Fluorescent compound with double excited state characteristic as well as preparation method and application thereof
By developing fluorescent compounds with dual excited-state properties and using electrospinning technology to prepare porous nanofilms, the problem of insufficient sensitivity in existing fluorescence detection technologies has been solved, enabling efficient and ultrasensitive detection of nerve agents.
Patent Information
- Application Number
- CN202511465226.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-14
- Publication Date
- 2026-01-06
AI Technical Summary
Existing fluorescence detection technologies lack sufficient sensitivity when detecting organophosphorus nerve agents, making it difficult to meet the detection requirements for extremely low lethal doses of sarin.
Develop fluorescent compounds with dual excited-state properties, combine them with electrospinning technology to prepare porous nanofilms, and utilize the nucleophilic groups in the fluorescent molecules to specifically react with nerve agents to achieve high-sensitivity detection.
It achieves a detection limit as low as 2.5 ppb for DCP vapor, meeting the needs of on-site testing and possessing efficient and sensitive nerve agent detection capabilities.
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Figure CN121270537A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of fluorescence sensing. Background Technology
[0002] Organophosphorus nerve agents are extremely threatening chemical warfare agents, and their misuse in wars and terrorist attacks seriously endangers human life and public safety. Therefore, the development of efficient and reliable nerve agent detection technologies is crucial and urgent. In recent years, fluorescence detection methods have attracted much attention due to their significant advantages, such as portable equipment, high sensitivity, diverse signal acquisition methods, and rapid response. Inspired by the mechanism of nerve agent poisoning, designing donor-acceptor (DA) fluorescent molecules containing nucleophilic groups is a mature strategy. The nucleophilic group undergoes a substitution reaction with the nerve agent, altering the molecular fluorescence signal, thereby enabling qualitative or quantitative detection.
[0003] Meanwhile, the excited-state properties of fluorescent materials have a decisive influence on sensing performance. Although various fluorescent detection mechanisms, such as photoinduced electron transfer (PET) and intramolecular charge transfer (ICT), have been developed, sarin, as a typical organophosphorus nerve agent, has an extremely low lethal dose (only 7 ppb), and the sensitivity of existing detection methods is still insufficient to meet practical needs. Therefore, there is an urgent need to develop a novel fluorescent probe to significantly enhance the detection performance of DCP (organophosphorus nerve agent mimics). This research is of great significance for promoting the development of efficient nerve agent detection technologies and ensuring public safety. Summary of the Invention
[0004] This invention aims to address the problem of insufficient sensitivity in the detection of organophosphorus nerve agents by existing fluorescence detection mechanisms, and further provides a fluorescent compound with dual excited-state characteristics, its preparation method, and its application.
[0005] A fluorescent compound exhibiting dual excited-state properties has the following general structural formula: ;
[0006] The A mentioned is -OH or -NH2;
[0007] The B mentioned is , , , , , or .
[0008] A method for preparing a fluorescent compound with dual excited-state properties, wherein B is... , , , , or It is performed in the following steps:
[0009] The brominated precursor, donor, and sodium tert-butoxide were sequentially added to a dry container, followed by the addition of dried 1,4-dioxane. The mixture was stirred for 5 to 30 minutes at room temperature and a stirring speed of 50 to 500 rpm to obtain a pre-activated reaction system. Bis(dibenzylacetone)palladium and tri-tert-butylphosphine were added to the pre-activated reaction system, and the mixture was refluxed for 6 to 48 hours at a nitrogen atmosphere and a temperature of 100 to 150°C. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the solvent was removed by rotary evaporation under reduced pressure to obtain the residue. Using dichloromethane / petroleum ether as the eluent, the residue was purified by silica gel column chromatography. The target component was collected and concentrated under reduced pressure to obtain a yellow solid, which is the fluorescent compound with excited-state intramolecular proton transfer properties.
[0010] The structural formula of the brominated precursor is as follows: The A is -OH or -NH2; the donor is 9,9-dimethylacrimidine, carbazole, phenothiazine, phenoxazine, 5,10-dihydrophenazine, or diphenylamine.
