Facile formation of a meso-meso linked porphyrin dimer catalyzed by a manganese(IV)-oxo porphyrin

A manganese(IV)-oxo porphyrin catalyzes C-C bond formation between zinc porphyrins at the meso-position with a two-electron oxidant to afford the meso-meso linked porphyrin dimer efficiently. The meso-meso linked dimer is formed via formation of the porphyrin radical cation, and the rate-determining step in the catalytic cycle is the formation of a manganese(IV)-oxo porphyrin with a two-electron oxidant.