Liquid Crystalline Phases in 4-Acetyl-4?- n -Alkanoyloxy-Azobenzenes

Abstract
The preparation and melting behaviour of the homologous series of 4-acetyl-4′-n-alkanoylox-azobenzenes, CH3-CO-C6H4-N˭N-C6H4-O-CO-(CH2) n -CH3, (with n ranging from zero to 16) is reported. The melting behaviour has been investigated by means of thermal microscopy and differential scanning calorimetry. The experimental results indicate for almost all the compounds the presence of solid state polymorphism and a type A smectic; for one compound a type B smectic phase is also present. Some homologs present, in addition, a nematic phase.