Abstract: | On the Structure of Ba2Wo3F4 and Ba2MoO3F4 Ba2WO2/2O2F2]F2 has been prepared for the first time as colourless single crystals (from powder, Au-tube, 680°C, 90 d). It crystallizes in the monoclinic (C c) crystal system with a = 1151.1, b = 938.2, c = 718.8 pm, ß = 126.17°, Z = 4. dx = 6.17, dpyk = 6.13 g · cm?3. (Fourcirclediffractometer PW 1100, Fa. Philips, MoKα-, ω-2Θ-scan, 1832 I0(hkl) R = 8.3, Rw = 7.4%). Parameters see in the text. The isotypic Ba2MoO3F4 has been prepared as powder (a = 1147.5, b = 937.0, c = 725.1 pm, ß = 126.42°). The structure shows chains of (WO2/2O2F2) groups along 001]. To establish O2? and F? on the positions IR and Raman Spectra are employed. The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed. |