氟代苯基二苯乙炔基异硫氰酸酯的合成与液晶性质研究

Synthesis and Properties of Fluorinated Isothiocyanate Phenyl-Tolane Liquid Crystal Compounds

通过偶联法合成了6种氟代苯基二苯乙炔基异硫氰酸酯液晶化合物。这些液晶均具有较高的Δn值,约为0.40～0.54。差热分析结果显示,具有更多取代氟原子的液晶化合物具有相对更低的熔点。将这些高Δn液晶化合物溶于商品炔类液晶材料时,氟原子为1、2的液晶化合物显示出更低的黏度。当这些混合液晶材料用于具有固定调制量的光学器件时,2个取代氟原子的液晶化合物显示出了更好的响应性能。这些液晶化合物在液晶光学器件中将具有一定的应用潜力。

Six kinds of LC materials with fluorinated isothiocyanate phenyl-tolane group were prepared via couple reaction. These LCs exhibit high birefringence, about 0.40-0.54. The DSC test results indicated that the melting point of LC compounds decreased with the atom number of fluorine increasing. When these LCs were mixed in the commercial alkyne LCs re- spectively, the LC compounds with 1 or 2 fluorine atoms exhibit low viscosity. When these mixed LC materials were used in optics device, the isothiocyanate phenyl-tolane LCs with 2 fluorine atoms have the best response performance. These LCs with high An and low rota- tional viscosity would have some application potential in LC optical device.