Double 3-(trifluoromethyl)salicylaldehyde 1,4-benzenedimethylamine schiff base, its preparation method and application

Abstract

The application discloses a kind of double 3-(trifluoromethyl) salicylaldehyde condensation 1,4-benzene dimethylamine schiff base, its preparation method and application, the double 3-(trifluoromethyl) salicylaldehyde condensation 1,4-benzene dimethylamine schiff base, structure is shown as formula I below: according to the double 3-(trifluoromethyl) salicylaldehyde condensation 1,4-benzene dimethylamine schiff base of the application has symmetry structure, and schiff base salicylaldehyde fragment, aldehyde group para hydrogen is replaced by methoxyl group.Such that the double 3-(trifluoromethyl) salicylaldehyde condensation 1,4-benzene dimethylamine schiff base provided by the application can meet the condition of body three-dimensional display application.I.e.can be in isomer excitation light source and color change excitation light source common irradiation intersection luminescence forms body pixel point.And photochromic, the reversible reaction speed of luminescence is fast, can construct a series of luminescence body pixel in space.Such, luminescence body pixel can be switched quickly, utilize human visual persistence realizes body three-dimensional display.

Description

Technical Field

[0001] This invention relates to the field of optical materials, and in particular to a bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base, its preparation method and application. Background Technology

[0002] Unlike projection-based light field imaging and integrated imaging, volumetric 3D display systems scan three-dimensional space using light spots or two-dimensional images, arranging these light spots, called "voxels," within the spatial volume to form three-dimensional objects. Viewers can directly perceive the spatial position (X, Y, Z) of these three-dimensional objects, gaining a superior visual experience. Currently, most volumetric 3D display systems rely on upconversion gases or solids as active light sources; however, these upconversion materials have low luminous efficiency, and it is difficult to fabricate larger display areas. Therefore, developing more efficient downconversion luminescent materials is of great significance for realizing volumetric 3D displays. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a bis-3-(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base with ultrafast, reversible molecular light-switching properties.

[0004] Another objective of this invention is to provide a method for preparing a bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base.

[0005] Another object of the present invention is to provide the application of a bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base.

[0006] According to the first aspect of the present invention, the bis-3-(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base has the structure shown in Formula I below:

[0007]

[0008]

[0009] The bis-3-(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base of this invention, according to a specific embodiment, has a symmetrical structure, with the trifluoromethyl group at the para-amino position stabilizing the molecular structure. This bis-3-(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base of the present invention exhibits ultrafast, reversible molecular light-switching performance. Under irradiation with an isomer excitation light source, it undergoes ESITT to generate an isomer; under irradiation with a color-changing excitation light source, the isomer is excited to emit light, and voxel point emission can be formed at the intersection of the two light sources. Therefore, the above two light sources can serve as active light sources for a volumetric 3D display system.

[0010] According to a second aspect of the present invention, the present invention provides a method for preparing a Schiff base of bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine, comprising the following steps: mixing p-methoxysalicylaldehyde and 1,4-phenylenediamine in anhydrous ethanol at a molar ratio of 2 to 2.5:1, refluxing for 2 to 4 hours, cooling, filtering, and washing to obtain the target product.

[0011] According to a third aspect of the present invention, the present invention provides an application of the bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base, wherein the bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base is applied to three-dimensional imaging.

[0012] According to some embodiments of the present invention, the bis3-(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base forms photopixel dots under the combined irradiation of a color-changing excitation light source and an isomer excitation light source.

[0013] According to some embodiments of the present invention, the following steps are included: uniformly dispersing the bis3-(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base in a medium to form the bis3-(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base photochromic material;

[0014] The photochromic material is irradiated with the isomer excitation light source and the color-changing excitation light source, and a photopixel point is formed at the intersection of the isomer excitation light source and the color-changing excitation light source.

[0015] By controlling the scanning path and scanning speed of the isomer excitation light source and the color-changing excitation light source in the photochromic material, three-dimensional imaging can be achieved.

[0016] According to some embodiments of the present invention, in the photochromic material, the weight ratio of the bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base and the medium is 1:5000 to 10000.

[0017] According to some embodiments of the present invention, the medium includes at least one selected from dichloromethane, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, ethanol, epoxy resin, and polymethyl methacrylate.

