Synthesis and mesomorphic properties of novel phenylbenzoate liquid crystals with a 4-2H-perfluoropropyl-1-butanol tail

Two series of novel liquid crystals, 4'-(2H-perfluoropropylbutyloxy)pnenyl 4-alkyloxybenzoates and 4'-(2H-perfluoropropylbutyloxy)phenyl 4-(n-perfluoroalkylalkyloxy)benzoates were synthesized and their liquid crystalline properties investigated. The compounds with a non-fluorinated achiral tail and a fluorinated achiral rail showed no smectic C phase, however, a more ordered B phase appeared with the increase of the achiral chain length. When the achiral terminal tail was fluorinated, a monotropic smectic C phase appeared and the stability of the smectic C phase increased as the fluorination extent of the achiral tail increased.