Organic compound with aggregation-induced emission effect and preparation method and application thereof

Abstract

The invention relates to the technical field of organic materials, and particularly discloses an organic compound with an aggregation-induced emission effect and a preparation method and application thereof. The novel boron difluoride compound with the aggregation-induced emission characteristic is synthesized, when the novel boron difluoride compound is used as a latent fingerprint developing agent, all three levels of fingerprint feature details can be shown through the hydrophobic interaction between the compound and oleic acid secreted by sweat, and therefore the latent fingerprint developing agent can be used for developing the latent fingerprint developing agent. The stability, old fingerprint extraction capability and hydrophobicity of the compounds lay a foundation for potential application of the compounds in the fields of forensic chemistry and criminal investigation, and the problem that in the prior art, an imaging mechanism between the boron difluoride compound and the LFPs is not clear is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of organic materials, and particularly relates to an organic compound with an aggregation-induced emission effect and a preparation method and application thereof. BACKGROUND

[0002] With the extensive and rapid development of information technology, people have adapted to using fingerprints to unlock mobile phones, mobile payments and access control, which is mainly due to the consistency of fingerprints throughout a person's life, which can serve as a person's personal identity or information bank. Therefore, fingerprint detection, with its extraordinary identification ability, has always been considered the cornerstone of forensic science and criminal investigation. Although deoxyribonucleic acid identification technology is developing rapidly, fingerprint detection is still widely accepted and used because it does not require the use of large instruments or equipment, and is known as the "King of Evidence". The visualization of latent fingerprints (LFPs) is a prerequisite for fingerprint identification, and latent fingerprints are the traces left by human fingerprints after they come into contact with the surface of an object. It is mainly composed of oil and water secreted by sweat. Generally speaking, it is difficult to detect the detailed features of LFPs with the naked eye at a crime scene. Traditional LFPs visualization methods include dust method, ninhydrin method, adhesive tape method and silver nitrate method, etc., which have low sensitivity and cannot meet the actual needs.

[0003] In recent years, organic compounds with aggregation-induced emission (AIE) activity have attracted more and more attention due to their low toxicity, flexible structure and unparalleled luminescent properties. Since the AIE effect based on tetraphenylethene (TPE) was reported in 2012, a large number of organic molecules with AIE activity have been developed, such as pyridine-1-ium bromide based on carbazole and triphenylamine (TPA), vitamin B6 cofactor derivatives, hydrazone-based derivatives, 1,8-naphthalimide derivatives, coumarin-based composites, organic metal complexes, Schiff bases and 2-naphthol-pyrrole propenoate, and compounds with imidazole, difluoroboron and phenol skeletons. Among the numerous compounds, difluoroboron compounds have attracted more and more attention due to their easy structural modification, excellent photochemical stability and strong biocompatibility. However, the actual presentation effect of the existing reported developing agents with AIE effect prepared by using difluoroboron compounds is not ideal. In the past reports, the visualization of LFPs is mainly achieved through the interaction between the oil secreted by sweat and the hydrazone compound, the zinc pincer complex of terpyridine and the amphiphilic TPE-based pyridine salt, respectively. On the other hand, TPE-naphthalimide-N-hydroxysuccinimide (TPE-NI-NHS) can bind to multiple targets of various components in fingerprint marks (such as cholesterol, lipids, glycine and lysozyme, etc.), which provides new inspiration for fingerprint visualization with broad application prospects.

[0004] Therefore, it is of important practical significance to further explore the imaging mechanism between difluoroboron compounds and LFPs. Summary of the Invention

[0005] In view of this, the present invention provides an organic compound with aggregation-induced emission effect, its preparation method and application, which solves the problem in the prior art that the imaging mechanism between difluoroboron compounds and LFPs is unclear.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: In a first aspect, the present invention provides an organic compound having an aggregation-induced emission effect, the structural formula of which is shown in Formula I:

[0007] Formula I; In Formula I, X1 represents a pyrene substituent or a triphenylamine substituent; X2 represents a pyrene substituent or a triphenylamine substituent; and X3 represents a pyrene substituent or a triphenylamine substituent.

[0008] Preferably, the organic compound having aggregation-induced emission effect includes compounds with the structure shown in 2py-BF2-TPA or 2TPA-BF2-py; , .

[0009] Secondly, the present invention provides a method for preparing the organic compound with aggregation-induced emission effect, wherein the method for preparing 2py-BF2-TPA includes the following steps: S1, under an inert atmosphere, 3,5-dibromoaniline, boric acid derivative, palladium catalyst and basic salt are mixed evenly, dissolved in toluene aqueous solution, and coupled at 90-110℃ to obtain the first compound; S2, under an inert atmosphere, the first compound and the second compound are mixed evenly, dissolved in an alcohol solvent, and condensed at 75-85℃ to obtain the third compound; S3, the third compound is dissolved in a dry, low-boiling-point organic solvent, triethylamine and boron trifluoride diethyl ether are added, mixed thoroughly, and a coordination reaction is carried out at 28-32℃ to obtain an organic compound with aggregation-induced emission effect.

[0010] Preferably, in S1, the boric acid derivative is 1-pyreneboronic acid or 4-(diphenylamino)phenylboronic acid.

[0011] Preferably, in S1, the molar ratio of 3,5-dibromoaniline, boric acid derivative, palladium catalyst and basic salt is 1:2-2.5:0.03-0.05:8.

[0012] Preferably, in S1, the total mass ratio of the 3,5-dibromoaniline, boric acid derivative, palladium catalyst, and basic salt to the toluene aqueous solution is 2g:60mL-3g:60mL; wherein the volume ratio of toluene to water in the toluene aqueous solution is 2-2.2:1.

[0013] Preferably, in S1, the reaction time of the coupling reaction is 10-14 hours.

[0014] Preferably, in S1, the palladium catalyst is Pd(PPh3)4.

[0015] Preferably, in S1, the basic salt is potassium carbonate.

[0016] Preferably, in S2, the structural formula of the first compound is: or .

