A naphthyl derivative for regulating photoresponse through thermal phase transition, and a preparation method and application thereof

Abstract

The application discloses a naphthyl derivative for regulating photoresponse through thermal phase change and a preparation method and application thereof. The naphthyl derivative is (2Z,4E)-2-(3-chlorophenyl)-5-(7-(dimethylamino)naphthalen-2-yl) penta-2,4-diphenyl nitrile, and Y crystal forms can be obtained by crystallization in solvents, wherein the Y crystal forms exhibit photo-inertness, and a unique SCSC phase change occurs when the Y crystal forms are heated to the vicinity of a melting point, the thermal phase change can make the Y crystal forms transform into Y transition crystal forms exhibiting photosensitivity, and the conversion from photo-inertness to photosensitivity is realized. The Y transition crystal forms can also be obtained by crystallization through a solvent method. The Y transition crystal forms are combined with PVA to prepare a composite film, the obtained composite film can be bent and twisted without affecting photoresponse performance, and the composite film is expected to be applied to a light brake. Further, conductive silver paste is coated on the surface of the composite film to make the composite film conductive, and the composite film is connected to a patch circuit to prepare a light-controlled switch, and the light-controlled switch is expected to be applied to the field of molecular robots.

Description

Technical Field

[0001] The present invention relates to a molecular crystal, in particular to a naphthyl derivative capable of regulating light response through thermal phase change, and a preparation method and application thereof. Background Art

[0002] Photons can transmit energy and information through various media without contact. Photomechanically responsive materials are excellent examples of materials that convert light energy into mechanical energy, with applications in optical switches, soft robotics, micropumps, and micromachinery. When photoreactive molecules are crystallized, they often exhibit macroscopic photomechanical properties such as twisting, curling, jumping, bending, and expansion under illumination. These materials have important applications in optical switches, photoactuators, artificial muscles, and other fields.

[0003] Current reports mainly focus on complexes and polymers, and research on organic molecular crystals is still relatively rare. Therefore, it is still challenging to design organic molecular crystals with novel structures and excellent performance. According to research, in order to obtain organic molecular crystals with excellent performance, it is necessary to have functional groups that can undergo photochemical reactions and groups that are conducive to effective stacking in the molecular structure. Based on the characteristics of the naphthalene ring such as good planarity, multiple reaction sites and easy modification, the applicant adjusts the stacking mode of the crystal by changing the substituents and changing their positions, and further introduces halogen atoms into the aromatic ring to control the arrangement mode by hydrogen bonding or halogen bonding interactions, hoping to obtain molecular crystals that meet the Schmidt topological rule and undergo [2+2] cycloaddition reactions. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a naphthyl derivative that regulates light response through thermal phase change, as well as its preparation method and application. The naphthyl derivative described in the present invention can obtain a photoinert crystal form through a solvent method. The photoinert crystal form can be converted into another crystal form that exhibits photosensitivity under specific heating conditions. The photosensitive crystal form after thermal conversion can be used in the fields of photodrive and optical switching.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A naphthyl derivative, the molecular formula of which is C 23 H 19 Cl1N2, chemical name is (2Z, 4E)-2-(3-chlorophenyl)-5-(7-(dimethylamino)naphthalen-2-yl)penta-2,4-dibenzonitrile, and its structure is shown in the following formula (I):

[0007]

[0008] The naphthyl derivative described in the present invention is a yellow powder in a molecular aggregate state. The applicant discovered in experiments that a solvent method can yield a photoinert crystalline form, referred to herein as Form Y. Upon heating, a phase transition occurs to yield another photosensitive crystalline form, referred to herein as Form Y.

[0009] A second aspect of the present invention provides a method for preparing the above-mentioned naphthyl derivative, comprising: placing (E)-3-(7-(dimethylamino)naphthalen-2-yl)propenal and 2-(3-chlorophenyl)acetonitrile in an alcohol solvent, reacting in the presence of an alkaline catalyst, filtering after completion of the reaction, collecting the filter cake, and drying to obtain the product.

