David Osborne - Flowing afterglow studies of dissociative electron-ion recombination for a series of single ring compounds at room temperature

Version 1

      Publication Details (including relevant citation   information):

      International Journal of Mass   Spectrometry

        Volume 305, Issue 1, 1 August 2011, Pages 35-39


      A series of dissociative electron-ion recombination reactions has   been studied at room temperature using a Flowing Afterglow with   Langmuir Probe (FALP) to determine the rate constants. Studied   species include protonated five and six membered single rings   with the heteroatoms, N, O and S and with or without   CH3 substituent groups attached to the rings. The   compounds studied are protonated benzene,   C6H7+; toluene,   C6H5CH4+; pyridine,   C5H5NH+; pyrimidine,   C4H4N2H+; 4-picoline,   C6H7NH+; cyclohexane,   C6H13+; 1,4 dioxane,   C4H8O2H+ all six   membered rings (all but the last two have π electrons in the   ring) with furan, C4H4OH+;   pyrrole, C4H5NH+;   1-methylpyrrole, C5H7NH+;   thiophene, C4H4SH+ and   pyrrolidine, C4H9NH+ all five   membered rings (with only the last mentioned having no π   electrons in the ring). Comparison is made with literature data   on some of the multi-ring systems (PAH's and PANH's). The   involvement of π electrons in the rings is discussed. Protonated   six membered rings have been shown to recombine ∼2 times faster   than five membered rings with the exception of 1,4 dioxane which   has no π electrons. The situation is very different for the   proton bound dimers, where five membered rings recombine somewhat   more rapidly than six membered rings, again with 1,4 dioxane   behaving very differently. These data are critically important in   chemically modeling the Titan ionosphere which is presently being   probed by apparatus onboard the Cassini spacecraft

      Address (URL): http://www.sciencedirect.com/science/article/pii/S1387380611001758