Crystal structure of CdSO4(H2O): a redetermination

Abstract

The crystal structure of the title compound, cadmium sulfate monohydrate or poly[(μ2-aqua)(μ4-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 Cd(2+) cation is coordinated by four O atoms of four sulfate anions and two O atoms of water mol-ecules, forming a distorted octa-hedral trans-[CdO6] polyhedron. Each sulfate anion bridges four Cd(2+) cations and each water mol-ecule bridges two Cd(2+) cations, leading to the formation of a three-dimensional framework, with Cd⋯Cd separations in the range 4.0757 (2)-6.4462 (3) Å. O-H⋯O hydrogen-bonding inter-actions of medium strength between the coordinating water mol-ecules and sulfate anions consolidate the crystal packing.

Keywords: cadmium sulfate monohydrate; crystal structure; hydrogen bonding; hydro­thermal synthesis; redetermination.

Fig. 1.

The coordination sphere around the Cd2+ cation with displacement ellipsoids drawn at the 50% probability level. [Symmetry codes: (i) x, 1/2 – y, 1/2 + z; (ii) –x, 1 – y, –z; (iii) 1 – x, -1/2 + y, 1/2 – z].

Fig. 2.

The three-dimensional framework structure of the title compound in a view along the b axis. Dashed lines indicate intermolecular O—H···O hydrogen-bonding interactions.