An alkoxytriphenylamine modified dithienylethene derivative and application thereof

Abstract

This invention belongs to the field of new materials technology, and more specifically, relates to an alkoxytriphenylamine conjugated modified dithienylethylene derivative and its applications. The dithienylethylene derivative has structural units as shown in formula (I): wherein R1O and R2O are each independently a C1-C4 alkoxy group, and Ar is a C6-C4 alkoxy group. 14 The aryl group. The alkoxytriphenylamine-modified dithienylethylene molecular switch designed in this invention has an absorption wavelength red-shifted to the visible light region, so that the ring-closing reaction can be driven by visible light, while the ring-opening reaction itself is driven by long-wavelength visible light. This achieves full visible light control of the dithienylethylene molecular switch and has strong and efficient visible light responsiveness and remarkable photoisomerization conversion rate.

Description

Technical Field

[0001] This invention belongs to the field of new materials technology, and more specifically, relates to an alkoxytriphenylamine-modified dithiophene ethylene derivative and its application. Background Technology

[0002] Molecular photoswitches (photochromic materials) can undergo reversible photochemical reactions, switching between two stable isomers with different properties. Thanks to their reversible photoresponsiveness, molecular photoswitches can be used as gating devices to convert the stimulation of incident light into changes in the macroscopic properties of the material, showing great potential in fields such as optical information storage, optoelectronic devices, and biological applications. Among them, dithienylethylene (DTE) molecular switches have been extensively studied due to their unique dual-state thermal stability, rapid response, excellent fatigue resistance, and excellent switching performance in the solid state. However, the closed-loop reaction of traditional DTE molecular switches usually requires ultraviolet light to drive it. High-energy ultraviolet light irradiation can cause irreversible damage to the material and may generate unwanted byproducts during the photoreaction, affecting the material's performance. At the same time, the low penetration of ultraviolet light limits the application of DTE molecular switches in the biological field. Furthermore, ultraviolet light is relatively expensive and difficult to integrate with conventional optical systems. Compared to ultraviolet light, visible light has lower energy and higher penetration, making it more suitable for practical applications. Therefore, the development of a fully visible light-driven dithiophene-based ethylene molecular switch is of great practical significance.

[0003] Furthermore, it can be noted that in existing studies, the open-ring conversion rate of DTE molecular switches is generally 100%, but the closed-ring conversion rate is difficult to achieve. Even under ultraviolet light irradiation, achieving a closed-ring conversion rate of over 90% for DTE molecular switches is challenging, and reports on DTE molecular switches with fully visible light-driven bidirectional quantitative conversion are extremely rare. In recent decades, with advancements in experimental techniques, the performance control of materials and devices has gradually shifted from the macroscopic level to the nanoscale, and even the single-molecule level, leading to a growing demand for molecular switches capable of bidirectional quantitative conversion. If a DTE molecular switch cannot achieve complete ring closure, it means that even when DTE reaches a photostable state, an open-ring isomer still exists in the switch system, preventing the system from accurately being in a single state and increasing uncertainty and uncontrollability in applications. For example, in biological applications, if the molecular switch cannot undergo complete bidirectional photoisomerization in cells, it may be unable to efficiently and precisely regulate biological activity; effective optical control of any biological function requires only one isomer to exist in the PSS. When the application of molecular switches extends down to the scale of single molecules and small molecular clusters, the ability to perform bidirectional quantitative conversion is a necessary condition for the accurate control of their physical properties.

