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

Abstract

The invention relates to a high-efficiency near-ultraviolet heat exciton compound with circular polarization property and application of the high-efficiency near-ultraviolet heat exciton compound in preparation of a circular polarization organic electroluminescent device, and belongs to the technical field of organic photoelectric materials. The organic electroluminescent material is a high-efficiency near-ultraviolet heat exciton compound with circular polarization property, nine pairs of near-ultraviolet enantiomers are successfully designed and synthesized by combining chiral group binaphthol with fluorene with high luminous efficiency, and the nine pairs of near-ultraviolet enantiomers all show obvious circular polarization luminous property and high fluorescence quantum yield. The electroluminescent devices prepared based on the nine pairs of near ultraviolet enantiomers all show near ultraviolet emission, and the external quantum efficiency is 3.9%, 3.1%, 4.5%, 7.5%, 6.3%, 5.0%, 10.3%, 9.2% and 11.6% respectively. A new visual angle is provided for developing a near ultraviolet heat exciton material with circular polarization luminescence and high efficiency at the same time, and 3D and wide color gamut display can be directly achieved in the future.

Description

Technical Field

[0001] The invention belongs to the technical field of organic photoelectric materials, and in particular relates to a high-efficiency near-ultraviolet thermoexciton compound with circular polarization properties and an application of the compound in preparing a circular polarization organic electroluminescent device. Background Art

[0002] Organic light-emitting diodes (OLEDs) have been widely used in wearable devices such as smartphones, car displays and smart watches due to their advantages such as health and environmental protection, surface light source characteristics, no flicker and low energy consumption, and have gradually been commercialized. In order to improve the visibility of the screen, it is usually necessary to introduce a polarizer into the device, but the introduction of this structure will cause 50% light loss. Circularly polarized organic light-emitting diodes (CP-OLEDs) can achieve the output of circularly polarized light without the need for additional optical elements, which not only simplifies the device structure but also reduces the manufacturing cost. This technology shows unique application potential in 3D display, anti-counterfeiting security applications and biomedicine. The breakthrough of CP-OLEDs technology will further promote the upgrading of the traditional information industry and has broad application prospects.

[0003] Materials are the material basis for the development of high-tech and modern civilization. Together with energy and information, they are considered to be the three pillar industries of the 21st century. In the past few decades, CP-OLEDs materials have made significant progress in both the visible light region and the long-wavelength infrared light region, and the device performance has reached a relatively ideal state. However, the research on short-wavelength near-ultraviolet emitting materials is almost blank. However, near-ultraviolet materials play an irreplaceable role in the industrial and medical fields, such as ultraviolet disinfection, photocuring manufacturing and special lighting. Therefore, in order to broaden the color gamut and further promote the technological innovation of near-ultraviolet light sources, it is of great significance to develop high-efficiency near-ultraviolet emitting CP-OLEDs materials while reducing development costs.

[0004] The excitons in the electroluminescence process 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 rate is only 25%, so the development of pure organic electroluminescent materials that can utilize triplet excitons through reverse intersystem crossing (RISC) has become an important topic in recent years. To date, the mechanisms for harvesting triplet excitons in organic fluorescent devices are mainly: triplet-triplet annihilation (TTA), thermally activated delayed fluorescence (TADF) and hot exciton mechanism. The upper limit of exciton utilization of TTA materials is only 62.5%, which is still obviously insufficient in improving device efficiency. Although TADF materials can theoretically achieve 100% exciton utilization, their strong charge transfer (CT) state characteristics between donors and acceptors are not conducive to deep blue light emission (CIE y<0.08). In addition, the radiative transition rate of TADF materials is slow, which usually leads to severe

