Experimental Determination of Dissociative Recombination Reaction Pathways and Absolute Reaction Cross-Sections of CH2OH+, CD2OD+ and CD2OD2+

Mathias Hamberg (1) , Wolf Dietrich Geppert (2) , Richard D Thomas (1) , Vitaly Zhaunerchyk (1) , Fabian Österdahl (3) , Anneli Ehlerding (1) , Magdalena Kaminska (4) , Jacek Semaniak (4) , Magnus af Ugglas (1) , Anders Källberg (5) , Andràs Paál (5) , Mats Larsson (1)

1 Physics Department
2 Physics
3 Physics Department
4 Swietokrzyska Akademy
5 Manne Siegbahn Laboratory

Measurements of the cross-sections and branching ratios of the dissociative recombination of the ions CH2OH+, CD2OD+ and CD2OD2+ have been performed at the CRYRING storage ring located in Stockholm, Sweden. Evaluation of the data yielded reaction rate coefficients of: 7.0 x 10-7( T/300) -0.78 cm3mol-1s -1 for CH2OH+; 7.5 x 10-7(T/300) -0.70 cm3 mol-1s-1 for CD2OD+ and 1.51 x 10-6(T/300)-0.66 cm3 mol-1s-1 for CD2OD2+. Calculation of the branching ratios for CH2OH+ and its deuterated isotopologue gave the following results for the DR reaction channels involving C-O bond fissure: H2O+CH (2.2%) and CH2+OH (5.5%) in the reaction of CH2OH+ as well as D2O+CD (5%) and CD2+OD (18%) for the dissociative recombination of CD2OD+. The remainder of the reaction flux kept the C-O bond intact: 92% for CH2OH+ and 77% for CD2OD+, respectively. Other recent measurements on the CH3OH2+ ion indicate dominating bond breaking between the heavy atoms which is conversely to this experiment. For CD2OD2+ CO-bond breaking was observed for 57% of the reaction flux.

Mots clés: Physical Sciences

Mathias Hamberg, Wolf Dietrich Geppert, Richard D Thomas, Vitaly Zhaunerchyk, Fabian Österdahl, et al.. Experimental Determination of Dissociative Recombination Reaction Pathways and Absolute Reaction Cross-Sections of CH2OH+, CD2OD+ and CD2OD2+. Molecular Physics, 2007, 105 (05-07), pp.899-906. ⟨10.1080/00268970701206642⟩. ⟨hal-00513081⟩