Dynamic covalent bond regulated light-activated solid-state luminescent material as well as preparation method and application thereof

Abstract

The invention discloses a dynamic covalent bond regulated light-activated solid-state luminescent material as well as a preparation method and application of the dynamic covalent bond regulated light-activated solid-state luminescent material. The novel solid-state luminescent material is constructed by utilizing a dynamic C-C bond in a halo addition reaction, the C-C bond not only can be dynamically formed and fractured during illumination, but also can connect two planar phenanthrene rings into a whole to shorten the intermolecular distance, and a molecular structure with relatively strong intramolecular pi-pi interaction is constructed, so that the novel solid-state luminescent material is prepared. Pi electron delocalization can be effectively promoted; in addition, due to introduction of the four-membered ring, molecules on the original plane become twisted, and close accumulation of the molecules can be effectively avoided; when the dynamic covalent bond is cracked under illumination, a brand new 9-cyanophenanthrene-based aggregation structure is obtained, and the structure has fluorescence emission which is more red-shifted than that of a self-assembled structure; meanwhile, the process also shows an obvious light activation behavior, so that the method has a good application prospect in the fields of information encryption and anti-counterfeiting.

Description

Technical Field

[0001] The present invention relates to the field of organic solid-state luminescent materials, and in particular to a light-activated solid-state luminescent material regulated by a dynamic covalent bond, and a preparation method and application thereof. Background Art

[0002] Currently, organic solid-state luminescent materials hold significant application prospects in optoelectronic devices, bioimaging, and information anti-counterfeiting. Generally speaking, the optical properties of these materials are influenced by π-electron delocalization, either chemically (e.g., molecular conjugation length, intramolecular charge transfer) or spatially (e.g., intermolecular π-π interactions), which can effectively red-shift the emission wavelength and improve luminescence efficiency. Regulating molecular stacking to achieve π-electron delocalization can avoid tedious and complex chemical synthesis while also endowing the materials with novel luminescent properties, offering enormous technological potential. To achieve this goal, bottom-up approaches such as self-assembly, co-assembly, and high-pressure confinement have been employed to construct organic solid-state luminescent materials with diverse stacking behaviors. However, due to the weak binding energy of non-covalent interactions, many molecular systems cannot form the desired π-π stacking pattern, and their stacking structure is still limited by molecular structure. Furthermore, for some rigid molecules that readily form π-π stacking, tight molecular stacking can completely quench the luminescent properties of the material. Therefore, developing new strategies for manipulating stacking structures to construct solid-state materials with superior luminescent properties is an urgent challenge. Summary of the Invention

[0003] The purpose of the present invention is to provide a new type of dynamic covalent bond-regulated light-activated solid-state luminescent material, a preparation method thereof, and an application thereof in information encryption and anti-counterfeiting.

[0004] To achieve the above objectives, the present invention provides a light-activated solid-state luminescent material regulated by a dynamic covalent bond, wherein the light-activated solid-state luminescent material is a 9-cyanophenanthrene cycloaddition adduct, and the structural formula of the 9-cyanophenanthrene cycloaddition adduct is as follows:

[0005]

[0006] Among them, the CC bond between the two phenanthrene rings is a dynamic covalent bond.

[0007] According to another aspect of the present invention, there is also provided a method for preparing the above-mentioned dynamic covalent bond-regulated light-activated solid-state luminescent material, comprising the following steps:

[0008] dispersing 9-cyanophenanthrene in a solvent to prepare a reaction solution; and

[0009] The reaction solution is irradiated with ultraviolet light to cause a photocycloaddition reaction of 9-cyanophenanthrene to obtain the 9-cyanophenanthrene cycloaddition adduct.

[0010] In the preparation method, the solvent is selected from one of dichloromethane and chloroform; the concentration of the reaction solution is 5 mg mL -1 .

[0011] In the preparation method, the wavelength of the ultraviolet light is 365 nm, and the irradiation time is 3 h to 6 h.

