18424-17-4Relevant articles and documents
Synthesis and characterisation of alkali metal and thallium polyfluoroantimonates, ASbnF5n+1 (n = 2, 3)
Benkic, Primoz,Jenkins, H. Donald Brooke,Ponikvar, Maja,Mazej, Zoran
, p. 1084 - 1092 (2006)
Reactions of AF (A = K, Rb, T1) with excess liquid SbF5 in anhydrous HF (or SO2) at room temperature give products having the composition ASb2F11. The reaction between CsF and a small excess of SbF5 in anhydrous HF (0.76 mmol of CsF + 4.19 mmol of SbF5 in 4 mL of aHF) yields CsSb2F11, whereas the reaction with a large excess of SbF5 (0.79 mmol of CsF + 23 mmol of SbF5 in 10 niLof aHF) yields the salt CsSb3F 16. Efforts to prepare similar compounds using the monofluorides of Li and Na led only to the already known ASbF6 compounds. Reactions of AF (A = Na, K, Rb, Cs) with liquid SbF5 at 85°C in the absence of solvents yield the products NaSbF6, ASb2F11 (A = K, Rb) and CsSb3F16, respectively. A single-crystal X-ray diffraction study on the salt KSb2F11 [orthorhombic, at 250 K, Pbca, with a = 1141.65(8), b = 1279.96(9), c = 3948.5(3) pm, V = 5.7699(7) nm3 and Z = 24] has shown it to be isostructural with AgSb2F11. CsSb2F11, on the other hand, is monoclinic at 250 K [P21/n, with a = 774.10(14), b = 1425.41(17)m, c = 951.30(15) pm, β = 113.226(6)°, V = 0.9646(3) nm 3 and Z = 4]. RbSb2F11 and TlSb 2F11 belong to yet a third structural type. Crystals of CsSb3F16 are orthorhombic at 200 K [Pca21, with a = 2207(3), b = 772.6(11), c = 1605(3) pm, V = 2.737(8) nm3 and Z = 8]. The vibrational spectra of Sb2F11- salts are consistent with the above crystallographic assignments, showing that Sb 2F11- anions deviate strongly from D 4h symmetry in having no symmetry at all (point group C1). The vibrational spectra of CsSb3F16 confirm the presence of Sb3F16- anions, which adopt a cis-fluorine-bridged geometry consistent with the crystal structure. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
Synthesis of Au(II) fluoro complexes and their structural and magnetic properties
Elder, Scott H.,Lucier, George M.,Hollander, Frederick J.,Bartlett, Neil
, p. 1020 - 1026 (2007/10/03)
Gold at ~20°C with F2 in anhydrous hydrogen fluoride (aHF) acidified with SbF5 dissolves to a red solution from which orange Au(II)(SbF6)2 crystallizes on removal of volatiles. Au(SbF6)2 is triclinic with a = 5.300(1) A?, b = 5.438(1) A?, c = 8.768(2) A?, α = 76.872(3)°, β = 88.736(3)°, γ = 68. 109(3)°, V = 227.79(7) A?3, and Z = 1, space group P1. Each Au(II) atom, at 1, is at the center of an elongated octahedron of F ligands; the four F's of the approximately square AuF4 unit are at 2.09(2) A? x 2 A? and 2.15(2) A? x 2, each F provided by a different SbF6 species. The two long Au-F interatomic distances are at 2.64(2) A?. The SbF6 are grossly distorted in their interactions with the Au. A cis pair of F ligands of each SbF6, make close approach to two different gold atoms, stretching Sb-F to 1.99(2) and 1.94(2) A?. In each case the Sb-F distances trans to these stretched Sb-F bonds are short, being 1.85(2) and 1.84(2) A?, respectively. Magnetic susceptibility measurements show antiferromagnetic coupling with a susceptibility decrease below 13 K. Solvolysis of Au(II)(SbF6)2 in aHF is accompanied by disproportionation: 4Au(SbF6)2 → Au + Au3F8 + 8SbF5(solv). Fluorination, at ~20°C, of the solution of Au(SbF6)2, in SbF5 acidified aHF, precipitates red crystals of triclinic Au(II){SbF6{2Au(II){Au(III)F4}2 with a(o) = 5.2345(2) A?, b(o) = 8.1218(1) A?, c(o) = 10.5977(3) A?, α = 100.090(2)°, β = 100.327(2)°, γ = 104.877(2)°, V = 416.63(2) A?3, space group P1, and Z = 1. It is a simple paramagnet. The structure shows two different Au(II) environments, each approximately square-coordinated by F ligands, one being coordinated trans by an F ligand of each of two SbF6 and similarly by an F ligand from each of two Au(III)F4 species. The other Au(II) is approximately square-coordinated via bridging F ligands to four different Au(III)F4 species. Au(II){SbF6}2Au(II){Au(III)F4]2 with KAuF4 in aHF yields Au3F8 free of metallic gold, the simple paramagnetism of which indicates the formulation Au(II){Au(III)F4}2.
