Thiophene site specific modified TAE material as well as preparation method and application thereof

Abstract

The invention discloses a thiophene site specific modified TAE material as well as a preparation method and application thereof, and relates to the technical field of organic optical functional materials. A main body structure of the TAE material specifically modified by thiophene sites is tetraarylethene, thiophene substitution exists on the tetraarylethene, and R groups are introduced to the tail end of thiophene, or the TAE material specifically modified by the thiophene sites is obtained. The invention also provides an application of the TAE material or the photochemical sensor specifically modified by the thiophene site in photochromism or mechanochromism or cell imaging or safe ink or anti-counterfeiting. According to the invention, through conjugate coupling of a thiophene ring and an ethylene bridged benzene ring, a diarylethene functional unit with light-induced isomerization capability is formed, and the aggregation-induced emission (AIE) performance of the material is remarkably improved while the light response activity is realized. The synergistic effect endows the material with revolutionary potential in the fields of light-operated bimodal patterning technology and multi-dimensional anti-counterfeiting application.

Description

Technical Field

[0001] The present invention relates to the technical field of organic photofunctional materials, and in particular to a thiophene site-specifically modified TAE material, a preparation method thereof, and an application thereof. Background Art

[0002] As an important branch of the field of photoresponsive functional materials, organic photofunctional materials have shown significant application potential in the development of multifunctional molecular machines and smart materials. However, traditional photochromic systems generally face the inherent defect of fluorescence quenching (Aggregation-Induced Quenching, ACQ) in the solid state or aggregated state, which seriously restricts their practical application. To address this key scientific issue, the aggregation-induced emission (AIE) theory proposed by Academician Tang Benzhong's team provides a revolutionary solution to break through the performance bottleneck of traditional photochromic materials. By constructing a non-planar conjugated skeleton and a restriction of intramolecular motion (RIM) mechanism, this theory successfully overcomes the ACQ effect, allowing the material to maintain efficient fluorescence emission in the solid state or in a high-concentration aggregate state, showing broad application prospects in chemical sensors, information storage, bioimaging, and food safety testing.

[0003] Tetraarylethenes (TAE) derivatives exhibit remarkable aggregation-induced emission (AIE) properties due to their unique molecular configurations. Their core structural feature stems from the free rotation of the aryl substituents. This dynamic intramolecular motion restriction allows them to dissipate excited-state energy through nonradiative decay channels in solution. In the solid or aggregated state, however, restricted intermolecular interactions trigger radiative transitions, resulting in efficient fluorescence emission. This unique property has earned them a prominent position among AIEgens. Even more strikingly, structural modification of TAE derivatives through molecular engineering approaches has enabled the synergistic integration of multiple photoresponsive properties. For example, the introduction of heterocyclic aromatic groups such as thiophene and pyrrole at the divinyl bridging sites not only enhances the intramolecular charge transfer (ICT) effect but also imparts reversible photochromic properties. Therefore, exploring the structure-activity relationship of these compounds through clever chemical structure manipulation not only facilitates the development of novel TAE molecules but also allows for precise control of their photoresponsive behavior to meet specific application requirements. Summary of the Invention

[0004] The present invention aims to address at least one of the technical problems existing in the prior art by providing a thiophene-site-specifically modified TAE material, its preparation method, and its application. Specifically, the present invention discloses an innovative strategy for constructing monothiophene-functionalized tetraarylethenes based on thiophene substitution site engineering. By precisely controlling the spatial configuration of the ethylene bridging unit and the thiophene ring, as well as the terminal groups, this strategy achieves synergistic regulation of the molecular photoresponsiveness and aggregation-induced emission (AIE) properties. The core innovation of this technical solution lies in the establishment of a three-dimensional "substitution site-end group effect-optical property" control model, which provides new insights for the development of multi-stimulus-responsive materials with both photochromic and AIE functions.

[0005] The technical solutions of the present invention are as follows: The first aspect of the present invention provides a thiophene site-specifically modified TAE material, the main structure of which is a tetraarylethylene, wherein a thiophene substitution exists on the tetraarylethylene, and an R group is introduced at the end of the thiophene. or .

[0006] This invention restructures the tetraphenylethylene backbone using thiophene motifs to construct a tetraarylethene derivative system (TAE-3-CHO / BT) with a monothiophene substitution configuration. This compound, through conjugated coupling of the thiophene ring with the ethylene-bridged benzene ring, forms a diarylethene functional unit capable of photoisomerization. While achieving photoresponsive activity, it also significantly enhances the aggregation-induced emission (AIE) performance of the material. This synergistic effect endows the material with revolutionary potential for applications in light-controlled dual-modal patterning and multidimensional anti-counterfeiting. Furthermore, the invention further achieves targeted optimization of the compound's photophysical properties and photochemical behavior by precisely manipulating the steric and electronic effects of the thiophene substituents by varying the substitution position of the thiophene ring. The essence of this structure-activity relationship can be attributed to the synergistic mechanism of intramolecular photocyclization reactivity and steric hindrance.

[0007] Preferably, the thiophene site-specifically modified TAE material has any of the following structural formulas: ; in, or .

[0008] The second aspect of the present invention provides a method for preparing the thiophene site-specifically modified TAE material, comprising the following steps: (1) Under a protective atmosphere, 2-bromo-1,1,2-triphenylethylene, an aldehyde-containing thiophene boronic acid compound, a palladium catalyst, a basic compound, and a first solvent are mixed to perform a Suzuki coupling reaction to prepare aldehyde intermediates with different substitution positions on the corresponding thiophene ring; (2) Under reflux stirring conditions, the aldehyde intermediate prepared in step (1) is mixed with 2-aminothiophenol, sodium metabisulfite and a second solvent for condensation reaction to obtain a thiophene site-specifically modified TAE material.

