Fluorenyl h-caicene nanopolymers, methods of making and using the same

Abstract

The application discloses fluorenyl grarphene nanopolymers, a preparation method and application thereof, and belongs to the technical field of luminescent materials. ‑2 The fluorenyl grarphene nanopolymer (PLG-Cz) is a conjugated grarphene nanopolymer and has excellent thermal stability and ozone stability. The PLG-Cz not only has excellent stability, but also is an excellent laser gain medium (the ASE threshold is 20.04 muJ*cm ‑2 ). In addition, a film assembled by the PLG-Cz exhibits excellent photonic crystal characteristics, and a PLED with the film as a light-emitting layer exhibits superior electroluminescent efficiency compared with a spin-coated film, and effectively inhibits efficiency roll-off. The unique multi-scale structure order of the film endows the film with high controllability of photoelectric properties, and provides a new direction and thought for the design and control field of photoelectric materials.

Description

Technical Field

[0001] This invention belongs to the field of luminescent materials technology, and particularly relates to a fluorene-based aromatic hydrocarbon nanopolymer, its preparation method, and its application. Background Technology

[0002] Since the advent of the first polymer-based organic light-emitting diode (PLED) in the 1990s, PLEDs have increasingly become an important development direction in the display technology field due to their significant advantages in flexible displays, energy efficiency, response speed, color performance, and cost-effectiveness. Compared with traditional liquid crystal display technology, PLED displays are particularly flexible, which provides endless possibilities for the design of new wearable devices and foldable electronic products. In addition, the wide variety of organic materials used in PLED technology provides great flexibility for customizing displays with specific light-emitting characteristics.

[0003] While organic polymer emissive layers have garnered significant attention in the field of organic light-emitting diodes (OLEDs), several challenges remain, such as the relatively unstable emission behavior of deep blue emissive conjugated polymers. Specifically, severe roll-off in emission efficiency and uncontrollable emission color purity occur over extended periods. Due to the inherent wide bandgap of deep blue polymers, they are prone to attracting narrow bandgap defect "guest" emission centers, including chemical (structural changes) and physical (aggregates, excimers, foreign impurities) defects, thus negatively impacting emission efficiency and color purity. Furthermore, energy level matching between the charge transport layer and the emissive layer in deep blue PLEDs remains a technical challenge. This mismatch can lead to an imbalance in charge injection and transport, resulting in charge accumulation. These issues adversely affect device performance and stability, limiting their practical application. Therefore, ensuring relatively superior charge transport behavior while pursuing single-emissive chromophore emission behavior is crucial. Adding to the complexity, when devices are exposed to adsorbed water and oxygen, excitons located in easily conjugated segments cause a significant performance degradation, which has become one of the obstacles to the commercialization of organic polymer emissive devices.

[0004] As a typical representative of organic wide-bandgap semiconductors, fluorene-based luminescent materials are among the most popular blue or sky-blue luminescent materials, possessing excellent photoelectric properties and multi-site modification characteristics. Polyfluorene exhibits excellent thermal stability, high photoluminescence quantum efficiency, and good charge transport properties, making it one of the most promising blue polymer materials in the OLED field. However, polyfluorene materials also suffer from luminescence instability, such as reduced color purity and decreased luminescence stability. The large bandgap also leads to lower carrier density and charge transport capacity in its amorphous state, affecting its luminescence efficiency. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a fluorenyl ligand nanopolymer, its preparation method, and its applications. The fluorenyl ligand nanopolymer of this invention exhibits excellent performance in improving carrier mobility, spectral stability, and morphological stability. This invention utilizes a seed covalent quantization-driven method to directly self-assemble a lattice framework into a photonic crystal microstructure, providing a new approach for cross-scale morphology-guided molecular design in the fields of organic mechatronics and intelligence. Simultaneously, by modulating multilayer cracks using molecular super-resistance etching technology, it successfully achieved efficient emission of deep blue random laser, which also provides a device structure-level approach for realizing organic electro-pumped lasers.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] One of the technical solutions of the present invention:

[0008] This invention provides a fluorene-based chromatophore nanopolymer (PLG-Cz), the structural formula of which is as follows:

[0009]

[0010] The number-average molecular weight (Mn) of the PLG-Cz is 36003, and the molecular weight distribution index (PDI) is 1.66. The Mn and PDI were obtained by GPC testing.

[0011] In conjugated polymers, the planarity and conjugation length of the chain segments are crucial to the photoelectric properties of the material. When polymer chains deviate from their planar conjugated structure due to twisting or entanglement, it can lead to changes in the band structure. The luminescence of conjugated polymers mainly originates from π-π* transitions, while chain twisting or entanglement can lead to the generation of additional energy levels, resulting in luminescence different from that of normal conjugated segments. The PLG-Cz of this invention has a smaller cell backbone, exhibiting excellent thermal and ozone stability, which provides strong support for its practical applications. Simultaneously, the carrier mobility of the fluorene-based chromatophore nanopolymer PLG-Cz, which employs a conjugated design strategy, is significantly higher than that of the non-conjugated PG-Cz. The efficiency of PLG-Cz is 2.2 times that of lattice-based nanopolymers with high carrier mobility (n is a positive integer from 3 to 100), which provides a reliable reference for the design of subsequent high carrier mobility lattice-based nanopolymers. PLG-Cz not only possesses excellent stability but is also an excellent laser gain medium (ASE threshold of 20.04 μJ·cm⁻¹). -2 This discovery provides a new molecular design strategy for the realization of organic electrically pumped lasers, and is expected to drive progress in the field.

[0012] The second technical solution of the present invention:

[0013] This invention provides a method for preparing the above-mentioned fluorene-based aromatic hydrocarbon nanopolymer, comprising the following steps:

[0014] (1) Under nitrogen protection, bipyridine, bis-(1,5-cyclooctadiene)nickel(0) and 1,5-cyclooctadiene were mixed, sealed, and then N,N-dimethylformamide was injected and heated at 75°C for 30 min.

[0015] (2) Dissolve the nanocells (LG-Cz) in toluene and inject them into the reaction system of step (1). React at 85°C for 6 days. Add a capping agent and purify, concentrate, reprecipitate with methanol, Soxhlet extract and dry the reaction mixture to obtain the fluorene chromarylene nanopolymer (PLG-Cz).

[0016] The structural formula of PLG-Cz is as follows:

[0017]

[0018] Furthermore, the preparation method of the LG-Cz is as follows: UDF-Cz... and IDF-DBr The mixture was stirred, boron trifluoride ether and dichloromethane were added, and the mixture was extracted with water and dichloromethane. The mixture was dried over anhydrous sodium sulfate and separated by column chromatography to obtain the LG-Cz.

[0019] In the preparation method of LG-Cz, the mass ratio of UDF-Cz to IDF-DBr is 100:73;

[0020] And / or, the eluent used in the column chromatography separation is a mixture of petroleum ether and dichloromethane, wherein the volume ratio of petroleum ether to dichloromethane is 3:1.

[0021] Furthermore, the preparation method of the UDF-Cz is as follows:

[0022] (1) Add 9-octyl-9H-carbazole to dichloromethane and add boron trifluoride ether;

[0023] (2) FOH-Br Add dichloromethane dropwise to the reaction system of step (1). After the addition is complete, extract with water and dichloromethane, dry with anhydrous sodium sulfate, and separate by column chromatography to obtain FOHCz-Br.

[0024]

[0025] (3) CH3COOK, pinacol diboronate, Pd(DPPF)Cl2 and the aforementioned FOHCz-Br were mixed, and under nitrogen protection, 1,4-dioxane (deoxygenated) was added. The mixture was reacted at 105°C for 12 h, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and obtained by rotary evaporation to obtain a product containing Bpin-FOH. Crude products;

[0026] (4) The FOHCz-Br, the crude product containing Bpin-FOH and Pd(PPh3)4 were mixed and, under nitrogen protection, oxygen-free K2CO3 / KF aqueous solution and oxygen-free toluene / tetrahydrofuran solution (Tol / THF solution) were added. The mixture was reacted at 85°C for 24 h, extracted with water and dichloromethane, dried with anhydrous sodium sulfate, and separated by column chromatography to obtain the UDF-Cz.