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

[0006] Thermionic materials are generated by high-energy triplet states (T m ,m≥2) to the singlet state (S n ,n≥1) utilizes triplet excitons, and the radiative transition of the S1 state is not affected, thus achieving the separation of exciton conversion and radiative transition. Therefore, the S1 state properties of the hot exciton material will not have a significant impact on the hRISC process, avoiding the problem that the S1 of the TADF material must be in a strong CT state. This advantage is conducive to the construction of high color purity near-ultraviolet materials. In addition, the lifetime of high-energy excited state excitons is short, and the hRISC process rate is fast enough to effectively alleviate the exciton annihilation caused by the accumulation of triplet excitons under high current density, which is conducive to obtaining high-efficiency, low roll-off near-ultraviolet CP-OLEDs materials. This patent proposes to develop new circularly polarized luminescent hot exciton near-ultraviolet materials and devices by combining molecular design with chemical synthesis, taking into account the dual advantages of circularly polarized luminescence and high luminescence efficiency, which is conducive to the direct realization of wide color gamut display in the future. Summary of the invention

[0007] To this end, the purpose of the present invention is to provide a high-efficiency near-ultraviolet thermoexciton compound with circular polarization properties and its application in the preparation of circularly polarized organic electroluminescent devices. The near-ultraviolet thermoexciton compound can be used as a light-emitting layer to prepare high-efficiency, high-brightness, low-roll-off near-ultraviolet circularly polarized OLEDs devices, which has the potential for practical application.

[0008] A high-efficiency near-ultraviolet thermoexciton compound with circular polarization properties, the structural formula of which is shown in (1):

[0009]

[0010] X is cyano (CN);

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

[0012] R is * indicates the same as L m Or the attachment position of the benzene ring.

[0013] Furthermore, the near-ultraviolet thermoexciton material with circular polarization properties described in the present invention has a structural formula as shown in one of the following:

[0014]

[0015] The near-ultraviolet thermoexciton compound with circular polarization property provided by the present invention is a chiral group binaphthol as a modification group, and a chiral induction strategy is used to make the luminescent molecule have circular polarization property. The near-ultraviolet thermoexciton compound integrates high luminous efficiency, high exciton utilization rate and excellent electroluminescent performance, and can be used as a doping material for preparing the light-emitting layer of a circularly polarized organic electroluminescent device. The main material is CBP, and the mass doping concentration of the near-ultraviolet thermoexciton compound is 5-20wt%. The circularly polarized organic electroluminescent device, except the light-emitting layer, has an organic functional layer of one or more of a hole injection layer, a hole transport layer, an exciton blocking layer, an electron transport layer, and an electron injection layer. The circularly polarized organic electroluminescent device can be used to prepare a near-ultraviolet circularly polarized organic electroluminescent display or an organic electroluminescent lighting source.

[0016] The principle of the present invention is that fluorene has an optical band gap of 3.9eV, a high luminous efficiency of 60-80% and abundant modification sites, and is an excellent candidate group for constructing near-ultraviolet materials. The molecule has a large steric hindrance, which helps to inhibit the π-π interaction between molecules, can not only improve the thermal stability of the molecule, but also enhance 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 are successfully designed and synthesized, namely 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 have high fluorescence quantum yield and obvious circularly polarized luminescence properties. The photoluminescence asymmetry factors in the undoped films are +1.36×10 -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 The electroluminescent devices prepared 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 have near-ultraviolet emission, 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), and the external quantum efficiency is 3.9%, 3.1%, 4.5%, 7.5%, 6.3%, 5.0%, 10.3%, 9.2% and 11.6%. This application provides a new perspective for the development of near-ultraviolet hot exciton materials with both circularly polarized luminescence and high efficiency, which is conducive to the direct realization of 3D and wide color gamut display in the future. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 : A schematic diagram of the structure of the organic electroluminescent device prepared by the present invention, in which 1 is a transparent glass substrate, 2 is an ITO conductive 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 the doped thin films obtained by doping R-OBN-CN-DMF, R-OBN-CN-DPF and R-OBN-CN-SBF in the main material CBP at a mass concentration of 5wt%, the main absorption peaks are located at 299nm, 296nm and 298nm respectively; the main emission peaks are located at 382nm, 383nm and 380nm, indicating that the materials can be used as organic near-ultraviolet materials to prepare electroluminescent devices;

