Gas-Phase Chemistry of CH3SOH, (-)CH2(+)SHOH, CH3SO(.), and (.)CH2SOH by Neutralization-Reionization Mass Spectrometry

Article abstract of DOI:10.1021/ja00202a005

The kinetically unstable molecules methanesulfenic acid (CH3SOH, 1) and its ylide isomer ((-)CH2(+)SHOH, 2) and the isomeric radicals CH3SO(.) and (.)CH2SOH exist as distinct species in the gas phase.CH3SOH was generated by flash-vacuum pyrolysis of methyl tert-butyl sulfoxide and by neutralization of the corresponding cation radical.The ylide (-)CH2(+)SHOH was prepared by neutralizaton of the distonic ion, (.)CH2(+)SHOH, generated from di-n-butyl sulfoxide by double hydrogen rearrangement.Upon collisional activation CH3SOH decomposes to CH3(.) and (.)SOH, while(-)CH2(+)SHOH affords mainly (.)CH2SH and (.)OH.Collisionally activated dissociation (CAD) spectra of the corresponding ions also distinguish these (C,H4,O,S)(.+) isomers.The isomeric radicals CH3SO(.) and (.)CH2SOH and ions CH3SO(+) and CH2SOH(+) were characterized through their neutralization-reionization and CAD mass spectra, respectively.Decomposition mechanisms consistent with deuterium labeling are proposed, and the relative stabilities of the (C,H4,O,S) isomers are estimated by MNDO calculations.