Darmstadt 2008 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 19: Kalte Moleküle III [gemeinsam mit MO]
Q 19.5: Vortrag
Dienstag, 11. März 2008, 15:00–15:15, 3G
Competing chemical dynamics in F− + CH3Cl — •Rico Otto, Jochen Mikosch, Sebastian Trippel, Christoph Eichhorn, Matthias Weidemüller, and Roland Wester — Physikalisches Institut, Universität Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg
Chemical reactions often show a variety of competing reaction mechanisms depending on the energy available. We have studied this for anion molecule nucleophilic substitution (SN2) reactions [1], which are described by a complex potential energy surface with a submerged barrier and by weak coupling of the relevant rotational-vibrational quantum states.
Here we present results for the anion molecule reaction F− + CH3I
which we studied in a crossed beam
imaging experiment at low energies between 0.3 - 12.5 eV. We have observed
three distinct reaction channels which we identified by time of flight analysis of
the formed product ions. By mapping the transfer from translational energy into
internal vibrational modes we could identify different reaction mechanisms
for each of these channels.
J. Mikosch, S. Trippel, C. Eichhorn, R. Otto, U. Lourderaj, J. X. Zhang,
W. L. Hase, M. Weidemüller, R. Wester, Science (in press)