Ge. Poirier et al., CRYSTALLINE-STRUCTURES OF PRISTINE AND HYDRATED MERCAPTOHEXANOL SELF-ASSEMBLED MONOLAYERS AN AU(111), The Journal of chemical physics, 104(18), 1996, pp. 7325-7328
The crystalline structure of hydroxy-functionalized hexanethiol self-a
ssembled monolayers on Au(111) were characterized using gas-phase tran
sport of molecular precursors and an ultrahigh vacuum scanning tunneli
ng microscope. In the pristine state the monolayer exhibits a commensu
rate lattice with an oblique primitive unit-cell of dimensions a=3, b=
root 13, alpha=a tan(2 root 3); a structure that is fundamentally diff
erent than the hexagonal lattice observed for methyl-terminated monola
yers. Hydration of the monolayer results in conversion to a polymorphi
c phase. These results demonstrate the importance of end-group chemica
l bonding in the molecular packing of this widely studied class of mat
erials.