Electronic structure and reactivity of high-valent oxo iron porphyrins

High valent oxo iron porphyrins have been prepared and characterized as models for compounds-I and compounds-II in heme enzymes. In this review, we survey studies of high valent oxo iron porphyrin complexes. Spectroscopic properties and reactivities of oxo iron(IV) porphyrin pi-cation radical complexes are summarized. Electron-withdrawing effects of meso-substituents and pyrrole beta-substituents on the electronic structure of oxo iron(IV) porphyrin pi-cation radicals are discussed. The effect of the axial ligand is also reviewed. Isoelectronic forms of oxo iron(IV) porphyrin pi-cation radical are reviewed. We have summarized the synthesis and characterization of oxo iron(IV) porphyrins as models for compounds-II. (C) 2002 Elsevier Science B.V. All rights reserved.