Imine compound and preparation method thereof as well as composite material and preparation method thereof

Abstract

The invention relates to the technical field of novel functional materials, in particular to an imine compound, a preparation method of the imine compound, a composite material and a preparation method of the composite material. The imine compound disclosed by the invention can generate reversible photoisomerization response through proton transfer and bond rotation in molecules of the imine compound; and the imine compound mainly exists in a molecular crystal state, so that the angle change between two naphthalene rings in a molecule caused by bond rotation can cause lattice deformation and further cause deformation of the whole molecular crystal, and therefore, the imine compound can show reversible photoisomerization response under visible light irradiation. According to the imine compound, when visible light illumination is given to the molecular crystal of the imine compound, photoinduced volume shrinkage and expansion can occur, the imine compound has strong light isomerization response under visible light, the functionality and application scene of the imine compound can be effectively expanded, and meanwhile the variety of photoisomerization materials can be enriched.

Description

Technical Field

[0001] The present invention relates to the technical field of novel functional materials, and particularly relates to an imine compound, a preparation method thereof, a composite material, and a preparation method thereof. Background Art

[0002] Photoisomerization materials are a special type of intelligent materials that can change their chemical structure under the action of light, and such changes are usually reversible, that is, the material can return to its original state after the light is removed. In recent years, photoisomerization materials have attracted much attention due to their potential applications in fields such as sensors, actuators, energy harvesting, display technologies, and biomedicine. For example, in the field of sensors, photoisomerization materials can be used to manufacture photosensitive sensors and photodetectors to detect changes in light intensity in the environment. In the field of actuators, photoisomerization materials can be used to manufacture photo-deformable materials to achieve fast and controllable mechanical motion. In the field of energy harvesting, photoisomerization materials can be used to manufacture solar cells and photoelectric conversion devices to efficiently convert light energy into electrical energy. In the field of display technologies, photoisomerization materials can be used to manufacture photochromic devices to achieve dynamic image display. In the field of biomedicine, photoisomerization materials can be used to manufacture drug delivery systems and bioimaging technologies to achieve precise medical treatment and diagnosis. Currently, the photoisomerization molecules reported in the literature mainly include compounds such as azobenzene, diarylethene, and spiropyran. These compounds can usually undergo reversible cis-trans isomerization or cyclization reactions under ultraviolet or visible light irradiation, thereby achieving the photochemical rearrangement of molecules.

[0003] Imines are another important class of photoisomerization molecules. Imine compounds with hydroxyl groups introduced into their molecular skeletons may achieve photoisomerization responses through intramolecular proton transfer and bond rotation. However, compared with compounds such as azobenzene, diarylethene, and spiropyran, there are still relatively few literature reports on the photoisomerization responses of imine compounds. Moreover, the imine compounds with photoisomerization responses reported in the current literature usually only respond to ultraviolet light, and imine compounds with photoisomerization responses under visible light irradiation are very rare. Therefore, the development of imine compounds with strong photoisomerization responses under visible light can not only effectively expand the functionality and application scenarios of such materials, but also enrich the types of photoisomerization materials.

[0004] In the process of practical applications, the photoinduced changes of photo-isomerizable molecules are usually limited to the microscopic scale, which restricts their effectiveness in practical applications. To overcome this limitation, researchers have started to explore the compounding of photo-isomerizable molecules with suitable polymer materials in order to achieve the amplification of microscopic deformation to macroscopic deformation. The polymer materials used for compounding usually have good optical transparency, sufficient mechanical strength, and good compatibility with photo-isomerizable molecules. By uniformly dispersing photo-isomerizable molecules in the polymer matrix, a new type of composite material can be constructed. This composite material not only retains the photosensitivity of photo-isomerizable molecules but also realizes the amplification of photoinduced deformation through the mechanical support of the polymer. Currently, this type of composite material has shown great application potential in fields such as sensors, actuators, and energy harvesting. However, currently, the amplification of photoinduced deformation of this type of composite material is still achieved under the irradiation of ultraviolet light. Summary of the Invention

[0005] The object of the present invention is to provide an imine compound to solve the problem that the photo-isomerizable molecules in imine compounds in the prior art cannot have a strong photo-isomerization response under visible light.

[0006] The present invention also provides a preparation method of an imine compound to solve the problem that the photo-isomerizable molecules in imine compounds in the prior art cannot have a strong photo-isomerization response under visible light.

