To use all functions of this page, please activate cookies in your browser.
With an accout for my.chemeurope.com you can always see everything at a glance – and you can configure your own website and individual newsletter.
- My watch list
- My saved searches
- My saved topics
- My newsletter
Ruthenium tetroxide (RuO4) is a yellow, 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.
Additional recommended knowledge
RuO4 is prepared by oxidation of ruthenium(III) chloride with NaIO4.
In a typical reactions featuring RuO4 as the oxidant, many forms of ruthenium usefully serve as precursors to RuO4, e.g. oxides hydrates or hydrated chloride.
Properties and Uses
RuO4 oxidizes virtually any hydrocarbon. For example, it will oxidize adamantane to 1-adamantanol. It is used in organic synthesis to oxidize alkynes to 1,2-diketones and primary alcohols to carboxylic acids. When used in this fashion, the ruthenium tetroxide is used in catalytic amounts and regenerated by the addition of sodium periodate to ruthenium(III) chloride and a solvent mixture of acetonitrile, water and carbon tetrachloride.
Because it is such an aggressive oxidant, reaction conditions are mild, generally room temperature. Although a strong oxidant, RuO4 oxidations do not perturb stereocenters that are not oxidized. Illustrative is the oxidation of the following diol to a carboxylic acid:
Oxidation of epoxy alcohols also occurs without degradation of the epoxide ring:
In terms of practical details, the substrate to be oxidized is typically dissolved in solvent such as CCl4, and acetonitrile is added as an aiding ligand to the catalytic cycle. Ether can then be added to precipitate and recover the ruthenium pre-catalyst.
Oxidative Catalyst and Mechanism
Although used as an oxidant, RuO4 is occasionally used as a catalytic for other oxidant. For an oxidation of cyclic alcohols with RuO4 as a catalyst and bromate as a base, RuO4 first takes up an extra O and H:
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Ruthenium_tetroxide". A list of authors is available in Wikipedia.|