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

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.