Structures and Properties of the C_6v Symmetric Mn₂Ge₁₂ Cluster and Its One-Dimensional Nanostructure

Symmetric clusters with high stability are potential building blocks for one-dimensional (1D) nanostructures. In this study, we report a stable C_6v symmetric Mn₂Ge₁₂ cluster which can serve as potential building blocks to construct a novel 1D nanostructure. Combined anion photoelectron spectroscopic and theoretical studies show that the anionic Mn₂Ge₁₂^- has a C_s symmetric cage structure with an ⁶A″ electronic state, while the neutral Mn₂Ge₁₂ adopts a C_6v symmetric Mn-capped hexagonal antiprism structure with a ³A₁ electronic state. Chemical bonding analysis reveals that the Mn 3d_σ/π orbitals interact with the Ge₁₂ unit forming two 14c-1e σ bonds and four 14c-2e σ bonds, while the Mn 3d_π/δ orbitals interact with the Ge₁₂ unit forming three 14c-2e π bonds. Mn₂Ge₁₂ exhibits σ and π aromaticities, with a total of 18 σ and 10 π electrons. Ab initio molecular dynamics simulation results indicate its high structural stability at 300 K. First-principles calculations predict that the constructed 1D [Mn₂Ge₁₂]_∞ nanostructure based on the Mn₂Ge₁₂ cluster has metallic and antiferromagnetic properties.