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

Abstract

The application discloses a tetraphenyl ethene-isoquinoline compound and a preparation method and application thereof, and the compound has the following general structure: Ar represents isoquinoline. The structural compound in the application scheme has strong fluorescence, and can present high contrast changes in fluorescence color before and after acid and alkali fumigation.

Description

TECHNICAL FIELD

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

[0002] With the rapid development of science and technology, the research of material science, especially functional organic compounds, has become one of the hotspots in the field of modern scientific research. Among these compounds, molecules with fluorescence properties have unique luminescent properties and show wide application prospects in the fields of biological imaging, chemical sensing, optoelectronic materials and fluorescent probes. Especially, fluorescent compounds that can change color under specific stimuli have great potential value in the fields of environmental monitoring, biological detection and drug release, as high-sensitivity sensors.

[0003] Tetraphenyl ethylene (TPE) and its derivatives are a class of compounds with aggregation-induced emission (AIE) properties. They hardly emit light in solution state, but can emit strong fluorescence in aggregated or solid state. This unique property makes tetraphenyl ethylene compounds widely concerned in the fields of solid-state luminescent materials, biological imaging and fluorescent probes. Isoquinoline and its derivatives are a class of aromatic compounds containing nitrogen heterocycles. They not only have good chemical stability and thermal stability, but also the nitrogen atoms in their structures are easy to be chemically modified, so as to introduce various functional groups.

[0004] Tan Jia-min et al. designed a new type of AIE molecule by fusing tetraphenyl ethylene and isoquinoline structural units in the paper "Design and synthesis of new aggregation-induced emission molecules based on isoquinoline skeleton structure" (Organic Chemistry, 2022, 42(11):8. DOI:10.6023 / cjoc202204038.). It was found that this class of molecules had good AIE phenomenon. 4-hydroxytetraphenyl ethylene was used as raw material to prepare different substituted o-alkynyl aromatic aldehyde compounds, and a series of new isoquinoline tetraphenyl ethylene type molecules were synthesized from the substrates. Spectral studies showed that this class of molecules had good AIE effect. Therefore, it is of great significance to develop more tetraphenyl ethylene-isoquinoline compounds. SUMMARY

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a tetraphenyl ethylene-isoquinoline compound. This class of compounds not only has good AIE effect, but also has acid-base stimulus response.

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

[0007] The application further provides the compound.

[0008] According to an aspect of the application, a tetraphenylethene-isoquinoline compound is provided, which has the following general structure:

[0009] Ar represents isoquinoline.

[0010] According to a preferred embodiment of the application, at least the following advantages are provided: the compound ISO-TPECNnQu has a D-A structure, has strong fluorescence, and after the solid powder is fumigated with hydrochloric acid vapor, a significant wavelength red shift is observed; when the deprotonated powder is deprotonated with ammonia vapor, the fluorescence wavelength of ISO-TPECN3Qu is further red-shifted, while the fluorescence wavelength of ISO-TPECN8Qu and ISO-TPECN4Qu is blue-shifted to different degrees, and the fluorescence wavelength of ISO-TPECN5Qu is directly blue-shifted to the initial state; due to the D-A structure, the electron-donating ability of TPE is enhanced after deprotonation by alkali fumigation, resulting in further red shift of the wavelength.

[0011] In some embodiments of the application, the tetraphenylethene-isoquinoline compound has a structure represented by one of the following formulas:

[0012]

[0013] According to another aspect of the application, a preparation method of the compound is provided, which comprises the following steps:

[0014] The cyano tetraphenylethene (TPECN) is reacted with the formaldehyde-substituted isoquinoline under a protective atmosphere to obtain the tetraphenylethene-isoquinoline compound.

[0015] According to the preparation method of the preferred embodiment of the application, at least the following advantages are provided: the preparation method of the application is simple to operate and has good industrial application prospects.

[0016] In some embodiments of the application, the preparation method further comprises a preparation step of cyano tetraphenylethene:

[0017] The cyano tetraphenylethene (TPECN) is reacted with the formaldehyde-substituted isoquinoline under a protective atmosphere to obtain the tetraphenylethene-isoquinoline compound. And to obtain the compound.

[0018] In some embodiments of the application, the preparation of the cyano tetraphenylethene is carried out under the catalysis of a palladium catalyst.

[0019] In some embodiments of the application, the palladium catalyst is Pd(PPh3)4.

[0020] In some embodiments of the present application, the cyanotetraphenyl ethene is prepared in an alkaline environment.

[0021] In some embodiments of the present application, the alkaline environment is generated by adding a carbonate.

[0022] In some embodiments of the present application, the carbonate is potassium carbonate or sodium carbonate.

[0023] In some embodiments of the present application, the cyanotetraphenyl ethene is prepared in a solution, and the solvent of the solution is at least one of tetrahydrofuran (THF), toluene or ethanol.

[0024] In some embodiments of the present application, a phase transfer catalyst is added in the preparation of the cyanotetraphenyl ethene, and the phase transfer catalyst is selected from tetrabutylammonium bromide (TBAB).