[0007] The present invention also provides a preparation method of a composite material of an imine compound to solve the problem that the composite material of imine compounds in the prior art cannot achieve the amplification of photoinduced deformation under visible light.

[0008] The present invention also provides a composite material of an imine compound to solve the problem that the composite material of imine compounds in the prior art cannot achieve the amplification of photoinduced deformation under visible light.

[0009] To solve the above problems, the present invention proposes an imine compound, and the technical solution adopted is: An imine compound, the general chemical structure formula of the imine compound is:

[0010] Among them, in Formula 1, Formula 2, Formula 3, Formula 4, Formula 5, and Formula 6, n is selected from any one of -NO2, F, and Cl.

[0011] The beneficial effect of the present invention is: The imine compounds of the present invention can exhibit reversible photo-isomerization responses through intramolecular proton transfer and bond rotation within the imine compounds; and since such imine compounds mainly exist in the form of molecular crystals, the angular change between the two naphthalene rings in the molecule caused by bond rotation can induce lattice deformation and further lead to the deformation of the entire molecular crystal. Therefore, it can exhibit reversible photo-isomerization responses under visible light irradiation. For the imine compounds of this application, when the molecular crystals of the imine compounds are irradiated with visible light, photo-induced volume shrinkage and expansion can occur. It has strong photo-isomerization responses under visible light, which can not only effectively expand the functionality and application scenarios of imine compounds, but also enrich the types of photo-isomerization materials.

[0012] The imine compounds have reversible photo-isomerization responses under visible light. The reversible photo-isomerization responses are generated through intramolecular proton transfer and bond rotation within the imine molecules in the imine compounds. The schematic diagram of the reversible photo-isomerization responses is as follows: 。

[0013] It shows that the chemical structure of the imine molecules of the imine compounds can change correspondingly before and after being irradiated with visible light.

[0014] The present invention also proposes a preparation method for imine compounds. The technical solution adopted is: A preparation method for imine compounds includes the following steps: 2-hydroxy-1-naphthaldehyde or 2-hydroxy-1-naphthaldehyde derivatives and 1-naphthylamine derivatives are dissolved in an organic solvent and then subjected to an aldehyde-amine condensation reaction to obtain a precipitate. The precipitate is filtered and washed to obtain imine compounds.

[0015] In order to obtain the above-mentioned imine compounds, preferably, the 2-hydroxy-1-naphthaldehyde derivatives are selected from one of 4-nitro-2-hydroxy-1-naphthaldehyde, 4-fluoro-2-hydroxy-1-naphthaldehyde, 4-chloro-2-hydroxy-1-naphthaldehyde, 3-nitro-2-hydroxy-1-naphthaldehyde, 3-fluoro-2-hydroxy-1-naphthaldehyde, and 3-chloro-2-hydroxy-1-naphthaldehyde; the 1-naphthylamine derivatives are selected from one of 1-naphthylmethylamine, 1-naphthylamine, 4-nitro-1-naphthylamine, 4-fluoro-1-naphthylamine, 4-chloro-1-naphthylamine, 3-nitro-1-naphthylamine, 3-fluoro-1-naphthylamine, 3-chloro-1-naphthylamine, 2-nitro-1-naphthylamine, 2-fluoro-1-naphthylamine, and 2-chloro-1-naphthylamine; the organic solvents are selected from at least one of ethanol, toluene, xylene, ethylbenzene, acetone, dimethyl sulfoxide, ethyl acetate, tetrahydrofuran, DMF, NMP, and chloroform.

[0016] To enable the aldehyde-amine condensation reaction to proceed fully, preferably, the temperature of the aldehyde-amine condensation reaction is 40 - 120°C, and the time is 0.5 - 24 hours.

[0017] The present invention also provides a method for preparing a composite material of an imine compound. The technical solution adopted is as follows: A method for preparing a composite material of an imine compound, comprising the following steps: The imine compound obtained by the above-mentioned imine compound or the preparation method of the above-mentioned imine compound and a polymer material are dissolved in a polar solvent and then compounded to obtain a mixed solution. The mixed solution is cast, dried, and heat-treated to obtain a composite material of an imine compound.

[0018] The beneficial effects of the present invention are: The composite material of the imine compound of the present invention realizes the conversion of the microscopic deformation of the photo-isomerizable molecule into the macroscopic deformation of the composite material, and it has a significant photo-induced deformation response under visible light irradiation. The preparation method of the composite material of the imine compound is simple and low in cost.

