High-efficiency narrow-band flexible stretchable electroluminescent material and preparation method and application thereof
Patent Information
- Application Number
- CN202610903758.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-23
- Publication Date
- 2026-08-21
AI Technical Summary
[0005]本发明的目的在于解决传统共轭电致发光材料刚性强、脆性大、本征可拉伸性差，以及现有可拉伸发光体系无法同时实现大形变与高性能发光的技术问题，提供一种高效窄带柔性可拉伸电致发光材料及其制备方法与应用
[0032](1) The stretchable electroluminescent material prepared in this invention uses flexible polynorbornene as the main chain and rigid light-emitting units covalently bonded by long alkyl spacer groups to construct a strain-shielding molecular structure. This structure allows mechanical tensile stress to be absorbed and released by the long alkyl spacer groups, avoiding direct stress transmission to the light-emitting core and achieving functional decoupling of mechanical and photoelectric properties. The material is prepared by ring-opening metasomatic polymerization, which has strong reaction controllability, unique design strategy, and novel structure.
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Figure CN122608848A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of optoelectronic materials and application technology, specifically a high-efficiency narrow-band flexible stretchable electroluminescent material, its preparation method and application. Background Technology
[0002] In recent years, with the rapid development of wearable displays, curved lighting, flexible sensing, soft robots, and artificial intelligence devices, there has been an urgent need for electroluminescent functional materials that combine high mechanical stretchability, stable luminescence performance, good film-forming properties, and solution processability. Intrinsic stretchable luminescent polymers, due to the covalent bonding between the luminescent units and the flexible matrix, exhibit high structural uniformity and strong interfacial stability, and can maintain stable luminescence performance under mechanical deformation, making them a core research direction in the field of flexible OLEDs.
[0003] Polynorbornene, with its unique advantages of good chain segment flexibility, high mechanical strength, excellent chemical stability, and controllable synthesis through ring-opening metathesis polymerization (ROMP), is considered an ideal matrix material for constructing high-performance stretchable polymer skeletons. However, existing stretchable electroluminescent materials and technologies still have significant shortcomings. Traditional luminescent materials are mostly rigid conjugated molecules or rigid polymers, which are intrinsically brittle and have poor stretchability, making it difficult to meet the requirements of flexible devices with large deformation. Moreover, existing stretchable luminescent systems are mostly prepared by physically blending luminescent materials with elastomers, resulting in poor compatibility between the luminescent unit and the elastic matrix and weak interfacial bonding. Under stretching, bending, and cyclic deformation, problems such as phase separation, luminescence quenching, efficiency decay, and device failure are prone to occur. Meanwhile, conventional flexible modification methods (such as shortening the conjugation length and introducing flexible side chains) easily damage the molecular conjugation structure, leading to a decrease in luminescence efficiency and a deterioration in spectral stability. They cannot maintain excellent photoelectric performance while possessing flexibility. Moreover, existing designs generally do not introduce effective strain shielding structures, and mechanical stress can be directly transferred to the luminescent core, causing conjugation plane distortion and exciton nonradiative recombination to intensify, resulting in a significant decrease in luminescence efficiency under deformation. They cannot achieve functional decoupling between mechanical deformation and luminescence performance. In addition, existing preparation processes generally suffer from harsh conditions, poor reaction controllability, and complex purification processes, making it difficult to achieve efficient synthesis of low-cost, solution-processable, and scalable flexible stretchable luminescent materials.
[0004] Currently, stretchable electroluminescent materials with polynorbornene as the main chain, covalently bonded luminescent units through long alkyl spacers, and decoupled from mechanical deformation and luminescence performance using a strain-shielding structure are still relatively scarce in existing technologies. Therefore, developing a novel, high-performance, easily prepared, and solution-processable norbornene-based flexible stretchable electroluminescent material that achieves a balance of high stretchability, high luminous efficiency, high stability, and excellent device performance has become a key technical problem urgently needing to be solved in this field, and is of great significance for promoting the practical development of flexible displays, wearable electronics, and intelligent optoelectronic devices. Summary of the Invention
[0005] The purpose of this invention is to solve the technical problems of traditional conjugated electroluminescent materials, such as high rigidity, brittleness, and poor intrinsic stretchability, as well as the inability of existing stretchable luminescent systems to simultaneously achieve large deformation and high-performance luminescence. This invention provides a high-efficiency narrow-band flexible stretchable electroluminescent material, its preparation method, and its applications. The high-efficiency narrow-band flexible stretchable electroluminescent material provided by this invention uses flexible polynorbornene as the main chain, with rigid luminescent units covalently bonded by long alkyl spacer groups to construct a strain-shielded molecular structure, achieving functional decoupling between mechanical deformation and luminescence performance. This material is prepared by ring-opening metathesis polymerization, a simple and controllable process that can be solution-processed. The resulting material possesses excellent mechanical properties, thermal stability, and photoelectric properties. Applying this material as a luminescent layer to flexible stretchable electroluminescent devices can produce stretchable optoelectronic devices with high stretchability, high luminous efficiency, high stability, and high color purity, effectively solving the industry problem of the difficulty in synergistically achieving the mechanical and photoelectric properties of traditional conjugated electroluminescent materials.
[0006] (I) This invention provides a high-efficiency narrow-band flexible stretchable electroluminescent material. The general structural formula of the electroluminescent material is as follows:
[0007]
[0008] Where m and n represent the number of repeating units, m takes values from 30 to 300, and n takes values from 3 to 12; Ar represents the conjugated structure, and Ar is selected from one of the following groups:
[0009]
[0010]
[0011] Where R represents H or Me, and * represents the connection position.
[0012] Furthermore, the electroluminescent material has one of the following structures:
[0013]
[0014] (II) This invention provides a method for preparing the above-mentioned electroluminescent material. The preparation method includes the following steps:
[0015] Step 1: Using monomer 5-norbornene-2,3-dicarboxylic anhydride and aminocarboxylic acid ( Using ) as raw material, norbornene intermediates with carboxyl sites on the side chain were prepared by imidization reaction;
[0016] Step 2: The norbornene intermediate with carboxyl sites on its side chain is combined with an aryl alcohol ( An esterification reaction was carried out to prepare a norbornene-based functionalized precursor.
