Aggregation-induced emission type fluorescent probe as well as preparation method and application thereof

Abstract

The invention discloses an aggregation-induced emission type fluorescent probe as well as a preparation method and application thereof, and belongs to the technical field of organic light-emitting functional materials. The phenazine-based fluorescent probe with the aggregation-induced emission (AIE) characteristic is innovatively prepared through systematic molecular structure-effect relationship regulation and control, and the phenazine-based fluorescent probe is applied to monitoring of monomer conversion efficiency in the photocuring reaction process and polarity change of a microenvironment in a formed polymer. By utilizing the AIE effect of the developed fluorescent material, the photocuring process (monomer conversion efficiency) can be quickly and conveniently visualized; by utilizing the intramolecular charge transfer (ICT) effect of the developed fluorescent material, the polarity change of the microenvironment in the polymer can be visualized. Therefore, the novel fluorescent probe developed by the invention can simultaneously realize visual monitoring of the monomer conversion efficiency and the polarity change of the microenvironment in the polymer in the photocuring reaction process, and has important significance for understanding a deep mechanism of functional attribute mutation of the photocuring polymer.

Description

Technical Field

[0001] The present invention relates to the technical field of organic light-emitting functional materials, and in particular to a class of aggregation-induced emission fluorescent probes and preparation methods and applications thereof (specifically, applications in monitoring monomer conversion efficiency and changes in the polarity of the internal microenvironment of a polymer during a photocuring reaction). Background Art

[0002] Photocuring has the characteristics of high efficiency, energy saving, environmental protection and wide adaptability. It is widely used in technical fields such as coatings, adhesives, inks and 3D printing. Photocuring is a technology that generates free radicals or cations by absorbing photons of specific wavelengths through photoinitiators, thereby initiating polymerization and cross-linking reactions of monomers and oligomers. During the photocuring process, the polymer chain continues to grow to form a high-molecular polymer with a network structure, thereby achieving curing. This process requires precise control of factors such as light intensity, illumination time, and the type and amount of photoinitiators to ensure the consistency and stability of the curing effect. By real-time monitoring of the degree of polymerization, not only can problems such as insufficient light and incomplete curing in the curing process be discovered and solved in a timely manner to ensure the consistency and stability of product quality, but also an in-depth understanding of the effects of different process parameters (such as light intensity, illumination time, type and amount of photoinitiators, etc.) on the curing effect can be obtained, and then these parameters can be optimized to improve production efficiency. In addition, with the continuous advancement of monitoring technology, this approach can also promote the continuous innovation and improvement of photocuring technology, opening up more possibilities for the preparation and application of polymer materials. In addition, since the changes in the polarity of the polymer's internal microenvironment during photocuring are closely related to the material's hardness, toughness, weather resistance and other properties, by monitoring the changes in the polarity of the polymer's internal microenvironment, we can also conduct in-depth research on the changing laws of material properties and provide strong support for material research and development.

[0003] Existing methods for monitoring the degree of photocuring polymerization include infrared spectroscopy, viscosity testing, surface hardness testing, and dilatometer methods. These methods have disadvantages such as large-scale equipment, high cost, high technical difficulty, incomplete information, and low sensitivity, and cannot respond to changes in the polarity of the microenvironment inside the polymer. Therefore, a method that can simultaneously monitor the monomer conversion efficiency and the polarity changes of the microenvironment inside the polymer during photocuring is urgently needed to solve the above problems.

[0004] Fluorescence sensing technology has important application prospects in the fields of biological diagnosis and treatment, food testing and information anti-counterfeiting. The core material in fluorescence sensing technology is fluorescent functional molecules, and rich material functional properties can be achieved through systematic molecular structure-activity relationship research. Therefore, it is of great research significance to prepare fluorescent functional materials by accurately designing fluorescent molecular structures for monitoring monomer conversion efficiency and changes in the polarity of the internal microenvironment of polymers during photocuring. Summary of the invention

[0005] The purpose of the present invention is to provide a class of aggregation-induced emission (AIE) fluorescent probes and their preparation methods and applications (specifically, applications in monitoring the conversion efficiency of photocurable monomers and changes in the polarity of the internal microenvironment of polymers) to solve the above-mentioned problems existing in the prior art.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] One of the technical solutions of the present invention: a type of aggregation-induced emission fluorescent probe (abbreviated as AIE fluorescent probe), the general structural formula of which is

[0008] Among them, R is

[0009] One of the above, R1 is selected from a hydrogen atom or a methoxy group, and R2 is selected from a hydrogen atom or a methoxy group.

[0010] More preferably, R is

[0011] Further preferably, the structural formula of the aggregation-induced emission fluorescent probe is as shown in Formula I, Formula II or Formula III:

[0012]

[0013] The above-mentioned aggregation-induced emission fluorescent probe is a type of electron donor-electron acceptor (DA) type AIE fluorescent material based on phenazine. In the aggregated state, the intramolecular motion of the AIE fluorescent material is restricted due to the enhanced intermolecular interaction, so that the excited state energy is released more in the form of radiation transition, thereby enhancing the fluorescence emission. The present invention mixes the above-mentioned electron donor-electron acceptor (DA) type AIE fluorescent material based on phenazine as a probe into the photocurable monomer. As the photocuring reaction proceeds, the degree of polymerization of the high molecular polymer formed by photocuring increases, the molecular weight gradually increases, the hardness gradually increases, and the restriction on the intramolecular motion of the AIE material will also increase, thereby showing a phenomenon of gradually enhanced fluorescence, which can be used to characterize the monomer conversion efficiency during the photocuring reaction; the present invention uses the phenazine core as an electron acceptor, grafts different electron donor units, and constructs an electron donor-electron acceptor (DA) structure, which improves the intramolecular charge transfer (ICT) effect of the fluorescent probe, so that the fluorescent probe has sensitive optical properties to the polarity change of the internal microenvironment of the polymer, and can monitor the polarity change of the internal microenvironment of the polymer during the photocuring reaction.

[0014] The second technical solution of the present invention: The preparation method of the above-mentioned aggregation-induced emission fluorescent probe comprises the following steps:

[0015] The aggregation-induced emission fluorescent probe is obtained by Suzuki reaction using the compound represented by formula IV and RB(OH)2 as reactants;

[0016] Or, the aggregation-induced emission fluorescent probe is obtained by carbon-nitrogen coupling reaction using the compound represented by formula IV and RH as reactants;

[0017]

[0018] Among them, R is

[0019] One of the above, R1 is selected from a hydrogen atom or a methoxy group, and R2 is selected from a hydrogen atom or a methoxy group.

