1,3-Diammonio-1,2,3-tride-oxy-cis-inositol sulfate

Tris(cis-2-hy-droxy-cyclo-hexane-1,3,5-tri-aminium) hydrogen sulfate octa-chloride dihydrate

The 2-hy­droxy­cyclo­hexane-1,3,5-triaminium (= H₃L³⁺) cation of the title compound, 3C₆H₁₈N₃O³⁺·8Cl⁻·HSO₄⁻·2H₂O, exhibits a cyclo­hexane chair with three equatorial ammonium groups and one axial hy­droxy group in an all-cis configuration. The hydrogen sulfate anion and two water mol­ecules lie on or in proximity to a threefold axis and are disordered. The crystal structure features N—H⋯Cl and O—H⋯Cl hydrogen bonds. Three C₃-symmetric motifs can be identified in the structure: (i) Two chloride ions (on the C₃-axis) together with three H₃L³⁺ cations constitute an [(H₃L)₃Cl₂]⁷⁺ cage. (ii) The lipophilic C₆H₆-sides of three H₃L³⁺ cations, which are oriented directly towards the C₃-axis, generate a lipophilic void. The void is filled with the disordered water mol­ecules and with the disordered part of the hydrogen sulfate ion. The hydrogen atoms of these disordered moieties were not located. (iii) Three H₃L³⁺ cations together with one HSO₄⁻ and three Cl⁻ counter-ions form an [(HSO₄)(H₃L)₃Cl₃]⁵⁺ cage. Looking along the C₃-axis, these three motifs are arranged in the order (cage 1)⋯(lipophilic void)⋯(cage 2). The crystal studied was found to be a racemic twin.

Redetermination of 1,3-diammonio-1,2,3-tride-oxy-cis-inositol dichloride

The crystal structure of the title compound, C₆H₁₆N₂O₃²⁺·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.