[0025] In some embodiments of the present application, the protective atmosphere is nitrogen or inert gas atmosphere.

[0026] In some embodiments of the present application, the reaction is carried out under catalytic conditions, and the catalyst used in the catalysis is at least one of tetrabutylammonium hydroxide (TBAH), piperidine or pyridine.

[0027] In some embodiments of the present application, the temperature of the reaction is 75-85℃. For example, the temperature is 80℃.

[0028] In some embodiments of the present application, the reaction time is 20-28h. For example, the reaction time is 24h.

[0029] In some embodiments of the present application, the reaction is carried out in a solution, and the solvent of the solution is at least one of ethanol, N,N-dimethylformamide or toluene.

[0030] In some embodiments of the present application, the preparation method further comprises a post-treatment step, specifically comprising collecting the reaction product and washing with ethanol.

[0031] According to another aspect of the present application, the above compound is used in the preparation of a fluorescent material.

[0032] According to another aspect of the present application, an acid-base detection or anti-counterfeiting material comprises

[0033] According to the application of the preferred embodiment, at least the following beneficial effects are achieved: the compound of the present application has strong aggregate fluorescence, and under the action of pH 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 other detections.

[0034] Other features and advantages of the present application will be set forth in the description that follows, and in part will be apparent from the description, or can be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0035] 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:

[0036] Figure 1 is a preparation route of the compound of Example 1 of the present application.

[0037] Figure 2 is a preparation route of the compound of Example 1 of the present application. 1 HNMR (deuterated chloroform).

[0038] Figure 3 is a preparation route of the compound of Example 1 of the present application. 13 CNMR (deuterated chloroform).

[0039] Figure 4 is a preparation route of the compound of Example 1 of the present application.

[0040] Figure 5 is a preparation route of the compound of Example 1 of the present application. 1 HNMR (deuterated chloroform).

[0041] Figure 6 is a preparation route of the compound of Example 1 of the present application. 13 CNMR (deuterated chloroform).

[0042] Figure 7 is a preparation route of the compound of Example 1 of the present application.

[0043] Figure 8 is a preparation route of the compound of Example 1 of the present application. 1 HNMR (deuterated chloroform).

[0044] Figure 9 is a preparation route of the compound of Example 1 of the present application. 13 CNMR (deuterated chloroform).

[0045] Figure 10 is a preparation route of the compound of Example 1 of the present application.

[0046] Figure 11 is a preparation route of the compound of Example 1 of the present application. 1 HNMR (deuterated chloroform).

[0047] Figure 12 is a preparation route of the compound of Example 1 of the present application. 13CNMR (deuterated chloroform).

[0048] Figure 13 is the mass spectrum of the product prepared in Example 4 of the present application.

[0049] Figure 14 are the emission and absorption spectra of the product powder prepared in Example 1 of the present application in tetrahydrofuran solution with different water contents (concentration: 10 μM): a) fluorescence spectrum; b) ultraviolet-visible spectrum.

[0050] Figure 15 are the PL and UV-vis absorption spectra of the product powder prepared in Example 2 of the present application in tetrahydrofuran solution with different water contents (concentration: 10 μM, excitation wavelength: 420 nm): a) fluorescence spectrum; b) ultraviolet-visible spectrum.

[0051] Figure 16 are the PL and UV-vis absorption spectra of the product powder prepared in Example 3 of the present application in tetrahydrofuran solution with different water contents (concentration: 10 μM, excitation wavelength: 420 nm): a) fluorescence spectrum; b) ultraviolet-visible spectrum.

[0052] Figure 17 are the PL and UV-vis absorption spectra of the product powder prepared in Example 4 of the present application in tetrahydrofuran solution with different water contents (concentration: 10 μM, excitation wavelength: 420 nm): a) fluorescence spectrum; b) ultraviolet-visible spectrum.

[0053] Figure 18 are the PL and UV-vis absorption spectra of the products prepared in Examples 2-4 of the present application in 6 solvents with different polarities: a ISO-TPECN4Qu; b ISO-TPECN5Qu; c ISO-TPECN8Qu.

[0054] Figure 19 are the PL spectra of the product 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, and P-HCl-NH3 represents the sample after acid fumigation and alkali fumigation.

[0055] Figure 20 are the fluorescence photos (365 nm) of the original sample of the product prepared in Example 1 of the present application after acid and alkali stimulation.

[0056] Figure 21 are the PL spectra and fluorescence photos of the product powder prepared in Example 2 of the present application under external stimuli: o represents the original sample, o-HCl represents the sample after acid fumigation, and o-HCl-NH3 represents the sample after acid fumigation and alkali fumigation.

[0057] Figure 22PL spectra and fluorescence photos of the product powder prepared in Example 3 under external stimulation: o represents the initial sample, o-HCl represents the sample after acid fumigation, and o-HCl-NH3 represents the sample after acid fumigation and alkali fumigation.

