Wave packet movements near the conical intersection between two excited potential surfaces may create observable molecular oscillations.
A femtosecond pump-probe experiment is performed on tetrakis(dimethylamino)ethylene. The evolution resulting from the pi-pi(*) excitation of the CC double bond corresponds to movement along a single adiabatic potential surface with deformation along several coordinates and passage near a conical intersection. Surprisingly, this movement excites the umbrella mode of the amino groups, resulting in a measurable oscillation regime.
Sorgues
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Laboratoire Francis Perrin, CEA/DRECAM/Service des Photons, Atomes et Molécules, C.E.N. Saclay, F-91191 Gif-sur-Yvette Cedex, France.
Mestdagh
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Visticot
J P
JP
Soep
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