Fluorenyl grignarene nano polymer as well as preparation method and application thereof

Abstract

The invention discloses a fluorenyl Grignarene nano polymer and a preparation method and application thereof, and belongs to the technical field of luminescent materials, the fluorenyl Grignarene nano polymer (PLG-Cz) is successfully synthesized through Yamamoto coupling reaction, and the fluorenyl Grignarene nano polymer is a conjugated Grignarene nano polymer and has excellent thermal stability and ozone stability. PLG-Cz not only has excellent stability, but also is an excellent laser gain medium (the ASE threshold value is 20.04 mu J.cm <-2 >). Besides, the thin film formed by PLG-Cz assembly shows excellent photonic crystal characteristics, a PLED with the thin film as a light-emitting layer shows excellent electroluminescence efficiency compared with a spin-coating film, efficiency roll-off is effectively inhibited, the thin film is endowed with high controllability of photoelectric properties due to the unique multi-scale structure orderliness, and the PLED has good application prospects. And a new direction and thought are provided for the field of design and regulation of photoelectric materials.

Description

Technical Field

[0001] The invention belongs to the technical field of luminescent materials, and in particular relates to a fluorenyl aromatic hydrocarbon nanopolymer and a preparation method and application thereof. Background Art

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

[0003] Although organic polymer light-emitting layers have received extensive attention in the field of organic light-emitting diodes (OLEDs), there are also some problems, such as the relatively unstable emission behavior of deep-blue emitting conjugated polymers. Specifically, the severe roll-off of emission efficiency and the uncontrollable emission color purity under long-term operation are prone to narrow-bandgap defect "guest" emission centers due to the inherent wide bandgap of deep-blue polymers, including chemical (structural changes) and physical (aggregation, excimer, foreign matter) defects, which have an adverse effect on emission efficiency and color purity. In addition, the energy level matching problem between the charge transport layer and the emission layer of deep-blue PLEDs has always been a technical challenge. This mismatch may lead to an imbalance in charge injection and transport, which in turn triggers the charge accumulation phenomenon. These problems will have an adverse effect on the performance and stability of the device, limiting its performance in practical applications. Therefore, while pursuing the emission behavior of a single luminescent chromophore, it is also crucial to ensure relatively excellent charge transport behavior. To complicate matters, when the device is exposed to adsorbed water and oxygen, the excitons located in the easily conjugated segments will cause a significant decrease in device performance, which has become one of the obstacles to the commercialization of organic polymer light-emitting devices.

[0004] As a typical representative of organic wide bandgap semiconductors, polyfluorene-based luminescent materials are one of the most popular blue or sky blue luminescent materials, with excellent optoelectronic properties and multi-site modification. Polyfluorene has excellent thermal stability, high photoluminescence quantum efficiency and good charge transport properties, which makes it one of the most promising blue light polymer materials in the field of OLED. However, polyfluorene materials also have unstable luminescence, such as reduced color purity and decreased luminescence stability. The larger band gap also leads to lower carrier density and charge transport capacity in the amorphous state, affecting its luminescence efficiency. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a fluorenyl lattice aromatic nanopolymer and its preparation method and application. The fluorenyl lattice aromatic nanopolymer of the present invention shows excellent performance in improving carrier mobility, spectral stability and morphological stability. The present invention directly self-assembles the polylattice skeleton into a photonic crystal microstructure through a covalent electron-driven method, which provides a new idea for cross-scale morphological guidance of molecular design in the field of organic mechatronics and intelligence; at the same time, by modulating multi-layer cracks with the help of molecular super-hindered etching technology, the efficient emission of deep blue random laser is successfully achieved, which also provides a device structure level idea for the realization of organic electric pumping laser.

[0006] To achieve the above object, the present invention provides the following technical solutions:

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

[0008] The present invention provides a fluorenyl lattice aromatic 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 are obtained through GPC testing.

[0011] In conjugated polymers, the planarity and conjugation length of the chain segments are crucial to the optoelectronic properties of the material. When the polymer chain deviates from its planar conjugated structure due to distortion or entanglement, the band structure may change. The luminescence of the conjugated polymer mainly comes from π-π* transitions, and the distortion or entanglement of the chain segments may lead to the generation of additional energy levels, thereby producing luminescence different from that of normal conjugated segments. The cell skeleton of the PLG-Cz of the present invention is smaller and exhibits excellent thermal stability and ozone stability, which provides a strong guarantee for its practical application. At the same time, the carrier mobility of the fluorenyl lattice aromatic nanopolymer PLG-Cz using a conjugated design strategy is higher than that of the non-conjugated PG-Cz ( n is a positive integer between 3 and 100), which also provides a reliable reference for the subsequent design of lattice-based nanopolymers with high carrier mobility. PLG-Cz not only has excellent stability, but is also an excellent laser gain medium (ASE threshold is 20.04 μJ·cm -2 ), this discovery provides a new molecular design strategy for the realization of organic electrically pumped lasers and is expected to promote progress in this field.

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

[0013] The present invention provides a method for preparing the above-mentioned fluorenyl aromatic hydrocarbon nanopolymer, comprising the following steps:

[0014] (1) Under nitrogen protection, bipyridine, bis-(1,5-cyclooctadiene) nickel (0) and 1,5-cyclooctadiene are mixed, sealed, and then N,N-dimethylformamide is injected and heated at 75°C for 30 minutes;

[0015] (2) dissolving the nanounit cell (LG-Cz) in toluene, injecting the nanounit cell (LG-Cz) into the reaction system of step (1), reacting at 85° C. for 6 days, adding a capping agent, purifying, concentrating, methanol re-precipitating, Soxhlet extracting and drying the reaction mixture to obtain the fluorenyl lattice aromatic nanopolymer (PLG-Cz);

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

[0017]

[0018] Furthermore, the preparation method of LG-Cz is as follows: UDF-Cz and IDF-DBr The mixture was mixed, and boron trifluoride ether and dichloromethane were added. After stirring evenly, the mixture was extracted with water and dichloromethane, 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, and the volume ratio of the petroleum ether to dichloromethane is 3:1.

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

[0022] (1) 9-octyl-9H-carbazole is added to dichloromethane, and then boron trifluoride ether is added;

[0023] (2) FOH-Br Add dichloromethane and add 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) CH 3 COOK, Pinacol borate, Pd(DPPF)Cl 2 and the FOHCz-Br, and under nitrogen protection, add deoxygenated 1,4-dioxane, react at 105°C for 12h, extract with water and dichloromethane, dry with anhydrous sodium sulfate, and obtain Bpin-FOH by rotary evaporation. of crude product;

[0026] (4) the FOHCz-Br, the crude product containing Bpin-FOH and Pd(PPh 3 ) 4 Mix, add deoxygenated K under nitrogen protection 2 CO 3 / KF aqueous solution and deoxygenated toluene / tetrahydrofuran solution (Tol / THF solution), react at 85°C for 24 hours, extract with water and dichloromethane, dry with anhydrous sodium sulfate, and separate by column chromatography to obtain the UDF-Cz.