[0058] Figure 23 PL spectra and fluorescence photos of the product powder prepared in Example 4 under external stimulation: o represents the initial sample, o-HCl represents the sample after acid fumigation, and o-HCl-NH3 represents the sample after acid fumigation and alkali fumigation. DETAILED DESCRIPTION

[0059] The concept and technical effects of the present application will be described below in combination with examples, so as to fully understand the purpose, features and effects of the present application. Obviously, the described examples are only some of the examples of the present application, but not all the examples. Based on the examples of the present application, other examples 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 examples are conventional methods unless otherwise specified. The materials and reagents used are commercially available unless otherwise specified. The same parameters are used in the same way in each example unless otherwise specified. The examples described below are exemplary and are used to explain the present application, and cannot be understood as limiting the present application.

[0060] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0061] Part of the raw material procurement information used in the following examples and comparative examples is shown in Table 1 below:

[0062] Table 1

[0063]

[0064]

[0065] The instrument information used in the following examples and comparative examples is shown in Table 2 below:

[0066] Table 2

[0067]

[0068] The methods and main parameter information used in the test characterization process are as follows:

[0069] Compound 1 H-NMR and 13 C-NMR were measured on a Bruker AVANCE NEO 500 spectrometer with deuterated chloroform as the solvent, tetramethylsilane (TMS) as the internal standard, to test the chemical structure of the compound.

[0070] Fluorescence spectra and ultraviolet-visible absorption spectra were used to analyze the photophysical properties of the compound. The excitation and emission slits of the fluorescence spectrum for AIE performance testing were 10 nm and 15 nm, and the rest were 3 nm and 5 nm.

[0071] X-ray diffractometer with Cu Kα (λ = 0.1541 nm) as the light source, test voltage 40 kV, 40 mA, used to characterize the aggregate structure of the compound.

[0072] Steady-state / transient combined fluorescence spectrometer and calibrated integrating sphere tested the fluorescence quantum efficiency of the compound.

[0073] Scanning electron microscope for observing the microstructure of the fiber membrane, operating voltage 15 kV.

[0074] The specific synthesis process of TPECN is as follows (refer 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):

[0075] Dissolve 1-bromo-1,2,2-triphenyl ethylene (1.74 g, 5.2 mmol) and 4-(cyanoethyl) phenylboronic acid (1.00 g, 6.2 mmol) in a mixture of toluene (40 mL), Aliquat 336 (methyltrioctylammonium chloride, 10 drops) and 2M aqueous potassium carbonate solution (10 ml). Stir under argon at room temperature for 0.5 h, add Pd(PPh3)4 (0.010 g, 8.70*10 -3 mmol), heat to 90°C for 24 h, then pour the mixture into water, extract with ethyl acetate three times. Dry the organic layer over anhydrous sodium sulfate. After removing the solvent under reduced pressure, the residue is chromatographed on a silica gel column with petroleum ether / CH2Cl2 (volume ratio 3:1) as the eluent to obtain intermediate 1 (1.30 g, yield 68%).

[0076] 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.

[0077] Example 1

[0078] In this example, a tetraphenylethene-isoquinoline compound Iso-TPECN3Qu was prepared, and the synthetic route thereof is shown in Figure 1 . Specifically, TPECN (1 g, 2.6 mmol) was added to a three-necked flask, 30 mL of anhydrous ethanol was added, and the mixture was dissolved under magnetic stirring. After complete dissolution, nitrogen was introduced, isoquinoline-3-carboxaldehyde (0.41 g, 2.6 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 filter residue was collected by suction filtration, and washed with ethanol for 3 times to obtain a light yellow solid powder (1.3 g, 80%).

[0079] 1 H NMR (500 MHz, CDCI3) δ 9.33 (s, 1H), 8.23 (s, 1H), 8.01 (dd, J = 8.3, 1.2 Hz, 1H), 7.91 (dd, J = 8.3, 1.1 Hz, 1H), 7.78-7.64 (m, 3H), 7.56-7.50 (m, 2H), 7.17-7.02 (m, 17H). 13 CNMR (500 MHz, CDCI3) δ 152.68, 146.13, 145.33, 143.44, 143.38, 143.27, 142.09, 140.58, 139.92, 135.81, 132.23, 132.05, 131.39, 131.32, 131.04, 128.69, 128.56, 127.93, 127.85, 127.80, 127.71, 127.52, 126.87, 126.72, 126.67, 125.55, 121.81, 117.83, 113.30.

[0080] The nuclear magnetic characterization data are shown in Figure 2-3 .

[0081] Example 2

[0082] In this example, a tetraphenylethene-isoquinoline compound Iso-TPECN3Qu was prepared, and the synthetic route thereof is shown in Figure 4The reaction solution was added with an appropriate amount of catalyst tetrabutylammonium hydroxide (0.49 g, 0.0019 mmol) after TPECN (1 g, 2.6 mmol) and isoquinoline-4-carboxaldehyde (0.4086 g, 2.6 mmol) were added and dissolved completely. After the reaction was completed, negative pressure filtration was performed, and the filter residue was dried in an oven after being washed with ethanol three times during the process. 1.30 g of yellow solid powder was obtained (yield 83%).

