High-efficiency near-ultraviolet hot exciton compound with circular polarization property and application in preparation of circular polarization organic electroluminescent device

Abstract

The application relates to a high-efficiency near-ultraviolet hot exciton compound with circular polarization properties and application in preparation of circular polarization organic electroluminescent devices, and belongs to the technical field of organic photoelectric materials. The organic electroluminescent material is a high-efficiency near-ultraviolet hot exciton compound with circular polarization properties. By combining a chiral group binaphthol with fluorene with high luminous efficiency, nine pairs of near-ultraviolet enantiomers are successfully designed and synthesized, which all show obvious circular polarization luminescence properties and high fluorescence quantum yield. Electroluminescent devices prepared based on the nine pairs of near-ultraviolet enantiomers all show near-ultraviolet emission, and the external quantum efficiencies are 3.9%, 3.1%, 4.5%, 7.5%, 6.3%, 5.0%, 10.3%, 9.2% and 11.6% respectively. The application provides a new perspective for developing near-ultraviolet hot exciton materials with circular polarization luminescence and high efficiency, and is favorable for directly realizing 3D and wide color gamut display in the future.

Description

Technical Field

[0001] This invention belongs to the field of organic optoelectronic materials technology, specifically relating to a high-efficiency near-ultraviolet thermal exciton compound with circular polarization properties and its application in the preparation of circularly polarized organic electroluminescent devices. Background Technology

[0002] Organic light-emitting diodes (OLEDs) have been widely used in smartphones, automotive displays, and wearable devices such as smartwatches due to their advantages including being healthy and environmentally friendly, surface light source characteristics, flicker-free operation, and low power consumption, and have gradually achieved commercialization. To improve screen visibility, polarizers are typically introduced into the device, but this structure results in a 50% light loss. Circularly polarized organic light-emitting diodes (CP-OLEDs), however, can achieve circularly polarized light output without additional optical components, simplifying the device structure and reducing manufacturing costs. This technology shows unique application potential in fields such as 3D displays, anti-counterfeiting and security applications, and biomedicine. Breakthroughs in CP-OLED technology will further drive the upgrading of the traditional information industry and have broad application prospects.

[0003] Materials are the foundation of high-tech development and modern civilization, and along with energy and information, they are considered one of the three pillar industries of the 21st century. Over the past few decades, CP-OLED materials have made significant progress in the visible light and long-wavelength infrared regions, with device performance reaching a relatively ideal state. However, research on short-wavelength near-ultraviolet (NIUV) emitting materials is almost nonexistent. Yet, NIUV materials play an irreplaceable role in industrial and medical fields, such as ultraviolet disinfection, photopolymerization manufacturing, and special lighting. Therefore, to broaden the color gamut and further promote technological innovation in near-ultraviolet light sources, developing high-efficiency NIUV-emitting CP-OLED materials while reducing development costs is of great significance.

[0004] In electroluminescence, excitons are directly generated by the recombination of electrons and holes, and their deactivation is a top-down process. In traditional fluorescent materials, the theoretical maximum exciton utilization is only 25%. Therefore, developing pure organic electroluminescent materials capable of utilizing triplet excitons via reverse system-reverse crossover (RISC) has become an important research topic in recent years. Currently, the main mechanisms for harvesting triplet excitons in organic fluorescent devices are triplet-triplet annihilation (TTA), thermally activated delayed fluorescence (TADF), and thermal exciton mechanisms. The upper limit of exciton utilization for TTA materials is only 62.5%, which is significantly insufficient for improving device efficiency. Although TADF materials can theoretically achieve 100% exciton utilization, their strong charge transfer (CT) state characteristics between donor and acceptor are unfavorable for deep blue light emission (CIE). yThe achievement of <0.08). Furthermore, the slow radiative transition rate of TADF materials typically leads to severe [problems / problems].

[0005] The significant efficiency roll-off problem hinders the practical application of circularly polarized materials.

[0006] Thermal exciton materials are produced through high-energy triplet states (T... m From m≥2) to singlet state (S n The high-energy reverse intersystem crossing (hRISC) process (n≥1) utilizes triplet excitons, and the radiative transition of the S1 state remains unaffected, achieving separation of exciton conversion and radiative transition. Therefore, the S1 state properties of thermal exciton materials do not significantly affect the hRISC process, avoiding the problem that TADF materials must have a strong CT state in S1. This advantage is beneficial for the construction of high-color-purity near-ultraviolet materials. In addition, the short lifetime of high-energy excited-state excitons and the sufficiently fast hRISC process rate can effectively alleviate exciton annihilation caused by the accumulation of triplet excitons at high current densities, thus facilitating the acquisition of high-efficiency, low-roll-off near-ultraviolet CP-OLEDs materials. This patent proposes to develop novel circularly polarized luminescent thermal exciton near-ultraviolet materials and devices by combining molecular design and chemical synthesis, taking into account the dual advantages of circularly polarized luminescence and high luminous efficiency, which is conducive to the direct realization of wide color gamut displays in the future. Summary of the Invention

[0007] Therefore, the purpose of this invention is to provide a high-efficiency near-ultraviolet thermal exciton compound with circular polarization properties and its application in the fabrication of circularly polarized organic electroluminescent devices. This near-ultraviolet thermal exciton compound can be used as a light-emitting layer to fabricate high-efficiency, high-brightness, and low-roll-off near-ultraviolet circularly polarized OLED devices, and has the potential for practical application.

[0008] A highly efficient near-ultraviolet thermal exciton compound with circular polarization properties has the structural formula shown in (1):

[0009]

[0010] X is a cyano group (CN);

[0011] L m for Where * indicates the connection position with R and the benzene ring; m is 0 or 1;

[0012] R is Where * indicates that it is related to L m Or the connection position of the benzene ring.

