Theoretical and experimental study of the fragmentation of protonated uracil

Different fragmentation channels of protonated uracil (UH+) have been studied in a combined experimental and theoretical study. Various ESI mass spectrometry fragmentation spectra have been obtained by using collision induced fragmentation at increasing energy. The fragment at 85 Th was observed for a 10 eV collision energy while those at 96 and 70 Th were observed for larger collision energy, (20 eV). From the theoretical point of view, the anti and syn tautomers of uracil protonated at the O8 position have been considered. DFT calculations allowed us to describe the main dissociation channels of UH+ observed from the mass spectra.