Abstract
It has been demonstrated that uracil has a preponderant tautomeric form, but it is also known that different tautomers co-exist in this equilibrium. In this work, mass spectrometry is used as a helpful tool to analyse the equilibria, using derivative compounds to forbid the presence of some tautomers and ion trap mass spectrometry to follow relevant fragmentation pathways. Theoretical calculations were performed to confirm tautomers abundance by energy minimization in gas phase. Analysis of mass spectra of uracil, three methyl-substituted uracils, 2-thiouracil and three benzouracils suggest that uracil exists mainly as three tautomers in gas phase: one major structure that corresponds to the classical structure of uracil (pyrimidine-2,4(1H,3H)-dione) bearing two carbonyls and two NH moieties, and two minor enolic forms (4-hydroxypyrimidin-2(1H)-one and 2-hydroxypyrimidin-4(1H)-one). Such tautomeric distribution is supported by theoretical calculations, which show that they are the three most stable tautomers.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.