Synthesis of ferroelectric liquid crystals with large spontaneous polarization

Abstract

The magnitude of spontaneous polarization of liquid crystals forming chiral smectic C phases is discussed in terms of a dipole moment and rotational barrier neighbouring the chiral centre of the liquid-crystalline molecules. Using quantitative relations obtained from a molecular-orbital calculation for some compounds having polar groups such as –CO₂–, –O– and –CO–, the molecular structure of a chiral dioxaborinane derivative with a large spontaneous polarization was designed; this was then synthesized and confirmed to form an S_c* phase exhibiting a large spontaneous polarization of 200 nC cm ^–2 as predicted.