[0018] According to some embodiments of the present invention, the isomer excitation source is ultraviolet light; and / or the color-changing excitation source is blue visible light.

[0019] According to some embodiments of the present invention, the wavelength of the ultraviolet light is 365 nm to 410 nm; and / or

[0020] The wavelength of the blue visible light is 440–470 nm.

[0021] According to some embodiments of the present invention, the photochromic material is irradiated with the ultraviolet light and the blue visible light, and the ultraviolet light and the blue visible light intersect on the photochromic material, forming a yellow voxel dot at the intersection.

[0022] By controlling the scanning path and scanning speed of the ultraviolet light and the blue visible light, a three-dimensional image of yellow fluorescence can be obtained.

[0023] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0025] Figure 1 Flowchart of the preparation process of bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base according to a specific embodiment of the present invention;

[0026] Figure 2 : The 1H NMR spectrum of the Schiff base of bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine according to a specific embodiment of the present invention;

[0027] Figure 3 The absorption spectrum of the Schiff base of bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine according to a specific embodiment of the present invention;

[0028] Figure 4 A voxel luminescence photograph of the intersection of ultraviolet and blue visible light in a photochromic material formed by bis(trifluoromethyl)salicylaldehyde condensation with 1,4-phenylenediamine Schiff base according to a specific embodiment of the present invention. Detailed Implementation

[0029] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. The embodiments of the present invention are described in detail below.

[0030] The following is for reference. Figure 2 and Figure 3 The present invention describes a bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base according to an embodiment of the first aspect of the present invention, the structure of which is shown in Formula I below:

[0031]

[0032] The bis-3-(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base according to a specific embodiment of the present invention has a symmetrical structure, with the trifluoromethyl group at the para-amino position exhibiting stable molecular structure properties. It possesses ultrafast, reversible molecular light-switching properties, undergoing ESIPT to generate isomers under isomer excitation light source irradiation, and then emitting light from the isomers under color-changing excitation light source irradiation. Voxel point emission can be formed at the intersection of these two light sources. Therefore, these two light sources can serve as active light sources for a volumetric 3D display system. Specifically, the photochromism of the bis-3-(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base of the present invention is caused by excited-state intramolecular proton transfer (ESIPT), an ultrafast photoinduced conversion in which a proton moves between two electronegative centers via intramolecular hydrogen bonding. ESIPT allows for rapid redistribution of excitation energy over ultrashort timescales (even femtoseconds), thereby enhancing the photostability of the excited-state molecule. During proton transfer, a significant redistribution of electron density is usually observed, leading to a large emission Stokes shift. This opens up the possibility of tunable luminescence and, through potential stable ground-state isomers, produces light coloration, enabling selective molecular light switching and information storage. Therefore, Schiff bases with molecular light-switching properties also have potential application value in the field of volumetric 3D displays. Here, a voxel is a term that corresponds to a pixel; a pixel is a point that constitutes a two-dimensional image, while a voxel is a point that constitutes a three-dimensional image. A 3D image is composed of many independent voxel points.

[0033] According to an embodiment of the second aspect of the present invention, the present invention provides a method for preparing a Schiff base of bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine, comprising the following steps: mixing p-methoxysalicylaldehyde and 1,4-phenylenediamine in anhydrous ethanol at a molar ratio of 2 to 2.5:1, refluxing for 2 to 4 hours, cooling, filtering, and washing to obtain the target product.

[0034] The preparation method of bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base according to a specific embodiment of the present invention is simple, has high yield, low production cost, and can be commercially produced on a large scale.

[0035] According to a third aspect of the present invention, the present invention provides an application of the bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base, which is applied to three-dimensional imaging.

