Dynamics of xenon inside hydrophobic cavities as probed by NMR relaxation of dissolved laser-polarized xenon

Longitudinal relaxation times T(sub 1) of laser-polarized xenon in water solutions containing alpha-cylodextrin and wheat nonspecific lipid transfer protein are measured. It reveals that even with an atom of high polarizability, such as xenon, the van der Waals energy is not sufficiently predominant to avoid large amplitude motions of an apolar guest around its average sites.