Bi53+‐Polykationen in geordneten und plastischen Kristallen von Bi5[AlI4]3 und Bi5[AlBr4]3 |
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| Authors: | Michael Ruck Prof Dr Folker Steden |
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| Institution: | 1. Dresden, Fachrichtung Chemie und Lebensmittelchemie der Technischen Universit?tProfessur für Anorganische Chemie II, Technische Universit?t Dresden, D‐01062 Dresden, Fax: (+49) 351‐463‐37287;2. Dresden, Fachrichtung Chemie und Lebensmittelchemie der Technischen Universit?t |
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| Abstract: | Bi53+ Polycations in Ordered and Plastic Crystals of Bi5AlI4]3 and Bi5AlBr4]3 Dark‐red air‐sensitive crystals of pentabismuth‐tris(tetrabromoaluminate) Bi5AlBr4]3 and black crystals of Bi5AlI4]3 have been crystallized from melts of Bi, BiX3 and AlX3 (X = Br, I). X‐ray diffraction on a single crystal of Bi5AlI4]3 (T = 293(2) K; space group Pnma; a = 2143.6(3) pm, b = 1889.1(1) pm, c = 811.74(5) pm) revealed an ordered packing of Bi53+ trigonal bipyramids and AlI4]? tetrahedra that corresponds to the PuBr3 structure type. Contrary to the so far known Bi53+ polycations with accurate D3h symmetry, the bismuth cluster found in Bi5AlI4]3 holds only Cs symmetry. The room temperature structure of the tetrabromoaluminate Bi5AlBr4]3, which is related to the AuCu3 type, shows a dynamic disorder of the Bi53+ polycations (T = 293(2) K; space group  ; a = 1766.2(3) pm). Slight cooling induces the transition into an ordered rhombohedral phase isostructural to Bi5AlCl4]3 (T = 260(2) K; space group  a = 1241.5(8) pm, c = 3041(2) pm). |
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| Keywords: | Bismuth Group‐subgroup relation Order‐disorder transition Polycation Twinning |
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