ultraviolet light response, low ring-opening and ring-closing conversion rate, and low molar absorptivity.

[0005] To achieve the above objectives, the present invention provides a triphenylamine phenyl conjugated modified dithienylethylene derivative having structural units as shown in formula (I):

[0006]

[0007] Wherein, R1 and R2 are each independently -H, C1-C4 alkyl, or C6-C 24 Aryl groups.

[0008] Preferably, both R1 and R2 are H.

[0009] According to another aspect of the present invention, a method for preparing the dithiophene ethylene derivative is provided, comprising the following steps:

[0010] (1) The triphenylamine phenyl monobromosubstituted compound R1 / R2-TPA-Ph-Br with the R1 and R2 groups, piperamide ester and potassium carbonate are dissolved in an organic solvent, and under nitrogen protection, the catalyst Pd(dppf)Cl2 is added to generate compound R1 / R2-TPA-Ph-Borate; wherein TPA represents triphenylamine, Ph represents phenyl, and Borate represents borate;

[0011] (2) 1,2-bis(5-bromo-2-methylthiophene-3-yl)perfluorocyclopentene, R1 / R2-TPA-Ph-Borate and potassium carbonate were dissolved in a solvent and, under nitrogen protection and in the presence of a phase transfer catalyst and a catalyst, the Br and borate groups were removed to generate a compound with the structural unit shown in formula (I).

[0012] According to another aspect of the present invention, the application of the triphenylamine phenyl conjugated modified dithienylethylene derivative described above in the preparation of a fully visible light-controlled molecular switch material is provided, wherein the molecular switch material is triggered by a visible light source to achieve its ring-closing reaction.

[0013] Preferably, the molecular switch material is a photochromic molecular switch material.

[0014] Preferably, the visible light wavelength range is 390–460 nm.

[0015] According to another aspect of the invention, a fully visible light-tunable triphenylamine phenyl conjugated dithiophene ethylene molecular switch is provided, comprising the triphenylamine phenyl conjugated dithiophene ethylene derivative.

[0016] In summary, compared with the prior art, the above-described technical solutions conceived by this invention have the following advantages:

[0017] Beneficial effects:

[0018] (1) This invention designs a triphenylamine phenyl-modified dithienylethylene molecular switch, which red-shifts the absorption wavelength to the visible light region, so that the closed-ring reaction can be controlled by visible light, while the open-ring reaction itself controls the wavelength in the visible light region, realizing the full visible light control of the dithienylethylene molecular switch photoisomerization reaction, and also has high visible light responsiveness and on / off ratio.

[0019] (2) In addition to having a closed-loop response with a conversion rate of up to 99.8% for ultraviolet light, the molecular switch of this invention also has a closed-loop response of nearly 100% for short-wavelength visible light. The preferred trigger wavelength range for the closed-loop reaction is 390nm-460nm. By using visible light in this band to replace ultraviolet light in practical applications such as optical information storage, the use of ultraviolet light can be avoided, thereby improving the fatigue resistance and photobleaching properties of the sample and preventing radiation damage to the observed sample and the operator.

[0020] (3) The TPAP-DTE shown in Formula (II) provided in the preferred embodiment of the present invention is a symmetrical triphenylamine phenyl-modified dithiophene ethylene molecular switch. Under 405nm illumination, it reaches a photostable state in 40s, and the on / off ratio can reach 305:1. It has excellent photochromic reversibility and fatigue resistance. Its absorption does not change significantly after ten alternating irradiations with 405nm and 620nm visible light, and its absorption is only 5% lower after irradiation with strong 405nm visible light for 2 hours.

[0021] (4) In the preferred embodiment of the present invention, TPAP-DTE achieves a closed-loop state conversion rate of 96.1% under 405nm visible light, which is a significant improvement compared to the conversion rate of previous visible light-controlled fluorescent molecular switches. It can also serve as an information storage medium for erasable and rewritable storage, anti-counterfeiting, and encryption of information.

[0022] (5) The preferred embodiment of the present invention, TPAP-DTE, exhibits excellent photoresponse capability under 405 nm visible light, and has a higher molar absorptivity (ε) compared to existing dithienylethylene fluorescent molecular switches. irr405 =5300M -1 cm -1 It can produce significant absorbance changes at lower light intensities, reducing the power requirements of the light source and the complexity of experimental operations, while also enhancing the switching effect and improving response speed and reliability.

