Triarylethene solid photochromic dyes and crystals thereof

Abstract

The application discloses a solid photochromic fluorescent compound containing a sulfoxide group and a synthesis method thereof. A bromine-containing triaryl ethylene fluorescent compound which is easy to synthesize is reacted with a diphenyl disulfide to obtain a sulfide fluorescent compound, and then the sulfide fluorescent compound is oxidized to obtain a sulfoxide fluorescent compound. In addition, through different crystallization methods, the triaryl styrene fluorescent compound containing the sulfoxide group can obtain two kinds of crystal with different packing modes, one of which has photochromic performance, and the relationship between the packing mode and the photochromic performance is conducive to research.

Description

Technical Field

[0001] This invention relates to the field of organic photochromic fluorescent materials, and more particularly to the application and preparation method of triarylethylene solid photochromic dyes. Background Technology

[0002] Photochromic materials undergo specific chemical reactions when exposed to light of a certain wavelength and intensity, resulting in changes in their structure and color. These changes are reversed by the application of light of a different wavelength, demonstrating the reversibility of the process. Combined with the precision and remote controllability of light stimulation, photochromic compounds, as a type of smart material, have attracted attention due to their wide applications in information storage, data encryption, and trademark anti-counterfeiting. Therefore, the construction and controllable adjustment of the properties of novel solid-state photochromic materials are of great significance for expanding the applications of these compounds.

[0003] Researchers have discovered that the photochromic properties of solid compounds are closely related to their conformation and structure (ACS Applied Materials Interfaces 2019, 11, 34526−34531). However, current reports mainly focus on altering the photochromic properties of compounds by changing their conformation through external stimuli such as heating, cooling, milling, and solvent fumigation. These methods fail to provide comparable crystal structure diagrams without altering the compound's structure, making it difficult to discern the influence of molecular conformation or packing patterns on their properties. Homopolymorphism offers the opportunity to adjust molecular packing patterns and physicochemical properties, enabling controllable regulation of compound properties (Current Organic Chemistry, 2017, 21, 236-248), while providing comparable crystal structure diagrams. This allows for a deeper understanding of the relationship between molecular conformation, packing patterns, and photostimulation responsiveness, which will contribute to truly explaining structure-activity relationships at the molecular level.

[0004] Currently, the main photochromic systems are spiropyrans, azo compounds, diarylethenes, and spiroxazines, primarily due to changes in the conjugated system caused by chemical reactions, such as proton transfer tautomerism, heterolytic and homolytic bond cleavage, cis-trans isomerism, and pericyclic reactions. However, we know that compounds can change color due to changes in their packing pattern. Photostimulation can alter the packing pattern of compounds, thereby causing color changes (Nature Communications, 2018, 9, 840). Furthermore, conformational changes are less likely to cause other side reactions, which is beneficial to the stability of the compound. Therefore, developing new photochromic compounds with conformational changes through photostimulation has significant potential. Summary of the Invention

[0005] The purpose of this invention is to provide a simple and high-yield method for preparing triarylethylene compounds containing sulfoxide groups.

[0006] Another object of the present invention is to provide a novel photochromic compound.

[0007] A third objective of this invention is to provide photochromic compounds with homogeneous polycrystalline structure for studying the structure-activity relationship between conformation and photochromic properties.

[0008] The technical solution of the present invention is as follows:

[0009] The molar ratio of substrate to oxidant is 1:0.5 to 1:1.2.

[0010] The oxidation reaction time is 0.1-24 h.

[0011] The oxidizing agent is m-chloroperoxybenzoic acid or hydrogen peroxide.

[0012] The purity of m-chloroperoxybenzoic acid is 75% or 85%.

[0013] The concentration of hydrogen peroxide is 15% or 30%.

[0014] The structure of the compound was determined by nuclear magnetic resonance and high-resolution mass spectrometry.

[0015] When preparing crystals via diffusion recrystallization, the preferred solvent is one of dichloromethane, ethyl acetate, acetonitrile, or tetrahydrofuran. For preparing single crystals, the preferred solvent is one or more of n-hexane, methanol, or toluene. The recrystallization temperature is -20 to 30 °C. Attached Figure Description

[0016] To further illustrate the features and technical content of the present invention, the accompanying drawings are provided for reference and explanation.

[0017] Figure 1 These are the ultraviolet-visible spectra before and after illumination. Figure 1 This indicates that the organic fluorescent dye described in the embodiments of the present invention has photochromic characteristics.

