Theoretical study of interactions between cavitand and fullerenes

Various interaction ways of cavitand and C-60 in 1:1 and 1:2 models have be en studied by molecular mechanics and molecular dynamics methods. Their min imal energy geometries are obtained and the intermolecular energies analyze d 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 c onfigurations (BCAV and XCAV), and two 1:1 and 1:2 models using the semi-em pirical molecular orbital method AM1. The computational results show that c avitand can encapsulate C-60 molecules. For the 1:1 models, the complex wit h 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. F rom these results, we predict that the final product, in an experimental pr ocess, should be in a stoichiometry 1:2, with the fullerenes positioned abo ve and below the XCAV cavities. (C) 2000 Elsevier Science B.V. All rights r eserved.