[0009] Preferably, in step (1), the thiophene boronic acid compound comprises one or more of 2-formylthiophene-3-boric acid, 2-formylthiophene-4-boric acid, and 5-formyl-2-thiophene boronic acid; The palladium catalyst comprises one or more of Pd(PPh3)4, Pd(dppf)Cl2, PdCl2(dppf)2 and Pd(OAc)2; The alkaline compound includes Na2CO3, Ba(OH)2, K3PO4, Cs2CO3, K2CO3, TiOH, KF, CsF, Bu4F, NaOH and i -One or more of PrNEt2; The first solvent comprises one or more of tetrahydrofuran, acetone, toluene, dichloromethane, N,N-dimethylformamide and acetonitrile.

[0010] Preferably, in step (1), the molar ratio of 2-bromo-1,1,2-triphenylethylene to the aldehyde-containing thiophene boronic acid compound is 1:1.1-2; The molar concentration of the palladium catalyst in the reaction solution is 8-13%; The ratio of the 2-bromo-1,1,2-triphenylethylene to the first solvent is 2 mmol to 0.1 mol: 80 to 250 mL; The alkaline compound is added in the form of a solid, and the molar ratio of the 2-bromo-1,1,2-triphenylethylene to the alkaline compound is 1:1.0-7.

[0011] Preferably, the temperature of the Suzuki coupling reaction in step (1) is 78-90° C., the time is 6-10 h, and the protective atmosphere is nitrogen atmosphere.

[0012] Preferably, in step (2), the molar ratio of the aldehyde intermediate to 2-aminothiophenol is 1:1-1.3; the amount ratio of 2-aminothiophenol to the second solvent is 2-4 mmol:4-10 mL; and the amount ratio of 2-aminothiophenol to the second solvent is 2.2-2.6 mmol:8-12 mL.

[0013] Preferably, the condensation reaction temperature in step (2) is 110-120°C and the reaction time is 2-6 hours; The second solvent is one or more of DMSO and N,N-dimethylformamide solution.

[0014] The third aspect of the present invention provides a photochemical sensor comprising the thiophene site-specifically modified TAE material.

[0015] The fourth aspect of the present invention provides the use of the thiophene site-specifically modified TAE material or the photochemical sensor in photochromism, mechanochromism, cell imaging, security ink, or anti-counterfeiting.

[0016] This study synthesized the target products, TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT, through precise molecular design, achieving synergistic optimization of photochromic and aggregation-induced emission (AIE) properties. These compounds demonstrate groundbreaking potential in optical security, bioimaging, and smart materials. Their technical features and innovative value are as follows: TAE-3 / 4-CHO and TAE-3 / 4-BT effectively suppress solution-state fluorescence emission. Upon excitation with ultraviolet (365 nm) light, they undergo a cycloaddition reaction that reversibly photochromizes, enabling optical security applications in materials devoid of fluorescence background. The introduction of a benzothiazole (BT) group significantly enhances intermolecular interactions, resulting in strong emission from TAE-3 / 4 / 5-BT in the solid or aggregated state, enabling staining of biological cells and potential use as a cell marker. Notably, the TAE-5-BT compound exhibits remarkable mechanochromic properties due to its twisted molecular configuration and compact crystal packing. This discovery has important applications in information security, storage devices, and mechanical sensors.

[0017] The present invention has at least one of the following beneficial effects: 1. Multifunctional integration: It realizes the effective combination of AIE and photochromic properties, breaking through the functional singleness limitation of traditional materials.

[0018] 2. Performance optimization: Through substituent site engineering and electronic effect regulation, precise tuning of spectral properties is achieved to meet the needs of different application scenarios.

[0019] 3. Biocompatibility: The developed compounds have low cytotoxicity and good biocompatibility, providing new tools for biomedical imaging.

[0020] 4. Application expansion: It provides revolutionary material solutions for optical switching devices, advanced anti-counterfeiting, information storage, and biological diagnosis and treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The UV-visible absorption spectra of compounds TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT in n-Hex solution as a function of 365 nm ultraviolet irradiation time; Figure 2The fluorescence emission spectra of compounds TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT in n-Hex solution change with 365 nm ultraviolet irradiation time; Figure 3 The UV-visible absorption spectra of compounds TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT in solid state as a function of 365 nm ultraviolet irradiation time; Figure 4 is the fluorescence lifetime of compound TAE-3 / 4 / 5-BT in THF solution; Figure 5 The fluorescence emission spectra of compound TAE-3 / 4 / 5-BT in solid state change with 365 nm ultraviolet irradiation time; Figure 6 Comparison of fluorescence emission spectra of compound TAE-3 / 4 / 5-BT in solid state and liquid state; Figure 7 The fluorescence spectra of compound TAE-3 / 4 / 5-BT and the fluorescence photos of the solution at different water volume percentages are shown; Figure 8 This is the particle size diagram of compound TAE-3 / 4 / 5-BT when it aggregates at a volume ratio of THF:H2O=1:9; Figure 9 This is a scanning electron microscopy photograph of compound TAE-3 / 4 / 5-BT in the aggregated state; Figure 10 X-ray diffraction pattern (A) and fluorescence emission spectrum (B) of compound TAE-5-BT before and after mechanical grinding; Figure 11 ORTAP images of TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT crystals; Figure 12 ORTAP diagram of the crystal structure of TAE-4 / 5-CHO and TAE-4-BT in the closed ring state of the compound; Figure 13 Crystal stacking diagram of compounds TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT crystals Figure 14 The crystal stacking diagram of the closed-ring structure of TAE-4 / 5-CHO and TAE-4-BT crystals; Figure 15 Application of compound TAE-3 / 4 / 5-BT in anti-counterfeiting ink; Figure 16 This is the cytotoxicity bar graph of compound TAE-3 / 4 / 5-BT within 10 h; Figure 17This is the fluorescence imaging of the compound TAE-3 / 4 / 5-BT in cells.

