MECHANISM, ENERGETICS, KINETICS AND DYNAMICS OF THE REACTION C2H6+.-]C2H4+.+H2

The distributions of relative translational energy released during (i) loss of H-2 from metastable CH3CH3+. ions, (ii) loss of HD from metastable CH3CD3+. ions and (iii) loss of D2 from metastable CD3CD3+. ions were measured. The relevant parts of the potential energy surface of the reaction C2H6+. --> C2H4+. + H-2 (including isotopic variants) were investigated using various theoretical methods (high-level ab initio quantum chemistry, RRKM calculations, dynamic reaction trajectory calculations). A consistent reaction model is presented which reproduces available experimental data. Quantum mechanical barrier tunnelling is found to be important, leading to an activation energy (on the microsecond time-scale) which is approximately 0.1 eV below the critical energy.