Synthesis of Schiff Bases Forming the First Room Temperature Ferroelectric Liquid Crystal—The Mora Series

Abstract

Condensation of chiral S-4-(6-methyl)octyloxy-2-hydroxybenzaldehyde (S-4-0- (6-methyl)octylresorcylaldehyde) with 4-alkylanilines (the MORA series, 3) gives low-melting Schiff bases showing chiral smectic C phases at or slightly above room temperature. The previously known MBRA series (4'-0- (2-methyl)-butyl- resorcylidene-4-alkylanilines, 1) has been extended by MBRA 4 and 12, both showing low-temperature smectic phases. Bis (S, S-4'-(2-methylbutyloxy-2-hydroxybenzylidene)-2-chloro-1,4-phenylene-diamine shows a cholesteric blue phase between 174 and 175 °C.