Photochromic cyano-containing fluorescent dye and preparation thereof

Abstract

The invention relates to a simple method for preparing a photochromic triphenyl acrylonitrile compound. Easily synthesized 2-(4-bromophenyl)-3, 3-diphenyl acetonitrile acrylonitrile reacts with diphenyl disulfide to obtain a thioether fluorescent compound, and then the thioether fluorescent compound is oxidized by using different oxidants to obtain the sulfoxide or sulfone fluorescent compound. The synthesized fluorescent compound has photochromic performance in a solution. Crystal with two conformations can be obtained from the triphenyl acrylonitrile compound containing the sulfoxide group through different recrystallization methods, and only one conformation has photochromic performance. The method has the advantages of simple operation and high yield. The crystal structure of the compound prepared by the method is beneficial to research on the relationship between solid conformation and photostimulation, and can be applied to memory storage materials.

Description

Technical Field

[0001] The invention relates to the field of organic color-changing fluorescent materials, in particular to a triphenylacrylonitrile photochromic fluorescent compound and a preparation method thereof. Background Art

[0002] Among many stimuli-responsive materials, photochromic materials have been widely used in information storage, smart windows, trademark anti-counterfeiting and other fields due to the reversibility of structural changes, precision of light stimulation, and remote controllability [1,2]. Therefore, the construction of new solid-state photochromic materials and the controllable regulation of their properties are of great significance for expanding the application of this type of compounds.

[0003] At present, the most studied are spiropyrans, azo compounds, diarylethenes, spirooxazines and other photochromics. Fluorescent switches that use fluorescence as output signals to express the switch state have the advantages of high sensitivity and fast response, and can also minimize the destruction of recorded information. Therefore, the development of solid photochromic materials with fluorescence as a low-destructive readout signal is a current research hotspot. Currently, the reported triarylethenes have photochromic properties in three states: solution, film, and crystal. However, the related technology lacks a method of controlling the photochromic properties of compounds by simple heating or solvent fumigation. Summary of the invention

[0004] The object of the present invention is to provide a triphenylacrylonitrile compound having photochromic properties which can be synthesized by a simple method.

[0005] The technical solution of the present invention is as follows: The molar ratio of substrate to oxidant is 1:0.8-1:5.

[0006] The oxidation reaction temperature is 0~30 ℃.

[0007] The reaction time of oxidation is 0.1-24 h.

[0008] The oxidizing agent is m-chloroperbenzoic acid.

[0009] The purity of meta-chloroperbenzoic acid is 75% or 85%.

[0010] The structures of the compounds were confirmed by NMR and high-resolution mass spectrometry.

[0011] In order to further illustrate the features and technical contents of the present invention, the accompanying drawings are provided for reference and explanation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a comparison diagram of the ultraviolet absorption spectra of the compound solution produced by the embodiment of the present invention before and after photochromism.

[0013] Figure 2 This is a fluorescence emission diagram of the compound crystal produced in the example. DETAILED DESCRIPTION

[0014] The following examples are helpful to further understand the present invention, but the contents of the present invention are not limited thereto.

[0015] Example (1) Synthesis of the intermediate phenyl triphenyl acrylonitrile sulfide

[0016] Under nitrogen, the synthesized bromotriphenylacrylonitrile (3.6 g, 10 mmol) and anhydrous THF (150 mL) were added to a 100 mL three-necked flask. When the temperature of the reaction system dropped to -78 °C, n-butyl lithium (10 mL, 1.6 mol / L, 16 mmol) was slowly added dropwise. After continuing to react at -78 °C for 0.5 h, diphenyl disulfide (2.62 g, 12 mmol) was added. After one hour, the temperature of the reaction system was raised to room temperature, and the reaction solution was extracted with 150 mL of dichloromethane (3×50 mL). The collected organic layer was washed three times with 100 mL of saturated salt solution, and then dried by adding anhydrous Na2SO4. The crude product obtained by desolventization was purified by silica gel column chromatography (petroleum ether (60–90 °C) as eluent) to obtain the intermediate product (3.03 g, yield 78%, white solid).

[0017] [2] Synthesis of target product

[0018] The intermediate product (416 mg, 1.14 mmol) and dichloromethane (20 mL) were added to a 50 mL round-bottom flask. When the system temperature dropped to 0°C, a total of 276 mg of m-chloroperbenzoic acid (75%, 1.71 mmol) was added to the reaction system in five portions. After the addition was completed and the reaction was allowed to proceed for 12 hours, 10 mL of saturated sodium bicarbonate solution was added to the reaction system, the organic phase was extracted with dichloromethane solution (3×20 mL), and then dried with anhydrous sodium sulfate. The solvent was removed under reduced pressure, and the crude product was separated and further purified by column chromatography (eluent: petroleum ether (60–90°C) / ethyl acetate = 5:1, v / v) to obtain the target product (360 mg, yield 89%). 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). HR-MS (ESI + ) m / z Calcd for C 26 H 20 SO [M+H] + 381.1308; found 381.1299.

[0019] The UV absorption spectrum of the solution of the product compound of this embodiment before and after photochromism is as follows Figure 1 The crystal fluorescence emission diagram of the compound is shown in Figure 2 shown.

Claims

1. A triphenylacrylcyanide photochromic fluorescent compound, characterized in that: Its general structure is as follows: , where X = SO, SO2.

2. The method for synthesizing the triphenylacrylcyanide photochromic fluorescent compound according to claim 1, characterized in that: The preparation method comprises the following steps: ①2-(4-bromophenyl)-3,3-diphenylacetonitrile acrylonitrile reacts with diphenyl disulfide, and then post-processes to obtain an intermediate product (sulfide compound); ； ② The sulfide compound is dissolved in a solvent, and 0.85 to 5 equivalents of an oxidant are used for post-treatment to obtain a sulfoxide or sulfone compound; ； 。 3. The method for synthesizing the photochromic fluorescent compound according to claim 2, characterized in that: The molar ratio of substrate to oxidant is 1:0.8-1:5; the oxidation reaction temperature is 0-30°C; the oxidation reaction time is 0.1-24 h; and the oxidant is m-chloroperbenzoic acid.

4. The method for synthesizing a photochromic fluorescent compound according to claim 3, characterized in that: The purity of the selected meta-chloroperbenzoic acid is 75% or 85%.

5. The triphenylacrylcyanide photochromic fluorescent compound according to claim 1 is used in preparing light-control materials or anti-counterfeiting products.

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