A spiropyran-based photochromic material, its preparation method and applications
By physically mixing TPE and SP derivatives, the spirooxazine material achieves rapid, multi-level color transitions, addressing the limitations of solid-state photophysical properties and enhancing information storage and encryption.
Patent Information
- Application Number
- CN202310480238.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-04-28
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2043-04-28
AI Technical Summary
Spiropyran photochromic materials have poor color discoloration performance in solid state and have single color changes, which limits their application in anti-counterfeiting and information storage encryption.
The tetraphenylethylene derivative and spiropyran derivative were physically mixed by solvent-assisted method, and a new spiropyran photochromic material was prepared using hydrogen bonds between molecules and van der Waals' forces to achieve energy resonance transfer between TPE and spiropyran, and achieve dynamic responses of various fluorescence colors.
It realizes reversible changes in a variety of fluorescent colors in the time dimension, improves the effects of information storage encryption and anti-counterfeiting, has fast color change speed and a wide range of color changes.
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Figure CN116655723B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of organic solid-state photochromic materials, and particularly relates to a spiropyran-based photochromic material, a preparation method thereof, and an application thereof. Background Art
[0002] Photochromic fluorescent materials have received extensive attention due to their excellent properties in storage, information recording and protection, information security, etc. Photochromic materials refer to certain compounds whose molecular structures will change under the action of light with a certain wavelength and intensity, resulting in corresponding changes in the light absorption peak, that is, the color, and this change is generally reversible. As a new type of intelligent material, photochromic materials can be widely used in fields such as anti-counterfeiting, information storage encryption, and national defense security. Especially spiropyran-based photochromic materials. However, due to the close packing of spiropyrans under a solid-state rigid structure, the free volume between molecules is too small, which greatly hinders the structural transformation between the closed-ring SP form and the open-ring MC form of spiropyrans, resulting in poor color-changing performance of spiropyrans. This greatly limits the application of spiropyran-based organic photochromic materials.
[0003] In recent years, many researchers have been committed to exploring how to increase the free volume required in the spiropyran conversion process and improve the photochromic performance of spiropyrans in the solid state. At present, although there are studies on introducing rigid steric groups or flexible long chains on spiropyran molecules to increase the free volume required for spiropyran isomerization, this method only solves whether spiropyrans can isomerize. The color change of spiropyran photochromism is single and limited in range, resulting in simple encrypted information, low anti-counterfeiting level, and being easy to crack. By introducing fluorescent steric groups on spiropyrans, although the energy resonance transfer between the fluorescent group donor and the spiropyran acceptor can be used to improve the photochromic performance of spiropyrans and expand their application fields, the synthesis is relatively complex and the cost is relatively high. Therefore, how to improve the solid-state photochromic performance of spiropyrans while enabling a wide range of color changes and better broadening the application of photochromic materials in anti-counterfeiting and information storage encryption is an important technical problem that needs to be solved by researchers in this field. Summary of the Invention
[0004] To solve the above technical problems, the present invention provides a spiropyran-based photochromic material, a preparation method thereof, and an application thereof.
[0005] To achieve the above object, the present invention provides a preparation method of a spiropyran-based photochromic material, comprising the following steps:
[0006] Using a tetraphenylethylene derivative and a spiropyran derivative as raw materials, physically mixing them by a solvent-assisted method to obtain a spiropyran-based photochromic material.
[0007] In the present invention, a novel dynamic spiropyran-based photochromic material is prepared by simply physically mixing a tetraphenylethylene derivative (TPE) and a spiropyran derivative (SP) using a solvent-assisted method and through non-covalent interactions (hydrogen bonds, van der Waals forces) between molecules. Under ultraviolet light irradiation, using the Förster resonance energy transfer (FRET) between TPE and spiropyran, the fluorescence color changes from the characteristic blue color of TPE to the red color of the spiropyran isomer (MC), realizing a dynamic light response of multiple fluorescence colors changing from cyan to purple and then to pink in the time dimension. Reversible multiple information storage encryption and advanced anti-counterfeiting are achieved, showing broad application prospects in the fields of information storage encryption and anti-counterfeiting.
[0008] Further, the solvent is tetrahydrofuran, and the reaction is carried out under stirring conditions after mixing. The temperature of the mixing and stirring is 25 °C and the time is 5 min. The preparation method of the spiropyran-based photochromic material of the present invention is simple and can be carried out at room temperature.
[0009] Further, the molar ratio of the tetraphenylethylene derivative to the spiropyran derivative is 1:1 - 10:1, preferably 1:1, 3:1 or 10:1, and more preferably 3:1.
