Synthesis and EPR studies of the first water-soluble N@C 60 derivative.

The first water-soluble derivative of the paramagnetic endohedral fullerene N@C-60 has been prepared through the covalent attachment of a single addend containing two permethylated b-cyclodextrin units to the surface of the carbon cage. The line width of the derivative's EPR signal is highly sensitive to both the nature of the solvent and the presence of Cu(II) ions in solution.