Assembling Ligand-Protected Gold Icosahedrons into Cyclic Superatomic Molecules with Superatomic Aromaticity

Gold clusters with high symmetry are promising building blocks for cluster assemblies due to their distinctive electronic structure and tunable physicochemical properties. Herein, two cyclic superatomic molecules, (Ir@Au₉)₆(AuCl₂)₆Cl₁₂ and (Ir@Au₉)₁₀(AuCl₂)₁₀Cl₂₀, were constructed via a bottom-up assembly strategy involving face-sharing of Au₃ triangles based on the structure of icosahedral W@Au₁₂ clusters. Chemical bonding analyses reveal that the 30e (Ir@Au₉)₆ and 50e (Ir@Au₉)₁₀ cores in these two clusters are analogues of C₆H₆ and C₁₀H₁₀, respectively, with both exhibiting superatomic aromaticity. Furthermore, by replacing Ir with Os, the obtained (Os@Au₉)₁₀(AuCl₂)₁₀Cl₂₀ cluster can be regarded as an electronic analogue of the C₁₀ ring, featuring dual aromaticity with five in-plane and five out-of-plane delocalized superatomic orbitals. Given the large size of the superatom, the 40e (Os@Au₉)₁₀ core exhibits alternating superatomic single and triple bonds, similar to the C₁₈ ring. This work extends the concept of aromaticity from the molecule scale to superatomic-molecule architectures and provides a practicable bottom-up assemble approach for constructing cyclic clusters with superatomic aromaticity.