Gas-phase cleavage of the novel iminium ions [R1CH+NCHR2 ↔ R1CHN+CHR2]: An experimental and computational study

The preparation of the novel iminium ions [R1CH+NCHR2 ↔ R1CHN+CHR2] and mechanistic study of their gas-phase reactions have been carried out by mass spectrometry and density functional theory. DFT calculations show that this kind of iminium ion is similar to the allene in structure. Two main reaction pathways have been assumed: one is the simple cleavage, including homolytic and heterolytic cleavages of the CC bond; the other might be the intramolecular cyclization, which is supported by the loss of HCN.