Gold trifluoride

Refiy, B., Kolonits, M., Schulz, A., Klapotke, T.M. and Hargittai, M. (2000) Intriguing Gold Trifluorides — Molecular Structure of Monomers and Dimers An Electron Diffraction and Quantum Chemical Study. Journal of the American Chemical Society, 122, 3127—3134. 

In contrast with the difluorides, the distribution of trifluorides extends to the third series of the transition metals, where iridium and gold trifluorides are fully characterized. In the second series, trifluorides are known for the elements from niobium to rhodium, with the exception of technetium, and in the first series, from titanium to cobalt. All the trifluorides have been characterized structurally, with earlier reports based on X-ray powder-diffraction data, since the compounds were not prepared in single-crystal form until more recently, when high-temperature, crystal-growth techniques became available. 

Fig. 3. The structure of gold trifluoride showing the arrangement of fluorine atoms in two adjacent planes, perpendicular to the sixfold axis. Double circles show atoms at 2 = 0 and single circles those at z = .

In the third series iridium trifluoride has a volume which is slightly larger than that for rhodium trifluoride, in line with the small increase in size of the metal atom. The anomalously high volume for gold trifluoride has already been discussed. 

Crystals of gold trifluoride are hexagonal, a = 5-149. c = 16-26 A, (7 = 373-3 A. D = 6-72, Z = 6, D, = 6-73, space-group P6i22-D,. The structure was determined from a Patterson projection, and refined by three-dimensional least squares, the final H being 0-090 for 193 reflections. 

Gold trifluoride is the least densely packed of the noble-metal trifluorides. This and the geometry of the fluorine ligand co-ordination are consistent with the antibonding nature of one of the electron pairs of the low-spin d electron configuration of gold(iii). 

Single crystals of gold trifluoride were grown by an improved technique. Freshly precipitated gold powder was treated with fluorine gas at 160 lb. in. and 360° in a monel reaction vessel whose top was cooled to 20°, and after 12—14 hr. bright golden-yellow needles of AuF, formed on the cooled surface. The crystals, which were elongated... 

The crystal structure of gold trifluoride is not like that of any known RXg compound although it can be viewed as a distorted form of the other noble-metal trifluoride structures. ... 

Magnetic Susceptibility of Gold Trifluoride.—The tri-fluoride prepared by Sharpe s method was treated with fluorine (ca. 1 atm.) at 260° in a monel can. The orange-yellow product so obtained was ground in an agate mortar in a dry-box, and the fine powder was well packed into a Pyrex Gouy tube which was subsequently sealed under... 

AuF3 GOLD TRIFLUORIDE 97 Bal2[g] BARIUM IODIDE (GAS) 145... 

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