DASA compound as well as preparation method and application thereof

Abstract

The invention relates to the technical field of photochromic materials, in particular to a DASA compound as well as a preparation method and application thereof. According to the DASA compound provided by the invention, two different chromophores are introduced into the compound and the electronic decoupling degree between the chromophores is regulated and controlled, so that each chromophore not only exerts an inherent light-induced switching function, but also realizes multi-wavelength regulation and multi-color change of a single-component material by virtue of a synergistic effect and response difference; meanwhile, the compound has good matrix compatibility, can stably adapt to a liquid-state matrix system and a solid-state matrix system, and synchronously has a multi-path multi-color visible light response characteristic and a rapid photochromic rate. The above comprehensive performance advantages form cooperative complementation, a key support is provided for practical application in the fields of information storage, encryption anti-counterfeiting materials and the like, and a wide technical application prospect is shown.

Description

Technical Field

[0001] This application relates to the field of photochromic materials technology, and in particular to a class of DASA compounds and their preparation methods and applications. Background Technology

[0002] Donor-acceptor Steinhaus adducts (DASAs) are a promising new class of visible-light photochromic materials. Since their initial report by Alaniz et al. in 2014, they have attracted widespread attention in various technological fields, including optical switches, information storage, and biomedicine. These compounds possess many unique advantages: they not only effectively absorb visible light but also exhibit rare negative photochromic response characteristics, while also possessing high structural modularity, excellent fatigue resistance, and simple synthesis routes. These advantages endow DASA materials with broad application prospects and provide a valuable solution to overcome the application limitations of other existing photochromic materials in the visible / near-infrared window. Despite their significant advantages, traditional DASA compounds still face key technological bottlenecks: their photochromic behavior can usually only be modulated by a single wavelength of light, achieving the interconversion between colored and colorless states, and the color change is mostly limited to a single hue. Although researchers have attempted to directly mix various traditional DASA materials with different structures to construct multi-component systems and achieve multimodal switching between two or more states, how to overcome the limitations of traditional two-state transitions and develop multi-response single-component DASA systems remains a major challenge that needs to be addressed in this field.

[0003] To address this challenge, Ran et al. (Ran Q, Zhang Y, Fang L, et al. Asymmetric Bis‐Dipolar Chromophore Design Enables Multi‐Route Multi‐Color Photochromism and Solid‐State Thermochromism[J]. Advanced Optical Materials, 2025, 13(31):e02448) proposed an innovative design approach using asymmetric bipolar chromophores, successfully synthesizing a novel bistimulated DASA molecule. This molecule exhibits excellent multi-path, multi-color visible light photochromic properties in a liquid matrix, and also achieves thermochromic response in the solid state, providing a new direction for the multi-state control of single-component DASA materials. However, this novel molecule still has significant drawbacks: when applied to a solid matrix, it almost cannot achieve color change under illumination, and the photoresponse effect is essentially lost. This directly limits the promotion and application of this molecule in key fields with stringent requirements for matrix compatibility and responsiveness, such as information storage and encryption anti-counterfeiting materials, optoelectronics and sensor devices.

[0004] Therefore, there is an urgent need to develop a novel DASA compound that can be adapted to both liquid and solid matrices and has the ability to achieve multi-channel and multi-color visible light response characteristics, so as to promote the practical application of related technologies. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects and shortcomings of existing multi-channel and multi-color visible light responsive DASA compounds, which are difficult to maintain high visible light response activity in both liquid and solid matrix environments, and to provide a class of DASA compounds.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned DASA compound.

[0007] Another object of the present invention is to provide the application of the above-mentioned DASA compound in the preparation of photochromic materials.

[0008] Another object of the present invention is to provide a photochromic material.

[0009] Another object of the present invention is to provide the application of the above-mentioned DASA compound or the above-mentioned photochromic material in the preparation of smart display materials, information storage and encryption anti-counterfeiting materials, optoelectronic and sensor devices, or any one or more of these.

[0010] The above-mentioned objective of this invention is achieved through the following technical solution:

[0011] This invention protects a class of DASA compounds, the structural formula of which is: ; Wherein, k = 1, 2, 3 or 4; The , It can be any one of the following distinct structures: .

[0012] This invention provides a class of DASA compounds that, by introducing two different chromophores and controlling the degree of electronic decoupling between them, enable each chromophore to not only perform its inherent photochromic switching function but also achieve multi-wavelength regulated multicolor changes in a single-component material through synergistic effects and response differences. Simultaneously, these compounds exhibit good matrix compatibility, stably adapting to both liquid and solid matrix systems, and simultaneously possess multi-path, multicolor visible light response characteristics and a rapid photochromic rate. These comprehensive performance advantages form a synergistic complement, providing crucial support for their practical applications in information storage and encryption / anti-counterfeiting materials, demonstrating broad technological application prospects.

[0013] Furthermore, the structural formula of the DASA compound is as follows: ; Among them, the , It can be any one of the following distinct structures: .

[0014] Furthermore, the DASA compound has any of the following structural formulas: , , .

[0015] Preferably, the structural formula of the DASA compound is: .

