Abstract Six tricopper cluster complexes of the type [Cu I Cu I Cu I (L)] 1+ supported by a series of multidentate ligands (L) have been developed as oxidation catalysts. These complexes are capable of mediating the facile oxygen-atom transfer to hydrocarbon substrates like cyclohexane, benzene, and styrene (C 6 H 12, C 6 H 6 and C 8 H 8) upon activation by hydrogen peroxide at room temperature. The processes are catalytic with ...