通过Suzuki反应合成了三种基于三苯胺/二苯砜的热激活延迟荧光(TADF)材料(1-3),采用紫外-可见(UV-Vis)吸收光谱、时间分辨荧光发射光谱、循环伏安(CV)测试、理论计算、热重分析和差示扫描量热法,系统地研究了三种材料的光物理、电化学、延迟荧光性能和热稳定性.材料1-3均为基于分子内电荷转移(ICT)的双极性分子.三种材料在薄膜中的单线态-三线态能级差分别为0.46、0.39和0.29 eV.荧光量子效率和荧光寿命的测试结果表明,三种材料均能发射延迟荧光,其中材料3具有最佳的延迟荧光性能.材料1-3的最高占有分子轨道(HOMO)能级分别为-4.91、-4.89和-4.89 eV.结合UV-Vis吸收光谱中得到的能隙(Eg)值,我们得到材料1-3的最低未占分子轨道(LUMO)能级,分别为-1.74、-1.89和-1.94 eV.热分析的结果表明,材料1-3具有其较高的热分解温度(Td,失重5%时的温度),分别为436、387和310 ℃. A series of thermally activated delayed fluorescence (TADF) materials (1-3) based on triphenylamine/diphenyl sulfone were synthesized by Suzuki cross-coupling reactions. The optical, electrochemical, delayed fluorescence, and thermal properties of these materials were characterized by UVVis spectroscopy, time-resolved fluorescence spectroscopic measurements, cyclic voltammetry (CV), theoretical calculations, thermal gravimetric analyses, and differential scanning calorimetry. Materials 1-3 are bipolar compounds based on intramolecular charge transfer (ICT), and they have small energy gaps between the singlet and triplet (ΔEST) of 0.46, 0.39, and 0.29 eV, respectively. The results of fluorescent quantum yields and fluorescent lifetime indicate that these materials can emit delayed fluorescence, and material 3 has the greatest potential as a TADF emitter among materials 1-3. The highest occupied molecular orbital (HOMO) energy levels of materials 1-3 were estimated to be -4.91, -4.89, and -4.89 eV, respectively. From the HOMO energy levels and the optical bandgap (Eg) values, the lowest unoccupied molecular orbital (LUMO) energy levels were estimated to be -1.74, -1.89, and -1.94 eV for materials 1-3, respectively. Thermal gravimetric analysis results reveal that materials 1-3 have high thermal decomposition temperatures (Td), corresponding to 5% weight loss at 436, 387, and 310 ℃, respectively
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