Pulse-Duration Effects on Competitive Reactions in Infrared Multiple-Photon Decomposition of CH2ClCHClF and CHClFCHClF

Article abstract of DOI:10.1021/j100412a038

Vibrationally excited 1,2-dichlorofluoroethane and 1,2-dichloro-1,2-difluoroethane have been observed to dissociate competitively via two channels to form vibrationally excited HCl and HF.The fluence dependences of the branching ratio have been measured for both "short"-pulse (80-ns fwhm) and "long"-pulse (80-ns fwhm with 1-μs-fwhm tail) irradiations.The branching ratio shows not only fluence dependence but also pulse-duration dependence, that is, intensity dependence.When the reactant pressure is 1.0 Torr, collisional deactivation is expected to occur to a considerable extent under long-pulse irradiation while it can be ignored under short-pulse irradiation.The experimental results are interpreted by using the exact stochastic method based on the energy-grained master equations, which take into account collisional deactivation.