Electron-impact-induced rearrangements of organic ions: IV—Hydrogen and carbon scrambling in [t-C3H8N]+ metastable ions

Independent loss of positional identity of the hydrogen and carbon atoms in t-C₃H₈N]⁺ metastable cations prior to fragmentation in the gas phase with loss of ethylene, has been demonstrated by ²H and ¹³C labelling experiments. The scrambling reaction is interpreted as a rearrangement in competition with the high activation energy unimolecular decompositions. The study of this fragmentation process indicates the occurrence of a primary isotope effect discriminating in favour of ²H and ¹³C retention in the original methylene group.