Reversible sidewall functionalization of buckytubes

Single-wall fullerene nanotubes have been made soluble in various organic solvents, including chloroform, methylene chloride, and tetrahydrofuran by covalently attaching alkanes to their sidewalls. Sidewall-alkylated nanotubes are obtained by reacting sidewall-fluorinated nanotubes with alkyl magnesium bromides in a Grignard synthesis or by reaction with alkyllithium precursors. Covalent attachment to the sidewalls was confirmed by UV–visible spectroscopy, which is also used to show that the alkane sidewall groups can be removed by oxidizing them in air to recover pristine nanotubes.