[0011] When B is The process is as follows: the brominated precursor and 4-boronic acid triphenylamine are dissolved in tetrahydrofuran, then water is added, potassium carbonate is added under a nitrogen atmosphere, and the mixture is stirred for 5 min to 60 min under a nitrogen atmosphere, at room temperature and a stirring speed of 100 rpm to 500 rpm. Then tetra(triphenylphosphine)palladium is added, and the mixture is stirred for 6 h to 48 h under a nitrogen atmosphere, at a temperature of 60℃ to 120℃ and a stirring speed of 100 rpm to 500 rpm. After the reaction is completed, the mixture is cooled to room temperature, filtered, and the solvent is removed by rotary evaporation under reduced pressure to obtain the residue. The residue is purified by silica gel column chromatography using dichloromethane / petroleum ether as the eluent. The target component is collected and concentrated under reduced pressure to obtain a yellow solid, which is the fluorescent compound with intramolecular proton transfer properties in the excited state.
[0012] The structural formula of the brominated precursor is as follows: The A mentioned is -OH or -NH2.
[0013] An application of a fluorescent compound with dual excited-state properties for the preparation of nerve agent detection films.
[0014] The beneficial effects of this invention are:
[0015] I. The fluorescent molecule developed in this invention possesses both TADF-ESIPT and HLCT-ESIPT characteristics, belonging to an innovative excited-state property system. This differs from the single excited-state mechanism of traditional nerve agent fluorescence sensing, providing a new molecular design dimension for precise control of sensing performance.
[0016] Second, the hydroxyl (-OH) and amino (-NH2) groups contained in the proton transfer donors of the fluorescent compounds of the present invention serve as nucleophilic groups, which not only provide the necessary structural basis for proton transfer of the fluorescent probe, but also directly endow the probe with recognition function and signal response mechanism through specific reactions with nerve agents.
[0017] Third, this invention employs electrospinning technology to prepare thin films, solving the problem of dense, non-porous traditional thin films. By optimizing the film morphology, porous nanofilms are prepared, establishing a correlation between film morphology and gas-sensing performance, achieving ultrasensitive detection of nerve agents. The detection limit (LOD) for DCP vapor is as low as 2.5 ppb, meeting the requirements for field detection (7 ppb). This embodiment not only provides theoretical support for the design of high-performance nerve agent sensing membranes but also ultimately achieves efficient and sensitive detection of nerve agents, expanding its potential for multi-scenario applications. Attached Figure Description
[0018] Figure 1 The hydrogen nuclear magnetic resonance spectrum of the HBO-DMAC compound prepared in Example 1;
[0019] Figure 2 The carbon NMR spectrum of the HBO-DMAC compound prepared in Example 1;
[0020] Figure 3 The mass spectrum of the HBO-DMAC compound prepared in Example 1 is shown.
[0021] Figure 4 This is a comparison of the fluorescence spectra of the HBO-DMAC thin film prepared in Example 2 before and after exposure to DCP gas;
[0022] Figure 5 The detection limit diagram of DCP for the HBO-DMAC thin film prepared in Example 2 is shown.
[0023] Figure 6 The graph shows the response time test results of the HBO-DMAC thin film prepared in Example 2 to DCP.
[0024] Figure 7 The graph shows the fluorescence quenching rate of the HBO-DMAC thin film prepared in Example 2 over time in the interfering gas.
[0025] Figure 8 The photostability test of the HBO-DMAC thin film prepared in Example 2. Detailed Implementation
[0026] Specific Implementation Method 1: This implementation method involves a fluorescent compound with dual excited-state characteristics, whose general structural formula is as follows: ;
[0027] The A mentioned is -OH or -NH2;
[0028] The B mentioned is , , , , , or .
[0029] The fluorescent compound with dual excited-state characteristics in this specific embodiment is an organic conjugated nitrogen heterocyclic molecule, and a benzoxazole structure is selected to construct the molecular backbone.
