Photoinduced electron transfer in a beta,beta'-pyrrolic fused ferrocene-(zinc porphyrin)-fullerene.

A donor-acceptor linked triad with a short spacer (Fc-ZnP-C60) 1 was designed and synthesised to attain the longest charge-separation lifetime, 630 micros, ever reported for triads at room temperature. The ferrocene electron donor and fullerene electron acceptor of triad 1 are attached to imidazole rings fused to opposite beta,beta'-pyrrolic positions of the zinc porphyrin. After excitation of the porphyrin, electron transfer to C60 occurs within 230 ps, followed by hole transfer to ferrocene after 500 ps to produce the long-lived charge-separated state.