Structural investigation of Au(111)/butylthiolate adsorption phases

• Published in: Physical chemistry chemical physics : PCCP 2010-01, Vol.12 (13), p.3229-3238
• Main Authors: Chaudhuri, A, Jackson, D C, Lerotholi, T J, Jones, Robert G, Lee, T-L, Detlefs, B, Woodruff, D P
• Format: Article
• Language: English
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/b921281g

The structures of the high-coverage ('standing-up') and low-coverage ('lying-down') phases of butylthiolate on Au(111) have been investigated by a range of experimental methods. Normal incidence X-ray standing waves, photoelectron diffraction and near-edge X-ray absorption fine structure results all identify the local S headgroup site as atop a surface Au atom in a bulk continuation site for both high- and low-coverage phases. Low energy electron diffraction shows the low-coverage phase to have a (12 x radical 3)rect. surface mesh with glide-line symmetry (pmg space group), the long dimension of this mesh being approximately four times the length of the butylthiolate molecule. A structural model is proposed for this phase based on two different enantiomers of an Au-adatom-dithiolate species that is consistent with these results and with recent finding for propylthiolate on this surface using low-temperature scanning tunnelling microscopy (O. Voznyy, J. J. Dubowski, J. T. Yates Jr. and P. Maksymovych, J. Am Chem. Soc., 2009, 131, 12989).