Ruthenium hexafluoride, also ruthenium(VI) fluoride (RuF<sub>6</sub>), is a compound of ruthenium and fluorine and one of the seventeen known binary hexafluorides.
Ruthenium hexafluoride was discovered by American radiochemists in 1961, soon after the discovery of technetium hexafluoride. It is made by a direct reaction of ruthenium metal in a gas stream of fluorine and argon at 400âÂÂ450 ðC. The yields of this reaction are less than 10%.
Ruthenium hexafluoride is a dark brown crystalline solid that melts at 54 ðC. The solid structure measured at âÂÂ140 ðC is orthorhombic space group Pnma. Lattice parameters are a = 9.313 ÃÂ, b = 8.484 à, and c = 4.910 à. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 3.68 g÷cm<sup>âÂÂ3</sup>.
The RuF<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 RuâÂÂF bond length is 1.818 à.