1,3-Dipolar cycloaddition of azomethine ylides to C-60 generates a family o
f fullerene derivatives, colloquially termed fulleropyrrolidines. In this p
aper, we report the synthesis and the electrochemical properties of fullero
pyrrolidine and fulleropyrrolidinium ion derivatives. Cyclic voltammetry me
asurements, performed using ultramicroelectrodes at -60 degrees C with scan
rates as high as 50 V/s, allowed, for the first time in fullerene derivati
ves, the observation of six fullerene-centered reductions. These derivative
s also exhibit enhanced electron-accepting properties with respect to both
the parent fulleropyrrolidine derivatives and C-60. Bulk electrolysis carri
ed out at the stage of the first reduction potential, gives rise to a stabl
e zwitterion, with both anion and cation located on the fullerene derivativ
es. (C) 2000 Elsevier Science Ltd. All rights reserved.