Journal
CHEMICAL SCIENCE
Volume 1, Issue 1, Pages 55-61Publisher
ROYAL SOC CHEMISTRY
DOI: 10.1039/c0sc00141d
Keywords
-
Categories
Funding
- Department of Energy Office of Basic Energy Sciences [DE-FG02-03ER15441]
- NSF [OISE-0530268]
- Max Planck Institute for Biophysical Chemistry
- Physical Chemistry at the University of Gottingen
Ask authors/readers for more resources
Vibrational overtone excitation is, in general, inefficiently stimulated by photons, but can under some circumstances be efficiently stimulated by electrons. Here, we demonstrate electron mediated vibrational overtone excitation in molecular collisions with a metal surface. Specifically, we report absolute vibrational excitation probabilities to nu = 1 and 2 for collisions of NO(nu = 0) with a Au(111) surface as a function of surface temperature from 300 to 985 K. In all cases, the observed populations of vibrationally excited NO are near those expected for complete thermalization with the surface, despite the fact that the scattering occurs through a direct single bounce mechanism of sub-ps duration. We present a state-to-state kinetic model, which accurately describes the case of near complete thermalization (a regime we call the strong coupling case) and use this model to extract state-to-state rate constants. This analysis unambiguously shows that direct vibrational overtone excitation dominates the production of nu = 2 and that, within the context of our model, the intrinsic strength of the overtone transition is of the same order as the single quantum transition, suggesting a possible way to circumvent optical selection rules in vibrational pumping of molecules. This result also suggests that previous measurements of vibrational relaxation of highly vibrationally excited NO exhibiting highly efficient multi-quantum jumps (Delta nu similar to -8) are mechanistically similar to vibrational excitation of NO(nu = 0).
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available