A high-brightness near-infrared II aggregation-induced emission material, its preparation method, and its applications.

Abstract

This invention discloses a novel high-brightness near-infrared II aggregation-induced emission material, its preparation method, and its applications. Its chemical structure has the following general formula: R is independently selected from one of the following, possessing a D-π-A-π-D structure. In the molecular structure, 4,8-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) acts as a strong electron acceptor. 3,4-bis((2-ethylhexyl)oxy)thiophene acts as both an electron-rich donor and a π-bridge, where the oxygen atom on the alkoxy chain can interact with the nitrogen atom of the acceptor, increasing structural rigidity. Simultaneously, it acts as a sterically hindered group, increasing the dihedral angle between the acceptor motif and the alkoxy group, making the overall molecular skeleton more twisted and ensuring its aggregation-induced emission properties. The strong D-A interaction can extend the absorption / emission wavelength. The near-infrared II aggregation-induced emission molecule of this invention has a simple synthetic route, low cost, good biocompatibility, and high fluorescence quantum yield.

Description

Technical Field

[0001] This invention relates to the field of fluorescent molecular probe technology, specifically to a high-brightness near-infrared II aggregation-induced emission material, its preparation method, and its applications. Background Technology

[0002] Bioimaging is a technology that visualizes biological processes in real-time and non-invasively, playing a vital role in medical development by monitoring human physiological processes. Compared to traditional imaging methods, fluorescence imaging is a dynamic visualization technology with advantages such as high sensitivity, high resolution, and low cost. However, most fluorescent molecules, located in the visible light region and near-infrared I region, generally suffer from poor tissue penetration depth, abundant tissue autofluorescence, and significant background noise, which greatly hinders their application in vivo. In contrast, near-infrared II fluorescent molecules have higher spatial resolution, deeper penetration into the biological matrix, lower optical absorption and scattering, and minimal tissue autofluorescence. Furthermore, near-infrared II fluorescent molecules are divided into organic and inorganic molecules. Compared to inorganic near-infrared II fluorescent molecules, organic small molecule therapeutic materials have advantages such as well-defined chemical structure / composition, tunable photophysical and photochemical properties, and good biosafety. However, fluorescence quenching occurs when organic molecules aggregate, while the emergence of aggregation-induced emission (AIE) materials effectively avoids this phenomenon, enabling their widespread application in the imaging diagnosis and treatment of diseases.

[0003] Compared to aggregation-induced emission materials in the visible and near-infrared I regions, near-infrared II aggregation-induced emission materials generally exhibit lower quantum yields. This lower fluorescence quantum yield significantly impacts imaging accuracy and signal-to-noise ratio, hindering their further development and clinical translation. Therefore, designing high-brightness near-infrared II aggregation-induced emission materials holds great promise for future applications. Summary of the Invention

[0004] The technical problem to be solved by this invention is to address the issue that existing near-infrared II aggregation-induced emission molecular imaging has a deep penetration depth but a very low quantum yield, and aims to enrich the existing near-infrared II aggregation-induced emission molecular material reserve.

[0005] Firstly, the technical solution adopted by the present invention to solve this technical problem is as follows: 3,4-bis((2-ethylhexyl)oxy)thiophene is introduced as an electron-rich donor unit (π-bridge), and triphenylamine or tetraphenylethylene is used as a rotor and electron donor (D), and 4,8-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) is used as a strong electron acceptor (A) to construct a high-brightness near-infrared II region aggregation-induced emission material, the general chemical formula of which is: Wherein, the near-infrared II region aggregation-induced emission material, R is independently selected from... and One of them.

[0006] Secondly, a method for preparing a high-brightness near-infrared II region aggregation-induced emission material includes the following steps:

[0007] Compounds V, VI, tetratriphenylphosphine palladium, potassium carbonate, and water were added to a tetrahydrofuran solvent and stirred and refluxed for two days under inert gas protection to obtain a reaction solution.

[0008] The general chemical structural formula of compound V is: ;

[0009] The general chemical structural formula of compound VI is: ; where R is independently selected from and One of them.

[0010] The reaction solution was purified to obtain the high-brightness near-infrared II region aggregation-induced emission material.

[0011] Optionally, in the preparation method of the novel near-infrared II aggregation-induced emission material, the stirring and reflux temperature is 115–125 °C, and the stirring and reflux time is 40–48 h.

