Influence of the solvent nature on the composition of isopolyvolframates of some s-elements

The influence of the nature of the medium on the composition of strontium and barium isopolyvolframates has been studied. It has been established that a stable phase of crystalline paravolframate of the composition Ме5[W12O40(OH)2]×n H2O is formed in an aqueous medium in the acidity range of 1.14-1.60. Strontium in aqueous dimethylformamide medium and acetonitrile medium forms aquasolvate of heptavolframate Sr3[W7O24] and paravolframate. Barium in an aqueous dimethylformamide medium is characterized by the formation of protonated heptavolframate and decavolframate of the composition Ba2[W10O32]·mC3H7ON; in an acetonitrile medium, the formation of heptavolframate and a new phase, undecavolframate Ba3[H2W11O37]∙16H2O, has been established. The compounds were identified by chemical, IR spectroscopic, X-ray phase analysis, and X-ray spectral microanalysis.