Features of chemical reactions at vanishing kinetic energy: the presence of internally “hot” reagents
Department of Chemistry and INFM, The University of Rome “La
Sapienza”, P.le A. Moro 5, 00185 Rome, Italy
Corresponding author: a email@example.com
Published online: 7 September 2004
The reactions between vibrationally and rotationally excited and molecules and the atom are analyzed at ultra-low collision energies using the Coupled Channels quantum approach. The aim of this work is to compare the relative efficiency of the reactive scattering event with that of the vibrational or rotational quenching process in the ultra-cold temperature regime in order to establish general trends, possibly amenable to experiments on this or on more complex systems. We have already compared the rotational de-excitation efficiency with the reactive one in the reaction [CITE] and we have seen in that case that rotational de-excitation is more efficient than reaction when going down to ultra-low energies. We are investigating here the vibrational excitation case when the internal energy of the molecule becomes large enough to be above the classical barrier, and we are also presenting new results for the rotationally hot partner. We find that, with vibrationally “hot” molecules, the reaction becomes more efficient than the relaxation process, while the relative efficiency of such processes when having rotationally hot molecular partners is much more system-dependent.
PACS: 34.10.+x – General theories and models of atomic and molecular collisions and interactions (including statistical theories, transition state, stochastic and trajectory models, etc.) / 34.50.Lf – Chemical reactions, energy disposal, and angular distribution, as studied by atomic and molecular beams / 34.20.Mq – Potential energy surfaces for collisions
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004