[0020] More preferably, R is When the aggregation-induced emission fluorescent probe is prepared, the method comprises the following steps:

[0021] The aggregation-induced emission fluorescent probe is obtained by Suzuki reaction using the compound represented by formula IV and 4-boric acid triphenylamine as reactants;

[0022] Or, the aggregation-induced emission fluorescent probe is obtained by carbon-nitrogen coupling reaction using the compound represented by formula IV and diphenylamine as reactants;

[0023]

[0024] Further preferably, the method for preparing the aggregation-induced emission fluorescent probe as shown in Formula I, Formula II or Formula III comprises the following steps:

[0025] Using 1,6-dibromophenazine (one of the compounds shown in Formula IV) and 4-boric acid triphenylamine as reactants, an aggregation-induced emission fluorescent probe shown in Formula II is obtained through Suzuki reaction;

[0026] Or, using 2,7-dibromophenazine (one of the compounds shown in Formula IV) and 4-boric acid triphenylamine as reactants, an aggregation-induced emission fluorescent probe shown in Formula III is obtained by Suzuki reaction;

[0027] Alternatively, 1,6-dibromophenazine (one of the compounds shown in formula IV) and diphenylamine are used as reactants to obtain an aggregation-induced emission fluorescent probe shown in formula I through a carbon-nitrogen coupling reaction.

[0028] Furthermore, the method of obtaining the aggregation-induced emission fluorescent probe by Suzuki reaction using the compound represented by formula IV and RB(OH)2 as reactants comprises: dissolving the compound represented by formula IV, RB(OH)2, catalyst 1 and inorganic base in a mixed solution of organic solvent 1 and water to perform Suzuki reaction to obtain the aggregation-induced emission fluorescent probe;

[0029] Alternatively, the method of obtaining the aggregation-induced emission fluorescent probe by a carbon-nitrogen coupling reaction using the compound represented by formula IV and RH as reactants includes: dissolving the compound represented by formula IV with RH, catalyst 2, catalyst ligand and organic base in an organic solvent 2 for a carbon-nitrogen coupling reaction to obtain the aggregation-induced emission fluorescent probe represented by formula I.

[0030] Further, the catalyst 1 is tetrakis(triphenylphosphine)palladium (Pd(PPh3)4), the inorganic base is potassium carbonate (K2CO3) or sodium carbonate (NaCO3), preferably potassium carbonate, and the molar ratio of the compound represented by formula IV to RB(OH)2, catalyst 1 and inorganic base is 1-1.5:2-4:0.03-0.05:5-10;

[0031] Or, the catalyst 2 is tris(dibenzylideneacetone)dipalladium-chloroform adduct (Pd2(dba)3CHCl3), the catalyst ligand is tri-tert-butylphosphine tetrafluoroborate (HPtBu3BF4), the organic base is sodium tert-butoxide (NaOtBu), and the molar ratio of the compound represented by formula IV to RH, catalyst 2, catalyst ligand and organic base is 1-1.5:2-4:0.015-0.03:0.15-0.3:5-7.

[0032] Further, the temperature of the Suzuki reaction is 80-100°C, preferably 100°C, and the time is 10-14h, preferably 12h;

[0033] Alternatively, the temperature of the carbon-nitrogen coupling reaction is 100-120° C., preferably 115° C., and the time is 20-30 h, preferably 24 h.

[0034] Furthermore, the organic solvent 1 is tetrahydrofuran (THF) or toluene (TOL); and the volume ratio of the organic solvent 1 to water is 5:1.

[0035] Furthermore, the organic solvent 2 is toluene (TOL).

[0036] Furthermore, the preparation method of the aggregation-induced emission fluorescent probe shown in Formula I, Formula II or Formula III comprises the following steps: With 4-triphenylamine borate Catalyst 1 and inorganic base are dissolved in a mixture of organic solvent 1 and water to carry out Suzuki reaction, thereby obtaining an aggregation-induced emission fluorescent probe (denoted as 1,6-TPAPZ) as shown in formula II;

[0037] Or, 2,7-dibromophenazine Suzuki reaction is carried out with 4-boric acid triphenylamine, catalyst 1 and inorganic base dissolved in a mixed solution of organic solvent 1 and water to obtain an aggregation-induced emission fluorescent probe (denoted as 2,7-TPAPZ) as shown in formula III;

[0038] Alternatively, 1,6-dibromophenazine and diphenylamine Catalyst 2, catalyst ligand and organic base are dissolved in organic solvent 2 to carry out carbon-nitrogen coupling reaction, and obtain an aggregation-induced emission fluorescent probe (denoted as 1,6-DPAPZ) as shown in formula I.

[0039] Further, in terms of molar ratio, 1,6-dibromophenazine: 4-triphenylamine borate: catalyst 1: inorganic base = 1-1.5: 2-4: 0.03-0.05: 5-10, preferably 1: 2: 0.037: 6.6;

[0040] Or, in terms of molar ratio, 2,7-dibromophenazine: 4-boric acid triphenylamine: catalyst 1: inorganic base = 1-1.5: 2-4: 0.03-0.05: 5-10, preferably 1: 2: 0.037: 6.6;

[0041] Or, in terms of molar ratio, 1,6-dibromophenazine: diphenylamine: catalyst 2: catalyst ligand: organic base = 1-1.5:2-4:0.015-0.03:0.15-0.3:5-7, preferably 1:2:0.02:0.2:6.4.

[0042] The third technical solution of the present invention: application of the above-mentioned aggregation-induced emission fluorescent probe in monitoring the change of monomer conversion efficiency and / or the change of polarity of the internal microenvironment of the polymer during the photocuring reaction.

[0043] Furthermore, the operating steps of the application include: mixing the aggregation-induced emission fluorescent probe with a monomer and a photoinitiator, performing a photocuring reaction under ultraviolet light irradiation, and monitoring changes in monomer conversion efficiency and / or changes in the polarity of the internal microenvironment of the polymer during the photocuring reaction based on changes in the fluorescence brightness and fluorescence wavelength of the aggregation-induced emission fluorescent probe in the reaction system during the photocuring reaction.

