含有2,3,5,6-四氟亚苯基的负性液晶合成及液晶性研究

Synthesis and Application of Negative Liquid Crystals Containing 2,3,5,6-Tetrafluorophenylene

设计并合成了两类含氟的负性液晶化合物,通过偏光显微镜和差示扫描量热仪的检测两类液晶化合物都为向列相液晶,且具有很好的液晶性能。全氟二苯乙炔类负性液晶具有很高的清亮点和低的黏度;全氟二苯亚乙基类负性液晶具有很低的黏度和小的双折射率,前者可作为自适应光学系统空间光调制器液晶材料;后者可作为TFT-LCD混合液晶材料中的减黏部分。两个目标化合物分别是通过sonogashira交叉偶联反应和钯催化加氢还原反应得到的。

Two kinds of fluorinated negative liquid crystal compounds were synthesized.Two series of nematic liquid crystals were measured by polarised optical microscopy with a heating stage and differential scanning calorimetry and their good mesomorphic properties were observed.For example,the negative liquid crystals introducing 1,4-perfluorophenylene to molecular structure of diphenyl acetylene have high birfringence and low rotational viscosity.The result shows that the liquid crystal compounds with ethylidene bridge could have low birfringence and low viscosity.The first type of compounds could be used in adaptive system like as application in construction of spatial light modulator;the second type of compounds could satisfy the requirements of a low viscosity component in TFT-LCD.Two target compounds were synthesized by sonogashira coupling reaction and then Pd/C catalytic hydrogenation.