2-phenyl substituted triarylethene photochromic materials, methods of making and applications thereof

Abstract

The present application relates to a kind of 2-phenyl substituted triarylethene photochromic material and preparation method and application, the prepared photochromic material can be by adjusting the steric hindrance and electron-withdrawing ability of 2-substituent group to the photochromic performance of triarylethene Realize significant regulation.This material has low raw material price, simple synthesis step, fast response and excellent fatigue resistance, so that the triarylethene material of original stimulus response single and between structure and photochromic property has no obvious rule is improved, is expected to have wide application prospect in high-speed information storage and fast biological imaging etc.In addition, the present application is suitable for anti-fake, photosensitive decoration, optical information storage, single-molecule logic gate, super-resolution fluorescence imaging, green printing and additive manufacturing etc. by different steric hindrance and electron-withdrawing substituent group to adjust photochromic color saturation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic photochromic materials, and relates to a 2-position phenyl-substituted triaryl ethylene photochromic material and a preparation method and application thereof, in particular to a 2-position phenyl-substituted triaryl ethylene photochromic material, a preparation method thereof, and application of the 2-position phenyl-substituted triaryl ethylene photochromic material in the fields of anti-counterfeiting, photosensitive decoration, optical information storage, single-molecule logic gate, super-resolution fluorescence imaging, green printing, and additive manufacturing. BACKGROUND

[0002] Photochromism refers to the phenomenon that a chemical substance undergoes a reversible color change after being irradiated by light of a certain wavelength (Pure and Applied Chemistry.2001, 73-4, 639-665), during which a significant change in the absorption spectrum occurs. The photochromic process is a reversible chemical change, while some substances undergo irreversible reactions after light irradiation, leading to color changes, which do not belong to the category of photochromism. In recent years, photochromic materials have been widely applied in the fields of photosensitive decoration, optical information storage, single-molecule logic gate, and optoelectronic devices, and have important application prospects in the fields of super-resolution fluorescence imaging, green printing, and additive manufacturing. Photochromic materials are divided into three categories: organic, inorganic, and organic-inorganic hybrid. Compared with inorganic photochromic materials, organic photochromic materials have the advantages of easy modification and processing, excellent fatigue resistance, the ability to be prepared into flexible devices, and good biocompatibility, and thus have become the focus of future research in the field of photochromic materials.

[0003] Organic photochromic materials can be divided into four categories according to their molecular structures: spiropyrans, diarylethenes, azobenzenes, and fulgides. Compounds containing azobenzene molecules are a kind of photoresponsive material based on cis-trans photoisomerization. The compounds can exhibit phenomena such as shrinkage and bending under light, but the color difference before and after light irradiation is small and the fatigue resistance is poor, which is not conducive to their practical application in the field of photochromism. Spiropyrans undergo isomerization and rearrangement before and after ultraviolet irradiation, and the color of the compounds changes from colorless to colored. However, spiropyrans are easily oxidized and degraded, which reduces the stability and fatigue resistance of the material and limits its practical application. Diarylethene compounds undergo reversible photocyclization reactions before and after ultraviolet irradiation, and the color changes. They have excellent photochromic properties, good thermal stability, and fatigue resistance. However, only the cis-conformation of diarylethene can be photochromic, so it is necessary to bridge the five-membered ring on the olefin bond to fix the cis-conformation, which makes the molecular structure of diarylethene complex and difficult to synthesize, limiting its application. Therefore, the present application proposes to design a triaryl ethylene structure to simplify the synthesis steps of photochromic molecules.

