Low-energy crossed-beam study of the proton-transfer reaction HCO+ + H2O → H3O+ + CO

We present a crossed-beam study of the title reaction over the relative energy range 0.64 to 4.04 eV. The reactively scattered H3O+ products are formed exclusively in a very narrow angular range in the backward direction relative to the incoming HCO+ projectile. The product translational energy distributions indicate that the fraction of the total available energy appearing in product translation increases from 45% at a collision energy 0.64 eV to 73% at 4.04 eV. We argue that deviations from predictions of the spectator stripping model can be correlated with the HCO+ reagent state preparation, an argument consistent with our observations on the related H2+ + H2O system [J. Phys. Chem., 85, 1515 (1981)]