Symmetrical benzophenanthrene room-temperature phosphorescent material as well as preparation method and application thereof
By simplifying the synthesis route, symmetrical benzo[a]phenanthrene room temperature phosphorescent materials were prepared, solving the problems of complex and unstable synthesis of benzo[a]phenanthrene materials. This enabled the preparation of efficient and long-life room temperature phosphorescent composite films with good luminescence properties and thermal stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-03-31
AI Technical Summary
Existing benzophenanthrene phosphorescent materials have complex synthesis processes, few varieties, and limited performance research. Furthermore, these materials are unstable in air and easily affected by mechanical forces, making it difficult to prepare efficient and long-life room-temperature phosphorescent thin films.
A symmetrical benzo[a]phenanthrene room temperature phosphorescent material was prepared by etherifying 4,4'-biphenyldiol with bromoisopropane via a simple synthetic route. The intermediate was then halogenated and reacted with saturated fatty acids to introduce ester groups. The symmetrical benzo[a]phenanthrene room temperature phosphorescent material was then added to a polymer solution and a long afterglow room temperature phosphorescent composite material was prepared using vacuum flash evaporation technology.
The synthesis process was simplified, the cost was reduced, and the thermal stability and molecular assembly characteristics of the material were improved. The prepared composite film has excellent luminescence properties and long afterglow performance.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of organic room temperature phosphorescent material preparation technology, and in particular to a symmetrical benzo[a]phenanthrene room temperature phosphorescent material, its preparation method and application. Background Technology
[0002] Organic room-temperature phosphorescence (RTP) materials, due to their unique photophysical properties such as long lifetime, large Stokes shift, and high exciton utilization, have great application potential in fields such as data encryption, anti-counterfeiting, information storage, and targeted positioning, making them an extremely important research direction in organic optoelectronic functional materials. However, how to efficiently construct room-temperature phosphorescent thin films with long lifetime, high quantum efficiency, and high environmental stability remains a challenging scientific problem. These materials suffer from limitations such as a single emission peak, poor stability and processability, extreme sensitivity of triplet excitons to moisture and oxygen in the air, and the susceptibility of phosphorescence in ordered lattice systems of RTP materials (such as crystals and host-guest doped materials) to mechanical forces (such as grinding and collisions). In recent years, researchers have discovered that incorporating organic phosphorescent molecules into polymer thin films, utilizing the rigid structure of the polymer itself and the strong interaction between the phosphorescent molecules and the polymer, can effectively suppress the movement of luminescent groups, thereby achieving long-lifetime luminescence of organic phosphorescent materials at room temperature. Among these, benzo[a]phenanthrene phosphorescent materials have emerged as candidates for high-performance organic phosphorescent materials due to their high luminous efficiency and lifetime. However, due to the complex synthesis process, there are relatively few types of benzo[a]phenanthrene phosphorescent materials, resulting in a scarcity of molecular species and limited performance research. Therefore, obtaining high-performance, simple-to-synthesize benzo[a]phenanthrene disk-shaped phosphorescent materials to promote the development of organic composite luminescent films is particularly important. Summary of the Invention
[0003] In view of this, the present invention provides a symmetrical benzo[a]phenanthrene room temperature phosphorescent material, its preparation method and application.
[0004] To achieve the above objectives, the present invention provides the following solution: One of the technical solutions of this invention is a symmetrical benzo[a]phenanthrene room temperature phosphorescent material, with the structural formula shown in Formula I; Formula I; In Formula I, R1 is an alkyl group having 4, 5, 6, 8, 9, 10 or 12 carbon atoms; R2 is an alkyl group having 1, 2, 3, 4, 5, 6, 8, 9, 10 or 12 carbon atoms.
