Bis-p-methoxysalicylaldehyde 1,4-benzenedimethylamine schiff base, preparation method and application thereof

Abstract

The application discloses a kind of double para-methoxy salicylaldehyde 1,4-benzene dimethylamine Schiff base, its preparation method and application, the double para-methoxy salicylaldehyde 1,4-benzene dimethylamine Schiff base, structure is as shown in following formula I: I.According to the double para-methoxy salicylaldehyde 1,4-benzene dimethylamine Schiff base of the application has symmetrical structure, and in the salicylaldehyde fragment of Schiff base, hydrogen is substituted by methoxy in aldehyde group para position.Such that the double para-methoxy salicylaldehyde 1,4-benzene dimethylamine Schiff base provided by the application can satisfy the condition of body three-dimensional display application.I.e.it can emit light and form body pixel point at the intersection of isomer excitation light source and color change excitation light source, and emitting body pixel point can be quickly switched, so, three-dimensional display can be realized using human visual persistence.

Description

Technical Field

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

[0002] The photochromic properties of Schiff bases have been applied in fields such as optical information storage, anti-counterfeiting, and textiles. However, the potential applications of Schiff bases in the field of volumetric 3D displays remain to be explored. 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(p-methoxysalicylic acid)-1,4-phenylenediamine Schiff base, which can form rapidly switching volume pixels under the combined irradiation of an isomer excitation light source and a color-changing excitation light source, thereby forming a three-dimensional image.

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

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

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

[0007]

[0008] The bis-p-methoxysalicylic acid acetal 1,4-phenylenediamine Schiff base according to a specific embodiment of the present invention has a symmetrical structure, and in the salicylaldehyde segment of the Schiff base, the hydrogen at the para-position of the aldehyde group is replaced by a methoxy group. This allows the bis-p-methoxysalicylic acid acetal 1,4-phenylenediamine Schiff base provided by the present invention to meet the requirements for volumetric 3D display applications. Specifically, it can emit light at the intersection of an isomer-excited light source and a color-changing excitation light source. The photochromic and luminescent reversible reaction is fast, enabling the construction of a series of luminescent voxels in space, and the voxels can be switched rapidly. Thus, volumetric 3D display (i.e., 3D imaging) is achieved by utilizing the persistence of human vision.

[0009] According to a second aspect of the present invention, the present invention provides a method for preparing a bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base, comprising the following steps: mixing p-methoxysalicylic acid and 1,4-phenylenediamine in anhydrous ethanol at a molar ratio of 2 to 3:1, refluxing for 2 to 4 hours, cooling, filtering, and washing to obtain the target product.

[0010] According to a third aspect of the present invention, the present invention provides an application of the bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base, wherein the bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base is applied to three-dimensional imaging.

[0011] According to some embodiments of the present invention, the bis(p-methoxysalicylic acid)-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.

[0012] According to some embodiments of the present invention, the following steps are included: uniformly dispersing the bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base in a medium to form the bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base photochromic material;

[0013] 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.

[0014] 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.

[0015] According to some embodiments of the present invention, in the photochromic material, the weight ratio of the bis(p-methoxysalicylic acid)-1,4-phenylenediamine Schiff base to the medium is 1:5000 to 10000.

[0016] According to some embodiments of the present invention, the medium includes at least one of dichloromethane, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide ethanol, epoxy resin, or polymethyl methacrylate.

[0017] 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.

[0018] According to some embodiments of the present invention, the wavelength of the ultraviolet light is 365 nm to 410 nm; and / or

[0019] The wavelength of the blue visible light is 440nm to 470nm.

[0020] 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.

[0021] 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.

