4-Alkyloxy-4'-stilbazoles New heterocyclic mesogens

Abstract

Abstract The synthesis of a new series of heterocyclic mesogens, the trans-4-alkyloxy-4'-stilbazoles (CnH2n+1OC6H4CH=CHC5H4N), is described and the phase behaviour is reported for all homologues between methyloxy (C1) and dodecyloxy (C12). For n < 3, the compounds are non-mesomorphic; monotropic smectic phases are observed for n = 3 and 4, whilst homologues with n = 5 to 12 show enantiotropic smectic phases. For comparison the synthesis and properties of two trans-4-alkyloxy-stilbenes are also reported. The phases are assigned on the basis of either X-ray data or optical textures.