Tetraphenylethylene-based aggregation-induced emission material with mechanochromism as well as preparation method and application of tetraphenylethylene-based aggregation-induced emission material

Abstract

The invention provides a tetraphenylethylene-based aggregation-induced emission material with mechanochromism as well as a preparation method and application thereof, and belongs to the technical field of fluorescent dyes. The tetraphenylethylene-based aggregation-induced emission material with the mechanochromism, disclosed by the invention, has a good aggregation-induced emission behavior. The preparation process is as follows: 4-acetylphenylboronic acid or 4-(1, 2, 2-triphenylvinyl) benzaldehyde is taken as an initial raw material, and is subjected to Knoevenagel condensation and other reactions to synthesize two compounds with aggregation-induced emission properties, and the structural formulas of the compounds are as follows: # imgabs0 #. And the luminescent material has good luminescent property in solution and solid. The material has remarkable aggregation-induced emission characteristics and force-induced discoloration behaviors, and has potential application value in the fields of information storage, encryption and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluorescent dyes, and particularly relates to a tetraphenylethylene-based aggregation-induced emission material. Background Art

[0002] In recent years, stimulus-responsive fluorescent materials with color-changing properties have become the focus of scientific research and have attracted much attention. The most prominent feature of such materials is that when exposed to various external stimuli, they can exhibit a flexibly adjustable apparent color, and even their fluorescent color will change accordingly. Among them, mechanochromic fluorescent materials, as a type of intelligent material, can change the fluorescent color or intensity when subjected to mechanical force stimulation, showing unique application value. However, traditional luminescent materials often show strong fluorescence under solution conditions, but in the aggregated state such as solids or thin films, due to the quenching effect caused by aggregation, they exhibit weak fluorescence or no fluorescence, which limits their application in real life.

[0003] Since the discovery of the aggregation-induced emission phenomenon by Tang Benzhong and his colleagues in 2001, fluorescent molecules with aggregation-induced emission or aggregation-induced emission enhancement properties show strong fluorescence in the aggregated state, providing a theoretical basis for the research of mechanochromic fluorescent materials, enabling researchers to start from the molecular structure design and develop materials with good luminescence performance and force sensitivity in the solid state. This has greatly broadened their applications in the fields of materials science, information storage and encryption, biomedicine, etc. For example, Patent Publication No. CN 115141117A discloses the preparation and application of aggregation-induced emission materials (Z-TPE-MB, Z-TPE-MB) with mechanochromism and photochromism. The luminescent materials Z-TPE-MB and Z-TPE-MB are respectively prepared by Knoevenagel condensation reaction of triphenylamine derivatives, tetraphenylethylene derivatives and methyl 4-(cyanomethyl)benzoate, and have aggregation-induced emission, mechanochromism and photochromism characteristics. In addition, in the field of biological detection, molecules with aggregation-induced emission (AIE) characteristics as fluorescent probes show advantages that are difficult to achieve by traditional fluorescent probe molecules. First, a large number of AIE probe molecules can bind to the substance to be detected, generating a high-brightness fluorescent signal. Different from traditional fluorescent molecules, even when aggregation occurs, AIE probe molecules will not undergo fluorescence quenching, greatly simplifying the fluorescence detection process and providing convenience for the detection work. Second, AIE probe molecules show the characteristic of a sharp increase in fluorescence in the aggregated state, which can be used as a quantitative basis for fluorescence amplification detection and can more accurately perform quantitative analysis on the substance to be detected.

[0004] As an essential trace element in the human body, iron ions play a crucial role in numerous biological processes. It participates in the synthesis of blood proteins, cytochromes, and enzymes, and also contributes to the formation of substances such as DNA and RNA. However, it should be noted that when iron ions are excessively deposited in the human body, a series of diseases will be triggered, including hemochromatosis, Parkinson's disease, Alzheimer's disease, diabetes, kidney and liver damage, anemia, and heart failure. Thus, both iron deficiency and iron overload are harmful to the human body. In view of this, selectively monitoring iron ions is of great significance. Currently reported methods for detecting iron ions include techniques such as atomic absorption spectrometry, colorimetry, spectrophotometry, and voltammetry. These methods generally have disadvantages such as expensive instruments and cumbersome preparation processes. Summary of the Invention

[0005] To address the above technical problems, the present invention proposes a tetraphenylethylene-based aggregation-induced emission material with mechanochromism, its preparation method, and application. Such materials have relatively high synthesis yields and good fluorescence properties. This synthesis method provides new design ideas for the synthesis of tetraphenylethylene-based aggregation-induced emission materials with mechanochromism, and has potential application value in fields such as information storage and encryption, and detecting Fe 2+ / Fe 3+ etc. in water samples. At the same time, it provides new design ideas for the synthesis of aggregation-induced emission molecules modified with tetraphenylethylene and has potential application value.

