Table of Contents
Advances in Chemistry
Volume 2016, Article ID 6080343, 8 pages
Research Article

Density Functional Investigation of the Inclusion of Gold Clusters on a CH3S Self-Assembled Lattice on Au(111)

1College of Science and Mathematics, University of the Virgin Islands, St. Thomas, VI, USA
2Department of Science, BMCC/CUNY, New York, NY 10007, USA

Received 27 May 2016; Accepted 28 July 2016

Academic Editor: Abhishek K. Mishra

Copyright © 2016 Darnel J. Allen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We employ first-principles density functional theoretical calculations to address the inclusion of gold (Au) clusters in a well-packed CH3S self-assembled lattice. We compute CH3S adsorption energies to quantify the energetic stability of the self-assembly and gold adsorption and dissolution energies to characterize the structural stability of a series of Au clusters adsorbed at the SAM-Au interface. Our results indicate that the inclusion of Au clusters with less than four Au atoms in the SAM-Au interface enhances the binding of CH3S species. In contrast, larger Au clusters destabilize the self-assembly. We attribute this effect to the low-coordinated gold atoms in the cluster. For small clusters, these low-coordinated sites have significantly different electronic properties compared to larger islands, which makes the binding with the self-assembly energetically more favorable. Our results further indicate that Au clusters in the SAM-Au interface are thermodynamically unstable and they will tend to dissolve, producing Au adatoms incorporated in the self-assembly in the form of CH3S-Au-SCH3 species. This is due to the strong S-Au bond which stabilizes single Au adatoms in the self-assembly. Our results provide solid insight into the impact of adatom islands at the CH3S-Au interface.