CN116789518A - 2-position phenyl-substituted triarylethylene photochromic materials and their preparation methods and applications - Google Patents

Abstract

The invention relates to a 2-position phenyl-substituted triarylethylene photochromic material and its preparation method and application. The prepared photochromic material can adjust the steric hindrance and electron-withdrawing ability of the 2-position substituent to triarylethylene. The photochromic properties of vinylethylene can be significantly controlled. This material has low raw material prices, simple synthesis steps, fast response and excellent fatigue resistance, which improves the original triarylethylene material with single stimulus response and no obvious pattern between structure and photochromic properties, and is expected to be used at high speeds. It has broad application prospects in areas such as information storage and rapid biological imaging. In addition, the present invention adjusts the photochromic color saturation through different steric hindrance and electron-withdrawing substituents, and is suitable for anti-counterfeiting, photosensitive decoration, optical information storage, single-molecule logic gates, super-resolution fluorescence imaging, green printing and additive manufacturing, etc. field.

Description

2-position phenyl substituted triarylethylene photochromic material and preparation method thereof application

Technical field

The invention belongs to the technical field of organic photochromic materials, and relates to a 2-position phenyl-substituted triarylethylene photochromic material and its preparation method and application, in particular to a 2-position phenyl-substituted triarylethylene photochromic material. Color-changing materials and their preparation methods and their applications in the fields of anti-counterfeiting, photosensitive decoration, optical information storage, single-molecule logic gates, super-resolution fluorescence imaging, green printing and additive manufacturing.

Background technique

Photochromism refers to the phenomenon of reversible color change of chemical substances after being irradiated with light of a certain wavelength (Pure and Applied Chemistry. 2001, 73-4, 639-665), which is accompanied by obvious changes in the absorption spectrum. The photochromic process is a reversible chemical change, and some substances undergo irreversible reactions after exposure to light, resulting in color changes. This irreversible change does not fall into the category of photochromism. In recent years, photochromic materials have been widely used in fields such as photosensitive decoration, optical information storage, single-molecule logic gates and optoelectronic devices, and have important application prospects in super-resolution fluorescence imaging, green printing, additive manufacturing and other fields. Photochromic materials are divided into three categories: organic, inorganic, and organic-inorganic hybrid. Compared with inorganic photochromic materials, organic photochromic materials are easy to modify and process, have excellent fatigue resistance, can be prepared into flexible devices, and have good Advantages such as biocompatibility have become the focus of research on the future development of photochromic materials.

Organic photochromic materials can be divided into four categories according to their molecular structures: spiropyran, diarylethene, azobenzene and fulgonic acid anhydride. Compounds containing azobenzene molecules are light-responsive materials based on cis-reflective isomerization. The compounds can undergo photo-induced deformation phenomena such as shrinkage and bending at the macroscopic level. However, the difference in color change before and after illumination is small and the anti-fatigue performance is poor, which is not conducive to Its practical application in the field of photochromism. The molecules of spiropyran compounds undergo isomerization and rearrangement before and after UV light irradiation, and the color of the compound changes from colorless to colored. However, spiropyran is easily oxidized and degraded, which reduces the stability and fatigue resistance of the material and limits its use. practical application. Diarylethene compounds will undergo a reversible photocyclization reaction and change color before and after ultraviolet irradiation. They have excellent photochromic properties, good thermal stability and fatigue resistance, but only the cis conformation diarylethene can be photochromic. It causes color change, so it is necessary to bridge the five-membered ring on the olefinic bond to fix the cis conformation. This makes the diarylethylene molecular structure complex and difficult to synthesize, which limits its application. Based on this, the present invention proposes to design a triarylethene structure to simplify the synthesis steps of photochromic molecules.

Currently, most of the triarylethene compounds reported by Yu et al. introduce different substituents at the 4-position of the benzene ring on the same side of the olefinic hydrogen to adjust the photochromic properties (J.Mater.Chem.C, 2021, 9, 11126-11131) , the reported compound structure and photoresponsive properties are single, and there is no obvious pattern between the structure and photochromic properties. Later, it was also reported that 4-position triarylethene compounds are used for 3D printing (Research, 2022, 9834140). There are relatively few studies on other substitution positions of triaryl groups, but the 2-position substitution of triarylethene photochromic molecules is Performance adjustment has a significant impact, and it is expected that the photochromic properties of triarylethene can be significantly controlled by adjusting the steric hindrance and electron-withdrawing ability of the 2-position substituent.