[0017] Preferably, in S2, the structure of the second compound is as follows: or .

[0018] Preferably, the Prepared according to existing technology (Yusong Du, Jiazhuang Tian, ​​Xiaozhou Jiang, Chunlin Chen, Yanhua Yang, Shulin Gao. Two Aggregation-Induced Emission Actives Triphenylamine-Based Salicylaldimine Compounds for Latent Fingerprints Detection[J]. ChemistrySelect, 2024, 9(30): e202402064.).

[0019] Preferably, the The preparation method includes the following steps: under an inert atmosphere, 5-bromosalicylic acid, 1-pyreneboronic acid, Pd(PPh3)4 and potassium carbonate are added to a flask, dissolved in toluene aqueous solution, and reacted at 95-105℃ for 0-14h to obtain the product.

[0020] More preferably, the molar ratio of 5-bromosalicylic acid, 1-pyreneboronic acid, Pd(PPh3)4 and potassium carbonate is 1.8-2:2-2.2:0.02:3.5-3.7.

[0021] More preferably, the total mass ratio of the 5-bromosalicylic acid, 1-pyreneboronic acid, Pd(PPh3)4 and potassium carbonate to the toluene aqueous solution is 1.2g:60mL-1.3g:60mL; wherein the volume ratio of toluene to water in the toluene aqueous solution is 2:1-2.2:1.

[0022] Preferably, in S2, the alcohol solvent is anhydrous ethanol.

[0023] Preferably, in S2, the molar ratio of the first compound and the second compound is 1:0.5-1.

[0024] Preferably, in S2, the mass-to-volume ratio of the first compound and the second compound to the alcohol solvent is 0.6g:50mL to 1.6:50mL.

[0025] Preferably, in S2, the condensation reaction takes 22-26 hours.

[0026] Preferably, in S3, the third compound is or .

[0027] Preferably, in S3, the low-boiling-point organic solvent is dichloromethane.

[0028] Preferably, in S3, the mass-to-volume ratio of the third compound to the low-boiling-point organic solvent is 0.2g:30mL to 0.3g:30mL.

[0029] Preferably, in S3, the molar ratio of the third compound, triethylamine, and boron trifluoride diethyl ether is 0.2-0.3:7-8:7-8.

[0030] Preferably, in S3, the reaction time of the coordination reaction is 23-26 hours.

[0031] Thirdly, the present invention provides a developer comprising the organic compound having the aggregation-induced emission effect.

[0032] Fourthly, the present invention provides an application of the developing agent in the fields of forensic chemistry or criminal investigation.

[0033] Beneficial effects: This invention first synthesizes two difluoroboron compounds (2py-BF2-TPA and 2TPA-BF2-py) exhibiting aggregation-induced emission (AIE) using 3,5-dibromoaniline as a base material and 1-pyreneboronic acid, 4-(diphenylamino)phenylboronic acid, palladium catalyst, aldehyde ligand, and boron trifluoride diethyl ether as main raw materials via Suzuki coupling, condensation, and coordination reactions. Optical performance tests show that both compounds exhibit intramolecular charge transfer and solvation-induced color changes, but the solvent-dependent fluorescence shift differs in organic solvents of different polarities, a phenomenon well explained by quantum chemical calculations. They exhibit significant AIE activity in a DMSO / water mixed solvent. Furthermore, their practical applications in the visualization of LFPs are explored. The developers prepared using these two difluoroboron compounds containing TPA and pyrene groups can clearly identify the detailed features at all levels of latent fingerprints on the surfaces of tin foil, blades, and aluminum plates. Furthermore, the stability, ability to extract old fingerprints, and hydrophobicity of 2py-BF2-TPA and 2TPA-BF2-py indicate their potential application value in forensic chemistry and criminal investigation. Clearly, the interaction between the two difluoroboron compounds and oleic acid secreted by sweat is a key factor in the development of potential latent fingerprints (LFPs). The technical solution of this invention effectively solves the problem of unclear imaging mechanisms between difluoroboron compounds and LFPs in existing technologies.

[0034] In summary, this invention synthesizes two novel boron difluoride compounds (2py-BF2-TPA and 2TPA-BF2-py) with AIE properties. 2TPA-BF2-py contains one pyrene group and two triphenylamine groups, while 2py-BF2-TPA contains one triphenylamine and two pyrene units. When used as fingerprint developing agents (LFPs), the hydrophobic interaction between these two compounds and oleic acid from sweat allows for the visualization of fingerprint details at all three levels (note: fingerprint features are typically classified into three levels). Their stability, ability to extract old fingerprints, and hydrophobicity lay the foundation for their potential applications in forensic chemistry and criminal investigation. Attached Figure Description