[0010] The tetraphenylethylene derivative of the present invention is prepared by a two-step amidation reaction of tetraphenylethylene with cholesterol, and the spiropyran derivative is prepared by a two-step amidation reaction of spiropyran with cholesterol.
[0011] Further, the structural formula of the tetraphenylethylene derivative is:
[0012]
[0013] Further, the preparation method of the tetraphenylethylene derivative is as follows: First, using compound A and ethylenediamine as raw materials, reacting under catalytic conditions to obtain compound B, and then reacting compound B with compound C under catalytic conditions to obtain the tetraphenylethylene derivative;
[0014] Compound A is Compound B is
[0015] Compound C is
[0016] Further, in the preparation method of the tetraphenylethylene derivative, the catalyst for the reaction of compound A and ethylenediamine is triethylamine, and the reaction time is 18 h;
[0017] When compound B reacts with compound C, the catalyst is a mixture composed of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl), 1-hydroxybenzotriazole (HOBT) and 4-dimethylaminopyridine (DMAP) in a molar ratio of 1.3:1:0.1, and the reaction time is 18 h.
[0018] The reaction route of the preparation method of the tetraphenylethylene derivative is as follows:
[0019]
[0020] Furthermore, the structural formula of the spiropyran derivative is:
[0021]
[0022] Furthermore, the preparation method of the spiropyran derivative is as follows: First, using compound A and ethylenediamine as raw materials, reacting under catalytic conditions to prepare compound B, and then reacting compound B with compound D under catalytic conditions to prepare the spiropyran derivative;
[0023] Compound A is Compound B is
[0024] Compound D is
[0025] Furthermore, in the preparation method of the spiropyran derivative, when compound A reacts with ethylenediamine, the catalyst is triethylamine and the reaction time is 18 h;
[0026] When compound B reacts with compound D, the catalyst is a mixture composed of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl), 1-hydroxybenzotriazole (HOBT) and 4-dimethylaminopyridine (DMAP) in a molar ratio of 1.3:1:0.1, and the reaction time is 18 h.
[0027] The reaction route of the preparation method of the spiropyran derivative is as follows:
[0028]
[0029] In the preparation methods of the tetraphenylethylene derivative and the spiropyran derivative, the solvent is dichloromethane, and the reactions are all carried out under a protective nitrogen atmosphere at room temperature.
[0030] The present invention also provides a spiropyran-based photochromic material obtained by the above preparation method.
[0031] The application of the spiropyran-based photochromic material in the fields of information storage encryption and anti-counterfeiting.
[0032] Compared with the prior art, the present invention has the following advantages and technical effects:
[0033] The present invention physically mixes a tetraphenylethylene derivative and a spiropyran derivative through simple solvent assistance, and prepares a novel spiropyran-based photochromic material through non-covalent interactions such as intermolecular hydrogen bonds (amide bonds) and van der Waals forces (cholesterol). Utilizing the certain overlap between the emission spectrum of TPE and the absorption spectrum of the spiropyran isomer (MC), energy resonance transfer (FRET) can occur between TPE and spiropyran, thereby enabling the new material to achieve a dynamic light response of multiple fluorescent colors that change from cyan to purple and then to pink in the time dimension, realizing reversible multiple information storage encryption and advanced anti-counterfeiting.
