Oxovanadium(IV) complexes with 14-membered macrocyclic ligands derived from dithiooxamide

Oxovanadium(IV) complexes, [VO(L)] SO₄, where L = 5, 7, 12, 14-R₄-2, 3, 9, 10-S₄-[14]-1, 5, 7, 12-tetraene-1, 4, 8, 11-N₄ have been prepared in methanol. Tentative structures of the complexes have been proposed on the basis of elemental analyses, 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 nitrogen temperature. The room temperature EPR spectra do not show anisotropy because of rapid tumbling of the molecules in solution but it is observed at liquid nitrogen temperature. The spectral studies support square pyramidal geometry for the oxovanadium (IV) complexes.