Imaging the Atomistic Dynamics of Single Proton Transfer and Combined Hydrogen/Proton Transfer in the O(–) + CH(3)I Reaction

[Image: see text] We report on reactive scattering studies of the proton transfer and combined hydrogen/proton transfer in the O(–) + CH(3)I reaction. We combine state-of-the-art crossed-beam velocity map imaging and quantum chemistry calculations to understand the dynamics for the formations of the CH(2)I(–) + OH and CHI(–) + H(2)O products. The experimental velocity- and angle-differential cross section show for both products and at all collision energies (between 0.3 and 2.0 eV) that the product ions are predominantly forward scattered. For the CHI(–) + H(2)O channel, the data show lower product velocities, indicative of higher internal excitation, than in the case of single proton transfer. Furthermore, our results suggest that the combined hydrogen/proton transfer proceeds via a two-step process: In the first step, O(–) abstracts one H atom to form OH(–), and then the transient OH(–) removes an additional proton from CH(2)I to form the energetically stable H(2)O coproduct.