Iodine dioxide is a binary

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

iodine Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at , and boils to a vi ...

and

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

with the chemical formula . Only stable as a dilute gas, this compound is one of many

iodine oxide Iodine oxides are chemical compounds of oxygen and iodine. Iodine has only two stable oxides which are isolatable in bulk, iodine tetroxide and iodine pentoxide, but a number of other oxides are formed in trace quantities or have been hypothesize ...

s, and "iodine dioxide" is sometimes used to describe its formal

dimer Dimer may refer to: * Dimer (chemistry), a chemical structure formed from two similar sub-units ** Protein dimer, a protein quaternary structure ** d-dimer ** TH-dimer * Dimer model, an item in statistical mechanics, based on ''domino tiling'' * ...

, the salt

diiodine tetroxide Diiodine tetraoxide, I2O4, is a chemical compound of oxygen and iodine. It belongs to the class of iodine oxides, and is a mixed oxide, consisting of iodine(III) and iodine(V) oxidation states. Synthesis The oxide is formed by the reaction of ho ...

(I₂O₄, Osup>+ O₃sup>−). It is formed, in

parts-per-trillion In science and engineering, the parts-per notation is a set of pseudo-units to describe the small values of miscellaneous dimensionless quantity, dimensionless quantities, e.g. mole fraction or mass fraction (chemistry), mass fraction. Since t ...

quantities, at the marine boundary layer and believed to mediate particulate nucleation therein. The

, originally from algaeic

diiodomethane Diiodomethane or methylene iodide, commonly abbreviated "MI", is an organoiodine compound. Diiodomethane is a very dense colorless liquid; however, it decomposes upon exposure to light liberating iodine, which colours samples brownish. It is slig ...

, is photooxidized to

iodine monoxide Iodine monoxide is a binary inorganic compound of iodine and oxygen with the chemical formula IO•. A free radical, this compound is the simplest of many iodine oxides. It is similar to the oxygen monofluoride, chlorine monoxide and bromine mono ...

, which then disproportionates to free iodine atoms and iodine dioxide. At a sufficiently large concentration, the particles then combine to form small grains of

References

{{Iodine compounds Iodine compounds Oxides