CsSc3F6[SeO3]2: A New Rare‐Earth Metal(III) Fluoride Oxoselenate(IV) With Sections Of The ReO3‐Type Structure |
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Authors: | Stefan Greiner Thomas Schleid |
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Institution: | Institut für Anorganische Chemie, Universit?t Stuttgart, Stuttgart, Germany |
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Abstract: | A new representative of rare‐earth metal(III) fluoride oxoselenates(IV) derivatized with alkali metals could be synthesized via solid‐state reactions. Colorless single crystals of CsSc3F6SeO3]2 were obtained through the reaction of Sc2O3, ScF3, and SeO2 (molar ratio 1:1:3) with CsBr as reactant and fluxing agent. For this purpose, corundum crucibles embedded as liners into evacuated silica ampoules were applied as containers for these reactions at 700 °C for seven days. The new quintenary compound crystallizes in the trigonal space group P3m1 with a = 565.34(4) and c = 1069.87(8) pm (c/a = 1.892) for Z = 1. The crystal structure of CsSc3F6SeO3]2 contains two crystallographically different Sc3+ cations. Each (Sc1)3+ is surrounded by six fluoride anions as octahedron, while the octahedra about (Sc2)3+ are formed by three fluoride anions and three oxygen atoms from three terminal SeO3]2– anions. The (Sc1)F6]3– octahedra link via common F– vertices to six fac‐(Sc2)F3O3]6– octahedra forming 2∞{Sc3F6O6]9–} layers parallel to (001). These layers are separated by oxygen‐coordinated Cs+ cations (C.N. = 12), arranging for the charge compensation, while Se4+ cations within the layers surrounded by three oxygen atoms as ψ1‐tetrahedral SeO3]2– units complete the structure. EDX measurements confirmed the composition of the title compound and single‐crystal Raman studies showed the typical vibrational modes of isolated SeO3]2– anions with ideal C3v symmetry. |
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Keywords: | Fluorides ReO3 structure Oxoselenates(IV) Cesium salts Scandium |
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