Rhenium(V)‐oxidepyrophosphate Re 2 O 3 (P 2 O 7 ) ‡

Re V 2 O 3 (P 2 O 7 ) was obtained in chemical vapour transport experiments (700 → 600 °C, addition of I 2 ; bronze coloured, needle shaped single crystals) as well as by isothermal heating. The crystal structure, which is isostructural to W V 2 O 3 (P 2 O 7 ), was refined from single‐crystal X‐ray diffraction data ( C 2/ c , Z = 4, a = 12.2503(5) Å, b = 12.6731(5) Å, c = 5.2188(2) Å, β = 89.968(2)°; 1194 independent reflections, 66 variables, 8 atoms in asymmetric unit, R 1 = 0.023, wR 2 = 0.049). It consists of [P 2 O 7 ] groups and highly distorted [ReO 6 ] octahedra [1.822(4) ≤ d (Re–O) ≤ 2.031(4) Å]. The latter forming ribbons [ReO 3/1 O 3/2 ], which can be regarded as sections of the ReO 3 structure type. The infrared spectrum of Re V 2 O 3 (P 2 O 7 ) is reported. An assignment of selected vibrational modes for Re–O and P–O is given.