[0010] The naphthyl derivatives of the present invention are synthesized from (E)-3-(7-(dimethylamino)naphth-2-yl)propenal and 2-(3-chlorophenyl)acetonitrile using a Knoevenagel condensation reaction. In the preparation method of the naphthyl derivatives, the ratio of (E)-3-(7-(dimethylamino)naphth-2-yl)propenal and 2-(3-chlorophenyl)acetonitrile is a stoichiometric ratio; the alcohol solvent is preferably methanol or ethanol, or a combination thereof; and the amount of the alcohol solvent used is preferably sufficient to dissolve all the raw materials involved in the reaction. Preferably, the amount is calculated based on the standard of adding 2 to 10 mL of the alcohol solvent to 1 mg of (E)-3-(7-(dimethylamino)naphth-2-yl)propenal. The base catalyst is a conventional base catalyst selected in the Knoevenagel condensation reaction, such as one or a combination of two or more selected from sodium hydroxide, sodium carbonate, neutral alumina, basic alumina and triethylamine. The amount of the base catalyst used is preferably 0.2 to 0.4 times the mass of (E)-3-(7-(dimethylamino)naphthalene-2-yl)acrolein.

[0011] In the above-mentioned method for preparing naphthyl derivatives, the reaction can be carried out with or without heating, preferably without heating, usually at 20-30° C. When the reaction is carried out at 20-30° C., the reaction time is preferably controlled within 3-6 hours.

[0012] The structure of the raw material (E)-3-(7-(dimethylamino)naphthalen-2-yl)propenal involved in the preparation method of the above-mentioned naphthyl derivative is shown in the following formula (II). It can be prepared by referring to the invention patent application with publication number CN117720436A, or it can be synthesized by a self-designed route;

[0013]

[0014] In the present application, (E)-3-(7-(dimethylamino)naphthalen-2-yl)acrolein is preferably prepared by the following method:

[0015] 1) Using 7-bromonaphthalene-2-ol and dimethylamine as raw materials and water as solvent, a solvothermal reaction is carried out in the presence of sodium metabisulfite. After the reaction is completed, the mixture is separated by ethyl acetate and water, and the organic layer is spin-dried to obtain a crude intermediate product.

[0016] In this step, the amount of sodium metabisulfite added is usually 1 to 2 times the mass of 7-bromonaphthalene-2-ol; the solvent thermal reaction is preferably carried out at 130 to 150° C., and the reaction time is controlled to be 96 to 120 hours.

[0017] Preferably, the crude product is purified before use in subsequent steps. Specifically, the crude product can be purified by silica gel column chromatography (n-hexane / ethyl acetate = 20-50:1, volume ratio) to obtain the purified intermediate product 7-bromo-N,N-dimethylnaphthalene-2-amine.

[0018] 2) The intermediate product, 3,3-diethoxyprop-1-ene, an organic solvent, a palladium catalyst and a weak base are placed in a reaction vessel, and tetrabutylammonium acetate is added or not, and a Heck reaction is carried out under atmosphere protection conditions. After the reaction is completed, the reaction is acidified and alkalized to obtain a crude product of (E)-3-(7-(dimethylamino)naphthalen-2-yl)acrolein.

[0019] In this step, the organic solvent can be tetrahydrofuran, N,N-dimethylformamide or 1,4-dioxane; the weak base can be one or a combination of triethylamine, diethylamine, sodium carbonate, potassium carbonate or cesium carbonate, and its amount is usually 1 to 3 times the weight of the intermediate product. The amount of tetrabutylammonium acetate added is usually 0.5 to 1.0 times the weight of the intermediate product. For palladium catalyst, its selection and amount are conventional choices in the prior art, preferably tetrakis(triphenylphosphine)palladium and / or bistriphenylphosphine palladium dichloride, and its amount is preferably 0.1 to 0.3 times the weight of the intermediate product. When the heck reaction is usually carried out at 110 to 130°C, the reaction time is usually controlled to be 96 to 120 hours.

[0020] The crude product is preferably purified before use in subsequent steps. Specifically, the crude product can be further purified by silica gel column chromatography (n-hexane / ethyl acetate = 20-50:1, volume ratio) to obtain purified (E)-3-(7-(dimethylamino)naphthalen-2-yl)propenal.

