Phase behaviour of some α,ω-dicarboxylic acids containing a mesogenic core

Abstract

Some α,ω-dicarboxylic acids containing, as a core, well known mesogenic groups have been synthesized and their phase behaviour has been investigated using DSC, optical and X-ray diffraction methods. A feature common to several of the compounds is the occurrence of an enantiotropic polymorphism with an additional phase stable between the low temperature solid phase and the isotropic liquid. The nature of this phase is discussed. Only one compound, among those studied, has shown definite mesomorphic behaviour (although monotropic) with a liquid-crystalline phase of probable smectic A type.