Bis-aryl hemi-indigo monomers, functional polymeric films and methods of making and using the same

Abstract

The application relates to the technical field of organic functional materials, and discloses a bis-aryl semi-indigo monomer, a functional polymer film and a preparation method and application thereof. The preparation method of the bis-aryl semi-indigo monomer comprises the following steps: dissolving a compound A and sodium hydride in an organic solvent, stirring and reacting to obtain a precursor solution; adding a bromide compound containing R 9 to the precursor solution to perform an alkylation reaction, then adding a saturated ammonium chloride solution to quench the reaction, separating and collecting an organic phase; washing, drying and concentrating the organic phase to obtain a crude product; purifying the crude product through column chromatography, and then performing recrystallization to obtain the bis-aryl semi-indigo monomer. The application introduces a polymerizable functional group into a bis-aryl semi-indigo mother nucleus structure to prepare a polymerizable bis-aryl semi-indigo monomer, the bis-aryl semi-indigo monomer has bidirectional visible light response characteristics, can realize E / Z configuration reversible isomerization under the driving of green light and red light dual visible light bands, and can realize rapid and reversible color change in the full visible light band.

Description

Technical Field

[0001] This application relates to the field of organic functional materials technology, specifically to a bisaryl indigo monomer, a functional polymer film, its preparation method, and its application. Background Technology

[0002] Responsive color-changing materials can change color under the influence of external fields (heat, force, light, electricity, magnetism, etc.), and have broad application prospects in optical anti-counterfeiting, stress sensing, information storage, and material damage detection. Among them, light stimulation has become an ideal signal input method for anti-counterfeiting systems due to its non-contact precise control, high spatiotemporal resolution, and multi-dimensional parameter programmability. By adjusting parameters such as wavelength, intensity, and spatial distribution of the light field, high-density optical information encryption and dynamic anti-counterfeiting can be achieved.

[0003] In the field of photoresponsive anti-counterfeiting, while classic photo-switching systems such as azobenzene, diarylethylene, and spiropyran are mature, they have significant limitations: their isomerization is mostly asymmetrical, exhibiting a "one-way visible light response and another-way ultraviolet light triggering" characteristic. Ultraviolet light not only poses potential hazards to biological tissues but also affects the cyclic reversibility and long-term stability of materials, limiting their safe application in everyday scenarios. In contrast, semi-indigo (HI), as a new type of photo-switching molecule, possesses a core advantage in its bidirectional visible light response, fundamentally avoiding the biocompatibility issues faced by traditional ultraviolet light-responsive systems. Furthermore, semi-indigo molecules offer abundant structural modification space, allowing for precise molecular design to flexibly control their photochromic properties and adapt to various anti-counterfeiting application needs.

[0004] Based on this, developing novel polymerizable diaryl indigo monomers and further exploring the application of indigo-based solid polymers in the field of anti-counterfeiting are of great significance for breaking through the technical bottlenecks of existing photochromic materials and promoting the innovative development of dynamic anti-counterfeiting technology. Summary of the Invention

[0005] This application provides a bisaryl semi-indigo monomer, a functional polymer film, its preparation method, and its application, aiming to solve the technical problems of poor biocompatibility and poor stability of existing photoresponsive materials due to the involvement of ultraviolet light.

[0006] To achieve the above objectives, the present application adopts the following technical solution.

[0007] In a first aspect, this application provides a diaryl semi-indigo monomer with the chemical structure shown in formula (1):

[0008] Equation (1)

[0009] Among them, R 1 ~R 8Each can be independently any one of -H, -CH3, CF3, -N(Me)2, -CN, or -OMe2;

[0010] R 9 For -(CH=CH) n -、-(CH2) n CH=CH2、-(CH2) n CHCH2、-(CH2OCH2) n Either CH=CH2 or -(CH2)nOCOC(CH3)=CH2, where n is an integer from 1 to 5.

[0011] Preferably, it is any one of the following compounds:

[0012]

[0013] .

[0014] A second aspect of this application provides a method for preparing the above-mentioned diaryl indigo monomer, comprising:

[0015] S1, Compound A and sodium hydride are dissolved in an organic solvent and stirred to react, yielding a precursor solution;

[0016] S2, add R to the forward driving fluid. 9 The brominated compound of the group undergoes an alkylation reaction. After the reaction is complete, a saturated ammonium chloride solution is added to quench the reaction. The organic phase is then separated and collected. The organic phase is washed, dried, and concentrated to obtain the crude product.

