Multiple redox state control of fullerene at room temperature through interfacial electrochemistry of ionic liquids

Control of the redox states of highly charged C60 anions in two ionic liquids (ILs) was investigated using cyclic voltammetry and differential pulse voltammetry. Highly charged reduced states of C605 - and C606 - could be produced and detected at room temperature by using an electrochemical interface between a multilayered C 60 adlayer on a Au(111) electrode and N-butyl-N-methylpyrrolidinium- based IL, whereas a tributylmethylammonium-based IL provided less than four redox waves of C60. The multiple redox states of C60 were precisely controlled by a step-by-step, one-electron redox process. The results of the present study suggest that both a wide potential window and the interaction between C60 anions and IL cations are important for controlling the multiple redox states of C60 at room temperature. © 2014 Elsevier B.V.