[0006] To achieve the above objectives, the technical solution of the present invention is realized as follows:

[0007] A tetraphenylethylene-based aggregation-induced emission material with mechanochromism has the following two structural formulas:

[0008]

[0009] A preparation method of a tetraphenylethylene-based aggregation-induced emission material with mechanochromism includes the following steps:

[0010] (1) Dissolve 4-acetylphenylboronic acid or 4-benzoyl phenylboronic acid, aminoacetonitrile hydrochloride, and catalyst I in solvent I for reaction to obtain compound a;

[0011] (2) Dissolve compound a, 4-(1,2,2-triphenylethylene) benzaldehyde, and catalyst II in solvent II for Knoevenagel condensation reaction I to obtain tetraphenylethylene-based aggregation-induced emission material T1 or T2.

[0012] The molar ratio of the 4-acetylphenylboronic acid or 4-benzoylbenzeneboronic acid, aminoacetonitrile hydrochloride, and catalyst I is 1:(1 - 3):(2 - 3); the ratio of the 4-acetylphenylboronic acid or 4-benzoylbenzeneboronic acid to solvent I is 1:(1 - 3) mmol / mL; the catalyst I is sodium nitrite; the solvent I is any one or more of 1,2-dichloroethane (DCE), toluene, and water; the reaction temperature in step (1) is 80 - 120 °C, and the time is 12 - 36 h.

[0013] Preferably, the solvent I is 1,2-dichloroethane and water with a volume ratio of 20:1, or toluene and water with a volume ratio of 20:1.

[0014] The molar ratio of the compound a, 4-(1,2,2-triphenylethynyl)benzaldehyde, and catalyst II is 1:(1.0 - 1.2):(1.5 - 2.2); the ratio of the compound a to solvent II is 1:(15 - 30) mmol / mL; the solvent II is any one or more of tetrahydrofuran, ethanol, and methanol; the catalyst II is sodium hydroxide or potassium hydroxide.

[0015] Preferably, the solvent II is tetrahydrofuran and ethanol with a volume ratio of 1:(3.0 - 3.5), or tetrahydrofuran and methanol with a volume ratio of 1:(3.0 - 3.5).

[0016] The temperature of the Knoevenagel condensation reaction I is 25 °C - 40 °C, and the reaction time is 2 - 6 h.

[0017] An aggregation-induced emission molecule modified with tetraphenylethylene has the following structural formula:

[0018]

[0019] A preparation method of an aggregation-induced emission molecule modified with tetraphenylethylene. The preparation method is: dissolving the tetraphenylethylene-based aggregation-induced emission material T1, malononitrile, and catalyst III in solvent III to carry out the Knoevenagel condensation reaction II to obtain the aggregation-induced emission molecule L1.

[0020] The molar ratio of the tetraphenylethylene-based aggregation-induced emission material T1, malononitrile, and catalyst III is 1:(3 - 3.2):(2 - 2.5); the ratio of the tetraphenylethylene-based aggregation-induced emission material T1 to solvent III is 1:(20 - 40) mmol / mL; the catalyst III is titanium tetrachloride and pyridine; the solvent III is dichloromethane.

[0021] The temperature of the Knoevenagel condensation reaction II is 25 °C - 40 °C, and the reaction time is 2 - 6 h.

[0022] Application of a kind of aggregation-induced emission molecule modified by tetraphenylethylene in detecting Fe 2+ / Fe 3+ ions

[0023] Advantages of the present invention:

[0024] (1) The two tetraphenylethylene-based luminescent materials provided by the present invention have good luminescent properties in solution and solid. They have remarkable aggregation-induced emission characteristics and mechanochromic behavior, and have potential application value in the fields of information storage and encryption, etc.

[0025] (2) Dissolve the above-mentioned molecules in tetrahydrofuran solution to prepare tetrahydrofuran / water mixed solutions with different water contents. When the water content gradually increases, the fluorescence is significantly enhanced compared with the pure tetrahydrofuran solution. When the water content increases to 99% or 95%, the fluorescence intensity increases to the maximum value. When the two fluorescent molecules are ground with mechanical force, the fluorescence color and emission wavelength change significantly. When fumigated with dichloromethane vapor, they can return to the original state. The fluorescence color changes from green to yellow, and the emission wavelengths are red-shifted by 20 nm and 26 nm respectively.