[0017] S3. The crude product was purified by column chromatography and then recrystallized to obtain the diaryl indigo monomer.

[0018] Preferably, compound A comprises any one of 2-((4-(dimethylamino)phenyl)(1,3-methylene)indololin-3-one, 2-((3,5-bis(trifluoromethyl)phenyl)(4-(dimethylamino)phenyl)-methylene)indololin-3-one, 2-((3,5-dimethoxyphenyl)(4-(dimethylamino)phenyl)methylene)indololin-3-one, or 4-((4-(dimethylamino)phenyl)(3-oxoindololin-2-ylidene)methyl)benzylnitrile;

[0019] The inclusion of R 9 The brominated compound of the group is any one of 3-bromo-1-propene, 4-bromo-1-butene, 5-bromo-1-pentene, or 4-bromo-1-butyne;

[0020] The molar ratio of compound A to the brominated compound is 1:1 to 10;

[0021] The molar ratio of compound A to sodium hydride is 1:1.5~10.

[0022] Preferably, the organic solvent in S1 includes any one of N,N-dimethylformamide, N,N-dimethylformamide, dimethyl sulfoxide, N,N-dimethylacetamide, or N-methylpyrrolidone;

[0023] The reaction described in S1 is carried out at a temperature of 0°C for a time of 15-60 minutes.

[0024] And / or,

[0025] The alkylation reaction in S2 is carried out at room temperature; the washing process specifically involves washing the organic phase sequentially with a saturated sodium bicarbonate solution, deionized water, and a saturated sodium chloride solution.

[0026] In S2, an anhydrous desiccant is used for drying, including anhydrous sodium sulfate or anhydrous magnesium sulfate; the concentration is vacuum concentration.

[0027] And / or,

[0028] In S3, the crude product was dissolved in dichloromethane and subjected to column chromatography; the eluent for column chromatography was a mixture of petroleum ether and ethyl acetate.

[0029] S3 uses a methanol / water system for recrystallization.

[0030] A third aspect of this application provides a method for preparing a functional polymer film, comprising:

[0031] The above-mentioned diaryl semi-indigo monomer was dissolved in toluene, and then the base components of Dow Corning DC184 (PDMS) and the curing agent were added in sequence and mixed evenly to obtain a homogeneous red intermediate product.

[0032] The red intermediate product is stirred at room temperature, then transferred to a mold and heated to cure, thus obtaining a functional polymer film.

[0033] Preferably, the mass ratio of the base component of Dow Corning DC184 (PDMS) to the curing agent is 10~5:1;

[0034] And / or,

[0035] The stirring rate is 200~700 r / min, and the stirring time is 5~10 min;

[0036] The heating and curing temperature is 60~80℃, and the time is 10~15h.

[0037] In a fourth aspect of this application, a functional polymer film prepared by the above-described preparation method is provided.

[0038] A fifth aspect of this application provides the application of the aforementioned functional polymer films in the field of photochromism.

[0039] Preferably, the functional polymer is subjected to reversible pattern writing and erasure by alternating irradiation with green and red dual visible light.

[0040] Compared with the prior art, the beneficial effects of this application are as follows:

[0041] This application utilizes precise molecular design to introduce polymerizable functional groups into the core structure of diaryl indigo, thereby preparing polymerizable diaryl indigo monomers. These monomers exhibit bidirectional visible light response characteristics, enabling reversible E / Z configuration isomerization under the drive of both green and red visible light bands, achieving rapid and reversible color changes across the entire visible light spectrum.

[0042] This application prepares a semi-indigo-based functional polymer film by crosslinking and curing polymerizable diaryl semi-indigo monomers with Dow Corning DC 184 (PDMS) via a hydrosilylation reaction. The semi-indigo units in the functional polymer film can achieve reversible E / Z configuration isomerization under dual visible light (green and red) wavelengths, thus enabling rapid and reversible color changes. Combined with the synergistic control of light field parameters (wavelength, etching time), reversible writing and erasing of patterns can be achieved. This characteristic fundamentally avoids the potential harm to biological tissues caused by traditional ultraviolet-responsive systems, making the functional film more suitable for anti-counterfeiting applications involving direct contact with the human body. It also possesses good thermal stability and mechanical properties, significantly improving the safety and practicality of photochromic technology in real-world applications and effectively solving the application limitations caused by ultraviolet light dependence in existing technologies. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 The proton NMR spectrum of the diaryl semi-indigo monomer prepared in Example 1;

[0045] Figure 2 This is a comparison of the reversible pattern writing and erasing effects of the functional polymer film HI-PDMS of this application. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0047] In the following description of this embodiment, the terms "including", "comprising", "having", and "containing" are all open-ended terms, meaning that they include but are not limited to.

