Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-52726 Wissenschaftlicher Artikel Jay, Raphael M.; Norell, Jesper; Eckert, Sebastian Oliver; Hantschmann, Markus; Beye, Martin; Kennedy, Brian; Quevedo, Wilson; Schlotter, William F.; Dakovski, Georgi L.; Minitti, Michael P.; Hoffmann, Matthias C.; Mitra, Ankush; Moeller, Stefan P.; Nordlund, Dennis; Zhang, Wenkai; Liang, Huiyang W.; Kunnus, Kristian; Kubicek, Katharina; Techert, Simone A.; Lundberg, Marcus; Wernet, Philippe; Gaffney, Kelly; Odelius, Michael; Föhlisch, Alexander Disentangling Transient Charge Density and Metal-Ligand Covalency in Photoexcited Ferricyanide with Femtosecond Resonant Inelastic Soft X-ray Scattering Soft X-ray spectroscopies are ideal probes of the local valence electronic structure of photocatalytically active metal sites. Here, we apply the selectivity of time resolved resonant inelastic X-ray scattering at the iron L-edge to the transient charge distribution of an optically excited charge-transfer state in aqueous ferricyanide. Through comparison to steady-state spectra and quantum chemical calculations, the coupled effects of valence-shell closing and ligand-hole creation are experimentally and theoretically disentangled and described in terms of orbital occupancy, metal-ligand covalency, and ligand field splitting, thereby extending established steady-state concepts to the excited-state domain. pi-Back-donation is found to be mainly determined by the metal site occupation, whereas the ligand hole instead influences sigma-donation. Our results demonstrate how ultrafast resonant inelastic X-ray scattering can help characterize local charge distributions around catalytic metal centers in short-lived charge-transfer excited states, as a step toward future rationalization and tailoring of photocatalytic capabilities of transition-metal complexes. Washington American Chemical Society 2018 11 The journal of physical chemistry letters 9 12 3538 3543 10.1021/acs.jpclett.8b01429 Institut für Physik und Astronomie OPUS4-44958 Wissenschaftlicher Artikel Beye, Martin; Öberg, Henrik; Xin, Hongliang; Dakovski, Georgi L.; Föhlisch, Alexander; Gladh, Jorgen; Hantschmann, Markus; Hieke, Florian; Kaya, Sarp; Kühn, Danilo; LaRue, Jerry; Mercurio, Giuseppe; Minitti, Michael P.; Mitra, Ankush; Moeller, Stefan P.; Ng, May Ling; Nilsson, Anders; Nordlund, Dennis; Norskov, Jens; Öström, Henrik; Ogasawara, Hirohito; Persson, Mats; Schlotter, William F.; Sellberg, Jonas A.; Wolf, Martin; Abild-Pedersen, Frank; Pettersson, Lars G. M.; Wurth, Wilfried Chemical Bond Activation Observed with an X-ray Laser The concept of bonding and antibonding orbitals is fundamental in chemistry. The population of those orbitals and the energetic difference between the two reflect the strength of the bonding interaction. Weakening the bond is expected to reduce this energetic splitting, but the transient character of bond-activation has so far prohibited direct experimental access. Here we apply time-resolved soft X-ray spectroscopy at a free electron laser to directly observe the decreased bonding antibonding splitting following bond-activation using an ultrashort optical laser pulse. Washington American Chemical Society 2016 5 The journal of physical chemistry letters 7 3647 3651 10.1021/acs.jpclett.6b01543 Institut für Physik und Astronomie OPUS4-37489 Wissenschaftlicher Artikel Schreck, Simon; Beye, Martin; Sellberg, Jonas A.; McQueen, Trevor; Laksmono, Hartawan; Kennedy, Brian; Eckert, Sebastian Oliver; Schlesinger, Daniel; Nordlund, Dennis; Ogasawara, Hirohito; Sierra, Raymond