title: Crossed-beams studies of the dynamics of the H-atom abstraction reaction, O(3P) + CH4 → OH + CH3, at hyperthermal collision energies.
abstract: The H-atom abstraction reaction, O((3)P) + CH(4) → OH + CH(3), has been studied at a hyperthermal collision energy of 64 kcal mol(-1) by two crossed-molecular-beams techniques. The OH products were detected with a rotatable mass spectrometer employing electron-impact ionization, and the CH(3) products were detected with the combination of resonance-enhanced multiphoton ionization (REMPI) and time-sliced ion velocity-map imaging. The OH products are mainly formed through a stripping mechanism, in which the reagent O atom approaches the CH(4) molecule at large impact parameters and the OH product is scattered in the forward direction: roughly the same direction as the reagent O atoms. Most of the available energy is partitioned into product translation. The dominance of the stripping mechanism is a unique feature of such H-atom abstraction reactions at hyperthermal collision energies. In the hyperthermal reaction of O((3)P) with CH(4), the H-atom abstraction reaction pathway accounts for 70% of the reactive collisions, while the H-atom elimination pathway to produce OCH(3) + H accounts for the other 30%.
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA.
authors.forename: Jianming
authors.initials: J
authors.lastname: Zhang
authors.forename: Sridhar A
authors.initials: SA
authors.lastname: Lahankar
authors.forename: Donna J
authors.initials: DJ
authors.lastname: Garton
authors.forename: Timothy K
authors.initials: TK
authors.lastname: Minton
authors.forename: Weiqing
authors.initials: W
authors.lastname: Zhang
authors.forename: Xueming
authors.initials: X
authors.lastname: Yang