Synthetic approaches to a variety of covalently linked porphyrin-fullerenehybrids

There is substantial interest in dyads in which C-60 is covalently linked t o electron donors, such as porphyrins, which absorb light strongly in the v isible region. We present here the details of the syntheses of such compoun ds, which can be broadly organized into categories depending upon the natur e of the linker joining the two chromophores. The structural aspects of int ramolecular electronic interaction that we have sought to explore have dict ated the synthetic strategies employed to generate these classes of molecul es. Flexible glycol linkers were used to allow close approach between the f ullerene and porphyrin, facilitating through-space interactions. These link ers also allowed studies of the effects of metal cation complexation. Napht halene and alkyne linkers were used to examine the possible effects a conju gated or aromatic linker might have on photophysical properties. Finally, s teroids were used as linkers in dyads expected to possess a large distance between the two chromophores, in which only through-bond interactions betwe en the fullerene and porphyrin should be possible.