Die Einwirkung von Ammoniumfluorid auf Scandium: Synthese und Kristallstrukturen von (NH4)3[ScF6] und [Cu(NH3)4]3[ScF6]2

Action of Ammonium Fluoride on Scandium: Synthesis and Crystal Structures of (NH₄)₃ScF₆] and Cu(NH₃)₄]₃ScF₆]₂ The action of (NH₄)F on scandium in copper ampoules yields either (NH₄)₃ScF₆] or ScF₃ and a small quantity of Cu(NH₃)₄]₃ScF₆]₂, respectively, depending upon the molar ratio of the educts (NH₄)F : Sc (6 : 1 and 4 : 1, respectively) and temperature. (NH₄)₃ScF₆] crystallizes with the cryolite type of structure: monoclinic, P2₁/n, Z = 2; a = 650.0(2); b = 651.4(2); c = 949.0(2) pm; β = 90.40(2)°, Cu(NH₃)₄]₃ScF₆]₂ is triclinic, P‐1, Z = 1; a = 821.1(2); b = 821.2(2); c = 822.7(2) pm; α = 90.04(3); β = 90.00(3); γ = 90.16(3)°. In its chemical behaviour against (NH₄)F, scandium parallels aluminium rather than gallium.