[0022] Figure 18 This is the synthetic route of compounds TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT.

[0023] Figure 19 The diagram shows the principle and physical picture of the application of compounds TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT in anti-counterfeiting materials. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] One embodiment of the present invention provides a TAE material with thiophene site-specific modification. The main structure of the TAE material with thiophene site-specific modification is a tetraarylethene, wherein a thiophene substitution exists on the tetraarylethene, and an R group is introduced at the end of the thiophene. or .

[0026] This invention proposes an innovative strategy for constructing thiophene-substituted tetraaryl molecules. By manipulating the attachment sites of the thiophene group and modifying the end groups, precise control of the molecular optical properties is achieved. This technical solution not only deepens scientific understanding of the photoresponse mechanisms of AIE materials but also provides key technical support for the development of a new generation of intelligent optoelectronic materials. The developed compounds show broad application prospects in optical switching devices, advanced anti-counterfeiting, information storage, and cell imaging, providing new perspectives and ideas for the design of organic photofunctional materials.

[0027] In some embodiments, there is a 3-thiophene, 4-thiophene, or 5-thiophene substitution on the tetraarylethene, and the thiophene site-specifically modified TAE material has any of the following structural formulas: ; in, or .

[0028] This paper proposes an innovative strategy for constructing thiophene-substituted tetraaryl molecules. Through site-selective modification of substituents and the introduction of terminal groups, precise control of the molecular optical properties is achieved. The core innovation of this technical solution lies in the establishment of a three-dimensional "site control-configuration-performance" control model. This has led to the successful development of a multifunctional molecular system with both bistable photochromic and aggregation-induced emission (AIE) properties, providing a revolutionary material solution for applications such as optical switching devices, advanced anti-counterfeiting, and bioimaging.

[0029] The inventors have discovered that TAE compounds substituted with thiophene at the 4-position have high photoreactivity and are ideal photoresponsive units suitable for constructing light-stimulus-responsive materials; those substituted with thiophene at the 5-position have strong fluorescence emission intensity and can be used as fluorophores for constructing organic materials. In addition, this series of compounds also exhibits excellent mechanochromic behavior and is suitable for the construction of mechanical sensors. It is worth noting that the introduction of the thiophene group helps to enhance the fluorescence emission intensity and AIE properties of the target product. In particular, the 3-thiophene-substituted TAE molecules have both excellent photochromic properties and significant AIE properties, achieving dual regulation of aggregation-induced emission and photochromic properties, and have great potential in the fields of organic optoelectronic materials, biochemical detection, anti-counterfeiting and cell imaging. Therefore, the present invention is the first to apply for protection of the construction strategy of thiophene-substituted tetraaryl molecules, the preparation method of regulating their optical properties by substituents and positions, and their application in security inks, intelligent anti-counterfeiting and cell fluorescence imaging technologies.

[0030] Another embodiment of the present invention provides a method for preparing a thiophene site-specifically modified TAE material, the reaction scheme is as follows: Figure 18 As shown, it comprises the following steps: (1) under a protective atmosphere, 2-bromo-1,1,2-triphenylethylene, an aldehyde-containing thiophene boronic acid compound (2-aldehyde thiophene-3-boric acid, 2-aldehyde thiophene-4-boric acid, 5-aldehyde-2-thiophene boronic acid), a palladium catalyst, an alkaline compound and a first solvent are mixed to carry out a Suzuki coupling reaction; (2) under heating reflux conditions, 3-(1,2,2-triphenylvinyl)thiophene-2-carboxaldehyde, 4-(1,2,2-triphenylvinyl)thiophene-2-carboxaldehyde, 5-(1,2,2-triphenylvinyl)thiophene-2-carboxaldehyde are mixed with 2-aminothiophenol, sodium metabisulfite and a second solvent respectively to carry out a condensation reaction.

[0031] In some embodiments, in step (1), the molar ratio of 2-bromo-1,1,2-triphenylethylene and the aldehyde-containing thiophene boronic acid compound (2-aldehyde thiophene-3-boric acid, 2-aldehyde thiophene-4-boric acid, 5-aldehyde-2-thiophene boronic acid) is 1:1.1~2.0, preferably 1:1.1~1.7, and more preferably 1:1.2~1.6; the molar concentration of the palladium catalyst in the reaction solution is 8~13%, preferably 9~12%, and more preferably 10%; the amount ratio of the 2-bromo-1,1,2-triphenylethylene and the first solvent is 2 mmol~100 mmol:80~250 mL, preferably 2 mmol~10 mmol:80~120; the alkaline compound is added in the form of a solid, and the molar ratio of the 2-bromo-1,1,2-triphenylethylene and the alkaline compound is 1:3~7, preferably 1:4~6.

[0032] In some embodiments, the temperature of the Suzuki coupling reaction in step (1) is 78-90°C, preferably 83°C, and the time is 6-10 hours, preferably 8 hours.

[0033] In some embodiments, after the Suzuki coupling reaction is completed, the present invention preferably performs post-treatment on the reaction solution, and the post-treatment preferably includes the following steps: The Suzuki coupling reaction solution was cooled to room temperature and then the solvent was removed by rotary evaporation to obtain a rotary evaporation residue; Extracting the residue from the rotary evaporation, and sequentially drying and filtering the obtained organic phase to obtain a filtrate; The filtrate was rotary evaporated to remove the solvent and then subjected to column chromatography to obtain pure TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT target products.