[0017] Step 3: The norbornene-based functionalized precursor is subjected to ring-opening metathesis polymerization (ROMP) in the presence of an organic solvent and a catalyst to prepare an electroluminescent material.
[0018] The reaction equation is as follows:
[0019] .
[0020] Furthermore, the specific content of step one is as follows: In an air environment, the monomer 5-norbornene-2,3-dicarboxylic anhydride is reacted with an aminocarboxylic acid (… The product is dissolved in an organic solvent, an organic base catalyst is added, and the reaction is carried out at 100-120℃ for 18-22 hours. After the reaction is completed, the product is cooled to room temperature, extracted, the solvent is removed under vacuum, and dried to obtain the norbornene-based functionalized precursor.
[0021] Furthermore, the specific content of step two is as follows: Under air conditions, the solid obtained in (2) is mixed with aryl alcohol ( The product is dissolved in an organic solvent, and a condensing agent, an acid-binding agent, and a catalyst are added. The mixture is reacted at room temperature for 24-48 hours. After the reaction is completed, the product is extracted, purified by column chromatography, and dried to obtain the norbornene-based functionalized precursor.
[0022] Further, the specific content of step three is as follows: under nitrogen protection, the norbornene-based functional prepolymer is dissolved in an organic solvent, a catalyst is added, and the polymerization reaction is carried out at room temperature for 5-15 minutes. Then, a polymerization terminator is added and the mixture is stirred for 30 minutes. After the reaction is completed, the reaction mixture is purified by passing it through an alkaline alumina column, and then extracted with hexane, methanol, and acetone solvents using a Soxhlet extractor for 24-72 hours respectively. Finally, after sedimentation, filtration, and drying, the elastomer is obtained, which is the target product, the norbornene-based flexible stretchable electroluminescent material.
[0023] Furthermore, in step one, the ratio of 5-norbornene-2,3-dicarboxylic anhydride, aminocarboxylic acid, organic solvent, and organic base catalyst is 10 mmol : 10 mmol : 100-300 mL : 1 mmol.
[0024] Furthermore, in step two, the ratio of norbornene intermediate with carboxyl group, aryl alcohol, organic solvent, condensing agent, acid-binding agent, and catalyst is 10 mmol: 10 mmol: 100-300 mL: 12 mmol: 12 mmol: 1 mmol.
[0025] Furthermore, in step three, the ratio of norbornene-based functionalized prepolymer, organic solvent, and catalyst is as follows:
[0026] 10mmol: 100-300mL: 0.03mmol.
[0027] Furthermore, in step one, the organic solvent is selected from toluene, xylene, and chlorobenzene, preferably toluene; the organic base catalyst is selected from triethylamine, N,N-diisopropylethylamine, pyridine, N-methylmorpholine, and 4-dimethylaminopyridine, preferably triethylamine.
[0028] Furthermore, in step two, the organic solvent is selected from dichloromethane, trichloromethane, 1,2-dichloroethane, and toluene, preferably dichloromethane; the condensing agent is selected from EDCI, DCC, and DIC, preferably EDCI; the acid-binding agent is selected from N,N-diisopropylethylamine, triethylamine, pyridine, and N-methylmorpholine, preferably N,N-diisopropylethylamine; and the catalyst is selected from 4-dimethylaminopyridine and 4-pyrrolidinylpyridine, preferably 4-dimethylaminopyridine.
[0029] Furthermore, in step three, the organic solvent is selected from one of dichloromethane, toluene, chlorobenzene, and 1,2-dichloroethane, preferably dichloromethane; the catalyst is selected from one of the first-generation Grubbs catalyst, the second-generation Grubbs catalyst, the third-generation Grubbs catalyst (G3), and the Hoveyda-Grubbs second-generation catalyst, preferably the third-generation Grubbs catalyst (G3); the polymerization terminator is selected from one of ethyl vinyl ether, methyl vinyl ether, n-butyl vinyl ether, and isobutyl vinyl ether, preferably ethyl vinyl ether.
[0030] (iii) The present invention also provides the application of the above-mentioned electroluminescent materials, which can be used as optoelectronic functional layer materials in the field of flexible and stretchable electronics, including stretchable organic electroluminescent devices, soft robots, artificial intelligence and wearable devices.
[0031] The present invention has the following beneficial effects:
[0032] (1) The stretchable electroluminescent material prepared in this invention uses flexible polynorbornene as the main chain and rigid light-emitting units covalently bonded by long alkyl spacer groups to construct a strain-shielding molecular structure. This structure allows mechanical tensile stress to be absorbed and released by the long alkyl spacer groups, avoiding direct stress transmission to the light-emitting core and achieving functional decoupling of mechanical and photoelectric properties. The material is prepared by ring-opening metasomatic polymerization, which has strong reaction controllability, unique design strategy, and novel structure.
[0033] (2) This invention uses a covalent bonding design of long alkyl spacer groups to connect rigid light-emitting units into the flexible polynorbornene main chain, which significantly improves the intrinsic stretchability of the elastomer. The material fracture strain can reach up to about 500%. During the stretching process, the light-emitting units are not easily damaged by stress failure, which fundamentally solves the technical problem of high intrinsic brittleness and non-stretchability of traditional rigid conjugated light-emitting materials.
