New Cu II and Ni II complexes of potentially tridentate N 2 O Schiff base ligands 1 and 2 have been synthesised and characterised. [Cu(2)(OH 2 )] + possesses a square planar geometry in the solid state whereas [Ni(1) 2 ] possesses a distorted octahedral geometry in which the amine donors of 1 coordinate weakly to the Ni II centre. EPR spectroscopy demonstrates that the N 2 O 2 coordination sphere of [Cu(2)(OH 2 )] + is retained in CH 2 Cl 2 solution. [Cu(2)(OH 2 )] + exhibits a reversible one electron oxidation at E 1/2 =0.54V versus [Fc] + /[Fc], the product of which has been characterised by UV–Vis absorption and EPR spectroscopies. The spectroscopic signature of the oxidised product is consistent with the formation of a stable phenoxyl radical ligand bound to a Cu II centre. [Ni(1) 2 ] possesses a reversible metal-based oxidation process at E 1/2 =0.03V versus [Fc] + /[Fc] and a further oxidation, attributed to the generation of a phenoxyl radical centre, at Epa=0.44V versus [Fc] + /[Fc]. UV–Vis absorption and EPR spectroscopic studies indicate that the lower potential process is a formal Ni III/II couple. In contrast, the pro-ligands 1H and 2H exhibit chemically irreversible oxidation processes at Epa=0.42 and 0.40V versus Fc + /Fc, respectively, and do not support the formation of stable phenoxyl radical species.