Organic room-temperature phosphorescent micromolecule gel and dynamic anti-counterfeiting device

Abstract

According to the organic room-temperature phosphorescent small-molecule gel and the dynamic anti-counterfeiting device, the organic room-temperature phosphorescent soft material with the dynamic phosphorescent characteristic has wide application value in the anti-counterfeiting field; the organic room-temperature phosphorescent soft material with time resolution and stimulation response characteristics can be used for preparing dynamic anti-counterfeiting devices which are difficult to imitate. The compound Cz-PtMO with room-temperature phosphorescence characteristic is synthesized by taking carbazole and trimethoxybenzoic acid as initial raw materials and carrying out one-step dehydration reaction. Cz-PtMO can form stable gel in a mixed solvent, and shows triple phosphorescence emission peaks at room temperature, and the phosphorescence lifetime of the Cz-PtMO is 241.2 ms, 82.6 ms and 63.5 ms respectively, so that the Cz-PtMO shows a time-resolved afterglow effect; and the gel is sensitive to heat, so that the organic room-temperature phosphorescent soft material with both time resolution and thermal stimulation response is constructed, and the organic room-temperature phosphorescent soft material has an important application prospect in the field of dynamic anti-counterfeiting.

Description

Technical Field

[0001] The present invention relates to organic room temperature phosphorescent small molecule gels and dynamic anti-counterfeiting devices, belonging to the technical field of anti-counterfeiting materials. Background Art

[0002] After being photoexcited, room temperature phosphorescent materials can undergo intersystem crossing (ISC) to the excited triplet state, and then radiatively decay from the triplet state to emit phosphorescence, with a lifetime reaching microseconds or even seconds. Due to its long lifetime, afterglow can still be observed after the excitation light stops, and it is widely used in fields such as information anti-counterfeiting encryption and bioimaging. To further enhance the anti-counterfeiting performance, people have begun to study organic room temperature phosphorescent materials with afterglow color and time changes or phosphorescence changes under external stimuli; organic room temperature phosphorescent materials with both time-resolved and stimulus-responsive properties have received more attention, and anti-counterfeiting devices prepared from them are extremely difficult to counterfeit.

[0003] Currently, the research on ultra-long room temperature phosphorescent materials mainly focuses on crystalline materials and host-guest doped polymer systems. Crystalline materials are difficult to process and have poor repeatability, which are subject to certain limitations in practical applications. The synthesis conditions of polymers are harsh, and polymers from different batches often have performance differences; on the other hand, the chemical structure of polymers is complex, and a large number of groups do not contribute to the absorption and emission of light (poor atom economy), and may also block the transmission of photoelectric and other signals in the system. As a new matrix for inducing room temperature phosphorescence, the supramolecular gel system has the characteristics of sensitive temperature response, easy processing, and good repeatability, and can well meet the requirements of practical applications in the field of dynamic anti-counterfeiting.

[0004] Supramolecular gels are three-dimensional network structures formed by non-covalent bond forces of intermolecular equilibrium, with a rigid microenvironment, which can thus protect triplet excitons. Heating can transform the gel into a homogeneous solution (phosphorescence quenching), and phosphorescence resumes after cooling to room temperature to form a gel. Therefore, gel materials with room temperature phosphorescent properties can be applied to dynamic anti-counterfeiting. However, there has been no report on room temperature phosphorescent gels with time resolution. Summary of the Invention

[0005] The present invention uses carbazole and trimethoxybenzoic acid as starting materials, undergoes a dehydration reaction under the condition of trifluoroacetic anhydride, and prepares an organic gelator Cz-PtMO with ultra-long room temperature phosphorescent emission. Surprisingly, the Cz-PtMO gel exhibits triple phosphorescent emission peaks at room temperature, with phosphorescence lifetimes of 241.2 ms (nm), 82.6 ms (nm), and 63.5 ms (nm) respectively, thus showing a time-resolved afterglow effect; and the gel is sensitive to heat, thereby constructing an organic room temperature phosphorescent soft material with both time resolution and heat stimulus response, which has important application prospects in the field of dynamic anti-counterfeiting.

