Alpha-cyanostyrene optical switch molecule based on visible light regulation and control as well as preparation and application thereof

Abstract

The invention relates to an alpha-cyanostyrene optical switch molecule based on visible light regulation and control as well as preparation and application of the alpha-cyanostyrene optical switch molecule. The molecule has a molecular structure as shown in a formula (I). Wherein the alpha-cyanostyrene unit endows the material with multiple photoresponse potential. Different substituent groups are introduced into a phenylacetonitrile structure, so that the absorption range of the phenylacetonitrile can be effectively regulated and controlled to a visible light region, and the fluorescence colors of different molecules are remarkably changed. Compared with other existing optical switches, the alpha-cyano styrene compound provided by the invention shows a reversible cis-trans isomerism behavior in an acetonitrile solution when being irradiated by visible light. Besides, when the compound is in a CH3CN / H2O mixture, a nano spherical assembly is formed due to an aggregation effect, so that the intermolecular distance is obviously reduced, the bimolecular cycloaddition induced by visible light is initiated, and finally, the fluorescence color is obviously changed.

Description

Technical Field

[0001] This article relates to the preparation and application of α-cyanostyrene photoswitchable molecules based on visible light regulation, belonging to the technical field of organic photoswitchable materials. Background Art

[0002] In recent years, with the development of the new material field, significant progress has been made in the research of photoswitchable molecules, which have been widely used in fields such as visualization technology, information storage, and optoelectronic devices. Under the irradiation of light with a specific wavelength, the molecular structure of such molecules changes, resulting in a change in the absorption spectrum intensity or position. Common photoswitchable molecules include azobenzene, imine and hydrazone, and spiropyran. These molecules can undergo Z / E isomerization or ring opening and closing under light irradiation. However, the isomerization of these photo-responsive molecules in the aggregated state is usually greatly inhibited.

[0003] α-Cyanostyrene molecules have become one of the most widely used photoswitches due to their aggregation-induced emission (AIE) properties. Through rational design, this type of molecule can undergo a series of photoreactions, including cis-trans isomerization, intramolecular ring closure, and [2+2] cycloaddition reactions. Especially the [2+2] topological cycloaddition in crystals has been widely used to construct a photo-responsive system with tunable fluorescence. According to Schmidt's rule, an almost anti-parallel arrangement with an atomic distance of is crucial for efficient [2+2] photodimerization. However, this principle mainly applies to the cycloaddition reaction in the crystalline phase. To activate the [2+2] cycloaddition reaction in solution, various strategies have been adopted, including hydrogen bonding, metal coordination, and host-guest interactions, etc. These methods aim to enhance the intermolecular interaction and weaken the intermolecular distance, thereby promoting the cycloaddition reaction. However, despite some progress, inducing [2+2] cycloaddition in the assembled state to achieve tunable fluorescence remains a major challenge. Summary of the Invention

[0004] Object of the Invention: To solve the above problems, the present invention provides a preparation method of α-cyanostyrene photoswitchable molecules based on visible light regulation. This type of photoswitchable molecule can not only undergo cis-trans isomerization in the solution state to achieve rapid conversion between two states, but also undergo [2+2] cycloaddition reaction in the aggregated state. This photo-responsive process has the advantages of fast response speed and significant fluorescence change, providing new ideas for the development of photo-responsive materials with tunable fluorescence.

[0005] The second object of the present invention is to provide a rapid method for optical information storage and erasure. By using an optical mask template, under the irradiation of light with a suitable wavelength, the writing and erasure of optical information can be achieved.

[0006] The third object of the present invention is to provide a method for information encryption and anti-counterfeiting based on the optical switch material of the present invention. This method utilizes the differences in fluorescence color change and light response speed among different optical switch molecules. By regulating the illumination time of different optical switch molecules, specific optical responses can be presented within different time windows. This time-dependent optical property effectively enhances the security and anti-counterfeiting ability of information.

[0007] Technical solution: A visible light-regulated α-cyanostyrene optical switch molecule, the structural formula of the optical switch molecule TCn is shown in formula (I):

[0008]

[0009] R = -H, -4-C n H 2n+1 , -4-OC n H 2n+1 , -4-CF 3 , -4-CN, -4-N(CH 3 ) 3 , -3,5-(CF 3 ) 2 , n = 1-6.

[0010] The optical switch molecule has a [2+2] cycloaddition fluorescence mode in the aggregated state under visible light; in a mixed solution of acetonitrile and water and in a hydrogel, the fluorescence color changes under light irradiation; the light source wavelength used for the optical switch molecule is 365 nm to 500 nm, and the light source irradiation time is 1 to 5 min.