[0035] Figure 1 Normalized absorption spectra of compounds 2py-BF2-TPA (excitation wavelength 365 nm) and 2TPA-BF2-py (excitation wavelength 350 nm) in different organic solvents; where, Figure 1 a is the normalized absorption spectrum of compound 2py-BF2-TPA in different organic solvents; Figure 1 b is the normalized absorption spectrum of compound 2TPA-BF2-py in different organic solvents; Figure 2Normalized fluorescence emission spectra of compounds 2py-BF2-TPA (excitation wavelength 365 nm) and 2TPA-BF2-py (excitation wavelength 350 nm) in different organic solvents; among them, Figure 2 a is the normalized fluorescence emission spectrum of compound 2py-BF2-TPA in different organic solvents; Figure 2 b is the normalized fluorescence emission spectrum of compound 2TPA-BF2-py in different organic solvents; Figure 3 Lippert-Mataga model diagrams of compounds 2py-BF2-TPA and 2TPA-BF2-py (both at a concentration of 1×10⁻⁶). -5 mol / L); where, Figure 3 a is a Lippert-Mataga model diagram of compound 2py-BF2-TPA (all concentrations are 1×10⁻⁶). - 5 mol / L); Figure 3 b is the Lippert-Mataga model diagram of compound 2TPA-BF2-py (all concentrations are 1×10⁻⁶). -5 mol / L); Figure 4 For compounds 2py-BF2-TPA and 2TPA-BF2-py in different f w Fluorescence-emission spectra of DMSO / water mixed solutions (excitation wavelength 365 nm, concentration 1 × 10⁻⁶) -5 mol / L); where, Figure 4 a represents compound 2py-BF2-TPA in different... f w Fluorescence-emission spectra of DMSO / water mixed solutions; Figure 4 b represents compound 2TPA-BF2-py in different... f w Fluorescence-emission spectrum of DMSO / water mixed solution; Figure 5 For compounds 2py-BF2-TPA and 2TPA-BF2-py in different f w Absorption spectra of DMSO / water mixed solutions (excitation wavelength 365 nm, concentration 1 × 10⁻⁶) -5 The compounds 2py-BF2-TPA and 2TPA-BF2-py (mol / L) showed different effects under 365nm ultraviolet light irradiation. f w Photos from that time; among them, Figure 5 a represents compound 2py-BF2-TPA in different... fw Absorption spectra of DMSO / water mixed solutions and the different absorption spectra of compound 2py-BF2-TPA under 365nm ultraviolet light irradiation. f w Photos taken at that time; Figure 5 b represents compound 2TPA-BF2-py in different... f w Absorption spectra of DMSO / water mixed solutions and the different absorption spectra of compound 2TPA-BF2-py under 365nm ultraviolet light irradiation. f w Photos taken at that time; Figure 6 For the frontier molecular orbitals of compounds 2py-BF2-TPA and 2TPA-BF2-py; Figure 7 The ESP surface and dipole moment of compounds 2py-BF2-TPA and 2TPA-BF2-py in the ground and excited states; Figure 8 Optical conformation diagrams of compounds 2py-BF2-TPA and 2TPA-BF2-py; Figure 9 Fluorescence images and specific characteristics of LFPs on three substrate surfaces after treatment with a mixed developer of compound 2py-BF2-TPA; Figure 10 Fluorescence images and specific characteristics of LFPs on three substrate surfaces after treatment with a mixed developer of compound 2TPA-BF2-py; Figure 11 Fluorescent photographs of latent fingerprints on tin foil surfaces after treatment with compounds 2py-BF2-TPA and 2TPA-BF2-py for different aging times; wherein, Figure 11 a is a fluorescent photograph of latent fingerprint imaging on a tin foil surface after treatment with compound 2py-BF2-TPA developer for different aging times; Figure 11 b is a fluorescent photograph of latent fingerprint imaging on the surface of tin foil after treatment with compound 2TPA-BF2-py developer for different aging times; Figure 12 This refers to fluorescence images of fresh, 3-day aged, and 5-day aged latent fingerprints deposited on tin foil under normal conditions after treatment with compounds 2py-BF2-TPA and 2TPA-BF2-py for different aging times; among them, Figure 12 a represents fluorescence images of fresh, 3-day aged, and 5-day aged latent fingerprints deposited on tin foil after treatment with compound 2py-BF2-TPA developer for different aging times. Figure 12b is a fluorescence image of a fresh, 3-day aged, and 5-day aged latent fingerprint deposited on a tin foil after treatment with compound 2TPA-BF2-py developer for different aging times. Figure 13 The number and location distribution of sweat pores on the latent fingerprint lines on the tin foil surface, as well as fluorescence micrographs and third-level feature detail analysis diagrams of local latent fingerprint areas, were obtained when compound 2py-BF2-TPA was used as a colorimetric agent. Figure 14 When using compound 2TPA-BF2-py as a colorimetric agent, the number and location distribution of sweat pores on the latent fingerprint lines on the tin foil surface, as well as the fluorescence micrographs and third-level feature detail analysis diagrams of the local latent fingerprint areas; Figure 15 2py-BF2-TPA (λ) ex =365 nm, c=1×10 -5 mol / L) and 2TPA-BF2-py (λ ex =365 nm, c=1×10 -5 mol / L) in a DMSO / water mixed solution f w Different fingerprint components were present in the 2py-BF2-TPA mixed solution (c=1×10⁻⁶) at a concentration of 60%. -3 In a 2TPA-BF2-py mixed solution, c = 1 × 10 mol / L. -3 The fluorescence emission spectrum at (mol / L) and the fluorescence photograph under 365 nm UV light illumination; among which, Figure 15 a is 2py-BF2-TPA (λ) ex =365 nm, c=1×10 -5 mol / L) in a DMSO / water mixed solution f w Different fingerprint components were present in the 2py-BF2-TPA mixed solution (c=1×10⁻⁶) at a concentration of 60%. -3 In a 2TPA-BF2-py mixed solution, c = 1 × 10 mol / L. -3 Fluorescence emission spectrum at (mol / L); Figure 15 b is 2TPA-BF2-py(λ) ex =365 nm, c=1×10 -5 mol / L) in a DMSO / water mixed solution f w Different fingerprint components were present in the 2py-BF2-TPA mixed solution (c=1×10⁻⁶) at a concentration of 60%. -3 In a 2TPA-BF2-py mixed solution, c = 1 × 10 mol / L. -3Fluorescence emission spectrum at (mol / L); Figure 15 c is a fluorescence image of 2py-BF2-TPA under 365 nm UV light illumination; Figure 15 d is a fluorescence image of 2TPA-BF2-py under 365 nm UV light irradiation; Figure 16 Water contact angle diagrams are shown for the surfaces of a blank aluminum plate and aluminum plates coated with compounds 2py-BF2-TPA and 2TPA-BF2-py, respectively; where, Figure 16 a is a diagram showing the water contact angle on the surface of a blank aluminum plate; Figure 16 b is a diagram showing the water contact angle of the aluminum plate surface coated with compound 2py-BF2-TPA; Figure 16 c is a diagram showing the water contact angle of an aluminum plate coated with compound 2TPA-BF2-py. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] All chemicals described in this manual were purchased from commercial suppliers and, unless otherwise specified, were used without further purification. All reactions were performed under an argon atmosphere in oven-dried glassware with magnetic stirring in an oil bath.

