Mechanism, energetics, kinetics and dynamics of the reaction C₂H₆+˙ → C₂H₄+˙ + H₂

The distributiosn of relative translational energy released during (i) loss of H 2 from metastable CH 3 CH 3 +˙ ions, (ii) loss of HD from metastable CH 3 CD 3 +˙ ions and (iii) loss of D 2 from metastable CD 3 CD 3 +˙ ions were measured. The relevant parts of the potential energy surface of the reaction C 2 H 6 +˙ → C 2 H 4 +˙ + 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.