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, Na-2(NH4)(7)[La5O(18))(2)].16H(2)O, 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.