Ruthenium tetroxide

Ruthenium tetroxide (RuO₄) is a diamagnetic tetrahedral ruthenium compound. As expected for a charge-neutral symmetrical oxide, it is quite volatile. The analogous OsO₄ is more widely used and better known. One of the few solvents in which it forms stable solutions is CCl₄.

Preparation

RuO₄ is prepared by oxidation of ruthenium chloride with NaIO₄.

8 Ru³⁺ + 5 IO₄^− + 12 H₂O → 8 RuO₄ + 5 I^− + 24 H⁺

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In typical reactions featuring RuO₄ as the oxidant, many forms of ruthenium usefully serve as precursors to RuO₄, such as oxide hydrates or hydrated chloride.

Because RuO₄ will readily decompose explosively at slightly elevated temperatures, most laboratories do not synthesize it directly, nor is it commercially available through major chemical vendors. Most laboratories instead use an anionic derivative from a salt of "TPAP" (tetrapropylammonium perruthenate), RuO₄. TPAP is synthesized by oxidizing RuCl₃ to...
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