[0004] At present, Yu et al. reported that the triarylethylene compounds were introduced with different substituents at the 4-position of the benzene ring on the same side of the alkene hydrogen to adjust the photochromic performance (J. Mater. Chem. C, 2021, 9, 11126-11131), the reported compound structure and photoresponsive properties are single, and there is no obvious rule between the structure and the photochromic properties. Then, the 4-position triarylethylene compound is reported for 3D printing (Research, 2022, 9834140), but the research on other substitution positions of triaryl is relatively less, but the 2-position substitution has a significant influence on the performance adjustment of triarylethylene photochromic molecules, and it is expected to realize significant regulation of the photochromic performance of triarylethylene by adjusting the steric hindrance and electron-withdrawing ability of the 2-position substituent. SUMMARY

[0005] Technical problems to be solved

[0006] In order to avoid the shortcomings of the prior art, the present application provides a 2-phenyl-substituted triarylethylene photochromic material, a preparation method and application, which solves the technical problem that the research on other substitution positions of triaryl ethylene is relatively less.

[0007] The purpose of the present application is to introduce phenyl, 4-fluorophenyl and 4-(trifluoromethyl) phenyl substituents with different electron-withdrawing ability and relatively small steric hindrance into the 2-position of the benzene ring on the same side of the alkene hydrogen in triarylethylene, and to design and synthesize a series of novel triphenylethylene compounds with simple synthesis process and high yield.

[0008] The second purpose of the present application is to study the influence of 2-position substituents on the photochromic properties of triarylethylene compounds by means of ultraviolet-visible absorption spectrum, time-resolved spectrum, X-ray diffraction and single crystal analysis, to put forward reasonable molecular design strategy, and to realize the regulation of the photochromic properties of triarylethylene.

[0009] The third purpose of the present application is to apply this 2-phenyl-substituted triarylethylene photochromic material with fast photoresponse to the fields of high-speed information storage, rapid biological imaging, green printing, anti-counterfeiting and additive manufacturing.

[0010] Technical scheme

[0011] A 2-phenyl-substituted triarylethylene photochromic material, characterized in that the molecular structure general formula is:

[0012]

[0013] wherein R0 and R1 are different modification groups, R1 is selected from fluorine, and R0 is selected from benzene, 4-fluorobenzene or 4-(trifluoromethyl) benzene.

[0014] The synthesis method of the 2-position phenyl-substituted triaryl ethylene photochromic material of claim 1 is characterized in that: the phenyl, 4-fluorobenzene or 4-(trifluoromethyl) benzene is introduced into the 2-position of the triaryl ethylene photochromic material, the steric hindrance and electron-withdrawing ability of the 2-position substituent group are adjusted, so that the triaryl ethylene photochromic material is colored pink, pink or deep pink after ultraviolet irradiation.

[0015] The synthesis method according to claim 2 is characterized in that the steps are as follows:

[0016] Step 1: reacting an aromatic ring, heterocyclic ring or derivative thereof containing a benzyl bromide substituent at one end with triethyl phosphite to prepare a phosphorus ylide reagent;

[0017] Step 2: using Witting reaction, adding a carbonyl group, tetrahydrofuran solution and potassium tert-butoxide to the phosphorus ylide reagent, and reacting under the action of strong base potassium tert-butoxide to prepare a triaryl ethylene skeleton;

[0018] Step 3: using Suzuki coupling reaction, reacting the triaryl ethylene skeleton with phenylboronic acid, 4-fluorobenzene boronic acid pinacol or 4-(trifluoromethyl) benzene boronic acid under the action of palladium catalyst to obtain the target compound, i.e. 2-position phenyl-substituted triaryl ethylene photochromic material.

[0019] The molar ratio of the aromatic ring, heterocyclic ring or derivative thereof containing a benzyl bromide substituent at one end to triethyl phosphite in step 1 is 1:1.5.

[0020] The molar ratio of the phosphorus ylide reagent to the carbonyl group in step 2 is 1:1.2.

[0021] The molar ratio of the triaryl ethylene skeleton to phenylboronic acid, 4-fluorobenzene boronic acid pinacol or 4-(trifluoromethyl) benzene boronic acid is 1:0.5.

