Synthesis and electrochemical properties of ionic fullerene derivatives

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.