Versatile interactions of boron fullerene B80 with gas molecules

Abstract

Stable all-boron fullerene B₈₀ supplements a family of elemental cage molecules. These molecules may initiate a drastic rise to intriguing new chemistry. The principal stability of B₈₀ was recently demonstrated using photoelectron spectroscopy. We report the systematic investigation of different aspects of B₈₀ interactions with small gas molecules—such as carbon dioxide, molecular hydrogen, hydrogen sulfide, hydrogen fluoride, ammonia and sulfur dioxide—employing density functional theory. We found peculiar interactions between B₈₀ and ammonia resulting in the formation of a weak boron–nitrogen covalent bond in one of their local-minimum configurations. Hydrogen fluoride maintains a weak hydrogen bond with B₈₀. The boron fullerene was found to be strongly polarizable, with its electron density distribution changing significantly even in the presence of low-polar gases. The binding energies of the gas molecules to B₈₀ are generally in direct proportion to their dipole moments. Valence bands are predominantly localized on B₈₀. According to the present findings, one of the prospective applications of B₈₀ in future may be gas capture and separation.