Electrochemical control of the regioselectivity in the exohedral functionalization of C60: the role of aromaticity.

In this work we show that the regioselectivity of the Diels-Alder, 1,3-dipolar, and carbene cycloadditions to C(60) changes from the usual [6,6] addition in neutral species to the [5,6] attack when the number of electrons added to the fullerenic cage increases. Changes in the aromaticity of the five- and six-membered rings of C(60) during the reduction process provide a rationale to understand this regioselectivity change.