Metastable-atom-stimulated desorption from dodecanethiolate self-assembled monolayers

The potential curves for the dissociation of dodecane cation are calculated in order to discuss the indirect mechanism of metastable-atom-stimulated desorption of CHx+ from dodecanethiolate self-assembled monolayers. A single excitation configuration interaction method is used for drawing up the potential diagrams in two different reaction coordinates: CH and CC. The potential barrier height obtained for the ejection of CH3+ was smaller than that of H+, suggesting that CHx+ desorption can be triggered by the excitation of molecular orbitals even if a molecule is only locally stimulated.