[0030] This specific embodiment designs fluorescent molecules that possess both thermally activated delayed fluorescence (TADF) and excited-state intramolecular proton transfer (ESIPT) properties, or both hybridized local charge transfer (HLCT) and ESIPT properties. Specifically, by employing strong donors such as phenothiazine, phenoxazine, and 9,9-dimethylacridine, fluorescent molecules can achieve both TADF and ESIPT properties; by employing medium-strength or weak donors such as carbazole, diphenylamine, triphenylamine, and 5,10-dihydrophenazine, fluorescent molecules can achieve both HLCT and ESIPT properties. TADF exhibits good tunability, displaying both high luminescence performance due to reverse intersystem crossing (RISC) and sensitive characteristics of the charge transfer (CT) state; HLCT combines the locally excited (LE) and CT states, with LE ensuring high luminescence efficiency and the CT state imparting sensitivity; and the nucleophilic group in the ESIPT molecule can specifically react with nerve agents and their mimics, providing a crucial guarantee for sensing sensitivity.
[0031] The beneficial effects of this embodiment are:
[0032] I. The fluorescent molecule developed in this embodiment has both TADF-ESIPT and HLCT-ESIPT characteristics, belonging to an innovative excited-state property system. It is different from the single excited-state mechanism of traditional nerve agent fluorescence sensing, and provides a new molecular design dimension for precise control of sensing performance.
[0033] II. In this embodiment, the hydroxyl (-OH) and amino (-NH2) groups contained in the proton transfer donor of the fluorescent compound serve as nucleophilic groups. They not only provide the necessary structural basis for proton transfer in the fluorescent probe, but also directly endow the probe with recognition function and signal response mechanism through specific reactions with nerve agents.
[0034] Third, this embodiment employs electrospinning technology to prepare thin films, solving the problem of traditional dense and non-porous thin films. By optimizing the film morphology, porous nanofilms are prepared, establishing a correlation between film morphology and gas-sensing performance, achieving ultrasensitive detection of nerve agents. The detection limit (LOD) for DCP vapor is as low as 2.5 ppb, meeting the requirements for field detection (7 ppb). This embodiment not only provides theoretical support for the design of high-performance nerve agent sensing membranes but also ultimately achieves efficient and sensitive detection of nerve agents, expanding its potential for multi-scenario applications.
[0035] Specific Implementation Method Two: This implementation method provides a method for preparing a fluorescent compound with dual excited-state characteristics, where B is... , , , , or It is performed in the following steps:
[0036] The brominated precursor, donor, and sodium tert-butoxide were sequentially added to a dry container, followed by the addition of dried 1,4-dioxane. The mixture was stirred for 5 to 30 minutes at room temperature and a stirring speed of 50 to 500 rpm to obtain a pre-activated reaction system. Bis(dibenzylacetone)palladium and tri-tert-butylphosphine were added to the pre-activated reaction system, and the mixture was refluxed for 6 to 48 hours at a nitrogen atmosphere and a temperature of 100 to 150°C. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the solvent was removed by rotary evaporation under reduced pressure to obtain the residue. Using dichloromethane / petroleum ether as the eluent, the residue was purified by silica gel column chromatography. The target component was collected and concentrated under reduced pressure to obtain a yellow solid, which is the fluorescent compound with excited-state intramolecular proton transfer properties.
[0037] The structural formula of the brominated precursor is as follows: The A is -OH or -NH2; the donor is 9,9-dimethylacrimidine, carbazole, phenothiazine, phenoxazine, 5,10-dihydrophenazine, or diphenylamine.
[0038] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 2 in that: the molar ratio of the brominated precursor to the donor is 1:(1~1.5); the molar ratio of the brominated precursor to sodium tert-butoxide is 1:(1~5); the molar ratio of the brominated precursor to the volume ratio of dried 1,4-dioxane is 1 mmol:(30~100) mL; the molar ratio of the brominated precursor to bis(dibenzylacetone)palladium is 1:(0.03~0.24); the molar ratio of the brominated precursor to tri-tert-butylphosphine is 1:(0.06~0.36); and the volume ratio of dichloromethane to petroleum ether is 1:(1~10). Everything else is the same as in Specific Implementation Method 2.