[0026] (3) According to the present invention, dicyanovinyl molecules can exhibit coordination ability to metal ions, which can not only change the internal structure and external interaction of molecules, but also may have a certain impact on optical properties. Combining with the aggregation-induced emission molecule modified by tetraphenylethylene, and using the good fluorescence emission ability of the compound in solution, the newly prepared aggregation-induced emission molecule modified by tetraphenylethylene has good luminescent properties in solution. And the above-mentioned probe molecules also have good solvatochromic behavior and aggregation-induced behavior. They can specifically detect Fe 2+ / Fe 3+ ions in tetrahydrofuran / water (v:v, 1:9) mixed solution, and the detection process has good selectivity and anti-interference ability. This has potential application value for detecting iron ions in water samples. Description of the drawings

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0028] Figure 1 1H NMR spectrum of fluorescent molecule T1

[0029] Figure 2 13C NMR spectrum of fluorescent molecule T1

[0030] Figure 3 1H NMR spectrum of fluorescent molecule T2.

[0031] Figure 4 13C NMR spectrum of fluorescent molecule T2.

[0032] Figure 5 Fluorescence emission spectrum of fluorescent molecule T1 (10 μM) in THF / H 2 2O mixed solvent.

[0033] Figure 6 Fluorescence intensity change curve of fluorescent molecule T1 (10 μM) with increasing water content in THF / H 2 2O mixed solvent (the inset is a photo of fluorescent molecule T1 under 365 nm ultraviolet light in different THF / H 2 2O mixed solvents).

[0034] Figure 7 Fluorescence emission spectrum of fluorescent molecule T2 (10 μM) in THF / H 2 2O mixed solvent.

[0035] Figure 8 Fluorescence intensity change curve of fluorescent molecule T2 (10 μM) with increasing water content in THF / H 2 2O mixed solvent (the inset is a photo of fluorescent molecule T2 under 365 nm ultraviolet light in different THF / H 2 2O mixed solvents).

[0036] Figure 9 Fluorescence emission spectra of the original sample, ground sample, and DCM-fumigated sample of fluorescent molecule T1.

[0037] Figure 10 Fluorescence emission spectra of the original sample, ground sample, and DCM-fumigated sample of fluorescent molecule T2.

[0038] Figure 11 Photos of fluorescent molecules (a) T1 and (b) T2 before and after grinding under 365 nm ultraviolet light.

[0039] Figure 12 1H NMR spectrum of fluorescent molecule L1.

[0040] Figure 13 13C NMR spectrum of fluorescent molecule L1.

[0041] Figure 14 Fluorescence response behavior of fluorescent molecule L1 (10 μM) to common ions (300 equiv.) in tetrahydrofuran / water (v:v, 1:9) mixed solution.

[0042] Figure 15 The graph showing the relationship between the maximum fluorescence intensity of the fluorescent molecule L1 (10 μM) and the Fe concentration in a tetrahydrofuran / water (v:v, 1:9) mixed solution. 2+

[0043] Figure 16 The graph showing the relationship between the maximum fluorescence intensity of the fluorescent molecule L1 (10 μM) and the Fe concentration in a tetrahydrofuran / water (v:v, 1:9) mixed solution. 3+

[0044] Figure 17 The normalized fluorescence emission spectra of the fluorescent molecule L1 (10 μM) in different solvents (the inset is a photo of the fluorescent molecule L1 under 365 nm ultraviolet light in different solvents).

[0045] Figure 18 The fluorescence emission spectrum of the fluorescent molecule L1 (10 μM) in a THF / H 2 O mixed solvent.

[0046] Figure 19 The fluorescence emission spectrum of the fluorescent molecule L1 (10 μM) in a THF / H 2 O mixed solvent, showing the change curve of fluorescence intensity with the increase of water content (the inset is a photo of the fluorescent molecule L1 under 365 nm ultraviolet light in different THF / H 2 O mixed solvents). Detailed implementation manners

[0047] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0048] Example 1

[0049] A preparation method of a tetraphenylethylene-based aggregation-induced emission material with force-induced color change, comprising the following steps:

[0050] (1) Preparation of compound 2a

[0051] The structural formula of compound 2a is:

[0052]

[0053] The reaction general formula is:

[0054]

