Perfluorinated or semi-perfluorinated alkyl chain containing achiral liquid crystals can display ferroelectric liquid crystalline properties, which have great potential applications to industry, therefore have attracted the attention of researchers. In this report, biphenylyl 4-perfluorohexylbenzoate liquid crystalline compounds ROC₆H₄C₆H₄O₂CC₆H₄C₆F₁₃ and C₃H₇C₆H₄C₆H₄O₂CC₆H₄C₆F₁₃, (R＝C_nH_2n＋1, n＝6, 8, 10, 12, 16) have been synthesized. Their mesogenic behavior was investigated with differential scanning calorimetry (DSC) and polarized op-tical microscopy (POM). The results showed that the alkyl chain compounds exhibited nematic phases with higher melting points, lower clearing points, therefore narrower mesophase temperature ranges. The per-fluoroalkyl chain containing molecules showed highly ordered smectic phases with lower melting points, higher clearing points and broader mesophases.

Key words: liquid crystal, 4-propylbiphenyl-4'-ol, perfluoroalkyl chain, fluorophilic effect, fluorophobic effect