[0048] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0049] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0050] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0051] Those skilled in the art should understand that in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0052] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood as each intermediate value between the upper and lower limits of the specifically disclosed range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this application. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0053] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0054] In a first aspect, this application provides a diaryl semi-indigo monomer, the chemical structure of which is shown in formula (1):

[0055] Equation (1)

[0056] Among them, R 1 ~R 8 Each can be independently any one of -H, -CH3, CF3, -N(Me)2, -CN, or -OMe2;

[0057] R 9 For -(CH=CH) n -、-(CH2) n CH=CH2、-(CH2) n CHCH2、-(CH2OCH2) n Either CH=CH2 or -(CH2)nOCOC(CH3)=CH2, where n is an integer from 1 to 5.

[0058] As a preferred embodiment of this application, the diaryl hemi-indigo monomer is any one of the following compounds:

[0059] 4-((1-(3-buten-1-yl)-3-oxoindoline-2-ylidene)(4-(dimethylamino)phenyl)methyl)benzonitrile, its chemical structure is as follows:

[0060]

[0061] 4-((1-allyl-3-oxoindoline-2-ylidene)(4-(dimethylamino)phenyl)methyl)benzonitrile, its chemical structure is as follows:

[0062]

[0063] 4-((4-(dimethylamino)phenyl)(3-oxo-1-(pent-4-en-1-yl)indoline-2-ylidene)methyl)benzonitrile, its chemical structure is as follows:

[0064]

[0065] The method for preparing the diaryl semi-indigo monomer of this application includes:

[0066] S1, Compound A and sodium hydride are dissolved in an organic solvent and stirred to react, yielding a precursor solution;

[0067] In this application, compound A includes any one of 2-((4-(dimethylamino)phenyl)(1,3-methylene)indololin-3-one, 2-((3,5-bis(trifluoromethyl)phenyl)(4-(dimethylamino)phenyl)-methylene)indololin-3-one, 2-((3,5-dimethoxyphenyl)(4-(dimethylamino)phenyl)methylene)indololin-3-one, or 4-((4-(dimethylamino)phenyl)(3-oxoindololin-2-ylidene)methyl)benzylnitrile, preferably 4-((4-(dimethylamino)phenyl)(3-oxoindololin-2-ylidene)methyl)benzylnitrile.

[0068] The organic solvent may be any one of N,N-dimethylformamide, N,N-dimethylformamide, dimethyl sulfoxide, N,N-dimethylacetamide, or N-methylpyrrolidone.

[0069] In this application, the molar ratio of compound A to sodium hydride is preferably 1:1.5~10; the reaction temperature is preferably 0℃, and the reaction time is 15~60 min. During the reaction, the color of the solution changes from red to green, accompanied by the generation of a large number of bubbles.

[0070] S2, add R to the forward driving fluid. 9 The brominated compound of the group undergoes an alkylation reaction. After the reaction is complete, a saturated ammonium chloride solution is added to quench the reaction. The organic phase is then separated and collected. The organic phase is washed, dried, and concentrated to obtain the crude product.

[0071] In this application, the inclusion of R 9 The brominated compound of the group is any one of 3-bromo-1-propene, 4-bromo-1-butene, 5-bromo-1-pentene, or 4-bromo-1-butyne; the molar ratio of compound A to the brominated compound is 1:1 to 10.

[0072] The alkylation reaction is carried out at room temperature. During the dropwise addition of the brominated compound, the solution color can be observed to change from green to red. The reaction progress can be monitored by thin-layer chromatography.

[0073] After the alkylation reaction was completed, a saturated ammonium chloride solution was added to quench the reaction. The aqueous phase and organic phase were separated, and the organic phase in the aqueous phase was extracted with ethyl acetate. The organic phases were then combined. The organic phase was washed sequentially with a saturated sodium bicarbonate solution, deionized water, and a saturated sodium chloride solution. After washing, the phase was dried with an anhydrous desiccant and then concentrated under vacuum to remove the solvent, yielding the crude product.

