Structures and Properties of the C6v 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 C6v 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 Cs symmetric cage structure with an 6A″ electronic state, while the neutral Mn2Ge12 adopts a C6v symmetric Mn-capped hexagonal antiprism structure with a 3A1 electronic state. Chemical bonding analysis reveals that the Mn 3dσ/π orbitals interact with the Ge12 unit forming two 14c-1e σ bonds and four 14c-2e σ bonds, while the Mn 3dπ/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.