Endohedral rare-earth fullerene complexes

Abstract

The technique or carbon-arc evaporation has been successfully utilized to encapsulate a wide variet y of rare-earth species in carbon cases. We have observed Mm@Cn (M = Ce, Nd, Sm. Eu, Gd, Tb, Dy, Ho or Er } species present in the toluene extracts of the carbon soot using laser desorption mass spectrometry. The presence of multiple-metal species appears to depend strongly on the metal-to-carbon atom ratio found in the starting rods, with the higher metal concentrations favouring multiple-metal incorporation. One often observed dimetallcfullerene is M2@C80. Molecular orbital arguments are presented to support a possible icosahedral structure for C80.