catena-Poly[[diaqua-nickel(II)]-bis-(μ-pyridine-4-sulfinato)-κN,O;κO,N].

In the title coordination polymer, Ni(C(5)H(4)NO(2)S)(2)(H(2)O)(2), the Ni(II) ion is located on an inversion centre and is octa-hedrally coordinated by two N and two O atoms of four symmetry-related and deprotonated pyridine-4-sulfinate (ps) ligands together with two water mol-ecules in axial positions. The ps(-) anions, acting as μ(2)-bridging ligands, link neighbouring Ni(II) ions into a chain structure along the c axis. These polymeric chains are extended into a three-dimensional framework via inter-molecular O-H⋯O hydrogen bonds with participation of the water mol-ecules.