[0034] While the present invention realizes the dynamic light response in the time dimension, the color change speed is fast. It can achieve the dynamic transformation of the multistage time gradient of the fluorescent color of the photochromic material from cyan to purple and then to pink within 5 minutes, realizing the dynamic light response of multiple fluorescent colors of the material, and having a more excellent information storage encryption function compared with most current information storage encryption materials. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:
[0036] Figure 1 It is an overlapping spectrum diagram of the fluorescence spectrum of TPE prepared in Example 1 of the present invention and the ultraviolet absorption spectrum in the ring-opening state of spiropyran, excitation wavelength: 365 nm;
[0037] Figure 2 It is the ultraviolet absorption spectrum of the novel photochromic material (TPE:SP = 10:1 (molar ratio)) prepared in Example 1 of the present invention under ultraviolet light irradiation at 365 nm for different times (inset: color change diagram of the solid powder after ultraviolet light irradiation at 365 nm for different times);
[0038] Figure 3 It is the fluorescence emission spectrum of the novel photochromic material (TPE:SP = 10:1 (molar ratio)) prepared in Example 1 of the present invention under ultraviolet light irradiation at 365 nm for different times and excited at a wavelength of 365 nm (inset: fluorescence color change diagram of the solid after ultraviolet light irradiation at 365 nm for different times);
[0039] Figure 4 It is the ultraviolet absorption spectrum of the novel photochromic material (TPE:SP = 3:1 (molar ratio)) prepared in Example 1 of the present invention under ultraviolet light irradiation at 365 nm for different times (inset: color change diagram of the solid powder after ultraviolet light irradiation at 365 nm for different times);
[0040] Figure 5 Fluorescence emission spectra of the novel photochromic material (TPE:SP = 3:1 (molar ratio)) prepared in Example 1 of the present invention under 365 nm ultraviolet light illumination for different times and excited at 365 nm wavelength (Insert: Diagram of the change in solid fluorescence color after 365 nm ultraviolet light illumination for different times);
[0041] Figure 6 Ultraviolet absorption spectra of the novel photochromic material (TPE:SP = 1:1 (molar ratio)) prepared in Example 1 of the present invention under 365 nm ultraviolet light illumination for different times (Insert: Diagram of the change in solid powder color after 365 nm ultraviolet light illumination for different times);
[0042] Figure 7 Fluorescence emission spectra of the novel photochromic material (TPE:SP = 1:1 (molar ratio)) prepared in Example 1 of the present invention under 365 nm ultraviolet light illumination for different times and excited at 365 nm wavelength (Insert: Diagram of the change in solid fluorescence color after 365 nm ultraviolet light illumination for different times). Detailed implementation manners
[0043] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be considered as a limitation to the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.
[0044] It should be understood that the terms described in the present invention are only for describing particular implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.
[0045] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.
[0046] Without departing from the scope or spirit of the present invention, various improvements and changes can be made to the specific embodiments of the description of the present invention, which are obvious to those skilled in the art. Other embodiments obtained from the description of the present invention are obvious to those skilled in the art. The description and examples of the present invention are merely exemplary.
[0047] Regarding the terms "comprising", "including", "having", "containing", etc. used herein, they are all open-ended terms, meaning including but not limited to.
[0048] The room temperature referred to in the present invention is the indoor temperature, which is well-known to those skilled in the art and will not be elaborated here; in particular, it should be noted that the room temperature referred to in the embodiments of the present invention is 25 °C.
[0049] Example 1
[0050] Preparation of a novel photochromic material:
[0051] (1) Synthesis of tetraphenylethylene derivative (TPE):
[0052] First step: Synthesis of compound B, the reaction formula is as follows:
[0053]
[0054] At 0 °C, ethylenediamine (5.08 mL, 94.022 mmol) and triethylamine (TEA) (0.66 mL, 4.732 mmol) were dissolved in 30 mL of dichloromethane, and then cholesteryl chloroformate (2 g, 4.704 mmol) was added dropwise to the solution, and the reaction solution was stirred under nitrogen at room temperature for 18 h. At the end of the reaction, it was filtered. The filtrate was washed four times with saturated brine, and the organic solvent was evaporated to dryness to obtain white solid compound B (1.92 g, 96% (yield, the same below)).
[0055] Second step: Synthesis of tetraphenylethylene derivative TPE, the reaction formula is as follows:
[0056]
[0057] Compound C (0.338 g, 0.9 mmol), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl) (0.2518 g, 1.3 mmol), 1-hydroxybenzotriazole (HOBT) (0.15 g, 1 mmol) and 4-dimethylaminopyridine (DMAP) (11.8 mg, 0.1 mmol) were placed in a 100 mL three-necked flask. 40 mL of ultradry dichloromethane was added and dissolved in an ice bath under nitrogen at 0 °C for 30 min. Then, Compound B (0.4724 g, 1 mmol) was weighed and dissolved in the solvent, and it was added dropwise to the reaction solution. The reaction was carried out at room temperature for 18 h. After filtering out the precipitate, it was washed 4 times with saturated brine, and the solvent was removed under reduced pressure to obtain a residue. Then, it was column chromatographed, purified and dried to obtain the tetraphenylethylene derivative TPE (0.4532 g, 60.6%).
[0058] The characterization data of the 1H NMR spectrum of TPE are as follows 1 H NMR(400MHz,Chloroform-d)δ7.54(d,J=7.9Hz,2H),7.10(dq,J=6.7,4.0,2.9Hz,14H),7.06–6.90(m,3H),5.37–5.32(m,1H),5.04(s,1H),4.46(s,1H),3.54(s,2H),3.39(s,2H),2.54–2.16(m,2H),1.99(t,J=17.3Hz,3H),1.84(d,J=11.6Hz,3H),1.66–0.79(m,32H),0.68(d,J=1.6Hz,3H).