[0006] Organic room-temperature phosphorescent small molecule. The structural formula of the organic room-temperature phosphorescent small molecule is: 。

[0007] The preparation method of the organic room-temperature phosphorescent small molecule includes the following steps: Under nitrogen conditions, dissolve carbazole and trimethoxybenzoic acid in a solvent, then dropwise add trifluoroacetic anhydride under stirring, and then dropwise add phosphoric acid, and react at room temperature. After the reaction is completed, quench the reaction with water. The product obtained after the reaction is purified to obtain an organic room-temperature phosphorescent soft material. The synthesis route is as follows: 。

[0008] The molar ratio of carbazole, trimethoxybenzoic acid, and trifluoroacetic anhydride is 1:(1 - 2):(3 - 5).

[0009] In some preferred cases, the molar ratio of carbazole, trimethoxybenzoic acid, and trifluoroacetic anhydride is 1:1.2:3.5.

[0010] The technical solution of the present invention also provides an organic room-temperature phosphorescent small molecule gel, and the organic phosphorescent material forms a gel material in an aqueous solution containing DMSO and DMF.

[0011] The gel concentration is greater than 20 mg / mL. The concentration refers to the mass concentration of the organic room-temperature phosphorescent small molecule in the DMSO aqueous solution or in the DMF aqueous solution.

[0012] It can be understood by those skilled in the art that the gel concentration is 20 - 50 mg / mL.

[0013] The volume concentration of the aqueous solution of DMSO and DMF is 30 - 90%.

[0014] In some preferred cases, the volume concentration of the aqueous solution of DMSO and DMF is 50 - 80%.

[0015] A dynamic anti-counterfeiting device includes the organic room-temperature phosphorescent small molecule gel.

[0016] In the dynamic anti-counterfeiting device, the dynamic anti-counterfeiting means having a fluorescence effect under stimulation, the fluorescence disappearing when the stimulation disappears, and the fluorescence reappearing when stimulated again, with a completely reversible dynamic anti-counterfeiting effect.

[0017] The stimulation is under conditions below room temperature and ultraviolet light irradiation. The temperature below room temperature refers to the temperature to ensure the gel state, such as a solid gel state can be achieved below 25°C. The ultraviolet light irradiation refers to ultraviolet light irradiation with a wavelength of 300 - 380 nm. In the following examples, ultraviolet light irradiation with a wavelength of 365 nm is used.

[0018] The dynamic phenomena are as follows: Under ultraviolet light irradiation - turning off ultraviolet light irradiation - turning on ultraviolet light irradiation, a completely reversible effect of fluorescence - fluorescence disappearance - fluorescence reappearance is achieved; Or under the conditions of normal temperature and below - heating to melting - returning to normal temperature and below, a completely reversible effect of fluorescence - fluorescence disappearance - fluorescence reappearance is achieved.

[0019] In the technical solution of the present invention, an organic room temperature phosphorescent soft material with dynamic phosphorescent properties is prepared, which has wide application value in the field of anti-counterfeiting; while an organic room temperature phosphorescent soft material with both time-resolved and stimulus-responsive properties can be used to prepare dynamic anti-counterfeiting devices that are difficult to imitate. The present invention uses carbazole and gallic acid as starting materials, and through a one-step dehydration reaction, a compound Cz-PtMO with room temperature phosphorescent properties is synthesized. Cz-PtMO can form a stable gel in a mixed solvent of DMSO and water, and shows triple phosphorescence emission peaks at room temperature, with phosphorescence lifetimes of 241.2 ms, 82.6 ms, and 63.5 ms respectively, thus showing a time-resolved afterglow effect; and the gel is sensitive to heat, thereby constructing an organic room temperature phosphorescent soft material with both time-resolved and thermally stimulus-responsive properties, which has important application prospects in the field of dynamic anti-counterfeiting. Description of the Drawings

[0020] Figure 1 1H NMR spectrum of Cz-PtMO.

[0021] Figure 2 13C NMR spectrum of Cz-PtMO.

[0022] Figure 3 High-resolution mass spectrum of Cz-PtMO.

[0023] Figure 4 (A) Sol-gel transition (under sunlight and 365 nm ultraviolet light); (B, C) Mechanical properties of the gel of Cz-PtMO in DMSO / H 2 2O (frequency is 6.28 rad s −1 , strain is 0.1%).

[0024] Figure 5 (A) 1H NMR spectra of the gel at different temperatures; (B) Fluorescence spectra during the sol-gel transition process.

[0025] Figure 6 (A) Single crystal structure of Cz-PtMO; (B) Steady-state and delayed spectra of the Cz-PtMO single crystal (inside: afterglow photo); (C) Lifetime of the Cz-PtMO single crystal at room temperature; (D) Lifetime of the Cz-PtMO single crystal at 77 K.