Contents of the invention

Technical issues to be solved

In order to avoid the deficiencies of the prior art, the present invention proposes a 2-position phenyl-substituted triarylethene photochromic material and its preparation method and application. It solves the relative problem of research on other substitution positions of triarylethene except the 4-position. Fewer technical issues.

The purpose of the present invention is to introduce phenyl, 4-fluorophenyl and 4-(trifluoromethyl)benzene substituents with different electron withdrawing abilities and relatively small steric hindrance into the same side benzene ring of the olefinic hydrogen in triarylethylene. 2-position, design and synthesize a series of new triptyrene compounds with simple synthesis process and high yield.

The second purpose of the present invention is to study the influence of the 2-position substituent on the photochromic properties of triarylethene compounds by means of ultraviolet-visible absorption spectroscopy, time-resolved spectroscopy, X-ray diffraction and single crystal analysis, and propose a reasonable Molecular design strategies to control the photochromic properties of triarylethenes.

The third purpose of the present invention is to apply this 2-position phenyl-substituted triarylethylene photochromic material with fast light response to the fields of high-speed information storage, rapid biological imaging, green printing, anti-counterfeiting, additive manufacturing and other fields.

Technical solutions

A 2-position phenyl-substituted triarylethylene photochromic material, characterized by the general molecular structure formula:

Among them, R0 and R1 are different modifying groups, R1 is selected from fluorine, and R0 is selected from benzene, 4-fluorobenzene or 4-(trifluoromethyl)benzene.

A method for synthesizing 2-position phenyl-substituted triarylethene photochromic materials according to claim 1, characterized in that phenyl and 4-fluorobenzene are introduced into the 2-position of the triarylethene photochromic material. Or 4-(trifluoromethyl)benzene, adjust the steric hindrance and electron-withdrawing ability of the 2-position substituent to make triarylethene photochromic, and introduce phenyl, 4-fluorobenzene or 4- (Trifluoromethyl)benzene compounds are pink, pink or dark pink in color after ultraviolet irradiation.

The synthesis method according to claim 2, characterized in that: the steps are as follows:

Step 1: Prepare a phosphorus ylide reagent by reacting an aromatic ring, aromatic heterocycle or derivatives thereof containing a benzyl bromide substituent at one end with triethyl phosphite;

Step 2: Using Witting reaction, add carbonyl, tetrahydrofuran solution, and potassium tert-butoxide to the phosphorus ylide reagent, and react under the action of potassium tert-butoxide, a strong base, to prepare a triarylethene skeleton; the pH of the solution is 13;

Step 3: Using Suzuki coupling reaction, the target compound is obtained by reacting the triarylethene skeleton with phenylboronic acid, 4-fluorophenylboronic acid pinacol ester or 4-(trifluoromethyl)phenylboronic acid under the action of palladium catalyst, respectively. 2-position phenyl substituted triarylethylene photochromic material.

In step 1, the reaction molar ratio of the aromatic ring, aromatic heterocycle or derivatives thereof containing a benzyl bromide substituent at one end and triethyl phosphite is 1:1.5.

In step 2, the molar ratio of phosphorus ylide reagent to carbonyl group is 1:1.2.

The molar ratio of the triarylethene skeleton to phenylboronic acid, 4-fluorophenylboronic acid pinacol ester or 4-(trifluoromethyl)phenylboronic acid is 1:0.5.

Described another synthetic method is characterized in that the steps are as follows:

Step 1): The difluoro substituent is obtained through the Wittig reaction between benzophenone derivatives and aromatic compounds or heterocyclic compounds containing triethyl phosphite groups in a tetrahydrofuran solution under the action of potassium tert-butoxide;

Step 2): The difluoro substituent is separately combined with an aromatic compound or heterocyclic compound containing boric acid, 4-fluorophenylboronic acid pinacol ester or 4-(trifluoromethyl)phenylboronic acid pinacol boronic acid ester group, in In tetrahydrofuran solution, under the action of potassium carbonate, the target compound, that is, the 2-position phenyl-substituted triarylethene photochromic material is obtained through tetrakis triphenylphosphine palladium catalysis.

