A series of fluorene-triphenylamine derivatives containing an electron donor-acceptor (D-A)structure based on 9,9-diarylfluorene was designed and synthesized. Their optical properties were investigated by UV-Vis spectroscopy and photoluminescence (PL) techniques in solution as well as in the solid state. The maximum PL emission wavelengths of the compounds ranged from 430 to 530 nm. A dual fluorescence phenomenon was observed in particular polar solvents and the relationship between emission properties and molecular structures was studied. The results reveal the existence of a charge transfer (CT) excited state in the molecules and the PL properties of these compounds depend on the structure of the compound and also on the polarity of the solvent. The molecular constitution of the compounds improves the hole-injection issues for fluorene-based materials because of the introduction of a triphenylamine group. Cyclic voltammetry (CV) shows that the highest occupied molecular orbital (HOMO) energy level of the compounds is located between -5.24 and -5.50 eV and it can be tailored by changing the electronegativity of the substituent group. Simultaneously, the spiro-skeleton molecular structure leads to an excellent glass transition temperature (192-206 ℃) and it retains good morphological stability. The thermogravimetric (TG) curves of the compounds show a thermal-decomposition temperature of higher than 400 ℃.%设计合成了一系列以三苯胺结构为核心的具有推电子-拉电子(D-A)结构的9,9-二芳基芴类有机小分子.研究了介质极性对吸收与发射光谱行为的影响及分子结构与其发光能力的关系.该类化合物荧光发射波长范围在430-530 nm.并在特定极性溶剂中观察到双重荧光现象.溶剂效应显示该类化合物随着介质极性的增加,分子内电荷转移态(ICT)的荧光发射峰波长先红移后蓝移且荧光强度降低,表现出扭曲的分子内电荷转移(TICT)行为.该类化合物的最高占有分子轨道(HOMO)能级位于-5.24- -5.50 eV,且可以通过改变取代基电负性的强弱来调节.所得化合物的玻璃化转变温度为192-206℃,热重分析(TGA)表明化合物的热分解温度都在400℃以上,具有良好的热稳定性.
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