[0055] ​​The preparation method is as follows: 4-Acetylphenylboronic acid (2.50 g, 15.2 mmol), aminoacetonitrile hydrochloride (2.81 g, 30.4 mmol), sodium nitrite (2.63 g, 38.1 mmol), DCE (30 mL) and water (1.5 mL) were successively added to a 100 mL round-bottom flask, and the mixture was refluxed and stirred at 100 °C for 24 h. After the reaction was completed, it was cooled to room temperature, and the solvent was concentrated under reduced pressure. It was purified by silica gel chromatography using petroleum ether / ethyl acetate (v / v 3:1) as the eluent to obtain 2a as a pale yellow liquid (1.34 g, 55% yield). 1 HNMR(600MHz,CDCl 3 ,298K)δ(ppm)8.00 - 7.95(m,2H),7.47 - 7.42(m,2H),3.82(s,2H),2.61(s,3H). 13 C NMR(151MHz,CDCl 3 ,298K)δ(ppm)197.3,136.9,135.1,129.1,128.2,117.1,26.6,23.6.

[0056] (2) Preparation of compound T1

[0057] The structural formula of compound T1 is:

[0058]

[0059] The reaction general formula is:

[0060]

[0061] The preparation method is as follows: 2a (426 mg, 2.7 mmol), 1a (964 mg, 2.7 mmol), THF (12 mL) and absolute ethanol (36 mL) were added to a 250 mL round-bottom flask, and stirred for 5 min until completely dissolved. Then sodium hydroxide (217 mg, 5.4 mmol) was dissolved in water (12 mL) and added dropwise to the reaction solution, and the mixture was stirred at room temperature for 4 h. After the reaction was completed, the reaction solution was filtered. The filter residue was washed with water and ethanol, then dissolved in dichloromethane, and purified by silica gel chromatography using petroleum ether / ethyl acetate (v / v 5:1) as the eluent to obtain T1 as a yellow-green solid (0.98 g, 73% yield). As Figure 1 and 2 shown, 1 H NMR(600MHz,CDCl 3, 298K) δ (ppm) 8.03 - 7.99 (m, 2H), 7.75 - 7.72 (m, 2H), 7.69 (d, J = 8.3 Hz, 2H), 7.52 (s, 1H), 7.17 - 7.10 (m, 11H), 7.08 - 7.02 (m, 6H), 2.63 (s, 3H). 13 C NMR (151 MHz, CDCl 3 , 298K) δ (ppm) 197.1, 147.3, 143.7, 143.3, 143.2, 143.1, 142.7, 139.9, 139.0, 137.1, 132.0, 131.4, 131.3, 131.3, 131.2, 129.1, 129.1, 127.9, 127.9, 127.7, 127.0, 126.8, 126.8, 126.0, 117.7, 109.5, 26.7. HRMS (ESI) m / z calcd for [C 37 H 27 NO + 502.2126 ([M + H] + ), found 502.2167.

[0062] Example 2

[0063] A preparation method of a tetraphenylethylene-based aggregation-induced emission material with force-induced color change, comprising the following steps:

[0064] (1) Preparation of compound 2b

[0065] The structural formula of compound 2b is:

[0066]

[0067] The reaction general formula is:

[0068]

[0069] The preparation method is as follows: Add 4-acetylphenylboronic acid (1.01 g, 4.5 mmol), aminoacetonitrile hydrochloride (0.84 g, 9.1 mmol), sodium nitrite (0.78 g, 11.3 mmol), DCE (20 mL) and water (1 mL) into a 100 mL round-bottom flask in sequence. Stir the mixture under reflux at 100 °C for 24 h. After the reaction is completed, cool it to room temperature, concentrate the solvent under reduced pressure, and purify it by silica gel chromatography using petroleum ether / ethyl acetate (v / v 3:1) as the eluent to obtain 2b as a light yellow liquid (260 mg, 26% yield). 1 HNMR (600 MHz, CDCl 3, 298 K) δ (ppm) 7.75 (ddd, J = 15.3, 8.1, 5.4 Hz, 4H), 7.56 (t, J = 7.5 Hz, 1H), 7.44 (ddd, J = 20.7, 7.7, 4.2 Hz, 4H), 3.82 (d, J = 3.4 Hz, 2H). 13 C NMR (151 MHz, CDCl 3 , 298 K) δ (ppm) 195.9, 195.9, 137.3, 137.3, 137.2, 134.6, 134.5, 134.5, 132.7, 130.8, 123.0, 128.4, 128.0, 117.4, 117.3, 23.6, 23.6.

