Rearrangements and fragmentations of [C₂H₅S]⁺ ions

Abstract

Abstract [C 2 H 5 S] + ions ( m / e 61) with different initial structures were generated in the mass spectrometer from twelve precursor ions. Abundance ratios of competing metastable ion decompositions were used to determine whether these ions decompose through the same or different reaction channels. It was concluded that all [C 2 H 5 S] + ions isomerize to a common structure or mixture of structures prior to decomposition in the first field free region. From 13 C labelling experiments it was concluded that [C 2 H 5 S] + ions generated from the molecular ions of 2‐propanethiol‐2‐[ 13 C], partially rearrange to a symmetrical structure before decomposition to [CHS] + and CH 4 , whereas in [C 2 H 5 S] + ions generated from the the molecular ions of 1,2‐bis‐(thiomethoxy‐[ 13 C]) ethane, the two carbon atoms become fully equivalent before CH 4 loss occurs.