[0011] The method for preparing the visible light-regulated α-cyanostyrene optical switch molecule is as follows:

[0012] (1) Prepare intermediate TA: Dissolve 3,4-ethylenedioxythiophene borate, 4-bromobenzaldehyde, cesium carbonate and Pd(PPh 3 ) 4 in dioxane / water, heat under reflux for reaction. After the reaction is completed, cool and then remove the solvent by distillation under reduced pressure. Extract with dichloromethane / water, separate and combine the organic phases, add anhydrous Na 2 SO 4 for drying, and remove the solvent by distillation under reduced pressure. The crude product is purified by column chromatography to obtain intermediate TA;

[0013] The reaction equation is as follows:

[0014]

[0015] (2) Preparation of the photoswitch molecule TCn: The prepared intermediate TA, the phenylacetonitrile derivative containing the substituent group R, and sodium hydroxide are refluxed and stirred in anhydrous ethanol overnight. After the reaction is completed, it is cooled, filtered by suction, washed, and dried to obtain the cyanostyrene molecule TCn;

[0016] The reaction equation is as follows:

[0017]

[0018] R = -H, -4-C n H 2n+1 、-4-OC n H 2n+1 、-4-CF 3 、-4-CN、-4-N(CH 3 ) 3 、-3,5-(CF 3 ) 2 , n = 1 - 6.

[0019] In step (1), the molar ratio of 3,4-ethylenedioxythiophene borate, 4-bromobenzaldehyde, cesium carbonate, Pd(PPh 3 ) 4 , dioxane, and water is 10:10:20:1:100 - 120:20; the heating temperature is 60 - 90 °C.

[0020] In step (2), the molar ratio of the intermediate TA, the phenylacetonitrile derivative containing the substituent group R, sodium hydroxide, and anhydrous ethanol is 1:1:2 - 4:20 - 40.

[0021] The application of the visible light-regulated α-cyanostyrene photoswitch molecule in the fields of information encryption and anti-counterfeiting, as well as optical anti-counterfeiting storage.

[0022] The application is reflected in the writing and erasing of optical information, and the specific steps are as follows:

[0023] (1) Hydrogel preparation: Agarose is added to water, and then the acetonitrile / aqueous solution of TCn is added. The mixture is heated to completely dissolve it, and then poured into a mold, left to stand and cooled to room temperature to form a hydrogel;

[0024] (2) Optical information storage: A photolithography mask is placed on the surface of the hydrogel, and a low-power handheld light source with an appropriate wavelength is used to irradiate above the hydrogel for a certain time for optical information writing. At this time, the optical information will be directly stored on the surface of the hydrogel;

[0025] (3) Optical information erasure: The mask is removed, and the hydrogel is continuously irradiated with a low-power handheld light source until the initial fluorescence color of the hydrogel completely changes. At this time, the optical information is erased, resulting in the disappearance of the written information.

[0026] The steps of applying optical information encryption and anti-counterfeiting are as follows:

[0027] (1) Material preparation: Weigh at least two kinds of photoswitch molecules TCn with different discoloration times and prepare a mixed solution of acetonitrile and water with a concentration of 1×10 -5 ~5×10 -5 mol / L, and the volume concentration f w =80~95%, and set aside; then weigh one of the photoswitch molecules TCn and prepare a DMF solution with a concentration of 1×10 -5 ~5×10 -5 mol / L, and set aside;

[0028] (2) Optical information storage: Drop the above solutions into different well plates according to the information to be stored to form the initial information. Under a handheld light source with a suitable wavelength, the optical information with fluorescence can be observed, and the optical information can be directly read at this time;

[0029] (3) Optical information erasure: Continue to irradiate with a handheld light source for a certain period of time. At this time, the fluorescence colors of the solutions all change, resulting in the disappearance of the written information.

[0030] The wavelength of the light source used is 365nm~500nm, and the irradiation time of the light source is 2min.

[0031] Beneficial effects: The photoswitch molecule of the present invention contains α-cyanostyrene and thiophene methoxy group, has good aggregation-induced emission properties, multiple photo-responsive potentials of cis-trans isomerization and [2+2] cycloaddition, and is beneficial to the isomerization of molecules in the aggregated state. By introducing different substituents into the phenylacetonitrile structure, its absorption range can be effectively regulated to the visible light region, and the fluorescence colors of different molecules can be significantly changed. Compared with other existing photoswitches, the α-cyanostyrene compound provided by the present invention shows reversible cis-trans isomerization behavior in acetonitrile solution when irradiated with visible light. When the compound is in the CH 3 CN / H 2 O mixture (f w =95%), due to the aggregation effect, nano-spherical assemblies are formed, resulting in a significant reduction in the intermolecular distance, thereby triggering a visible light-induced bimolecular cycloaddition, and finally causing a significant change in its fluorescence color. The photoswitch molecule prepared by the present invention can achieve [2+2] cycloaddition in the aggregated state, has the advantages of fast response speed, obvious photochromism, high sensitivity, visible light wavelength response, etc., and has good application prospects in the field of photoswitch materials.

[0032] The present invention also discloses a method for optical information storage and erasure based on the optical switch material of the present invention. Utilizing the fast responsiveness of the optical switch molecules, the writing and erasure of optical information are achieved by changing the light irradiation time. Compared with other technologies, the information writing speed of the present invention is fast, the sensitivity is high, the contrast is good, and it has good potential for optical information erasure and writing.