[0034] (3) The material of the present invention achieves synergistic optimization of thermal stability, photoelectric performance and processing applicability: the thermal decomposition temperature is between 270 and 340 °C, and it can withstand the thermal annealing process of the device; taking the multiple resonance thermally activated delayed fluorescence (MR-TADF) type light-emitting unit as an example, it can achieve narrowband electroluminescence with a half-width of up to 38 nm, a current efficiency of up to 19.7 cd / A, and a peak external quantum efficiency of 16.4%; the covalent bonding and strain shielding design strategy can be adapted to various light-emitting units such as traditional fluorescence, phosphorescence, traditional thermally activated delayed fluorescence (TADF) and multiple resonance thermally activated delayed fluorescence (MR-TADF), and can achieve narrowband / broadband light emission control according to requirements; the material has excellent solubility and can be used to prepare uniform light-emitting films through spin coating process. It is a multifunctional stretchable electroluminescent material with high efficiency, high thermal stability and good processability. Attached Figure Description
[0035] Figure 1 The thermogravimetric curve of the elastomer;
[0036] Figure 2 The tensile test curve of the elastomer;
[0037] Figure 3 The narrow-band electroluminescence spectrum of the elastomer;
[0038] Figure 4 Brightness-voltage curves are used to characterize the organic electroluminescence properties of elastomers.
[0039] Figure 5 The current efficiency-brightness curve is a test diagram used to characterize the organic electroluminescence properties of elastomers. Detailed Implementation
[0040] The technical solution of the present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited to the embodiments described.
[0041] Example 1
[0042] choose (n=5), Ar is Preparation of elastomer PNB-Ar1:
[0043]
[0044] 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10.0 mmol), 6-aminohexanoic acid ( (n=5, 1.31 g, 10 mmol) was placed in a 500 mL two-necked reaction flask equipped with a stir bar and a reflux condenser and sealed. Triethylamine (Et3N, 0.1 g, 1.0 mmol) and toluene (200 mL) were then added. The reaction system was heated to 110 °C and reacted for 20 h, then cooled to room temperature. After the reaction was completed, the solvent was removed under vacuum. The remaining solid was dissolved in DCM and extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed again under vacuum to obtain solid 1.
[0045] Solid 1 (2.77 g, 10.0 mmol) and 1-pyrene methanol (2.32 g, 10.0 mmol) were placed in a 500 mL two-necked reaction flask and sealed. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 2.30 g, 12.0 mmol), N,N-diisopropylethylamine (DIPEA, 1.55 g, 12.0 mmol), 4-dimethylaminopyridine (DMAP, 0.12 g, 1.0 mmol), and DCM (300 mL) were added. The reaction system was stirred at room temperature for 36 h. After the reaction was complete, the mixture was extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography to finally obtain solid 2.
[0046] Solid 2 (4.91 g, 10 mmol) was placed in a 250 mL double-necked flask and sealed. Nitrogen gas was purged three times. DCM (150 mL) was added to the reaction flask. Under rapid stirring, a third-generation Grubbs catalyst (G3, 26.5 mg, 0.03 mmol) dissolved in 3 mL of DCM was rapidly injected via a syringe. After reacting for 10 min, 1 mL of ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for another 30 min to terminate the reaction. The reaction mixture was purified by alkaline alumina column chromatography, then Soxhlet extracted with n-hexane, methanol, and acetone for 48 h. Finally, the polymer was precipitated three times in methanol, filtered, and dried to obtain elastomer PNB-Ar1 (4.7 g, yield approximately 95%).
[0047] Example 2
[0048] choose (n=5), Ar is Preparation of elastomer PNB-Ar2:
[0049]
[0050] 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10.0 mmol), 6-aminohexanoic acid ( (n=5, 1.31 g, 10 mmol) was placed in a 500 mL two-necked reaction flask equipped with a stir bar and a reflux condenser and sealed. Triethylamine (Et3N, 0.1 g, 1.0 mmol) and toluene (200 mL) were then added. The reaction system was heated to 110 °C and reacted for 20 h, then cooled to room temperature. After the reaction was completed, the solvent was removed under vacuum. The remaining solid was dissolved in DCM, extracted three times successively with water and saturated brine, dried over anhydrous sodium sulfate, and the solvent was removed again under vacuum to obtain solid 1.
[0051] Solid 1 (2.77 g, 10.0 mmol) and 10-phenyl-9-anthracene methanol (2.84 g, 10.0 mmol) were placed in a 500 mL two-necked reaction flask and sealed. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 2.30 g, 12.0 mmol), N,N-diisopropylethylamine (DIPEA, 1.55 g, 12.0 mmol), 4-dimethylaminopyridine (DMAP, 0.12 g, 1.0 mmol), and DCM (300 mL) were added. The reaction system was stirred at room temperature for 36 h. After the reaction was complete, the mixture was extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography to finally obtain solid 2.
[0052] Solid 2 (5.4 g, 10 mmol) was placed in a 500 mL double-necked flask and sealed. Nitrogen gas was purged three times. DCM (200 mL) was added to the reaction flask. Under rapid stirring, a third-generation Grubbs catalyst (G3, 26.5 mg, 0.03 mmol) dissolved in 4 mL of DCM was rapidly injected via a syringe. After reacting for 10 min, 1 mL of ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for another 30 min to terminate the reaction. The reaction mixture was purified by alkaline alumina column chromatography, then Soxhlet extracted with n-hexane, methanol, and acetone for 48 h. Finally, the polymer was precipitated three times in methanol, filtered, and dried to obtain elastomer PNB-Ar2 (5.0 g, yield approximately 92%).
[0053] Example 3
[0054] choose (n=7), Ar is Preparation of elastomer PNB-Ar3:
[0055]
[0056] 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10.0 mmol), 8-aminooctanoic acid ( (n=7, 1.59 g, 10 mmol) was placed in a 500 mL two-necked reaction flask equipped with a stir bar and a reflux condenser and sealed. Triethylamine (Et3N, 0.1 g, 1.0 mmol) and toluene (200 mL) were then added. The reaction system was heated to 110 °C and reacted for 20 h, then cooled to room temperature. After the reaction was completed, the solvent was removed under vacuum. The remaining solid was dissolved in DCM and extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed again under vacuum to obtain solid 1.