[0004] To meet practical application needs, there is an urgent need to develop DTE molecular switches that achieve bidirectional quantitative conversion under fully visible light driving. Currently, strategies for achieving fully visible light driving of DTE molecular switches mainly include: extending π-conjugation, triplet-triplet energy transfer, upconversion nanoparticles, multiphoton absorption, and intramolecular proton transfer. For example, in TTET, Zhang et al. achieved fully visible light-controlled photochromism by introducing a sensitizer with a narrow singlet-triplet bandgap into DTE. In UCNP, Neil R. Branda et al. combined lanthanide-doped upconversion nanoparticles with DTE, enabling remote control of its switching using near-infrared light of different power densities. In multiphoton absorption, Masahiro Irie and Hiroshi Miyasaka et al. employed a non-resonant high-order multiphoton absorption process, using near-infrared femtosecond laser pulses of different intensities to control the photochromic process of DTE. In IPT, Zhu et al. incorporated IPT functional groups into DTE units, achieving a closed-loop process of DTE driven by 450 nm visible light. However, these strategies all have their limitations and shortcomings. For example, triplet-triplet energy transfer systems are easily affected by oxygen in the environment; upconversion nanoparticles and multiphoton absorption methods require more complex instruments or structures; and intramolecular proton transfer systems depend on solvent polarity, making them difficult to apply in practice. In contrast, extending the π-conjugation of molecules is the simplest and most feasible method with fewer restrictions. By designing molecules to extend the π-conjugation length of DTE, the HOMO-LUMO band gap of the open-ring isomer can be reduced, causing its absorption wavelength to redshift into the visible light region, thus improving its response to visible light. Moreover, the target molecule can be obtained through simple chemical synthesis. However, since the contribution of the excited singlet state of the hexadelith moiety in the center of DTE decreases with the extension of π-conjugation, the photoreactivity of DTE is significantly suppressed, and it may even lose its photochromic ability.

[0005] CN117050049A developed a series of dithienylethylene molecular switches, but they still fall short of complete isomerization conversion. The equilibrium constant Kpss (Kpss = [open form] / [closed form]) for photocyclization and its reverse reaction under 405 nm light irradiation is relatively small, only around 26, failing to achieve bidirectional quantitative conversion under fully visible light driven conditions. Furthermore, they suffer from low molar absorptivity and poor photosensitivity. To address these issues, this invention designs and develops new molecules to obtain visible light-controlled molecular switches with higher photoisomerization conversion rates and even more superior bidirectional quantitative conversion and photochromic properties. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an alkoxytriphenylamine conjugated modified dithienylethylene derivative and its application, thereby solving the technical problems of existing DTE molecular switches, such as the need for ultraviolet light response, small reaction equilibrium constant, incomplete ring-closure conversion, and low molar absorptivity.

[0007] To achieve the above objectives, the present invention provides an alkoxytriphenylamine conjugated modified dithienylethylene derivative having structural units as shown in formula (I) or formula (II):

[0008]

[0009]

[0010] Among them, R1O and R2O are each independently C1-C4 alkoxy groups, and Ar is C6-C4. 14 Aryl groups.

[0011] Preferably, the dithienylethylene derivative has structural units as shown in formula (I), wherein R1O and R2O are each independently C1-C2 alkoxy groups, and Ar is a C6-C8 aryl group.

[0012] Preferably, the dithienylethylene derivative has structural units as shown in formula (ii), wherein R1O and R2O are each independently C1-C2 alkoxy groups.

[0013] According to another aspect of the invention, the use of the alkoxytriphenylamine conjugated modified dithienylethylene derivative is provided in its application as a molecular switch material for full visible light modulation or in the preparation of such materials.

[0014] Preferably, the molecular switch material is a photochromic molecular switch material.

[0015] Preferably, the visible light wavelength range for driving the molecular switch material to undergo a closed-loop reaction is 400–440 nm.

[0016] According to another aspect of the invention, a fully visible light-tunable alkoxytriphenylamine conjugated modified dithienylethylene molecular switch is provided, comprising the alkoxytriphenylamine conjugated modified dithienylethylene derivative.

[0017] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages:

[0018] (1) The present invention designs an alkoxytriphenylamine-modified dithienylethylene molecular switch, which enables the closed-ring reaction to be driven by visible light, while the open-ring reaction itself is regulated in the visible light region, realizing the full visible light regulation of the dithienylethylene molecular switch photoisomerization reaction, and has both high visible light responsiveness and photoisomerization conversion rate.