[0083] 1 H NMR (500 MHz, CDC13) δ 9.31 (s, 1H), 8.97 (d, J = 1.1 Hz, 1H), 8.09 - 8.02 (m, 2H), 7.93 (dd, J = 8.4, 1.0 Hz, 1H), 7.79 (ddd, J = 8.3, 6.9, 1.3 Hz, 1H), 7.70 (ddd, J = 8.1, 6.9, 1.1 Hz, 1H), 7.56 - 7.50 (m, 2H), 7.22 - 7.02 (m, 17H). 13 C NMR (500 MHz, CDC13) δ 154.37, 145.91, 143.44, 143.35, 143.04, 142.37, 139.85, 135.87, 133.99, 132.30, 131.48, 131.45, 131.41, 128.69, 128.16, 128.10, 128.04, 128.01, 127.85, 127.04, 126.90, 126.86, 125.74, 122.89, 117.21, 117.13.

[0084] C 38 H 27 ESI+ HRMS m / z calcd for N2 511.2183 [M+H], found 511.2183 [M+H].

[0085] NMR characterization data are shown in Figure 5-6 and the mass spectrum is shown in Figure 7 .

[0086] Example 3

[0087] In this example, a tetraphenylethene-isoquinoline compound Iso-TPECN5Qu was prepared, and the synthetic route thereof is shown in Figure 4 . The method was similar to the synthesis of ISO-TPECN4Qu described above, and the raw material isoquinoline-5-carboxaldehyde was added instead of isoquinoline-4-carboxaldehyde. 1.20 g of light yellow solid was obtained (yield 71%).

[0088] 1H NMR (500 MHz, CDC13) δ 9.31 (d, J = 0.9 Hz, 1H), 8.61 (d, J = 6.0 Hz, 1H), 8.30 (dd, J = 7.3, 1.1 Hz, 1H), 8.12 - 8.04 (m, 2H), 7.79 - 7.68 (m, 2H), 7.55 - 7.49 (m, 2H), 7.18 - 7.03 (m, 17H). 13 C NMR (500 MHz, CDC13) δ 153.47, 145.89, 144.15, 143.45, 143.35, 142.38, 139.84, 137.20, 134.44, 132.32, 131.59, 131.47, 131.46, 131.40, 130.98, 130.42, 130.10, 128.71, 128.09, 128.01, 127.85, 127.23, 127.03, 126.90, 126.86, 125.67, 117.47, 116.48, 116.32, 1.16.

[0089] C 38 H 27 ESI+ HRMS m / z calcd for N2 512.2181 [M+H], found 512.2181 [M+H].

[0090] NMR characterization data are shown in Figure 8-9 and mass spectrum is shown in Figure 10 .

[0091] Example 4

[0092] In this example, a tetraphenylethene-isoquinoline compound Iso-TPECN8Qu was prepared, and the synthetic route thereof is shown in Figure 4 . The synthesis of ISO-TPECN8Qu: the method was similar to the synthesis of ISO-TPECN4Qu described above, wherein the raw material added was isoquinoline-8-carboxaldehyde, an isomer of isoquinoline-4-carboxaldehyde, and the obtained 1.10 g of light yellow solid had a yield of 78%.

[0093] 1 H NMR (500 MHz, CDC13) δ 9.31 (d, J = 0.9 Hz, 1H), 8.61 (d, J = 6.0 Hz, 1H), 8.30 (dd, J = 7.3, 1.1 Hz, 1H), 8.12 - 8.04 (m, 2H), 7.79 - 7.68 (m, 2H), 7.55 - 7.49 (m, 2H), 7.18 - 7.03 (m, 17H). 13C NMR (500 MHz, CDC13) δ 148.53, 145.99, 144.02, 143.45, 143.43, 143.33, 142.41, 139.85, 137.20, 136.17, 132.35, 132.17, 131.48, 131.45, 131.41, 130.23, 129.01, 128.19, 128.10, 128.02, 127.84, 127.08, 126.90, 126.85, 126.59, 125.71, 121.17, 117.37, 117.07.

[0094] C 38 H 27 ESI+ HRMS m / z calcd for N2 511.2177 [M+H], found 511.2177 [M+H].

[0095] NMR characterization data are shown in Figure 11-12 and mass spectrum is shown in Figure 13 .

[0096] Test Example

[0097] This test example tests the performance of the tetraphenyl ethene-isoquinoline compound prepared in the examples. Among them:

[0098] 1. AIE performance test

[0099] Prepare a sample solution with water content of 0%-95%: take tetrahydrofuran as the solvent and prepare 50 mL of mother liquor with a concentration of 1.0 x 10 -4 mol / L of product, take 10 clean stoppered test tubes and add 1 mL of mother liquor by pipette, then add tetrahydrofuran and pure water according to the water content of 0%-90%, for example, prepare a sample solution with 10% water content, i.e. add 1 mL of mother liquor, 8 mL of tetrahydrofuran, and 1 mL of pure water.