[0012] According to another aspect of the present invention, an anti-counterfeiting film comprising the light-activated solid-state luminescent material regulated by dynamic covalent bonds as described above is also provided, and the 9-cyanophenanthrene cycloaddition adduct dissolved in a solvent is spin-coated on a glass sheet or a quartz sheet to obtain the anti-counterfeiting film.

[0013] In the anti-counterfeiting film provided by the present invention, the solvent is selected from one of dichloromethane and chloroform; the concentration of the 9-cyanophenanthrene cycloaddition adduct is 10 mg mL -1 ; The size of the glass sheet or quartz sheet is (1 cm to 2 cm) × (1 cm to 2 cm).

[0014] According to yet another aspect of the present invention, there is provided a use of the anti-counterfeiting film as described above in information encryption.

[0015] In the application provided by the present invention, the application comprises the following steps:

[0016] Placing the anti-counterfeiting film under a mask having a preset pattern, and irradiating the mask with ultraviolet light to generate a fluorescent pattern corresponding to the preset pattern on the anti-counterfeiting film, thereby realizing information writing;

[0017] The mask is removed, and the anti-counterfeiting film is continuously irradiated with ultraviolet light, so that the fluorescent pattern on the anti-counterfeiting film corresponding to the preset pattern is erased.

[0018] In the application provided by the present invention, the mask is made of metal; the wavelength of the ultraviolet light is 254 nm, and the irradiation time is 10 minutes to 20 minutes.

[0019] The implementation of the present invention can achieve the following beneficial effects:

[0020] The present invention utilizes the dynamic C-C bond in a photocycloaddition reaction to construct a novel solid-state luminescent material. The resulting dynamic covalent bond-regulated light-activated solid-state luminescent material is a 9-cyanophenanthrene cycloaddition adduct, wherein the C-C bond between the two phenanthrene rings is a dynamic covalent bond. The C-C bond can not only dynamically form and break upon illumination, but also connect the two planar phenanthrene rings into a whole to shorten the intermolecular distance, constructing a molecular structure with strong intramolecular π-π interaction, which can effectively promote π electron delocalization. In addition, the introduction of the four-membered ring distorts the originally planar molecule, which can effectively avoid close stacking of the molecules. When the dynamic covalent bond is cleaved under illumination, a new aggregated structure based on 9-cyanophenanthrene is obtained, which has a more red-shifted fluorescence emission than its self-assembled structure. At the same time, the process also exhibits obvious photoactivation behavior, and thus has good application prospects in the fields of information encryption and anti-counterfeiting. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only embodiments of the present invention. Those skilled in the art can also derive other drawings based on the provided drawings without inventive work.

[0022] Figure 1 Shown is the preparation route of 9-cyanophenanthrene cycloaddition adduct;

[0023] Figure 2 Shown is the solid-state photoactivated fluorescence spectrum of the 9-cyanophenanthrene cycloaddition adduct;

[0024] Figure 3 Shown is a comparison of the solid-state photoactivated fluorescence of 9-cyanophenanthrene cycloaddition adduct and the solid-state fluorescence of 9-cyanophenanthrene self-assembly;

[0025] Figure 4 Schematic diagram showing the application of anti-counterfeiting film prepared from 9-cyanophenanthrene cycloaddition adduct in information encryption. DETAILED DESCRIPTION

[0026] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, and not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments described in this specification without inventive effort are also within the scope of protection of the present invention.

[0027] A dynamic covalent bond is a chemical bond that can be broken and restored under specific conditions. It allows the material to form a whole and separate under external stimulation. Combining the materials in a covalent (high binding energy) manner will provide an assembly driving force that is completely different from the material itself, which can form different stacking behaviors. And when the "separation" process can be realized in the solid state, due to the limitations of molecular motion, the separated materials can still maintain their original "covalent stacking". Therefore, the reversible properties of dynamic covalent bonds are expected to realize the construction of new solid-state light-emitting materials. Among the many dynamic covalent bonds, the use of dynamic CC bonds in photocycloaddition reactions to construct new solid-state light-emitting materials has great advantages.

