LAUSR

Reactions between ASbF6 (A = Rb, Cs) and [XeF5][SbF6] in anhydrous HF in 1:1 molar ratios yielded isotypic A[XeF5][SbF6]2 compounds upon crystallization. The A[XeF5][SbF6]2 (A = Rb, Cs) salts crystallize in two crystal modifications at low (α phase, 150 K) and ambient (β phase, 296 K) temperatures. Similar reactions between CsBiF6 and [XeF5][SbF6] (1:1) yielded mixed-cation/mixed-anion compounds Cs[XeF5][BixSb1–xF6]2 (x = 0.37–0.39). One of the two crystallographic positions of the pnictogen atoms is randomly occupied with both Bi (ca. 40 %) and Sb (ca. 60 %) atoms. The simultaneous presence of both [SbF6]– and [BiF6]– has been confirmed by Raman spectroscopy. The low- and high-temperature phases of Bi/Sb mixed-anion compounds are isotypic with the corresponding A[XeF5][SbF6]2 (A = Rb, Cs) phases. No reactions were observed in the AAsF6 (A = Rb, Cs)/[XeF5][AsF6], ASbF6 (A = K, [H3O]+)/[XeF5][SbF6], and KBF4/[XeF5][SbF6] systems. In the CsBF4/[XeF5][SbF6] system, a metathetical reaction occurred, leading to [XeF5][BF4] (orthorhombic at 150 K, Pbca space group) and CsSbF6. The latter reacted further with [XeF5][SbF6], yielding Cs[XeF5][SbF6]2. A double-displacement reaction also proceeded between Cs2MnF6 and [XeF5][SbF6] to give [XeF5]2[MnF6] and CsSbF6. The reaction between CsPF6 and [XeF5][SbF6] proceeded with the displacement of the weaker Lewis acid, PF5, with the stronger one, SbF5, resulting in [Xe2F11][SbF6] and CsSbF6, which reacted with [XeF5][SbF6] to yield Cs[XeF5][SbF6]2.