The synthesis and solution and solid-state structural characterization of a family of amine bis(phenolate) [ONNO]-vanadium complexes is reviewed. These compounds have oxi dation states ranging from vanadium(II) to vanadium(V), and were evaluated as olefin polymerization catalysts. In association with EtAlCl2 cocatalyst, we studied the homo polymerization of ethylene, propene, and 1-hexene, as w...