2ème atelier international
J. Phys. IV France 05 (1995) C4-365-C4-378
Sub-Picosecond Time-Resolved Spectroscopy of Energetic Materials : the Nitromethane and Nitro-StilbenesC. Rajchenbach, G. Jonusauskas and C. Rulliere
Centre de Physique Moléculaire Optique et Hertzienne (CPMOH), UA 283 du CNRS, Université de Bordeaux I, 351 Cours de la Libération, 33405 Talence cedex, France
Using sub-picosecond CARS experiment we observed direct photolysis of liquid nitromethane after pulse excitation at 299 nm. We measured the dynamic behaviour under excitation of three main ground state Raman lines at 917 cm-l, 1400 cm-l and 2968 cm-1. We deduced an excited state lifetime of 1.1 +/- 0.3 ps and we measured a photolysis quantum yield at 299 nm of 24% +/- 5%. Using "pump-probe" experiments we observed the evolution of excited states of eight nitro-stilbene derivatives including 2,4,6,2',4',6'-hexanitro-stilbene (HNS). In the studied compounds important non-radiative desexcitation channels have been observed and their possible role on explosive process is discussed.
© EDP Sciences 1995