[0027] In the preparation method of UDF-Cz: in steps (1) and (2), the mass ratio of 9-octyl-9H-carbazole to FOH-Br is 1.83:0.608;

[0028] And / or, in step (2), the eluent used in the column chromatography separation is a mixture of petroleum ether and dichloromethane, wherein the volume ratio of petroleum ether to dichloromethane is 10:1;

[0029] And / or, in step (3), the mass ratio of FOHCz-Br, pinacol diboronic acid ester, Pd(DPPF)Cl2 and CH3COOK is 0.726:0.304:0.044:5.87;

[0030] And / or, in step (4), the mass ratio of FOHCz-Br, the crude product containing Bpin-FOH and Pd(PPh3)4 is 0.799:0.865:0.058, and the eluent used in the column chromatography separation is a mixture of petroleum ether and dichloromethane, with a volume ratio of petroleum ether to dichloromethane of 8:1.

[0031] Furthermore, the preparation method of the IDF-DBr is as follows:

[0032] Method 1:

[0033] a. Mix Mg and iodine granules, add tetrahydrofuran (THF) and part of 4-n-octyloxybromobenzene under nitrogen protection, initiate the reaction by blowing hot air, then add tetrahydrofuran and the remaining 4-n-octyloxybromobenzene in an ice-water bath, and react at 60°C for 3 hours. The molar ratio of Mg to 4-n-octyloxybromobenzene is 1:1:0.03.

[0034] b. Under nitrogen protection, 2-bromo-7-iodo-9-fluorenone was heated to 85°C, tetrahydrofuran and the reaction solution obtained in step a were added, and the mixture was stirred for 24 h to obtain a solution containing 2-bromo-7-iodo-9-(4-octoxyphenyl)-9H-fluorenol. After cooling to room temperature, the solution was quenched with saturated NH4Cl solution, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography to obtain the 2-bromo-7-iodo-9-(4-octoxyphenyl)-9H-fluorenol. The eluent used in the column chromatography was a mixture of petroleum ether and dichloromethane, and the volume ratio of petroleum ether to dichloromethane was 4:1.

[0035] c. 2-Bromo-7-iodo-9-(4-octoxyphenyl)-9H-fluorenol (1.32 g, 2.23 mmol), pinacol diboronate (0.850 g, 3.345 mmol), palladium acetate (10 mg, 0.045 mmol), CuI (85 mg, 0.45 mmol), PPh3 (12 mg, 0.45 mmol), and Cs2CO3 (1.09 g, 2.23 mmol) were placed in a dried three-necked reaction flask, then the atmosphere was purged and nitrogen was used for protection. 10 mL of oxygen-free acetonitrile was injected and the reaction was carried out at room temperature for 7 h. The mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. The crude product containing Bpin-FOH-Br was used directly in the subsequent reactions.

[0036] d. 2-Bromo-7-iodo-9-(4-octoxyphenyl)-9H-fluorenol (0.650 g, 1.1 mmol), Bpin-FOH-Br (crude product, 0.875 g), and Pd(PPh3)4 (0.058 g, 0.05 mmol) were placed in a dried three-necked reaction flask. The flask was then evacuated and protected with nitrogen. A K2CO3 / KF aqueous solution (4 mol, 15 mL) that had been bubbled for 2 h was injected into the three-necked reaction flask. The reaction was carried out at 85 °C for 14 h. The reaction was quenched with water, extracted with dichloromethane, dried with anhydrous sodium sulfate, and separated by column chromatography to obtain the IDF-DBr. The eluent used in the column chromatography was a mixture of petroleum ether, dichloromethane, and ethyl acetate, with a ratio of petroleum ether:dichloromethane:ethyl acetate of 8:1:0.3 (volume ratio).

[0037] Method 2:

[0038] a. 2-Bromo-9-fluorenone, 9-fluorenone-2-boronate, and Pd(PPh3)4 were mixed, and under nitrogen protection, oxygen-free K2CO3 / KF aqueous solution and oxygen-free toluene / tetrahydrofuran solution were added. The mixture was reacted at 85°C for 24 h, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography to obtain BFOD. The eluent used in the column chromatography separation is dichloromethane;

[0039] b. Mix fluorene, FeCl3, chloroform, and liquid bromine. Under light-protected conditions, react the mixture at 25°C for 48 hours. After the reaction, add Na2S2O3 solution until the dark color disappears. Filter and collect the precipitate. Wash with water until the filtrate becomes neutral. Dry the filter cake and use it directly in the next reaction step. The composition of the filter cake is BFOD-DBr.

[0040]

[0041] c. Mix Mg and iodine granules, add tetrahydrofuran (THF) and part of 4-n-octyloxybromobenzene under nitrogen protection, initiate the reaction by blowing hot air, and then add tetrahydrofuran and the remaining 4-n-octyloxybromobenzene in an ice-water bath, and react at 60°C for 2-3 hours.

[0042] d. Under nitrogen protection, the filter cake was heated to 85°C, Grignard reagent was added, and the reaction was quenched with saturated NH4Cl solution after 24 h. The mixture was extracted with water and dichloromethane, dried with anhydrous sodium sulfate, and separated by column chromatography to obtain the IDF-DBr. The eluent used in the column chromatography was a mixture of petroleum ether, dichloromethane, and ethyl acetate, with a volume ratio of 8:1:0.3.

[0043] In Method 2, the mass ratio of 2-bromo-9-fluorenone, 9-fluorenone-2-boronate, and Pd(PPh3)4 is 3.10:3.67:0.416; the concentration of the K2CO3 / KF aqueous solution is 4M; the volume ratio of toluene to tetrahydrofuran in the toluene / tetrahydrofuran solution is 1:1; and the ratio of bifluorenone, FeCl3, chloroform, and liquid bromine is 1.05g:0.65g:45mL:10mL.

[0044] Method 3:

[0045] a. A mixture of diphenylboronic acid diester, methyl 2-iodo-5-bromobenzoate, and Pd(PPh3)4 was added under nitrogen protection. Oxygen-free K2CO3 / KF aqueous solution and oxygen-free toluene / tetrahydrofuran solution were added, and the mixture was reacted at 85°C for 24 h. After cooling to room temperature, the mixture was extracted with water and dichloromethane. The extract was concentrated and dried under vacuum, and recrystallized with ethanol to obtain DMDB-QPD.

[0046]

[0047] b. The DMDB-QPD was added to 50.0 mL of 80 wt.% H2SO4 (prepared from 10.0 mL of H2O and 40.0 mL of concentrated (99.99 wt.%) H2SO4) and stirred at 120 °C for 12 h. During this period, the white solid turned dark brown. The reaction mixture was then poured into ice water and filtered to collect the brown powder. The collected product (i.e., the brown powder) was washed with sodium bicarbonate solution and water until the filtrate was neutral. The filter cake was dried and used directly for the next step of the reaction. The composition of the filter cake was BFOD-DBr.

[0048] c. Mix Mg and iodine granules, add THF and part of 4-n-octyloxybromobenzene under nitrogen protection, initiate the reaction by blowing hot air, then add tetrahydrofuran and the remaining 4-n-octyloxybromobenzene in an ice-water bath, and react at 60°C for 2-3 hours.

[0049] d. Under nitrogen protection, the filter cake is heated to 85°C, Grignard reagent is added, and after reacting for 24 h, it is quenched with saturated NH4Cl solution, extracted with water and dichloromethane, dried with anhydrous sodium sulfate, and separated by column chromatography to obtain the IDF-DBr. The eluent used in the column chromatography is a mixture of petroleum ether, dichloromethane, and ethyl acetate, and the volume ratio of petroleum ether, dichloromethane, and ethyl acetate is 8:1:0.3.

[0050] In Method 3, the molar ratio of p-biphenylboronic acid diester to methyl 2-iodo-5-bromobenzoate is 1:2; the concentration of the K2CO3 / KF aqueous solution is 4M; and the volume ratio of toluene to tetrahydrofuran in the toluene / tetrahydrofuran solution is 1:1.

