ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Cross sections for the reaction H+2+H2→H+3+H, differential in scattering angle and recoil energy, are measured in a molecular-beam experiment at c.m. collision energies of 1.5, 2.3, 3.5, and 5.3 eV. Resonantly enhanced four-photon ionization prepares H+2 in selected vibrational-state distributions, allowing a systematic exploration of the effects of reactant energy on the product angular and energy distributions. Angular data are interpreted on the basis of competition between H+3 formation and collision-induced dissociation. The nominal atom-transfer (AT) and proton-transfer (PT) processes are identified respectively with forward and backward scattered H+3. Effects of reactant energy on AT and PT cross sections in H+2+H2 are compared with previous observations on D+2+H2 and H+2+D2. The fraction of the available energy appearing as H+3+H recoil ranges from 26% to 39% depending on reactant conditions. Previous surface-hopping trajectory calculations successfully predict most of the observed trends. Evidence is given for the existence of long-lived H+3 with internal energy in excess of the dissociation limit.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.461704
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