Nonstatistical Translational Energy Distribution of H2 Elimination Products from Co+(3F4) + Propane

Abstract

The velocity map imaging technique is applied to mass-selected CoC2H4+ + CH4 and CoC3H6+ + H2 elimination products from the Co+(3F4) + propane reaction studied under crossed-beam conditions at 0.19 eV collision energy. For both products, we obtain the joint scattering probability distribution P(E,ϑ), where E and ϑ are the product translational energy and scattering angle. Both angular distributions are forward-backward symmetric and only modestly anisotropic. Both product translational energy distributions P(E) are in fairly good agreement with earlier results of Bowers and co-workers, indicating that the earlier distributions were dominated by reaction of ground-state Co+. The fraction of the total available energy deposited into product translation is 0.13 for CH4 and 0.44 for H2. For CH4 products, P(E) is cold and would be readily fit by orbiting-transition-state phase-space theory (OTS−PST) without an exit-channel barrier. Evidently, incipient CoC2H4+ + CH4 products equilibrate in the Co+(C2H4)(CH4) e...