Molecular dynamics in crystalline C60·2CHBr3

The nature of the molecular motion of C60 in crystalline C60·2CHBr3 has been determined by solid-state NMR. In the 193–295 K temperature range the C60 molecules undergo fast isotropic reorientation, similar to that in pure C60. The activation energy of reorientation of the C60 cages is 65 meV, with a corresponding rotational diffusion constant at 298 K of 9.6×10−11 s−1.