Encapsulation of halide anions in perhydrogenated silicon fullerene: X −@Si 20H 20 (X = F, Cl, Br, I)

Abstract

We report the results of a density functional study of the encapsulation of halide anions into the dodecahedral cage of the perhydrogenated silicon fullerene Si 20H 20. The HOMO–LUMO energy gap of the endohedral complexes X −@Si 20H 20 (X = F, Cl, Br, I) is only ∼0.5 eV larger than that computed for the empty fullerene. The amount of charge that is being transferred from the encapsulated anion to the fullerene increases from F − (∼10%) to I − (>70%). Only the encapsulation of Br − does not alter the cage thus indicating that this spherical anion might be employed in the anion-templated synthesis of the elusive Si 20H 20 cluster.