[0026] Figure 7 (A) Steady-state and delayed spectra of the Cz-PtMO gel state; (B) Afterglow image of Cz-PtMO gel at room temperature; (C) Lifetime of the gel at different temperatures.

[0027] Figure 8 Delayed spectra, fluorescence and afterglow photos of the Cz-PtMO gel state gel at different temperatures. A is the delayed spectrum of the Cz-PtMO gel state gel at different temperatures, and B includes the afterglow effect diagrams under the on or off state of the ultraviolet lamp at 25 °C and 75 °C.

[0028] Figure 9 Anti-counterfeiting device made of Cz-PtMO gel. Among them, A is the fluorescence of the number "8" observed under ultraviolet lamp irradiation, B is the afterglow of the orange number "9" observed after turning off the ultraviolet lamp, C is that only the number "7" with a longer lifetime and a later color change to green is shown after 0.4 s, D is that the fluorescence effect shows the number "8" after heating to 60 °C to form a semi-gel, and E is the effect diagram of no afterglow phenomenon after heating to 60 °C to form a semi-gel. Detailed implementation method

[0029] Example 1 Under nitrogen conditions, dissolve carbazole (2.0 g, 12.4 mmol) and trimethoxybenzoic acid (3.2 g, 14.88 mmol) in 50 mL of dichloromethane, then dropwise add trifluoroacetic anhydride (6.1 mL, 43.4 mmol) under stirring, and then dropwise add a few drops of phosphoric acid (98% phosphoric acid), and react at room temperature for 6 h. After the reaction is completed, add a few drops of water to quench the reaction, and wash with saturated brine 5 times. The organic layer is dried with anhydrous Na 2 SO 4 After drying, it is concentrated. The crude product is purified by column chromatography (silica gel, ethyl acetate: petroleum ether = 1:3) to obtain a white solid; then the white solid is recrystallized three times with ethanol to obtain a pure product (yield 53%). 1 1H NMR (400 MHz, CDCl 3 ): δ 8.05 - 7.97 (m, 2H), 7.60 - 7.53 (m, 2H), 7.39 - 7.32 (m, 4H), 6.97 (s, 2H), 3.97 (s, 3H), 3.80 (s, 6H); 13 13C NMR (100 MHz, CDCl 3): δ 169.08, 153.44, 141.66, 139.11, 130.42, 126.71, 125.94, 123.39, 119.79, 115.77, 106.56, 61.12, 56.31; HRMS (ESI) m / z: [M+H] + calcd for C 22 H 20 NO 4 362.1392, found: 362.1355. (As shown in Figure 1 、 2 、Figure 3).

[0030] Example 2 The gelation behavior of the above-prepared Cz-PtMO in different solvents was studied by the inversion method: Cz-PtMO was dissolved in the solvent to be tested under heating conditions (the mass concentration of Cz-PtMO relative to the solvent to be tested was 2 w.t%). After cooling to room temperature (room temperature refers to 25 °C), if a stable gel (non-flowing after inversion) could be formed, it was considered that a gel was formed.

[0031] The solvents to be tested mentioned above were n-hexane, cyclohexane, toluene, acetonitrile, acetone, tetrahydrofuran, methanol, ethanol, DMSO (anhydrous), DMF (anhydrous), H 2 O, DMSO / H 2 O (1:1 v / v), DMF / H 2 O (1:1 v / v).

[0032] It was found that Cz-PtMO formed stable gels in DMSO / H 2 O (1:1 v / v) and DMF / H 2 O (1:1 v / v), and the minimum gelation concentrations were 20 mg / mL and 28 mg / mL, respectively. As shown in Figure 4 A, taking the DMSO / H 2 O gel of Cz-PtMO as an example, in the dilute solution (the upper part of the figure), it did not emit light under either sunlight or 365 nm ultraviolet light, but in the gel state (the lower part of the figure), it showed purple luminescence under ultraviolet light. In the solvents to be tested DMSO (anhydrous), DMF (anhydrous), H 2 O, gelation could not be achieved. It was found through experiments that in DMSO or DMF solvents, stable gels could be achieved when the volume concentrations of DMSO and DMF were 30 - 80%. In the examples of this case, the stable gel achieved under the condition of mixing DMSO or DMF with water at 1:1 was taken as a test case. Example 3 Thixotropy test: The DMSO / H of Cz-PtMO was subjected to a thixotropy test using dynamic oscillation testing 2 O gels ( Figure 4 ). For the DMSO / H of Cz-PtMO 2 O gels, a strain sweep was first performed at a constant angular frequency of 6.28 rad.s -1 . When the strain value was less than 9.6%, G` was significantly greater than G``, indicating that the gel had a certain elasticity. As the strain value increased, G` gradually decreased and G`` gradually exceeded G`, indicating that the organogel gradually broke and finally completely collapsed. In the frequency sweep experiment, under the angular frequency condition of 0.1 - 62 rad.s -1 , the G` of the gel was always greater than G``, indicating that it had good tolerance to external forces.

