Bis(1-chloro-2,2,4,4-tetramethyl-3-oxocyclobutan-1-yl)pentasulfane: an occupancy modulated structure

Acta Crystallogr B. 2004 Aug;60(Pt 4):416-23. doi: 10.1107/S0108768104010699. Epub 2004 Jul 19.

Abstract

The title compound crystallizes in the space group P2(1)/n and may be described by a partial ordering of a 1:1 disordered P2(1)/a parent structure with the c axis halved. The pentasulfane chain completes a full turn of a helix, which gives molecules containing left- or right-handed helices similar spatial requirements and allows them to be interchanged. The structure can be redescribed as containing 0.732 (1) of an ordered P2(1)/n structure and 0.268 (1) of a 1:1 disordered P2(1)/a structure, implying that 0.134 (1) of the molecule sites contain molecules of the opposite hand to that predicted by an ordered P2(1)/n structure. It is found that the average molecular position in the asymmetric unit is not the same for each component and that these structural differences must be recognized to obtain a satisfactory refinement.