Neutron powder diffraction study of perdeuterodimethyl sulfone

The crystal structure of perdeuterodimethyl sulfone, (CD3)2SO2 or C2D6O2S, has been refined at 4.5 K against high-resolution neutron powder diffraction data. The structure determined previously by Sands [Z. Kristallogr. (1963), 119, 245-251] at ambient temperature is shown to remain down to liquid helium temperature, and at 4.5 K the S - C and S - O bond distances are 1.441 (2) and 1.760 (2) Å, respectively. The mol-ecules are distorted tetra-hedra with C 2v point symmetry (crystallographic symmetry m2m for S and m for C, O and one D atom) and are linked through a network of weak hydrogen bonds in the C-centred ortho-rhom-bic structure.