[0019] To enable the polymer material to have good optical transparency, sufficient mechanical strength, and good compatibility with the photo-isomerizable molecule, preferably, the polymer material is selected from any one of polyvinylidene fluoride, poly(vinylidene fluoride-trifluoroethylene), poly(vinylidene fluoride-hexafluoropropylene), polyvinyl chloride, polyethylene terephthalate, and polycarbonate.

[0020] To enable the imine compound to be fully dissolved, preferably, the polar solvent includes at least one of toluene, xylene, ethylbenzene, dimethyl sulfoxide, ethyl acetate, acetone, chloroform, tetrahydrofuran, DMF, and NMP.

[0021] To fully dry the polar solvent in the composite material of the imine compound and effectively remove the residual polar solvent and improve the crystallinity, preferably, the drying temperature is 40 - 120°C, and the time is 0.25 - 10 hours; the heat treatment temperature is 80 - 150°C, and the time is 0.5 - 24 hours.

[0022] The present invention also provides a composite material of an imine compound. The technical solution adopted is as follows: A composite material of an imine compound, which is prepared by the preparation method of the composite material of the imine compound described above.

[0023] The beneficial effects of the present invention are: The composite material of the imine compound of the present application can produce significant photoinduced deformation under visible light. It can generate a high photoinduced deformation displacement of 2 mm under visible light irradiation, showing a significant photoinduced deformation response, which proves that the composite material of the imine compound of the present application can be used to construct photoactuators, artificial muscles and soft robots. Description of the Drawings

[0024] Figure 1 1H NMR spectrum of N-(1-naphthalenemethyl)-2-hydroxy-1-naphthalimine obtained in Example 1 of the preparation method of the imine compound of the present invention.

[0025] Figure 2 1H NMR spectrum of N-(4-nitro-1-naphthyl)-2-hydroxy-1-naphthalimine obtained in Example 2 of the preparation method of the imine compound of the present invention.

[0026] Figure 3 Morphologies of the molecular crystal of N-(1-naphthalenemethyl)-2-hydroxy-1-naphthalimine obtained in Example 1 of the preparation method of the imine compound of the present invention before and during light irradiation.

[0027] Figure 4 Morphologies of the molecular crystal of N-(4-nitro-1-naphthyl)-2-hydroxy-1-naphthalimine obtained in Example 2 of the preparation method of the imine compound of the present invention before and during light irradiation.

[0028] Figure 5 Reversible photoinduced deformation displacement change curve of the composite material of the imine compound obtained in Example 1 of the preparation method of the composite material of the imine compound of the present invention under blue light irradiation.

[0029] Figure 6 Reversible photoinduced deformation displacement change curve of the composite material of the imine compound obtained in Example 2 of the preparation method of the composite material of the imine compound of the present invention under green light irradiation. Detailed Description of the Invention

[0030] The photo-isomerized molecules in the imine compounds in the prior art cannot have a strong photo-isomerization response under visible light. The present invention provides an imine compound, and the general chemical structure formula of the imine compound is:

[0031] Wherein, in Formula 1, Formula 2, Formula 3, Formula 4, Formula 5 and Formula 6, n is selected from any one of -NO2, F and Cl.

[0032] The technical concept of the present invention is as follows: For the imine compounds of the present application, in the imine molecules containing aromatic rings, the carbon-nitrogen double bond forms a conjugated system with the aromatic ring, which expands the range of electron delocalization, thereby enhancing the molecular structure stability and increasing the energy barrier of its photoisomerization reaction. Usually, ultraviolet light with higher energy is required for excitation. Introducing a methylene group into the molecular skeleton can effectively break the conjugated system and localize the electron distribution, thereby improving the photoreaction activity. Similarly, introducing strong electron-withdrawing groups such as nitro or fluorine atoms can reduce the electron cloud density of the aromatic ring and weaken its conjugation with the imine group, thus reducing the photoresponse energy barrier and increasing the photoreaction activity. Therefore, the imine compounds of the present invention can produce reversible photoisomerization responses through intramolecular proton transfer and bond rotation within the imine compounds; and since such imine compounds mainly exist in the form of molecular crystals, the angular change between the two naphthalene rings in the molecule caused by bond rotation can cause lattice deformation and further lead to the deformation of the entire molecular crystal. Therefore, it can exhibit a reversible photoisomerization response under visible light irradiation. For the imine compounds of the present application, when visible light is irradiated on the molecular crystals of the imine compounds, photoinduced volume shrinkage and expansion can occur. It has a strong photoisomerization response under visible light, which can not only effectively expand the functionality and application scenarios of imine compounds, but also enrich the types of photoisomerization materials.