[0044] As the UV-curing reaction time increases, the fluorescence brightness and wavelength of the AIE fluorescent probe in the reaction system will change. Therefore, the monomer conversion efficiency and the changes in the internal microenvironment polarity of the formed polymer during the photocuring process can be monitored based on the changes in the fluorescence brightness and wavelength of the AIE fluorescent probe.

[0045] Technical solution four of the present invention: application of the above-mentioned aggregation-induced emission fluorescent probe in polarity detection.

[0046] Furthermore, the application of the aggregation-induced emission fluorescent probe in polarity detection includes but is not limited to the application in solvent polarity detection.

[0047] The present invention synthesizes a class of aggregation-induced emission molecules based on phenazine through reasonable molecular design, and introduces a DA structure to enhance the ICT effect of the molecule, thereby improving the sensitivity of the fluorescent probe to environmental polarity. The technical solution proposed by the present invention to apply the above-mentioned phenazine-based AIE fluorescent probe to monitor the monomer conversion efficiency and the polarity changes of the internal microenvironment of the formed polymer during the photocuring reaction is an innovative and practical technical solution.

[0048] During the photocuring process, the polymer material gradually polymerizes and cross-links, resulting in an increase in the hardness of the polymer material. This physical change will limit the intramolecular movement of the fluorescent probe, thereby increasing the fluorescence intensity of the AIE fluorescent probe. By measuring the change in the fluorescence intensity of the fluorescent probe, the progress of the photocuring reaction and the degree of polymerization of the polymer can be indirectly reflected. The AIE fluorescent probe with a DA structure has a good sensitivity to environmental polarity, and the changes in the polarity of the internal microenvironment of the polymer can be monitored by monitoring the light color and fluorescence quantum efficiency changes of the fluorescent probe.

[0049] Based on the high sensitivity and selectivity of the AIE fluorescent probe, it can accurately capture subtle changes in the photocuring process. At the same time, this method does not require destruction or additional processing of the sample, and is widely applicable to complex systems and practical application scenarios. In addition, the fluorescent probe is also multifunctional. It can not only monitor the degree of photocuring, but also synchronously monitor the polarity changes of the internal microenvironment of the polymer, opening up a new research path for in-depth exploration of the relationship between the structure and performance of polymer materials.

[0050] In the study of the AIE fluorescent probe of the present invention monitoring the polymer polymerization dynamics and the polarity change of the internal microenvironment of the polymer, as the monomer is gradually converted into a polymer, the three AIE fluorescent probes of the present invention all show a blue shift of the maximum emission wavelength and a significant increase in fluorescence intensity. This phenomenon shows that with the continuous increase in the degree of polymerization, the formation and cross-linking of the polymer chain leads to a decrease in the polarity of the local environment, and the viscosity of the system also increases. The blue shift of the maximum emission wavelength usually reflects the change in the microenvironment in which the AIE fluorescent probe is located, because the close arrangement and conformational adjustment of the polymer chain reduce the polarity of the environment, thereby affecting the electronic structure and excited state properties of the AIE fluorescent probe. The enhancement of fluorescence intensity directly reflects the role of the AIE effect, that is, with the construction of the polymer network, the movement of the AIE fluorescent probe is restricted and aggravated, so that more excited state energy is released in the form of radiation transition (i.e., fluorescence emission). These findings not only reveal the microscopic mechanism in the polymer polymerization process, but also provide a new perspective and method for monitoring the changes in the structure and performance of polymer materials using AIE fluorescent probes.

[0051] The present invention discloses the following technical effects:

[0052] The present invention innovatively prepares a type of phenazine-based fluorescent probe with aggregation-induced emission (AIE) characteristics through systematic molecular structure-activity relationship regulation, and applies it to monitoring the monomer conversion efficiency and the changes in the internal microenvironment polarity of the formed polymer during the photocuring reaction. The AIE effect of the developed fluorescent material can be used to quickly and conveniently visualize the photocuring process (monomer conversion efficiency); the intramolecular charge transfer (ICT) effect of the developed fluorescent material can be used to visualize the changes in the internal microenvironment polarity of the polymer. Therefore, the new fluorescent probe developed by the present invention can simultaneously realize the visual monitoring of the monomer conversion efficiency and the changes in the internal microenvironment polarity of the polymer during the photocuring reaction, which is of great significance for understanding the deep mechanism of the functional property mutation of photocurable polymers. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 The synthetic route of the compounds in Examples 1-3;

[0055] Figure 2The fluorescence intensity changes of the compounds obtained in Examples 1-3 in a tetrahydrofuran / water mixed solvent as the water content increases, wherein (A) is 1,6-DPAPZ, (B) is 1,6-TPAPZ, and (C) is 2,7-TPAPZ;

[0056] Figure 3 HOMO and LUMO energy levels of compounds 1,6-DPAPZ, 1,6-TPAPZ and 2,7-TPAPZ calculated based on M06-2X / 6-31G (d, p) function;

[0057] Figure 4 The absorption spectra of the compounds obtained in Examples 1-3 in different solvents, wherein (A) is 1,6-DPAPZ, (B) is 1,6-TPAPZ, and (C) is 2,7-TPAPZ;

[0058] Figure 5 The fluorescence spectra of the compounds obtained in Examples 1-3 in different solvents, wherein (A) is 1,6-DPAPZ, (B) is 1,6-TPAPZ, and (C) is 2,7-TPAPZ;

[0059] Figure 6 It is the monitoring of the photocuring process of the mixed system of hydroxypropyl methacrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone, wherein (A) is the in-situ infrared monitoring, (B) is the double bond conversion rate detected by in-situ infrared, (C) is the water contact angle monitoring, (D) is the 1,6-DPAPZ probe monitoring, (E) is the 1,6-TPAPZ probe monitoring, and (F) is the 2,7-TPAPZ probe monitoring;

[0060] Figure 7 It is the monitoring of the photocuring process of the mixed system of 2-hydroxyethyl acrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone, wherein (A) is the in-situ infrared monitoring, (B) is the double bond conversion rate detected by in-situ infrared, (C) is the water contact angle monitoring, (D) is the 1,6-DPAPZ probe monitoring, (E) is the 1,6-TPAPZ probe monitoring, and (F) is the 2,7-TPAPZ probe monitoring;

[0061] Figure 8 It is to monitor the photocuring process of the mixed system of acrylic acid and 2-hydroxy-2-methyl-1-phenyl-1-propanone, wherein (A) is in-situ infrared monitoring, (B) is the double bond conversion rate detected by in-situ infrared, (C) is water contact angle monitoring, (D) is 1,6-DPAPZ probe monitoring, (E) is 1,6-TPAPZ probe monitoring, and (F) is 2,7-TPAPZ probe monitoring. DETAILED DESCRIPTION

[0062] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0063] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0064] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0065] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0066] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0067] In the first aspect of the present invention, a type of aggregation-induced emission fluorescent probe (AIE fluorescent probe for short) is provided, the general structural formula of which is

[0068] Among them, R is

[0069] One of the above, R1 is selected from a hydrogen atom or a methoxy group, and R2 is selected from a hydrogen atom or a methoxy group.

