Exohedral Cupro­fullerene: Sequentially Expanding Metal Olefin Up to a C₆₀@Cu₂₄ Rhombicuboctahedron

Exohedral cupro­fullerenes with 6-, 12-, or 24-nuclearity were obtained by utilizing fluoro­carboxylic/​dicarboxylic acid under solvo­thermal conditions. The 24-nuclear molecule presents a C₆₀@Cu₂₄ core–shell structure with a rhombi­cuboctahedron Cu₂₄ coated on the C₆₀ core, representing the highest nuclearity in metallo­fullerene. The resultant complexes show an efficient absorption of visible light as opposed to the pristine C₆₀. TD-DFT calculations revealed the charge transfer from Cu­(I) and O atoms to the fullerene moiety dominates the photo­physical process.