Synthesis and characterisation of alkali metal and thallium polyfluoroantimonates, ASbnF5n+1 (n=2, 3)

the other hand, is monoclinic at 250 K [P2(1)/n, with a 774.10(14), b = 1425.41(17)m, c = 951.30(15) pm, beta 113.226(6)degrees, V = 0.9646(3) nm(3) and Z = 4]. RbSb2F11 and TISb2F11 belong to yet a third structural type. Crystals of CsSb3F16 are orthorhombic at 200 K [Pca2(1), with a = 2207(3), b = 772.6(11), c = 1605(3) pm, V = 2.737(8) nm(3) and Z = 8]. The vibrational spectra of Sb2F11- salts are consistent with the above crystallographic assignments, showing that Sb2F11- anions deviate strongly from D-4h symmetry in having no symmetry at all (point group C-1). The vibrational spectra of CsSb3F16 confirm the presence of Sb3F16- anions, which adopt a cis-fluorine-bridged geometry consistent with the crystal structure. (c) Wiley-VCH Verlag GmbH & Co.