A new manganese-beta-heptanitro-porphyrin with extreme redox potentials: spectral, electrochemical and catalytic properties

摘要

Manganese tetra-(2,6-dichlorophenyl)-beta-heptanitroporphyrin was prepared by selective heptanitration of Zn(TDCPP = tetra-(2,6-dichlorophenyl)porphyrin), demetallation of the resulting porphyrin and treatment with Mn(OAc)(2). It exists as a high-spin Mn(II) complex and it is electrochemically oxidized to the corresponding Mn(LII) complex which exhibits the highest redox potential reported so far for an Mn(III) porphyrin (+940 mV versus SCE). Moreover it acts as a three-electron reservoir after three successive, reversible reductions at potentials unusually high for such reactions (+43, -220 and -745 mV versus SCE). It is also a good catalyst for alkene epoxidation and alkane hydroxylation by PhIO which constitutes a non-classical behavior for an Mn(II) porphyrin, (C) 1998 Elsevier Science S.A. All rights reserved. [References: 15]