A Basic Bismuth(III) Dodecahydro-closo-dodecaborate Hydrate: [Bi6O4(OH)4] [B12H12]3·10H2O.

Colorless, hexagonally plate-shaped single crystals of the new title compound are prepared from an aqueous solution of (H3O)2[B12H12] (obtained by passing a solution of Cs2[B12H12] in water through a strongly acidic ion-exchange column) and Bi2O3 (20 °C, 5 d).