Berlin 2008 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 59: Molecular Nanostructures
O 59.10: Vortrag
Donnerstag, 28. Februar 2008, 11:45–12:00, MA 041
Bottom-up construction of covalently bound molecular nanostructures — •Leonhard Grill1, Matthew Dyer2, Leif Lafferentz1, Mats Persson2, Maike Peters3, and Stefan Hecht3 — 1Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, Berlin — 2Department of Chemistry, University of Liverpool, Liverpool L69 3BX, UK — 3Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, Berlin
The ultimate goal of molecular electronics consists in the use of single functionalized molecules for circuits at the atomic scale. In possible future applications, such molecular arrays need to be highly stable and allow charge transport between the molecular building blocks. Hence, covalent bonds are desired for the intermolecular connections. However, up to now only rather weak interactions have been reported for supramolecular networks on surfaces.
We report on the controlled formation of covalently bound networks of porphyrin molecules on a gold surface upon deposition of thermally activated molecular building blocks and their subsequent chemical reaction at predefined connection points [1]. Scanning tunneling spectroscopy measurements, lateral manipulation, and density functional theory calculations unambiguously reveal the covalent character of the intermolecular bonds. Furthermore, we show that the dimensions and shape of these nanostructures can be precisely engineered by controlling the number of bromine substituents of the molecular building block, leading to the formation of dimers, chains and networks.
[1] L. Grill et al., Nature Nanotech. 2, 687 (2007).