Structure cristalline du composé Hg3-xSbx(S+Se)2+xI2-x(x≃ 0.1)

Abstract

Single crystals of the mercury chalcohalide Hg3-xSbx(S+Se)2+xI2-x(x≃ 0.1) (mercury antimony sulfide selenide iodide), were grown by a chemical transport reaction. The structure contains three independentA(Hg/Sb) atoms; each atom is strongly covalently bonded with twoX(Se/S) atoms to form approximately linearX–A–Xunits. TheX–A–Xunits link to formA4X4rings, which are combined into infinite crankshaft-type bands running along the [100] direction. Four equatorialE(I/X= Se,S) atoms at relatively long distances complete the distorted octahedral coordination ofA(Hg/Sb). The crystal under investigation was twinned by non-merohedry with a refined twin domain fraction of 0.814 (6):0.186 (6). The structure is isotypic with Hg3Se2I2[Beck & Hedderich (2000).J. Solid State Chem.151, 73–76], but the current determination reveals a coupled substitution, with partial replacement of Hg+2by Sb+3, balanced by the equivalent substitution of I−1by S−2and Se−2. Bond-valence calculations are consistent with this relative substitution model.