[0033] The present invention also discloses an application in the encryption and anti-counterfeiting of optical information. By combining compounds with different fluorescence colors and light response speeds, the information encryption and anti-counterfeiting effects can be achieved by changing the light irradiation time. This method can conveniently display different information, ensure the security of information, and at the same time has functions such as self-destruction after reading, greatly enhancing the anti-counterfeiting ability. This technology has broad application potential and high value in the field of information encryption and anti-counterfeiting, and can effectively improve the security and privacy protection of information. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is the middle ultraviolet absorption spectrogram of the optical switch molecule TC1 in Example 3 of the present invention under different light irradiation times;

[0035] Figure 2 It is the fluorescence spectrogram of the optical switch molecule TC1 in Example 4 of the present invention under different light irradiation times;

[0036] Figure 3 It is the middle ultraviolet absorption spectrogram of the optical switch molecule TC2 in Example 5 of the present invention under different light irradiation times;

[0037] Figure 4 It is the fluorescence emission spectrogram of the optical switch molecule TC2 in Example 6 of the present invention under different light irradiation times;

[0038] Figure 5 It is the application of the optical switch molecule TC1 in optical information erasure and writing in Example 7;

[0039] Figure 6 It is the application of the optical switch molecules TC1 and TC2 in information encryption and anti-counterfeiting in Example 8.

[0040] Figure 7 It is the middle ultraviolet absorption spectrogram of the optical switch molecule TC3 in Example 10 of the present invention under different light irradiation times;

[0041] Figure 8 It is the fluorescence spectrogram of the optical switch molecule TC3 in Example 11 of the present invention under different light irradiation times;

[0042] Figure 9 It is the application of the optical switch molecules TC2 and TC3 in information encryption and anti-counterfeiting in Example 12. DETAILED DESCRIPTION OF THE INVENTION

[0043] To better understand the content of the present invention patent, the following further elaborates on the present invention in combination with specific implementation cases, including the synthesis and application examples of the photoswitch molecule. The implementation cases are only for illustrative purposes and not for limitation. The actual implementation methods include but are not limited to the following implementation cases. Other implementation cases obtained by those skilled in the art without making creative changes also fall within the protection scope of the present invention.

[0044] Specifically, a α-cyanostyrene photoswitch molecule was designed and synthesized, and its molecular structural formula is as follows:

[0045]

[0046] R = -H, -4-C n H 2n+1 、-4-OC n H 2n+1 、-4-CF 3 、-4-CN、-4-N(CH 3 ) 3 、-3,5-(CF 3 ) 2 , n = 1 - 6.

[0047] The photoswitch molecule has a [2 + 2] cycloaddition fluorescence mode in the aggregated state under visible light; in a mixed solution of acetonitrile and water and in a hydrogel, the fluorescence color changes under light irradiation; the light source wavelength used for the photoswitch molecule is 365 nm - 500 nm, and the light source irradiation time is 1 - 5 min.

[0048] The present invention discloses a preparation method of a photoswitch molecule based on α-cyanostyrene, which comprises the following operation steps:

[0049] (1) Preparation of intermediate TA: Dissolve 3,4-ethylenedioxythiophene borate (UA, purchased from Shanghai Merck Pharmaceutical Technology Co., Ltd.), 4-bromobenzaldehyde, cesium carbonate and Pd(PPh 3 ) 4 in dioxane / water, and reflux for 12 h by heating. After the reaction is completed, cool to room temperature, distill off the solvent under reduced pressure, and extract three times with dichloromethane / water. Separate and combine the organic phases, add anhydrous Na 2 SO 4 for drying, distill off the solvent under reduced pressure, and purify the crude product by column chromatography to obtain intermediate TA;

[0050] The reaction equation is as follows:

[0051]

[0052] The 3,4-ethylenedioxythiophene borate (UA), 4-bromobenzaldehyde, cesium carbonate, Pd(PPh3 ) 4 The molar ratio of 3,4 - ethylenedioxythiophene borate (UA), 4 - bromobenzaldehyde, cesium carbonate, Pd(PPh

[0053] ), dioxane, and water is: 10:10:20:1:(100 - 120):20. The heating temperature is 60 - 90 °C; 3 ) 4 The molar ratio of 3,4 - ethylenedioxythiophene borate (UA), 4 - bromobenzaldehyde, cesium carbonate, Pd(PPh

[0054] ), dioxane, and water is: 10:10:20:1:100:20. The heating temperature is 85 °C;

[0055] (2) Preparation of the photoswitch molecule TCn: The prepared intermediate TA is refluxed and stirred overnight with a substituted - group - containing phenylacetonitrile derivative and sodium hydroxide in absolute ethanol. After the reaction is completed, it is cooled, filtered, washed, and dried to obtain the compound TCn;

[0056]

[0057] The molar ratio of the intermediate TA, the substituted - group - containing phenylacetonitrile derivative, sodium hydroxide, and absolute ethanol is: 1:1:(2 - 4):(20 - 40).

[0058] As an optimization, the molar ratio of the intermediate TA, the substituted - group - containing phenylacetonitrile derivative, sodium hydroxide, and absolute ethanol is: 1:1:3:20.

[0059] (3) [2 + 2] Cycloaddition photochromic behavior of the photoswitch:

[0060] The photoswitch molecule of the present invention refers to the [2 + 2] cycloaddition occurring in the aggregated state of the material under visible light, resulting in a change in fluorescence color.