[0100] Prepare a sample solution with water content of 95%: take tetrahydrofuran as the solvent and prepare 10 mL of mother liquor with a concentration of 1.0 x 10 -4 mol / L of product, take clean stoppered test tubes and add 0.5 mL of mother liquor by pipette, then add 0.5 mL of mother liquor and 9.5 mL of pure water according to the water content of 95%.

[0101] The above 0%-95% sample solution needs to be immediately sealed with a glass stopper to prevent evaporation. Since the sample is not soluble in water, it needs to be ultrasonically treated for 1 minute to fully mix and homogenize, and then immediately perform the relevant test.

[0102] The above are tested by using a fluorescence spectrometer (Shimadzu RF-6000) and a UV-Vis spectrophotometer (SHIMADZU / UV-2700) to obtain the fluorescence emission spectrum and the UV-Vis spectrum of the compound ISO-TPECNnQu under different water content conditions.

[0103] The emission and absorption spectra of the compound Iso-TPECNnQu in tetrahydrofuran / water mixed solutions with different water contents are shown in Figure 14-17

[0104] As can be seen from Figure 14 , in the tetrahydrofuran / water mixed solution with a water content of Iso-TPECN3Qu less than 80%, the fluorescence intensity is weak and changes little with the water content. When the water content of the system is greater than or equal to 80%, the fluorescence intensity of Iso-TPECN3Qu begins to increase; when the water content is 95%, the fluorescence intensity is 56 times stronger than that in pure tetrahydrofuran solution. At the same time, in the UV-Vis spectrum, when the water content is less than 80%, there is basically no change in the long wave direction. When the water content is greater than or equal to 80%, the long wave direction of the UV-Vis absorption spectrum appears a tailing phenomenon, which is caused by the Mie effect. It can be seen that the change trend of the fluorescence spectrum and the UV-Vis absorption spectrum of Iso-TPECN3Qu compound in the system with different water contents is consistent.

[0105] As can be seen from Figure 15 , the fluorescence intensity of ISO-TPECN4Qu compound in tetrahydrofuran is very weak; when the water content of the system is less than 80%, the fluorescence intensity remains very weak and changes little, but when the water content increases, the fluorescence intensity also increases with the increase of the water content, and when the water content reaches 90% and above, the fluorescence intensity increases sharply, and when the water content reaches 95%, the fluorescence intensity is 30 times that in tetrahydrofuran, which indicates that the fluorescence intensity of the ISO-TPECN4Qu system will also increase with the increase of the water content. The UV-Vis spectrum of the compound shows that when the water content is high, a serious tailing phenomenon can be observed in the long wave direction of the absorption spectrum, which is caused by the scattering of the incident ultraviolet light by the nanoparticles in the system, i.e. the Mie effect, which indicates that a high water content will cause the compound molecules to form aggregates in the solution. In conclusion, ISO-TPECN4Qu exhibits significant aggregation-induced emission (AIE) characteristics according to the fluorescence emission spectrum and the UV-Vis spectrum.

[0106] The AIE performance of ISO-TPECN5Qu is shown in Figure 16 . As can be seen from Figure 16 , similar to ISO-TPECN4Qu, ISO-TPECN5Qu also exhibits significant aggregation-induced emission (AIE) characteristics. ​

[0107] The AIE performance of ISO-TPECN8Qu is shown in Figure 17 Fig. 2. As can be seen from Figure 17 the combination of the fluorescence emission spectrum and the UV-Vis spectrum, it can be concluded that ISO-TPECN8Qu, like ISO-TPECN4Qu, exhibits significant aggregation-induced emission (AIE) characteristics.

[0108] In summary, the compounds of the present application all have obvious AIE performance.

[0109] 2. Solvent effect

[0110] Due to the introduction of electron-withdrawing groups and electron-donating groups, ISO-TPECNnQu is a typical D-A compound. A small amount of the compound was dissolved in different solvents, including n-hexane, ethyl acetate, THF, absolute ethanol, dimethylformamide, and DMSO. Subsequently, the fluorescence emission spectrum and the UV-Vis spectrum of each solution were tested. If the measured fluorescence spectrum shows significant red shift or blue shift in different solvents, it indicates that the compound has good solvent effect.

[0111] The solvent effect test results of ISO-TPECN4Qu are shown in Figure 18 a). As can be seen from the figure, the PL of the compound in the 6 solvents of different polarity. As can be seen from the figure, according to the difference in solvent polarity, it can be observed that the maximum absorption wavelength of ISO-TPECN4Qu is also different, mainly due to the intramolecular charge transfer, and the solvent effect caused by the PL is obvious. With the increase of solvent polarity (from n-hexane to DMSO), it is observed that the fluorescence emission color of the solution of the compound ISO-TPECN4Qu gradually changes from blue to orange, and the emission wavelength gradually red shifts from 514 nm to 614 nm, with a maximum wavelength shift of up to 100 nm. This indicates that ISO-TPECN4Qu has good solvent effect.

