Syntheses, characterization and mesomorphic properties of new bis(alkoxyphenylazo)-substituted N,N′ salicylidene diiminato Ni(ii), Cu(ii) and VO(iv) complexes

Abstract

A series of tetradentate Schiff base ligands N,N′-bis[5-(4-n-alkoxy)phenylazosalicylidene]alkyldiamine(n-alkoxy = butyloxy, octyloxy) homologues based on 1,2 diaminoethane and 1,3 diaminopropane have been synthesized and characterized by IR, NMR and mass spectroscopy. For all the ligands the nickel(II), copper(II) and oxovanadium(IV) complexes have been synthesized and characterized by elemental analyses and IR spectroscopy. The thermal behavior of these compounds was examined by differential scanning calorimetry (DSC) and polarizing microscopic observations. None of the Schiff-base ligands and butoxy containing complexes exhibit liquid crystalline properties but the octyloxy containing metal complexes show a smectic A mesophase.