[0027] In the preparation method of UDF-Cz: in step (1) and step (2), the mass ratio of the 9-octyl-9H-carbazole to the 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, and the volume ratio of the petroleum ether to dichloromethane is 10:1;

[0029] And / or, in step (3), the FOHCz-Br, the biboric acid pinacol ester, the Pd(DPPF)Cl 2 and the CH 3 The mass ratio of COOK is 0.726:0.304:0.044:5.87;

[0030] And / or, in step (4), the FOHCz-Br, the crude product containing Bpin-FOH and the Pd(PPh 3 ) 4 The mass ratio of is 0.799:0.865:0.058, 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 8:1.

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

[0032] Method 1:

[0033] a. Mix Mg and iodine particles, add tetrahydrofuran (THF) and part of 4-n-octyloxybromobenzene under nitrogen protection, blow hot air to initiate the reaction, then add tetrahydrofuran and the remaining 4-n-octyloxybromobenzene in an ice water bath, react at 60 ° C for 3h, the molar ratio of the Mg to the 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 stirred for 24 hours to obtain a solution containing 2-bromo-7-iodo-9-(4-octyloxyphenyl)-9H-fluorenol, which was cooled to room temperature and saturated with NH 4 The product was quenched with Cl 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-octyloxyphenyl)-9H-fluorenol, wherein the eluent used for the column chromatography separation was a mixture of petroleum ether and dichloromethane, and the volume ratio of the petroleum ether to dichloromethane was 4:1;

[0035] c. 2-bromo-7-iodo-9-(4-octyloxyphenyl)-9H-fluorenol (1.32 g, 2.23 mmol), biboric acid pinacol ester (0.850 g, 3.345 mmol), palladium acetate (10 mg, 0.045 mmol), CuI (85 mg, 0.45 mmol), PPh 3 (12 mg, 0.45 mmol), Cs 2 CO 3 (1.09 g, 2.23 mmol) was placed in a dried three-necked reaction bottle, then ventilated and protected with nitrogen, deoxygenated acetonitrile (10 mL) was injected, and the mixture was reacted for 7 h at room temperature, extracted with dichloromethane, dried over anhydrous sodium sulfate, and the solvent was removed by rotary evaporation. The crude product containing Bpin-FOH-Br was directly used in the next reaction;

[0036] d. 2-bromo-7-iodo-9-(4-octyloxyphenyl)-9H-fluorenol (0.650 g, 1.1 mmol), Bpin-FOH-Br (crude product, 0.875 g), Pd(PPh 3 ) 4 (0.058 g, 0.05 mmol) was placed in a three-necked reaction bottle that had been dried, and then ventilated with nitrogen protection, and K 2 CO 3 / KF aqueous solution (4 mol, 15 mL) was injected into a three-necked reaction bottle, reacted at 85° C. for 14 h, quenched with water, extracted with dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography to obtain the IDF-DBr. The eluent used for column chromatography separation was a mixture of petroleum ether, dichloromethane and ethyl acetate, with petroleum ether: dichloromethane: ethyl acetate = 8:1:0.3 (volume ratio);

[0037] Method 2:

[0038] a. 2-bromo-9-fluorenone, 9-fluorenone-2-boronate and Pd(PPh 3 ) 4 Mix, add deoxygenated K under nitrogen protection2 CO 3 / KF aqueous solution and deoxygenated toluene / tetrahydrofuran solution, react at 85°C for 24h, extract with water and dichloromethane, dry with anhydrous sodium sulfate, and separate by column chromatography to obtain BFOD The eluent used in the column chromatography separation is dichloromethane;

[0039] b. Add difluorenone, FeCl 3 , chloroform and liquid bromine were mixed, and the reaction system was placed at 25°C for 48 hours under light-proof conditions. After the reaction was completed, Na 2 S 2 O 3 The solution was stirred until the dark color of the solution disappeared, and the precipitate was collected by filtration, and the filtrate was washed with water until the filtrate became neutral. The filter cake was dried and directly used for the next reaction. The composition of the filter cake was BFOD-DBr

[0040]

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

[0042] d. Under nitrogen protection, the filter cake was heated to 85°C, and the Grignard reagent was added. After reacting for 24 hours, saturated NH 4 The solution was quenched with Cl, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography to obtain the IDF-DBr. The eluent used in the column chromatography separation was a mixture of petroleum ether, dichloromethane and ethyl acetate, and the volume ratio of the petroleum ether, dichloromethane and ethyl acetate was 8:1:0.3;

[0043] In method 2, the 2-bromo-9-fluorenone, the 9-fluorenone-2-boronate and the Pd(PPh 3 ) 4 The mass ratio of K is 3.10:3.67:0.416; 2 CO 3 The concentration of the KF / KF aqueous solution is 4M, the volume ratio of toluene to tetrahydrofuran in the toluene / tetrahydrofuran solution is 1:1; the bifluorenone, the FeCl 3 , the ratio of the chloroform to the liquid bromine is: 1.05 g: 0.65 g: 45 mL: 10 mL;

[0044] Method 3:

[0045] a. Prepare biphenyl borate, 2-iodo-5-bromobenzoic acid methyl ester and Pd(PPh 3 )4 Mix, add deoxygenated K under nitrogen protection 2 CO 3 / KF aqueous solution and deoxygenated toluene / tetrahydrofuran solution were reacted at 85°C for 24 hours, cooled to room temperature, extracted with water and dichloromethane, and the extract was concentrated and dried in a vacuum, and recrystallized from ethanol to obtain DMDB-QPD

[0046]

[0047] b. Add the DMDB-QPD to 50.0 mL of 80 wt.% H 2 SO 4 (by 10.0 mL H 2 O and 40.0 mL concentrated (99.99 wt.%) H 2 SO 4 Preparation), stirred at 120 ° C for 12 hours, during which the white solid turned dark brown, then the reaction mixture was poured into ice water and filtered to collect brown powder, the collected product (i.e. brown powder) was washed with sodium bicarbonate solution and water until the filtrate was neutral, and the filter cake was dried and directly used in the next reaction, the composition of the filter cake was BFOD-DBr;

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

[0049] d. Under nitrogen protection, the filter cake was heated to 85°C, and the Grignard reagent was added. After reacting for 24 hours, saturated NH 4 The solution was quenched with Cl, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography to obtain the IDF-DBr. The eluent used for the column chromatography separation was a mixture of petroleum ether, dichloromethane and ethyl acetate, and the volume ratio of the petroleum ether, dichloromethane and ethyl acetate was 8:1:0.3.

