Structure and formation of gaseous [C4H5O]+ Ions. II–Ions of the type HCC$$ \mathop {\rm C}\limits^{\rm + } $$(OH)(CH3)

Abstract Loss of an alkyl group X⋅ from acetylenic alcohols HCCCX(OH)(CH 3 ) and gas phase protonation of HCCCOCH 3 are both shown to yield stable HCC $$ \mathop {\rm C}\limits^{\rm + } $$ (OH)(CH 3 ) ions. Ions of this structure are unique among all other [C 4 H 5 O] + isomers by having m / z 43 [C 2 H 3 O] + as base peak in both the metastable ion and collisional activation spectra. It is concluded that the composite metastable …