Pentapotassium dodecatungstoborate(III) hexadecahydrate

Abstract

The title compound, K5[BW12O40]·16H2O, contains a [BW12O40]5- polyanion of 222 crystallographic symmetry, with a central tetrahedrally coordinated BIII atom surrounded by four groups of three edge-sharing octahedra (W3O13 subunits), which are linked in turn to each other and to the central BO4 tetrahedron by shared O atoms at the vertices. There is a crystallographically unique B-O bond of 1.554(10) Å, while the average W-O distances are 2.344 (17) Å for four coordinate O atoms, 1.917 (12) and 1.89 (2) Å for two coordinate O atoms within and connecting the W3O13 subunits, respectively, and 1.709 (8) Å for terminal O atoms. Not all of the K+ ions and H2O groups were located.