Ultrafast non-adiabatic fragmentation dynamics of doubly charged uracil in gas and liquid phase

International audienceWe have studied the fragmentation of uracil in both gas phase and water environments. We have applied a combination of time-dependent density functional theory and Born-Oppenheimer molecular dynamics methods to investigate fragmentation of doubly-charged uracil. We also present the results of new ion/ion coincidence measurements in which uracil fragments are produced in collisions with 100 keV protons. Breaking of the molecule in more than two fragments mainly arises from inner shell two-electron vacancies. Orbitals of similar energy and/or localized in similar bonds can lead to very different fragmentation patterns, thus showing the importance of the intramolecular chemical environment. Simulations performed in a liquid environment predict the formation of very different fragments