[0022] The other synthesis method is characterized in that the steps are as follows:

[0023] Step 1): reacting a benzophenone derivative with an aromatic compound or heterocyclic compound containing a triethyl phosphite group in a tetrahydrofuran solution under the action of potassium tert-butoxide to obtain a difluoro-substituted compound by Wittig reaction;

[0024] Step 2): reacting the difluoro-substituted compound with an aromatic compound or heterocyclic compound containing a boronic acid, 4-fluorobenzene boronic acid pinacol or 4-(trifluoromethyl) benzene boronic acid pinacol boronic acid group in a tetrahydrofuran solution under the action of potassium carbonate to obtain the target compound, i.e. 2-position phenyl-substituted triaryl ethylene photochromic material, by tetraphenylphosphonium palladium catalysis.

[0025] The molar ratio of the aromatic compound containing triethyl phosphite in the step 1) to the benzophenone derivative is 1:1.2.

[0026] The molar ratio of the difluoro-substituted compound to the aromatic compound or heterocyclic compound containing a boronic acid or pinacol boronate group in the step 2) is 1:0.5.

[0027] The application of the 2-position phenyl-substituted triaryl ethylene photochromic material is characterized by being used in the fields of anti-counterfeiting, photosensitive decoration, optical information storage, single-molecule logic gate, super-resolution fluorescence imaging, green printing and additive manufacturing.

[0028] Advantages

[0029] The 2-position phenyl-substituted triaryl ethylene photochromic material, the preparation method and the application provided by the application can significantly regulate the photochromic performance of triaryl ethylene by adjusting the steric hindrance and electron-withdrawing ability of the 2-position substituent group. The material has the advantages of low price of raw materials, simple synthesis steps, fast response and excellent fatigue resistance, so that the originally single stimulus response and the structure and the photochromic property of the triaryl ethylene material have no obvious rules, and the material is improved, and has a wide application prospect in the fields of high-speed information storage and fast biological imaging. In addition, the application regulates the color saturation of the photochromic material by different steric hindrance and electron-withdrawing substituents, and is suitable for the fields of anti-counterfeiting, photosensitive decoration, optical information storage, single-molecule logic gate, super-resolution fluorescence imaging, green printing and additive manufacturing.

[0030] The application introduces phenyl, 4-fluorobenzene and 4-(trifluoromethyl) benzene at the 2-position of the triaryl ethylene photochromic material, significantly regulates the photochromic performance of triaryl ethylene by adjusting the steric hindrance and electron-withdrawing ability of the 2-position substituent group, and makes up for the deficiency that triaryl ethylene compounds are usually introduced with different substituents at the 4-position of the benzene ring on the same side of the ethylene hydrogen to regulate the photochromic performance. The application lays a foundation for further research on how substituents affect the photochromic performance of triaryl ethylene compounds.

[0031] The series of triphenyl ethylene derivatives of the application all have fluorescence switching properties, the luminous intensity of the compound decreases with the increase of the ultraviolet light irradiation time, and can recover to the initial state after stopping the light irradiation. At the same time, the compound shows fast photoresponse in the photochromic property, and the fast photoresponse material is expected to be used in the fields of high-speed information storage and biological imaging.

[0032] The application introduces electron-withdrawing groups to stabilize the closed ring structure of the compound, improve the saturated absorbance of the closed ring isomer, and further improve the photochromic efficiency. The application provides a reasonable molecular design strategy for developing functional materials with fast response characteristics and high saturated absorbance.

[0033] The compound of the present application can also have good photochromic properties in a crystal state. The molecules of a crystal do not have photochromic properties due to the regular arrangement, but the compound of the present application is found by single crystal analysis that when the steric hindrance of the substituent group is small, the molecules are arranged loosely in space, the compound is easy to twist intramolecularly when excited by ultraviolet light, and thus the photochromic phenomenon occurs in the crystal state. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 UV-Vis absorption spectra of three end products of the present application in dichloromethane solution (1.0 x 10-5M). The absorption peaks of the three compounds are located at 304 nm, 304 nm and 305 nm, respectively. The black line is the UV-Vis absorption spectrum of the target product Example 1, the dark gray line is the UV-Vis absorption spectrum of the target product Example 2, and the light gray line is the UV-Vis absorption spectrum of the target product Example 3.

