Regiospecifically [alpha]-[super 13]C-labeled porphyrins for studies of ground-state hole transfer in multiporphyrin arrays

A p-diphenylethyne-linked zinc porphyrin dyad with two [super 13]C atoms and one unlabeled was prepared to understand ground-state hole/electron-transfer process in oxidized multiporphyrin architectures. The slower hole-transfer rate compared to that of meso-diphenylethyne-linked, electron-rich porphyrin dyads is attributed to the [a.sub.2u] HOMO with substantial electron/spin density at the meso-carbons.