[0016] This invention protects a method for preparing the above-mentioned DASA compound, comprising the following steps: S1. The donor molecule undergoes tert-butyloxycarbonylation, methylation and detert-butyloxycarbonylation reactions in the presence of a tert-butyloxycarbonylating agent, a methylating agent and a detert-butyloxycarbonylating agent, respectively, to obtain intermediate product 1. ; S2. The intermediate product 1 obtained in step S1 is reacted with a tert-butyloxycarbonylating agent to undergo a tert-butyloxycarbonylation reaction to obtain intermediate product 2; ; S3. Mix the intermediate product 2 obtained in step S2, the acceptor molecule and the organic solvent, and react thoroughly to obtain intermediate product 3; ; S4. The intermediate product 3 obtained in step S3 is subjected to a detert-butyloxycarbonylation reaction with a detert-butyloxycarbonylating agent to obtain intermediate product 4. ; S5. Mix the intermediate product 4 obtained in step S4, the acceptor molecule and the organic solvent, and react thoroughly to obtain the DASA compound; ; The definitions of k, R1, and R2 are consistent with those described above; The receptor molecule can be any two of the following structures: .

[0017] Further, step S1 specifically includes the following steps: the donor molecule is subjected to tert-butyloxycarbonylation with a tert-butyloxycarbonylating agent to obtain precursor 1; the obtained precursor 1 is subjected to methylation reaction with a methylating agent to obtain precursor 2; the obtained precursor 2 is subjected to detert-butyloxycarbonylation reaction with a detert-butyloxycarbonylating agent, followed by post-treatment to obtain intermediate product 1.

[0018] Furthermore, the tert-butyloxycarbonylating agent includes one or more of ditert-butyl dicarbonate, tert-butyl chloroformate, and 2-(tert-butyloxyformyloxyimino)-2-phenylacetonitrile.

[0019] Furthermore, in step S1, the molar ratio of the donor molecule to the tert-butyloxycarbonylating agent is 1:(2~6).

[0020] Preferably, in step S1, the molar ratio of the donor molecule to the tert-butyloxycarbonylating agent is 1:(3~5).

[0021] Furthermore, the organic solvent 1 used in the tert-butoxycarbonylation reaction includes one or more of methanol, tetrahydrofuran, and dichloromethane.

[0022] Furthermore, the mass-to-volume ratio of the donor molecule to the organic solvent 1 is 1 g: (10~30) mL.

[0023] Preferably, the mass-to-volume ratio of the donor molecule to the organic solvent 1 is 1 g: (15~25) mL.

[0024] Furthermore, in step S1, the temperature of the tert-butoxycarbonylation reaction is room temperature.

[0025] Furthermore, in step S1, the tert-butyloxycarbonylation reaction takes 2-4 hours.

[0026] Furthermore, in step S1, the tert-butoxycarbonylation reaction also includes a post-processing step.

[0027] Furthermore, the post-treatment of the tert-butoxycarbonylation reaction includes solvent removal, washing, and drying.

[0028] Furthermore, the solvent removal is performed by rotary evaporation, retaining the concentrate.

[0029] Furthermore, the washing involves washing the resulting concentrate with n-hexane.

[0030] Furthermore, the drying process involves drying the washed concentrate.

[0031] Furthermore, the methylation reaction is carried out in the presence of a base. The base can abstract an active hydrogen from the substrate to generate a highly reactive anionic intermediate, thereby promoting the smooth progress of the methylation reaction.

[0032] Furthermore, the base includes one or more of sodium tert-butoxide, sodium hydride, and triethylamine.

[0033] Preferably, the base is sodium tert-butoxide. Sodium tert-butoxide is a non-nucleophilic strong base, and its large steric hindrance effectively suppresses side reactions with the methylating agent, thereby enabling it to selectively abstract active hydrogen from the substrate and promote the formation of the target methylated product.

[0034] Furthermore, the molar ratio of the base to the methylating agent is 1:(1~1.5).

[0035] Furthermore, the methylating agent includes halomethanes and / or methyl esters.

[0036] Furthermore, the halomethane includes potassium iodide and / or potassium bromide.

[0037] Furthermore, the methyl ester compounds include one or more of dimethyl sulfate, methyl toluenesulfonate, and dimethyl carbonate.

[0038] Preferably, the methylating agent is potassium iodide.

[0039] Furthermore, the molar ratio of the donor molecule to the methylating agent is 1:(3.5~5).

[0040] Preferably, the molar ratio of the donor molecule to the methylating agent is 1:(4~4.4).

[0041] Furthermore, the organic solvent 2 used in the methylation reaction includes one or more of tetrahydrofuran, dichloromethane, and methanol.

[0042] Furthermore, the mass-to-volume ratio of the donor molecule to the organic solvent 2 is 1 g: (10~30) mL.

[0043] Preferably, the mass-to-volume ratio of the donor molecule to the organic solvent 2 is 1 g: (15~25) mL.

[0044] Furthermore, the methylation reaction is performed at room temperature.

[0045] Furthermore, the methylation reaction takes 2 to 4 hours.

[0046] Furthermore, the methylation reaction also includes a post-processing step.

[0047] Furthermore, the post-treatment of the methylation reaction includes solvent removal.

[0048] Preferably, the solvent removal is performed by rotary evaporation.

[0049] Furthermore, the detert-butoxycarbonylating agent includes one or more of zinc bromide, trifluoroacetic acid, and titanium tetrachloride.

[0050] Furthermore, the molar ratio of the donor molecule to the detert-butyloxycarbonylating agent is 1:(5~7).

[0051] Furthermore, the organic solvent 3 used in the detert-butyloxycarbonylation reagent includes one or two of dichloromethane, chloroform, and tetrahydrofuran.