[0051] This invention synthesizes fluorene-based chromatophore nanopolymers (PLG-Cz), which are conjugated chromatophore nanopolymers, using diarylfluorene as the smallest basic unit cell in the backbone. Three different synthetic strategies were employed to synthesize IDF-DBr, and the performance of these strategies in terms of synthesis difficulty, yield, and synthesis cycle was comprehensively evaluated. Ultimately, the optimal IDF-Br synthesis route (Method 1) was determined using iodobromo-tert-ol as the starting material. This strategy cleverly utilizes the difference in reactivity between bromine and iodine to achieve precise and efficient synthesis of monosubstituted borate esters. Subsequently, IDF-Br was synthesized in high yield via the Suzuki reaction (coupling reaction) without organic solvent involvement. This synthetic route not only exhibits significantly high yield and reusability but also demonstrates environmental friendliness, providing a solid foundation for the large-scale production of building blocks and paving the way for the industrialization of chromatophore nanopolymers. PLG-Cz was successfully prepared using Yamamoto polymerization.

[0052] The third technical solution of the present invention:

[0053] The present invention also provides the application of the above-mentioned fluorene-based aromatic hydrocarbon nanopolymers in the preparation of electroluminescent devices.

[0054] Fluorenyl argyl aromatic hydrocarbon nanopolymers can be deposited on devices using drop casting, solvent casting, solvothermal annealing, or spin coating methods to obtain electroluminescent devices.

[0055] The fourth technical solution of the present invention:

[0056] The present invention also provides an electroluminescent thin film prepared from the above-mentioned fluorene-based aromatic hydrocarbon nanopolymer.

[0057] For example, the electroluminescent thin film is prepared by drop casting, solvent casting, solvothermal annealing or spin coating.

[0058] Compared with the prior art, the present invention has the following advantages and technical effects:

[0059] In the preparation of the conjugated lattice aromatic hydrocarbon nanopolymer PLG-Cz in this invention, the Suzuki reaction using water as a solvent was employed to prepare its monomers, demonstrating excellent environmental friendliness and green properties. The target polymer product PLG-Cz was successfully synthesized via a Yamamoto coupling reaction, and its stability was compared with that of the previously synthesized lattice-based nanopolymer PG-Cz under different conditions. PLG-Cz exhibited excellent thermal and ozone stability, providing strong support for its practical applications. Furthermore, the carrier mobility of the lattice-based nanopolymer PLG-Cz, designed using a conjugated strategy, was 2.2 times that of the non-conjugated PG-Cz, providing a reliable reference for the design of subsequent high-carrier-mobility lattice-based nanopolymers. In addition to its excellent stability, PLG-Cz is also an excellent laser gain medium (ASE threshold of 20.04 μJ·cm⁻¹). -2 This discovery provides a new molecular design strategy for the realization of organically electrically pumped lasers, and is expected to drive progress in this field. Furthermore, the thin film assembled from PLG-Cz exhibits excellent photonic crystal properties. The PLED using it as the emitting layer demonstrates superior electroluminescence efficiency compared to spin-coated films, and effectively suppresses efficiency roll-off. Its unique multi-scale structural order endows the thin film with high tunability of photoelectric properties, providing new directions and ideas for the design and control of optoelectronic materials. Attached Figure Description

[0060] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0061] Figure 1 The 2-bromo-7-iodo-9-(4-octoxyphenyl)-9H-fluorenol in Example 1 1 1H NMR (Hypertaneous Nuclear Magnetic Spectroscopy);

[0062] Figure 2 The 1H NMR spectrum of 2-bromo-7-iodo-9-fluorenone, I-FOH-Br, and IDF-DBr in Example 1;

[0063] Figure 3 For FOHCz-Br in Example 1 1 1H NMR (Hypertaneous Nuclear Magnetic Spectroscopy);

[0064] Figure 4 For example, UDF-Cz in Example 1 1 1H NMR (Hypertaneous Nuclear Magnetic Spectroscopy);

[0065] Figure 5 For BFOD in Example 2 1 1H NMR (Hypertaneous Nuclear Magnetic Spectroscopy);

[0066] Figure 6 For example, IDF-DBr in Example 2 1 1H NMR (Hypertaneous Nuclear Magnetic Spectroscopy);

[0067] Figure 7 The superimposed 1H NMR spectrum of p-biphenylboronic acid diester, methyl 2-iodo-5-bromobenzoate and the final product in Example 3;

[0068] Figure 8 The electrochemical spectrum of PLG-Cz in Example 1;

[0069] Figure 9 The TGA spectrum (a) and DSC spectrum (b) of PLG-Cz in Example 1 are shown.

[0070] Figure 10 The angle-resolved reflectance spectrum of the solvothermal annealed film

[0071] Figure 11 This is a schematic diagram of the hole-dominant device (ITO / PEDOT:PSS / Polymer / MoO3 / Al) of the present invention;

[0072] Figure 12 In the middle (a), the EL spectra (10V) of spin-coated thin films and solvothermal annealed thin films (self-assembled) are shown, and (b) the EQE and current density curves of spin-coated thin films and solvothermal annealed thin films (self-assembled) devices are shown. Detailed Implementation

[0073] 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.

[0074] 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. Every smaller range between any stated value or intermediate value within a stated range, and 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.

[0075] 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.

[0076] 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 readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0077] 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.

[0078] Unless otherwise specified, the room temperature in this invention is 25±2℃.

[0079] All raw materials and reagents used in the embodiments of this invention were purchased commercially.

[0080] The synthetic route of the fluorene-based chromatophore nanopolymer PLG-Cz of this invention is as follows:

[0081]

[0082] (a) K2CO3 / KF, Pd(PPh3)4, 85℃, 24h; (b) BF3·OEt2, CH2Cl2, 24h; (c) Bipyridine, Ni(COD)2, 1,5-cyclooctadiene, toluene / DMF, 85℃, 6 days.

[0083] As an example, the method for preparing electroluminescent thin films using the drop casting method is as follows: PLG-Cz is mixed with toluene to make the concentration of the PLG-Cz toluene solution 5-10 mg / mL. -1 To ensure the appropriate polymer concentration in the solution, the solution should not be too viscous due to excessive concentration, affecting the uniformity of the coating, nor too thin, affecting subsequent experimental observation and performance testing. Drop casting is performed in a dust-free, room-temperature environment to avoid contamination from dust and other impurities, while also facilitating solvent evaporation and film formation. 100 μL of PLG-Cz toluene solution is measured using a pipette and applied to a 1.5 cm × 1.5 cm quartz plate. At room temperature, the toluene solvent completely evaporates after 15 minutes, leaving a uniform PLG-Cz film. This drop-cast film (i.e., the PLG-Cz film) is used for subsequent optical performance testing, structural characterization, and other studies.

[0084] As an example, the method for preparing electroluminescent thin films using solvent casting is as follows: PLG-Cz is mixed with toluene solvent to form a homogeneous PLG-Cz toluene solution with a concentration of 2–10 mg·mL⁻¹. -1 The prepared PLG-Cz toluene solution is transferred to a suitable sample vial or other vessel, and the cap is placed on top to prevent rapid evaporation of the toluene. The vessel is then placed at room temperature to allow the toluene solvent to evaporate slowly; this process typically takes 3 to 7 days, depending on the initial amount of solvent, the size of the vessel, and environmental conditions. As the solvent gradually evaporates, PLG-Cz gradually deposits at the bottom of the vessel, forming a large-area continuous film. This film formation process is bottom-up, ensuring the uniformity and consistency of the film. Once the solvent has completely evaporated, the film is essentially formed, but it may still be relatively soft and fragile. To improve the film's stability and mechanical strength, it is dried at 80°C. This step removes any residual solvent molecules from the film and strengthens its internal structure, making it more robust and durable.

[0085] As an example, the method for preparing electroluminescent thin films using solvothermal annealing is as follows: PLG-Cz is dissolved in DCE, and the concentration is controlled at 0.2–5 mg / mL. -1Ethanol was added to the above solution, and the mixture was heated to 75°C and stirred continuously for 30 minutes. PLG-Cz molecules gradually aggregated to form tiny spherical structures, i.e., nanospheres. The mixture was then left to stand at room temperature. During this process, the nanospheres continued to grow and aggregate. After 5 minutes, the solution changed from clear to emulsified. This emulsion was formed by the dispersion of PLG-Cz nanospheres in the solvent and has special optical properties and surface activity. The emulsion was left to stand for another 2 to 3 days, and the nanospheres gradually deposited at the bottom of the container, forming a uniform nanosphere film (also called a microsphere film). The nanosphere film was then placed in a closed environment filled with a good solvent (toluene) for 2 days of fumigation treatment. During this process, the vapor of the good solvent interacted with the nanosphere film, causing the polymer molecules in the film to rearrange and pack tightly, thereby improving the crystallinity and stability of the film.

