Novel fluorinated liquid crystals. Part VI. The synthesis and phase transition of novel cholesteric liquid crystals containing 1,4-tetrafluorophenylene units

Article abstract of DOI:10.1016/0022-1139(94)03048-0

1-<4-n-Alkoxy-2,3,5,6-tetrafluorophenyl)ethynyl>-4-<(4-((S)-2-methylbutoxy)-2,3,5,6-tetrafluorophenyl)ethynyl>benzenes have been prepared from the starting material 1-pentafluorophenyl-2-trimethylsilylacetylene.Textural observation by polarizing microscopy showed that these materials were cholesteric liquid crystals when the terminal alkoxy chains were of sufficient length.The effect of symmetrical tetrafluoro substitution of phenyl groups on the mesomorphic behaviour is also discussed.