Isostructural crystal packing and hydrogen bonding in alkyl-ammonium tin(IV) chloride compounds

The three isostructural compounds butyl-ammonium hexa-chlorido-tin(IV), pentyl-ammonium hexa-chlorido-tin(IV) and hexyl-ammonium hexa-chlorido-tin(IV), (C n H2n+1NH3)2[SnCl6], with n = 4, 5 and 6, respectively, crystallize as inorganic-organic hybrids. As such, the structures consist of layers of [SnCl6]^2- octa-hedra, separated by hydro-carbon layers of inter-digitated butyl-ammonium, pentyl-ammonium or hexyl-ammonium cations. Corrugated layers of cations alternate with tin(IV) chloride layers. The asymmetric unit in each compound consists of an anionic component comprising one Sn and two Cl atoms on a mirror plane, and two Cl atoms in general positions; the two cations lie on another mirror plane. Application of the mirror symmetry generates octa-hedral coordination around the Sn atom. All compounds exhibit bifurcated and simple hydrogen-bonding inter-actions between the ammonium groups and the Cl atoms, with little variation in the hydrogen-bonding geometries.