Ti(III), VO(IV), Cr(III), Fe(III), MoO2(VI) AND WO2(VI) COMPLEXES OF NEW TRIDENTATE SCHIFF BASE LIGAND: SYNTHESIS, SPECTRAL CHARACTERIZATION, THERMAL AND BIOLOGICAL STUDIES

Abstract

A new Schiff base ligand derived from the condensation of pyrazine-2-carbohydrazide with 2-hydroxy-4- methoxybenzophenone and its Complexes of Ti(III), VO(IV), Cr(III), Fe(III), MoO2(VI) and WO2(VI) have been prepared and characterized by elemental analysis, molar conductance, spectral, magnetic moment measurement, PXRDs, SEM and thermogravimetric analysis. The elemental analyses suggest 1:1 metal to ligand stoichiometry for all the complexes. The hydrazone ligand acted as bi-negative tridentate coordinating through the phenolic oxygen, azomethine nitrogen and enolic oxygen atom forming a five/six membered chelating rings. On the basis of various physicochemical studies, octahedral geometry was proposed for Fe(III), Cr(III), Ti(III), MoO2(VI) and WO2(VI) complexes and square pyramidal geometry to VO(IV) complex. The Schiff base and metal complexes have been evaluated for antimicrobial activities which shows that all the complexes were found more active than the ligand. Furthermore, kinetic parameters were determined from the thermal data by using both Freeman-Carroll and SharpWentworth methods and comparable values are obtained.