Rhenium hexafluoride, also rhenium(VI) fluoride, (ReF<sub>6</sub>) is a compound of rhenium and fluorine and one of the seventeen known binary hexafluorides.
Rhenium hexafluoride is made by combining rhenium heptafluoride with additional rhenium metal at 300 ðC in a pressure vessel.
The compound is a Lewis acid and strong oxidant, adducting potassium fluoride and oxidizing nitric oxide to nitrosyl:
Rhenium hexafluoride is a liquid at room temperature. At 18.5 ðC, it freezes into a yellow solid. The boiling point is 33.7 ðC.
The solid structure measured at âÂÂ140 ðC is orthorhombic space group Pnma. Lattice parameters are a = 9.417 ÃÂ, b = 8.570 à, and c = 4.965 à. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 4.94 g÷cm<sup>âÂÂ3</sup>.
The ReF<sub>6</sub> molecule itself (the form important for the liquid or gas phase) has octahedral molecular geometry, which has point group (O<sub>h</sub>). The ReâÂÂF bond length is 1.823 à.
Rhenium hexafluoride is a commercial material used in the electronics industry for depositing films of rhenium.