[0023] (6) In the preferred embodiment of the present invention, TPAP-DTE showed a decrease in absorption value of only 4% after continuous irradiation with 405 nm light for 2 hours, which is better than the dithiophene ethylene fluorescent molecular switch of the prior art in terms of anti-photobleaching and excellent stability. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the detailed synthetic route for the molecular switch prepared in Example 1 of the present invention.

[0025] Figure 2 The graph shows the variation of the absorption spectrum of the molecular switch obtained by the preparation process in Example 1 of this invention in tetrahydrofuran with the duration of irradiation by 405nm / 365nm / 625nm light.

[0026] Figure 3 The graph shows the absorption spectrum of the molecular switch obtained by the preparation process of Comparative Example 1 of this invention in tetrahydrofuran as a function of irradiation time with 405nm / / 625nm light.

[0027] Figure 4 The images show the photobleaching test results of the molecular switches prepared by the processes of Example 1 and Comparative Examples 2 and 3 of this invention under continuous irradiation at 405 nm.

[0028] Figure 5 The photoisomerization conversion rate of the molecular switch obtained by the preparation process in Example 1 of this invention was measured by nuclear magnetic resonance spectroscopy at 405 nm and 365 nm.

[0029] Figure 6 The image shows the fatigue resistance test results of the molecular switch obtained by the preparation process in Example 1 of this invention in THF solution and polymethyl methacrylate (PMMA).

[0030] Figure 7 This experiment demonstrates the erasable and rewritable information storage of the molecular switch prepared by the process described in Example 1 of this invention under full visible light. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] This invention provides a triphenylamine phenyl conjugated modified dithienylethylene derivative having structural units as shown in formula (I):

[0033]

[0034] Wherein, R1 and R2 are each independently -H, C1-C4 alkyl, or C6-C 24 The aryl group; in a preferred embodiment, R1 and R2 are each independently selected from -H, methyl and ethyl.

[0035] When both R1 and R2 are H, as shown in formula (II), it is abbreviated as TPAP-DTE; DTE represents perfluorocyclopentadithiophene ethylene.

[0036]

[0037] In some embodiments, the method for preparing the dithiophene ethylene derivative of the present invention includes the following steps:

[0038] (1) The triphenylamine phenyl monobromosubstituted compound R1 / R2-TPA-Ph-Br with the R1 and R2 groups, piperamide ester and potassium carbonate are dissolved in an organic solvent, and under nitrogen protection, the catalyst Pd(dppf)Cl2 is added to generate compound R1 / R2-TPA-Ph-Borate; wherein TPA represents triphenylamine, Ph represents phenyl, and Borate represents borate;

[0039] (2) 1,2-bis(5-bromo-2-methylthiophene-3-yl)perfluorocyclopentene (Br-DTE-Br), R1 / R2-TPA-Ph-Borate and potassium carbonate were dissolved in a solvent, and under nitrogen protection, in the presence of a phase transfer catalyst and a catalyst, the Br and borate groups were removed to generate a compound with the structural unit shown in formula (I).

[0040] In some embodiments, the organic solvent in step (1) is one or more of anhydrous 1,4-dioxane, dimethylformamide, toluene, and water, or a mixture of ethylene glycol dimethyl ether and water. The solvent in step (2) is a mixed solution of ethylene glycol dimethyl ether and water, wherein the mass ratio of ethylene glycol dimethyl ether to water is (3.5-4.5):1. The phase transfer catalyst in step (2) is tetrabutylammonium hydrogen sulfate, and the catalyst is Pd(PPh3)4.

[0041] The triphenylamine phenyl conjugated modified dithiophene ethylene derivative of this invention can be used to prepare molecular switch materials that are tunable under fully visible light, and the ring-closing reaction of these molecular switch materials is triggered by a visible light source. In a preferred embodiment, the molecular switch material is a photochromic molecular switch material. The visible light wavelength range is 390–460 nm.

