Aqueous copper(III) and nickel(III) tetra-aza-macrocyclic complexes

The copper(III) and nickel(III) complexes with the novel tetra-aza-macrocycle 1,4,8,11-tetra-azacyclotetradecane-5,7-dionato(2–)(L2)2–, which contains two deprotonated amido groups, can be generated in aqueous solution by chemical or anodic oxidation of the corresponding CuII and NiII species and the authenticity of the oxidation states is demonstrated by voltammetric and e.s.r. investigations.