[0061] 1) Add 1 - 10 wt% of agarose to water, then add the acetonitrile / water solution of TCn, and heat the mixture to 100 °C to completely dissolve it. Then pour it into a mold, let it stand and cool to room temperature to form a hydrogel. Using a low - power handheld light source with an appropriate wavelength for optical information writing on the hydrogel, it can be seen that the fluorescence color changes from green to blue.

[0062] The wavelength of the light source used for the photoswitch molecule is 365 nm - 500 nm, and the light source irradiation time is 1 - 5 min.

[0063] As an optimization, the agarose is 1 wt%, the wavelength of the light source used for the photoswitch molecule is 420 nm, and the light source irradiation time is 2 min.

[0064] 2) Add the compound TCn at a concentration of 1×10 -5 ~5×10 -5 mol / L to a mixed solution of acetonitrile and water (f w = 80 - 95%), drop the solution into the card slot, and use a low-power handheld light source with an appropriate wavelength to write optical information on the hydrogel. It can be seen that the fluorescence color changes from green to blue.

[0065] The preferred light source wavelength used for the optical switch molecule is 365 nm - 500 nm, and the preferred light source irradiation time is 2 min.

[0066] As an optimization, the concentration of TCn is 1×10 -5 mol / L, the mixed solution of acetonitrile and water (f w = 95%), the light source wavelength used for the optical switch molecule is 420 nm, and the light source irradiation time is 2 min.

[0067] The present invention also discloses an optical information writing and erasing method, comprising the following steps:

[0068] (1) Hydrogel preparation: Add 1 - 10 wt% of agarose to water, then add the acetonitrile / aqueous solution of TCn, and heat the mixture to 100°C to completely dissolve it. Then pour it into a mold, let it stand and cool to room temperature to form a hydrogel.

[0069] (2) Optical information storage: Place the photolithography mask on the surface of the hydrogel, and use a low-power handheld light source with an appropriate wavelength to irradiate above the hydrogel for a certain time to write optical information. At this time, the optical information will be directly stored on the surface of the hydrogel.

[0070] (3) Optical information erasure: Remove the template, and continue to use the low-power handheld light source to irradiate the hydrogel until all the initial fluorescence colors of the hydrogel change. At this time, the optical information is erased, resulting in the disappearance of the written information.

[0071] The preferred light source wavelength used for the optical switch molecule is 365 nm - 500 nm, and the preferred light source irradiation time is 2 min.

[0072] As an optimization, the agarose is 1 wt%, the light source wavelength used for the optical switch molecule is 420 nm, and the light source irradiation time is 2 min.

[0073] The α-cyanostyrene optical switch molecule TCn based on visible light regulation described in the present invention, the structural formula of the optical switch molecule is shown in formula (I):

[0074]

[0075] R = -H, -4-C n H2n+1 , -4-OC n H 2n+1 , -4-CF 3 , -4-CN, -4-N(CH 3 ) 3 , -3,5-(CF 3 ) 2 , n = 1 - 6.

[0076] Furthermore, a preparation method of an α-cyanostyrene photoswitch molecule based on visible light regulation comprises the following steps:

[0077] (1) Prepare intermediate TA:

[0078] Dissolve 3,4-ethylenedioxythiophene borate (UA), 4-bromobenzaldehyde, cesium carbonate, and Pd(PPh 3 ) 4 in dioxane / water, and heat under reflux for 12 h. After the reaction is completed, cool to room temperature, distill off the solvent under reduced pressure, and extract three times with dichloromethane / water. Separate and combine the organic phases, add anhydrous Na 2 SO 4 to dry, distill off the solvent under reduced pressure, and purify the crude product by column chromatography to obtain intermediate TA;

[0079] The reaction equation is as follows:

[0080]

[0081] (2) Prepare photoswitch molecule TC1:

[0082] Reflux and stir the obtained intermediate TA with phenylacetonitrile and sodium hydroxide in absolute ethanol overnight. After the reaction is completed, cool, filter, wash, and dry to obtain photoswitch molecule TC1;

[0083] The reaction equation is as follows:

[0084]

[0085] (3) Prepare photoswitch molecule TC2:

[0086] Reflux and stir the obtained intermediate TA with 4-methoxyphenylacetonitrile and sodium hydroxide in absolute ethanol overnight. After the reaction is completed, cool, filter, wash, and dry to obtain photoswitch molecule TC2;

[0087] The reaction equation is as follows:

[0088]

[0089] In step (1), the UA, 4-bromobenzaldehyde, cesium carbonate, Pd(PPh3 ) 4 The molar ratio of dioxane, water is: 10:10:20:1:(100 - 120):20. The heating temperature is 60 - 90 °C; in step (2), the molar ratio of intermediate TA, methoxy-substituted cyanostyrene, sodium hydroxide and absolute ethanol is: 1:1:(2 - 4):(20 - 40). In step (3), the molar ratio of intermediate TA, methoxy-substituted cyanostyrene, sodium hydroxide and absolute ethanol is: 1:1:(2 - 4):(20 - 40).

