Geometric and electronic properties of anionic precious metal gold doped boron clusters AuB n − (n = 10–20)

Abstract

Recently, the Au–B covalent bonds in gold doped boron clusters has attracted great attention. However, there are fewer theoretical reports on exploration their ground state structures and stabilities, especially for the medium sizes. Here, we study the structural evolution and electronic properties of the anionic Au doped boron clusters with medium sizes of n from 10 to 20 using the unbiased cluster structural searches combined with density functional theory (DFT) calculations. The results reveal that the quasi-planar AuB18 − (1A, C 1) cluster shows excellent stability and a large vertical separation energy (VDE) of 4.25 eV. The good consistency between the computationally simulated photoelectron spectra and the experimental spectra strongly supports the correctness of our low-lying structures. Further bonding analyses show that the well-stabilized aromatic AuB18 − cluster is due to the active σ interactions between Au atom (6s orbitals) and B units (2p orbitals), as well as the large number of σ–bonds in the B18 − moiety with π-aromaticity. These findings enriched the family of Au-B alloy clusters and metal-doped boron-based aromatic clusters, which provide valuable information for the experimental characterization and preparation of boron-rich alloy nanoclusters in the future.