[0012] Optionally, in the preparation method of the high-brightness near-infrared II region aggregation-induced emission material, the molar ratio of compound V to VI is 1:2.5 to 3.5.

[0013] Optionally, in the method for preparing the novel near-infrared II region aggregation-induced emission material, the concentration of compound V in the reaction solution is 1–2 M.

[0014] Optionally, in the method for preparing the high-brightness near-infrared II region aggregation-induced emission material, the molar ratio of compound V to tetraphenylphosphine palladium is 10-20:1.

[0015] Optionally, the method for preparing the high-brightness near-infrared II aggregation-induced emission material, wherein purifying the reaction solution to obtain the high-brightness near-infrared II aggregation-induced emission material specifically includes:

[0016] The reaction solution was stirred, then extracted, and the organic phases in the extracted reaction solution were combined.

[0017] The reaction solution after merging the organic phases was dried, and the dried reaction solution was concentrated under reduced pressure to obtain the crude product.

[0018] The crude product was purified to obtain the high-brightness near-infrared II aggregation-induced emission material.

[0019] Optionally, in the method for preparing the high-brightness near-infrared II aggregation-induced emission material, the step of purifying the crude product to obtain the high-brightness near-infrared II aggregation-induced emission material includes:

[0020] The crude product was purified by silica gel column chromatography using a mixture of petroleum ether and dichloromethane as the eluent to obtain the high-brightness near-infrared II aggregation-induced emission material.

[0021] Optionally, in the method for preparing the high-brightness near-infrared II aggregation-induced emission material, the volume ratio of petroleum ether to dichloromethane in the eluent is 10:1 to 1:2.

[0022] Thirdly, the application of the high-brightness near-infrared II aggregation-induced emission material described in the first aspect in the preparation of fluorescence imaging reagents.

[0023] Beneficial Effects: Compared with existing technologies, the near-infrared II aggregation-induced emission molecule provided by this invention has a novel D-π-A-π-D structure. This type of material uses different substituted triphenylamine or tetraphenylethylene structural units as electron donors in the molecular system, 3,4-bis((2-ethylhexyl)oxy)thiophene as a π-bridge in the molecular system, and 4,8-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) structural units as electron acceptors to construct a novel high-brightness material with near-infrared II aggregation-induced emission properties. Compared with commercial IR 26 reagents (quantum yield 0.5%), the relative fluorescence quantum yield of this aggregation-induced emission material is as high as 25.3%. Attached Figure Description

[0024] Figure 1 This is a synthesis route diagram of the high-brightness NIR-II AIE material prepared in the embodiments of the present invention.

[0025] Figure 2 This is the 1H NMR spectrum of the TPE-HEXOXY material prepared in deuterated dichloromethane in the embodiments of the present invention.

[0026] Figure 3 This is the carbon NMR spectrum of the TPE-HEXOXY material prepared in deuterated dichloromethane in the embodiments of the present invention.

[0027] Figure 4 This is a high-resolution mass spectrum of the TPE-HEXOXY material prepared in the embodiments of the present invention.

[0028] Figure 5This is the 1H NMR spectrum of the TPA-HEXOXY material prepared in deuterated chloroform in the embodiments of the present invention.

[0029] Figure 6 This is the carbon NMR spectrum of the TPA-HEXOXY material prepared in deuterated chloroform in the embodiments of the present invention.

[0030] Figure 7 This is a high-resolution mass spectrum of the TPA-HEXOXY material prepared in the embodiments of the present invention.

[0031] Figure 8 This is the absorption spectrum of the TPA-HEXOXY and TPE-HEXOXY materials prepared in the embodiments of the present invention at a concentration of 10 µM in tetrahydrofuran.

[0032] Figure 9 This is a broken line diagram of the fluorescence emission spectra of TPE-HEXOXY and TPA-HEXOXY prepared in the embodiments of the present invention in a mixed solvent of tetrahydrofuran and water.