[0057] Solid 1 (0.30 g, 1 mmol), 2-[9-(diphenylphosphono)-9'-phenyl-9H,9'H-2,2'-bifluorenyl]methanol (0.54 g, 1 mmol) were placed in a 100 mL two-necked reaction flask and sealed. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 0.230 g, 1.2 mmol), N,N-diisopropylethylamine (DIPEA, 0.15 g, 1.2 mmol), 4-dimethylaminopyridine (DMAP, 0.012 g, 0.1 mmol), and DCM (30 mL) were added. The reaction system was stirred at room temperature for 36 h. After the reaction was complete, the mixture was extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography to finally obtain solid 2.
[0058] Solid 2 (0.83 g, 1 mmol) was placed in a 100 mL double-necked flask and sealed. Nitrogen gas was purged three times. DCM (30 mL) was added to the reaction flask. Under rapid stirring, the third-generation Grubbs catalyst (G3, 2.65 mg, 0.003 mmol) dissolved in 0.5 mL of DCM was rapidly injected via syringe. After reacting for 10 min, 1 mL of ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for another 30 min to terminate the reaction. The reaction mixture was purified by alkaline alumina column chromatography, then Soxhlet extracted with n-hexane, methanol, and acetone for 48 h. Finally, the polymer was precipitated three times in methanol, filtered, and dried to obtain elastomer PNB-Ar3 (0.7 g, yield approximately 84%).
[0059] Example 4
[0060] choose (n=7), Ar is Preparation of elastomer PNB-Ar4:
[0061]
[0062] 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10.0 mmol), 8-aminooctanoic acid ( (n=7, 1.59 g, 10 mmol) was placed in a 500 mL two-necked reaction flask equipped with a stir bar and a reflux condenser and sealed. Triethylamine (Et3N, 0.1 g, 1.0 mmol) and toluene (200 mL) were then added. The reaction system was heated to 110 °C and reacted for 20 h, then cooled to room temperature. After the reaction was completed, the solvent was removed under vacuum. The remaining solid was dissolved in DCM and extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed again under vacuum to obtain solid 1.
[0063] Solid 1 (0.3 g, 1 mmol), (4-(hydroxymethyl)-2-(3-(trifluoromethyl)-1H-pyrazol-5-yl)pyridine)bis[1-(2,4-difluorophenyl)-1H-pyrazole]iridium(III) (0.8 g, 1 mmol) were placed in a 100 mL two-necked reaction flask and sealed. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 0.23 g, 1.2 mmol), N,N-diisopropylethylamine (DIPEA, 0.15 g, 1.2 mmol), 4-dimethylaminopyridine (DMAP, 0.012 g, 0.1 mmol), and DCM (30 mL) were added. The reaction system was stirred at room temperature for 36 h. After the reaction was complete, the mixture was extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography to finally obtain solid 2.
[0064] Solid 2 (1.1 g, 1 mmol) was placed in a 100 mL double-necked flask and sealed. Nitrogen gas was purged three times. DCM (30 mL) was added to the reaction flask. Under rapid stirring, a third-generation Grubbs catalyst (G3, 2.65 mg, 0.003 mmol) dissolved in 0.5 mL of DCM was rapidly injected via a syringe. After reacting for 10 min, 1 mL of ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for another 30 min to terminate the reaction. The reaction mixture was purified by alkaline alumina column chromatography, then Soxhlet extracted with n-hexane, methanol, and acetone for 48 h. Finally, the polymer was precipitated three times in methanol, filtered, and dried to obtain elastomer PNB-Ar4 (1 g, yield approximately 90%).
[0065] Example 5
[0066] choose (n=7), Ar is Preparation of elastomer PNB-Ar5:
[0067]
[0068] 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10.0 mmol), 8-aminooctanoic acid ( (n=7, 1.59 g, 10 mmol) was placed in a 500 mL two-necked reaction flask equipped with a stir bar and a reflux condenser and sealed. Triethylamine (Et3N, 0.1 g, 1.0 mmol) and toluene (200 mL) were then added. The reaction system was heated to 110 °C and reacted for 20 h, then cooled to room temperature. After the reaction was completed, the solvent was removed under vacuum. The remaining solid was dissolved in DCM and extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed again under vacuum to obtain solid 1.
[0069] Solid 1 (0.3 g, 1 mmol), (4-(hydroxymethyl)pyridine-2-carboxylic acid)bis[2-(3-acetyl-2,4-difluorophenyl)pyridine]iridium(III) (0.7 g, 1 mmol) were placed in a 100 mL two-necked reaction flask and sealed. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 0.23 g, 1.2 mmol), N,N-diisopropylethylamine (DIPEA, 0.15 g, 1.2 mmol), 4-dimethylaminopyridine (DMAP, 0.012 g, 0.1 mmol), and DCM (30 mL) were added. The reaction system was stirred at room temperature for 36 h. After the reaction was complete, the mixture was extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography to finally obtain solid 2.
[0070] Solid 2 (1 g, 1 mmol) was placed in a 100 mL double-necked flask and sealed. Nitrogen gas was purged three times. DCM (30 mL) was added to the reaction flask. Under rapid stirring, a third-generation Grubbs catalyst (G3, 2.65 mg, 0.003 mmol) dissolved in 0.5 mL of DCM was rapidly injected via a syringe. After reacting for 10 min, 1 mL of ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for another 30 min to terminate the reaction. The reaction mixture was purified by alkaline alumina column chromatography, then Soxhlet extracted with n-hexane, methanol, and acetone for 48 h. Finally, the polymer was precipitated three times in methanol, filtered, and dried to obtain elastomer PNB-Ar5 (0.85 g, yield approximately 85%).
[0071] Example 6
[0072] choose (n=5), Ar is Preparation of elastomer PNB-Ar6:
[0073]
[0074] 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10.0 mmol), 6-aminohexanoic acid ( (n=5, 1.31 g, 10 mmol) was placed in a 500 mL two-necked reaction flask equipped with a stir bar and a reflux condenser and sealed. Triethylamine (Et3N, 0.1 g, 1.0 mmol) and toluene (200 mL) were then added. The reaction system was heated to 110 °C and reacted for 20 h, then cooled to room temperature. After the reaction was completed, the solvent was removed under vacuum. The remaining solid was dissolved in DCM and extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed again under vacuum to obtain solid 1.