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

In the step 2), the reaction molar ratio between the difluoro substituent and the aromatic compound or heterocyclic compound containing boric acid or pinacol borate ester group is 1:0.5.

An application of the 2-position phenyl-substituted triarylethylene photochromic material, which is characterized in that it is used for anti-counterfeiting, photosensitive decoration, optical information storage, single-molecule logic gates, super-resolution fluorescence imaging, and green printing and additive manufacturing fields.

beneficial effects

The invention proposes a 2-position phenyl-substituted triarylethene photochromic material, its preparation method and application. The prepared photochromic material can adjust the steric hindrance and electron-withdrawing ability of the 2-position substituent. The photochromic properties of triarylethenes can be significantly regulated. This material has low raw material prices, simple synthesis steps, fast response and excellent fatigue resistance, which improves the original triarylethylene materials that have a single stimulus response and no obvious pattern between structure and photochromic properties. It is expected to be used at high speeds. It has broad application prospects in areas such as information storage and rapid biological imaging. In addition, the present invention adjusts the photochromic color saturation through different steric hindrance and electron-withdrawing substituents, and is suitable for anti-counterfeiting, photosensitive decoration, optical information storage, single-molecule logic gates, super-resolution fluorescence imaging, green printing and additive manufacturing, etc. field.

The present invention introduces phenyl, 4-fluorobenzene and 4-(trifluoromethyl)benzene into the 2-position of the triarylethylene photochromic material, and adjusts the steric hindrance and electron-withdrawing ability of the 2-position substituent to triarylethylene. The photochromic properties of ethylene can be significantly regulated, which makes up for the shortcoming that most triarylethene compounds introduce different substituents at the 4-position of the benzene ring on the same side of the olefinic hydrogen to adjust the photochromic properties. It lays the foundation for in-depth research on how substituents affect the photochromic properties of triarylethene compounds.

A series of triptyrene derivatives of the present invention all have fluorescence switching properties. The luminous intensity of the compounds decreases with the increase of ultraviolet illumination time, and can be restored to the initial state after the illumination is stopped. At the same time, the compound shows fast photoresponsiveness in photochromic properties. This fast photoresponsive material is expected to be used in fields such as high-speed information storage and biological imaging.

The present invention introduces electron-withdrawing groups to stabilize the closed-ring structure of the compound, improve the saturated absorbance of the closed-ring isomer, and thereby improve the photochromic efficiency. This invention provides a rational molecular design strategy for the development of functional materials with fast response properties and high saturation absorbance.

The compounds involved in the present invention can also have good photochromic properties in the crystalline state. Crystal molecules usually do not have photochromic properties due to their neat arrangement. However, the compound of the present invention has been found through single crystal analysis that when the steric hindrance of the substituent is small, the molecules will The compounds are loosely arranged in space and are prone to intramolecular twisting when excited by ultraviolet light, thus producing photochromic phenomena in the crystalline state.

Description of the drawings

Figure 1 shows the UV-visible absorption spectra of three final products of the present invention in methylene chloride solution (1.0×10-5M). The absorption peaks of the three compounds are located at 304nm, 304nm and 305nm respectively. The black line is the UV-visible absorption spectrum of the target product Example 1, the dark gray line is the UV-visible absorption spectrum of the target product Example 2, and the light gray line is the UV-visible absorption spectrum of the target product Example 3.

Figure 2 is a time-resolved reflection spectrum of the three final product powders of the present invention during the photochromic recovery process and a photograph of the color change of the powder before and after illumination. Different absorbance values in the time-resolved spectrum represent the color saturation of the three compounds. The absorbances of the three compounds increase gradually. Example 3 has the largest absorbance and the deepest color. (a) is the time-resolved reflection spectrum of Example 1, (b) is the time-resolved reflection spectrum of Example 2, and (c) is the time-resolved reflection spectrum of Example 3.

Figure 3 is a photochromic cycle diagram of three final product powders of the present invention. The photochromic cycle performance can reflect the fatigue resistance of the material. The cycle times of the three materials are more than 20 times, proving their strong fatigue resistance. (a) is a cycle diagram of Example 1, (b) is a cycle diagram of Example 2, and (c) is a cycle diagram of Example 3.