[0038] All reactions of air-sensitive compounds were performed using the Schlenk technique under dry argon. The reaction progress was monitored by thin-layer chromatography (TLC), with UV-254 fluorescent indicator used for spot observation. Column chromatography was performed using silica gel (200-300 mesh). 1 H NMR and 13 All 1000 C NMR spectra were recorded using a Bruker Aschend 400 spectrometer in deuterated solvent. NMR chemical shifts were reported in ppm using the residual protonated solvent as an internal standard. High-resolution mass spectrometry (HRMS) was performed using a Thermo Fisher Orbitrap Exploris 120 mass spectrometer.

[0039] Photophysical properties were measured. Absorption spectra were measured using a Shimadzu UV3600Plus UV-Vis-NIR spectrophotometer in a 1 cm quartz cell, and fluorescence measurements were performed using an Edinburgh FS5 fluorescence spectrophotometer at room temperature.

[0040] To better illustrate the present invention, further examples are provided below.

[0041] Example 1 This embodiment provides an organic compound 2py-BF2-TPA with aggregation-induced emission effect, specifically including the following steps: In S1, a mixture of compound 3,5-dibromoaniline (0.503 g, 2.0 mmol), 1-pyreneboronic acid (1.082 g, 4.4 mmol), Pd(PPh3)4 (0.046 g, 0.04 mmol), K2CO3 (1.104 g, 8.0 mmol), toluene (40 mL), and distilled water (20 mL) was placed in a flask and heated to 100 °C for 12 h under a nitrogen atmosphere. After cooling to room temperature, the reaction mixture was extracted with CH2Cl2 (2 × 50 mL), followed by solvent removal by rotary evaporation. The crude product was purified by silica gel column chromatography using a mixture of dichloromethane and n-hexane (1 / 2, v / v) as eluent to give 0.402 g of compound 2py-NH2. Yield: 40.77%. 1 HNMR (400 MHz, DMSO-d6) δ 8.45 (d, J = 9.6 Hz, 2H, ArH), 8.38 (d, J = 8.0 Hz, 2H, ArH), 8.32 (t, J = 8.0 Hz, 4H, ArH), 8.25-8.19 (m, 6H, ArH), 8.17 (d, J = 8.0 Hz, 2H, ArH), 8.11 (t, J = 7.9 Hz, 2H, ArH), 7.02 (d, J = 1.2 Hz, 2H, ArH), 6.98 (t, J = 1.2 Hz, 1H, ArH), 5.61 (s, 2H, -NH2). 13 C NMR (101 MHz, DMSO-d6) δ 149.54, 141.67, 138.35, 131.46, 130.92, 130.47, 128.19, 128.01, 127.87, 127.77, 126.85, 125.74, 125.50, 125.40, 124.66, 124.58, 120.52, 115.46. S2, under a nitrogen atmosphere, a mixture of compound 2py-NH2 (0.401 g, 0.81 mmol), TPA-CHO (0.293 g, 0.80 mmol), and ethanol (50 mL) was placed in a flask and heated to 80 °C for 24 h. After cooling to room temperature, the reaction mixture was filtered to collect a yellow solid. The crude product was purified by silica gel column chromatography using a mixture of dichloromethane and n-hexane (1 / 2, v / v) as eluent to give 0.646 g of compound 2py-TPA. Yield: 95.7%. 1 H NMR (400 MHz, DMSO-d6) δ 13.06 (s, 1H, -OH), 9.34 (s, 1H, -CH=N-), 8.44 (dd, J = 7.6 Hz, 2.0 Hz, 4H, ArH), 8.35 (t, J = 7.6 Hz, 3H, ArH), 8.30-8.25 (m, 9H, ArH), 8.13 (t, J = 7.6 Hz, 2H, ArH), 8.01 (d, J = 2.4 Hz, 1H, ArH), 7.88 (d, J = 1.6 Hz, 2H, ArH), 7.80 (s, 1H, ArH), 7.73 (dd, J = 8.4 Hz, 2.0 Hz, 1H, ArH), 7.57 (d, J = 8.4 Hz, 2H, ArH), 7.32 (t, J = 8.4 Hz, 4H, ArH), 7.08 (d, J = 8.8 Hz, 2H, ArH), 7.04 (dd, J = 8.4 Hz, 1.6 Hz, 7H, ArH). 13 C NMR (101 MHz, CDCl3) δ162.74, 158.13, 146.44, 142.05, 141.57, 137.17, 134.43, 132.65, 132.47, 131.49, 130.37, 130.12, 129.83, 128.31, 128.23, 127.45, 127.24, 126.86, 126.62, 126.31, 126.17, 125.16, 124.44, 124.15, 123.94, 123.77, 123.75, 123.52, 123.33, 122.70, 122.14, 119.09, 115.05. In S3, a boron trifluoride diethyl ether solution (1 mL, 7.9 mmol) was added dropwise over 10 minutes to a mixture of compound 2py-TPA (0.204 g, 0.24 mmol) and anhydrous dichloromethane (30 mL). The reaction mixture was reacted at 30 °C for 24 h. The reaction mixture containing boron trifluoride diethyl ether and triethylamine was then extracted with saturated NaHCO3 solution (3 × 50 mL), and the solvent was evaporated to dryness. The crude product was purified by silica gel column chromatography using a mixture of dichloromethane and n-hexane (1 / 2, v / v) as eluent to give 0.13 g of compound 2py-BF2-TPA. Yield: 61.03%, Melting point: 195 °C. 1 H NMR (400 MHz, DMSO- d 6) δ 9.60 (s, 1H, -CH=N-), 8.48 (q, J = 8.0 Hz, 4H, ArH), 8.37-8.28 (m, 12H, ArH), 8.19 (s, 2H, ArH), 8.15 (t, J = 7.2 Hz, 3H, ArH), 8.08 (t, J = 2.4 Hz, 2H, ArH), 7.59 (d, J = 8.4 Hz, 2H, ArH), 7.34 (t, J = 8.0 Hz, 4H, ArH), 7.25 (d, J = 8.8 Hz, 1H, ArH), 7.08-7.04 (m, 8H, ArH). 13 C NMR (101 MHz, DMSO-) d 6) δ167.72, 160.67, 160.05, 159.89, 147.56, 147.47, 147.22, 142.42, 142.38, 136.67, 135.83, 132.77, 132.49, 131.44, 131.26, 131.16, 130.85, 130.09, 130.03, 128.84, 128.61, 128.45, 128.24, 127.86, 127.61, 127.49, 127.06, 126.99, 126.15, 125.76, 125.60 125.51, 124.87, 124.75, 124.67, 124.61, 124.51, 124.46, 124.38, 124.22, 123.94, 123.75, 123.54, 122.93, 120.11, 119.39, 117.72, 116.95. 19 F NMR (376 MHz, DMSO- d 6) δ -131.86, -131.90.HRMS (m / z): [M + H] + calcd for C 63 H 40 BF2N2O, 889.3170; found, 889.3196. Example 2 This embodiment provides an organic compound 2TPA-BF2-py with aggregation-induced emission effect, specifically including the following steps: In S1, under a nitrogen atmosphere, a mixture of compound 3,5-dibromoaniline (0.503 g, 2.0 mmol), 4-(diphenylamino)phenylboronic acid (1.235 g, 4.27 mmol), Pd(PPh3)4 (0.046 g, 0.04 mmol), K2CO3 (1.104 g, 8.0 mmol), toluene (40 mL), and distilled water (20 mL) was placed in a flask and heated to 100 °C for 12 h. After cooling to room temperature, the reaction mixture was extracted with dichloromethane (2 × 50 mL), followed by solvent removal using a rotary evaporator. The crude product was purified by silica gel column chromatography using a mixture of ethyl acetate and petroleum ether (1 / 6, v / v) as eluent to give 0.667 g of compound 2TPA-NH2. Yield: 57.6%. 