[0033] Specifically, the preparation method of the imine compound includes the following steps: Dissolve 2-hydroxy-1-naphthaldehyde or 2-hydroxy-1-naphthaldehyde derivative and 1-naphthylamine derivative in an organic solvent. After the two are completely dissolved, heat the solution to 40 - 120 °C and carry out the aldehyde-amine condensation reaction for 0.5 - 24 hours; after the aldehyde-amine condensation reaction ends and cools to room temperature, filter the obtained precipitate and wash the precipitate repeatedly with absolute ethanol to obtain the imine compound. Among them, the 2-hydroxy-1-naphthaldehyde derivative is selected from one of 4-nitro-2-hydroxy-1-naphthaldehyde, 4-fluoro-2-hydroxy-1-naphthaldehyde, 4-chloro-2-hydroxy-1-naphthaldehyde, 3-nitro-2-hydroxy-1-naphthaldehyde, 3-fluoro-2-hydroxy-1-naphthaldehyde, and 3-chloro-2-hydroxy-1-naphthaldehyde; the 1-naphthylamine derivative is selected from one of 1-naphthylmethylamine, 1-naphthylamine, 4-nitro-1-naphthylamine, 4-fluoro-1-naphthylamine, 4-chloro-1-naphthylamine, 3-nitro-1-naphthylamine, 3-fluoro-1-naphthylamine, 3-chloro-1-naphthylamine, 2-nitro-1-naphthylamine, 2-fluoro-1-naphthylamine, and 2-chloro-1-naphthylamine; the organic solvent is selected from at least one of ethanol, toluene, xylene, ethylbenzene, acetone, dimethyl sulfoxide, ethyl acetate, tetrahydrofuran, DMF, NMP, and chloroform.

[0034] Taking the imine compound N-(1-naphthylmethyl)-2-hydroxy-1-naphthalene methanimine as an example, its specific reaction formula is shown as follows: 。

[0035] Specifically, the preparation method of the composite material of the imine compound includes the following steps: After the above-mentioned imine compound and the polymer material are dissolved in a polar solvent and stirred and compounded, a mixed solution is obtained. The mixed solution is cast, dried, and heat-treated to obtain the composite material of the imine compound. Among them, the drying temperature is 40 - 120 °C, and the time is 0.25 - 10 hours; the heat treatment temperature is 80 - 150 °C, and the time is 0.5 - 24 hours.

[0036] The following specifically describes the implementation process of the present invention with reference to specific examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. Additionally, it should be noted that for the sake of description, only the parts related to the invention are shown in the examples. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following will refer to the embodiments to specifically describe the present application. It should be noted that the endpoints and any values within the ranges disclosed herein are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values within each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0037] In the following embodiments, among the raw materials used, the CAS number of 2-hydroxy-1-naphthaldehyde is 708-06-5; the CAS number of 4-nitro-1-naphthylamine is 776-34-1; the CAS number of 1-naphthylmethylamine is 118-31-0; the CAS number of polyvinylidene fluoride is 24937-79-9; the CAS number of poly(vinylidene fluoride-trifluoroethylene) is 28960-88-5. The remaining raw materials are all ordinary commercially available products that can be directly purchased or can be prepared according to the conventional techniques in the art.

[0038] I. Specific Embodiments of the Preparation Method of the Imine Compound of the Present Invention Example 1 The chemical structural formula of the imine compound provided in this example is: 。

[0039] The preparation method of this imine compound includes the following steps: Dissolve 2-hydroxy-1-naphthaldehyde and 1-naphthylamine in absolute ethanol. After complete dissolution of both, heat the solution to 50 °C and carry out the aldehyde-amine condensation reaction for 5 hours. After the aldehyde-amine condensation reaction is completed and cooled to room temperature, filter the obtained yellow precipitate (product), and repeatedly wash the yellow precipitate with absolute ethanol to obtain the imine compound, namely N-(1-naphthylmethyl)-2-hydroxy-1-naphthalimine.

