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Influence of Adsorption on Electrochemical Reduction of Pyridinium Derivatives
Nováková Lachmanová, Štěpánka ; Dupeyre, G. ; Lainé, P. P. ; Hromadová, Magdaléna
Two expanded pyridinium-based compounds 1 and 2 were studied by cyclic voltammetry in two different environments. The nonaqueous solution suppresses the adsorption of the compounds on the electrode surface. Adsorption process in aqueous environment was confirmed by typical shape of the curve as well as by the linear dependence of peak current on the scan rate. The shift of standard redox potential in aqueous solution compared to nonaqueous environment toward more negative potential indicates the adsorption of reactant on the electrode surface. Larger shift observed for flat conjugated molecule 1 confirms its stronger adsorption than for the second molecule.
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Investigation of Single Molecule Charge Transport Properties and Geometrical Arrangement in Terpyridine Architectures Supported by the Tetraphenylmethane Tripod
Kolivoška, Viliam ; Sebechlebská, Táňa ; Šebera, Jakub ; Gasior, Jindřich ; Lindner, M. ; Lukášek, J. ; Valášek, M. ; Mayor, M. ; Mészáros, G. ; Hromadová, Magdaléna
Tripodal platforms were engineered recently to realize a well-defined directional contact between metallic electrodes and molecular architectures dedicated to serve as working elements for electronic applications. In this work we employ cyclic voltammetry, scanning tunneling microscopy break junction technique and theoretical approaches based on the combination of density functional theory and non-equilibrium Green´s function to investigate the geometrical arrangement and single molecule charge transport in terpyridine-based architectures supported by tetraphenylmethane tripod. We demonstrate that this architecture adopts a favorable geometrical arrangement capable of forming highly conductive molecular junctions and is thus suitable to serve as a basis for working molecular switches.
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Charge Transport through Molecular Towers Based on Tetraphenylmethane Tripods
Kolivoška, Viliam ; Šebera, Jakub ; Lindner, M. ; Valášek, M. ; Mayor, M. ; Mészáros, G. ; Gasior, Jindřich ; Hromadová, Magdaléna
Molecular platforms with multiple anchors were introduced recently to provide robust\ncoupling between molecular electronic components and metallic electrodes. In this work,\ncharge transport in tower-shaped single molecule conductors based on tetraphenylmethane\ntripod possessing three thiol anchors is investigated by scanning tunneling microscopy break\njunction technique. The effect of tripod substitution pattern and number of repeating units in\nmolecule is addressed. The substitution was found to influence conductance value in early\nstages of molecular junction evolution, where tower lays parallel to surface. In late stages, the\ncharge is transported through principal molecular axis and junction breaks thermally in tilted\nconfiguration.
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