1 H NMR (400 MHz, DMSO- d 6) δ 7.57 (d,J = 8.8 Hz, 4H, ArH), 7.33 (t, J = 8.0 Hz, 8H, ArH), 7.07-6.98 (m, 17H, ArH), 6.78 (d, J = 1.6 Hz, 2H, ArH), 5.24 (s, 2H, -NH2). 13 C NMR (101 MHz, DMSO- d 6) δ 149.98, 147.61, 146.95, 141.39, 135.67, 130.04, 128.05, 124.43, 123.96, 123.54, 112.97, 111.17. S2, under a nitrogen atmosphere, a mixture of 5-bromosalicylic acid (0.245 g, 1.8 mmol), 1-pyreneboronic acid (0.496 g, 2.0 mmol), Pd(PPh3)4 (0.024 g, 0.02 mmol), K2CO3 (0.497 g, 3.6 mmol), toluene (40 mL), and distilled water (20 mL) was added to a flask, and the mixture was heated to 100 °C for 12 h. After cooling to room temperature, the reaction mixture was extracted with dichloromethane (2 × 50 mL), followed by solvent removal using a rotary evaporator. The crude product was purified by silica gel column chromatography using a mixture of dichloromethane and n-hexane (1 / 6, v / v) as eluent to give compound py-CHO. Subsequently, under a nitrogen atmosphere, a mixture of compound 2TPA-NH2 (1.158 g, 2.0 mmol), py-CHO (0.396 g, 1.23 mmol), and ethanol (50 mL) was added to a flask, and the mixture was heated to 80 °C for 24 h. After cooling to room temperature, the reaction mixture was filtered, and a yellow solid was collected. The crude product was purified by silica gel column chromatography using a mixture of dichloromethane and n-hexane (1 / 2, v / v) as eluent to give 0.997 g of compound 2TPA-py. Yield: 91.72%. 1 H NMR (400 MHz, DMSO- d 6) δ 13.36 (s, 1H, -OH), 9.34 (s, 1H, -CH=N-), 8.39 (d, J = 8.0 Hz, 1H, ArH), 8.34 (d, J = 7.6 Hz, 1H, ArH), 8.31 (d, J= 7.6 Hz, 1H, ArH), 8.24 (d, J = 1.2 Hz, 2H, ArH), 8.20 (s, 2H, ArH), 8.12-8.06 (m, 2H, ArH), 7.99 (d, J = 2.0 Hz, 1H, ArH), 7.82 (t, J = 8.8 Hz, 5H, ArH), 7.73-7.69 (m, 3H, ArH), 7.35 (t, J = 7.6 Hz, 8H, ArH), 7.25 (d, J = 8.4 Hz, 1H, ArH), 7.09-7.05 (m, 16H, ArH). 13 C NMR (101 MHz, DMSO- d 6) δ 164.78, 160.39, 158.55, 149.68, 147.58, 147.45, 142.03, 136.70, 135.71, 134.74, 133.93, 131.61, 131.47, 130.91, 130.51, 130.11, 129.38, 128.56, 128.27, 128.20, 127.94, 127.90, 126.95, 125.85, 125.80, 125.47, 125.09, 124.67, 123.81, 123.61, 123.13 119.91, 118.38, 117.55. In step S3, a solution of boron trifluoride diethyl ether (1 mL, 7.2 mmol) was added dropwise over 10 min to a mixture of compound 2TPA-py (0.301 g, 0.34 mmol) and anhydrous dichloromethane (30 mL) in the presence of triethylamine (1 mL, 7.9 mmol). The reaction mixture was then reacted at 30 °C for 24 h. The reaction mixture containing boron trifluoride diethyl ether and triethylamine was then extracted with saturated sodium bicarbonate solution (3 × 50 mL), and the solvent was evaporated to dryness. The crude product was purified by silica gel column chromatography using a mixture of dichloromethane and n-hexane (1 / 2, v / v) as eluent to give 0.06 g of compound 2TPA-BF2-py. Yield: 18.93%, Melting point: 183 °C. 1 H NMR (400 MHz, DMSO- d 6) δ9.55 (s, 1H, -CH=N-), 8.42-8.32 (m, 3H, ArH), 8.26-8.03 (m, 8H, ArH), 8.00 (t, J = 5.2 Hz, 1H, ArH), 7.93 (s, 1H, ArH), 7.82-7.70 (m, 5H, ArH), 7.40-7.31 (m, 9H, ArH), 7.10-7.07 (m, 16H, ArH). 13 C NMR (101 MHz, DMSO-) d 6) δ 167.38, 164.77, 158.38, 147.92, 147.59, 147.47, 147.40, 143.76, 142.19, 142.04, 141.48, 135.68, 135.39, 133.95, 133.21, 132.82, 131.45, 130.88, 130.82, 130.13, 130.10, 128.59, 128.55, 128.25, 128.10, 128.08, 127.87, 127.03, 126.02, 125.65, 125.55 124.96, 124.77, 124.67, 124.47, 123.92, 123.81, 123.59, 120.29, 119.21. 19 F NMR (376 MHz, DMSO- d 6) δ -131.63, -131.67. HRMS (m / z): [M + H] + calcd for C 65 H 45 BF2N3O, 932.3618; found, 932.3640. To further demonstrate the technical effectiveness of 2TPA-BF2-py and 2py-BF2-TPA provided by this invention, the following tests were conducted on the two organic compounds: 1. Absorption and emission spectra in solution To investigate the optical properties of two difluoroboron compounds in a single solvent, their UV-Vis absorption and fluorescence emission spectra were measured using seven organic solvents of different polarities. The corresponding test data are listed in Table 1. Figure 1As shown, for 2py-BF2-TPA and 2TPA-BF2-py, they both exhibit two major absorption bands at approximately 280 nm and 345 nm. The former is attributed to an intramolecular π-π* transition, while the latter is attributed to an ICT transition between the electron-donating TPA group and the electron-withdrawing difluoroboron moiety. Furthermore, a slight shift in their absorption spectra was observed with increasing organic solvent polarity, indicating a small difference in dipole moments between the equilibrium ground state and the Frank-Condon excited state. The emission spectra of both compounds change with increasing organic solvent polarity (e.g., ...). Figure 2 As shown in the figure, it exhibits typical ICT characteristics. Furthermore, the shift in the emission spectrum of 2py-BF2-TPA is more pronounced, indicating a stronger DA interaction than 2TPA-BF2-py. Solvation-induced color changes in both compounds can also be observed with the naked eye under UV light.