[0070] As a preferred embodiment of the present invention, the structural formula of the aggregation-induced emission fluorescent probe is as shown in Formula I, Formula II or Formula III:

[0071]

[0072] The second aspect of the present invention provides a method for preparing the above-mentioned aggregation-induced emission fluorescent probe, comprising the following steps:

[0073] The compound represented by formula IV, RB(OH)2, catalyst 1 and inorganic base are dissolved in a mixture of organic solvent 1 and water to carry out Suzuki reaction to obtain the aggregation-induced emission fluorescent probe;

[0074] Or, the compound represented by formula IV is dissolved in organic solvent 2 with RH, catalyst 2, catalyst ligand and organic base to carry out carbon-nitrogen coupling reaction to obtain an aggregation-induced emission fluorescent probe represented by formula I;

[0075]

[0076] Among them, R is

[0077] One of the above, R1 is selected from a hydrogen atom or a methoxy group, and R2 is selected from a hydrogen atom or a methoxy group.

[0078] As a preferred embodiment of the present invention, the method for preparing the aggregation-induced emission fluorescent probe as shown in Formula I, Formula II or Formula III comprises the following steps:

[0079] 1,6-dibromophenazine (one of the compounds shown in Formula IV) is dissolved in a mixture of organic solvent 1 and water to carry out a Suzuki reaction with 4-triphenylamine borate, catalyst 1 and an inorganic base to obtain an aggregation-induced emission fluorescent probe shown in Formula II (denoted as 1,6-TPAPZ);

[0080] Alternatively, 2,7-dibromophenazine (one of the compounds shown in Formula IV) is dissolved in a mixture of organic solvent 1 and water to carry out a Suzuki reaction with 4-triphenylamine borate, catalyst 1 and an inorganic base to obtain an aggregation-induced emission fluorescent probe shown in Formula III (denoted as 2,7-TPAPZ);

[0081] Alternatively, 1,6-dibromophenazine is dissolved in organic solvent 2 with diphenylamine, catalyst 2, catalyst ligand and organic base to carry out carbon-nitrogen coupling reaction to obtain an aggregation-induced emission fluorescent probe (denoted as 1,6-DPAPZ) as shown in formula I.

[0082] As an embodiment of the present invention, the catalyst 1 is tetrakis(triphenylphosphine)palladium (Pd(PPh3)4), the inorganic base is potassium carbonate (K2CO3) or sodium carbonate (NaCO3), preferably potassium carbonate, and the molar ratio of the compound represented by formula IV to RB(OH)2, catalyst 1 and inorganic base is 1-1.5:2-4:0.03-0.05:5-10;

[0083] Or, the catalyst 2 is tris(dibenzylideneacetone)dipalladium-chloroform adduct (Pd2(dba)3CHCl3), the catalyst ligand is tri-tert-butylphosphine tetrafluoroborate (HPtBu3BF4), the organic base is sodium tert-butoxide (NaOtBu), and the molar ratio of the compound represented by formula IV to RH, catalyst 2, catalyst ligand and organic base is 1-1.5:2-4:0.015-0.03:0.15-0.3:5-7.

[0084] As an embodiment of the present invention, the temperature of the Suzuki reaction is 80-100°C, preferably 100°C, and the time is 10-14h, preferably 12h;

[0085] Alternatively, the temperature of the carbon-nitrogen coupling reaction is 100-120° C., preferably 115° C., and the time is 20-30 h, preferably 24 h.

[0086] As an embodiment of the present invention, the organic solvent 1 is tetrahydrofuran or toluene; the volume ratio of the organic solvent 1 to water is 5:1.

[0087] As an embodiment of the present invention, the organic solvent 2 is toluene.

[0088] As a preferred embodiment of the present invention, the Suzuki reaction is carried out under a nitrogen atmosphere; the carbon-nitrogen coupling reaction is carried out under a nitrogen atmosphere.

[0089] As a preferred embodiment of the present invention, after the Suzuki reaction is completed, the process further includes extraction, washing, drying and column chromatography; the extraction agent is dichloromethane, and the number of extractions is three times; the washing agent is saline; the drying agent is anhydrous sodium sulfate; the eluent for the column chromatography is dichloromethane and ethyl acetate, and the volume ratio of dichloromethane to ethyl acetate is 6:1.

[0090] As a preferred embodiment of the present invention, after the carbon-nitrogen coupling reaction is completed, the process further includes extraction, washing, drying and column chromatography operations; the extraction agent is dichloromethane, and the number of extractions is three times; the washing reagent is brine; the drying agent is anhydrous sodium sulfate; the eluent for the column chromatography is ethyl acetate and petroleum ether, and the volume ratio of ethyl acetate to petroleum ether is 1:6.

[0091] As a preferred embodiment of the present invention, the preparation method of 1,6-dibromophenazine comprises: and potassium tert-butoxide (tBuOK) were dissolved in tetrahydrofuran at -78°C, stirred for 10 min, and then 1-bromo-2-nitrobenzene was added Tetrahydrofuran was slowly added dropwise, and the mixture was stirred at -78°C for 1 hour. After the reaction, extraction, washing, drying, and column chromatography were performed to obtain 3-bromo-N-(2-bromophenyl)-2-nitrosoaniline. The 3-bromo-N-(2-bromophenyl)-2-nitrosoaniline and N,O-bis(trimethylsilyl)acetamide (BSA) were dissolved in acetonitrile (ACN), and then refluxed and stirred at 100° C. under nitrogen for 12 hours to obtain the 1,6-dibromophenazine.

[0092] As a preferred embodiment of the present invention, the molar ratio of the 2-bromoaniline, potassium tert-butoxide and 1-bromo-2-nitrobenzene is 1:3:1; the molar ratio of the 3-bromo-N-(2-bromophenyl)-2-nitrosoaniline and N, O-bis(trimethylsilyl)acetamide is 1:5.

