[CH3SO2]+, [CH3SO3H2]+and [CH3SO2OCH3H]+, positive even-electron ions from hexavalent sulfur compounds, have been studied by Fourier transform ion cyclotron resonance and collision-induced dissociation (CID). These ions showed no evidence of undergoing S → O methyl group shift, at variance with easy skeletal rearrangements frequently postulated for ionized sulfones and sulfonyl derivatives. A proton affinity value of 184 ± 2 kcal mol-1has been obtained for methanesulfonic acid by the bracketing procedure, but the site of proton attachment in [CH3SO3H2]+ions could not be established, either by CID or kinetic evidence. The methylation of SO2by (CH3)2F+ions has been ascertained to yield [CH3SO2]+ions methylated on oxygen, in analogy to the same reaction observed in a superacid medium. © 1992.
de Petris, G., Fornarini, S., & Occhiucci, G. (1992). Protonated methanesulfonic acid and related ions: a study of their gas phase structure and reactivity. International Journal of Mass Spectrometry and Ion Processes, 112(2–3), 231–246. https://doi.org/10.1016/0168-1176(92)80007-N