Dissociative recombination of protonated methanol
2006 (English)In: Faraday discussions (Online), ISSN 1364-5498, E-ISSN 1359-6640, Vol. 133, 177-190 p.Article in journal (Refereed) Published
The branching ratios of the different reaction pathways and the overall rate coefficients of the dissociative recombination reactions of CH3OH2+ and CD3OD2+ have been measured at the CRYRING storage ring located in Stockholm, Sweden. Analysis of the data yielded the result that formation of methanol or deuterated methanol accounted for only 3 and 6% of the total rate in CH3OH2+ and CD3OD2+, respectively. Dissociative recombination of both isotopomeres mainly involves fragmentation of the C–O bond, the major process being the three-body break-up forming CH3, OH and H (CD3, OD and D). The overall cross sections are best fitted by s = 1.2 ± 0.1 × 10-15 E-1.15±0.02 cm2 and s = 9.6 ± 0.9 × 10-16 E-1.20±0.02 cm2 for CH3OH2+ and CD3OD2+, respectively. From these values thermal reaction rate coefficients of k(T) = 8.9 ± 0.9 ×10-7 (T/300)-0.59±0.02 cm3 s-1 (CH3OH2+) and k(T) = 9.1 ± 0.9 × 10-7 (T/300)-0.63±0.02 cm3 s-1(CD3OD2+) can be calculated. A non-negligible formation of interstellar methanol by the previously proposed mechanism via radiative association of CH3+ and H2O and subsequent dissociative recombination of the resulting CH3OH2+ ion to yield methanol and hydrogen atoms is therefore very unlikely.
Place, publisher, year, edition, pages
Cambridge: Royal Society of Chemistry , 2006. Vol. 133, 177-190 p.
Atom and Molecular Physics and Optics
Research subject Chemical Physics
IdentifiersURN: urn:nbn:se:su:diva-38761OAI: oai:DiVA.org:su-38761DiVA: diva2:314600