[0013] Furthermore, the near-ultraviolet thermal exciton material with circularly polarized properties described in this invention has one of the following structural formulas:

[0014]

[0015] The near-ultraviolet thermal exciton compound with circularly polarized properties provided by this invention uses the chiral group binaphthol as a modifying group and employs a chiral induction strategy to endow the luminescent molecules with circularly polarized properties. This near-ultraviolet thermal exciton compound combines high luminous efficiency, high exciton utilization, and excellent electroluminescence performance, and can be used as a dopant material to prepare the luminescent layer of circularly polarized organic electroluminescent devices. The host material is CBP, and the mass doping concentration of the near-ultraviolet thermal exciton compound is 5-20 wt%. In addition to the luminescent layer, the organic functional layers of this circularly polarized organic electroluminescent device are one or more of the following: hole injection layer, hole transport layer, exciton blocking layer, electron transport layer, and electron injection layer. This circularly polarized organic electroluminescent device can be used to prepare near-ultraviolet circularly polarized organic electroluminescent displays or organic electroluminescent lighting sources.

[0016] The principle of this invention is as follows: Fluorene possesses an optical band gap of 3.9 eV, a high luminescence efficiency of 60-80%, and abundant modification sites, making it an excellent candidate group for constructing near-ultraviolet materials. The molecule has large steric hindrance, which helps suppress intermolecular π-π interactions, improving not only the thermal stability of the molecule but also the morphological stability of the film, while maintaining near-ultraviolet emission and high solid-state fluorescence yield. By combining the characteristics of chiral groups and thermal exciton materials, nine pairs of near-ultraviolet emitting enantiomers were successfully designed and synthesized: R / S-OBN-CN-DMF, R / S-OBN-CN-DPF, R / S-OBN-CN-SBF, R / S-(p)-OBN-CNPDMF, R / S-(p)-OBN-CNPDPF, R / S-(p)-OBN-CNPSBF, R / S-(o)-OBN-CNPDMF, R / S-(o)-OBN-CNPDPF, and R / S-(o)-OBN-CNPSBF. They exhibit high fluorescence quantum yield and obvious circularly polarized luminescence properties, with photoluminescence asymmetry factors of +1.36 × 10⁻⁶ in undoped thin films. -3 / -1.29×10 -3 +2.42×10 -3 / -1.65×10 -3 +1.03×10 -3 / -1.47×10 -3 +8.93×10 -4 / -8.22×10 -4 +7.77×10 -4 / -7.87×10 -4 +9.50×10 -4 / -1.09×10 -3 +1.05×10 -3 / -0.92×10-3 +0.99×10 -3 / -1.45×10 -3 and +2.33×10 -3 / -3.01×10 -3 Electroluminescent devices fabricated based on R / S-OBN-CN-DMF, R / S-OBN-CN-DPF, R / S-OBN-CN-SBF, R / S-(p)-OBN-CNPDMF, R / S-(p)-OBN-CNPDPF, R / S-(p)-OBN-CNPSBF, R / S-(o)-OBN-CNPDMF, R / S-(o)-OBN-CNPDPF, and R / S-(o)-OBN-CNPSBF all exhibit near-ultraviolet emission, according to CIE. The coordinates are (0.173,0.047), (0.173,0.047), (0.169,0.036), (0.159,0.039), (0.160,0.038), (0.161,0.031), (0.161,0.037), (0.163,0.053), and (0.161,0.034), with external quantum efficiencies of 3.9%, 3.1%, 4.5%, 7.5%, 6.3%, 5.0%, 10.3%, 9.2%, and 11.6%, respectively. This application provides a new perspective for developing near-ultraviolet thermal exciton materials that simultaneously exhibit circularly polarized luminescence and high efficiency, which is beneficial for the direct realization of 3D and wide color gamut displays in the future. Attached Figure Description

[0017] Figure 1 : A schematic diagram of the structure of the organic electroluminescent device prepared by the present invention. In the figure, 1 is a transparent glass substrate, 2 is an ITO conductive thin film anode, 3 is a hole injection layer, 4 is a hole transport layer, 5 is an exciton blocking layer, 6 is an organic light-emitting layer, 7 is an electron transport layer, and 8 is a cathode.

[0018] Figure 2 The absorption and emission spectra of doped films obtained by doping R-OBN-CN-DMF, R-OBN-CN-DPF, and R-OBN-CN-SBF into the host material CBP at a mass concentration of 5 wt% are shown. The main absorption peaks are located at 299 nm, 296 nm, and 298 nm, respectively; the main emission peaks are located at 382 nm, 383 nm, and 380 nm, respectively, indicating that the material can be used as an organic near-ultraviolet material to prepare electroluminescent devices.

[0019] Figure 3The absorption and emission spectra of doped films obtained by doping R-(p)-OBN-CNPDMF, R-(p)-OBN-CNPDPF, R-(p)-OBN-CNPSBF, R-(o)-OBN-CNPDMF, R-(o)-OBN-CNPDPF and R-(o)-OBN-CNPSBF with a mass concentration of 20 wt% in the host material CBP are shown. The main absorption peaks are located at 333 nm, 333 nm, 332 nm, 332 nm, 333 nm and 332 nm, respectively; the main emission peaks are located at 390 nm, 391 nm, 390 nm, 397 nm, 396 nm and 397 nm, respectively. This indicates that the material can be used as an organic near-ultraviolet material to prepare electroluminescent devices.