[0052] Furthermore, the mass-to-volume ratio of the donor molecule to the organic solvent 3 is 1 g: (10~30) mL.

[0053] Preferably, the mass-to-volume ratio of the donor molecule to the organic solvent 3 is 1 g: (15~25) mL.

[0054] Furthermore, the detert-butyloxycarbonylation reaction is performed at room temperature.

[0055] Furthermore, the time for the detert-butyloxycarbonylation reaction is 0.1 to 1 h.

[0056] Furthermore, the detert-butoxycarbonylation reaction also includes a post-treatment step.

[0057] Furthermore, the post-processing includes extraction and solvent removal.

[0058] Furthermore, the solvent system for extraction is a mixture of dichloromethane and water.

[0059] Preferably, the volume ratio of dichloromethane to water is 1:(0.05~0.5).

[0060] More preferably, the volume ratio of dichloromethane to water is 1:(0.1~0.3).

[0061] Furthermore, the solvent removal is achieved through rotary evaporation.

[0062] Furthermore, the molar ratio of intermediate product 1 to tert-butyloxycarbonylating agent is 1:(2~3).

[0063] Furthermore, in step S2, a catalyst is also used in the tert-butyloxycarbonylation reaction.

[0064] Furthermore, the catalyst comprises one or more of 4-dimethylaminopyridine, triethylamine, and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

[0065] Furthermore, the molar ratio of intermediate product 1 to catalyst is 1:(0.1~0.3).

[0066] Furthermore, the mass-to-volume ratio of the intermediate product 1 to the organic solvent 1 is 1 g: (10~30) mL.

[0067] Preferably, the mass-to-volume ratio of the intermediate product 1 to the organic solvent 1 is 1 g: (14~18) mL.

[0068] Furthermore, in step S2, the temperature of the tert-butyloxycarbonylation reaction is room temperature.

[0069] Furthermore, in step S2, the time for the tert-butoxycarbonylation reaction is 36-60 h.

[0070] Preferably, in step S2, the time for the tert-butyloxycarbonylation reaction is 45-50 h.

[0071] Furthermore, in step S2, the tert-butoxycarbonylation reaction also includes a post-processing step.

[0072] Furthermore, the post-processing includes column chromatography and drying.

[0073] Furthermore, the chromatographic column used in the column chromatography is a silica gel column.

[0074] Furthermore, the eluent for the column chromatography is a combination of petroleum ether and ethyl acetate.

[0075] Furthermore, the volume ratio of petroleum ether to ethyl acetate is 1:(0.05~0.2).

[0076] Preferably, the volume ratio of petroleum ether to ethyl acetate is 1:(0.08~0.12).

[0077] Furthermore, the molar ratio of the intermediate product 2 to the acceptor molecule is 1:(1~3).

[0078] Furthermore, in step S3, the organic solvent includes one or more of dichloromethane, tetrahydrofuran, and methanol.

[0079] Furthermore, the mass-to-volume ratio of the intermediate product 2 to the organic solvent is 1 g: (40~80) mL.

[0080] Preferably, in step S3, the reaction also uses a catalyst.

[0081] More preferably, the catalyst comprises one or more of 1,1,1,3,3,3-hexafluoro-2-propanol, trifluoroethanol, and perfluorotert-butanol.

[0082] Furthermore, the mass-to-volume ratio of the intermediate product 2 to the catalyst is 1 g: (8~12) mL.

[0083] Furthermore, in step S3, the reaction temperature is room temperature.

[0084] Furthermore, in step S3, the reaction time is 24-72 h.

[0085] Furthermore, in step S3, the reaction also includes a post-processing step.

[0086] Furthermore, the post-processing includes evaporation and concentration, dissolving and dispersing the concentrate, filtration, washing, and drying.

[0087] Furthermore, the solvent for dissolving and dispersing is a combination of tetrahydrofuran and n-hexane.

[0088] Preferably, the volume ratio of tetrahydrofuran to n-hexane is 1:(20~60).

[0089] More preferably, the volume ratio of tetrahydrofuran to n-hexane is 1:(35~45).

[0090] Furthermore, the solvent used for washing is a combination of tetrahydrofuran and n-hexane.

[0091] Preferably, the volume ratio of tetrahydrofuran to n-hexane is 1:(35~45).

[0092] Furthermore, the molar ratio of the intermediate product 3 to the detert-butyloxycarbonylating agent is 1:(10~30).

[0093] Furthermore, the molar ratio of the intermediate product 3 to the detert-butyloxycarbonylating agent is 1:(18~22).

[0094] Furthermore, the mass-to-volume ratio of the intermediate product 3 to the organic solvent 3 is 1 g: (40~60) mL.

[0095] Furthermore, in step S4, the temperature of the detert-butyloxycarbonylation reaction is -5 to 5 °C.

[0096] Furthermore, in step S4, the detert-butyloxycarbonylation reaction takes 4-6 days. Considering that the chemical bond stability of intermediate 3 is slightly weak, conventional detert-butyloxycarbonylation reaction conditions may damage its structure; therefore, milder conditions are chosen to complete this deprotection process.

[0097] Furthermore, in step S4, the detert-butoxycarbonylation reaction also includes a post-treatment step.

[0098] Furthermore, the post-processing includes extraction and solvent removal.