[0075] Solid 1 (0.27 g, 1 mmol), N,N-bis(2-(1H-pyrazol-1-yl)yl)-3-(hydroxymethyl)aniline platinum(II) (0.6 g, 1 mmol) were placed in a 100 mL two-necked reaction flask and sealed. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 0.23 g, 1.2 mmol), N,N-diisopropylethylamine (DIPEA, 0.15 g, 1.2 mmol), 4-dimethylaminopyridine (DMAP, 0.012 g, 0.1 mmol), and DCM (30 mL) were added. The reaction system was stirred at room temperature for 36 h. After the reaction was complete, the mixture was extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography to finally obtain solid 2.
[0076] Solid 2 (0.87 g, 1 mmol) was placed in a 200 mL double-necked flask and sealed. Nitrogen gas was purged three times. DCM (20 mL) was added to the reaction flask. Under rapid stirring, a third-generation Grubbs catalyst (G3, 2.65 mg, 0.003 mmol) dissolved in 0.5 mL of DCM was rapidly injected via a syringe. After reacting for 10 min, 1 mL of ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for another 30 min to terminate the reaction. The reaction mixture was purified by alkaline alumina column chromatography, then Soxhlet extracted with n-hexane, methanol, and acetone for 48 h. Finally, the polymer was precipitated three times in methanol, filtered, and dried to obtain elastomer PNB-Ar6 (0.78 g, yield approximately 89%).
[0077] Example 7
[0078] choose (n=5), Ar is Preparation of elastomer PNB-Ar7:
[0079]
[0080] 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10.0 mmol), 6-aminohexanoic acid ( (n=5, 1.31 g, 10 mmol) was placed in a 500 mL two-necked reaction flask equipped with a stir bar and a reflux condenser and sealed. Triethylamine (Et3N, 0.1 g, 1.0 mmol) and toluene (200 mL) were then added. The reaction system was heated to 110 °C and reacted for 20 h, then cooled to room temperature. After the reaction was completed, the solvent was removed under vacuum. The remaining solid was dissolved in DCM, extracted three times with water and saturated brine, dried over anhydrous sodium sulfate, and the solvent was removed again under vacuum to obtain solid 1.
[0081] Solid 1 (0.27 g, 1 mmol), 2-(4-(9-(4-(hydroxymethyl)phenyl)-9H-carbazol-3-yl)phenyl)-9H-thioxanth-9-one 10,10-dioxide (0.51 g, 1 mmol) were placed in a 100 mL two-necked reaction flask and sealed. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 0.23 g, 1.2 mmol), N,N-diisopropylethylamine (DIPEA, 0.15 g, 1.2 mmol), 4-dimethylaminopyridine (DMAP, 0.012 g, 0.1 mmol), and DCM (30 mL) were added. The reaction system was stirred at room temperature for 36 h. After the reaction was complete, the mixture was extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography to finally obtain solid 2.
[0082] Solid 2 (0.77 g, 1 mmol) was placed in a 100 mL double-necked flask and sealed. Nitrogen gas was purged three times. DCM (20 mL) was added to the reaction flask. Under rapid stirring, a third-generation Grubbs catalyst (G3, 2.65 mg, 0.003 mmol) dissolved in 0.5 mL of DCM was rapidly injected via a syringe. After reacting for 10 min, 1 mL of ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for another 30 min to terminate the reaction. The reaction mixture was purified by alkaline alumina column chromatography, then Soxhlet extracted with n-hexane, methanol, and acetone for 48 h. Finally, the polymer was precipitated three times in methanol, filtered, and dried to obtain elastomer PNB-Ar7 (0.68 g, yield approximately 88%).
[0083] Example 8
[0084] choose (n=9), Ar is Preparation of elastomer PNB-Ar8:
[0085]
[0086] 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10.0 mmol) and 10-aminodecanoic acid ( (n=9, 1.87 g, 10 mmol) was placed in a 500 mL two-necked reaction flask equipped with a stir bar and a reflux condenser and sealed. Triethylamine (Et3N, 0.1 g, 1.0 mmol) and toluene (200 mL) were then added. The reaction system was heated to 110 °C and reacted for 20 h, then cooled to room temperature. After the reaction was completed, the solvent was removed under vacuum. The remaining solid was dissolved in DCM and extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed again under vacuum to obtain solid 1.
[0087] Solid 1 (0.33 g, 1 mmol), 2'-(9-(2-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-9H-carbazole-3-yl)-9,9'-spirobis[9H-fluorene]-2-ylmethanol (0.77 g, 1 mmol) were placed in a 100 mL two-necked reaction flask and sealed. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 0.23 g, 1.2 mmol), N,N-diisopropylethylamine (DIPEA, 0.15 g, 1.2 mmol), 4-dimethylaminopyridine (DMAP, 0.012 g, 0.1 mmol), and DCM (30 mL) were added. The reaction system was stirred at room temperature for 36 h. After the reaction was complete, the mixture was extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography to obtain solid 2.
[0088] Solid 2 (1.05 g, 1 mmol) was placed in a 100 mL double-necked flask and sealed. Nitrogen gas was purged three times. DCM (30 mL) was added to the reaction flask. Under rapid stirring, a third-generation Grubbs catalyst (G3, 2.65 mg, 0.003 mmol) dissolved in 0.5 mL of DCM was rapidly injected via a syringe. After reacting for 10 min, 1 mL of ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for another 30 min to terminate the reaction. The reaction mixture was purified by alkaline alumina column chromatography, then Soxhlet extracted with n-hexane, methanol, and acetone for 48 h. Finally, the polymer was precipitated three times in methanol, filtered, and dried to obtain elastomer PNB-Ar8 (0.91 g, yield approximately 86%).
