Mesomorphic Homologous Series I. 2-Methyl-5-(4′-n-Alkoxycinnamoyloxy)pyridines II. 4-(4′-n-Alkoxycinnamoyloxy)toluenes

Abstract

Two homologous series of mesomorphic esters containing pyridine ring and aromatic nucleus have been synthesized and mesomorphic behaviour of their members studied. In series I, the first two and seventh members are non-mesomorphic. The propyl to hexyl derivatives show nematic phase (either monotropic or enantiotropic). The smectic phase commences from the amyl derivative as monotropic and continues till the last member studied. In series II, methyl to dodecyl derivatives exhibit nematic phase (either monotropic or enantiotropic) except the ethyl homolog which is non-mesomorphic. The smectic phase commences from the octyl derivative as enantiotropic and continues till the octadecyl derivative. Plots of transition temperatures against the number of carbon atoms in alkyl chain in series I and II behave in a normal manner. The thermal stability of the series I is compared with that of series II.