Synthetic and spectral studies of oxovanadium (IV) complexes with pyrazolines & isoxazolines

Abstract

A few oxovanadium (IV) complexes of the type VOL₂ [LH = 3-(2- hydroxy-l-naphthyl)-5-(4-X-phenyl)-2-isoxazoline; X = H, CI, OMe] have been prepared and characterized. IR spectral studies indicate coordination of the ligand through phenolic oxygen and tertiary nitrogen to the metal. Electronic spectral and magnetic susceptibility studies indicate the presence of a single unpaired electron while EPR studies confirm that the unpaired electron is present in the <em>d_xy</em> orbital. EPR spectra recorded in pyridine show that the V=O bond is weakened leading to stronger in-plane bonds due to axial coordination of pyridine trans to the vanadyl oxygen.