catena-Poly[[[(5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­aza­cyclo­tetra­decane-κ⁴N)nickel(II)]-μ-oxido-[dioxidotungstate(VI)]-μ-oxido] tetra­hydrate]

In the title compound, {[NiWO₄(C₁₆H₃₆N₄)]·4H₂O}_n, the Ni^II ion lies on an inversion center and is octahedrally coordinated by four N atoms of the tetradentate macrocyclic 5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­aza­cyclo­tetra­decane (L) ligand in the equatorial plane and two O atoms of [WO₄]²⁻ anions in axial positions. Each [WO₄]²⁻ anion bridges two adjacent [NiL]²⁺ cations, forming a chain along [001]. The chains are further connected via N—H...O, O—H...O and C—H...O hydrogen-bonding inter­actions, generating a three-dimensional structure.