[0070] (2) Preparation of Compound T2

[0071] The structural formula of Compound T2 is:

[0072]

[0073] The reaction general formula is:

[0074]

[0075] The preparation method is as follows: 2b (160 mg, 0.7 mmol), 1a (287 mg, 0.79 mmol), THF (2 mL) and absolute ethanol (6 mL) were added to a 100 mL round-bottom flask, stirred for 5 min until completely dissolved, then sodium hydroxide (55 mg, 1.1 mmol) was dissolved in water (2 mL) and added dropwise to the reaction solution, and the mixture was stirred at room temperature for 4 h. After the reaction was completed, the reaction solution was filtered. The filter residue was washed with water and ethanol, then dissolved in dichloromethane and purified by silica gel chromatography with petroleum ether / ethyl acetate (v / v 5:1) as the eluent to obtain T2 as a yellow-green solid (238 mg, 59% yield). As Figure 3 and 4 shown, 1 HNMR (600 MHz, CDCl 3 , 298 K) δ (ppm) 7.87 (d, J = 8.4 Hz, 2H), 7.83 - 7.79 (m, 2H), 7.78 - 7.73 (m, 2H), 7.73 - 7.68 (m, 2H), 7.65 - 7.59 (m, 1H), 7.51 (dd, J = 15.4, 7.6 Hz, 3H), 7.17 - 7.09 (m, 11H), 7.09 - 7.01 (m, 6H). 13 C NMR (151 MHz, CDCl 3, 298 K) δ (ppm) 195.7, 147.2, 143.6, 143.3, 143.2, 143.1, 142.7, 139.9, 138.5, 137.7, 137.4, 132.7, 132.0, 131.4, 131.3, 131.3, 131.3, 130.8, 123.0, 129.1, 128.4, 127.9, 127.9, 127.7, 127.0, 126.8, 126.8, 125.7, 117.7, 109.6. HRMS(ESI) m / z calcd for [C 42 H 29 NO + 564.2283 ([M + H] + ), found 564.2325.

[0076] Test Example 1

[0077] Using tetrahydrofuran as the good solvent and water as the poor solvent, the fluorescence emission spectra of T1 were tested at a concentration of 10 μM in different f w . When the water content increased from 0% to 70%, its fluorescence intensity remained basically unchanged, but when the water content increased to 99%, its fluorescence intensity increased significantly ( Figure 5 and Figure 6 ).

[0078] Using [solvent name] as the good solvent and water as the poor solvent, the fluorescence emission spectra of T2 were tested at a concentration of 10 μM in different f w . When the water content increased from 0% to 70%, its fluorescence intensity remained basically unchanged, but when the water content increased to 95%, its fluorescence intensity increased significantly ( Figure 7 and Figure 8 ).

[0079] The original sample of T1 showed green emission with an emission wavelength at 499 nm. After grinding, it turned yellow and the emission wavelength increased to 519 nm, with a red shift of 20 nm. The ground sample could return to its original state after being fumigated with dichloromethane vapor, indicating that this mechanochromic behavior is reversible ( Figure 9 ).

[0080] The original sample of T2 showed green emission with an emission wavelength at 508 nm. After grinding, it turned yellow and the emission wavelength increased to 504 nm, with a red shift of 26 nm. The ground sample could return to its original state after being fumigated with dichloromethane vapor, indicating that this mechanochromic behavior is reversible ( Figure 10 ).

[0081] Photographs were taken of ( Figure 11 a) T1 and (Figure 11 b) Fluorescence photographs of T2 before and after grinding under 365 nm ultraviolet light. After grinding, the color changed from the original green to yellow, and returned to the original state after fumigation with dichloromethane.

[0082] Example 3

[0083] A preparation method of a tetraphenylethylene-based aggregation-induced emission material with mechanochromism, comprising the following steps:

[0084] (1) Preparation of compound 2a

[0085] The structural formula of compound 2a is:

[0086]

[0087] The preparation method is as follows: 4-Acetylphenylboronic acid (2.50 g, 15.2 mmol), aminoacetonitrile hydrochloride (1.4 g, 15 mmol), sodium nitrite (2 g, 30 mmol), DCE (40 mL) and water (5 mL) were successively added to a 100 mL round-bottom flask, and the mixture was refluxed and stirred at 80 °C for 36 h. After the reaction was completed, it was cooled to room temperature, and the solvent was concentrated under reduced pressure. It was purified by silica gel chromatography using petroleum ether / ethyl acetate (v / v 3:1) as the eluent to obtain 2a as a pale yellow liquid.