[0042] This invention also provides a fully visible-light-tunable triphenylamine phenyl conjugated dithienylethylene molecular switch, comprising the aforementioned triphenylamine phenyl conjugated dithienylethylene derivative. The triphenylamine phenyl-dithienylethylene molecular switch provided by this invention can be applied to visible-light-driven molecular switches. This molecular switch achieves "on" and "off" behavior under the control of two visible light beams and can be used as an information storage medium for data encryption and anti-counterfeiting. This invention designs a symmetrical triphenylamine phenyl-dithienylethylene molecular switch by conjugating triphenylamine with dithienylethylene. This molecular switch not only possesses excellent photochromic and switching performance but also achieves photoisomerization behavior under full visible light.

[0043] It is generally believed that extending the conjugation would red-shift the absorption wavelength of the dithiophene-ethylene molecule to the visible light region, potentially enabling a visible light response. Therefore, extending the π-conjugation is currently the simplest and most direct strategy for achieving visible light-driven DTE molecular switches. However, numerous studies have shown that extending the π-conjugation usually reduces photochromic efficiency or even eliminates the photo-switching capability. Unlike existing technologies, this invention introduces a triphenylamine phenyl group, causing a small portion of the molecule's absorption wavelength to red-shift to the visible light region without excessive extension. This results in a molecular switch with good photochromic performance, demonstrating that this invention selects an appropriate conjugation extension structure while maintaining favorable photophysical properties. Furthermore, the introduction of the triphenylamine group may effectively regulate the excited-state energy of the molecule, ensuring sufficient energy for photochromic or photo-switching reactions during photoexcitation. Through molecular design, this invention not only maintains excellent photochromic reversibility but also preserves its good visible light responsiveness and near 100% bidirectional light conversion efficiency.

[0044] Furthermore, CN112409324A discloses a linear rigid dithiophene ethylene molecular switch containing triphenylamine-alkynyl groups, which differs from the molecular switch of this invention only in the alkynyl group and the phenyl group. Since the phenyl group is rotatable and has an angle with the adjacent benzene ring, potentially causing steric hindrance, theoretically, the conjugation of the molecular switch after replacing the phenyl group in this invention is not stronger than that of the alkynyl group. In fact, according to numerous prior art studies, stronger conjugation does not necessarily lead to higher photochromic efficiency or the optical switching capability of the molecular switch.

[0045] The following is an example:

[0046] Example 1

[0047] A dithiophene-ethylene molecular switch as shown in formula (II), where R1 and R2 are H, is abbreviated as TPAP-DTE, and its synthetic route is as follows: Figure 1 As shown, it includes the following steps:

[0048] (1) Reference for the synthesis process of Br-DTE-Br (Li Chong, Synthesis, Properties and Applications of Diarylethylene Fluorescent Molecular Switches [D]. Wuhan, Wuhan National Research Center for Optoelectronics, Huazhong University of Science and Technology, 2015: 28-32).

[0049] (2) Under nitrogen atmosphere, 4-bromo-4'-(diphenylamino)biphenyl (1.0 g, 2.5 mmol), bipinnaborate (1.3 g, 5.0 mmol), and potassium acetate (0.74 g, 7.5 mmol) were added to a 100 mL two-necked flask. 50 mL of redistilled 1,4-dioxane was added to dissolve the precipitate completely. The mixture was then evacuated and purged with nitrogen three times. Pd(dppf)Cl2 catalyst (0.05 g) was added, and the mixture was purged with nitrogen three times under vacuum. The mixture was then heated to 80 °C and reacted for 16 h. After the reaction solution cooled to room temperature, it was extracted with dichloromethane, washed three times with deionized water, and dried overnight with anhydrous Na2SO4. A column chromatography separation was performed using an eluent (dichloromethane: petroleum ether = 1:3) to obtain a pale yellow powder. The powder was then recrystallized from n-hexane to obtain 0.66 g of white crystals, with a yield of 75%.