G.; Segtnan, Vegard H.; Kubicek, Katharina; Schlotter, William F.; Dakovski, Georgi L.; Moeller, Stefan P.; Bergmann, Uwe; Techert, Simone; Pettersson, Lars G. M.; Wernet, Philippe; Bogan, Michael J.; Harada, Yoshihisa; Nilsson, Anders; Föhlisch, Alexander Reabsorption of soft x-ray emission at high x-ray free-electron laserfluences We report on oxygen K-edge soft x-ray emission spectroscopy from a liquid water jet at the Linac Coherent Light Source. We observe significant changes in the spectral content when tuning over a wide range of incident x-ray fluences. In addition the total emission yield decreases at high fluences. These modifications result from reabsorption of x-ray emission by valence-excited molecules generated by the Auger cascade. Our observations have major implications for future x-ray emission studies at intense x-ray sources. We highlight the importance of the x-ray pulse length with respect to the core-hole lifetime. College Park American Physical Society 2014 6 Physical review letters 113 15 10.1103/PhysRevLett.113.153002 Institut für Physik und Astronomie OPUS4-43687 misc Eckert, Sebastian Oliver; Norell, Jesper; Miedema, Piter S.; Beye, Martin; Fondell, Mattis; Quevedo, Wilson; Kennedy, Brian; Hantschmann, Markus; Pietzsch, Annette; van Kuiken, Benjamin E.; Ross, Matthew; Minitti, Michael P.; Moeller, Stefan P.; Schlotter, William F.; Khalil, Munira; Odelius, Michael; Föhlisch, Alexander Ultrafast Independent N-H and N-C Bond Deformation Investigated with Resonant Inelastic X-Ray Scattering The femtosecond excited-state dynamics following resonant photoexcitation enable the selective deformation of N-H and N-C chemical bonds in 2-thiopyridone in aqueous solution with optical or X-ray pulses. In combination with multiconfigurational quantum-chemical calculations, the orbital-specific electronic structure and its ultrafast dynamics accessed with resonant inelastic X-ray scattering at the N 1s level using synchrotron radiation and the soft X-ray free-electron laser LCLS provide direct evidence for this controlled photoinduced molecular deformation and its ultrashort time-scale. 2017 7 Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe 1115 urn:nbn:de:kobv:517-opus4-436873 10.25932/publishup-43687 Mathematisch-Naturwissenschaftliche Fakultät OPUS4-43668 misc Eckert, Sebastian Oliver; Norell, Jesper; Miedema, Piter S.; Beye, Martin; Fondell, Mattis; Quevedo, Wilson; Kennedy, Brian; Hantschmann, Markus; Pietzsch, Annette; van Kuiken, Benjamin E.; Ross, Matthew; Minitti, Michael P.; Moeller, Stefan P.; Schlotter, William F.; Khalil, Munira; Odelius, Michael; Föhlisch, Alexander Untersuchung unabhängiger N-H- und N-C-Bindungsverformungen auf ultrakurzen Zeitskalen mit resonanter inelastischer Röntgenstreuung Die Femtosekundendynamik nach resonanten Photoanregungen mit optischen und Röntgenpulsen ermöglicht eine selektive Verformung von chemischen N-H- und N-C-Bindungen in 2-Thiopyridon in wässriger Lösung. Die Untersuchung der orbitalspezifischen elektronischen Struktur und ihrer Dynamik auf ultrakurzen Zeitskalen mit resonanter inelastischer Röntgenstreuung an der N1s-Resonanz am Synchrotron und dem Freie-Elektronen-Laser LCLS in Kombination mit quantenchemischen Multikonfigurationsberechnungen erbringen den direkten Nachweis dieser kontrollierten photoinduzierten Molekülverformungen und ihrer ultrakurzen Zeitskala. 