The influence of molecular mobility on the properties of networks of gold nanoparticles and organic ligands

Beilstein Journal of Nanotechnology

M. Venkata Kamalakar¹  Edwin J. Devid²  Sense Jan van der Molen²  Christian Kübel³  Mario Ruben³  Paulo N. Martinho³  Tibebe Lemma⁴  Úna Prendergast⁴  Tia. E. Keyes⁴  Jean-François Dayen⁵  Bernard Doudin⁵ 

[1] Department of Microtechnology and Nanoscience, Chalmers University of Technology, SE-41296 Göteborg, Sweden;Huygens-Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands;Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany;School of Chemical Science, Dublin City University (DCU), Dublin 9, Ireland;Université de Strasbourg, IPCMS-CMRS UMR 7504, 23 Rue du Loess, 67034 Strasbourg, France;

关键词: aromatic capping ligands;    gold nanoparticles;    molecular charge transport;    self-assembly;    surface enhanced Raman spectroscopy;   

DOI  :  10.3762/bjnano.5.177

来源: DOAJ

【 摘 要 】

We prepare and investigate two-dimensional (2D) single-layer arrays and multilayered networks of gold nanoparticles derivatized with conjugated hetero-aromatic molecules, i.e., S-(4-{[2,6-bipyrazol-1-yl)pyrid-4-yl]ethynyl}phenyl)thiolate (herein S-BPP), as capping ligands. These structures are fabricated by a combination of self-assembly and microcontact printing techniques, and are characterized by electron microscopy, UV–visible spectroscopy and Raman spectroscopy. Selective binding of the S-BPP molecules to the gold nanoparticles through Au–S bonds is found, with no evidence for the formation of N–Au bonds between the pyridine or pyrazole groups of BPP and the gold surface. Subtle, but significant shifts with temperature of specific Raman S-BPP modes are also observed. We attribute these to dynamic changes in the orientation and/or increased mobility of the molecules on the gold nanoparticle facets. As for their conductance, the temperature-dependence for S-BPP networks differs significantly from standard alkanethiol-capped networks, especially above 220 K. Relating the latter two observations, we propose that dynamic changes in the molecular layers effectively lower the molecular tunnel barrier for BPP-based arrays at higher temperatures.

【 授权许可】

Unknown