Synthesis and characterization of the Anderson-Evans tungstoantimonate [Na5(H2O)18{(HOCH2)2CHNH3}2][SbW6O24].

A novel tungstoantimonate, [Na5(H2O)18{(HOCH2)2CHNH3}2][SbVWVI6O24] (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 [SbVWVI6O24]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.