Reactions of energetic hydrogen atoms with bromine and hydrogen bromide

Abstract

The reactions of high energy hydrogen atoms with HBr and Br₂ have been studied using the classical trajectory technique. Comparison of the excitation functions obtained for H, D and T atoms reacting with Br₂ shows a high energy isotope effect which favours the heavier isotope. The functions are considered in the light of the available experimental evidence for scavenger competition in hot tritium chemistry.

Excitation functions for reaction of H and D atoms with HBr and DBr suggest that at collision energies below ≈ 500 kJ mol^–1 the hydrogen atomic exchange reaction is considerably more efficient than the H-abstraction reaction. Values of the average H-abstraction cross section and hot reaction rate constant ratios predicted from the calculated excitation functions are compared with the available experimental data; good agreement is obtained.