[0050] In method 3, the molar ratio of biphenyl borate and 2-iodo-5-bromobenzoic acid methyl ester is 1:2; 2 CO 3 The concentration of the KF / KF aqueous solution is 4 M, and the volume ratio of toluene to tetrahydrofuran in the toluene / tetrahydrofuran solution is 1:1.

[0051] The present invention uses diarylfluorene as the basic unit cell with the smallest skeleton size as a repeating unit to synthesize a fluorenyl lattice aromatic nanopolymer (PLG-Cz), which is a conjugated lattice aromatic nanopolymer. The present invention uses three different synthesis strategies to synthesize IDF-DBr, and comprehensively evaluates the performance of these strategies in terms of synthesis difficulty, yield and synthesis cycle, and finally determines that iodobromo tertiary alcohol is used as the starting material as the optimal IDF-Br synthesis path (i.e., method one). This strategy cleverly utilizes the difference in reaction activity between bromine and iodine, and realizes the precise and efficient synthesis of monosubstituted borate products. Subsequently, IDF-Br is synthesized in high yield through Suzuki reaction (Suzuki coupling reaction) without the participation of organic solvents. This synthesis route not only has a significant high yield and reusability, but also is characterized by its environmental friendliness, providing a solid foundation for the large-scale production of building units, paving the way for the industrial development of nano-lattice aromatic polymers, and successfully preparing PLG-Cz using Yamamoto polymerization.

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

[0053] The present invention also provides the use of the fluorenyl aromatic hydrocarbon nano polymer in the preparation of an electroluminescent device.

[0054] The fluorenyl lattice aromatic hydrocarbon nano polymer is formed into a film on the device by a drop casting film forming method, a solvent casting method, a solvent thermal annealing method or a spin coating film forming method to obtain an electroluminescent device.

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

[0056] The present invention also provides an electroluminescent film prepared from the fluorenyl aromatic hydrocarbon nano polymer.

[0057] Exemplarily, the electroluminescent film is prepared by drop casting, solvent casting, solvent thermal annealing or spin coating.

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

[0059] In the process of preparing the conjugated lattice aromatic nanopolymer PLG-Cz of the present invention, the Suzuki reaction with water as the solvent is used to prepare the polymerization monomer, which has good environmental friendliness and green environmental protection characteristics. Through the Yamamoto coupling reaction, the target polymerization product PLG-Cz was successfully synthesized, and its stability under different conditions was compared with that of the lattice-based nanopolymer PG-Cz synthesized in the previous group. PLG-Cz exhibits excellent thermal stability and ozone stability, which provides a strong guarantee for its practical application. At the same time, the carrier mobility of the lattice-based nanopolymer PLG-Cz using the conjugated design strategy is 2.2 times that of the non-conjugated PG-Cz, which also provides a reliable reference for the subsequent design of high carrier mobility lattice-based nanopolymers. PLG-Cz not only has excellent stability, but is also an excellent laser gain medium (ASE threshold is 20.04μJ·cm -2 ), this discovery provides a new molecular design strategy for the realization of organic electrically pumped lasers, and is expected to promote progress in this field. In addition, the film formed by PLG-Cz assembly exhibits excellent photonic crystal properties. The PLED with it as the light-emitting layer exhibits superior electroluminescent efficiency compared to the spin-coated film, and effectively suppresses the efficiency roll-off phenomenon. Its unique multi-scale structural order gives the film a high degree of controllability in terms of optoelectronic properties, providing new directions and ideas for the design and regulation of optoelectronic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0061] Figure 1 is the 2-bromo-7-iodo-9-(4-octyloxyphenyl)-9H-fluorenol in Example 1 1 H NMR nuclear magnetic hydrogen spectrum;

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

[0063] Figure 3 is the FOHCz-Br in Example 1 1 H NMR nuclear magnetic hydrogen spectrum;

[0064] Figure 4 is the UDF-Cz in Example 1 1 H NMR nuclear magnetic hydrogen spectrum;

[0065] Figure 5 is the BFOD in Example 2 1 H NMR nuclear magnetic hydrogen spectrum;

[0066] Figure 6 is the IDF-DBr in Example 2 1 H NMR nuclear magnetic hydrogen spectrum;

[0067] Figure 7 The superposition of H NMR spectra of biphenyl borate diester, 2-iodo-5-bromobenzoic acid methyl ester and the final product in Example 3;

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

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

[0070] Fig.10 Angle-resolved reflectance spectra of the solvothermally annealed films

[0071] Fig.11 The hole-dominant device (ITO / PEDOT:PSS / Polymer / MoO 3 / Al) structural diagram;

[0072] Fig.12 (a) is the EL spectrum (10V) of the spin-coated film and the solvent thermal annealing film (self-assembly), and (b) is the EQE and current density curve of the spin-coated film and the solvent thermal annealing film (self-assembly) devices. DETAILED DESCRIPTION

[0073] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0074] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0075] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0076] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0077] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0078] Unless otherwise specified, the room temperature in the present invention is 25±2°C.

[0079] The raw materials and reagents used in the examples of the present invention are all purchased from commercial sources.

[0080] The synthetic route of the fluorenyl lattice aromatic nanopolymer PLG-Cz of the present invention is as follows:

[0081]

[0082] (a)K 2 CO 3 / KF,Pd(PPh 3 ) 4 ,85℃,24h;(b)BF 3 ·OEt 2 ,CH 2 Cl 2 , 24h; (c) bipyridine, Ni(COD) 2 ,1,5-cyclooctadiene, toluene / DMF, 85°C, 6 days.

[0083] As an example, the method of preparing an electroluminescent film by drop casting is as follows: PLG-Cz is mixed with toluene to make the concentration of the PLG-Cz toluene solution be 5 to 10 mg·mL -1To ensure that the concentration of the polymer in the solution is appropriate, neither too high a concentration will cause the solution to be too viscous, affecting the uniformity of the coating, nor too low a concentration will cause the film to be insufficiently thick, affecting subsequent experimental observations and performance tests. Drop casting is carried out in a dust-free room temperature environment to avoid contamination by impurities such as dust, and is also conducive to the volatilization of the solvent and the formation of the film layer. Use a pipette to measure 100 μL of PLG-Cz toluene solution and apply it to a 1.5 cm × 1.5 cm quartz sheet. At room temperature, the toluene solvent will completely evaporate after 15 minutes, leaving a uniform PLG-Cz film layer. The drop-cast film (i.e., PLG-Cz film layer) is used for subsequent optical performance testing, structural characterization and other studies.

