A lanthanum(III) complex with a lacunary polyoxotungstate: Na₂(NH₄)₇[La(W₅O₁₈)₂]·16H₂O

The crystal structure of a lanthanum polyoxotungstate complex, viz. hepta­ammonium disodium decatungstolanthanate hexadecahydrate, Na₂(NH₄)₇[La<(W₅O₁₈)₂]·16H₂O, has been determined by single-crystal X-ray diffraction at 100 (2) K in the space group C2/c. The [La(W₅O₁₈)₂]^9- polyoxoanion has the central La³⁺ cation located on a twofold rotation axis. The close packing of the polyoxoanion-supported lanthanum(III) complexes with Na⁺ and NH₄⁺ cations leads to the formation of several intersecting undulating channels, where the water mol­ecules of crystallization are located and involved in strong hydrogen bonds.