[0099] Furthermore, the solvent system for the extraction is a combination of water and dichloromethane.

[0100] Preferably, the volume ratio of dichloromethane to water is 1:(0.05~0.5).

[0101] More preferably, the volume ratio of dichloromethane to water is 1:(0.1~0.3).

[0102] Furthermore, the solvent removal is achieved through rotary evaporation.

[0103] Furthermore, the molar ratio of the intermediate product 4 to the acceptor molecule is 1:(4~6).

[0104] Preferably, in step S5, the reaction also uses a catalyst.

[0105] More preferably, the catalyst comprises one or more of 1,1,1,3,3,3-hexafluoro-2-propanol, trifluoroethanol, and perfluorotert-butanol.

[0106] Furthermore, the mass-to-volume ratio of the intermediate product 4 to the catalyst is 1 g: (4~8) mL.

[0107] Furthermore, in step S5, the organic solvent includes one or more of dichloromethane, tetrahydrofuran, and methanol.

[0108] Furthermore, the mass-to-volume ratio of the intermediate product 4 to the organic solvent is 1 g: (40~80) mL.

[0109] Furthermore, the mass-to-volume ratio of the intermediate product 4 to the organic solvent is 1 g: (50~70) mL.

[0110] Furthermore, in step S5, the reaction temperature is room temperature.

[0111] Furthermore, in step S5, the reaction time is 8 to 16 hours.

[0112] Furthermore, in step S5, the reaction also includes a post-processing step.

[0113] Furthermore, the post-processing includes evaporation and concentration, dissolving and dispersing the concentrate, filtration, washing, and drying.

[0114] Furthermore, the solvent for dissolving and dispersing is a combination of tetrahydrofuran and n-hexane.

[0115] Preferably, the volume ratio of tetrahydrofuran to n-hexane is 1:(40~60).

[0116] Furthermore, the solvent used for washing is a combination of tetrahydrofuran and n-hexane.

[0117] Preferably, the volume ratio of tetrahydrofuran to n-hexane is 1:(40~60).

[0118] This invention protects the application of the aforementioned DASA compound in the preparation of photochromic materials.

[0119] This invention protects a photochromic material, wherein the photochromic material comprises the aforementioned DASA compound.

[0120] Furthermore, the photochromic material also includes a matrix.

[0121] Furthermore, the matrix includes a solid matrix and / or a liquid matrix.

[0122] Preferably, the raw material of the solid matrix includes a polymer.

[0123] Furthermore, the polymer includes one or more of polyvinyl chloride (PVC), polyethylene oxide (PEO), and polyacrylonitrile (PAN).

[0124] Furthermore, the polymer is PVC.

[0125] Preferably, the liquid matrix includes one or more of chloroform solution, tetrahydrofuran solution, and ethanol solution.

[0126] More preferably, the liquid matrix is ​​a chloroform solution.

[0127] This invention protects the use of the aforementioned DASA compound or the aforementioned photochromic material in any one or more of the following: preparation of smart display materials, information storage and encryption anti-counterfeiting materials, optoelectronic and sensor devices.

[0128] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a class of DASA compounds that, by introducing two different chromophores and controlling the degree of electronic decoupling between them, enable each chromophore to not only perform its inherent photochromic switching function but also achieve multi-wavelength regulated multicolor changes in a single-component material through synergistic effects and response differences. Simultaneously, these compounds exhibit good matrix compatibility, stably adapting to both liquid and solid matrix systems, and simultaneously possess multi-path, multicolor visible light response characteristics and a rapid photochromic rate. These comprehensive performance advantages form a synergistic complement, providing crucial support for their practical applications in information storage and encryption / anti-counterfeiting materials, demonstrating broad technological application prospects. Attached Figure Description

[0129] Figure 1 This is a flowchart illustrating the preparation process of the DASA compound in Example 1.

[0130] Figure 2This is the UV-Vis absorption spectrum of the DASA compound in Example 1 during the multipath photochromic process in a solid matrix.

[0131] Figure 3 This is a schematic diagram of the multipath photochromic process of the DASA compound in a solid matrix in Example 1.

[0132] Figure 4 The images show the UV-Vis absorption spectra of the DASA compounds in Example 1 under different illuminations in a solid matrix. Figure a shows the UV-Vis spectrum of DASA1 under 550 nm irradiation; Figure b shows the UV-Vis spectrum of DASA1 under 550 nm irradiation followed by 630 nm irradiation; Figure c shows the UV-Vis spectrum of DASA1 under 630 nm irradiation; Figure d shows the UV-Vis spectrum of DASA1 under 630 nm irradiation followed by 550 nm irradiation; and Figure e shows the UV-Vis spectrum of DASA1 under white light irradiation.

[0133] Figure 5 The images show the UV-Vis absorption spectra of the DASA compounds in Comparative Example 1 in a solid matrix under different illuminations; Figure a shows the UV-Vis spectrum of DASA4 under 630 nm irradiation; Figure b shows the UV-Vis spectrum of DASA4 under 550 nm irradiation.

[0134] Figure 6 The image shows the UV-Vis absorption spectrum of the DASA compound in Comparative Example 2 in a solid matrix under white light irradiation.

[0135] Figure 7 This is the UV-Vis absorption spectrum of the DASA compound in Example 1 during the multipath photochromic process in a liquid matrix.

[0136] Figure 8 This is a schematic diagram of the multipath photochromic process of the DASA compound in a liquid matrix in Example 1.

