The Cu(II) and Pd(II) complexes of rraru-octaethylchlorin (OEC) and octaethylisobacteriochlorin (OEiBC) were synthesized and characterized. The redox behavior of these complexes and of the octaethylporphyrin complexes Cu(OEP) and Pd(OEP) were investigated in nonaqueous media. Potentials were determined by cyclic voltammetry in butyronitrile, methylene chloride, and dimethylformamide solutions. Oxidized and reduced species derived from these complexes were characterized by spectroscopic means. The first oxidation of all six complexes afforded M(II) cation radicals. The palladium(II) hydroporphyrin cation radicals were unstable on the time scale of electrolysis in all three solvents. With the exception of Cu(OEiBC), electrochemical reduction of the complexes afforded M(II) anion radicals. Chemical reduction of these complexes did not give the anion radicals, but instead proceeded directly on to the phlorin anion or chlorin-phlorin anion complexes, M(OEPH)" and M(OECH)", respectively. Electrochemical or chemical reduction of Cu(OEiBC) afforded the stable diamagnetic Cu'(OEiBC)" anion. Unlike other Cu'N, complexes, Cu'(OEiBC)" does not appear to have measurable affinity for additional ligands. The rate of oxidation of the highly reducing Cu'(OEiBC)" anion by 02 or by alkyl halides is slower than for Ni'(OEiBC)", an anion with a nearly equal reduction potential.