Crown ether doped polymer-based organic blue phosphorescent material and application thereof
The crown ether-doped polymer material addresses the inefficiencies and instability of pure organic luminescent materials by enhancing triplet exciton population and molecular rigidity, enabling high-efficiency, long-lasting blue phosphorescence for luminescent displays and coatings.
Patent Information
- Application Number
- CN202510742482.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-05
- Publication Date
- 2025-07-15
AI Technical Summary
Current pure organic long persistent luminescent materials face challenges in promoting intersystem crossing from singlet to triplet states and suppressing triplet exciton non-radiative transitions, leading to low efficiency and instability, while crystalline materials suffer from poor processability and mechanical flexibility, limiting their commercial applications.
A crown ether-doped polymer-based material is developed, where small molecule crown ether derivatives are incorporated into a polymer matrix through hydrogen bonding, enhancing molecular rigidity and promoting triplet exciton population, resulting in efficient and stable blue phosphorescence.
The crown ether-doped polymer material achieves high efficiency and long-lasting blue phosphorescence with improved processability and mechanical flexibility, suitable for applications in luminescent displays and coatings.
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Figure CN120309773A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of preparation of pure organic long - afterglow materials, and particularly relates to a class of crown - ether - derivative - doped polymer - based long - life and high - efficiency blue organic long - afterglow materials, and the application of such materials in afterglow display and luminescent coatings. Background Art
[0002] In recent years, pure organic long - afterglow materials have received great attention due to their broad application prospects in fields such as data encryption, information anti - counterfeiting, bio - imaging, and flexible optoelectronic devices. Compared with inorganic and metal - organic systems, pure organic long - afterglow materials have low cost, excellent processability, and outstanding biocompatibility, thus becoming a current research hotspot. However, limited by the relatively weak spin - orbit coupling of organic molecules themselves, the intersystem crossing efficiency is low; triplet excitons are easily quenched by thermal motion, oxygen, water molecules, etc. in the air, resulting in an increase in non - radiative transitions, making it difficult for organic molecules to achieve efficient phosphorescent emission at room temperature. Therefore, how to effectively promote the intersystem crossing process between singlet and triplet states and inhibit the non - radiative transitions of triplet excitons is the key challenge in constructing high - performance organic long - afterglow materials. To address this problem, various strategies have been developed, including: enhancing spin - orbit coupling by introducing heavy atoms (such as Cl, Br, etc.), heteroatoms (such as O, N, S, P, etc.) or aromatic carbonyl groups to increase the number of triplet excitons; improving the rigid environment of molecules by methods such as H - aggregation, crystal engineering, host - guest doping, etc., to reduce the energy loss caused by molecular vibration. Although these strategies have made remarkable progress, the most common method to achieve long afterglow currently still relies on constructing a rigid structure through crystallization. However, crystalline organic long - afterglow materials have poor processability and mechanical flexibility, and due to the difficulty in precisely controlling the crystal structure, their reproducibility is low, which greatly limits their commercial applications. In contrast, amorphous polymer materials have better processability, higher mechanical flexibility, better reproducibility and stability. Therefore, developing high - performance amorphous organic long - afterglow materials has become a very promising research direction.
[0003] Crown ethers are a class of molecules with a macrocyclic structure and rich host - guest chemical properties. The abundant oxygen atoms therein can promote intersystem crossing and increase the filling rate of triplet excitons, and at the same time can enhance molecular rigidity through host - guest interactions. Therefore, reasonably utilizing this property of crown ethers is expected to achieve the preparation of efficient amorphous organic long - afterglow materials. Given the excellent processing adaptability and mechanical flexibility of amorphous organic long - afterglow materials, such materials are expected to show broad application prospects in afterglow display and luminescent coatings. Summary of the Invention
[0004] In view of the above problems, the object of the present invention is to provide a crown ether-doped polymer-based organic room-temperature phosphorescent material, which can achieve high-efficiency and long-lifetime blue phosphorescent emission through the interaction between the crown ether derivative and the polymer matrix.
