Mesogenic Property of k-(4-Substituted phenylazo) tropolones

Abstract

It is reported that 5-(4-alkoxyphenylazo)- and 5-(4-alkylphenylazo)tropolones and their methyl ethers are not mesogenic. We observed, however, the corresponding sigmatropic ester derivatives exhibited smectic mesophases. The substituent effect of the phenyl ring on the thermal stability was discussed; alkoxyl groups are more favored than alkoxycarbonyl and alkyl groups. Thus we investigated the mesogenic property of 5-(4-substituted phenylazo)tropolones.