Poly[[hexaaqua(μ2-oxalato-κ4O1,O2:O1′,O2′)bis(μ3-pyridine-2,4-dicarboxylato-κ4N,O2:O2′:O4)dilanthanum(III)] monohydrate]

Abstract

In the polymeric title compound, {[La2(C7H3NO4)2(C2O4)(H2O)6]·H2O}n, the La3+ cation is nine-coordinated in a distorted LaNO8 tricapped trigonal–prismatic geometry formed by three pyridinedicarboxylate anions, one oxalate anion and three water molecules. The oxalate anion is located on an inversion center. The oxalate and pyridinedicarboxylate anions bridge the La3+ cations, forming a two-dimensional polymeric complex parallel to (010). Intermolecular O—H...O hydrogen bonding and weak C—H...O hydrogen bonding is present in the crystal structure and π–π stacking [centroid–centroid distance = 3.571 (3) Å] is observed between parallel pyridine rings of adjacent molecules. The uncoordinated water molecule shows an occupancy of 0.5.