David Dolphin, Felton, R.H., Borg, D.C., and Fajer, J.
J. Am. Chem. Soc.
Controlled-potential oxidation of Zn meso-tetraphenylporphyrin (ZnTPP) at 1.1 V vs. SCE in CH2Cl2-Pr4NClO4 results in 2 successive reversible 1-electron oxidations. The first step generates a π-cation radical ZnTPP+., removal of the 2nd electron gives ZnTPP 2+ which is stable in the absence of nucleophiles and can be quantitative reduced to ZnTPP. The addition of MeOH to ZnTPP2+ gives I. The addition of KI to I in HOAc brings about a rapid and quantitative reduction and demetalation to H 4TPP2+ . The isoporphyrins were characterized by absorption and NMR spectra.