Ge. Poirier et al., CRYSTALLINE-STRUCTURES OF PRISTINE AND HYDRATED MERCAPTOHEXANOL SELF-ASSEMBLED MONOLAYERS AN AU(111), The Journal of chemical physics, 105(5), 1996, pp. 2089-2092
The crystalline structures of hydroxy-functionalized hexanethiol self-
assembled monolayers on Au(111) were characterized using gas-phase tra
nsport of molecular precursors and an ultrahigh vacuum scanning tunnel
ing microscope. In the pristine state the monolayer exhibits a commens
urate lattice with an oblique primitive unit-cell of dimensions a = 3,
b = root 13, alpha = a tan(2 root 3); a structure that is fundamental
ly different than the hexagonal lattice observed for methyl-terminated
monolayers. Hydration of the monolayer results in conversion to a pol
ymorphic phase. These results demonstrate the importance of end-group
chemical bonding in the molecular packing of this widely studied class
of materials.