| Abstract
| - Alkanethiol molecules in solution displace 1-adamantanethiolate self-assembled monolayers onAu{111}, ultimately leading to complete molecular exchange. Specifically, here, fast insertion ofn-dodecanethiolate at defects in the original 1-adamantanethiolate monolayer nucleates an island growthphase, which is followed by slow ordering of the n-dodecanethiolate domains into a denser and morecrystalline form. Langmuir-based kinetics, which describe alkanethiolate adsorption on bare Au{111}, failto model this displacement reaction. Instead, a Johnson−Mehl−Avrami−Kolmogorov model of perimeter-dependent island growth yields good agreement with kinetic data obtained by Fourier transform infraredspectrometry over 100-fold variation in n-dodecanethiol concentration. Rescaling the growth rate at eachconcentration collapses all the data onto a single universal curve, suggesting that displacement is a scale-free process. The rate of displacement varies as the square-root of the n-dodecanethiol concentrationacross the 0.01−1.0 mM range studied.
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