A tetraphenyl ethene-quinoline compound, and a preparation method and application thereof

Abstract

The application discloses a tetraphenyl ethene-quinoline compound and a preparation method and application thereof. The compound has the following general structure: wherein Ar represents a quinoline group. The structural compound of the application scheme has strong fluorescence, and not only retains the multiple stimulus response of the quinoline group, but also can present high contrast changes in fluorescence color before and after acid fumigation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fluorescent materials, in particular to a tetraphenylethene-quinoline compound and a preparation method and application thereof. BACKGROUND

[0002] In recent years, mechano-chromic compounds have attracted extensive attention due to their unique physical properties. In particular, recently, a new type of mechano-chromic compound TPE-HXD was reported in Chinese patent application CN118005600A. The unique feature of TPE-HXD is that it can change from weak blue fluorescence to bright cyan fluorescence under mechanical force, accompanied by a significant increase in fluorescence quantum yield, about 6.5 times. This change is attributed to the difference in molecular packing mode and intermolecular interaction force, resulting in different photophysical properties of the two crystals. However, TPE-HXD compound mainly responds to mechanical force, which has great limitations in some complex and variable application scenarios.

[0003] In order to meet the demand for multifunctional materials in practical applications, it is particularly important to develop AIE (aggregation-induced emission) compounds with multiple stimulus responses. Such compounds usually achieve multiple stimulus response characteristics by introducing different functional groups or nitrogen heterocycles (such as pyridine, quinoline, imidazole, and thiazole). Among them, quinoline groups show great potential in preparing multiple stimulus response AIE compounds due to their structural design diversity and flexibility, as well as good structural stability and fluorescence properties. For example, Gong et al. successfully synthesized derivative QDPS by introducing quinoline groups on diphenyl sulfone. QDPS not only exhibits multiple stimulus response performance, but also realizes the transition from blue fluorescence to green fluorescence after TFA fumigation, and restores to the initial state by TEA treatment. However, although QDPS shows fluorescence color change after acid fumigation, its fluorescence contrast is low, and the fluorescence is quenched under extreme acidic conditions (pH = 1), which limits its application in some fields.

[0004] Therefore, it is of great significance to develop a quinoline derivative that not only has the multiple stimulus response characteristics of quinoline groups, but also can realize high contrast of sample fluorescence color before and after acid fumigation. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application proposes a tetraphenylethene-quinoline compound, which not only has multiple stimulus responses, but also shows high contrast in fluorescence color before and after acid fumigation.

[0006] The present application also proposes a preparation method of the above-mentioned compound.

[0007] The present application also proposes an application of the above-mentioned compound.

[0008] According to one aspect of the present application, a tetraphenyl ethene-quinoline compound is provided, which has the following general structure:

[0009]

[0010] In the formula, Ar represents a quinoline group.

[0011] According to one preferred embodiment of the present application, at least the following advantages are provided: the compound of the present application has strong fluorescence, which not only retains the multiple stimuli response of the quinoline group, but also presents high contrast change in fluorescence color before and after acid fumigation.

[0012] In some embodiments of the present application, the compound has a structure as shown in one of the following formulas:

[0013]

[0014] According to another aspect of the present application, a preparation method of the compound is provided, which comprises the following steps:

[0015] Under a protective atmosphere, reacting cyanotetraphenyl ethene (TPECN) with ArCHO to obtain the tetraphenyl ethene-quinoline compound.

[0016] According to the preparation method of one preferred embodiment of the present application, at least the following advantages are provided: the preparation method of the present application is simple to operate and has good industrial application prospect.

[0017] In some embodiments of the present application, the protective atmosphere is nitrogen or inert gas atmosphere.

[0018] In some embodiments of the present application, the reaction is carried out under catalytic conditions, and the catalyst used in the catalysis is selected from at least one of tetrabutylammonium hydroxide (TBAH), pyridine or piperidine.

[0019] In some embodiments of the present application, the reaction temperature is 75-85°C. For example, it is 80°C.

[0020] In some embodiments of the present application, the reaction time is 20-28h. For example, it is 24h.

[0021] In some embodiments of the present application, the reaction is carried out in a solution state, and the solution state uses at least one of ethanol, N,N-dimethylformamide or toluene as a solvent.

[0022] In some embodiments of the present application, the preparation method further comprises a post-treatment step, specifically comprising collecting the reaction product and washing it with ethanol.

[0023] In some embodiments of the present application, the preparation method further comprises a step of preparing cyanotetraphenyl ethylene.

[0024] reacting with to obtain.

[0025] In some embodiments of the present application, the preparation of cyanotetraphenyl ethylene is catalyzed by a palladium catalyst.

[0026] In some embodiments of the present application, the palladium catalyst is Pd(PPh3)4.

[0027] In some embodiments of the present application, the preparation of cyanotetraphenyl ethylene is carried out in an alkaline environment.

[0028] In some embodiments of the present application, the alkaline environment is generated by adding a carbonate.

[0029] In some embodiments of the present application, the carbonate is potassium carbonate or sodium carbonate.

[0030] In some embodiments of the present application, the preparation of cyanotetraphenyl ethylene is carried out in a solution, and the solvent of the solution is at least one of tetrahydrofuran (THF), ethanol or toluene.

[0031] In some embodiments of the present application, the preparation of cyanotetraphenyl ethylene is further added with a phase transfer catalyst selected from tetrabutylammonium bromide (TBAB). The reaction solution has an aqueous phase and an organic phase, and the addition of the phase transfer catalyst can help the reactants to transfer from one phase to another phase where the reaction can occur, thereby accelerating the reaction rate of the heterogeneous system.

[0032] In some embodiments of the present application, the ArCHO has a structure as shown in one of the following formulas:

[0033]

[0034] According to still another aspect of the present application, there is provided a use of the above-mentioned compound in the preparation of a fluorescent material.

[0035] According to yet another aspect of the present application, there is provided a fiber membrane, wherein the raw material for preparing the fiber membrane comprises the above-mentioned compound.

[0036] In some embodiments of the present application, the method for preparing the fiber membrane comprises the following steps:

[0037] The above tetraphenyl ethene-quinoline compound and polymer are weighed and dissolved in a DMF / DCM (preferably, v / v = 1 / 1-3; more preferably, v / v = 1 / 2) mixed solution to prepare an electrostatic spinning solution, the solution is loaded into a syringe, and is extruded from a spinneret at a speed of 0.8-1.2 mL / h (preferably 1.0 mL / h) under the action of high-voltage static electricity to form a fiber; wherein the spinning voltage is 15-20 kV (preferably 17 kV), and the working distance is 11-15 cm (preferably 13 cm).

[0038] In some embodiments of the present application, the polymer comprises at least one of cellulose acetate (CA), polystyrene (PS) and polylactic acid (PLA). The compound of the present application has good fluorescence stability in different polymer matrices.

[0039] In some embodiments of the present application, a silicone oil paper is used as a grounding collector in the preparation of the fiber film.

[0040] According to another aspect of the present application, the above compound or the above fiber film is applied in the field of detection.

[0041] In some embodiments of the present application, the detection comprises at least one of the following detection contents:

[0042] 1) acidic substance; 2) basic substance.

[0043] In some embodiments of the present application, the compound comprises at least one of

[0044]

[0045]

[0046] In some embodiments of the present application, the compound comprises at least one of The detection comprises at least one of the following detection contents:

[0047] 1) anti-counterfeiting; 2) product defect; 3) stress.

[0048] In some embodiments of the present application, the detection comprises the following steps: applying the detection content to the surface of the above compound or fiber film, irradiating the compound by a UV light source as an excitation light source, and observing the fluorescence change.

[0049] In some embodiments of the present application, the detection content can be applied to the surface or inside of the product to be detected without complex operations such as photo-induced polymerization, the detection method of the present application is simple and convenient to operate, has high detection efficiency, can realize batch full-automatic detection, and has good industrial application prospect. ​

[0050] In some preferred embodiments of the present application, the applying comprises at least one of coating, dipping, fumigation. The detection content is applied to the surface of the product to be detected by coating, dipping or fumigation, etc., which is simple and convenient.

[0051] In some preferred embodiments of the present application, the wavelength of the ultraviolet light source is 320-405 nm; preferably 345-385 nm; more preferably 365 nm.

[0052] According to another aspect of the present application, a material comprises

[0053] The material can be used to prepare at least one of the following products:

[0054] 1) toys; 2) shape memory materials; 3) impact-resistant protective materials; 4) force sensor materials; 5) mechanical probe materials; 6) optical switch materials; 7) anti-counterfeiting materials; 8) flexible electronic products; 9) intelligent packaging materials.

[0055] According to the application of a preferred embodiment of the present application, at least the following beneficial effects are achieved: the compound of the present application has strong fluorescence, and due to the highly twisted spatial conformation of the tetraphenyl ethylene, the molecular packing is relatively loose, so it is easy to change its packing mode under external stimulation, and under the action of external stimulation, the fluorescence emission wavelength will be red-shifted, and the fluorescence color will change, which has good application prospect in acid-base detection and anti-counterfeiting detection. After being prepared into a fiber film, its specific surface area is larger, so its response to external stimulation is faster.

