D-a structure regulates intramolecular charge transfer to realize double-wavelength stimulation response thin film long afterglow material and preparation method and application thereof

Abstract

The present application relates to the field of light stimulus response material, in particular to a kind of D-A structure regulation intramolecular charge transfer realizes double-wavelength stimulus response film long afterglow material and its preparation method and application, the film long afterglow material is host-guest doped type, the host is polyvinyl alcohol, the guest is D-A type triphenylphosphonium derivative.In the D-A structure regulation intramolecular charge transfer of the present application realizes double-wavelength stimulus response film long afterglow material, the single host has no photoexcitation phosphorescence characteristics, the single guest only has weak photoexcitation phosphorescence characteristics, and the film material presents the regulation of double-wavelength photoexcitation after being excited by ultraviolet light by being doped into film by guest and host.Based on D-A structure, the design idea and application prospect of single-component double-wavelength stimulus response film long afterglow material are greatly expanded.

Description

Technical Field

[0001] This invention relates to the field of photostimulation-responsive materials, and in particular to a class of DA structure-regulated intramolecular charge transfer-controlled thin film long-afterglow materials for achieving dual-wavelength stimulation response, as well as their preparation methods and applications. Background Technology

[0002] Functional organic donor-acceptor (DA) structures are one of the core architectures for modern organic optoelectronic materials design. Through the ingenious bonding of electron donor and acceptor units within the molecular backbone, these structures can generate significant intramolecular charge transfer effects, thereby precisely controlling the leading molecular orbital energy levels and optical band gap of the material. This unique push-pull electron property makes DA structures exhibit enormous application potential in optoelectronic devices such as organic light-emitting diodes (OLEDs), field-effect transistors (FETs), and data storage and encryption.

[0003] It is worth noting that many DA molecules can exhibit different luminescent colors in response to external stimuli. This phenomenon stems from changes in the charge transfer state within the molecule, and these changes are usually visible to the naked eye. Therefore, such materials are highly sought after in cutting-edge fields such as information security anti-counterfeiting and intelligent sensing. However, developing high-performance photoresponsive DA molecules still faces significant challenges. The key lies in establishing a clear structure-property relationship between molecular structure and photoelectric properties to guide efficient molecular design.

[0004] Currently, research in this field focuses on systematically regulating the strength, connection sites, and molecular spatial configuration of donors and acceptors to deeply explore their intrinsic relationship with material properties, aiming to lay a solid theoretical foundation for the innovative design of next-generation high-performance, multifunctional organic optoelectronic materials. For example, Professor Chen Runfeng's research group at the School of Materials Science and Engineering, Nanjing University of Posts and Telecommunications, is conducting research on DA-type molecular structures, exploring how to effectively regulate fluorescence and phosphorescence behavior based on locally excited (LE) and intramolecular charge transfer (ICT) states in solid films by controlling the DA aggregation mode. The study found that the dihedral angle (φ) between donor (D) and acceptor (A) units is sensitive to the aggregation state; as φ decreases, DA coupling strengthens, the energy of the excited state changes, and the ICT characteristics weaken; while due to the lack of DD stacking, the energy of the LE state remains essentially unchanged. This aggregation-induced excited-state energy rearrangement phenomenon is particularly significant in systems with a high degree of aggregation, thus having a significant impact on the trapping and luminescence behavior of triplet excitons (Chem. Mater. 2023, 35, 6405). 6414).

[0005] It is worth noting that, in addition to controlling the excited-state properties through molecular structure design, the macroscopic aggregation state of the material and the matrix environment also have a decisive influence on the luminescence behavior. Especially in achieving efficient room-temperature phosphorescence, selecting a suitable material system and aggregation mode is crucial. In the design of organic room-temperature phosphorescent materials, polymers, due to their long-chain structure, possess excellent flexibility and mechanical properties, making them ideal host materials. Their high molecular weight and interwoven structure can effectively construct a rigid microenvironment, suppressing the decay of triplet excitons of phosphorescent chromophores through non-radiative pathways; simultaneously, the polymer matrix can also act as a barrier to isolate oxygen and water vapor, thereby significantly reducing the quenching of triplet excitons. Based on the above mechanisms, doping small-molecule phosphors into polymers is an effective strategy for achieving high-performance, flexible room-temperature phosphorescent materials (J. Am. Chem. Soc. 2025, 147, 1474). 1481; Sci. China Mater. 2022, 65, 2160–2168; Adv. Mater. 2025, 37, 2507618). After small molecules and polymers form films, the compounds can be arranged in a specific spatial order. Therefore, the introduction of the polymer matrix has a significant impact on the luminescent properties.

[0006] However, traditional host-guest doping systems face challenges in terms of long-term stability and functional integration. Especially in doped systems relying on physical mixing, phase separation and other problems may occur, affecting the material's stability and performance. If the stabilizing function of the "host" and the luminescent properties of the "guest" can be integrated into a single molecule through chemical bonds, it is hoped that while maintaining excellent luminescent performance, the phase separation problem can be fundamentally solved, and more complex stimulus-response functions can be achieved. This approach has driven a strategic shift in research paradigms from "multi-component physical doping" to "single-component chemical integration." Furthermore, developing single-component, dual-wavelength stimulus-response, long-persistence pure organic materials has always been a key focus and challenge in the field of photostimulation-responsive materials. To achieve their superior performance and expand their application boundaries, the key lies in breaking through traditional thinking and adopting innovative molecular construction strategies to achieve precise control of different photophysical processes (such as intersystem crossing and charge transfer) within a single molecule, thereby efficiently integrating dual-wavelength stimulus-response characteristics and fundamentally solving their application challenges.

