A class of fluorine-modified 2,4,6-triphenylpyrylium salt derivatives, their preparation method and application in mechanochromic materials

Abstract

The present invention discloses a class of fluorine-modified 2,4,6-triphenylpyrylium salt derivatives, a preparation method thereof, and an application thereof in mechanochromic materials. The fluorine-modified 2,4,6-triphenylpyrylium salt derivative organic small molecules have good responsiveness to mechanical force stimulation. Compound I can achieve a red shift in emission wavelength by grinding, and compound II can achieve a blue shift in emission wavelength by grinding. These derivatives can meet the requirements of high-sensitivity response and multi-type signal output, and have broad application prospects as mechanochromic materials.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanochromic materials, and more specifically, to a class of fluorine-modified 2,4,6-triphenylpyrylium salt derivatives, a preparation method thereof, and an application thereof in mechanochromic materials. Background Art

[0002] Mechanochromic materials can undergo significant changes in their photophysical properties (e.g., emission wavelength, quantum yield, and lifetime) when stimulated by external mechanical forces (including static pressure and shear). This unique stimulus-responsiveness makes them promising as smart materials for applications in stress sensing, memory chips, data storage, information security, and other fields.

[0003] At present, organic small molecules have been widely used in the construction of mechanochromic materials. For example, by structurally modifying luminescent groups such as carbazole, triphenylamine, and pyrene, molecules can be given better mechanochromic properties. Usually, the change in the stacking pattern or molecular conformation of the compound under external mechanical stimulation is the main reason why the material exhibits mechanochromic properties. However, most of the organic mechanochromic molecules reported so far have neutral molecular structures, and pure organic ionic mechanochromic molecules are still very rare. Compared with neutral molecules, ionic compounds have more flexible stacking methods and stronger electrostatic forces between molecules, so they may show more unique stimulus response signal changes.

[0004] Pyrylium salts, as ionic compounds, can exhibit excellent luminescence properties through structural modification. However, the application of such structures in the construction of mechanochromic materials remains underexplored. In particular, the construction of materials that achieve highly sensitive responses to mechanical force stimulation and multi-type signal output through structural modification remains challenging. Summary of the Invention

[0005] In view of this, the present invention provides a class of fluorine-modified 2,4,6-triphenylpyrylium salt derivatives, which are used to meet the performance requirements of high-sensitivity response and multi-type signal output under mechanical force stimulation.

[0006] The technical solutions of the present invention are as follows:

[0007] The first aspect of the present invention is to provide a fluorine-modified 2,4,6-triphenylpyrylium salt derivative having the structural formula shown in Formula I or Formula II:

[0008] 、 .

[0009] The second aspect of the present invention is to provide a method for preparing the fluorine-modified 2,4,6-triphenylpyrylium salt derivative described in the first aspect, comprising the following steps:

[0010] S1. A fluorine-modified acetophenone is condensed with benzaldehyde under alkaline conditions to produce a chalcone derivative intermediate;

[0011] S2. further reacting the obtained chalcone derivative intermediate with fluorine-modified acetophenone, and adding a p-toluenesulfonate anion donor to obtain the fluorine-modified 2,4,6-triphenylpyrylium salt derivative;

[0012] The fluorine-modified acetophenone has the structural formula shown in Formula III:

[0013] ;

[0014] In formula III, R1 and R2 are each differently selected from F or H.

[0015] Furthermore, in step S1, the molar ratio of the fluorine-modified acetophenone, benzaldehyde, and base is 1:(1-1.1):(1.2-1.3).

[0016] Furthermore, in step S1, the reaction temperature is room temperature, and the reaction time is 18 to 24 hours.

[0017] Furthermore, step S1 also includes post-treatment steps: extracting the reaction product, washing the organic phase, drying, removing the solvent and separating by column chromatography to obtain a chalcone derivative intermediate.

[0018] Furthermore, in step S2, the reaction process is carried out under an inert atmosphere, firstly the temperature is raised to 40-50°C, the p-toluenesulfonate anion donor is added in batches, and then the temperature is raised to reflux for reaction for 36-48 hours.

