Nuclear magnetic relaxation study of fully deuterated sulfolan

Molecular motions of the fully deuterated sulfolan molecule (C4D8O2S) have been studied in the solid state by NMR measurements of the deuteron spin‐lattice relaxation times in the laboratory (T1) and rotating (T1ρ) frame. In the crystalline phase, it has been found that the relaxation is determined by the ring puckering motion of the molecule. The plastic crystal phase is found to exhibit effects from both isotropic reorientation and translational diffusion. The modified nature of this phase and the plastic–crystalline transition of the deuterated as compared to the undeuterated solid is discussed in terms of the C–H—O hydrogen bonding between molecules.