SeBr3[AlBr4] und TeI3[AlI4] – zwei weitere Vertreter des SCl3[AlCl4]-Strukturtyps

SeBr₃AlBr₄] and TeI₃AlI₄] – two further Compounds in the SCl₃AlCl₄] Structure Type The reaction of SeBr₄ and AlBr₃ in a closed glass ampoule at 150°C yields quantitatively SeBr₃AlBr₄] in form of yellow moisture sensitive crystals. From Te, two equivalents of I₂, and AlI₃ one obtains TeI₃AlI₄] in form of dark red, moisture sensitive crystals. Both compounds crystallize monoclinic in the space group Pc (SeBr₃AlBr₄]: a = 670.7(7) pm, b = 663.9(5) pm, c = 1 428.6(2) pm, β = 101.21(9)°, TeI₃AlI₄]: a = 731.9(1) pm, b = 730.8(1) pm, c = 1 565.5(3) pm, β = 102.01(2)°). They are isotypic and have the SCl₃AlCl₄] structure type. The structures are built of tetrahedral AlX₄^? ions and of pyramidal EX₃⁺ ions (E = S, Se, Te; X = Cl, Br, I). The chalcogen atoms are additionally coordinated by halogen atoms of surrounding AlX₄^? ions, corresponding to a strongly distorted octahedral coordination EX₃₊₃.