Osmium dioxide is an

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemis ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

OsO₂. It exists as brown to black crystalline powder, but single crystals are golden and exhibit metallic conductivity. The compound crystallizes in the

rutile Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer polymorphs of TiO2 are known, including anatase, akaogiite, and brookite. Rutile has one of the highest refractive indices at visib ...

structural motif, i.e. the connectivity is very similar to that in the mineral rutile.

Preparation

OsO₂ can be obtained by the reaction of

osmium Osmium (from Greek grc, ὀσμή, osme, smell, label=none) is a chemical element with the symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metal in the platinum group that is found as a trace element in alloys, ...

with a variety of oxidizing agents, including,

sodium chlorate Sodium chlorate is an inorganic compound with the chemical formula Na ClO3. It is a white crystalline powder that is readily soluble in water. It is hygroscopic. It decomposes above 300 °C to release oxygen and leaves sodium chloride. Sever ...

, osmium tetroxide, and

nitric oxide Nitric oxide (nitrogen oxide or nitrogen monoxide) is a colorless gas with the formula . It is one of the principal oxides of nitrogen. Nitric oxide is a free radical: it has an unpaired electron, which is sometimes denoted by a dot in its ...

at about 600 °C. Using chemical transport, one can obtain large crystals of OsO₂, sized up to 7x5x3 mm³. Single crystals show metallic resistivity of ~15 μΩ cm. A typical transport agent is via the reversible formation of volatile OsO₄: : OsO₂ + O₂ OsO₄

Reactions

OsO₂ does not dissolve in water, but is attacked by dilute

hydrochloric acid Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid. It is a component of the gastric acid in the dige ...

. The crystals have

structure. Unlike osmium tetroxide, OsO₂ is not toxic.

References

{{oxides Osmium compounds Transition metal oxides