[0040] Example 2 The chemical structural formula of the imine compound provided in this example is:

[0041] The preparation method of this imine compound includes the following steps: Dissolve 2-hydroxy-1-naphthaldehyde and 4-nitro-1-naphthylamine in absolute ethanol. After complete dissolution of both, heat the solution to 75 °C and carry out the aldehyde-amine condensation reaction for 5 hours. After the aldehyde-amine condensation reaction is completed and cooled to room temperature, filter the obtained red precipitate (product), and repeatedly wash the red precipitate with absolute ethanol to obtain the imine compound, namely N-(4-nitro-1-naphthyl)-2-hydroxy-1-naphthalimine.

[0042] In this application, the 2-hydroxy-1-naphthaldehyde derivative is selected from one of 4-nitro-2-hydroxy-1-naphthaldehyde, 4-fluoro-2-hydroxy-1-naphthaldehyde, 4-chloro-2-hydroxy-1-naphthaldehyde, 3-nitro-2-hydroxy-1-naphthaldehyde, 3-fluoro-2-hydroxy-1-naphthaldehyde, and 3-chloro-2-hydroxy-1-naphthaldehyde, and the obtained imine compound has the same effect as the above-mentioned imine compound.

[0043] In this application, the 1-naphthylamine derivative is selected from one of 1-naphthylamine, 4-fluoro-1-naphthylamine, 4-chloro-1-naphthylamine, 3-nitro-1-naphthylamine, 3-fluoro-1-naphthylamine, 3-chloro-1-naphthylamine, 2-nitro-1-naphthylamine, 2-fluoro-1-naphthylamine, and 2-chloro-1-naphthylamine, and the obtained imine compound has the same effect as the above-mentioned imine compound.

[0044] In this application, the organic solvent is selected from at least one of toluene, xylene, ethylbenzene, acetone, dimethyl sulfoxide, ethyl acetate, tetrahydrofuran, DMF, NMP, and chloroform, and the composite material of the obtained imine compound has the same effect as the composite material of the above-mentioned imine compound.

[0045] II. Specific examples of the preparation method of the composite material of the imine compound of the present invention Example 1 The preparation method of the composite material of the imine compound provided in this example includes the following steps: First, N-(1-naphthalenemethyl)-2-hydroxy-1-naphthalimine and poly(vinylidene fluoride-trifluoroethylene) were dissolved in N,N-dimethylformamide (DMF) and stirred for complexation overnight to obtain a mixed solution. Then, the uniformly mixed solution was cast on a clean glass plate and dried in an oven at 80 °C for 2 h to obtain a composite film. Next, after the composite film was naturally cooled to room temperature, it was peeled off from the glass plate and heat-treated in a vacuum oven at 100 °C for 5 h to obtain a thin film of the composite material of the imine compound. Among them, the volume of the thin film of the composite material of the imine compound was 25 mm × 3 mm × 60 μm. Example 2 The preparation method of the composite material of the imine compound provided in this example includes the following steps: First, N-(4-nitro-1-naphthyl)-2-hydroxy-1-naphthalimine and polyvinylidene fluoride were dissolved in N,N-dimethylformamide (DMF) and stirred for complexation overnight to obtain a mixed solution. Then, the uniformly mixed solution was cast on a clean glass plate and dried in an oven at 80 °C for 2 h to obtain a composite film. Next, after the composite film was naturally cooled to room temperature, it was peeled off from the glass plate and heat-treated in a vacuum oven at 100 °C for 5 h to obtain a thin film of the composite material of the imine compound. Among them, the volume of the thin film of the composite material of the imine compound was 25 mm × 3 mm × 60 μm.

[0046] In this application, the polymer material is selected from any one of poly(vinylidene fluoride-hexafluoropropylene), polyvinyl chloride, polyethylene terephthalate, and polycarbonate, and the composite material of the imine compound is obtained therefrom.

[0047] In this application, the polar solvent includes at least one of toluene, xylene, ethylbenzene, dimethyl sulfoxide, ethyl acetate, acetone, chloroform, tetrahydrofuran, and NMP, and the composite material of the imine compound obtained therefrom has the same effect as the above composite material of the imine compound.