[0084] As an example, the method of preparing an electroluminescent film by solvent casting is as follows: PLG-Cz is mixed with a toluene solvent to form a uniform PLG-Cz toluene solution with a concentration of 2 to 10 mg·mL -1 , transfer the prepared PLG-Cz toluene solution to an appropriate sample bottle or other container, cover the bottle cap to prevent toluene from evaporating too quickly, and then place the container at room temperature to allow the toluene solvent to evaporate slowly. This process usually takes 3 to 7 days, depending on the initial amount of solvent, the size of the container, and environmental conditions. As the solvent gradually evaporates, PLG-Cz will gradually deposit at the bottom of the container and form a large area of ​​continuous film. The formation process of this film is bottom-up, which ensures the uniformity and consistency of the film. When the solvent is completely evaporated, the film has been basically formed, but the film may still be relatively soft and fragile at this time. In order to improve the stability and mechanical strength of the film, the film is dried at 80°C. This step can remove the solvent molecules that may remain in the film, while strengthening the internal structure of the film, making it more durable.

[0085] As an example, the method of preparing electroluminescent thin films by solvothermal annealing is as follows: PLG-Cz is dissolved in DCE and the concentration is controlled at 0.2-5 mg·mL -1, add ethanol to the above solution, heat the mixed solution to 75°C, and continue stirring for 30 minutes. The PLG-Cz molecules gradually aggregate to form tiny spherical structures, namely nanospheres. The mixed solution is left to stand at room temperature. During this process, the nanospheres will continue to grow and aggregate. After 5 minutes, the solution changes from clear to emulsified. This emulsion is formed by the dispersion of PLG-Cz nanospheres in the solvent and has special optical properties and surface activity. Continue to let the emulsion stand for 2 to 3 days, and the nanospheres will gradually settle at the bottom of the container to form a uniform nanosphere film (also called microsphere film). The nanosphere film is 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 will interact with the nanosphere film, causing the polymer molecules in the film to rearrange and tightly stack, thereby improving the crystallinity and stability of the film.

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

[0087] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in the art and are not the focus of the present invention.

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

[0089] Example 1

[0090] Synthesis of IDF-DBr, the synthesis route is as follows:

[0091]

[0092] (a) Mg, THF, 85℃, 24h; (b) PdAc, acetonitrile, CuI, PPh 3 ,Cs 2 CO 3 ,25℃,12h;(c)K 2 CO 3 / KF,Pd(PPh 3 ) 4 ,85℃,24h.

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

[0094] a. Add Mg (2.81 g, 0.116 mol) and iodine (two grains) to a three-necked reaction bottle, then evacuate and protect with nitrogen. Use a syringe to inject a small amount of 4-n-octyloxybromobenzene (3.70 g, 0.010 mmol) and THF (20 mL) into the reactor, blow hot air to initiate the reaction, then place the reaction device in an ice water bath and slowly add THF (20 mL) and the remaining 4-n-octyloxybromobenzene (30.23 g, 0.106 mol), and place the reaction system at 60 ° C for 3 hours;

[0095] b. Add 2-bromo-7-iodo-9-fluorenone (14.63 g, 0.038 mol) to another set of dried equipment, then evacuate and protect with nitrogen. Then heat to 85°C, then slowly add THF (80 mL) and the reaction solution of reaction a, stir for 24 hours to obtain a solution containing I-FOH-Br. After cooling to room temperature, add saturated NH 4 The product was quenched with Cl solution, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography. The eluent was petroleum ether: dichloromethane = 4:1 (volume ratio, the same below). 18.37 g of viscous liquid (i.e., I-FOH-Br) was obtained. The yield was 81.7%. 1 H NMR (400 MHz, CDCl 3 ): 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=8Hz,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 (100 MHz, CDCl 3 ): 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 BrIO 2 :590.03; found:590.02.

[0096] 2-Bromo-7-iodo-9-(4-octyloxyphenyl)-9H-fluorenol 1 H NMR nuclear magnetic hydrogen spectrum Figure 1 shown.

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

[0098] I-FOH-Br (1.32 g, 2.23 mmol), biboric acid pinacol ester (0.850 g, 3.345 mmol), palladium acetate (10 mg, 0.045 mmol), CuI (85 mg, 0.45 mmol), PPh 3 (12 mg, 0.45 mmol), Cs 2 CO 3 (1.09 g, 2.23 mmol) was placed in a three-necked reaction bottle that had been dried, and then ventilated and protected with nitrogen. Deoxygenated acetonitrile (10 mL) was injected and reacted for 12 h at room temperature. It 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 directly used in the next reaction;

[0099] Synthesis of target product IDF-DBr:

[0100] I-FOH-Br (0.650 g, 1.1 mmol), Bpin-FOH-Br (crude product, 0.875 g), Pd(PPh 3 ) 4 (0.058 g, 0.05 mmol) was placed in a three-necked reaction bottle that had been dried, and then ventilated with nitrogen protection. 2 CO 3 / KF aqueous solution (4M, 15 mL) was injected into a three-necked reaction bottle and reacted at 85°C for 24 hours. The mixture was quenched with water, extracted with dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography with the eluent being petroleum ether: dichloromethane: ethyl acetate = 8:1:0.3 to obtain 613 mg of a white solid (IDF-DBr) with a yield of 60%.

[0101] In order to confirm that the final product of the above method is IDF-DBr, the hydrogen spectrum of 2-bromo-7-iodo-9-fluorenone, I-FOH-Br, and IDF-DBr was tested (see Figure 2 ), we can see that in I-FOH-Br 1 The H NMR spectrum showed hydrogen signals of alkoxy chains (3.91-3.94 ppm) and hydroxyl peaks (2.43 ppm), confirming the synthesis of I-FOH-Br. 1The hydrogen signals of the hydroxyl peak (2.43ppm) and the alkoxy chain (3.91-3.94ppm) still existed in the H NMR spectrum, and the number of hydrogen integrals was doubled. After integrating and summing the hydrogen spectrum, the total number was 56, which was equal to the theoretical number of hydrogen. In summary, the synthesis of IDF-DBr was confirmed.

[0102] Synthesize UDF-Cz, the synthesis route is as follows:

[0103]

[0104] (a)BF 3 ·OEt 2 ,CH 2 Cl 2 ,25℃,24h;(b)K 2 CO 3 / KF,Pd(PPh 3 ) 4 ,THF / toluene, 85°C, 24h.

