Post-Synthetic Modification of a Porous Hydrocarbon Cage to Give a Discrete Co 24 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 m 2  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 Co 2 (CO) 8 results in exhaustive metalation of its 12 alkyne groups to give the Co 24 (CO) 72 adduct of the cage in good yield.