No abstract

The structure of the title compound, (C5H7N5)2[SnCl6]Cl2·4H2O, can be described as alternating layers of C5H7N52+ and [SnCl6]2− ions along the b axis, the SnIV atom lying on a twofold axis. The chloride ions are located between the organic entities, forming hydrogen bonds with the N atoms and water molecules. Layers of adeninium cations and hexa­chloro­stannate anions are linked by anion–cation, cation–water and water–water hydrogen bonds. This three‐dimensional complex network of hydrogen bonds ensures the cohesion of the ionic structure.

Key indicatorsSingle-crystal X-ray study T = 293 K Mean '(C±C) = 0.004 A Ê R factor = 0.036 wR factor = 0.090 Data-to-parameter ratio = 7.4For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e. # 2002 International Union of Crystallography Printed in Great Britain ± all rights reserved The title salt, l-HisH 2 2+ Á2NO 3 À , contains two nitrate anions and one l-histidinium dication. The anions and cations are linked to each other through strong hydrogen bonds, formed by all H atoms covalently bonded to the N and O atoms of the l-histidinium dications. This three-dimensional complex network of hydrogen bonds ensures the cohesion of the ionic structure.

The crystal structure of the title compound, C8H12N+·Cl−·H2O, consists of hydro­phobic layers of dimethyl­anilinium cations parallel to the bc plane alternated by hydro­philic layers of chloride anions and water mol­ecules. The layers are linked by N—H⋯O and N—H⋯Cl hydrogen bonds involving the ammonium groups of the cations. The cohesion of the ionic structure is further stabilized by O—H⋯Cl hydrogen-bonding inter­actions.

Key indicatorsSingle-crystal X-ray study T = 296 K Mean (C-C) = 0.007 Å R factor = 0.041 wR factor = 0.106 Data-to-parameter ratio = 19.5For details of how these key indicators were automatically derived from the article, see