Bi37InBr48: A polar subhalide with Bi95+ polycations, complex bromobismuthate(III) anions [Bi3Br13]4- and [Bi7Br30]9-, and pentabromoindate(III) anions [InBr5]2-

Article abstract of DOI:10.1002/zaac.200390062

Black crystals of Bi₃₇InBr₄₈ were synthesized from bismuth, indium and BiBr₃ by cooling stoichiometric melts from 570 K to 470 K. X-ray diffraction on powders and single-crystals revealed that the compound crystallizes with space group P 6₃ (a = 2262.6(4); c = 1305.6(2) pm). The Bi₉⁵⁺ polycations in the polar crystal structure have the shape of heavily distorted tricapped trigonal prisms with approximate C_s symmetry. The high complexity of the structure results from three coexisting types of anionic groups: Three edge-sharing [BiBr₆] octahedra constitute the trigonal bromobismuthate(III) anion [Bi₃Br₁₃]^4-. Four [BiBr₆] and three [BiBr₅] polyhedra share common vertices to form the [Bi₇Br₃₀]^9- hemi-sphere, in which the trigonal bipyramid of the pentabromoindat(III) ion [InBr₅]^2- is embedded.