[0137] Figure 9 The image shows the 1H NMR spectrum of the DASA compound in Example 1.

[0138] Figure 10 Figure a is a schematic diagram of the fabrication scheme of the multi-level optical storage device of DASA compound in Experiment Example 4; Figure b is a schematic diagram of the working principle scheme of the multi-level optical storage device; Figure c is a schematic diagram of the encoding of multi-level optical storage; Figure d is a schematic diagram of the encoding and decryption path of optical information in an optical storage device information recording and conversion scheme. Detailed Implementation

[0139] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0140] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0141] Figure 4 a represents Figure 4 Figure a in the middle, Figure 4 b represents Figure 4 The order of the other graphs follows the same pattern, starting with graph b.

[0142] Example 1: DASA compound and its preparation method A DASA compound, DASA1, has the following structural formula: ; The above-mentioned DASA compound DASA1 can be prepared by the following methods (e.g.) Figure 1 (as shown) S1. 4,4',4''-triaminotriphenylmethane (5.00 g, 17.29 mmol, 1.0 eq.), 100 mL methanol, and di-tert-butyl dicarbonate (15.1 g, 69.16 mmol, 4.0 eq.) were mixed and stirred for 3 h to obtain precursor 1. Precursor 1 was rotary evaporated, washed with n-hexane, and dried to obtain precursor 2. Precursor 2 was then dissolved in 100 mL tetrahydrofuran, and sodium tert-butoxide (6.65 g, 69.16 mmol, 4.0 eq.) was added and stirred at room temperature for 1 h. Then, iodomethane (10.31 g, 72.62 mmol, 4.2 eq.) was added and stirred for 3 h. After rotary evaporation, a white powder was obtained, which was then dissolved in 100 mL DCM and treated with trifluoroacetic acid (11.8 g, 103.74 mmol, 6.0 eq.) for 0.5 h. h, the treatment solution was extracted with dichloromethane-water (volume ratio 1:0.2), the organic phase was collected, and then the solvent in the organic phase was removed by rotary evaporation to obtain intermediate product 1 (4.85 g, yield 84.7%). S2. Intermediate 1 (3.0 g, 9.06 mmol, 1.0 eq.), 4-dimethylaminopyridine (221 mg, 1.81 mmol, 0.20 eq.), and 50 mL of tetrahydrofuran were mixed and dissolved. Then, di-tert-butyl dicarbonate (total 4.9 g, 22.65 mmol, 2.5 eq.) was added in two portions to obtain a mixture. The mixture was then stirred at room temperature for 48 hours. After the reaction, the mixture was subjected to silica gel column chromatography (elution buffer V). 石油醚 V 乙酸乙酯Purify (10:1), dry, and obtain intermediate 2 (1.8 g, yield 37.42%). S3. Intermediate product 2 (100 mg, 0.19 mmol, 1.0 eq.) and the acceptor molecule 4-(2-furanmethyl)-2,4-dihydro-2-phenyl-5-(trifluoromethyl)-3H-pyrazole-3-one (201 mg, 0.38 mmol, 2.0 eq.) were dissolved in 6 mL of dichloromethane, and then 1 mL of 1,1,1,3,3,3-hexafluoro-2-propanol was added. The mixture was stirred for 48 hours, and the solvent was removed by rotary evaporation. The remaining solid was dissolved in 5 mL of tetrahydrofuran and poured into 200 mL of n-hexane. The suspension was filtered, and the filtrate was removed by suction filtration. The residue was washed with a mixed solvent of tetrahydrofuran and n-hexane at a volume ratio of 1:40, and dried to obtain intermediate product 3 (122 mg, yield 76.72%). S4. Intermediate product 3 (100 mg, 0.12 mmol, 1.0 eq.) was dissolved in 5 mL of dichloromethane, and zinc bromide (500 mg, 2.41 mmol, 20.2 eq.) was added in portions. The mixture was stirred at 0 °C in the dark for 5 days. After monitoring by mass spectrometry to ensure the removal of all Boc groups, 20 mL of water was added to the flask, and the system was extracted with 100 mL of dichloromethane. The extraction was repeated 3 times, and the organic phase was collected. The solvent was then removed by rotary evaporation to obtain intermediate product 4 (47 mg, yield 61.39%). S5. Intermediate product 4 (100 mg, 0.16 mmol, 1.0 eq.), the acceptor molecule 5-(furan-2-methylene)-2,2-dimethyl-1,3-dioxane-4,6-dione (174 mg, 0.78 mmol, 5.0 eq.), and 0.6 mL of 1,1,1,3,3,3-hexafluoro-2-propanol were dissolved in 6 mL of dichloromethane. The mixture was stirred for 12 hours, and the solvent was removed by rotary evaporation. The remaining solid was dissolved in 5 mL of tetrahydrofuran and poured into 250 mL of n-hexane. The suspension was filtered, and the filtrate was removed by suction filtration. The residue was washed with a mixed solvent of tetrahydrofuran and n-hexane at a volume ratio of 1:50, and dried to obtain purple solid DASA1 (122 mg, yield 86.89%).

[0143] Example 2: DASA compound and its preparation method The structural formula of a DASA compound, DASA2, is shown below: ; The difference between the preparation method and Example 1 is that in step S5, the receptor molecule 5-(furan-2-methylene)-2,2-dimethyl-1,3-dioxane-4,6-dione is replaced with 5-(furan-2-methylene)-2,2-diethyl-1,3-dioxane-4,6-dione; DASA2 is thus prepared.

