Crystal structure of sodium (1S)-d-mannit-1-yl­sulfonate

The title salt, Na(+)·C(6)H(13)O(9)S(−) [systematic name: sodium (1S,2S,3S,4R,5R)-1,2,3,4,5,6-hexa­hydroxy­hexane-1-sulfonate], is formed by reaction of d-mannose with sodium bis­ulfite (sodium hydrogen sulfite) in water. The anion has an open-chain structure with the S atom and the C atoms of the carbohydrate chain forming an essentially planar zigzag chain in which the absolute values of the torsion angles lie between 173.6 (2) and 179.9 (3)°. The sodium cations are penta-­coordinated by O atoms, with one link to a carbohydrate O atom and four to O atoms of sulfonate residues in separate anions, thus creating a three-dimensional network. The carbohydrate anions are arranged in a head (–SO(3) (−)) to head (–SO(3) (−)) arrangement, thereby forming two parallel sheets linked through coordination to sodium ions, with each sheet containing inter­molecular hydrogen bonds between the anionic residues. Unusually, the double sheets are not connected to neighbouring sets of double sheets, either by ion coordination or inter­molecular hydrogen bonding.