[0019] (2) The preferred trigger wavelength range for the molecular opening and closing reaction of the present invention is 400nm-420nm. This band of visible light replaces ultraviolet light and can be used in practical applications such as optical information storage. This avoids the use of ultraviolet light, improves the fatigue resistance and photobleaching properties of the sample, and avoids radiation damage to the observed sample and the operator.

[0020] (3) The 2MeO-TPA-Ph-DTE shown in Formula (III) provided in the preferred embodiment of the present invention is a symmetrical dimethoxytriphenylamine phenyl-modified dithiophene ethylene molecular switch. It reaches a photostable state in 60s under 405nm illumination. It exhibits excellent photochromic reversibility, fatigue resistance, and anti-photobleaching properties. Its absorption does not change significantly after ten alternating irradiations with 405nm and 620nm visible light. After 100 cycles, the absorption loss is only 1.16%. After 2 hours of irradiation with strong 405nm visible light, the absorption loss is only 3.13%. After a 1600-hour bistable aging test (85°C, 85% relative humidity), it still retains photochromic capabilities, demonstrating excellent bistable performance and anti-aging ability.

[0021] (4) In the preferred embodiment of the present invention, MeO-TPA-Ph-DTE achieves a closed-loop conversion rate of 100% under 405nm visible light, and the photoreaction equilibrium constant Kpss tends to positive infinity. Compared with the previous visible light-controlled fluorescent molecule opening and closing-loop conversion rate, it not only represents a quantitative improvement but also a qualitative leap. Furthermore, it can be used as an information storage medium for erasable and rewritable recording, anti-counterfeiting, and encryption of information.

[0022] (5) The preferred embodiment of the present invention, 2MeO-TPA-Ph-DTE, exhibits excellent photoresponse capability under 405nm visible light, and has a higher molar absorptivity (ε) compared to existing dithienylethylene fluorescent molecular switches. 405 =21900M -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. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the detailed synthetic route for the molecular switch prepared in Example 1 of the present invention.

[0024] Figure 2 The graph shows the absorption spectrum of the molecular switch prepared in Example 1 of this invention in tetrahydrofuran as a function of irradiation time with 405nm / 365nm / 625nm light.

[0025] Figure 3 The photoisomerization conversion rate of the molecular switch prepared in Example 1 of this invention was measured by high performance liquid chromatography under 405nm LED light and laser irradiation.

[0026] Figure 4 The photoisomerization conversion rate of the molecular switch prepared in Example 1 of this invention was measured by 1H NMR spectroscopy under 405nm LED light and laser irradiation.

[0027] Figure 5 The photoisomerization conversion rate of the molecular switch prepared in Example 2 of this invention was measured by hydrogen nuclear magnetic resonance spectroscopy under 405nm LED irradiation.

[0028] Figure 6 The graphs show the fatigue resistance and photobleaching resistance of the molecular switch prepared in Example 1 of this invention in tetrahydrofuran (THF) solution, and its anti-aging performance in polymethyl methacrylate (PMMA).

[0029] Figure 7 This is a schematic diagram of the experiment on the erasable and rewritable information recording of the molecular switch prepared in Example 1 of the present invention under full visible light control. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0031] The embodiments of the present invention are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and processes are given. However, the protection scope of the present invention is not limited to the following embodiments. The process parameters in the following embodiments that do not specify specific conditions are generally in accordance with conventional conditions.

[0032] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0033] In this invention, unless otherwise specified and / or stated, all values ​​relating to component amounts are in parts by weight throughout. Process parameters in the following examples that do not specify particular conditions are generally performed under conventional conditions.

[0034] The present invention provides an alkoxytriphenylamine conjugated modified dithienylethylene derivative having structural units as shown in formula (I) or formula (II):

[0035]

[0036] R1O and R2O are each an independent C1-C4 alkoxy group, and Ar is a C6-C4 alkoxy group. 14 The aryl group; in a preferred embodiment, R1O and R2O are each independently C1-C2 alkoxy groups, and Ar is a C6-C8 aryl group.

[0037] In a preferred embodiment, R1O and R2O are both methoxy MeO, and Ar is phenyl, as shown in formula (iii), abbreviated as 2MeO-TPA-Ph-DTE; DTE represents perfluorocyclopentadithiophene ethylene.