[0086] As an example, the steps of spin coating film formation are as follows: Prepare a PLG-Cz solution with a concentration of 10 mg / mL (solvent is toluene), and use a pipette to draw 80 μL and drop it onto a quartz plate. Set the spin coating time to 30 seconds and the rotation speed to 1200 rpm / s. Long spin coating time helps the solution to spread fully on the substrate and form a uniform film.

[0087] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0088] The technical solution of the present invention will be further illustrated by the following embodiments.

[0089] Example 1

[0090] The synthetic route for synthesizing IDF-DBr is as follows:

[0091]

[0092] (a) Mg, THF, 85℃, 24h; (b) Palladium acetate, acetonitrile, CuI, PPh3, Cs2CO3, 25℃, 12h; (c) K2CO3 / KF, Pd(PPh3)4, 85℃, 24h.

[0093] Synthesis of the target product I-FOH-Br:

[0094] a. Add Mg (2.81 g, 0.116 mol) and iodine (two grains) to a three-necked reaction flask, then evacuate the gas and protect with nitrogen. Inject a small amount of 4-n-octyloxybromobenzene (3.70 g, 0.010 mmol) and THF (20 mL) into the reactor using a syringe, and initiate the reaction by blowing hot air. Then, place the reaction apparatus in an ice-water bath and slowly add THF (20 mL) and the remaining 4-n-octyloxybromobenzene (30.23 g, 0.106 mol). Place the reaction system at 60 °C for 3 h.

[0095] b. In another dried apparatus, 14.63 g (0.038 mol) of 2-bromo-7-iodo-9-fluorenone was added, followed by evacuation and nitrogen protection. The mixture was then heated to 85 °C, and THF (80 mL) and the reaction solution from reaction a were slowly added. The mixture was stirred for 24 h to obtain a solution containing I-FOH-Br. After cooling to room temperature, the solution was quenched with saturated NH4Cl solution, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography using petroleum ether:dichloromethane = 4:1 (volume ratio, the same below) as the eluent, yielding 18.37 g of a viscous liquid (i.e., I-FOH-Br), with a yield of 81.7%. The I-FOH-Br... 1 H NMR (400MHz, CDCl3): δ (ppm) 7.71-7.63 (m, 2H), 7.49 (s, 2H), 7.43-7.36 (m, 2H), 7.26-7.23 (t, J = 12Hz, 2H), 6.82-6.80 (d, J = 8 Hz,2H),3.94-3.91(t,J=12Hz,2H),2.43(s,1H),1.79-1.72(m,2H),1.45-1.28(m,10H),0.90-0.86(t,J=16Hz,3H).I-FOH-Br 13 C NMR (100MHz, CDCl3): δ (ppm) 158.61, 152.26, 151.99, 138.23, 138.04, 137.45, 134.07, 133.49, 132.29, 128.22, 126.47, 122 .66,121.84,121.60,114.44,94.03,83.03,68.09,31.88,29.42,29.32,29.26,26.09,22.75,14.24.HRMS(ESI,m / z):calcd for C 27 H 28 BrIO2:590.03; found:590.02.

[0096] 2-Bromo-7-iodo-9-(4-octoxyphenyl)-9H-fluorenol 11H NMR 1H NMR spectrum as follows Figure 1 As shown.

[0097] Synthesis of the target product Bpin-FOH-Br:

[0098] I-FOH-Br (1.32 g, 2.23 mmol), pinacol diboronate (0.850 g, 3.345 mmol), palladium acetate (10 mg, 0.045 mmol), CuI (85 mg, 0.45 mmol), PPh3 (12 mg, 0.45 mmol), and Cs2CO3 (1.09 g, 2.23 mmol) were placed in a dried three-necked reaction flask, and the mixture was purged under nitrogen protection. 10 mL of deoxygenated acetonitrile was added, and the reaction was carried out at room temperature for 12 h. The mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. The crude product containing I-FOH-Br was used directly in subsequent reactions.

[0099] Synthesis of the target product IDF-DBr:

[0100] I-FOH-Br (0.650 g, 1.1 mmol), Bpin-FOH-Br (crude product, 0.875 g), and Pd(PPh3)4 (0.058 g, 0.05 mmol) were placed in a dried three-necked reaction flask, and the mixture was then purged under nitrogen protection. A K2CO3 / KF aqueous solution (4 M, 15 mL) pre-bubbled for 2 h was injected into the flask, and the reaction was carried out at 85 °C for 24 h. The mixture was quenched with water, extracted with dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography using petroleum ether:dichloromethane:ethyl acetate = 8:1:0.3, yielding 613 mg of a white solid (IDF-DBr), yield: 60%.

[0101] To confirm that the final product of the above method was IDF-DBr, the 1H NMR spectra of 2-bromo-7-iodo-9-fluorenone, I-FOH-Br, and IDF-DBr were tested (see [link to NMR spectra]). Figure 2 From this, we can see that in I-FOH-Br 1 The presence of hydrogen signals from alkoxy groups (3.91–3.94 ppm) and hydroxyl groups (2.43 ppm) in the 1H NMR spectrum confirmed the synthesis of I-FOH-Br. In IDF-DBr... 1 The 1H NMR spectrum still shows hydrogen signals of hydroxyl peak (2.43 ppm) and alkoxy chain (3.91-3.94 ppm), and the number of hydrogen integrals is double. After integrating and summing the 1H NMR spectrum, the total number is 56, which is equal to the theoretical number of hydrogens. In summary, the synthesis of IDF-DBr is confirmed.

[0102] The synthetic route for UDF-Cz is as follows:

[0103]

[0104] (a) BF3·OEt2,CH2Cl2,25℃,24h; (b) K2CO3 / KF,Pd(PPh3)4,THF / toluene,85℃,24h.

[0105] Synthesis of the target product FOHCz-Br:

[0106] 9-Octyl-9H-carbazole (1.83 g, 6.54 mmol) was placed in a dried reaction flask and dissolved in dichloromethane (20 mL). Then, 1.03 g of boron trifluoride diethyl ether (BF3·OEt2) was added. FOH-Br (0.608 g, 1.31 mol) was dissolved in 600 mL of dichloromethane and added dropwise through a constant pressure dropping funnel. After the FOH-Br solution was completely added, the reaction was carried out for 24 h. The mixture was then extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography using petroleum ether:dichloromethane = 10:1 as the eluent, yielding 745 mg of a white solid (FOHCz-Br), with a yield of 78.2%. 1 1H NMR 1H NMR spectrum as follows Figure 3 As shown. FOHCz-Br 1 H NMR (400MHz, CDCl3): δ (ppm) 7.95-7.93 (d, J = 8Hz, 1H), 7.87 (s, 1H), 7.76-7.74 (d, J = 7.6Hz, 1H), 7.65-7.6 3(d,J=8.4Hz,1H),7.58(s,1H),7.49-7.43(m,2H),7.41-7.36(m,2H),7.34-7.29(m,2H),7.25(s,1H),7.17 -7.13(t,J=15.6Hz,3H),6.787-6.765(d,J=7.2Hz,2H),4.25-4.21(t,J=14.4Hz,2H),3.93-3.90(t,J=12.8 Hz,2H),1.87-1.72(m,4H),1.44-1.41(m,2H),1.39-1.23(m,20H),0.88-0.84(t,J=16.4Hz,5H).FOHCz-Br 13CNMR (100MHz, CDCl3): δ (ppm) 157.00, 153.40, 151.14, 139.71, 138.32, 138.01, 137.81, 136.60, 134.62,129.43,128.41,128.15,127.05,126.38,125.23,125.01,124.56,121.59,121.53,120.4 4,120.28,119.37,119.14,118.51,117.59,113.13,107.59,107.48,66.87,63.99,42.09,30.78, 30.75,28.32,28.26,28.21,28.12,27.96,26.26,25.04,21.62,21.56,13.08.MALDI-ToF-MS:m / z calcd for[M]C 47 H 52 BrNO: 725.32; found: 725.15.