[0056] Other features and advantages of the present application will be set forth in the specification, and in part will become apparent from the specification, or can be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0057] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0058] Figure 1 Fig. 1 is the fluorescence spectrum and absorption spectrum of the compound TPECNnQu (concentration: 10 μM) prepared in Examples 1-4 of the present application in a tetrahydrofuran solution / water mixture solution with different water contents: a, c, e, g) fluorescence spectrum, the inset is a fluorescence photo under irradiation of a 365 nm ultraviolet lamp; b, d, f, h) ultraviolet-visible spectrum.

[0059] Figure 2Fig. 5 is the fluorescence spectrum and UV-Vis absorption spectrum of the compound TPECNnQu (concentration: 10 μM) prepared in Example 5 of the present application in tetrahydrofuran solution / water mixed solution with different water contents, and the inserted picture is the fluorescence photo under 365 nm UV light irradiation.

[0060] Figure 3 Fig. 6 is the fluorescence spectrum and UV-Vis absorption spectrum of the compound TPECNnQu (concentration: 10 μM) prepared in Example 6 of the present application in tetrahydrofuran solution / water mixed solution with different water contents, and the inserted picture is the fluorescence photo under 365 nm UV light irradiation.

[0061] Figure 4 Fig. 7 is the fluorescence spectrum and UV-Vis absorption spectrum of the compound TPECNnQu (concentration: 10 μM) prepared in Example 7 of the present application in tetrahydrofuran solution / water mixed solution with different water contents, and the inserted picture is the fluorescence photo under 365 nm UV light irradiation.

[0062] Figure 5 Fig. 8 is the fluorescence spectrum and UV-Vis absorption spectrum of the compound TPECNnQu (concentration: 10 μM) prepared in Example 8 of the present application in tetrahydrofuran solution / water mixed solution with different water contents, and the inserted picture is the fluorescence photo under 365 nm UV light irradiation.

[0063] Figure 6 Fig. 9 is the PL spectrum of the compound TPECNnQu prepared in Examples 5-8 of the present application in 7 solvents with different polarities.

[0064] Figure 7 Fig. 10 is the fluorescence spectrum of the compound TPECNnQu prepared in Examples 1-4 of the present application after different treatments: a) TPECN2Qu; b) TPECN5Qu; c) TPECN6Qu; d) TPECN7Qu.

[0065] Figure 8 Fig. 11 is the fluorescence spectrum of the compound TPECNnQu prepared in Examples 1-4 of the present application after different treatments: a) TPECN2Qu; b) TPECN5Qu; c) TPECN6Qu; d) TPECN7Qu.

[0066] Figure 9 Fig. 12 is the fluorescence spectrum of the compound TPECNnQu prepared in Examples 5-8 of the present application after different treatments: the PL spectrum of o, g, a, f of F1 TPECN1Qu; F2 TPECN3Qu; F3 TPECN4Qu; F4 TPECN8Qu, and the inserted picture is the photo of the sample under UV light irradiation in four states.

[0067] Figure 10XRD patterns of TPECNnQu after different treatments: a) TPECN2Qu; b) TPECN5Qu; c) TPECN6Qu; d) TPECN7Qu.

[0068] Figure 11 XRD patterns of TPECN1Qu (o, g, a, f) four samples prepared in Example 5 of the present application; (right) Time-resolved fluorescence decay curves of TPECN1Qu before and after grinding, inset: fluorescence decay parameters of the synthesized compound before and after grinding.

[0069] Figure 12 XRD patterns of TPECN3Qu (o, g, a, f) four samples prepared in Example 6 of the present application; (right) Time-resolved fluorescence decay curves of TPECN3Qu before and after grinding, inset: fluorescence decay parameters of the synthesized compound before and after grinding.

[0070] Figure 13 XRD patterns of TPECN4Qu (o, g, a, f) four samples prepared in Example 7 of the present application; (right) Time-resolved fluorescence decay curves of TPECN4Qu before and after grinding, inset: fluorescence decay parameters of the synthesized compound before and after grinding.

[0071] Figure 14 XRD patterns of TPECN8Qu (o, g, a, f) four samples prepared in Example 8 of the present application; (right) Time-resolved fluorescence decay curves of TPECN8Qu before and after grinding, inset: fluorescence decay parameters of the synthesized compound before and after grinding.

[0072] Figure 15 PL spectra of TPECN7Qu powder prepared in Example 1 of the present application under external stimuli: P represents the original sample, P-HCl represents the sample after acid fumigation; P-HCl-NH3 represents the sample after acid fumigation and alkali fumigation.

[0073] Figure 16 Fluorescence photos (365 nm) of the original sample of TPECN2Qu prepared in Example 1 of the present application and after acid and alkali stimulation.

[0074] Figure 17PL spectra of the powders of the compounds TPECNnQu prepared in Examples 5-8 of the present application under external stimulus: PL spectra of the original sample (o), original sample acid fumigation (o-h), original sample acid fumigation and then base fumigation (o-h-n), sample after grinding (g), sample after grinding and acid fumigation (g-h), sample after grinding and acid fumigation and then base fumigation (g-h-n) of L1 TPECN1Qu; L2 TPECN4Qu; L3 TPECN3Qu; L4 TPECN8Qu, inset: photos of each sample under ultraviolet light.

[0075] Figure 18 Electron microscope images of the fiber membrane prepared in Example 9 of the present application: a) SEM image of CA-TPECN2Qu micro-nano fiber membrane; b) local enlarged view.

[0076] Figure 19 Macroscopic and microscopic images of the PLA-TPECN2Qu and PS-TPECN2Qu micro-nano fiber membranes prepared in Example 9 of the present application: a) daylight lamp photo; b) ultraviolet lamp photo; c) inverted fluorescence microscope photo; d) daylight lamp photo; e) ultraviolet lamp photo; f) inverted fluorescence microscope photo.

[0077] Figure 20 PL spectra of the CA-TPECN2Qu micro-nano fiber membrane prepared in Example 9 of the present application under external stimulus.

[0078] Figure 21 Fluorescence photos (365 nm) of the CA-TPECN2Qu micro-nano fiber membrane prepared in Example 9 of the present application under external stimulus.

[0079] Figure 22 PL spectra of the fiber membranes CA-TPECNnQu (n = 1, 4, 3 or 8) prepared in Example 9 of the present application under external stimulus: fluorescence emission spectra of N1 TPECN1Qu; N2 TPECN4Qu; N3 TPECN3Qu; N4 TPECN8Qu original sample (x), original sample acid fumigation (X-h), original sample acid fumigation and then base fumigation (X-h-n) sample, inset: fluorescence photos of the samples under ultraviolet light (365 nm) irradiation in 3 states. DETAILED DESCRIPTION

[0080] The concept and the technical effects of the present application will be described clearly and completely in combination with the embodiments, so as to fully understand the purposes, features and effects of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application. The test methods used in the embodiments are conventional methods, unless otherwise specified. The materials and reagents used, unless otherwise specified, can be obtained from commercial reagents and materials. The same parameters in each embodiment have the same values, unless otherwise specified. The following described embodiments are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0081] The part of raw materials used in the following examples and comparative examples are shown in Table 1 as follows:

[0082] Table 1

[0083]

[0084] The instrument information used in the following examples and comparative examples is shown in Table 2 as follows:

[0085] Table 2

[0086]

[0087] The methods and main parameter information used in the test characterization process are as follows:

[0088] Compound 1 H-NMR and 13 C-NMR were measured on a Bruker AVANCE NEO 500 spectrometer with deuterated chloroform as solvent and tetramethylsilane (TMS) as internal standard, which was used to test the chemical structure of the compound.

[0089] Fluorescence spectrum and ultraviolet-visible absorption spectrum were used to analyze the photophysical properties of the compound. The excitation and emission slits of the fluorescence spectrum for AIE performance test were 10 nm and 15 nm, and the others were 3 nm and 5 nm.

[0090] X-ray diffractometer with Cu Kα (λ = 0.1541 nm) as light source, test voltage 40 kV, 40 mA, was used to characterize the aggregate structure of the compound.

[0091] Acton SP2750 spectrometer collected the photoluminescence data of the compound, with liquid nitrogen-cooled CCD (SPE-10) as power detector.

[0092] Steady-state / transient combined fluorescence spectrometer and calibrated integrating sphere tested the fluorescence quantum efficiency of the compound.

[0093] Scanning electron microscope was used to observe the microstructure of the fiber membrane, and the operating voltage was 15 kV.

[0094] The specific synthesis process of TPECN is as follows (referring to the literature Zhang X, Zhang X, Yang B, et al. Facile preparation of water dispersible red fluorescent organic nanoparticles and their cell imaging applications [J]. Tetrahedron, 2014, 70 (22): 3553-3559. Preparation):

[0095] Under the condition of nitrogen, 1-bromo-1,2,2-triphenylstyrene (1.74 g, 5.2 mmol) and 4-(cyanoethyl) phenylboronic acid (1.00 g, 6.2 mmol) were dissolved in a mixture of toluene (40 mL), Aliquat 336 (methyltrioctylammonium chloride, 10 drops) and 2M aqueous potassium carbonate solution (10 ml). Stirring under argon at room temperature for 0.5 h, adding Pd(PPh3)4(0.010 g, 8.70*10 -3 mmol), after heating to 90℃ for 24 h, the mixture was poured into water, extracted with ethyl acetate three times. The organic layer was dried over anhydrous sodium sulfate. After removing the solvent under reduced pressure, the residue was chromatographed on a silica gel column with petroleum ether / CH2Cl2(v / v 3:1) as eluent to obtain intermediate 1 (1.30 g, yield 68%).

