Structure and reactions of cobalt corroles

Electrochemical studies on the cobalt corroies indicate that they are complexes of cobalt(III); these can exist as square planar, pyramidal, or octahedral complexes. Reaction of cobalt corrole with phenyl-lithium gives a phenyl derivative of cobalt(II) corrole where the additional phenyl group is probably attached to a nitrogen atom. Oxidation of triphenylphosphinecobalt(III) corroles with a high potential quinone causes conversion of the methyl groups at C-3 and C-17 into formyl substituents. Cobalt corroles may be obtained by a direct 2 + 2-type synthesis, and a related method has been used for the preparation of cobalt complexes of corrole itself.