(4-Oxido-2-oxo-1,2-dihydro­pyrimidine-5-carboxyl­ato-κ(2) O (4),O (5))(4-oxido-2-oxo-1,2-dihydro­pyrimidin-3-ium-5-carboxyl­ato-κ(2) O (4),O (5))bis­(1,10-phenanthroline-κ(2) N,N′)gadolinium(III) dihydrate

The title compound, [Gd(C(5)H(2)N(2)O(4))(C(5)H(3)N(2)O(4))(C(12)H(8)N(2))(2)]·2H(2)O, was obtained from a solvothermal reaction of 2,4-dihydroxy­pyrimidine-5-carboxylic acid (H(3)iso), GdCl(3)·6H(2)O and 1,10-phenanthroline (phen). The Gd(III) ion is located on a twofold rotation axis and is coordinated by four N atoms from two chelating phen ligands and four O atoms (5-carboxyl­ate and 4-oxido O atoms) from H(2)iso(−) and Hiso(2−) ligands. The mol­ecules are linked into a three-dimensional network by N—H⋯O, N—H⋯N and O—H⋯O hydrogen bonds. The H atom involved in an N—H⋯N hydrogen bond is disordered around a twofold rotation axis with half occupancy.