[0039] Specific Implementation Method Four: This implementation method provides a method for preparing a fluorescent compound with dual excited-state characteristics, where B is... The process is as follows: the brominated precursor and 4-boronic acid triphenylamine are dissolved in tetrahydrofuran, then water is added, potassium carbonate is added under a nitrogen atmosphere, and the mixture is stirred for 5 min to 60 min under a nitrogen atmosphere, at room temperature and a stirring speed of 100 rpm to 500 rpm. Then tetra(triphenylphosphine)palladium is added, and the mixture is stirred for 6 h to 48 h under a nitrogen atmosphere, at a temperature of 60℃ to 120℃ and a stirring speed of 100 rpm to 500 rpm. After the reaction is completed, the mixture is cooled to room temperature, filtered, and the solvent is removed by rotary evaporation under reduced pressure to obtain the residue. The residue is purified by silica gel column chromatography using dichloromethane / petroleum ether as the eluent. The target component is collected and concentrated under reduced pressure to obtain a yellow solid, which is the fluorescent compound with intramolecular proton transfer properties in the excited state.
[0040] The structural formula of the brominated precursor is as follows: The A mentioned is -OH or -NH2.
[0041] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method Four in that: the molar ratio of the brominated precursor to triphenylamine 4-borate is 1:(1~1.5); the molar ratio of the brominated precursor to tetrahydrofuran is 1 mmol:(4~100) mL; the molar ratio of the brominated precursor to water is 1 mmol:(1~25) mL; the molar ratio of the brominated precursor to potassium carbonate is 1:(2~10); the molar ratio of the brominated precursor to tetra(triphenylphosphine)palladium is 1:(0.03~0.6); and the volume ratio of dichloromethane to petroleum ether is 1:(1~10). All other aspects are the same as in Specific Implementation Method Four.
[0042] Specific Implementation Method Six: This implementation method describes the application of a fluorescent compound with dual excited-state characteristics in the preparation of a nerve agent detection membrane.
[0043] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method Six in that the nerve agent detection membrane is placed in a gas containing the nerve agent and its simulant, and detection is performed based on changes in fluorescence intensity. Everything else is the same as in Specific Implementation Method Six.
[0044] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method Six or Seven in that the nerve agent detection membrane is specifically prepared according to the following steps:
[0045] ① An electrospinning precursor was prepared using a fluorescent compound with dual excited-state properties, polyacrylonitrile, cellulose acetate and DMF;
[0046] ② Place the electrospinning precursor in a syringe and electrospin under the following conditions: the distance between the receiving plate and the injection needle should be 5cm~25cm, the positive voltage should be 5kV~15kV, the negative voltage should be -0.5kV~-1.5kV, and the injection speed should be 0.01mm / min~1mm / min. Finally, collect the film and dry it at a temperature of 50℃~100℃. Other procedures are the same as in specific embodiments six or seven.
[0047] Specific Embodiment Nine: This embodiment differs from Specific Embodiments Six to Eight in that: the mass ratio of polyacrylonitrile to the fluorescent compound with dual excited-state characteristics in step ① is 1:(0.01~1); the mass ratio of polyacrylonitrile to cellulose acetate in step ① is 1:(0.5~5); and the mass ratio of polyacrylonitrile to DMF in step ① is 1 mg:(0.01~1) mL. Everything else is the same as in Specific Embodiments Six to Eight.
[0048] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods Six to Nine in that: in step ①, polyacrylonitrile and cellulose acetate are added to DMF and stirred until the solution is completely transparent. Then, a fluorescent compound with dual excited-state characteristics is added to obtain a blend. The blend is stirred for 1 to 24 hours at a temperature of 15℃ to 30℃ and a stirring speed of 100 rpm to 500 rpm to obtain an electrospinning precursor. The rest is the same as in Specific Implementation Methods Six to Nine.
[0049] The beneficial effects of the present invention are verified using the following embodiments:
[0050] Example 1:
[0051] A fluorescent compound exhibiting dual excited-state properties, its structural formula is as follows: .
