The dissociative recombination of hydrocarbon ions. III. Methyl-substituted benzene ring compounds

C. Rebrion-Rowe, T. Mostefaoui, S. Laubé, J. B. A. Mitchell
2000 Journal of Chemical Physics  
The recombination of electrons with cyclic ions produced via ion-molecule reactions between atomic precursor ions and methyl-substituted benzene ring compounds ͑toluene, ortho-, and para-xylene and mesitylene͒ has been studied at 300 K using a flowing afterglow Langmuir probe-mass spectrometer apparatus. Differing amounts of energy can be deposited into the daughter ions depending upon which atomic precursor is used. It has been found that same-mass daughter ions formed from different
more » ... different precursors displayed different recombination rate coefficients indicating that different isomeric forms were reacting. In particular, the benzene ring of the toluene cation expands to a seven-membered ring following isomerization to the cycloheptatriene form. H atom abstraction allows two different isomeric daughter ions to be formed that do not interconvert and that display different recombination rates. A similar behavior was observed for the xylenes and for mesitylene. All recombination rates lie in the range from 10 Ϫ7 to 10 Ϫ6 cm 3 s Ϫ1 and display no apparent relation with size nor with the aromaticity of the ions.
doi:10.1063/1.1286974 fatcat:j5s36a4dtrb3tk5fg3jyq6tjqy