Exchange reactions of hydrogen atoms with SiD4: an inversion mechanism?

Abstract

The reaction H + SiD₄→ D + SiH₃D is found to have a much lower threshold than the corresponding exchange reaction of H with CD₄. The D atom carries away most of the initial translational energy of the H atom. When the H-atom velocity distribution is anisotropic, the D-atom velocity distribution is anisotropic in the same sense. The exchange cross-sections for the reaction H + SiH₃D are about one half of those for SiD₄. All this evidence leads to the conclusion that the mechanism of the exchange is an inversion.