Novel fluorinated liquid crystals. Part 9.—Synthesis and mesomorphic properties of 4-(n-alkoxycarbonyl)phenyl 4-[(4-n-alkoxy-2,3,5,6-tetrafluorophenyl)ethynyl]benzoates

Abstract

Two new homologous series of 4-(n-alkoxycarbonyl)phenyl 4-[(4-n-alkoxy-2,3,5,6-tetrafluorophenyl)ethynyl]benzoates have been synthesized from 1-pentafluorophenyl-2-trimethylsilylacetylene as a starting material. Study by thermal polarizing microscopy and DSC analysis showed that they were enantiotropic liquid crystals with smectic A and nematic phases. The effect of the terminal groups on the mesomorphic behaviour is discussed.