Poly[[tetraaquadi-μ4-oxalato-μ2-oxalato-dineodymium(III)] dihydrate]

Abstract

The title compound, {[Nd2(C2O4)3(H2O)4]·2H2O}n, was synthesized hydrothermally in the presence of bis(carboxyethylgermanium) sesquioxide. It is isostructural with the corresponding Pr compound [Yang et al. (2009). Acta Cryst. E65, m1152–m1153]. The Nd3+ cation is nine-coordinated and its coordination polyhedron can be described as a distorted tricapped trigonal prism. Two Nd3+ ions are connected by two O atoms from two oxalate ions to give a dinuclear Nd2 unit. The unit is further linked to four others via four oxalate ions yielding a layerparallel to (0-11). The linkages between the layers by neighbouring oxalate anions lead to a three-dimensional framework with channels along the c axis. The coordinating and free water molecules are located in the channels and make contact with each other and the host framework by weak O—H...O hydrogen bonds.