Molecular Physics seminar

Collision Induced Dissociation in Biomolecule Cations

by Linda Giacomozzi (Atomic Physics)

Europe/Stockholm
FB55

FB55

Description
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)