[0052] The preparation method of the above-mentioned fluorescent compound with dual excited-state characteristics is carried out according to the following steps:
[0053] The brominated precursor HBO-Br (145 mg, 0.5 mmol), 9,9-dimethylacridine (DMAC, 146 mg, 0.7 mmol), and sodium tert-butoxide (NaO(t-Bu), 202 mg, 1 mmol) were sequentially added to a 150 mL dry double-necked flask. Then, 30 mL of dry 1,4-dioxane was added. The mixture was stirred for 30 min at room temperature and 500 rpm to obtain a pre-activated reaction system. Bis(dibenzylacetone)palladium (Pd(dba)) was added to the pre-activated reaction system. The system was subjected to nitrogen purging three times and refluxed at 120°C for 24 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the solvent was removed by rotary evaporation under reduced pressure to obtain the residue. The residue was purified by silica gel column chromatography using dichloromethane / petroleum ether as the eluent. The target component was collected and concentrated under reduced pressure to obtain a yellow solid, which is the fluorescent compound with dual excited state characteristics (HBO-DMAC compound).
[0054] The structural formula of the brominated precursor HBO-Br is as follows: The structural formula of the 9,9-dimethylacridine is as follows: The volume ratio of dichloromethane to petroleum ether is 1:10.
[0055] The synthetic route for the fluorescent compound exhibiting dual excited-state characteristics is as follows:
[0056] .
[0057] Example 2: Application of the fluorescent compound with dual excited-state characteristics prepared in Example 1, used in the preparation of nerve agent detection films.
[0058] The nerve agent detection membrane is prepared according to the following steps:
[0059] ① Add 800 mg of polyacrylonitrile and 400 mg of cellulose acetate to 10 mL of DMF and stir until the solution is completely transparent. Then add 10 mg of the HBO-DMAC compound prepared in Example 1 to obtain a blend. Stir the blend for 5 h at a temperature of 25 °C and a stirring speed of 500 rpm to obtain an electrospinning precursor.
[0060] ② Place the electrospinning precursor in a syringe and electrospin under the conditions that the distance between the receiving plate and the injection needle should be 20 cm, the positive voltage should be 10 kV, the negative voltage should be -1.5 kV, and the injection speed should be 0.04 mm / min. Finally, collect the film and dry it at a temperature of 60℃ to obtain the HBO-DMAC film.
[0061] Figure 1 The figure shows the 1H NMR spectrum of the HBO-DMAC compound prepared in Example 1; as can be seen from the figure, 1 H NMR(500 MHz, Chloroform-d) δ 11.72 (s, 1H), 8.28 (d, J = 8.3 Hz, 1H), 7.86 –7.74 (m, 1H), 7.70 – 7.59 (m, 1H), 7.46 (ddd, J = 22.8, 6.8, 2.4 Hz, 4H), 7.18 (d, J = 2.0 Hz, 1H), 7.06 – 6.94 (m, 5H), 6.50 (dd, J = 8.2, 1.4 Hz, 2H), 1.70 (s, 6H).
[0062] Figure 2 The figure shows the carbon NMR spectrum of the HBO-DMAC compound prepared in Example 1; as can be seen from the figure, 13 C NMR(126 MHz, Chloroform-d) δ 161.35, 159.68, 148.15, 145.22, 139.27, 138.87,129.70, 128.29, 125.38, 124.62, 124.17, 120.66, 120.03, 118.48, 118.36,113.55, 109.72, 109.14, 35.04, 29.97.
[0063] Figure 3 The mass spectrum of the HBO-DMAC compound prepared in Example 1 is shown in the figure; as can be seen from the figure, ESI-MS (m / z): [M+H] + calcd. for C 28 H 22 N2O2, 418.50; found 419.21.
[0064] 0.5 mL of liquid DCP was transferred into a 500 mL sealed gas bag and allowed to stand at 25 °C for 12 h to allow the DCP to fully evaporate and reach gas-liquid equilibrium, resulting in saturated DCP vapor with a concentration of 132 ppm. Subsequently, a certain volume of saturated DCP vapor was precisely extracted using a medical syringe and injected into pre-prepared blank gas bags for gradient dilution, thus preparing a series of DCP gas samples with different concentrations.
[0065] The HBO-DMAC thin film prepared in Example 2 was exposed to DCP gas samples of different concentrations for 2 min, and then removed; its fluorescence spectrum at different DCP concentrations was measured using a Shimadzu RF-6000 fluorescence spectrometer with excitation at 420 nm.