[0033] To further confirm the formation of the gel, a thixotropy test was performed on the DMSO / H of Cz-PtMO 2 O gels. As shown in B of Figure 4 and C of 4, taking the DMSO / H of Cz-PtMO 2 O gel as an example, its storage modulus G` reached more than 1000 Pa, while the loss modulus G`` was lower than 250 Pa, proving the formation of the gel. At the same time, the critical strain value was 10.27%, indicating that the gel had a certain resistance to external pressure and the gel was relatively stable.

[0034] Example 4 Temperature-dependent property test: In a nuclear magnetic tube, Cz-PtMO powder was suspended in a 1:1 mixed solvent of DMSO-d6 / D 2 O (concentration 25 mg / mL), heated and dissolved, then cooled to room temperature to form a gel. Then the sample was placed in a nuclear magnetic instrument, and the temperature of the magnet was set to test the nuclear magnetic hydrogen spectrum at different temperatures.

[0035] To study the self-assembly mode of Cz-PtMO in DMSO / H 2 O, the temperature-dependent nuclear magnetic hydrogen spectrum was measured. As shown in Figure 5As shown in A, as the temperature increased from 25 °C to 75 °C, the protons at different positions of the carbazole unit showed a phenomenon of upfield shift. Notably, the protons of the methoxy group shifted significantly upfield: at room temperature, the protons of the methoxy group and the water peak in DMSO-d6 could be well resolved, located at 4.16 and 3.58 ppm respectively; when the temperature reached 70 °C, they merged into a broader peak with a chemical shift of 3.56 ppm, and the upfield shift of the methoxy group reached 0.60 ppm. Variable-temperature 1H NMR spectra showed that the increase in temperature caused the gel to gradually transform into a sol, which led to a slight change in the intermolecular interaction between adjacent carbazole units and further changed the electron density of these protons. However, the electron cloud density of the methyl group on the methoxy group was significantly increased, indicating a strong interaction between the methoxy group and the methoxy group or carbazole on the adjacent molecule.

[0036] After heating the DMSO / H 2 O gel of Cz-PtMO to a sol, its steady-state fluorescence spectrum was measured ( Figure 5 as shown in B). First, it was heated to a sol, and the fluorescence spectrum at this temperature was measured; then it was naturally cooled, and the fluorescence spectrum was measured every 5 seconds until room temperature, and the last curve was measured. This spectrum reflected the fluorescence spectrum of the gel at different temperatures. It was found that its luminescence was very weak, and the emission peak was mainly located at 450 nm. The sol was placed at room temperature and slowly cooled, and the steady-state fluorescence spectrum during the cooling process was measured. During the cooling process, the intensity of fluorescence emission gradually increased; this was because in the hot sol state, the molecular motion was intensified, making the non-radiative transition enhanced, and the molecular motion was inhibited after cooling. Especially after cooling to room temperature to form a gel, the fluorescence emission intensity was the strongest. Interestingly, in the gel state (i.e., 25 °C), a new emission peak appeared at 617 nm, which was obviously due to the intermolecular interaction in the gel state and the formation of molecular aggregates.