[0019] Preferably, the inert atmosphere is nitrogen, the solvent used in the reaction is dichloromethane, and the reflux reaction temperature is 70-90°C.

[0020] Furthermore, in step S2, the p-toluenesulfonate anion donor is selected from p-toluenesulfonic acid, p-toluenesulfonic acid salt or p-toluenesulfonic acid hydrate.

[0021] Furthermore, in step S2, the molar ratio of the chalcone intermediate, the fluorine-modified acetophenone and the p-toluenesulfonate anion donor is (2-2.2): (1-1.1):1.

[0022] Furthermore, step S2 also includes a step of post-processing the reaction product: concentrating the solvent by distillation under reduced pressure, precipitating and acid-washing to obtain a solid, and recrystallizing to obtain the fluorine-modified 2,4,6-triphenylpyrylium salt derivative.

[0023] The third aspect of the present invention is to propose the use of the fluorine atom-modified 2,4,6-triphenylpyrylium salt derivative described in the first aspect or the fluorine atom-modified 2,4,6-triphenylpyrylium salt derivative obtained by the preparation method described in the second aspect in the preparation of mechanochromic materials.

[0024] Furthermore, the mechanochromic material can be used in fields including, but not limited to, writing and recording, mechanical sensing, anti-counterfeiting, and information storage.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The fluorine-containing 2, 4, 6-triphenylpyrylium salt derivative organic small molecule described in the present invention has good responsiveness to mechanical force stimulation. Compound I can achieve a red shift in emission wavelength by grinding, and Compound II can achieve a blue shift in emission wavelength by grinding. These materials can meet the requirements of high-sensitivity response and multi-type signal output, and have broad application prospects as mechanochromic materials.

[0027] The fluorine-containing atom-modified 2, 4, 6-triphenylpyrylium salt derivatives described in the present invention have a simple synthesis process and can be obtained through a simple aldol condensation reaction and an addition reaction. Moreover, the raw materials are cheap and readily available, the preparation cost is low, the overall molar yield of the synthetic route is greater than 40%, and the product purity is greater than 97%, which can be used for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is the H NMR spectrum of compound I having mechanochromic properties;

[0029] Figure 2 The fluorescence emission spectra of compound I solid before and after grinding are shown in FIG. 1 , wherein the excitation wavelength is λ ex = 400 nm;

[0030] Figure 3 is the time-resolved decay curve of Compound I solid before and after grinding;

[0031] Figure 4 The luminescence photos of Compound I solid before and after grinding under 365 nm ultraviolet light;

[0032] Figure 5 is the H NMR spectrum of compound II having mechanochromic properties;

[0033] Figure 6 The fluorescence emission spectrum of compound II solid before and after grinding; the excitation wavelength is λ ex = 400nm;

[0034] Figure 7is the time-resolved decay curve of Compound II solid before and after grinding;

[0035] Figure 8 These are luminescence photographs of Compound II solid before and after grinding under 365 nm ultraviolet light. DETAILED DESCRIPTION

[0036] The following are specific implementation examples of the present invention, which are preferred and detailed descriptions of the present invention. It should be understood that the specific implementation examples described in this specification are only for explaining the present invention and are not intended to limit the present invention.

[0037] In one embodiment, a method for preparing a fluorine-containing modified 2, 4, 6-triphenylpyrylium salt derivative is provided, comprising the steps of:

[0038] 1) Slowly add fluorinated acetophenone and benzaldehyde to a solvent and stir at room temperature for 5 minutes. Then add an aqueous base solution and continue stirring at room temperature. After the reaction is complete, remove the solvent by vacuum distillation, wash with water, and purify by column chromatography to obtain a chalcone intermediate.

[0039] 2) Add the chalcone intermediate and fluorinated acetophenone to a two-necked flask, add solvent to dissolve, and under inert gas, stir and heat. Add the p-toluenesulfonate anion donor in batches. Continue heating and reflux. After the reaction is complete, concentrate the solvent by vacuum distillation to precipitate. Wash the solid with an acidic aqueous solution and recrystallize to obtain the fluorine-modified 2, 4, 6-triphenylpyrylium salt derivative.

