Competitive reactions of protonated polyamines in the gas phase

The chemical ionization mass spectra of polyamines have been used to determine the importance of competing intramolecular reactions of protonated molecules in the gas phase. Multifunctional molecules react if possible in the order of intramolecular displacement-cyclization reactions, stabilization of the protonated molecular ion through collision stabilized intramolecular hydrogen bond formation and fragmentation of an isolated protonated function. Intramolecular nucleophilic displacement reactions closely parallel the relative rates of cyclization reactions in solution. These reactions may occur from protonated functions which are neither the initial nor the most stable sites of protonation.