Charge separation in a novel artificial photosynthetic reaction center lives 380 ms

An extremely long-lived charge-separated state has been achieved successful ly using a ferrocene-zincporphyrin-freebaseporphyrin-fullerene tetrad which reveals a cascade of photoinduced energy transfer and multistep electron t ransfer within a molecule in frozen media as well as in solutions. The life time of the resulting charge-separated state (i.e., ferricenium ion-C-60 ra dical anion pair) in a frozen benzonitrile is determined as 0.38 s, which i s more than one order of magnitude longer than any other intramolecular cha rge recombination processes of synthetic systems, and is comparable to that observed for the bacterial photosynthetic reaction center. Such an extreme ly long lifetime of the tetrad system has been well correlated with the cha rge separated lifetimes of two homologous series of porphyrin-fullerene dya d and triad systems.