[0033] Figure 10 The quantum yield in water of the TPE-HEXOXY NPs and TPA-HEXOXY NPs prepared in the embodiments of the present invention is shown. Detailed Implementation

[0034] The preparation method of the high-brightness near-infrared II aggregation-induced emission material provided by this invention is further described in detail below to make the objectives, technical solutions, and advantages of this invention clearer and more explicit. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or according to the product specification. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various modifications or alterations to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0035] Compared to the near-infrared I region, near-infrared II region aggregation-induced emission materials are accompanied by an increase in absorption wavelength. Since the non-radiative relaxation process between the zero vibrational level of the excited state and the higher vibrational level of the ground state quenches the fluorescence of the molecule, its quantum yield often decreases. Therefore, even though many near-infrared II region aggregation-induced emission materials have been reported, their quantum yields are relatively low, resulting in relatively poor imaging quality in the near-infrared II region.

[0036] To address the aforementioned problems, embodiments of the present invention provide a novel high-brightness near-infrared diode.

[0037] Aggregation-induced emission molecular materials, wherein the general chemical structural formula is: Wherein, the near-infrared II region aggregation-induced emission material, R is independently selected from... and One of them.

[0038] In this embodiment, the high-brightness near-infrared II aggregation-induced emission material has a novel D-π-A-π-D structure. In the molecular structure, 4,8-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) acts as a strong electron acceptor, and 3,4-bis((2-ethylhexyl)oxy)thiophene acts as an electron-rich donor and π-bridge. The oxygen atom on the alkoxy chain can interact with the nitrogen atom of the acceptor, increasing the structural rigidity. On the other hand, it also acts as a sterically hindered group, increasing the dihedral angle between the acceptor motif and the acceptor motif, making the overall molecular skeleton more twisted and ensuring its aggregation-induced emission characteristics. The strong DA effect can prolong the absorption / emission wavelength, so that the relative fluorescence quantum yield of the near-infrared II aggregation-induced emission material with this novel structure can be as high as 25.3% (see experimental results below).

[0039] Based on the same inventive concept, the present invention also provides a method for preparing the above-mentioned high-brightness near-infrared II region aggregation-induced emission molecules, comprising the following steps:

[0040] S10. Compounds V, VI, tetraphenylphosphine palladium, potassium carbonate, and water are added to tetrahydrofuran solvent and stirred under reflux under inert gas protection to obtain a reaction solution.

[0041] The general chemical structural formula of compound V is: ;

[0042] The general chemical structural formula of compound VI is: ; where R is independently selected from and One of them;

[0043] The reaction solution was purified to obtain the high-brightness near-infrared II region aggregation-induced emission material.

[0044] like Figure 1 As shown, according to Figure 1 Compound VII was prepared using the synthetic route shown.

[0045] Step 1): Synthesis of Compound II

[0046] Compound I (12 g, 83.22 mmol), trifluoromethanesulfonic acid (0.365 mL, 4.16 mmol), and 82 mL of 2-ethylhexanol were added to a 250 mL round-bottom flask. The mixture was purged three times with dry nitrogen and stirred overnight at 100 °C under a nitrogen atmosphere. After cooling to room temperature, the reaction was checked for completion by TLC, and the solvent was removed by rotary evaporation. The crude product was purified by column chromatography to give a pale yellow oil, II (12.95 g, 45.7% yield). 1 H NMR (500 MHz, Chloroform-d) δ6.16 (s, 2H), 3.85 – 3.84 (d, J = 6.0 Hz, 4H), 1.78 – 1.72 (m, 2H), 1.46 –1.41 (m, 4H), 1.33 (tq, J = 10.4, 5.2, 4.3 Hz, 12H), 0.94 – 0.89 (m, 12H). 13 CNMR (126 MHz, Chloroform-d) δ 148.37, 97.23, 73.41, 39.64, 30.97, 29.44,24.33, 23.40, 14.39, 11.50.

[0047] Step 2): Synthesis of Compound III

[0048] A solution of compound II (2 g, 5.9 mmol) was added to dry THF (40 mL), cooled to -78 °C under argon atmosphere, and 2.8 mL, 7.1 mmol of n-butyllithium was added dropwise. The mixture was stirred at -78 °C for 2 h, followed by the addition of tributyltin chloride (1.9 mL, 7.1 mmol). The reaction mixture was cooled to room temperature and stirred overnight. The mixture was washed three times with potassium fluoride solution and ethyl acetate, and then dried over anhydrous sodium sulfate. The solution was concentrated under reduced pressure to give compound III, which was used directly in the next step without further purification.

