Title: Ruthenium Tetroxide
CAS Registry Number: 20427-56-9
Additional Names: Ruthenium(VIII) oxide
Molecular Formula: O4Ru
Molecular Weight: 165.07
Percent Composition: O 38.77%, Ru 61.23%
Line Formula: RuO4
Literature 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. Vapors irritating to eyes and respiratory tract. 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.
Melting point: mp 25.4°
Boiling point: bp 40°
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).