[0019] Figure 3The invention discloses 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 in a main material CBP at a mass concentration of 20 wt %, wherein the main absorption peaks are located at 333 nm, 333 nm, 332 nm, 332 nm, 333 nm and 332 nm, respectively; and the main emission peaks are located at 390 nm, 391 nm, 390 nm, 397 nm, 396 nm and 397 nm, respectively, indicating that the materials can be used as organic near-ultraviolet materials to prepare electroluminescent devices;

[0020] Figure 4 The circularly polarized photoluminescence spectra (upper figure) and photoluminescence asymmetry factor curves (lower figure) of R / S-OBN-CN-DMF, R / S-OBN-CN-DPF and R / S-OBN-CN-SBF in the undoped thin film state are +1.36×10 -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 circularly polarized photoluminescence spectra (upper figure) and photoluminescence asymmetry factor curves (lower figure) 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 the undoped film state are +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 ;

[0022] Figure 6 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 in a 5wt% mass concentration in the main material CBP, the maximum external quantum efficiencies of which are 3.9%, 3.1% and 4.5%, respectively; the inset is the electroluminescence spectrum of the doped device, the main peaks of which are all at 396nm;

[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 prepared in Example 11 in a concentration of 20 wt% in the host material CBP, the maximum external quantum efficiencies of which are 7.5%, 6.3%, 5.0%, 10.3%, 9.2% and 11.6%, respectively;

[0024] Figure 8 It is the electroluminescence spectrum of the doped device 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 into the main material CBP at a mass concentration of 20wt%, and the main peaks of the spectrum are at 424nm, 416nm, 412nm, 404nm, 404nm and 404nm, respectively. DETAILED DESCRIPTION

[0025] Example 1: This example is 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, heated to 120 ° C and stirred for 12 hours. After cooling to room temperature, the reaction mixture was poured into water (100 mL), and the reaction mixture was extracted three times with dichloromethane and water. The combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:4) to obtain a white solid (422 mg) with a yield of 65%. Mass spectrum 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), DMF Bin (310 mg, 1.3 mmol), K2CO3 (1.11 g, 5 mmol), Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, and then 20 mL toluene and 10 mL water were added, heated to 90 ° C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL), extracted with dichloromethane and water three times, and the combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:4) to obtain a white solid (491 mg) with a yield of 88%.

[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 is 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), Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, and then 20 mL toluene and 10 mL water were added, heated to 90 ° C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL), extracted with dichloromethane and water three times, and the combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:4) to obtain a white solid (625 mg) with a yield of 89%.

[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 is 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), Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, and then 20 mL toluene and 10 mL water were added, heated to 90 ° C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL), extracted with dichloromethane and water three times, and the combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:4) to obtain a white solid (588 mg) with a yield of 84%.

[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 is 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), Pd(PPh3)4 (348 mg, 0.3 mmol) were mixed and added to a 100 mL flask, and then 20 mL toluene and 10 mL water were added, heated to 90 ° C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL), extracted with dichloromethane and water three times, and the combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:3) to obtain a white solid (1.38 g) with a yield of 79%.

[0042]

[0043] Synthesis of PhDMFBin: PhDMFBr (1.37 g, 5 mmol), diboronic acid pinacol ester (1.65 g, 6.5 mmol), potassium acetate (1.47 g, 15 mmol), (1,1'-bis(diphenylphosphino)ferrocene) palladium dichloride (0.12 g, 0.15 mmol), and 50 mL of dioxane were added to a 100 mL round-bottom flask. Stir and reflux at 85 °C for 72 hours under nitrogen. After the reaction, 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 spectrum 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), Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, and then 20 mL toluene and 10 mL water were added, heated to 90 ° C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL), extracted with dichloromethane and water three times, and the combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:4) to obtain a white solid (445 mg) with a yield of 68%.

