Berlin 2018 – scientific programme
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O: Fachverband Oberflächenphysik
O 114: Nanostructures at surfaces: 1D and 2D structures and networks IV
O 114.3: Talk
Friday, March 16, 2018, 11:00–11:15, MA 141
On-surface transmetalation of porphyrins — Diana Hötger1, •Markus Etzkorn1,2, Claudius Morchutt1, Patrick Alexa1, Doris Grumelli3, Jan Dreiser4, Heriberto Fabio Busnengo5, Paula Abufager5, Sebastian Stepanow6, Rico Gutzler1, and Klaus Kern1,7 — 1Max Planck Institut für Festkörperforschung, Stuttgart, Germany — 2Institut für Angewandte Physik, Technische Universität Braunschweig, Germany — 3Universidad Nacional de La Plata, Argentina — 4Paul Scherrer Institute, Swiss Light Source, Villigen, Switzerland — 5Insituto de Física, Rosario, Argentina — 6Swiss Federal Institute of Technology Zurich, Switzerland — 7Institut de Physique, Ecole Polytechnique Fédérale de Lausanne, Switzerland
We have investigated the transmetalation of metal porphyrin monolayer networks self-assembled on Au(111) using X-ray absorption, scanning tunneling microscopy and DFT studies. In the X-ray absorption the coordinated metal centers show the expected clear multiplet structure as a result of the ligand field. When depositing Co on the networks formed by Fe-porphyrins at room temperature, we find strong evidence of an efficient metal cation exchange in the spectra. The Co absorption spectra now show a clear multiplet structure similar to the one of Co-porphyrins while the Fe spectra become much more metallic in character. The process is unidirectional as we find no signs of transmetalation for Fe deposited on Co-porphyrins. We have also observed similar signatures of transmetalation for Cu-porphyrins when depositing Co. The latter finding illustrates the differences to transmetalation in solution.