[0040] In the above embodiment, the fluorinated acetophenone has the structural formula shown in Formula III:

[0041] ;

[0042] In formula III, R1 and R2 are each selected from F or H;

[0043] The entire preparation process route is as follows:

[0044] .

[0045] The obtained fluorine-containing atom-modified 2, 4, 6-triphenylpyrylium salt derivative has the structural formula shown in Formula I or Formula II:

[0046] 、 .

[0047] In the above embodiment, the obtained fluorine-containing atom-modified 2, 4, 6-triphenylpyrylium salt derivative organic small molecule has good responsiveness to mechanical force stimulation, compound I can achieve red shift of emission wavelength by grinding, and compound II can achieve blue shift of emission wavelength by grinding.

[0048] In a preferred embodiment, step 1) is an aldol condensation reaction using common alkaline catalysts, including potassium hydroxide and potassium carbonate: weak bases suitable for substrates sensitive to strong bases, requiring heating in a polar solvent (such as DMF, DMSO); piperidine: an organic weak base, commonly used for reactions in the absence of solvents or under ethanol conditions, with mild reaction and good selectivity.

[0049] In a preferred embodiment, the solvent used in the reaction of step 1) can be ethanol, methanol or ethanol-water solution, more preferably ethanol.

[0050] In a preferred embodiment, in step 1), taking sodium hydroxide as an alkaline catalyst as an example, the molar ratio of the fluorine-modified acetophenone, benzaldehyde and sodium hydroxide is 1:(1-1.1):(1.2-1.3).

[0051] In a preferred embodiment, the room temperature in step 1) is 25±5° C., and the reaction time is 18 to 24 hours.

[0052] In a preferred embodiment, in step 1), the eluent selected for column chromatography separation and purification is petroleum ether:ethyl acetate = 10:1.

[0053] In a preferred embodiment, in step 2), the reaction temperature is first raised to 40-50°C, and after adding the p-toluenesulfonate anion donor in batches, the temperature is raised to reflux for 36-48 hours. Preferably, the reaction solvent is dichloromethane or toluene, and the reflux reaction temperature is 70-90°C.

[0054] In a preferred embodiment, in step 2), the p-toluenesulfonate anion donor is selected from p-toluenesulfonic acid or p-toluenesulfonic acid hydrate.

[0055] In a preferred embodiment, in step 2), the molar ratio of the chalcone intermediate, the fluorine-modified acetophenone, and the p-toluenesulfonate anion donor is (2-2.2):(1-1.1):1.

[0056] In a preferred embodiment, in step 2), the acidic aqueous solution used for washing is a dilute hydrochloric acid solution with a pH of 1 to 2.5.

[0057] The following are preferred implementation examples. Unless otherwise specified, the reagents used are commercially available standard reagents in the field, and the experimental methods used are methods known in the field.

[0058] Example 1

[0059] Synthesis of Compound I:

[0060]

[0061] The synthetic route is as follows:

[0062]

[0063] In the reaction formula, NaOH is sodium hydroxide, EtOH is ethanol, TsOH·H2O is p-toluenesulfonic acid monohydrate, 1,4-dichloroethane is 1, 2-dichloroethane, and N2 is nitrogen.

[0064] The specific synthesis steps are as follows:

[0065] 1. Add 4-fluoroacetophenone (4.00 g, 28.96 mmol), benzaldehyde (3.07 g, 26.63 mmol) and ethanol (80 mL) to a round-bottom flask and stir at 25°C for 5 min. Then slowly add an aqueous solution of sodium hydroxide (1.39 g, 34.75 mmol, 50 mL of water) and continue stirring at room temperature for 24 h. After the reaction is completed, the reaction solution is extracted three times with dichloromethane, and the organic phases are combined, dried over anhydrous sodium sulfate, and the solvent is removed by distillation under reduced pressure to obtain a crude product. The crude product is separated and purified by column chromatography (petroleum ether: ethyl acetate = 20:1) to obtain a white solid ( E )-1-(4-fluorophenyl)-3-phenyl-2-propen-1-one, with a molar yield of 96.1% and a purity of 98.3%;

