Predicting the properties of a new class of host-guest complexes: C60 fullerene and CB[9] cucurbituril.

DFT, semi-empirical and classical molecular dynamics methods were used to describe the structure and stability of the inclusion complex formed by the fullerene C60 and the cucurbituril CB[9]. Our results indicate a high structural compatibility between the two monomers, which is evident from the potential energy curve for the inclusion process of the C60 into the CB[9] cavity. The interaction between the two monomers is mainly of the van der Waals type and leads to a highly stable complex. Thermal contributions and environmental interaction are taken into account by the free energy of binding of -224 kJ mol(-1), indicating that even in aqueous medium the complex remains very stable.