Interaction of Pyridine Derivatives with Gold (111) Surface as a Model for Adsorption to Large Nanoparticles
D. Mollenhauer, N. Gaston, E. Voloshina and B. Paulus – 2013
In recent years pyridine derivatives, namely 4-(N,N-dimethylamino)pyridine and 4-methoxypyridine, were found to be excellent agents for the stabilization of gold nanoparticles. In order to gain a better understanding of these systems we have simulated the interaction of gold nanoparticles with pyridine and pyridine derivatives with donor substituents in position 4 by quantum-chemical calculations. The relatively large nanoparticles were modeled by the most stable and relevant surface, Au(111). To account for dispersion effects within the density functional theory approach a dispersion correction in the D3 scheme was applied. Due to the dispersion effects the preferred orientation on Au(111) changed from perpendicular for pyridine to parallel for pyridine derivatives. In addition, the adsorption at edges and corner sites of nanoparticles was considered through the use of gold ad-atoms on the surface. For the pyridine–gold interaction a change of the nature of binding was observed.