[0005] To achieve the above object, the present invention adopts the following technical solutions: The first object of the present invention is to protect a crown ether-doped polymer-based organic blue phosphorescent material, which is prepared by doping a small molecule crown ether derivative as a guest molecule into a polymer. Among them, the small molecule crown ether derivative enhances the molecular rigidity of the polymer and prolongs its phosphorescence lifetime through hydrogen bond interaction on the carboxyl group and ether chain.
[0006] Further, the small molecule crown ether derivative is any one of the following formulas: 。
[0007] Further, the polymer is polyvinyl alcohol.
[0008] Further, the room-temperature phosphorescence quantum efficiency of the obtained material reaches 13.3%, the room-temperature phosphorescence lifetime reaches 491.6 ms, and stable blue phosphorescent emission is presented.
[0009] The second object of the present invention is to protect a preparation method of the crown ether-doped polymer-based organic blue phosphorescent material, which is to heat and stir the small molecule crown ether derivative and the polymer in water to dissolve and form a uniform mixture, and then use the solution casting method to make an amorphous film and dry and cure it.
[0010] Further, the mass ratio of the small molecule crown ether derivative to the polymer used is 1:100.
[0011] Further, the temperature of the heating and stirring is 100 °C and the time is 3 hours.
[0012] Further, the drying temperature is 50 °C.
[0013] The third object of the present invention is to protect the application of the crown ether-doped polymer-based organic blue phosphorescent material in afterglow display or luminescent coating.
[0014] Further, the application method is specifically to construct a long afterglow coating on the surface of the target object by casting or dipping. Specifically, the object to be treated (such as plant branches and leaves, animal models or bionic structures, etc.) is immersed in a solution containing the material so that its surface is fully coated with the material, and then taken out and dried at an appropriate temperature, or directly soak the object to be treated in a solution containing the material and dry the solvent, so as to form a stable phosphorescent coating on the surface of the object.
[0015] Crown ethers contain abundant oxygen atoms, which can promote intersystem crossing and increase the filling rate of triplet excitons. Meanwhile, the oxygen atoms in crown ethers can enhance the molecular rigidity through host-guest interactions and inhibit the non-radiative transitions of triplet excitons. In the present invention, a polyvinyl alcohol polymer rich in hydroxyl groups is selected as the host, and a small molecule crown ether derivative is doped into the polyvinyl alcohol. By forming a tight hydrogen bond network with the crown ether, it can achieve high-performance blue room-temperature phosphorescence, and the obtained material has the characteristics of long lifetime, high efficiency, high transparency, and good flexibility, which is conducive to meeting the actual application requirements of organic room-temperature phosphorescence in afterglow display and luminescent coating fields.
[0016] The beneficial effects of the present invention are as follows: (1) The preparation method of the present invention has the characteristics of simple operation, low cost, low toxicity, and good repeatability.
[0017] (2) By doping a small amount of crown ether as the guest into the polyvinyl alcohol, the present invention can easily prepare blue phosphorescence emission with long lifetime and high efficiency, and the material has good film-forming property, transparency, and mechanical flexibility.
[0018] (3) The material prepared by the present invention can form a stable phosphorescent coating on the surface of objects with different morphologies or materials through simple casting or dip coating methods, has good processing adaptability and application extensibility, and shows excellent prospects in the fields of afterglow display and luminescent coating. Description of the Drawings
[0019] Figure 1 Figures showing the luminescence of the pure organic long afterglow materials CEO10@PVA and CEO8@PVA prepared in Examples 2 and 3 under ultraviolet light irradiation and after irradiation.
[0020] Figure 2 Phosphorescence spectra of the pure organic long afterglow materials CEO10@PVA and CEO8@PVA prepared in Examples 2 and 3.
[0021] Figure 3 Room temperature lifetime decay curves of the pure organic long afterglow materials CEO10@PVA and CEO8@PVA prepared in Examples 2 - 3.
