Vibrationally resolved inelastic scattering and charge transfer in H + +C2H2 collisions
Abstract
Differential total cross sections and time-of-flight spectra for inelastic scattering and charge transfer of protons with acetylene have been measured in a crossed molecular beam apparatus at 30 eV collision energy. Both vibrational excitation of the C-C stretch and C-H stretch vibrations are resolved in the time-of-flight spectra. The angular distributions indicate the existence of a potential well in the entrance channel of 1.2 eV. The angle dependence of the time-of-flight spectra reveal that the stiff C-H stretch vibrations are preferentially excited in grazing collisions by long range electrostatic multipole interactions, whereas the C-C stretch vibrations although softer are only excited by a short range interaction. The vibrational normal modes observed to be excited can be explained in terms of a proposed potential hypersurface and the associated nonadiabatic couplings and vibronic symmetry correlations.
- Publication:
-
Journal of Chemical Physics
- Pub Date:
- December 1991
- DOI:
- 10.1063/1.461328
- Bibcode:
- 1991JChPh..95.7969A
- Keywords:
-
- Acetylene;
- Gas-Ion Interactions;
- Hydrogen Ions;
- Inelastic Scattering;
- Proton Scattering;
- Vibrational Spectra;
- Angular Distribution;
- Charge Transfer;
- Molecular Beams;
- Time Of Flight Spectrometers;
- Atomic and Molecular Physics