Preparation method and bulk three-dimensional application of 4-{[(E)-(2-phenylpropyl-2-yl) nitrogen subunit] methyl} benzene-1, 3-diphenol Schiff base

Abstract

The invention discloses a preparation method and volumetric three-dimensional application of 4-{[(E)-(2-phenylpropyl-2-yl) nitrogen subunit] methyl} benzene-1, 3-diphenol Schiff base, and particularly, the molecular structure of the Schiff base compound is as shown in the following formula (I): # imgabs0 #, R1 is C1-6 alkyl, R2 is aryl, and R3 is C1-12 alkyl. The Schiff base compound is high in transparency and good in light transmission in media such as solutions and solids, and can be stably stored and used for a long time.

Description

Technical Field

[0001] The present invention relates to the field of optical materials, and in particular to a preparation method and three-dimensional application of a 4-{[(E)-(2-phenylpropan-2-yl)nitrogenylidene]methyl}benzene-1,3-diphenol Schiff base. Background Art

[0002] The current 3D display technology can be divided into four categories: spectroscopic stereo glasses, automatic spectroscopic stereo display, hologram, and volumetric 3D display. The first two categories should be familiar to everyone. They all use parallax to give people a sense of 3D display: slightly different images are displayed for the left eye and the right eye respectively, thereby deceiving the brain and giving the observer a 3D feeling. Since the 3D scene constructed by artificially creating parallax is not natural, it increases the mental burden of the observer, so it will cause headaches if you watch it for a long time. Holograms do not use digital means, but the interference and diffraction of light waves. It can generally only generate static 3D optical scenes, and there are also requirements for the viewing angle. Therefore, for the time being, it is not suitable for human-computer interaction applications. Volumetric 3D display is different from the first three. It is a 3D technology that can truly achieve dynamic effects. It allows you to see the 3D perspective images that are generally "suspended" in the air in science fiction movies. Volumetric 3D display technology can currently be roughly divided into two types: scanning volume display and solid-state volume display. Among them, solid-state display technology mostly uses two light sources to form "spatial voxels" in the dielectric material, and draws three-dimensional images through the movement of spatial voxels, thereby achieving the purpose of three-dimensional display. It has the advantages of good vibration resistance, high brightness, and large-screen display.

[0003] In terms of volumetric 3D display applications, organic photochromic materials have shown great potential. Among them, Schiff base photochromic materials have attracted widespread attention from researchers due to their convenient synthesis, simple structure, fast color change speed, and cheap raw materials. However, in terms of volumetric 3D display, Schiff base dielectric materials still have many limiting factors in their application, such as weak photochromic fluorescence, strong single-frequency fluorescence, low material transparency, difficulty in selecting excitation and emission wavelengths, complex color change mechanism, and slow recovery speed. Summary of the invention

[0004] In order to solve the technical problem of the application of Schiff base with optical switching performance in volumetric three-dimensional display in the prior art, the present invention provides a preparation method of 4-{[(E)-(2-phenylpropane-2-yl) nitrogen subyl] methyl} benzene-1,3-diphenol Schiff base and its application in volumetric three-dimensional display. The solution reagent of the material has high transparency, no body color, stable properties, and has photofluorescence color change, that is, optical switching characteristics; under the excitation of two beams of light sources with specific wavelengths, photochromism and spatial fluorescence emission can be achieved, that is, "spatial voxel points" can be formed. The photochromic process of the material is a reversible process of thermal recovery. When there is no excitation light at room temperature, it can quickly recover to the initial state without fluorescence emission, which can realize the rapid automatic erasure of three-dimensional voxel points and achieve a real-time refresh dynamic display effect.

[0005] In the first aspect of the present invention, the present invention provides a Schiff base compound. According to an embodiment of the present invention, the molecular structure of the Schiff base compound is shown in the following formula (I):

[0006]

[0007] Among them, R 1 C 1-6 alkyl,

[0008] R 2 is an aryl group,

[0009] R 3 C 1-12 alkyl.

