Berlin 2018 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 59: Nanostructures at surfaces: 1D and 2D structures and networks I

O 59.6: Vortrag

Mittwoch, 14. März 2018, 11:45–12:00, MA 141

Exchanging the central metal atoms in adsorbed macrocycles — •Alexandra Rieger¹, Stephan Schnidrig², Benjamin Probst², Karl-Heinz Ernst¹, and Christian Wäckerlin¹ — ¹Swiss Federal Laboratories for Material Science and Technology, Dübendorf, Switzerland — ²University of Zurich, Switzerland

Surface adsorbed macrocycles exhibit a number of interesting physical and chemical properties, many of them are determined by their transition metal centers. We report on the substitution of the transition metals in surface-adsorbed pyrphyrin (P), a porphyrin-related macrocycle. Using scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS), we demonstrate a defined hierarchy in this replacement process, that is: Ni substitutes Cu, Fe substitutes Cu and Fe substitutes Ni, although less efficiently. The Cu to Ni and Cu to Fe atom replacement reactions are surprisingly efficient and proceed completely at 423 K. These results open up new possibilities to study coordination chemistry in solvent free environment. Furthermore, we show that the atomic hydrogen produced by on-surface metalation can lead to the scision of the cyano groups on the rim of the macrocycle which desorb as hydrogen cyanide. This result implies that atomic hydrogen, which is produced in numerous on-surface reactions, can induce interesting reactions.