Controlling the confinement of fullerene C 60 molecules using a saddle shape Ni(II) macrocycle

A saddle-shaped Ni-macrocycle bearing flexible benzyl arms, Ni(TBTAA), 1, has been prepared and structurally authenticated in the solid state as a toluene adduct, with the toluene residing in the extended cavity of the macrocycle, close to two of benzylic substituents. The Ni-macrocycle forms a crystalline inclusion complex with fullerene C60, {C60∩(1)2}·(toluene)5, 2, which has each fullerene encapsulated by two macrocycles involving ππ interactions to the phenyl lined face of the macrocycles, as well as CHπ from the benzyl groups and toluene molecules closing up the fullerene surface. The CHπ for the benzyl groups effectively increases the steric demands of the macrocycle over the surface of the fullerene, circumventing any fullerenefullerene interactions. The nature of the interactions in the fullerene complex has been probed using Hirshfeld surface analysis.