[0038]

[0039] In some embodiments, the method for preparing the dithiophene ethylene derivative according to formula (I) of the present invention includes the following steps:

[0040] (1) A triphenylamine aryl brominated compound R1 / R2-TPA-Br with the R1O and R2O groups, aryl diboronic acid B(OH)2-Ar-B(OH)2 (e.g., terephthalic acid), and potassium carbonate are dissolved in an organic solvent. Under nitrogen protection, a catalyst Pd(PPh3)4 is added to generate compound R1O / R2O-TPA-Ar-B(OH)2; wherein TPA represents triphenylamine and Ar represents C6-C 14 The aryl group, B(OH)2 represents the boric acid group;

[0041] (2) Dissolve 1,2-bis(5-bromo-2-methylthiophene-3-yl)perfluorocyclopentene, R1O / R2O-TPA-Ar-B(OH)2 and potassium carbonate in a solvent, and under nitrogen protection, in the presence of a phase transfer catalyst and a catalyst, remove Br and boric acid groups respectively to generate a compound with the structural unit shown in formula (I).

[0042] In other embodiments, the method for preparing the dithiophene ethylene derivative according to formula (II) of the present invention includes the following steps:

[0043] 1,2-bis(5-bromo-2-methylthiophene-3-yl)perfluorocyclopentene, the triphenylamine borate compound R1O / R2O-TPA-B(OH)2 containing the R1O and R2O groups, and potassium carbonate were dissolved in an organic solvent. Under nitrogen protection and in the presence of a phase transfer catalyst and a catalyst, the Br and borate groups were removed, respectively, to generate a compound with the structural unit shown in formula (II). Here, TPA represents triphenylamine, and B(OH)2 represents a borate group.

[0044] In some embodiments, the organic solvent in step (1) is one or more of anhydrous 1,4-dioxane, dimethylformamide, a mixture of toluene and water, and 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 bisulfate, and the catalyst is Pd(PPh3)4.

[0045] The alkoxytriphenylamine aryl conjugated dithiophene ethylene derivative described in 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 driven by a visible light source. In a preferred embodiment, the molecular switch material is a photochromic molecular switch material. Preferably, the ring-closing reaction of the molecular switch of this invention can be driven in the visible light wavelength range of 400–440 nm, and more preferably, 100% isomerization conversion can be achieved in the visible light wavelength range of 400–420 nm.

[0046] This invention also provides a fully visible-light-tunable alkoxytriphenylamine conjugated modified dithienylethylene molecular switch, comprising the aforementioned dimethoxytriphenylamine conjugated modified dithienylethylene derivative. The dimethoxytriphenylamine-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 erasable and rewritable information recording, data encryption, and anti-counterfeiting. This invention designs a symmetrical dimethoxytriphenylamine-dithienylethylene molecular switch by extending the molecular π-conjugation strategy to conjugate triphenylamine and dithienylethylene. This molecular switch not only possesses excellent photochromic and switching performance but also achieves photoisomerization behavior under full visible light.

[0047] The key to maintaining photochromic efficiency and photo-switching capability lies in balancing the adverse effects of conjugation extension through molecular structure adjustment, photophysical property optimization, and excited-state energy regulation. Extending π-conjugation is the simplest and most direct strategy; however, extending π-conjugation usually reduces photochromic efficiency or even eliminates photo-switching capability. Unlike existing technologies, this invention introduces dimethoxytriphenylamine, causing a small redshift of the molecule's absorption wavelength into the visible light region without excessive extension. This results in a molecular switch with good photochromic performance, demonstrating that the invention selects an appropriate conjugation extension structure while maintaining favorable photophysical properties. Furthermore, the triphenylamine group is a good electron donor with excellent charge transfer capabilities, promoting physical processes such as charge transfer and photoelectric conversion. The methoxy group attached to it also exhibits an electron-donating effect, giving the modified group a strong electron-donating effect. Its introduction may effectively regulate the excited-state energy of the molecule, ensuring sufficient energy for photochromic or photo-switching reactions during photoexcitation. In particular, by introducing dimethoxytriphenylamine phenyl, the closed-ring conversion rate reaches 100% under 405nm visible light, and the photoreaction equilibrium constant Kpss tends to positive infinity, realizing bidirectional complete quantitative conversion under full visible light drive, and the molar absorptivity is significantly improved compared with existing molecular switches.