[0105] Synthesis of target product FOHCz-Br:

[0106] 9-Octyl-9H-carbazole (1.83 g, 6.54 mmol) was placed in a dried reaction bottle, dissolved in dichloromethane (20 mL), and then 1.03 g of boron trifluoride etherate (BF 3 ·OEt 2 ), FOH-Br (0.608 g, 1.31 mol) was dissolved in 600 mL of dichloromethane and placed in a constant pressure dropping funnel, and dripped dropwise. After the FOH-Br solution was dripped and reacted for 24 hours, it was extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography. The eluent was petroleum ether: dichloromethane = 10:1, and 745 mg of white solid (i.e., FOHCz-Br) was obtained. The yield was 78.2%. 1 H NMR nuclear magnetic hydrogen spectrum Figure 3 As shown. FOHCz-Br 1 H NMR (400 MHz, CDCl 3): δ (ppm) 7.95-7.93 (d, J = 8Hz, 1H), 7.87 (s, 1H), 7.76-7.74 (d, J = 7.6Hz, 1H), 7.65-7.63 (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=12.8Hz,2 H),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 13 CNMR (100MHz, CDCl 3 ): δ(ppm)157.00,153.40,151.14,139.71,138.32,138.01,137.81,136.60,134.62,129.43 ,128.41,128.15,127.05,126.38,125.23,125.01,124.56,121.59,121.53,120.44,120.28, 119.37,119.14,118.51,117.59,113.13,107.59,107.48,66.87,63.99,42.09,30.78,30.7 5,28.32,28.26,28.21,28.12,27.96,26.26,25.04,21.62,21.56,13.08.MALDI-ToF-MS:m / z calcd for[M]C 47 H 52 BrNO:725.32; found:725.15.

[0107] Synthesis of target product Bpin-FOH:

[0108] FOHCz-Br (0.726 g, 1 mmol), biboric acid pinacol ester (0.304 g, 1.2 mmol), Pd(DPPF)Cl 2 (0.044 g, 0.06 mmol), CH 3COOK (5.87 g, 59.8 mmol) was placed in a three-necked reaction bottle that had been dried, and then ventilated and protected with nitrogen. Deoxygenated 1,4-dioxane (25 mL) was injected, and the reaction was carried out at 105°C for 12 h, 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 directly used in the next reaction;

[0109] Synthesis of target product UDF-Cz:

[0110] FOHCz-Br (0.799 g, 1.1 mmol), Bpin-FOH (crude product, 0.865 g), Pd(PPh 3 ) 4 (0.058 g, 0.05 mmol) was placed in a three-necked reaction bottle, and then ventilated with nitrogen protection. Deoxygenated K 2 CO 3 20 mL of 4M / KF aqueous solution and 1:1 Tol / THF solution were injected into a three-necked reaction bottle, reacted at 85°C for 24 h, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, separated by chromatography, and the eluent was petroleum ether: dichloromethane = 8:1, to obtain 844 mg of a white solid (UDF-Cz), with a yield of 59.3%. 1 H NMR nuclear magnetic hydrogen spectrum Figure 4 As shown. UDF-Cz 1 H NMR (400 MHz, CDCl 3 ): 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),3.89-3.8 5(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 (100 MHz, CDCl 3): δ(ppm)158.00,153.06,152.78,141.07,141.05,140.86,139.78,139.41,139.29,138.55,138.53,136.58, 136.56,129.42,127.73,127.39,126.71,126.41,126.37,125.58,124.98,122.88,122.68,122.65,120.55,1 20.43,120.27,119.78,119.77,118.70,118.68,114.19,108.65,108.52,68.00,65.10,43.26,31.96,31.93, 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 N 2 O 2 :1293.81; found:1293.44.

[0111] Synthesize LG-Cz, the synthesis route 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) are added to a three-necked flask, and then boron trifluoride ether (0.131 mL) and dichloromethane (210 mL) are added, the mixture is stirred at 25°C for 24 h, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, separated by column chromatography, and the eluent is petroleum ether: dichloromethane = 3:1, to obtain 105 mg of white solid (ie, LG-Cz), with a yield of 62.1%. 1 H NMR (400 MHz, CDCl 3): 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 (m, 13H), 6.90 - 6.48 (m, 12H), 4.19 - 4.00 (m, 4H), 3.99 - 3.78 (m, 8H), 1.78 - 1.64 (m, 12H), 1.39 - 1.13 (m, 60H), 0.87 - 0.82 (m, 19H). For LG-Cz 13 C NMR (100 MHz, CDCl 3 ): δ(ppm) 158.27, 158.06, 157.91, 154.65, 152.87, 152.57, 151.71, 151.59, 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 Br 2 N 2 O 4 : 2187.05; found: 2187.06.

[0114] PLG-Cz was synthesized by the following synthesis route:

[0115]

[0116] In a nitrogen-protected glove box, 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 added into a 250 mL reaction tube in sequence and sealed tightly. 20 mL of N,N-dimethylformamide solvent was injected, and the whole system was heated at 75 °C for 30 min to activate the catalyst. Nanounit cell (LG-Cz) (0.360 g, 0.164 mmol) Dissolved in 15mL of dry and deoxygenated toluene, then injected into the reaction tube, reacted at 85°C for 6 days, then added 2mL of bromobenzene as a capping agent to the reaction system, after the reaction was completed, the reaction mixture was transferred to a chromatography column pre-filled with 35cm of neutral alumina, and pressure purified using THF as an eluent, the eluted solution was concentrated, and reprecipitated with methanol, filtered and collected the reprecipitated product, and after 5 days of Soxhlet extraction, finally vacuum dried to obtain a light yellow solid product PLG-Cz. Through GPC (gel permeation chromatography) testing (under PS system), it was determined that the Mn of the obtained PLG-Cz was 36003 and the PDI was 1.66.

[0117] Example 2

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

[0119]

[0120] (a)K 2 CO 3 / KF,Pd(PPh 3 ) 4 ,THF / toluene, 85℃, 24h; (b)FeCl 3 , chloroform, 85℃, 48h; (c) Mg, THF, 85℃, 24h.

[0121] Synthesis of 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(PPh 3 ) 4 (0.416 g, 0.36 mmol), then evacuate the gas and protect it with nitrogen. Inject deoxygenated K 2 CO3 / KF aqueous solution (4M, 10mL) and deoxygenated tetrahydrofuran / toluene solution (1:1, v:v, 40mL), react at 85°C for 24h. Extract with water and dichloromethane several times, dry with anhydrous sodium sulfate, separate under pressure by column chromatography, eluent is pure dichloromethane, and finally obtain 2.96g of light yellow solid, yield: 68.8%. BFOD 1 H NMR nuclear magnetic hydrogen spectrum Figure 5 , BFOD 1 HNMR (400 MHz, CDCl 3 ): 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 (100 MHz, CDCl 3 ):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 O 2 :358.10; found:359.10.

