Competition between Two High-Density Assemblies of Poly(phenyl)thiols on Au(111)

LEONARDO PEIRETTI; PAOLA QUAINO; FREDERIK TIELENS

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington; Año: 2016 vol. 120 p. 25462 - 25472

1932-7447

The interaction between aromatic thiols andthe Au(111) surface was investigated using periodic densityfunctional theory (DFT). Different self-assembled monolayers(SAMs) organizations were investigated, namely with differentsurface reconstructions (flat unreconstructed Au(111) andadatom Au(111) surface). DFT energetics on geometricallyoptimized SAMs and electronic analysis by means of projecteddensity of states and the crystal orbital Hamilton populationmethod were used to interpret the differences in theadsorption properties. It was found that the adsorption energydifference between the arylthiol chains adsorbed in T-shapedSAMs and adsorbed on flat unreconstructed Au(111)diminishes from long aryl thiols (tpt) to the short ones (dptand mpt), indicating that the unreconstructed surface becomes more competitive energetically for short-chain arylthiols (dpt andmpt). Moreover, the nature of the Au−S bond was found to be independent of the chain size. This leads us to conclude that thereconstruction, if any, is only dependent on the side-chain interactions.