Magnesium chloride tetrahydrate, MgCl2·4H2O

Abstract

The title compound, MgCl2·4H2O, was crystallized at 403 K and its structure determined at 200 K. The structure is built up from MgCl2(H2O)4octahedra with atransconfiguration. Each complex is situated on a crystallographic twofold axis, with the rotation axis aligned along one H2O—Mg—OH2axis. They are connected by a complex network of O—H...Cl hydrogen bonds. The structure contains two-dimensional sections that are essentially identical to those in the reported tetrahydrates of CrCl2, FeCl2, FeBr2and CoBr2, but they are stacked in a different manner in MgCl2·4H2O compared with the transition metal structures.