Abstract: | From a comparison of the metastable ion bundance ratios for loss of C2H4 and H2S from C3H7S]+ ions in a series of alkyl thio ethers and thiols it was concluded that in most compunds these ion s isomerize to a common structure prior to decomposition in the first field free region. The mechanism for C2H4 loss from the C3H7S]+ ion gen erated from CH3SCH2CH3 was investigated in detail using 13C and 2H labelling. A rearrangement with formation of a cyclic intermediate prior to the decompistion reaction is proposed. The fragmentation is preceded by extensive hydrogen scrabling. The carbon atoms of the expelled C2H4 molecule are those of the CH2?CH3 moiety. |