Redetermination of 1,3-diammonio-1,2,3-tride­oxy-cis-inositol dichloride

The crystal structure of the title compound, C(6)H(16)N(2)O(3) (2+)·2Cl(−), has been reported previously by Palm [Acta Cryst. (1967 ▶), 22, 209–216] from Weisenberg camera data, with R1 = 10.5%, isotropic refinement of non-H atoms and H atoms not located. We remeasured a data set of the title compound and present a more precise structure determination. The asymmetric unit contains two unique 1,3-diammonio-1,2,3-tride­oxy-cis-inositol cations and four Cl(−) counter-ions. The cyclo­hexane rings of both inositol cations adopt chair conformations with two axial hy­droxy groups. An extended network of hydrogen bonds is formed. The four chloride counter ions are hydrogen bonded to the hydroxy and ammonium groups of the cations by N—H⋯Cl and O—H⋯Cl interactions. The cations are aligned into wavy layers by cation⋯cation interactions of the form N—H⋯O(ax), N—H⋯O(eq) and O(ax)—H⋯O(eq). Intramolecular hydrogen bonding between the axial hydroxy groups is, however, not observed.