[0090] The present invention also discloses the optical information encryption and anti-counterfeiting applications based on the optical switch material in the present invention, including the following steps:

[0091] (1) Password design: Add small molecule TC1 at a concentration of 1×10 -5 ~5×10 -5 mol / L into a mixed solution of acetonitrile and water (f w = 80 - 95%) to obtain green fluorescence. Add small molecule TC2 at a concentration of 1×10 -5 ~5×10 -5 mol / L into a mixed solution of acetonitrile and water (f w = 80 - 95%) to obtain green fluorescence. Add small molecule TC2 at a concentration of 1×10 -5 ~5×10 - 5 mol / L into a DMF solution to obtain blue fluorescence, and drop these three solutions into different well plate slots according to a certain order according to the information to be stored respectively to form the initial information.

[0092] (2) Information encryption: Use a small-power handheld light source with a suitable wavelength to write optical information on the liquid in the above slot. The mixed solution of acetonitrile and water (f w = (80 - 95)%) of small molecule TC2 first undergoes a [2 + 2] cycloaddition, and the fluorescence color changes from green to blue, realizing information encryption.

[0093] (3) Information clearing: Irradiate the solution prepared in the previous step with a light source continuously. The mixed solution of acetonitrile and water (f w = 80 - 95%) of small molecule TC1 also undergoes a [2 + 2] cycloaddition, and the fluorescence color changes from green to blue, and all fluorescence changes to a single blue color, realizing information clearing.

[0094] Among them, in the above step (2), the wavelength of the light source used is 365 nm - 500 nm, and the light source irradiation time is 2 min.

[0095] In step (3), the wavelength of the light source used is 365 nm to 500 nm, and the irradiation time of the light source is 2 min.

[0096] As an optimization, for TC1 and TC2 in step (2), the concentration is 1×10 -5 mol / L, and the mixed solution of acetonitrile and water (f w = 95%). The wavelength of the light source used for the photoswitch molecule is 420 nm, and the irradiation time of the light source is 2 min.

[0097] As an optimization, in step (3), the mixed solution of acetonitrile and water used (f w = 95%). The wavelength of the light source used for the photoswitch molecule is 420 nm, and the irradiation time of the light source is 2 min.

[0098] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0099] Example 1:

[0100] This example is a preparation method of the photoswitch molecule TCn. All intermediates in the present invention are prepared by the following steps:

[0101] (1) Preparation of intermediate TA:

[0102] Take 1072 mg of 3,4-ethylenedioxythiophene borate (UA) (Shanghai Merck Chemical Technology Co., Ltd.), 925 mg of 4-bromobenzaldehyde, 20 mL of 1,4-dioxane and 5 mL of water in a flask, stir evenly, pass nitrogen for 5 min, and under nitrogen protection, add 203 mg of Pd(PPh 3 ) 4 and 2.443 g of cesium carbonate, stir and reflux at 80 °C for 10 h, and cool the reaction to room temperature. After the reaction is completed, distill off the solvent under reduced pressure, and extract three times with dichloromethane / water. Separate and combine the organic phases, add anhydrous Na 2 SO 4 dry, distill off the solvent under reduced pressure, and purify the crude product by column chromatography (petroleum ether:dichloromethane, 4:1) to obtain a light yellow solid TA;

[0103] Among them, the molar ratio of UA, phenylboronic acid benzaldehyde, cesium carbonate, Pd(PPh 3 ) 4 , dioxane, and water is: 10:10:20:1:100:10:20;

[0104] The reaction equation is as follows:

[0105]

[0106] The nuclear magnetic resonance hydrogen spectrum data of the prepared intermediate TA are as follows:1 1H NMR (600 MHz, Chloroform-d) δ 9.97 (s, 1H), 7.87 (d, J = 8.4 Hz, 4H), 6.43 (s, 1H), 4.37 (d, J = 8.3 Hz, 2H), 4.28 (d, J = 8.3 Hz, 2H).

[0107] (2) Preparation of the optical switch molecule TC1:

[0108] Dissolve 0.21 g of TA, 0.08 g of cyanobenzene and 0.04 g of sodium hydroxide in 30 mL of absolute ethanol, and react at room temperature for 12 h under a nitrogen atmosphere. Filter to collect the precipitate, wash it three times with cold methanol (3 times × 15 mL / time), and dry it under vacuum to obtain the green solid TC1;

[0109] The molar ratio of the intermediate TA, cyanobenzene, sodium hydroxide and absolute ethanol is: 1:1:3:20;

[0110] The reaction equation is as follows:

[0111]

[0112] The 1H NMR data of the prepared compound TC1 are as follows: 1 1H NMR (600 MHz, DMSO-d 6 ) δ 8.02 (s, 1H), 7.98 (d, J = 8.5 Hz, 2H), 7.82 (d, J = 8.4 Hz, 2H), 7.77 (d, J = 7.8 Hz, 2H), 7.52 (t, J = 7.7 Hz, 2H), 7.48 - 7.42 (m, 1H), 6.74 (s, 1H), 4.40 - 4.36 (m, 2H), 4.30 - 4.26 (m, 2H).

