J. Phys. IV France 04 (1994) C9-385-C9-392
Free electron laser infrared irradiation of molecules isolated in matrices as a tool for molecular relaxation studiesP. Roubin1, J.M. Berset2, S. Cardonatto1, H. Dubost3, J. Lefèvre3 and J.M. Ortéga2
1 P2IM, URA 773, Université de Provence, 13397 Marseille cedex 20, France
2 LURE, Bât. 209D, Université Paris-Sud, 91405 Orsay cedex, France
3 LPPM, Bât. 213, Université Paris-Sud, 91405 Orsay cedex, France
The selective excitation of different vibrational modes of the CH2D-CH2D molecule isolated in a xenon matrix at 7 K has been performed using the free electron laser source CLIO. The aim of these experiments was to test the selectivity of the different intramolecular couplings involved in the isomerization induced by the infrared irradiation. Kinetics measurements have been recorded using FT-IR spectroscopy as a probe of the sample composition and the modifications of the quantum yield with the excited mode have been obtained. Preliminary results show that the local environment strongly influences the reaction rate. Although the overall behavior of the quantum yield with energy is consistent with a RRKM process, a non statistical redistribution of the energy among the different modes is observed in some cases.
© EDP Sciences 1994