[0048] The following is an example:

[0049] Example 1

[0050] A dithiophene-ethylene molecular switch as shown in formula (I), wherein R1O and R2O are both methoxy MeO, and Ar is phenyl, with the corresponding structural formula shown in formula (III), abbreviated as 2MeO-TPA-Ph-DTE, and its synthetic route is as follows. Figure 1 As shown, it includes the following steps:

[0051] (1) Reference for the synthesis process of DTE-2Br (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).

[0052] (2) Synthesis of 2MeO-TPA-Ph-B(OH)2: Under a nitrogen atmosphere, 4-bromo-4',4”-dimethoxytriphenylamine (4.00 g, 10.40 mmol), 1,4-phenylenediboronic acid (8.64 g, 52.13 mmol), and potassium carbonate (3.60 g, 26.05 mmol) were added to a 500 mL two-necked flask. Then, 200 mL of ethylene glycol dimethyl ether and 50 mL of deionized water were added (the solvent was purged with nitrogen for 15 minutes beforehand to remove oxygen) to fully dissolve the reactants. The flask was then evacuated and purged with nitrogen. Nitrogen gas was circulated three times. Then, the catalyst Pd(PPh3)4 (0.60 g, 0.52 mmol) was added. The reaction was circulated three more times, then evacuated under nitrogen gas, and heated to 80 °C for 2 h. After the reaction was complete, the reaction solution was cooled and extracted with dichloromethane. The organic phase solution was washed successively with 1 vol.% hydrochloric acid solution, saturated brine, and deionized water, and dried overnight with anhydrous sodium sulfate. The crude product was separated by column chromatography using dichloromethane:methanol = 50:1 as the eluent, yielding 672 mg of a light yellow-green powder, with a yield of 15%. 1 H NMR(600MHz,DMSO-d6)δ8.01(s,2H),7.82(d,J=7.1Hz,2H),7.54(dd,J=18.0,7.5Hz,4H), 7.06(d,J=7.6Hz,4H), 6.93(d,J=7.8Hz,4H), 6.83(d,J=7.6Hz,2H), 3.75(d,J=1.5Hz,6H). 13 C NMR (151MHz, DMSO-d6) δ156.32,148.52,141.70,140.44,135.21,131.90,127.77,127.28,125.26,119.88,115.48,55.73.

[0053] (3) Synthesis of 2MeO-TPA-Ph-DTE: Under a nitrogen atmosphere, 2MeO-TPA-Ph-B(OH)2 (272 mg, 0.60 mmol), DTE-2Br (106 mg, 0.20 mmol), and potassium carbonate (277 mg, 2.00 mmol) were added to a 50 mL two-necked flask. Then, 20 mL of ethylene glycol dimethyl ether and 5 mL of deionized water were added (the solvent was purged with nitrogen for 15 minutes beforehand to remove oxygen) to fully dissolve the reactants. The mixture was then evacuated and purged with nitrogen three times. Next, the catalyst Pd(PPh3)4 (35 mg, 0.30 mmol) was added. The mixture was purged with nitrogen three more times and heated to 80 °C for 12 h. After the reaction was complete, the reaction solution was cooled and extracted with dichloromethane. The organic phase solution was washed once each with 1 vol.% hydrochloric acid solution, saturated brine, and deionized water, and dried overnight with anhydrous sodium sulfate. The crude product was separated by column chromatography using dichloromethane:petroleum ether = 1:1 as the eluent to obtain 113 mg of dark green powder, with a yield of 50%. 1 H NMR (600MHz, DMSO-d6) δ7.66 (s, 8H), 7.58-7.49 (m, 6H), 7.06 (d, J = 8.4Hz, 8H), 6.93 ( d,J=8.3Hz,8H),6.83(d,J=8.3Hz,4H),3.75(s,12H),2.01(s,6H).HR-MS:calculated for C 67 H 53 F6N2O4S2 + [M+1] + :1127.33, found:1127.33. HPLC purity:99.18%.