[0020] Figure 4 The graph shows the circularly polarized photoluminescence spectra (top) and photoluminescence asymmetry factor curves (bottom) of R / S-OBN-CN-DMF, R / S-OBN-CN-DPF, and R / S-OBN-CN-SBF in the undoped thin film state, which are +1.36 × 10⁻⁶. -3 / -1.29×10 -3 +2.42×10 -3 / -1.65×10 -3 and +1.03×10 -3 / -1.47×10 -3 ;

[0021] Figure 5 The graphs show the circularly polarized photoluminescence spectra (top) and photoluminescence asymmetry factor curves (bottom) of R / S-(p)-OBN-CNPDMF, R / S-(p)-OBN-CNPDPF, R / S-(p)-OBN-CNPSBF, R / S-(o)-OBN-CNPDMF, R / S-(o)-OBN-CNPDPF, and R / S-(o)-OBN-CNPSBF in their undoped thin film states, respectively, with values ​​of +8.93 × 10⁻⁶. -4 / -8.22×10 -4 +7.77×10 -4 / -7.87×10 -4 +9.50×10 -4 / -1.09×10 -3 +1.05×10 -3 / -0.92×10 -3 +0.99×10 -3 / -1.45×10 -3 and +2.33×10 -3 / -3.01×10 -3 ;

[0022] Figure 6 The figures show the external quantum efficiency curves of the doped devices obtained by doping R-OBN-CN-DMF, R-OBN-CN-DPF and R-OBN-CN-SBF prepared in Example 10 into the host material CBP at a mass concentration of 5 wt%. The maximum external quantum efficiencies are 3.9%, 3.1% and 4.5%, respectively. The inset shows the electroluminescence spectra of the doped devices, with the main peak of each spectrum located at 396 nm.

[0023] Figure 7 The external quantum efficiency curves of the doped devices obtained by doping R-(p)-OBN-CNPDMF, R-(p)-OBN-CNPDPF, R-(p)-OBN-CNPSBF, R-(o)-OBN-CNPDMF, R-(o)-OBN-CNPDPF and R-(o)-OBN-CNPSBF with a mass concentration of 20 wt% into the host material CBP are shown. The maximum external quantum efficiencies are 7.5%, 6.3%, 5.0%, 10.3%, 9.2% and 11.6%, respectively.

[0024] Figure 8 The electroluminescence spectra of doped devices obtained by doping R-(p)-OBN-CNPDMF, R-(p)-OBN-CNPDPF, R-(p)-OBN-CNPSBF, R-(o)-OBN-CNPDMF, R-(o)-OBN-CNPDPF and R-(o)-OBN-CNPSBF with a mass concentration of 20 wt% in the host material CBP are shown. The main peaks of the spectra are located at 424 nm, 416 nm, 412 nm, 404 nm, 404 nm and 404 nm, respectively. Detailed Implementation

[0025] Example 1: This example describes the preparation of R / S-OBN-CN-DMF, and the steps are as follows:

[0026] Synthesis of R / S-OBN-CN: 2-Bromo-4,5-difluorobenzonitrile (305.2 mg, 1.4 mmol), R / S-binaphthol (400.4 mg, 1.4 mmol), and K₂CO₃ (483 mg, 3.5 mmol) were mixed, and 20 mL of anhydrous DMF was added. The mixture was heated to 120 °C and stirred for 12 hours. After cooling to room temperature, the reaction mixture was poured into water (100 mL). The reaction mixture was extracted three times with dichloromethane and water. The bound organic layer was condensed under vacuum and purified by column chromatography with a mixture of dichloromethane / petroleum ether (v / v 1:4) to give a white solid (422 mg), with a yield of 65%. Mass spectrometry (MALDI-TOF) (m / z) [M + The measured value is 464.12, and the theoretical value is 464.01.

[0027]

[0028] Synthesis of R / S-OBN-CN-DMF: R / S-OBN-CN (464 mg, 1 mmol), DMFpin (310 mg, 1.3 mmol), K₂CO₃ (1.11 g, 5 mmol), and Pd(PPh₃)₄ (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, followed by 20 mL of toluene and 10 mL of water. The mixture was heated to 90 °C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL). The reaction mixture was extracted three times with dichloromethane and water, and the bound organic layer was condensed under vacuum and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (1:4 v / v) to give a white solid (491 mg) in 88% yield.

[0029] R-OBN-CN-DMF: 1 H NMR (500MHz, CD2Cl2) δ8.24–8.08(m,3H),8.05(d,J=8.1Hz,2H),7.90(d,J=7.7Hz,2H),7.84(s,1H),7.80(s,1H),7.72(s ,1H),7.70–7.50(m,8H),7.46(d,J=7.2Hz,1H),7.44(s,1H),7.42(d,J=3.4Hz,1H),1.59(s,6H).MALDI-TOF(m / z):Calcd for C 42 H 27 NO2, 577.68; Found: 577.13 [M] + ].S-OBN-CN-DMF: 1 H NMR (500MHz, CD2Cl2): δ8.12(d,J=5.4Hz,1H),8.10(d,J=5.4Hz,1H),8.05(d,J=8.3 Hz,2H),7.90(d,J=7.8Hz,1H),7.84(dd,J=5.1,3.4Hz,1H),7.79(s,1H),7.72(s,1H) ,7.61–7.59(m,1H),7.57(dd,J=9.8,2.2Hz,4H),7.53(dt,J=6.8,4.1Hz,3H),7.46(d ,J=7.5Hz,2H),7.45(s,1H),7.42–7.39(m,2H),1.58(s,6H).MALDI-TOF(m / z):Calcd for C 42 H 27NO2, 577.68; Found: 577.25 [M] + ].

[0030]

[0031] Example 2: This example describes the preparation of R / S-OBN-CN-DPF, and the steps are as follows:

[0032] Synthesis of (R / S)-OBN-CN-DPF: R / S-OBN-CN (464 mg, 1 mmol), DPFBin (471 mg, 1.3 mmol), K2CO3 (1.11 g, 5 mmol), and Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, followed by 20 mL of toluene and 10 mL of water. The mixture was heated to 90 °C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL). The reaction mixture was extracted three times with dichloromethane and water, and the combined organic layer was condensed under vacuum and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (1:4 v / v) to give a white solid (625 mg) in 89% yield.

