Rhenium heptafluoride

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Rhenium heptafluoride
IUPAC name rhenium heptafluoride, heptafluoridorhenium
Identifiers
CAS number [17029-21-9]
Properties
Molecular formula ReF7
Molar mass 319.196 g/mol
Appearance Bright yellow
Melting point

48.3°C
Boiling point

73.72°C
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

Rhenium heptafluoride is the compound with the formula ReF7. It is a yellow low melting solid, and is the only thermally stable metal heptafluoride. [1]. It has a distorted pentagonal bipyramidal structure (similar to IF7), which was confirmed by neutron diffraction at 1.5K.[2] The structure is non-rigid as evidenced by electron diffraction studies.[3].
It can be prepared from the elements at 400°C.[4] With fluoride donors,e.g CsF the ReF8− anion is formed, which has a square antiprismatic structure [5] With antimony pentafluoride, SbF5, a fluoride acceptor, the ReF6+ cation is formed.[4].

[edit] References

  1. ^ Greenwood, N. N.; Earnshaw, A. (1997). Chemistry of the Elements, 2nd Edition, Oxford:Butterworth-Heinemann. ISBN 0-7506-3365-4. 
  2. ^ Vogt T., Fitch A. N., Cockcroft J. K. (1994). "Crystal and Molecular Structures of Rhenium Heptafluoride". Science 263: 1265. doi:10.1126/science.263.5151.1265. PMID 17817431. 
  3. ^ Jacob, E. Jean; Bartell, L.S.J. (1970). "Electron Diffraction Study of Rhenium Fluorides. II. Structure, Pseudorotation, and Anharmonic Coupling of Modes in ReF7". The Journal of Chemical Physics 53: 2235. doi:10.1063/1.1674318. 
  4. ^ a b A. F. Holleman; Wiberg, Egon; Wiberg, Nils (2001). Inorganic Chemistry. Boston: Academic Press. ISBN 0-12-352651-5. 
  5. ^ Hwang, I; Seppelt, K. (2000). "The structures of ReF8− and UF82−". Journal of Fluorine Chemistry 102: 69. doi:10.1016/S0022-1139(99)00248-1.