[0007] In summary, DA molecular design plays a bridging role in the relationship between multi-component and single-component stimulus-responsive materials. Through intramolecular charge transfer and excited-state modulation, it is possible not only to effectively modulate dual-wavelength photoexcitation response characteristics but also to provide new solutions for the functional integration and stability of materials. With a deeper understanding of DA structures, future research is expected to further expand the application boundaries of optoelectronic materials, promoting their application in high-efficiency, flexible, and long-persistence organic optoelectronic devices. Summary of the Invention

[0008] To address the shortcomings of current single-component dual-wavelength stimulus-responsive long-persistence thin film materials, one objective of this invention is to provide a dual-wavelength stimulus-responsive long-persistence thin film material that achieves dual-wavelength stimulus-responsive long-persistence thin film material by regulating intramolecular charge transfer through DA structure, thereby modulating its photophysical luminescence behavior by controlling the intensity of intramolecular charge transfer.

[0009] The second objective of this invention is to provide a method for preparing a dual-wavelength stimulus-responsive long-afterglow thin film material by regulating intramolecular charge transfer through DA structure. This method employs a simple and direct physical mixing approach, achieving regulation of the material's photophysical properties in a non-complex synthesis process.

[0010] The third objective of this invention is to provide an application of a long afterglow thin film material with dual-wavelength stimulus response achieved by regulating intramolecular charge transfer through DA structure.

[0011] The fourth objective of this invention is to provide another application of long afterglow thin film materials that achieve dual-wavelength stimulus response by regulating intramolecular charge transfer through DA structure.

[0012] One of the technical solutions adopted to achieve the objective of this invention is: a long afterglow thin film material with dual-wavelength stimulus response, wherein the long afterglow thin film material is a host-guest doped material, the host being polyvinyl alcohol and the guest being a DA-type triphenylphosphine derivative.

[0013] This invention investigates the photostimulation response behavior of a series of DA-type triphenylphosphine derivatives doped into a PVA (polyvinyl alcohol) matrix. The matrix is ​​polyvinyl alcohol (PVA), whose long-chain structure provides a rigid environment for guest molecules, effectively suppressing nonradiative transitions and isolating oxygen, thereby stabilizing triplet excitons and promoting long-lasting afterglow emission. The guest molecules are DA-type triphenylphosphine derivatives; from a molecular design perspective, these guest molecules exhibit varying degrees of DA characteristics: the phosphine cation center acts as an electron acceptor, while the attached aromatic amine and other functional groups act as electron donors, enhancing intramolecular charge transfer effects and promoting intersystem crossing, thus laying the foundation for long-lasting afterglow emission. This invention explores the structure-property relationship between the donor strength in the DA structure and its dual-wavelength response optical properties by systematically controlling the donor strength.

[0014] Preferably, the DA-type triphenylphosphine derivative is PPh3. + -PhNMe2, PPh3 + -TPA, PPh3 + -PhOMe and PPH3 + Any one of -C3NMe2. The main component is polyvinyl alcohol (PVA), as shown in the structural formula ( The guest is provided with a rigid environment to isolate oxygen and reduce triplet exciton annihilation; the guest is PPh3. + -PhNMe2, PPh3 + -TPA, PPh3 + -PhOMe or PPH3 + Any one of the -C3NMe2 molecules, with the following structural formulas: ), ( (IV) and (V) can regulate the photophysical luminescence behavior by controlling the intensity of intramolecular charge transfer.

[0015] .

[0016] object( ) and subject ( The film formed by doping, under room temperature conditions, exhibits bluish-green fluorescence emission after brief excitation by a 310 nm UV lamp, followed by a weak green afterglow after the UV lamp is turned off; after continuous activation by a 254 nm UV lamp, it again exhibits bluish-green fluorescence emission after brief excitation by a 310 nm UV lamp, followed by a strong and persistent bluish-green afterglow after the UV lamp is turned off; while after continuous activation by a 365 nm UV lamp, followed by brief excitation by a 310 nm UV lamp, it exhibits deep blue fluorescence emission, followed by a strong and persistent light blue afterglow after the UV lamp is turned off. (Object (III) and Subject (...)) The doped film, after brief excitation by a 310 nm UV lamp, exhibits blue fluorescence emission, followed by a dim green afterglow upon lamp shutdown. Upon continuous activation by a 254 nm UV lamp and brief excitation by a 310 nm UV lamp, it exhibits blue fluorescence emission, followed by a bright green afterglow upon lamp shutdown. However, upon continuous activation by a 365 nm UV lamp and brief excitation by a 310 nm UV lamp, it exhibits blue fluorescence emission, followed by a bright dark green afterglow upon lamp shutdown. (Object (IV) and Subject (IV)) The doped film, after brief excitation by a 310 nm UV lamp, exhibits blue fluorescence emission; upon turning off the UV lamp, it emits bright green phosphorescence. Upon continuous activation by 254 nm and 365 nm UV lamps, followed by brief excitation by a 310 nm UV lamp, it consistently emits pale blue fluorescence; upon turning off the UV lamp, it consistently emits a bright green afterglow. The guest (V) and the host (V) When doped to form a thin film, it emits weak fluorescence after brief excitation by a 310 nm UV lamp, and emits weak green phosphorescence after the UV lamp is turned off. When continuously activated by 254 nm and 365 nm UV lamps, it emits weak blue fluorescence after brief excitation by a 310 nm UV lamp, and emits weak green phosphorescence after the UV lamp is turned off, which is almost invisible to the naked eye.

[0017] Preferably, the synthetic route for the guest molecule is as follows: A. The PPh3 + The preparation method of -PhNMe2 includes the following steps: A1. Under a protective atmosphere, dimethylaminobenzaldehyde is reduced to 4-(dimethylamino)benzyl alcohol using a reducing agent. A2. Under a protective atmosphere, 4-(dimethylamino)benzyl alcohol and triphenylphosphine hydrobromide were refluxed at 60-70°C in a solvent atmosphere according to the stoichiometric ratio. After the reaction was completed, the PPh3 was purified to obtain the PPh3. + -PhNMe2; Preferably, in step A1, the reducing agent is sodium borohydride, and the molar ratio of dimethylaminobenzaldehyde to the reducing agent is 1:1.5.

