Theoretical study of interactions between cavitand and fullerenes

Various interaction ways of cavitand and C-60 in 1:1 and 1:2 models have been studied by molecular mechanics and molecular dynamics methods. Their minimal energy geometries are obtained and the intermolecular energies analyzed in detail. HF/6-31G single point energy calculations for both 1:1 and 1:2 adducts are performed. Moreover, calculations were made for two cavitand configurations (BCAV and XCAV), and two 1:1 and 1:2 models using the semi-empirical molecular orbital method AM1. The computational results show that cavitand can encapsulate C-60 molecules. For the 1:1 models, the complex with the largest interaction energy is that with C-60 Situated below the XCAV, and for the 1:2 models that with C-60 Situated above and below the XCAV. From these results, we predict that the final product, in an experimental process, should be in a stoichiometry 1:2, with the fullerenes positioned above and below the XCAV cavities. (C) 2000 Elsevier Science B.V. All rights reserved.