[0022] 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

[0023] 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:

[0024] Figure 1 Flowchart of the preparation process of bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base according to a specific embodiment of the present invention;

[0025] Figure 2 : The 1H NMR spectrum of the Schiff base of bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine according to a specific embodiment of the present invention;

[0026] Figure 3 The absorption spectrum of the Schiff base of bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine according to a specific embodiment of the present invention;

[0027] Figure 4 A voxel luminescence photograph at the intersection of ultraviolet and blue visible light in a photochromic material formed by bis(p-methoxysalicylic acid) acetal condensed with 1,4-phenylenediamine Schiff base. According to a specific embodiment of the present invention, this is a voxel luminescence photograph of a photochromic material formed by the intersection of ultraviolet and blue visible light. Detailed Implementation

[0028] 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.

[0029] The following is for reference. Figure 2 and Figure 3 The present invention describes a bis(p-methoxysalicylic acid) 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:

[0030]

[0031] The bis(p-methoxysaliyl)-1,4-phenylenediamine Schiff base according to a specific embodiment of the present invention has a symmetrical structure, and in the salicylaldehyde segment of the Schiff base, the hydrogen at the para-position of the aldehyde group is replaced by a methoxy group. This allows the bis(p-methoxysaliyl)-1,4-phenylenediamine Schiff base provided by the present invention to meet the requirements for volumetric 3D display applications. Specifically, it can emit light at the intersection of an isomer-excited light source and a color-changing excitation light source. Furthermore, the reversible reaction speed of photochromism and luminescence is fast, enabling the construction of a series of luminescent voxels in space, and the voxels can be switched rapidly. Thus, volumetric 3D display (i.e., 3D imaging) is achieved by utilizing the persistence of human vision. Specifically, bis(p-methoxysaliyl)-1,4-phenylenediamine is a symmetrical Schiff base, a Schiff base molecule with excited-state proton transfer properties, and has wide applications in the field of photochromism. Schiff bases with this structure have potential application value in optical memory storage and optical switches. Meanwhile, Schiff bases and their derivatives exhibit excellent fatigue resistance, with their photochromic forms in the crystalline state having lifetimes ranging from sub-microseconds to hundreds of days. The initial and photochromic forms differ significantly in nonlinear optical properties, making them suitable for optical logic devices based on high-harmonic generation. The simplest and most commonly assumed photochromic cycle of the Schiff base family is as follows: Upon excitation of the initial enol (trans-enol) tautomer, an ultrafast excited-state intramolecular proton transfer (ESIPT) occurs, producing an excited-state keto tautomer (cis-ketone or its zwitterionic form), exhibiting a typical strong Stokes shift fluorescence band. Then, structural changes resulting from the cleavage of intramolecular hydrogen bonds (rotation around C=C or CN bonds) produce a long-lived photochromic tautomer (trans-ketone or its zwitterionic form) in the ground state. Additionally, a voxel is a term used to distinguish between pixels and 3D images. A pixel is a point that constitutes a 2D image, while a voxel is a point that constitutes a 3D image. A 3D image is composed of many independent voxel points.

[0032] According to an embodiment of the second aspect of the present invention, in combination Figure 1 The present invention provides a method for preparing a Schiff base of bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine, comprising the following steps: mixing p-methoxysalicylic acid and 1,4-phenylenediamine in anhydrous ethanol at a molar ratio of 2 to 3:1, refluxing for 2 to 4 hours, cooling, filtering, and washing to obtain the target product.

[0033] The preparation method of bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base according to a specific embodiment of the present invention has low raw material cost, simple and easy preparation method, and is conducive to industrial production.

[0034] According to a third aspect of the present invention, the present invention provides an application of the bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base, which is applied to three-dimensional imaging.

