The crystal and molecular structure of meso-ethane-1,2-bis(methyl sulphoxide), with some results from neglect of a small anomalous dispersion signal in a centrosymmetric case

Abstract

The structure of the title compound, crystallizing in space group P1 with Z= 1, was solved by Patterson methods. Full-matrix least-squares refinement was based on 579 counter-collected data corrected for absorption and anomalous dispersion. The final R is 0.021 (Rw=0"030). Bond lengths and angles in the sulphoxide group are compared with those of other organic sulphoxides. A short central C-C bond of 1.516 (2) A can be explained qualitatively as a secondary rehybridization effect on C caused by the electron-withdrawing property of the O atoms. Neglect of anomalous dispersion corrections gives rise to significant changes in scale factor and vibrational parameters for the heavier atoms in good agreement with quantitative predictions by Gilli & Cruickshank [Acta Cryst. (1973). B29, 1983-1985.The largest coordinate shift of an H atom corresponds to a change in the C-H length of 3a. Dispersion effects in the final difference map are small and cannot explain the observed negative density regions near the S atoms.

(R,S)-1,2-Bis(benzylsulfinyl)ethane

“…The molecule has a center of symmetry at the midpoint of the central CÐC bond. A similar situation was found in (R,S)-1,2bis(methylsul®ny)ethane (Svinning et al, 1976) and (R,S)-1,2bis(phenylsul®ny)ethane (Cattalini et al, 1979). All the C and S atoms between the two phenyl rings are coplanar; this plane is perpendicular to the planes of the phenyl rings, which are parallel to each other.…”

“…Compounds of the type RS(O)(CH 2 ) n S(O)R exist as diastereoisomeric rac and meso forms which have different melting points. X-ray crystal structure analyses of the disulfoxides (R = methyl, n-propyl and phenyl) proved that the higher melting isomer is the meso form and the lower is the rac form (Svinning et al, 1976;Shao et al, 1989;Cattalini et al, 1979). As part of our systematic investigation of the coordination chemistry of disulfoxides, we recently synthesized a meso form of 1,2-(benzylsul®nyl)ethane, (I).…”

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

“…This bond is slightly longer in MPSO 2, 1.525 (3) A, than in some closely related structures: 1.516 (2) A in meso-l,2-bis(methylsulfinyl)ethane (Svinning et al, 1976), 1.515 (3) A in 1-methylsulfonyl-2-methylsulfinylethane (Berg, Bruun & Mo, 1978) and 1.515 (2) A in 1,2-bis(methylsulfonyl)ethane (Mo et al, 1979).…”

“…A short central C-C bond in the fragment -SO 2-CHz-CH2-SO 2-can be anticipated as a secondary effect of rehybridization at S (Svinning, Mo & Bruun, 1976). This bond is slightly longer in MPSO 2, 1.525 (3) A, than in some closely related structures: 1.516 (2) A in meso-l,2-bis(methylsulfinyl)ethane (Svinning et al, 1976), 1.515 (3) A in 1-methylsulfonyl-2-methylsulfinylethane (Berg, Bruun & Mo, 1978) and 1.515 (2) A in 1,2-bis(methylsulfonyl)ethane (Mo et al, 1979).…”

Structure of the tri-o-thymotide–ethyl methyl sulfoxide (2:1) clathrate. Crystallographic estimation of the enantioselectivity

“…No peak of significant intensity revealed the location of the disordered methylene groups. In order to make up for the lack of a reasonable structure for the guest molecule the relevant internal molecular parameters were taken from the geometry of meso-l,2-bis-(methylsulfinyl)ethane (Svinning, Mo & Bruun, 1976). The resulting conformation (Fig.…”