[0113] Example 2:

[0114] Preparation of the optical switch molecule TC2:

[0115] Dissolve 0.21 g of TA, 0.10 g of 4-methoxycyanobenzene and 0.04 g of sodium hydroxide in 30 mL of absolute ethanol, and react at room temperature for 12 h under a nitrogen atmosphere. Filter to collect the precipitate, wash it three times with cold methanol (3 times × 15 mL / time), and dry it under vacuum to obtain the yellow solid TC2;

[0116] The molar ratio of the intermediate TA, cyanobenzene, sodium hydroxide and absolute ethanol is: 1:1:3:20;

[0117] The reaction equation is as follows:

[0118]

[0119] The 1H NMR data of the prepared compound TC2 are as follows: 1 H NMR(600MHz,Acetonitrile-d 3 )δ7.91(d,J=8.5Hz,2H),7.84(d,J=8.5Hz,2H),7.67(d,J=8.8Hz,2H),7.63(s,1H),7.03(d,J=8.8Hz,2H),6.47(s,1H),4.34(d,J=4.3Hz,2H),4.25(d,J=8.3Hz,2H),3.84(s,3H).

[0120] Example 3:

[0121] This example is the [2+2] cycloaddition UV absorption test of the photoswitch molecule TC1 prepared in Example 1.

[0122] The [2+2] cycloaddition behavior of a mixed solution of molecule TC1 in acetonitrile and water under specific visible light irradiation was studied using UV absorption spectroscopy. The main peak of the UV absorption spectrum in the initial state was 378 nm. When irradiated with light at a specific wavelength of 420 nm, the peak at 378 nm decreased, and the peak at 320 nm increased, indicating that the [2+2] cycloaddition photoisomerization behavior occurred, as shown in the appendix Figure 1 as follows.

[0123] Example 4:

[0124] This example is the [2+2] cycloaddition fluorescence test of the photoswitch molecule TC1 prepared in Example 1.

[0125] The [2+2] cycloaddition behavior of a mixed solution of molecule TC1 in acetonitrile and water under specific visible light irradiation was studied using fluorescence spectroscopy. The main peak of the fluorescence spectrum in the initial state was 519 nm. When irradiated with light at a specific wavelength of 420 nm, the peak at 519 nm decreased and gradually blue-shifted to 481 nm, indicating that the [2+2] cycloaddition photoisomerization behavior occurred, as shown in the appendix Figure 2 as follows.

[0126] Example 5:

[0127] This example is the [2+2] cycloaddition UV absorption test of the photoswitch molecule TC2 prepared in Example 2.

[0128] The [2+2] cycloaddition behavior of a mixed solution of molecule TC2 in acetonitrile and water under specific visible light irradiation was studied using UV absorption spectroscopy. The main peak of the UV absorption spectrum in the initial state was 393 nm. When irradiated with light at a specific wavelength of 420 nm, the peak at 393 nm decreased, and the peak at 323 nm increased, indicating that the [2+2] cycloaddition photoisomerization behavior occurred, as shown in the appendixFigure 3 as shown

[0129] Example 6:

[0130] This example is the [2+2] cycloaddition fluorescence test of the optical switch molecule TC2 prepared in Example 2.

[0131] The [2+2] cycloaddition behavior of a mixed solution of acetonitrile and water of molecule TC2 under specific visible light irradiation was studied using fluorescence spectroscopy. The main peak of the fluorescence spectrum in the initial state was 510 nm. Under irradiation with light of a specific wavelength of 420 nm, the peak at 510 nm decreased and gradually blue-shifted to 465 nm, indicating that [2+2] cycloaddition photoisomerization occurred, as shown Figure 4 as shown

[0132] Example 7:

[0133] This example is the application of the optical switch molecule TC1 in optical information writing and erasing.

[0134] The optical switch molecule can undergo [2+2] cycloaddition photoisomerization under light irradiation, and information writing and erasing can be achieved by controlling the light source irradiation time.

[0135] As Figure 5 shown, agarose was added to water at 1 wt%, and heated to 100 °C to completely dissolve it. Subsequently, the optical switch material TC1 used in Example 1 was added to the agarose solution at a concentration of 1×10 -5 mol / L, mixed evenly, further heated to complete dissolution and then poured into a mold, left to stand and cooled to room temperature to form a hydrogel. The initial fluorescence color of the material was green. A photolithographic mask of a butterfly pattern was placed above the surface of the hydrogel, and irradiated with a 420 nm light source for a certain period of time. It could be observed that [2+2] cycloaddition occurred in the part of the butterfly irradiated by the light source, and the fluorescence color changed to blue. The part blocked by the photolithographic mask did not undergo [2+2] cycloaddition, and the fluorescence color remained green unchanged. Thus, the writing of the butterfly pattern information was completed. After removing the mask, the entire hydrogel part was continuously irradiated with a 420 nm light source until the fluorescence color of the hydrogel all changed to blue, resulting in the disappearance of the written butterfly information, thereby achieving optical information erasing.

