Redetermination of diaquatetrakis(dimethylformamide-κO)magnesium dichloride

Abstract

The crystal structure of the title compound, [Mg(C3H7NO)4(H2O)2]Cl2, in which the Mg ion lies on a crystallographic inversion centre, confirms that of the previous room-temperature study [Pavanello et al. (1995). Main Group Met. Chem. 18, 9–19]. This redetermination at 113 K has improved geometry precision by almost an order of magnitude [e.g. Mg—O(w) (w = water) distances = 2.094 (4) and 2.0899 (7) Å in the old and new structures, respectively] and allowed the water H atoms to be located and their positions refined. In the crystal, O—H...Cl hydrogen bonds between the two aqua ligands of the complex molecule and neighboring chloride counter-anions generate supramolecular chains propagating along [010]. The dicationic [Mg(DMF)4(H2O)2] unit (DMF is dimethylformamide) adopts a slightly distorted octahedral geometry in which the Mg atom is coordinated by four DMF O atoms in a pseudo-tetragonal arrangement and two trans aqua ligands.