Abstract
Novel non-symmetrical bent-shaped liquid crystals based on a laterally substituted naphthalene central core and a semifluorinated terminal chain in one arm are presented. The non-substituted (X=H), methyl- (X=CH3) and chloro-substituted compounds (X=Cl) exhibit formation of a B2 phase, the antiferroelectric character of which was proved by electrooptic, dielectric and X-ray studies. In the cyano-substituted materials, the B7 phase appeared. Increasing the length of the polyfluorinated unit leads to an increase of the transition temperatures and broadening of the temperature interval of the B2 and B7 phases, respectively. The length of the perfluorobutyl unit in the terminal chain is sufficient to support the formation of lamellar phases.
Acknowledgements
This project was supported by the Czech Science Foundation (project P204/11/0723) and research project AVOZ10100520.