GIAO-DFT-NMR characterization of fullerene-cucurbituril complex: the effects of the C-60@CB[9] host-guest mutual interactions

Magnetic shielding constants for an isolated fullerene C-60, cucurbituril CB[9], and the host-guest complex C-60@CB[9] were calculated as a function of separation of the monomers. Our results in the gas phase and water indicate a significant variation of the magnetic properties for all atoms of the monomers in the complex and after liberation of fullerene C-60 from the interior of the CB[9] cavity. The interaction between the two monomers results in a charge transfer that collaborates with a redistribution of electron density to deshield the monomers.