Detailed ways

The present invention will now be further described with reference to the embodiments and drawings:

The general molecular formula of a 2-position phenyl-substituted triarylethene photochromic material of the present invention is as shown in general formula (1):

General formula (1):

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

Synthesis method: Introduce phenyl, 4-fluorobenzene or 4-(trifluoromethyl)benzene into the 2-position of the triarylethene photochromic material, and adjust the steric hindrance and electron-withdrawing ability of the 2-position substituent so that Triarylethene is photochromic. Compared with compounds in which phenyl, 4-fluorobenzene or 4-(trifluoromethyl)benzene are introduced into the 2-position, the colors after UV irradiation are pink, pink or dark pink respectively.

One of the synthesis methods:

Step 1: Prepare phosphorus ylide reagent by reacting an aromatic ring, aromatic heterocyclic ring or derivatives thereof containing a benzyl bromide substituent at one end with triethyl phosphite (80-100 degrees, Example 85 degrees); ordinary SN ₂ reaction;

In step 2, the ratio of phosphorus ylide reagent to carbonyl group is 1:1.2.

Step 2: Using Witting reaction, add carbonyl, tetrahydrofuran solution, and potassium tert-butoxide (ice bath, Example 0°C) to the phosphorus ylide reagent, react under the action of strong base potassium tert-butoxide to prepare a triarylethene skeleton; The pH of the solution is 13;

Step 3: Use Suzuki coupling reaction (80-100 degrees, Example 85 degrees), and react with phenylboronic acid, 4-fluorophenylboronic acid pinacol ester or 4-(trifluoromethyl)benzene through the triarylethene skeleton Boric acid reacts under the action of a palladium catalyst to obtain the target compound, which is a 2-position phenyl-substituted triarylethylene photochromic material.

The ratio of the triarylethene skeleton to phenylboronic acid, 4-fluorophenylboronic acid pinacol ester or 4-(trifluoromethyl)phenylboronic acid is 1:0.5.

Synthesis method two:

Step 1): The benzophenone derivative and an aromatic compound or heterocyclic compound containing a triethyl phosphite group are reacted in a tetrahydrofuran solution under the action of potassium tert-butoxide to obtain a difluoro substituent (80 ~100 degrees, embodiment 85 degrees);

The ratio of aromatic compounds containing triethyl phosphite to benzophenone derivatives in step 1) is 1:1.2.

Step 2): The difluoro substituent is separately combined with an aromatic compound or heterocyclic compound containing boric acid, 4-fluorophenylboronic acid pinacol ester or 4-(trifluoromethyl)phenylboronic acid pinacol boronic acid ester group, in In tetrahydrofuran solution, under the action of potassium carbonate, the target compound, that is, the 2-position phenyl-substituted triarylethene photochromic material is obtained through tetrakis triphenylphosphine palladium catalysis.

In the step 2), the reaction ratio between the difluoro substituent and the aromatic compound or heterocyclic compound containing boric acid or pinacol borate ester group is 1:0.5.

The present invention will be further described below through specific implementation examples, but the present invention is not limited to this specific example.

Example 1:

(1) Synthesis of intermediate [4,4'-(2-(2-iodophenyl)ethylene-1,1-diyl)bisfluorobenzene]

Add 2-iodobenzyl bromide (2.00g, 6.74mmol) and triethyl phosphite (1.68g, 10.10mmol) to a 250mL double-necked flask under an argon atmosphere, reflux at 85°C for 6 hours and then stop heating to obtain the phosphorus ylide reagent. 2-Iodophenyl diethyl phosphate. Then add tetrahydrofuran (50mL) and 4,4'-difluorobenzophenone (1.78g, 8.08mmol) to the flask in an ice-water bath. After the drugs are completely dissolved, slowly add potassium tert-butoxide (2.27g, 20.21mmol). , the reaction was stopped after stirring for 3 hours at room temperature. The reaction solution was concentrated by distillation under reduced pressure, extracted and separated 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. 1.95g of light yellow solid was obtained, with a yield of 69.14%. 1H NMR (500MHz, CDCl3) δ7.82(d,J＝7.9Hz,1H),7.31(dd,J＝7.1,5.5Hz,2H),7.25(d,J＝0.9Hz,1H),7.07-6.97 (m,5H),6.91(t,J=8.3Hz,2H),6.84-6.76(m,3H).