[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 is 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), Pd(PPh3)4 (348 mg, 0.3 mmol) were mixed and added to a 100 mL flask, and then 20 mL toluene and 10 mL water were added, heated to 90 ° C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL), extracted with dichloromethane and water three times, and the combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:3) to obtain a white solid (1.92 g) with a yield of 81%.

[0050]

[0051] Synthesis of PhDPFBin: PhDPFBr (2.37 g, 5 mmol), pinacol diboron (1.65 g, 6.5 mmol), potassium acetate (1.47 g, 15 mmol), (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride (0.12 g, 0.15 mmol), and 50 mL of dioxane were added to a 100 mL round-bottom flask. Stir and reflux at 85 °C for 72 hours under nitrogen. After the reaction, use 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 spectrum 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), Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, and then 20 mL toluene and 10 mL water were added, heated to 90 ° C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL), and the reaction mixture was extracted three times with dichloromethane and water, and the combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:4) to obtain a white solid (490 mg) with a yield of 63%. 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 is 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), SBFBin (2.34 g, 6.5 mmol), K2CO3 (2.07 g, 15 mmol), Pd(PPh3)4 (348 mg, 0.3 mmol) were mixed and added to a 100 mL flask, and then 20 mL toluene and 10 mL water were added, heated to 90 ° C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL), extracted with dichloromethane and water three times, and the combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:3) to obtain a white solid (2.03 g) with a yield of 86%.

[0057]

[0058] Synthesis of PhSBFBin: PhSBFBr (2.36 g, 5 mmol), pinacol diboron (1.65 g, 6.5 mmol), potassium acetate (1.47 g, 15 mmol), (1,1'-bis(diphenylphosphino)ferrocene)palladium dichloride (0.12 g, 0.15 mmol), and 50 mL of dioxane were added to a 100 mL round-bottom flask. Stir and reflux at 85 °C for 72 hours under nitrogen. After the reaction, use 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 spectrum 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), Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, and then 20 mL toluene and 0 mL water were added, heated to 90 ° C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL), and the reaction mixture was extracted three times with dichloromethane and water, and the combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:4) to obtain a white solid (535 mg) with a yield of 69%. 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 is 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), potassium acetate (5.89 g, 60 mmol) were mixed and added to a 100 mL flask, stirred at 120 ° C for 12 hours, then added a dehydrating agent, cooled to room temperature and continued to react for 72 hours. Three extractions were performed, and the organic layers were combined and concentrated. Subsequently, purification was performed to obtain 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: Add binaphthol (2.87 g, 10 mmol), 2FBrCN (2.18 g, 10 mmol), potassium carbonate (2.76 g, 20 mmol) to a 100 mL flask, add 60 mL of dimethylformamide, heat to 120 ° C and stir for 24 hours. Then cool to room temperature, extract three times and combine the organic layers. Then purify to obtain 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), Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, and then 20 mL toluene and 10 mL water were added, heated to 90 ° C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL), extracted with dichloromethane and water three times, and the combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:4) to obtain a white solid (425 mg) with a yield of 65%. 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 is 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), Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, and then 20 mL toluene and 10 mL water were added, heated to 90 ° C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL), extracted with dichloromethane and water three times, and the combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:4) to obtain a white solid (467 mg) with a yield of 60%. 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 is 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), Pd(PPh3)4 (70 mg, 0.06 mmol) were mixed and added to a 100 mL flask, and then 20 mL toluene and 10 mL water were added, heated to 90 ° C and stirred for 24 hours. After cooling to room temperature, the reaction mixture was poured into water (50 mL), and the reaction mixture was extracted three times with dichloromethane and water, and the combined organic layers were condensed in vacuo and purified by column chromatography with a mixed eluent of dichloromethane / petroleum ether (volume ratio 1:4) to obtain a white solid (512 mg) with a yield of 66%. 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 light-emitting layer materials (emitters), and 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 preparation process is as follows: Preparation of the substrate indium tin oxide (ITO) conductive glass: The substrate is cleaned in ultrasonic bath with deionized water, isopropanol, acetone, toluene, acetone, and isopropanol for 20 minutes each, and then dried in an oven for use. After the surface of the ITO conductive glass is treated in a UV ozone cleaner for 40 minutes, it is moved into a vacuum evaporation device (the pressure in the chamber is less than 2×10 -4 Pa); on the anode ITO conductive glass, vacuum evaporate the hole injection layer HATCN with a thickness of 5nm; on HATCN, vacuum evaporate the hole transport layer TAPC with a thickness of 25nm: on TAPC, evaporate the exciton blocking layer TCTA with a thickness of 15nm; on TCTA, evaporate the light-emitting layer CBP: (R-OBN-CN-DMF, R-OBN-CN-DPF or R-OBN-CN-SBF) (mass doping concentration is 5wt%) with a thickness of 20nm; on the light-emitting layer, evaporate the electron transport layer TmPyPB with a thickness of 40nm; on TmPyPB, evaporate the electron transport layer LiF with a thickness of 1nm; on LiF, evaporate the cathode Al with a thickness of 100nm. The external quantum efficiency curve of the prepared circularly polarized organic electroluminescent device is shown in Figure 6 The detailed electroluminescent 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 light-emitting layer materials, and 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 preparation process of the device is similar to that of Example 10. The external quantum efficiency curve of the prepared circularly polarized organic electroluminescent device is shown in Figure 7 The detailed electroluminescent performance data of the device are listed in Table 2.

