The electronic structure of Ge9[Si(SiMe3)3]3−: a superantiatom complex

Abstract

We report on the electronic structure of Ge₉[Si(SiMe₃)₃]₃⁻. Systematic density functional theory analysis of the electronic shell structure of the cluster and its derivatives reveals that the Ge₉[Si(SiMe₃)₃]₃⁻ and its neutral counterpart have electronic shells that can be explained using the superatom model. The ligand–core interaction of these complexes is distinctly different from previously identified gold, gallium, and aluminium superatom complexes, indicating an electron-donating rather than electron-withdrawing ligand. We modify the electron-counting rule for this case and introduce a simple picture for superatom and superantiatom complexes. Discussions comparing shell models, Zintl clusters, the superhalogen Al₁₃ and superatom complexes to Ge₉[Si(SiMe₃)₃]₃⁻ are presented.