Fullerenes are a class of carbon molecules having an even number of carbon atoms arranged in the form of a closed hollow cage, typically spheroid, wherein the carbon-carbon bonds define a polyhedral structure.
Fullerene monolayers have been described. See, e.g., K. Chen, et al. J. Am. Chem. Soc., 115 (1993) 1193 (the self-assembled monolayer (SAM) of covalently bonded fullerenes on (MeO).sub.3 Si(CH.sub.2).sub.3 NH.sub.2 -modified oxide surfaces), and in W. B. Calwell, et al. Langmuir, 9 (1993) 1945 (SAM on HS(CH.sub.2)NH.sub.2 -modified gold surfaces).
Similarly, some fullerenes with relatively small functional groups or addends such as amido, alkoxy, and halides have been described. See, e.g., U.S. Pat. No. 5,177,248; European Application No. 546,718 (treatment of unfunctionalized fullerenes with trifluoromethanesulfonic acid and nucleophiles to form alkoxylated fullerenes); European Application No. 575,129 (treatment of unfunctionalized fullerenes with sulfuric acid to form sulfated fullerenes).
However, few macromolecules have been attached to fullerenes. K. L. Wooley, et al. (J. Am. Chem. Soc., 115 (1993) 9836) attached two dendritic (highly branched, fan-shaped) polyphenylethers to a bifunctionalized fullerene with an ether linkage. A broad mixture of products with between 1 and 10 polystyrene chains attached was obtained from reacting unfunctionalized fullerenes with living polystyrene (carbon-carbon linkage) (E. T. Samulski, et al., Chem. Mater., 4 (1992) 1153). Unfunctionalized fullerene have also been grafted with some cross-linking to an amine-containing linear polymer (carbon-nitrogen linkage) (A. O. Patil, et al., Polymer Bull., 30 (1993) 187).