[0074] The anhydrous desiccant is anhydrous sodium sulfate or anhydrous magnesium sulfate, preferably anhydrous magnesium sulfate.

[0075] S3. The crude product was purified by column chromatography and then recrystallized to obtain the diaryl indigo monomer.

[0076] Specifically, the crude product is dissolved in dichloromethane, adsorbed onto silica gel powder, and purified by column chromatography. After collecting the target component, it is recrystallized in a methanol / water system to obtain the final product, diaryl indigo monomer. The eluent used in the column chromatography is a mixture of petroleum ether and ethyl acetate.

[0077] This application utilizes precise molecular design to introduce polymerizable functional groups into the core structure of diaryl indigo, thereby preparing polymerizable diaryl indigo monomers. These monomers exhibit bidirectional visible light response characteristics, enabling reversible E / Z configuration isomerization under the drive of both green and red visible light bands, achieving rapid and reversible color changes across the entire visible light spectrum.

[0078] This application prepares a semi-indigo-based functional polymer film by crosslinking and curing polymerizable diaryl semi-indigo monomers with Dow Corning DC 184 (PDMS) via a hydrosilylation reaction. Specifically, the preparation method of the functional polymer film of this application includes:

[0079] The above-mentioned diaryl indigo monomer was dissolved in toluene, and then Dow Corning DC184 (PDMS) base component and curing agent were added in sequence and mixed evenly to obtain a homogeneous red intermediate product. The red intermediate product was stirred at room temperature and then transferred to a mold for heating and curing to obtain a functional polymer film.

[0080] In this application, the mass ratio of the base component of Dow Corning DC184 (PDMS) to the curing agent of Dow Corning DC184 (PDMS) is preferably 10 to 5:1. Within this ratio range, the film can be completely cured while possessing good flexibility and stability.

[0081] The stirring rate is 200~700 r / min, and the stirring time is 5~10 min. Within this parameter range, the raw materials can be fully mixed to form a uniform and stable reaction mixture, avoiding the impact of uneven mixing on the photoresponse performance of the film.

[0082] The heating and curing temperature is 60~80℃, and the time is 10~15h. Within this parameter range, the solvent can be completely evaporated, and the film can be fully formed.

[0083] The mold is preferably a tetrafluoroethylene (PTFE) mold.

[0084] The functional polymer thin film prepared in this application can achieve reversible E / Z configuration isomerization under the drive of green and red dual visible light bands, thereby realizing rapid and reversible color change of the thin film; combined with the synergistic control of light field parameters (wavelength, etching time), it can complete the reversible writing and erasing of patterns, and can be used in the field of photochromism.

[0085] The described semi-indigo-based functional polymer film can achieve reversible color changes under the drive of visible light of a specific wavelength. The underlying mechanism is that the semi-indigo units in the film undergo Z→E isomerization under green light irradiation and E→Z isomerization under red light irradiation, resulting in a reversible color transition. After multiple cycles of pattern etching and erasure, the pattern remains clearly visible. Furthermore, the entire process does not require ultraviolet light, exhibiting high operational safety, fast response speed, and excellent cycle stability, making it suitable for reusable optical anti-counterfeiting and temporary information storage applications.

[0086] The aforementioned characteristics of the functional polymer film of this application fundamentally avoid the potential harm to biological tissues caused by traditional ultraviolet light responsive systems, making the functional film more suitable for anti-counterfeiting application scenarios that come into direct contact with the human body. At the same time, it has good thermal stability and mechanical properties, significantly improving the safety and practicality of photochromic technology in practical applications, and effectively solving the application limitations caused by ultraviolet light dependence in the prior art.

[0087] The present application will be further described below through specific embodiments.

