Incorporation of Sulfate or Selenate Groups into Oxotellurates(IV): III. Compounds with Magnesium or Zinc |
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Authors: | Matthias Weil Mahdi Shirkhanlou |
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Affiliation: | Institute for Chemical Technologies and Analytics, Division Structural Chemistry, TU Wien, Vienna, Austria |
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Abstract: | The mixed oxochalcogenate compounds Mg2(SO4)(TeO3)(H2O), Mg3(SO4)(TeO3)(OH)2(H2O)2, Zn2(SeO4)(TeO3), and Zn4(SO4)(TeO3)3 were obtained under hydrothermal conditions (210 °C, autogenous pressure). Structure analyses using single‐crystal X‐ray data revealed tellurium in all four compounds to be present in oxidation state +IV, whereas sulfur or selenium atoms exhibit an oxidation state of +VI. In the crystal structures of the two magnesium compounds, [MgO5(H2O)] octahedra [Mg2(SO4)(TeO3)(H2O) structure, isotypic with the Co and Mn analogues] or [MgO4(OH)2] and [MgO4(OH)2(H2O)2] octahedra [Mg3(SO4)(TeO3)(OH)2(H2O)2 structure, novel structure type] as well as trigonal‐pyramidal TeO32– anions make up metal oxotellurate sheets, which are bridged by SO42– anions. The polar crystal structure of Zn2(SeO4)(TeO3) is isotypic with Zn2(MoO4)(TeO3) and consists of [ZnO4] tetrahedra, [ZnO6] octahedra, SeO42– and TeO32– anions as principal building units that are connected into a framework structure. Such a structural arrangement, with basically the same coordination polyhedra as in Zn2(SeO4)(TeO3) but with SO42– instead of SeO42– anions, is also found in the tellurium‐rich compound Zn4(SO4)(TeO3)3 that crystallizes in a novel structure type. |
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Keywords: | Crystal engineering Hydrothermal synthesis Oxotellurates(IV) Magnesium Zinc Mixed oxochalcogenates Crystal structure |
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