C—H...O contacts in the crystal structure of 1,3-dithiane 1,1,3,3-tetraoxide

Abstract

The crystal structure of 1,3-dithiane 1,1,3,3-tetraoxide, C4H8O4S2, has been determined to examine the intermolecular C—H...O hydrogen bonds in a small molecule with highly polarized hydrogen atoms. The crystals are monoclinic, space group Pn, with a = 4.9472 (5), b = 9.9021 (10), c = 7.1002 (7) Å and β = 91.464 (3)° with Z = 2. The molecules form two stacks parallel to the a axis with the molecules being one a translation distance from each other. This stacking involves axial hydrogen atoms on one molecule and the axial oxygen atoms on the adjacent molecule in the stack. None of these C—H...O contacts is particularly short (all are > 2.4 Å). The many C—H...O contacts between the two stacks involve at least one equatorial hydrogen or oxygen atom. Again, no unusually short contacts are found. The whole crystal structure basically consists of a complex network of C—H...O contacts with no single, linear C—H...O contacts, only contacts that involve two (bifurcated), and mostly three or four neighbors.