Poly[[hexa­aqua­(μ(2)-oxalato-κ(4) O (1),O (2):O (1′),O (2′))bis­(μ(3)-pyridine-2,4-dicarboxyl­ato-κ(4) N,O (2):O (2′):O (4))dilanthanum(III)] monohydrate]

In the polymeric title compound, {[La(2)(C(7)H(3)NO(4))(2)(C(2)O(4))(H(2)O)(6)]·H(2)O}(n), the La(3+) cation is nine-coordinated in a distorted LaNO(8) 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 La(3+) 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.