Tetradentate Schiff base oxovanadium(IV) complexes

Eleven oxovanadium(IV) complexes of tetradentate Schiff bases, obtained by condensating two moles of an o-hydroxycarbonyl compound with a diamine, have been prepared and characterized by elemental analysis, m.p., and i.r. and electronic spectra. The i.r. and electronic spectra of the free ligand and the complexes are compared and discussed. The Gaussian analysis of the vis. spectra of the complexes, normally C-1 or C-s, in MeCN yielded four peaks at ca. 12000, 15000, 17700 and 20000-23000 cm(-1), assigned to the four d-d transitions.