[0034] In some embodiments, the extraction solvent is preferably dichloromethane; the drying agent is preferably anhydrous sodium sulfate; the eluent for column chromatography separation is preferably petroleum ether. - Ethyl acetate mixture; the volume ratio of petroleum ether to ethyl acetate in the mixture is preferably 15:1. The present invention does not particularly require the specific methods of the rotary evaporation and filtration operations; methods well known to those skilled in the art can be used. In the present invention, TAE-3-CHO, obtained after column chromatography separation, is a light cyan solid, TAE-4-CHO is a white solid, and TAE-5-CHO is a yellow-green solid.

[0035] In the present invention, the molar ratio of TAE-3 / 4 / 5-CHO to 2-aminothiophenol in step (2) is 1:1-1.3, preferably 1:1.2; the amount ratio of 2-aminothiophenol to the second solvent is 2-4 mmol:4-10 mL, preferably 2-3 mmol:8-10 mL.

[0036] In the present application, the temperature of the condensation reaction in step (2) is 110-120℃, and the time is 2-6h, preferably 3-4h; the second solvent is one or several of DMSO solution, N, N-dimethylformamide solution.

[0037] After the condensation reaction is completed, the present application preferably performs post-treatment on the reaction solution, and the post-treatment preferably comprises the following steps: adding ice water to the condensation reaction solution to quench and obtain a solid product; washing the solid with purified water for multiple times to remove residual sodium pyrosulfite in the product; performing column chromatography separation on the obtained solid, and recrystallizing the obtained substance to obtain pure TAE-3 / 4 / 5-BT.

[0038] In the present application, the extractant for extraction is preferably dichloromethane; the drying agent for drying is preferably anhydrous sodium sulfate; the eluent for column chromatography separation is preferably a petroleum ether-ethyl acetate mixture; the volume ratio of petroleum ether and ethyl acetate in the mixture is preferably 1:1; the present application does not have special requirements for the specific method of the rotary evaporation, filtration and other operations, and the method well known to those skilled in the art can be used. In the present application, the obtained TAE-3-BT after recrystallization is a light blue solid, the obtained TAE-4-BT is a white solid, and the obtained TAE-5-BT is a goose yellow solid.

[0039] The preparation method provided by the present application only involves Suzuki coupling reaction and aldehyde amine condensation reaction, and compared with common tetraphenyl ethylene, diphenyl ethylene, anthracene compounds, the raw material cost is low, the synthesis method and step are simpler, the functionality of the target product is more abundant, and the method has a wide application prospect.

[0040] Another embodiment of the present application provides an application of the thienyl site-specifically modified TAE material or photochemical sensor in photochromism, force-induced color change, cell imaging, security ink or anti-counterfeiting.

[0041] Specifically, the thienyl site-specifically modified TAE material is prepared into a photochemical sensor, and the photochemical sensor is applied in photochromism, force-induced color change, cell imaging, security ink or anti-counterfeiting.

[0042] The application of the present application is based on a design strategy of an adjustable photochromic material with AIE activity, and the open-loop and closed-loop changes are as shown in formula I and Figure 19 . This invention constructs a tetraarylethene derivative system (TAE-3-CHO / BT) with a monothiophene substitution configuration. This compound, through conjugated coupling of a thiophene ring with a vinyl-bridged benzene ring, forms a diarylethene functional unit capable of photoisomerization. While achieving photoresponsive activity, it also significantly enhances the material's aggregation-induced emission (AIE) performance. This synergistic effect endows the material with revolutionary potential in light-controlled dual-modal patterning technology and multidimensional anti-counterfeiting applications. The reversible photoresponsive properties of TAE materials, based on thiophene site-specific modification, enable applications in photochromism, mechanochromism, cell imaging, security inks, and anti-counterfeiting.

[0043] The present invention is further described in detail below with reference to specific examples, but the present invention is not limited to the following specific examples.

[0044] Example 1 Preparation of 3-(1,2,2-triphenylvinyl)thiophene-2-carboxaldehyde (TAE-3-CHO) and 2-(3-(1,2,2-triphenylvinyl)thiophen-2-yl)-2,7a-dihydrobenzo[d]thiazole (TAE-3-BT) (synthetic route is shown in Formula II): (1) Preparation of TAE-3-CHO: Under nitrogen, 2-bromo-1,1,2-triphenylethylene (1.00 g, 2.98 mmol) and Pd(Dppf)Cl2 (10 mol%) were dissolved in 80.0 mL of THF. After stirring for 15 min, 2-formylthiophene-3-boronic acid (0.75 g, 4.80 mmol) and Na2CO3 (2.0 g, 18.87 mmol) were added. The mixture was heated at reflux for 8 h, quenched by addition of water, and cooled to room temperature. The THF solvent was removed by rotary evaporation, and the mixture was extracted with dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate. The mixture was filtered, the solvent was removed by rotary evaporation, and column chromatography was performed using a mixture of petroleum ether and ethyl acetate as the eluent to obtain a light cyan solid (0.96 g, 2.62 mmol), namely, TAE-3-CHO, in a 65% yield.

