Light-induced electron transfer of a supramolecular bis(zinc porphyrin)-fullerene triad constructed via a diacetylamidopyridine/uracil hydrogen-bonding motif

Using a diacetylamidopyridine/uracil complementary hydrogen-bonding motif, a novel bis(zinc porphyrin)-fullerene supramolecular triad is constructed and characterized. The geometry of the triad deduced from DFT-MO studies revealed the presence of the "three-point" hydrogen bonding and that one of the porphyrin units of the dimer is closer to the fullerene entity. Picosecond time-resolved emission and anosecond transient absorption techniques were employed, respectively, to evaluate the kinetics of electron transfer and to characterize the electron-transfer products. The positioning of the porphyrin entity with respect to the fullerene entity (near or far) seems to influence the kinetics of charge-separation and charge-recombination events, thus delineating the structural importance of the studied supramolecular triad in governing the electron-transfer rates.