Abstract
Using density functional theory we report detailed reaction path calculations for the reaction Of acetone with the Silicon (001) surface. We identify the key reaction intermediates of associative adsorption and the transition states between them. This resolves the identity of the one-dimer intermediate observed ill STM experiments and its role ill the formation of several two-dimer-wide end products of dissociation. Key to the understanding of the dissociation mechanism is the ambiphilic character of the two reactants, that is the simultaneous expression of electrophilic and nucleophilic reactivities in both the surface and the acetone molecule.