Five vanadium complexes possessing the VO3+ motif with NO4 coordination have been synthesized and characterized by 1H and 13C NMR, UV-Vis, FTIR and cyclic voltammetry. These complexes favour trigonal bipyramidal geometry. In DMF solution, complexes 1 and 5 have shown reversible redox behaviour in the presence of l-ascorbic acid or l-cysteine ethyl ester in air as monitored by electronic absorption and EPR studies. © 1995.