[0018] Preferably, in step A2, the solvent is chloroform.

[0019] B. The PPh3 + The preparation method of TPA includes the following steps: B1. Under a protective atmosphere, 4-diphenylaminobenzaldehyde is reduced to 4-diphenylaminobenzyl alcohol using a reducing agent; B2. Under a protective atmosphere, 4-diphenylaminobenzyl alcohol and triphenylphosphine hydrobromide were refluxed at 60-70°C in a solvent atmosphere according to the stoichiometric ratio. After the reaction was completed, the mixture was purified to obtain PPh3. + -TPA; Preferably, in step B1, the reducing agent is sodium borohydride, and the molar ratio of β-diphenylaminobenzaldehyde to the reducing agent is 1:1.5.

[0020] Preferably, in step B2, the solvent is chloroform.

[0021] C. The PPh3 + The preparation method of -PhOMe includes the following steps: Under a protective atmosphere, triphenylphosphine hydrobromide and p-methoxybenzyl alcohol were reacted in a solvent atmosphere at 75-85°C according to the stoichiometric ratio. After the reaction was completed, the mixture was purified to obtain PPh3. + -PhOMe; Preferably, in step C, the solvent is acetonitrile.

[0022] D. The PPh3 + The preparation method of -C3NMe2 includes the following steps: D1. Prepare PPh3 by reacting triphenylphosphine with 1,3-dibromopropane in a solvent atmosphere at 100-120°C according to the stoichiometric ratio. + -C3Br; D2, PPH3 + -C3Br and dimethylamine were mixed uniformly in a solvent atmosphere according to the stoichiometric ratio, and then reacted at 75-85℃. After the reaction was completed, the mixture was purified to obtain PPh3. + -C3NMe2; Preferably, in step D1, the solvent is toluene; Preferably, in step D2, the solvent is a mixture of methanol and water, specifically PPh3. + -C3Br was added to a methanol solution, followed by an aqueous solution of dimethylamine, with a volume ratio of methanol to water of 1:2.

[0023] The sample mixing involved in this invention does not require a specific order of addition; it employs physical ultrasonic mixing and allows for natural evaporation and drying at room temperature. The guest molecule synthesis steps are simple, and the raw materials are inexpensive and yield high results.

[0024] Preferably, the doping mass fraction of the guest in the host is 1%-5%.

[0025] Preferably, the excitation wavelength range of the thin film long afterglow material is 254-365 nm.

[0026] The second objective of this invention is achieved by the following technical solution: a method for preparing a long-afterglow thin film material with dual-wavelength stimulus response by regulating intramolecular charge transfer using the DA structure, comprising the following steps: mixing the host and guest in a solvent atmosphere and then obtaining the long-afterglow thin film material with dual-wavelength stimulus response by solution evaporation.

[0027] Preferably, it includes the following steps: S1. Weigh the main polyvinyl alcohol and add it to the solvent until completely dissolved to prepare the main solution; S2, Weigh the object PPh3 + -PhNMe2, PPh3 + -TPA, PPh3 + -PhOMe or PPH3 + -C3NMe2 is dissolved in the main solution in step S1, mixed evenly, and after the solvent has completely evaporated, a thin film long afterglow material with dual-wavelength stimulus response is obtained.

[0028] Preferably, the solvent is ultrapure water or methanol.

[0029] Preferably, the synthetic route for the guest molecule is as follows: .

[0030] The third objective of this invention is achieved through the following technical solution: the application of a dual-wavelength stimulus-responsive thin film long afterglow material using the DA structure to regulate intramolecular charge transfer, which is then applied in the field of anti-counterfeiting.

[0031] The fourth objective of this invention is achieved through the following technical solution: the application of a dual-wavelength stimulus-responsive thin film long-afterglow material with DA structure regulating intramolecular charge transfer, which is then applied in the field of antibacterial dressings.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention achieves a dual-wavelength stimulus-responsive thin film with long afterglow by regulating intramolecular charge transfer through DA structure. The main raw material, polyvinyl alcohol (PVA), is a water-soluble polymer with good film-forming properties, biocompatibility, and chemical stability. Its abundant -OH groups can interact with dopant molecules through van der Waals forces and hydrogen bonds. This physicochemical confinement effect significantly reduces the energy dissipation of triplet excitons and avoids possible phase separation. The guest molecule is a DA-type triphenylphosphine derivative with varying degrees of DA characteristics. The phosphine cation center acts as an electron acceptor, while the connected aromatic amine and other functional groups act as electron donors, enhancing the intramolecular charge transfer effect and promoting intersystem crossing, thus laying the foundation for long afterglow emission.

[0033] 2. In the dual-wavelength stimulus-responsive long-persistence thin film material of this invention, the host alone has no photoexcited phosphorescence properties, and the guest alone has only weak photoexcited phosphorescence properties. However, when the guest and host are doped together and excited by ultraviolet light, the thin film material exhibits dual-wavelength photoexcitation. The realization of dual-wavelength stimulus-responsive long-persistence thin film materials based on the DA structure greatly expands the design ideas and application prospects of single-component dual-wavelength stimulus-responsive long-persistence thin film materials.

[0034] 3. The DA structure of this invention enables the modulation of dual-wavelength stimulus-response thin film long afterglow material, which is a thin film of small molecule doped polymer. The characteristic of the DA structure to modulate the dual-wavelength stimulus response is rare in such photostimulation-response thin film materials.

[0035] 4. The preparation method of this invention does not require single-crystal cultivation of the host and guest molecules, nor does it require cultivation of donor-acceptor co-crystals. The sample is mixed using physical methods, and then the DA structure-regulated intramolecular charge transfer dual-wavelength stimulus-responsive thin film long-afterglow material of this invention is obtained through solution evaporation. The process is simple and easy to operate, and is a relatively mature research method.