[0123] Synthesis of target product BFOD-DBr:

[0124] To a three-necked reaction flask, bifluorenone (1.05 g, 2.79 mmol), FeCl 3 (0.65 g, 4 mmol), chloroform (45 mL) and liquid bromine (10 mL), and set up the waste gas treatment device for the liquid bromine reaction. Under light-proof conditions, the reaction system was placed at 25 ° C for 48 h. After the experiment, Na 2 S 2 O 3 The solution was stirred until the dark color disappeared, and the precipitate was collected by filtration and then rinsed with water several times until the filtrate became neutral. The filter cake was dried and used directly in the next reaction.

[0125] Synthesis of target product IDF-DBr:

[0126] a. Add Mg (2.82 g, 116 mmol) and iodine (two grains) to a three-necked reaction bottle, evacuate three times, and add a nitrogen balloon for protection. Use a syringe to inject a small amount of 4-n-octyloxybromobenzene (4.56 g, 16 mmol) and ultra-dry THF (20 mL) into the reactor, blow hot air to initiate the reaction, then place the reaction device 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 BFOD-DBr (15.48 g, crude product) to another three-necked reaction bottle, evacuate three times, add nitrogen balloon protection, heat to 85 ° C, then slowly add Grignard reagent, react for 24 hours, and then use saturated NH 4 The mixture was quenched with Cl solution, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography. The eluent was petroleum ether: dichloromethane: ethyl acetate = 8:1:0.3. 1.25 g of white solid was obtained. The yield was 8.2%. IDF-DBr 1 H NMR nuclear magnetic hydrogen spectrum Figure 6 , IDF-DBr 1 H NMR (400 MHz, CDCl 3 ): 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), 7.2 9-7.27(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 (100 MHz, CDCl 3): δ(ppm)158.84,153.06,153.02,151.22,151.15,141.66,141.47,138.15,138.11 ,138.03,137.98,134.13,134.09,132.34,132.32,128.49,128.34,126.68,123.54, 123.51,122.33,121.68,120.64,114.54,114.51,83.46,83.44,68.13,31.95,30.20 ,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 Br 2 O 4 :928.25; found:928.54.

[0128] Example 3

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

[0130]

[0131] (a)K 2 CO 3 / KF,Pd(PPh 3 ) 4 ,THF / toluene, 85°C, 24h; (b)H 2 SO 4 ,H 2 O, 120℃, 12h; (c) Mg, THF, 85℃, 24h.

[0132] Synthesis of target product DMDB-QPD:

[0133] To a three-necked reaction flask, add biphenyl borate (544 mg, 1.34 mmol), methyl 2-iodo-5-bromobenzoate (920 mg, 2.70 mmol) and Pd(PPh 3 ) 4 (77 mg, 0.067 mmol), then evacuate the gas and protect it with nitrogen. Inject deoxygenated K 2 CO 3 / KF aqueous solution (4M, 10mL) and tetrahydrofuran / toluene solution (1:1, 40mL), heated to 85°C for 24h. After cooling to room temperature, deionized water was added, and dichloromethane was extracted three times. The extract was concentrated and dried in a vacuum. In the purification stage, 609mg of white solid (DMDB-QPD) was obtained by recrystallization with ethanol, with a yield of 78.3%. 1 H NMR (400 MHz, CDCl 3 ): 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, CDCl 3 ): 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 Br 2 O 4 :579.97; found:580.76.

[0134] By superposition of H NMR spectra of biphenylboronic acid diester, 2-iodo-5-bromobenzoic acid methyl ester and the final product ( Figure 7 ) It can be seen that the methoxy group in methyl 2-iodo-5-bromobenzoate appears in the hydrogen spectrum of the final product, and the integrated number of hydrogen is 2 times, confirming that the final product has a bilateral structure with two methoxy groups. At the same time, after integrating the number of hydrogens in the nuclear magnetic resonance, the total number of hydrogens is found to be 20, which finally confirms that DMDB-QPD is successfully synthesized.

[0135] Synthesis of target product BFOD-DBr:

[0136] DMDB-QPD (577 mg, 1 mmol) was added to 80 wt.% H 2 SO 4 (by 10.0 mL H 2 O and 40.0 mL concentrated (99.99 wt.%) H 2 SO 4The mixture was added to 50.0 mL of 4-nitropropene (prepared) and stirred at 120° C. for 12 h, during which 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 in the next reaction.

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

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

[0139] The electrochemical test of redox of PLG-Cz was carried out by voltammetric method. The results are as follows Figure 8 As shown in the figure, by analyzing the voltammetric characteristic curve by the tangent method, the band gap of PLG-Cz was determined to be 3.36 eV, which is significantly larger than the band gap value of PG-Cz (3.33 eV). This not only reveals the unique electronic structure characteristics of PLG-Cz, but also indicates its application prospect as a potential blue light polymer material in the optoelectronic field, and provides a solid theoretical basis for the preparation of PLG-Cz in PLED devices.

[0140] The TGA spectrum of PLG-Cz (a) and the DSC spectrum of PLG-Cz (b) are shown in Fig. 9 As shown in the figure, it can be seen that when the weight loss of polymer PLG-Cz exceeds 5%, the corresponding thermal decomposition temperature is 332°C, which has a high thermal decomposition temperature and good heat resistance. No obvious endothermic or exothermic peaks were found in the DSC curve, so there is no obvious glass transition temperature or melting point between 25 and 260°C. PLG-Cz not only exhibits excellent thermal stability (T d =332℃) and blue light emission (CIE coordinates are (0.16, 0.08)). PLG-Cz, with its large steric effect, effectively weakens the fluorescence quenching effect caused by molecular aggregation. At the same time, its shorter fluorescence lifetime indicates that PLG-Cz is a potential laser gain medium. In addition, PLG-Cz exhibits excellent aging resistance in an ozone environment, and its stability is significantly better than other materials. In terms of UV light stability, the spectrum of PLG-Cz changes little, indicating that the photo-oxidation stability of the material can be effectively improved through reasonable molecular design.

