Department Highly Sensitive X-ray Spectroscopy

Department

Our research interest is in fundamental electronic properties of metal centers and metal clusters in gaseous and liquid environments. Our aim is to arrive at a fundamental understanding of energy levels, spin states, oxidation states, and valence electron delocalization in coordination entities of 3d and 4f transition elements that allows for tailoring of electronic and magnetic properties.

We make use of the local and element-specific nature of core-level excitation to investigate electronic structure in ultra-dilute gaseous, solvated, and liquid samples, which allows us to directly probe the effect of coordination and solvation on the metal center by following changes in spin state or oxidation state.

Sample preparation for gas-phase studies is performed in situ, either via gas-phase chemistry of sputtered metal ions, or from solution via electrospray ionization. We are able to follow stepwise coordination of metal centers ligand by ligand from coordinatively unsaturated to coordinatively saturated complexes.

Liquid phase studies complement our gas-phase work and allow for a deeper understanding of the effects of solvation or hydration on ions, molecules, and coordination entities. Investigating and comparing properties of the same ion or coordination entity in gas phase and in solution allows us to directly study the effect of solvation.

Our research requires development of new apparatus and new techniques for highly-sensitive soft-x-ray spectroscopy of ultra-dilute targets, which does not only allow us to employ truly unique experimental capabilities but also offers these capabilities to our collaborators and users. Given the highly interdisiplinary nature of the problems we address, our research uses approaches from the areas of both, physics and chemistry.

Our group is based in Berlin, with strong ties to Universität Freiburg, where we are involved in teaching and research activities.