MD simulations of singly deprotonated alkanedithiolat SAMs The reactive force field that was used in this work was originally parameterized and validated for alkanemonothiolates on small clusters or SAM surfaces. It was also applied to but not validated for breakjunction simulations of gold with 1,8-bis(methylthio)octane and methylsulfide-functionalized trans-α,ω-diphenyloligoenes. It has however not been applied to α,ω-alkanedithiols. To study the stability of the reactive force field, MD simulations of singly deprotonated alkanedithiols on Au(111) surfaces were performed. Au(111) surfaces were chosen, as theoretical studies suggested that they are the most frequently occurring domains on GNPs. If not stated otherwise, singly deprotonated dithiol ligands were added to the hollow sites of the surfaces with a distance of 2 Å from the sulfur atom towards the center of the gold atoms in the top layer. During some MD simulations, dissociation of ligands or reactions of the free thiol group in dithiol molecules were observed (see Supporting Information, Section S2.4),