[0089] Example 9
[0090] choose (n=9), Ar is Preparation of elastomer PNB-Ar9:
[0091]
[0092] 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10.0 mmol) and 10-aminodecanoic acid ( (n=9, 1.87 g, 10 mmol) was placed in a 500 mL two-necked reaction flask equipped with a stir bar and a reflux condenser and sealed. Triethylamine (Et3N, 0.1 g, 1.0 mmol) and toluene (200 mL) were then added. The reaction system was heated to 110 °C and reacted for 20 h, then cooled to room temperature. After the reaction was completed, the solvent was removed under vacuum. The remaining solid was dissolved in DCM and extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed again under vacuum to obtain solid 1.
[0093] Solid 1 (0.33 g, 1 mmol), 2-(3-(hydroxymethyl)-9H-carbazole-9-yl)-2',5,5'-tris(9H-carbazole-9-yl)-[1,1'-biphenyl]-4,4'-dianitrile (0.83 g, 1 mmol) were placed in a 100 mL two-necked reaction flask and sealed. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 0.23 g, 1.2 mmol), N,N-diisopropylethylamine (DIPEA, 0.15 g, 1.2 mmol), 4-dimethylaminopyridine (DMAP, 0.012 g, 0.1 mmol), and DCM (30 mL) were added. The reaction system was stirred at room temperature for 36 h. After the reaction was complete, the mixture was extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography to obtain solid 2.
[0094] Solid 2 (1.21 g, 1 mmol) was placed in a 100 mL double-necked flask and sealed. Nitrogen gas was purged three times. DCM (30 mL) was added to the reaction flask. Under rapid stirring, a third-generation Grubbs catalyst (G3, 2.65 mg, 0.003 mmol) dissolved in 0.5 mL of DCM was rapidly injected via a syringe. After reacting for 10 min, 1 mL of ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for another 30 min to terminate the reaction. The reaction mixture was purified by alkaline alumina column chromatography, then Soxhlet extracted with n-hexane, methanol, and acetone for 48 h. Finally, the polymer was precipitated three times in methanol, filtered, and dried to obtain elastomer PNB-Ar9 (1.1 g, yield approximately 91%).
[0095] Example 10
[0096] choose (n=5), Ar is Preparation of elastomer PNB-Ar10 when (R=Me):
[0097]
[0098] 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10.0 mmol), 6-aminohexanoic acid ( (n=5, 1.31 g, 10 mmol) was placed in a 500 mL two-necked reaction flask equipped with a stir bar and a reflux condenser and sealed. Triethylamine (Et3N, 0.1 g, 1.0 mmol) and toluene (200 mL) were then added. The reaction system was heated to 110 °C and reacted for 20 h, then cooled to room temperature. After the reaction was completed, the solvent was removed under vacuum. The remaining solid was dissolved in DCM, extracted three times with water and saturated brine, washed three times with saturated brine, dried over anhydrous sodium sulfate, and the solvent was removed again under vacuum to obtain solid 1.
[0099] Solid 1 (0.27 g, 1 mmol), 2,8,12,16-tetratert-butyl-10-(4-(hydroxymethyl)phenyl)-5,11-dihydro-5,11-diaza-10-boronazotetraphenyl (0.74 g, 1 mmol) were placed in a 100 mL two-necked reaction flask and sealed. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 0.23 g, 1.2 mmol), N,N-diisopropylethylamine (DIPEA, 0.15 g, 1.2 mmol), 4-dimethylaminopyridine (DMAP, 0.012 g, 0.1 mmol), and DCM (30 mL) were added. The reaction system was stirred at room temperature for 36 h. After the reaction was complete, the mixture was extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography to finally obtain solid 2.
[0100] Solid 2 (1.0 g, 1 mmol) was placed in a 100 mL double-necked flask and sealed. Nitrogen gas was purged three times. DCM (30 mL) was added to the reaction flask. Under rapid stirring, a third-generation Grubbs catalyst (G3, 2.65 mg, 0.003 mmol) dissolved in 0.5 mL of DCM was rapidly injected via syringe. After reacting for 10 min, 1 mL of ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for another 30 min to terminate the reaction. The reaction mixture was purified by alkaline alumina column chromatography, then Soxhlet extracted with n-hexane, methanol, and acetone for 48 h. Finally, the polymer was precipitated three times in methanol, filtered, and dried to obtain elastomer PNB-Ar10 (0.87 g, yield approximately 87%).
[0101] Example 11
[0102] choose (n=7), Ar is Preparation of elastomer PNB-Ar11 when (R=Me):
[0103]
[0104] 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10.0 mmol), 8-aminooctanoic acid ( (n=7, 1.59 g, 10 mmol) was placed in a 500 mL two-necked reaction flask equipped with a stir bar and a reflux condenser and sealed. Triethylamine (Et3N, 0.1 g, 1.0 mmol) and toluene (200 mL) were then added. The reaction system was heated to 110 °C and reacted for 20 h, then cooled to room temperature. After the reaction was completed, the solvent was removed under vacuum. The remaining solid was dissolved in DCM, extracted three times with water and saturated brine, washed three times with saturated brine, dried over anhydrous sodium sulfate, and the solvent was removed again under vacuum to obtain solid 1.
[0105] Solid 1 (0.3 g, 1 mmol), 3,7-di-tert-butyl-10-(4-(hydroxymethyl)phenyl)-10H-oxa-9-boronanthracene (0.49 g, 1 mmol) were placed in a 100 mL two-necked reaction flask and sealed. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 0.23 g, 1.2 mmol), N,N-diisopropylethylamine (DIPEA, 0.15 g, 1.2 mmol), 4-dimethylaminopyridine (DMAP, 0.012 g, 0.1 mmol), and DCM (30 mL) were added. The reaction system was stirred at room temperature for 36 h. After the reaction was complete, the mixture was extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography to finally obtain solid 2.