[0045] (2) Preparation of TAE-3-BT: TAE-3-CHO (0.73 g, 2.00 mmol) and 2-aminothiophenol (0.30 g, 2.40 mmol) prepared in reaction (1) and sodium metabisulfite (0.20 g, 1.05 mmol) were dissolved in 10.0 mL of dimethyl sulfoxide solution, heated to 110°C, and refluxed for 3 h. After the reaction was completed, the mixture was slowly poured into 200 mL of clean water. The precipitate was filtered, washed three times with clean water (30 mL), and dried to obtain a crude product. Recrystallization was performed using methanol to obtain a light yellow solid 2-(3-(1,2,2-triphenylvinyl)thiophen-2-yl)-2,7a-dihydrobenzo[d]thiazole (0.56 g, 1.18 mmol) with a yield of 59%; Formula II Example 2 Preparation of 4-(1,2,2-triphenylvinyl)thiophene-2-carboxaldehyde (TAE-4-CHO) and 2-(4-(1,2,2-triphenylvinyl)thiophen-2-yl)benzothiazole (TAE-4-BT) (synthetic route is shown in Formula III): (1) Preparation of TAE-4-CHO: Under nitrogen, 2-bromo-1,1,2-triphenylethylene (2.00 g, 5.97 mmol) and Pd(Dppf)Cl2 (10 mol%) were dissolved in 80.0 mL of THF. After stirring for 15 min, 2-formylthiophene-4-boronic acid (1.12 g, 7.16 mmol) and Na2CO3 (2.0 g, 18.87 mmol) were added. The mixture was heated to reflux for 8 h, quenched by addition of water, and cooled to room temperature. The THF solvent was removed by rotary evaporation, and the mixture was extracted with dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate. The mixture was filtered, the solvent was removed by rotary evaporation, and column chromatography was performed using a mixture of petroleum ether and ethyl acetate as the eluent to obtain a white solid (1.58 g, 4.31 mmol), namely, TAE-4-CHO, in a 72% yield.

[0046] (2) Preparation of TAE-4-BT: TAE-4-CHO (0.73 g, 2.00 mmol) and 2-aminothiophenol (0.30 g, 2.40 mmol) and sodium metabisulfite (0.20 g, 1.05 mmol) prepared from reaction (1) were dissolved in 10.0 mL of dimethyl sulfoxide solution, heated to 110°C, and refluxed for 3 h. After the reaction was completed, it was slowly poured into 200 mL of water. The precipitated material was filtered, washed with water (30 mL) three times, and dried to obtain a crude product. Recrystallization with methanol gave 2-(4-(1,2,2-triphenylvinyl)thiophen-2-yl)benzothiazole (0.63 g, 1.33 mmol) as a white solid, yield: 66 %; Formula III Example 3 Preparation of 5-(1,2,2-triphenylvinyl)thiophene-2-carboxaldehyde (TAE-5-CHO) and 2-(5-(1,2,2-triphenylvinyl)thiophen-2-yl)benzothiazole (TAE-5-BT) (Synthesis route as shown in Formula IV): (1) Preparation of TAE-5-CHO: Under nitrogen protection, 2-bromo-1,1,2-triphenylstyrene (1.34 g, 4.00 mmol) and Pd (Dppf)Cl2(10 mol%) were dissolved in 80.0 mL of THF, stirred for 15 min, and then 5-formyl-2-thiopheneboronic acid (0.75 g, 4.80 mmol) and Na2CO3(2.0 g, 18.87 mmol) were added. After being heated to reflux for 8 h, the reaction was quenched with water and cooled to room temperature. The THF solvent was removed by rotary evaporation, extracted with dichloromethane, and the organic phases were combined and dried over anhydrous sodium sulfate. Filtration and rotary evaporation to remove the solvent were performed, and column chromatography was performed using a mixture of petroleum ether and ethyl acetate as the eluent to obtain a white solid (1.24 g, 3.38 mmol), which was TAE-5-CHO, yield: 85 %.