[0005] The second technical solution of the present invention is a method for preparing the above-mentioned symmetrical benzo[a]phenanthrene room temperature phosphorescent material, comprising the following steps: Step 1: Under nitrogen protection, 4,4'-biphenyl hydroquinone is etherified with bromoisopropane to obtain intermediate 1; Intermediate 1 is halogenated with elemental iodine to obtain intermediate 2; Intermediate 2 is subjected to alkaline conditions in which a hydroxyl group replaces an iodine molecule to yield intermediate 3; Intermediate 3 undergoes an etherification reaction with a haloalkane to give intermediate 4; Intermediate 4 reacts with compound A via a Schall reaction to yield 2,7-dihydroxy-3,6,10,11-tetraalkoxybenzophenanthrene; Step 2: 2,7-Dihydroxy-3,6,10,11-tetraalkoxybenzophenanthrene and saturated fatty acids react under the action of a catalyst to generate the symmetrical benzophenanthrene room temperature phosphorescent material. The compound A is at least one of phthalic acid dimethyl ether, phthalic acid diethyl ether, phthalic acid dipropyl ether, phthalic acid dibutyl ether, and phthalic acid dipentyl ether.
[0006] The third technical solution of this invention is the application of the above-mentioned symmetrical benzophenanthrene room temperature phosphorescent material in the preparation of long afterglow room temperature phosphorescent composite materials.
[0007] The fourth technical solution of this invention is a method for preparing a long-afterglow room-temperature phosphorescent composite material, comprising the following steps: The above-mentioned symmetrical benzophenanthrene room temperature phosphorescent material was added to a polymer solution to obtain a precursor solution. The precursor solution was then coated onto the substrate surface, and the long afterglow room temperature phosphorescent composite material was obtained using vacuum flash evaporation technology.
[0008] The fifth technical solution of the present invention is a long afterglow room temperature phosphorescent composite material prepared by the above-mentioned preparation method.
[0009] The present invention discloses the following technical effects: This invention provides a diester-substituted symmetrical benzophenanthrene room temperature phosphorescent material and its preparation method. The synthesis process is simple, the yield is high, it is easy to purify, and it can be mass-produced. Moreover, the introduced symmetrical ester group can not only improve the thermal stability of the material, but also optimize the molecular assembly characteristics, thereby improving the luminescence properties of the prepared room temperature phosphorescent composite film. Attached Figure Description
[0010] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0011] Figure 1The NMR spectrum of intermediate 1 in Example 1; Figure 2 The NMR spectrum of intermediate 2 in Example 1; Figure 3 The NMR spectrum of intermediate 3 in Example 1; Figure 4 The NMR spectrum of intermediate 4 in Example 1; Figure 5 The NMR spectrum of 2,7-dihydroxy-3,6,10,11-tetraalkoxybenzophenanthrene in Example 1 is shown. Figure 6 The NMR spectrum of 2,7-diesteryl-3,6,10,11-tetraalkoxybenzophenanthrene in Example 2; Figure 7 The fluorescence excitation and emission spectra (a), and phosphorescence excitation and emission spectra (b) of the T5DP27 composite film in Application Example 1 are shown. Figure 8 For the afterglow development of the T5DP27 composite film in Application Example 1; Figure 9 Thermogravimetric analysis curve of 2,7-diesteryl-3,6,10,11-tetraalkoxybenzophenanthrene in Example 2. Detailed Implementation
[0012] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.
[0013] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.
[0014] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.
[0015] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.
[0016] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.
[0017] This invention, through extensive experimental research, develops a benzo[x]phenanthrene room-temperature phosphorescent material with high luminescence quantum yield and long luminescence lifetime. This benzo[x]phenanthrene room-temperature phosphorescent material uses benzo[x]phenanthrene as the luminescent group, and its assembly characteristics are enhanced through modification of the ester side chains. Subsequently, the benzo[x]phenanthrene phosphorescent material is introduced as a dopant into polymer matrices such as polyvinyl alcohol and polystyrene acrylonitrile. The polymer matrix enhances the interaction between singlet and triplet excitons, suppresses nonradiative recombination of triplet excitons, and prepares a highly efficient, long-lifetime room-temperature phosphorescent composite film.
[0018] The first aspect of this invention provides a symmetrical benzo[a]phenanthrene room temperature phosphorescent material, with the structural formula shown in Formula I; Formula I; In Formula I, R1 is an alkyl group with 4, 5, 6, 8, 9, 10, or 12 carbon atoms (i.e., R1 = C). n H 2n+1 (n=4, 5, 6, 8, 9, 10, 12); R2 is an alkyl group with 1, 2, 3, 4, 5, 6, 8, 9, 10 or 12 carbon atoms (i.e., R2=C). n H 2n+1 , n=1, 2, 3, 4, 5, 6, 8, 9, 10, 12).
