Low energy crossed beam study of the reactions of C/sup +/ with CH/sub 4/

Journal Article · Sun Sep 01 04:00:00 EDT 1985 · J. Chem. Phys.; (United States)

OSTI ID:5622338

Curtis, R A; Farrar, J M

We present a crossed molecular beam study of the reactions of C/sup +/ with CH/sub 4/ over the relative energy range from 0.66 to 2.38 eV. CH/sup +//sub 3/ production involves a direct rebound collision mechanism. Production of C/sub 2/H/sup +//sub 3/ and C/sub 2/H/sup +//sub 2/ proceeds through unimolecular decay of long-lived collision complexes. Hydrogen atom emission proceeds through a rotating ethylene cation and yields a polarized angular distribution of reaction products. The kinetic energy distributions for vinyl cation production place nearly three times as much of the available energy in translation as a statistical model predicts. At low collision energy, C/sub 2/H/sup +//sub 2/ production proceeds through molecular hydrogen elimination and the angular distribution for reaction products is polarized perpendicularly to the initial relative velocity vector. At a higher collision energy of 2.38 eV, the complex decays in a fraction of a rotational period. The lifetime of 0.03 ps inferred from the asymmetry in the angular distribution is in good agreement with a statistical calculation incorporating nonadiabatic couplings among the excited and ground states of C/sub 2/H/sup +//sub 4/. The recoil distribution at this energy is dramatically narrower than at the lower collision energy and is consistent with the sequential ejection of two hydrogen atoms through a metastable C/sub 2/H/sup +//sub 3/ intermediate.

• Research Organization: Department of Chemistry, University of Rochester, Rochester, New york 14627
• OSTI ID: 5622338
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 83:5; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKANES
ATOMIC IONS
BEAMS
CARBON IONS
CHARGED PARTICLES
CHEMICAL REACTIONS
COLLISIONS
ENERGY RANGE
EV RANGE
EV RANGE 01-10
HYDROCARBONS
ION COLLISIONS
ION-MOLECULE COLLISIONS
IONS
METHANE
MOLECULAR BEAMS
MOLECULE COLLISIONS
ORGANIC COMPOUNDS