Post-Synthetic Modification of a Porous Hydrocarbon Cage to Give a Discrete Co₂₄ Organometallic Complex

A new alkyne-based hydrocarbon cage was synthesized in high overall yield using alkyne-alkyne coupling in the cage forming step. The cage is porous and displays a moderately high BET surface area (546 m²  g^-1 ). The cage loses crystallinity on activation and thus is porous in its amorphous form, while very similar cages have been either non-porous, or retained crystallinity on activation. Reaction of the cage with Co₂ (CO)₈ results in exhaustive metalation of its 12 alkyne groups to give the Co₂₄ (CO)₇₂ adduct of the cage in good yield.