Electrochemical preparation of stable nickel(III) complexes with tetradentate macrocyclic ligands in aqueous solutions
Abstract
Stable solution of NiIII complexes of the 14-membered macrocylic ligands (I), (II), and (III) were obtained by electrochemical oxidation on gold and platinum electrodes of the corresponding NiII complexes in mild acidic aqueous solutions in the presence of sulphate; the NiIII complexes formed represent a new kind of strong, easily accessible, single-electron, oxidizing agent with E°ca. 1 V vs. standard hydrogen electrode (S.H.E.) in aqueous media.