Iridium fluoride is a volatile and highly reactive yellow solid, with an octahedral molecular structure (Ir–F bond length is 183.3 pm). It is one of only a few compounds with iridium in its highest oxidation state, +6. It is formed directly at 300 °C from the constituent elements, iridium

Iridium

Iridium is the chemical element with atomic number 77, and is represented by the symbol Ir. A very hard, brittle, silvery-white transition metal of the platinum family, iridium is the second-densest element and is the most corrosion-resistant metal, even at temperatures as high as 2000 °C...

 and fluorine

Fluorine

Fluorine is the chemical element with atomic number 9, represented by the symbol F. It is the lightest element of the halogen column of the periodic table and has a single stable isotope, fluorine-19. At standard pressure and temperature, fluorine is a pale yellow gas composed of diatomic...

, but it is thermally unstable and must be frozen out of the gaseous reaction mixture to avoid dissociation.