Self-assembled monolayers of alkanethiols on Au(111): surface structures, defects and dynamics

Abstract

The surface structures, defects and dynamics of self-assembled monolayers (SAMs) on Au(111) are reviewed. In the case of the well-known c(4 x 2) and radical 3 x radical 3 R30 degrees surface structures, the present discussion is centered on the determination of the adsorption sites. A more complex scenario emerges for the striped phases, where a variety of surface structures that depends on surface coverage are described. Recently reported surface structures at non-saturation coverage show the richness of the self-assembly process. The study of surface dynamics sheds light on the relative stability of some of these surface structures. Typical defects at the alkanethiol monolayer are shown and discussed in relation to SAMs applications.

Exchange Reactions between Alkanethiolates and Alkaneselenols on Au{111}

“…The C−H peaks of the C12Se film emerge with increasing exposure time, and the reaction terminates after complete D12 monolayer displacement. The relative ratio of peak intensities remains largely static throughout the displacement process, which implies that there is little reorganization during displacement (for example, we see no evidence of a transition between lying-down and standing-up phases, 86 as might be observed for deposition onto a bare substrate). Molecules are thus found in their near-final orientations shortly after incorporation into the film.…”

“…There are numerous phases of even simple alkanethiolates and alkaneselenolates on Au{111}. 26,86,111 We observed a monolayer transition from a full-coverage sulfur-bound C10 SAM to a full-coverage selenium-bound C12Se, taking note of how the gold substrate directs the progression of the reaction and the structures of the products.…”

The interface structure of n-alkylthiolate self-assembled monolayers on coinage metal surfaces

“…In general, however, these methods do not provide any direct, and certainly no quantitative, information on the S-headgroup/metal interface structure. As such, they are not reviewed here, but are covered elsewhere [1,2,3,4].…”

Analysis of the Surface Coverage of a Self-Assembled Monolayer of Octadecyl Silane on a Si(100) Surface by Infrared External-Reflection Spectroscopy

“…4 Exceptionally, a gold surface is known to form a highly stable chemical bonding with a thiol compound. 2,5 Depending on the surface orientation of the substrate, 4 an appropriate concentration of the reacting solution and temperature, the lattice structure varies a lot, but basically the chemical reaction goes quite positively on gold.…”