Mesomorphism Comparision of Azo-Esters and Chalcone-Esters

Abstract

One chalcone-ester homologous series of mesogens α-4-[4’-nalkoxy benzoyloxy phenyl β-4”Nitro benzoyl ethylenes (A) and one azo-ester homologous series of mesogens p-(p’-n-alkoxybenzoyloxy) phenyl azo-p”-methoxy benzene (B) being structurally similar are discussed. Both series (A) and (B) differ in respect of central bridges linking two phenyl ringsand terminal groups linking with one phenyle ring.Mesomorphic properties start from 6th member of series (A) and (B. In series (A), 6th to 14th members show both smectogenic and nematogenic properties, and the 16th member show only nematogenic property. While in series (B), 1st to 10thmembers show nematogenic properties.Thermal stability of series (A) is relatively high as compared to series (B). Transition temperatures are observed through hot stage polarizing microscope by the miscibility method. Analytical data support the structure of molecules.