Rates of the reaction C2H3+H-2 -> C2H4+H

Journal article

The reaction C2H3 + H2 → C 2H4 + H has been studied by different direct ab initio approaches. Accurate rate constants in the temperature range 200-1200 K have been derived by time-independent scattering theory, employing R-matrix propagation on a 2D reduced dimensional G3B3 potential energy surface. Reported experimental reaction rates at room temperature vary over 3 orders of magnitude as they have to be determined indirectly. The computed room temperature rate of 2.1 × 10-18 cm3 molecule-1 s-1 in this study should remove this ambiguity. At higher temperatures the calculated rates meet experimental rates from direct measurements very well. The use of a reduced dimensionality model is justified by comparing full-dimensional semiclassical tunnelling contributions to those derived on a 2D potential with the same method. The employed semiclassical approach (small curvature tunnelling) yields very similar rates to the scattering approach, thus showing that small curvature tunnelling is a very reliable method to describe reactions like these.

Authors: Tautermann, C; Wellenzohn, B; Clary, D

• Publication status: Published
• Journal: MOLECULAR PHYSICS
• Volume: 104
• Issue: 1
• Pages: 151-158
• Publication date: 2006-01-10
• DOI: 10.1080/00268970500235669
• EISSN: 1362-3028
• ISSN: 0026-8976
• Language: English