[0047] (2) Preparation of TAE-5-BT: TAE-5-CHO (0.73 g, 2.00 mmol) prepared in reaction (1) and 2-aminothiophenol (0.30 g, 2.40 mmol) and sodium metabisulfite (0.20 g, 1.05 mmol) were dissolved in 10.0 mL of dimethyl sulfoxide solution, heated to 110 ° C, and refluxed for 3 h. After the reaction was completed, it was slowly poured into 200 mL of clean water. The precipitate was filtered, washed three times with clean water (30 mL), and dried to obtain a crude product. Recrystallization was performed with methanol to obtain a light yellow solid 2-(4-(1,2,2-triphenylvinyl)thiophen-2-yl)benzothiazole (0.72 g, 1.53 mmol) with a yield of 76%; Formula IV The characterization data of each compound in Examples 1 to 3 are as follows: Figure 1Figure 3 UV-visible absorption spectra of compounds TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT in n-Hex as a function of 365 nm ultraviolet irradiation time; (A) UV-visible absorption spectra of TAE-3-CHO in n-Hex as a function of 365 nm ultraviolet irradiation time; with increasing irradiation time, the absorption peak at 293 nm gradually decreases, an isosbestic point appears at 398 nm, a new absorption peak gradually appears at 468 nm, and reaches light saturation after 120 s of illumination. As the illumination time increases, the absorption platform at 398-534 nm gradually decreases; (B) UV-visible absorption spectra of compound TAE-4-CHO in n-Hex as a function of 365 nm ultraviolet irradiation time; with increasing irradiation time, the absorption peak at 308 nm gradually decreases, and an isosbestic point appears at 398 nm. A new absorption peak gradually appears at 468 nm, and reaches light saturation after 120 s of illumination. As the illumination time increases, the absorption platform at 398-534 nm gradually decreases. The absorption peak at 475 nm gradually decreases, an isosbestic point appears at 400 nm, a new absorption peak gradually appears at 475 nm, and reaches light saturation after 5 s of illumination. As the illumination time increases, the absorption platform at 400-541 nm gradually decreases; (C) is the UV-visible absorption spectrum of compound TAE-5-CHO in n-Hex as a function of 365 nm ultraviolet irradiation time; as the irradiation time increases, an isosbestic point appears at 427 nm, a new absorption peak gradually appears at 468 nm, and reaches light saturation after 5 s of illumination. As the illumination time increases, the absorption platform at 427-578 nm gradually decreases; (D) is the UV-visible absorption spectrum of compound TAE-3-BT in n-Hex as a function of 365 nm ultraviolet irradiation time; as the irradiation time increases, the absorption peak at 354 nm gradually decreases, and reaches light saturation after 10 The absorption peak at 314 nm gradually decreased with the increase of irradiation time, and reached the light saturation state after 180 s. The absorption peak at 427-619 nm gradually decreased with the extension of illumination time. (E) is the UV-visible absorption spectrum of compound TAE-4-BT in n-Hex as a function of 365 nm ultraviolet irradiation time. As the irradiation time increased, the absorption peak at 314 nm gradually decreased, and reached the light saturation state after 180 s. (F) is the UV-visible absorption spectrum of compound TAE-5-BT in n-Hex as a function of 365 nm ultraviolet irradiation time. As the irradiation time increased, the absorption peak at 378 nm gradually decreased, and reached the light saturation state after 150 s. Figure 2Figure 2 shows the fluorescence emission spectra of compounds TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT in n-Hex as a function of 365 nm ultraviolet irradiation time; (A) shows the fluorescence emission spectrum of compound TAE-3-CHO in n-Hex as a function of 365 nm ultraviolet irradiation time; with the increase of irradiation time, the emission wavelength blue-shifted from 425 nm to 414 nm, the fluorescence significantly enhanced, and reached saturation at 360 s; (B) shows the fluorescence emission spectrum of compound TAE-4-CHO in n-Hex as a function of 365 nm ultraviolet irradiation time; with the increase of irradiation time, the emission wavelength blue-shifted from 498 nm to 485 nm, the fluorescence significantly enhanced, and reached saturation at 240 s; (C) shows the fluorescence emission spectrum of compound TAE-5-CHO in n-Hex as a function of 365 nm ultraviolet irradiation time; with the increase of irradiation time, the emission wavelength blue-shifted from 425 nm to 414 nm, the fluorescence significantly enhanced, and reached saturation at 360 s. nm red-shifted to 432 nm, the fluorescence was significantly enhanced, and reached saturation at 360 s; (D) is the fluorescence emission spectrum of compound TAE-3-BT as a function of 365 nm ultraviolet irradiation time; with the increase of irradiation time, the emission wavelength blue-shifted from 437 nm to 455 nm, the fluorescence was significantly enhanced, and reached saturation at 420 s; (E) is the fluorescence emission spectrum of compound TAE-4-BT as a function of 365 nm ultraviolet irradiation time in n-Hex; with the increase of irradiation time, the emission wavelength blue-shifted from 425 nm to 396 nm, the fluorescence was significantly enhanced, and reached saturation at 300 s; (F) is the fluorescence emission spectrum of compound TAE-5-BT as a function of 365 nm ultraviolet irradiation time in n-Hex; with the increase of irradiation time, the emission wavelength blue-shifted from 459 nm to 452 nm, the fluorescence was significantly enhanced, and reached saturation at 570 s; Figure 3 The UV-visible absorption spectra of the compounds TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT in the solid state change with the 365 nm ultraviolet irradiation time; (A) is the UV-visible absorption spectrum of the solid compound TAE-3-CHO changing with the 365 nm ultraviolet irradiation time; (B) is the UV-visible absorption spectrum of the solid compound TAE-4-CHO changing with the 365 nm ultraviolet irradiation time; (C) is the UV-visible absorption spectrum of the solid compound TAE-5-CHO changing with the 365 nm ultraviolet irradiation time; (D) is the UV-visible absorption spectrum of the solid compound TAE-3-BT changing with the 365 nm ultraviolet irradiation time; (E) is the UV-visible absorption spectrum of the solid compound TAE-4-BT changing with the 365 nm ultraviolet irradiation time; (F) is the UV-visible absorption spectrum of the solid compound TAE-5-BT changing with the 365 nm ultraviolet irradiation time; Figure 4 The fluorescence lifetimes of compounds TAE-3 / 4 / 5-CHO and TAE-3 / 4 / 5-BT in THF are shown in Figure 2. 1, 2, and 3 in (A) are TAE-3-CHO, TAE-5-CHO, and TAE-4-CHO, respectively; 4, 5, and 6 in (B) are TAE-4-BT, TAE-3-B, and TAE-5-BT, respectively. The figure shows that the fluorescence lifetime of compound TAE-3-CHO is 0.3210 ns; the fluorescence lifetime of compound TAE-4-CHO is 0.2163 ns; the fluorescence lifetime of compound TAE-5-CHO is 0.4033 ns; the fluorescence lifetime of compound TAE-3-BT is 0.3192 ns; the fluorescence lifetime of compound TAE-4-BT is 0.1830 ns; and the fluorescence lifetime of compound TAE-5-BT is 0.7474 ns. Figure 5 The fluorescence emission spectra of compound TAE-3 / 4 / 5-BT in the solid state change with 365 nm ultraviolet irradiation time; (A) is the fluorescence emission spectrum change spectrum of compound TAE-3-BT; (B) is the fluorescence emission spectrum change spectrum of compound TAE-4-BT; (C) is the fluorescence emission spectrum change spectrum of compound TAE-5-BT; Figure 6 Comparison of the solid-state and liquid fluorescence emission spectra of compound TAE-3 / 4 / 5-BT; (A) is the solid-state and liquid fluorescence emission spectra of compound TAE-3-BT; (B) is the solid-state and liquid fluorescence emission spectra of compound TAE-4-BT; (C) is the solid-state and liquid fluorescence emission spectra of compound TAE-5-BT; Figure 7 The fluorescence spectra of the compound TAE-3 / 4 / 5-BT and the fluorescence photos of the solution under different water volume percentage conditions; (A) is the fluorescence spectra of the compound TAE-3-BT and the fluorescence photos of the solution under different water volume percentage conditions; the concentration of TAE-3-BT is 2.0×10 -5mol / L, using THF as the organic solvent. As shown in the figure, TAE-3-BT forms a dilute solution with low fluorescence intensity when the good solvent (THF) is high. When the volume fraction of the poor solvent (water) reaches 90%, it aggregates in water to form nanoparticles. The fluorescence intensity of the aggregated solution is 9.5 times higher than that of the non-aggregated solution, indicating that the compound provided by the present invention has significant aggregation-induced emission (AIE) properties. (B) is a fluorescence spectrum of the compound TAE-4-BT and fluorescence photographs of solutions under conditions of different water volume percentages. When the volume fraction of the poor solvent (water) in the solution reaches 50%, aggregation occurs in water to form nanoparticles. The fluorescence intensity of the solution in the aggregated state is 16.4 times higher than that in the non-aggregated solution, indicating that the compound provided by the present invention has significant aggregation-induced emission (AIE) properties. (C) is a fluorescence spectrum of the compound TAE-5-BT and fluorescence photographs of solutions under conditions of different water volume percentages. When the volume fraction of the poor solvent (water) in the solution reaches 70%, aggregation occurs in water to form nanoparticles. The fluorescence intensity of the solution in the aggregated state is 23.3 times higher than that in the non-aggregated solution, indicating that the compound provided by the present invention has significant aggregation-induced emission (AIE) properties. Figure 8 Figure 2 is a particle size diagram of compound TAE-3 / 4 / 5-BT when aggregated at a volume ratio of THF:H2O=1:9; (A) is a particle size diagram of compound TAE-3-BT when aggregated at a volume ratio of THF:H2O=1:9, and it can be seen that the average particle size in the aggregated state is 249 nm; (B) is a particle size diagram of compound TAE-4-BT when aggregated at a volume ratio of THF:H2O=1:9, and it can be seen that the average particle size in the aggregated state is 238 nm; (C) is a particle size diagram of compound TAE-5-BT when aggregated at a volume ratio of THF:H2O=1:9, and it can be seen that the average particle size in the aggregated state is 376 nm; Figure 9 These are scanning electron micrographs of the aggregated state of compound TAE-3 / 4 / 5-BT; (A) is compound TAE-3-BT; (B) is compound TAE-4-BT; (C) is compound TAE-5-BT; Figure 10 X-ray diffraction pattern (A) and fluorescence emission spectrum (B) of compound TAE-5-BT before and after mechanical grinding; Example 4 Application in Anti-Counterfeiting Ink Based on the photochromic properties of the compounds prepared in Examples 1 to 3, the compounds obtained in Examples 1 to 3 were used to prepare anti-counterfeiting inks. The preparation method included: using ethanol as a solvent and TAEs as a developer to prepare the required mother liquor, then adding 30% by mass of polyacrylic acid resin to the system, and stirring evenly to obtain an ink sample.

