C60Ph5Cl has electrochemical properties strikingly different from pristine C-60: the cyclovoltammetric curves show that, in the first reduction peak, two electrons are sequentially and irreversibly injected at the same potential. Analysis of the corresponding kinetics suggests that the carbon-chlorine bond is concomitantly severed and that back-oxidation of the resulting fragments regenerates the pristine fullerene derivative. The different oxidation states of this derivative of C-60 therefore repel and attract the chlorine atom, a property that further adds to the well-known special character of fullerene anions.