8301. Ruthenium Tetroxide

Nomenclature

CAS number: 20427-56-9
Ruthenium(VIII) oxide.
O4Ru; mol wt 165.07.
O 38.77%, Ru 61.23%.
RuO4.

Description and references

Prepd by fusing Ru with KMnO4 and KOH in a proportion of 1:2:20. Lab procedures: Ruff, Vidic, Z. Anorg. Allg. Chem. 136, 49 (1924); Grube in Handbook of Preparative Inorganic Chemistry vol. 2, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1965) p 1599. Crystal structure: Tréhoux et al., C. R. Seances Acad. Sci. Ser. C 268, 246 (1969). Review of use as oxidizing agent: P. N. Rylander, Organic Syntheses with Noble Metal Catalysts (Academic Press, New York, 1973) pp 134-144.

Properties

Golden-yellow monoclinic prisms. Very volatile, sublimes at room temp. Handle in hood only. mp 25.4°. bp 40°. Sparingly sol in water, about 2.0% (w/v) at 20°. Freely sol in carbon tetrachloride, other chlorinated solvents. Also sol in bromine, liquid SO2. Reacts explosively with alcohol and filter paper.

Caution

Direct contact with vapors may be irritating to eyes and respiratory tract.

Use

Oxidizing agent similar to osmium tetroxide, but more difficult to handle. The solvents normally employed in OsO4 oxidations (ether, benzene, pyridine) cannot be used because of their violent reaction with RuO4. Only CCl4 is recommended: Djerassi, Engle, J. Am. Chem. Soc. 75, 3838 (1953).