[0066] Figure 4 This is a comparison of the fluorescence spectra of the HBO-DMAC thin film prepared in Example 2 before and after exposure to DCP gas; Figure 5 The detection limit diagram for DCP of the HBO-DMAC film prepared in Example 2 is shown. Through analysis of the test data, the LOD of the HBO-DMAC electrospun film for DCP was further determined to be 2.3 ppb, which is far lower than the acute exposure lethal concentration of sarin (7 ppb).
[0067] Figure 6 The figure shows the response time test results of the HBO-DMAC film prepared in Example 2 to DCP; as can be seen from the figure, the response time of the HBO-DMAC film is less than 5s.
[0068] The anti-interference performance of the HBO-DMAC film prepared in Example 2 was tested in the detection of DCP gas. Specifically, the prepared HBO-DMAC film was inserted into a cuvette and excited at 420 nm. The fluorescence intensity of the film at 480 nm was monitored using a Shimadzu RF-6000 fluorescence spectrometer. Subsequently, the following different gases were injected into the system and the response was monitored: DCP (0.53 ppm), dimethyl methyl phosphate (200 ppm), triethyl phosphate (99 ppm), 2-chloroethyl ethyl sulfide (38 ppm), hydrochloric acid (20 ppm), acetic acid (120 ppm), toluene (380 ppm), ethanol (780 ppm), ethyl acetate (100 ppm), water (32000 ppm), aniline (200 ppm), and triethylamine (70 ppm). The fluorescence intensity was monitored using a fluorescence spectrometer. Figure 7 The graph shows the fluorescence quenching rate of the HBO-DMAC film prepared in Example 2 over time in the presence of interfering gases. As can be seen from the graph, when DCP concentration of 0.53 ppm is injected into the system, the fluorescence quenching rate of the HBO-DMAC film reaches 36%. However, when exposed to the other 11 interfering substances, the fluorescence quenching rate of the film remains low, less than 6%. This result fully demonstrates the excellent anti-interference selective recognition performance of the film against DCP.
[0069] The photostability of thin films is an important factor in evaluating sensing films. Thin films with good stability can effectively reduce detection costs. The HBO-DMAC thin film prepared in Example 2 was irradiated with a Shimadzu RF-6000 fluorescence spectrometer at 420 nm excitation. Figure 8The photostability test of the HBO-DMAC film prepared in Example 2 is shown in the figure. As can be seen from the figure, the HBO-DMAC film exhibits excellent stability after continuous irradiation for 90 seconds, effectively avoiding photobleaching and making it very suitable for practical applications.
Claims
1. A fluorescent compound having a dual excited state property, characterized in that It has a general structure of ; Said A is -OH or -NH2; The B is , , , , , or .
2. The method for preparing a fluorescent compound with dual excited-state characteristics as described in claim 1, characterized in that... When said B is , , , , or then it is done in the following steps: The brominated precursor, the donor and sodium tert-butoxide are sequentially added into a dry container, then dry 1,4-dioxane is added, under the conditions of room temperature and stirring speed of 50rpm~500rpm, stirring for 5min~30min, to obtain a pre-activated reaction system; to the pre-activated reaction system, bis(dibenzylideneacetone)palladium and tri-tert-butylphosphine are added, under the conditions of nitrogen atmosphere and temperature of 100℃~150℃, refluxing for 6h~48h, after the reaction is completed, cooling to room temperature, filtering, the filtrate is concentrated under reduced pressure to remove the solvent, to obtain a residue, the residue is purified by silica gel column chromatography with dichloromethane / petroleum ether as eluent, the target component is collected and concentrated under reduced pressure, to obtain a yellow solid, which is a fluorescent compound with excited state intramolecular proton transfer property; The brominated precursor has a structural formula of A is -OH or -NH2; and the donor is 9,9-dimethylacridine, carbazole, phenothiazine, phenoxazine, 5,10-dihydrophenoxazine, or diphenylamine.
