A Study of Mesomorphism Properties and their Relation to the Molecular Structure of Novel chalcone Derivatives

Balvani V. N.; Chauhan M. L.

Abstract

A Study of Mesomorphism Properties and their Relation to the Molecular Structure of Novel chalcone Derivatives

Author(s): Balvani V. N. and Chauhan M. L.

A novel chalconyl homologous series of liquid crystalline derivatives RO -C₆H₄-COO - C₆H₄-CO - CH=CH - C₆H₄– OC₄H₉(n) (para) have been synthesized and studied with view to correlate the liquid crystal (LC) behavioral properties and the molecular structure of a substance. Present novel series consisted of thirteen homologue members (C₁ to C₁₈) whose, only nematogenic mesomorphism commences from C₅homologue and continued up to C₁₈ homologue in enantiotropic manner with absence of smectogenic character. Transition temperatures and textures of nematic phase were determined using an optical polarizing microscopy equipped with a heating stage (POM). Transition curve Cr-N/I behaved in normal manner. Textures of the nematic phase are threaded or schlieren. Analytical and spectral data supported molecular structures of homologues. Thermal stability for nematic is 118.22 C° and the degree of mesomorphism vary from 10.0°C to 36.0°C at the C₁₈and C₆homologue respectively. It is a middle ordered melting type series, whose relative group efficiency order for nematic derived.