[0036] 5. The DA structure of the present invention regulates intramolecular charge transfer to realize a dual-wavelength stimulus-responsive thin film long afterglow material. It relies on the rigid environment provided by the host to the object, so that the material exhibits photoexcited afterglow emission. This feature can be applied to information anti-counterfeiting technology.

[0037] 6. The DA structure of this invention regulates intramolecular charge transfer to achieve a dual-wavelength stimulus-responsive thin film with long afterglow. The guest material used has the effect of destroying bacterial cell membranes based on its own cationic properties. In addition, the material exhibits a significant photothermal antibacterial effect under ultraviolet light and can be applied to wound healing and other fields. Attached Figure Description

[0038] Figure 1 The guest molecule PPh3 in Example 1 of this invention + -PhNMe2 1 H NMR spectrum; Figure 2 The guest molecule PPh3 in Example 1 of this invention + -PhNMe2 13 C NMR spectrum; Figure 3 The guest molecule PPh3 in Example 2 of this invention + -TPA 1 H NMR spectrum; Figure 4 The guest molecule PPh3 in Example 2 of this invention + -TPA 13 C NMR spectrum; Figure 5 The guest molecule PPh3 in Example 3 of this invention + -PhOMe 1 H NMR spectrum; Figure 6 The guest molecule PPh3 in Example 3 of this invention + -PhOMe 13 C NMR spectrum; Figure 7 The guest molecule PPh3 in Example 4 of this invention + -C3NMe2 1 H NMR spectrum; Figure 8 The guest molecule PPh3 in Example 4 of this invention + -C3NMe2 13 C NMR spectrum; Figure 9 A is the guest molecule PPh3 in Example 1 of this invention. + HPLC spectrum of -PhNMe2; Figure 9 B is the guest molecule PPh3 in Example 2 of this invention. + -HPLC spectrum of TPA; Figure 9 C is the guest molecule PPh3 in Example 3 of this invention. + HPLC spectrum of PhOMe; Figure 9 D is the guest molecule PPh3 in Example 4 of this invention. + HPLC spectrum of -C3NMe2; Figure 10 The object in Embodiment 5 of the present invention ( ) and subject ( Photos of the thin film material before and after activation by ultraviolet light irradiation; Figure 11 The object in Embodiment 5 of the present invention ( ) and subject ( Phosphorescence spectra of the thin film material before and after activation at 254 nm and 365 nm, respectively; Figure 12 The object in Embodiment 5 of the present invention ( ) and subject ( Phosphorescence decay curves of the thin film material before and after activation at 254 nm and 365 nm, respectively; Figure 13 In Embodiment 6 of the present invention, the object (Ⅲ) and the subject (Ⅲ) Photos of the thin film material before and after activation by ultraviolet light irradiation; Figure 14 In Embodiment 6 of the present invention, the object (Ⅲ) and the subject (Ⅲ) Phosphorescence spectra of the thin film material before and after activation at 254 nm and 365 nm, respectively; Figure 15 In Embodiment 6 of the present invention, the object (Ⅲ) and the subject (Ⅲ) Phosphorescence decay curves of the thin film material before and after activation at 254 nm and 365 nm, respectively; Figure 16 In Embodiment 7 of the present invention, the object (Ⅳ) and the subject (Ⅳ) Photos of the thin film material before and after activation by ultraviolet light irradiation; Figure 17 In Embodiment 7 of the present invention, the object (Ⅳ) and the subject (Ⅳ) Phosphorescence spectra of the thin film material before and after activation at 254 nm and 365 nm, respectively; Figure 18 In Embodiment 7 of the present invention, the object (Ⅳ) and the subject (Ⅳ) Phosphorescence decay curves of the thin film material before and after activation at 254 nm and 365 nm, respectively; Figure 19 In Embodiment 8 of the present invention, the object (V) and the subject ( Photos of the thin film material before and after activation by ultraviolet light irradiation; Figure 20 In Embodiment 8 of the present invention, the object (V) and the subject ( Phosphorescence spectra of the thin film material before and after activation at 254 nm and 365 nm, respectively; Figure 21 In Embodiment 8 of the present invention, the object (V) and the subject ( Phosphorescence decay curves of the thin film material before and after activation at 254 nm and 365 nm, respectively; Figure 22 These are photos taken in Example 9 of this invention, showing the UV lamp turned off before activation and the UV lamp turned off after activation when a thin film material with dual-wavelength stimulus response characteristics is used for information anti-counterfeiting. Figure 23 This is the photothermal curve in Example 10 of the present invention. Figure 24 This is a photograph of the antibacterial treatment used in Example 11 of this invention. Detailed Implementation

[0039] The present invention will be further illustrated below through examples, the purpose of which is solely to provide a better understanding of the invention. Therefore, the examples given do not limit the scope of protection of the present invention. All raw materials and reagents used are commercially available or purified using conventional methods described in the literature. The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0040] Example 1 A method for preparing a long afterglow thin film material with dual-wavelength stimulus response by regulating intramolecular charge transfer using a DA structure includes the following steps: S1, main molecule ( Preparation of polyvinyl alcohol (PVA) solution: Weigh 6 g of PVA and place it in a dry and clean 250 mL round-bottom flask. Add 60 mL of ultrapure water and stir slowly at 120 rpm for 2 h at room temperature. Then stir at 95 °C for 2 h. After the sample is completely dissolved, a uniform 100 mg / mL colorless and transparent solution is obtained.