[0049] Step 3): Synthesis of Compound IV

[0050] Compound III (2.52 g, 4 mmol), 4,8-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) (352 mg, 1 mmol), tetraphenylphosphine palladium (116 mg, 0.1 mmol), and ultra-dry toluene (30 mL) were added to a 100 mL round-bottom flask. The mixture was stirred at 110 °C for 24 hours under a nitrogen atmosphere. The reaction solution was quenched with saturated potassium fluoride solution, the mixture was poured into water and extracted with ethyl acetate, and then dried over anhydrous sodium sulfate. The solution was concentrated under vacuum, and the residue was purified by column chromatography to give compound IV (510 mg, 58% yield) as a blue solid. 1 H NMR(500 MHz, Chloroform-d) δ 6.56 (s, 2H), 3.98 – 3.94 (dd, J = 8.2, 4.2 Hz,8H), 1.77 – 1.76 (m, 2H), 1.56 – 1.45 (m, 8H), 1.38 – 1.32 (dq, J = 6.9, 3.3Hz, 8H), 1.28 – 1.23 (d, J = 4.8 Hz, 4H), 0.98 – 0.91 (m, 26H), 0.69 – 0.66(t, J = 6.9 Hz, 6H), 0.54 –0.51 (t, J = 7.4 Hz, 6H). 13 C NMR (126 MHz, Chloroform-d) δ 153.21, 150.82, 146.74, 117.23, 115.04, 99.66, 75.19, 72.47, 40.21, 39.91, 31.02, 30.47, 29.48, 29.18, 24.31, 23.69, 23.41, 23.24, 14.44,14.31, 11.55, 11.09.

[0051] Step 4): Synthesis of Compound V

[0052] A mixture of compound IV (205 mg, 0.235 mmol) in N,N-dimethylformamide (12 mL) and acetonitrile (6 mL) was refluxed to 65 °C under a nitrogen atmosphere. Under a nitrogen atmosphere, N-bromosuccinimide (35.6 mg, 0.2 mmol) and hydrogen bromide solution (0.2 mL) were added to the mixture every hour for a total of three times, and the reaction was allowed to proceed overnight. After the reaction was complete, the mixture was cooled to room temperature and extracted with ethyl acetate and water. The organic phase was then dried over anhydrous sodium sulfate and concentrated under vacuum to give a crude product, which was purified by column chromatography to give compound V (41 mg, 18.6% yield). 1 H NMR (600 MHz,Methylene Chloride-d2) δ 4.15 –4.13 (td, J = 5.4, 2.1 Hz, 4H), 3.75 –3.73 (t,J = 6.1 Hz, 4H), 1.78 –1.76 (p, J = 6.1 Hz, 2H), 1.64 –1.62 (dt, J = 14.0,7.0 Hz, 2H), 1.53 –1.51 (dd, J = 13.9, 7.0 Hz, 4H), 1.48 –1.45 (dt, J = 8.0,6.5 Hz, 2H), 1.41 –1.35 (dddd, J = 18.2, 13.2, 6.4, 2.7 Hz, 8H), 1.23 – 1.21 (q, J = 6.0 Hz, 2H), 1.03 – 0.97 (m, 14H), 0.96 – 0.89 (qd, J = 7.4, 3.3 Hz, 14H), 0.71 – 0.69 (t, J = 7.2 Hz, 6H), 0.52 – 0.49 (t, J = 7.5 Hz, 6H). 13 C NMR(151 MHz, Methylene Chloride-d2) δ 152.67, 149.21, 148.38, 116.57, 113.83,100.57, 76.36, 75.85, 40.37, 40.03, 30.26, 30.03, 29.16, 28.86, 23.64, 23.27,23.12, 22.89, 13.92, 13.76, 10.99, 10.57.