[0107] Synthesis of the target product Bpin-FOH:

[0108] FOHCz-Br (0.726 g, 1 mmol), pinacol diboronate (0.304 g, 1.2 mmol), Pd(DPPF)Cl2 (0.044 g, 0.06 mmol), and CH3COOK (5.87 g, 59.8 mmol) were placed in a dried three-necked reaction flask, and the mixture was purged under nitrogen protection. 25 mL of deoxygenated 1,4-dioxane was injected, and the reaction was carried out at 105 °C for 12 h. The mixture was extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. The crude product containing Bpin-FOH was used directly in subsequent reactions.

[0109] Synthesis of the target product UDF-Cz:

[0110] FOHCz-Br (0.799 g, 1.1 mmol), Bpin-FOH (crude product, 0.865 g), and Pd(PPh3)4 (0.058 g, 0.05 mmol) were placed in a three-necked flask, and the mixture was purged under nitrogen protection. 2 mL of deoxygenated K2CO3 / KF aqueous solution (4 M) and 20 mL of Tol / THF solution (1:1) were injected into the flask. The reaction was carried out at 85 °C for 24 h. Extraction was performed with water and dichloromethane, followed by drying with anhydrous sodium sulfate. Separation was achieved by column chromatography using petroleum ether:dichloromethane = 8:1 as the eluent, yielding 844 mg of a white solid (UDF-Cz), with a yield of 59.3%. UDF-Cz... 1 1H NMR 1H NMR spectrum as follows Figure 4 As shown. UDF-Cz 1 H NMR (400MHz, CDCl3): δ (ppm) 7.94-7.92 (m, 2H), 7.88-7.86 (d, J = 8Hz, 2H), 7.76-7.74 (d, J = 8Hz, 4H), 7.67(s,2H),7.53-7.51(m,2H),7.45-7.44(d,J=4Hz,2H),7.39-7.29(m,8H),7.24-7.22(t,J=8Hz,2H ),7.21-7.16(m,6H),7.11-7.06(m,2H),6.75-6.71(t,J=16Hz,4H),4.20-4.17(t,J=12Hz,4H),3.89 -3.85(m,4H),1.81-1.71(m,8H),1.42-1.37(m,4H),1.32-1.21(m,38H),0.87-0.84(m,10H).UDF-Cz 13 C NMR (100MHz, CDCl3): δ (ppm) 158.00, 153.06, 152.78, 141.07, 141.05, 140.86, 139.78, 139.41, 139.29, 138.55, 13 8.53,136.58,136.56,129.42,127.73,127.39,126.71,126.41,126.37,125.58,124.98,122.88,122.68,122.65, 120.55,120.43,120.27,119.78,119.77,118.70,118.68,114.19,108.65,108.52,68.00,65.10,43.26,31.96,31 .93,29.85,29.52,29.48,29.38,29.30,29.15,27.45,26.24,22.80,22.74,14.25,14.22.MALDI-ToF-MS:m / zcalcd for[M]C 94 H 104 N2O2: 1293.81; found: 1293.44.

[0111] The synthetic route for LG-Cz is as follows:

[0112]

[0113] The specific synthesis method of LG-Cz is as follows: UDF-Cz (100 mg, 77.28 mmol) and IDF-DBr (73 mg, 78 mmol) were added to a three-necked flask, followed by the addition of boron trifluoride diethyl ether (0.131 mL) and dichloromethane (210 mL). The mixture was stirred at 25 °C for 24 h, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography using petroleum ether:dichloromethane = 3:1 as the eluent, yielding 105 mg of a white solid (i.e., LG-Cz), with a yield of 62.1%. LG-Cz... 1 H NMR (400MHz, CDCl3): δ (ppm) 8.19-7.97 (m, 2H), 7.86-7.80 (m, 2H), 7.76-7.64 (m, 7H), 7.61-7.48 (m, 7H), 7.46-7.28 (m, 10H), 7.23-6.94 LG-Cz 13C NMR (100MHz, CDCl3): δ (ppm) 158.27, 158.06, 157.91, 154.65, 152.87, 152.57, 151.71, 151.5 9,142.27,142.02,141.54,140.28,139.79,139.58,139.29,139.23,138.86,138.56,138.09, 137.54,136.04,135.76,135.09,134.98,130.79,129.89,129.71,129.49,129.28,129.05,128.97,128.03,127.80,127.55,127.35,127.27,127.13,126.46,126.28,125.73,125.68,122. 29,122.06,121.89,121.45,121.26,120.73,120.55,119.86,118.44,114.46,114.35,114.20,109.49,109.28,108.78,68.02,67.95,67.93,65.28,65.18,65.03,64.88,64.77,53.57,43 .39,43.31,41.49,36.21,34.81,34.67,31.97,31.92,29.85,29.44,29.34,29.24,27.40,27. 36,26.26,26.16,22.80,22.77,20.85,20.59,18.91,14.25,14.23,11.59.MALDI-ToF-MS:m / z calcd for[M]C 148 H 156 Br2N2O4:2187.05; found:2187.06.

[0114] The synthetic route for PLG-Cz is as follows:

[0115]

[0116] In a nitrogen-protected glove box environment, bipyridine (0.284 g, 1.82 mmol), bis-(1,5-cyclooctadiene)nickel (0) (0.5 g, 1.82 mmol), and 1,5-cyclooctadiene (0.25 mL) were sequentially added to a 250 mL reaction tube and tightly sealed. 20 mL of N,N-dimethylformamide solvent was then injected, and the entire system was heated at 75 °C for 30 min to activate the catalyst. Nanocell cells (LG-Cz) (0.360 g, 0.164 mmol) were then added. The solution was dissolved in 15 mL of dried and deoxygenated toluene, and then injected into a reaction tube. The reaction was carried out at 85 °C for 6 days. Then, 2 mL of bromobenzene was added as a capping agent. After the reaction was complete, the reaction mixture was transferred to a chromatography column pre-packed with 35 cm of neutral alumina. Purification was performed under pressure using THF as the eluent. The eluted solution was concentrated and reprecipitated with methanol. The reprecipitated product was filtered and collected. After Soxhlet extraction for 5 days, the final product was dried under vacuum to obtain a pale yellow solid, PLG-Cz. GPC (gel permeation chromatography) analysis (PS system) determined the Mn of the obtained PLG-Cz to be 36003 and the PDI to be 1.66.

[0117] Example 2

[0118] Same as Example 1, except that the synthetic route of IDF-DBr is as follows:

[0119]

[0120] (a) K2CO3 / KF, Pd(PPh3)4, THF / toluene, 85℃, 24h; (b) FeCl3, chloroform, 85℃, 48h; (c) Mg, THF, 85℃, 24h.

[0121] Synthesis of the target product BFOD:

[0122] 2-Bromo-9-fluorenone (3.10 g, 12 mmol), 9-fluorenone-2-boronic acid ester (3.67 g, 12 mmol), and Pd(PPh3)4 (0.416 g, 0.36 mmol) were added to a three-necked reaction flask, followed by evacuation and nitrogen protection. A deoxygenated K2CO3 / KF aqueous solution (4 M, 10 mL) and a deoxygenated tetrahydrofuran / toluene solution (1:1, v:v, 40 mL) were injected, and the reaction was carried out at 85 °C for 24 h. The mixture was extracted multiple times with water and dichloromethane, dried over anhydrous sodium sulfate, and then separated by column chromatography under pressure using pure dichloromethane as the eluent. The final product was a pale yellow solid, 2.96 g, yield: 68.8%. (BFOD) 1 The 1H NMR spectrum is shown in the figure. Figure 5 BFOD's 1HNMR (400MHz, CDCl3): δ (ppm) 7.92 (s, 2H), 7.77-7.76 (d, J = 7.2Hz, 2H), 7.70-7.68 (d, J = 6.4Hz, 2H), 7.62-7. 61(d,J=7.6Hz,2H),7.58-7.56(d,J=7.2Hz,2H),7.54-7.50(t,J=14.4Hz,2H),7.34-7.26(t,J=14.8Hz,2H). 13 C NMR (100MHz, CDCl3): δ (ppm) 143.10, 142.76, 139.87, 133.90, 133.44, 131.84, 128.23, 123.49, 121.57, 119.86, 119.53. HRMS (ESI, m / z): calcd forC 26 H 14 O2:358.10; found:359.10.