[0021] The third aspect of the present invention provides two crystal forms of the naphthyl derivative, one of which is a Y crystal form, which belongs to the orthorhombic system, the Pna21 space group, and the unit cell parameters are: α = 90.00°, β = 90.00°, γ = 90.00°. This crystal form is yellow needle-shaped crystals and is optically inert.

[0022] Another crystal form of the naphthyl derivative provided by the present invention is a Y-transformation crystal form, which belongs to the cubic crystal system, the P-1 space group, and the unit cell parameters are: α=76.307(3)°,β=84.908(3)°,γ=82.954(3)°. This crystal form is orange needle-shaped crystal and exhibits photosensitivity.

[0023] The fourth aspect of the present invention provides a method for preparing the two crystal forms of the naphthyl derivatives, wherein:

[0024] The preparation method of Form Y is as follows: the naphthyl derivative is recrystallized in a mixed solvent consisting of dichloromethane and ethanol or methanol, wherein the volume ratio of dichloromethane to ethanol or methanol is 1:3-10, more preferably 1:6-7.

[0025] The Y-transformation crystal form is prepared by heating the Y-transformation crystal form to a phase transition point and maintaining the temperature at that temperature until the color of the crystals completely changes to orange. The phase transition point is 150-153°C. Typically, the color of the crystals completely changes from yellow to orange after maintaining the temperature at that temperature for 10-30 minutes, preferably for 20-30 minutes.

[0026] The Y-transformation crystalline form can also be prepared by solvent crystallization, specifically by recrystallizing the naphthyl derivative in a mixed solvent of dichloromethane and n-hexane or petroleum ether. The volume ratio of dichloromethane to n-hexane or petroleum ether is preferably 1:3-10, more preferably 1:6-7.

[0027] The applicant has found through experiments that the Y-transformed crystal form exhibits photosensitivity, and its light response range extends from ultraviolet light to green light in visible light, which is specifically manifested as backlight bending, and the light response is reversible. The crystal form that bends after the light response can be restored to its original state when away from ultraviolet light or heated. The Y-crystal form exhibits photoinertness, and has no photoresponse phenomenon under ultraviolet and visible light irradiation, but a unique SCSC phase transition occurs when heated to near the melting point. This thermal phase transition changes the stacking of the Y-crystal form and transforms it into a Y-transformed crystal form that can respond to light, realizing the transformation from photoinertness to photosensitivity. This tandem reaction connecting thermal phase change and photoresponse is rarely found in molecular crystal forms and is worthy of in-depth research. Similarly, this means of regulating photoresponse by thermal phase change also provides a new approach for designing and preparing photoresponsive molecular crystal forms.

[0028] The fifth aspect of the present invention provides a composite film comprising the above-mentioned Y-transform crystal form. The thickness of the composite film is determined according to needs and can be 25 to 150 μm.

[0029] The composite film can be prepared using conventional methods, preferably as follows: the Y-transform crystal is ground and dispersed in a solvent, a substrate is added, and the mixture is stirred evenly. The resulting viscous liquid is poured into a mold, dried, and peeled off. The solvent can be ethanol or water; the substrate can be selected from PVA (polyvinyl alcohol), chitosan, polyvinylidene fluoride, and polypropylene, preferably a 10-25 wt% aqueous solution of PVA, more preferably a 10 wt% aqueous solution of PVA; and the mass ratio of the Y-transform crystal to the PVA aqueous solution can be 1-3:10.

[0030] A sixth aspect of the present invention provides a photoactuator made of the composite film described above.

[0031] Specifically, the composite film can be made into the photoactuator by cutting, folding, and multiple fixed connections, and the shape of the composite film is two-dimensional or three-dimensional.

[0032] The seventh aspect of the present invention provides the use of the above-mentioned Y-transition crystal form or the above-mentioned composite film in photoinduced driving.

[0033] Furthermore, irradiation is performed using 365 nm ultraviolet light extending to green light (such as 490 nm) in the visible light.

[0034] A seventh aspect of the present invention provides use of the Y-transition crystal form or the composite film in preparing a light-operated switch.

