A novel tungstoantimonate, [Na5(H2O)18{(HOCH2)2CHNH3}2][SbVWVI 6O24] (SbW6 ), was synthesized from an aqueous solution and structurally characterized by single-crystal X-ray diffraction, which revealed C2/c symmetry. The structure contains two serinol [(HOCH2)2CHNH3]+ and five Na+ cations, which are octahedrally surrounded by 18 water molecules, and one [SbVWVI 6O24]7− anion. The serinol molecules also play a critical role in the synthesis by acting as a mild buffering agent. Each of the WVI and SbV ions is six-coordinated and displays a distorted octahedral motif. A three-dimensional supramolecular framework is formed via hydrogen-bonding interactions between the tungstoantimonates and cations. Powder X-ray diffraction, elemental analysis, thermogravimetric analysis and IR spectroscopy were performed on SbW6 to prove the purity, to identify the water content and to characterize the vibrational modes of the crystallized phase.

The title polyoxometalate-based organic–inorganic hybrid compound, [Na6(C3H10NO2)4][W12O40(OH)2]·10H2O, consists of a di-μ 3-hydroxido-tetra-μ 3-oxido-octadeca-μ-oxido-octadecaoxidododecatungstate (paradodecatungstate B) anion, [W12O40(OH)2]10–, and six sodium cations coordinated by the oxygen ions of the polyanions, serinol ligands protonated at the N atom, and water molecules. The centrosymmetric paratungstate B anion shows characteristic features in terms of bond lengths and angles. The three-dimensional framework structure is established by bonding of the sodium cations with oxygen ions of the paratungstate B anions and a network consisting of N—H...O and O—H...O hydrogen bonds of medium strength between the protonated serinol cations, water molecules and the paratungstate B anions. The title compound was also characterized by means of elemental analysis, IR spectroscopy and thermogravimetric analysis.