Twelve new complexes of oxovanadium(IV) sulphate with quadridentate Schiff base ligands have been prepared and characterized by elemental analyses, molar conductance, i.r., far i.r., electronic and e.s.r. spectra, magnetic susceptibility measurements and thermogravimetric analysis. The complexes have been found to have a composition (VOL)SO4.H20. The lone water molecule is uncoordinated as proved by i.r. spectra as well as thermo gravimetric analysis. The electronic spectra and e.s.r. spectra show a distorted octahedral nature of the complexes. From the electronic spectral bands, the values of radial parameters, normalized spherical harmonic Hamiltonian parameters and McClure parameters have been calculated. On the basis of these data, the degree of distortion or tetragonality was given and the comparative distribution of electron density in the x, y and z planes has been calculated. Finally, the parameters to denote the extent of σ and πbonding in axial and horizontal planes were calculated. It was found that there is a greater degree of overlap in the xy plane than in the z plane thereby making an appreciable contribution to covalency in this plane. The same conclusion can also be drawn by the molecular orbital parameters calculated using e.s.r. data. © 1987, Taylor & Francis Group, LLC. All rights reserved.