Synthesis and structural characterization of novel ternary thio- and selenometallates of rubidium and cesium

The dissertation deals with the synthesis and structural characterization of new ternary solid state compounds. All compounds feature isolated or condensed tetrahedra [TQ₄]^5- in an alkali metal substructure. In the ternary phase diagrams of alkali metal-aluminium-chalcogen and alkali metal-indium-chalcogen Cs₆Al₂S₆, Cs₁₀Al₆S₁₄, Rb₄Al₂S₅, CsAlS₂, CsAlSe₂, CsAl₃S₅, Cs₆In₂S₆ and Cs₄In₂S₅ were synthesized and characterized. The crystal structure of Cs₆Al₂S₆ and Cs₆In₂S₆ feature isolated double tetrahedra [T₂S₆]^6-. Cs₁₀Al₆S₁₄ has an approximately 14 Aa long oligoanion. In Rb₄Al₂S₅, Cs₄In₂S₅, CsAlS₂, and CsAlSe₂ the characteristic structural elements are one-dimensional polyanions. The two-dimensional structure of CsAl₃S₅ is built up by alternating aluminium-sulfur and cesium layers. Ternary aluminates as well as ternary in-dates enlarge the number of compounds on the binary section of T₂Q₃ and M₂Q in the phase systems M-Al-Q and M-In-Q. Also the crystal structure of Cs₂S₂O₃.H₂O was established. With IR- and Raman spectroscopy a broad hydrogen bond system between the terminal sulfur atoms of the thiosulfate tetrahedra [S₂O₃]^2- and water molecules was analyzed. In addition the synthesis and crystal structure of Ce₆Ga_3.33S₁₄ and Ce₄(Si₂O₇)S₃ were introduced. Ce₆Ga_3.33S₁₄ was first published in the 1960s. The crystal structure is isotypic to Ce₆Al_3.33S₁₄. In 2000 Schleid released Ce₄(Si₂O₇)S₃. Ce₄(Si₂O₇)S₃ was obtained as byproduct in the reaction of Ce₆Ga_3.33S₁₄.