| Abstract: | Three homologous series of 4-(n-polyfluoroalkoxycarbonyl)phenyl 4-[(4-n-alkoxyphenyl)ethynyl] benzoates have been synthesized from 1,1,3-trihydroperfluoropropanol, 1,1,5-trihydroperfluoropentanol and 1,1,7-trihydroperfluoroheptanol. Polarizing microscopic textural observations and DSC measurements of the phase transitions of these compounds show that most of them are thermotropic liquid crystals with smectic A and very broad smectic C phases; furthermore, several show very narrow monotropic SmB phases. The effect of the terminal polyfluoroalkoxy and alkoxy groups on the mesomorphic behaviour is also discussed. |