[0088] Example 1

[0089] The bisaryl indigo monomer 4-((1-(3-buten-1-yl)-3-oxoindoline-2-ylide)(4-(dimethylamino)phenyl)methyl)benzonitrile prepared in this embodiment has the following chemical structure:

[0090]

[0091] Its preparation methods include:

[0092] S1, 4-((4-(dimethylamino)phenyl)(3-oxoindoline-2-ylidene)methyl)benzyl nitrile (100 mg, 0.274 mmol) and sodium hydride (82.2 mg, 2.05 mmol) were added to a 10 mL Schlenk tube. After removing air by pumping out the air, nitrogen gas was introduced into the Schlenk tube. Under the nitrogen atmosphere, 3 mL of N,N-dimethylformamide was added. The color of the solution changed from red to green instantly upon addition of the N,N-dimethylformamide solution, accompanied by the generation of a large number of bubbles. The reaction was carried out by stirring at 0 °C for 15 min to obtain the precursor solution.

[0093] S2, 4-bromo-1-butene (166 μL, 1.64 mmol) was added dropwise to the precursor solution. After the addition was complete, the color of the precursor solution returned to red. The mixture was transferred to room temperature and the reaction was continued for 12 h. The reaction progress could be monitored by thin-layer chromatography (TLC, with petroleum ether: ethyl acetate as the developing solvent = 3:1).

[0094] After the raw materials have reacted completely, a saturated ammonium chloride solution (10 mL) is added to quench the reaction, and then the aqueous phase and organic phase are separated. The organic phase in the aqueous phase is extracted with ethyl acetate (3 × 50 mL), and the combined organic phase is washed successively with a saturated sodium bicarbonate solution (3 × 100 mL), deionized water (3 × 100 mL), and a saturated sodium chloride solution (3 × 100 mL), and then dried over anhydrous magnesium sulfate; finally, the solvent is removed by vacuum concentration to obtain the crude product.

[0095] S3. The crude product was dissolved in dichloromethane (CH2Cl2), adsorbed onto silica gel powder, and purified by column chromatography (silica gel, eluent: petroleum ether: ethyl acetate = 100:0 → 75:25). After collecting the target fraction, it was recrystallized from methanol / water (MeOH / H2O) to obtain the final product 4-((1-(3-buten-1-yl)-3-oxoindoline-2-ylidene)(4-(dimethylamino)phenyl)methyl)benzonitrile, which was a red fine powder with a yield of 70%.

[0096] Its synthesis process is as follows:

[0097]

[0098] Example 2

[0099] The bisaryl semi-indigo monomer 4-((1-allyl-3-oxoindoline-2-ylide)(4-(dimethylamino)phenyl)methyl)benzonitrile prepared in this embodiment has the following chemical structure:

[0100]

[0101] Its preparation methods include:

[0102] S1, 4-((4-(dimethylamino)phenyl)(3-oxoindoline-2-ylidene)methyl)benzyl nitrile (100 mg, 0.274 mmol) and sodium hydride (82.2 mg, 2.05 mmol) were added together to a 10 mL Schlenk tube. After removing the air by pumping out the air, nitrogen gas was introduced into the Schlenk tube. Under the nitrogen atmosphere, 3 mL of N,N-dimethylformamide was added. The reaction was carried out by stirring at 0 °C for 15 min to obtain the precursor solution.

[0103] S2, 3-bromo-1-propene (148 μL, 1.64 mmol) was added dropwise to the precursor solution. After the addition was complete, the color of the precursor solution returned to red. The mixture was transferred to room temperature and the reaction was continued for 12 h. The reaction progress could be monitored by thin-layer chromatography (TLC, with petroleum ether: ethyl acetate as the developing solvent = 3:1).

[0104] After the raw materials have reacted completely, a saturated ammonium chloride solution (10 mL) is added to quench the reaction, and then the aqueous phase and organic phase are separated. The organic phase in the aqueous phase is extracted with ethyl acetate (3 × 50 mL), and the combined organic phase is washed successively with a saturated sodium bicarbonate solution (3 × 100 mL), deionized water (3 × 100 mL), and a saturated sodium chloride solution (3 × 100 mL), and then dried over anhydrous magnesium sulfate; finally, the solvent is removed by vacuum concentration to obtain the crude product.

[0105] S3, the crude product was dissolved in dichloromethane (CH2Cl2), adsorbed onto silica gel powder, and purified by column chromatography (silica gel, eluent: petroleum ether: ethyl acetate = 100:0 → 75:25). After collecting the target fraction, it was recrystallized from methanol / water (MeOH / H2O) to give the final product 4-((1-allyl-3-oxoindoline-2-ylidene)(4-(dimethylamino)phenyl)methyl)benzonitrile, in 50% yield.