[0010] According to an embodiment of the present invention, the compound may further include at least one of the following additional technical features:

[0011] According to an embodiment of the present invention, R 1 It is methyl or ethyl.

[0012] According to an embodiment of the present invention, R 2 It is phenyl.

[0013] According to an embodiment of the present invention, R 3 It is methyl or ethyl.

[0014] According to an embodiment of the present invention, the compound represented by formula (I) is The -OCH3 of this compound is conjugated with the benzene ring, and the -C=N- is also conjugated with the benzene ring, which increases the conjugated system. In addition, both -OCH3 and -C=N- have electron-donating ability, which greatly increases the electron cloud density of the benzene ring, providing favorable conditions for the interconversion between the enol form and the keto form of the Schiff base, and playing a key role in its rapid response.

[0015] In another aspect of the present invention, the present invention also provides a method for preparing the Schiff base compound described above. According to an embodiment of the present invention, the method comprises: subjecting the compound represented by formula (A) and the compound represented by formula (B) to a reflux reaction to obtain the compound represented by formula (I);

[0016]

[0017] Among them, R 1 C 1-6 alkyl,

[0018] R 2 is an aryl group,

[0019] R 3 C 1-12 The raw materials of this method are easy to obtain, the cost is low, the synthesis and purification methods are simple and the yield is high, and the requirements for production equipment are low and large-scale production can be achieved.

[0020] According to an embodiment of the present invention, the above method may further include at least one of the following additional technical features:

[0021] According to an embodiment of the present invention, R 1 It is methyl or ethyl.

[0022] According to an embodiment of the present invention, R 2 It is phenyl.

[0023] According to an embodiment of the present invention, R 3 It is methyl or ethyl.

[0024] According to an embodiment of the present invention, the compound represented by formula (A) is 4-methoxysalicylaldehyde.

[0025] According to an embodiment of the present invention, the compound represented by formula (B) is 2-phenylpropan-2-amine.

[0026] According to an embodiment of the present invention, the compound represented by formula (I) is

[0027] According to an embodiment of the present invention, the temperature of the reflux reaction is 85-95°C.

[0028] According to an embodiment of the present invention, the reflux reaction time is 3 to 6 hours.

[0029] According to an embodiment of the present invention, the reflux reaction further includes a post-treatment operation.

[0030] According to an embodiment of the present invention, the post-treatment operation includes cooling, filtering, washing and recrystallizing the reflux reaction liquid.

[0031] According to an embodiment of the present invention, the molar ratio of the compound represented by formula (A) to the compound represented by formula (B) is 1:1.2-3.

[0032] According to an embodiment of the present invention, the molar ratio of the 4-methoxysalicylaldehyde to the 2-phenylpropan-2-amine is 1:1.2-3.

[0033] According to an embodiment of the present invention, the reflux reaction is carried out in ethanol.

[0034] According to an embodiment of the present invention, the ethanol is anhydrous ethanol.

[0035] According to an embodiment of the present invention, the molar ratio of the ethanol to the 4-methoxysalicylaldehyde is 30-100:1.

[0036] According to an embodiment of the present invention, the present invention further proposes the use of the Schiff base compound described above or the Schiff base compound prepared according to the above method in volumetric three-dimensional display.

[0037] According to an embodiment of the present invention, the above application may further include at least one of the following additional technical features:

[0038] According to an embodiment of the present invention, the display medium is one or more mixed solvents of acetonitrile, methyl tert-butyl ether, dimethyl sulfoxide, and ethyl acetate of 4-{[(E)-(2-phenylpropan-2-yl)nitrogenylidene]methyl}benzene-1,3-diphenol Schiff base, or a solid material doped in epoxy resin or polymethyl methacrylate.

