Title: Osmium Tetroxide
CAS Registry Number: 20816-12-0
Additional Names: Osmic acid
Molecular Formula: O4Os
Molecular Weight: 254.23
Percent Composition: O 25.17%, Os 74.83%
Line Formula: OsO4
Literature References: Prepd by heating (at 300-400°) finely divided osmium metal in a stream of air or oxygen. Lab prepn: Grube in Handbook of Preparative Inorganic Chemistry vol. 2, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1965) pp 1603-1604. Use in treatment of arthritis: M. Nissilä et al., Scand. J. Rheumatol. 5, 111 (1977); A. S. Hendricson et al., Acta Orthop. Scand. 52, 17 (1982). Review of chemistry and biochemistry: W. P. Griffith, Platinum Met. Rev. 18, 94-96 (1974); of toxicity: E. Browning, Toxicity of Industrial Metals (Appleton-Century-Crofts, New York, 2nd ed., 1969) pp 261-266.
Properties: Pale yellow solid; monoclinic crystals. Vapor poisonous! Safeguards necessary when opening container. Acrid, chlorine-like odor. Minimum perceptible concn 0.02 mg/liter of air. mp 40.6°. d 5.10 (calc): Ueki et al., Acta Crystallogr. 19, 157 (1965). bp760 130.0°; bp400 109.3°; bp200 89.5°; bp100 71.5°; bp60 59.4°. Begins to sublime and distil well below the boiling point. Vapor press at 27°: 11 mm. Critical temp 405°; crit press. 170 atm. Sol in benzene. Soly at 25° (g/100 g): water 7.24; carbon tetrachloride 375: Anderson, Yost, J. Am. Chem. Soc. 60, 1822 (1938). Also sol in alc, ether, ammonium hydroxide, phosphorus oxychloride.
Melting point: mp 40.6°
Boiling point: bp760 130.0°; bp400 109.3°; bp200 89.5°; bp100 71.5°; bp60 59.4°
Density: d 5.10 (calc): Ueki et al., Acta Crystallogr. 19, 157 (1965)
CAUTION: Potential symptoms of overexposure are irritation of eyes and respiratory system; lacrimation, visual disturbance; conjunctivitis; headache; coughing; dyspnea; dermatitis. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 238.
Use: Oxidizing agent, particularly for converting olefins to glycols. Catalyzes chlorate, peroxide, periodate, and other oxidations: P. N. Rylander, Organic Syntheses with Noble Metal Catalysts (Academic Press, New York, 1973) pp 121-144. As fixing and staining agent for cell and tissue studies. |