Speaker
Pragya Chopra
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany; Institute of Physical Chemistry, Christians-Albrecht-Universität zu Kiel, Kiel, Germany; The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany)
Description
Polycyclic aromatic hydrocarbons (PAHs) are assumed to be key players in interstellar chemistry [1]. Their interaction with energy-rich radiation can trigger the competing processes of ionization, fragmentation and dehydrogenation. Ultra-short pulses of ionizing radiation in a pump-probe experiment present a powerful tool to disentangle the underlying chemical processes that may occur during these events in the interstellar medium.
In this work, we present results from our study of the ultrafast fragmentation of three medium sized PAHs - fluorene, phenanthrene and pyrene. These molecules were ionized using extreme ultraviolet radiation at 30.3 nm provided by the free-electron laser (FEL) at Hamburg, FLASH [2]. Their reaction dynamics in the femtosecond regime were probed using 800 nm NIR pulses which were temporally delayed relative to the pump FEL pulse. This allowed us to observe the time dependent yield of different ion channels produced during the interaction. The goal of these experiments was to determine the lifetimes of the excited cationic PAHs following extreme ultraviolet excitation, and to identify the preferred reaction pathways of these molecules under such conditions. Here, we will present recent insights from our analysis.
[1] EAS Publications Series, 2011, 46, 3.
[2] J. Phys. B, 2010, 43,194002
Primary author
Pragya Chopra
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany; Institute of Physical Chemistry, Christians-Albrecht-Universität zu Kiel, Kiel, Germany; The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany)
Co-authors
Alexander Lemmens
(Radboud University, FELIX Laboratory, The Netherlands; Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, The Netherlands)
Amanda Steber
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany; Institute of Physical Chemistry, Christians-Albrecht-Universität zu Kiel, Kiel, Germany; The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany)
Anouk Rijs
(Radboud University, FELIX Laboratory, The Netherlands)
Bastian Manschwetus
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany)
Benjamin Erk
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany)
Christopher Passow
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany)
Claire Vallance
(The Chemistry Research Laboratory, University of Oxford, United Kingdom)
Daniel Ramm
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany)
Daniel Rolles
(Kansas State University, Kansas, USA)
David Heathcote
(The Chemistry Research Laboratory, University of Oxford, United Kingdom)
Dimitrios Rompotis
(European XFEL GmbH, Schenefeld, Germany)
Donatella Loru
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany; Institute of Physical Chemistry, Christians-Albrecht-Universität zu Kiel, Kiel, Germany; The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany)
Farzaneh Ziaee
(Kansas State University, Kansas, USA)
Felix Allum
(The Chemistry Research Laboratory, University of Oxford, United Kingdom)
Hansjochen Köckert
(The Chemistry Research Laboratory, University of Oxford, United Kingdom)
Jan Lahl
(Department of Physics, Lund University, Sweden)
Jason Lee
(The Chemistry Research Laboratory, University of Oxford, United Kingdom)
Jasper Peschel
(Department of Physics, Lund University, Sweden)
Jochen Küpper
(Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany; The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany; Department of Physics, Universität Hamburg, Hamburg, Germany)
Joss Wiese
(Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany)
Lanhai He
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany)
Mark Brouard
(The Chemistry Research Laboratory, University of Oxford, United Kingdom)
Mehdi Mohammad Kazemi
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany)
Melanie Schnell
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany; Institute of Physical Chemistry, Christians-Albrecht-Universität zu Kiel, Kiel, Germany; The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany)
Melby Johny
(Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany)
Michael Burt
(The Chemistry Research Laboratory, University of Oxford, United Kingdom)
Nora Schirmel
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany)
Pavel Olshin
(Saint Petersburg State University, Saint Petersburg, Russia)
Per Johnsson
(Department of Physics, Lund University, Sweden)
Rebecca Boll
(European XFEL GmbH, Schenefeld, Germany)
Robert Mason
(The Chemistry Research Laboratory, University of Oxford, United Kingdom)
Sadia Bari
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany)
Sebastian Trippel
(Center for Free-Electron Laser Science (CFEL), Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany; The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany)
Simon Dörner
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany)
Sylvain Maclot
(Department of Physics, Lund University, Sweden)
Sébastien Gruet
(Laboratorie de Physique des Lasers, Atomes et Molécules, Université Lille, France)
Terrence Mullins
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany)
Xuemei Cheng
(Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany)