[0096] The above operation was repeated several times, and the prepared product was mixed and used for the preparation of the product of the following examples.

[0097] Example 1

[0098] In this example, a tetraphenylstyrene-quinoline compound TPECN5Qu was prepared. The specific process was as follows: TPECN (2.23 g, 6 mmol) was added to a three-necked flask, 60 mL of anhydrous ethanol was added, and it was dissolved under magnetic stirring. After complete dissolution, nitrogen was introduced, quinoline-5-carboxaldehyde (1.10 g, 7 mmol) was added, the temperature was raised to 80℃, and an appropriate amount of catalyst TBAH was added, and the reaction was carried out for 24 h. After the reaction was completed, it was filtered under suction, and the filter residue was washed with ethanol repeatedly for 3 times to obtain a light yellow solid powder (2.31 g, 75%).

[0099] The nuclear magnetic characterization results are as follows:

[0100] 1H NMR (500 MHz, Chloroform-d) δ 9.31 (s, 1H), 8.60 (d, J = 6.0 Hz, 1H), 8.30 (dd, J = 7.3, 1.1 Hz, 1H), 8.11 (s, 1H), 8.06 (d, J = 8.1 Hz, 1H), 7.76 (d, J = 6.0 Hz, 1H), 7.74 - 7.68 (m, 1H), 7.55 - 7.49 (m, 2H), 7.21 - 7.02 (m, 17H); 13 C NMR (126 MHz, CDCI3) δ 153.46, 145.87, 144.15, 143.43, 143.33, 142.36, 139.82, 137.20, 134.41, 132.31, 131.57, 131.46, 131.44, 131.39, 130.95, 130.40, 130.08, 128.69, 128.08, 128.00, 127.84, 127.20, 127.02, 126.89, 126.85, 125.93, 125.65, 117.46, 116.46, 116.28, 77.42, 77.40, 77.16, 77.15, 76.91, 76.89.

[0101] Example 2

[0102] A tetraphenylethene-quinoline compound TPECN2Qu was prepared in this example. Specifically, TPECN (2.23 g, 6 mmol) was added to a three-necked flask, 60 mL of anhydrous ethanol was added, and the mixture was dissolved under magnetic stirring. After complete dissolution, nitrogen was introduced, quinoline-2-carboxaldehyde (1.10 g, 7 mmol) was added, the temperature was raised to 80°C, and an appropriate amount of catalyst TBAH was added. The reaction was carried out for 24 h. After the reaction was completed, the filtrate was collected by suction filtration, and the filter residue was washed repeatedly with ethanol for 3 times to obtain a light yellow solid powder (2.31 g, 75%).

[0103] The nuclear magnetic characterization results are as follows:

[0104] 1 H NMR (500 MHz, Chloroform-d) δ 8.25 (d, J = 8.6 Hz, 1H), 8.12 (dd, J = 16.0, 8.5 Hz, 2H), 7.85 (dd, J = 8.1, 1.4 Hz, 1H), 7.78 - 7.74 (m, 2H), 7.62 - 7.53 (m, 3H), 7.17 - 7.01 (m, 17H); 13CNMR (126 MHz, CDCI3) δ 143.19, 143.06, 142.15, 140.62, 139.70, 136.81, 131.97, 131.65, 131.26, 131.19, 130.17, 129.57, 127.80, 127.75, 127.59, 127.45, 126.79, 126.63, 126.58, 125.60, 120.60, 77.16, 76.91, 76.65.

[0105] Example 3

[0106] A tetraphenylethene-quinoline compound TPECN7Qu was prepared in this example. Specifically, TPECN (2.23 g, 6 mmol) was added to a three-necked flask, and 60 mL of anhydrous ethanol was added and dissolved under magnetic stirring. After complete dissolution, nitrogen was introduced, quinoline-7-carboxaldehyde (1.10 g, 7 mmol) was added, and the temperature was raised to 80°C. An appropriate amount of catalyst TBAH was added, and the reaction was carried out for 24 h. After the reaction was completed, the filter residue was collected by suction filtration and washed with ethanol for 3 times to obtain a light yellow solid powder (2.31 g, 75%).

[0107] The nuclear magnetic characterization results are as follows:

[0108] 1 H NMR (500 MHz, Chloroform-d) δ 8.97 (dd, J = 4.3, 1.7 Hz, 1H), 8.33 (s, 1H), 8.28 (dd, J = 8.6, 1.8 Hz, 1H), 8.18 (d, J = 8.5 Hz, 1H), 7.90 (d, J = 8.6 Hz, 1H), 7.68 (s, 1H), 7.49 (d, J = 8.5 Hz, 2H), 7.45 (dd, J = 8.3, 4.2 Hz, 1H), 7.22 - 7.00 (m, 17H); 13 C NMR (500 MHz, CDCI3) δ 151.45, 148.10, 145.43, 143.40, 143.37, 143.26, 142.13, 140.60, 139.84, 135.75, 134.95, 132.11, 132.02, 131.37, 131.33, 131.31, 129.16, 128.64, 127.95, 127.87, 127.72, 126.89, 126.75, 126.70, 125.43, 125.31, 122.25, 117.80, 113.13.

[0109] Example 4

[0110] A tetraphenylethene-quinoline compound TPECN6Qu was prepared in this example. Specifically, TPECN (2.23 g, 6 mmol) was added to a three-necked flask, and then 60 mL of anhydrous ethanol was added and dissolved under magnetic stirring. After complete dissolution, nitrogen was introduced, and isoquinoline-6-carboxaldehyde (1.10 g, 7 mmol) was added. The temperature was raised to 80°C, and an appropriate amount of catalyst TBAH was added. The reaction was carried out for 24 h. After the reaction was completed, filtration was performed under suction, and the filter residue was washed repeatedly with ethanol three times to obtain a light yellow solid powder (2.31 g, 75%).

[0111] The nuclear magnetic resonance characterization results are as follows:

[0112] 1 H NMR (500 MHz, Chloroform-d) δ 8.96 (dd, J = 4.2, 1.7 Hz, 1H), 8.33 (d, J = 1.6 Hz, 1H), 8.23 (dd, J = 8.4, 1.7 Hz, 1H), 8.16 (d, J = 1.3 Hz, 2H), 7.63 (s, 1H), 7.50 - 7.43 (m, 3H), 7.18 - 7.02 (m, 17H); 13 C NMR (126 MHz, CDCl3) δ 151.89, 148.78, 145.50, 143.47, 143.35, 142.25, 140.42, 139.91, 136.85, 132.23, 132.13, 132.08, 131.47, 131.44, 131.40, 130.35, 129.68, 129.38, 128.24, 128.04, 127.98, 127.83, 126.98, 126.86, 126.82, 125.45, 122.09, 117.96, 112.78, 77.41, 77.16, 76.90.

[0113] Example 5

[0114] A tetraphenylethene-quinoline compound TPECN1Qu was prepared in this example. Under N2 atmosphere, dry and pure white TPECN (2.2260 g, 6 mmol) was added to a 100 mL three-necked flask, and then anhydrous ethanol (60 mL) was added. After complete dissolution under magnetic stirring, isoquinoline-1-carboxaldehyde (1.1002 g, 7 mmol) was added, and the temperature was raised to 90°C. After complete dissolution, an appropriate amount of catalyst tetrabutylammonium hydroxide (12 drops) was added. After the reaction was completed, filtration was performed under suction with ethanol washing. After the collected filter residue was dried in an oven, a total of 2.3112 g of light yellow solid was obtained, with a yield of 75.53%.

[0115] The nuclear magnetic resonance characterization results are as follows:

[0116] 1 H NMR (500 MHz, Chloroform-d) δ 8.71 (d, J = 5.6 Hz, 1H), 8.25 (s, 1H), 8.16 (dd, J = 8.5, 1.0 Hz, 1H), 7.92 - 7.87 (m, 1H), 7.77 - 7.69 (m, 2H), 7.65 (ddd, J = 8.3, 6.9, 1.3 Hz, 1H), 7.62 - 7.56 (m, 2H), 7.19 - 6.95 (m, 17H); 13 C NMR (126 MHz, CDC13) δ 151.38, 145.74, 143.25, 143.20, 143.10, 142.37, 142.11, 139.71, 136.35, 135.44, 132.00, 131.97, 131.26, 131.21, 131.18, 130.26, 127.87, 127.83, 127.75, 127.59, 127.11, 126.79, 126.63, 126.58, 125.86, 123.82, 122.01, 117.99, 117.34, 77.16, 76.91, 76.65.

[0117] Example 6

[0118] In this example, a tetraphenylethene-quinoline compound TPECN3Qu was prepared, and the synthesis method was similar to the above examples. The isomer quinoline-3-carboxaldehyde of isoquinoline-1-carboxaldehyde was added as raw material, and 2.7474 g of light yellow solid was obtained, with a yield of 89.80%.

