Rhenium heptafluoride

Chembox new
ImageFile =
ImageSize =
IUPACName = rhenium heptafluoride, heptafluoridorhenium
OtherNames =
Section1 = Chembox Identifiers
CASNo = 17029-21-9
PubChem =
SMILES =
Section2 = Chembox Properties
Formula = ReF₇
MolarMass = 319.196 g/mol
Appearance = Bright yellow
Density =
MeltingPt = 48.3°C
BoilingPt = 73.72°C
Solubility =
Section3 = Chembox Hazards
MainHazards =
FlashPt =
Autoignition =

Rhenium heptafluoride is the compound with the formula ReF₇. It is a yellow low melting solid, and is the only thermally stable metal heptafluoride. Greenwood&Earnshaw] . It has a distorted pentagonal bipyramidal structure (similar to IF₇), which was confirmed by neutron diffraction at 1.5K. [cite journal | doi = 10.1126/science.263.5151.1265 | title = Crystal and Molecular Structures of Rhenium Heptafluoride | year = 1994 | author = Vogt T., Fitch A. N., Cockcroft J. K. | journal = Science | volume = 263 | pages = 1265 | pmid = 17817431] The structure is non-rigid as evidenced by electron diffraction studies. [cite journal | doi = 10.1063/1.1674318 | title = Electron Diffraction Study of Rhenium Fluorides. II. Structure, Pseudorotation, and Anharmonic Coupling of Modes in ReF7 | year = 1970 | author = Jacob, E. Jean; Bartell, L.S.J. | journal = The Journal of Chemical Physics | volume = 53 | pages = 2235] .
It can be prepared from the elements at 400°C.cite book |author=A. F. Holleman; Wiberg, Egon; Wiberg, Nils |title=Inorganic Chemistry |publisher=Academic Press |location=Boston |year=2001 |pages= |isbn=0-12-352651-5 |oclc= |doi= |accessdate=] With fluoride donors,e.g CsF the ReF₈⁻ anion is formed, which has a square antiprismatic structure [cite journal | doi = 10.1016/S0022-1139(99)00248-1 | title = The structures of ReF₈⁻ and UF₈²⁻ | year = 2000 | author = Hwang, I; Seppelt, K. | journal = Journal of Fluorine Chemistry | volume = 102 | pages = 69] With antimony pentafluoride, SbF₅, a fluoride acceptor, the ReF₆⁺ cation is formed..

References