Controlling the confinement of fullerene C60 molecules using a saddle shape Ni(ii) macrocycle

Abstract

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 π⋯π interactions to the phenyl lined face of the macrocycles, as well as CH⋯π from the benzyl groups and toluene molecules closing up the fullerene surface. The CH⋯π for the benzyl groups effectively increases the steric demands of the macrocycle over the surface of the fullerene, circumventing any fullerene⋯fullerene interactions. The nature of the interactions in the fullerene complex has been probed using Hirshfeld surface analysis.