[0039] According to an embodiment of the present invention, the mass ratio of the 4-{[(E)-(2-phenylpropan-2-yl)nitrogenylidene]methyl}benzene-1,3-diphenol Schiff base to the solvent is preferably 1:5000-10000.

[0040] According to an embodiment of the present invention, the method of volumetric three-dimensional display application is as follows:

[0041] (1) selecting a photochromic light source and an excitation light source for the photochromic isomer respectively;

[0042] (2) making the two light sources in step (1) intersect vertically inside the material to generate light-emitting voxel points;

[0043] (3) Control the light source scanning path and scanning speed to achieve volumetric three-dimensional applications.

[0044] According to an embodiment of the present invention, the excitation light source of the photochromic light source is 365nm-410nm blue light.

[0045] According to an embodiment of the present invention, the photochromic isomers are ultraviolet light and 440-470nm blue light.

[0046] According to the embodiments of the present invention, the present invention has at least one of the following technical effects:

[0047] 1) The 4-{[(E)-(2-phenylpropan-2-yl)nitrogenylidene]methyl}benzene-1,3-diphenol Schiff base provided in the present invention has readily available raw materials, low cost, simple synthesis and purification methods with high yield, low requirements on production equipment and can be produced on a large scale.

[0048] 2) The 4-{[(E)-(2-phenylpropan-2-yl)nitrogenylidene]methyl}benzene-1,3-diphenol Schiff base provided in the present invention, wherein -OCH3 is conjugated with the benzene ring and -C=N- is also conjugated with the benzene ring, thereby increasing the conjugated system, and both -OCH3 and -C=N- have electron-donating ability, thereby greatly increasing the electron cloud density of the benzene ring, providing favorable conditions for the interconversion between the enol form and the keto form of the Schiff base, and playing a key role in its rapid response.

[0049] 3) The intersection emits strong light and has a fast response speed. Under the action of one beam of light, ESIPT occurs to produce isomers, and another beam of light excites the isomers to emit light. The intersection of the two light sources can control the light emission of the voxel point. Its excellent response speed can be used as an active light source for the volumetric three-dimensional display system.

[0050] 4) The 4-{[(E)-(2-phenylpropan-2-yl)azine-ylidene]methyl}benzene-1,3-diphenol Schiff base provided in the present invention has high transparency and good light transmittance in solutions, solids and other media, and can be stably stored and used for a long time.

[0051] According to the embodiments of the present invention, the compound represented by formula (I) of the present invention is The difference is that the -C(=O)OR1 structure of the above-mentioned substance is connected to the benzene ring and has a strong electron-withdrawing ability, while the -OR 1 It has strong electron-donating ability and is conjugated with the benzene ring, -C=N- is also conjugated with the benzene ring, which increases the conjugated system. In addition, -OCH3 and -C=N- both have electron-donating ability, which greatly increases the electron cloud density of the benzene ring, providing favorable conditions for the interconversion of the Schiff base enol form and keto form, and plays a key role in its rapid response.

[0052] Terms and Definitions

[0053] Unless otherwise specified, the terms and definitions used in this application, including the specification and claims, are as follows.

[0054] The term "C 1-12The term "alkyl" is understood to mean preferably a linear or branched saturated monovalent hydrocarbon radical having 1 to 12 carbon atoms; the term "C1-C6 alkyl" is understood to mean a linear or branched saturated monovalent hydrocarbon radical having 1, 2, 3, 4, 5 or 6 carbon atoms. The alkyl radical is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl , 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl or 1,2-dimethylbutyl, etc. or their isomers. In particular, the radical has 1, 2, 3, 4, 5, 6 carbon atoms ("C1-C6 alkyl"), such as methyl, ethyl, propyl, butyl, isopropyl, isobutyl, sec-butyl, tert-butyl, more particularly, the radical has 1, 2 or 3 carbon atoms ("C1-C3 alkyl"), such as methyl, ethyl, n-propyl or isopropyl.