[0112] The solvent effect of ISO-TPECN5Qu is similar to that of ISO-TPECN4Qu, as shown in Figure 18 b). As can be seen from the figure, with the increase of solvent polarity (from n-hexane to DMSO), it is observed that the fluorescence emission color of the solution of the compound ISO-TPECN5Qu gradually changes from blue to orange, and the emission wavelength gradually red shifts from 526 nm to 611 nm, with a maximum wavelength shift of up to 85 nm. This indicates that ISO-TPECN5Qu has good solvent effect.

[0113] The solvent effect of ISO-TPECN8Qu is similar to that of ISO-TPECN4Qu, as shown in Figure 18c) shown. As can be seen from the figure, with the increase of solvent polarity (from n-hexane to DMSO), the color of the fluorescence emission of the solution of compound ISO-TPECN8Qu is gradually changed from blue to orange, and the emission wavelength is gradually red-shifted from 527 nm to 617 nm, with a maximum wavelength shift of up to 90 nm. This shows that ISO-TPECN5Qu has good solvent effect.

[0114] ISO-TPECN3Qu also has similar phenomenon. In summary, the synthesized compounds ISO-TPECNnQu all have solvent effect, according to related research, it is speculated that there is intramolecular charge transfer (ICT) effect between the tetraphenylethylene and isoquinoline molecules; ISO-TPECN4Qu and ISO-TPECN8Qu have the rule that the wavelength gradually increases with the gradual increase of solvent polarity in 6 solvents; among them, ISO-TPECN5Qu has the fourth polarity in 6 solvents, but the measured fluorescence peak is the smallest peak value 526 nm together with n-hexane, the reason is that in possible ethanol, the existence of hydroxyl group affects the distribution of electron cloud and thus affects ICT, so that the red shift is not obvious.

[0115] Further, in order to better study the reason why the tetraphenylethylene-isoquinoline compound of the present application scheme presents different fluorescence changes in different solvents, Gaussian 09 311-G(d, p) is used for theoretical calculation. The results show that on the HOMO orbit of the compound, the electron cloud is mainly distributed on the TPE group, and on the LUMO orbit, the electron cloud is mainly distributed on the isoquinoline structure, so that the electron cloud distribution is completely separated. This shows that the compound has relatively obvious electron transfer, therefore, the compound is prone to electron transfer to form ICT state in polar solvents. In polar solvents, the dipole moment of the charge separation state is reduced, the energy is lower and more stable, so that the energy gap difference between the charge separation state and the ground state is reduced, thereby causing the fluorescence wavelength to be red-shifted with the increase of solvent polarity in polar solvents. The results of this theoretical calculation are consistent with the previous test results.

[0116] 3. Acid-base stimulus responsive properties

[0117] Since the N on the isoquinoline ring of compound Iso-TPECN3Qu has the property of protonation and deprotonation, the experiment was carried out to study its acid stimulation response. The sample of the example was subjected to treatment by acid vapor (HCl) and base vapor (NH3) fumigation to test its response time and fluorescence change. At 25°C, a small amount of hydrochloric acid solution or ammonia water was placed in a closed desiccator (hydrochloric acid aqueous solution was used, and the content of HCl was 36%-38%; the base solution used ammonia water, and the content of NH3 was 25%-28%). 10-15 ml of hydrochloric acid or ammonia water solution was placed in a desiccator of about 6.28 liters, and the container was filled with acid or base vapor at room temperature (about 25°C) for about 30 minutes. After the acid vapor and ammonia vapor filled the desiccator, the sample was placed in a petri dish and put into the desiccator. The fluorescence change was observed using a 365 nm ultraviolet lamp, and the response time was recorded.

[0118] The original powder solid of compound ISO-TPECNnQu, i.e. ISO-TPECNnQu-O, and the solid powder after grinding the original sample, i.e. ISO-TPECNnQu-g, were placed together in a closed container containing HCl vapor (room temperature and normal pressure) and left for about 3h until the color of the solid powder was different from that of ISO-TPECNnQu-O and ISO-TPECNnQu-g, respectively. Then, the acid-fumigated ISO-TPECNnQu-O and ISO-TPECNnQu-g were taken out of the closed container filled with HCl vapor and each was divided into two parts, named ISO-TPECNnQu-O-h, ISO-TPECNnQu-O-h-n, ISO-TPECNnQu-g-h, and ISO-TPECNnQu-g-h-n, respectively. The samples labeled ISO-TPECNnQu-O-h-n and ISO-TPECNnQu-g-h-n were placed in a closed container filled with NH3 (room temperature and normal pressure) for about 10 minutes. The color of the solid powder ISO-TPECNnQu-O-h-n and ISO-TPECNnQu-g-h-n was observed after 10 minutes to see if there was any change in the color of the acid-fumigated solid powder, and whether it was similar to ISO-TPECNnQu-O and ISO-TPECNnQu-g, respectively. The changes in the color of the original, acid-fumigated, and base-fumigated sample powders were observed using an ultraviolet lamp, and photographs were taken under sunlight, 365 nm ultraviolet lamp, respectively. Fluorescence spectrum test was carried out, and the fluorescence spectra of compound ISO-TPECNnQu samples O, O-h, O-h-n, g, g-h, and g-h-n were obtained, respectively.