[0050] (3) Under nitrogen atmosphere, add TPAB (200 mg, 0.44 mmol), Br-DTE-Br (106 mg, 0.20 mmol), and potassium carbonate (277 mg, 2.0 mmol) to a 50 mL two-necked flask. Add 8 mL of ethylene glycol dimethyl ether and 2 mL of water (the solvent is purged with nitrogen for 10 minutes to remove oxygen). Add the solution to the flask to fully dissolve the raw materials. Vacuum the flask three times and purge with nitrogen. Add the phase transfer catalyst tetrabutylammonium bisulfate (0.01 g) and the catalyst Pd(PPh3)4 (0.01 g). Repeat the process three times, purging with nitrogen, and heat to 90 °C for 6 h. After the reaction, extract with dichloromethane, wash three times with deionized water, and dry overnight with anhydrous Na2SO4. Separate by column chromatography using eluent (dichloromethane: petroleum ether = 1:3) to obtain 0.16 g of pale green powder, with a yield of 82%. 1 H NMR(600MHz,Chloroform-d)δ7.62(s,7H),7.54-7.49(m,4H),7.34(s,2H),7.33-7.28(m, 31H),7.19-7.15(m,11H),7.07(t,J=7.3Hz,4H),2.02(d,J=4.5Hz,6H),1.29(s,1H),0.93 -0.84(m,4H),0.82(dt,J=7.7,4.0Hz,2H),0.10(d,J=3.2Hz,9H). 13 C NMR(151MHz,Chloroform-d)δ147.59,147.51,142.00,141.22,140.17,133.99,131.77,129.38, 129.33,127.70,127.54,127.08,125.95,124.77,124.57,123.73,123.11,122.25,14.63,1.05.

[0051] Comparative Example 1

[0052]

[0053] A dithienylethylene compound as shown in formula (III), abbreviated as CZPP-DTE. Its synthetic route is as follows: Figure 1 As shown, it includes the following steps:

[0054] Add [4'-(carbazole-9-yl)-4-biphenyl]boric acid (90 mg, 0.25 mmol), DTE-2Br (63 mg, 0.12 mmol), and potassium carbonate (82 mg, 0.6 mmol) to a 50 mL two-necked flask. Add 12 mL of ethylene glycol dimethyl ether and 3 mL of water (the solvent is purged with nitrogen for 10 minutes to remove oxygen) to fully dissolve the starting materials. The mixture is then evacuated and purged with nitrogen three times. Add the phase transfer catalyst tetrabutylammonium hydrogen sulfate (0.02 g) and the catalyst Pd(PPh3)4 (0.02 g). Repeat the purging process three times, evacuating with nitrogen, and then heat to 80 °C for 24 h. Finally, perform column chromatography with petroleum ether to obtain 110 mg of a light blue powder, with a yield of 90%. 1H NMR(600MHz,Chloroform-d)δ8.20(dt,J=7.8,1.0Hz,4H),7.90-7.85(m,4H), 7.79-7.74(m,4H),7.74-7.67(m,8H),7.52(dt,J=8.2,0.9Hz,4H),7.46(ddd, J=8.2,7.0,1.2Hz,5H),7.42(s,2H),7.34(ddd,J=7.9,7.0,1.0Hz,5H),2.06( s,6H),1.33-1.27(m,4H),0.94-0.83(m,4H),0.10(dd,J=4.2,1.4Hz,1H).13C NMR(151MHz,Chloroform-d)δ141.78,141.57,140.81,139.75,139.33,137.18,132.66,128. 30,127.68,127.45,126.15,126.05,126.01,123.48,122.60,120.38,120.07,109.83,14.69.

[0055] Comparative Example 2

[0056] A dithiophene-ethylene compound as shown in formula (iv), abbreviated as TPA-DTE, is synthesized by the following steps:

[0057]

[0058] Under nitrogen protection, anhydrous K₂CO₃, 4-(diphenylamine)phenylboronic acid pinacol ester, Br-DTE-Br, and V were rapidly added to a two-necked flask. 去离子水 :V 乙二醇二甲醚 The mixture was prepared by a 1:4 ratio of hydrogen to phosphorus, evacuated and purged with nitrogen three times, and then palladium catalyst and a small amount of phase transfer catalyst (PTC) were added and stirred until homogeneous to ensure an oxygen-free reaction system. The reaction was then heated at 90°C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, washed with distilled water until neutral, extracted with ethyl acetate, and evaporated to dryness to obtain the crude product. Dichloromethane and petroleum ether were mixed as the developing solvent, and the crude product was purified by silica gel column chromatography to obtain a red solid product. 1 H NMR(600MHz, CD2Cl2)δ(ppm):7.69(d,J=8.5Hz,4H),7.62-7.58(m,9H),7.43-7.40(m,11H),7.27(d,J=8.8Hz,4H),6.87(s,2H),2.25(s,6H).MS(m / z):C 51 H 36 F6N2S2,854.97.