[0019] A second aspect of the present invention provides a method for preparing the above-mentioned symmetrical benzo[a]phenanthrene room temperature phosphorescent material, comprising the following steps: Step 1: Under nitrogen protection, 4,4'-biphenyl hydroquinone is etherified with bromoisopropane to obtain intermediate 1; Intermediate 1 is halogenated with elemental iodine to obtain intermediate 2; Intermediate 2 is subjected to alkaline conditions in which a hydroxyl group replaces an iodine molecule to yield intermediate 3; Intermediate 3 undergoes an etherification reaction with a haloalkane to give intermediate 4; Intermediate 4 reacts with compound A via a Schall reaction to yield 2,7-dihydroxy-3,6,10,11-tetraalkoxybenzophenanthrene; Step 2: 2,7-Dihydroxy-3,6,10,11-tetraalkoxybenzophenanthrene and saturated fatty acids react under the action of a catalyst to generate the symmetrical benzophenanthrene room temperature phosphorescent material. The compound A is at least one of phthalic acid dimethyl ether, phthalic acid diethyl ether, phthalic acid dipropyl ether, phthalic acid dibutyl ether, and phthalic acid dipentyl ether.
[0020] The structural formula of the 2,7-dihydroxy-3,6,10,11-tetraalkoxybenzophenanthrene is as follows: Formula II; In Formula II, R1 and R2 are the same as R1 and R2 in claim 1.
[0021] Compared with existing technologies, the advantages of this invention in synthesizing 2,7-dihydroxy-3,6,10,11-tetraalkoxybenzophenanthrene are: the synthetic route is short, the reaction conditions are mild and safe, and the use of dangerous reagents such as butyllithium is avoided; the synthesis process has a high yield, no expensive metal catalysts are used, and the production cost can be reduced; the intermediate is obtained by direct filtration and recrystallization, which can be commercially produced.
[0022] The catalyst is dicyclohexylcarbodiimide and 4-dimethylaminopyridine.
[0023] The present invention does not impose any particular limitation on the amount of catalyst used, or the ratio of dicyclohexylcarbodiimide to 4-dimethylaminopyridine; any amount and ratio known to those skilled in the art that can cause the Schall reaction may be used.
[0024] In a preferred embodiment of the present invention, the structural formula of the intermediate 1 is as follows: .
[0025] In a preferred embodiment of the present invention, the structural formula of the intermediate 2 is as follows: .
[0026] In a preferred embodiment of the present invention, the structural formula of the intermediate 3 is as follows: .
[0027] In a preferred embodiment of the present invention, the structural formula of the intermediate 4 is as follows: .
[0028] Step 2 further includes steps of filtration, vacuum distillation, and purification after the reaction is completed.
[0029] The reaction in step 2 is carried out at 80°C.
[0030] This invention provides a method for synthesizing a diester-substituted symmetrical benzo[a]phenanthrene room-temperature phosphorescent material. The preparation method provided by this invention simplifies the synthesis process of 2,7-position diester-substituted benzo[a]phenanthrene disk-shaped liquid crystal compounds, reduces their preparation cost, and imparts excellent luminescent properties.
[0031] The third aspect of the present invention provides the application of the above-mentioned symmetrical benzophenanthrene room temperature phosphorescent material in the preparation of long afterglow room temperature phosphorescent composite materials.
[0032] A fourth aspect of this invention provides a method for preparing a long-afterglow room-temperature phosphorescent composite material, comprising the following steps: The above-mentioned symmetrical benzophenanthrene room temperature phosphorescent material was added to a polymer solution to obtain a precursor solution. The precursor solution was then coated onto the substrate surface, and the long afterglow room temperature phosphorescent composite material was obtained using vacuum flash evaporation technology.
[0033] This invention does not impose any special limitations on the conditions for vacuum flash evaporation technology; the vacuum flash evaporation conditions commonly used by those skilled in the art can be adopted.
