Berlin 2008 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 18: Poster Session I - MA 141/144 (Atomic Wires; Size-Selected Clusters; Nanostructures; Metal Substrates: Clean Surfaces+Adsorption of Organic / Bio Molecules+Solid-Liquid Interfaces+Adsorption of O and/or H; Surface or Interface Magnetism; Oxides and Insulators: Clean Surfaces)

O 18.47: Poster

Montag, 25. Februar 2008, 18:30–19:30, Poster F

Mechanochemistry of thiolates on gold surfaces — •Jordi Ribas, Nisanth N. Nair, and Dominik Marx — Lehrstuhl fuer Theoretische Chemie, Ruhr Universitaet Bochum, 44780 Bochum

The capability to manipulate molecules on the atomic scale by Atomic Force Microscopy techniques has recently made it possible to induce and control chemical reactions and to construct new nanoscale architectures by applying external mechanical forces. The system consisting of thiolate molecules adsorbed on gold surfaces is not only well accessible to such experiments but previous theoretical work [1] has shown that it is possible to draw gold nanowires when alkylic thiolates are pulled off a stepped gold surface or off small gold clusters.

In this contribution we will present the results of the computational studies we have carried out to explore which nanostructures are generated and which chemical phenomena take place when other more complex thiolates rather than the alkylic ones are pulled off a gold surface. Specifically, we will compare the mechanochemical behavior of alkylic and aromatic thiolates and we will explore the mechanochemistry of bidentate and tridentate thiolates. These simulations have been performed by means of DFT static calculations and ab initio molecular dynamics calculations. Overall, our results have implications for the stability and degradation of molecule/metal junctions as used, for instance, in coatings and molecular electronics.

[1] (a) Krüger, D.; Fuchs, H.; Rousseau, R.; Marx, D.; Parrinello, M. Phys. Rev. Lett. 2002, 89, 186402; (b) Krüger, D.; Rousseau, R.; Fuchs, H.; Marx, D. Angew. Chem Int. Ed. 2003, 42, 2251.