Crystalline material with photoinduced fluorescence discoloration response and preparation method thereof

Abstract

The invention discloses a crystalline material with photoluminescence discoloration response and a preparation method thereof. A common fluorescent material styrene is selected as a main body, a fluorine-containing organic matter is taken as an object, the main body and the object are uniformly mixed with an organic solvent, and the mixture is naturally volatilized in a room-temperature environment to obtain the fluorescent crystalline material with photochromic response. The material can realize the fluorescence color change from cyan to yellow under the irradiation of an ultraviolet lamp, and can keep stable under the stimulation of acid and alkali. The series of styrene-fluoride materials synthesized through reasonable design and solvent selection realize wide-range color regulation and control of fluorescence by utilizing a photoinduced fluorescence discoloration behavior, and have potential application value in the fields of information secrecy and safety detection.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of intelligent response fluorescent functional materials, and in particular relates to a crystalline material with photoluminescent color change response and a preparation method thereof. Background Art

[0002] In the past few decades, photoresponsive molecules have attracted extensive attention due to their potential applications in actuators, molecular devices, sensors, and biomimetic fields. Using light as an external stimulus is advantageous because it is environmentally friendly, non-invasive, and allows contactless spatiotemporal control. Current photochromic systems include stilbenes, azobenzenes, spiropyrans, and diarylethenes, which induce structural changes through light stimulation, resulting in reversible or irreversible photoresponsive properties.

[0003] The present invention is based on the idea of ​​expanding light-stimulus-responsive materials, using diphenylethylene as the main molecule for preparing functionalized organic crystal materials and fluorine-containing organic small molecules as guest molecules. By using a simple volatilization method, a light-stimulus-responsive functional material is obtained, which expands the choice of crystalline materials in terms of stimulus response. In addition, the material has potential application value in information confidentiality, security detection and anti-counterfeiting, and biomedical fields. Summary of the invention

[0004] The present invention provides a crystalline material with a photofluorescent color change response and a preparation method thereof. The present invention prepares a type of photofluorescent color change response crystalline material with a wide color change range by studying the self-assembly of diphenylethylene and fluorine-containing organic small molecules.

[0005] The preparation method of the crystalline material with photoluminescent color change response is as follows: weigh a certain proportion of styrene and fluorine-containing organic matter, add a completely soluble organic solvent, mix them evenly by ultrasonication, and volatilize them naturally at room temperature to obtain rod-shaped crystals.

[0006] The fluorine-containing organic compound is one or more of tetrafluorophthalonitrile, tetrafluoroterephthalonitrile, tetrafluoroisophthalonitrile, octafluoronaphthalene, pentafluorobenzene and hexafluorobenzene.

[0007] The input molar ratio of the host and guest styrene and the fluorine-containing organic matter is 1:0.1-20.

[0008] The organic solvent is one or a mixture of two of methanol, ethanol, chloroform, dichloromethane, n-hexane, acetonitrile, acetone, tetrahydrofuran, toluene and the like.

[0009] After the styrene, the fluorine-containing organic matter and the organic solvent are uniformly mixed, the concentration of styrene is 0.004-0.4 mol / mL.

[0010] The ultrasonic time in the preparation method is 30 min-120 min.

[0011] The time required to obtain the crystals is 2 days to 15 days.

[0012] The beneficial effects of the present invention are: First, the method is simple to prepare. Fluorescent eutectic materials with photochromic response can be obtained by volatilization, which provides conditions for mass production. Second, the fluorescent color-changing material has a stable structure and still has this property under acid and alkali conditions, which can meet the use of certain extreme conditions; Third, the color of the fluorescent color-changing material changes significantly. Under ultraviolet light, the cyan fluorescence gradually dims and then transitions to yellow fluorescence. It has a high anti-counterfeiting level and a wide color rendering range.

[0013] In summary, the crystalline fluorescent material with photochromic response provided by the present invention is simple to prepare, has a stable structure, and can be applied to the fields of information confidentiality and security detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 These are photos of the photoluminescent color-changing crystals provided in Example 1 of the present invention before and after irradiation with ultraviolet light.

[0015] Figure 2 This is the photoluminescent color-changing emission spectrum provided in Example 1 of the present invention.