[0119] The nuclear magnetic characterization results are as follows:

[0120] 1 H NMR (500 MHz, Chloroform-d) δ 8.71 (d, J = 5.6 Hz, 1H), 8.25 (s, 1H), 8.16 (dd, J = 8.5, 1.0 Hz, 1H), 7.92 - 7.87 (m, 1H), 7.77 - 7.69 (m, 2H), 7.65 (ddd, J = 8.3, 6.9, 1.3 Hz, 1H), 7.62 - 7.56 (m, 2H), 7.19 - 6.95 (m, 17H); 13C NMR (126 MHz, CDC13) δ 151.49, 148.43, 145.78, 143.44, 143.30, 142.35, 139.86, 137.31, 135.11, 132.28, 131.74, 131.47, 131.43, 131.39, 131.20, 129.42, 128.94, 128.06, 127.99, 127.83, 127.67, 127.54, 127.04, 127.01, 126.88, 126.84, 125.45, 117.72, 113.85, 77.41, 77.16, 76.90.

[0121] Example 7

[0122] A tetraphenylethene-quinoline compound TPECN4Qu was prepared in this example, and the synthesis method was similar to the above examples. The isomer quinoline-4-carboxaldehyde of isoquinoline-1-carboxaldehyde was added as raw material, and 2.7252 g of light yellow solid was obtained, with a yield of 89.06%.

[0123] The nuclear magnetic characterization results are as follows:

[0124] 1 H NMR (500 MHz, Chloroform-d) δ 9.02 (d, J = 4.5 Hz, 1H), 8.19 (dd, J = 8.5, 1.3 Hz, 1H), 8.12 (s, 1H), 7.95 (dd, J = 8.5, 1.3 Hz, 1H), 7.85 (d, J = 4.4 Hz, 1H), 7.78 (ddd, J = 8.3, 6.7, 1.4 Hz, 1H), 7.61 (ddd, J = 8.2, 6.8, 1.3 Hz, 1H), 7.57 - 7.51 (m, 2H), 7.19 - 7.04 (m, 17H); 13 C NMR (126 MHz, CDC13) δ 151.49, 148.43, 145.78, 143.44, 143.30, 142.35, 139.86, 137.31, 135.11, 132.28, 131.74, 131.47, 131.43, 131.39, 131.20, 129.42, 128.94, 128.06, 127.99, 127.83, 127.67, 127.54, 127.04, 127.01, 126.88, 126.84, 125.45, 117.72, 113.85, 77.41, 77.16, 76.90.

[0125] Example 8

[0126] A tetraphenylethene-quinoline compound TPECN8Qu was prepared in this example, and the synthesis method was similar to the above examples. Isomeric quinoline-8-carboxaldehyde was added as raw material. A total of 2.1874 g of light yellow solid was obtained, and the yield was 71.48%.

[0127] The nuclear magnetic characterization results are as follows:

[0128] 1 H NMR (500 MHz, Chloroform-d) δ 8.96-8.90 (m, 2H), 8.60-8.53 (m, 1H), 8.20 (dd, J = 8.2, 1.7 Hz, 1H), 7.91 (dd, J = 8.1, 1.3 Hz, 1H), 7.66 (t, J = 7.8 Hz, 1H), 7.61-7.56 (m, 2H), 7.48 (dd, J = 8.2, 4.2 Hz, 1H), 7.20-7.02 (m, 17H); 13 C NMR (126 MHz, CDCl3) δ 150.19, 146.52, 145.13, 143.63, 143.54, 143.50, 141.96, 140.12, 138.51, 136.66, 132.56, 132.08, 131.50, 131.45, 130.40, 129.10, 128.38, 128.07, 127.93, 127.81, 126.94, 126.78, 126.73, 126.61, 125.76, 121.91, 118.40, 112.98, 77.41, 77.16, 76.91.

[0129] Example 9

[0130] A fibrous membrane was prepared in this example. 0.05 g of tetraphenylethene-quinoline compound TPECNnQu (the product prepared in the above example was used as raw material), 1 g of polymer (CA, polystyrene (PS) or PLA) was dissolved in 8.95 g of DMF / DCM (v / v = 1 / 2) mixed solution to prepare an electrospinning solution. Then, the solution was loaded into a 10 mL syringe, and the solution was extruded from the spinneret at a speed of 1 mL / h, and the solution was spun under the action of high voltage static electricity. The spinning voltage was 17 kV, the working distance was 13 cm, and the silicon oil paper was used as the ground collector.

[0131] Test Example

[0132] The performance of the tetraphenylethene-quinoline compound and the fibrous membrane prepared in the example was tested in this test example. Among them:

[0133] 1. AIE performance test

[0134] Using tetrahydrofuran (THF) as solvent, 0.0051 g of the pure target product was taken and 50 mL of the mixture was prepared with a concentration of 2.0 × 10 -4 mol / L mother liquor, respectively, according to the water content of 0%-90% sample solution, first with a pipette to take 1mL mother liquor in a 10mL clean test tube, according to the required sample solution concentration ratio to add purified water and THF (first add THF, then add purified water), for example, 20% water content sample solution, namely add 1mL mother liquor, 7mL THF, 2mL purified water. After the solution is prepared, the remaining mother liquor is sealed and stored. The prepared sample solution is ultrasonicated for 5min. After the ultrasonication is completed, it is promptly tested. The sample solution is tested using a UV-visible photometer (SHIMADZU / UV-2700) and a fluorescence spectrometer (Shimadzu RF-6000), respectively, to obtain the UV absorption spectrum and fluorescence spectrum of TPECNnQu in solutions with different water contents.

[0135] The emission and UV-Vis spectra of compounds TPECN2Qu, TPECN5Qu, TPECN6Qu and TPECN7Qu in tetrahydrofuran / water mixed solutions with different water contents are shown in Figure 2. Figure 1 As shown. Figure 1 As can be seen in the figure, the fluorescence intensity of TPECN2Qu, TPECN5Qu, TPECN6Qu, and TPECN7Qu in THF / water mixtures with a water content below 80% is weak and changes little with water content. When the water content is greater than or equal to 80%, the fluorescence intensity begins to increase; at a water content of 90%, the fluorescence intensity increases by 4.3, 35, 15, and 27.5 times, respectively, compared to that in pure THF solution. Furthermore, in the UV-Vis absorption spectra, when the water content is less than 80%, the long-wavelength direction remains essentially unchanged. However, when the water content exceeds 80%, a tailing phenomenon appears in the long-wavelength direction of the UV-Vis absorption spectra, which is caused by the Mie effect. This indicates that the fluorescence spectra of this series of isomeric compounds with different water contents follow the same trend as the UV-Vis absorption spectra.

[0136] For TPECN1Qu, the test results are as follows Figure 2As shown in the figure, the fluorescence intensity is very weak when the solution contains only THF and the mother liquor. When the water content is below 70%, the fluorescence intensity is very weak with minimal fluctuations. When the water content exceeds 70%, reaching 80% and above, the fluorescence intensity rises sharply. At 90%, the fluorescence intensity reaches its maximum, five times that of the solution with 0% water content. This indicates that the fluorescence intensity increases with increasing water content. The absorption spectrum shows that when the water content is below 70%, the absorption peak fluctuates very little. When the water content exceeds 70%, reaching 80% and above, the UV absorption peak fluctuates more and the maximum UV absorption peak shows a significant enhancement. This phenomenon is due to the scattering of incident UV light by nanoparticles formed by the small organic compound molecules in the solution. Combining the fluorescence and UV absorption spectra, it is concluded that the compound TPECN1Qu exhibits an AIE effect.

[0137] like Figure 3 As shown, the compound TPECN3Qu, like TPECN1Qu, exhibits very weak fluorescence intensity with minimal fluctuations when the water content of the solution is below 70%. When the water content exceeds 70%, reaching 80% and above, the fluorescence intensity rises sharply. The fluorescence intensity reaches its maximum at 90% water content, reaching five times that of a solution with 0% water content. This indicates that the fluorescence intensity increases with increasing water content. However, the fluorescence intensity of TPECN3Qu is significantly greater than that of TPECN1Qu, and its UV absorption spectrum reveals differences in the fluorescence emitted under UV illumination, which is attributed to the different structures of its constituent molecules. UV absorption spectra of TPECN3Qu / THF / H2O mixtures with varying water contents show that the absorption peaks change with water content in the same manner as TPECN1Qu. Combining the fluorescence and UV absorption spectra, it is concluded that the compound TPECN3Qu, like TPECN1Qu, exhibits an AIE effect.

[0138] like Figure 4As shown, the test results of TPECN 4Qu show that, as TPECN1Qu, it has certain fluorescence intensity when only THF and mother liquor are in the solution; when the water content is at 10%, it is slightly enhanced relative to 0%, and a larger red shift phenomenon occurs. Moreover, from 10% to 70%, its fluorescence intensity gradually decreases, which is probably mainly due to the result of the mutual competition of the aggregation-induced emission effect and the solvent effect of the compound; when the water content reaches 80% and 90%, the fluorescence intensity is greatly enhanced; the ultraviolet absorption spectrum of the mixed solution of TPECN4Qu / THF / H2O with different water contents shows that the ultraviolet spectrum changes little at 0%-70%, and the absorption peak is obviously enhanced at 80% and 90%, and the spectrum appears tailing at the long wave, which is roughly the same as that of TPECN1Qu, but in the compound TPECN4Qu, it is more obvious, which is caused by the Mie effect. In conclusion, the fluorescence spectrum and the ultraviolet absorption spectrum can draw the conclusion that the compound TPECN4Qu indeed has certain AIE effect.