[0035] Figure 2 Time-resolved reflectance spectra of the three end product powders of the present application during the photochromic recovery process and the color change photographs of the powders before and after light irradiation. The different absorbance values of the time-resolved spectra represent the color saturation of the three compounds, and the absorbance of the three compounds increases successively, with the absorbance of Example 3 being the largest and the color being the deepest. (a) is the time-resolved reflectance spectrum of Example 1, (b) is the time-resolved reflectance spectrum of Example 2, and (c) is the time-resolved reflectance spectrum of Example 3.

[0036] Figure 3 Photochromic cycle diagram of the three end product powders of the present application. The photochromic cycle performance can reflect the fatigue resistance of the material, and the cycle times of the three materials are all more than 20 times, proving that they have strong fatigue resistance. (a) is the cycle diagram of Example 1, (b) is the cycle diagram of Example 2, and (c) is the cycle diagram of Example 3. DETAILED DESCRIPTION

[0037] The present application will be further described in conjunction with the examples and drawings:

[0038] A 2-position phenyl-substituted triaryl ethylene photochromic material of the present application has a general molecular formula as shown in general formula (1):

[0039] General formula (1):

[0040]

[0041] wherein R0 and R1 are modifying groups, R0 and R1 are different, and the modifying group R1 in the structure is selected from fluorine, and R0 is selected from benzene, 4-fluorobenzene and 4-(trifluoromethyl)benzene.

[0042] Synthesis method: introducing phenyl, 4-fluorobenzene or 4-(trifluoromethyl) benzene at 2-position of triarylethylene photochromic material, adjusting the steric hindrance and electron-withdrawing ability of 2-position substituent, so that the triarylethylene photochromic, the color of the compound after ultraviolet irradiation is pink, pink or deep pink respectively.

[0043] Synthesis method one:

[0044] Step 1: reacting aromatic ring, aromatic heterocycle or its derivative containing benzyl bromide substituent with triethyl phosphite (80-100 degrees, example 85 degrees) to prepare phosphorus ylide reagent; ordinary SN2 reaction;

[0045] The ratio of phosphorus ylide reagent to carbonyl in step 2 is 1:1.2.

[0046] Step 2: using Witting reaction, adding carbonyl, tetrahydrofuran solution, potassium tert-butoxide (ice bath, example 0℃) to the phosphorus ylide reagent, and reacting under the action of strong base potassium tert-butoxide to prepare triarylethylene skeleton material; the PH of the solution is 13;

[0047] Step 3: using Suzuki coupling reaction (80-100 degrees, example 85 degrees), reacting triarylethylene skeleton material with phenylboronic acid, 4-fluorobenzene boronic acid pinacol or 4-(trifluoromethyl) benzene boronic acid under the action of palladium catalyst to obtain the target compound, i.e. 2-phenyl substituted triarylethylene photochromic material.

[0048] The ratio of triarylethylene skeleton material to phenylboronic acid, 4-fluorobenzene boronic acid pinacol or 4-(trifluoromethyl) benzene boronic acid is 1:0.5.

[0049] Synthesis method two:

[0050] Step 1): diphenone derivative and aromatic compound or heterocyclic compound containing triethyl phosphite group, in tetrahydrofuran solution, under the action of potassium tert-butoxide, through Wittig reaction to obtain difluoro-substituted compound (80-100 degrees, example 85 degrees);

[0051] The ratio of aromatic compound containing triethyl phosphite to diphenone derivative in step 1) is 1:1.2.

[0052] Step 2): reacting difluoro-substituted compound with aromatic compound or heterocyclic compound containing boronic acid, 4-fluorobenzene boronic acid pinacol or 4-(trifluoromethyl) benzene boronic acid pinacol boronic acid group, in tetrahydrofuran solution, under the action of potassium carbonate, through tetraphenylphosphonium palladium catalysis to obtain the target compound, i.e. 2-phenyl substituted triarylethylene photochromic material.

