Symmetry-Driven Assembly of a Penta-Shell Keplerate Cuprofullerene for Metallofullerene Frameworks

Two metallofullerene frameworks (MFFs) constructed from a penta-shell Keplerate cuprofullerene chloride, C₆₀ @Cu₂₄ @Cl₄₄ @Cu₁₂ @Cl₁₂ , have been successfully prepared via a C₆₀ -templated symmetry-driven strategy. The icosahedral cuprofullerene chloride is assembled on a C₆₀ molecule through [η² -(C=C)]-Cu^I and Cu^I -Cl coordination bonds, resulting in the penta-shell Keplerate with the C₆₀ core canopied by 24 Cu, 44 Cl, 12 Cu and 12 Cl atoms that fulfill the tic@rco@oae@ico@ico penta-shell polyhedral configuration. By sharing the outmost-shell Cl atoms, the cuprofullerene chlorides are connected into 2D or 3D (snf net) frameworks. TD-DFT calculations reveal that the charge transfer from the outmost Cu^I and Cl to C₆₀ core is responsible for their light absorption expansion to near-infrared region, implying anionic halogenation may be an effective strategy to tune the light absorption properties of metallofullerene materials.