| Autor: |
Tang, X. N., Xu, H., Zhang, T., Hou, Y., Chang, C., Ng, C. Y., Chiu, Y., Dressler, R. A., Levandier, D. J. |
| Předmět: |
|
| Zdroj: |
Journal of Chemical Physics; 4/22/2005, Vol. 122 Issue 16, p164301, 11p, 3 Charts, 4 Graphs |
| Abstrakt: |
The endothermic proton transfer reaction, H2+(υ+)+He→HeH++H(ΔE=0.806 eV), is investigated over a broad range of reactant vibrational levels using high-resolution vacuum ultraviolet to prepare reactant ions either through excitation of autoionization resonances, or using the pulsed-field ionization-photoelectron-secondary ion coincidence (PFI-PESICO) approach. In the former case, the translational energy dependence of the integral reaction cross sections are measured for υ+=0–3 with high signal-to-noise using the guided-ion beam technique. PFI-PESICO cross sections are reported for υ+=1–15 and υ+=0–12 at center-of-mass collision energies of 0.6 and 3.1 eV, respectively. All ion reactant states selected by the PFI-PESICO scheme are in the N+=1 rotational level. The experimental cross sections are complemented with quasiclassical trajectory (QCT) calculations performed on the ab initio potential energy surface provided by Palmieri et al. [Mol. Phys. 98, 1839 (2000)]. The QCT cross sections are significantly lower than the experimental results near threshold, consistent with important contributions due to resonances observed in quantum scattering studies. At total energies above 2 eV, the QCT calculations are in excellent agreement with the present results. PFI-PESICO time-of-flight (TOF) measurements are also reported for υ+=3 and 4 at a collision energy of 0.6 eV. The velocity inverted TOF spectra are consistent with the prevalence of a spectator-stripping mechanism. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