[0035] After coating the surface of the composite film with conductive silver paste, the composite film becomes conductive. After connecting it to a patch circuit, it can be made into a light-controlled switch, which is expected to be used in fields such as molecular robotics.

[0036] Compared with the prior art, the present invention is characterized in that:

[0037] 1. The naphthyl derivative provided by the present invention is a molecular aggregation state, and a Y crystal form can be obtained by crystallization in a solvent, and the Y crystal form exhibits photoinertness. When the Y crystal form is heated to near the melting point, a unique SCSC phase transition will occur. This thermal phase transition changes the stacking of the Y crystal form and transforms it into a Y transition crystal form that can respond to light, thereby realizing the transformation from photoinertness to photosensitivity. The tandem reaction connecting the thermal phase transition and the photoresponse in the present invention is rarely found in molecular crystals and is worthy of in-depth research. Moreover, the present invention provides a new approach for the design and preparation of photoresponsive molecular crystals by regulating the photoresponse through thermal phase transition.

[0038] 2. By combining the photoresponsive Y-transition crystal form with PVA to form a composite film, the resulting composite film inherits the photoresponsive characteristics of the Y-transition crystal form while also enhancing the mechanical properties of the molecular crystal. The composite film can be bent and twisted without affecting its photoresponsive performance, and is expected to be used in optical brakes.

[0039] 3. Conductive silver paste is coated on the surface of the composite film to make it conductive. After connecting it to a patch circuit, it can be made into a light-controlled switch, which is expected to be used in fields such as molecular robotics.

[0040] 4. The preparation method of the present invention has mild reaction conditions, uses relatively common reagents with minimal pollution, and is safe and reliable. The intermediate products involved do not require stringent reaction and storage conditions, are simple to synthesize, and are suitable for a wide range of applications. The Y transition crystal form is chemically stable and can be stored long-term in the dark, while the Y crystal form does not require storage in the dark and is chemically stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of the intermediate product 7-bromo-N,N-dimethylnaphthalene-2-amine prepared in Example 1.

[0042] Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of (E)-3-(7-(dimethylamino)naphthalen-2-yl)acrolein prepared in Example 1.

[0043] Figure 3 These are the hydrogen nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of the naphthyl derivative (2Z,4E)-2-(3-chlorophenyl)-5-(7-(dimethylamino)naphthalen-2-yl)penta-2,4-dibenzonitrile prepared in Example 1, where (a) is the hydrogen spectrum and (b) is the carbon spectrum.

[0044] Figure 4 This is the powder X-ray diffraction spectrum of the Y-transformation crystal form prepared in Example 5.

[0045] Figure 5 This is the powder X-ray diffraction spectrum of the Y crystal form prepared in Example 4.

[0046] Figure 6 This is the molecular stacking diagram of the Y-transformation crystal prepared in Example 5.

[0047] Figure 7 This is the molecular stacking diagram of the Y crystal form prepared in Example 4.

[0048] Figure 8 This is the thermogravimetric analysis diagram of the Y-transformation crystal prepared in Example 5.

[0049] Figure 9 This is the thermogravimetric analysis diagram of the Y crystal form prepared in Example 4.

[0050] Figure 10These are photoresponse diagrams of the Y-transformation crystal form prepared in Example 5; wherein, (a) is a photoresponse diagram of the Y-transformation crystal form when the Y-transformation crystal form is irradiated with visible light, (b) is a photoresponse diagram of the Y-transformation crystal form when the Y-transformation crystal form is irradiated with 365nm ultraviolet light, (c) is a photoresponse diagram of the Y-transformation crystal form when the Y-transformation crystal form is irradiated with 405nm ultraviolet light, and (d) is a photoresponse diagram of the Y-transformation crystal form when the Y-transformation crystal form is irradiated with 490nm green light.

[0051] Figure 11 These are diagrams showing the light response of the composite film in Application Example 2; wherein, (a) is a diagram showing the initial state of the composite film, (b) is a diagram showing the light response of the composite film under illumination with a wavelength of 490 nm from bottom to top, and (c) is a diagram showing the light response of the composite film under illumination with a wavelength of 295 nm from bottom to top.