[0093] As a preferred embodiment of the present invention, the preparation method of 2,7-dibromophenazine comprises: and potassium tert-butoxide were dissolved in tetrahydrofuran at -78°C, stirred for 10 min, and then 1-bromo-4-nitrobenzene was added Tetrahydrofuran was slowly added dropwise, and the mixture was stirred at -78°C for 1 hour. After the reaction, 5-bromo-N-(4-bromophenyl)-2-nitrosoaniline was obtained by extraction, washing, drying, and column chromatography. The 5-bromo-N-(4-bromophenyl)-2-nitrosoaniline and N,O-bis(trimethylsilyl)acetamide (BSA) were dissolved in acetonitrile, and then refluxed and stirred at 100° C. under nitrogen for 12 h to obtain the 2,7-dibromophenazine.

[0094] As a preferred embodiment of the present invention, the molar ratio of the 4-bromoaniline, potassium tert-butoxide and 1-bromo-4-nitrobenzene is 1:3:1; the molar ratio of the 5-bromo-N-(4-bromophenyl)-2-nitrosoaniline and N, O-bis(trimethylsilyl)acetamide is 1:5.

[0095] The third aspect of the present invention provides the use of the above-mentioned aggregation-induced emission fluorescent probe in monitoring the change of monomer conversion efficiency and / or the change of polarity of the internal microenvironment of the polymer during the photocuring reaction.

[0096] As an embodiment of the present invention, the operating steps of the application include: mixing the aggregation-induced emission fluorescent probe with a monomer and a photoinitiator, performing a photocuring reaction under ultraviolet light irradiation, and monitoring the changes in the monomer conversion efficiency and / or the changes in the polarity of the internal microenvironment of the polymer during the photocuring reaction according to the changes in the fluorescence brightness and fluorescence wavelength of the aggregation-induced emission fluorescent probe in the reaction system during the photocuring reaction.

[0097] As a preferred embodiment of the present invention, the monomer includes hydroxypropyl methacrylate, 2-hydroxyethyl acrylate or acrylic acid; and the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0098] As a preferred embodiment of the present invention, the usage ratio of the aggregation-induced emission fluorescent probe to the monomer and the photoinitiator is 0.04 μmol:2 mL:20 μL.

[0099] As a preferred embodiment of the present invention, the power of the ultraviolet light is 25mW / cm 2 .

[0100] The fourth aspect of the present invention provides the use of the above-mentioned aggregation-induced emission fluorescent probe in polarity detection.

[0101] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0102] The room temperature involved in the specific implementation manner of the present invention specifically refers to "25±2°C".

[0103] All raw materials used in the following embodiments, test examples and application examples are common commercially available products.

[0104] Except for the compounds of formula I, formula II and formula III prepared in Examples 1-3, the compounds of other structures that meet the requirements of claim 1 all have effects equivalent to or similar to those of the compounds of formula I, formula II and formula III.

[0105] Example 1

[0106] Synthesis of AIE fluorescent probe 1,6-DPAPZ (compound shown in Formula I) (synthetic route as shown in Figure 1 The steps are as follows:

[0107] (1) Synthesis of the ring-closed intermediate 1,6-dibromophenazine

[0108] 2-Bromoaniline (2.05 g, 12 mmol) and potassium tert-butoxide (4.03 g, 36 mmol) were dissolved in tetrahydrofuran (15 mL) at -78 ° C. After stirring for 10 min, tetrahydrofuran (10 mL) containing 1-bromo-2-nitrobenzene (2.41 g, 12 mmol) was slowly added dropwise using a constant pressure funnel, and the mixture was stirred at this temperature for 1 h. The reaction mixture was then extracted three times with ethyl acetate, then washed with brine, and then the organic layer was dried over anhydrous sodium sulfate, and then column chromatography was performed using ethyl acetate and petroleum ether (the volume ratio of ethyl acetate to petroleum ether was 1:9) as eluents to obtain 3-bromo-N-(2-bromophenyl)-2-nitrosoaniline. The ring-opening intermediate 3-bromo-N-(2-bromophenyl)-2-nitrosoaniline (356 mg, 1 mmol) and N, O-bis(trimethylsilyl)acetamide (BSA) (1.2 mL, 5 mmol) were dissolved in acetonitrile (5 mL), and then refluxed and stirred at 100 ° C. under nitrogen for 12 h. After the mixture was cooled, the precipitated product was filtered and washed three times with a small amount of acetonitrile. After vacuum drying, the closed-ring intermediate 1,6-dibromophenazine was obtained.

[0109] (2) Synthesis of 1,6-DPAPZ

[0110] 1,6-dibromophenazine (1 g, 2.95 mmol), diphenylamine (1 g, 5.91 mmol), tri(dibenzylideneacetone)dipalladium-chloroform adduct (63 mg, 0.06 mmol), tri-tert-butylphosphine tetrafluoroborate (171 mg, 0.59 mmol) and sodium tert-butoxide (1.8 g, 18.75 mmol) obtained in step (1) were added to anhydrous toluene (20 mL), and then refluxed and stirred at 115° C. under nitrogen for 24 h to carry out a carbon-nitrogen coupling reaction. After the reaction mixture was cooled, it was extracted three times with dichloromethane and then washed with brine. The organic layer was then dried over anhydrous sodium sulfate and separated and purified by column chromatography. The eluent was ethyl acetate and petroleum ether (the volume ratio of ethyl acetate to petroleum ether was 1:6) to obtain a red powder 1,6-DPAPZ (910 mg) with a yield of 60%.

[0111] The characterization data of 1,6-DPAPZ obtained are: 1 H NMR(400MHz,cd2cl2)δ7.72(dd,J=8.7,1.5Hz,2H),7.66(t,J=8.0Hz,2H),7.58(dd, J=7.1,1.5Hz,2H),7.24-7.18(m,8H),7.07(d,J=8.0Hz,8H),6.98(t,J=8.0Hz,4H).