[0053] Step 5): Synthesis of compound TPE-HEXOXY

[0054] Compound V (489 mg, 0.475 mmol), 1-(4-phenylboronic acid pinacol ester)-1,2,2-triphenylene (678 mg, 1.48 mmol), potassium carbonate (309 mg, 2.2 mmol), tetraphenylphosphine palladium (55 mg, 0.0475 mmol), water (1.2 mL), and tetrahydrofuran (40 mL) were added to a 100 mL pressure-resistant flask. The reaction was carried out for two days, monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature and extracted with ethyl acetate and water. The organic phase was then dried over anhydrous sodium sulfate and concentrated under vacuum to obtain the crude product. The crude product was purified by column chromatography to give compound TPE-HEXOXY (130 mg, 18% yield). Figures 2 to 4 , 1 H NMR(500 MHz, Methylene Chloride-d2) δ 7.58 – 7.56 (m, 4H), 7.15 – 7.05 (m, 34H), 3.97 (ddd, J = 6.8, 4.6, 2.6 Hz, 4H), 3.76 (t, J = 6.0 Hz, 4H), 1.71 – 1.68(m, 2H), 1.32 – 1.25 (m, 16H), 1.03 – 0.86 (m, 30H), 0.73 – 0.70 (t, J = 7.2Hz, 6H), 0.52 – 0.49 (t, J = 7.5 Hz, 6H). 13 C NMR (126 MHz, Methylene Chloride-d2) δ 152.80, 146.39, 143.80, 143.71, 143.60, 143.17, 141.39, 140.59, 131.50,131.32, 131.21, 131.07, 128.51, 127.74, 127.67, 127.62, 126.59, 126.48,126.42, 126.33, 114.87, 76.17, 40.30, 40.10, 30.28, 30.07, 29.10, 28.91,23.56, 23.29, 23.08, 22.91, 13.77, 10.91, 10.58.

[0055] Step Six): Synthesis of compound TPA-HEXOXY

[0056] Compound V (396 mg, 0.385 mmol), 4-(diphenylamino)phenylboronic acid pinacol ester (0.446 mg, 1.2 mmol), potassium carbonate (250 mg, 1.8 mmol), tetraphenylphosphine palladium (45 mg, 0.0385 mmol), water (0.9 mL), and tetrahydrofuran (30 mL) were added to a 100 mL pressure-resistant flask. The reaction was carried out for two days, monitored by TLC. After the reaction was complete, the mixture was cooled to room temperature and extracted with ethyl acetate and water. The organic phase was then dried over anhydrous sodium sulfate and concentrated under vacuum to obtain the crude product. The crude product was purified by column chromatography to give compound TPA-HEXOXY (100 mg, 19.1% yield). Figure 5 To Figure 7, 1 H NMR(500 MHz, Chloroform-d) δ 7.70 – 7.68 (d, J = 8.8 Hz, 4H), 7.30 – 7.28 (d, J= 8.5 Hz, 6H), 7.27 – 7.26 (d, J = 1.8 Hz, 2H), 7.15 – 7.13 (d, J = 1.2 Hz, 8H), 7.10 – 7.09 (d, J = 6.6 Hz, 4H), 7.07 – 7.04 (t, J = 7.4 Hz, 4H), 4.03–4.02 (d, J = 6.1 Hz, 4H), 3.88 – 3.84 (m, 4H), 1.73 – 1.70 (m, 2H), 1.53 – 1.51 (m, 2H), 1.44 – 1.41 (d, J = 6.8 Hz, 2H), 1.32 – 1.26 (td, J = 7.9, 3.8Hz, 12H), 1.05 – 0.95 (m, 18H), 0.90 – 0.86 (m, 12H), 0.74 – 0.71 (t, J = 7.1Hz, 6H), 0.55 – 0.52 (t, J = 7.4 Hz, 6H). 13C NMR (126 MHz, Chloroform-d) δ152.85, 150.83, 147.60, 147.33, 146.03, 129.45, 129.39, 128.28, 127.07,124.70, 124.58, 123.21, 123.07, 114.42, 114.37, 76.29, 75.79, 40.38, 40.18,30.40, 30.20, 29.19, 29.03, 23.67, 23.40, 23.17, 23.02, 14.21, 14.10, 11.21, 10.89.

[0057] like Figure 8 As shown, Figure 8 This is the absorption spectrum of the TPA-HEXOXY and TPE-HEXOXY materials prepared in the embodiments of the present invention at a concentration of 10 µM in tetrahydrofuran.

[0058] like Figure 9 As shown: Figure 9 The graphs show the fluorescence emission spectra of TPE-HEXOXY and TPA-HEXOXY prepared in the embodiments of the present invention in a mixed solvent of tetrahydrofuran and water. It can be seen that the synthesized molecules all have the property of aggregation-induced emission.