[0119] If the fluorescence emission spectrum of ISO-TPECNnQu-h is obviously changed compared with ISO-TPECNnQu-O, i.e. a certain red shift or blue shift or obvious change in intensity occurs, it indicates that the synthesized compound ISO-TPECNnQu has good acid-induced color change performance; if the fluorescence emission spectrum of ISO-TPECNnQu-h-n is similar to that of ISO-TPECNnQu-O, it indicates that the fluorescence emission spectrum of ISO-TPECNnQu-h-n changes after being smoked by base and returns to the original state of O, which indicates that the synthesized compound ISO-TPECNnQu has good acid-induced color change reversibility.

[0120] After the initial powder of Iso-TPECN3Qu was smoked by hydrochloric acid vapor, its fluorescence color changed obviously: from the initial blue fluorescence to green fluorescence, and the emission wavelength also red-shifted from the initial 463 nm to 510 nm, which indicated that the solid powder of Iso-TPECN3Qu had obvious acid stimulation response. When the sample after acid smoking was deprotonated by ammonia vapor, it was found that the fluorescence maximum emission wavelength further red-shifted (536 nm) and did not completely recover to the initial state (as shown in Figure 19 and 20 It may be due to the fact that Iso-TPECN3Qu is a D-A structure, and after protonation, the increase in molecular conjugation causes the fluorescence maximum emission wavelength to red-shift. However, after deprotonation, the electron-donating ability of TPE is enhanced, leading to further red-shift of the wavelength.

[0121] As shown in Figure 21 , the maximum emission wavelength of ISO-TPECN4Qu-O is 503 nm, and the fluorescence color is green. Interestingly, when the ISO-TPECN4Qu-h sample was exposed to HCl vapor for 10 minutes, the sample powder color and fluorescence emission spectrum both changed obviously, the fluorescence color changed from the initial green to orange, and the fluorescence emission spectrum changed from the initial 503 nm to 606 nm, with a red shift of 103 nm, which indicated that the solid ISO-TPECN4Qu-O had obvious acid stimulation response characteristics. When the ISO-TPECN4Qu-h sample was again placed in a sealed ammonia vapor for 10 minutes, the sample again showed the initial green fluorescence, indicating that the solid ISO-TPECN4Qu-O had reversible acid-induced color change performance.

[0122] Similarly to ISO-TPECN4Qu-O, as shown in Figure 22As shown, ISO-TPECN5Qu-O has a maximum emission wavelength of 517 nm and emits green fluorescence. Similarly, after exposure to HCl vapor for a period of time, the powder color and fluorescence emission spectrum of the ISO-TPECN5Qu-h sample also undergo significant changes, with the fluorescence color changing from its initial green to dark orange, and the emission spectrum shifting from its initial 517 nm to 591 nm, a 74 nm red-shift. This indicates that solid ISO-TPECN5Qu-O exhibits distinct acid-responsive properties. When the ISO-TPECN5Qu-h sample is again exposed to sealed ammonia vapor for 10 minutes, the sample regains its initial green fluorescence, demonstrating that solid ISO-TPECN5Qu-O exhibits reversible acid-induced color change. Unlike ISO-TPECN4Qu, the emission wavelength shifts blue after alkaline fumigation and then returns to the same wavelength as the original sample. However, the acid-induced red shift in ISO-TPECN5Qu is less pronounced than in ISO-TPECN4Qu.

[0123] Similar to ISO-TPECN4Qu-O, such as Figure 23 As shown, ISO-TPECN8Qu-O has a maximum emission wavelength of 486 nm and emits a blue-green fluorescence color. Similarly, after exposure to HCl vapor for 10 minutes, the powder color and fluorescence emission spectrum of the ISO-TPECN8Qu-h sample also undergo significant changes, with the fluorescence color changing from the initial blue-green to orange-red, and the fluorescence emission spectrum shifting from the initial 486 nm to 621 nm, a red shift of 135 nm. This demonstrates that solid ISO-TPECN8Qu-O exhibits distinct acid-responsive properties. When the ISO-TPECN8Qu-h sample is again exposed to sealed ammonia vapor for 10 minutes, the sample regains its initial green fluorescence, demonstrating that solid ISO-TPECN8Qu-O exhibits reversible acid-induced color change. Unlike ISO-TPECN4Qu, the acid-induced red shift is more pronounced for ISO-TPECN8Qu than for ISO-TPECN4Qu.

