Subsequent studies have indicated that RuF 4 produced by this way is impure. The pure, pink compound was isolated for the first time in 1992 by reacting KRuF 6 with AsF 5 at 20 °C in anhydrous hydrofluoric acid, with strict exclusion of water and oxygen. This synthesis exploits the very strong fluoride ion accepting capabilities of the Lewis acid AsF 5.[4][5]
K2RuF6 + 2AsF5 → RuF4 + 2KAsF6
Physical properties
RuF 4 in the solid state is polymeric, with a three-dimensional structure of corrugated layers containing RuF6 octahedra joined by shared fluorine atoms. The crystalline structure is similar to that of vanadium tetrafluoride and is monoclinic, space groupP21/n, with lattice constants a = 560.7 pm, b = 494.6 pm, and c =514.3 pm, β = 121.27°.[6]
Ruthenium tetrafluoride is an extremely reactive compound which darkens immediately upon contact with moisture, and reacts violently with water to deposit ruthenium dioxide. The compound can be stored in glass containers, which are, however, attacked if the sample is heated above 280 °C.
^Esteban, G. L.; Kerr, J. A.; Trotman-Dickenson, A. F.; Gronowitz, S.; Katritzky, A. R.; Reavill, R. E.; Ridgewell, B. J.; Green, M.; Hudson, R. F.; Brimacombe, J. S.; How, M. J.; Acheson, R. M.; Miller, G. R.; Plunkett, A. O.; Cavell, R. G.; Clark, H. C.; Holloway, J. H.; Peacock, R. D.; Ebsworth, E. a. V.; Mays, M. J.; Handford, B. O.; Whalley, W. B.; Grundon, M. F.; Reynolds, B. E.; Sayigh, A. a. R.; Ulrich, Henri; Rubinfeld, J.; Palmer, P. J.; Hollingsworth, B. L.; Tuck, D. G.; Bott, R. W.; Eaborn, C.; Hashimoto, T.; Craig, J. Cymerman; Moyle, M.; Tidd, B. K.; Arthur, H. R.; Ollis, W. D.; Greenwood, N. N.; Wallbridge, M. G. H.; Bentley, K. W.; Dyke, S. F.; Marshall, A. R.; Smith, E. E.; Whelan, W. J.; Finan, P. A.; Ahmed, M. T.; Swallow, A. J. (1 January 1963). "Notes". Journal of the Chemical Society (Resumed): 3879–3919. doi:10.1039/JR9630003879. ISSN0368-1769. Retrieved 10 April 2023.