Photoinduced charge transfer in fullerene–donor dyads: A theoretical study

Density functional theory and time dependent density functional theory calculations have been carried out on hybrid systems of interest for photoinduced charge transfer, consisting of dyads of fulleropyrolidine as acceptor and pyrene, dithiapyrene, tetrathiofulvalene and porphyrin as donors. When the donor molecules are in close proximity to fullerene, charge transfer (D → A∗) and in some cases also fullerene (A → A∗) excitations contribute to the donor absorption (D → D∗) transition. When the donor is attached to a spacer chain, D → D∗, D → A∗ and A → A∗ are calculated as separate transitions, their near-degeneracy suggestive of the occurrence of charge and/or energy transfer through interaction of these states.