Poly[[hexa­aqua­(μ₂-oxalato-κ⁴O¹,O²:O^1′,O^2′)bis(μ₃-pyridine-2,4-dicarboxyl­ato-κ⁴N,O¹:O^1′:O⁴)dicerium(III)] monohydrate]

In the polymeric title compound, {[Ce₂(C₇H₃NO₄)₂(C₂O₄)(H₂O)₆]·H₂O}_n, the Ce³⁺ cation is nine-coordinated in a distorted CeNO₈ tricapped trigonal–prismatic geometry, formed by three pyridine-2,4-dicarboxyl­ate anions, one oxalate anion and three water mol­ecules. The mid-point of the oxalate anion is located on an inversion center. The oxalate and pyridine-2,4-dicarboxyl­ate anions bridge the Ce³⁺ cations, forming a two-dimensional polymeric complex parallel to (010). Inter­molecular classical O—H...O hydrogen bonding and weak C—H...O hydrogen bonding are present in the crystal structure and π–π stacking [centroid–centroid distance = 3.558 (2) Å] is observed between parallel pyridine rings of adjacent mol­ecules. The uncoordinated water mol­ecule shows an occupancy of 0.5.