H.‐J. Lunk

Crystal structure of copper perrhenate tetrahydrate, Cu(ReO4)2·4H2O

Abstract Single crystals of Cu(ReO4)2·4H2O were prepared from an aqueous solution at room temperature. The structure has been studied by X-ray diffractometry and was refined to R and Rw values of 0.096 and 0.116 respectively. The salt crystallizes in triclinic symmetry belonging to the space group P 1 ( the lattice constants are a=6.317 A , b=6.993 A , c=7.208 A , α=63.24°, β=71.49° and γ=74.22°; Z=1 ). The structure is formed by ReO4 tetrahedra and distorted CuO6 octahedra and bears a close relationship to Mg(ReO4)2·4H2O. The thermal stability of Cu(ReO4)2·4H2O has been studied by in situ X-ray diffraction, thermogravimetry and differential thermal analysis.

Zur kristallstruktur von strontiumperrhenat-sesquihydrat Sr(ReO4)2·1,5H2O

Abstract Single crystals of Se(ReO 4 ) 2 ·1.5H 2 O were prepared at room temperature from an aqueous solution of Sr(ReO 4 ) 2 . The structure has been studied by X-ray diffractometry and was refined to the R and R w values of 0.100 and 0.118 respectively. The salt crystallizes in monoclinic symmetry belonging to the space group P 2 1 / n (the lattice constants constants a = 13.207 A , b = 10.028 A , c = 13.538 A and β = 92.3°; Z = 8 ). The three-dimensional network is formed by ReO 4 tetrahedra and SrO 9 polyhedra connected by their corners. The water molecules are coordinated exclusively with Sr 2+ . Structure relations with other perrhenates are discussed.