Ferroelectric and antiferroelectric liquid crystals derived from (S)‐1‐methyl‐2‐(2′‐methylsulphanylethoxy)ethanol

Abstract

An optically active chiral material, (S)‐1‐methyl‐2‐(2′‐methylsulphanylethoxy)ethanol was prepared by the treatment of (S)‐propylene oxide with 2‐methlylsulphanylethanol under basic conditions. Its derivatives, the (R)‐1‐methyl‐2‐(2′‐methylsulphanylethoxy)ethyl 4‐(4′‐alkoxybiphenyl‐1‐carboxyloxy)benzoates, MMSEEmCB (m = 7–12), were then prepared for investigation of their mesomorphic properties. The results show that the materials with shorter alkyl chains (m = 7–9) favour the formation of the antiferroelectric phase, while materials with longer alkyl chains (m = 10–12) favour the formation of the ferroelectric SmC* phase. Switching current behaviour, electro‐optical response, dielectric constant, spontaneous polarization and apparent tilt angle for the materials in the SmC* and phases were studied.