[0088] (2) Preparation of compound T1

[0089] The structural formulas of compound T1 and 1a are:

[0090]

[0091] The preparation method is as follows: 2a (426 mg, 2.7 mmol), 1a (1.17 g, 3.3 mmol), THF (15 mL) and absolute ethanol (45 mL) were added to a 250 mL round-bottom flask, and stirred for 5 min until completely dissolved. Then sodium hydroxide (477 mg, 11.9 mmol) was dissolved in water (12 mL) and added dropwise to the reaction solution, and the mixture was stirred at room temperature for 4 h. After the reaction was completed, the reaction solution was filtered. The filter residue was washed with water and ethanol, dissolved in dichloromethane, and purified by silica gel chromatography using petroleum ether / ethyl acetate (v / v 5:1) as the eluent to obtain T1 as a yellow-green solid.

[0092] Example 4

[0093] A preparation method of a tetraphenylethylene-based aggregation-induced emission material with mechanochromism, comprising the following steps:

[0094] (1) Preparation of compound 2b

[0095] The structural formula of compound 2b is as follows:

[0096]

[0097] The preparation method is as follows: 4-Acetylphenylboronic acid (1.01 g, 4.5 mmol), aminoacetonitrile hydrochloride (1.26 g, 13.7 mmol), sodium nitrite (0.93 g, 13.5 mmol), DCE (9 mL), and water (1 mL) were successively added to a 100 mL round-bottom flask, and the mixture was refluxed and stirred at 120 °C for 12 h. After the reaction was completed, it was cooled to room temperature, and the solvent was concentrated under reduced pressure. It was purified by silica gel chromatography using petroleum ether / ethyl acetate (v / v 3:1) as the eluent to obtain 2b as a pale yellow liquid.

[0098] (2) Preparation of compound T2

[0099] The structural formulas of compound T2 and 1a are as follows:

[0100]

[0101] The preparation method is as follows: 2b (160 mg, 0.7 mmol), 1a (287 mg, 0.79 mmol), THF (2 mL), and absolute ethanol (6 mL) were added to a 100 mL round-bottom flask, and stirred for 5 min until completely dissolved. Then potassium hydroxide (78 mg, 1.4 mmol) was dissolved in water (2 mL) and added dropwise to the reaction solution, and the mixture was stirred at room temperature for 6 h. After the reaction was completed, the reaction solution was filtered. The filter residue was washed with water and ethanol, dissolved in dichloromethane, and purified by silica gel chromatography using petroleum ether / ethyl acetate (v / v 5:1) as the eluent to obtain T2 as a yellowish-green solid.

[0102] Example 5

[0103] A preparation method of an aggregation-induced emission molecule modified by tetraphenylethylene, comprising the following steps:

[0104] (1) Preparation of compound 1a

[0105] The structural formula of compound 1a is as follows:

[0106]

[0107] The reaction general formula is as follows:

[0108]

[0109] The preparation method is as follows: 4-Acetylphenylboronic acid (2.50 g, 15.2 mmol), aminoacetonitrile hydrochloride (2.81 g, 30.4 mmol), sodium nitrite (2.63 g, 38.1 mmol), DCE (30 mL) and water (1.5 mL) were successively added to a 100 mL round-bottom flask, and the mixture was refluxed and stirred at 100 °C for 24 h. After the reaction was completed, it was cooled to room temperature, and the solvent was concentrated under reduced pressure. It was purified by silica gel chromatography using petroleum ether / ethyl acetate (v / v 3:1) as the eluent to obtain 1a as a pale yellow liquid (1.34 g, 55% yield). 1 H NMR(600MHz,CDCl 3 ,298K)δ(ppm)8.00 - 7.95(m,2H),7.47 - 7.42(m,2H),3.82(s,2H),2.61(s,3H). 13 C NMR(151MHz,CDCl 3 ,298K)δ(ppm)197.3,136.9,135.1,129.1,128.2,117.1,26.6,23.6.

[0110] (2) Preparation of Compound 1c

[0111] The structural formula of Compound 1c is:

[0112]

[0113] The reaction general formula is:

[0114]