[0112] Example 2

[0113] Synthesis of AIE fluorescent probe 1,6-TPAPZ (compound shown in Formula II) (synthetic route as shown in Figure 1 The steps are as follows:

[0114] 1,6-Dibromophenazine (912 mg, 2.70 mmol), 4-triphenylamine borate (1.6 g, 5.40 mmol), tetrakis(triphenylphosphine)palladium (115 mg, 0.1 mmol) and K2CO3 (2.4 g, 18 mmol) obtained in step (1) of Example 1 were added to a mixture of tetrahydrofuran and water (the volume ratio of tetrahydrofuran to water was 25 mL:5 mL), and then refluxed at 100°C under nitrogen for 12 h to carry out Suzuki reaction. After the reaction mixture was cooled, it was extracted three times with dichloromethane and then washed with brine. The organic layer was then dried over anhydrous sodium sulfate and purified by column chromatography using a mixed solution of dichloromethane and ethyl acetate (the volume ratio of dichloromethane to ethyl acetate was 6:1) as the eluent to obtain orange powder 1,6-TPAPZ (1.1 g) with a yield of 61%.

[0115] The characterization data of 1,6-TPAPZ obtained are: 1 HNMR(400MHz,cd2cl2)δ8.18(dd,J=6.6,3.2Hz,2H),7.88(t,J=3.2Hz,2H),7.78(d,J=8.5Hz,2H),7.67(d ,J=3.8Hz,4H),7.59(d,J=4.3Hz,4H),7.33(t,J=8.0Hz,8H),7.22(d,J=7.6Hz,8H),7.09(t,J=8.0Hz,4H).

[0116] Example 3

[0117] Synthesis of AIE fluorescent probe 2,7-TPAPZ (compound shown in Formula III) (synthetic route as shown in Figure 1 The steps are as follows:

[0118] (1) Synthesis of the ring-closed intermediate 2,7-dibromophenazine

[0119] 4-Bromoaniline (2.05 g, 12 mmol) and potassium tert-butoxide (4.03 g, 36 mmol) were dissolved in tetrahydrofuran (15 mL) at -78 °C, stirred for 10 min, and then 1-bromo-4-nitrobenzene (2.42 g, 12 mmol) dissolved in tetrahydrofuran (10 mL) was slowly added dropwise using a constant pressure funnel, and the mixture was stirred at this temperature for 1 h. The reaction mixture was then extracted three times with ethyl acetate, then washed with brine, and then the organic layer was dried over anhydrous sodium sulfate, and then column chromatography was performed using ethyl acetate and petroleum ether (the volume ratio of ethyl acetate to petroleum ether was 1:8) as eluents to obtain 5-bromo-N-(4-bromophenyl)-2-nitrosoaniline. The ring-opening intermediate 5-bromo-N-(4-bromophenyl)-2-nitrosoaniline (356 mg, 1 mmol) and N, O-bis(trimethylsilyl)acetamide (BSA) (1.2 mL, 5 mmol) were dissolved in acetonitrile (5 mL), and then refluxed and stirred at 100 ° C. under nitrogen for 12 h. After the mixture was cooled, the precipitated product was filtered and washed three times with a small amount of acetonitrile. After vacuum drying, the closed-ring intermediate 2,7-dibromophenazine was obtained.

[0120] (2) Synthesis of 2,7-TPAPZ

[0121] 2,7-Dibromophenazine (463 mg, 1.37 mmol), 4-triphenylamine borate (792 mg, 2.74 mmol), tetrakis(triphenylphosphine)palladium (58 mg, 0.05 mmol) and K2CO3 (1.2 g, 9 mmol) obtained in step (1) were added to a mixture of tetrahydrofuran and water (the volume ratio of tetrahydrofuran to water was 12.5 mL:2.5 mL), and then refluxed at 100°C under nitrogen for 12 h to carry out Suzuki reaction. After the mixture was cooled, it was extracted three times with dichloromethane and then washed with brine. The organic layer was then dried over anhydrous sodium sulfate and purified by column chromatography. The eluent was dichloromethane and ethyl acetate (the volume ratio of dichloromethane to ethyl acetate was 6:1) to obtain yellow powder 2,7-TPAPZ (602 mg) with a yield of 66%.

[0122] The characterization data of 2,7-TPAPZ obtained are: 1 H NMR(400MHz,cd2cl2)δ8.63(s,2H),8.47(d,J=2.8Hz,2H),8.42(d,J=1.2Hz,2H),7.93(d,J=8.6Hz,4 H),7.77(t,J=6.8Hz,4H),7.34(dd,J=13.6,7.0Hz,8H),7.19(d,J=7.9Hz,8H),7.14(t,J=7.6Hz,4H).

[0123] Test Example 1

[0124] Performance Characterization

[0125] Figure 2 The fluorescence intensity of the compounds (AIE fluorescent probes) obtained in Examples 1-3 in a tetrahydrofuran / water mixed solvent with increasing water content (the volume concentration of water in the mixed solvent is 0, 20, 40, 60, 80, 99 Vol%, respectively, and the concentration of the AIE fluorescent probe in the mixed solvent is 10 μM), wherein (A) is the fluorescence intensity of 1,6-DPAPZ, (B) is the fluorescence intensity of 1,6-TPAPZ, and (C) is the fluorescence intensity of 2,7-TPAPZ. From (A), it can be seen that as the volume percentage of water in the poor solvent increases, the fluorescence intensity of 1,6-DPAPZ gradually increases; from (B) and (C), it can be seen that as the volume percentage of water in the poor solvent increases, the fluorescence intensity of 1,6-TPAPZ and 2,7-TPAPZ first decreases and then increases. The decrease in the first half is attributed to the fact that more water is introduced, the polarity of the environment in which the fluorescent probe is located increases, and the ICT effect quenches their fluorescence. In the second half, as the poor solvent continues to increase, the material becomes more and more aggregated, the molecules are constrained, and their internal motion is restricted, which reduces the non-radiative transition energy dissipation, so the fluorescence emission is enhanced; the emission wavelengths of the three fluorescent probes are getting bluer and bluer, which is caused by the change in the polarity of the environment. This shows that compounds 1,6-DPAPZ, 1,6-TPAPZ and 2,7-TPAPZ all show obvious AIE characteristics and can be used as fluorescent probes to monitor the monomer conversion efficiency during photocuring.

[0126] Figure 3 The HOMO and LUMO energy levels of compounds 1,6-DPAPZ, 1,6-TPAPZ and 2,7-TPAPZ calculated based on the M06-2X / 6-31G(d,p) function. By analyzing the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the molecules, it can be seen that the HOMO electrons of the three molecules are distributed throughout the molecular skeleton, while the LUMO electrons are concentrated on the phenazine skeleton, showing typical LE and CT transitions, indicating that the three synthesized phenazine-based AIE fluorescent probes all have obvious ICT effects.

