Osmium iodides

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Osmium iodide refers to compounds of osmium with the formula OsIn. Several have been mentioned in the literature, but only the triiodide has been verified by X-ray crystallography. [1] [2]

Contents

Osmium(I) iodide

Osmium(I) iodide is the iodide of osmium with the formula OsI. It is a metallic grey solid produced by the reaction of osmium tetroxide and hydroiodic acid heated in a water bath for 48 hours in a carbon dioxide atmosphere. This compound is amorphous. [2]

Osmium(II) iodide

Osmium(II) iodide is the iodide of osmium with the formula OsI2. It is a black solid [3] produced by the reaction of osmium tetroxide and hydroiodic acid at 250 °C in nitrogen: [2]

This compound decomposes in contact with water. [3]

Osmium(III) iodide

Osmium(III) iodide is the iodide of osmium with the formula OsI3. This black solid is produced by heating hexaiodoosmic acid(H2OsI6). [2] This compound is insoluble in water. [3]

Iodoosmates (IV)

What was claimed to be osmium(IV) iodide was produced by the reaction of osmium dioxide and hydroiodic acid. [4] However on attempted reproduction, this substance was found to be hexaiodoosmic acid H2OsI6. When heated this did not form a tetraiodo compound, and instead formed mono, di, and tri-iodo osmium compounds. The ammonium salt, (NH4)2OsI6, is known. [2]

When potassium iodide is added to a solution containing osmium tetroxide and hydrochloric acid, a green solution of H[OsI5(H2O)] is obtained, which also contains potassium hexaiodoosmate K2OsI6 and a mixed halidoosmate of the type K2OsClxIx. [5]

Solution of
H[OsI5(H2O)] Os22HI.jpg
Solution of H[OsI5(H2O)]

References

  1. Köhler, J. (2014). "Halides: Solid-State Chemistry". Encyclopedia of Inorganic and Bioinorganic Chemistry. pp. 1–22. doi:10.1002/9781119951438.eibc0078.pub2. ISBN   9781119951438.
  2. 1 2 3 4 5 Fergusson, J. E.; Robinson, B. H.; Roper, W. R. (1962). "405. Iodides of osmium and rhenium". Journal of the Chemical Society (Resumed): 2113. doi:10.1039/JR9620002113.
  3. 1 2 3 George K. Schweitzer; Lester L. Pesterfield (2009). The Aqueous Chemistry of the Elements (Ebook). Oxford University Press. p. 321. ISBN   9780199742196 . Retrieved 11 November 2021.
  4. "The Chemistry of Osmium". the Sciences. Vol. 35, no. 904supp. Scientific American. 1893. pp. 14453–14454. doi:10.1038/scientificamerican04291893-14453supp.
  5. Fenn E.; Nyholm R.S.; Owston P.G.; Turco A. (1961). "Reaction of Osmium Tetroxide with Iodide Ions" . Journal of Inorganic and Nuclear Chemistry. 17: 387–390. doi:10.1016/0022-1902(61)80168-1 . Retrieved 2 December 2025.