Prompt and delayed fragmentation of bromouracil cations ionized by multiply charged ions

The fragmentation of singly and multiply charged 5-bromouracil molecules (C4H3N2O2Br) induced by collisions with slow multiply charged ions has been studied. The emission of neutral fragments as well as charge separating decay channels are identified as a function of the projectile charge state. In the first case, delayed loss of neutral moieties, occurring on a μs time scale, indicates a wider internal energy distribution resulting in a power law decay. In the second case, the most important decay channels, leading to the formation of Br+, HNCO+ and CO+/NHCH+, are discussed showing that in many processes intramolecular H-migration occurs before fragmentation. Furthermore, molecular rearrangement may lead to delayed charge separating processes. Although the dication of bromouracil is unstable, smaller doubly charged systems created by the loss of neutral fragments are found to be (meta) stable.