[0022] Figure 4 Figures showing the luminescence of the object with a surface luminescent coating prepared in Example 4 before and after irradiation with fluorescent lamp and 275 nm ultraviolet light. Detailed Embodiments
[0023] A crown ether-doped polymer-based organic blue phosphorescent material is prepared by dispersing a small molecule crown ether derivative as a guest molecule in a host polyvinyl alcohol matrix at a mass ratio of 1:100, adding water and stirring evenly, heating and stirring at 100 °C for 3 hours to dissolve it and form a homogeneous solution, then using the solution casting method to make an amorphous film, and drying and curing it at 50 °C.
[0024] The small molecule crown ether derivative is any one of the following formulas: 。
[0025] To make the content of the present invention easier to understand, the technical solutions of the present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited thereto.
[0026] Unless otherwise specifically stated, various raw materials, reagents, instruments and equipment used in the present invention can be obtained through market purchases or can be prepared by existing methods.
[0027] Example 1 Synthesis of Crown Ether (CEO10)
[0028] Step 1) In a round-bottom flask, successively add methyl 3,4-dihydroxy-2-methylbenzoate (2.5 g, 14.9 mmol), potassium carbonate (K2CO3, 2.3 g, 16.8 mmol) and 30 mL of acetonitrile. Heat the reaction mixture to 85 °C and stir continuously for 3 hours, then cool the reaction system to room temperature. Add benzyl bromide (5.8 g, 16.8 mmol) thereto and continue the reaction for 24 hours. Filter the reaction mixture to remove the solid, and remove the solvent under reduced pressure. Dissolve the residual solid in dichloromethane, wash it successively with water and saturated brine, then dry the organic layer with anhydrous magnesium sulfate, filter and concentrate the filtrate. Purify the obtained crude product by column chromatography (petroleum ether / ethyl acetate, volume ratio 35:1) to finally obtain a white solid product cw-1 (1.6 g, yield 23.8%).
[0029] Step 2) Dissolve triethylene glycol (2.0 g, 10.3 mmol) in 14.0 mL of tetrahydrofuran, and dissolve sodium hydroxide (2.01 g, 25.1 mmol) in 7.0 mL of water. Cool and mix the above two solutions at 0 °C, then slowly add p-toluenesulfonyl chloride (5.86 g, 30.8 mmol). After continuously stirring at low temperature for 10 minutes, raise the mixture to room temperature and continue stirring for 48 hours. Then add 15 mL of water to the reaction system and remove tetrahydrofuran under reduced pressure. Extract the residual liquid with dichloromethane, wash the combined organic phases successively with water and saturated brine, then dry the organic layer with anhydrous magnesium sulfate, and finally obtain a colorless oily product cw-2 (5.02 g, yield 97.0%).
[0030] Step 3) Add product cw-1 (1.17 g, 4.52 mmol), product cw-2 (1.136 g, 2.26 mmol), potassium carbonate (1.25 g, 9.04 mmol) and 35 mL of acetonitrile into a round-bottom flask in sequence. Then heat the reaction mixture to 85 °C and continuously stir at this temperature for 18 hours. After the reaction is completed, cool to room temperature, filter the reaction mixture, and remove the solvent under reduced pressure. Dissolve the residual solid in dichloromethane, wash successively with water and saturated brine, then dry the organic phase with anhydrous magnesium sulfate, filter and concentrate the filtrate, and purify the obtained crude product by column chromatography (petroleum ether / ethyl acetate, volume ratio 3:1) to obtain a white solid product cw-3 (1.45 g, yield 95.4%).
[0031] Step 4) Add product cw-3 (1.56 g, 2.31 mmol) and 10% palladium on carbon (1.56 mg) into a round-bottom flask in sequence, and then add 15 mL of dichloromethane. Stir the reaction under a hydrogen atmosphere at room temperature for 24 hours. After the reaction is completed, filter the reaction mixture and remove the solvent under reduced pressure. Purify the obtained crude product by column chromatography (ethyl acetate / dichloromethane, volume ratio 3:2) to obtain a white solid product cw-4 (0.90 g, yield 78.6%).
