Tetra­aqua­tetra­kis­(4,4′-bipyridine dioxide-κO)terbium(III) octa­cyanidotungstate(V)

In the title compound, [Tb(C₁₀H₈N₂O₂)₄(H₂O)₄][W(CN)₈], both metal atoms are eight-coordinated. The Tb^III ion displays a dodeca­hedral geometry, while the W^v ion exhibits a distorted square-anti­prismatic geometry. The Tb atoms are located on a special position of site symmetry -4, whereas the W atoms are located on a twofold rotation axis. The cations are linked by O—H...O hydrogen bonds. The title compound is isotypic with the corresponding and previously described Mo compound [Qian & Yuan (2011). Acta Cryst. E67, m845].