In house research

We provide novel and fundamental insight into the interplay of bonding, structure and ultrafast dynamics in molecular systems with various x-ray tools. We develop new methods and instrumentation for time-resolved and steady-state soft x-ray spectroscopy with a particular emphasize on liquid samples.


Molecular dynamics and mapping of potential energy surfaces with sub-natural linewidth RIXS

By means of Resonant Inelastic X-ray Scattering (RIXS) with sub-natural line width resolution, we explore the dynamics of molecules via their vibrational progressions. While the progressions' energy positions are connected to the shape and location of the ground state potential, their intensity distribution mirrors the excited states; thus, they can be used to map the molecule's potential energy surfaces.  For this we perform high-resolution experiments at the SLS (Switzerland), SOLEIL (France), and in the future even at BESSY II.

Spatial Quantum Beats in Vibrational Resonant Inelastic Soft X-Ray Scattering at Dissociating States in Oxygen, A. Pietzsch, Y.-P. Sun, F. Hennies, Z. Rinkevicius, H. O. Karlsson, T. Schmitt, V. N. Strocov, J. Andersson, B. Kennedy, J. Schlappa, A. Föhlisch, J.-E. Rubensson, and F. Gel’mukhanov, Phys. Rev. Lett. 106, 153004, (2011)
Intramolecular soft modes and intermolecular interactions in liquid acetone,
Y. P. Sun, F. Hennies, A. Pietzsch, B. Kennedy, T. Schmitt, V. N. Strocov, J. Andersson, M. Berglund, J. E. Rubensson, K. Aidas, F. Gel’mukhanov, M. Odelius, and A. Föhlisch, Phys. Rev. B 84, 132202, (2011) 


Bonding and structure in molecular systems

We use established spectroscopic methods at synchrotron radiation light sources to unravel the interplay of bonding and structure in molecular systems. We use a combination of non-resonant and resonant photoelectron spectroscopy (RPES), resonant inelastic soft x-ray scattering (RIXS) on liquid jets and complementary investigations at infrared (IR) wavelengths. We study aqueous solutions ranging from simple model cases such as solvated 3d-transition-metal ions to technologically relevant compounds.

Ultrafast hybridization screening in Fe3+ aqueous solution S. Thürmer, R. Seidel, W. Eberhardt, S.E. Bradforth, and B. Winter J Am Chem Soc 133 (32): 12528-12535 (2011).


X-ray femtochemistry – An x-ray view on molecular dynamics

We explore the energy landscapes and dynamic pathways in molecular systems atom by atom and on their respective atomic length and time scales in order to unveil fundamental correlations of transient electronic structures and nuclear dynamics to gain a novel understanding of photochemical dissociation, charge transfer and isomerisation reactions to ultimately develop new schemes for controlling chemical reactions. For this we perform time-resolved experiments in the lab, at BESSYII and at free-electron laser sources such as FLASH in Hamburg (Germany) and the Linac Coherent Light Source (LCLS) in Stanford (USA).

Ph. Wernet, M. Odelius, K. Godehusen, J. Gaudin, O. Schwarzkopf, W. Eberhardt, Real-time evolution of the valence electronic structure in a dissociating molecule, Phys. Rev. Lett. 103, 013001 (2009).


Novel methods and instrumentation for x-ray spectroscopy of molecular systems

We develop and establish novel methods and instrumentation for applications of soft x-rays to molecular systems with particular emphasizes on ultrashort pulses and liquid samples. (nanoFilmXAS, flexRIXS, Sub-natural Linewidth RIXS)

S. Schreck, G. Gavrila, C. Weniger, Ph. Wernet, A sample holder for soft x-ray absorption spectroscopy of liquids in transmission mode, Rev. Sci. Instrum. 82, 103101 (2011).
Bernd Winter and Manfred Faubel, Photoemission from Liquid Aqueous Solutions, Chem. Rev. 106, 1176 (2006).