The vinyloxonium cation, {article}{empty}{document}CH₂ = CH - O⁺ H₂{document}, a stable [C2H5O]+ species in the gas phase

The charge stripping mass spectra of [C2H5O]+ ions permit the clear identification of four distinct species: {article}{empty}{document}CH₃ - O - C⁺ H₂{document} , {article}{empty}{document}CH₃ - C⁺ H - OH{document} , and {article}{empty}{document}CH₂ = CH - O⁺ H₂{document} . The latter, the vinyloxonium ion, has not been identified before. It is generated from ionized n‐butanol and 1,3‐propanediol. Its heat of formation is estimated to be 623±12 kJ mol−1. The charge stripping method is more sensitive to these ion structures than conventional collisional activation, which focuses attention on singly charged fragment ions.