[0059] (2) Synthesis of the spiropyran derivative (SP), and the reaction formula is as follows:
[0060]
[0061] Compound D (0.342 g, 0.9 mmol), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl) (0.2518 g, 1.3 mmol), 1-hydroxybenzotriazole (HOBT) (0.15 g, 1 mmol) and 4-dimethylaminopyridine (DMAP) (11.8 mg, 0.1 mmol) were placed in a 100 mL three-necked flask. 40 mL of ultradry dichloromethane was added, and the mixture was dissolved in an ice bath under nitrogen at 0 °C for 30 min. Then, compound B (0.4724 g, 1 mmol) was weighed and dissolved in the solvent, and then added dropwise to the reaction solution. The reaction was carried out at room temperature for 18 h. After filtering out the precipitate, it was washed 4 times with saturated brine, and the solvent was removed under reduced pressure to obtain a residue. Then, it was column chromatographed, purified and dried to obtain the spiropyran derivative SP (0.5847 g, 73%).
[0062] The characterization data of the 1H NMR spectrum of SP are as follows: 1 H NMR (400 MHz, Chloroform-d) δ 8.01 (d, J = 8.4 Hz, 2H), 7.18 (t, J = 7.6 Hz, 1H), 7.08 (d, J = 7.2 Hz, 1H), 6.96–6.84 (m, 2H), 6.73 (d, J = 8.6 Hz, 1H), 6.65 (d, J = 7.8 Hz, 1H), 6.13 (s, 1H), 5.84 (d, J = 10.4 Hz, 1H), 5.35 (s, 1H), 4.76 (s, 1H), 4.44 (s, 1H), 3.82–3.44 (m, 2H), 3.28 (d, J = 5.8 Hz, 2H), 3.19 (s, 2H), 2.44 (ddd, J = 45.0, 14.5, 7.4 Hz, 2H), 2.33–2.20 (m, 2H), 2.01 (d, J = 13.7 Hz, 2H), 1.94 (s, 1H), 1.85 (d, J = 17.2 Hz, 4H), 1.43 (s, 9H), 1.26 (d, J = 6.1 Hz, 6H), 1.12 (d, J = 10.1 Hz, 7H), 1.00 (s, 5H), 0.91 (d, J = 6.4 Hz, 3H), 0.86 (dd, J = 6.6, 1.8 Hz, 6H), 0.68 (s, 3H).
[0063] (3) Preparation of a novel photochromic material:
[0064] The tetraphenylethylene derivative TPE and the spiropyran derivative SP were dissolved in tetrahydrofuran in different molar ratios (1:1, 3:1 and 10:1), stirred at room temperature for 5 min, the solvent was rotary evaporated, and dried to obtain the novel photochromic material.
[0065] The overlapping spectra of the fluorescence spectrum of the TPE prepared in Example 1 of the present invention and the ultraviolet absorption spectrum in the ring-opening state of spiropyran are shown in Figure 1 Figure shown, excitation wavelength: 365 nm.
[0066] The ultraviolet absorption spectra of the novel photochromic material (TPE:SP = 10:1 (molar ratio)) prepared in Example 1 of the present invention under ultraviolet light of 365 nm for different times are as shown in Figure 2 Figure shown: The fluorescence emission spectra under excitation at a wavelength of 365 nm after ultraviolet light of 365 nm is irradiated for different times are as shown in Figure 3 Figure shown.
[0067] The ultraviolet absorption spectra of the novel photochromic material (TPE:SP = 3:1 (molar ratio)) prepared in Example 1 of the present invention under ultraviolet light of 365 nm for different times are as shown in Figure 4 Figure shown: The fluorescence emission spectra under excitation at a wavelength of 365 nm after ultraviolet light of 365 nm is irradiated for different times are as shown in Figure 5 Figure shown.
[0068] The ultraviolet absorption spectra of the novel photochromic material (TPE:SP = 1:1 (molar ratio)) prepared in Example 1 of the present invention under ultraviolet light of 365 nm for different times are as shown in Figure 6 Figure shown: The fluorescence emission spectra under excitation at a wavelength of 365 nm after ultraviolet light of 365 nm is irradiated for different times are as shown in Figure 7 Figure shown.
