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 sigma = 1.2 +/- 0.1 x 10(-15) E-1.15 +/- 0.02 cm(2) and sigma = 9.6 +/- 0.9 x 10(-16) E-1.20 +/- 0.02 cm(2) for CH3OH2+ and CD3OD2+, respectively. From these values thermal reaction rate coefficients of k(T) = 8.9 +/- 0.9 x 10(-7) (T/300) (- 0.59 +/- 0.02) cm(3) s(-1) (CH3OH2+) and k( T) = 9.1 +/- 0.9 x 10(-7) (T/ 300) (- 0.63 +/- 0.02) cm(3) 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
2006. Vol. 133, 177-190 p.
Dense Interstellar Clouds, Gas-Grain Chemistry, Branching Ratios, Radiative Association, Surface-Chemistry, Organic-Molecules, Comet-P/Halley, Abundance, Models, Ch3oh
IdentifiersURN: urn:nbn:se:kth:diva-41735DOI: 10.1039/b516010cISI: 000241786200013ScopusID: 2-s2.0-33750595626OAI: oai:DiVA.org:kth-41735DiVA: diva2:445191
QC 201110032011-10-032011-09-302011-10-03Bibliographically approved