The cyclic voltammetric (CV) study of a series of novel bisfulleropyrrolidines (3) and bisfulleropyrrolidinium
ions (4) is reported. The eight possible stereoisomers of each series were systematically
investigated under strictly aprotic conditions that allowed the observation of up to four and five subsequent
reversible reductions in 3 and 4, respectively. Because of the stabilizing effect of positive charges, a
significant enhancement of the electronegative properties was observed in 4. In fact, 4-trans-2 and 4-trans-1
result among the strongest reversible electron-accepting C60 oligoadducts. Furthermore, the study evidenced
that, in both 3 and 4, the CV pattern, and in particular the potential separation between the second and
third reductions, changes significantly with the addition pattern. A sequential ð-electron model that simulates
the effect of subsequent reductions of C60 bis-adducts gives a good correlation (r > 0.96) with the cyclic
voltammetry data when the molecules are divided in two sets dependent on the location of the addends in
the same or in opposite hemispheres.