[0033] R-OBN-CN-DPF: 1 H NMR (500MHz, CD2Cl2) δ8.30–8.05(m,4H),8.04(d,J=4.2Hz,1H),7.97(d,J=7.6H z,1H),7.91(d,J=7.4Hz,1H),7.75(s,2H),7.67(s,2H),7.63(d,J=7.7Hz,2H),7. 58(d,J=6.7Hz,2H),7.56–7.50(m,3H),7.49(d,J=6.3Hz,1H),7.49–7.41(m,3H), 7.38(dd,J=15.7,8.0Hz,2H),7.29(d,J=13.2Hz,7H).MALDI-TOF(m / z):Calcdfor C 52 H 31 NO2:701.83; Found:701.24 [M] + ].S-OBN-CN-DPF: 1H NMR(500MHz,DMSO)δ8.23–8.17(m,2H),8.12(d,J=8.1Hz,3H),8.07(s,1H),8.04(d, J=7.5Hz,1H),7.77(d,J=8.8Hz,1H),7.72(d,J=1.9Hz,1H),7.70(d,J=6.6Hz,2H),7 .62–7.56(m,3H),7.51(t,J=6.3Hz,2H),7.49(d,J=5.9Hz,1H),7.46(d,J=7.5Hz,1H ),7.41–7.35(m,3H),7.30–7.20(m,8H),7.20–7.14(m,2H).MALDI-TOF(m / z):Calcd for C 52 H 31 NO2, 701.83; Found: 701.01 [M] + ].

[0034]

[0035] Example 3: This example describes the preparation of R / S-OBN-CN-SBF, and the steps are as follows:

[0036] Synthesis of R / S-OBN-CN-SBF: R / S-OBN-CN (464 mg, 1 mmol), SBFBin (468 mg, 1.3 mmol), K2CO3 (1.11 g, 5 mmol), and Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, followed by 20 mL of toluene and 10 mL of water. The mixture was heated to 90 °C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL). The reaction mixture was extracted three times with dichloromethane and water, and the bound organic layer was condensed under vacuum and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (1:4 v / v) to give a white solid (588 mg) in 84% yield.

[0037] R-OBN-CN-SBF: 1 H NMR (500MHz, CD2Cl2) δ8.06 (d, J=7.9Hz, 5H), 8.04–

[0038] 7.97(m,3H),7.94(d,J=7.3Hz,2H),7.88–7.63(m,3H),7.54(d,J=5.9Hz,3H) ,7.51(d,J=6.7Hz,1H),7.51–7.48(m,1H),7.47(s,1H),7.44(dd,J=13.2,5. 3Hz,3H),7.32(d,J=18.8Hz,1H),7.21(dd,J=12.8,6.6Hz,2H),6.95(d,J=12 .6Hz,1H),6.93–6.81(m,2H),6.78(d,J=7.5Hz,1H).MALDI-TOF(m / z):Calcd for C 52 H 29 NO2, 699.81; Found: 699.22 [M] + ].S-OBN-CN-SBF: 1 H NMR (500MHz, DMSO) δ8.21(d,J=7.9Hz,1H),8.17(d,J=9.0Hz,1H),8.15–8.11(m,2H),8.10(d,J=8.4Hz,2 H),8.02(d,J=7.6Hz,2H),7.95(s,1H),7.71(d,J=9.1Hz,2H),7.64(d,J=8.8Hz,1H),7.57(t,J=7.2Hz,2H ),7.45(t,J=7.1Hz,4H),7.41(t,J=7.5Hz,2H),7.35(t,J=8.4Hz,2H),7.20(d,J=7.4Hz,1H),7.16(dd,J =13.4,5.9Hz,2H),6.88(s,1H),6.68(t,J=7.2Hz,2H),6.63(d,J=7.6Hz,1H).MALDI-TOF(m / z):Calcdfor C 52 H 29 NO2, 699.81; Found: 699.45 [M] + ].

[0039]

[0040] Example 4: This example describes the preparation of R / S-(p)-OBN-CNPDMF, and the steps are as follows:

[0041] Synthesis of PhDMFBr: p-Bromoiodobenzene (1.41 g, 5 mmol), DMFBin (1.55 g, 6.5 mmol), K2CO3 (2.07 g, 15 mmol), and Pd(PPh3)4 (348 mg, 0.3 mmol) were mixed and added to a 100 mL flask, followed by 20 mL of toluene and 10 mL of water. The mixture was heated to 90 °C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL). The reaction mixture was extracted three times with dichloromethane and water, and the bound organic layer was condensed under vacuum and purified by column chromatography with a dichloromethane / petroleum ether (v / v) eluent to give a white solid (1.38 g) in 79% yield.

[0042]

[0043] Synthesis of PhDMFBin: PhDMFBr (1.37 g, 5 mmol), pinacol diborate (1.65 g, 6.5 mmol), potassium acetate (1.47 g, 15 mmol), and (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride (0.12 g, 0.15 mmol), along with 50 mL of dioxane, were added to a 100 mL round-bottom flask. The mixture was stirred and refluxed at 85 °C for 72 hours under nitrogen atmosphere. After the reaction was complete, the volume was increased by V... 水 :V 二氯甲烷 =1:1 extraction three times, the organic phase was collected and concentrated, and then purified by column chromatography to obtain a white powder with a yield of 77%. Mass spectrometry MALDI-TOF (m / z) [M + The measured value is 396.11, and the theoretical value is 396.34.

[0044]

[0045] Synthesis of R / S-(p)-OBN-CNPDMF: R / S-OBN-CN (464 mg, 1 mmol), PhDMFBin (515 mg, 1.3 mmol), K2CO3 (1.11 g, 5 mmol), and Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, followed by 20 mL of toluene and 10 mL of water. The mixture was heated to 90 °C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL). The reaction mixture was extracted three times with dichloromethane and water, and the bound organic layer was condensed under vacuum and purified by column chromatography with a mixture of dichloromethane / petroleum ether (v / v 1:4) to give a white solid (445 mg) in 68% yield.

