Ions interacting with complex molecular systems: The effect of a surrounding environment

This paper highlight results from studies of keV-ion impact on complex molecules and molecular clusters, which have been carried out at the ARIBE facility in Caen (France) during the last decade. Studies of fullerenes, Polycyclic Aromatic Hydrocarbons (PAHs), and biomolecules are reviewed with focus on the effect of a surrounding environment when ions interact with weakly bound clusters of theses species. One common result is that charge and energy are rapidly shared between the individual molecules in the clusters, in contrast to e.g. weakly bound atomic clusters where the charge stay localized to a few atoms from which the electrons are removed during the collisions. Another important finding is that ion collisions may induce reactions within clusters such as e.g. proton transfer and different types of molecular growth processes. In the latter case, these processes may be driven by prompt non-statistical atom knockouts in billiard-ball like atom-atom collisions favouring highly reactive fragments. In contrast, statistical fragmentation in general yields different and less reactive fragments.