[0034] In a preferred embodiment of the present invention, the polymer in the polymer solution is polyvinyl alcohol or polystyrene nitrile, and the solvent is N,N-dimethylformamide; the mass concentration of the symmetrical benzophenanthrene room temperature phosphorescent material in the polymer solution is 0.5%-5%.
[0035] The fifth aspect of the present invention provides a long afterglow room temperature phosphorescent composite material prepared by the above-described preparation method.
[0036] Unless otherwise specified, the technical solutions described in this invention are all conventional solutions in the field, and the reagents or raw materials used are all purchased from commercial channels or are publicly available unless otherwise specified.
[0037] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0038] Example 1 The specific synthetic steps and conditions for 2,7-dihydroxy-3,6,10,11-tetraalkoxybenzophenanthrene are as follows: (1) Synthesis of 4,4'-diisopropylbiphenyl 18.6 g of 4,4′-biphenyl, 27.6 g of potassium carbonate, 1.6 g of tetrabutylammonium bromide, and 0.2 g of potassium iodide were sequentially added to a three-necked flask containing 150 mL of acetonitrile. The mixture was magnetically stirred at 50 °C for 30 min, and 30.7 g of bromoisopropane was added dropwise. The reaction system was heated to 85 °C and refluxed under nitrogen protection. The reaction progress was monitored by thin-plate chromatography. After the reaction was complete, the mixture was filtered using a Buchner funnel. The filter cake was washed with dichloromethane, the organic solvent was removed by vacuum distillation, and the tetrabutylammonium bromide was removed by washing with ethanol. The mixture was then filtered and dried to obtain 24.6 g of a white solid, namely 4,4′-diisopropylbiphenyl (intermediate 1), with a yield of 91%. The NMR spectrum is shown below. Figure 1 As shown, 1 H NMR (500 MHz, Chloroform-d) δ: 7.48 – 7.42 (m, 4H), 6.96 – 6.87 (m,4H), 4.56 (h, J = 6.0 Hz, 2H), 1.36 (d, J = 6.0 Hz, 12H). (2) Synthesis of 3,3'-diiodo-4,4'-diisopropylbiphenyl 13.5 g of intermediate 1, 12.7 g of elemental iodine, and 5.7 g of periodic acid were sequentially added to a three-necked flask containing 100 mL of a mixed solution (deionized water, glacial acetic acid, and concentrated sulfuric acid in a volume ratio of 90:10:1). The reaction system was incubated at 80 °C for 24 h, and the reaction progress was monitored by thin-plate chromatography. After the reaction was complete, the mixture was washed three times in 5 M sodium sulfite solution, extracted with ethyl acetate, dried over anhydrous magnesium sulfate, and the solution was removed by vacuum distillation. Recrystallization from ethanol yielded 24.3 g of a white lumpy solid, namely 3,3'-diiodo-4,4'-diisopropylbiphenyl (intermediate 2), with a yield of 93%; the NMR spectrum is shown below. Figure 2 As shown. 1 H NMR (500 MHz, Chloroform-d) δ: 7.92 (d, J = 2.3 Hz, 2H), 7.41 (dd, J = 8.4, 2.3 Hz, 2H), 6.85 (d, J = 8.5 Hz, 2H), 4.58 (m, 2H), 1.41 (d, J = 6.1 Hz, 12H). (3) Synthesis of 3,3'-dihydroxy-4,4'-diisopropylbiphenyl 21 g of intermediate 2, 19 g of cuprous iodide, 22.4 g of potassium hydroxide, and 100 g of polyethylene glycol 600 were sequentially added to a three-necked flask containing 200 mL of deionized water. The reaction system was stirred magnetically and reacted at 130 °C for 24 h, with the reaction progress monitored by thin-plate chromatography. After the reaction was complete, the mixture was poured into 500 mL of water, and the pH was adjusted to 4 using concentrated sulfuric acid. The mixture was filtered using a Buchner funnel, the filter cake was washed with ethyl acetate, and then extracted with ethyl acetate. The solution was dried over anhydrous magnesium sulfate, and the solution was removed by vacuum distillation. Recrystallization from ethanol yielded 7.8 g of a white solid, namely 3,3'-dihydroxy-4,4'-diisopropylbiphenyl (intermediate 3), with a yield of 64%. The NMR spectrum is shown below. Figure 3 As shown. 