title: An unexpected oxidation: NaK5Cl2(S2O6)2revisited.
abstract: The title compound, NaK5Cl2(S2O6)2[systematic name: sodium penta-potassium dichloride bis-(di-thio-nate)], arose as an unexpected product from an organic synthesis that used di-thio-nite (S2O42-) ions as a reducing agent to destroy excess permanganate ions. Compared to the previous study [Stanley (1953 ▸).Acta Cryst.6, 187-196], the present tetra-gonal structure exhibits a root 2a× root 2a×csuper-cell due to subtle changes in the orientations of the di-thio-nate anions. The structure can be visualized as a three-dimensional framework of [001] columns of alternatingtrans-NaO4Cl2and KO4Cl2octa-hedra cross-linked by the di-thio-nate ions with the inter-stices occupied by KO6Cl2polyhedra to generate a densely packed three-dimensional framework. The asymmetric unit comprises two sodium ions (site symmetries 4 and -4, four potassium ions (site symmetries = -4, 4, 1 and 1), three chloride ions (site symmetries = 4, 4 and 2) and two half-di-thio-nate ions (all atoms on general positions). Both di-thio-nate ions are completed by crystallographic inversion symmetry. The crystal chosen for data collection was found to be rotationally twinned by 180° about the [100] axis in reciprocal space with a 0.6298 (13):0.3702 (13) domain ratio.
authors.affiliation: Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland.
authors.forename: William T A
authors.initials: WT
authors.lastname: Harrison
authors.affiliation: Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland.
authors.forename: M John
authors.initials: MJ
authors.lastname: Plater
keywords: crystal structure; di­thio­nate; redetermination; super-cell