Solid State Nuclear Magnetic Resonance, Vol. 71, Elsevier, 17 July 2015.
We report a quantitative measure of the nonexponential 1H spin-lattice relaxation resulting from methyl group (CH3) rotation in six polycrystalline van der Waals solids. We briefly review the subject in general to put the report in context. We then summarize several significant issues to consider when reporting 1H or 19F spin-lattice relaxation measurements when the relaxation is resulting from the rotation of a CH3 or CF3 group in a molecular solid.