Photoinduced electron-transfer processes in fullerene-based donor - Acceptor systems

Photoinduced electron-transfer processes in fullerene-based donor-acceptor dyads (D-B-A) in homogeneous and cluster systems are summarized. Stabilization of charge has been achieved through the use of fullerene substituted-aniline/heteroaromatic dyads with tunable ionization potentials and also by using fullerene clusters. The rate constants for charge separation (k(CS)) and charge recombination (k(CR)) in fullerene substituted-aniline/heteroaromatic dyads show that forward electron transfer falls in the normal region of the Marcus curve and the back electron transfer in the inverted region of the Marcus parabola. Clustering of fullerene-based dyads assists in effective delocalization of the separated charge and thereby slows down the back electron transfer in these cases.