Crossed-beam universal-detection reactive scattering of radical beams characterized by laser-induced-fluorescence: the case of C-2 and CN

Continuous supersonic beams of dicarbon (C-2) and cyano (CN) radicals have been generated by a high-pressure radio-frequency discharge beam source starting from dilute mixtures in rare gases of suitable precursor molecules. Their internal quantum state distributions have been characterized by laser-induced-fluorescence (LIF) in a new crossed molecular beam-laser apparatus. These supersonic beams have been used to study the reactive scattering of C-2 and CN radicals with unsaturated hydrocarbons. This paper reports here on the C-2 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.