[0028] The present invention provides a method for preparing a light-activated solid-state luminescent material regulated by a dynamic covalent bond, and the synthesis route thereof is as follows: Figure 1 As shown. Figure 1 As shown, the preparation method comprises the following steps:

[0029] (1) Dispersing 9-cyanophenanthrene in a solvent to prepare a reaction solution:

[0030] (2) irradiating the reaction solution with ultraviolet light to cause 9-cyanophenanthrene to undergo a photocycloaddition reaction, thereby obtaining the 9-cyanophenanthrene cycloaddition adduct having the structure shown below, wherein the C-C bond between the two phenanthrene rings is a dynamic covalent bond.

[0031]

[0032] Specifically, in this embodiment, 9-cyanophenanthrene is dispersed in a solvent selected from dichloromethane or chloroform to a concentration of 5 mg mL -1 then, reacting under 365nm ultraviolet light for 3 to 6 hours, so that 9-cyanophenanthrene undergoes a photocycloaddition reaction to obtain the 9-cyanophenanthrene cycloaddition adduct.

[0033] The present invention utilizes the dynamic C-C bond in a photocycloaddition reaction to construct a novel solid-state luminescent material. The C-C bond between the two phenanthrene rings can not only dynamically form and break upon illumination, but also shorten the intermolecular distance, promoting π electron delocalization. This can effectively promote a red shift in the material's emission wavelength and improve luminous efficiency. In addition, the four-membered ring adducts typically exhibit a distorted stereochemical structure, which can effectively avoid the luminescence quenching problem caused by close packing of molecules.

[0034] Figure 2 Shown is the solid-state photoactivated fluorescence spectrum of the 9-cyanophenanthrene cycloaddition adduct; Figure 3The figure shows a comparison of the solid-state photoactivated fluorescence of the 9-cyanophenanthrene cycloaddition adduct and the solid-state fluorescence of the 9-cyanophenanthrene self-assembly. When the dynamic covalent bond is cleaved under light, a new aggregate structure based on 9-cyanophenanthrene is obtained, as shown in FIG. Figure 3 As shown, the fluorescence wavelength of the structure (9-cyanophenanthrene cycloaddition adduct-activated) is around 416 nm, while the fluorescence wavelength of the 9-cyanophenanthrene self-assembled structure is around 388 nm. Therefore, the fluorescence emission of the structure (9-cyanophenanthrene cycloaddition adduct-activated) is more red-shifted than that of the 9-cyanophenanthrene self-assembled structure. Figure 2 As shown, the fluorescence intensity gradually increased with the increase of illumination time, so the process also exhibited obvious photoactivation behavior.

[0035] The present invention also provides an anti-counterfeiting film comprising the above-mentioned light-activated solid-state luminescent material regulated by dynamic covalent bonds, which is obtained by spin-coating the 9-cyanophenanthrene cycloaddition adduct dissolved in a solvent on a glass sheet or a quartz sheet.

[0036] Specifically, in one embodiment of the present invention, the 9-cyanophenanthrene cycloaddition adduct is dissolved in dichloromethane or chloroform to a concentration of 10 mg mL -1 Then, the solution is spin-coated on a glass sheet or quartz sheet with a size of (1 cm to 2 cm) x (1 cm to 2 cm) using a KW-4A tabletop spin coater to obtain the anti-counterfeiting film. The rotation speed of the KW-4A tabletop spin coater is 500 rpm to 2000 rpm.

[0037] When the dynamic covalent bonds of the 9-cyanophenanthrene cycloaddition adduct are cleaved under light, a new aggregation structure based on 9-cyanophenanthrene is obtained. This process not only has obvious photoactivation behavior, but the new aggregation structure also has a more red-shifted fluorescence emission than the 9-cyanophenanthrene self-assembly structure. Therefore, the film prepared based on this 9-cyanophenanthrene cycloaddition adduct has good application prospects in the fields of information encryption and anti-counterfeiting.

