The Al₅₀Cp*₁₂ cluster - A 138-electron closed shell (L = 6) superatom

Metal clusters stabilized by a surface ligand shell represent an interesting intermediate state of matter between molecular metal-ligand complexes and bulk metal. Such "metalloid" clusters are characterized by the balance between metal-metal bonds in the core and metal-ligand bonds at the exterior of the cluster. In previous studies, the electronic stability for the Al₅₀Cp*₁₂ cluster was not fully understood. We show here that the known cluster Al₅₀Cp*₁₂ can be considered as an analogue to a giant atom ("superatom") with 138 sp electrons organized in concentric angular momentum shells up to L = 6 symmetry. Metal clusters stabilized by a surface ligand shell represent an interesting intermediate state of matter between molecular metal-ligand complexes and bulk metal. We show here that the known cluster Al₅₀Cp*₁₂ can be considered as an analogue to a giant atom ("superatom") with 138 sp electrons organized in concentric angular momentum shells up to L = 6 symmetry.