D abstraction and Cl abstraction in the reaction of energetic hydrogen atoms with CD2Cl2

Abstract

‘Hot’ hydrogen atoms produced by photolysis of gaseous HBr or HI react with CD₂Cl₂ by D abstraction, H*+ CD₂Cl₂→ HD + CDCl₂(1) and by Cl abstraction, H*+ CD₂Cl₂→ HCl + CD₂Cl. (2) The integral probability of reaction (1) has been measured for several defined initial translational energies of the hydrogen atom, and the phenomenological threshold energy is 41 ± 4 kJ mol^–1. Integral probabilities for reaction (2) have also been determined, and the threshold for Cl abstraction is 43 ± 10 kJ mol^–1. For initial translational energies in the range 66–120 kJ mol^–1, the ratio of the integral probabilities of Cl abstraction and of D abstraction varies between 2.1 ± 0.8 and 2.5 ± 0.5.