[0052] Figure 12 These are diagrams showing the light response of the composite film after being coated with conductive silver paste and connected to the patch circuit in Example 3; wherein, (d) is a simulated design diagram of the light-controlled circuit, (e) is a real picture of the circuit in an open circuit state, and (f) is a real picture of the composite film being bent under 490nm light and connected to the circuit to light up the small lamp. DETAILED DESCRIPTION

[0053] In order to better explain the technical solution of the present invention, the present invention is further described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

[0054] Example 1: Preparation of naphthyl derivatives

[0055] 1) 2 g of 7-bromonaphthalene-2-ol, 3.2 g of sodium metabisulfite, 8 g of water, and 5.04 g of dimethylamine were placed in a hydrothermal reactor and reacted in an oven at 140°C for 96 h. After the reaction, the mixture was separated with ethyl acetate and water, the organic layer was spin-dried, and the residue was separated by silica gel column chromatography (n-hexane / ethyl acetate = 30:1, volume ratio) to obtain the intermediate product 7-bromo-N,N-dimethylnaphthalene-2-amine. The H NMR spectrum of the obtained intermediate product is as follows: Figure 1 shown.

[0056] 2) 3 g of 7-bromo-N,N-dimethylnaphthalene-2-amine, 4.5 g of 3,3-diethoxyprop-1-ene, 0.45 g of bistriphenylphosphine palladium dichloride, and 6 g of potassium carbonate were dissolved in 30 mL of N,N-dimethylformamide and stirred in a constant temperature oil bath at 120°C under a nitrogen atmosphere for 96 h. After the reaction, 1 mL of hydrochloric acid was added for 1 h (to deprotect and expose the aldehyde group), followed by basification with sodium bicarbonate (to remove excess acid). After basification, the mixture was separated with dichloromethane and water, the organic layer was spin-dried, and the residue was separated by silica gel column chromatography (n-hexane / ethyl acetate = 30:1, volume ratio) to obtain (E)-3-(7-(dimethylamino)naphthalen-2-yl)propenal. The resulting (E)-3-(7-(dimethylamino)naphthalen-2-yl)propenal had a hydrogen nuclear magnetic resonance spectrum as shown below. Figure 2 shown.

[0057] 3) 30 mg of (E)-3-(7-(dimethylamino)naphthalen-2-yl)propenal, 20 mg of 2-(3-chlorophenyl)acetonitrile, and 8 mg of sodium hydroxide were dissolved in 35 mL of ethanol and stirred at 25°C for 4 h. After the reaction, the filter cake was collected and dried to obtain a yellow powder weighing 35 mg, with a yield of 73.24%.

[0058] The yellow powder obtained in this example was subjected to H NMR and C NMR analysis. Figure 3 Therefore, it can be determined that the obtained yellow powder is the naphthyl derivative of the present invention, namely (2Z, 4E)-2-(3-chlorophenyl)-5-(7-(dimethylamino)naphthalen-2-yl)penta-2,4-dibenzonitrile, whose structure is shown in the following formula (I):

[0059]

[0060] Example 2: Preparation of naphthyl derivatives

[0061] Example 1 was repeated, except that in step 3), basic alumina was used instead of sodium hydroxide, and methanol was used instead of ethanol.

[0062] Finally, 28 mg of yellow powder was obtained with a yield of 58.6%.

[0063] The yellow powder obtained in this example was subjected to H NMR and C NMR analyses, confirming that the yellow powder was the naphthyl derivative of the present invention.

[0064] Example 3: Preparation of naphthyl derivatives

[0065] Example 1 was repeated, except that in step 3), triethylamine was used instead of sodium hydroxide.

[0066] Finally, 25 mg of yellow powder was obtained with a yield of 52.3%.

[0067] The yellow powder obtained in this example was subjected to H NMR and C NMR analyses, confirming that the yellow powder was the naphthyl derivative of the present invention.

[0068] Example 4: Preparation of Crystal Form Y

[0069] 10 mg of the naphthyl derivative prepared according to the method described in Example 1 was placed in a 10 mL glass vial. 1 mL of dichloromethane was added to dissolve the product, followed by 6 mL of ethanol. The product was allowed to evaporate for 120 h. Yellow needle-like crystals were observed to precipitate in the vial. The crystals were collected, dried, and designated as Form Y. The yield was 98%.