[0106] Its synthesis process is as follows:

[0107]

[0108] Example 3

[0109] The bisaryl semi-indigo monomer 4-((4-(dimethylamino)phenyl)(3-oxo-1-(pent-4-en-1-yl)indoline-2-ylidene)methyl)benzonitrile prepared in this embodiment has the following chemical structure:

[0110]

[0111] Its preparation methods include:

[0112] S1, 4-((4-(dimethylamino)phenyl)(3-oxoindoline-2-ylidene)methyl)benzyl nitrile (100 mg, 0.274 mmol) and sodium hydride (82.2 mg, 2.05 mmol) were added together to a 10 mL Schlenk tube. After removing the air by pumping out the air, nitrogen gas was introduced into the Schlenk tube. Under the nitrogen atmosphere, 3 mL of N,N-dimethylformamide was added. The reaction was carried out by stirring at 0 °C for 15 min to obtain the precursor solution.

[0113] S2, 5-bromo-1-pentene (184 μL, 1.64 mmol) was added dropwise to the precursor solution. After the addition was complete, the color of the precursor solution returned to red. The mixture was transferred to room temperature and the reaction was continued for 12 h. The reaction progress could be monitored by thin-layer chromatography (TLC, with petroleum ether: ethyl acetate as the developing solvent = 3:1).

[0114] After the raw materials have reacted completely, a saturated ammonium chloride solution (10 mL) is added to quench the reaction, and then the aqueous phase and organic phase are separated. The organic phase in the aqueous phase is extracted with ethyl acetate (3 × 50 mL), and the combined organic phase is washed successively with a saturated sodium bicarbonate solution (3 × 100 mL), deionized water (3 × 100 mL), and a saturated sodium chloride solution (3 × 100 mL), and then dried over anhydrous magnesium sulfate; finally, the solvent is removed by vacuum concentration to obtain the crude product.

[0115] S3. The crude product was dissolved in dichloromethane (CH2Cl2), adsorbed onto silica gel powder, and purified by column chromatography (silica gel, eluent: petroleum ether: ethyl acetate = 100:0 → 75:25). After collecting the target fraction, it was recrystallized from methanol / water (MeOH / H2O) to give the final product 4-((4-(dimethylamino)phenyl)(3-oxo-1-(pent-4-en-1-yl)indoline-2-ylidene)methyl)benzonitrile, in 50% yield.

[0116] Its synthesis process is as follows:

[0117]

[0118] Example 4

[0119] This application provides a functional polymer film, the preparation method of which includes:

[0120] The bisaryl semi-indigo monomer (2.1 mg) prepared in Example 1 was completely dissolved in toluene (2 ml) in a 20 ml vial. Dow Corning DC 184 base component (2.0 g) was added while stirring continuously. Then, Dow Corning DC 184 curing agent (0.2 g) was added and further stirred to obtain a red mixture.

[0121] The above red mixture was stirred for another 5 minutes at room temperature, and then quickly transferred to a polytetrafluoroethylene (PTFE) mold. The mold was placed in an oven and cured at 60°C for 12 hours to finally obtain a red functional polymer film, denoted as HI-PDMS.

[0122] The diaryl hemi-indigo monomer of Example 1 of this application was tested, and its 1H NMR spectrum is as follows: Figure 1 As shown. From Figure 1It can be seen that the target bisaryl semi-indigo monomer in Example 1, 4-((1-(3-buten-1-yl)-3-oxoindoline-2-ylidene)(4-(dimethylamino)phenyl)methyl)benzonitrile, was successfully synthesized.

[0123] The functional polymer film HI-PDMS prepared in Example 4 of this application was subjected to photochromic application, and the pattern was reversibly written and erased on it, as detailed below:

[0124] Information writing: Using 505nm visible light as the configuration transformation "activation signal", the Z→E isomerization of the semi-indigo photosensitive unit in the target area of ​​the thin film is precisely induced by mask exposure technology to form a pattern with significant visual contrast with the background, thereby realizing explicit information storage;

[0125] Information erasure: Using 625nm visible light as a "recovery signal", the semi-indigo photosensitive unit is isomerized from E configuration to Z configuration, causing the pattern to disappear and the film to return to the initial state without information.