3. The method for preparing a fluorescent compound with dual excited-state characteristics according to claim 2, characterized in that... The molar ratio of the brominated precursor to the donor is 1:(1~1.5); the molar ratio of the brominated precursor to sodium tert-butoxide is 1:(1~5); the molar ratio of the brominated precursor to dry 1,4-dioxane is 1mmol:(30~100)mL; the molar ratio of the brominated precursor to bis(dibenzylideneacetone)palladium is 1:(0.03~0.24); the molar ratio of the brominated precursor to tri-tert-butylphosphine is 1:(0.06~0.36); the volume ratio of dichloromethane to petroleum ether is 1:(1~10).
4. The method for preparing a fluorescent compound with dual excited-state characteristics as described in claim 1, characterized in that... When the B is is carried out by the following steps: adding the brominated precursor and 4-boronic acid triphenylamine into tetrahydrofuran to dissolve, then adding water, and then adding potassium carbonate under a nitrogen atmosphere, and stirring for 5 min to 60 min under a nitrogen atmosphere, at room temperature, and at a stirring speed of 100 rpm to 500 rpm, then adding tetrakis(triphenylphosphine)palladium, and stirring for 6 h to 48 h under a nitrogen atmosphere, at a temperature of 60°C to 120°C, and at a stirring speed of 100 rpm to 500 rpm, cooling to room temperature after the reaction is completed, filtering, removing the solvent from the filtrate by rotary evaporation under reduced pressure, obtaining a residue, subjecting the residue to silica gel column chromatography purification with dichloromethane / petroleum ether as the eluent, collecting the target component and concentrating under reduced pressure, and obtaining a yellow solid, which is the fluorescent compound having the excited-state intramolecular proton transfer property; The brominated precursor has a structural formula of A is -OH or -NH2.
5. The method for preparing a fluorescent compound with dual excited-state characteristics as described in claim 4, characterized in that... The molar ratio of the brominated precursor to 4-boronic acid triphenylamine is 1:(1~1.5); the molar ratio of the brominated precursor to tetrahydrofuran is 1mmol:(4~100)mL; the molar ratio of the brominated precursor to water is 1mmol:(1~25)mL; the molar ratio of the brominated precursor to potassium carbonate is 1:(2~10); the molar ratio of the brominated precursor to tetrakis(triphenylphosphine)palladium is 1:(0.03~0.6); the volume ratio of dichloromethane to petroleum ether is 1:(1~10).
6. The application of a fluorescent compound with dual excited-state characteristics as described in claim 1, characterized in that... It is used for the preparation of nerve toxic agent detection film.
7. Use of a fluorescent compound having dual excited state properties according to claim 6, characterized in that The nerve toxic agent detection film is placed in nerve toxic agent and its simulation gas, and the detection is carried out according to the change of fluorescence intensity.
8. The use of a fluorescent compound having dual excited state properties according to claim 6, characterized in that The nerve toxic agent detection film is prepared according to the following steps: ①a static spinning precursor is prepared by using a fluorescent compound with double excited state characteristics, polyacrylonitrile, cellulose acetate and DMF; ②the static spinning precursor is placed in a syringe, and electrospinning is carried out under the conditions of distance between receiving plate and injection needle of 5cm~25cm, positive voltage of 5kv~15kv, negative voltage of -0.5kv~-1.5kv and injection speed of 0.01mm / min~1mm / min, and finally the film is collected and dried at a temperature of 50℃~100℃.
9. Use of a fluorescent compound having dual excited state properties according to claim 8, characterized in that The mass ratio of the polyacrylonitrile described in step ① to the fluorescent compound with the double-excited state characteristics is 1:(0.01-1); the mass ratio of the polyacrylonitrile described in step ① to the cellulose acetate is 1:(0.5-5); and the mass of the polyacrylonitrile described in step ① to the volume of DMF is 1 mg:(0.01-1) mL.
10. The use of a fluorescent compound having dual excited state properties according to claim 8, characterized in that In step ①, the polyacrylonitrile and the cellulose acetate are added into DMF, and stirred and mixed until the solution is completely transparent, then the fluorescent compound with the double-excited state characteristics is added to obtain a blend, and the blend is stirred at a temperature of 15-30°C and a stirring speed of 100-500 rpm for 1-24 h to obtain an electrostatic spinning precursor.