[0066] 2. Add ( E )-1-(4-fluorophenyl)-3-phenyl-2-propen-1-one (1.50 g, 6.63 mmol) and 4-fluoroacetophenone (0.46 g, 3.31 mmol) were dissolved in 5 mL of 1,2-dichloroethane. The mixture was evacuated, filled with nitrogen, and heated to 50°C. After stirring for a period of time, p-toluenesulfonic acid monohydrate (0.63 g, 3.15 mmol) was added portionwise. The temperature was further raised to 85°C and the reaction was refluxed for 48 h. After the reaction, the solvent was removed by distillation under reduced pressure. A small amount of dichloromethane was added to dissolve the remaining crude product. The solution was slowly added to a beaker filled with diethyl ether, and the solid-liquid mixture was separated by centrifugation. The solid sample was washed several times with an aqueous solution adjusted to pH 2.00 with hydrochloric acid, then dissolved in a small amount of dichloromethane and slowly added to a beaker filled with diethyl ether. The solid-liquid mixture was separated by centrifugation and dried to obtain Compound I as a yellow solid powder with a molar yield of 45.2% and a purity of 99.3%. H NMR spectra Figure 1 As shown, 1H NMR (600 MHz, D2O) δ 8.68 (s, 2H), 8.37 (d, J = 6.8 Hz, 4H), 8.17 (d, J =8.0 Hz, 2H), 7.79 (d, J = 7.8 Hz, 1H), 7.71 (t, J = 7.8 Hz, 2H), 7.64 (d, J = 8.0Hz, 2H), 7.45 (t, J = 8.6 Hz, 4H), 7.33 (d, J = 7.9 Hz, 2H), 2.36 (s, 3H).

[0067] Example 2

[0068] The synthesis steps of compound I are as follows:

[0069] 1. Add 4-fluoroacetophenone (4.00 g, 28.96 mmol), benzaldehyde (3.07 g, 26.63 mmol) and methanol (80 mL) to a round-bottom flask and stir at 20°C for 5 min. Then slowly add potassium hydroxide (1.95 g, 34.75 mmol, 50 mL of water) aqueous solution and continue stirring at 20°C for 24 h. After the reaction is completed, the reaction solution is extracted three times with dichloromethane, and the organic phases are combined, dried over anhydrous sodium sulfate, and the solvent is removed by distillation under reduced pressure to obtain a crude product. The crude product is separated and purified by column chromatography (petroleum ether: ethyl acetate = 20:1) to obtain a white solid ( E )-1-(4-fluorophenyl)-3-phenyl-2-propen-1-one, with a molar yield of 95.0% and a purity of 98.1%;

[0070] 2. Add ( E)-1-(4-fluorophenyl)-3-phenyl-2-propen-1-one (1.50 g, 6.63 mmol) and 4-fluoroacetophenone (0.46 g, 3.31 mmol) were dissolved in 5 mL of toluene. The mixture was evacuated, flushed with nitrogen, and heated to 45°C. After stirring for a period of time, p-toluenesulfonic acid (0.54 g, 3.15 mmol) was added portionwise. The temperature was continued to rise to 85°C and the reaction was refluxed for 48 h. After the reaction, the solvent was removed by distillation under reduced pressure. A small amount of dichloromethane was added to dissolve the remaining crude product. The solution was slowly added to a beaker filled with diethyl ether, and the solid-liquid mixture was separated by centrifugation. The solid sample was washed several times with a solution of hydrochloric acid adjusted to pH 2.00, then dissolved in a small amount of dichloromethane and slowly added to a beaker filled with diethyl ether. The solid-liquid mixture was separated by centrifugation and dried to obtain a yellow solid powder with a molar yield of 44.1% and a purity of 99.1%. Proton nuclear magnetic resonance spectroscopy identified it as Compound I.

