Synthesis and structure determination of copper perrhenate, CuReO4

Copper(I) perrhenate, CuReO 4 , has been synthesized as a single-phase sample in sealed silica tubes at 500–800 °C, and its structure was determined for the first time by single-crystal X-ray diffraction. CuReO 4 forms a new structure type derived from the diamond-structure and crystallizes in space group I 4 1 cd with lattice parameters a =13.6965(5) A and c =7.7729(5) A, Z =16 (rotation method data acquisition using ω and ϕ scans, R 1 =0.0191, w R 2 =0.0403). Cu and Re atoms are tetrahedrally coordinated by O atoms, these tetrahedra are corner-shared, forming spirally twisted rings of 4-6-8-10- Me O 4 like Si x O y -rings in some silicon dioxide modifications or aluminosilicates. According to low-temperature powder X-ray diffraction and differential thermal analysis, CuReO 4 shows no phase transition down to 80 K and up to its melting point, 703 K.