[0046] R-(p)-OBN-CNPDMF: 1H NMR (500MHz, CD2Cl2) δ8.19–8.08(m,3H),8.05(d,J=8.1Hz,2H),8.02–7.85(m,4H),7.82(d,J=12.7Hz,2H),7.78–7.69(m,3 H),7.56(dt,J=14.2,7.9Hz,8H),7.50–7.43(m,2H),7.41(dd,J=12.9,6.8Hz,1H),1.59(s,6H).MALDI-TOF(m / z):Calculate C 48 H 31 NO2: 653.78; Found: 653.28 [M] + ].S-(p)-OBN-CNPDMF: 1 H NMR (500MHz, CD2Cl2) δ8.12(d,J=5.3Hz,1H),8.10(d,J=5.3Hz,1H),8.06(s,1H),8.04(s,1H),7.88(dd, J=8.0,3.8Hz,3H),7.83(d,J=1.5Hz,1H),7.81(d,J=3.8Hz,2H),7.73(d,J=8.3Hz,3H),7.71(d,J=1.6Hz, 1H),7.60(s,1H),7.58(d,J=5.3Hz,2H),7.56(d,J=4.5Hz,3H),7.54(d,J=4.1Hz,1H),7.52(d,J=1.6Hz, 1H),7.45(dd,J=15.4,7.7Hz,2H),7.39(dd,J=7.0,5.9Hz,1H),1.59(s,6H).MALDI-TOF(m / z):Calculate C 48 H 31 NO2: 653.78; Found: 653.61 [M] + ].

[0047]

[0048] Example 5: This example describes the preparation of R / S-(p)-OBN-CNPDPF, and the steps are as follows:

[0049] Synthesis of PhDPFBr: p-bromoiodobenzene (1.41 g, 5 mmol), DPFBin (2.35 g, 6.5 mmol), K2CO3 (2.07 g, 15 mmol), and Pd(PPh3)4 (348 mg, 0.3 mmol) were mixed and added to a 100 mL flask, followed by 20 mL of toluene and 10 mL of water. The mixture was heated to 90 °C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL). The reaction mixture was extracted three times with dichloromethane and water, and the combined organic layer was condensed under vacuum and purified by column chromatography with a dichloromethane / petroleum ether (v / v) eluent to give a white solid (1.92 g) in 81% yield.

[0050]

[0051] Synthesis of PhDPFBin: PhDPFBr (2.37 g, 5 mmol), pinacol diborate (1.65 g, 6.5 mmol), potassium acetate (1.47 g, 15 mmol), and (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride (0.12 g, 0.15 mmol), along with 50 mL of dioxane, were added to a 100 mL round-bottom flask. The mixture was stirred and refluxed at 85 °C for 72 hours under nitrogen atmosphere. After the reaction was complete, the volume was increased by V... 水 :V 二氯甲烷 =1:1 extraction three times, the organic phase was collected and concentrated, and then purified by column chromatography to obtain a white powder with a yield of 74%. Mass spectrometry MALDI-TOF (m / z) [M + The measured value is 520.01, and the theoretical value is 520.48.

[0052]

[0053] Synthesis of R / S-(p)-OBN-CNPDPF: R / S-OBN-CN (464 mg, 1 mmol), PhDPFBin (677 mg, 1.3 mmol), K2CO3 (1.11 g, 5 mmol), and Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, followed by 20 mL of toluene and 10 mL of water. The mixture was heated to 90 °C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL). The reaction mixture was extracted three times with dichloromethane and water, and the bound organic layer was condensed under vacuum and purified by column chromatography with a mixture of dichloromethane / petroleum ether (v / v 1:4) to give a white solid (490 mg) in 63% yield. R-(p)-OBN-CNPDPF: 1H NMR(500MHz,CD2Cl2)δ8.11(d,J=7.0Hz,3H),8.05(s,2H),7.95(s,1H),7.90(s,1H),7.76(s,5H), 7.68(s,2H),7.64–7.51(m,7H),7.47(s,4H),7.30(d,J=3.9Hz,10H).MALDI-TOF(m / z):Calculate C 58 H 35 NO2: 777.92; Found: 777.28 [M] + ].S-(p)-OBN-CNPDPF: 1 H NMR (500MHz, DMSO) δ8.24(d,J=3.0Hz,1H),8.22(d,J=3.0Hz,1H),8.14(d,J=8.2Hz,2H),8.11(s,1H),8.08(d ,J=8.0Hz,1H),8.01(d,J=7.5Hz,1H),7.86–7.82(m,2H),7.81(d,J=3.6Hz,2H),7.74(dd,J=8.7,4.3Hz,4H),7 .68(s,1H),7.60(t,J=7.5Hz,2H),7.51(d,J=7.5Hz,1H),7.48(d,J=9.2Hz,2H),7.45(d,J=7.4Hz,1H),7.41– 7.35(m,3H),7.30(t,J=7.6Hz,4H),7.25(d,J=6.5Hz,2H),7.22(d,J=8.1Hz,4H).MALDI-TOF(m / z):Calculate C 58 H 35 NO2: 777.92; Found: 777.41 [M] + ].

[0054]

[0055] Example 6: This example describes the preparation of R / S-(p)-OBN-CNPSBF, and the steps are as follows:

[0056] Synthesis of PhSBFBr: p-Bromoiodobenzene (1.41 g, 5 mmol), SFBpin (2.34 g, 6.5 mmol), K₂CO₃ (2.07 g, 15 mmol), and Pd(PPh₃)₄ (348 mg, 0.3 mmol) were mixed and added to a 100 mL flask. Then, 20 mL of toluene and 10 mL of water were added, and the mixture was heated to 90 °C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL). The reaction mixture was extracted three times with dichloromethane and water, and the combined organic layer was condensed under vacuum and purified by column chromatography with a dichloromethane / petroleum ether (v / v) eluent to give a white solid (2.03 g) in 86% yield.