[0041] S2, guest molecules ( PPh3 + Synthesis of PhNMe2 , p-Dimethylaminobenzaldehyde (0.75 g, 5 mmol) and sodium borohydride (0.28 g, 7.5 mmol) were dissolved in 100 mL of dry methanol and reacted under nitrogen protection at 30 °C for 2 h with stirring. After the reaction was complete, the mixture was extracted with ethyl acetate, and the ethyl acetate was removed by rotary evaporation. The crude product was then purified by silica gel column chromatography (eluent: ethyl acetate: dichloromethane = 1:10) and recrystallized to give 4-(dimethylamino)benzyl alcohol. 4-(dimethylamino)benzyl alcohol (1.52 g, 10 mmol) and triphenylphosphine hydrobromide (3.12 g, 9.1 mmol) were then dissolved in 60 mL of chloroform and refluxed at 65 °C for 2 h with stirring. After removing the chloroform by rotary evaporation, the crude product was purified by silica gel column chromatography (eluent: methanol: dichloromethane = 1:30) and recrystallized to give a white solid (II) (4.01 g, 84.3%).

[0042] Figure 1 The product shown is 1 The H NMR (400 MHz, DMSO) spectrum shows that... δ 7.92 – 7.87(m, 3H), 7.74 (td, J 1 = 7.64 Hz J 2=3.56 Hz, 6H), 7.67 – 7.62 (m, 6H), 6.77 (dd, J 1 = 8.88 Hz J 2 = 2.44 Hz (2H), 6.53 (d, J = 8.76 Hz, 2H), 5.01 (d, J = 14.6 Hz, 2H), 2.83 (s, 6H), proving that the target product was synthesized.

[0043] Figure 2 The product shown is 13 From the C NMR (101 MHz, DMSO) spectrum, it can be seen that: δ The values ​​150.488, 150.455, 135.43, 135.40, 134.57, 134.48, 131.97, 131.92, 130.56, 130.44, 119.11, 118.26, 113.76, 113.67, 112.58, 112.55, 28.38, and 27.93 correspond to the carbon positions in the compound's structure, indicating the synthesis of the compound.

[0044] Figure 9Figure A shows the HPLC spectrum of the obtained product. The graph shows only one signal peak, indicating the purity of the compound. S3. Weigh the guest compound from step S2 (…). The mass is 3 mg, and it is placed in a clean, dry container.

[0045] S4. Measure the main body in step S1 ( Dissolve the sample weighed in step S3 in 3 mL of solution with a doping ratio of 1% by mass, disperse it uniformly by ultrasonication, and obtain a thin film material with photostimulation response after the solvent has completely evaporated.

[0046] Example 2 S1, main molecule ( Preparation of polyvinyl alcohol (PVA) solution: Weigh 6 g of PVA and place it in a dry and clean 250 mL round-bottom flask. Add 60 mL of ultrapure water and stir slowly at 120 rpm for 2 h at room temperature. Then stir at 95 °C for 2 h. After the sample is completely dissolved, a uniform 100 mg / mL colorless and transparent solution is obtained.

[0047] S2, Guest molecule (III)PPh3 + -TPA synthesis: , 4-Diphenylaminobenzaldehyde (2.73 g, 10 mmol) and sodium borohydride (0.57 g, 15 mmol) were dissolved in 30 mL of methanol and 90 mL of dichloromethane and stirred at 30 °C for 2 h under nitrogen protection. The mixture was then extracted with ethyl acetate, and the organic solvent was removed by rotary evaporation. The resulting product was purified by silica gel column chromatography (eluent: dichloromethane) and recrystallized to obtain 4-diphenylaminobenzyl alcohol (2.23 g, 81%). Subsequently, 4-diphenylaminobenzyl alcohol (2.21 g, 7.7 mmol) and triphenylphosphine hydrobromide (2.4 g, 7 mmol) were dissolved in 45 mL of chloroform and refluxed at 65 °C for 2 h. After removing chloroform by rotary evaporation, the crude product was purified by silica gel column chromatography (eluent: methanol: dichloromethane = 1:20), and recrystallized to give a white solid (3.73 g, 88.7%).

[0048] Figure 3 The product shown is 1 From the H NMR (400 MHz, DMSO) spectrum, it can be seen that: δ 7.92 – 7.88(m, 3H), 7.78 – 7.67 (m, 12H), 7.33 – 7.29 (m, 4H), 7.0 (t,J = 7.38 Hz, 2H), 6.96 (d, J = 7.52 Hz, 4H), 6.85 (dd, J 1 = 8.72 Hz J 2 = 2.4 Hz, 2H), 6.76 (d, J =8.36 Hz, 2H), 5.10 (d, J = 15 Hz, 2H), proving that the target product was synthesized.

[0049] Figure 4 The product shown is 13 From the C NMR (100 MHz, DMSO) spectrum, it can be seen that: δ The values ​​147.84, 147.80, 147.24, 135.54, 135.51, 134.58, 134.49, 132.32, 132.27, 130.62, 130.50, 130.09, 124.59, 123.88, 123.44, 123.40, 121.65, 121.56, 118.82, 117.97, 28.24, and 27.78 correspond to the carbon positions of the compound, indicating its successful synthesis.

[0050] Figure 9 Figure B shows the HPLC spectrum of the obtained product. As can be seen from the figure, there is only one signal peak, indicating the purity of the compound.

[0051] S3. Weigh 3 mg of the object (III) from step S2 and place it in a clean, dry container.

[0052] S4. Measure the main body in step S1 ( Dissolve the sample weighed in step S3 in 3 mL of solution with a doping ratio of 1% by mass, disperse it uniformly by ultrasonication, and obtain a thin film material with photostimulation response after the solvent has completely evaporated.

[0053] Example 3 S1, main molecule ( Preparation of polyvinyl alcohol (PVA) solution: Weigh 6 g of PVA and place it in a dry and clean 250 mL round-bottom flask. Add 60 mL of ultrapure water and stir slowly at 120 rpm for 2 h at room temperature. Then stir at 95 °C for 2 h. After the sample is completely dissolved, a uniform 100 mg / mL colorless and transparent solution is obtained.

