Abstraction fraction in the reaction of deuterium atoms with HBr and HI

Abstract
The reaction between D atoms and HX molecules (X=Br or I) may result in either abstraction of H atoms to yield HD+X or exchange of H atoms to yield DX+H. This reaction was studied at 300°K by photolyzing HX+DX+He mixtures with monochromatic light at two wavelengths. It was found that the abstraction fraction is 0.76±0.10 for X=Br and 0.88±0.08 for X=I. These results are discussed in terms of the dynamics of these reactions.