Novel Ferroelectric Liquid Crystals Derived from n-Alkyl Esters of (R)-3-Hydroxybutanoic Acid (II), the Correlation between Their Ferroelectric Properties and Their Molecular Structure

Abstract

Abstract The temperature dependence of the spontaneous polarization (Ps) and the optical tilt angle (θ) of the following series of novel ferroelectric liquid crystals, derived from normal alkyl esters of (R)-3-hydroxybutanoic acid, have been investigated. (Remark: Graphics omitted.) The magnitude of Ps and θ depends on the kind of linkage groups and their position in the core moiety as well as on the lengths of both terminal chains. The Ps’s for I(m,n) and II(m,n) show a maximum at (m,n)=(10, 3), whereas their θ’s increase with the m and do not change very much with n. In comparison with four analogues (I(10,3), II(10,3), III(10,3), and IV(10,3)), which have the same terminal chains, but which show a different phase sequence, the magnitudes of Ps and θ are in the orders of: III(10,3)>IV(10,3)>I(10,3)∼II(10,3) and III(10,3)>I(10,3)>II(10,3)>IV(10,3) respectively. Among all the compounds, the III(10,3) shows the maximum Ps as high as 1100 μCm−2 in the chiral smectic C phase and as high as 1750 μCm−2 in the chiral smectic I phase.