[0139] As shown, TPECN8Qu shows the characteristics of normal fluorescence intensity with the increase of water content, only the fluorescence emitted under the irradiation of ultraviolet light is different, which is caused by the different structures of the constituent molecules; the ultraviolet absorption spectrum results of the mixed solution of TPECN8Qu / THF / H2O with different water contents show that when the water content is below 70%, the absorption peak fluctuation range is very small, when the water content is greater than 70%, reaches 80% and above, the ultraviolet absorption peak fluctuation slightly increases and the maximum absorption peak of the ultraviolet absorption peak appears slightly enhanced phenomenon. In conclusion, the fluorescence spectrum and the ultraviolet absorption spectrum can draw the conclusion that the compound TPECN8Qu indeed has certain AIE effect. Figure 5 2、Solvent effect

[0140] In order to judge whether the synthesized organic compound has solvent effect, a small amount of organic compound is dissolved in different solvents DMSO, DMF, anhydrous ethanol, ethyl acetate, THF, dichloromethane, n-hexane, and the fluorescence emission spectrum test is carried out, if the fluorescence spectrum measured in different solvents has obvious red shift or blue shift phenomenon, it can be explained that the compound has good solvent effect.

[0141]

[0142] ​The remaining mother liquor was used in the AIE test to configure sample solutions in the test of the solvent effect of the target product. 1 mL of the mother liquor was taken into 7 10 mL test tubes, respectively, and was naturally evaporated or boiled dry, and then 10 mL of DMSO, DMF, anhydrous ethanol, ethyl acetate, THF, DCM, and n-hexane was taken, respectively. After the sample solution was configured, ultrasonic treatment was performed together for 5 min, and then the test was performed in time after the ultrasonic treatment. The sample solution was tested by using an ultraviolet-visible spectrophotometer (SHIMADZU / UV-2700) and a fluorescence spectrometer (Shimadzu RF-6000), and the ultraviolet absorption spectrum and the fluorescence spectrum of TPECNnQuA in different water content solutions were obtained.

[0143] The test results are shown in Figure 6 From the figure, it can be seen that for the organic compound TPECN1Qu, it has certain fluorescence emission in the seven different polarity solvents. When the solvents used are anhydrous ethanol, DMSO, and DMF, the peak positions of the maximum fluorescence intensity are all near 620 nm, in DCM, THF, and ethyl acetate solvents, the peak positions are all near 575 nm, and in n-hexane solvent, the peak position is about 500 nm. The fluorescence spectrum of TPECN1Qu between different polarity solvents has a large red shift / blue shift phenomenon, and the maximum wavelength moves by more than 75 nm, which shows that the compound TPECN1Qu has good solvent effect.

[0144] Like TPECN1Qu, TPECN3Qu has a large red shift / blue shift phenomenon in the wavelength between different polarity solvents, and the maximum wavelength moves by more than 100 nm, which shows that the compound TPECN3Qu has good solvent effect.

[0145] TPECN4Qu has fluorescence emission in the seven different polarity solvents. When the solvents used are anhydrous ethanol, DMSO, and DMF, the peak positions of the maximum fluorescence intensity are all near 640 nm, in THF and ethyl acetate solvents, the peak positions of the maximum fluorescence intensity are all near 580 nm, in dichloromethane, the peak position is near 620 nm, and in n-hexane solvent, the peak position is about 500 nm. The fluorescence spectrum of the compound TPECN4Qu between different polarity solvents has a large red shift / blue shift phenomenon, and the maximum wavelength moves by more than 140 nm, which shows that the compound TPECN4Qu has good solvent effect.

[0146] TPECN8Qu emits fluorescence in all of the seven different polarity solvents, and the fluorescence intensity is very weak in n-hexane. When the solvents used are anhydrous ethanol, DMSO and DMF, the maximum fluorescence intensity is peaked at about 480 nm, and in DCM, THF and ethyl acetate solvents, the peak position is about 475 nm. The PL spectra of TPECN8Qu between different polarity solvents have a small red shift / blue shift phenomenon, only about 5 nm, which shows that the solvent effect of compound TPECN8Qu is not obvious or does not have solvent effect.

[0147] 3. Study on the mechano-chromic properties

[0148] Due to the highly twisted spatial conformation of tetraphenyl ethene, the molecular packing is relatively loose, so it is easy to change its packing mode under external stimulation. The initial state (Pristine) of the target product TPECNnQu sample is denoted as TPECNnQu-o; the sample after being ground in a agate mortar is denoted as TPECNnQu-g; the sample is placed on a heating stage after being ground, and gradually heated, and the sample is observed under irradiation of a 365 nm ultraviolet lamp during the heating process, and the heating is stopped when the fluorescence color changes completely and stably, and this sample is denoted as TPECNnQu-a; the TPECNnQu-g is placed in a closed DCM atmosphere for 3 h, and this sample is denoted as TPECNnQu-f. Then the photos of the o, g, a and f samples under irradiation of a 365 nm ultraviolet lamp are taken. The samples are tested by XRD and PL, and the XRD and PL of the o, g, a and f samples of TPECNnQu are obtained.

[0149] The original sample and the ground sample of the synthesized compound are tested by steady-state / transient fluorescence spectrometer for fluorescence lifetime decay, and the test conditions are: stable power CO1 below -20℃, slit range of 0.01-18 nm, excitation spectral scanning range (according to the excitation wavelength of each compound), starting frequency of 20000160 Hz, ending frequency of 2260 Hz, emission between 2000-3000 cps, source light path of Xenon Lamp, and detector light path of PMT900.

[0150] As shown in Figure 7 , after being ground, the fluorescence emission wavelength of compound TPECN7Qu changes from the original 481 nm to 502 nm, i.e. red shift of 21 nm. Figure 8The fluorescence color change of the compound can be observed intuitively from the fluorescence photos of the initial sample and the ground sample under a 365 nm ultraviolet lamp. However, when the ground sample of the compound TPECN7Qu is reversibly tested by using dichloromethane solvent fumigation and annealing, it is found that the annealing of the compound TPECN7Qu cannot restore the initial fluorescence color. The experimental results show that due to the different treatment conditions, the aggregate structure of the compound changes, thereby causing the three light-emitting phenomena. However, the compression fluorescence discoloration of the compounds TPECN2Qu, TPECN5Qu and TPECN6Qu is not obvious, which may be because the three compounds have good crystallinity, and the grinding cannot destroy their aggregate structure, so that the compression fluorescence discoloration is not obvious. In summary, the different quinoline connection positions have a significant influence on the compression discoloration range of the compound, which shows that the different substitution positions can have a certain regulation effect on the change.

[0151] The piezochromic performance test results of TPECN1Qu, TPECN3Qu, TPECN4Qu and TPECN8Qu are shown in FIGS. 1-4, respectively. Figure 9 As can be seen from the figures, for TPECN1Qu, TPECN1Qu-o emits yellow-green fluorescence, and the corresponding maximum emission wavelength is 492 nm; the fluorescence of TPECN1Qu-g solid changes to strong yellow, and at the same time, the fluorescence maximum emission wavelength also red shifts from 492 nm to 532 nm, producing a red shift of 40 nm, showing good piezochromic performance; the fluorescence of TPECN1Qu-a and TPECN1Qu-f samples changes to the same yellow-green fluorescence as the original sample, and the fluorescence maximum emission wavelength also remains consistent with the original sample (TPECN1Qu-o). This shows that TPECN1Qu has good piezochromic reversibility.

[0152] For the compound TPECN3Qu, TPECN3Qu-o emits light yellow-green fluorescence, and the corresponding maximum emission wavelength is 511 nm; the fluorescence of TPECN3Qu-g solid changes to strong yellow, and at the same time, the fluorescence maximum emission wavelength also red shifts from 511 nm to 535 nm, producing a red shift of 24 nm, showing good piezochromic performance; the fluorescence of TPECN3Qu-a and TPECN3Qu-f samples changes to the same fluorescence as the original sample, and the fluorescence color of the sample TPECN3Qu-f is closer to the original sample, which shows that TPECN3Qu has good piezochromic reversibility, and the reversibility under the induction of a good solvent is better than the annealing treatment.

[0153] For compound TPECN4Qu, TPECN4Qu-o emits yellow-green fluorescence, and the corresponding maximum emission wavelength is 484 nm; the fluorescence of TPECN4Qu-g solid turns into strong yellow, and at the same time, the maximum emission wavelength of fluorescence is red-shifted from 484 nm to 527 nm, resulting in a red shift of 43 nm, which shows good mechanochromic performance; the fluorescence of TPECN4Qu-a and TPECN4Qu-f samples turns into similar fluorescence as the original sample, and the fluorescence color of sample TPECN4Qu-f is closer to the original sample, which shows that TPECN4Qu has good mechanochromic reversibility, and the reversibility under the induction of a good solvent is better than the effect of annealing treatment.

[0154] For compound TPECN8Qu, TPECN8Qu-o emits yellow-green fluorescence, and the corresponding maximum emission wavelength is 496 nm; the fluorescence of TPECN8Qu-g solid turns into strong yellow, and at the same time, the maximum emission wavelength of fluorescence is red-shifted from 496 nm to 528 nm, resulting in a red shift of 32 nm, which shows good mechanochromic performance; the fluorescence of TPECN8Qu-a and TPECN8Qu-f samples turns into similar fluorescence as the original sample, and the fluorescence color of sample TPECN8Qu-f is closer to the original sample, which shows that TPECN8Qu has good mechanochromic reversibility, and the reversibility under the induction of a good solvent is better than the effect of annealing treatment.