[0042] To better understand the solvent-dependent fluorescence shift in solution, we fitted the Lippert-Mataga model plot, where the Stokes shift (Δ) v st ) and orientation polarity (Δ) in 7 organic solvents f ) are used as the x-axis and y-axis, respectively. For example... Figure 3 As shown, the two fitted curves exhibit a good linear relationship (R² of 2py-BF²-TPA). 2 = 0.89468, R of 2TPA-BF2-py 2 = 0.95188), which confirms that the dipole-dipole interaction between the solvent molecules and the two solute molecules is the cause of the solvent-dependent behavior. Due to the additional TPA donor, the linear relationship of 2TPA-BF2-py is better than that of 2py-BF2-TPA, indicating a greater degree of intramolecular charge transfer. This is because the band gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital is smaller, which is confirmed by subsequent theoretical calculations. Furthermore, the slopes of the two graphs were found to be 16002.83 and 5360.65 cm⁻¹, respectively. -1 On the one hand, the positive slope indicates that the dipole moment of the ICT excited state is greater than that of the ground state, due to the large amount of charge redistribution caused by the relaxation of the initially formed Frank-Condon excited state. On the other hand, the slope of 2py-BF2-TPA is larger, indicating that the change in dipole moment between its ground and excited states is greater than that of 2TPA-BF2-py.

[0043] 2. Aggregation-induced emission properties Optical properties in binary solvents were tested using DMSO and water, where DMSO is a good solvent for both compounds and water is a poor solvent. Figure 4As shown, in pure DMSO, the emission wavelengths of 2py-BF2-TPA and 2TPA-BF2-py are located at approximately 520 nm and 410 nm, respectively. When the volume fraction of water in the DMSO / water mixture (… f w As the concentration gradually increases from 0% to 40%, the emission wavelength and intensity of 2py-BF2-TPA show relatively small changes. Furthermore, as shown in Figure 5, the change in the absorption curve is also small. f w When the concentration reaches 50%, the emission wavelength redshifts to approximately 620 nm, the intensity also increases, and the emission color changes significantly from green to red. This indicates that 2py-BF2-TPA exists as a single molecule in pure DMSO, and in DMSO / water mixtures... f w This form is maintained even when it reaches 40%. f w When the concentration reaches 50%, the dispersed molecules in the mixture aggregate to form aggregates. Free rotation around the intramolecular single bonds is suppressed, and this restriction of intramolecular rotation opens up radiative relaxation pathways. Typical AIE phenomena are observed. Simultaneously, the tail of the absorption spectrum shifts upwards in the long-wavelength region, indicating the presence of aggregates. f w When reaching 100%, the emission spectrum profile (including wavelength and intensity) and fluorescence color remain almost unchanged. However, due to the Mie scattering effect caused by aggregate formation, the absorption intensity gradually decreases, and the spectrum gradually redshifts. For 2TPA-BF2-py, in f w When the concentration is 40%, a new fluorescence peak appears around 580 nm, and the tail of the absorption spectrum shifts upward. Subsequently, the fluorescence peak around 410 nm disappears, and as... f w The increase in [amount] leads to enhanced emission intensity. These phenomena also indicate that 2TPA-BF2-py possesses AIE characteristics.