[0054] S2, Guest molecule (IV) PPh3+ -PhOMe synthesis: , Triphenylphosphine hydrobromide (3.43 g, 10 mmol) and p-methoxybenzyl alcohol (1.38 g, 10 mmol) were dissolved in dry acetonitrile and stirred at 80 °C for 3 h under nitrogen protection. After removing acetonitrile by rotary evaporation, the crude product was purified by silica gel column chromatography (eluent: methanol: dichloromethane = 1:30), and recrystallized to give a white solid (IV) (4.41 g, 95.2%).

[0055] Figure 5 The product is shown. 1 From the H NMR (400 MHz, DMSO) spectrum, it can be seen that: δ 7.91 (t, J = 7.16Hz, 3H), 7.7 (td, J 1 = 7.84 Hz J 2 = 3.48 Hz, 6H), 7.66 (dd, J 1 = 7.76 Hz J 2 = 4.56Hz, 6H), 6.88 (dd, J 1 = 8.64 Hz J 2 = 2.16 Hz (2H), 6.79 (d, J = 8.56 Hz, 2H), 5.10(d, J = 15.08 Hz, 2H), 3.69 (s, 3H), proving that the target product was synthesized.

[0056] Figure 6 The product is shown. 13 The C NMR (100 MHz, DMSO) spectrum shows that... δ The values ​​159.66, 159.62, 135.55, 135.52, 134.57, 134.47, 132.51, 132.44, 130.63, 130.51, 119.60, 119.50, 118.81, 117.98, 114.78, 114.75, 55.63, 28.16, and 27.70 correspond to the carbon positions of the compound, indicating its successful synthesis.

[0057] Figure 9 Figure C shows the HPLC spectrum of the obtained product. As can be seen from the figure, there is only one signal peak, indicating the purity of the compound.

[0058] S3. Weigh 3 mg of the object (IV) from step S1 and place it in a clean, dry container.

[0059] S4, measure the main body in step S1 ( Dissolve the sample weighed in step S3 in 3 mL of solution with a doping ratio of 1% by mass, disperse it uniformly by ultrasonication, and obtain a thin film material with photostimulation response after the solvent has completely evaporated.

[0060] Example 4 S1, main molecule ( Preparation of polyvinyl alcohol (PVA) solution: Weigh 6 g of PVA and place it in a dry and clean 250 mL round-bottom flask. Add 60 mL of ultrapure water and stir slowly at 120 rpm for 2 h at room temperature. Then stir at 95 °C for 2 h. After the sample is completely dissolved, a uniform 100 mg / mL colorless and transparent solution is obtained.

[0061] S2, Guest molecule (V) PPh3 + Synthesis of -C3NMe2: , Triphenylphosphine (3.93 g, 15 mmol) and 1,3-dibromopropane (6.06 g, 30 mmol) were added to 60 mL of toluene and stirred at 120 °C for 12 h under nitrogen protection. After removing the toluene by rotary evaporation, the crude product was purified by silica gel column chromatography (eluent: methanol: dichloromethane = 1:20), and recrystallized to obtain a white solid PPh3. + -C3Br (2.35 g, 42.3%).

[0062] PPH3 + -C3Br (1.11 g, 3 mmol) was added to 2 mL of methanol solution, followed by 4 mL of dimethylamine aqueous solution. The mixture was stirred at room temperature for 1 h, then transferred to 80 °C and stirred for 18 h. After removing methanol by rotary evaporation, the crude product was purified by silica gel column chromatography (eluent: methanol: dichloromethane = 1:20). Recrystallization yielded a white solid (1.14 g, 91.8%).

[0063] Figure 7 The product is shown. 1 The H NMR (400 MHz, DMSO) spectrum shows that: δ 9.81 (s, 1H), 7.92 (td, J 1 = 9.08 Hz J2= ​​1.84 Hz, 3H), 7.87 – 7.76 (m, 13H), 3.81 – 3.73 (m,2H), 3.28 (t, J = 7.44 Hz (2H), 2.75 (s, 6H), proving the successful synthesis of the target product.

[0064] Figure 8 The product is shown. 13 The C NMR (101 MHz, DMSO) spectrum shows that... δ The values ​​135.60, 135.57, 134.23, 134.13, 130.88, 130.76, 118.88, 118.02, 56.80, 56.59, 19.02, 18.49, 17.84, and 17.82 correspond to the carbon positions of the compound, indicating its successful synthesis.

[0065] Figure 9 Figure D shows the HPLC spectrum of the obtained product. As can be seen from the figure, there is only one signal peak, indicating the purity of the compound.

[0066] S3. Weigh 3 mg of the object (V) from step S2 and place it in a clean, dry container.

[0067] S4. Measure the main body in step S1 ( Dissolve the sample weighed in step S3 in 3 mL of solution with a doping ratio of 1% by mass, disperse it uniformly by ultrasonication, and obtain a thin film material with photostimulation response after the solvent has completely evaporated.

[0068] Example 5 S1. The thin film material in Example 1, after brief excitation by a 310 nm UV lamp, exhibits bluish-green fluorescence emission, and after the UV lamp is turned off, it emits a weak green afterglow; after continuous activation by a 254 nm UV lamp for 5 minutes, followed by brief excitation by a 310 nm UV lamp, it exhibits bluish-green fluorescence emission, and after the UV lamp is turned off, it emits a strong and persistent bluish-green afterglow; while after continuous activation by a 365 nm UV lamp for 5 minutes, followed by brief excitation by a 310 nm UV lamp, it exhibits deep blue fluorescence emission, and after the UV lamp is turned off, it emits a strong and persistent light blue afterglow. Figure 10 As shown.

[0069] S2, The phosphorescence spectra of the thin film material in Example 1 before and after activation are as follows: Figure 11 As shown, phosphorescence emission is enhanced after continuous ultraviolet light irradiation.

