A single-strand helical coordination polymer: catena-poly­[[[tri­aqua­nickel(II)]-μ-2,2′-bi­pyridine-3,3′-di­carboxyl­ato-κ³N,N′:O] monohydrate]

The asymmetric unit of the title compound, {[Ni(C₁₂H₆N₂O₄)(H₂O)₃]·H₂O}_n, is composed of a lattice water mol­ecule and a nickel(II) ion that is coordinated by three water mol­ecules and the two N atoms of a 2,2′-bi­pyridine-3,3′-di­carboxyl­ate ligand. The twist of the 2,2′-bi­pyridine-3,3′-di­carboxyl­ate unit and the coordination of one carboxyl­ate group to a symmetry-related Ni^II atom generate a helical chain that runs along the b axis. Intrahelical hydrogen bonds participate in controlling the orientation of the helices, and both right-handed and left-handed helices are connected by interhelical hydrogen bonds into two-dimensional sheets.