title: A manganese(V)-oxo π-cation radical complex: influence of one-electron oxidation on oxygen-atom transfer.
abstract: One-electron oxidation of Mn(V)-oxo corrolazine 2 affords 2(+), the first example of a Mn(V)(O) π-cation radical porphyrinoid complex, which was characterized by UV-vis, EPR, LDI-MS, and DFT methods. Access to 2 and 2(+) allowed for a direct comparison of their reactivities in oxygen-atom transfer (OAT) reactions. Both complexes are capable of OAT to PPh(3) and RSR substrates, and 2(+) was found to be a more potent oxidant than 2. Analysis of rate constants and activation parameters, together with DFT calculations, points to a concerted OAT mechanism for 2(+) and 2 and indicates that the greater electrophilicity of 2(+) likely plays a dominant role in enhancing its reactivity. These results are relevant to comparisons between Compound I and Compound II in heme enzymes.
authors: Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States.
authors: Katharine A
authors: KA
authors: Prokop
authors: Heather M
authors: HM
authors: Neu
authors: Sam P
authors: SP
authors: de Visser
authors: David P
authors: DP
authors: Goldberg
mesh_terms: D002412:Cations / Q000737:chemistry*; D004583:Electrons; D008345:Manganese / Q000737:chemistry*; D008665:Metalloporphyrins / Q000737:chemistry*; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*
chemical_list: D002412:Cations; D008665:Metalloporphyrins; C518639:manganese(V)-oxo corrolazine; D008345:Manganese; D010100:Oxygen