Crystal structure of CdSO4(H2O): a redetermination

The crystal structure of the title compound, cadmium sulfate monohydrate or poly[(2-aqua)(4-sulfato)cadmium], was redetermined based on modern CMOS (complementary metal oxide silicon) data. In comparison with the previous study [Bregeault & Herpin (1970). Bull. Soc. Fr. Mineral. Cristallogr. 93, 37-42], all non-H atoms were refined with anisotropic displacement parameters and the hydrogen-bonding pattern unambiguously established due to location of the hydrogen atoms. In addition, a significant improvement in terms of precision and accuracy was achieved. In the crystal, the Cd2+ cation is coordinated by four O atoms of four sulfate anions and two O atoms of water molecules, forming a distorted octahedral trans-[CdO6] polyhedron. Each sulfate anion bridges four Cd2+ cations and each water molecule bridges two Cd2+ cations, leading to the formation of a threedimensional framework, with Cd center dot center dot center dot Cd separations in the range 4.0757 (2)-6.4462 (3) angstrom. O-H center dot center dot center dot O hydrogen -bonding interactions of medium strength between the coordinating water molecules and sulfate anions consolidate the crystal packing.