[0059] Comparative Example 3

[0060] A dithienylethylene compound as shown in formula (v) (the synthesis steps of which can be found in patent document CN112409324A), its name is abbreviated as 2(TPA-AC)-DTE:

[0061]

[0062] Results Analysis

[0063] Figure 1 The synthesis steps and photochromic process of the molecular switches obtained by the preparation processes of Example 1 and Comparative Example 1 are demonstrated. Under irradiation with a beam of visible light (<450 nm), the TPAP-DTE molecule undergoes a photoisomerization reaction, changing from an open-ring state to a closed-ring state. Under irradiation with another beam of visible light (>500 nm), it can revert to the initial open-ring state; this process is reversible. In contrast, the CZPP-DTE molecule cannot undergo photocyclization under visible light irradiation; only ultraviolet light can drive the photocyclization reaction. Similarly, under irradiation with another beam of visible light (>500 nm), it can revert to the initial open-ring state.

[0064] Figure 2 The molecular switch TPAP-DTE obtained by the preparation process in Example 1 was prepared in tetrahydrofuran solution (1×10⁻⁶). -5The photochromic properties of TPAP-DTE (M). Content a shows the absorption spectrum of TPAP-DTE under 405 nm visible light irradiation; content b shows the absorption spectrum of TPAP-DTE in the PSS state under 365 nm / 405 nm irradiation; content c shows the absorption spectrum of TPAP-DTE under 625 nm visible light irradiation; and content d compares the molar absorptivity of TPAP-DTE in Example 1 and TPA-DTE in Comparative Example 2 (optical power density 405 nm: 2.00 mW / cm²). 2 365nm: 2.00mW / cm 2 625nm: 10.00mW / cm 2 It can be seen that TPAP-DTE exhibits excellent photochromic reversibility and switching performance under both ultraviolet and visible light. It reaches a photostable state after 40s of irradiation with 405nm visible light. Simultaneously, when irradiated to the PSS state with the same power of 365nm ultraviolet light, the absorbance at 615nm is not significantly different from that under 405nm light, indicating that 405nm light has almost the same effect as 365nm. Experimental results show that TPAP-DTE in THF solution can achieve a photoisomerization ring-closing reaction effect that is essentially equivalent to that under 365nm ultraviolet light at 405nm. Comparing the TPAP-DTE of Example 1 with the phenyl-free molecular TPA-DTE of Comparative Example 2, it was found that the molar absorptivity of TPAP-DTE at 405nm can be increased by four times (the molar absorptivity ε of TPAP-DTE at 405nm is ε). irr405 =5300M -1 cm -1 The molar absorptivity ε of TPA-DTE at 405 nm is... irr405 =1300M -1 cm -1 Furthermore, its molar absorptivity in the ultraviolet region is much higher than that of TPA-DTE, and it has a more sensitive response to both visible and ultraviolet light.

[0065] Figure 3 Contents a and b are the molecular switches CZPP-DTE prepared by the process of Comparative Example 1 in tetrahydrofuran solution (1×10⁻⁶). -5 The photochromic properties of CZPP-DTE were observed. It can be seen that under 405nm visible light irradiation, the response of CZPP-DTE is weak, and it shows virtually no response to visible light.

[0066] Figure 4 The images show the photobleaching resistance test results for Examples 1, 2, and 3. After continuous irradiation with 405nm light for 2 hours (405nm: 20.00mW / cm²), the light was applied... 2In Example 1, the absorption value of TPAP-DTE decreased by only 4%, while that of Comparative Example 2 decreased by 6%. In Comparative Example 3, 2(TPA-AC)-DTE was almost completely photobleached, with an absorption value decrease of 90%. This indicates that under continuous light irradiation, 2(TPA-AC)-DTE will gradually lose its molecular switching performance, while TPAP-DTE has good resistance to photobleaching and excellent stability.

