Liquid crystals made of banana-shaped molecules

Abstract

Liquid crystals made of rod-like molecules are known for well over a century. The nematic phase with a purely 'orientational order of the rods and different types of layered arrangements which produce one-dimensionally periodic smectic phases are exhibited by compounds with rod-like molecules. Liquid crystals made of disc-like molecules were discovered just over 26 years ago and columnar phases with 2-dimensionally periodic structures are commonly found in such materials. Liquid crystals made of bent-core (BC) or banana-shaped molecules were discovered in 1996 and are now known to exhibit over a dozen different types of unique structures. We have found that by judiciously choosing compounds with rod-like and BC molecules, their binary mixtures exhibit several induced liquid crystalline phases, including a biaxial smectic A phase. The article gives an overview of the subject.