1 H NMR (500 MHz, Chloroform-d) δ: 7.14(d, J = 2.3 Hz, 2H), 7.00 (dd, J = 8.3, 2.2 Hz, 2H), 6.88 (d, J = 8.3 Hz, 2H), 5.73(s, 2H), 4.60 (m, 2H), 1.38 (d, J = 6.0 Hz, 12H). (4) Synthesis of 3,3'-dibutoxy-4,4'-diisopropylbiphenyl 6 g of intermediate 3, 7 g of potassium carbonate, 0.3 g of tetrabutylammonium bromide, and 0.1 g of potassium iodide were sequentially added to a three-necked flask containing 50 mL of acetonitrile. The mixture was magnetically stirred at 50 °C for 30 min. 6.8 g of n-butane bromide was added dropwise, and the reaction mixture was heated to 85 °C and refluxed. The reaction progress was monitored by thin-plate chromatography. After the reaction was complete, the mixture was filtered using a Buchner funnel. The filter cake was washed with dichloromethane, the organic solvent was removed by vacuum distillation, and the mixture was washed with ethanol to remove tetrabutylammonium bromide. The mixture was then filtered, dried, and 7.6 g of a white solid, namely 3,3'-dibutoxy-4,4'-diisopropylbiphenyl (intermediate 4), was obtained, with a yield of 92%. The NMR spectrum is shown below. Figure 4 As shown. 1 H NMR(500 MHz, Chloroform-d) δ: 7.10 – 7.02 (m, 4H), 6.95 (d, J = 8.1 Hz, 2H), 4.48 (h, J = 6.1 Hz, 2H), 4.05 (t, J = 6.6 Hz, 4H), 1.86 – 1.76 (m, 4H), 1.52(m, 4H), 1.36 (d, J = 6.0 Hz, 12H). (5) Synthesis of 2,7-dihydroxy-3,6,10,11-tetraalkoxybenzophenanthrene (2,7-dihydroxy-2,7,10,11-tetrabutoxybenzophenanthrene) 6 g of intermediate 4 and 3.4 g of o-phthalobutyl ether were sequentially added to a three-necked flask containing 20 mL of dichloromethane. Under nitrogen atmosphere and magnetic stirring, 4.9 g of anhydrous ferric chloride (FeCl3) was slowly added. The mixture was stirred at 50 °C for 4 h, and the reaction progress was monitored by thin-layer chromatography. After the reaction was complete, the substrate was poured into 200 mL of ice-cold methanol, resulting in a light gray precipitate. The precipitate was purified by column chromatography to give 5.14 g of a white solid, namely 2,7-dihydroxy-3,6,10,11-tetraalkoxybenzophenanthrene, with a yield of 56%. The NMR spectrum is shown below. Figure 5 As shown. 1 H NMR (500 MHz, Chloroform-d) δ 7.95 (s, 2H), 7.81 (s, 2H), 7.71 (s,2H), 5.89 (s, 2H), 4.28 (t, J = 6.3 Hz, 4H), 4.21 (t, J = 6.6 Hz, 4H), 1.96 –1.89 (m, 8H), 1.60 (m, 8H), 1.05 (m, 12H). The synthesis route is shown below:
[0039] Example 2 The synthetic method of 2,7-diesteryl-3,6,10,11-tetraalkoxybenzophenanthrene (2,7-dipentyl-3,6,10,11-tetraalkoxybenzophenanthrene compound, labeled T5DP27) is as follows: Under nitrogen protection, 2,7-dihydroxy-3,6,10,11-tetrabutoxybenzophenanthrene (0.5 g, 9.11 × 10⁻⁶) was... - 4 0.214 g of dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP) were sequentially added to a three-necked flask containing 20 mL of anhydrous dichloromethane (DCM). After magnetic stirring for 15 minutes, 0.214 g of n-valeric acid (2.09 × 10⁻⁶ mol) was added using a syringe. -3The solution was injected with mol of the solution and reacted at 40 °C for 12 hours, with the reaction progress monitored by thin-layer chromatography. After the reaction was complete, the substrate was poured into a Buchner funnel and filtered to remove N,N-dicyclohexylurea (DCU) generated during the reaction. The filter cake was washed with dichloromethane, the organic solvent was removed by vacuum distillation, and the product was purified by column chromatography to give 0.56 g of a white solid, namely 2,7-diesteryl-3,6,10,11-tetraalkoxybenzophenanthrene, with a yield of 86%. The NMR spectrum is shown below. Figure 6 As shown in (a), the infrared spectrum is as follows: Figure 6 As shown in (b).
