Formation of gold-methanethiyl self-assembled monolayers.
The energetics of formation of thiyl-gold self-assembled monolayers is investigated using density-functional theory simulations. It is found that the chemisorption of dimethyl disulfide on the reconstructed Au(111) (22 x radical3) surface is most favored at the fcc reconstruction stripe, with initial physisorption leading to disulfide dissociation, adatom/vacancy-pair formation, and then, at a coverage of 7.8% sulfur atoms per gold atom, surface reconstruction lifting. At higher coverages, monolayer formation proceeds similarly on the unreconstructed surface, leading to surface pitting. Formation of the analogous adatom/vacancy-pair bound dissociated adsorbate complex on exposure of the clean unreconstructed surface to methanethiol is shown to be endothermic, however.
Wang
Yun
Y
School of Chemistry, The University of Sydney, NSW 2006, Australia.
Hush
Noel S
NS
Reimers
Jeffrey R
JR
D006046:Gold / Q000737:chemistry*; D008697:Methane / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation
D006046:Gold; D008697:Methane