23739-18-6Relevant academic research and scientific papers
Disproportionation of Ag(II) to Ag(I) and Ag(III) in fluoride systems and syntheses and structures of (AgF+)2AgF4-MFe6 - salts (M = As, Sb, Pt, Au, Ru)
Shen, Ciping,Z?emva, Boris,Lucier, George M.,Graudejus, Oliver,Allman, John A.,Bartlett, Neil
, p. 4570 - 4577 (2008/10/08)
Interaction of Ag+ salts in anhydrous liquid hydrogen fluoride, aHF, with AgF4- salts gives amorphous red-brown diamagnetic AgIAgIIIF4, which transforms exothermally to brown, paramagnetic, microcrystalline AgIIF2 below 0°C. AgIAuIIIF4 prepared from Ag+ and AuF4- in aHF has a tetragonal unit cell and a KBrF4 type lattice, with a = 5.788(1) A?, c = 10.806(2) A?, and Z = 4. Blue-green AgIIFAsF6 disproportionates in aHF (in the absence of F- acceptors) to colorless AgIAsF6 and a black pseudotrifluoride, (AgIIF+)2AgIIIF4 -AsF6-. The latter and other (AgF)2AgF4MF6 salts are also generated by oxidation of AgF2 or AgF+ salts in aHF with F2 or in solutions of O2+MF6- salts (M = As, Sb, Pt, Au, Ru). Single crystals of (AgF)2AgF4AsF6 were grown from an AgFAsF6/AsF5 solution in aHF standing over AgF2 or AgFBF4, with F2 as the oxidant. They are monoclinic, P2/c, at 20°C, with a = 5.6045(6) A?, b = 5.2567(6) A?, c = 7.8061(8) A?, β = 96.594(9)°, and Z = 1. The structure consists of (AgF)nn+ chains (F-Ag-F = 180°, Ag-F-Ag = 153.9(11)°, Ag-F = 2.003(4) A?), parallel to c, that enclose stacks of alternating AgF4- and AsF6-, each anion making bridging contact with four Ag(II) cations of the four surrounding chains caging them. There is no registry between the ordered array in one cage and that in any neighboring cage . The F-ligand anion bridges between the anions and, with the Ag(II) of the chains, generates a trifluoride-like structure. (AgF)2AgF4AsF6 [like other (AgF)nn+ salts] is a temperature-independent paramagnet except for a Curie tail below 50 K.
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.