2017 7 Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe 1121 urn:nbn:de:kobv:517-opus4-436688 10.25932/publishup-43668 Mathematisch-Naturwissenschaftliche Fakultät OPUS4-39165 Wissenschaftlicher Artikel Eckert, Sebastian Oliver; Beye, Martin; Pietzsch, Annette; Quevedo, Wilson; Hantschmann, Markus; Ochmann, Miguel; Ross, Matthew; Minitti, Michael P.; Turner, Joshua J.; Moeller, Stefan P.; Schlotter, William F.; Dakovski, Georgi L.; Khalil, Munira; Huse, Nils; Föhlisch, Alexander Principles of femtosecond X-ray/optical cross-correlation with X-ray induced transient optical reflectivity in solids The discovery of ultrafast X-ray induced optical reflectivity changes enabled the development of X-ray/optical cross correlation techniques at X-ray free electron lasers worldwide. We have now linked through experiment and theory the fundamental excitation and relaxation steps with the transient optical properties in finite solid samples. Therefore, we gain a thorough interpretation and an optimized detection scheme of X-ray induced changes to the refractive index and the X-ray/optical cross correlation response. (C) 2015 AIP Publishing LLC. Melville American Institute of Physics 2015 4 Applied physics letters 106 6 10.1063/1.4907949 Institut für Physik und Astronomie OPUS4-43664 Wissenschaftlicher Artikel Eckert, Sebastian Oliver; Norell, Jesper; Miedema, Piter S.; Beye, Martin; Fondell, Mattis; Quevedo, Wilson; Kennedy, Brian; Hantschmann, Markus; Pietzsch, Annette; van Kuiken, Benjamin; Ross, Matthew; Minitti, Michael P.; Moeller, Stefan P.; Schlotter, William F.; Khalil, Munira; Odelius, Michael; Föhlisch, Alexander Untersuchung unabhängiger N-H- und N-C-Bindungsverformungen auf ultrakurzen Zeitskalen mit resonanter inelastischer Röntgenstreuung Die Femtosekundendynamik nach resonanten Photoanregungen mit optischen und Röntgenpulsen ermöglicht eine selektive Verformung von chemischen N-H- und N-C-Bindungen in 2-Thiopyridon in wässriger Lösung. Die Untersuchung der orbitalspezifischen elektronischen Struktur und ihrer Dynamik auf ultrakurzen Zeitskalen mit resonanter inelastischer Röntgenstreuung an der N1s-Resonanz am Synchrotron und dem Freie-Elektronen-Laser LCLS in Kombination mit quantenchemischen Multikonfigurationsberechnungen erbringen den direkten Nachweis dieser kontrollierten photoinduzierten Molekülverformungen und ihrer ultrakurzen Zeitskala. 2017 5 Angewandte Chemie 129 22 6184 6188 10.1002/ange.201700239 Mathematisch-Naturwissenschaftliche Fakultät OPUS4-46652 Wissenschaftlicher Artikel Eckert, Sebastian Oliver; Norell, Jesper; Miedema, Piter S.; Beye, Martin; Fondell, Mattis; Quevedo, Wilson; Kennedy, Brian; Hantschmann, Markus; Pietzsch, Annette; Van Kuiken, Benjamin E.; Ross, Matthew; Minitti, Michael P.; Moeller, Stefan P.; Schlotter, William F.; Khalil, Munira; Odelius, Michael; Föhlisch, Alexander Ultrafast Independent N-H and N-C Bond Deformation Investigated with Resonant Inelastic X-Ray Scattering The femtosecond excited-state dynamics following resonant photoexcitation enable the selective deformation of N-H and N-C chemical bonds in 2-thiopyridone in aqueous solution with optical or X-ray pulses. In combination with multiconfigurational quantum-chemical calculations, the orbital-specific electronic structure and its ultrafast dynamics accessed with resonant inelastic X-ray scattering at the N 1s level using synchrotron radiation and the soft X-ray free-electron laser LCLS provide direct evidence for this controlled photoinduced molecular deformation and its ultrashort time-scale. Weinheim Wiley-VCH 2017 5 Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition 56 6088 6092 10.1002/anie.201700239 Institut für Physik und Astronomie