A NEW MANGANESE-BETA-HEPTANITRO-PORPHYRIN WITH EXTREME REDOX POTENTIALS - SPECTRAL, ELECTROCHEMICAL AND CATALYTIC PROPERTIES

Manganese etra-(2,6-dichlorophenyl)-beta-heptanitroporphyrin was prepa red by selective heptanitration of Zn(TDCPP = tetra-(2,6-dichloropheny l)porphyrin), demetallation of the resulting porphyrin and treatment w ith Mn(OAc)(2). It exists as a high-spin Mn(II) complex and it is elec trochemically oxidized to the corresponding Mn(LII) complex which exhi bits the highest redox potential reported so far for an Mn(III) porphy rin (+940 mV versus SCE). Moreover it acts as a three-electron reservo ir after three successive, reversible reductions at potentials unusual ly high for such reactions (+43, -220 and -745 mV versus SCE). It is a lso a good catalyst for alkene epoxidation and alkane hydroxylation by PhIO which constitutes a non-classical behavior for an Mn(II) porphyr in, (C) 1998 Elsevier Science S.A. All rights reserved.