[0040] 1 H NMR (500 MHz, CDCl3) δ 8.03 (s, 2H), 7.85 (s, 2H), 7.71 (s, 2H), 4.21 (m, J = 7.0 Hz, 8H), 2.68 (t, J = 7.6 Hz, 4H), 1.91 (m, J = 8.5, 6.5 Hz, 4H),1.85 (s, 8H), 1.62 -1.52 (m, 12H), 1.05 - 1.00 (m, 18H). In the FT-IR plot (as in 6(b)), the wavenumber is 3100 cm⁻¹. -1 The stretching vibration of the unsaturated -CH bond appeared at 2940 cm⁻¹, which is the vibration peak of the -CH bond on the benzo[a]phenanthrene-ring; -1 and 2860 cm -1 The stretching vibration of the saturated -CH bond appears at 1720 cm⁻¹, originating from the vibrational peaks of the methyl and methylene groups. -1 The characteristic peak of the carbonyl-C=O bond appeared at the position.
[0041] The chemical structure of the target product T5DP27 can be determined by ¹H NMR and FT-IR spectra.
[0042] The synthesis route is shown below:
[0043] Application Example 1 The preparation steps of the long-afterglow room-temperature phosphorescent composite film (T5DP27 composite film) are as follows: 1 g of polyacrylonitrile was dissolved in 10 mL of N,N-dimethylformamide (DMF) to prepare a polymer matrix with a concentration of 0.1 g / mL. 2 mg, 2 mg, 5 mg, and 10 mg of T5DP27 were added to polymer matrices containing 0.4 g, 0.2 g, 0.1 g, and 0.1 g of polyacrylonitrile, respectively (i.e., 4 mL, 2 mL, 1 mL, and 1 mL of polymer matrix), and completely dissolved under magnetic stirring. These solutions were then used to prepare composite film precursors containing 0.5%, 1%, 5%, and 10% phosphorescent molecules (i.e., T5DP27), as shown in Table 1. The prepared precursor solutions were coated onto clean glass slides, and films were formed using vacuum flash evaporation.
[0044] Table 1. Preparation of composite films using T5DP27 as an additive
[0045] Fluorescence excitation spectrum of T5DP27 composite film (content 1%) Figure 7 As shown by the black line in (a), the T5DP27 composite film exhibits only a weak fluorescence excitation peak at 316 nm within the 200 nm to 360 nm wavelength range. Using this ultraviolet light as the fluorescence excitation source, the fluorescence emission spectrum of the T5DP27 composite film in the 350 nm to 800 nm range (…) Figure 7 (a) Red line), whose maximum fluorescence emission wavelength is 407 nm, indicating that the T5DP27 composite film has blue fluorescence under ultraviolet light irradiation.
[0046] Based on the phosphorescence excitation spectrum peaks of the T5DP27 composite film in the 200nm to 360nm wavelength range ( Figure 7 (b) Black line indicates that the material exhibits strong phosphorescence excitation at 301 nm. Using 310 nm ultraviolet light as the excitation source for the phosphorescence emission spectrum, the phosphorescence emission spectrum of the T5DP27 composite film from 350 nm to 800 nm was obtained. Figure 7 (b) Red line). The results show that the material can emit phosphorescence at 485 nm when excited by 301 nm ultraviolet light.
[0047] Based on the luminescence phenomenon of the T5DP27 composite film, it can be seen that introducing T5DP27 with a benzophenanthrene core structure as an additive into the polyacrylonitrile matrix to prepare the composite film can endow the composite film with good phosphorescence properties.
