Self-Assembled Monolayers of 2-Adamantanethiol on Au{111}: Control of Structure and Displacement

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2009-04, Vol.113 (16), p.3895-3903
• Main Authors: Kim, Moonhee, Hohman, J. Nathan, Morin, Elizabeth I, Daniel, Thomas A, Weiss, Paul S
• Format: Article
• Language: English
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp810048n

We have investigated the formation of 2-adamantanethiolate self-assembled monolayers on Au{111} and their displacement by n-dodecanethiol, using scanning tunneling microscopy, X-ray photoelectron spectroscopy, and infrared reflection absorption spectroscopy. Well-ordered 2-adamantanethiolate monolayers undergo rapid and significant molecular exchange upon exposure to n-dodecanethiol solutions, but their structures and intermolecular interactions template the growth of n-dodecanethiolate domains. Annealing 2-adamantanethiolate monolayers at 78 °C decreases the density of vacancy islands, while increasing the overall order and the average domain sizes in the films. This results in slower displacement by n-dodecanethiol molecules, as compared to unannealed monolayers. The secondary sulfur position on the adamantyl cage influences the lattice structure and exchange of 2-adamantanethiolate monolayers by alkanethiols.