[0037] Example 5 Steady-state and delayed spectra of Cz-PtMO single crystal: During the detection, the excitation wavelength λ ex = 370 nm; Lifetime of Cz-PtMO single crystal at room temperature: During the detection, the excitation wavelength λ ex = 370 nm; Lifetime of Cz-PtMO single crystal at 77 K: During the detection, the excitation wavelength λ ex = 370 nm; To accurately clarify the intermolecular interaction of Cz-PtMO, single crystal structures were cultivated in different solvents. As Figure 6As shown in A, the two aromatic ring systems in the Cz-PtMO molecule exhibit a certain twisted structure, and there is also a certain dihedral angle between them and the carbonyl group in the middle. Among them, the angle between the carbazole ring and the carbonyl group is 37.5°, while the angle between the benzene ring and the carbonyl group is 38.5°. Such a twisted structure is conducive to the formation of intermolecular π-π stacking structures between the carbazole and benzene rings and the aromatic rings in adjacent molecules. At the same time, the presence of trimethoxy groups is also conducive to the formation of various non-covalent bond interactions. As expected, there are various different dimers in the crystal structure of Cz-PtMO. In the dimer1 structure, the carbazole rings in the two molecules show planar stacking, and the planar overlapping part reaches 36%, and the intermolecular distance is 3.52 Å, indicating that the π-π interaction is relatively strong. At the same time, the trimethoxy groups also have a certain overlap with the benzene rings in adjacent molecules, and the distance between the oxygen atom and the benzene ring is 3.83 Å, proving that there are strong π-π stacking interactions between the carbazole and benzene rings and the carbazole and benzene rings in adjacent molecules in dimer1. In dimer2, there is a certain non-covalent bond interaction between the carbonyl group and the protons on the benzene ring in the adjacent molecule, and there are C…C and C-H…C interactions between the methoxy groups and the carbazole in the adjacent molecule. In dimer3, there is a C-H…C interaction between the methoxy group and the carbazole in the adjacent molecule. In dimer4, there is a C-H…O interaction between the methoxy group and the carbazole in the adjacent molecule. These non-covalent bond interactions make the molecular packing relatively tight, and the density reaches 1.33 g / cm -3 .

[0038] Under the irradiation of a 365 nm ultraviolet lamp, the Cz-PtMO crystal emits purple light. In the steady-state emission spectrum, the emission peaks are located at 470 nm, 535 nm, 613 nm, and 650 nm respectively. In the delayed spectrum, however, three peaks at 535 nm, 610 nm, and 650 nm appear, indicating that the latter three peaks in the steady-state spectrum are triplet luminescence. The lifetimes of the emission peaks of the triplet luminescence were measured at different temperatures. At 77 K, the lifetimes of the three peaks are all longer than those at room temperature, indicating that the emission of these three peaks is phosphorescence. It is worth mentioning that at room temperature, the lifetimes of these three phosphorescence peaks are 155.6 ms, 39.2 ms, and 33.3 ms respectively. Therefore, the crystal shows a mixed color - orange of three colors after the ultraviolet light excitation is turned off. However, as time prolongs, the luminescence of the short-lived component gradually disappears, while the color (green) of the long-lived component is retained, showing the characteristics of time resolution.

[0039] Steady-state and delayed spectra of the Cz-PtMO gel state: The gel was placed in a sample cell, the excitation wavelength λex = 370 nm was set to measure the steady-state spectrum, and the excitation wavelength λex = 370 nm and the delay time of 1 ms were set to measure the delayed spectrum.

[0040] Lifetime of the gel at different temperatures: The lifetimes were tested at room temperature (25 °C) and under liquid nitrogen conditions (77 K), and the excitation wavelength λex was set to 370 nm.

[0041] Cz-PtMO also exhibited multiple emission peaks in the gel state, with the highest emission peaks located at 472 nm and 607 nm respectively; however, in the delayed spectrum, multiple emission peaks similar to those of a crystal appeared, located at 533 nm, 605 nm, and 650 nm respectively. The lifetimes of the individual emission peaks in the delayed spectrum at different temperatures were tested (as shown in Figure 7 Figure C). The lifetimes at 77 K were all higher than those at room temperature, so they were all phosphorescent emissions. It is worth mentioning that in the gel state of Cz-PtMO, its lifetime was higher than that in the crystal state; among them, the emission lifetime at 533 nm was the longest, reaching 241 ms, while the lifetimes of the long-wavelength emissions were shorter, thus also showing time-resolved afterglow. However, in the steady-state spectrum, the peak area of the delayed emission was significantly smaller than that of the fluorescence emission peak, and the emission intensity was lower.