[0127] Figure 4 are the absorption spectra of the compounds obtained in Examples 1-3 in different solvents (the concentration of the compounds in the solvents is 10 μM), wherein (A) is the absorption spectrum of 1,6-DPAPZ in different solvents, (B) is the absorption spectrum of 1,6-TPAPZ in different solvents, and (C) is the absorption spectrum of 2,7-TPAPZ in different solvents. Figure 4It can be seen that with the increase of solvent polarity, the absorption peak wavelengths of the three molecules remain basically unchanged, indicating that the molecules are basically not affected by changes in environmental polarity in the ground state and have stable ground state optical properties.

[0128] Figure 5 are the fluorescence spectra of the compounds obtained in Examples 1-3 in different solvents (the concentration of the compounds in the solvents is 10 μM), wherein (A) is the fluorescence spectrum of 1,6-DPAPZ in different solvents, (B) is the fluorescence spectrum of 1,6-TPAPZ in different solvents, and (C) is the fluorescence spectrum of 2,7-TPAPZ in different solvents. Figure 5 It can be found that with the increase of solvent polarity (the polarity of n-hexane, toluene, ether, ethyl acetate, tetrahydrofuran, dichloromethane, and N,N-dimethylformamide increases in turn), from n-hexane to N,N-dimethylformamide, 1,6-DPAP red-shifted by 199nm, 1,6-TPAP red-shifted by 252nm, and 2,7-TPAP red-shifted by 170nm; the emission peak wavelengths of the three molecules all underwent a significant red-shift, indicating that the molecules are very sensitive to changes in environmental polarity in the excited state and have a strong ICT effect, and can be used as fluorescent probes to monitor changes in the polarity of the internal microenvironment of the polymer during photocuring.

[0129] Test Example 2

[0130] Application of AIE fluorescent probes in monitoring changes in monomer conversion efficiency and / or changes in the polarity of the internal microenvironment of polymers during photocuring reactions

[0131] One of the compounds (AIE fluorescent probes) obtained in Example 1-3 was mixed with a monomer and a photoinitiator (the amount of AIE fluorescent probe was 0.04 μmol, the amount of photocurable monomer was 2 mL, and the amount of photoinitiator was 20 μL) and exposed to ultraviolet light (25 mW / cm 2 ) was used to perform photocuring reaction, and the photocuring reaction process was monitored. The experimental group without adding AIE fluorescent probe was used as the infrared monitoring control group and the water contact angle monitoring control group.

[0132] Figure 6The monitoring results of the photocuring process of the mixed system of hydroxypropyl methacrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone are shown in Figure 1. Among them, (A) is in-situ infrared monitoring, (B) is the double bond conversion rate detected by in-situ infrared, (C) is water contact angle monitoring, (D) is 1,6-DPAPZ probe monitoring, (E) is 1,6-TPAPZ probe monitoring, and (F) is 2,7-TPAPZ probe monitoring. From (A) and (B), it can be seen that during the photocuring process of the mixed system of hydroxypropyl methacrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone, The characteristic absorption peak of the carbon-carbon double bond in the in-situ infrared monitoring image gradually weakens with the extension of ultraviolet light irradiation time. For every 10s of ultraviolet light irradiation, the characteristic absorption peak of the carbon-carbon double bond weakens to a certain extent, tends to be flat at 60s, and then weakens very slowly; from the water contact angle monitoring (C), it can be seen that the water contact angle of the mixed system of hydroxypropyl methacrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone gradually increases during the photocuring process, indicating that this mixed system becomes more and more hydrophobic with the increase of photocuring time, and also reflects the decrease of its polarity. From the monitoring images (D), (E), and (F) of the photocuring process of the three phenazine-based AIE fluorescent probes, it can be seen that under ultraviolet light irradiation, the fluorescence intensity and fluorescence wavelength of the three fluorescent probes in this mixed system begin to change within 60-120s, and maintain good consistency; the fluorescence intensity increases rapidly, indicating that the mixed system restricts the intramolecular motion of the fluorescent probe more and more; the fluorescence wavelength decreases rapidly, and the emission blue shifts, indicating that the polarity of the microenvironment where the probe is located becomes smaller. Combining the data from in-situ infrared monitoring and fluorescent probe monitoring, the fluorescent probe monitoring method can sensitively respond to the degree of curing of this photocurable material mixture system and can accurately reflect changes in the polarity of the internal microenvironment of the polymer.

[0133] Figure 7The monitoring results of the photocuring process of the mixed system of 2-hydroxyethyl acrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone are shown in Figure 1. Among them, (A) is in-situ infrared monitoring, (B) is the double bond conversion rate detected by in-situ infrared, (C) is the water contact angle monitoring, (D) is the 1,6-DPAPZ probe monitoring, (E) is the 1,6-TPAPZ probe monitoring, and (F) is the 2,7-TPAPZ probe monitoring. From (A) and (B), it can be seen that the photocuring process of the mixed system of 2-hydroxyethyl acrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone is During the process, the characteristic absorption peak of the carbon-carbon double bond in the in-situ infrared monitoring image gradually weakens with the extension of the ultraviolet light irradiation time. For every 5s of ultraviolet light irradiation, the characteristic absorption peak of the carbon-carbon double bond weakens to a certain extent, tends to be flat at 20s, and then weakens very slowly; from the water contact angle monitoring (C), it can be seen that the water contact angle of the mixed system of 2-hydroxyethyl acrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone gradually increases during the photocuring process, indicating that this mixed system becomes more and more hydrophobic with the increase of photocuring time, and also reflects the decrease of its polarity. From the monitoring images (D), (E), and (F) of the photocuring process of the three phenazine-based AIE fluorescent probes, it can be seen that the fluorescence intensity and fluorescence wavelength of the three fluorescent probes begin to change within 10-20s of ultraviolet light irradiation of this mixed system, and maintain good consistency; the fluorescence intensity increases rapidly, indicating that the mixed system restricts the intramolecular motion of the fluorescent probe more and more; the fluorescence wavelength decreases rapidly, and the emission blue shifts, indicating that the polarity of the microenvironment where the probe is located decreases. Combining the data from in-situ infrared monitoring and fluorescent probe monitoring, the fluorescent probe monitoring method can sensitively respond to the degree of curing of this photocurable material mixture system and can accurately reflect changes in the polarity of the internal microenvironment of the polymer.