[0144] The other steps and conditions are the same as in Example 1.

[0145] Example 3: DASA compound and its preparation method The structural formula of a DASA compound, DASA3, is shown below: ; The preparation method differs from that in Example 1 in that, in step S3, the receptor molecule 4-(2-furanmethyl)-2,4-dihydro-2-phenyl-5-(trifluoromethyl)-3H-pyrazol-3-one is replaced with 5-(furan-2-methylene)-2,2-diethyl-1,3-dioxane-4,6-dione; and in step S5, the receptor molecule 5-(furan-2-methylene)-2,2-dimethyl-1,3-dioxane-4,6-dione is replaced with 4-(2-furanmethyl)-2,4-dihydro-2-phenyl-5-(trifluoromethyl)-3H-pyrazol-3-one; thus, DASA3 is prepared.

[0146] The other steps and conditions are the same as in Example 1.

[0147] Comparative Example 1: DASA Compounds and Their Preparation Methods The structural formula of a DASA compound, DASA4, is shown below: ; The above-mentioned DASA compound DASA4 was prepared according to Ran Q, Zhang Y, Fang L, et al. Asymmetric Bis‐Dipolar Chromophore Design Enables Multi‐Route Multi‐Color Photochromism and Solid‐State Thermochromism[J]. Advanced Optical Materials, 2025, 13(31):e02448. S1. In a 250 mL flask, 4,4'-diaminodiphenyl ether (3.0 g, 14.99 mmol, 1.0 eq.) was completely dissolved in 100 mL of methanol, followed by the addition of di-tert-butyl dicarbonate (10.00 g, 45.82 mmol, 3.06 eq.). The mixture was ultrasonically dispersed to ensure homogeneity. The mixture was stirred for 3 hours to prepare the intermediate (the reaction progress was monitored by thin-layer chromatography (TLC)). After the reaction was completed, the intermediate was rotary evaporated and washed thoroughly with n-hexane to obtain a white powder. The obtained intermediate was dissolved in 100 mL of tetrahydrofuran (THF), followed by the addition of sodium tert-butoxide (3.30 g, 31.22 mmol, 2.08 eq.) and methyl iodide (10.0 g, 70.45 mmol, 4.70 eq.). After stirring at room temperature for 12 hours, the mixture was filtered, and the solvent was removed by rotary evaporation to obtain a green powder. The green powder was dissolved in dichloromethane (DCM), and then treated with trifluoroacetic acid to finally obtain a yellow oily product D2 (3.12 g, yield 91.2%). S2. In a 100 mL flask, D2 (1.0 g, 4.38 mmol, 1.0 eq.) obtained in step S1 and 4-dimethylaminopyridine (100 mg, 0.819 mmol, 0.19 eq.) were completely dissolved in 40 mL of tetrahydrofuran (THF). The system was heated to reflux, and di-tert-butyl carbonate was continuously added. The reaction progress was monitored by thin-layer chromatography (TLC) and mass spectrometry until Boc-D2 was the major product in the system (this process usually does not exceed 24 hours). The system was then cooled to room temperature. The mixture was purified by silica gel column chromatography (eluent: petroleum ether PE: ethyl acetate EA = 5:1) to obtain a brown oily product Boc-D2 (521 mg, yield 36.27%). S3. In a 10 mL flask, the oily product Boc-D2 (100 mg, 0.30 mmol, 1.0 eq.) obtained in step S2, 4-(2-furanmethyl)-2,4-dihydro-2-phenyl-5-(trifluoromethyl)-3H-pyrazol-3-one (184 mg, 0.60 mmol, 2.0 eq.) and 4 mL of dichloromethane were mixed, and then 1 mL of 1,1,1,3,3,3-hexafluoro-2-propanol was added. The mixture was stirred in the dark for 24 h. The solvent was removed by rotary evaporation, and the remaining solid was dissolved in 2 mL of tetrahydrofuran. 250 mL of n-hexane was added, and the suspension was filtered. The filtrate was removed by suction filtration, and the residue was washed with a mixture of tetrahydrofuran and n-hexane (volume ratio 1:60) to obtain a blue solid. S4. Dissolve the blue solid obtained in step S3 completely in 2 mL of dichloromethane, and add zinc bromide (total amount about 500 mg, 2.22 mmol, 7.4 eq.) in portions. Stir in the dark for 24 h, and monitor by mass spectrometry to ensure the removal of all Boc groups. Then add 20 mL of water, extract the mixture with 100 mL of dichloromethane to remove the solvent, and obtain a blue powder. S5. The blue powder obtained in step S4 and 5-(furan-2-methylene)-2,2-diethyl-1,3-dioxane-4,6-dione (60 mg, 0.24 mmol, 0.8 eq.) were dissolved in 2 mL of dichloromethane, and then 0.5 mL of 1,1,1,3,3,3-hexafluoro-2-propanol were added. The mixture was stirred in the dark for 24 h. After removing the solvent, the remaining solid was dissolved in 1 mL of tetrahydrofuran and then poured into 250 mL of n-hexane. The suspension was filtered, and the residue was washed with a mixture of tetrahydrofuran and n-hexane (volume ratio 1:50) to obtain a dark blue solid DASA4 (72 mg, yield 30.61%).

