[60]Fullerene-stoppered porphyrinorotaxanes. Pronounced elongation of charge-separated state lifetimes

A series of Sauvage-type porphyrinorotaxanes containing [60]fullerene stoppers have been synthesized by a convergent route. Photoinduced energy transfer and electron-transfer reactions in these rotaxanes yield long-distance charge-separated radical-pair states, whose lifetimes in solution at ambient temperatures are as high as 32 μs, depending on the distance between the fullerene and zinc porphyrin chromophores.