[0071] Example 3

[0072] The synthesis steps of compound I are as follows:

[0073] 1. Add 4-fluoroacetophenone (4.00 g, 28.96 mmol), benzaldehyde (3.07 g, 26.63 mmol) and ethanol (80 mL) to a round-bottom flask and stir at 27°C for 5 min. Slowly add piperidine (2.95 g, 34.75 mmol) and continue stirring at 27°C for 24 h. After the reaction is completed, the reaction solution is extracted three times with dichloromethane, and the organic phases are combined, dried over anhydrous sodium sulfate, and the solvent is removed by vacuum distillation to obtain a crude product. The crude product is separated and purified by column chromatography (petroleum ether: ethyl acetate = 20:1) to obtain a white solid ( E )-1-(4-fluorophenyl)-3-phenyl-2-propen-1-one, with a molar yield of 93.2% and a purity of 98.4%;

[0074] 2. Add ( E)-1-(4-fluorophenyl)-3-phenyl-2-propen-1-one (1.50 g, 6.63 mmol) and 4-fluoroacetophenone (0.46 g, 3.31 mmol) were dissolved in 5 mL of 1,2-dichloroethane. The mixture was evacuated, filled with nitrogen, and heated to 50°C. After stirring for a period of time, p-toluenesulfonic acid monohydrate (0.63 g, 3.15 mmol) was added portionwise. The temperature was further raised to 90°C and the reaction was refluxed for 40 h. After the reaction, the solvent was removed by distillation under reduced pressure. A small amount of dichloromethane was added to dissolve the remaining crude product. The solution was slowly added to a beaker filled with diethyl ether, and the solid-liquid mixture was separated by centrifugation. The solid sample was washed several times with an aqueous solution adjusted to pH 2.00 with hydrochloric acid, then dissolved in a small amount of dichloromethane and slowly added to a beaker filled with diethyl ether. The solid-liquid mixture was centrifuged and dried to obtain the compound as a yellow solid powder with a molar yield of 45.4% and a purity of 99.4%. The product was identified as compound I by hydrogen nuclear magnetic resonance spectroscopy.

[0075] Example 4

[0076] Synthesis of compound II:

[0077]

[0078] The synthetic route is as follows:

[0079]

[0080] In the reaction formula, NaOH is sodium hydroxide, EtOH is ethanol, TsOH·H2O is p-toluenesulfonic acid monohydrate, 1,4-dichloroethane is 1, 2-dichloroethane, and N2 is nitrogen.

[0081] The specific synthesis steps are as follows:

[0082] 1. Add 2-fluoroacetophenone (4.00 g, 28.96 mmol), benzaldehyde (3.07 g, 26.63 mmol) and ethanol (80 mL) to a round-bottom flask and stir at 25°C for 5 min. Then slowly add an aqueous solution of sodium hydroxide (1.39 g, 34.75 mmol, 50 mL of water) and continue stirring at 25°C for 24 h. After the reaction is completed, the reaction solution is extracted three times with dichloromethane, and the organic phases are combined, dried over anhydrous sodium sulfate, and the solvent is removed by distillation under reduced pressure to obtain a crude product. The crude product is separated and purified by column chromatography (petroleum ether: ethyl acetate = 20:1) to obtain a yellow oily liquid ( E )-1-(2-fluorophenyl)-3-phenyl-2-propen-1-one, with a molar yield of 78.5% and a purity of 97.3%;

[0083] 2. Add ( E)-1-(2-fluorophenyl)-3-phenyl-2-propen-1-one (1.50 g, 6.63 mmol) and 2-fluoroacetophenone (0.46 g, 3.31 mmol) were dissolved in 5 mL of 1,2-dichloroethane. The mixture was evacuated, filled with nitrogen, and heated to 50°C. After stirring for a period of time, p-toluenesulfonic acid monohydrate (0.63 g, 3.15 mmol) was added portionwise. The temperature was continued to rise to 85°C and the reaction was refluxed for 48 h. After the reaction, the solvent was removed by distillation under reduced pressure. A small amount of dichloromethane was added to dissolve the remaining crude product. The solution was slowly added to a beaker filled with diethyl ether, and the solid-liquid mixture was separated by centrifugation. The solid sample was washed several times with an aqueous solution adjusted to pH 2.00 with hydrochloric acid, then dissolved in a small amount of dichloromethane and slowly added to a beaker filled with diethyl ether. The solid-liquid mixture was separated by centrifugation and dried to obtain Compound II as a yellow solid powder with a molar yield of 51.3% and a purity of 98.2%. H NMR spectra Figure 5 As shown, 1 H NMR (600 MHz, D2O) δ 8.78 (s, 2H), 8.25 (t, J = 7.7 Hz, 2H), 8.20 (d, J =7.8 Hz, 2H), 7.85 (q, J = 8.1 Hz, 3H), 7.73 (t, J = 7.7 Hz, 2H), 7.68 (d, J = 7.9Hz, 2H), 7.55 (t, J = 7.7 Hz, 2H), 7.50 (dd, J = 12.0, 8.4 Hz, 2H), 7.36 (d, J =8.0 Hz, 2H), 2.39 (s, 3H).