[0054] Example 2

[0055]

[0056] A dithiophene-ethylene compound, as shown in formula (iv), is abbreviated as 2MeO-TPA-DTE. Its synthetic route is as follows: Figure 1 As shown, it includes the following steps:

[0057] Under a nitrogen atmosphere, [4-[bis(4-methoxyphenyl)amino]phenyl]boronic acid (154 mg, 0.44 mmol), DTE-2Br (106 mg, 0.20 mmol), and potassium carbonate (277 mg, 2.00 mmol) were added to a 50 mL two-necked flask. Then, 20 mL of ethylene glycol dimethyl ether and 5 mL of deionized water were added (the solvent was pre-purged with nitrogen for 15 minutes to remove oxygen) to fully dissolve the reactants. The mixture was evacuated and purged with nitrogen three times. Next, the catalyst Pd(PPh3)4 (12 mg, 0.01 mmol) was added. The mixture was purged with nitrogen three more times and heated to 80 °C for 12 h. After the reaction was complete, the reaction solution was cooled and extracted with dichloromethane. The organic phase was washed successively with 1 vol.% hydrochloric acid solution, saturated brine, and deionized water, and dried overnight with anhydrous sodium sulfate. The crude product was separated by column chromatography using dichloromethane:petroleum ether = 1:3 as the eluent to obtain 115 mg of dark green powder, with a yield of 59%. 1 H NMR(600MHz,DMSO-d6)δ7.42(d,J=7.9Hz,4H),7.27(s,2H),7.04(d,J=7.8Hz, 8H), 6.93 (d, J=7.8Hz, 8H), 6.76 (d, J=7.9Hz, 4H), 3.75 (s, 12H), 1.93 (s, 6H). 13 C NMR(151MHz,DMSO-d6)δ156.46,148.84,142.51,140.13,140.10,127.37,126.69,125.42,124.55,121.00,119.69,115.50,55.73,14.47.HR-MS: calculated for C 55 H 45 F6N2O4S2 + [M+1] + :975.26,found : 975.27. HPLC purity: 96%.

[0058] Results Analysis

[0059] Figure 1The synthesis steps and photochromic process of the molecular switches obtained by the preparation processes in Examples 1 and 2 are demonstrated. Under irradiation with a beam of visible light (<450nm), the 2MeO-TPA-Ph-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 (>500nm), it can revert to the initial open-ring state. This process is reversible, and its closed-ring conversion rate is 100%, enabling bidirectional quantitative conversion under full visible light control. In contrast, the closed-ring conversion rate of 2MeO-TPA-DTE under visible light drive is 97%, failing to achieve 100% bidirectional quantitative conversion under full visible light.

[0060] Figure 2 The molecular switch 2MeO-TPA-Ph-DTE obtained by the preparation process in Example 1 was prepared in tetrahydrofuran solution (3×10⁻⁶). -6 The photochromic properties of M). Content a shows the absorption spectrum of 2MeO-TPA-Ph-DTE under 405nm visible light irradiation; content b shows the absorption spectrum of 2MeO-TPA-Ph-DTE under 625nm visible light irradiation; content c compares the absorption spectra of 2MeO-TPA-Ph-DTE in the PSS state under 365nm / 405nm irradiation; content d compares the absorbance of 2MeO-TPA-Ph-DTE from Example 1 and Example 2 at 405nm (optical power density 405nm: 2.00mW / cm²). 2 365nm: 2.00mW / cm 2 625nm: 10.00mW / cm 2 It can be seen that 2MeO-TPA-Ph-DTE exhibits excellent photochromic reversibility and switching performance under both ultraviolet and visible light. It reaches a photostable state after 60 seconds of irradiation with 405nm visible light. Simultaneously, when irradiated to the PSS state with the same power of 365nm ultraviolet light, the absorbance at 620nm is not significantly different from that under 405nm light, indicating that 405nm light has almost the same effect as 365nm. Experimental results show that 2MeO-TPA-Ph-DTE in THF solution can achieve a photoisomerization ring-closure reaction effect that is essentially equivalent to that under 365nm ultraviolet light at 405nm.