[0136] Example 8:

[0137] This example is the application potential of the optical switch molecules TC1 and TC2 in information encryption and anti-counterfeiting, as shown Figure 6 shown. A DMF solution of compound TC2 was prepared at a concentration of 1×10 -5 mol / L, showing blue fluorescence. It was dropped into a well plate to form the digital information "27" with blue fluorescence. The compound TC2 was prepared at a concentration of 1×10 -5Prepare a mixed solution of acetonitrile and water at a concentration of w = 95%). It shows green fluorescence. Supplement and drop it into the empty well plate, and together with the DMF solution of TC2, form the number "80". In addition, prepare a mixed solution of acetonitrile and water with compound TC1 at a concentration of 1×10 -5 mol / L (f w = 95%), which shows green fluorescence. Drop it into the remaining positions of the well plate except for the filled ones. Initially, the well plate shows the number "27" with blue fluorescence under a 365 nm light source. When the solution filled in the well plate is irradiated with a 420 nm light source, the mixed solution of acetonitrile and water of TC2 (f w = 95%) first undergoes a [2+2] cycloaddition. The fluorescent color of the filled part of the well plate changes from green to blue, so the number becomes "80", realizing the decryption of optical information. When continuing to irradiate the solution in the well plate with light of this wavelength, the mixed solution of acetonitrile and water of TC1 (f w = 95%) will also undergo a [2+2] cycloaddition, resulting in the fluorescent color of the filled part of its well plate changing from green to blue. Therefore, all the fluorescent colors become a single blue fluorescence, and the digital information "80" disappears, thus realizing the erasure of optical information.

[0138] Example 9:

[0139] This example is carried out according to the preparation method of the photoswitch molecule TC1 prepared in Example 1. The difference is that the cyanobenzene in step 2 is replaced by 3,5-trifluoromethylphenylacetonitrile, and the prepared photoswitch molecule is labeled as photoswitch molecule TC3. Its molecular structure is as follows:

[0140]

[0141] The 1H NMR data of the prepared photoswitch molecule TC3 are as follows: 1 H NMR(600MHz,DMSO-d6)δ8.38(d,J = 4.4Hz,3H),8.19(s,1H),8.04(d,J = 8.3Hz,3H),7.85(d,J = 8.3Hz,2H),6.77(s,1H),4.41–4.36(m,3H),4.31–4.26(m,3H).

[0142] Example 10:

[0143] This example is the [2+2] cycloaddition ultraviolet absorption test of the photoswitch molecule TC3 prepared in Example 3.

[0144] The [2+2] cycloaddition behavior of a mixed solution of acetonitrile and water of molecule TC3 under specific visible light irradiation was studied using ultraviolet absorption spectroscopy. In the initial state, the main peak of the ultraviolet absorption spectrum was 388 nm. When irradiated with light of a specific wavelength of 420 nm, the peak at 388 nm decreased, and the peak at 319 nm increased, indicating that [2+2] cycloaddition photoisomerization behavior occurred, as shown in the appendix Figure 7 as follows.

[0145] Example 11:

[0146] This example was the [2+2] cycloaddition fluorescence test of the photoswitch molecule TC3 prepared in Example 3.

[0147] The [2+2] cycloaddition behavior of a mixed solution of acetonitrile and water of molecule TC3 under specific visible light irradiation was studied using fluorescence spectroscopy. In the initial state, the main peak of the fluorescence spectrum was 550 nm. When irradiated with light of a specific wavelength of 420 nm, the peak at 510 nm decreased and gradually blue-shifted to 490 nm, indicating that [2+2] cycloaddition photoisomerization behavior occurred, as shown in the appendix Figure 8 as follows.

[0148] Example 12:

[0149] This example was about the application potential of the photoswitch molecules TC2 and TC3 in information encryption and anti-counterfeiting, as shown in the appendix Figure 9 as follows. According to a concentration of 1×10 -5 mol / L, mixed solutions of acetonitrile and water of compounds TC2 and TC3 (f w = 95%) were respectively dropped into the well plate to form the numbers "7" (green fluorescence) and "8"

[0150] (yellow fluorescence). The DMF solution of compound TC2 (blue fluorescence) was used to fill the remaining positions of the well plate filled with the number "7", and the DMF solution of compound TC3 (green fluorescence) was used to fill the remaining positions of the well plate filled with the number "8". In the initial state, the well plate showed the number "7" with green fluorescence and the number "8" with yellow fluorescence under a 365 nm light source, recording the digital information. When the solution filled in the well plate was irradiated with a 420 nm light source, the mixed solutions of acetonitrile and water of TC2 and TC3 (f w = 95%) respectively underwent [2+2] cycloaddition. The fluorescence color of the number "7" changed from green to blue, and the fluorescence color of the number "8" changed from yellow to green. Therefore, the digital information "78" disappeared, thus achieving the erasure of information.

[0151] Since there are many types of photoswitch molecules of cyanostyrene and a large number of examples in the present invention, and the properties of different compounds obtained only by changing the substitution groups are relatively similar. Therefore, the present invention only provides the experimental data of some examples and comparative examples:

[0152]

[0153]

[0154] As can be seen from the above embodiments, the α-cyanostyrene photoswitch molecule prepared by the present invention has the property of rapid visible light response, can achieve [2+2] cycloaddition reaction and significant fluorescence color change, has good stability and fast response speed, and has good application prospects in the field of fluorescent photoswitch materials. In addition, this molecule also shows potential applications in optical information storage, encryption and anti-counterfeiting. By utilizing the fluorescence color difference of the material before and after light response and the different cycloaddition rates of different molecules, the writing, modification and erasure of optical information are realized, thereby achieving the encryption, decryption and anti-counterfeiting of optical information.