[0053] The reaction ratio of the difluoro-substituted compound to the aromatic compound or heterocyclic compound containing a boronic acid or pinacol boronic ester group in the step 2) is 1:0.5.

[0054] The present application is further illustrated by the following specific examples, but the present application is not limited to this specific example.

[0055] Example 1:

[0056] (1) Synthesis of intermediate 【4,4'-(2-(2-iodophenyl)vinyl-1,1-diyl)difluorobenzene】

[0057]

[0058] A 250 mL two-necked flask was charged with 2-iodobenzyl bromide (2.00 g, 6.74 mmol) and triethyl phosphite (1.68 g, 10.10 mmol) under argon atmosphere, and the phosphorus ylide reagent 2-iodophenyl diethyl phosphonate was obtained by refluxing at 85°C for 6 h. Then, tetrahydrofuran (50 mL) and 4,4'-difluorobenzophenone (1.78 g, 8.08 mmol) were added to the flask in an ice-water bath, and after the chemicals were completely dissolved, potassium tert-butoxide (2.27 g, 20.21 mmol) was slowly added, and the reaction was stopped after stirring at room temperature for 3 h. The reaction solution was concentrated by distillation under reduced pressure, extracted with dichloromethane and saturated brine, and the organic phase was collected and dried. The crude product was purified by silica gel column chromatography, and the eluent was n-hexane. A yellowish solid was obtained in a yield of 1.95 g, 69.14%.1H NMR (500 MHz, CDCl3) δ 7.82 (d, J = 7.9 Hz, 1H), 7.31 (dd, J = 7.1, 5.5 Hz, 2H), 7.25 (d, J = 0.9 Hz, 1H), 7.07-6.97 (m, 5H), 6.91 (t, J = 8.3 Hz, 2H), 6.84-6.76 (m, 3H).

[0059] (2) Synthesis of the target product of Example 1

[0060]

[0061] Into a 250 mL two-necked flask, intermediate 【4,4'-(2-(2-iodophenyl)vinyl-1,1-diyl) difluorobenzene】 (1.89 g, 4.51 mmol) and phenylboronic acid (0.50 g, 4.10 mmol) were added under argon atmosphere, followed by tetrahydrofuran (50 mL), aqueous potassium carbonate solution (4.1 M, 3 mL) and catalyst tetrakis(triphenylphosphine)palladium (0.05 g, 0.06 mmol). The reaction was stopped after refluxing at 85 °C for 18 h. The reaction was concentrated by distillation under reduced pressure, extracted with dichloromethane and saturated brine, and the organic phase was collected and dried. The crude product was purified by silica gel column chromatography, eluting with n-hexane. A white solid was obtained, 0.86 g, yield 56.95%.1H NMR (500 MHz, CDCl3) δ 7.38-7.32 (m, 4H), 7.31-7.26 (m, 2H), 7.22 (td, J = 7.5, 1.0 Hz, 1H), 7.18-7.14 (m, 2H), 7.09-7.01 (m, 3H), 6.99 (d, J = 7.8 Hz, 1H), 6.97-6.89 (m, 4H), 6.72 (s, 1H).

[0062] The product of this example was prepared into a 1.0 x 10 -5 M dichloromethane solution, and the absorption peak of the compound was measured at 304 nm, corresponding to a molar extinction coefficient of 2.06 x 10 4 The UV-Vis absorption spectrum of the compound in dichloromethane solution was measured as shown by the blue line. Figure 1

[0063] The product of this example had photochromic properties in amorphous state under irradiation of a 365 nm LED UV light source, gradually changing from white powder to pink, due to the increase in intramolecular conjugation, and the low-energy absorption band of the reflection spectrum gradually increased at about 511 nm; when the irradiation was stopped, the color of the compound quickly recovered to white within 5 s. The time-resolved reflection spectrum during the photochromic recovery process and the photos of the powder before and after irradiation were measured as shown in Figure 3 (a).

