Monofunctionalized fullerene derivatives

In summary, functionalization of Ceo shows that a single hydrophilic addend is not sufficient to prevent the strong hydrophobic 3-dimensional interactions among the fullerene moieties and the resulting tendency to form aggregates. This precludes formation of stable monomers of monofunctionalized fullerene derivatives in aqueous solution and leads to the irreversible formation of clusters. 

Because monofunctionalization of fullerenes shows that a single hydrophilic addend is insufficient to prevent the strong hydrophobic interactions among the compounds [89, 90, 93, 94], multiple functionalized derivatives were examined as water-soluble probes. In particular, introduction of a second hydrophilic ligand (e.g., pyrrolidinium salts or carboxylates) to the fullerene core enhances the surface coverage of the hydrophobic fullerene surface. In turn, it was expected that fullerene aggregation might be suppressed. It should be stated that these water-soluble derivatives are important alternatives to the y-CD-incorporated and surfactant-embedded fullerenes. 

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