[0148] Comparative Example 2: DASA Compounds and Their Preparation Methods The structural formula of a DASA compound, DASA5, is shown below: ; The preparation method differs from that in Example 1 in that: in step S1, 4,4',4''-triaminotriphenylmethane is replaced with N,N-bis(4-aminophenyl)-1,4-phenylenediamine; DASA5 is prepared. The structural difference between DASA5 and DASA1 in Example 1 is that the central atom of DASA1 is a carbon atom, while that of DASA5 is a nitrogen atom.

[0149] The other steps and conditions are the same as in Example 1.

[0150] Experimental Example 1: Physical Properties of DASA Compounds in Solid Matrix 1. Experimental Methods 1 g of PVC was dissolved in 20 mL of tetrahydrofuran solution to obtain a homogeneous and transparent polymer solution, which was then stirred at 60 °C. Subsequently, 1 mg of the DASA compounds obtained in Examples 1 and 1-2 were weighed and mixed with 1 mL of the polymer solution to prepare a PVC-DASA composite solution. 0.3 mL of the PVC-DASA composite solution was uniformly coated onto the surface of a 2.5 cm × 6.5 cm quartz sheet and allowed to air dry in the dark to obtain a uniform and smooth solid composite film. Characterization using a micrometer and electronic balance showed that the average thickness of the composite film remained at approximately 0.012 mm, and the average loading of DASA1 in the film was 4 wt%. Finally, the photochromic properties of the obtained polymer film were tested using UV-Vis absorption spectroscopy, and the changes in its absorption spectrum under different illumination conditions were recorded.

[0151] 2. Experimental Results The results are as follows Figures 2-6 As shown, the photochromic properties and spectral characteristics of DASA1 in Example 1 are as follows: Regarding spectral characteristics ( Figure 2 DASA1 exhibits a broad absorption spectrum in the visible light region, with two absorption peaks at 581 nm and 631 nm. It is speculated that the broad absorption band originates from the superposition of absorption bands from two chromophores involving different receptors within the molecule. Regarding photochromic response, DASA1 demonstrates efficient and controllable photochromic response under different wavelengths of light. Figure 3 Specifically: using 550 nm light (60 mW cm⁻¹) -2 After irradiating the sample for approximately 60 seconds, the ultraviolet-visible spectrum gradually red-shifted over time, and the color changed from indigo to blue. Figure 4 a); Based on this, after passing through 630 nm light (78.11 mW cm⁻¹) -2 When irradiated, the absorption spectral intensity continues to decrease, and the color further fades to colorless. Figure 4 b); If DASA1 is directly irradiated at 630 nm for about 80 s, its absorption spectrum gradually decreases over time, and its color changes from indigo blue to light purple. Figure 4 c), after being irradiated with a 550 nm laser, the spectrum red-shifts and the color fades to colorless. Figure 4 d); Notably, in white light (78.2 mW cm⁻¹) -2 Under direct irradiation, DASA1 changes from indigo blue to colorless in just 40 seconds. Figure 4 e); In contrast, the photochromic properties of the comparative samples all failed to meet the requirements: DASA4 in Comparative Example 1 at 630 nm ( Figure 5 a) or 550 nm ( Figure 5b) Under wavelength irradiation, the absorption spectral intensity decreased only slightly or remained almost unchanged, always maintaining a deep blue color, with no effective color change response; DASA5 in Comparative Example 2, under white light irradiation ( Figure 6 Although it can change from dark blue to colorless, it takes as long as 60 minutes, which is 90 times longer than that of Example 1. The response efficiency is extremely low and cannot meet the needs of rapid application.

[0152] The multipath photochromic capabilities of DASA2-3 in solid matrices in Examples 2-3 are basically the same as those in Example 1, and will not be repeated here.

[0153] Experimental Example 2: Physical Properties of DASA Compounds in Liquid Matrix 1. Experimental Methods Measure 20 mL of solution with a concentration of 1×10 -5 Using a chloroform solution of M as the liquid matrix, 1 mg of DASA1 obtained in Example 1 was added, and the mixture was magnetically stirred for 15 min until the DASA compound was completely dissolved, thus obtaining a homogeneous and transparent "DASA-chloroform" liquid composite system. After the system stabilized, the photochromic properties of the liquid composite system were tested using a UV-Vis absorption spectrometer: with pure 1×10 -5 M chloroform solution served as a blank control. The absorption spectrum changes of the system were continuously monitored and recorded under the same wavelength illumination conditions as in Experiment 1 to characterize the photochromic response characteristics of DASA in a liquid matrix.

[0154] 2. Experimental Results The results are as follows Figures 7-8 As shown, the visible light absorption peak of the DASA 1 chloroform solution is formed by the superposition of two central absorption peaks at 582 nm and 630 nm. Furthermore, under the same illumination conditions as in Example 1, DASA 1 exhibits different color-changing behaviors in solid and liquid matrices (chloroform solution). This difference is presumably related to the influence of the confined space in the solid matrix and the free environment in the liquid matrix on the asymmetric isomerism of the molecules. Specifically, the photochromic behavior of the chloroform solution system was analyzed: after irradiating the original DASA 1 chloroform solution with 550 nm light and then removing the light source, the solution color was observed to significantly change from the initial state to green. Based on this green state, further continuous irradiation with 630 nm light caused the solution color to gradually fade, eventually becoming colorless. This phenomenon directly proves that DASA 1 in Example 1 has good matrix adaptability and can achieve a stable visible light response in both liquid and solid matrices.