[0044] 3. Theoretical Calculation To better elucidate the aforementioned optical properties, we performed time-dependent density functional theory (TD-DFT) calculations at the CAM-B3LYP / 6-31G(d,p) level. Details of the theoretical calculations are listed in the electronic support information. Figure 6As shown, the lowest unoccupied molecular orbitals (LUMOs) of both compounds are located around the acceptor difluoroboron moiety, while the highest occupied molecular orbitals (HOMOs) are located at the donor TPA group. The HOMO-1 distributions of the two compounds are located around the pyrene group and another TPA moiety in 2py-BF2-TPA, and around the pyrene group and another TPA moiety in 2TPA-BF2-py, respectively. The clearly separated electron distributions confirm the existence of the ICT transition. The HOMO / LUMO levels of 2py-BF2-TPA and 2TPA-BF2-py are -6.47 / -1.83 eV and -6.36 / -1.75 eV, respectively, with calculated band gaps of 4.46 eV and 4.61 eV, respectively. It was found that due to the presence of an additional TPA donor, the HOMO level of 2TPA-BF2-py is higher than that of 2py-BF2-TPA, and the band gap of 2TPA-BF2-py is smaller than that of 2py-BF2-TPA, which is more favorable for ICT transitions. Furthermore, the electrostatic potential (ESP) surface and dipole moment (μ) of the ground and excited states were obtained. Figure 7 As shown, in both the ground and excited states, the entire molecule of both compounds is covered by a continuous positive ESP region (red), while the negative ESP regions (blue) are located at the difluoroboron groups. At this point, the μ values ​​of 2py-BF2-TPA and 2TPA-BF2-py in the ground state are 6.32 D and 5.98 D, respectively, and the μ values ​​in the excited state are 7.50 D and 6.06 D, respectively. The change in μ value between the ground and excited states is small for both compounds, but the change in 2py-BF2-TPA (1.18 D) is greater than that of 2TPA-BF2-py (0.08 D). On the other hand, the μ value in the excited state is greater than that in the ground state, which is related to... Figure 1 and Figure 3 The test results are consistent with those in the test.

[0045] In addition, such as Figure 8 As shown, the dihedral angle between the TPA group benzene ring and the adjacent benzene ring of the difluoroboron unit in 2py-BF2-TPA is 39.24°, the dihedral angle between the difluoroboron unit and the bridged benzene ring is 50.83°, and the dihedral angles between the pyrene substituent and the bridged benzene ring are 58.12° and 55.06°, respectively. Furthermore, the TPA group exhibits a typical propeller-like structure. The results indicate that 2py-BF2-TPA has a non-coplanar twisted conformation. For 2TPA-BF2-py, the dihedral angles between the TPA group benzene ring and the bridged benzene ring are 37.29° and 39.42°, respectively; the dihedral angle between the pyrene substituent and the adjacent benzene ring of the difluoroboron unit is 56.70°, and the dihedral angle between the difluoroboron unit and the bridged benzene ring is 44.41°. Therefore, 2TPA-BF2-py also has a non-coplanar twisted conformation. The twisted molecular spatial configuration is beneficial for the generation of AIE properties.

[0046] 4. LFPs imaging Based on AIE test results, the imaging performance of the two compounds in LFPs was explored. The results showed that the optimal conditions for the developing agent were a mixture of DMSO / water (c = 1 × 10⁻⁶). -6 (mol / L, fw = 60%), the Фf and τ of the two developers were tested to be 1.38% and 1.29%, and 1.14 and 1.47 ns, respectively. Volunteers washed their hands with soap and water and dried them, then rubbed their foreheads with their right thumb and left index finger. They then pressed the mixture onto clean surfaces of tin foil, a blade, and an aluminum plate to obtain LFPs. Finally, the two developers were sprayed onto the LFP areas, and after 20 minutes, the three substances were slightly soaked in distilled water. After all samples dried, LFP images were captured using a Huawei Mate 30 smartphone. Figure 9-10 As shown, the fluorescence colors of LFPs photographed on different substrate surfaces exhibit color differences, and even the fluorescence colors of developers using the same compound show significant variations. This is related to the substrate, including the light reflection and hydrophobicity of different surfaces. Nevertheless, under ultraviolet light, the photographs still reveal clear fingerprint patterns and distinct textures.

[0047] like Figure 9-10 As shown, after using 2py-BF2-TPA developer, the characteristic details of the right thumb can be clearly detected from the same area of ​​the fingerprints, including the first layer (rings and triangles), the second layer (terminals, hooks, short ridges, and folds), and the third layer (pores). With 2TPA-BF2-py developer, the characteristic details of the left index finger can also be easily detected, such as the rings and deltas in the first-level characteristic details, the second-level characteristic details (including islands, terminations, bifurcations, breaks, and folds), and the pores in the third-level characteristic details. While the details in the first layer are vein features of the fingerprint and are insufficient as evidence of personal identification, the details in the second and third layers are macroscopic and microscopic features of the fingerprint ridges and grooves, respectively, and can serve as preliminary evidence of personal identification.

[0048] In particular, the quantitative data for the third layer of detail is more precise. For example, using LFPs imaging of the tin foil surface... Figure 11 As shown, under normal conditions, the outlines, ridges, and grooves of LFPs remain very clear after five days. Notably, the location and number of sweat pores are still clearly visible, indicating their stability. Over time, the luminous color changes, likely due to the evaporation of sweat components and oxidation by air. Furthermore, in real life, fingerprints typically age for several days, so we also investigated the imaging capabilities of aged fingerprints, such as... Figure 12As shown. The results indicate that LFPs on the tin foil surface can still be observed after five days of aging, and the feature details of the first layer are well preserved. Compared with 2TPA-BF2-py, 2py-BF2-TPA makes it easier to identify the ridges and grooves of LFPs, but the location and number of marked sweat pores remain. After five days of aging, an increase in the number of sweat pores was observed, which is attributed to the evaporation of sweat components causing the pores to shrink. These results confirm the stability of the two compounds in LFP imaging and their potential for extracting aged fingerprints. To better evaluate the fine structure of LFPs, some detailed features, including the shape of the ridges, the edge width of the ridges, the width of the grooves, and the diameter of the pores, can be clearly observed and finely measured under an optical microscope, such as... Figure 13-14 As shown. Figure 13 As shown, the widths of the ridge and groove of the right thumb are between 140-375 µm and 115-165 µm, respectively. Figure 14 As shown, the width of the ridge and groove of the left index finger ranges from 128-210 µm and 163-186 µm, respectively. Furthermore, the average pore diameters of areas A and B on the right thumb are approximately 101 µm and 93 µm, respectively, while the average pore diameters of areas A and B on the left index finger are approximately 177.5 µm and 132 µm, respectively.