[0032] Step 5) The product cw-2 (0.91 g, 1.82 mmol), the product cw-4 (0.90 g, 1.81 mmol) and K2CO3 (0.50 g, 3.63 mmol) were added to 10 mL of acetonitrile, and the mixture was refluxed and stirred at 85 °C for 24 h under nitrogen protection. After the reaction, it was cooled to room temperature, the reaction mixture was filtered, and the solvent was removed under reduced pressure. The residual solid was dissolved in dichloromethane and washed with saturated brine. The organic phase was dried over anhydrous magnesium sulfate, then the filtrate was filtered and concentrated, and the obtained crude product was purified by column chromatography (dichloromethane / methanol, volume ratio 60:1) to obtain a white solid cw-5 (0.29 g, yield 24.1%).
[0033] Step 6) In a 50 mL round-bottom flask, potassium hydroxide (0.19 g, 3.35 mmol), 25 mL of deionized water and the product cw-5 (0.60 g, 0.91 mmol) were added in sequence. The reaction mixture was stirred at 85 °C overnight. After the reaction, it was cooled to room temperature, and concentrated hydrochloric acid was added dropwise to adjust the pH of the solution to 2. Then the reaction mixture was filtered, and the obtained solid was washed with water and dried in an oven at 50 °C overnight to finally obtain a white solid product CEO10 (0.56 g, yield 97.6%). Its structure was characterized as follows: 1 H NMR (600 MHz, DMSO- d 6): δ 12.63 (s, 2H), δ 7.54-7.52 (q, 2H), δ 7.43(d, 2H), δ 7.04-7.02 (d, 2H), δ 4.15-4.09 (m, 8H), δ 3.77-3.74 (q, 8H), δ3.64-3.62(t, 8H), δ 3.55-3.54 (t, 8H).
[0034] Example 2 Preparation of pure organic long afterglow materials Weigh 2 mg of the crown ether CEO10 prepared in Example 1 and 200 mg of polyvinyl alcohol (PVA) into a 20 mL glass bottle, add 8 mL of deionized water, stir and heat to 100 °C, keep for 3 h. After the solution was completely clarified, it was evenly dropped on the surface of a clean glass substrate and transferred to an oven at 50 °C to dry into a film, obtaining a 1 wt.% pure organic long afterglow material CEO10@PVA.
[0035] Example 3 Replace the tetraethylene glycol used in step 2) of Example 1 with an equivalent amount of triethylene glycol, and perform other operations in the same manner as in Example 1 to obtain the crown ether CEO8. Its structure was characterized as follows: 1 H NMR (600 MHz, DMSO-d 6): δ 12.63 (s, 2H), δ 7.54 - 7.52 (q, 2H), δ 7.42 (d, 2H), δ 7.03 - 7.02 (d, 2H), δ 4.15 - 4.09 (m, 8H), δ 3.79 - 3.76 (q, 8H), δ 3.67 (s, 8H).
[0036] Weigh 2 mg of the prepared crown ether CEO8 and 200 mg of polyvinyl alcohol (PVA) respectively into a 20 mL glass bottle, add 8 mL of deionized water, stir and heat to 100 °C, keep for 3 h. After the solution becomes completely clear, evenly drop it on the surface of a clean glass substrate, and then transfer it to an oven at 50 °C to dry into a film, obtaining a 1 wt.% pure organic long - afterglow material CEO8@PVA.
[0037] Figure 1 It is the luminescence situation diagrams of the pure organic long - afterglow materials prepared in Examples 2 and 3 under ultraviolet light irradiation and after irradiation. As can be seen from the figures, the pure organic long - afterglow materials CEO10@PVA and CEO8@PVA prepared in Examples 2 and 3 show strong blue luminescence under 275 nm ultraviolet light irradiation, and the blue luminescence persists for several seconds after turning off the ultraviolet light, showing the long - afterglow phenomenon.
[0038] Figure 2 It is the phosphorescence spectra of the pure organic long - afterglow materials prepared in Examples 2 and 3. As can be seen from the figures, the phosphorescence spectral peaks of the pure organic long - afterglow materials CEO10@PVA and CEO8@PVA prepared in Examples 2 and 3 are both located at 438 nm, showing stable blue phosphorescence emission.