[0080] Table 2: Electroluminescent performance data of devices with a mass doping ratio of 5wt% 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

[0081]

[0082]

[0083] Table 3: Electroluminescent performance data of devices with a mass doping ratio of 10wt% 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

[0084]

[0085]

[0086] Table 4: Electroluminescent performance data of devices with a mass doping ratio of 20wt% 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

[0087]

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

[0089]

[0090] The above description is only 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 in the protection scope of the present invention.

Claims

1. A high-efficiency near-ultraviolet thermoexciton compound with circular polarization properties, the structural formula of which is shown in (1): X is cyano (CN); L m for Wherein * indicates the connection position with R and the benzene ring; m is 0 or 1; R is * indicates the same as L m Or the attachment position of the benzene ring.

2. A high-efficiency near-ultraviolet thermoexciton compound with circular polarization properties as claimed in claim 1, wherein the structural formula is as shown in one of the following:

3. Use of a high-efficiency near-ultraviolet thermoexciton compound with circular polarization properties as claimed in claim 1 or 2 in the preparation of a circularly polarized organic electroluminescent device, characterized in that: The near-ultraviolet thermoexciton compound is used as a doping material for preparing a light-emitting layer of a circularly polarized organic electroluminescent device. The main material is CBP, and the mass doping concentration of the near-ultraviolet thermoexciton compound is 5-20wt%.

4. The use of a high-efficiency near-ultraviolet thermoexciton compound with circular polarization properties in the preparation of a circularly polarized organic electroluminescent device as claimed in claim 3, characterized in that: The organic functional layer of the circularly polarized organic electroluminescent device other than the light-emitting layer is one or more of a hole injection layer, a hole transport layer, an exciton blocking layer, an electron transport layer and an electron injection layer.

5. The use of a high-efficiency near-ultraviolet thermoexciton compound with circular polarization properties in the preparation of a circularly polarized organic electroluminescent device as claimed in claim 4, characterized in that: The circularly polarized organic electroluminescent device is used for preparing a near-ultraviolet circularly polarized organic electroluminescent display or an organic electroluminescent lighting source.

Images