Separation and Selective Formation of Fullerene Adducts within an MII8L6 Cage

The self-assembly of 4-fold-symmetric porphyrins with FeII or ZnII gave a new cubic MII8L6 cage framework with electron-deficient walls. This cage bound C60-indene or C60-anthracene bisadducts selectively, whereas unfunctionalized fullerenes and monoadducts were not encapsulated. The FeII8L6 cage also enabled the reaction of C60 and anthracene to yield the bisadducts selectively under conditions where no reaction was observed in the absence of the cage. These findings have relevance in the context of polymer solar cells, where C60 bisadducts have found use as electron acceptors, because these adducts currently require laborious and time-consuming syntheses and purification.