[0126] The functional polymer film HI-PDMS underwent multiple cycles of writing and erasing, and its physical image is shown below. Figure 2 As shown. From Figure 2 It is evident that after multiple write-erase cycles, the color contrast of the HI-PDMS film decreases negligibly, and the final engraved rose pattern remains clearly discernible, demonstrating excellent cycle stability. This provides crucial performance support for practical applications such as reusable anti-counterfeiting labels and temporary information storage.

[0127] Although this application has been described in detail in this specification with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, such modifications or improvements made without departing from the spirit of this application are all within the scope of protection claimed in this application.

Claims

1. A diaryl indigo monomer, characterized in that, Its chemical structure is shown in formula (1): Equation (1) Among them, R 1 ~R 8 Each can be independently any one of -H, -CH3, CF3, -N(Me)2, -CN, or -OMe2; R 9 For -(CH=CH) n -、-(CH2) n CH=CH2、-(CH2) n CHCH2、-(CH2OCH2) n Either CH=CH2 or -(CH2)nOCOC(CH3)=CH2, where n is an integer from 1 to 5.

2. The diaryl indigo monomer according to claim 1, characterized in that, It is any one of the following compounds: 。 3. The method for preparing the diaryl indigo monomer according to claim 1, characterized in that, include; S1, Compound A and sodium hydride are dissolved in an organic solvent and stirred to react, yielding a precursor solution; S2, add R to the forward driving fluid. 9 The brominated compound of the group undergoes an alkylation reaction. After the reaction is complete, a saturated ammonium chloride solution is added to quench the reaction. The organic phase is then separated and collected. The organic phase is washed, dried, and concentrated to obtain the crude product. S3. The crude product was purified by column chromatography and then recrystallized to obtain the diaryl indigo monomer.

4. The preparation method according to claim 3, characterized in that, Compound A comprises any one of 2-((4-(dimethylamino)phenyl)(1,3-methylene)indololin-3-one, 2-((3,5-bis(trifluoromethyl)phenyl)(4-(dimethylamino)phenyl)-methylene)indololin-3-one, 2-((3,5-dimethoxyphenyl)(4-(dimethylamino)phenyl)methylene)indololin-3-one, or 4-((4-(dimethylamino)phenyl)(3-oxoindololin-2-methylene)methyl)benzylnitrile; The inclusion of R 9 The brominated compound of the group is any one of 3-bromo-1-propene, 4-bromo-1-butene, 5-bromo-1-pentene, or 4-bromo-1-butyne; The molar ratio of compound A to the brominated compound is 1:1 to 10; The molar ratio of compound A to sodium hydride is 1:1.5~10.

5. The preparation method according to claim 3, characterized in that, The organic solvent mentioned in S1 includes any one of N,N-dimethylformamide, dimethyl sulfoxide, N,N-dimethylacetamide or N-methylpyrrolidone; The reaction described in S1 is carried out at a temperature of 0°C for a time of 15-60 minutes. And / or, The alkylation reaction in S2 is carried out at room temperature; the washing process specifically involves washing the organic phase sequentially with a saturated sodium bicarbonate solution, deionized water, and a saturated sodium chloride solution. In S2, an anhydrous desiccant is used for drying, including anhydrous sodium sulfate or anhydrous magnesium sulfate; the concentration is vacuum concentration. And / or, In S3, the crude product was dissolved in dichloromethane and subjected to column chromatography; the eluent for column chromatography was a mixture of petroleum ether and ethyl acetate. S3 uses a methanol / water system for recrystallization.

6. A method for preparing a functional polymer film, characterized in that, include: The diaryl semi-indigo monomer described in claim 1 or 2 is dissolved in toluene, and then Dow Corning DC184 (PDMS) base component and curing agent are added sequentially and mixed evenly to obtain a uniform red intermediate product. The red intermediate product is stirred at room temperature, then transferred to a mold and heated to cure, thus obtaining a functional polymer film.

7. The preparation method according to claim 6, characterized in that, The mass ratio of the base component to the curing agent in Dow Corning DC184 (PDMS) is 10~5:1; And / or, The stirring rate is 200~700 r / min, and the stirring time is 5~10 min; The heating and curing temperature is 60~80℃, and the time is 10~15h.

8. The functional polymer film prepared by the preparation method according to claim 6 or 7.

9. The application of the functional polymer film according to claim 8 in the field of photochromism.

10. The application according to claim 9, characterized in that, The functional polymer is subjected to reversible pattern writing and erasure by alternating irradiation with green and red dual visible light.

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