Darstellung und Kristallstruktur von β-[SeCl3][MoOCl4]

Preparation and Crystal Structure of β-[SeCl₃][MoOCl₄] The reaction of Se₄[MoOCl₄] and Te₄[MoOCl₄] with SOCl₂ as solvent at 150 °C and 80 °C yields [SeCl₃][MoOCl₄] and [TeCl₃][MoOCl₄] respectively within 3 to 6 days as yellow-brown, moisture-sensitive crystals. [TeCl₃][MoOCl₄] was obtained in the already known monoclinic form, while β-[SeCl₃][MoOCl₄] crystallizes in a new polymorphic triclinic form (P1¯, Z = 2, a = 752.7(2), b = 812.8(2), c = 956.9(3) pm, α = 92.55(3)°, β = 111.63(2)°, γ = 107.39(3)°). The structure contains centrosymmetric tetranuclear units ([SeCl₃]₂[Mo₂O₂Cl₈]) which are analogous to the entities found in the structure of [SCl₃][MoOCl₄]. The packing of the molecules in β-[SeCl₃][MoOCl₄] and [SCl₃][MoOCl₄] is distinctely different.