Coordination chemistry of oxovanadium(V) complexes with active Schiff bases: synthetic, spectral, and antimicrobial approach

Abstract

The Schiff bases, 3-(indolin-2-one)hydrazinecarbothioamide (L1H), 3-(indolin-2-one)hydrazinecarboxamide (L2H), 5,6-dimethyl-3-(indolin-2-one)hydrazinecarbothioamide (L3H), and 5,6-dimethyl-3-(indolin-2-one)hydrazinecarboxamide (L4H), have been synthesized by the condensation of 1H-indol-2,3-dione and 5,6-dimethyl-1H-indol-2,3-dione with the corresponding hydrazinecarbothioamide and hydrazinecarboxamide, respectively. The complexes of oxovanadium and ligands have been characterized by elemental analyses, melting points, conductance measurements, molecular weight determinations, and IR, 1H NMR and UV spectral studies. These studies showed that the ligands coordinated to the oxovanadium in a monobasic bidentate fashion through oxygen or sulfur and the nitrogen donor system. Thus, penta-and hexacoordinated environment around the vanadium atom has been proposed. All the complexes and their parent organic moieties have been screened for their biological activity on several pathogenic fungi and bacteria and were found to possess appreciable fungicidal and bactericidal properties.