Study of an azoester novel homologous series: 4-[4â?²-n-alkoxy benzoyloxy]-3-methoxy phenyl azo- 3â?³- chloro benzenes

Titled homologous series consists of eleven members. Methyl to pentyl and dodecyl to hexadecyl homologues are nonmesomorphic, while; hexyl, octyl and decyl members of the series are mesomorphic. All the three mesomorphic homologues are enantiotropic nematogenic without exhibition of any smectogenic character even in the monotropic condition. Analytical data supports the molecular structures of homologues. Transition temperatures are determined by optical polarizing microscope with heating stage. Mesomorphism exhibited by the series is very poor with short range mesophaselength varying from 24°C to 26°C. Average thermal stability for nematic is 132.6. Thus, series is partly nematogenic with middle ordered melting type. The texture of the nematic mesophase is threaded or schlieren type. Mesomorphic properties of titled series are compared with, structurally similar homologous series.