Structural and electronic insights into Au2C20− cluster: A superhalogen with dual aromaticity

Abstract

This study delves into the exploration of the geometrical and electronic characteristics of the Au₂C₂₀⁻ anion and its neutral counterpart using DFT and ab initio calculations. We found that the lowest-energy isomers of Au₂C₂₀⁻ anion and Au₂C₂₀ neutral exhibit striking differences in their planar cyclic structures. Notably, an in-depth analysis of electron localization and adaptive natural density partitioning provides the presence of both σ and π double aromaticity, along with significant electron delocalization. Furthermore, The C − C bonds exhibit a more pronounced covalent character compared to the Au − C bonds, thereby contributing to the superhalogen properties of Au₂C₂₀⁻ anion.