[0106] Solid 2 (0.77 g, 1 mmol) was placed in a 100 mL double-necked flask and sealed. Nitrogen gas was purged three times. DCM (30 mL) was added to the reaction flask. Under rapid stirring, a third-generation Grubbs catalyst (G3, 2.65 mg, 0.003 mmol) dissolved in 0.5 mL of DCM was rapidly injected via syringe. After reacting for 10 min, 1 mL of ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for another 30 min to terminate the reaction. The reaction mixture was purified by alkaline alumina column chromatography, then Soxhlet extracted with hexane, methanol, and acetone for 48 h. Finally, the polymer was precipitated three times in methanol, filtered, and dried to obtain elastomer PNB-Ar11 (0.69 g, yield approximately 89%).
[0107] Example 12
[0108] choose (n=9), Ar is Preparation of elastomer PNB-Ar12:
[0109]
[0110] 5-norbornene-2,3-dicarboxylic anhydride (1.64 g, 10.0 mmol) and 10-aminodecanoic acid ( (n=9, 1.87 g, 10 mmol) was placed in a 500 mL two-necked reaction flask equipped with a stir bar and a reflux condenser and sealed. Triethylamine (Et3N, 0.1 g, 1.0 mmol) and toluene (200 mL) were then added. The reaction system was heated to 110 °C and reacted for 20 h, then cooled to room temperature. After the reaction was completed, the solvent was removed under vacuum. The remaining solid was dissolved in DCM and extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed again under vacuum to obtain solid 1. Solid 1 (0.33 g, 1 mmol), 2,8,12,18-tetratert-butyl-10-(4-(hydroxymethyl)phenyl)-5,15-dihydro-5,15-diaza-10,20-dibora-1,11-dithiazopentabenzene (0.81 g, 1 mmol) were placed in a 100 mL two-necked reaction flask and sealed. 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 0.23 g, 1.2 mmol), N,N-diisopropylethylamine (DIPEA, 0.15 g, 1.2 mmol), 4-dimethylaminopyridine (DMAP, 0.012 g, 0.1 mmol), and DCM (30 mL) were added. The reaction system was stirred at room temperature for 36 h. After the reaction was complete, the mixture was extracted three times successively with water and saturated brine. After drying with anhydrous sodium sulfate, the solvent was removed under vacuum to obtain the crude product. The crude product was purified by silica gel column chromatography to obtain solid 2.
[0111] Solid 2 (1.21 g, 1 mmol) was placed in a 100 mL double-necked flask and sealed. Nitrogen gas was purged three times. DCM (30 mL) was added to the reaction flask. Under rapid stirring, a third-generation Grubbs catalyst (G3, 2.65 mg, 0.003 mmol) dissolved in 0.5 mL of DCM was rapidly injected via syringe. After reacting for 10 min, 1 mL of ethyl vinyl ether was added to quench the polymerization reaction, and stirring was continued for another 30 min to terminate the reaction. The reaction mixture was purified by alkaline alumina column chromatography, then Soxhlet extracted with n-hexane, methanol, and acetone for 48 h. Finally, the polymer was precipitated three times in methanol, filtered, and dried to obtain elastomer PNB-Ar12 (1.1 g, yield approximately 91%).
[0112] Example 13
[0113] OLED devices were fabricated using the elastomer prepared in the above embodiments.
[0114] After ultrasonic cleaning, the ITO glass is treated with oxygen plasma. The sheet resistance of the ITO glass is 10 Ω / cm. 2 The hole injection layer is PEDOT, and the emitting layer uses any one of PNB-Ar1, PNB-Ar2, PNB-Ar3, PNB-Ar4, PNB-Ar5, PNB-Ar6, PNB-Ar7, PNB-Ar8, PNB-Ar9, PNB-Ar10, PNB-Ar11, and PNB-Ar12. Both the hole injection layer and the emitting layer are fabricated using a spin coating method. The cathode electrodes are made of LiF / Al.
[0115] The performance of the prepared elastomer and the OLED device were tested, and the test results are as follows:
[0116] Table 1 Electroluminescence performance of OLED devices
[0117]
[0118] (1) Figure 1 The graph shows the thermogravimetric analysis (Td, 5%) of the norbornene-based luminescent elastomers (PNB-Ar1, PNB-Ar4, PNB-Ar7, PNB-Ar10, PNB-Ar12) prepared in this invention. The Td values are all no lower than 270 °C, with some reaching as high as 340 °C, indicating excellent thermal stability. This property ensures that the materials do not undergo significant thermal decomposition during subsequent device fabrication processes (such as vacuum evaporation and thermal annealing) and under actual operating conditions, meeting the basic requirements for thermal stability in organic optoelectronic devices and providing a fundamental guarantee for the long-term stable operation of the devices.
[0119] (2) Figure 2 The figure shows the tensile test curves of the elastomers. As can be seen from the figure, the series of luminescent elastomers prepared in this invention all exhibit typical elastomer mechanical behavior, possessing excellent intrinsic flexibility and stretchability. Among them, PNB-Ar1 has the highest fracture strain reaching 500%, and the fracture strains of the other materials are significantly higher than those of traditional rigid conjugated luminescent materials. This fully demonstrates that the molecular design with polynorbornene as the main chain and long alkyl spacer groups covalently bonded to the luminescent units can effectively endow the materials with excellent tensile properties and mechanical stability. The long alkyl spacer groups can play a strain shielding role, absorbing and releasing mechanical tensile stress, avoiding the direct transmission of stress to the luminescent conjugated structure, thereby achieving functional decoupling between mechanical deformation and photoelectric performance, allowing the material to maintain structural integrity and luminescence stability under large strain. The above results show that this invention solves the key problems of rigidity, brittleness, and intrinsic non-stretchability of traditional conjugated electroluminescent materials at the molecular level, and the obtained materials can meet the practical application requirements of flexible and stretchable optoelectronic devices for high deformation and high stability.
[0120] (3) Figure 3 is the electroluminescence spectrum of the elastomer; When the MR-TADF series elastomers (PNB-Ar10, PNB-Ar11, PNB-Ar12) of the present invention are used as the OLED light-emitting layer, they can achieve narrow-band emission with a half-width of 38 nm, and have high color purity, which can meet the application requirements of stretchable high-definition display.
