Synthesis, Characterization and Antimicrobial Studies of Oxo Vanadium (IV & V) Complexes with Semi and Thiosemicarbazones of Furan-2-Carbaldehyde and Pyrrole-2-carbaldehyde

Oxovanadium (IV & V) complexes were synthesized from semi- and thiosemicarbazones (L1, HL2, HL3 and H2L4) derived from furan-2-carbaldehyde (L1, HL2) and pyrrole-2-carbaldehyde (HL3, H2L4). The solid isolated complexes were characterized through elemental analysis, UV-Visible spectra, I.R spectra, 1H NMR spectra, mass spectra, magnetic susceptibilities and molar conductance measurements. The isolated complexes except [VO(L2)(OH)2].H2O are paramagnetic in nature and having square pyramidal geometry. Molar conductance values justify the proposed structure with their electrolytic nature. The electronic spectra of these complexes are interpreted by using the Vanquickenborne and MacGlynn ordering xy<xz, yz< x2-y2<z2. The only oxovanadium(V) complex [VO(L2)(OH)2].H2O was synthesized from an alkaline solution of the ligand L2 in aqueous-ethanol and was found to be diamagnetic and distorted octahedral in geometry. The cyclic votammetric studies of the complexes in DMSO were studied to explore the redox behavior of complexes. The free ligands and some of its complexes showed considerable biological activities as antibacterial and as well as possessing antifungal properties.