[0115] The preparation method is as follows: 1a (426 mg, 2.7 mmol), 1b (964 mg, 2.7 mmol), THF (12 mL) and absolute ethanol (36 mL) were added to a 250 mL round-bottom flask, stirred for 5 min until completely dissolved, then sodium hydroxide (217 mg, 5.4 mmol) was dissolved in water (12 mL) and added dropwise to the reaction solution, and the mixture was stirred at room temperature for 4 h. After the reaction was completed, the reaction solution was filtered. The filter residue was washed with water and ethanol and then dissolved in dichloromethane. It was purified by silica gel chromatography using petroleum ether / ethyl acetate (v / v 5:1) as the eluent to obtain 1c as a yellow-green solid (0.98 g, 73% yield). 1 H NMR(600MHz,CDCl 3, 298K) δ (ppm) 8.03 - 7.99 (m, 2H), 7.75 - 7.72 (m, 2H), 7.69 (d, J = 8.3 Hz, 2H), 7.52 (s, 1H), 7.17 - 7.10 (m, 11H), 7.08 - 7.02 (m, 6H), 2.63 (s, 3H). 13 C NMR (151 MHz, CDCl 3 , 298K) δ (ppm) 197.1, 147.3, 143.7, 143.3, 143.2, 143.1, 142.7, 139.9, 139.0, 137.1, 132.0, 131.4, 131.3, 131.3, 131.2, 129.1, 129.1, 127.9, 127.9, 127.7, 127.0, 126.8, 126.8, 126.0, 117.7, 109.5, 26.7. HRMS (ESI) m / z calcd for [C 37 H 27 NO + 502.2126 ([M + H] + ), found 502.2167.

[0116] (3) Preparation of Compound L1

[0117] The structural formula of Compound L1 is:

[0118]

[0119] The reaction general formula is:

[0120]

[0121] The preparation method is as follows: Add 1c (202 mg, 0.4 mmol) and malononitrile (75 μL, 1.2 mmol) into a 50 mL three-necked round-bottom flask, displace argon three times, and add dry dichloromethane (10 mL) to dissolve. Dissolve titanium tetrachloride (171 mg, 0.9 mmol) in dry dichloromethane (2 mL), and add it dropwise to the reaction flask at 0 °C, and stir for 30 min. Slowly add pyridine (0.4 mL) into the flask, transfer it to an oil bath, and react at 40 °C for 3 h. After the reaction is completed, pour the reaction solution into water (30 mL), and extract it 3 times with DCM (20 mL × 3). Combine the organic phases, dry with anhydrous sodium sulfate and then concentrate under reduced pressure, and purify by silica gel chromatography using dichloromethane / petroleum ether (v / v 2:3) as the eluent to obtain L1 as an orange-yellow solid (178 mg, 81% yield). As Figure 12 and 13 shown, 1 HNMR (600 MHz, CDCl3 , 298 K) δ (ppm) 7.77 (d, J = 8.5 Hz, 2H), 7.69 (d, J = 8.4 Hz, 2H), 7.66 - 7.61 (m, 2H), 7.51 (s, 1H), 7.17 - 7.11 (m, 11H), 7.08 - 7.01 (m, 6H), 2.66 (s, 3H). 13 C NMR (151 MHz, CDCl 3 , 298 K) δ (ppm) 173.8, 147.5, 144.0, 143.2, 143.2, 143.1, 142.8, 139.9, 138.6, 136.1, 132.1, 131.4, 131.3, 131.3, 129.2, 128.3, 128.0, 128.0, 127.7, 127.0, 126.8, 126.4, 117.5, 112.7, 112.6, 108.9, 85.1, 24.1. HRMS (ESI) m / z calcd for [C 40 H 27 N 3 + 550.2239 ([M + H] + ), found 550.2282.

[0122] Test Example 2

[0123] The fluorescence intensity of the aggregation-induced emission molecule modified with tetraphenylethylene prepared in Example 5 in a tetrahydrofuran / water (v:v, 1:9) mixed solution is greatly affected by Fe 2+ / Fe 3+ , but is basically not affected by other metal ions ( Figure 14 ). When Fe 2+ / Fe 3+ is added to the solution, the fluorescence intensity of compound L1 (10 μM) decreases significantly.

[0124] When Fe 2+ / Fe 3+ is gradually added to the tetrahydrofuran / water (v:v, 1:9) mixed solution of L1 molecules, the fluorescence emission is quenched, but no obvious change in the fluorescence spectrum profile is observed. In the titration experiment, the maximum value of the fluorescence intensity of the solution to be measured shows a good linear relationship with the content of Fe 2+ / Fe 3+ at low concentrations ( Figure 15 and Figure 16 ).

[0125] The fluorescence molecule modified with tetraphenylethylene has a good solvatochromic effect. Compound L1 ( Figure 17)Fluorescence emission spectra in different solvents.

[0126] Using tetrahydrofuran as a good solvent and water as a poor solvent, the fluorescence emission spectra of L1 were tested at a concentration of 10 μM in different f w . When the water content increased from 0% to 70%, its fluorescence intensity remained basically unchanged, but when the water content increased to 99%, its fluorescence intensity increased significantly ( Figure 18 and Figure 19 ).