[0036] According to embodiments of the present invention, this invention provides an application of the bis(trifluoromethyl)salicylaldehyde 1,4-phenylenediamine Schiff base in three-dimensional imaging. The bis(trifluoromethyl)salicylaldehyde 1,4-phenylenediamine Schiff base of this invention possesses ultrafast, reversible molecular light-switching properties. Under irradiation with an isomer excitation light source, it undergoes ESIPT to generate an isomer. Under irradiation with a color-changing excitation light source, the isomer is excited to emit light. Voxel point emission can be formed at the intersection of the two light sources. Therefore, the two light sources can serve as active light sources for a volumetric three-dimensional display system. The photochromism of the bis(trifluoromethyl)salicylaldehyde 1,4-phenylenediamine Schiff base of this invention is caused by excited-state intramolecular proton transfer (ESIPT), an ultrafast photoinduced conversion in which a proton moves between two electronegative centers via intramolecular hydrogen bonding. ESIPT allows for rapid redistribution of excitation energy over ultrashort timescales (even femtoseconds), thereby enhancing the photostability of the excited-state molecule. During proton transfer, there is usually a significant redistribution of electron density, resulting in a large emission Stokes shift, which opens up the possibility of tunable luminescence and can generate photocoloring through potential stable ground-state isomers, enabling selective molecular light switching and information storage.

[0037] According to some embodiments of the present invention, the bis-3-(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base forms photoluminescent voxels under the combined irradiation of a color-changing excitation light source and an isomer excitation light source. The bis-3-(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base according to a specific embodiment of the present invention possesses ultrafast, reversible molecular light-switching performance. Under the action of the isomer excitation light source, an ESIT occurs to produce an isomer, and the color-changing excitation light source excites the isomer to emit light. The voxel emission can be controlled by converging these two light sources. Therefore, the above two light sources can serve as active light sources for a volumetric 3D display system to obtain photoluminescent voxels.

[0038] According to some embodiments of the present invention, the method includes the following steps: uniformly dispersing bis(trifluoromethyl)salicylaldehyde 1,4-phenylenediamine Schiff base in a medium to form a photochromic material of bis(trifluoromethyl)salicylaldehyde 1,4-phenylenediamine Schiff base. This configuration results in a photochromic material formed by uniformly dispersing bis(trifluoromethyl)salicylaldehyde 1,4-phenylenediamine Schiff base in a medium, exhibiting uniform morphology, high stability, and ease of imaging.

[0039] The photochromic material is irradiated with both an isomer excitation source and a color-changing excitation source, forming a photobulk point at the intersection of the two sources. This setup allows the isomer excitation source and the color-changing excitation source to work together, causing the photochromic material to exhibit a photochromic phenomenon, thus forming the photobulk point.

[0040] An isomer excitation source is used to excite the bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base to undergo a structural change. A color-changing excitation source is used in conjunction with the isomer excitation source to form photopixel dots. In this setup, the isomer excitation source irradiates the photochromic material, stimulating a structural change in the bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base; the color-changing excitation source simultaneously irradiates the photochromic material, causing it to change color in conjunction with the isomer excitation source, thus forming photopixel dots, which can be rapidly switched. This can be applied to the field of 3D imaging. Thus, the two light sources act as a photochromic switch for obtaining photopixel dots from the photochromic material.

[0041] Three-dimensional imaging can be achieved by controlling the scanning paths and scanning speeds of the isomer excitation light source and the color-changing excitation light source. In this setup, the combination of the isomer excitation light source and the photochromic material changes color, thus forming voxel dots, which can be rapidly switched. By utilizing the persistence of vision and controlling the scanning paths and scanning speeds of the two light sources illuminating the photochromic material, a three-dimensional image formed by voxel transformation can be obtained.

[0042] The application of the bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base of the present invention in the formation of photochromic dots or three-dimensional images involves simultaneously irradiating the photochromic material with an isomer excitation light source and a color-changing excitation light source to achieve the formation of photochromic dots in the photochromic material. Furthermore, the photochromic dots can be rapidly switched, utilizing the persistence of human vision to achieve volumetric three-dimensional display (i.e., three-dimensional imaging).

[0043] According to some embodiments of the present invention, in the photochromic material, the weight ratio of bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base to the medium is 1:5000 to 10000. With this setting, the content of bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base in the photochromic material is moderate, the photochromic material is colorless, and the photochromic phenomenon is obvious.