[0155] From the above analysis, it can be seen that the TPECNnQu compounds have good mechanochromic reversibility. After different condition treatment, the fluorescence properties are closely related to the aggregation structure. Since these compounds are composed of benzene rings with relatively stable molecular structure, the chemical molecular structure cannot change under the physical action of grinding, solvent fumigation and annealing. The fluorescence color of the solid sample TPECNnQu changes under these physical actions, therefore, it is speculated that the molecular aggregation structure of TPECNnQu changes under the action of external force such as grinding. In order to explore whether the molecular aggregation structure changes, XRD experiment and fluorescence lifetime decay test are carried out on the above four kinds of treated samples (o, g, a, f). Therefore, the X-ray diffraction is used to characterize the changes of the aggregation structure of the samples treated under different conditions, such as Figures 10 to 14As can be seen from the figure, the XRD curves of the ground sample and the annealed sample and the solvent fumigation sample of the TPECN7Qu compound after grinding all have more strong and sharp diffraction peaks, indicating that the molecules in this state mainly exist in a crystalline manner, and the wavelength red shift of the ground sample may be that the layer-by-layer slip of the molecular stacking is caused by grinding. In contrast, the ground samples of compounds TPECN2Qu, TPECN5Qu and TPECN6Qu still have many sharp diffraction peaks, indicating that grinding does not change the compound from an ordered crystalline state to an amorphous state, and the discoloration of the sample after grinding is not obvious, which is highly consistent with the experimental results.

[0156] For TPECN1Qu, there are many obvious sharp diffraction peaks on the XRD curve of the original sample TPECN1Qu-o, which indicates that the molecules of TPECN1Qu-o have good crystallinity; the XRD curve of TPECN1Qu-g is relatively smooth, and the diffraction peaks are significantly weakened or disappeared, which indicates that the molecular structure arrangement of the sample after force stimulation becomes disordered, and the aggregation state changes from crystalline state to amorphous state; the peak positions of the curves of TPECN1Qu-a and TPECN1Qu-f are the same as those of the original sample, and the peaks are more sharp, which indicates that after the solvent fumigation and annealing, the crystallinity becomes stronger, and the induced crystallization effect of annealing is stronger than that of solvent fumigation treatment, which is the same as the result of the fluorescence emission spectrum. The fluorescence lifetime decay test result shows that the fluorescence lifetime decay of compound TPECN1Qu before and after grinding all passes through one relaxation path, and through the equation <τ> = A1τ1, it is known that the average lifetime of the sample before and after grinding is 1.3222 ns and 4.0195 ns, respectively, and the average lifetime after grinding is greatly improved, which is very likely that under the action of this external force of grinding, the aggregation state structure of the compound changes to disorder, which is consistent with the test structure of XRD.

[0157] Like TPECN1Qu, the XRD curve of the original TPECN3Qu-o has more obvious sharp diffraction peaks, which indicates that the molecular arrangement of TPECN3Qu-o is relatively regular and has good crystallinity; the XRD curve of TPECN3Qu-g is relatively smooth, and the diffraction peaks are obviously weakened or disappeared, indicating that the molecular structure of the sample after a certain force stimulation becomes disordered, and the aggregate state changes from crystalline to amorphous state; the XRD curves of TPECN3Qu-a and TPECN3Qu-f show that the peak positions of the diffraction peaks are the same as those of the original sample, and the peaks obtained by solvent fumigation are stronger than those by annealing, which indicates that the crystallinity of the compound after good solvent fumigation and annealing becomes stronger, and the effect of solvent fumigation on inducing crystallization is stronger than that of annealing, which is the same as the result of fluorescence emission spectrum. The fluorescence lifetime decay test result shows that the fluorescence lifetime decay of compound TPECN3Qu before and after grinding passes through one relaxation path, and through the equation <τ> = A1τ1, it is known that the average lifetime of the sample before and after grinding is 3.7999 ns and 4.3122 ns, respectively, and the average lifetime after grinding is improved, which is likely to be that the aggregate structure of the compound changes to disorder under the action of grinding force, which is consistent with the test structure of XRD. The conclusion is also consistent with that of compound TPECN1Qu.

[0158] Like TPECN1Qu, the XRD curve of the original TPECN3Qu-o has more obvious sharp diffraction peaks, which indicates that the molecular arrangement of TPECN3Qu-o is relatively regular and has good crystallinity; the XRD curve of TPECN3Qu-g is relatively smooth, and the diffraction peaks are obviously weakened or disappeared, indicating that the molecular structure of the sample after a certain force stimulation becomes disordered, and the aggregate state changes from crystalline to amorphous state; the XRD curves of TPECN3Qu-a and TPECN3Qu-f show that the peak positions of the diffraction peaks are the same as those of the original sample, and the peaks obtained by solvent fumigation are stronger than those by annealing, which indicates that the crystallinity of the compound after good solvent fumigation and annealing becomes stronger, and the effect of solvent fumigation on inducing crystallization is stronger than that of annealing, which is the same as the result of fluorescence emission spectrum. The fluorescence lifetime decay test result shows that the fluorescence lifetime decay of compound TPECN3Qu before and after grinding passes through one relaxation path, and through the equation <τ> = A1τ1, it is known that the average lifetime of the sample before and after grinding is 3.7999 ns and 4.3122 ns, respectively, and the average lifetime after grinding is improved, which is likely to be that the aggregate structure of the compound changes to disorder under the action of grinding force, which is consistent with the test structure of XRD. The conclusion is also consistent with that of compound TPECN1Qu.

[0159] By analyzing the XRD patterns and fluorescence lifetime decay curves of these compounds, it is found that the molecular aggregation state structure has changed to amorphous. Therefore, it can be concluded that the change of fluorescence color is due to the change of molecular aggregation state structure under the action of grinding.

[0160] 4. Acid-base stimulus responsive properties

[0161] The target product TPECNnQu-o and TPECNnQu-g were respectively placed in a sealed container filled with HCl vapor for a period of time (at room temperature, about 25℃, for more than 4h), and the treated samples were marked as TPECNnQu-o-h and TPECNnQu-g-h. Half of the obtained samples were placed in a sealed container filled with NH3 for a period of time (at room temperature, about 25℃, for more than 4h), and the obtained samples were marked as TPECNnQu-o-h-n and TPECNnQu-g-h-n. The photos of the four state samples under 365nm ultraviolet lamp irradiation were taken, and then the fluorescence spectrometer was used to test them in time to obtain their fluorescence spectra. Since HCl and NH3 are very volatile, there is a small amount of acid-base solution in the sealed container, and after a period of time, the whole container will be filled. A period of time is needed to allow the sample to be fully protonated or deprotonated.

[0162] Since the N on the quinoline ring of the compound TPECNnQu has the properties of protonation and deprotonation, this experiment studies its acid stimulus response (the samples prepared in Examples 1-8 are treated by acid vapor (HCl) and base vapor (NH3) fumigation, and the response time and fluorescence change are tested. The results are shown in Figures 15 to 17 ). A small dryer is used as a sealed container, and a petri dish containing HCl or NH3 is placed at the bottom of the dryer. After a period of time at room temperature, wait for the vapor to fill the entire container, then put the sample petri dish, use 365nm ultraviolet lamp to observe and record the fluorescence change, and record the response time. At 25℃, a small amount of hydrochloric acid solution or ammonia water (hydrochloric acid aqueous solution, HCl content 36%-38%; base solution uses ammonia water, NH3 content 25%-28%) is placed in a sealed dryer (cylindrical dryer with a diameter of about 0.2m, a height of about 0.2m, and a volume of about 6.28dm 3 ). After about 30 minutes at room temperature (about 25℃), the container is filled with acid or base vapor), the sample is placed in a petri dish and placed in the dryer, and a 365nm ultraviolet lamp is used to observe the fluorescence change and record the response time.

[0163] As an example of TPECN2Qu, the fluorescence emission of TPECN2Qu initial powder changed obviously after hydrochloric acid vapor fumigation: the fluorescence color changed from green to red, and the emission wavelength also changed from 504 nm to 680 nm, which indicated that the solid powder of TPECN2Qu had obvious acid stimulation response. In addition, the sample fluorescence color changed to yellow-green after ammonia vapor fumigation of P-HCl powder, which did not completely recover to the initial state (as shown in Figure 16 The pressure-induced fluorescence color change of compound TPECN7Qu was more obvious. In order to explore whether the acid-base stimulation response behavior of the compound can be adjusted by changing the stacking mode between molecules, the acid stimulation response of the ground samples of TPECN5Qu, TPECN6Qu and TPECN7Qu was studied, and the results are shown in Table 3.

[0164] Table 3

[0165]

[0166] As can be seen from Table 3, hydrochloric acid vapor can also greatly change the emission fluorescence of the ground sample, and the emission wavelength changes from 502 nm to 652 nm. When deprotonation is carried out using ammonia vapor, the sample does not recover to the ground state (530 nm). It can be seen that both the acid fumigated sample of the initial sample and the acid fumigated sample after grinding have a large degree of red shift. The experimental results show that the connection position of the quinoline group not only has a regulating effect on the pressure-induced fluorescence color change, but also has a regulating effect on the acid-base stimulation response.

