Electron capture induced dissociation of nucleotide anions in water nanodroplets.

We have studied the outcome of collisions between the hydrated nucleotide anion adenosine 5^′-monophosphate (AMP) and sodium. Electron capture leads to hydrogen loss as well as water evaporation regardless of the initial number m of water molecules attached to the parent ion (m≤=16). The yield of dianions with microsecond lifetimes increases strongly with m, which is explained from dielectric screening of the two charges by the water nanodroplet. For comparison, collision induced dissociation results in water losses with no or very little damage of the AMP molecule itself [ABSTRACT FROM AUTHOR]