Fullerene bisadduct regioisomers containing an asymmetric diamide tether

Four macrocyclic bis(pyrrolidino)fullerene regioisomers with e-edge, e-face, trans-4 and cis-2 addition patterns were synthesized from the corresponding monoadduct by Prato's cycloaddition in a yield of 50%, and fully characterized by spectroscopic techniques. Bisadduct regioisomers were isolated easily in a pure form using dry-flash column chromatography. The relative ratio of the isolated regioisomers e-edge/e-face/trans-4/cis-2 was 1.0:1.9:1.5:4.9. Morphology of self-assembled structures of the four bisadduct regioisomers in solution was characterized using scanning electron microscopy.