[0048] See the results Figures 11 to 15 .

[0049] Figure 11 ORTAP images of compound TAE crystals; (A) is compound TAE-3-CHO; (B) is compound TAE-4-CHO; (C) is compound TAE-5-CHO; (D) is compound TAE-3-BT; (E) is compound TAE-4-BT; (F) is compound TAE-5-BT; Figure 12 ORTAP diagrams of the closed-ring crystal structures; (A) is the closed-ring state of the compound TAE-4-CHO; (B) is the closed-ring state of the compound TAE-5-CHO; (C) is the closed-ring state of the compound TAE-4-BT; Figure 13 The crystal stacking diagram of compound TAE crystals; (A) is compound TAE-3-CHO; (B) is compound TAE-4-CHO; (C) is compound TAE-5-CHO; (D) is compound TAE-3-BT; (E) is compound TAE-4-BT; (F) is compound TAE-5-BT; Figure 14 Crystal stacking diagrams of closed-ring structures; (A) is the closed-ring state of the compound TAE-4-CHO; (B) is the closed-ring state of the compound TAE-5-CHO; (C) is the closed-ring state of the compound TAE-4-BT; Figure 15 The application of compound TAE-3 / 4 / 5-BT in anti-counterfeiting ink; A1–C1 correspond to compound TAE-3-BT; A2–C2 correspond to compound TAE-4-BT; A3–C3 correspond to compound TAE-5-BT; Experimental Example 5: Cytotoxicity Experiment The MTT cytotoxicity test of compound TAE-3 / 4 / 5-BT was performed using a specific cytotoxicity detection kit (purchased from Beyotime Biotechnology) to assess cell viability. The specific experimental steps were as follows: 100 μL of PBS solution was added to the outer wells of a 96-well plate to prevent edge effects, and then a HeLa cell suspension of appropriate density (100 μL / well) was inoculated into the remaining wells and cultured in a 37°C, 5% CO2 incubator for 12 h. After growth was completed, the cells were washed three times with PBS buffer to remove residual culture components. Subsequently, 100 μL of culture medium containing different concentrations of TAE compounds (5, 10, 20, and 30 μM) was added to each experimental well and culture continued. After 24 h, the culture medium was removed, the cells were washed three times with PBS solution, and fresh culture medium (100 μL) and MTT solution (10 μL, 5 mg mL -1 ), placed in a constant temperature incubator and incubated for 4 hours. After the end, the supernatant was aspirated and 100 μL of formazan solution was added to each well and incubated for another 4 hours. Finally, the absorbance of the formazan solution was measured at a wavelength of 570 nm using a MultiskanFC microplate reader (Thermo Scientific). In this MTT assay, each concentration of TAEs was repeated 5 times. The results are shown in Figure 16 .

