Chloroosmic acid
Chloroosmic acid is an inorganic chemical compound with the chemical formula. It exists as a dark hygroscopic solid. It forms a hexahydrate.
Synthesis
Hexachloroosmic acid can be prepared by reducing osmium tetroxide in hydrochloric acid with alcohol and heating. Ferrous chloride is sometimes used in place of alcohol.Another way of preparing it is by dissolving osmium dioxide in hydrochloric acid.
It can also be prepared by reducing potassium osmate with hydrochloric acid under heating.
Properties
Solid crystals of hexachloroosmic acid have been described as reddish-purple in color, while commercial vendors describe it as black. In solution, it exhibits colors ranging from yellowish green to reddish brown. Owing to its highly hygroscopic nature, solutions of hexachloroosmic acid can be evaporated down to a syrup without crystallization. As an acid, it is corrosive.Reactions
When strong alkali is added to hexachloroosmic acid, it decomposes and precipitates osmium dioxide.It also reacts with alkali chlorides to yield hexachloroosmate salts, such as ammonium hexachloroosmate(IV).
The coordination complex can be made by reacting chloroosmic acid in ethanol with dimethyl sulfoxide.