[0070] S3, The phosphorescence decay curves of the thin film material in Example 1 before and after photoactivation are as follows: Figure 12As shown, phosphorescence lifetime increases after continuous irradiation with 245 nm and 365 nm ultraviolet lamps.

[0071] Example 6 S1. The thin film material in Example 2, after brief excitation by a 310 nm UV lamp, emits blue fluorescence, and after the UV lamp is turned off, it emits a weak green afterglow. After continuous activation by a 254 nm UV lamp for 5 minutes, followed by brief excitation by a 310 nm UV lamp, the fluorescence color does not change, but after the UV lamp is turned off, it emits a strong and persistent green afterglow. After continuous activation by a 365 nm UV lamp for 5 minutes, followed by brief excitation by a 310 nm UV lamp, it emits deep blue fluorescence, and after the UV lamp is turned off, it emits a strong and persistent green afterglow, accompanied by a weak blue afterglow. Figure 13 As shown.

[0072] S2, The phosphorescence spectra of the thin film material before and after activation in Example 2 are as follows: Figure 14 As shown, phosphorescence emission is enhanced after continuous ultraviolet light irradiation.

[0073] S3, The phosphorescence decay curves of the thin film material in Example 2 before and after photoactivation are as follows: Figure 15 As shown, phosphorescence lifetime increases after continuous irradiation with 245 nm and 365 nm ultraviolet lamps.

[0074] Example 7 S1. The thin film material in Example 3 emits weak blue fluorescence after brief excitation by a 310 nm UV lamp, and emits a green afterglow after the UV lamp is turned off. After continuous activation by a 254 nm UV lamp for 5 minutes, followed by brief excitation by a 310 nm UV lamp, the fluorescence emission is enhanced, but the afterglow intensity increases after the UV lamp is turned off. However, after continuous activation by a 365 nm UV lamp for 5 minutes, followed by brief excitation by a 310 nm UV lamp, the afterglow intensity only changes slightly. Figure 16 As shown.

[0075] S2, Phosphorescence spectra of the thin film material before and after activation in Example 3 are as follows: Figure 17 As shown, phosphorescence emission is enhanced after continuous ultraviolet light irradiation.

[0076] S3, The phosphorescence decay curves of the thin film material in Example 3 before and after photoactivation are as follows: Figure 18 As shown, phosphorescence lifetime increases after continuous irradiation with 245 nm and 365 nm ultraviolet lamps.

[0077] Example 8 S1. The thin film material in Example 4 emits weak blue fluorescence after brief excitation by a 310 nm UV lamp, and emits a weak green afterglow after the UV lamp is turned off. After continuous activation by a 254 nm UV lamp for 5 minutes, followed by brief excitation by a 310 nm UV lamp, fluorescence emission is enhanced, but the green afterglow intensity increases after the UV lamp is turned off. However, after continuous activation by a 365 nm UV lamp for 5 minutes, followed by brief excitation by a 310 nm UV lamp, the afterglow color redshifts and the intensity increases significantly. Figure 19 As shown.

[0078] S2, Phosphorescence spectra of the thin film material before and after activation in Example 3 are as follows: Figure 20 As shown, phosphorescence emission is enhanced after continuous ultraviolet light irradiation.

[0079] S3, The phosphorescence decay curves of the thin film material in Example 3 before and after photoactivation are as follows: Figure 21 As shown, phosphorescence lifetime increases after continuous irradiation with 245 nm and 365 nm ultraviolet lamps.

[0080] Example 9 S1. Place the thin film material from Example 1 under the mask and irradiate it with ultraviolet light to imprint the pattern information.

[0081] S2. Next, observe the pattern information in the thin film. For example... Figure 22 As shown, a short exposure to ultraviolet light can clearly reveal a light green rhomboid pattern; after 5 minutes of exposure to 365 nm ultraviolet light, a dark blue "grass leaf" pattern can be clearly observed; after 5 minutes of exposure to 254 nm ultraviolet light, a dark green "grass stem" pattern and a "four-leaf clover" pattern with dark blue "grass leaves" and dark green "grass stems" can be clearly observed.

[0082] Example 10 S1. The thin film materials from Examples 1-4 were subjected to a 365 nm ultraviolet lamp (210 mW·cm⁻¹). -2 Irradiate vertically at a distance of 3 cm for 15 min.

[0083] S2. Record the surface temperature changes of the sample using a FLUKE TIS60+ infrared thermal imaging camera. Set the recording frequency in segments during the kinetic heating process: record once every 5 seconds for the first 2 minutes, once every 10 seconds for the 2-5 minutes, and once every 30 seconds for the 5-15 minutes.

[0084] S3, such as Figure 23 As shown, a photothermal heating curve is plotted based on time-temperature data, and the maximum equilibrium temperature is calculated.

[0085] Example 11 S1. Staphylococcus aureus and Escherichia coli were selected as the model strains for Gram-positive and Gram-negative bacteria, respectively. After thawing the frozen strains, they were inoculated into Luria-Bertani (LB) medium and cultured in a constant temperature shaking incubator at 37 ℃ for 15 h until the stationary phase.

[0086] S2. The concentration of the original bacterial culture was determined using the plate count method. The bacterial culture, incubated for 15 h, was serially diluted 10-fold, with 100 µL of each diluted culture evenly spread onto LB agar plates and incubated overnight at 37 ℃. Colony growth in the LB medium at different dilutions was observed. After seven dilutions, the colony count was determined to be in the single digits. Based on this, the original bacterial concentration was calculated to be 1 × 10⁻⁶. 8 CFU·mL - ¹. The bacterial culture was concentrated 10 times to obtain a final concentration of 1×10⁻⁶. 9 CFU·mL - ¹A bacterial suspension is prepared for use.

