Dresden 2009 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 42: Poster Session II (Nanostructures at surfaces: arrays; Nanostructures at surfaces: Dots, particles, clusters; Nanostructures at surfaces: Other; Nanostructures at surfaces: Wires, tubes; Metal substrates: Adsorption of O and/or H; Metal substrates: Clean surfaces; Metal substrates: Adsorption of organic/bio moledules; Metal substrates: Solid-liquid interfaces; Metal substrates: Adsorption of inorganic molecules; Metal substrates: Epitaxy and growth; Heterogeneous catalysis; Surface chemical reactions; Ab-initio approaches to excitations in condensed matter; Organic, polymeric, biomolecular films– also with adsorbates; Particles and clusters)

O 42.63: Poster

Mittwoch, 25. März 2009, 17:45–20:30, P2

Formation of metal-organic networks of azobenzene molecular switches on a Au(111) surface — •Christoph Limbach, Nils Henningsen, Katharina J. Franke, and Jose Ignacio Pascual — Freie Universität Berlin, Berlin, Germany

Azobenzene is a model molecular system for conformational switches, whose adsorption on metal surfaces has lately attracted a lot of interest due to its possible application to switchable molecular electronic devices. Using low temperature scanning tunnelling microscopy and spectroscopy(STM/STS)we investigate the coadsorption of di-meta-cyano azobenzene (DMC) molecules and cobalt atoms on a Au(111) surface. Room temperature co-deposition of both species results in the formation of metal-organic chains as well as small clusters. dI/dV spectroscopy and conductance maps plotting the distribution of unoccupied resonances are used to localize the coordination bonds between Co atoms and DMC. We find that coordination bonds can be formed indistinguishably at two intramolecular sites: the cyano termination and the di-azo bridge (N=N). This leads us to conclude that the metal organic bond is probably mediated by the lone-pair electrons of nitrogen atoms, as found recently [1]. We envision a controlled modification of the transition metal properties by switching the molecular ligands. [1] U. Schlickum et. al. Nano Lett. 7, 3813, 12007