[0127] Example 6

[0128] A preparation method of an aggregation-induced emission molecule modified with tetraphenylethylene, comprising the following steps: (3) Preparation of compound L1

[0129] The structural formulas of compound L1 and 1c are:

[0130]

[0131] The preparation method is as follows: Add 1c (202 mg, 0.4 mmol) and malononitrile (80 μL, 1.28 mmol) into a 50 mL three-necked round-bottom flask, displace argon three times, and add dry dichloromethane (14 mL) to dissolve. Dissolve titanium tetrachloride (152 mg, 0.8 mmol) in dry dichloromethane (2 mL), and add it dropwise into the reaction flask at 0 °C, and stir for 30 min. Slowly add pyridine (0.5 mL) into the flask, transfer it to an oil bath, and react at 25 °C for 6 h. After the reaction is completed, pour the reaction solution into water (30 mL), and extract it 3 times with DCM (20 mL × 3). Combine the organic phases, dry them with anhydrous sodium sulfate, and concentrate them under reduced pressure. Purify by silica gel chromatography using dichloromethane / petroleum ether (v / v 2:3) as the eluent to obtain L1 as an orange-yellow solid.

[0132] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A tetraphenylethylene-based aggregation-induced emission material with mechanochromic properties, characterized in that: It has the following two structural formulas:

2. The method for preparing the tetraphenylethylene-based aggregation-induced emission material with mechanochromism according to claim 1, characterized in that: The following steps are involved: (1) dissolving 4-acetylphenylboronic acid or 4-benzoylphenylboronic acid, aminoacetonitrile hydrochloride and catalyst I in solvent I for reaction to obtain compound a; (2) Compound a, 4-(1,2,2-triphenylvinyl)benzaldehyde and catalyst II are dissolved in solvent II to carry out Knoevenagel condensation reaction I to obtain tetraphenylethylene aggregation-induced emission material T1 or T2.

3. The method for preparing the tetraphenylethylene-based aggregation-induced emission material with mechanochromism according to claim 2, characterized in that: The molar ratio of the 4-acetylphenylboronic acid or 4-benzoylphenylboronic acid, aminoacetonitrile hydrochloride and catalyst I is 1:(1-3):(2-3); the ratio of the 4-acetylphenylboronic acid or 4-benzoylphenylboronic acid to solvent I is 1:(1-3)mmol / mL; the catalyst I is sodium nitrite; the solvent I is any one or more of 1,2-dichloroethane, toluene and water; the reaction temperature in step (1) is 80-120°C and the reaction time is 12-36h.

4. The method for preparing the tetraphenylethylene-based aggregation-induced emission material with mechanochromism according to claim 2, characterized in that: The molar ratio of the compound a, 4-(1,2,2-triphenylvinyl)benzaldehyde and catalyst II is 1:(1.0-1.2):(1.5-2.2); the ratio of the compound a to the solvent II is 1:(15-30)mmol / mL; the solvent II is any one or more of tetrahydrofuran, ethanol and methanol; and the catalyst II is sodium hydroxide or potassium hydroxide.

5. The method for preparing the tetraphenylethylene-based aggregation-induced emission material with mechanochromism according to claim 2, characterized in that: The temperature of the Knoevenagel condensation reaction I is 25°C-40°C, and the reaction time is 2-6h.

6. An aggregation-induced emission molecule modified with tetraphenylethylene, characterized in that: Has the following structural formula:

7. The method for preparing the aggregation-induced emission molecule based on tetraphenylethylene modification according to claim 6, characterized in that: The preparation method is as follows: dissolving tetraphenylethylene-based aggregation-induced emission material T1, malononitrile and catalyst III into solvent III to carry out Knoevenagel condensation reaction II to obtain aggregation-induced emission molecule L1.

8. The method for preparing the aggregation-induced emission molecule modified with tetraphenylethylene according to claim 6, characterized in that: The molar ratio of the tetraphenylethylene aggregation-induced emission material T1, malononitrile and catalyst III is 1:(3-3.2):(10-20); the ratio of the tetraphenylethylene aggregation-induced emission material T1 and the solvent III is 1:(20-40)mmol / mL; the catalyst III is titanium tetrachloride and pyridine; and the solvent III is dichloromethane.

9. The method for preparing aggregation-induced emission molecules modified with tetraphenylethylene according to claim 6, characterized in that: The temperature of the Knoevenagel condensation reaction II is 25° C.-40° C., and the reaction time is 2-6 hours.

10. The aggregation-induced emission molecule based on tetraphenylethylene modification according to claim 6 is used to detect Fe 2+ / Fe 3+ Application in.

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