[0084] Example 5

[0085] The specific synthesis steps of compound II are as follows:

[0086] 1. Add 2-fluoroacetophenone (4.00 g, 28.96 mmol), benzaldehyde (3.07 g, 26.63 mmol) and methanol (80 mL) to a round-bottom flask and stir at 20°C for 5 min. Then slowly add potassium hydroxide (1.95 g, 34.75 mmol, 50 mL of water) aqueous solution and continue stirring at 20°C for 24 h. After the reaction is completed, the reaction solution is extracted with dichloromethane three times, and the organic phases are combined, dried over anhydrous sodium sulfate, and the solvent is removed by vacuum distillation to obtain a crude product. The crude product is separated and purified by column chromatography (petroleum ether: ethyl acetate = 20:1) to obtain a yellow oily liquid ( E )-1-(2-fluorophenyl)-3-phenyl-2-propen-1-one, with a molar yield of 78.7% and a purity of 97.5%;

[0087] 2. Add ( E )-1-(2-fluorophenyl)-3-phenyl-2-propen-1-one (1.50 g, 6.63 mmol) and 2-fluoroacetophenone (0.46 g, 3.31 mmol) were dissolved in 5 mL of toluene. The mixture was evacuated, filled with nitrogen, and heated to 50°C. After stirring for a period of time, p-toluenesulfonic acid (0.54 g, 3.15 mmol) was added portionwise. The temperature was continued to rise to 90°C and the reaction was refluxed for 40 h. After the reaction, the solvent was removed by distillation under reduced pressure. A small amount of dichloromethane was added to dissolve the remaining crude product. The solution was slowly added to a beaker filled with diethyl ether, and the solid-liquid mixture was separated by centrifugation. The solid sample was washed several times with a solution of hydrochloric acid adjusted to pH 2.00, then dissolved in a small amount of dichloromethane and slowly added to a beaker filled with diethyl ether. The solid-liquid mixture was separated by centrifugation and dried to obtain a yellow solid powder with a molar yield of 51.4% and a purity of 98.4%. The compound was identified as Compound II by H NMR spectroscopy.

[0088] Example 6

[0089] The specific synthesis steps of compound II are as follows:

[0090] 1. Add 2-fluoroacetophenone (4.00 g, 28.96 mmol), benzaldehyde (3.07 g, 26.63 mmol) and diethyl ether (80 mL) to a round-bottom flask and stir at 27°C for 5 min. Slowly add piperidine (2.95 g, 34.75 mmol) and continue stirring at 27°C for 24 h. After the reaction is completed, the reaction solution is extracted three times with dichloromethane, and the organic phases are combined, dried over anhydrous sodium sulfate, and the solvent is removed by vacuum distillation to obtain a crude product. The crude product is separated and purified by column chromatography (petroleum ether: ethyl acetate = 20:1) to obtain a yellow oily liquid ( E )-1-(2-fluorophenyl)-3-phenyl-2-propen-1-one, with a molar yield of 76.1% and a purity of 97.0%;

