Abstract
The interaction of multiply charged ions (He, , and Xe) with gas-phase pericondensed polycyclic aromatic hydrocarbon (PAH) molecules of coronene (CH) and pyrene (CH) is studied for low-velocity collisions ( a.u.). The mass spectrometric analysis shows that singly and up to quadruply charged intact molecules are important reaction products. The relative experimental yields are compared with the results of a simple classical over-the-barrier model. For higher molecular charge states, the experimental yields decrease much more strongly than the model predictions due to the instabilities of the multiply charged PAH molecules. Even-odd oscillations with the number of carbon atoms, , in the intensity distributions of the H fragments indicate a linear chain structure of the fragments similar to those observed for ion-C collisions. The latter oscillations are known to be due to dissociation energy differences between even- and odd- -chain molecules. For PAH molecules, the average numbers of H atoms attached to the H chains are larger for even- reflecting acetylenic bond systems.
1 More- Received 3 December 2010
DOI:https://doi.org/10.1103/PhysRevA.83.022704
© 2011 American Physical Society