Rb6In2S6 und Rb4In2S5, zwei neue Thioindate mit isolierten und verknüpften [In2S6]6- Anionen / Rb6In2Se6 and Rb4ln2S5, Two NEW Thioindates with Isolated and Connected [In2S6]6- Anions Respectively

Abstract

Abstract The hitherto unknown title compounds were prepared by a disproportionation reaction starting from elementary rubidium and indium monosulfide. Rb4ln2S5 crystallizes in the triclinic system (P1̄) with the lattice constants a = 931.7(2); b = 1097.6(3);c = 761.2(2)pm; a = 111.32°(2); β = 94.70°(2); γ = 103.70°(2) (Z = 2) and Rb6In2S6 in the monoclinic system (C2/m) with the lattice constants a = 895.3(2); b = 1356.9(2); c = 791.8(2) pm; β = 101.53°(2) (Z = 2). The quasi molecular [In2Se6]6- group which is isoelectronic with the gas phase molecule In2Cl6 consists of two edge sharing InS4 tetrahedra and is the basic unit of Rb6ln2S6 as well as of Rb6In2S6. The formation process, structural relationships between the two compounds and their possible role in the phase diagram of the components Rb2S and In2S3 are discussed.