[0091] 2. Add ( E )-1-(2-fluorophenyl)-3-phenyl-2-propen-1-one (1.50 g, 6.63 mmol) and 2-fluoroacetophenone (0.46 g, 3.31 mmol) were dissolved in 5 mL of toluene. The mixture was evacuated, filled with nitrogen, and heated to 45°C. After stirring for a period of time, p-toluenesulfonic acid (0.54 g, 3.15 mmol) was added portionwise. The temperature was continued to rise to 85°C and the reaction was refluxed for 48 hours. After the reaction, the solvent was removed by distillation under reduced pressure. A small amount of dichloromethane was added to dissolve the remaining crude product. The solution was slowly added to a beaker filled with diethyl ether, and the solid-liquid mixture was separated by centrifugation. The solid sample was washed several times with an aqueous solution adjusted to pH 2.00 with hydrochloric acid, then dissolved in a small amount of dichloromethane and slowly added to a beaker filled with diethyl ether. The solid-liquid mixture was separated by centrifugation and dried to obtain a yellow solid powder with a molar yield of 51.2% and a purity of 98.0%. The compound was identified as Compound II by H NMR spectroscopy.

[0092] Experimental Example 1 Detection of the Fluorescence Mechanochromic Properties of Compound I

[0093] Compound I of Example 1 was processed and tested in the following different ways.

[0094] 1) The fluorescence emission spectrum of a solid sample of Compound I was measured using 400 nm excitation light. The maximum fluorescence emission peak of Compound I was 518 nm, and the solid-state fluorescence quantum yield was 4.45%.

[0095] 2) Compound I solid was thoroughly ground in a mortar and its fluorescence emission spectrum was measured using 400 nm excitation light. The maximum fluorescence emission peak of the ground Compound I was 592 nm, and the solid-state fluorescence quantum yield was 2.16%.

[0096] 3) Take a solid sample of Compound I and measure its luminescence lifetime at the maximum emission wavelength using a transient fluorescence spectrometer.

[0097] 4) The solid of Compound I was ground thoroughly in a mortar and the luminescence lifetime at the maximum emission wavelength was measured using a transient fluorescence spectrometer.

[0098] 5) Take a solid sample of Compound I, irradiate it with 365 nm UV light, and take a fluorescence photograph.

[0099] 6) The solid of Compound I was thoroughly ground in a mortar, irradiated with 365 nm ultraviolet light, and a fluorescence photograph was taken.

[0100] like Figure 2As shown, compound I exhibits mechanoresponsive fluorescence. When compound I was thoroughly ground with a pestle, the maximum fluorescence emission wavelength red-shifted from 518 nm to 592 nm. The fluorescence quantum yield decreased from 4.45% to 2.16%. The lifetimes of the compound's emission wavelengths at 518 nm and 592 nm were 1.97 ns and 18.11 ns, respectively, before and after grinding. Figure 3 Under 365 nm ultraviolet light, it can be clearly seen that mechanical grinding causes the fluorescence color of the compound to change from green to yellow ( Figure 4 The above results indicate that the photophysical properties of compound I will change significantly after being stimulated by mechanical force, indicating that it has mechanochromic properties.

[0101] Experimental Example 2 Detection of the Fluorescence Mechanochromic Properties of Compound II

[0102] Compound II was processed and tested in the following different ways.

[0103] 1) The fluorescence emission spectrum of the prepared solid compound II was measured using 400 nm excitation light. Compound II had two emission peaks at 487 nm and 546 nm, respectively, and the solid-state fluorescence quantum yield was 7.35%.

[0104] 2) The prepared solid compound II was thoroughly ground in a mortar and its fluorescence emission spectrum was measured using 400 nm excitation light. The ground compound II exhibited two emission peaks at 487 nm and 530 nm, respectively, with a solid-state fluorescence quantum yield of 2.74%.

[0105] 3) Take a solid sample of the prepared compound II and test the luminescence lifetimes of its two emission peaks using a transient fluorescence spectrometer.

[0106] 4) The prepared solid of Compound II was placed in a mortar and ground thoroughly, and the luminescence lifetimes of its two emission peaks were measured using a transient fluorescence spectrometer.

[0107] 5) Take a solid sample of the prepared compound II, irradiate it with 365 nm ultraviolet light, and take a fluorescence photograph of it.

