title: Vibrational energy transfer near a dissociative adsorption transition state: State-to-state study of HCl collisions at Au(111).
abstract: In this work we seek to examine the nature of collisional energy transfer between HCl and Au(111) for nonreactive scattering events that sample geometries near the transition state for dissociative adsorption by varying both the vibrational and translational energy of the incident HCl molecules in the range near the dissociation barrier. Specifically, we report absolute vibrational excitation probabilities for HCl(v = 0 → 1) and HCl(v = 1 → 2) scattering from clean Au(111) as a function of surface temperature and incidence translational energy. The HCl(v = 2 → 3) channel could not be observed-presumably due to the onset of dissociation. The excitation probabilities can be decomposed into adiabatic and nonadiabatic contributions. We find that both contributions strongly increase with incidence vibrational state by a factor of 24 and 9, respectively. This suggests that V-T as well as V-EHP coupling can be enhanced near the transition state for dissociative adsorption at a metal surface. We also show that previously reported HCl(v = 0 → 1) excitation probabilities [Q. Ran et al., Phys. Rev. Lett. 98, 237601 (2007)]-50 times smaller than those reported here-were influenced by erroneous assignment of spectroscopic lines used in the data analysis.
authors: Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
authors: Jan
authors: J
authors: Geweke
authors: Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
authors: Pranav R
authors: PR
authors: Shirhatti
authors: Department of Natural Sciences, The Open University of Israel, 4353701 Ra'anana, Israel.
authors: Igor
authors: I
authors: Rahinov
authors: Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
authors: Christof
authors: C
authors: Bartels
authors: Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
authors: Alec M
authors: AM
authors: Wodtke