Site-specific interrogation of an ionic chiral fragment during photolysis using an X-ray free-electron laser
Markus Ilchen, Philipp Schmidt, Nikolay M. Novikovskiy, Gregor Hartmann, Patrick Rupprecht, Ryan Coffee, Arno Ehresmann, Andreas Galler, Nick Hartmann, Wolfram Helml, Zhirong Huang, Ludger Inhester, Alberto Lutman, James MacArthur, T. Maxwell, Michael Meyer, Valerija Music, H.-D. Nuhn, T. Osipov, D. Ray, Thomas Wolf, Sadia Bari, Peter Walter, Zheng Li, Stefan Moeller, André Knie, Philipp V. Demekhin
Abstract
Abstract Short-wavelength free-electron lasers with their ultrashort pulses at high intensities have originated new approaches for tracking molecular dynamics from the vista of specific sites. X-ray pump X-ray probe schemes even allow to address individual atomic constituents with a ‘trigger’-event that preludes the subsequent molecular dynamics while being able to selectively probe the evolving structure with a time-delayed second X-ray pulse. Here, we use a linearly polarized X-ray photon to trigger the photolysis of a prototypical chiral molecule, namely trifluoromethyloxirane (C 3 H 3 F 3 O), at the fluorine K-edge at around 700 eV. The created fluorine-containing fragments are then probed by a second, circularly polarized X-ray pulse of higher photon energy in order to investigate the chemically shifted inner-shell electrons of the ionic mother-fragment for their stereochemical sensitivity. We experimentally demonstrate and theoretically support how two-color X-ray pump X-ray probe experiments with polarization control enable XFELs as tools for chiral recognition.