[0044] According to some embodiments of the present invention, the medium includes at least one selected from dichloromethane, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, ethanol, epoxy resin, and polymethyl methacrylate. The bis(trifluoromethyl)salicylic acid 1,4-phenylenediamine Schiff base provided in this invention exhibits high transparency, good stability, and good reversibility in media such as solutions, epoxy resins, and polymethyl methacrylate, which is beneficial for commercial applications. Specifically, when the medium is one or more organic solvents such as dichloromethane, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, or ethanol, the bis(trifluoromethyl)salicylic acid 1,4-phenylenediamine Schiff base dissolves in the aforementioned organic solvent to form a solution of the bis(trifluoromethyl)salicylic acid 1,4-phenylenediamine Schiff base. When the medium is at least one of epoxy resin and polymethyl methacrylate, the methoxysalicylic acid acetal 1,4-phenylenediamine Schiff base is dispersed in the polymer of epoxy resin and / or polymethyl methacrylate to form a solid optical material. For example, the formation of the solid optical material may include the following process: uniformly mixing the methoxysalicylic acid acetal 1,4-phenylenediamine Schiff base, epoxy resin and / or polymethyl methacrylate, adding an initiator (azobisisobutyronitrile), and reacting for 3 to 4 hours to form the above-mentioned solid optical material. The solid-liquid ratio of the initiator to methyl methacrylate satisfies: 1 mg to 3 mg : 0.5 ml to 1.5 ml. Thus, the 3-(trifluoromethyl)salicylic acid acetal 1,4-phenylenediamine Schiff base of the specific embodiment of the present invention exhibits high transparency and light color in solutions and media such as epoxy resin and polymethyl methacrylate, and can be stably stored and used for a long time.

[0045] According to some embodiments of the present invention, the excitation source for the isomer is ultraviolet light. This configuration provides strong ultraviolet light energy, sufficient to provide enough energy for the structural change of the Schiff base of bis(trifluoromethyl)salicylic acid acetal 1,4-phenylenediamine.

[0046] According to other embodiments of the invention, the color-changing excitation light source is blue visible light. This configuration allows the blue visible light to provide the energy or illumination required to generate photovoxel dots from the structurally modified bis-3-(trifluoromethyl)salicylic acid acetal 1,4-phenylenediamine Schiff base (cis-ketone or its zwitterionic form).

[0047] According to some embodiments of the present invention, the wavelength of the ultraviolet light is 365 nm to 410 nm. This setting provides a suitable wavelength range and sufficient energy for the ultraviolet light.

[0048] According to other embodiments of the present invention, the wavelength of blue visible light is 440–470 nm. This setting provides a suitable wavelength range for blue visible light, which is sufficient to meet the requirements for forming optical voxels.

[0049] According to some embodiments of the present invention, a photochromic material is irradiated with ultraviolet light and blue-visible light. The ultraviolet and blue-visible light converge within the photochromic material, forming yellow voxel dots at the convergence point. By controlling the scanning path and scanning speed of the ultraviolet and blue-visible light within the photochromic material, a three-dimensional image of yellow fluorescence is obtained. In this configuration, by controlling the scanning path and scanning speed of the photochromic material simultaneously irradiated with ultraviolet and blue-visible light, a three-dimensional image of yellow fluorescence can be formed within the photochromic material. This satisfies the image and color requirements of three-dimensional imaging.

[0050] Specific exemplary embodiments

[0051] Example 1

[0052] A bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base, with the structure shown in Formula I below:

[0053]

[0054] Its preparation method is as follows:

[0055] 9.00 g of 3-(trifluoromethyl)salicylaldehyde and 2.72 g of 1,4-phenylenediamine were mixed in 60 mL of anhydrous ethanol and refluxed for 4 h. The mixture was then rotary evaporated to a volume of 10 mL, cooled to 0 °C, and a precipitate was formed. The precipitate was filtered and washed three times with cold ethanol to obtain the target product. Figure 1 This is a process flow diagram of the preparation method. Figure 2 and Figure 3 The two images are the 1H NMR spectrum and absorption spectrum of the target product, respectively.

[0056] Example 2

[0057] A bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base, with the structure shown in Formula I below:

[0058]

[0059] Its preparation method is as follows:

[0060] 4.18 g of 3-(trifluoromethyl)salicylaldehyde and 1.36 g of 1,4-phenylenediamine were mixed in 40 mL of anhydrous ethanol and refluxed for 2 h. The mixture was then rotary evaporated to a volume of 6 mL and cooled to 0 °C to produce a precipitate. The precipitate was filtered and washed three times with cold ethanol to obtain the target product.

