A Crystalline Tri-thorium Cluster: When Metal σ-Aromaticity Just Isn’t Enough

This study provides multiple incontrovertible evidences that the crystalline tri-thorium cluster recently synthesized by Liddle and co-workers is truly σ-aromatic, but the role of aromaticity is limited to shape molecular-response properties rather than stability. The latter is shown to be determined by the unprecedented multicenter charge-shift bonding pattern involving thorium and chlorine atoms. This study extends the range of the charge-shift bonding beyond transition metals, and may have potential implications for future attempts to design and synthesize new stable actinide complexes.