[0123] Synthesis of the target product BFOD-DBr:

[0124] Bifluorenone (1.05 g, 2.79 mmol), FeCl3 (0.65 g, 4 mmol), chloroform (45 mL), and liquid bromine (10 mL) were added sequentially to a three-necked reaction flask. An exhaust gas treatment device for the liquid bromine reaction was set up. Under light-protected conditions, the reaction system was placed at 25 °C for 48 h. After the experiment, Na2S2O3 solution was added until the dark color of the solution disappeared. The precipitate was collected by filtration and then washed with water several times until the filtrate became neutral. The filter cake was dried and used directly for the next step of the reaction.

[0125] Synthesis of the target product IDF-DBr:

[0126] a. Add Mg (2.82 g, 116 mmol) and iodine (two grains) to a three-necked reaction flask, evacuate three times, and protect with a nitrogen balloon. Inject a small amount of 4-n-octyloxybromobenzene (4.56 g, 16 mmol) and ultra-dry THF (20 mL) into the reactor using a syringe, initiate the reaction by blowing hot air, then place the reaction apparatus in an ice-water bath, slowly add THF (20 mL) and the remaining 4-n-octyloxybromobenzene (27.10 g, 95 mmol), and then place the reaction system at 60 °C for 3 hours;

[0127] b. Add 15.48 g of crude BFOD-DBr to another three-necked reaction flask, evacuate three times, protect with a nitrogen balloon, heat to 85°C, then slowly add Grignard reagent. After reacting for 24 h, quench with saturated NH4Cl solution, extract with water and dichloromethane, dry to anhydrous sodium sulfate, and separate by column chromatography using petroleum ether:dichloromethane:ethyl acetate = 8:1:0.3, to obtain 1.25 g of white solid, yield: 8.2%. 1 The 1H NMR spectrum is shown in the figure. Figure 6 IDF-DBr 1 H NMR (400MHz, CDCl3): δ (ppm) 7.66-7.64 (d, J = 8Hz, 2H), 7.59-7.55 (m, 2H), 7.52-7.50 (t, J = 8Hz, 4H), 7.48-7.46 (d, J = 8Hz, 2H), 7.44 (s ,2H),7.29-7.27(m,4H),6.81-6.77(m,4H),3.92-3.87(m,4H),2.49(s,2H),1.76-1.71(m,4H),1.39-1.26(m,20H),0.88-0.85(m,6H). 13 C NMR (100MHz, CDCl3): δ (ppm) 158.84, 153.06, 153.02, 151.22, 151.15, 141.66, 141.47, 1 38.15,138.11,138.03,137.98,134.13,134.09,132.34,132.32,128.49,128.34,126.68 ,123.54,123.51,122.33,121.68,120.64,114.54,114.51,83.46,83.44,68.13,31.95,3 0.20,29.86,29.50,29.49,29.43,29.41,29.37,26.20,22.79,14.23.MALDI-ToF-MS:m / z calcdfor[M]C 54 H 56 Br2O4: 928.25; found: 928.54.

[0128] Example 3

[0129] Same as Example 1, except that the synthetic route of IDF-DBr is as follows:

[0130]

[0131] (a) K2CO3 / KF, Pd(PPh3)4, THF / toluene, 85℃, 24h; (b) H2SO4, H2O, 120℃, 12h; (c) Mg, THF, 85℃, 24h.

[0132] Synthesis of the target product DMDB-QPD:

[0133] Add diphenylboronic acid diester (544 mg, 1.34 mmol), methyl 2-iodo-5-bromobenzoate (920 mg, 2.70 mmol), and Pd(PPh3)4 (77 mg, 0.067 mmol) to a three-necked reaction flask, then evacuate and protect under nitrogen. Inject deoxygenated K2CO3 / KF aqueous solution (4 M, 10 mL) and tetrahydrofuran / toluene solution (1:1, 40 mL), and react at 85 °C for 24 h. After cooling to room temperature, add deionized water, extract three times with dichloromethane, concentrate and dry the extract under vacuum, and recrystallize from ethanol during the purification stage to obtain 609 mg of white solid (i.e., DMDB-QPD), yield: 78.3%. DMDB-QPD... 1 H NMR (400MHz, CDCl3): δ (ppm) 8.00-7.99 (d, J=4.8Hz, 2H), 7.70-7.67 (m, 6H), 7.39-7.36 (d, J= 8Hz, 2H), 7.31 (s, 1H), 7.29 (s, 1H), 3.70 (s, 6H). 13 C NMR (100 MHz, CDCl3): δ(ppm)166.60,139.93,138.63,138.23,133.30,131.75,131.28,131.26,127.71,125.77,120.19,51.30.MALDI-ToF-MS: m / z calcd for[M]C 28 H 20 Br2O4: 579.97; found: 580.76.

[0134] The NMR spectra of biphenylboronic acid diester, methyl 2-iodo-5-bromobenzoate, and the final product were analyzed by superimposed 1H NMR spectra. Figure 7 As can be seen, the methoxy group in methyl 2-iodo-5-bromobenzoate appears in the proton NMR spectrum of the final product, and the number of hydrogen atoms is twice that of the total hydrogen atoms, confirming that the final product has a two-sided structure with two methoxy groups. Furthermore, by integrating the number of hydrogen atoms in the NMR spectrum, the total number of hydrogen atoms is found to be 20, thus confirming the successful synthesis of DMDB-QPD.

[0135] Synthesis of the target product BFOD-DBr:

[0136] DMDB-QPD (577 mg, 1 mmol) was added to 50.0 mL of 80 wt.% H2SO4 (prepared from 10.0 mL H2O and 40.0 mL concentrated (99.99 wt.%) H2SO4) and stirred at 120 °C for 12 h. During this period, the white solid turned dark brown. The reaction mixture was poured into ice water and filtered to collect the brown powder. The collected product was washed with sodium bicarbonate solution and water until the filtrate was neutral. The filter cake was dried and used directly for the next step of the reaction.

[0137] The synthesis process of the target product IDF-DBr is the same as in Example 2.

[0138] Taking the PLG-Cz prepared in Example 1 as an example, performance tests were conducted as follows:

[0139] The redox electrochemical tests of PLG-Cz were performed using the voltammetric characteristic method, and the results are as follows: Figure 8 As shown, the band gap of PLG-Cz was determined to be 3.36 eV by analyzing the current-voltage characteristic curve using the tangent method. This value is significantly larger than that of PG-Cz (3.33 eV), which not only reveals the unique electronic structure characteristics of PLG-Cz, but also indicates its promising application prospects as a blue light-emitting polymer material in the optoelectronic field, providing a solid theoretical basis for the fabrication of PLG-Cz in PLED devices.

[0140] The TGA spectrum (a) and DSC spectrum (b) of PLG-Cz are as follows: Figure 9 As shown, the thermal decomposition temperature of polymer PLG-Cz exceeding 5% is 332℃, exhibiting a high thermal decomposition temperature and good heat resistance. No obvious endothermic or exothermic peaks were found in the DSC curve, therefore there is no significant glass transition temperature or melting point between 25 and 260℃. PLG-Cz not only demonstrates excellent thermal stability (T... d With a fluorescence lifetime of 332℃ and blue light emission (CIE coordinates (0.16, 0.08)), PLG-Cz effectively mitigates the fluorescence quenching effect caused by molecular aggregation due to its large steric hindrance. Simultaneously, its short fluorescence lifetime indicates that PLG-Cz is a potential laser gain medium. Furthermore, PLG-Cz exhibits excellent aging resistance in ozone environments, with significantly better stability than other materials. Regarding ultraviolet light stability, PLG-Cz shows minimal spectral changes, indicating that photo-oxidation stability can be effectively improved through rational molecular design.