[0057]

[0058] Synthesis of PhSBFBin: PhSBFBr (2.36 g, 5 mmol), pinacol diborate (1.65 g, 6.5 mmol), potassium acetate (1.47 g, 15 mmol), and (1,1'-bis(diphenylphosphine)ferrocene)palladium dichloride (0.12 g, 0.15 mmol), along with 50 mL of dioxane, were added to a 100 mL round-bottom flask. The mixture was stirred and refluxed at 85 °C for 72 hours under nitrogen atmosphere. After the reaction was complete, the volume was increased by V... 水 :V 二氯甲烷 =1:1 extraction three times, the organic phase was collected and concentrated, and then purified by column chromatography to obtain a white powder with a yield of 72%. Mass spectrometry MALDI-TOF (m / z) [M + The measured value is 518.04, and the theoretical value is 518.46.

[0059]

[0060] Synthesis of R / S-(p)-OBN-CNPSBF: R / S-OBN-CN (464 mg, 1 mmol), PhSBFBin (674 mg, 1.3 mmol), K2CO3 (1.11 g, 5 mmol), and Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, followed by 20 mL of toluene and 0 mL of water. The mixture was heated to 90 °C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL). The reaction mixture was extracted three times with dichloromethane and water, and the bound organic layer was condensed under vacuum and purified by column chromatography with a mixture of dichloromethane / petroleum ether (v / v 1:4) to give a white solid (535 mg) in 69% yield. R-(p)-OBN-CNPSBF: 1H NMR(500MHz,CD2Cl2)δ8.26–8.07(m,3H),8.06(s,1H),8.05–7.99(m,2H),8.00–7.90(m,3H),7.76(dd,J=12.0,5.6Hz,3H),7.73–7.49 (m,10H),7.45(dd,J=7.4,3.0Hz,4H),7.31–7.14(m,3H),7.04(s,1H),6.79(d,J=7.5Hz,2H),6.76(s,1H).MALDI-TOF(m / z):Calculate C 58 H 33 NO2: 775.91; Found: 775.25 [M] + ].S-(p)-OBN-CNPSBF: 1 HNMR (500MHz, DMSO) δ8.23–8.20(m,1H),8.19–8.16(m,1H),8.12(d,J=8.2Hz,2H),8.10(d,J=7.8 Hz,1H),8.07(d,J=5.2Hz,2H),8.05(s,1H),7.85(d,J=8.0Hz,1H),7.71(d,J=8.8Hz,2H),7.64–7. 57(m,7H),7.58(s,1H),7.51–7.46(m,2H),7.43(t,J=7.2Hz,3H),7.39–7.34(m,2H),7.16(t,J=6 .0Hz,3H),6.91(s,1H),6.70(d,J=7.6Hz,2H),6.64(d,J=7.5Hz,1H).MALDI-TOF(m / z):Calculate C 58 H 33 NO2: 775.91; Found: 775.66 [M] + ].

[0061]

[0062] Example 7: This example describes the preparation of R / S-(o)-OBN-CNPDMF, and the steps are as follows:

[0063] Synthesis of intermediate 2FBrCN: 6-bromo-2,3-difluorobenzaldehyde (4.42 g, 20 mmol), hydroxylamine hydrochloride (1.67 g, 24 mmol), and potassium acetate (5.89 g, 60 mmol) were mixed and added to a 100 mL flask. The mixture was stirred at 120 °C for 12 hours, followed by the addition of a dehydrating agent. The mixture was cooled to room temperature and reacted for another 72 hours. Three extractions were performed, and the combined organic layers were concentrated. Purification yielded a white solid product (190 mg), with a yield of 87%. 1 H NMR(500MHz, DMSO)δ7.91–7.83(m,1H),7.79(ddd,J=9.1,4.2,1.6Hz,1H).MALDI-TOF(m / z):CalculateC7H2BrF2N:218.00; Found:217.93[M + ].

[0064]

[0065] Synthesis of intermediate R / S-(o)-OBN-CN: Naphthol (2.87 g, 10 mmol), 2FBrCN (2.18 g, 10 mmol), and potassium carbonate (2.76 g, 20 mmol) were mixed and added to a 100 mL flask. Then, 60 mL of dimethylformamide was added, and the mixture was heated to 120 °C and stirred for 24 hours. The mixture was then cooled to room temperature and extracted three times, with the organic layers combined. Purification was then performed to give a white solid product (297 mg), with a yield of 64%. R-(o)-OBN-CN: 1 H NMR (500MHz, DMSO) δ8.26(d,J=8.9Hz,1H),8.23(d,J=8.9Hz,1H),8.15(t,J=9.1Hz,2H),7.76(d,J=8.8Hz,1H),7.72(d,J=8.8Hz,1 H),7.63(dt,J=16.0,7.8Hz,4H),7.51(t,J=7.6Hz,2H),7.40(d,J=3.2Hz,1H),7.38(d,J=3.2Hz,1H).MALDI-TOF(m / z):Calculate C 27 H 14 BrNO2: 464.32; Found: 464.11 [M] + ].S-(o)-OBN-CN: 1H NMR (500MHz, CD2Cl2) δ8.12(d,J=8.9Hz,1H),8.09(d,J=8.9Hz,1H),8.04(t,J=8.1Hz,2H),7.62(d,J=8.9Hz,1H),7.58(d d,J=11.6,7.5Hz,2H),7.53(dd,J=8.4,4.5Hz,2H),7.50–7.46(m,4H),7.44(d,J=7.6Hz,1H).MALDI-TOF(m / z):Calculate C 27 H 14 BrNO2: 464.32; Found: 464.21 [M] + ].