[0070] Example 5: Preparation of Y-transformation crystal form

[0071] 10 mg of Form Y crystals prepared according to the method described in Example 4 were heated to 150°C and maintained at this temperature for 20 minutes. The crystals completely changed from their initial yellow color to orange. Heating was stopped, and the crystals were cooled to room temperature. The crystals were collected and dried, and recorded as Form Y transformation. The yield was 95%.

[0072] The two crystals obtained in Example 4 and Example 5 were characterized:

[0073] 1. Powder X-ray Diffraction Analysis

[0074] The obtained Y transformation crystal form and Y crystal form were subjected to powder XRD analysis, and the results were as follows: Figure 4 and Figure 5 As shown, it can be seen that the two crystals have completely different stacking methods.

[0075] 2. Single Crystal X-ray Diffraction Analysis

[0076] The Y-transition crystal and Y-form of appropriate size were selected and placed on a SuperNova X-ray single crystal diffractometer using graphite monochromatized Mo-Kα radiation. The main crystal data and correction parameters of the two crystal forms are shown in Table 1 below, their partial bond length and bond angle data are shown in Table 2 and Table 3 below, and the molecular stacking diagrams of the two crystal forms are shown in Table 2 and Table 3 below. Figure 6 and Figure 7 shown.

[0077] Table 1: Crystal data and structural optimization parameters of Y-transform / Y-form

[0078]

[0079] Table 2: Some bond lengths of Y-transition crystal form and bond angle / ° data

[0080]

[0081]

[0082]

[0083] Table 3: Some bond lengths of Y crystal form and bond angle / ° data

[0084]

[0085] 3. Thermogravimetric analysis

[0086] Thermogravimetric analysis of the Y transformation crystal form and the Y crystal form were performed respectively, and the results were as follows: Figure 8 and Figure 9 As shown, no phase change occurs in the Y transformation crystal form before melting, and the Y crystal form undergoes a thermal phase change at the melting point.

[0087] 4. Light Response Behavior Analysis

[0088] The specific response of the Y-transformation crystal under different wavelengths of light is as follows: Figure 10 As shown, it can be seen that the Y-transformed crystal produces obvious backlight bending after being exposed to light.

[0089] Example 6: Preparation of Crystal Form Y

[0090] 10 mg of the naphthyl derivative prepared according to the method described in Example 1 was placed in a 10 mL glass vial. 1 mL of dichloromethane was added for dissolution, followed by 6 mL of methanol. The solution was allowed to evaporate for 132 hours. Yellow needle-shaped crystals were observed to precipitate in the vial. The crystals were collected and dried, yielding 97%. Single crystal diffraction analysis and other analyses confirmed that the resulting yellow needle-shaped crystals were Form Y of the present invention.

[0091] Example 7: Preparation of Crystal Form Y

[0092] The preparation was carried out according to the method of Example 4, except that the amount of ethanol was changed to 3 mL. After 96 hours of evaporation, yellow needle-shaped crystals precipitated in the glass bottle. The crystals were collected and dried, with a yield of 96%. The resulting yellow needle-shaped crystals were analyzed by single crystal diffraction and other methods, confirming that the obtained yellow needle-shaped crystals were the Y crystal form described in the present invention.

[0093] Example 8: Preparation of Y-transformation crystal form

[0094] 10 mg of the naphthyl derivative prepared according to the method described in Example 1 was placed in a 10 mL glass vial. 1 mL of dichloromethane was added and dissolved, followed by 6 mL of petroleum ether. The solution was allowed to evaporate for 60 h. Orange needle-shaped crystals were observed to precipitate in the vial. The crystals were collected and dried, yielding 98%. Single crystal diffraction analysis and other analyses confirmed that the resulting orange needle-shaped crystals were the Y-transformation crystalline form described herein.