[0035] According to embodiments of the present invention, the present invention provides an application of the bis(p-methoxysaliyl)-1,4-phenylenediamine Schiff base in three-dimensional imaging. On one hand, the bis(p-methoxysaliyl)-1,4-phenylenediamine Schiff base of the present invention has a fluorescence control function; that is, the bis(p-methoxysaliyl)-1,4-phenylenediamine Schiff base of the present invention can construct luminescent voxels in the imaging space under simultaneous excitation by two different light sources (an isomer excitation source and a color-changing excitation source). The internal structure of the bis(p-methoxysaliyl)-1,4-phenylenediamine Schiff base can be altered by illumination, thereby generating fluorescence. The fluorescence generation process and principle are as follows: After the initial enol (trans-enol) tautomer is excited, an ultrafast intramolecular proton transfer (ESIPT) occurs, producing an excited-state keto tautomer (cis-ketone or its zwitterionic form). Then, through structural changes resulting from the cleavage of intramolecular hydrogen bonds (rotation around the C=C or CN bond), a photochromic tautomer (trans-ketone or its zwitterionic form) is generated in the ground state. Then, under the excitation of a color-changing excitation light source, the photochromic tautomer can construct luminescent voxels or three-dimensional images in the imaging space. On the other hand, the bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base of this invention can construct luminescent voxels in the imaging space under the simultaneous excitation of two different light sources (isomeric excitation light source and color-changing excitation light source), and can recover in a very short time; that is, when one of the isomer excitation light source and the color-changing excitation light source stops irradiation, the luminescent voxels can be rapidly eliminated. In this way, the luminescent voxels can be switched rapidly, utilizing the persistence of human vision to achieve volumetric 3D display (i.e., 3D imaging). Therefore, the ability to construct spatial voxels using the bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base of this invention, which allows for rapid switching, is of great significance for promoting the advancement and widespread application of volumetric 3D display technology.

[0036] According to some embodiments of the present invention, the bis(p-methoxysaliyl)-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. In a specific embodiment of the present invention, the bis(p-methoxysaliyl)-1,4-phenylenediamine Schiff base can construct photoluminescent voxels in the imaging space under simultaneous excitation by two different light sources (an isomer excitation light source and a color-changing excitation light source), and can recover within a very short time, enabling rapid switching of a series of photoluminescent voxels, thus achieving three-dimensional volumetric display by utilizing the persistence of human vision.

[0037] According to some embodiments of the present invention, the method includes the following steps: uniformly dispersing bis(p-methoxysalicylic acid) 1,4-phenylenediamine Schiff base in a medium to form a photochromic material of bis(p-methoxysalicylic acid) 1,4-phenylenediamine Schiff base. This configuration results in a photochromic material formed by uniformly dispersing bis(p-methoxysalicylic acid) 1,4-phenylenediamine Schiff base in a medium, exhibiting uniform morphology, high stability, and ease of imaging.

[0038] Photochromic materials are irradiated with both isomeric and color-changing excitation sources, forming photopixel dots at the intersection of these sources. This setup utilizes the isomeric excitation source to excite the Schiff base of bis(p-methoxysalicylic acid)-1,4-phenylenediamine, causing a structural change, while the color-changing excitation source works in conjunction with the isomeric excitation source to form photopixel dots or three-dimensional images. The combined effect of the isomeric and color-changing excitation sources causes the photochromic material to exhibit photochromic behavior, thus forming photopixel dots.

[0039] By controlling the scanning path and scanning speed of the isomer excitation source and the color-changing excitation source in the photochromic material, three-dimensional imaging can be achieved. In this configuration, the isomer excitation source and the color-changing source work together to change the color of the photochromic material, thus forming voxel dots, which can be rapidly switched. By utilizing the persistence of vision in humans and controlling the scanning path and scanning speed of the two light sources illuminating the photochromic material, a three-dimensional image formed by voxel transformation can be obtained.

[0040] The application of the bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base of the present invention in the formation of photochromic voxels and subsequently three-dimensional images employs both isomer-excitation and color-changing excitation light sources to simultaneously irradiate the photochromic material, thereby achieving the formation of photochromic voxels within the material, with rapid switching between the luminescent voxels. Utilizing the persistence of human vision, the scanning path and scanning speed of the two light sources irradiating the photochromic material are controlled to achieve volumetric three-dimensional display (i.e., three-dimensional imaging).

[0041] According to some embodiments of the present invention, in the photochromic material, the weight ratio of the bis(p-methoxysalicylic acid)-1,4-phenylenediamine Schiff base to the medium is 1:5000 to 10000. With this setting, the content of the bis(p-methoxysalicylic acid)-1,4-phenylenediamine Schiff base in the photochromic material is moderate, the photochromic material is colorless, and the photochromic phenomenon is obvious.

