Regensburg 2010 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 41: Poster Session I (Semiconductor Substrates: Epitaxy and growth; Semiconductor Substrates: Adsorbtion; Semiconductor Substrates: Solid-liquid interfaces; Semiconductor Substrates: Clean surfaces; Oxides and insulators: Epitaxy and growth; Oxides and insulators: Adsorption; Oxides and insulators: Clean surfaces; Organic, polymeric and biomolecular films - also with adsorbates; Organic electronics and photovoltaics, Surface chemical reactions; Heterogeneous catalysis; Phase transitions; Particles and clusters; Surface dynamics; Surface or interface magnetism; Electron and spin dynamics; Spin-Orbit Interaction at Surfaces; Electronic structure; Nanotribology; Solid/liquid interfaces; Graphene; Others)
O 41.102: Poster
Dienstag, 23. März 2010, 18:30–21:00, Poster B1
Ordered structure of viologen monolayers on a Copper electrode surface — •Emilia Sak1,3, Min Jiang1, Knud Gentz1, Ralf Troff2, Christoph Schalley2, Aleksander Krupski3, and Klaus Wandelt1 — 1Institute of Physical and Theoretical Chemistry , University of Bonn , Wegelerstr. 12, 53115 Bonn , Germany — 2Institute Chemistry and Biochemistry , Free University of Berlin,Taknstr.3, 14195 Berlin,Germany — 3Institute of Experimental Physics, University of Wroclaw , pl.Maksa Borna 9 , 53-204 Wrocław, Poland
As a typical molecule in the redox-active viologen family, dibenzyl-viologens (DBV) has been studied by means of EC-STM on a Cu(100) electrode. DBV2+ dications adsorb on a chloride modified Cu(100) electrode surface forming a laterally well ordered 2D array of supramolecular cavitand ensembles. Based on these observations we designed new molecules, such as dimetyl-DBV (DMDBV) and tetrametyl-DBV (TMDBV) in order to study in influence of extra substituents. So far, we found two redox peaks P1/P1’( P1 - 305 mV, P1’ -240 mV) in the cyclic voltammogram of Cu(100) in a mixture of 10mM HCl and 0,1mM DMDBV for values of Ework > - 420 mV vs RHE. STM images, show that DMDBV molecules form a stable and ordered adlayer structure which also looks like a chessboard with two kinds of mirror domains. When the applied potential is decreased to -400 mV, no obvious structural changes are visible.