Direct translation-to-vibrational energy transfer of HCl on gold: Measurement of absolute vibrational excitation probabilities
نویسندگان
چکیده
Vibrational excitation of HCl molecules (m = 0 ! 1) has been observed when HCl molecular beams at energies of 0.59–1.37 eV are scattered from a Au(111) surface at low surface temperature (Ts = 273 K). The incident and scattered HCl is probed state-selectively using 2 + 1 REMPI. The vibrational excitation probability depends strongly on incidence kinetic energy, Ei, exhibiting a threshold near Ei = 0.57 eV. We measured the absolute vibrational excitation probability which varies from 10 6 to 10 5 over this energy range, 1–2 orders of magnitude higher than the thermal equilibrium expectation value. The magnitude of the excitation probability, the near specular angular distributions of the scattered m = 1 molecules and the dramatic narrowing of the angular distribution near threshold are all consistent with a direct translation to vibration (T–V) mechanical energy transfer mechanism. 2006 Elsevier B.V. All rights reserved. PACS: 79.20.Rf; 34.50.Ez; 68.35.Ja
منابع مشابه
Vibrational energy transfer near a dissociative adsorption transition state: State-to-state study of HCl collisions at Au(111).
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 p...
متن کاملElectron hole pair mediated vibrational excitation in CO scattering from Au(111): incidence energy and surface temperature dependence.
We investigated the translational incidence energy (Ei) and surface temperature (Ts) dependence of CO vibrational excitation upon scattering from a clean Au(111) surface. We report absolute v = 0 → 1 excitation probabilities for Ei between 0.16 and 0.84 eV and Ts between 473 and 973 K. This is now only the second collision system where such comprehensive measurements are available - the first i...
متن کاملObservation of direct vibrational excitation in gas-surface collisions of CO with Au(111): a new model system for surface dynamics.
We report vibrational excitation of CO from its ground (v = 0) to first excited (v = 1) vibrational state in collision with Au(111) at an incidence energy of translation of E(I) = 0.45 eV. Unlike past work, we can exclude an excitation mechanism involving temporary adsorption on the surface followed by thermalization and desorption. The angular distributions of the scattered CO molecules are na...
متن کاملOn the determination of absolute vibrational excitation probabilities in molecule-surface scattering: case study of NO on Au(111).
We describe a method to obtain absolute vibrational excitation probabilities of molecules scattering from a surface based on measurements of the rotational state, scattering angle, and temporal distributions of the scattered molecules and apply this method to the vibrational excitation of NO scattering from Au(111). We report the absolute excitation probabilities to the v = 1 and v = 2 vibratio...
متن کاملDirect dynamics study of energy transfer and collision-induced dissociation: Effects of impact energy, geometry, and reactant vibrational mode
Quasiclassical, direct dynamics trajectories, calculated at the B3LYP/6-31G** level of the theory, have been used to study the energy transfer dynamics and collision-induced dissociation ~CID! of formaldehyde cation in collisions with Ne. Effects of varying collision energy were probed for ground state H2CO , and H2CO 1 with excitation in three different vibrational modes: n6 1 ~in-plane CH2 ro...
متن کامل