[0042] Since the triplet emission of the gel is very sensitive to temperature, the delayed spectra of Cz-PtMO gel at different temperatures (25 °C, 35 °C, 45 °C, 55 °C, 65 °C, 75 °C) were tested (as shown in Figure 8 Figure). As the temperature increased, the delayed emission intensity of Cz-PtMO gel gradually decreased, and decreased to 16% of the initial state after 75 °C. Therefore, Cz-PtMO gel showed visible orange afterglow at room temperature, but the afterglow disappeared after heating to 75 °C; after cooling to room temperature, the afterglow recovered again, showing a dual dynamic effect of time resolution and temperature reversibility, which is suitable for making dynamic anti-counterfeiting devices.

[0043] Example 6 Dynamic anti-counterfeiting device A dynamic anti-counterfeiting device was prepared using Cz-PtMO gel. First, a digital "8" pattern was made, where the digit "7" was made of the DMSO / H 2 O gel of Cz-PtMO, and the remaining part of the digit "9" was made by combining a compound with short-lived orange phosphorescent emission (2,8-dibenzoyldibenzofuran), while the remaining part was composed of a fluorescent material (2-(9-anthryl)-4,5-diphenyl-1H-imidazole) with similar fluorescence but no phosphorescence. Under irradiation with a 365 nm ultraviolet lamp, the fluorescence of the digital "8" could be clearly observed (as shown in Figure 9 Figure A); after turning off the ultraviolet lamp, the afterglow of the orange digit "9" was observed (as shown in Figure 9 Figure B), and only the digit "7" with a longer lifetime and a later color change to green was shown after 0.4 s. After heating to 60 °C to form a semi-gel, the fluorescence did not change significantly, but the afterglow completely disappeared. This process could be completely reversibly repeated, showing a good dynamic anti-counterfeiting effect.

[0044] The technical solution of the present invention synthesizes an organic room temperature phosphorescent gel soft material Cz-PtMO with both time-resolved and stimulus-responsive properties in one step. The gel exhibits triple phosphorescence emission peaks at room temperature. Due to the large differences in the lifetimes of these three emission peaks, time-resolved afterglow characteristics appear. At the same time, the Cz-PtMO gel is sensitive to thermal response, thus constructing an organic room temperature phosphorescent soft material with both time-resolved and thermal stimulus-responsive properties, which has important application prospects in the field of dynamic anti-counterfeiting.

Claims

1. Organic room temperature phosphorescent small molecule, characterized in that: The structural formula of the organic room temperature phosphorescent small molecule is: 。 2. The method for preparing an organic room temperature phosphorescent small molecule according to claim 1, characterized in that: The steps include: Under nitrogen conditions, carbazole and trimethoxybenzoic acid are dissolved in a solvent, trifluoroacetic anhydride is added dropwise under stirring, and then phosphoric acid is added dropwise, and the mixture is reacted at room temperature. After the reaction is completed, water is added to quench the reaction, and the product obtained after the reaction is purified to obtain an organic room temperature phosphorescent small molecule.

3. The method for preparing an organic room temperature phosphorescent small molecule according to claim 2, characterized in that: The molar ratio of carbazole, trimethoxybenzoic acid and trifluoroacetic anhydride is 1:(1-2):(3-5).

4. The method for preparing an organic room temperature phosphorescent small molecule according to claim 3, characterized in that: The molar ratio of carbazole, trimethoxybenzoic acid and trifluoroacetic anhydride is 1:1.2:3.

5.

5. An organic room temperature phosphorescent small molecule gel, characterized in that: The organic room temperature phosphorescent small molecule according to claim 1 is added to an aqueous solution containing DMSO and DMF to form a gel material.

6. The organic room temperature phosphorescent small molecule gel according to claim 5, characterized in that: The gel concentration is greater than 20 mg / mL.

7. The organic room temperature phosphorescent small molecule gel according to claim 5, characterized in that: The volume concentration of the DMSO aqueous solution or the DMF aqueous solution is 30-90%.

8. The organic room temperature phosphorescent small molecule gel according to claim 7, characterized in that: The volume concentration of the aqueous solution of DMSO and DMF is 50-80%.

9. A dynamic anti-counterfeiting device, characterized in that: The invention comprises the organic room temperature phosphorescent small molecule gel as described in any one of claims 5 to 8.

10. The dynamic anti-counterfeiting device according to claim 9, characterized in that: The dynamic anti-counterfeiting refers to a completely reversible dynamic anti-counterfeiting effect that has a fluorescent effect under stimulation, disappears when the stimulation disappears, and reappears when stimulated again.

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