Acta Cryst. (2013). E69, m7-m8 [ doi:10.1107/S1600536812048672 ]
Abstract: The title salt, K+·C6H7O9S-·2H2O, formed by reaction of dehydro-L-ascorbic acid with potassium hydrogen sulfite in water, crystallizes as colourless plates. The potassium ion is coordinated by eight O atoms arising from hydroxy or sulfonate groups. The sulfonate group is bonded to the C atom neighbouring that of the lactone carbonyl group. As is commonly observed in crystalline L-ascorbic acid derivatives, the O atom of the primary hydroxy group is linked to the second C atom from the lactone C atom, forming a hemi-acetal function, thereby creating a bicyclic system of two fused five-membered rings, both of which have envelope conformations with one of the shared C atoms as the flap. Addition of the sulfur nucleophile occurs from the less hindered face. One of the two independent lattice water molecules has hydrogen bonds to sulfonate O atoms of two different anions and is the acceptor of bonds from hydroxy groups of two further anions; the second lattice water molecule donates to the carbonyl and a hydroxy O atom in different anions, and accepts from a hydroxy O atom in a further anion. Thus, through K-O coordination and hydrogen bonds, the potassium cations, sulfonate anions and water molecules are linked in a three-dimensional network.
Hyper-Text Markup Language (HTML) file
Chemdraw file (2.8 kbytes)
Chemical Markup Language (CML) file (4.9 kbytes)
To open or display or play some files, you may need to set your browser up to use the appropriate software. See the full list of file types for an explanation of the different file types and their related mime types and, where available links to sites from where the appropriate software may be obtained.
The download button will force most browsers to prompt for a file name to store the data on your hard disk.
Where possible, images are represented by thumbnails.
Copyright © International Union of Crystallography