Rhenium (VII) fluoride

Crystal structure
__ Re 7+      __ F -
General
Surname	Rhenium (VII) fluoride
other names	Rhenium heptafluoride
Ratio formula	ReF 7
Brief description	yellow solid
External identifiers / databases
CAS number 17029-21-9 PubChem 123369 Wikidata Q421025
properties
Molar mass	319.20 g mol −1
Physical state	firmly
density	4.3 g cm −3
Melting point	48.3 ° C
boiling point	73.7 ° C
safety instructions
GHS hazard labeling no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Rhenium (VII) fluoride , usually also called rhenium heptafluoride , is a chemical compound of the elements rhenium and fluorine and belongs to the fluoride group . It is the only known thermally stable metal heptafluoride.

Extraction and presentation

Rhenium (VII) fluoride is produced by reacting the elements at 400 ° C.

${\displaystyle \mathrm {2\ Re+7\ F_{2}\longrightarrow 2\ ReF_{7}} }$

properties

Rhenium (VII) fluoride is a yellow solid that melts at low temperatures. It has a distorted pentagonal bipyramidal structure similar to that of iodine heptafluoride . Below the phase transition at 153  K , the crystal lies in the triclinic space group space group C 1 (space group no. 2, position 3) with the lattice constants a = 5.5039  Å , b = 8.5026  Å , c = 9.0916  Å , α = 88.512 °, β = 93.842 ° and γ = 89.496 ° in front. At higher temperatures the crystal changes into a cubic structure with the space group space group Im 3 m (space group no. 229) with a lattice constant a = 6.2027  Å .

Individual evidence

1. ↑ ^{a b c d} WebElements: Rhenium heptafluoride
2. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
3. ↑ Greenwood, Norman N .; Earnshaw, Alan. (1997), Chemistry of the Elements (2nd ed.), Oxford: Butterworth-Heinemann, ISBN 0-08037941-9 .
4. ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 1625.
5. ↑ The numbering of this axis position does not correspond to the order of the International Tables for Crystallography , because it is not listed there.
6. ^ Vogt T., Fitch AN, Cockcroft JK: Crystal and Molecular Structures of Rhenium Heptafluoride . In: Science . 263, No. 5151, 1994, p. 1265. doi : 10.1126 / science.263.5151.1265 . PMID 17817431 .