[0048] T5DP27 composite films containing different concentrations of T5DP27 were placed under a strong ultraviolet lamp at room temperature and irradiated for 10 seconds. The afterglow lifetime and luminescence intensity of the T5DP27 composite films prepared with different concentrations of T5DP27 (1%, 5%, 10%, and 0.5%) were recorded. The test results show that the luminescence performance of the T5DP27 composite films decreases with increasing concentration. Even at concentrations below 1%, the composite films exhibit weak afterglow lifetime and luminescence intensity. Figure 8 As shown, the afterglow lifetime of the T5DP27 composite film (T5DP27 concentration of 1%) recorded by the mobile phone can reach 10s. However, the afterglow lifetime of the T5DP27 composite film visible to the naked eye can reach more than 20s.
[0049] The above data indicate that the afterglow performance of the composite film doped with phosphorescent molecule T5DP27 is consistent with its phosphorescence phenomenon, suggesting that the afterglow of the composite film mainly originates from phosphorescence caused by the recovery of triplet excitons to the ground state. Furthermore, based on the effect of phosphorescent molecule concentration on the afterglow lifetime of the composite film, it can be concluded that lower concentrations of phosphorescent molecules are more beneficial to increasing the afterglow lifetime of the composite film.
[0050] TGA was used to measure the thermal stability of T5DP27, such as Figure 9 As shown, the thermal decomposition temperature of T5DP27 is 375 ℃ when it loses 5% of its weight. The above TGA test results indicate that T5DP27 possesses good thermal stability.
[0051] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.
Claims
1. A symmetric triphenylene room temperature phosphorescent material, characterized in that, The structural formula is shown as Formula I; Formula I; In Formula I, R1 is an alkyl group with 4, 5, 6, 8, 9, 10 or 12 carbon atoms; and R2 is an alkyl group with 1, 2, 3, 4, 5, 6, 8, 9, 10 or 12 carbon atoms.
2. A method for preparing the symmetrical triphenylene room temperature phosphorescent material according to claim 1, characterized by, The method comprises the following steps: Step 1, under the protection of nitrogen, etherification reaction of 4,4'-diphenol and isopropyl bromide is carried out to obtain intermediate 1; Halogenation reaction of intermediate 1 with iodine is carried out to obtain intermediate 2; Under alkaline conditions, intermediate 2 is reacted to replace the iodine with a hydroxyl group to obtain intermediate 3; Etherification reaction of intermediate 3 with a halogenated hydrocarbon is carried out to obtain intermediate 4; Scholl reaction of intermediate 4 with compound A is carried out to obtain 2,7-dihydroxy-3,6,10,11-tetraalkoxytriphenylene; Step 2, reaction of 2,7-dihydroxy-3,6,10,11-tetraalkoxytriphenylene and a saturated aliphatic acid under the action of a catalyst to obtain the symmetrical triphenylene room-temperature phosphorescent material; The compound A is at least one of o-dioxane, o-diethyl ether, o-dipropyl ether, o-dibutyl ether and o-dipentyl ether.
3. The production method according to claim 2, characterized by, The structural formula of the intermediate 1 is .
4. The preparation method according to claim 2, characterized in that, The structural formula of the intermediate 2 is .
5. The preparation method according to claim 2, characterized in that, The structural formula of the intermediate 3 is .
6. The preparation method according to claim 2, characterized in that, The structural formula of the intermediate 4 is .
7. Use of the symmetrical triphenylene room-temperature phosphorescent material according to claim 1 in the preparation of a long-afterglow room-temperature phosphorescent composite material.
8. A method of preparing a long-persistence room-temperature phosphor composite material, characterized by, The method comprises the following steps: The symmetrical triphenylene room-temperature phosphorescent material according to claim 1 is added to a polymer solution to obtain a precursor solution, the precursor solution is coated on the surface of a substrate, and a vacuum flash technology is used to obtain the long-afterglow room-temperature phosphorescent composite material.
9. The method for preparing the long-afterglow room-temperature phosphorescent composite material according to claim 8, characterized in that, The polymer in the polymer solution is polyvinyl alcohol or polystyrene, and the solvent is N,N-dimethylformamide; the mass concentration of the symmetrical triphenylene room-temperature phosphorescent material in the polymer solution is 0.5%-5%.
10. The long-afterglow room-temperature phosphorescent composite material prepared by the preparation method according to claim 8 or 9.