[0141] The film-forming property of organic light-emitting materials during solution processing is crucial for the manufacture of high-efficiency organic optoelectronic devices. Good film-forming properties can ensure that the organic material forms a uniform, continuous and defect-free film during the preparation process, which is essential for achieving efficient charge injection and transfer, improving the luminous efficiency of the device, and ensuring the stability and life of the device. Defects and non-uniformities in the film in PLED devices will lead to inconsistencies in the light-emitting area, thereby reducing the overall luminous efficiency. Secondly, in industrial production, film-forming properties determine whether the organic light-emitting material can be efficiently coated on a large area of ​​substrate, which is of great significance for reducing costs and achieving commercial production. Therefore, the present invention simultaneously studies the film-forming property of PLG-Cz by means of theoretical calculation and film roughness analysis: 5 mg PLG-Cz is weighed and dissolved in 1 mL toluene, and ultrasonicated in an ultrasonic cleaning machine for 1 minute to enable it to be fully dissolved in the toluene solvent, 90 μL is measured with a pipette, and dropped on the substrate, 1200 rpm / min is maintained for 30 seconds, and after the solvent in the film is completely evaporated, it is observed by atomic force microscopy (AFM), and it is found that the height difference of the PLG-Cz film is only 6.5 nm, with a uniform and flat surface. In addition, the surface roughness of the PLG-Cz film is only 2.86 nm, which further confirms the superiority of PLG-Cz in surface flatness.

[0142] Three kinds of thin films were prepared by drop casting, solvent casting and solvothermal annealing, respectively, and the reflectance spectrum of the solvothermal annealing film was studied by angle-resolved reflectance spectroscopy ( Fig.10 ), and found that in its reflection spectrum, there are a series of interference fringes with significant periodicity. These interference fringes are i (incident angle) ranges from 0° to 60°, with θ i As the wavelength increases, the interference fringes gradually move toward the short-wave direction, showing obvious angular resolution characteristics. The solvent-thermal annealed film exhibits typical one-dimensional photonic crystal characteristics. In contrast, other films of PLG-Cz do not show interference fringes with periodic structures. Instead, they show some messy peaks, and there is no angle-dependent spectral shift feature. The reflection characteristics in the microsphere film only come from the disordered light scattering caused by the rough surface (it should be noted that when testing, the place with rainbow fringes cannot be selected for testing. This is because the film thickness here is extremely uneven, resulting in equal thickness interference, and there will be no stacked structure). The effective refractive index of PLG-Cz is: n eff =1.754 (λ=745~603nm), 1.805 (λ=609~550nm), 1.858 (λ=559~508nm) and 1.931 (λ=519~474nm), among which, when λ=483.58~437.61nm, n eff=2.01, almost reaching the highest level of conjugated polymers (n≈2). The above results show that the solvent thermal annealing film has a high refractive index and the n eff The value is higher than that of the polyfluorene film with β-phase (refractive index (n) = 1.7-1.8), so PLG-Cz can obtain high-efficiency LED and ASE emission by modulating photon confinement and population inversion.

[0143] The present invention manufactures hole-dominated devices (ITO / PEDOT:PSS / Polymer / MoO 3 / Al) to study the transport capacity of PLG-Cz ( Fig.11 PG-Cz and PLG-Cz spin-coated film devices were prepared using toluene solution. 1 / 2 At 700-1100 (V cm -1 ) 1 / 2 In the range of 10 -6 ~10 -5 cm 2 V -1 s -1 Among them, PLG-Cz exhibits the highest hole mobility at 948 (V cm -1 ) 1 / 2 When the carrier mobility is 6.4×10 -6 cm 2 V - 1 s -1 This high hole mobility indicates that PLG-Cz may have excellent electroluminescent properties. -1 ) 1 / 2 When , the hole mobility of PLG-Cz is about 2.2 times that of PG-Cz, which indicates that the lattice-based conjugated structure design is helpful to improve the carrier mobility.

[0144] In order to study its efficiency in actual devices (PLED), a non-doped solution-processed device was prepared, and its device structure from bottom to top was: ITO / PEDOT:PSS(40nm) / PLG-Cz(40nm) / TPBi(40nm) / LiF(1nm) / Al(100nm).

[0145] In the electroluminescence (EL) spectrum, the spin-coated PLED exhibits an EL peak at 428 nm and has low energy emission, showing poor color purity ( Fig.12 In contrast, the EL spectrum of the PLG-Cz self-assembled PLED shows stable deep blue emission and high color purity. The turn-on voltage of the spin-coated PLED is about 6.2 V, and the maximum brightness is 364.8 cd·m-2 , the maximum current efficiency is 0.50cd·A -1 , the maximum power efficiency is 0.18lm·W -1 At the same time, compared with the spin-coated PLED, the maximum external quantum efficiency (EQE) of the self-assembled device was improved from 0.27% to 0.48% ( Fig.12 (b)), effectively suppressing the efficiency roll-off. Therefore, this self-assembly shows a great improvement in electroluminescence efficiency, which may be due to the mesoscopic order driven by nanolattice with low optical loss.

[0146] Solvent thermal annealing was used to prepare a one-dimensional photonic crystal film (the reflection spectrum satisfies the Bragg-Snell diffraction equation). The optical waveguide properties of the photonic crystal film show that it can effectively guide light to propagate inside the material, increasing the external quantum efficiency (EQE) of PLED from 0.27% to 0.48%, and suppressing the efficiency roll-off. At the same time, the waveguide properties of PLG-Cz are combined with its spontaneous radiation characteristics, making it possible to realize high-performance laser devices. These research results not only help to enhance 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 only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A fluorenyl aromatic nanopolymer, characterized in that: The structural formula is as follows: The number average molecular weight of the fluorenyl aromatic hydrocarbon nanopolymer is 36003, and the molecular weight distribution index is 1.

66.

2. A method for preparing the fluorenyl aromatic nanopolymer according to claim 1, characterized in that: The following steps are involved: (1) Under nitrogen protection, bipyridine, bis-(1,5-cyclooctadiene) nickel (0) and 1,5-cyclooctadiene are mixed, sealed, and then N,N-dimethylformamide is injected and heated at 75°C for 30 minutes; (2) dissolving the nanounit cells in toluene, injecting the nanounit cells into the reaction system of step (1), reacting at 85° C. for 6 days, adding a capping agent, purifying, concentrating, methanol reprecipitating, Soxhlet extracting and drying the reaction mixture to obtain the fluorenyl aromatic nanopolymer; The structural formula of the nanocell is as follows:

3. The method for preparing the fluorenyl aromatic nanopolymer according to claim 2, characterized in that: The preparation method of the nanocell is as follows: UDF-Cz and IDF-DBr are mixed, boron trifluoride ether and dichloromethane are added, and after the reaction is completed, extraction is performed with water and dichloromethane, drying is performed with anhydrous sodium sulfate, and separation is performed by column chromatography to obtain the nanocell; The structural formula of the UDF-Cz is: The structural formula of the IDF-DBr is:

4. The method for preparing the fluorenyl aromatic nanopolymer 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, and the volume ratio of the petroleum ether to dichloromethane is 3:

1.