[0121] (4) Figure 4 The brightness-voltage curves are used to characterize the organic electroluminescence properties of the elastomers. The start-up voltages of all devices are below 7 V, indicating good charge injection and transport performance. With increasing driving voltage, the device brightness increases exponentially. Within the 10-12 V voltage range, the brightness of each device reaches over 10³ cd / m², with PNB-Ar12 exhibiting the best brightness performance, reaching a peak brightness of 5812 cd / m². These results demonstrate that this series of elastomer materials can effectively achieve electroluminescence, and by controlling the length of the long alkyl spacer groups, the dispersion state and charge transport behavior of the light-emitting units can be optimized, significantly improving the device brightness performance.
[0122] (5) Figure 5 The current efficiency-luminescence curves are used to characterize the organic electroluminescence properties of the elastomer. The PNB-Ar12 device exhibits the highest peak current efficiency, reaching approximately 15 cd / A, and shows a low efficiency roll-off during luminance enhancement, maintaining a high efficiency level even at a luminance of 10³ cd / m², indicating excellent exciton utilization and low nonradiative recombination loss. Other samples also showed stable current efficiency output without severe efficiency degradation, verifying the practicality of the material of this invention as a light-emitting layer. These results demonstrate that through covalent bonding and strain-shielded structural design, the light-emitting units are uniformly dispersed in the elastomer matrix, effectively suppressing concentration quenching and triplet-triplet annihilation, thereby endowing the device with efficient and stable electroluminescence performance.
[0123] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention.
Claims
1. A high-efficiency narrow-band flexible stretchable electroluminescent material, characterized in that, The general structural formula of the electroluminescent material is as follows: ； Where m takes values from 30 to 300, and n takes values from 3 to 12; Ar represents the conjugated structure, and Ar is selected from one of the following groups: ； ； Where R represents H or Me, and * represents the connection position.
2. The electroluminescent material according to claim 1, characterized in that, The electroluminescent material has one of the following structures: 。 3. The method for preparing the electroluminescent material according to claim 1, characterized in that, The preparation method includes the following steps: Step 1: Using monomer 5-norbornene-2,3-dicarboxylic anhydride and aminocarboxylic acid... Using [a specific ingredient] as raw material, norbornene intermediates with carboxyl sites on the side chain were prepared by imidization reaction; Step 2: The norbornene intermediate with carboxyl sites on its side chain is combined with an aryl alcohol. An esterification reaction was carried out to prepare a norbornene-based functionalized precursor. Step 3: The norbornene-based functionalized precursor is subjected to ring-opening metathesis polymerization in the presence of organic solvent and catalyst to prepare an electroluminescent material. The reaction equation is as follows: 。 4. The method for preparing the electroluminescent material according to claim 3, characterized in that, The specific details of step one are as follows: In an air environment, the monomer 5-norbornene-2,3-dicarboxylic anhydride and aminocarboxylic acid are reacted... Dissolved in an organic solvent, an organic base catalyst is added, and the mixture is reacted at 100-120℃ for 18-22 hours to obtain norbornene intermediates with carboxyl sites on the side chains.
5. The method for preparing the electroluminescent material according to claim 4, characterized in that, The specific details of step two are as follows: In an air environment, norbornene intermediates with carboxyl sites on their side chains are combined with aryl alcohols. Dissolve it in an organic solvent, add a condensing agent, an acid-binding agent, and a catalyst, and react at room temperature for 24-48 hours to obtain a norbornene-based functionalized precursor.
6. The method for preparing the electroluminescent material according to claim 5, characterized in that, The specific details of step three are as follows: Under nitrogen protection, the norbornene-based functional precursor was dissolved in an organic solvent, a catalyst was added, and the polymerization reaction was carried out at room temperature for 5-15 minutes. After that, a polymerization terminator was added, and the mixture was stirred for 30 minutes to obtain a norbornene-based flexible stretchable electroluminescent material.
7. The method for preparing the electroluminescent material according to claim 6, characterized in that, In step one, the ratio of 5-norbornene-2,3-dicarboxylic anhydride, aminocarboxylic acid, organic solvent, and organic base catalyst is 10 mmol : 10 mmol : 100-300 mL : 1 mmol. In step two, the ratio of norbornene intermediate with carboxyl group, aryl alcohol, organic solvent, condensing agent, acid-binding agent, and catalyst is 10 mmol: 10 mmol: 100-300 mL: 12 mmol: 12 mmol: 1 mmol; In step three, the ratio of norbornene-based functionalized prepolymer, organic solvent, and catalyst is as follows: 10mmol: 100-300mL: 0.03mmol.
8. The method for preparing the electroluminescent material according to claim 6, characterized in that, In step one, the organic solvent is selected from toluene, xylene, and chlorobenzene, preferably toluene; the organic base catalyst is selected from triethylamine, N,N-diisopropylethylamine, pyridine, N-methylmorpholine, and 4-dimethylaminopyridine. In step two, the organic solvent is selected from dichloromethane, trichloromethane, 1,2-dichloroethane, and toluene, preferably dichloromethane; the condensing agent is selected from EDCI, DCC, and DIC; the acid-binding agent is selected from N,N-diisopropylethylamine, triethylamine, pyridine, and N-methylmorpholine; and the catalyst is selected from 4-dimethylaminopyridine and 4-pyrrolidinylpyridine. In step three, the organic solvent is selected from one of dichloromethane, toluene, chlorobenzene, and 1,2-dichloroethane; the catalyst is selected from one of the first-generation Grubbs catalyst, the second-generation Grubbs catalyst, the third-generation Grubbs catalyst, and the second-generation Hoveyda-Grubbs catalyst; and the polymerization terminator is selected from one of ethyl vinyl ether, methyl vinyl ether, n-butyl vinyl ether, and isobutyl vinyl ether.
9. The application of the electroluminescent material according to claim 1, characterized in that, The electroluminescent material is used as an optoelectronic functional layer material in flexible and stretchable electronic devices.