[0055] The term "aryl" is understood to mean any stable 6-10 membered monocyclic or bicyclic aromatic group, for example, phenyl, naphthyl, tetrahydronaphthyl, indanyl or biphenyl. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0057] Figure 1 The present invention provides a process flow chart for preparing 4-{[(E)-(2-phenylpropan-2-yl)nitrogenylidene]methyl}benzene-1,3-diphenol Schiff base;

[0058] Figure 2 The hydrogen nuclear magnetic spectrum of the 4-{[(E)-(2-phenylpropan-2-yl)nitrogenylidene]methyl}benzene-1,3-diphenol Schiff base provided by the present invention;

[0059] Figure 3 The absorption spectrum of the 4-{[(E)-(2-phenylpropan-2-yl)nitrogenylidene]methyl}benzene-1,3-diphenol Schiff base provided by the present invention;

[0060] Figure 4 The present invention provides luminescent photos of 4-{[(E)-(2-phenylpropan-2-yl)nitrogen subunit]methyl}benzene-1,3-diphenol Schiff base voxel points. a) Photo of a solution of a Schiff base material, b) Photo of the intersection of a Schiff base solution excited by two light sources of different wavelengths. DETAILED DESCRIPTION

[0061] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0062] The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0063] Example 1

[0064] The specific synthesis steps of 4-{[(E)-(2-phenylpropan-2-yl)nitrogenylidene]methyl}benzene-1,3-diphenol provided by the present invention are as follows:

[0065] 1.52 g of 4-methoxysalicylaldehyde and 1.62 g of 2-phenylpropan-2-amine were mixed in 40 mL of anhydrous ethanol, and the mixture was refluxed for 4 h. The mixture was allowed to stand at room temperature or at low temperature to generate a precipitate. After the precipitate was generated, the precipitate was filtered to obtain the precipitate, which was washed with cold ethanol and then recrystallized (the recrystallization process comprises placing the precipitate in a small amount of solvent to prepare a supersaturated solution, and the solvent includes but is not limited to ethanol, ethyl acetate, dichloromethane, tetrahydrofuran, etc., heating and stirring until completely dissolved, and then naturally cooling to room temperature. The dissolved precipitate was slowly precipitated, and the precipitate was filtered and rinsed) to obtain the target product. Figure 2 and Figure 3 They are the H NMR spectrum and absorption spectrum of the target product, respectively.

[0066] Example 2

[0067] The specific synthesis steps of 4-{[(E)-(2-phenylpropan-2-yl)nitrogenylidene]methyl}benzene-1,3-diphenol provided by the present invention are as follows:

[0068] Mix 1.52 g of 4-methoxysalicylaldehyde and 2.03 g of 2-phenylpropan-2-amine in 40 mL of anhydrous ethanol, reflux for 4 hours, let stand at room temperature or at low temperature to produce precipitation, filter the precipitate, wash with cold ethanol and recrystallize to obtain the target product.

[0069] Example 3

[0070] The specific synthesis steps of 4-{[(E)-(2-phenylpropan-2-yl)nitrogenylidene]methyl}benzene-1,3-diphenol provided by the present invention are as follows:

[0071] Mix 1.52 g of 4-methoxysalicylaldehyde and 4.05 g of 2-phenylpropan-2-amine in 40 mL of anhydrous ethanol, reflux for 4 h, let stand at room temperature or at low temperature to produce a precipitate, filter the precipitate, wash with cold ethanol and recrystallize to obtain the target product.

[0072] Example 4

[0073] The application method of the 4-{[(E)-(2-phenylpropan-2-yl)nitrogen subyl]methyl}benzene-1,3-diphenol Schiff base provided by the present invention in volumetric three-dimensional display is as follows:

[0074] (1) Prepare a 0.15 mg / mL solution of 4-{[(E)-(2-phenylpropan-2-yl)azine-ylidene]methyl}benzene-1,3-diphenol dimethyl sulfoxide, such as Figure 4 As shown in a, it is a transparent solution.