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

6. The method for preparing the fluorenyl aromatic nanopolymer according to claim 5, characterized in that: In step (1) and step (2), the molar ratio of the 9-octyl-9H-carbazole to the 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, and the volume ratio of the petroleum ether to dichloromethane is 10:1; And / or, in step (3), the molar ratio of the FOHCz-Br, the diboric acid pinacol ester, the Pd(DPPF)Cl2 and the CH3COOK is 1:1.2:0.06:59.8; And / or, in step (4), the mass ratio of the FOHCz-Br, the crude product containing Bpin-FOH and the 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, and the volume ratio of the petroleum ether and dichloromethane is 8:

1.

7. The method for preparing fluorenyl aromatic nanopolymer according to claim 3, characterized in that: The IDF-DBr is prepared by any of the following methods: Method 1: a. Mix Mg and iodine particles, add tetrahydrofuran and part of 4-n-octyloxybromobenzene under nitrogen protection, blow hot air to initiate the reaction, then add tetrahydrofuran and the remaining 4-n-octyloxybromobenzene in an ice water bath, and react at 60°C for 3h; 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 stirred for 24 hours to obtain a solution containing 2-bromo-7-iodo-9-(4-octyloxyphenyl)-9H-fluorenol, which was cooled to room temperature, 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-octyloxyphenyl)-9H-fluorenol; c. Mix I-FOH-Br, bipyraclostrobin, palladium acetate, CuI, PPh3 and Cs2CO3, inject deoxygenated acetonitrile under nitrogen protection, react for 7 hours at room temperature, extract with dichloromethane, dry over anhydrous sodium sulfate, remove the solvent by rotary evaporation, and use the crude product containing Bpin-FOH-Br directly for the next reaction; d. Mix 2-bromo-7-iodo-9-(4-octyloxyphenyl)-9H-fluorenol, the crude product containing Bpin-FOH-Br and Pd(PPh3)4, inject K2CO3 / KF aqueous solution under nitrogen protection, react at 85°C for 14h, quench with water, extract with dichloromethane, dry over anhydrous sodium sulfate, and separate by column chromatography to obtain the IDF-DBr; Method 2: a. Mix 2-bromo-9-fluorenone, 9-fluorenone-2-boronate and Pd(PPh3)4, add deoxygenated K2CO3 / KF aqueous solution and deoxygenated toluene / tetrahydrofuran solution under nitrogen protection, react at 85°C for 24h, extract with water and dichloromethane, dry with anhydrous sodium sulfate, separate by column chromatography to obtain BFOD, wherein the eluent used in the column chromatography separation is dichloromethane, and the structural formula of the BFOD is: b. Mix difluorenone, FeCl3, chloroform and liquid bromine, and place the reaction system at 25°C for 48 hours under light-proof conditions. After the reaction, add Na2S2O3 solution until the dark color of the solution disappears, filter and collect the precipitate, rinse with water until the filtrate becomes neutral, and use the filter cake directly in the next reaction after drying. The composition of the filter cake is BFOD-DBr, and the structural formula of the BFOD-DBr is: c. Mix Mg and iodine particles, add tetrahydrofuran and part of 4-n-octyloxybromobenzene under nitrogen protection, blow hot air to initiate the reaction, then add tetrahydrofuran and the remaining 4-n-octyloxybromobenzene in an ice water bath, and react at 60°C for 2 to 3 hours; d. Under nitrogen protection, the filter cake was heated to 85 ° C, a Grignard reagent was added, and the reaction was quenched with a saturated NH4Cl solution after 24 hours, extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and separated by column chromatography to obtain the IDF-DBr. The eluent used for the column chromatography separation was a mixture of petroleum ether, dichloromethane and ethyl acetate, and the volume ratio of the petroleum ether, dichloromethane and ethyl acetate was 8:1:0.3; Method 3: a. The biphenyl borate diester, methyl 2-iodo-5-bromobenzoate and Pd(PPh3)4 were mixed, and under nitrogen protection, deoxygenated K2CO3 / KF aqueous solution and deoxygenated toluene / tetrahydrofuran solution were added, and the reaction was carried out at 85°C for 24 hours. After cooling to room temperature, the extract was extracted with water and dichloromethane, and the extract was concentrated and dried in vacuo, and recrystallized from ethanol to obtain DMDB-QPD, the structural formula of which is: b. The DMDB-QPD was added to 50.0 mL of 80 wt.% H2SO4, stirred at 120 ° C for 12 h, the reaction mixture was poured into ice water, filtered to collect brown powder, and the brown powder was washed with sodium bicarbonate solution and water until the filtrate was neutral. The filter cake was dried and directly used in the next reaction. The composition of the filter cake was BFOD-DBr; c. Mix Mg and iodine particles, add tetrahydrofuran and part of 4-n-octyloxybromobenzene under nitrogen protection, blow hot air to initiate the reaction, then add tetrahydrofuran and the remaining 4-n-octyloxybromobenzene in an ice water bath, and react at 60°C for 2 to 3 hours; d. Under nitrogen protection, the filter cake was heated to 85° C., a Grignard reagent was added, and the reaction was continued for 24 h, followed by quenching with a saturated NH4Cl solution, extraction with water and dichloromethane, drying with anhydrous sodium sulfate, and separation by column chromatography to obtain the IDF-DBr. The eluent used for the column chromatography separation was a mixture of petroleum ether, dichloromethane and ethyl acetate, and the volume ratio of the petroleum ether, dichloromethane and ethyl acetate was 8:1:0.

3.

8. The method for preparing fluorenyl aromatic nanopolymer according to claim 7, characterized in that: In method 1, the molar ratio of the Mg to the 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 the petroleum ether to dichloromethane is 4:1; And / or, in method 2, the molar ratio of the 2-bromo-9-fluorenone, the 9-fluorenone-2-boronate and the Pd(PPh3)4 is 1:1:0.03; the concentration of the K2CO3 / KF aqueous solution is 4M, the volume ratio of toluene and tetrahydrofuran in the toluene / tetrahydrofuran solution is 1:1; the ratio of the bifluorenone, the FeCl3, the chloroform and the liquid bromine is: 1.05g:0.65g:45mL:10mL; And / or, in method three, the molar ratio of the biphenyl boric acid diester and the 2-iodo-5-bromobenzoic acid methyl ester is 1:2; the concentration of the K2CO3 / KF aqueous solution is 4M, and the volume ratio of toluene and tetrahydrofuran in the toluene / tetrahydrofuran solution is 1:

1.

9. Use of the fluorenyl aromatic hydrocarbon nanopolymer according to claim 1 in the preparation of an electroluminescent device.

10. An electroluminescent film, characterized in that: The nanopolymer is prepared from the fluorenyl aromatic hydrocarbon nanopolymer described in claim 1.

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