Redetermination of [EuCl2(H2O)6]Cl

Abstract

The crystal structure of the title compound, hexaaquadichloridoeuropium(III) chloride, was redetermined with modern crystallographic methods. In comparison with the previous study [Lepert et al. (1983). Aust. J. Chem. 36, 477–482], it could be shown that the atomic coordinates of some O atoms had been confused and now were corrected. Moreover, it was possible to freely refine the positions of the H atoms and thus to improve the accurracy of the crystal structure. [EuCl2(H2O)6]Cl crystallizes with the GdCl3·6H2O structure-type, exhibiting discrete [EuCl2(H2O)6]+ cations as the main building blocks. The main blocks are linked with isolated chloride anions via O—H...Cl hydrogen bonds into a three-dimensional framework. The Eu3+ cation is located on a twofold rotation axis and is coordinated in the form of a Cl2O6 square antiprism. One chloride anion coordinates directly to Eu3+, whereas the other chloride anion, situated on a twofold rotation axis, is hydrogen bonded to six octahedrally arranged water molecules.