Synthesis, characterization and mesomorphism of chalcone mesogens: α-4-alkoxybenzoyl β-4/-heptyloxy phenyl ethylene

A new mesogenic homologous series : RO-C6H6-CH=CH-CO-C6H6-OC7H15 have been synthesized and studied with a view to understand establish the effect of molecular structure on mesomorphic properties and characterized by a combination of elemental analysis and standard spectroscopic methods (IR, 1HNMR and elemental analysis). In present series mesomorphism commences from C4 homologue, C4 and C5 exhibit only enantiotropic nematicmesophase whereas C6 to C18 exhibit enantiotropic nematic as well as smectic mesophase. The thermometric behaviours of novel homologue substances and their textures were determined by an optical polarizing microscopy (POM) equipped with a heating stage. Textures of a nematic phases are threaded or schlieren. The textures of smectic phase are directly judged from the heating top as smectic-A. The mesomorphic properties of present series were compared with other two structurally analogous series.