含氟极性端基取代的四氟二苯乙炔类液晶的合成与相变性质  

Synthesis and mesomorphic properties of tetrafluorotolane-based liquid crystals with fluorinated polar end-groups

作　　者：李衡峰[1] 闻建勋[2] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083 [2]中国科学院上海有机化学研究所,上海200032

出　　处：《中南大学学报（自然科学版）》2007年第1期9-13,共5页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(29974038)

摘　　要：设计并合成了3个系列的含氟极性端基取代的四氟二苯乙炔类液晶化合物,其相态和相变温度通过用偏光显微镜观察织构并经DSC确认得到。其中含三氟甲基和三氟甲氧基的液晶化合物系列都显示有1个很宽的近晶A相和1个较窄的向列相。其向列相的温度范围随着末端烷氧基端链的长度增长而迅速减小。由于末端氢原子的存在,含二氟甲氧基的四氟二苯乙炔类液晶化合物增大了分子末端吸引力,而只出现1个温度约为100℃的向列相;同时,二氟甲氧基不仅具有很大的极性,其液晶化合物还有较高的电压保持率,是潜在的向列型液晶显示材料。Three series of tetrafluorotolane-based liquid crystalline compounds with a fluorinated polar end-group were designed and synthesized. Their phase transition temperatures were measured by differential scanning calorimetor DSC and phase recognition was observed by polarizing optical microscope. The liquid crystalline compounds containing the trifluoromethyl and trifluoromethoxy group exhibit a broad smectic A phase, and a narrow nematic phase, the temperature range of nematic phase is decreased rapidly along with the increase of the length of alkoxy chain. The liquid crystals with difluoromethoxy group exhibit a wide nematic phase （about 100 ℃） for the reason of the existence of hydrogen atom, which increases the end-attraction force. With respect to the polarity, stability and voltage holding rate of the difluoromethoxy containing compounds, the compounds with difluoromethoxy group have very good potential application in liquid crystal display.

关 键 词：液晶 四氟二苯乙炔 合成 相变性质 

分 类 号：TN104.3[电子电信—物理电子学]