[0124] Table 3 Comparison of wavelength shifts of compound ISO-TPECNnQu acid fumigation

[0125]

[0126] In summary, the acid-induced color change performance of the compound ISO-TPECNnQu is discussed, and the red shift of the fluorescence emission spectrum of the original sample and the acid fumigated sample is compared and analyzed. As shown in Table 3, the acid fumigation red shift wavelength of the compound ISO-TPECNnQu is ISO-TPECN8Qu>ISO-TPECN4Qu>ISO-TPECN5Qu>ISO-TPECN3Qu, and the reversible acid-induced color change performance is ISO-TPECN8Qu>ISO-TPECN4Qu>ISO-TPECN5Qu>ISO-TPECN3Qu. The difference in acid-induced color change performance is due to the difference in the position of the substituent group, which causes the difference in the red shift wavelength after acid fumigation, and ultimately leads to the difference in the acid-induced color change performance.

[0127] In ISO-TPECN4Qu and ISO-TPECN4Qu-HCl, the electrons are all transferred from the tetraphenylstyryl group to the quinoline group, indicating that the isoquinoline has strong electron-withdrawing ability, which promotes the transfer of electrons to the isoquinoline group. At the same time, the energy gap difference between LUMO and HOMO after protonation is reduced to a certain extent (from 0.12 eV to 0.10 eV), indicating that the red shift of the synthesized small molecule after acid fumigation is due to the effect of ICT state, which causes it to become a different excited state.

[0128] In ISO-TPECN5Qu and ISO-TPECN5Qu-HCl, the electrons are all transferred from the tetraphenylstyryl group to the quinoline group, indicating that the isoquinoline has strong electron-withdrawing ability, which promotes the transfer of electrons to the isoquinoline group. At the same time, the energy gap difference between LUMO and HOMO after protonation is reduced to a certain extent (from 0.12 eV to 0.11 eV), indicating that the red shift of the synthesized small molecule after acid fumigation is due to the effect of ICT state, which causes it to become a different excited state.

[0129] In ISO-TPECN8Qu and ISO-TPECN8Qu-HCl, the electrons are all transferred from the tetraphenylstyryl group to the quinoline group, indicating that the isoquinoline has strong electron-withdrawing ability, which promotes the transfer of electrons to the isoquinoline group. At the same time, the energy gap difference between LUMO and HOMO after protonation is reduced to a certain extent (from 0.12 eV to 0.10 eV), indicating that the red shift of the synthesized small molecule after acid fumigation is due to the effect of ICT state, which causes it to become a different excited state.

[0130] In summary, the present application scheme by introducing isoquinoline group, showed its different photo-physical properties with quinoline series compounds. The pressure-induced color change of Iso-TPECNnQu is not obvious, through XRD analysis found that the grinding before and after the molecular aggregation structure has no obvious change is the direct cause of pressure-induced color change is not obvious. Its solid powder after hydrochloric acid fumigation, show obvious wavelength red shift, with ammonia water vapor to protonated powder deprotonation, ISO-TPECN3Qu fluorescence wavelength further red shift, and ISO-TPECN8Qu, ISO-TPECN4Qu have different degrees of blue shift, ISO-TPECN5Qu is directly blue shift to the initial state. Since Iso-TPECNnQu is a D-A structure, alkali fumigation deprotonation, strengthen the TPE electron-donating ability, resulting in further red shift of wavelength.

[0131] The above detailed description of the embodiments of the present application, but the present application is not limited to the above-mentioned embodiments, within the scope of knowledge possessed by those skilled in the art, can also be made under the premise of not departing from the purpose of the present application, various changes.

Claims

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

2. The tetraphenyl-stilbenes-isoquinolines compound according to claim 1, characterized in that: The structural formula of the tetraphenyl ethene-isoquinoline compound is shown in one of the following formulas: 。 3. The method for preparing tetraphenylethylene-isoquinoline compounds according to claim 1 or 2, wherein: The method comprises the following steps: under a protective atmosphere, the mixture was heated to 80°C and stirred for 2 hours. The tetraphenylstyrene-isoquinoline compound was prepared by reacting the isoquinoline substituted with a formaldehyde group.

4. The method of claim 3, wherein: The preparation method further comprises a preparation step of To make With reaction, i.e.

5. The method of claim 3, wherein: The protective atmosphere is nitrogen or inert gas atmosphere.

6. The method of claim 3, wherein: The The reaction with isoquinoline-3-carboxaldehyde is carried out under catalytic conditions using at least one catalyst selected from the group consisting of tetrabutylammonium hydroxide, piperidine or pyridine.

7. The method of claim 3, wherein: The The temperature for the reaction with isoquinoline-3-carboxaldehyde is 75-85 °C; and / or, the The time for the reaction with isoquinoline-3-carboxaldehyde is 20-28 h.

8. The method of claim 3, wherein: The The reaction with isoquinoline-3-carboxaldehyde is carried out in solution, with at least one of ethanol, N,N-dimethylformamide or toluene as solvent.

9. Use of the tetraphenyl ethene-isoquinoline compound according to claim 1 in the preparation of a fluorescent material.

10. An acid-base detecting or anti-counterfeiting material, characterized by: The fluorescent material comprises the tetraphenyl ethene-isoquinoline compound according to claim 1.

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