X-ray study of structure and charge density of 1-methylsulfonyl-2-phenylsulfonylethane

Crystal structure of 1-(methylsulfonyl)-2-(p-methoxyphenylthio)ethane at 87 K. A comparative study of two different crystals

The structure of 1-(methylsulfonyl)-2-(p-methoxyphenylthio)ethane, C10H14O3S2, was determined from an X-ray diffraction study of two different crystals, A and B, at 87 K. The space group is monoclinic, P21/c, a = 10.859(1), b = 5.310(1), c = 19.934(3) Å, β = 98.49(2)° and Z = 4 from high-order reflections for crystal B. Intensities were collected to (sin θ)/λ = 0.650 for crystal A and to 0.904 Å−1 for B with MoK[unk] radiation. The structure was solved by direct methods. Parameters derived for crystal A (R = 0.029 for 2418 F0 ) and from the data with (sinθ)/ λ &lt; 0.650 Å−1 for B (R = 0.032 for 2402 F0 ) were compared and analysed by half-normal probability plots and by χ 2 tests. The agreement is very good. The slopes in all plots are < 1.0 indicating a slight overestimation of the standard deviates. A normal probability plot of the two sets of observed F 2 [(sin θ/λ &lt; 0.65 Å−1] has a slope very close to 1.0. Least-squares refinements have been carried out with various subsets of data for crystal B. The parameters from the refinement with (sin θ)λ &gt; 0.75 Å−1 were taken to give the best description of the structure (R = 0.027, 1387 F 0). The refined bond lengths in the fragment containing S and the phenyl ring were corrected for thermal motion. Before correction the ring C—C bonds are about 0.0034 Å longer than the values from the refinement with all data. Bonding parameters at the S atoms corroborate previous observations for some closely related sulfide and sulfone structures. The distortions from C 2v symmetry in the para-substituted phenyl ring is largely effected by the OCH3 group which is confirmed from a comparison of various parasubstituted anisoles. The observed reversible change in colour of the crystals, from colourless at room temperature to pale purple at 87 K seems to be related to a shortening of an intermolecular S…Ph contact.