Tetrathiafulvalene–flavin dyads: electron transfer promoted by metal cations

Tetrathiafulvalene–flavin dyads 1 and 2 are reported. Both absorption and ESR spectral studies show that the intramolecular electron transfer occurs from TTF to flavin units in dyads 1 and 2 in the presence of Pb2+/Sc3+. But, the electron transfer is more efficient for dyad 1 in the presence of Pb2+/Sc3+. Electrochemical studies manifest that coordination of dyads 1 and 2 with Pb2+/Sc3+ play an important role in facilitating the electron transfer within dyads 1 and 2.