[0067] Figure 5 The photoisomerization conversion rates of the molecular switch obtained by the preparation process in Example 1 of this invention were measured by NMR spectroscopy at 405 nm and 365 nm. The chemical shift of the methyl peak on the thiophene in the DTE of the open-ring state TPAP-DTE-o in deuterated dichloromethane was 2.05 ppm. After the molecule was converted to the closed-ring state, a new single peak appeared at 2.25 ppm. The photoisomerization conversion rate of the closed-ring state was calculated to be as high as 96.5% by integrating the area, indicating a bidirectional, quasi-quantitative, and reversible photochemical conversion.

[0068] Figure 6 This image shows the fatigue resistance test results of the molecular switch obtained by the preparation process in Example 1 of this invention in THF solution and polymethyl methacrylate (PMMA). Content a shows the THF (1×10⁻⁶) solution of TPAP-DTE. -5 The absorption changes of solution M at 615 nm under alternating visible light (405 nm, 10 s) and red light (625 nm, 5 min) irradiation. Content b shows the absorption changes of the PMMA film (2 wt%) of TPAP-DTE at 616 nm under alternating visible light (405 nm, 3 min) and red light (625 nm, 6 min) irradiation. (405 nm: 2.00 mW / cm²) 2 625nm: 20.00mW / cm 2 Under alternating irradiation at 405 nm and 625 nm, TPAP-DTE can undergo both forward and reverse photochromic reactions. After 10 cycles, the absorption of the open-ring and closed-ring states remained essentially unchanged, indicating that TPAP-DTE molecules exhibit good switching fatigue resistance and photochromic bistableness in both tetrahydrofuran and PMMA films.

[0069] Figure 7 This invention presents an experiment demonstrating the erasable and rewritable information storage of a molecular switch prepared using the process described in Example 1 of this invention under full visible light. Information can be written into a QR code using 405nm visible light through different masks, and then erased using a longer wavelength light (620nm). This process is reversible.

[0070] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An all- visible light regulated triphenylamine phenyl conjugated modified dithienylethene derivative, characterized in that, It has a structural unit as shown in formula (I): Formula (I) Wherein, R1, R2 are both -H.

2. The method for preparing the dithienylethylene derivative as described in claim 1, characterized in that, Comprising the following steps: (1) dissolving triphenylamine phenyl monobromine substituted compound R1 / R2-TPA-Ph-Br with R1, R2 groups, bispinacol borate and potassium carbonate in an organic solvent, adding catalyst Pd(dppf)Cl2 under nitrogen protection, to generate compound R1 / R2-TPA-Ph-borate; wherein, TPA represents triphenylamine, Ph represents phenyl, and Borate represents borate; (2) dissolving 1,2-bis(5-bromo-2-methylthiophene-3-yl)perfluorocyclopentane, R1 / R2-TPA-Ph-borate and potassium carbonate in a solvent under nitrogen protection, and in the presence of phase transfer catalyst and catalyst, to make them respectively lose Br and borate groups, to generate a compound with the structural unit shown in formula (I).

3. The production method according to claim 2, wherein The organic solvent in step (1) is a mixture of anhydrous 1,4-dioxane, dimethylformamide, toluene and water or a mixture of ethylene glycol dimethyl ether and water.

4. The production method according to claim 2, wherein The solvent in step (2) is a mixed solution of ethylene glycol dimethyl ether and water, and the mass ratio of ethylene glycol dimethyl ether to water is (3.5-4.5):

1.

5. The production method according to claim 2, wherein The phase transfer catalyst in step (2) is tetrabutylammonium hydrogen sulfate, and the catalyst is Pd(PPh3)4.

6. Use of the triphenylamine phenyl conjugated modified dithienyl ethylene derivative of claim 1 in the preparation of a full visible light regulated molecular switch material, and the molecular switch material triggers its ring closure reaction using a visible light source.

7. Use according to claim 6, wherein The molecular switch material is a photochromic molecular switch material.

8. The use according to claim 6, wherein The wavelength range of the visible light is 390-460 nm.

9. An all- visible light regulated triphenylamine phenyl conjugated modified dithienylethene molecular switch, characterized in that, It contains the triphenylamine phenyl conjugated modified dithienyl ethylene derivative of claim 1.

Images