[0059] like Figure 10 As shown: Figure 10 The fluorescence quantum yields of the TPE-HEXOXY NPs and TPA-HEXOXY NPs prepared in this embodiment of the invention are shown to be much greater than those of the commercially available near-infrared fluorescent dye IR 26.

[0060] In summary, this invention discloses a method for preparing a high-brightness near-infrared II aggregation-induced emission material. The general chemical formula of the novel near-infrared II aggregation-induced emission molecule is as follows: In this context, the near-infrared II region aggregation-induced emission material, R, is independently selected from... and One of them. The near-infrared II aggregation-induced emission molecule of the present invention is an aggregation-induced emission material with a novel D-π-A-π-D structure. This type of material uses different substituted triphenylamine or tetraphenylethylene structural units as the first electron donor in the molecular system, 3,4-bis((2-ethylhexyl)oxy)thiophene as the second electron donor or π-bridge in the molecular system, and 4,8-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) structural units as electron acceptors to construct a novel high-brightness material with near-infrared II aggregation-induced emission properties. Compared with the commercial IR26 reagent (quantum yield 0.5%), this aggregation-induced emission material has a quantum yield of 25.3% under 808 nm laser irradiation, which is much greater than that of the near-infrared fluorescent dye IR26 (quantum yield 0.5%).

[0061] Based on the same inventive concept, this invention also provides an application of the aforementioned high-brightness near-infrared II aggregation-induced emission material in the preparation of fluorescence imaging reagents. Because this material exhibits aggregation-induced emission in the near-infrared II region and possesses a high quantum yield, it can achieve high imaging accuracy when used for fluorescence imaging. This makes it widely applicable in the imaging diagnosis and treatment of diseases, demonstrating broad application prospects.

[0062] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A high-brightness near-infrared II region aggregation-induced emission material, characterized in that, Its general structural formula is as follows: Where R is .

2. A method for preparing a high-brightness near-infrared II region aggregation-induced emission material as described in claim 1, characterized in that, The method includes: Compounds V, VI, tetratriphenylphosphine palladium, carbonate, and water were added to a tetrahydrofuran solvent and stirred under reflux under inert gas protection to obtain a reaction solution. The general chemical structural formula of compound V is: ; The general chemical structural formula of compound VI is: Where R is ; The reaction solution was purified to obtain the high-brightness near-infrared II region aggregation-induced emission material.

3. The method for preparing the high-brightness near-infrared II aggregation-induced emission material according to claim 2, characterized in that, The temperature of the stirring and reflux is 115–125 °C, and the stirring and reflux time is 40–48 h.

4. The method for preparing the high-brightness near-infrared II aggregation-induced emission material according to claim 2, characterized in that, The molar ratio of compound V to VI is 1:2.5 to 3.

5.

5. The method for preparing the high-brightness near-infrared II aggregation-induced emission material according to claim 2, characterized in that, The concentration of compound V in the reaction solution is 1–2 M; the carbonate is selected from potassium carbonate, sodium carbonate, and cesium carbonate.

6. The method for preparing the high-brightness near-infrared II aggregation-induced emission material according to claim 2, characterized in that, The molar ratio of compound V to tetratriphenylphosphine palladium is 10–20:

1.

7. The method for preparing the high-brightness near-infrared II aggregation-induced emission material according to claim 2, characterized in that, The reaction solution is purified to obtain the high-brightness near-infrared II aggregation-induced emission material, which specifically includes: The reaction solution was stirred, then extracted, and the organic phases in the extracted reaction solution were combined. The reaction solution after merging the organic phases was dried, and the dried reaction solution was concentrated under reduced pressure to obtain the crude product. The crude product was purified to obtain the high-brightness near-infrared II aggregation-induced emission material.

8. The method for preparing the novel near-infrared II aggregation-induced emission material according to claim 7, characterized in that, The step of purifying the crude product to obtain the high-brightness near-infrared II aggregation-induced emission material includes: The crude product was purified by silica gel column chromatography using a mixture of petroleum ether and dichloromethane as the eluent to obtain the high-brightness near-infrared II aggregation-induced emission material.

9. The method for preparing the high-brightness near-infrared II aggregation-induced emission material according to claim 8, characterized in that, The volume ratio of petroleum ether to dichloromethane in the eluent is 10:1 to 1:

2.

10. The application of the high-brightness near-infrared II aggregation-induced emission material as described in claim 1 in the preparation of fluorescence imaging reagents.

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