[0039] Figure 3 It is the lifetime decay curve diagrams corresponding to the phosphorescence emission peaks of the pure organic long - afterglow materials prepared in Examples 2 and 3. As can be seen from the figures, the phosphorescence lifetimes of the pure organic long - afterglow materials CEO10@PVA and CEO8@PVA prepared in Examples 2 and 3 reach 478.3 ms and 491.6 ms respectively.
[0040] Example 4 Replace the tetraethylene glycol used in step 2) of Example 1 with an equivalent amount of diethylene glycol, and perform other operations the same as in Example 1 to obtain crown ether CEO6, and its structural characterization is as follows: 1 H NMR (600 MHz, DMSO - d6): δ 12.66 (s, 2H), δ 7.57 - 7.55 (m, 2H), δ 7.44 - 7.43 (t, 2H), δ 7.06 - 7.04 (q, 2H), δ 4.17 - 4.14 (d, 8H), δ 3.87 (s, 8H).
[0041] Weigh 2 mg of the prepared crown ether CEO6 and 200 mg of polyvinyl alcohol (PVA) separately into a 20 mL glass bottle, add 8 mL of deionized water, stir and heat to 100 °C, and keep for 3 h. After the solution becomes completely clear, evenly drop it on the surface of a clean glass substrate, and then move it to an oven at 50 °C to dry into a film, obtaining a 1 wt.% pure organic long afterglow material CEO6@PVA.
[0042] Example 5 Prepare a luminescent coating on the surface of an object by dip coating: Specifically, soak a bionic butterfly or a miniature handmade pine tree in an aqueous solution formed by blending crown ether CEO8 and polyvinyl alcohol (mass ratio 1:100). After its surface is fully wetted, take it out and dry it at 50 °C for 30 minutes, then a stable transparent phosphorescent coating can be formed on the surface of the object. The dried sample shows an obvious blue long afterglow luminescence phenomenon under 275 nm ultraviolet light excitation.
[0043] Figure 4 Pictures of the bionic butterfly and the miniature handmade pine tree with a luminescent coating on their surfaces before and after irradiation by a fluorescent lamp and a 275 nm ultraviolet lamp. As can be seen from the figure, there is no obvious difference between the object with the luminescent coating and the original object under the fluorescent lamp. After 275 nm ultraviolet excitation, both the artificial pine tree and the bionic butterfly show blue long afterglow. Among them, the wing surface of the bionic butterfly can achieve a flexible visual luminescent pattern, and the artificial pine tree also retains a complete luminescent layer on the natural curved surface, showing excellent flexible adhesion and luminescence stability. At the same time, due to the good flexibility of the luminescent coating, the butterfly can freely change the wing extension angle by folding, which proves that this material has potential application prospects in the fields of afterglow display and luminescent coating.
[0044] The above are only the preferred embodiments of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope covered by the present invention.
Claims
1. A crown ether-doped polymer-based organic blue phosphorescent material, characterized in that, The material is prepared by doping a small molecule crown ether derivative as a guest molecule into a polymer. The small molecule crown ether derivative enhances the molecular rigidity of the polymer and prolongs its phosphorescence lifetime through hydrogen bonding interactions on the carboxyl group and ether chain.
2. The crown ether-doped polymer-based organic blue phosphorescent material according to claim 1, characterized in that, The small molecule crown ether derivative is any one of the following formulas: 。 3. The crown ether-doped polymer-based organic blue phosphorescent material according to claim 1, wherein The polymer is polyvinyl alcohol.
4. The crown ether-doped polymer-based organic blue phosphorescent material according to claim 1, wherein The preparation of the material is to add the small molecule crown ether derivative and the polymer into water, heat and stir to dissolve them and form a uniform mixture, and then use the solution casting method to make a film, and dry and cure it.
5. The crown ether-doped polymer-based organic blue phosphorescent material according to claim 4, wherein The mass ratio of the small molecule crown ether derivative to the polymer used is 1:
100.
6. The crown ether-doped polymer-based organic blue phosphorescent material according to claim 4, wherein The temperature of the heating and stirring is 100 °C and the time is 3 hours.
7. Application of the crown ether-doped polymer-based organic blue phosphorescent material as described in claim 1 in afterglow display or light-emitting coating.