catena-Poly[[bis(μ-2-sulfonatobenzoato)bis[triaquagadolinium(III)]]-μ-oxalato].

The asymmetric unit of the title coordination polymer, [Gd(2)(C(7)H(4)O(5)S)(2)(C(2)O(4))(H(2)O)(6)](n) or [Gd(2-SB)(ox)(0.5)(H(2)O)(3)](2n) (2-SB is 2-sulfonatobenzoate and ox is oxalate), (I), consists of one Gd(III) ion, one 2-SB anion, three coordinated water molecules and one half of an ox ligand. The ox ligand is located on a crystallographic inversion centre.