Density Functional Theory Study of the Surface Adsorption and Dissociation of Copper(I) Acetamidinates on Cu(110) Surfaces

Metal amidinates are common compounds with many applications, and are of particular value as precursors for the chemical deposition of thin metal films on solid surfaces. In order to better understand those processes, the surface chemistry of copper(I)–N,N′-dimethylacetamidinate on Cu(110) single-crystal surfaces has been studied using first-principles quantum-mechanics calculations. Most metal amidinates exist as dimers (or tetramers) in the gas phase. Here, it was found that the initial steps of the adsorption and dissociation of those dimers on metal surfaces depend on their surface coverage. At low coverages, it was found that the copper(I)–N,N′-dimethylacetamidinate dimer initially binds to the Cu surface by occupying two bridge sites, with the four N atoms on top of adjacent surface Cu atoms. This configuration is, however, not stable, so the adsorbed dimer undergoes dissociation soon after via the shedding of one of the ligands; in this more stable configuration, both Cu atoms from the inorganic pr...