Ruthenium hexafluoride

Ruthenium hexafluoride, also ruthenium(VI) fluoride (RuF6), is a compound of ruthenium and fluorine and one of the seventeen known binary hexafluorides.

Synthesis
Ruthenium hexafluoride is made by a direct reaction of ruthenium metal in a gas stream of fluorine and argon at 400–450 °C. The yields of this reaction are less than 10%.


 * + 3 →

Description
Ruthenium hexafluoride is a dark brown crystalline solid that melts at 54 °C. The solid structure measured at −140 °C is orthorhombic space group Pnma. Lattice parameters are a = 9.313 Å, b = 8.484 Å, and c = 4.910 Å. There are four formula units (in this case, discrete molecules) per unit cell, giving a density of 3.68 g·cm−3.

The RuF6 molecule itself (the form important for the liquid or gas phase) has octahedral molecular geometry, which has point group (Oh). The Ru–F bond length is 1.818 Å.