MOLECULAR-DYNAMICS AND TUNNELING IN SUPRAMOLECULAR COMPLEXES

Inelastic neutron scattering has been used to study molecular tunnelli ng and intramolecular vibrational modes in several inclusion complexes of calixarenes. In methyl-containing guest molecules the free rotor l imit is approached, and the splitting of the librational modes appears to be very sensitive to the details of the particle motion. The exper imental spectra are interpreted in the framework of different models, and the potential barriers obtained are compared with molecular mechan ics calculations.