[0049] To further understand the LFP imaging mechanism of the two compounds, we investigated the response of sweat and sebum components. It is understood that the main components of sweat and sebum include cholesterol, amino acids (such as glycine), sodium chloride, urea, glucose, lactic acid, and oleic acid (key components of lipids). These were added, respectively, to blank solutions containing compounds 2py-BF2-TPA and 2TPA-BF2-py (DMSO / water mixture, c = 1 × 10⁻⁶). -5 In a solution containing mol / L, fw = 60% (labeled as a blank solution). For example... Figure 15 As shown, under UV illumination, only the oleic acid-containing sample emitted a significantly different color than the other samples, and a new fluorescence peak appeared around 460 nm. Therefore, we can infer that the specific response of 2py-BF2-TPA to oleic acid is a key factor in LFP imaging. Figure 15 As shown, a specific response to oleic acid was also observed in solutions containing 2TPA-BF2-py. This response behavior is due to the inherent lipophilicity and hydrophobicity of compounds 2py-BF2-TPA and 2TPA-BF2-py, as well as the low polarity and high viscosity of oleic acid, resulting in maximum fluorescence emission at short wavelengths.

[0050] To evaluate the hydrophobicity of the two compounds, their water contact angles on the aluminum plate surface were also tested. Figure 16As shown, the water contact angle of the clean aluminum plate is 77.23°. When the two compounds are dissolved in dichloromethane, coated onto the aluminum plate respectively, and dried, the water contact angles increase to 92.82° and 89.59° respectively, indicating that the coatings formed by the two compounds are hydrophobic. This suggests that the latent fingerprint imaging patterns derived from compounds 2py-BF2-TPA and 2TPA-BF2-py possess a certain degree of water resistance, thereby improving their weather resistance in practical applications.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An organic compound exhibiting aggregation-induced emission effect, characterized in that, Its structural formula is shown in Formula I: In Formula I, X1 represents a pyrene substituent or a triphenylamine substituent; X2 represents a pyrene substituent or a triphenylamine substituent; and X3 represents a pyrene substituent or a triphenylamine substituent.

2. The organic compound with aggregation-induced emission effect as described in claim 1, characterized in that, Compounds including those with the structure shown in 2py-BF2-TPA or 2TPA-BF2-py; 3. The method for preparing the organic compound with aggregation-induced emission effect as described in claim 1 or 2, characterized in that, The preparation method of the 2py-BF2-TPA includes the following steps: S1, under an inert atmosphere, 3,5-dibromoaniline, boric acid derivative, palladium catalyst and basic salt are mixed evenly, dissolved in toluene aqueous solution, and coupled at 90-110℃ to obtain the first compound; S2, under an inert atmosphere, the first compound and the second compound are mixed evenly, dissolved in an alcohol solvent, and condensed at 75-85℃ to obtain the third compound; S3, the third compound is dissolved in a dry, low-boiling-point organic solvent, triethylamine and boron trifluoride diethyl ether are added, mixed thoroughly, and a coordination reaction is carried out at 28-32℃ to obtain an organic compound with aggregation-induced emission effect.

4. The method for preparing the organic compound with aggregation-induced emission effect as described in claim 3, characterized in that, In S1, the boric acid derivative is 1-pyreneboronic acid or 4-(diphenylamino)phenylboronic acid; In S1, the molar ratio of 3,5-dibromoaniline, boric acid derivative, palladium catalyst, and basic salt is 1:2-2.5:0.03-0.05:8; In S1, the total mass ratio of the 3,5-dibromoaniline, boric acid derivative, palladium catalyst, and basic salt to the toluene aqueous solution is 2 g:60 mL - 3 g:60 mL; wherein the volume ratio of toluene to water in the toluene aqueous solution is 2-2.2:

1. In S1, the reaction time of the coupling reaction is 10-14 h.

5. The method for preparing the organic compound with aggregation-induced emission effect as described in claim 3, characterized in that, In S1, the palladium catalyst is Pd(PPh3)4; In S1, the basic salt is potassium carbonate.

6. The method for preparing the organic compound with aggregation-induced emission effect as described in claim 3, characterized in that, In S2, the structural formula of the first compound is: In S2, the structure of the second compound is as follows: In S2, the alcohol solvent is anhydrous ethanol; In S2, the molar ratio of the first compound and the second compound is 1:0.5-1; In S2, the mass-to-volume ratio of the first compound and the second compound to the alcohol solvent is 0.6 g: 50 mL - 1.6: 50 mL; In S2, the condensation reaction takes 22-26 hours.

7. The method for preparing the organic compound with aggregation-induced emission effect as described in claim 3, characterized in that, In S3, the third compound is In S3, the low-boiling-point organic solvent is dichloromethane; In S3, the mass-to-volume ratio of the third compound to the low-boiling-point organic solvent is 0.2g:30mL to 0.3g:30mL; In S3, the molar ratio of the third compound, triethylamine, and boron trifluoride diethyl ether is 0.2-0.3:7-8:7-8; In S3, the reaction time of the coordination reaction is 23-26 hours.

8. A developer, characterized in that, Including organic compounds with aggregation-induced emission effect as described in claim 1 or 2.

9. The application of a developing agent as described in claim 8 in the fields of forensic chemistry or criminal investigation.

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