(2) Synthesis of target product Example 1

Add the intermediate [4,4'-(2-(2-iodophenyl)ethylene-1,1-diyl)bisfluorobenzene] (1.89g, 4.51mmol) and benzene to a 250mL double-necked flask under an argon atmosphere. Boric acid (0.50g, 4.10mmol), then add tetrahydrofuran (50mL), potassium carbonate aqueous solution (4.1M, 3mL) and catalyst tetrakis(triphenylphosphine)palladium (0.05g, 0.06mmol), and reflux at 85°C for 18h. Stop reacting. The reaction solution was concentrated by distillation under reduced pressure, extracted and separated 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. 0.86g of white solid was obtained, with a yield of 56.95%. 1HNMR (500MHz, CDCl3) δ7.38-7.32(m,4H),7.31-7.26(m,2H),7.22(td,J＝7.5,1.0Hz,1H),7.18-7.14(m,2H),7.09 -7.01(m,3H),6.99(d,J＝7.8Hz,1H),6.97-6.89(m,4H),6.72(s,1H).

The product of this example was prepared into a methylene chloride solution with a concentration of 1.0×10 ^-5 M. The measured absorption peak of the compound was located at 304 nm, and the corresponding molar extinction coefficient was 2.06×10 ⁴ . The measured UV-visible absorption spectrum of the compound in dichloromethane solution is shown as the blue line in Figure 1.

Under the irradiation of 365nm LED ultraviolet light source, the product of this example has photochromic properties in the amorphous form, gradually turning from white powder to pink, which is attributed to the increase in intramolecular conjugation and the low-energy absorption of the reflection spectrum at about 511nm. The band gradually increased; when the illumination was stopped, the color of the compound quickly returned to white within 5 s. The time-resolved reflectance spectrum measured during the photochromic recovery process and the photos of the powder before and after illumination are shown in Figure 3(a).

The product in this example reaches a steady state under UV irradiation for 2 seconds and returns to the initial state within 5 seconds. The fatigue resistance of the material is tested by collecting the highest point and lowest point of the compound at the maximum absorption wavelength and drawing a photochromic cycle diagram. The measured photochromic cycle diagram is shown in Figure 2(a). After the compound was alternately irradiated with UV-visible light for 20 times, its photochromic intensity did not weaken significantly, showing good reversibility.

Example 2:

Referring to step (2) of Example 1, 4-fluorophenylboronic acid pinacol ester was used instead of phenylboronic acid to synthesize the target compound Example 2. The crude reaction product was purified by silica column chromatography to obtain 0.95 g of white solid, with a yield of 54.68%. 1H NMR (500MHz, CDCl3) δ7.30-7.27(m,2H),7.23(qd,J＝7.8,1.4Hz,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).

The product of this example was prepared into a methylene chloride solution with a concentration of 1.0×10 ^-5 M. The measured absorption peak of the compound was located at 304 nm, and the corresponding molar extinction coefficient was 1.80×10 ⁴ . The measured UV-visible absorption spectrum of the compound in dichloromethane solution is shown as the black line in Figure 1.

Under the irradiation of 365nm LED ultraviolet light source, the product of this example has photochromic properties in the amorphous form, gradually turning from white powder to pink, which is attributed to the increase in intramolecular conjugation and the low energy reflection spectrum at about 509nm. The absorption band gradually increased; when the illumination was stopped, the color of the compound quickly returned to white within 6 seconds. The time-resolved reflectance spectrum measured during the photochromic recovery process and its photos before and after powder illumination are shown in Figure 3(b).

The product in this example reaches a steady state after 4 seconds of UV illumination and returns to the initial state within 6 seconds. The fatigue resistance of the material is tested by collecting the highest and lowest points of the compound at the maximum absorption wavelength and drawing a photochromic cycle diagram. The measured photochromic cycle diagram is shown in Figure 2(b). After the compound was alternately irradiated with UV-visible light for 20 times, its photochromic intensity did not weaken significantly, showing good reversibility.