[0016] Figure 3 These are photos of the photofluorescent color-changing powder provided in Example 2 of the present invention before and after irradiation with ultraviolet light. DETAILED DESCRIPTION

[0017] The present invention is further described below by means of specific examples, but the protection scope of the present invention is not limited thereto.

[0018] Example 1 In a 50 ml transparent quartz vial, 62 mg of diphenylethylene, 40 mg of tetrafluorophthalonitrile and 30 ml of methanol were added in sequence, where the ratio of diphenylethylene to tetrafluorophthalonitrile was 1:1. Mix well and ultrasonicate for 30 min, then place at room temperature for evaporation. After 10 days, a eutectic material with photoluminescent color change response was obtained. Figure 1 As shown in the figure, the crystal first experiences a decrease in cyan fluorescence intensity under UV light, and then transforms into yellow fluorescence. During the transformation process, due to cis-trans isomerization, some crystals will experience a decrease in volume.

[0019] Characterization of the product: Single crystal X-ray diffraction data analysis shows that the above product crystallized at P21 / n space group, monoclinic system, stacked into a layered structure through halogen bonds and pp interactions.

[0020] The powder diffraction XRD analysis of the product showed that new peaks appeared, indicating that new substances were produced and had higher purity.

[0021] like Figure 2 As shown in the figure, under 365 nm excitation, as the irradiation time increases, the emission peak of the fluorescence emission spectrum red-shifts from 463 nm to 536 nm, achieving a transition of the fluorescence color from cyan to yellow.

[0022] Example 2 In a 50 ml transparent quartz vial, 62 mg of diphenylethylene, 40 mg of tetrafluorophthalonitrile and 30 ml of dichloromethane were added in sequence, wherein the ratio of diphenylethylene to tetrafluorophthalonitrile was 1:1. The mixture was evenly mixed and ultrasonicated for 30 minutes, and then allowed to volatilize at room temperature. After 5 days, a eutectic material with a photoluminescent color change response was obtained, such as Figure 3 shown.

[0023] The product was characterized in the same manner as in Example 1.

[0024] Example 3 62 mg of diphenylethylene, 120 mg of tetrafluorophthalonitrile and 30 ml of dichloromethane were added to a 50 ml transparent quartz vial in sequence, where the ratio of diphenylethylene to tetrafluorophthalonitrile was 1:3. Mix well and ultrasonicate for 30 minutes, then place at room temperature for evaporation, and obtain a eutectic material with photoluminescent color change response after 6 days.

[0025] The product was characterized in the same manner as in Example 1.

[0026] In summary, diphenylethylene and fluorine-containing organic matter are self-assembled to obtain a eutectic material with photofluorescent color response, which can achieve a wide range of color response under ultraviolet light and has good acid and alkali resistance, and has good application prospects in the fields of information confidentiality and security detection.

Claims

1. A crystalline material having a photoluminescent color change response and a preparation method thereof, characterized in that: The specific preparation steps are: weigh a certain proportion of styrene and fluorine-containing organic matter, add a completely soluble organic solvent, mix them evenly by ultrasonication, and evaporate them naturally at room temperature to obtain rod-shaped crystals.

2. The preparation method according to claim 1, characterized in that: The fluorine-containing organic compound is one or more of tetrafluorophthalonitrile, tetrafluoroterephthalonitrile, tetrafluoroisophthalonitrile, octafluoronaphthalene, pentafluorobenzene and hexafluorobenzene.

3. The preparation method according to claim 1, characterized in that: The input molar ratio of the host and guest styrene and the fluorine-containing organic matter is 1:0.1-20.

4. The preparation method according to claim 1, characterized in that: The organic solvent is one or a mixture of two of methanol, ethanol, chloroform, dichloromethane, n-hexane, acetonitrile, acetone, tetrahydrofuran, toluene and the like.

5. The preparation method according to claim 1, characterized in that After the styrene, the fluorine-containing organic matter and the organic solvent are uniformly mixed, the concentration of styrene is 0.004-0.4 mol / mL.

6. The preparation method according to claim 1, characterized in that The ultrasonic time is 30 min-120 min.

7. The preparation method according to claim 1, characterized in that: The time required to obtain crystals is 2 to 15 days.

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