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Molecular Physics seminar

Collision Induced Dissociation in Biomolecule Cations

by Linda Giacomozzi (Atomic Physics)

FB55 ()


We have recently measured absolute cross sections for knockout of single carbon atoms in collisions between PAH ions and noble gases [1] [2] [3]. The knockout process in PAH molecules can result in highly reactive fragments, which are not formed in statistical fragmentation [4]. These fragments may be key intermediate steps in the formation of larger molecules in the interstellar medium. The knockout mechanism is expected to be important for any molecular system with a center-of-mass collision energy around 100 eV and down to the threshold energy for this process. PAHs are ideal for studying these processes as they have a planar rigid structure and the single carbon loss is strongly suppressed when the fragmentation is statistical [1] [2] [3]. Biomolecules on the other hand are typically non-planar and more fragile systems, and it is more complicated to distinguish non-statistical fragmentation processes from statistical ones. In this work, we have studied collisions between biomolecular ions and noble gas atoms. The experiments were carried out with the aid of a single pass collision setup, which is a part of the DESIREE facility [5] [6] at Stockholm University. We will present preliminary results on first Collision Inducted Dissociation experiments with biomolecules (Adenosine 5’-monophosphate, Adenine and Adenosine) at a center-of-mass energies of about 100 eV. We will also present early results from an experiment on porphine ions in the same energy range. References [1] M. H. Stockett et al, Phys. Rev. A. 89 032701 (2014) [2] M. H. Stockett et al, Phys. Chem. Chem Phys. 16 21980 (2014) [3] M. Gatchell et al, Int. J. Mass Spectrom. 365-366 260-265 (2014) [4] T. Chen et al, J. Chem. Phys. 140 224306 (2014) [5] H. T. Schmidt et al, Rev. Sci. Instrum. 84 055115 (2013) [6] R. D. Thomas et al, Rev. Sci. Instrum. 82 065112 (2011)