Synthesis and mesogenic properties of three- and four-ring compounds with a fluoroisothiocyanatobiphenyl moiety

Abstract

The syntheses and mesomorphic properties of 4-alkylcyclohexyl- and 4-alkylcyclohexylethyl and 4-alkylbicyclohexyl-3-fluoro- and 3,5-difluorobiphenyl-4-isothiocyanates are described. The compounds are low melting, very broad range nematic liquid crystals and are very useful for the formulation of nematic mixtures of low viscosity and with a moderately high birefringence (0.3–0.35). The refractive indices, bulk viscosity and dielectric anisotropy extrapolated from Demus' ester mixture for the prepared compounds are presented.

Keywords:

• nematic isothiocyanates
• syntheses
• phase transitions
• bulk viscosity
• refractive indices
• dielectric anisotropy
• nematic mixtures

Acknowledgements

The work was carried out under Polish Ministry of Sciences and Information PBS 826 and project NATO PDD(TC)-(CBP.EAP.CLG 983701)