Example 3:

Referring to step (2) of Example 1, 4-(trifluoromethyl)phenylboronic acid was used instead of phenylboronic acid to synthesize the target compound Example 3. The crude reaction product was purified by silica column chromatography to obtain 1.17 g of white solid, with a yield of 63.59%. 1H NMR (500MHz, CDCl3) δ7.56 (d, J = 8.1Hz, 2H), 7.40 (d, J = 8.0Hz, 2H), 7.24 (t, J = 3.7Hz, 2H), 7.18-7.13 (m ,3H),7.08(d,J=7.7Hz,1H),6.99-6.93(m,2H),6.93-6.85(m,4H),6.70(s,1H).

The product of this example was prepared into a methylene chloride solution with a concentration of 1.0×10 ^-5 M. The measured absorption peak of the compound was located at 305 nm, and the corresponding molar extinction coefficient was 1.80×10 ⁴ . The measured UV-visible absorption spectrum of the compound in dichloromethane solution is shown in the red line in Figure 1.

Under the irradiation of 365nm LED ultraviolet light source, the product of this example has photochromic properties in the amorphous form, gradually changing from white powder to deep pink. This is attributed to the increase in intramolecular conjugation, and the reflection spectrum is at about 509nm. The low-energy absorption band gradually increased; when the illumination was stopped, the color of the compound quickly returned to white within 52 s. In addition, when the powder of Example 3 is irradiated with an ultraviolet lamp for 2s, the degree of photochromism can exceed the saturation absorbance of Example 2. The time-resolved reflectance spectrum measured during the photochromic recovery process and the photos of the powder before and after illumination are shown in Figure 3(c).

The product in this example reaches a steady state after 15 seconds of UV irradiation and returns to the initial state within 52 seconds. The fatigue resistance of the material is tested by collecting the highest point and lowest point of the compound at the maximum absorption wavelength and drawing a photochromic cycle diagram. The measured photochromic cycle diagram is shown in Figure 2(c). After the compound was alternately irradiated with UV-visible light for 20 times, its photochromic intensity did not weaken significantly, showing good reversibility.

By comparing the photochromic properties of three embodiments of the present invention, it was found that as the electron-withdrawing ability of the substituent increases, the saturated absorbance of the compound gradually increases, and the photochromic color changes from pink to pink and finally to deep pink. The compounds are respectively The steady state was reached within 2s, 4s and 15s of UV illumination, and returned to the initial state within 5s, 6s and 52s. This is because the three compounds have lower energy barriers during the photochromic process, allowing the compounds to quickly achieve photocyclization reactions after illumination. And Example 3 showed extremely high saturation absorbance under short-time UV illumination. This is because the trifluoromethyl group with strong electron-withdrawing ability was introduced into the triptyrene structure, which made the photochromic degree of Compound Example 3 significant. improve. The photochromic cycle test showed that the photochromic intensity of the three compounds did not weaken significantly after being alternately irradiated with UV-visible light for 20 times, showing good reversibility.

Table 1: Maximum fluorescence emission wavelength, color change response time, recovery time, maximum color change ultraviolet absorption wavelength and number of photochromic cycles of the final product in solid in each example

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

To sum up, in the present invention, by introducing benzene, 4-fluorobenzene and 4-(trifluoromethyl)benzene substituents with relatively small steric hindrance into the 2-position of the benzene ring on the same side of the hydrogen bond in triptyrene, the design A series of triptyrene derivatives were synthesized. The fast photoresponsive characteristics of the three compounds were studied through UV-visible absorption spectroscopy and time-resolved UV-visible reflection spectroscopy. This fast photoresponsive material is expected to have broad application prospects in fields such as high-speed information storage and rapid biological imaging. Inventive Example 3 shows excellent photochromic properties because the introduction of electron-withdrawing groups can stabilize the closed ring structure of the compound, thereby improving the photochromic efficiency of the compound. Therefore, introducing a trifluoromethyl substituent with strong electron-withdrawing ability into the triarylethene structure can significantly increase the saturation absorbance of the ring-closed isomer, which provides a reasonable molecule for the development of functional materials with fast response characteristics and high saturation absorbance. Design Strategy. The preparation method of the invention has a simple process and is suitable for applications in the fields of anti-counterfeiting, photosensitive decoration, optical information storage, single-molecule logic gates, super-resolution fluorescence imaging, green printing and additive manufacturing. As mentioned above, those of ordinary skill in the art can make various other corresponding changes and modifications based on the technical solutions and technical concepts of the present invention, and all of these changes and modifications should fall within the protection scope of the claims of the present invention.

