Designing Metal/Molecule Nanocontacts from Mechanochemical Considerations

MARTIN E. ZOLOFF MICHOFF; JORDI RIBAS-ARINO; DOMINIK MARX

Donostia / San Sebastián

Congreso; PSI-K 2015 CONFERENCE; 2015

PSI-K

Thiolate-gold interfaces have been intensively studied for many decades using severalexperimental and computational techniques, mainly due to the different potentialtechnological applications of these hybrid interfaces. Only lately, it has been found that theconsideration of the mechanical properties of such metal/molecule hybrids becomes a crucialfactor in the design of such nanoscale devices.There has been a growing interest in multidentate thiolate ligands to build such interfaces.Nevertheless, there is not much information available regarding how these self-assembledmonolayers or nanojunctions respond to external stress.In this work, we shed some light into this topic by investigating, by means of electronicstructure calculations, the thermal and mechanical desorption of a series of bidentantethiolated ligands adsorbed on a defective gold surface. The focus of our work has been set onthe effect of the length of the carbon bridge separating the anchoring sulfur atoms on therupture of the respective molecule/gold junctions.We found that the preferred thermally activated desorption product is the detachment of thecyclic disulfides, in all cases. In contrast, mechanical detachment leads to cyclic goldcomplexes, in which metal atoms are extracted from the surface and kept in tweezer-likearrangements by the sulfur atoms.