[0061] Comparing the 2MeO-TPA-Ph-DTE of Example 1 with the phenyl-free 2MeO-TPA-DTE of Example 2, it was found that the molar absorptivity of 2MeO-TPA-Ph-DTE at 405 nm could be increased by approximately 3 times (the molar absorptivity ε of 2MeO-TPA-Ph-DTE at 405 nm is...). 405 =21900M -1 cm -1The molar absorptivity ε of 2MeO-TPA-DTE at 405 nm is... 405 =7566M -1 cm -1 Furthermore, its molar absorptivity in the ultraviolet region is much higher than that of 2MeO-TPA-DTE, and it has a more sensitive response to both visible and ultraviolet light.

[0062] Figure 3 and Figure 4The photoisomerization conversion rates of the molecular switch prepared by the process in Example 1 of this invention, measured by high-performance liquid chromatography (HPLC) and hydrogen nuclear magnetic resonance (NMR) spectroscopy under 405 nm irradiation, show that the closed-loop conversion rate of 2MeO-TPA-Ph-DTE reached 100%, and Kpss approached positive infinity, achieving bidirectional quantitative conversion driven by fully visible light. First, HPLC was used to test the 2MeO-TPA-Ph-DTE before and after 405 nm irradiation. The mobile phase was a binary solvent of cyclohexane and dichloromethane with a volume ratio of 0.7:0.3. It was found that 2MeO-TPA-Ph-DTE-o stabilized at around 10.2 min, while 2MeO-TPA-Ph-DTE-c eluted at around 8.6 min. After 2MeO-TPA-Ph-DTE-o reached a photosteady state under 405 nm irradiation, 2MeO-TPA-Ph-DTE-pss only showed a peak at 8.6 min, with no residual open-ring state observed. This indicates that after reaching a photosteady state under 405 nm irradiation, 2MeO-TPA-Ph-DTE-o is quantitatively converted to 2MeO-TPA-Ph-DTE-oc. To further verify this conclusion, 1H NMR spectroscopy was used to reinforce the analysis. The chemical shifts of the methyl group on the thiophene ring in 2MeO-TPA-Ph-DTE-o and 2MeO-TPA-Ph-DTE-c in DMSO-d6 are 2.01 ppm and 2.12 ppm, respectively. By comparing the integral areas of 2MeO-TPA-Ph-DTE-o and 2MeO-TPA-Ph-DTE-pss, the ring-closure conversion rate of 2MeO-TPA-Ph-DTE under 405 nm visible light irradiation can be calculated to be 100%. Furthermore, the chemical shifts of the two isomers in the low-field region are significantly different. The open-ring state has a singlet peak at 7.66 ppm, a multiplet peak at 7.58-7.49 ppm, and three doublets in the range of 7.10-6.80 ppm. After 405 nm irradiation, 2MeO-TPA-Ph-DTE-pss has a multiplet peak at 7.81-7.68 ppm, a doublet peak at 7.61 ppm, and a singlet peak at 7.04 ppm in the range of 7.12-6.78 ppm, which is attributed to hydrogen on the two thiophene rings. It can be seen that the peak type and chemical shift of 2MeO-TPA-Ph-DTE-pss are significantly different from those of the open-ring state, and the peaks of the open-ring isomer are basically not visible. It can be basically considered that 2MeO-TPA-Ph-DTE is quantitatively converted under 405 nm visible light irradiation, which is consistent with the HPLC determination results. 2MeO-TPA-Ph-DTE is a reliable molecular switch material that can achieve bidirectional quantitative conversion under full visible light driving.