[0108] 6) The prepared solid of Compound II was thoroughly ground in a mortar and irradiated with 365 nm ultraviolet light to capture a fluorescence image.

[0109] like Figure 6As shown, compound II exhibits mechanical fluorescence responsiveness. When compound II is thoroughly ground with a pestle, its emission peak at 546 nm blue-shifts to 530 nm, while the emission peak at 487 nm remains unchanged. The fluorescence quantum yield decreases from 7.35% to 2.74%. Before grinding, the compound's emission peak lifetimes at 546 nm and 487 nm are 4.07 ns and 0.98 ns, respectively. After grinding, the compound's emission peak lifetimes at 530 nm and 487 nm are 3.72 ns and 1.37 ns, respectively. Figure 7 Under 365 nm ultraviolet light, it can be clearly seen that mechanical grinding causes the fluorescence color of the compound to change from yellow-green to green ( Figure 8 The above results indicate that the photophysical properties of compound II will change significantly after being stimulated by mechanical force, indicating that it has mechanochromic properties.

[0110] Finally, a few points should be explained. Although the present invention has been described in detail above using general descriptions and specific embodiments, on the basis of the present invention, the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solution of the embodiments of the present invention.

Claims

1. A fluorine-modified 2,4,6-triphenylpyrylium salt derivative, characterized in that: The fluorine-modified 2,4,6-triphenylpyrylium salt derivative has the structural formula shown in Formula II: 。 2. The method for preparing the fluorine-modified 2,4,6-triphenylpyrylium salt derivative according to claim 1, characterized in that the steps include: S1. A fluorine-modified acetophenone is condensed with benzaldehyde under alkaline conditions to produce a chalcone derivative intermediate; S2. further reacting the obtained chalcone derivative intermediate with fluorine-modified acetophenone, and adding a p-toluenesulfonate anion donor to obtain the fluorine-modified 2,4,6-triphenylpyrylium salt derivative; The fluorine-modified acetophenone has the structural formula shown in Formula III: ； In formula III, R1 is H and R2 is F.

3. The preparation method according to claim 2, characterized in that In step S1: the molar ratio of the fluorine-modified acetophenone, benzaldehyde, and base is 1:(1-1.1):(1.2-1.3); and / or the reaction temperature is room temperature, and the reaction time is 18-24 hours.

4. The preparation method according to claim 2, characterized in that Step S1 also includes post-processing steps: extracting the reaction product, washing the organic phase, drying, removing the solvent and separating by column chromatography to obtain the chalcone derivative intermediate.

5. The preparation method according to claim 2, characterized in that In step S2, the reaction process is carried out under an inert atmosphere, firstly the temperature is raised to 40-50° C., p-toluenesulfonate anion donor is added in batches, and then the temperature is raised to reflux for reaction for 36-48 hours.

6. The preparation method according to claim 2, characterized in that In step S2, the p-toluenesulfonate anion donor is selected from p-toluenesulfonic acid or p-toluenesulfonic acid hydrate.

7. The preparation method according to claim 2, characterized in that In step S2, the molar ratio of the chalcone intermediate, the fluorine-modified acetophenone, and the p-toluenesulfonate anion donor is (2-2.2): (1-1.1):

1.

8. The preparation method according to claim 2, characterized in that Step S2 also includes a step of post-processing the reaction product: concentrating the solvent by distillation under reduced pressure, precipitating and acid-washing to obtain a solid, and recrystallizing to obtain the fluorine-modified 2,4,6-triphenylpyrylium salt derivative.

9. Application of fluorine-modified 2,4,6-triphenylpyrylium salt derivatives in the preparation of mechanoluminescent materials, characterized in that: The fluorine-modified 2,4,6-triphenylpyrylium salt derivative has a structural formula shown in Formula I or Formula II: 、 。 10. The use according to claim 9, characterized in that The fluorine-modified 2,4,6-triphenylpyrylium salt derivative of the formula I changes from fluorescent green to yellow upon mechanical stimulation; And / or, the fluorine atom-modified 2,4,6-triphenylpyrylium salt derivative of the structure of Formula II changes from fluorescent yellow to green after being stimulated by mechanical force.

Images