@article{6901, author = {J. M. Bakker and R. K. Sinha and T. Besson and M. Brugnara and P. Tosi and J . Y. Salpin and P. Maitre}, title = {Tautomerism of Uracil Probed via Infrared Spectroscopy of Singly Hydrated Protonated Uracil}, abstract = {Tautomerism of the nucleobase uracil is characterized in the gas phase through IR photodissociation spectroscopy of singly hydrated protonated uracil created with tandem mass spectrometric methods in a commercially available Fourier transform ion cyclotron resonance mass spectrometer. Protonated Uracil ions generated by electrospray ionization are re-solvated ill a low-pressure collision cell filled with a mixture of water vapor seeded in argon. Their structure is investigated by IR photodissociation spectroscopy in the NH and OH stretching region (2500-3800 cm(-1)) with a tabletop IR laser Source and in the 1000-2000 cm(-1) range with a free-electron laser. In both regions the IR photodissociation spectrum exhibits well-resolved spectral signatures that point to the presence of two different types of structure for monohydrated protonated uracil, which result from the two lowest-energy tautomers of uracil. Ab initio calculations confirm that no water-catalyzed tautomerization occurs during the re-solvation process, indicating that the two protonated forms of uracil directly originate from the electrospray process.}, year = {2008}, journal = {Journal of Physical Chemistry A}, volume = {112}, number = {48}, pages = {12393-12400}, month = {Dec}, isbn = {1089-5639}, url = {://000261218100014 }, note = {ISI Document Delivery No.: 376YETimes Cited: 0Cited Reference Count: 46}, language = {English}, }