[0038] The present invention also provides an application of the anti-counterfeiting film in information encryption, such as Figure 4 As shown, when in use, the anti-counterfeiting film is placed under a mask having a preset pattern, and ultraviolet light is irradiated above the mask, so that a fluorescent pattern corresponding to the preset pattern is generated on the anti-counterfeiting film, thereby realizing information writing; the mask is removed, and the anti-counterfeiting film is continued to be irradiated with ultraviolet light, so that the fluorescent pattern corresponding to the preset pattern on the anti-counterfeiting film is erased, thereby realizing information erasure.

[0039] Specifically, in one embodiment of the present invention, an anti-counterfeiting film is placed under a metal mask plate, wherein a preset pattern related to the information to be encrypted is formed on the mask plate using a laser; then, 254nm ultraviolet light is used to irradiate the mask plate for 10 to 20 minutes, so that the dynamic covalent bonds of the 9-cyanophenanthrene cycloaddition adduct on the anti-counterfeiting film are cleaved under light, resulting in photoactivation, and then a fluorescent pattern corresponding to the pattern on the mask plate is generated on the anti-counterfeiting film, thereby realizing the writing of the information to be encrypted; when the information is not needed, the mask plate can be removed and 254nm ultraviolet light can be directly used to irradiate the anti-counterfeiting film for 10 to 20 minutes, so that all areas of the anti-counterfeiting film undergo a fluorescent reaction, thereby obtaining an anti-counterfeiting film without a pattern, that is, the fluorescent pattern corresponding to the preset pattern on the anti-counterfeiting film is erased, thereby realizing the erasure of the information.

[0040] The film prepared based on the 9-cyanophenanthrene cycloaddition adduct provided by the present invention has light responsiveness and can exhibit obvious light-activated fluorescence behavior. This dynamic property makes the film have great advantages in information encryption, and can realize dynamic writing, erasing and rewriting of information as required. When making anti-counterfeiting marks or labels, the fluorescent pattern of the film can be used to ensure the authenticity and traceability of the product, thereby improving the anti-counterfeiting performance of the product. Because the film has dynamic light responsiveness and fluorescence characteristics, its information encryption and anti-counterfeiting functions are safer and more reliable than traditional methods. By encrypting and decrypting information in a light-activated manner, it is possible to effectively prevent information from being illegally obtained or tampered with.

[0041] The present invention will be further described below by way of specific examples, but is not limited thereto. The raw materials used in the examples are all conventional commercially available products unless otherwise specified. It should be noted that any process not specifically described below is within the skill of those skilled in the art, as can be realized or understood with reference to the prior art. Reagents or instruments used that do not indicate the manufacturer are deemed to be conventional products that can be purchased commercially.

[0042] Example 1 Preparation of a Dynamic Covalent Bond-Controlled Light-Activated Solid-State Luminescent Material

[0043] Disperse 9-cyanophenanthrene in dichloromethane to a concentration of 5 mg mL -1 then, reacting under 365nm ultraviolet light for 6 hours, so that 9-cyanophenanthrene undergoes a photocycloaddition reaction to obtain the 9-cyanophenanthrene cycloaddition adduct.

[0044] Figure 2 Shown is the solid-state photoactivated fluorescence spectrum of the 9-cyanophenanthrene cycloaddition adduct; Figure 3 The figure shows the comparison of the solid-state photoactivated fluorescence of 9-cyanophenanthrene cycloaddition adduct and the solid-state fluorescence of 9-cyanophenanthrene self-assembly. Figure 3As shown in FIG, the fluorescence wavelength of the 9-cyanophenanthrene cycloaddition adduct after photoactivation is about 416 nm, while the fluorescence wavelength of the 9-cyanophenanthrene self-assembled structure is about 388 nm. Therefore, the structure (9-cyanophenanthrene cycloaddition adduct-activated) has a more red-shifted fluorescence emission than the 9-cyanophenanthrene self-assembled structure. Figure 2 As shown, the fluorescence intensity gradually increased with the increase of illumination time, so the process also exhibited obvious photoactivation behavior.