[0167] As can be seen from Figure 17 , for compound TPECN1Qu, TPECN1Qu-o emits yellow-green fluorescence, and the corresponding maximum emission wavelength is 492 nm; the fluorescence of TPECN1Qu-o-h solid after acid fumigation changes to dark yellow, showing poor acid-induced color change performance; the solid fluorescence of TPECN1Qu-o-h-n changes to light yellow, and the maximum emission wavelength is 497 nm, which indicates that the acid-induced color change performance of TPECN1Qu is poor. Similarly, the acid-induced color change of the ground sample was explored, and the test results are shown in the figure. Different from the original sample, the acid fumigated sample is dark brown under ultraviolet light, and after alkali fumigation, the sample returns to the color of the ground sample, which indicates that TPECN1Qu-g also has good acid-induced color change reversibility, which indicates that the pressure-induced color change and the acid-induced color change can coexist, and then we conclude that TPECN1Qu has certain dual stimulation performance of pressure-induced color change and acid-induced color change.

[0168] For TPECN3Qu, TPECN3Qu-o emits yellow-green fluorescence, and the corresponding maximum emission wavelength is 511 nm; the fluorescence of TPECN3Qu-o-h solid turns into light yellow, and the maximum emission peak is located at 526 nm, which has a red shift of 15 nm, and exhibits certain acid-induced color change performance; the fluorescence color of TPECN3Qu-o-h-n turns into yellow-green, which shows that TPECN3Qu has good acid-induced color change reversibility. The same as the sample after grinding, the acid-induced color change was explored, and the test results are shown in the figure, and the compound TPECN3Qu also has good force-induced color change and acid-induced color change dual stimulation performance.

[0169] For compound TPECN4Qu, TPECN4Qu-o emits yellow-green fluorescence, and the corresponding maximum emission wavelength is 484 nm; the fluorescence of TPECN4Qu-o-h solid turns into orange red, and the maximum emission peak is located at 594 nm, which has a large red shift, and shows good acid-induced color change performance; the fluorescence color of TPECN4Qu-o-h-n turns into yellow, and the maximum emission peak is located at 547 nm, which has a certain recovery relative to the original sample, which shows that TPECN4Qu has poor acid-induced color change reversibility. The same as the sample after grinding, the acid-induced color change was explored, and the test results are shown in the figure, and the same as TPECN1Qu, the compound TPECN4Qu has certain force-induced color change and acid-induced color change dual stimulation performance.

[0170] For compound TPECN8Qu, TPECN8Qu-o emits yellow-green fluorescence, and the corresponding maximum emission wavelength is 496 nm; the fluorescence of TPECN8Qu-o-h solid is light yellow-green, and the maximum emission peak is located at 499 nm, and the fluorescence color of TPECN8Qu-o-h-n is yellow-green, and the maximum emission peak is located at 497 nm, which shows that TPECN8Qu does not have acid-induced color change performance, that is, TPECN8Qu only has good force-induced color change performance, so the compound TPECN8Qu does not have force-induced color change and acid-induced color change dual stimulation performance. The results show that the compounds TPECN3Qu and TPECN4Qu have good acid-induced color change performance, and the acid-induced color change performance of TPECN1Qu and TPECN8Qu is poor.

[0171] In order to explore the reason of acid discoloration, considering that the quinoline group contains a strong electron-withdrawing N atom, the molecular simulation of TPECN1Qu, TPECN3Qu, TPECN4Qu and TPECN8Qu crystal structures was carried out by using Gaussian 09 program to investigate the influence of TICT effect on fluorescence. The results show that for TPECN1Qu and TPECN1Qu-HCl, the electrons are transferred from the tetraphenyl ethylene group to the quinoline group, that is, the intramolecular electron transfer occurs, indicating that the quinoline structure has strong electron-withdrawing ability. But after acid fumigation, the electron cloud distribution only changes slightly, that is, the quinoline structure in TPECN1Qu does not show a significant increase in electron-withdrawing ability after protonation, so the fluorescence color is approximately the same. For TPECN3Qu and TPECN3Qu-HCl, the electrons are transferred from the tetraphenyl ethylene group to the quinoline group, that is, the intramolecular electron transfer occurs, indicating that the quinoline structure has strong electron-withdrawing ability. After acid fumigation, the electron cloud distribution changes significantly, mainly distributed in the quinoline structure in the LUMO energy level, indicating that the quinoline structure in TPECN3Qu shows more significant electron-withdrawing ability after protonation, which promotes the transfer of electrons to the protonated quinoline group. Moreover, the LUMO and HOMO energy levels after protonation also decrease significantly, the energy level difference changes from 3.05 eV to 2.80 eV, which indicates that after acid fumigation, the two crystals become different excited states due to the effect of TICT, so the fluorescence color is different, and the fluorescence wavelength red shifts. For TPECN4Qu and TPECN4Qu-HCl, the electrons are transferred from the tetraphenyl ethylene group to the quinoline group, that is, the intramolecular electron transfer occurs, indicating that the quinoline structure has strong electron-withdrawing ability. The LUMO and HOMO energy levels of TPECN4Qu-HCl after protonation are significantly lower than those of TPECN4Qu, the energy level difference changes from 3.11 eV to 2.51 V, which indicates that after acid fumigation, the two crystals become different excited states due to the effect of TICT, and the energy gap decreases, so the fluorescence color is different, and the fluorescence wavelength red shifts. For TPECN8Qu and TPECN8Qu-HCl, the electrons are transferred from the tetraphenyl ethylene group to the quinoline group, that is, the intramolecular electron transfer occurs, indicating that the quinoline structure has strong electron-withdrawing ability. After acid fumigation, the electron cloud distribution changes significantly, the energy level difference changes from 3.03 eV to 2.20 eV, which indicates that after acid fumigation, the two crystals become different excited states due to the effect of TICT, so the fluorescence color is slightly different.

[0172] 5. Acid-base stimulus response performance of micro-nanofiber membrane

[0173] From the above test results, it is found that the TPECNnQu series compounds need relatively long time in the acid-base stimulation test in powder state, because the acid vapor first contacts the outermost layer of the powder, and it takes time to diffuse to the inner layer. Therefore, in order to shorten the required time, the TPECNnQu series compounds are respectively compounded with cellulose acetate (CA) to prepare spinning solution, and the corresponding micro-nano fiber membrane is prepared by electrospinning technology, and then the acid-base stimulation response performance is studied. As shown in Figure 18 , the prepared composite fiber membrane surface is uniform and smooth, and no granular aggregates are observed, indicating that the TPECN2Qu compound has good compatibility with CA, and the addition of the TPECN2Qu compound will not affect the spinning performance of CA. Other compounds have similar properties, and to avoid redundancy, they are not shown one by one.

[0174] The TPECN2Qu compound is respectively compounded with polystyrene (PS) and polylactic acid (PLA) to prepare micro-nano fiber membranes, in order to explore the fluorescence stability of the TPECN2Qu compound in different polymers. As shown in Figure 19 , the PLA-TPECN2Qu micro-nano fiber membrane and the PS-TPECN2Qu micro-nano fiber membrane emit green fluorescence under 365nm ultraviolet lamp, and from the inverted fluorescence microscope photos, it can be seen that the TPECN2Qu compound is uniformly dispersed in the PS and PLA polymers. The results show that the TPECN2Qu compound has good fluorescence stability in different polymers.

[0175] The TPECN2Qu compound is respectively compounded with polystyrene (PS) and polylactic acid (PLA) to prepare micro-nano fiber membranes, in order to explore the fluorescence stability of the TPECN2Qu compound in different polymers. As shown in Figure 19 , the PLA-TPECN2Qu micro-nano fiber membrane and the PS-TPECN2Qu micro-nano fiber membrane emit green fluorescence under 365nm ultraviolet lamp, and from the inverted fluorescence microscope photos, it can be seen that the TPECN2Qu compound is uniformly dispersed in the PS and PLA polymers. The results show that the TPECN2Qu compound has good fluorescence stability in different polymers.

[0176] During the acid stimulation response experiment, the CA-TPECN2Qu micro-nano fiber membrane changes from yellow-green to red after being fumigated with hydrochloric acid vapor for about 3s (as shown in Figure 20 ), and the maximum emission wavelength of fluorescence also shifts from 497nm to 650nm, with a red shift of 153nm (as shown in Figure 21Deprotonation with NH3 vapor restored the wavelength to its initial state. However, the ground TPECN2Qu sample, discussed above, did not return to the G state after alkaline vapor fumigation, likely due to the sample's aggregation. These experimental results demonstrate that the large surface area of ​​electrospun micro-nanofibers significantly enhances HCl sensing capabilities. CA-TPECN5Qu, CA-TPECN6Qu, and CA-TPECN7Qu micro-nanofiber membranes also exhibit similar performance, as shown in Table 4.

[0177] Table 4

[0178]

[0179] As shown in Table 4, after hydrochloric acid vapor fumigation, the maximum fluorescence emission wavelength of all fiber membranes exhibited varying degrees of red-shift, with the CA-TPECN2Qu and CA-TPECN7Q micro-nanofiber membranes exhibiting a greater degree of red-shift, consistent with the results discussed above. These experimental results demonstrate that the large surface area and high porosity of electrospun films enhance the sensing capability of HCl vapor. Such reversible acid-base stimuli-responsive micro-nanofilms have applications in acid detection and anti-counterfeiting.

