Electrochemistry of Bis(pyridine)cobalt (Nitrophenyl)corroles in Nonaqueous Media

A series of bis(pyridine)cobalt corroles with one or three nitrophenyl groups on the meso positions of the corrole macrocycle were synthesized and characterized as to their electrochemical and spectroscopic properties in dichloromethane, benzonitrile, and pyridine. The potentials for each electrode reaction were measured by cyclic voltammetry and the electron-transfer mechanisms evaluated by analysis of the electrochemical data combined with UV-visible spectra of the neutral, electroreduced, and electroxidized forms of the corroles. The proposed electronic configurations of the initial compounds and the prevailing redox reactions involving the electroactive central cobalt ion, the electroactive conjugated macrocycle, and the electroactive meso-nitrophenyl groups are all discussed in terms of solvent binding and the number of the nitrophenyl groups and other substituents on the meso-nitrophenyl rings of the compounds.