Exohedral interaction in cationic lithium metallofullerenes

Abstract

AbstractWe present a density functional theory study on the exohedral interaction between a singly positively charged lithium atom and fullerenes: Li+–C n , n= 70, 60 and 50. We have found that the interaction is of electrostatic nature: the cation polarizes the π electronic cloud of the fullerene in an ion-induced dipole attraction. We show that these systems present a shallow potential energy surface where the local minima correspond to the interaction of the cation on top of one pentagonal or one hexagonal face of the fullerene and transition states connect them through a movement of the cation over a C–C bond. The type of interaction and the shape of the potential energy surface give rise to the so-called planetary systems, where the alkali cation is revolving around the carbon cage in orbits. The studied systems present several pathways that are more likely than others to behave as potentially favorable orbits.KeywordsExohedral fullerenesMetallofullerenesDFT