Poly[[tetra-μ3-acetato-hexa-μ2-acetato-diaqua-μ2-oxalato-tetrapraseodymium(III)] dihydrate].

The title complex, {[Pr(4)(C(2)H(3)O(2))(10)(C(2)O(4))(H(2)O)(2)]·2H(2)O}(n), was synthesized under hydrothermal conditions from praseodymium acetate and the ionic liquid 1-butyl-3-methylimidazolium chloride via an in situ oxalate-ligand synthesis. The compound is a two-dimensional polymer and in the structure presents tightly bound planes parallel to (100), which are in turn linked into a three-dimensional network by hydrogen bonds involving both coordinated and solvent water molecules. The oxalate anion lies across an inversion centre and acts as a bridge between pairs of Pr atoms within a tetranuclear segment of the polymer.