The Role of Gold in Modifying the Structural Stabilities, Superhalogen Properties, and Double Aromaticity of Cyclic Carbon Clusters: Insights From AuC20− and AuC20

Abstract

In this study, we investigate the geometries, stabilities, and electronic characteristics of the AuC₂₀⁻ anion and its neutral counterpart, using advanced computational methods, including B3LYP and PBE0 functionals with the def2-TZVPPD basis set. Our results reveal that the lowest-lying isomers of both clusters exhibit remarkable planar cyclic structures, with the Au atom effectively mimicking the role of a carbon atom, thereby enhancing the overall stability and robustness of the configurations. Notably, we find that the C–C bonds demonstrate greater covalent character compared to Au–C bonds, which enhances the clusters' superhalogen properties. Additionally, analysis of electron localization, natural population, and adaptive natural density partitioning provides insights into the charge distribution and delocalized bonding networks, highlighting σ and π double aromaticity and significant electron delocalization. These findings pave the way for further exploration of metal-doped carbon structures, positioning them as valuable candidates for advancements in catalysis and the development of next-generation electronic materials.