σ-Hole and σ-lump interactions between gold clusters Aun (n = 2-8) and benzene.

In this study, the non-covalent interactions between gold cluster and benzene have been evaluated at the PBE0-D3/def2-TZVP level of theory. Gold clusters Aun (n = 2-8) were used as σ-hole and σ-lump donors, and benzene was the corresponding electron-donating and -accepting molecule. The molecular electrostatic potential of Au clusters was analyzed, and the optimized structures and interaction energies of the Aun (n = 2-8) Bz complexes with σ-hole or σ-lump interaction were studied. Strong σ-hole and relative weak σ-lump interactions exist between Au cluster and benzene. With the help of atoms-in-molecules analysis and plotting of non-covalent interaction map, the interaction zones of the complexes were found out. The nature of these interactions was revealed through energy decomposition analysis by using the symmetry-adapted perturbation theory. σ-Hole interactions are dominated by electrostatic interaction, while σ-lump interactions are mainly driven by dispersion. This study can enrich the knowledge of interaction between Au cluster and π-systems and design of new materials based on coinage metal of σ-hole and σ-lump interactions.