Antiferroelectric liquid crystals having a semi‐fluorinated alkane positioned at the chiral tail

Abstract

An optically active semi‐fluorinated alkanol, (S)‐1‐methyl‐2‐(2,2,3,3,3‐pentafluoropropyloxy)ethanol, was prepared by the treatment of 2,2,3,3,3‐pentafluoropropanol with (S)‐propylene oxide under basic conditions. This alkanol was used as a chiral building block for the synthesis of a series of novel chiral materials, the (R)‐4‐[1‐methyl‐2‐(2,2,3,3,3‐pentafluoropropyloxy)ethyloxycarbonyl]phenyl 4′‐alkyloxybiphenyl‐4‐carboxylates, MPFPECPmBC (m = 8–12), that have a semi‐fluorinated alkane positioned at the chiral tail. It was found that all the materials possess enantiotopic SmA*, ferroelectric SmC* and antiferroelectric phases. The basic electro‐optical properties of the chiral materials in the SmC* and phases were measured. The results show that the maximum P _s values are in the range 69–92 nC cm⁻² and the maximum apparent title angles are in a range of 24°–33°.