[0075] (2) Through absorption spectroscopy and continuously adjustable laser testing, it was found that 365nm ultraviolet light is the best wavelength for producing photochromism, and 450nm blue light is the fluorescence excitation light source for the isomers.

[0076] (3) Figure 4 , the two light sources intersect vertically with the inside of the material, such as Figure 4 , generating voxel light. The scanning path and scanning speed of the two light sources can be controlled by a computer to complete the volumetric three-dimensional display.

[0077] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0078] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A Schiff base compound, characterized in that The molecular structure of the Schiff base compound is shown in the following formula (I): Among them, R 1 C 1-6 alkyl, R 2 is an aryl group, R 3 C 1-12 alkyl.

2. The Schiff base compound according to claim 1, characterized in that R 1 is methyl or ethyl; Optionally, R 2 is phenyl; Optionally, R 3 is methyl or ethyl; Optionally, the compound represented by formula (I) is 3. A method for preparing the Schiff base compound according to claim 1 or 2, characterized in that: include: The compound represented by formula (A) and the compound represented by formula (B) are subjected to a reflux reaction to obtain a compound represented by formula (I); Among them, R 1 C 1-6 alkyl, R 2 is an aryl group, R 3 C 1-12 alkyl.

4. The method according to claim 3, characterized in that R 1 is methyl or ethyl; Optionally, R 2 is phenyl; Optionally, R 3 is methyl or ethyl; Optionally, the compound represented by formula (A) is 4-methoxysalicylaldehyde; Optionally, the compound represented by formula (B) is 2-phenylpropan-2-amine; Optionally, the compound represented by formula (I) is Optionally, the temperature of the reflux reaction is 85 to 95°C; Optionally, the reflux reaction time is 3 to 6 hours; Optionally, the reflux reaction further includes a post-treatment operation; Optionally, the post-treatment operation includes cooling, filtering, washing and recrystallizing the reflux reaction solution; Optionally, the molar ratio of the compound represented by formula (A) to the compound represented by formula (B) is 1:1.2-3; Optionally, the molar ratio of the p-4-methoxy salicylaldehyde to the 2-phenylpropan-2-amine is 1:1.2-3; Optionally, the reflux reaction is carried out in ethanol; Optionally, the ethanol is anhydrous ethanol; Optionally, the molar ratio of the ethanol to the 4-methoxysalicylaldehyde is 30 to 100:

1.

5. Use of the Schiff base compound according to claim 1 or 2 or the Schiff base compound prepared by the method according to any one of claims 3 to 4 in volumetric three-dimensional display.

6. The use according to claim 5, characterized in that: The display medium is one or more mixed solvents of acetonitrile, methyl tert-butyl ether, dimethyl sulfoxide, and ethyl acetate of 4-{[(E)-(2-phenylpropan-2-yl)nitrogenylidene]methyl}benzene-1,3-diphenol Schiff base, or a solid material doped in epoxy resin or polymethyl methacrylate.

7. The use according to claim 6, characterized in that: The preferred mass ratio of the 4-{[(E)-(2-phenylpropan-2-yl)azine-ylidene]methyl}benzene-1,3-diphenol Schiff base to the solvent is 1:5000-10000.

8. The use according to claim 5, characterized in that: The method of volumetric three-dimensional display application is as follows: (1) selecting a photochromic light source and an excitation light source for the photochromic isomer respectively; (2) making the two light sources in step (1) intersect vertically inside the material to generate a light-emitting voxel point (i.e., the intersection point emits light); (3) Control the light source scanning path and scanning speed to achieve volumetric three-dimensional applications.

9. The use according to claim 8, characterized in that: The excitation light source of the photochromic light source is 365nm-410nm blue light.

10. The use according to claim 8, characterized in that: The photochromic isomers are ultraviolet light and 440-470nm blue light.

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