具有氟烷基边链和手性中心液晶化合物的合成及液晶性研究

本文设计合成了十个含氟烷基边链和手性中心的液晶化合物，并通过DSC和偏光显微镜对它们的液晶性进行了研究。其中二环系液晶化合物不显示液晶相或仅显示单边近晶A相。三环系液晶化合物中较长的氟烷基边链有利于近晶相的形成，且当液晶核另一端的烷氧基链的长度适中时，在氟烷基边链和液晶核之间具有手性中心的液晶分子显示了手性近晶C相和其它液晶相。

Synthesis and Mesomorphic Properties of Chiral Mesogens Bearing Fluorinated Alkyl Terminal Tails

Ten chirai mesogenic compounds containing fluorinated alkyl terminal tails were prepared and characterized by IR, NMR, MS. The phase transition behavior was investigated by DSC and polarized optical microscope. Two-ring liquid crystal compounds exhibited no mesogenic phase or only a monotropic smectic A phase. The longer fluori- natal alkyl chain on the three-ring was advantageous to the formation of smectic phase. The mesogens with chiral center located between fluorinated tail and mesogenic core exhibited chiral smectic C phase and other smectic phases when the alkoxyl adhering to the other side of the mesogenic core was of intermediate length.