[0141] The film-forming properties of organic light-emitting materials during solution processing are crucial for manufacturing high-performance organic optoelectronic devices. Good film-forming properties ensure the formation of uniform, continuous, and defect-free thin films during preparation, which is essential for achieving efficient charge injection and transport, improving device luminous efficiency, and ensuring device stability and lifespan. In PLED devices, defects and inhomogeneities in the thin film lead to inconsistent light-emitting areas, thereby reducing overall luminous efficiency. Furthermore, in industrial production, film-forming properties determine whether organic light-emitting materials can be efficiently coated onto large-area substrates, which is significant for cost reduction and commercial production. Therefore, this invention simultaneously investigated the film-forming properties of PLG-Cz using theoretical calculations and film roughness analysis: 5 mg of PLG-Cz was dissolved in 1 mL of toluene and ultrasonically cleaned for 1 minute to ensure complete dissolution in the toluene solvent. 90 μL was then pipetted onto a substrate and maintained at 1200 rpm / min for 30 seconds until the solvent in the film completely evaporated. Atomic force microscopy (AFM) revealed that the height difference of the PLG-Cz film was only 6.5 nm, exhibiting a uniform and flat surface. Furthermore, the surface roughness of the PLG-Cz film was only 2.86 nm, further confirming the superior surface smoothness of PLG-Cz.

[0142] Three types of thin films were prepared by drop casting, solvent casting, and solvent thermal annealing, respectively, and are designated as drop-cast film, solvent-cast film, and solvent thermal annealed film. The reflectance spectrum of the solvent thermal annealed film was studied by angle-resolved reflectance spectroscopy. Figure 10 It was found that its reflection spectrum exhibits a series of interference fringes with significant periodicity, and these interference fringes at θ i The range of (incident angle) is generally present from 0° to 60°, and with θ i As the wavelength increases, the interference fringes gradually shift towards shorter wavelengths, exhibiting clear angle-resolved characteristics. The solvothermal annealed film displays typical one-dimensional photonic crystal properties. In contrast, other films of PLG-Cz do not show periodic interference fringes; instead, they exhibit random peak shapes and lack angle-dependent spectral shift characteristics. The reflectivity in the microsphere film arises solely from disordered light scattering caused by the rough surface (it should be noted that during testing, areas with rainbow fringes should not be selected, as this results in uniform thickness interference due to extreme film thickness inhomogeneity, preventing the presence of layered structures). The effective refractive index of PLG-Cz is: n eff = 1.754 (λ = 745–603 nm), 1.805 (λ = 609–550 nm), 1.858 (λ = 559–508 nm), and 1.931 (λ = 519–474 nm), where, when λ = 483.58–437.61 nm, n eff=2.01, almost reaching the highest level for conjugated polymers (n≈2). These results indicate that the solvothermal annealed film possesses a high refractive index, and this n... eff The value is higher than that of polyfluorene films with β-phase (refractive index (n) = 1.7~1.8), so PLG-Cz can achieve high-efficiency LED and ASE emission by modulating photon confinement and population inversion.

[0143] This invention fabricates a hole-dominated device (ITO / PEDOT:PSS / Polymer / MoO3 / Al) to study the transmission capability of PLG-Cz. Figure 11 Spin-coated film devices of PG-Cz and PLG-Cz were prepared using toluene solution. For electric field E... 1 / 2 In 700-1100 (V cm) -1 ) 1 / 2 Within the specified range, the hole mobility of both polymers is at 10. -6 ~10 -5 cm 2 V -1 s -1 Among them, PLG-Cz exhibited the highest hole mobility at 948 (V cm⁻¹). -1 ) 1 / 2 At that time, the carrier mobility was 6.4 × 10⁻⁶. -6 cm 2 V - 1 s -1 This high hole mobility suggests that PLG-Cz may possess excellent electroluminescence properties. At 707 (V cm⁻¹) -1 ) 1 / 2 At that time, the hole mobility of PLG-Cz was about 2.2 times that of PG-Cz, which indicates that the lattice-based conjugated structure design helps to improve carrier mobility.

[0144] To investigate its efficiency in a practical device (PLED), an undoped solution-processed device was fabricated, with the device structure from bottom to top as follows: ITO / PEDOT:PSS (40nm) / PLG-Cz (40nm) / TPBi (40nm) / LiF (1nm) / Al (100nm).

[0145] In electroluminescence (EL) spectroscopy, spin-coated PLEDs exhibit an EL peak at 428 nm and display low-energy emission, resulting in poor color purity. Figure 12 (a)). In contrast, the EL spectrum of the PLG-Cz self-assembled PLED exhibits stable deep blue emission and high color purity. The spin-coated PLED has an on-time of approximately 6.2 V and a maximum luminance of 364.8 cd·m. -2The maximum current efficiency is 0.50 cd·A. -1 The maximum power efficiency is 0.18 lm·W. -1 Meanwhile, compared to spin-coated PLEDs, the maximum external quantum efficiency (EQE) of the self-assembled device increased from 0.27% to 0.48%. Figure 12 In (b), the efficiency roll-off was effectively suppressed. Therefore, this self-assembly shows a significant improvement in electroluminescence efficiency, which may be due to the mesoscale order driven by nanolattice structure, resulting in lower optical loss.

[0146] One-dimensional photonic crystal films (with reflection spectra satisfying the Bragg-Snell diffraction equation) were fabricated using a solvothermal annealing method. The optical waveguide properties of the photonic crystal film demonstrate its ability to effectively guide light propagation within the material, increasing the external quantum efficiency (EQE) of PLEDs from 0.27% to 0.48% and suppressing efficiency roll-off. Furthermore, the waveguide properties of PLG-Cz, combined with its spontaneous emission characteristics, offer possibilities for realizing high-performance laser devices. These research results not only contribute to enhancing the status of PLG-Cz in the field of optoelectronics but also provide new directions and possibilities for the development of future organic optoelectronic devices.

[0147] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A fluorene-based chromatophore nanopolymer, characterized in that, The structure is as follows: The fluorene-based aromatic hydrocarbon nanopolymer has a number-average molecular weight of 36,003 and a molecular weight distribution index of 1.

66.

2. A method for preparing the fluorene-based argyl aromatic hydrocarbon nanopolymer according to claim 1, characterized in that, Includes the following steps: (1) Under nitrogen protection, bipyridine, bis-(1,5-cyclooctadiene)nickel(0) and 1,5-cyclooctadiene were mixed, sealed, and then N,N-dimethylformamide was injected and heated at 75°C for 30 min. (2) Dissolve the nanocells in toluene and inject them into the reaction system of step (1). React at 85°C for 6 days. Add a capping agent and purify, concentrate, reprecipitate in methanol, extract with Soxhlet and dry the reaction mixture to obtain the fluorene chromarylene nanopolymer. The structural formula of the nanocell is as follows:

3. The method for preparing fluorene-based aromatic hydrocarbon nanopolymers according to claim 2, characterized in that, The nanocells are prepared as follows: UDF-Cz and IDF-DBr are mixed, boron trifluoride ether and dichloromethane are added, and after the reaction is stirred, the mixture is extracted with water and dichloromethane, dried with anhydrous sodium sulfate, and separated by column chromatography to obtain the nanocells. The structural formula of the UDF-Cz is: The structural formula of IDF-DBr is:

4. The method for preparing fluorene-based aromatic hydrocarbon nanopolymers according to claim 3, characterized in that, The mass ratio of UDF-Cz to IDF-DBr is 100:73; And / or, the eluent used in the column chromatography separation is a mixture of petroleum ether and dichloromethane, wherein the volume ratio of petroleum ether to dichloromethane is 3:

1.

5. The method for preparing fluorene-based aromatic hydrocarbon nanopolymers according to claim 3, characterized in that, The preparation method of the UDF-Cz is as follows: (1) Add 9-octyl-9H-carbazole to dichloromethane and add boron trifluoride ether; (2) FOH-Br was added to dichloromethane dropwise into the reaction system of step (1). After the addition was complete, the mixture was extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography to obtain FOHCz-Br. The structural formula of FOH-Br is: The structural formula of the FOHCz-Br is: (3) CH3COOK, pinacol diboronic acid ester, Pd(DPPF)Cl2, and the aforementioned FOHCz-Br were mixed. Under nitrogen protection, 1,4-dioxane (deoxygenated) was added, and the mixture was reacted at 105°C for 12 h. The mixture was extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and rotary evaporated to obtain a crude product containing Bpin-FOH. The structural formula of Bpin-FOH is: (4) The FOHCz-Br, the crude product containing Bpin-FOH and Pd(PPh3)4 were mixed and, under nitrogen protection, oxygen-free K2CO3 / KF aqueous solution and oxygen-free toluene / tetrahydrofuran solution were added. The mixture was reacted at 85°C for 24 h, extracted with water and dichloromethane, dried with anhydrous sodium sulfate, and separated by column chromatography to obtain the UDF-Cz.

