Kinetics study of two-channel hydrogen and deuterium atom reactions with interhalogen molecules

Rate constants and the ratio of rates of two available reaction channels (branching ratios) for the reactions of hydrogen and deuterium atoms with FCl, ICl, and BrF molecules were measured using a fast-flow reactor with RF discharge as source of atoms and with superheterodyne ESR spectrometer as detector. For the reaction with FCl a substantial difference was found in branching ratios when substituting hydrogen atoms with deuterium ones: ΓD+FCl/ΓH+FCl = 3.3±0.2. The results are compared with the known experimental data and theoretical calculations; in particular, the possible influence of light atom (H or D) migration in collision complex on reaction mechanism is discussed.