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O: Fachverband Oberflächenphysik

O 2: Metal substrates: Solid-liquid interfaces

O 2.1: Vortrag

Montag, 22. März 2010, 11:15–11:30, H31

Self-organized Porphyrin monolayers on iodine-modified noble metal surfaces — •Michael Schneider, Christian Schlaup, and Klaus Wandelt — Inst. f. Phys. u. Theo. Chem., Universität Bonn, Wegelerstr. 12 D-53115, Bonn, Germany

In the field of template chemistry, new and interesting phenomena can be discovered at gold /electrolyte interfaces in the presence of anions and supramolecules as function of electrode potentials. The spontaneous self-assembly of organic molecules is considered a promising bottom-up technique in nanotechnology to create surface patterns and electronic devices. Porphyrins are important organic compounds in the fields of biology and technology. They open a series of potential applications in cancer therapy, or as catalysts and sensors. Halide-modified Au(111)-surfaces are desirable substrates due to their long range order. Iodide-modified Au(111)-surfaces show electrocompression and phase transitions dependent on the electrode potential, as shown in previous works . Our studies with STM and cyclic voltammetry not only reproduce previous works about Tetra (N-methyl-4-pyridyl)-porphyrin molecules (TMPyP) on iodide-modified Au(111)-surfaces, but provide an even more precise understanding. Namely, it is found that the TMPyP layer exhibits a long-range periodic superstructure beyond the molecular arrangement. This research complements one of our previous studies regarding adsorption of the same molecule on halide-modified copper-surfaces , allowing comparisons between systems with the same molecules but different substrates.