[0048] III. Experimental Examples Experimental Example 1 Nuclear Magnetic Resonance Hydrogen Spectrum Detection of Imine Compounds The imine compound prepared in Example 1 of the preparation method of the above imine compound was subjected to nuclear magnetic resonance hydrogen spectrum detection. Specifically, the obtained imine compound was dissolved in deuterated chloroform and detected by nuclear magnetic resonance hydrogen spectrum. The results are as Figure 1 shown. It can be concluded that the successful synthesis of the N-(1-naphthalenemethyl)-2-hydroxy-1-naphthalimine molecule was verified by nuclear magnetic resonance hydrogen spectrum. 1 H NMR (600 MHz, Chloroform- d, δ): 14.97 (s, 1H), 8.93 (d, 1H), 8.05 (d, 1H), 7.91 (dd, 1H), 7.85 (d, 1H), 7.80 (d, 1H), 7.69 (d, 1H), 7.64 – 7.56 (m, 2H), 7.56 – 7.44 (m, 3H), 7.44 – 7.36 (m, 1H), 7.25 – 7.21 (m, 1H), 6.97 (d, 1H), 5.28 (s, 2H).

[0049] The imine compound prepared in Example 2 of the preparation method of the above imine compound was subjected to nuclear magnetic resonance hydrogen spectrum detection. Specifically, the obtained imine compound was dissolved in deuterated chloroform and detected by nuclear magnetic resonance hydrogen spectrum. The results are as Figure 2 shown. It can be concluded that the successful synthesis of N-(4-nitro-1-naphthyl)-2-hydroxy-1-naphthalimine methyleneimine molecule was verified by nuclear magnetic resonance hydrogen spectrum. 1H NMR (600 MHz, Chloroform-d, δ): 14.89 (d, 1H), 9.56 (d, 1H), 8.71 (dd, 1H), 8.42 (dd, 1H), 8.38 (d, 1H), 8.20 (d, 1H), 7.94 (d, 1H), 7.84–7.77 (m, 2H), 7.70 (ddt, 1H), 7.58 (tt, 1H), 7.42 (ddt, 1H), 7.31 (d, 1H), 7.24 (d, 1H).

[0050] Experimental Example 2 Detection of the morphology of the molecular crystal of the imine compound before and during light irradiation The morphology of the molecular crystal of the imine compound prepared in Example 1 of the preparation method of the above imine compound was detected before and during light irradiation. Specifically, the molecular crystal of N-(1-naphthylmethyl)-2-hydroxy-1-naphthalimine methyleneimine was irradiated with 450 nm blue light for 5 min, and the three-dimensional size change of the molecular crystal before and after irradiation was measured by AFM. The detection results are as Figure 3 shown. It can be seen that the length, width and height of the molecular crystal of N-(1-naphthylmethyl)-2-hydroxy-1-naphthalimine methyleneimine changed from 839.50, 843.50 and 303.957 nm before light irradiation to 796.15, 813.92 and 263.342 nm after light irradiation, showing a volume shrinkage of about 20%.

[0051] The morphology of the molecular crystal of the imine compound prepared in Example 2 of the preparation method of the above imine compound before and during light irradiation was detected. Specifically, the molecular crystal of N-(4-nitro-1-naphthyl)-2-hydroxy-1-naphthalene methimine was irradiated with 450 nm blue light for 5 minutes, and the three-dimensional size change of the molecular crystal before and after irradiation was measured using AFM. The detection results are as Figure 4 shown. It can be seen that the length, width, and height of the molecular crystal of N-(4-nitro-1-naphthyl)-2-hydroxy-1-naphthalene methimine changed from 2.72 μm, 518.16 nm, and 98.764 nm before light irradiation to 2.72 μm, 581.96 nm, and 103.292 nm after light irradiation, showing a volume expansion of about 17%.

[0052] Experimental Example 3 Detection of reversible photoinduced deformation displacement of the composite material of the imine compound The thin film of the composite material of the imine compound prepared in Example 1 of the preparation method of the above imine compound was irradiated with periodic 450 nm blue light with a power density of 50 mW / cm 2 , and its reversible photoinduced deformation displacement change was detected. The detection results are as Figure 5 shown. It can be seen that the thin film of the composite material of N-(1-naphthylmethyl)-2-hydroxy-1-naphthalene methimine can produce a high photoinduced deformation displacement of about 2 mm under periodic 450 nm blue light irradiation with a power density of 50 mW / cm 2 .

[0053] The thin film of the composite material of the imine compound prepared in Example 2 of the preparation method of the above imine compound was irradiated with periodic 532 nm green light with a power density of 50 mW / cm 2 , and its reversible photoinduced deformation displacement change was detected. The detection results are as Figure 6 shown. It can be seen that the thin film of the composite material of N-(4-nitro-1-naphthyl)-2-hydroxy-1-naphthalene methimine can produce a high photoinduced deformation displacement of about 1.4 mm under periodic 532 nm green light irradiation with a power density of 50 mW / cm 2 .

