Reactions of O(+) With C(n)H(2n+2), n=2-4: A Guided-Ion Beam Study
Abstract
We have measured absolute reaction cross sections for the interaction of 0+ with ethane, propane, and n-butane at collision energies in the range from near thermal to approximately 20 eV, using the guided-ion beam (GIB) technique. We have also measured product recoil velocity distributions using the GIB time-of-flight (TOF) technique for several product ions at a series of collision energies. The total cross sections for each alkane are in excess of 100 Angstrom(exp 2) at energies below ^2 eV, and in each case several ionic products arise. The large cross sections suggest reactions that are dominated by large impact parameter collisions, as is consistent with a scenario in which the many products derive from a near-resonant, dissociative charge-transfer process that leads to several fragmentation pathways. The recoil velocities, which indicate product ions with largely thermal velocity distributions, support this picture. Several product ions, most notably the C2H3+ fragment for each of the alkanes; exhibit enhanced reaction efficiency as collision energy increases, which can be largely attributed to endothermic channels within the dissociative charge-transfer mechanism.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 15, 2004
- Accession Number
- ADA423356
Entities
People
- D. J. Levandier
- Rainer A. Dressler
- Y. Chiu
Organizations
- Air Force Research Laboratory