[0155] The present invention provides a new solution for the technical field of organic fluorescent photoswitch materials. Those skilled in the art can make several modifications and changes without departing from the principle of the present invention, and these changes are also within the protection scope of the claims of the present invention.

Claims

1. An α-cyanostyrene photoswitch molecule based on visible light regulation, characterized in that: The structural formula of the optical switch molecule TCn is shown in formula (I): R=-H、-4-C n H 2n+1 、-4-OC n H 2n+1 、-4-CF3、-4-CN、-4-N(CH3)3、-3,5-(CF3)2,n=1-6。 2. The α-cyanostyrene photoswitch molecule based on visible light regulation according to claim 1, characterized in that: The optical switch molecule has a [2+2] cycloaddition fluorescence mode in an aggregated state under visible light; in a mixed solution of acetonitrile and water and in a hydrogel, the fluorescence color changes under light irradiation; the wavelength of the light source used by the optical switch molecule is 365nm to 500nm, and the light source irradiation time is 1 to 5min.

3. A method for preparing the visible light-controlled α-cyanostyrene photoswitch molecule according to claim 1 or 2, characterized in that: Here are the steps: (1) Preparation of intermediate TA: 3,4-ethylenedioxythiophene borate, 4-bromobenzaldehyde, cesium carbonate and Pd(PPh3)4 were dissolved in dioxane / water, heated to reflux for reaction, and after completion of the reaction, the solvent was removed by distillation under reduced pressure after cooling, and extracted with dichloromethane / water, and the organic phases were separated and combined, and dried by adding anhydrous Na2SO4, and the solvent was removed by distillation under reduced pressure. The crude product was purified by column chromatography to obtain intermediate TA; The reaction equation is as follows: (2) Preparation of optical switch molecule TCn: The prepared intermediate TA, a benzyl cyanide derivative containing a substituent group R and sodium hydroxide are refluxed and stirred in anhydrous ethanol overnight. After the reaction is completed, the cyanostyrene molecule TCn is obtained after cooling, filtration, washing and drying, where n is a natural number; The reaction equation is as follows: R=-H、-4-C n H 2n+1 、-4-OC n H 2n+1 、-4-CF3、-4-CN、-4-N(CH3)3、-3,5-(CF3)2,n=1-6。 4. The method for preparing an α-cyanostyrene photoswitch molecule regulated by visible light according to claim 3, characterized in that: In step (1), the molar ratio of 3,4-ethylenedioxythiophene borate, 4-bromobenzaldehyde, cesium carbonate, Pd(PPh3)4, dioxane and water is 10:10:20:1:100-120:20; and the heating temperature is 60-90°C.

5. The method for preparing an α-cyanostyrene photoswitch molecule regulated by visible light according to claim 3, characterized in that: In step (2), the molar ratio of the intermediate TA, the benzyl cyanide derivative containing the substituent group R, sodium hydroxide and anhydrous ethanol is 1:1:2-4:20-40.

6. Application of the α-cyanostyrene photoswitch molecule based on visible light regulation as described in claim 1 or 2 in the fields of information encryption and anti-counterfeiting and optical anti-counterfeiting storage.

7. The use according to claim 6, characterized in that: The application is embodied in optical information writing and erasing, and the specific steps are as follows: (1) Preparation of hydrogel: agarose was added to water, followed by a TCn acetonitrile / water solution, and the mixture was heated to completely dissolve, then poured into a mold, allowed to stand and cooled to room temperature to form a hydrogel; (2) Optical information storage: Place the photolithography mask on the surface of the hydrogel, and use a low-power handheld light source of appropriate wavelength to illuminate the hydrogel for a certain period of time to write optical information. At this time, the optical information will be directly stored on the hydrogel surface; (3) Optical information erasure: Remove the template and continue to use a low-power handheld light source to illuminate the hydrogel until the initial fluorescent color of the hydrogel changes completely. At this time, the optical information is erased, causing the written information to disappear.

8. The use according to claim 6, characterized in that: The steps of applying optical information encryption and anti-counterfeiting are: (1) Material preparation: Weigh at least two optical switch molecules TCn with different color change durations and configure them into 1×10 -5 ~5×10 - 5 mol / L mixed solution of acetonitrile and water, volume concentration f w = 80-95% for standby use; then weigh one of the optical switch molecules TCn and configure 1×10 -5 ~5×10 -5 mol / L DMF solution, for later use; (2) Optical information storage: The above solutions are dropped into different well plates according to the information to be stored to form initial information. Under a handheld light source with a suitable wavelength, optical information with fluorescence can be observed. At this time, the optical information can be directly read; (3) Optical information erasure: Continue to use the handheld light source for a certain period of time. At this time, the fluorescent color of the solution changes, causing the written information to disappear.

9. The use according to claim 8, characterized in that: The wavelength of the light source used is 365nm~500nm, and the irradiation time of the light source is 2min.

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