[0054] This shows that significant photoinduced volume changes can be observed when the molecular crystal of the imine compound of the present application is irradiated with visible light. It has a strong photo-isomerization response under visible light, which can not only effectively expand the functionality and application scenarios of imine compounds, but also enrich the types of photo-isomerization materials. The composite material of the amine compound of the present invention realizes the conversion of the microscopic deformation of the photo-isomerization molecule into the macroscopic deformation of the composite material, and it has a significant photoinduced deformation response under visible light irradiation.

[0055] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An imine compound, characterized in that, The general chemical structure formula of the imine compound is as follows: Among them, in Formula 1, Formula 2, Formula 3, Formula 4, Formula 5 and Formula 6, n is selected from any one of -NO2, F and Cl.

2. The imine compound according to claim 1, wherein The imine compound has a reversible photo-isomerization response under visible light. The reversible photo-isomerization response is generated by intramolecular proton transfer and bond rotation of the imine in the imine compound. The schematic diagram of the reversible photo-isomerization response is as follows: 。 3. The method for preparing an imine compound according to claim 1 or 2, characterized in that, It includes the following steps: 2-hydroxy-1-naphthaldehyde or a 2-hydroxy-1-naphthaldehyde derivative and a 1-naphthylamine derivative are dissolved in an organic solvent and then subjected to an aldehyde-amine condensation reaction to obtain a precipitate. The precipitate is filtered and washed to obtain the imine compound.

4. The method for preparing an imine compound according to claim 3, wherein The 2-hydroxy-1-naphthaldehyde derivative is selected from one of 4-nitro-2-hydroxy-1-naphthaldehyde, 4-fluoro-2-hydroxy-1-naphthaldehyde, 4-chloro-2-hydroxy-1-naphthaldehyde, 3-nitro-2-hydroxy-1-naphthaldehyde, 3-fluoro-2-hydroxy-1-naphthaldehyde and 3-chloro-2-hydroxy-1-naphthaldehyde; the 1-naphthylamine derivative is selected from one of 1-naphthylmethylamine, 1-naphthylamine, 4-nitro-1-naphthylamine, 4-fluoro-1-naphthylamine, 4-chloro-1-naphthylamine, 3-nitro-1-naphthylamine, 3-fluoro-1-naphthylamine, 3-chloro-1-naphthylamine, 2-nitro-1-naphthylamine, 2-fluoro-1-naphthylamine and 2-chloro-1-naphthylamine; the organic solvent is selected from at least one of ethanol, toluene, xylene, ethylbenzene, acetone, dimethyl sulfoxide, ethyl acetate, tetrahydrofuran, DMF, NMP and chloroform.

5. The preparation method of the imine compound according to claim 3, wherein, The temperature of the aldehyde-amine condensation reaction is 40 - 120 °C, and the time is 0.5 - 24 hours.

6. A method for preparing a composite material of an imine compound, characterized in that, It includes the following steps: The imine compound prepared by the imine compound described in Claim 1 or 2 or the preparation method of the imine compound described in any one of Claims 3 - 5 is dissolved in a polar solvent and compounded to obtain a mixed solution. The mixed solution is cast, dried and heat-treated to obtain a composite material of the imine compound.

7. The method for preparing the composite material of the imine compound according to claim 6, characterized in that, The polymer material is selected from any one of polyvinylidene fluoride, poly(vinylidene fluoride-trifluoroethylene), poly(vinylidene fluoride-hexafluoropropylene), polyvinyl chloride, polyethylene terephthalate and polycarbonate.

8. The preparation method of the composite material of the imine compound according to claim 6, characterized in that, The polar solvent includes at least one of toluene, xylene, ethylbenzene, dimethyl sulfoxide, ethyl acetate, acetone, chloroform, tetrahydrofuran, DMF and NMP.

9. The preparation method of the composite material of the imine compound according to claim 6, characterized in that, The temperature of the drying is 40 - 120 °C, and the time is 0.25 - 10 hours; the temperature of the heat treatment is 80 - 150 °C, and the time is 0.5 - 24 hours.

10. A composite material of an imine compound, characterized in that, It is prepared by the preparation method of the composite material of the imine compound described in any one of Claims 6 - 9.

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