Rhenium heptafluoride is the compound with the formula ReF7. It is a yellow low melting solid and is the only thermally stable metal heptafluoride. It has a distorted pentagonal bipyramidal structure similar to IF7, which was confirmed by neutron diffraction at 1.5 K. The structure is non-rigid, as evidenced by electron diffraction studies.
Production, reactions and properties
Rhenium heptafluoride can be prepared from the elements at 400 °C:4
2 Re + 7 F2 → 2 ReF7It also can be produced by the explosion of rhenium metal under sulfur hexafluoride. 5
It hydrolyzes under a base to form perrhenic acid and hydrogen fluoride:6
ReF7 + 4H2O → HReO4 + 7HFWith fluoride donors such as CsF, the ReF−8 anion is formed, which has a square antiprismatic structure.7 With antimony pentafluoride, SbF5, a fluoride acceptor, the ReF+6 cation is formed.8
References
Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8. 978-0-08-037941-8 ↩
Vogt T.; Fitch A. N.; Cockcroft J. K. (1994). "Crystal and Molecular Structures of Rhenium Heptafluoride". Science. 263 (5151): 1265–7. Bibcode:1994Sci...263.1265V. doi:10.1126/science.263.5151.1265. PMID 17817431. S2CID 20013073. /wiki/Bibcode_(identifier) ↩
Jacob, E. Jean; Bartell, L.S.J. (1970). "Electron Diffraction Study of Rhenium Fluorides. II. Structure, Pseudorotation, and Anharmonic Coupling of Modes in ReF7" (PDF). The Journal of Chemical Physics. 53 (6): 2235. Bibcode:1970JChPh..53.2235J. doi:10.1063/1.1674318. hdl:2027.42/70852. https://deepblue.lib.umich.edu/bitstream/2027.42/70852/2/JCPSA6-53-6-2235-1.pdf ↩
A. F. Holleman; Wiberg, Egon; Wiberg, Nils (2001). Inorganic Chemistry. Boston: Academic Press. ISBN 0-12-352651-5. 0-12-352651-5 ↩
Richard L. Johnson; Bernard Siegel (1969). "On the synthesis of ReF7 and the existence of ReF2 and ReF3". Journal of Inorganic and Nuclear Chemistry. 31 (8): 2391–2396. doi:10.1016/0022-1902(69)80569-5. /wiki/Doi_(identifier) ↩
J.G.Malm; H.Selig (1961). "The vapour-pressures and other properties of ReF6 and ReF7". Journal of Inorganic and Nuclear Chemistry. 20 (3): 189–197. doi:10.1016/0022-1902(61)80267-4. /wiki/Doi_(identifier) ↩
Hwang, I; Seppelt, K. (2000). "The structures of ReF−8 and UF2−8". Journal of Fluorine Chemistry. 102 (1–2): 69–72. doi:10.1016/S0022-1139(99)00248-1. /wiki/Doi_(identifier) ↩
A. F. Holleman; Wiberg, Egon; Wiberg, Nils (2001). Inorganic Chemistry. Boston: Academic Press. ISBN 0-12-352651-5. 0-12-352651-5 ↩