Synthesis and ferroelectric properties of the thioester liquid crystals derived from (2s)-2-(6-hydroxy-2-naphthyl)propionic acid

A new homologous of chiral thioesters, hexyl (2S)-2-(6-(4-(alkoxyphenyl) benzoyloxy-2′-naphthyl)thiopropionates, HmPBNTP (m=8-14) has been synthesized for the study of mesomorphic and physical properties. All compounds are mesogenic and all mesophases are enantiotropic. Compounds with longer alkyl chain length (m=13 and 14) exhibit exclusive ferroelectric Sc* phase, other compounds (m=8-12) possess SA and SC* phases. Novel ferrielectric SCγ* phase was found by the dielectric measurement. Depending on the alkyl chain length m, these chiral thioesters display three different phase transition sequences: I-SA-SC*C, I-SA-SC*-SCγ*-C and I-SC*-SCγ*-C. The magnitude of spontaneous polarization (Ps) and dielectric constant of the materials were also measured and reported.