[0095] Example 9: Preparation of Y-transformation crystal form

[0096] 10 mg of Form Y crystals prepared according to the method described in Example 6 were heated to 153°C and maintained at this temperature for 25 minutes. The crystals completely turned from their initial yellow color to orange. Heating was stopped, the crystals were cooled to room temperature, collected, and dried. The yield was 95%. Single crystal diffraction analysis and other analyses confirmed that the resulting orange needle-shaped crystals were the Form Y transformation crystal described in the present invention.

[0097] Application Example 1: Preparation of composite membrane

[0098] The Y-transform crystal prepared according to the method described in Example 5 was ground into a powder in an agate mortar. This powder was then mixed with a 10 wt% PVA aqueous solution at a mass ratio of 1 g:2 mL and stirred to obtain a uniform viscous solution. This viscous solution was dropwise added to a clean, dry glass mold and dried in a constant temperature oven at 30°C. After complete solvent evaporation, the composite film was peeled off from the glass mold to obtain a composite film.

[0099] Application Example 2: Photoresponse Analysis of Composite Films

[0100] The composite film prepared in Example 1 was cut into rectangular pieces of 1 cm × 0.5 cm, and one end of the piece was fixed to one end of a glass sheet, and a weight twice the weight of the composite film was fixed to the other end. The composite film was irradiated from bottom to top with 490 nm green light or 295 nm ultraviolet light, and the process was recorded with a camera. Figure 11 It was found that under 490nm green light or 295nm ultraviolet light irradiation, the composite film quickly bends backlight and can easily lift objects twice its own weight, indicating that the composite film has the potential to be used in optical brakes.

[0101] Application Example 3: Analysis of the Light Response of a Photosensitive Switch

[0102] The composite film prepared in Example 1 was cut into rectangular pieces of 2 cm × 0.5 cm, and a conductive silver paste (brand: Yingxun, model: EN-06B8) was coated on one side. The composite film coated with the conductive silver paste was placed in a 30°C oven and dried for 24 hours, then taken out. The dried composite film was adhered to the patch circuit with the conductive silver paste, and the patch circuit adhered with the composite film was placed in a 30°C oven and dried for 24 hours. The composite film was irradiated from bottom to top with a green light of 490 nm wavelength, and the process was recorded with a camera, as shown in FIG. Figure 12 It was found that under the irradiation of green light with a wavelength of 490nm, the composite film bent upward and contacted the switch contacts, successfully lighting up the small lamp.

Claims

1. A Y crystal form of a naphthyl derivative, characterized in that: The structure of the naphthyl derivative is shown in the following formula (I): (I)； The Y crystal form of the naphthyl derivative belongs to the orthorhombic system. Pna2 1 Space group, unit cell parameters are: a =7.3564(3)Å, b =38.593(2)Å, c =6.4478(3)Å, α=90.00°, β =90.00°, γ =90.00°.

2. The method for preparing the Y crystal form of the naphthyl derivative according to claim 1, characterized in that: The naphthyl derivative represented by the following formula (I) is placed in a mixed solvent consisting of dichloromethane and ethanol or methanol and recrystallized; (I)。 3. A Y-transformation crystal form of a naphthyl derivative, characterized in that: The structure of the naphthyl derivative is shown in the following formula (I): (I)； The Y-transformation crystal form of the naphthyl derivative belongs to the cubic system. P-1 Space group, unit cell parameters are: a =7.8329(3)Å, b =15.1246(6)Å, c =15.8451(6)Å, α=76.307(3)°, β =84.908(3)°, γ =82.954(3)°.

4. The method for preparing the Y-transformation crystal form of the naphthyl derivative according to claim 3, characterized in that: Heating the Y crystal form according to claim 1 to a phase transition point and maintaining the temperature until the color of the crystals completely turns orange; or The naphthyl derivative represented by the following formula (I) is placed in a mixed solvent consisting of dichloromethane and n-hexane or petroleum ether and recrystallized; (I)。 5. A composite film, characterized in that: Including the crystal form according to claim 3.

6. A photo-driven actuator, characterized in that: It is made from the composite membrane described in claim 5.

7. Use of the crystal form according to claim 3 or the composite film according to claim 5 in photo-driven driving or in the preparation of a light-controlled switch.

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