[0018] Figure 2 It is a fluorescence emission spectrum. Figure 2 Studies have shown that the two crystal structures of the organic fluorescent dyes described in the embodiments of the present invention have different emission wavelengths. Detailed Implementation

[0019] The following examples will help to further understand the present invention, but the scope of the present invention is not limited thereto. Example

[0020]

[0021] Under nitrogen atmosphere, the intermediate bromotriphenylethylene (3.35 g, 10 mmol) and anhydrous THF (100 mL) were added to a 250 mL three-necked flask. When the reaction system temperature dropped to -78 °C, n-butyllithium (8 mL, 2.5 mol / L, 20 mmol) was slowly added dropwise. After continuing the reaction at -78 °C for 1 h, diphenyl disulfide (2.62 g, 12 mmol) was added. One hour later, the reaction system temperature was raised to room temperature, and stirring was continued for two hours. 50 mL of saturated NH4Cl solution was slowly added to the reaction flask. The reaction solution was then extracted three times with 150 mL of organic solvent DCM solution. The collected organic layer was washed three times with 50 mL of saturated NaCl solution. An appropriate amount of anhydrous Na2SO4 was added for drying. Finally, the solvent was removed by rotary evaporation under negative pressure (-0.1 MPa) using a water pump. The crude product was purified by silica gel column chromatography (petroleum ether (60–90℃) as eluent) to obtain a sulfide compound (1.9 g, yield 52%, white solid, melting point 97℃). 1 H NMR (400 MHz, CDCl3) δ 7.31 – 7.18 (m, 11H, Ar-H), 7.18 – 7.08 (m, 4H, Ar-H), 7.00 (s, 1H), 6.98 (s, 1H), 6.89 –6.82 (m, 3H, Ar-H). 13 C NMR (100 MHz, CDCl3) δ 143.4, 143.1, 140.3, 136.3,135.5, 134.4, 131.4, 130.39, 130.35, 130.3, 129.3, 128.9, 128.4, 127.74,127.69, 127.4, 127.3. HR-MS (ESI + ) m / z Calcd for C 26 H 20 S [M+H] +365.1358; found365.1356. A thioether compound (416 mg, 1.14 mmol) and DCM (50 mL) were added to a 100 mL round-bottom flask. When the system temperature dropped to 0 °C, m-chloroperoxybenzoic acid (75%, 393.5 mg, 1.71 mmol) was added to the reaction system in several portions. Two hours later, 50 mL of saturated sodium bicarbonate solution was added to the reaction system, and the reaction mixture was then extracted three times with 150 mL of organic solvent DCM solution. An appropriate amount of anhydrous sodium sulfate was added to the collected organic layer for drying. Finally, the solvent was removed by rotary evaporation under negative pressure (-0.1 MPa) using a water pump. The crude product was further purified by column chromatography (eluent: petroleum ether (60–90 °C) / DCM = 3:1, v / v) to obtain the target product (434 mg, yield 85%, white solid, melting point 116 °C). 1 H NMR (400 MHz, CDCl3) δ 7.56 (d, J = 3.8 Hz, 2H, Ar-H), 7.45 – 7.18(m, 13H, Ar-H), 7.08 (dd, J = 26.0, 5.5 Hz, 4H, Ar-H), 6.88 (s, 1H). 13 C NMR (101MHz, CDCl3) δ 145.5, 145.0, 143.3, 142.9, 140.6, 139.8, 131.1, 130.4, 130.3,129.4, 128.9, 128.4, 128.1, 127.9, 127.8, 126.6, 124.84, 124.82. HR-MS (ESI + )m / z Calcd for C 26 H 20 SO [M+H] + 381.1308; found 381.1299.

Claims

1. A triarylethene solid photochromic fluorescent dye characterized in that, The structural general formula is as follows: ， Wherein, X = SO, SO2; R = methyl, methoxy, fluorine, chlorine.

2. The synthesis method of the triarylethylene solid photochromic fluorescent dye in claim 1, the preparation method comprising the following steps: ① Compound 1 is reacted with diphenyl disulfide, and an intermediate product (sulfide compound 2) is obtained after treatment; ； ② Sulfide compound 2 is dissolved in a solvent, 0.5-1.2 equivalents of an oxidizing agent are used, and a sulfoxide compound is obtained after treatment. 。 3. The method of claim 2, wherein the synthesis of the triarylethene photochromic fluorescent compound is characterized by: The molar ratio of the substrate to the oxidizing agent is 1:0.5-1:1.2; the oxidation reaction temperature is 0-30 ℃; the oxidation reaction time is 0.1-24 h; and the oxidizing agent is meta-chloro peroxide benzoic acid or hydrogen peroxide.

4. The method of claim 3, wherein the synthesis of the triarylethene photochromic fluorescent compound is characterized by: The purity of the selected meta-chloro peroxide benzoic acid is 75% or 85%, and the concentration of the hydrogen peroxide is 30% or 15%.

5. The method for producing crystals of a triarylethylene photochromic fluorescent compound according to claim 4, characterized by: When diffused recrystallization is performed, the selected good solvent is one or more of dichloromethane, ethyl acetate, acetonitrile, and tetrahydrofuran; the selected poor solvent is one or more of n-hexane, methanol, and toluene; and the recrystallization temperature is -20-30 ℃.

6. The triarylethylene solid photochromic fluorescent dye in claim 1 is applied to prepare a trademark anti-counterfeiting product.

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