Claims (10)

1. A 2-position phenyl-substituted triarylethylene photochromic material, characterized by the general molecular structure formula: Among them, R0 and R1 are different modifying groups, R1 is selected from fluorine, and R0 is selected from benzene, 4-fluorobenzene or 4-(trifluoromethyl)benzene. 2. A method for synthesizing a 2-position phenyl-substituted triarylethene photochromic material according to claim 1, characterized in that: phenyl, 4- Fluorobenzene or 4-(trifluoromethyl)benzene, adjust the steric hindrance and electron-withdrawing ability of the 2-position substituent to make triarylethene photochromic, introduce phenyl, 4-fluorobenzene or The color of 4-(trifluoromethyl)benzene compounds is pink, pink or dark pink after ultraviolet irradiation. 3. The synthesis method according to claim 2, characterized in that: the steps are as follows: Step 1: Prepare a phosphorus ylide reagent by reacting an aromatic ring, aromatic heterocycle or derivatives thereof containing a benzyl bromide substituent at one end with triethyl phosphite; Step 2: Using Witting reaction, add carbonyl, tetrahydrofuran solution, and potassium tert-butoxide to the phosphorus ylide reagent, and react under the action of potassium tert-butoxide, a strong base, to prepare a triarylethene skeleton; the pH of the solution is 13; Step 3: Using Suzuki coupling reaction, the target compound is obtained by reacting the triarylethene skeleton with phenylboronic acid, 4-fluorophenylboronic acid pinacol ester or 4-(trifluoromethyl)phenylboronic acid under the action of palladium catalyst, respectively. 2-position phenyl substituted triarylethylene photochromic material. 4. The synthetic method according to claim 3, characterized in that: in step 1, the reaction molar ratio of the aromatic ring, aromatic heterocyclic ring or derivatives thereof containing a benzyl bromide substituent at one end and triethyl phosphite is 1 :1.5. 5. The synthesis method according to claim 2, characterized in that the steps are as follows: in step 2, the molar ratio of phosphorus ylide reagent to carbonyl group is 1:1.2. 6. The synthetic method according to claim 3, characterized in that: the molar ratio of the triarylethene skeleton to phenylboronic acid, 4-fluorophenylboronic acid pinacol ester or 4-(trifluoromethyl)phenylboronic acid is 1:0.5. 7. The synthesis method according to claim 2, characterized in that the steps are as follows: Step 1): The difluoro substituent is obtained through the Wittig reaction between benzophenone derivatives and aromatic compounds or heterocyclic compounds containing triethyl phosphite groups in a tetrahydrofuran solution under the action of potassium tert-butoxide; Step 2): The difluoro substituent is separately combined with an aromatic compound or heterocyclic compound containing boric acid, 4-fluorophenylboronic acid pinacol ester or 4-(trifluoromethyl)phenylboronic acid pinacol boronic acid ester group, in In tetrahydrofuran solution, under the action of potassium carbonate, the target compound, that is, the 2-position phenyl-substituted triarylethene photochromic material is obtained through tetrakis triphenylphosphine palladium catalysis. 8. The synthesis method according to claim 7, wherein the molar ratio of the aromatic compound containing triethyl phosphite to the benzophenone derivative in step 1) is 1:1.2. 9. The synthetic method according to claim 7, characterized in that: in the step 2), the reaction molar ratio between the difluoro substituent and the aromatic compound or heterocyclic compound containing boric acid or pinacol borate ester group is 1: 0.5. 10. Application of the 2-position phenyl-substituted triarylethene photochromic material according to claim 1, characterized in that: used for anti-counterfeiting, photosensitive decoration, optical information storage, single-molecule logic gates, and super-resolution Fluorescence imaging, green printing and additive manufacturing fields.