Dynamical study of the H5O+2+H3O−2 neutralization reaction using the polarization model

Computer-generated classical trajectories have been used to simulate reactive collisions between the gas phase ionic species H5O+2 and H3O−2. Two cases have been considered, corresponding, respectively, to the isotopic choices H3 16O−2 and D3 18O−2 for the anion. Two hundred trajectories were constructed for each case, with initial conditions corresponding to zero incident energy. The multidimensional potential energy hypersurface required for the dynamics was supplied by the ’’polarization model.’’ Distributions were calculated for exit angles and for excitation energies of the water molecules produced by the exothermic reaction. Product molecules whose oxygens have anionic origin tend to be ’’hotter’’ than those with cationic origin. Most of the collisions entail simple proton transfer as expected for neutralization; however, approximately 3% exhibit concerted transfer of three protons or deterons. Isotropic labeling of the anion causes little change in the various product distributions, and seems thereby to afford a means to verify present results experimentally.