Rhenium heptafluoride

Rhenium heptafluoride is the compound with the formula ReF₇. It is a yellow low melting solid and is the only thermally stable metal heptafluoride.^[2] It has a distorted pentagonal bipyramidal structure similar to IF₇, which was confirmed by neutron diffraction at 1.5 K.^[3] The structure is non-rigid, as evidenced by electron diffraction studies.^[4]

Rhenium heptafluoride

Names
IUPAC name rhenium heptafluoride, heptafluoridorhenium
Identifiers
CAS Number	17029-21-9 Y
3D model (JSmol)	Interactive image
ChemSpider	26323924 N
PubChem CID	123369
UNII	H54U6B0W52 Y
CompTox Dashboard (EPA)	DTXSID50168826
InChI InChI=1S/7FH.Re/h7*1H;/q;;;;;;;+7/p-7 N Key: HFHBKXWKPQUYIA-UHFFFAOYSA-G N InChI=1/7FH.Re/h7*1H;/q;;;;;;;+7/p-7/rF7Re/c1-8(2,3,4,5,6)7 Key: HFHBKXWKPQUYIA-KLJGHBABAK
SMILES F[Re](F)(F)(F)(F)(F)F
Properties
Chemical formula	ReF7
Molar mass	319.196 g/mol
Appearance	Bright yellow crystalline solid
Density	4.3 g/cm3
Melting point	48.3 °C (118.9 °F; 321.4 K)
Boiling point	73.72 °C (164.70 °F; 346.87 K)
Solubility in water	Reacts
Vapor pressure	13.41 kPa[1]
Structure
Crystal structure	triclinic, aP16
Space group	P1 (No. 2)
Thermochemistry
Enthalpy of fusion (ΔfH⦵fus)	7.53 kJ/mol[1]
Enthalpy of vaporization (ΔfHvap)	30.77 kJ/mol[1]
Related compounds
Related compounds	Osmium heptafluoride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Production, reactions and properties

Rhenium heptafluoride can be prepared from the elements at 400 °C:^[5]

2 Re + 7 F₂ → 2 ReF₇

It also can be produced by the explosion of rhenium metal under sulfur hexafluoride. ^[6]

It hydrolyzes under a base to form perrhenic acid and hydrogen fluoride:^[1]

ReF₇ + 4H₂O → HReO₄ + 7HF

With 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.^[5]