[0045] Example 2 Preparation of an anti-counterfeiting film containing the above-mentioned light-activated solid-state luminescent material regulated by dynamic covalent bonds

[0046] The 9-cyanophenanthrene cycloaddition adduct prepared in Example 1 was dissolved in chloroform to a concentration of 10 mg mL -1 then, the solution was spin-coated on a quartz plate having a size of 2 cm × 2 cm using a KW-4A desktop spin coater to obtain the anti-counterfeiting film.

[0047] Example 3 Application of the Anti-Counterfeiting Film in Information Encryption

[0048] The anti-counterfeiting film prepared in Example 2 is placed under a metal mask plate engraved with a preset pattern; then, 254nm ultraviolet light is used to irradiate the mask plate for 10 minutes to generate a fluorescent pattern corresponding to the pattern on the mask plate on the anti-counterfeiting film, thereby realizing the writing of the information to be encrypted; when the information is no longer needed, the mask plate is removed and 254nm ultraviolet light is directly used to irradiate the anti-counterfeiting film for 20 minutes to obtain an anti-counterfeiting film without a pattern, thereby realizing the erasure of the information.

[0049] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A light-activated solid-state luminescent material regulated by a dynamic covalent bond, characterized in that: The light-activated solid-state luminescent material is a 9-cyanophenanthrene cycloaddition adduct, and the structural formula of the 9-cyanophenanthrene cycloaddition adduct is as follows: Among them, the CC bond between the two phenanthrene rings is a dynamic covalent bond.

2. The method for preparing a light-activated solid-state luminescent material regulated by a dynamic covalent bond according to claim 1, characterized in that: The following steps are involved: dispersing 9-cyanophenanthrene in a solvent to prepare a reaction solution; and The reaction solution is irradiated with ultraviolet light to cause a photocycloaddition reaction of 9-cyanophenanthrene to obtain the 9-cyanophenanthrene cycloaddition adduct.

3. The preparation method according to claim 2, characterized in that The solvent is selected from one of dichloromethane and chloroform; the concentration of the reaction solution is 5 mg mL -1 .

4. The preparation method according to claim 2, characterized in that The wavelength of the ultraviolet light is 365 nm, and the irradiation time is 3 hours to 6 hours.

5. An anti-counterfeiting film comprising the light-activated solid-state luminescent material controlled by dynamic covalent bonds as claimed in claim 1, characterized in that: The 9-cyanophenanthrene cycloaddition adduct dissolved in a solvent is spin-coated on a glass sheet or a quartz sheet to obtain the anti-counterfeiting film.

6. The anti-counterfeiting film according to claim 5, characterized in that: The solvent is selected from one of dichloromethane and chloroform; the concentration of the 9-cyanophenanthrene cycloaddition adduct is 10 mg mL -1 ; The size of the glass sheet or quartz sheet is (1 cm to 2 cm) × (1 cm to 2 cm).

7. Use of the anti-counterfeiting film according to claim 5 in information encryption.

8. The use according to claim 7, characterized in that The application comprises the following steps: Placing the anti-counterfeiting film under a mask having a preset pattern, and irradiating the mask with ultraviolet light to generate a fluorescent pattern corresponding to the preset pattern on the anti-counterfeiting film, thereby realizing information writing; The mask is removed, and the anti-counterfeiting film is continuously irradiated with ultraviolet light, so that the fluorescent pattern on the anti-counterfeiting film corresponding to the preset pattern is erased.

9. The use according to claim 8, characterized in that The mask is made of metal; the wavelength of the ultraviolet light is 254 nm, and the irradiation time is 10 to 20 minutes.

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