Vibrational Relaxation of Highly Vibrationally Excited CO Scattered from Au(111): Evidence for CO- Formation

Roman J V Wagner; Niklas Henning; Bastian C Krüger; G Barratt Park; Jan Altschäffel; Alexander Kandratsenka; Alec M Wodtke; Tim Schäfer

doi:10.1021/acs.jpclett.7b02207

Vibrational Relaxation of Highly Vibrationally Excited CO Scattered from Au(111): Evidence for CO^- Formation

J Phys Chem Lett. 2017 Oct 5;8(19):4887-4892. doi: 10.1021/acs.jpclett.7b02207. Epub 2017 Sep 26.

Authors

Roman J V Wagner¹, Niklas Henning¹, Bastian C Krüger¹, G Barratt Park^{1

2}, Jan Altschäffel^{1

2}, Alexander Kandratsenka², Alec M Wodtke^{1

2

3}, Tim Schäfer¹

Affiliations

¹ University of Goettingen , Institute of Physical Chemistry, Tammannstraße 6, 37077 Goettingen, Germany.
² Department of Dynamics at Surfaces, Max-Planck-Institute for Biophysical Chemistry , Am Faßberg 11, 37077 Goettingen, Germany.
³ International Center for Advanced Studies of Energy Conversion, University of Goettingen , Tammannstraße 6, 37077 Goettingen, Germany.

PMID: 28930463
DOI: 10.1021/acs.jpclett.7b02207

Abstract

Electronically nonadiabatic dynamics can be important in collisions of molecules at surfaces; for example, when vibrational degrees of freedom of molecules are coupled to electron-hole-pair (EHP) excitation of a metal. Such dynamics have been inferred from a host of observations involving multiquantum relaxation of NO molecules scattered from metal surfaces. Electron transfer forming transient NO^- is thought to be essential to the nonadiabatic coupling. The question remains: is this behavior usual? Here, we present final vibrational state distributions resulting from the scattering of CO(v_i = 17) from Au(111), which exhibits significantly less vibrational relaxation than NO(v_i = 16). We explain this observation in terms of the lower electron affinity of CO compared to NO, a result that is consistent with the formation of a transient CO^- ion being important to CO vibrational relaxation.