Charge separation and exoelectron generation in collisions of sodium clusters with O2, Cl2 and C60

Near thermal energy collisions of sodium clusters with O2, Cl2 and C60 are shown to lead to the production of large amounts of molecular ions. In the case of C60, charge separation to form Nax+ and C60− is facilitated by the collision kinetic energy. In contrast, in a process driven by the reaction exoergicity of dissociative chemisorption, O2 and Cl2 collisions can give rise to electron emission to yield NaxX2+. Both collision outcomes bear analogies to charging phenomena previously observed at bulk surfaces and to reactions of alkali atoms and dimers in the gas phase.