[0155] Example 3 Characterization of DASA compounds 1. Experimental Methods The DASA1 in Example 1 was analyzed by nuclear magnetic resonance spectroscopy.

[0156] 2. Experimental Results The results of the proton nuclear magnetic resonance spectrum are as follows Figure 9 As shown, the signal peak integral ratios corresponding to hydrogen atoms in different chemical environments perfectly match the theoretical number of various hydrogen atoms in the DASA1 molecular structure. This result verifies the correctness of the product structure at the hydrogen atom composition level, directly confirming the successful preparation of DASA1.

[0157] Experimental Example 4: Application of DASA Compounds in Multi-Level Optical Storage 1. Experimental Methods Figure 10 The core structure and working principle of multi-level optical storage devices are demonstrated: the device uses a 1.5cm × 1.5cm glass substrate, on which a 200 nm thick silver reflective layer is prepared by vacuum phase deposition. Then, the PVC-DASA composite solution prepared in Example 1 is coated onto the reflective layer by a blade coating method and allowed to air dry to form a 0.012 mm information recording layer with DASA 1 as the core. Figure 10 a). The working principle is divided into two parts: "information writing-reading" and "status encoding": when information is written ( Figure 10 b) Using light of a specific wavelength and intensity (550 nm, 60 mW) cm -2 630 nm, 55 mW cm -2 The recording layer is illuminated to regulate the photochromic state of DASA1. During information reading, a weaker laser is used as the detection source, utilizing the spectral differences between the "written" and "unwritten" states (580 nm peak corresponds to 550 nm illumination change, 631 nm peak corresponds to 630 nm illumination change) to achieve signal detection. Simultaneously, binary encoding rules are defined to distinguish four storage states: "11" for no illumination, "01" for 630 nm illumination only, "10" for 550 nm illumination only, and "00" for dual-wavelength illumination. Figure 10 c).

[0158] 2. Experimental Results To verify the practical application feasibility and information storage accuracy of this optical storage device, a 4×3 pixel matrix was constructed as the storage unit. Information was custom-written based on the ASCII binary encoding rules of computer characters: each row of the matrix was mapped one-to-one with a character. The first row of binary information "01000001" (corresponding to the binary value of the character "A" in ASCII encoding) corresponds to the character "A", the second row of binary data "01000010" corresponds to the character "B", and the third row of binary data "01000011" corresponds to the character "C". Therefore, the resulting information is "ABC". Figure 10d). The experimental results directly demonstrate that optical storage devices based on DASA1 can stably achieve accurate conversion and multi-level storage of "binary data to character information", fully verifying the application potential of DASA1 as a photochromic material in the field of optical storage devices.

[0159] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A class of DASA compounds, characterized in that, The structural formula of the DASA compound is: ； Wherein, k = 1, 2, 3 or 4; The , It can be any one of the following distinct structures: 。 2. The DASA compound according to claim 1, characterized in that, The structural formula of the DASA compound is: ； Among them, the , It can be any one of the following distinct structures: 。 3. The DASA compound according to claim 2, characterized in that, The DASA compound has any of the following structural formulas: 、 、 。 4. A method for preparing the DASA compound according to any one of claims 1 to 3, characterized in that, Includes the following steps: S1. The donor molecule undergoes tert-butyloxycarbonylation, methylation and detert-butyloxycarbonylation reactions in the presence of a tert-butyloxycarbonylating agent, a methylating agent and a detert-butyloxycarbonylating agent, respectively, to obtain intermediate product 1. ； S2. The intermediate product 1 obtained in step S1 is reacted with a tert-butyloxycarbonylating agent to undergo a tert-butyloxycarbonylation reaction to obtain intermediate product 2; ； S3. Mix the intermediate product 2 obtained in step S2, the acceptor molecule and the organic solvent, and react thoroughly to obtain intermediate product 3; ； S4. The intermediate product 3 obtained in step S3 is subjected to a detert-butyloxycarbonylation reaction with a detert-butyloxycarbonylating agent to obtain intermediate product 4. ； S5. Mix the intermediate product 4 obtained in step S4, the acceptor molecule and the organic solvent, and react thoroughly to obtain the DASA compound; ； Wherein, the definitions of k, R1, and R2 are consistent with those of any one of claims 1 to 3; The receptor molecule can be any two of the following structures: 。 5. The preparation method according to claim 4, characterized in that, The tert-butyloxycarbonylating agent includes one or more of ditert-butyl dicarbonate, tert-butyl chloroformate, and 2-(tert-butyloxyformyloxyimino)-2-phenylacetonitrile.

6. The preparation method according to claim 4, characterized in that, The methylating agents include halomethanes and / or methyl esters.

7. The preparation method according to claim 4, characterized in that, The detert-butoxycarbonylating agent includes one or more of zinc bromide, trifluoroacetic acid, and titanium tetrachloride.

8. The use of the DASA compound according to any one of claims 1 to 3 in the preparation of photochromic materials.

9. A photochromic material, characterized in that, The photochromic material includes the DASA compound according to any one of claims 1 to 3.

10. The use of the DASA compound of any one of claims 1 to 3 or the photochromic material of claim 9 in the preparation of smart display materials, information storage and encryption anti-counterfeiting materials, optoelectronic and sensor devices in any one or more of these applications.

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