Ion-molecule reactions involving methyl isocyanide and methyl cyanide

摘要

Ion-molecule reactions involving methyl isocyanide and methyl cyanide have been performed in a new rf-only hexapole collision cell inserted in a large-scale tandem mass spectrometer. Beside protonation processes, N-methyl cyanogen ions (CH3N+CCN) and 1-methyleneiminium-1-ethylenium ions (CH2CN+CH2) have been produced in high yield and fully characterized by high-energy collisional activation. The unimolecular chemistry of the molecular ions of caffeine (1,3,7-trimethyl xanthine) has been revisited on the basis of these new results.