[0064] The product of this example reached a steady state under UV irradiation for 2 s and recovered to the initial state within 5 s, and the fatigue resistance of the material was tested by drawing a photochromic cycle diagram by collecting the highest point and the lowest point of the compound at the maximum absorption wavelength. The measured photochromic cycle diagram is shown in Figure 2 (a). After 20 times of alternating irradiation of UV-Vis light, the photochromic intensity of the compound did not significantly weaken, showing good reversibility.

[0065] Example 2:

[0066] ​

[0067] The target compound was synthesized according to the procedure of Step (2) of Example 1, using 4-fluorophenylboronic acid pinacol ester instead of phenylboronic acid. The crude product was purified by silica column chromatography to give a white solid 0.95 g in 54.68% yield. 1H NMR (500 MHz, CDC13) δ 7.30-7.27 (m, 2H), 7.23 (qd, J = 7.8, 1.4 Hz, 2H), 7.18-7.14 (m, 2H), 7.09 (td, J = 7.6, 1.8 Hz, 1H), 7.04-6.89 (m, 9H), 6.68 (s, 1H).

[0068] The product of this example was formulated into a solution with a concentration of 1.0 x 10 -5 The UV-Vis absorption spectrum of the compound in dichloromethane solution was measured and the absorption peak of the compound was found to be at 304 nm, corresponding to a molar extinction coefficient of 1.80 x 10 4 The UV-Vis absorption spectrum of the compound in dichloromethane solution was measured and the absorption peak of the compound was found to be at 304 nm, corresponding to a molar extinction coefficient of 1.80 x 10 Figure 1 The UV-Vis absorption spectrum of the compound in dichloromethane solution was measured and the absorption peak of the compound was found to be at 304 nm, corresponding to a molar extinction coefficient of 1.80 x 10

[0069] The product of this example exhibited photochromic properties in the amorphous state under irradiation of a 365 nm LED UV light source, gradually changing from white powder to pink, due to an increase in intramolecular conjugation, and the low-energy absorption band at about 509 nm in the reflectance spectrum gradually increased; when the irradiation was stopped, the color of the compound rapidly returned to white within 6 s. The time-resolved reflectance spectrum during the photochromic recovery process and the photographs of the powder before and after irradiation were measured and are shown in Figure 3 (b).

[0070] The product of this example reached a steady state after 4 s of UV irradiation and returned to the initial state within 6 s. The fatigue resistance of the material was tested by collecting the highest point and the lowest point of the compound at the maximum absorption wavelength to draw a photochromic cycle diagram. The photochromic cycle diagram was measured and is shown in Figure 2 (b). The compound showed good reversibility, as there was no significant weakening of the photochromic intensity after 20 cycles of alternating UV-Vis irradiation.

[0071] Example 3:

[0072]

[0073] The target compound was synthesized according to the procedure of Step (2) of Reference Example 1 using 4-(trifluoromethyl)phenylboronic acid instead of phenylboronic acid. The crude product was purified by silica column chromatography to give a white solid 1.17 g in 63.59% yield.1H NMR (500 MHz, CDCI3) δ 7.56 (d, J = 8.1 Hz, 2H), 7.40 (d, J = 8.0 Hz, 2H), 7.24 (t, J = 3.7 Hz, 2H), 7.18-7.13 (m, 3H), 7.08 (d, J = 7.7 Hz, 1H), 6.99-6.93 (m, 2H), 6.93-6.85 (m, 4H), 6.70 (s, 1H).

[0074] The product of this example was formulated into a concentration of 1.0 x 10 -5 The molar extinction coefficient of the compound was measured to be 1.80 x 10 4 The UV-Vis absorption spectrum of the compound in dichloromethane solution is shown by the red line. Figure 1

[0075] The product of this example exhibited photochromic properties in amorphous state under 365 nm LED UV light source, the compound gradually changed from white powder to deep pink, due to the increase of intramolecular conjugation, the low energy absorption band at about 509 nm in reflectance spectrum gradually increased; when the light was stopped, the color of the compound quickly recovered to white within 52 s. In addition, the photochromic degree of Example 3 powder irradiated by UV lamp for 2 s could exceed the saturated absorbance of Example 2. The time-resolved reflectance spectrum during the photochromic recovery process and the photos of the powder before and after irradiation are shown in Figure 3 (c).

