Synthesis and spectroscopic studies on oxovanadium(IV) complexes with hydrazones containing indole ring

A new series of complexes of type [VO(L)H₂O] (L = hydrazone ligands derived from isatin and aromatic acid hydrazides) has been prepared. Tentative structures of the complexes have been proposed on the basis of elemental analysis, electrical conductance, magnetic moment and spectral (IR, electronic and EPR) data. The X-band EPR spectra of all the complexes were recorded at room temperature and at liquid N₂ temperature. The room temperature EPR spectra do not show anisotropy because of rapid tumbling of molecules in solution. The spectral studies support square-pyramidal geometry for the vanadium(IV) complexes.