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 molecules are distorted tetrahedra 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 orthorhombic structure.