Vertical channeling of pyridine molecules ejected in ion bombardment experiments

Recent secondary ion mass spectrometry experiments of organic molecules on metal surfaces show that the bonding geometry of the molecule on the surface is reflected in the polar angle distributions. Specifically, the polar distribution of pyridine molecules ejected from a σ-bonded configuration on a Ag{111} is narrower than the polar distribution of benzene molecules ejected from a π-bonded configuration. Classical dynamics calculations presented here identify a new channeling mechanism in which the σ-bonded pyridine molecules on the surface focus the ejection direction of other pyridine molecules.