Crossed-beam universal-detection reactive scattering of radical beams characterized by laser-induced-fluorescence: the case of C2 and CN

Piergiorgio Casavecchia (1) , Francesca Leonori (2) , Kevin M. Hickson (3) , Sébastien D. Le Picard (4) , Xingan Wang (5) , Raffaele Petrucci (2) , Paolo Foggi (2) , Nadia Balucani (2)

1 Dipartimento di Chimica
2 Dipartimento di Chimica [Perugia]
3 ISM - Institut des Sciences Moléculaires
4 IPR - Institut de Physique de Rennes
5 State Key Laboratory of Molecular Reaction Dynamics

We have generated continuous supersonic beams of dicarbon (C2) and cyano (CN) radicals by a high-pressure radio-frequency discharge beam source starting from dilute mixtures in rare gases of suitable precursor molecules. We have subsequently characterized their internal quantum state distributions by laser-induced-fluorescence (LIF) in a new crossed molecular beam-laser apparatus. We have used these supersonic beams to study the reactive scattering of C2 and CN radicals with unsaturated hydrocarbons. We report here on the C2 and CN radical beam characterization by LIF and on dynamics studies of the reactions CN + C2H2 (acetylene) and CN + CH3CCH (methylacetylene) by the crossed molecular beam scattering technique with universal mass spectrometric detection and time-of-flight analysis. The role of CN rovibrational excitation on the dynamics of the CN + C2H2 reaction is discussed with reference to previous dynamics and kinetics studies. These reactions are of interest in the chemistry of planetary atmospheres (Titan) and the interstellar medium as well as in combustion.

Mots clés: Physical Sciences

Piergiorgio Casavecchia, Francesca Leonori, Kevin M. Hickson, Sébastien D. Le Picard, Xingan Wang, et al.. Crossed-beam universal-detection reactive scattering of radical beams characterized by laser-induced-fluorescence: the case of C2 and CN. Molecular Physics, 2010, 108 (07-09), pp.1097-1113. ⟨10.1080/00268971003657110⟩. ⟨hal-00596291⟩