[0066]

[0067] Synthesis of R / S-(o)-OBN-CNPDMF: R / S-(o)-OBN-CN (464 mg, 1 mmol), PhDMFBin (515 mg, 1.3 mmol), K2CO3 (1.11 g, 5 mmol), and Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, followed by 20 mL of toluene and 10 mL of water. The mixture was heated to 90 °C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL). The reaction mixture was extracted three times with dichloromethane and water, and the bound organic layer was condensed under vacuum and purified by column chromatography with a mixture of dichloromethane / petroleum ether (v / v 1:4) to give a white solid (425 mg) in 65% yield. R-(o)-OBN-CNPDMF: 1 H NMR(500MHz,CD2Cl2)δ8.13(dd,J=9.9,7.1Hz,3H),8.06(d,J=4.2Hz,2H),8.0 2–7.85(m,4H),7.80(d,J=15.8Hz,2H),7.79–7.69(m,4H),7.67(dd,J=8.2,3. 1Hz,1H),7.55(dd,J=28.8,9.4Hz,5H),7.47(d,J=6.1Hz,2H),7.41(d,J=4.2Hz,1H),7.38–7.18(m,1H),1.60(d,J=2.7Hz,6H).MALDI-TOF(m / z):Calculate C 48 H 31 NO2: 653.78; Found: 653.12 [M] + ].S-(o)-OBN-CNPDMF: 1H NMR (500MHz, CD2Cl2) δ8.12(t,J=8.7Hz,2H),8.06(d,J=5.0Hz,1H),8.05(d,J=5.0Hz,1H),7.87(dd,J=8.0,6.3Hz,3H ),7.84–7.82(m,1H),7.82–7.80(m,1H),7.73(s,1H),7.72(td,J=3.3,1.6Hz,2H),7.70–7.64(m,2H),7.60(dd,J=2.8, 1.7Hz,1H),7.59(dd,J=5.4,4.2Hz,2H),7.55(t,J=7.1Hz,2H),7.54–7.50(m,1H),7.49–7.44(m,2H),7.42(dt,J=4.2 ,2.1Hz,1H),7.39(dd,J=6.4,1.2Hz,1H),7.37(d,J=8.4Hz,1H),1.58(d,J=12.2Hz,6H).MALDI-TOF(m / z):CalculateC 48 H 31 NO2: 653.78; Found: 653.24 [M] + ].

[0068]

[0069] Example 8: This example describes the preparation of R / S-(o)-OBN-CNPDPF, and the steps are as follows:

[0070] R / S-(o)-OBN-CN (464 mg, 1 mmol), PhDPFBin (677 mg, 1.3 mmol), K₂CO₃ (1.11 g, 5 mmol), and Pd(PPh₃)₄ (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, followed by 20 mL of toluene and 10 mL of water. The mixture was heated to 90 °C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL). The reaction mixture was extracted three times with dichloromethane and water, and the bound organic layer was condensed under vacuum and purified by column chromatography with a mixture of dichloromethane / petroleum ether (v / v 1:4) to give a white solid (467 mg) in 60% yield. R-(o)-OBN-CNPDPF: 1H NMR (500MHz, CD2Cl2) δ8.28–8.09(m,3H),8.06(s,2H),7.95(d,J=7.2Hz,1H),7.90(s,1H),7.77(s,4H),7. 73–7.62(m,4H),7.56(d,J=19.8Hz,5H),7.48(d,J=4.4Hz,4H),7.31(s,11H).MALDI-TOF(m / z):Calculate C 58 H 35 NO2: 777.92; Found: 777.27 [M] + ].S-(o)-OBN-CNPDPF: 1 HNMR(500MHz,DMSO)δ8.29–8.23(m,4H),8.16(s,4H),8.10–8.06(m,2H),8.03–8.00(m,2H),7.85(s,2H),7.81(s,3H),7.73(s,1H),7. 70(s,2H),7.66(s,2H),7.48(d,J=8.4Hz,3H),7.30(d,J=7.6Hz,4H),7.25(s,2H),7.22(d,J=7.9Hz,4H).MALDI-TOF(m / z):CalculateC 58 H 35 NO2: 777.92; Found: 777.48 [M] + ].

[0071]

[0072] Example 9: This example describes the preparation of R / S-(o)-OBN-CNPSBF, and the steps are as follows:

[0073] Synthesis of R / S-(o)-OBN-CNPSBF: R / S-(o)-OBN-CN (464 mg, 1 mmol), PhSBFBin (674 mg, 1.3 mmol), K2CO3 (1.11 g, 5 mmol), and Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, followed by 20 mL of toluene and 10 mL of water. The mixture was heated to 90 °C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL). The reaction mixture was extracted three times with dichloromethane and water, and the bound organic layer was condensed under vacuum and purified by column chromatography with a mixture of dichloromethane / petroleum ether (v / v 1:4) to give a white solid (512 mg) in 66% yield. R-(o)-OBN-CNPSBF: 1H NMR(500MHz,CD2Cl2)δ8.12–8.07(m,2H),8.05–8.01(m,3H),7.95(dd,J=12.1,7.7Hz,3H),7.77(d,J=8.0Hz,1H),7.65(d,J=8.9Hz,1H),7.60(d,J=8.3Hz,4H),7.58–7.54(m,5H),7.52(d,J=9.4Hz,1H),7.44(dd,J=13.3,6.3Hz,5H),7.25(d,J=8.5Hz,1H),7.18(t,J=7.5Hz,3H),7.05(s,1H),6.80(d,J=7.6Hz,2H),6.75(d,J=7.6Hz,1H). 1 H NMR MALDI-TOF(m / z):Calculate C 58 H 33 NO2:775.91;Found:775.23[M + ].S-(o)-OBN-CNPSBF: 1 H NMR(500MHz,DMSO)δ8.25(d,J=8.9Hz,1H),8.22(d,J=8.9Hz,1H),8.18(d,J=8.0Hz,1H),8.15(d,J=6.5Hz,1H),8.13(s,1H),8.09(d,J=7.7Hz,1H),8.05(d,J=7.6Hz,2H),7.85(d,J=8.0Hz,1H),7.82(d,J=8.5Hz,1H),7.66(d,J=8.9Hz,1H),7.65–7.58(m,7H),7.51(t,J=6.8Hz,2H),7.45(d,J=6.9Hz,1H),7.42(d,J=8.1Hz,3H),7.39(d,J=8.2Hz,2H),7.20–7.13(m,3H),6.91(d,J=1.3Hz,1H),6.70(d,J=7.6Hz,2H),6.64(d,J=7.5Hz,1H).MALDI-TOF(m / z):Calculate C 58 H 33 NO2:775.91;Found:775.25[M + ].

