Crystal structure of bis(propane-1,3-diaminium) hexafluoridoaluminate diaquatetrafluoridoaluminate tetrahydrate

Abstract

The title compound, (C3H12N2)2[AlF6][AlF4(H2O)2]·4H2O, was obtained by a solvothermal method in ethanol as solvent and with aluminium hydroxide, HF and 1,3-diaminopropane as educts. The asymmetric unit contains a quarter each of two crystallographically independent propane-1,3-diammonium dications, [AlF6]3- and [AlF4(H2O)2]- anions and four water molecules. The cations, anions and three of the independent water molecules are situated on special positions mm, while the fourth water molecule is disordered about a mirror plane. In the crystal, intermolecular N-H⋯F and O-H⋯F hydrogen bonds link the cations and anions into a three-dimensional framework with the voids filled by water molecules, which generate O-H⋯O hydrogen bonds and further consolidate the packing.