[0042] 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, or polymethyl methacrylate. The bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base provided in this invention exhibits high transparency, good stability, and 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(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base is dissolved in the above-mentioned organic solvent to form a solution of the bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base. When the medium is at least one selected from epoxy resin and polymethyl methacrylate, the bis(p-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 solid optical materials may include the following process: uniformly mixing methoxysalicylic acid acetal condensed with 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.

[0043] 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(p-methoxysalicylic acid)-1,4-phenylenediamine.

[0044] 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 photopixel dots from the structurally modified bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base (cis-ketone or its zwitterionic form).

[0045] 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.

[0046] According to other embodiments of the present invention, the wavelength of blue visible light is 440 nm to 470 nm. This setting provides a suitable wavelength range for blue visible light, which is sufficient to meet the requirements for forming optical voxels.

[0047] 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 can be 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.

[0048] Specific exemplary embodiments

[0049] Example 1

[0050] A bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base, with the structure shown in Formula I below:

[0051]

[0052] Its preparation method is as follows:

[0053] 3.19 g of p-methoxysalicylaldehyde and 1.36 g of 1,4-phenylenediamine were mixed in 50 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 filtered to obtain the precipitate. The precipitate was 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.

[0054] Example 2

[0055] A bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base, with the structure shown in Formula I below:

[0056]

[0057] Its preparation method is as follows:

[0058] 1.90 g of p-methoxysalicylaldehyde and 0.68 g of 1,4-phenylenediamine were mixed in 25 mL of anhydrous ethanol and refluxed for 3 h. The mixture was then rotary evaporated to a volume of 5 mL, cooled to 0 °C, filtered to obtain the precipitate, and washed three times with cold ethanol to obtain the target product.

[0059] Example 3

[0060] The application of a bis(p-methoxysalicylic acid) acetal 1,4-phenylenediamine Schiff base in volumetric three-dimensional display (three-dimensional imaging) includes the following steps:

[0061] 1) Prepare a 0.1 mg / mL dimethyl sulfoxide solution of p-methoxysalicylic acid acetal 1,4-phenylenediamine, such as... Figure 4 As shown in a, the solution is colorless and transparent, which is the photochromic material;

[0062] 2) 365nm ultraviolet light and 450nm blue light are used as the excitation source for the isomer and the excitation source for the color-changing effect, respectively. The two light sources intersect perpendicularly inside the material, such as... Figure 4 b. The two light sources emit light at their intersection. By controlling the scanning paths of the two light sources within the aforementioned photochromic material, volumetric 3D display (3D imaging) can be achieved.

[0063] In the description of this invention, "a plurality of" means two or more.

[0064] In the description of this specification, the 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.

[0065] 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. The application of bis(4-methoxysalicylaldehyde)-p-phenylenediamine, characterized in that, The structure of the bis(4-methoxysalicylaldehyde) p-phenylenediamine is shown in Formula I below: Ⅰ； The bis(4-methoxysalicylaldehyde) p-phenylenediamine is used in three-dimensional imaging.

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

3. The application according to claim 2, characterized in that, The process includes the following steps: uniformly dispersing the bis(4-methoxysalicylaldehyde) p-phenylenediamine in a medium to form the bis(4-methoxysalicylaldehyde) p-phenylenediamine photochromic material; 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. 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.

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

5. The application according to claim 3, characterized in that, The medium includes at least one of dichloromethane, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide ethanol, epoxy resin, and polymethyl methacrylate.

6. The application according to claim 3, characterized in that, The isomer excitation source is ultraviolet light; and / or the color-changing excitation source is blue visible light.

7. The application according to claim 6, characterized in that, The wavelength of the ultraviolet light is 365nm to 410nm; and / or The wavelength of the blue visible light is 440nm to 470nm.

8. The application according to claim 7, 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