CHEMICALLY MODIFIED CARBON ELECTRODES .17. METALATION OF IMMOBILIZED TETRA(AMINOPHENYL)PORPHYRIN WITH MANGANESE, IRON, COBALT, NICKEL, COPPER AND ZINC, AND ELECTROCHEMISTRY OF DIPROTONATED TETRAPHENYLPORPHYRIN

Tetra(aminophenyl)porphyrin can be amide-bonded to oxidized glassy carbon surfaces following activation with acetyl chloride or thionyl chloride, with the latter affording higher coverage. The immobilized porphyrin can be metallated with manganese, iron, cobalt, nickel, copper and zinc. The metalloporphyrins undergo electrochemical reactions in DMSO solvent at metal and ring-centered reduction potentials expected on the basis of solution molecular analogs. In the case of iron-metallated porphyrin, electrochemistry can be done in aqueous acid, where a clear but porphyrin-debilitating dioxygen catalysis is observable. A small reverse wave at ca. -0.4 V vs. NaSCE in CH3CN and DMSO solvent is interpreted as reoxidation of diprotonated surface bound porphyrin. © 1979 Elsevier Sequoia S.A.