Cadmium iodide complexes with dimethylsulphoxide, and their crystal structures

The crystalline compounds [{CdI2(dmso)}n] (1,) and [Cd2I4(dmso)4] (2,) provide a structural sequence illustrating the conversion of CdI2 into the ionic derivatives [Cd(dmso)6]2+ [Cd(dmso)I3]2− · EtOH (3,) and [Cd(dmso)6]2+ CdI42− (4,), with increasing proportions of dmso. (1,) comprises polymeric chains with Cd centres linked by bridging iodide atoms, and alternately in four‐ and six‐coordination. (2,) is a binuclear segment of the chains and can be seen as the structural forerunner of the ionic compounds (3,) and (4,). The ion packing in (3,) is loose, with lattice ethanol.