Chapter II

Transition metal complexes containing Schiff base ligands are of interest to model the active sites of biologically important molecules. In particular, Schiff base derivatives of hydrazones exhibit various bioactivities and play vital role in certain physiological functions as well. Hydrazones and their metal complexes exhibit wide range of biological and pharmaceutical activities that includes antimicrobial, antituberculostatic, anticancer and antioxidant behavior. In addition, hydrazones also serve as an excellent polydentate chelating agent capable of forming coordination complexes with variety of both transition and inner transition metal cations. Metal complexes derived from hydrazides of carboxylic acids have been extensively investigated due to the high physiological activities of the free ligands and the presence of a chelatophore group of donor atoms in the coordination sphere. 1-4