[0074]

[0075] Example 10: A circularly polarized organic electroluminescent device, using organic near-ultraviolet small molecules with molecular structures of R-OBN-CN-DMF, R-OBN-CN-DPF and R-OBN-CN-SBF as the light-emitting layer material (emitters). The structure of the organic electroluminescent device is as follows: ITO / HATCN (6nm) / TAPC (25nm) / TCTA / 5wt%emitters: CBP (20nm) / TmPyPB (40nm) / LiF (1nm) / Al (100nm).

[0076] The device fabrication process is as follows: Preparation of the indium tin oxide (ITO) conductive glass substrate: The substrate is sequentially cleaned with deionized water, isopropanol, acetone, toluene, and acetone in an ultrasonic bath for 20 minutes each, and then dried in an oven for later use. After surface treatment of the ITO conductive glass in an ultraviolet ozone cleaner for 40 minutes, it is transferred to a vacuum evaporation equipment (cavity pressure < 2 × 10⁻⁶). -4 On the anode ITO conductive glass, a hole injection layer HATCN with a thickness of 5 nm was vacuum-deposited; on the HATCN, a hole transport layer TAPC with a thickness of 25 nm was vacuum-deposited; on the TAPC, an exciton blocking layer TCTA with a thickness of 15 nm was deposited; on the TCTA, a light-emitting layer CBP:(R-OBN-CN-DMF, R-OBN-CN-DPF, or R-OBN-CN-SBF) (mass doping concentration of 5 wt%) with a thickness of 20 nm was deposited; on the light-emitting layer, an electron transport layer TmPyPB with a thickness of 40 nm was deposited; on the TmPyPB, an electron transport layer LiF with a thickness of 1 nm was deposited; on the LiF, a cathode Al with a thickness of 100 nm was deposited. The external quantum efficiency curve of the fabricated circularly polarized organic electroluminescent device is shown in Figure 1. Figure 6 As shown. Detailed electroluminescence performance data of the device are listed in Table 1.

[0077] Table 1: Electroluminescence performance data of devices R-OBN-CN-DMF, R-OBN-CN-DPF and R-OBN-CN-SBF

[0078]

[0079] Example 11: A circularly polarized organic electroluminescent device, using organic near-ultraviolet small molecules with molecular structures of R-(p)-OBN-CNPDMF, R-(p)-OBN-CNPDPF, R-(p)-OBN-CNPSBF, R-(o)-OBN-CNPDMF, R-(o)-OBN-CNPDPF, and R-(o)-OBN-CNPSBF as the emitting layer material. The structure of the organic electroluminescent device is as follows: ITO / HATCN (6nm) / TAPC (25nm) / TCTA (15nm) / x wt% emitters in CBP:PIBzPCN (20nm) / TmPyPB (40nm) / LiF (1nm) / Al (120nm) (mass doping concentration ratio x = 5, 10, and 20%). The fabrication process of the device is similar to that of Example 10. The external quantum efficiency curve of the fabricated circularly polarized organic electroluminescent device is shown below. Figure 7 As shown in the figure. Detailed electroluminescence performance data of the device are listed in Table 2.

[0080] Table 2: Electroluminescence performance data of devices R-(p)-OBN-CNPDMF, R-(p)-OBN-CNPDPF, R-(p)-OBN-CNPSBF, R-(o)-OBN-CNPDMF, R-(o)-OBN-CNPDPF and R-(o)-OBN-CNPSBF with a mass doping ratio of 5wt%.

[0081]

[0082]

[0083] Table 3: Electroluminescence performance data of devices R-(p)-OBN-CNPDMF, R-(p)-OBN-CNPDPF, R-(p)-OBN-CNPSBF, R-(o)-OBN-CNPDMF, R-(o)-OBN-CNPDPF and R-(o)-OBN-CNPSBF with a mass doping ratio of 10 wt%.

[0084]

[0085]

[0086] Table 4: Electroluminescence performance data of devices R-(p)-OBN-CNPDMF, R-(p)-OBN-CNPDPF, R-(p)-OBN-CNPSBF, R-(o)-OBN-CNPDMF, R-(o)-OBN-CNPDPF and R-(o)-OBN-CNPSBF with a mass doping ratio of 20 wt%.

[0087]

[0088] The structural formulas of the materials used in the organic electroluminescent devices of Examples 10-11 are as follows, and all are commercially available:

[0089]

[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A highly efficient near-ultraviolet thermal exciton compound with circular polarization properties, the structural formula of which is shown in (1): X is a cyano group; L m for Where * indicates the connection position with R and the benzene ring; m is 0 or 1; R is Where * indicates that it is related to L m Or the connection position of the benzene ring.

2. A high-efficiency near-ultraviolet thermal exciton compound with circularly polarized properties as described in claim 1, wherein the structural formula is shown in one of the following:

3. The application of a high-efficiency near-ultraviolet thermal exciton compound with circularly polarized properties as described in claim 1 or 2 in the preparation of circularly polarized organic electroluminescent devices, characterized in that: This near-ultraviolet thermal exciton compound is used as a dopant to prepare the light-emitting layer of a circularly polarized organic electroluminescent device. The host material is CBP, and the mass doping concentration of the near-ultraviolet thermal exciton compound is 5–20 wt%.

4. The application of a high-efficiency near-ultraviolet thermal exciton compound with circularly polarized properties as described in claim 3 in the preparation of circularly polarized organic electroluminescent devices, characterized in that: The organic functional layers of this circularly polarized organic electroluminescent device, excluding the light-emitting layer, are one or more of the following: hole injection layer, hole transport layer, exciton blocking layer, electron transport layer, and electron injection layer.

5. The application of a high-efficiency near-ultraviolet thermal exciton compound with circularly polarized properties as described in claim 4 in the fabrication of circularly polarized organic electroluminescent devices, characterized in that: This circularly polarized organic electroluminescent device is used to fabricate near-ultraviolet circularly polarized organic electroluminescent displays or organic electroluminescent lighting sources.

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