Interfacial charge rearrangement and intermolecular interactions: Density-functional theory study of free-base porphine adsorbed on Ag(111) and Cu(111)

摘要

We employ dispersion-corrected density-functional theory to study theadsorption of tetrapyrrole 2H-porphine (2H-P) at Cu(111) and Ag(111). Variouscontributions to adsorbate-substrate and adsorbate-adsorbate interactions aresystematically extracted to analyze the self-assembly behavior of this basicbuilding block to porphyrin-based metal-organic nanostructures. This analysisreveals a surprising importance of substrate-mediated van der Waalsinteractions between 2H-P molecules, in contrast to negligible directdispersive interactions. The resulting net repulsive interactions rationalizethe experimentally observed tendency for single molecule adsorption.