[0087] S3. Add 10 µL of the bacterial suspension from Examples 1 and 2 to the surface of the membrane, and cover it with another identical membrane to form a "sandwich" structure, ensuring full contact between the bacterial suspension and the membrane. After 1 hour of contact, transfer the membrane and bacterial suspension to a centrifuge tube containing 990 µL of PBS, and vortex to fully elute the bacteria. After appropriate dilution of the eluent, inoculate 10 µL onto an LB agar plate using the drop plate method or the spread plate method, and incubate at 37°C. o Incubate at C for 12-16 hours, take photos and count the number of colonies, and calculate the antibacterial rate according to the formula.

[0088] S4, such as Figure 24 As shown, the film materials in Examples 1 and 2 exhibit good antibacterial properties against both Escherichia coli and Staphylococcus aureus.

[0089] This invention utilizes four triphenylphosphine derivative molecules doped into a PVA film, and achieves a long-afterglow material with dual-wavelength stimulus-responsive film by controlling intramolecular charge transfer through the DA structure. The guest small molecule synthesis involves fewer steps, milder reaction conditions, and a simple and readily available preparation method, which is beneficial for the development and application of single-component dual-wavelength stimulus-responsive materials.

[0090] The above specific embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A long afterglow thin-film material with dual-wavelength stimulus response, characterized in that, DA structure regulates intramolecular charge transfer. The thin film long afterglow material is a host-guest doped type, wherein the host is polyvinyl alcohol and the guest is a DA-type triphenylphosphine derivative.

2. The long afterglow thin film material with dual-wavelength stimulus response achieved by regulating intramolecular charge transfer using the DA structure according to claim 1, characterized in that, The DA-type triphenylphosphine derivative is PPh3. + -PhNMe2, PPh3 + -TPA, PPH3 + -PhOMe and PPH3 + Any one of -C3NMe2, with the specific structure shown below: 。 3. The long afterglow thin film material with dual-wavelength stimulus response achieved by regulating intramolecular charge transfer according to claim 1, characterized in that, The synthetic route for the guest molecule is as follows: A. The PPh3 + The preparation method of -PhNMe2 includes the following steps: A1. Under a protective atmosphere, dimethylaminobenzaldehyde is reduced to 4-(dimethylamino)benzyl alcohol using a reducing agent. A2. Under a protective atmosphere, 4-(dimethylamino)benzyl alcohol and triphenylphosphine hydrobromide were refluxed at 60-70°C in a solvent atmosphere according to the stoichiometric ratio. After the reaction was completed, the PPh3 was purified to obtain the PPh3. + -PhNMe2; B. The PPh3 + The preparation method of TPA includes the following steps: B1. Under a protective atmosphere, 4-diphenylaminobenzaldehyde is reduced to 4-diphenylaminobenzyl alcohol using a reducing agent; B2. Under a protective atmosphere, 4-diphenylaminobenzyl alcohol and triphenylphosphine hydrobromide were refluxed at 60-70°C in a solvent atmosphere according to the stoichiometric ratio. After the reaction was completed, the mixture was purified to obtain PPh3. + -TPA; C. The PPh3 + The preparation method of -PhOMe includes the following steps: Under a protective atmosphere, triphenylphosphine hydrobromide and p-methoxybenzyl alcohol were reacted in a solvent atmosphere at 75-85°C according to the stoichiometric ratio. After the reaction was completed, the mixture was purified to obtain PPh3. + -PhOMe; D. The PPh3 + The preparation method of -C3NMe2 includes the following steps: D1. Prepare PPh3 by reacting triphenylphosphine with 1,3-dibromopropane in a solvent atmosphere at 100-120°C according to the stoichiometric ratio. + -C3Br; D2, PPH3 + -C3Br and dimethylamine were mixed uniformly in a solvent atmosphere according to the stoichiometric ratio, and then reacted at 75-85℃. After the reaction was completed, the mixture was purified to obtain PPh3. + -C3NMe2.

4. The long afterglow thin film material with dual-wavelength stimulus response achieved by regulating intramolecular charge transfer according to claim 1, characterized in that, The doping mass fraction of the guest in the host is 1%-5%.

5. The long afterglow thin film material with dual-wavelength stimulus response achieved by regulating intramolecular charge transfer according to any one of claims 1-4, characterized in that, The excitation wavelength range of the thin-film long afterglow material is 254-365nm.

6. A method for preparing a long afterglow thin film material with dual-wavelength stimulus response achieved by regulating intramolecular charge transfer according to any one of claims 1-5, characterized in that, The process includes the following steps: mixing the subject and object in a solvent atmosphere and then preparing a thin film long afterglow material with dual-wavelength stimulus response by solution evaporation.

7. The preparation method according to claim 6, characterized in that, Includes the following steps: S1. Weigh the main polyvinyl alcohol and add it to the solvent until completely dissolved to prepare the main solution; S2, Weigh the object PPh3 + -PhNMe2, PPh3 + -TPA, PPh3 + -PhOMe or PPH3 + -C3NMe2 is dissolved in the main solution in step S1, mixed evenly, and after the solvent has completely evaporated, a thin film long afterglow material with dual-wavelength stimulus response is obtained.

8. The preparation method according to claim 6 or 7, characterized in that, The solvent is water or methanol.

9. The application of a long-afterglow thin film material with DA structure-regulated intramolecular charge transfer to achieve dual-wavelength stimulus response, as described in any one of claims 1-5, or a long-afterglow thin film material with DA structure-regulated intramolecular charge transfer to achieve dual-wavelength stimulus response, prepared by the preparation method described in any one of claims 6-8, characterized in that, It can be applied to the field of anti-counterfeiting.

10. The application of a long-afterglow thin film material with DA structure-regulated intramolecular charge transfer to achieve dual-wavelength stimulus response as described in any one of claims 1-5, or a long-afterglow thin film material with DA structure-regulated intramolecular charge transfer to achieve dual-wavelength stimulus response as described in any one of claims 6-8, characterized in that, It is applied in the field of antibacterial dressings.

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