Abstract: | Ytterbium(III) tetraaquatris(tetraoxorhenate(VII)), Yb(ReO4)3(H2O)4, was prepared by the reaction of Yb2O3 with concentrated HReO4 at room temperature. The colorless compound crystallizes in the monoclinic space group P21/n (No. 14) with four formula units per unit cell (a=730.5(1) pm, b=1484.1(5) pm, c=1311.7(2) pm, β=93.69(1)). The main feature of the crystal structure is the formation of chains ∞1Yb(H2O)4(ReO4)2(ReO4)2/2] running along 100]. This arrangement shows distorted cubic antiprisms of Yb(H2O)4(ReO4)2(ReO4)2/2] interconnected via the ReO4− ligands. The chains are held together in the solid by hydrogen bonding. The compound is paramagnetic and follows the Curie-Weiss law with a magnetic moment of 4.0 μB at room temperature and θ=−42 K. It loses hydration water in two steps at temperatures below 400 K; decomposition begins at 850 K, forming Yb2O3(Re2O7)2 and is complete at 1350 K leading to Yb2O3 as final product. |