[0180] The results of the acid-base stimulation test of CA-TPECNnQu (n=1, 3, 4 or 8) are as follows Figure 22 As shown. For CA-TPECN1Qu, the original micro-nanofiber membrane exhibited a pale yellow-green fluorescence under UV light (365nm). After acid fumigation, the fluorescence of the sample shifted to a pale dark yellow, and after ammonia fumigation, the fluorescence color returned to pale green. The fluorescence emission spectrum showed that the maximum emission wavelength shifted from 527nm to 624nm and finally to 497nm, a significant red-to-blue shift. This demonstrates a certain degree of reversibility in acid-induced color change. The acid-induced color change properties of the CA-TPECN1Qu micro-nanofiber membrane are superior to those of the compound TPECN1Qu. Moreover, the test results show that the maximum fluorescence emission wavelength of the original sample of the micro-nanofiber membrane is very close to that of the sample after TPECN1Qu grinding, and the fluorescence color is also similar. This is because the aggregated structure of TPECN1Qu is destroyed during the spinning process and becomes amorphous, that is, the chemical structure of TPECN1Qu in the CA-TPECN1Qu micro-nanofiber membrane made of compound TPECN1Qu is in an amorphous state. Therefore, we can also conclude that the CA-TPECN1Qu micro-nanofiber membrane has no mechanochromic properties.

[0181] For CA-TPECN3Qu, the micro-nanofiber membrane was yellow-green fluorescence under the irradiation of ultraviolet lamp (365 nm), and the fluorescence of the sample after acid fumigation changed into yellow-orange color, and the fluorescence color of the sample after ammonia fumigation changed into light green color. The fluorescence emission spectrum showed that the maximum emission wavelength experienced a process of moving from 520 nm to 584 nm and then to 525 nm, that is, a large red shift and then a blue shift. It showed good acid-induced color change reversibility. The acid-induced color change performance of CA-TPECN3Qu micro-nanofiber membrane was also excellent as the compound TPECN3Qu. Moreover, the test results showed that the fluorescence maximum emission wavelength of the original sample of the micro-nanofiber membrane was very close to that of the ground sample of TPECN3Qu, and the fluorescence color was also close. After alkali fumigation, the fluorescence color and the maximum emission wavelength of the sample were consistent with those of the ground sample of TPECN3Qu. This was because the aggregate structure of TPECN3Qu was destroyed in the spinning process and became amorphous. That is, the chemical structure of TPECN3Qu in the CA-TPECN3Qu micro-nanofiber membrane made of compound TPECN3Qu was in an amorphous state. Therefore, it can also be concluded that the CA-TPECN3Qu micro-nanofiber membrane has no mechanical color change performance.

[0182] For CA-TPECN4Qu, the micro-nanofiber membrane was yellow fluorescence under the irradiation of ultraviolet lamp (365 nm), and the fluorescence of the sample after acid fumigation changed into dark red, and the fluorescence color of the sample after ammonia fumigation changed into light yellow. The fluorescence emission spectrum showed that the maximum emission wavelength experienced a process of moving from 538 nm to 635 nm and then to 540 nm, that is, a large red shift and then a blue shift. It showed good acid-induced color change reversibility. The acid-induced color change performance of CA-TPECN3Qu micro-nanofiber membrane was also excellent as the compound TPECN3Qu. Moreover, the test results showed that the fluorescence maximum emission wavelength of the original sample of the micro-nanofiber membrane was very close to that of the ground sample of TPECN4Qu, and the fluorescence color was also close. After alkali fumigation, the fluorescence color and the maximum emission wavelength of the sample were consistent with those of the ground sample of TPECN4Qu. This was because the aggregate structure of TPECN4Qu was destroyed in the spinning process and became amorphous. That is, the chemical structure of TPECN4Qu in the CA-TPECN4Qu micro-nanofiber membrane made of compound TPECN4Qu was in an amorphous state. Therefore, it can also be concluded that the CA-TPECN4Qu micro-nanofiber membrane has no mechanical color change performance.

[0183] For CA-TPECN8Qu, the micro-nanofiber membrane was light green fluorescence under the irradiation of ultraviolet lamp (365 nm), and the fluorescence of the sample after acid fumigation changed to green, and the fluorescence of the sample after ammonia fumigation changed to light green again. The fluorescence emission spectrum showed that the maximum emission wavelength moved from 508 nm to 492 nm and then to 496 nm, which experienced a small blue shift and then a red shift. It showed poor acid-induced color reversibility, which was similar to the original sample of compound TPECN8Qu. Different from other fiber membranes, the fiber membrane experienced a blue shift and then a red shift during acid fumigation.

[0184] In summary, the scheme of the present application endows the compound with multiple stimulus response by introducing quinoline group. And by changing the substitution position of quinoline, different substitution sites of tetraphenylethene-quinoline compounds are designed and synthesized. These compounds have certain differences in their photophysical properties due to different substitution positions, but they all have significant AIE performance and solvent effect. Compounds TPECN7Qu, TPECN1Qu, TPECN3Qu, TPECN4Qu and TPECN8Qu have obvious pressure-induced color change properties, and the fluorescence color changes from light blue to green under mechanical force, and the wavelength red shifts by 21 nm. And after fumigation or annealing in solvent DCM, it can well restore the initial fluorescence emission maximum wavelength and restore the original fluorescence color. In terms of acid-base stimulus response, after fumigation with hydrochloric acid, the red shift of the maximum fluorescence emission wavelength of compound TPECN7Qu is the largest (182 nm), followed by compound TPECN2Qu, TPECN1Qu, TPECN3Qu and TPECN4Qu. The corresponding color change of the ground sample also occurs obviously, realizing the high contrast change of the fluorescence color of the sample after acid fumigation. It shows that the different substitution positions of quinoline have certain regulation effect on fluorescence emission. TPECN7Qu, TPECN1Qu, TPECN3Qu and TPECN4Qu all have good dual-stimulus performance, that is, the force-induced color change performance and acid-induced color change performance can be simultaneously possessed. After the original sample is ground and placed in a hydrogen chloride atmosphere for fumigation, the maximum emission wavelength will still experience obvious red shift, and the red shift is more obvious than that of the original acid fumigation. The fluorescence color of the corresponding sample will also change, and after the sample is fumigated with ammonia for a period of time, the sample will restore to the original fluorescence color, and the maximum emission wavelength will also restore to the original position.

[0185] The micro-nanofiber membranes obtained by electrospinning of the mixture of the synthesized compound samples TPECN7Qu, TPECN1Qu, TPECN3Qu, TPECN4Qu and TPECN8Qu and CA all have the same acid color-reversible performance as the ground sample of the synthesized compound itself, that is, the fiber membranes will have a relatively large red shift after acid fumigation, and a large blue shift after alkali fumigation, and return to a fluorescence color close to or the same as that of the ground sample of the synthesized compound. The electrospun thin films prepared by compounding these compounds with CA have the largest red shift of fluorescence wavelength after hydrochloric acid vapor fumigation, and the response time to acid is shortened from 10 s in the powder state to 3 s, improving the HCl transmission ability of the compound.

[0186] The above has described the embodiments of the present application in detail, but the present application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims

1. A tetraphenylstilbene-quinoline compound, characterized by: The compound has the following general structural formula: In the formula, Ar represents quinolinyl.

2. The tetraphenylethylene-quinoline compound according to claim 1, wherein: The compound has the following structural formula: 。 3. A method of preparing the tetraphenylstyryl-quinolines according to claim 1 or 2, characterized in that: The method comprises the following steps: Under protective atmosphere, The tetraphenylethylene-quinoline compound is prepared by reacting with ArCHO.

4. The production method according to claim 3, characterized by: The protective atmosphere is nitrogen or inert gas atmosphere.

5. The production method according to claim 3, characterized by: The reaction comprises at least one of the following conditions: 1) under catalytic conditions, the catalysis uses at least one of the following catalysts: tetrabutylammonium hydroxide, pyridine or piperidine; 2) the temperature of the reaction is 75-85℃; 3) the time of the reaction is 20-28h; 4) the reaction is carried out in solution, and the solution uses at least one of the following solvents: ethanol, N,N-dimethylformamide or toluene.

6. The production method according to claim 3, characterized by: The structural formula of the ArCHO is shown in one of the following formulas: .

7. Use of the tetraphenylstyrene-quinoline compound according to claim 1 or 2 in the preparation of a fluorescent material.

8. A fibrous membrane characterized by: The fiber film is prepared from the tetraphenylstyrene-quinoline compound according to claim 1 or 2.

9. Use of the tetraphenylstilbenes-quinolines compound according to claim 1 or 2 or the fibrous membrane according to claim 8 in the field of detection reagents, characterized in that: The detection comprises at least one of the following detection contents: 1) acid; 2) base.

10. Use of a compound for the manufacture of a detection reagent, characterized in that: The compound is selected from The detection includes at least one of the following detection contents: 1) anti-counterfeiting; 2) product defect; 3) stress.

11. A material characterized in that: comprising ; the material can be used to make at least one of the following products: 1) toy; 2) shape memory material; 3) impact-resistant protective material; 4) force sensor material; 5) mechanical probe material; 6) optical switch material; 7) anti-counterfeiting material; 8) flexible electronic product; 9) intelligent packaging material.

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