[0061] Example 3

[0062] The application of a bis(trifluoromethyl)salicylaldehyde acetal 1,4-phenylenediamine Schiff base in volumetric three-dimensional display (three-dimensional imaging) includes the following steps:

[0063] 1) Prepare an acetonitrile solution of 0.15 mg / mL of bis(trifluoromethyl)salicylic acid acetal condensed with 1,4-phenylenediamine Schiff base, such as... Figure 4 As shown in a, the solution is slightly yellow and transparent;

[0064] 2) Through absorption spectroscopy and continuously tunable laser testing, 365nm ultraviolet light was determined as the optimal wavelength for photochromism, and 450nm blue light was used as the fluorescence excitation source for the isomers. Figure 4 b, No voxel points when excited alone at 365nm; two light sources intersect perpendicularly within the material, such as... Figure 4 c. This generates voxel point illumination. The scanning paths and speeds of the two light sources can be controlled separately by a computer to complete the volumetric 3D display.

[0065] In the description of this invention, "a plurality of" means two or more.

[0066] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0067] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A bis-3-(trifluoromethyl)salicylaldehyde acetal-1,4-phenylenediamine, characterized in that, The structure is shown in Equation I below: Ⅰ。 2. The method for preparing bis-3-(trifluoromethyl)salicylic acid acetal-1,4-phenylenediamine according to claim 1, characterized in that, The process includes the following steps: 3-(trifluoromethyl)salicylaldehyde and 1,4-phenylenediamine are mixed in anhydrous ethanol at a molar ratio of 2 to 2.5:1, refluxed for 2 to 4 hours, cooled, filtered, and washed to obtain the target product.

3. The application of bis-3-(trifluoromethyl)salicylaldehyde-1,4-phenylenediamine according to claim 1 or the bis-3-(trifluoromethyl)salicylaldehyde-1,4-phenylenediamine prepared by the method of claim 2, characterized in that, The bis-3-(trifluoromethyl)salicylaldehyde acetal-1,4-phenylenediamine is used in three-dimensional imaging.

4. The application according to claim 3, characterized in that, The bis-3-(trifluoromethyl)salicylaldehyde-1,4-phenylenediamine forms photopixel dots under the combined irradiation of a color-changing excitation light source and an isomer excitation light source.

5. The application according to claim 3 or 4, characterized in that, The process includes the following steps: uniformly dispersing the bis-3-(trifluoromethyl)salicylaldehyde-1,4-phenylenediamine in a medium to form the photochromic material of the bis-3-(trifluoromethyl)salicylaldehyde-1,4-phenylenediamine; The photochromic material is irradiated with an isomer excitation light source and a color-changing excitation light source, and a photopixel point is formed at the intersection of the isomer excitation light source and the color-changing excitation light source. By controlling the scanning path and scanning speed of the isomer excitation light source and the color-changing excitation light source in the photochromic material, three-dimensional imaging can be achieved.

6. The application according to claim 5, characterized in that, In the photochromic material, the weight ratio of bis-3-(trifluoromethyl)salicylaldehyde acetal-1,4-phenylenediamine to the medium is 1:5000-10000.

7. The application according to claim 5, characterized in that, The medium includes at least one of dichloromethane, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, ethanol, epoxy resin, and polymethyl methacrylate.

8. The application according to claim 5, characterized in that, The isomer excitation source is ultraviolet light; and / or the color-changing excitation source is blue visible light.

9. The application according to claim 8, characterized in that, The wavelength of the ultraviolet light is 365nm to 410nm; and / or The wavelength of the blue visible light is 440–470 nm.

10. The application according to claim 8, characterized in that, When the photochromic material is irradiated with ultraviolet light and blue-visible light, the ultraviolet light and blue-visible light converge on the photochromic material, forming a yellow voxel dot at the convergence point. By controlling the scanning path and scanning speed of the ultraviolet light and the blue visible light in the photochromic material, a three-dimensional image of yellow fluorescence can be obtained.

Images