[0134] Figure 8The monitoring results of the photocuring process of the mixed system of acrylic acid and 2-hydroxy-2-methyl-1-phenyl-1-propanone are as follows: (A) is in-situ infrared monitoring, (B) is the double bond conversion rate detected by in-situ infrared, (C) is water contact angle monitoring, (D) is 1,6-DPAPZ probe monitoring, (E) is 1,6-TPAPZ probe monitoring, and (F) is 2,7-TPAPZ probe monitoring. From (A) and (B), it can be seen that during the photocuring process of the mixed system of acrylic acid and 2-hydroxy-2-methyl-1-phenyl-1-propanone, the characteristic absorption peak of the carbon-carbon double bond in the in-situ infrared monitoring image will gradually weaken with the extension of the ultraviolet light irradiation time. For every 5s increase in ultraviolet light irradiation, the characteristic absorption peak of the carbon-carbon double bond will weaken to a certain extent, tend to be flat at 20s, and then the degree of weakening is extremely slow; from the water contact angle monitoring (C), it can be obtained that the water contact angle of the mixed system of acrylic acid and 2-hydroxy-2-methyl-1-phenyl-1-propanone during the photocuring process gradually increases, indicating that this mixed system becomes more and more hydrophobic with the increase of photocuring time, which also reflects the decrease in its polarity. From the monitoring diagrams (D), (E), and (F) of the photocuring process of the three phenazine-based AIE fluorescent probes, it can be seen that the fluorescence intensity and wavelength of the three fluorescent probes began to change within 0-20 seconds of ultraviolet light irradiation, and maintained good consistency; the fluorescence intensity increased rapidly, indicating that the mixed system restricted the intramolecular motion of the fluorescent probe more and more; the fluorescence wavelength decreased rapidly, and the emission blue shifted, indicating that the polarity of the microenvironment in which the fluorescent probe was located became smaller. Combining the data of in-situ infrared monitoring and fluorescent probe monitoring, the fluorescent probe monitoring method can make a sensitive response to the curing degree of this photocurable material mixed system, and can accurately reflect the changes in the polarity of the internal microenvironment of the polymer.

[0135] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A type of aggregation-induced emission fluorescent probe, characterized in that: The general structural formula of the aggregation-induced emission fluorescent probe is: Among them, R is One of the above, R1 is selected from a hydrogen atom or a methoxy group, and R2 is selected from a hydrogen atom or a methoxy group.

2. The aggregation-induced emission fluorescent probe according to claim 1, characterized in that The structural formula of the aggregation-induced emission fluorescent probe is shown in Formula I, Formula II or Formula III:

3. The method for preparing the aggregation-induced emission fluorescent probe according to claim 1, characterized in that: The following steps are involved: The aggregation-induced emission fluorescent probe is obtained by Suzuki reaction using the compound represented by formula IV and RB(OH)2 as reactants; Or, the aggregation-induced emission fluorescent probe is obtained by carbon-nitrogen coupling reaction using the compound represented by formula IV and RH as reactants; Among them, R is One of the above, R1 is selected from a hydrogen atom or a methoxy group, and R2 is selected from a hydrogen atom or a methoxy group.

4. The method for preparing the aggregation-induced emission fluorescent probe according to claim 2, characterized in that: The following steps are involved: Using 1,6-dibromophenazine and 4-triphenylamine borate as reactants, an aggregation-induced emission fluorescent probe shown in formula II is obtained through Suzuki reaction; Or, using 2,7-dibromophenazine and 4-triphenylamine borate as reactants, an aggregation-induced emission fluorescent probe represented by formula III is obtained by Suzuki reaction; Alternatively, 1,6-dibromophenazine and diphenylamine are used as reactants to obtain an aggregation-induced emission fluorescent probe as shown in formula I through a carbon-nitrogen coupling reaction.

5. The preparation method according to claim 3, characterized in that: The method of using the compound represented by Formula IV and RB(OH)2 as reactants to obtain the aggregation-induced emission type fluorescent probe through Suzuki reaction comprises: dissolving the compound represented by Formula IV, RB(OH)2, catalyst 1 and inorganic base in a mixed solution of organic solvent 1 and water to carry out Suzuki reaction to obtain the aggregation-induced emission type fluorescent probe; Alternatively, the method of obtaining the aggregation-induced emission fluorescent probe by a carbon-nitrogen coupling reaction using the compound represented by formula IV and RH as reactants includes: dissolving the compound represented by formula IV with RH, catalyst 2, catalyst ligand and organic base in an organic solvent 2 for a carbon-nitrogen coupling reaction to obtain the aggregation-induced emission fluorescent probe represented by formula I.

6. The preparation method according to claim 5, characterized in that: The catalyst 1 is tetrakis(triphenylphosphine)palladium, the inorganic base is potassium carbonate or sodium carbonate, and the molar ratio of the compound represented by formula IV to RB(OH)2, the catalyst 1 and the inorganic base is 1-1.5:2-4:0.03-0.05:5-10; Or, the catalyst 2 is tris(dibenzylideneacetone)dipalladium-chloroform adduct, the catalyst ligand is tri-tert-butylphosphine tetrafluoroborate, the organic base is sodium tert-butoxide, and the molar ratio of the compound represented by formula IV to RH, catalyst 2, catalyst ligand and organic base is 1-1.5:2-4:0.015-0.03:0.15-0.3:5-7.

7. The preparation method according to claim 5, characterized in that: The temperature of the Suzuki reaction is 80-100°C and the time is 10-14h; Alternatively, the carbon-nitrogen coupling reaction is carried out at a temperature of 100-120° C. and for a time of 20-30 h.

8. Use of the aggregation-induced emission fluorescent probe according to any one of claims 1 to 2 in monitoring changes in monomer conversion efficiency and / or changes in the polarity of the internal microenvironment of a polymer during a photocuring reaction.

9. The use according to claim 8, characterized in that The application operation steps include: mixing the aggregation-induced emission fluorescent probe with a monomer and a photoinitiator, performing a photocuring reaction under ultraviolet light irradiation, and monitoring the changes in the monomer conversion efficiency and / or the changes in the polarity of the internal microenvironment of the polymer during the photocuring reaction according to the changes in the fluorescence brightness and fluorescence wavelength of the aggregation-induced emission fluorescent probe in the reaction system during the photocuring reaction.

10. Use of the aggregation-induced emission fluorescent probe according to any one of claims 1 to 2 in polarity detection.

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