[0063] Figure 5The photoisomerization conversion rate of the molecular switch obtained by the preparation process in Example 2 of this invention was measured by 1H NMR spectroscopy under 405nm irradiation. The chemical shifts of the methyl group on the thiophene ring in 2MeO-TPA-DTE-o and 2MeO-TPA-DTE-c in DMSO-d6 were 1.93ppm and 2.01ppm, respectively. By comparing the integral areas of 2MeO-TPA-DTE-o and 2MeO-TPA-DTE-pss, the ring-closure conversion rate of 2MeO-TPA-DTE under 405nm visible light irradiation can be calculated to be 97%, and Kpss is approximately 32.

[0064] Figure 6 These are test graphs showing the fatigue resistance, photobleaching resistance, and anti-aging performance of the molecular switch obtained by the preparation process in Example 1 of this invention. Content a shows the THF (3×10⁻⁶) of 2MeO-TPA-Ph-DTE. -6 The absorption changes of solution M at 620 nm under alternating irradiation with visible light (405 nm, 1 min) and red light (625 nm, 4 min). Content b is the THF (3 × 10⁻⁶) of 2MeO-TPA-Ph-DTE. -6 The absorption changes of solution M at 620 nm under continuous irradiation with visible light (405 nm) and ultraviolet light (365 nm), respectively. (405 nm: 23.00 mW / cm²) 2 365nm: 10.00mW / cm 2 Content c presents the anti-aging performance (85℃ and 85% relative humidity) test of a 2 wt.% PMMA film of 2MeO-TPA-Ph-DTE, including photographs of the open-ring and PSS states (irradiated at 405 nm) before and after 1600 h of aging. During the aging test, the absorbance changes of the open-ring and PSS states at 620 nm were monitored, and photo-switching cycles were performed after the aging test. Under alternating irradiation at 405 nm and 625 nm, 2MeO-TPA-Ph-DTE exhibited both forward and reverse photochromic reactions. After 10 cycles, the absorption of the open-ring and closed-ring states remained essentially unchanged. Under 2 hours of 365 nm UV irradiation, the absorbance of 2MeO-TPA-Ph-DTE-pss at 620 nm decreased by 13.3%, indicating significant damage to the molecular switch. However, under 405nm visible light irradiation, the photochromic activity decreased by only 3.13% after 2 hours, indicating a significant improvement in the photobleaching resistance of 2MeO-TPA-Ph-DTE. After 1600 hours of aging testing, no significant changes were observed in the properties of the 2MeO-TPA-Ph-DTE molecule, which still exhibits good photochromic reversibility. This demonstrates that the 2MeO-TPA-Ph-DTE molecular switch possesses good switching fatigue resistance, photobleaching resistance, and bistable nature.

[0065] Filter paper was immersed in a 2MeO-TPA-Ph-DTE / PMMA (2wt.%) solution to ensure uniform saturation, and then dried. Different photomasks were then applied to the filter paper, and information was written using 405nm light and erased using 625nm light, enabling a writing-erasing cycle for different types of information. Figure 7 This is a schematic diagram of an experiment on the erasable and rewritable information recording of the molecular switch obtained by the preparation process in Example 1 of this invention under full visible light control. Various flower patterns can be written using 405nm visible light through different masks, and the information can be erased using another long wavelength light (625nm). This process is reversible.

[0066] 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 alkoxytriphenylamine conjugated modified dithienylethylene derivative, characterized in that, It has structural units as shown in Equation (I): Formula (1) In formula (a), R1O and R2O are each independently C1-C2 alkoxy groups, and Ar is a C6-C8 aryl group.

2. The application of the alkoxytriphenylamine conjugated modified dithienylethylene derivative as described in claim 1 in its use or preparation of molecular switch materials for full visible light modulation.

3. The application as described in claim 2, characterized in that, The molecular switch material is a photochromic molecular switch material.

4. The application as described in claim 3, characterized in that, The visible light wavelength range for driving the molecular switch material to undergo a closed-loop reaction is 400–440 nm.

5. A fully visible-light-tunable alkoxytriphenylamine conjugated dithiophene ethylene molecular switch, characterized in that, It comprises a dithiophene ethylene derivative conjugated with alkoxytriphenylamine as described in claim 1.

Images