Purification of small bandgap fullerenes

Abstract

A process for purification of the previously insoluble empty fullerenes and endohedral metallofullerenes was developed, based on sublimation from the soot and subsequent solubilization by electrochemical reduction. The newly purified fullerenes were shown to have small gaps between filled and unfilled electronic states. They are expected to be amphoteric, and have been observed to transfer electrons to the traditionally soluble fullerenes. Isolation of anionic endohedral metallofullerenes by chromatographic methods similar to those used for empty fullerenes was demonstrated. Also, wavelength and distance resolved fast photography of laser--ablated HOPG elucidated the interactions between emitting carbon species in different components of the resulting plume.