[0076] The product of this example reached a steady state under UV light irradiation for 15 s and recovered to the initial state within 52 s, the fatigue resistance of the material was tested by drawing the photochromic cycle diagram by collecting the highest point and the lowest point of the compound at the maximum absorption wavelength. The photochromic cycle diagram is shown in Figure 2 (c). The compound showed good reversibility without significant weakening of photochromic intensity after 20 times of alternating irradiation of UV-Vis light.

[0077] ​By comparing the photochromic properties of the three embodiments of the present application, it is found that as the electron-withdrawing ability of the substituent group increases, the saturated absorbance of the compound gradually increases, the photochromic color changes from pink to pink and finally to deep pink, and the compound reaches a steady state within 2s, 4s and 15s of ultraviolet light irradiation, respectively, and returns to the initial state within 5s, 6s and 52s. This is because the three compounds have a low energy barrier during the photochromic process, which enables the compound to quickly undergo photocyclization reaction after irradiation. And example 3 shows extremely high saturated absorbance under short time ultraviolet irradiation, because the introduction of trifluoromethyl with strong electron-withdrawing ability in the triphenyl ethylene structure makes the photochromic degree of compound example 3 significantly improved. The photochromic cycle test shows that the photochromic intensity of the three compounds does not decrease significantly after 20 times of alternating ultraviolet-visible light irradiation, showing good reversibility.

[0078] Table 1: Maximum fluorescence emission wavelength of final product in solid, color change response time, recovery time, maximum color change ultraviolet absorption wavelength and photochromic cycle number in each embodiment

[0079]

[0080] Note: The emission spectrum and cycle performance of the solid are measured by Ocean Optics QE65PRO spectrometer with Ocean Optics R600-125F reflection probe.

[0081] In summary, a series of triphenyl ethylene derivatives are designed and synthesized by introducing phenyl, 4-fluorobenzene and 4-(trifluoromethyl) benzene substituents with relatively small steric hindrance to the 2-position of the phenyl ring on the same side of the hydrogen bond in triphenyl ethylene. The fast photoresponse characteristics of the three compounds are studied by ultraviolet-visible absorption spectrum and time-resolved ultraviolet-visible reflection spectrum. This kind of fast photoresponsive material is expected to have broad application prospects in the fields of high-speed information storage and fast biological imaging. The excellent photochromic properties of the inventive example 3 are due to the introduction of electron-withdrawing groups to stabilize the closed ring structure of the compound, thereby improving the photochromic efficiency of the compound. Therefore, the introduction of trifluoromethyl substituent with strong electron-withdrawing ability into the triaryl ethylene structure can significantly improve the saturated absorbance of the closed ring isomer, which provides a reasonable molecular design strategy for developing functional materials with fast response characteristics and high saturated absorbance. The preparation method of the present application is simple and suitable for application in the fields of anti-counterfeiting, photosensitive decoration, optical information storage, single molecule logic gate, super-resolution fluorescence imaging, green printing and additive manufacturing. As described above, those skilled in the art can make other various corresponding changes and modifications according to the technical solutions and technical concepts of the present application, and all these changes and modifications shall belong to the protection scope of the claims of the present application.

Claims

1. A 2-phenyl-substituted triarylethene photochromic material, characterized in that The general molecular structure formula is: Wherein, R0 and R1 are different modifying groups, R1 is selected from fluorine, and R0 is selected from benzene or 4-fluorobenzene.

2. A method for synthesizing the 2-phenyl-substituted triarylethene photochromic material according to claim 1, characterized in that: The following steps are involved: Step 1): ; Step 2): , or, .

3. Use of the 2-phenyl-substituted triarylethene photochromic material according to claim 1, characterized in that: Used in anti-counterfeiting, photosensitive decoration, optical information storage, single-molecule logic gates, super-resolution fluorescence imaging, green printing or additive manufacturing.

Images