Crystal structure of poly[[hexaaquatris(μ-3,6-dioxocyclohexa-1,4-diene-1,4-diolato)dierbium(III)] octadecahydrate]

Abstract

The title lanthanide complex, [Er2(C6H2O4)3(H2O)6]·18H2O, is isostructural with its La, Gd, Yb and Lu analogues. The Er3+ ion, located on a threefold rotation axis, is nine-coordinated in a distorted tricapped trigonal–prismatic geometry, which is completed by six oxygen atoms from three dhbq2− ligands and three oxygen atoms from coordinated water molecules. Each dhbq2− ligand acts in a μ2-bis(bidentate) bridging mode to connect two Er3+ ions to form honeycomb (6,3) two-dimensional sheets extending in the ab plane, having an Er...Er separation of 8.7261 (2) Å. In the crystal, extensive O—H...O hydrogen-bonding interactions involving the coordinated water molecules and the water molecules of crystallization, as well as the oxygen atoms of the dhbq2− ligands, generate an overall three-dimensional supramolecular network.

Keywords

• crystal structure
• coordination polymers
• dioxybenzoquinone
• erbium(III)
• lanthanide