[0050] Figure 16 The cytotoxicity bar graphs of compounds TAE-3 / 4 / 5-BT within 10 hours are shown in Figure 2. (A) is compound TAE-3-BT; (B) is compound TAE-4-BT; (C) is compound TAE-5-BT. Experimental Example 6: Cell Imaging Experiment HeLa cells were cultured in DMEM supplemented with 10% (mass fraction) bovine serum, the culture atmosphere was 5% CO2-95% air, and the culture temperature was maintained at 37°C. During the experiment, the cells were seeded in a 20 mm cell culture dish and treated overnight. The HeLa cells were then rinsed with phosphate-buffered saline (PBS) and then stained with substances (i.e., TAE-3 / 4 / 5-BT, all at a concentration of 20 μM) in the culture medium for 30 minutes. After incubation, the HeLa cells were rinsed three times with PBS to remove unbound staining substances, and finally the cells were imaged and observed using an OLYMPUS FV1000 confocal laser scanning microscope, using the fluorescence emission at 430-530 nm as the collection channel. The results are shown in the figure. Figure 17 shown.

[0051] Figure 17The fluorescence imaging diagrams of the cells containing the compound TAE-3 / 4 / 5-BT are shown, where A1–C1 correspond to the fluorescence dark field imaging diagrams, bright field imaging diagrams and superimposed field imaging diagrams of the cells in the blank control group, respectively; A2–C2 correspond to the fluorescence dark field imaging diagrams, bright field imaging diagrams and superimposed field imaging diagrams of the cells containing the compound TAE-3-BT, respectively; A3–C3 correspond to the fluorescence dark field imaging diagrams, bright field imaging diagrams and superimposed field imaging diagrams of the cells containing the compound TAE-4-BT, respectively; A4–C4 correspond to the fluorescence dark field imaging diagrams, bright field imaging diagrams and superimposed field imaging diagrams of the cells containing the compound TAE-5-BT, respectively. Figure 17 As can be seen, the compound TAE-3 / 4 / 5-BT provided by the present invention can effectively enter HeLa cells and exhibit good cell staining function. Therefore, the compound provided by the present invention can be used as a cell fluorescence marker and has potential application value in the field of cell dyes.

[0052] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A thiophene site-specifically modified TAE material, characterized in that: Its main structure is tetraarylethene, wherein there is thiophene substitution on the tetraarylethene, and R group is introduced at the end of thiophene. or .

2. The thiophene site-specifically modified TAE material according to claim 1, characterized in that: It has any of the following structural formulas: ； in, or .

3. The method for preparing the thiophene site-specifically modified TAE material according to any one of claims 1 to 2, characterized in that: The following steps are involved: (1) Under a protective atmosphere, 2-bromo-1,1,2-triphenylethylene, an aldehyde-containing thiophene boronic acid compound, a palladium catalyst, a basic compound, and a first solvent are mixed to perform a Suzuki coupling reaction to prepare aldehyde intermediates with different substitution positions on the corresponding thiophene ring; (2) Under reflux stirring conditions, the aldehyde intermediate prepared in step (1) is mixed with 2-aminothiophenol, sodium metabisulfite and a second solvent for condensation reaction to obtain a thiophene site-specifically modified TAE material.

4. The preparation method according to claim 3, characterized in that In step (1), The thiophene boronic acid compound comprises one or more of 2-formylthiophene-3-boric acid, 2-formylthiophene-4-boric acid, and 5-formyl-2-thiophene boronic acid; The palladium catalyst comprises one or more of Pd(PPh3)4, Pd(dppf)Cl2, PdCl2(dppf)2 and Pd(OAc)2; The alkaline compound includes Na2CO3, Ba(OH)2, K3PO4, Cs2CO3, K2CO3, TiOH, KF, CsF, Bu4F, NaOH and i -One or more of PrNEt2; The first solvent comprises one or more of tetrahydrofuran, acetone, toluene, dichloromethane, N,N-dimethylformamide and acetonitrile.

5. The preparation method according to claim 3, characterized in that In step (1), The molar ratio of 2-bromo-1,1,2-triphenylethylene to the aldehyde-containing thiophene boronic acid compound is 1:1.1-2; The molar concentration of the palladium catalyst in the reaction solution is 8-13%; The ratio of the 2-bromo-1,1,2-triphenylethylene to the first solvent is 2 mmol to 0.1 mol: 80 to 250 mL; The alkaline compound is added in the form of a solid, and the molar ratio of the 2-bromo-1,1,2-triphenylethylene to the alkaline compound is 1:1.0-7.

6. The preparation method according to claim 3, characterized in that The temperature of the Suzuki coupling reaction in step (1) is 78-90° C., the time is 6-10 h, and the protective atmosphere is nitrogen atmosphere.

7. The preparation method according to claim 3, characterized in that In step (2), the molar ratio of the aldehyde intermediate to 2-aminothiophenol is 1:1-1.3; the amount ratio of 2-aminothiophenol to the second solvent is 2-4 mmol:4-10 mL; and the amount ratio of 2-aminothiophenol to the second solvent is 2.2-2.6 mmol:8-12 mL.

8. The preparation method according to claim 3, characterized in that The condensation reaction temperature in step (2) is 110-120°C and the reaction time is 2-6 h; The second solvent is one or more of DMSO and N,N-dimethylformamide solution.

9. A photochemical sensor, characterized in that The invention relates to a TAE material comprising the thiophene site-specifically modified material according to any one of claims 1 to 2.

10. Use of the thiophene site-specifically modified TAE material according to any one of claims 1 to 2 or the optical chemical sensor according to claim 9 in photochromism, mechanochromism, cell imaging, security ink, or anti-counterfeiting.

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