Scanning tunneling microscopy studies of Au(111) derivatized with organothiols

Atomic resolution scanning tunneling microscopy (STM) images of various-sized organothiols adsorbed on Au(111) display a (√3 × √3)R30° structure, even when the ω-substituent size (4.3-13 Å) is so large that such a packing should not be possible. The observation of a (√3 × √3)R30° structure for thiols that should pack less densely suggests that the observed images are of gold electronic distributions that have been perturbed by the adsorbed thiol. © 1992 American Chemical Society

Scanning tunneling microscopy and quartz crystal microbalance studies of Au exposed to sulfide, thiocyanate, and n-octadecanethiol

Atomic resolution STM images of Au(111) treated with solutions of Na2S, H2S, or NaSCN display patterns of atoms in the shape of squares with nearest-neighbor distances of 0.27 ± 0.3 nm. QCM data demonstrate that Au dissolves in aqueous solutions of sulfide and thiocyanate with O2 present. The square pattern observed is ascribed to images of Au atoms on a reconstructed Au(111) surface caused by dissolution of Au by sulfide or thiocyanate. n-Octadecanethiol/Au(111) surfaces damaged by the STM tip display a similar square pattern, indicating removal of Au atoms by the tip in a manner analogous to the dissolution process observed for sulfide or thiocyanate. © 1993 American Chemical Society

Observation of n-Octadecanethiol Multilayer Formation from Solution onto Gold

Formation of multilayers was observed when gold substrates were immersed in air-saturated, ethanolic solutions of n-octadecanethiol. The scanning tunneling microscope (STM) was used to image the multilayers and to etch the organic layers by using the interaction between the STM tip and the organic layers. In addition, ex situ measurements of the mass change using a quartz crystal microbalance (QCM) revealed formation of approximately 4 monolayers after 6 days of immersion of the gold substrate in the n-octadecanethiol ethanol solution. © 1993, American Chemical Society. All rights reserved