6. The method for preparing fluorene-based aromatic hydrocarbon nanopolymers according to claim 5, characterized in that, In steps (1) and (2), the molar ratio of 9-octyl-9H-carbazole to FOH-Br is 5:1; And / or, in step (2), the eluent used in the column chromatography separation is a mixture of petroleum ether and dichloromethane, wherein the volume ratio of petroleum ether to dichloromethane is 10:1; And / or, in step (3), the molar ratio of FOHCz-Br, pinacol diboronic acid ester, Pd(DPPF)Cl2 and CH3COOK is 1:1.2:0.06:59.8; And / or, in step (4), the mass ratio of FOHCz-Br, the crude product containing Bpin-FOH and Pd(PPh3)4 is 0.799:0.865:0.058, and the eluent used in the column chromatography separation is a mixture of petroleum ether and dichloromethane, with a volume ratio of petroleum ether to dichloromethane of 8:

1.

7. The method for preparing fluorene-based aromatic hydrocarbon nanopolymers according to claim 3, characterized in that, The IDF-DBr is prepared using any of the following methods: Method 1: a. Mix Mg and iodine granules, add tetrahydrofuran and part of 4-n-octyloxybromobenzene under nitrogen protection, initiate the reaction by blowing hot air, then add tetrahydrofuran and the remaining 4-n-octyloxybromobenzene in an ice-water bath, and react at 60°C for 3 hours. b. Under nitrogen protection, 2-bromo-7-iodo-9-fluorenone was heated to 85°C, tetrahydrofuran and the reaction solution obtained in step a were added, and the mixture was stirred for 24 h to obtain a solution containing 2-bromo-7-iodo-9-(4-octoxyphenyl)-9H-fluorenol. After cooling to room temperature, the solution was quenched with saturated NH4Cl solution, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography to obtain the 2-bromo-7-iodo-9-(4-octoxyphenyl)-9H-fluorenol, denoted as I-FOH-Br; c. Mix I-FOH-Br, pinacol diborate, palladium acetate, CuI, PPh3, and Cs2CO3. Under nitrogen protection, inject deoxygenated acetonitrile and react at room temperature for 7 hours. Extract with dichloromethane, dry with anhydrous sodium sulfate, remove solvent by rotary evaporation, and use the crude product containing Bpin-FOH-Br directly in subsequent reactions. The structural formula of Bpin-FOH-Br is as follows: d. 2-Bromo-7-iodo-9-(4-octoxyphenyl)-9H-fluorenol, the crude product containing Bpin-FOH-Br, and Pd(PPh3)4 were mixed and injected into an aqueous K2CO3 / KF solution under nitrogen protection. The reaction was carried out at 85°C for 14 h, quenched with water, extracted with dichloromethane, dried with anhydrous sodium sulfate, and separated by column chromatography to obtain the IDF-DBr. Method 2: a. 2-Bromo-9-fluorenone, 9-fluorenone-2-boronate, and Pd(PPh3)4 were mixed, and under nitrogen protection, deoxygenated K2CO3 / KF aqueous solution and deoxygenated toluene / tetrahydrofuran solution were added. The mixture was reacted at 85°C for 24 h, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography to obtain bifluorenone, denoted as BFOD. The eluent used in the column chromatography was dichloromethane. The structural formula of BFOD is: b. Mix fluorene, FeCl3, chloroform, and liquid bromine. Under light-protected conditions, place the reaction system at 25°C for 48 hours. After the reaction is complete, add Na2S2O3 solution until the dark color of the solution disappears. Filter and collect the precipitate. Wash with water until the filtrate becomes neutral. Dry the filter cake and use it directly in the next step of the reaction. The composition of the filter cake is BFOD-DBr, and the structural formula of BFOD-DBr is: c. Mix Mg and iodine granules, add tetrahydrofuran and part of 4-n-octyloxybromobenzene under nitrogen protection, initiate the reaction by blowing hot air, then add tetrahydrofuran and the remaining 4-n-octyloxybromobenzene in an ice-water bath, and react at 60°C for 2-3 hours to obtain Grignard reagent; d. Under nitrogen protection, the filter cake was heated to 85°C, Grignard reagent was added, and the reaction was quenched with saturated NH4Cl solution after 24 h. The mixture was extracted with water and dichloromethane, dried with anhydrous sodium sulfate, and separated by column chromatography to obtain the IDF-DBr. The eluent used in the column chromatography was a mixture of petroleum ether, dichloromethane, and ethyl acetate, with a volume ratio of 8:1:0.

3. Method 3: a. A mixture of p-biphenylboronic acid diester, methyl 2-iodo-5-bromobenzoate, and Pd(PPh3)4 was added under nitrogen protection, and oxygen-free K2CO3 / KF aqueous solution and oxygen-free toluene / tetrahydrofuran solution were added. The mixture was reacted at 85°C for 24 h, cooled to room temperature, and extracted with water and dichloromethane. The extract was concentrated and dried under vacuum, and recrystallized with ethanol to obtain DMDB-QPD. The structural formula of DMDB-QPD is: b. Add the DMDB-QPD to 50.0 mL of 80 wt.% H2SO4, stir at 120 °C for 12 h, pour the reaction mixture into ice water, filter to collect brown powder, wash the brown powder with sodium bicarbonate solution and water until the filtrate is neutral, dry the filter cake and use it directly for the next step of the reaction, the composition of the filter cake is BFOD-DBr; c. Mix Mg and iodine granules, add tetrahydrofuran and part of 4-n-octyloxybromobenzene under nitrogen protection, initiate the reaction by blowing hot air, then add tetrahydrofuran and the remaining 4-n-octyloxybromobenzene in an ice-water bath, and react at 60°C for 2-3 hours to obtain Grignard reagent; d. Under nitrogen protection, the filter cake is heated to 85°C, Grignard reagent is added, and after reacting for 24 h, it is quenched with saturated NH4Cl solution, extracted with water and dichloromethane, dried with anhydrous sodium sulfate, and separated by column chromatography to obtain the IDF-DBr. The eluent used in the column chromatography is a mixture of petroleum ether, dichloromethane, and ethyl acetate, and the volume ratio of petroleum ether, dichloromethane, and ethyl acetate is 8:1:0.

3.

8. The method for preparing the fluorene-based argyl aromatic hydrocarbon nanopolymer according to claim 7, characterized in that, In Method 1, the molar ratio of Mg to 4-n-octyloxybromobenzene is 1:1; in step b, the eluent used in the column chromatography separation is a mixture of petroleum ether and dichloromethane, and the volume ratio of petroleum ether to dichloromethane is 4:

1. And / or, in Method 2, the molar ratio of 2-bromo-9-fluorenone, 9-fluorenone-2-boronate, and Pd(PPh3)4 is 1:1:0.03; the concentration of the K2CO3 / KF aqueous solution is 4M; the volume ratio of toluene to tetrahydrofuran in the toluene / tetrahydrofuran solution is 1:1; and the ratio of bifluorenone, FeCl3, chloroform, and liquid bromine is 1.05g:0.65g:45mL:10mL. And / or, in Method 3, the molar ratio of the p-biphenylboronic acid diester to the methyl 2-iodo-5-bromobenzoate is 1:2; the concentration of the K2CO3 / KF aqueous solution is 4M; and the volume ratio of toluene to tetrahydrofuran in the toluene / tetrahydrofuran solution is 1:

1.

9. The application of the fluorene-based aromatic hydrocarbon nanopolymer according to claim 1 in the preparation of electroluminescent devices.

10. An electroluminescent thin film, characterized in that, It is prepared from the fluorene-based aromatic hydrocarbon nanopolymer according to claim 1.

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