[0069] It can be seen from the ultraviolet absorption spectrum and the fluorescence emission spectrum that the novel photochromic material prepared by the present invention is very sensitive to ultraviolet light irradiation. It can be seen from the ultraviolet absorption spectrum that the peak intensity at 575 nm of the novel photochromic material after ultraviolet light irradiation becomes stronger with the extension of the irradiation time and reaches the maximum value at 5 min, improving the photochromic performance of spiropyran in the solid state; it can be seen from the fluorescence emission spectrum that the TPE characteristic emission peak at 458 nm of the novel photochromic material after ultraviolet light irradiation decreases and is accompanied by a small blue shift, and the MC fluorescence emission peak at 646 nm increases and is accompanied by a small red shift. With the extension of the irradiation time, the fluorescence intensity at 458 nm continuously weakens, indicating that obvious energy resonance transfer occurs between TPE and spiropyran under ultraviolet light irradiation, realizing multiple dynamic fluorescence color responses of the material.
[0070] For the novel photochromic material (TPE:SP = 10:1 (molar ratio)) prepared by the present invention, after its solid powder is irradiated with ultraviolet light at a wavelength of 365 nm for 2 s to 5 min, the color and fluorescence color of the solid powder change significantly. The color of the solid powder changes from off-white to purple, and the fluorescence color changes from cyan-blue to blue-violet, indicating that the photochromic response speed of the photochromic metal complex material prepared by the present invention is fast.
[0071] The novel photochromic material prepared by the present invention (TPE:SP = 3:1 (molar ratio)), after its solid powder is irradiated with ultraviolet light with a wavelength of 365 nm for 2 s to 5 min, the color and fluorescence color of the solid powder change significantly. The color of the solid powder changes from off-white to dark purple, and the fluorescence color changes from cyan-blue to blue-violet, and finally to pink, indicating that the photochromic response speed of the photochromic metal complex material prepared by the present invention is fast.
[0072] The novel photochromic material prepared by the present invention (TPE:SP = 1:1 (molar ratio)), after its solid powder is irradiated with ultraviolet light with a wavelength of 365 nm for 2 s to 5 min, the color and fluorescence color of the solid powder change significantly. The color of the solid powder changes from off-white to dark purple, and the fluorescence color changes from cyan-blue to blue-violet, then to pink, and finally to red, indicating that the photochromic response speed of the photochromic metal complex material prepared by the present invention is fast.
[0073] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.
Claims
1. A preparation method of a spiropyran-based photochromic material, characterized in that, It includes the following steps: Using a tetraphenylethylene derivative and a spiropyran derivative as raw materials, physical mixing is carried out by a solvent-assisted method to prepare a spiropyran-based photochromic material; The solvent is tetrahydrofuran; The molar ratio of the phenyl ethylene derivative to the spiropyran derivative is 1:1 - 10:
1. The structural formula of the tetraphenylethylene derivative is: The structural formula of the spiropyran derivative is:
2. The preparation method of the spiropyran-based photochromic material according to claim 1, wherein The preparation method of the tetraphenylethylene derivative is: First, using compound A and ethylenediamine as raw materials, reacting under catalytic conditions to prepare compound B, and then reacting compound B with compound C under catalytic conditions to prepare the tetraphenylethylene derivative; The compound A is The compound B is The compound C is 3. The preparation method of the spiropyran-based photochromic material according to claim 2, wherein When compound A reacts with ethylenediamine, the catalyst is triethylamine and the reaction time is 18 h; When compound B reacts with compound C, the catalyst is a mixture composed of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 1-hydroxybenzotriazole and 4-dimethylaminopyridine in a molar ratio of 1.3:1:0.1, and the reaction time is 18 h.
4. The preparation method of the spiropyran-based photochromic material according to claim 1, characterized in that, The preparation method of the spiropyran derivative is: First, using compound A and ethylenediamine as raw materials, reacting under catalytic conditions to prepare compound B, and then reacting compound B with compound D under catalytic conditions to prepare the spiropyran derivative; The said Compound A is Compound B is Compound D is 5. The preparation method of the spiropyran-based photochromic material according to claim 4, characterized in that, When compound A reacts with ethylenediamine, the catalyst is triethylamine and the reaction time is 18 h; When compound B reacts with compound D, the catalyst is a mixture composed of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 1-hydroxybenzotriazole and 4-dimethylaminopyridine in a molar ratio of 1.3:1:0.1, and the reaction time is 18 h.
6. A spiropyran-based photochromic material, characterized in that, Prepared by the preparation method according to any one of claims 1 - 5.
7. Application of the spiropyran-based photochromic material according to claim 6 in the fields of information storage encryption and anti-counterfeiting.