2D C-13 NMR OF THE STRUCTURAL TRANSITION IN SOLID C-60

Two-dimensional (2D) <<separation of interactions>> C-13 NMR spectra o f powdered C60 have been measured above and below the structural phase transition at T(c) = 260 K. The comparison between experimental and s imulated C-13 powder lineshapes rules out any kind of uniaxial jump re orientations around a single direction below T(c), as recently suggest ed. The spectra are, however, compatible with a pseudorandom sequence of small-amplitude uniaxial reorientations around at least three diffe rent axes separated by 60-degrees resulting in a quasi-isotropic reori entational motion which gradually freezes out at lower temperatures.