Trioxidane

Not to be confused with Trioxane.

Trioxidane

Structural formula of trioxidane with explicit hydrogens
Names
IUPAC name Trioxidane
Other names Dihydrogen trioxide Hydrogen trioxide Water-Air Dihydroxy ether
Identifiers
CAS Number	14699-99-1 N
ChEBI	CHEBI:46736 Y
ChemSpider	145859 Y
Gmelin Reference	200290
Jmol 3D model	Interactive image
PubChem	166717
InChI InChI=1S/H2O3/c1-3-2/h1-2H Y Key: JSPLKZUTYZBBKA-UHFFFAOYSA-N Y InChI=1/H2O3/c1-3-2/h1-2H Key: JSPLKZUTYZBBKA-UHFFFAOYAV
SMILES OOO
Properties
Chemical formula	H2O3
Molar mass	50.01 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Trioxidane (also systematically named μ-trioxidanediidodihydrogen), also called hydrogen trioxide or dihydrogen trioxide, is an inorganic compound with the chemical formula H[O]
₃H (also written as [H(μ-O
₃)H] or [H
₂O
₃]). It is one of the unstable hydrogen polyoxides. In aqueous solutions, trioxidane decomposes to form water and singlet oxygen:

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The reverse reaction, the addition of singlet oxygen to water, typically does not occur in part due to the scarcity of singlet oxygen. In biological systems, however, ozone is known to be generated from singlet oxygen, and the presumed mechanism is an antibody-catalyzed production of trioxidane from singlet oxygen.

Preparation

Trioxidane can be obtained in small, but detectable, amounts in reactions of ozone and hydrogen peroxide, or by the electrolysis of water. Larger quantities have been prepared by the reaction of ozone with organic reducing agents at low temperatures in a variety of organic solvents such as the anthraquinone process, and it is also formed during the decomposition of organic hydrotrioxides (ROOOH).

The reaction of ozone with hydrogen peroxide is known as the "peroxone process". This mixture has been used for some time for treating groundwater contaminated with organic compounds. The reaction produces H₂O₃ and H₂O₅.

Structure

In 2005, trioxidane was observed experimentally by microwave spectroscopy in a supersonic jet. The molecule exists in a skewed structure, with an oxygen–oxygen–oxygen–hydrogen dihedral angle of 81.8°. The oxygen–oxygen bond lengths of 142.8 picometer are slightly shorter than the 146.4 pm oxygen–oxygen bonds in hydrogen peroxide. Various dimeric and trimeric forms also seem to exist. It is slightly more acidic than hydrogen peroxide, dissociating into H⁺ and OOOH⁻.

250px

Reactions

Trioxidane readily decomposes into water and singlet oxygen, with a half-life of about 16 minutes in organic solvents at room temperature, but only milliseconds in water. It reacts with organic sulfides to form sulfoxides, but little else is known of its reactivity.

Recent research found that trioxidane is the active ingredient responsible for the antimicrobial properties of the well known ozone/hydrogen peroxide mix. Because these two compounds are present in biological systems as well it is argued that an antibody in the human body can generate trioxidane as a powerful oxidant against invading bacteria. The source of the compound in biological systems is the reaction between singlet oxygen and water (which proceeds in either direction, of course, according to concentrations), with the singlet oxygen being produced by immune cells.

Computational chemistry predicts that more oxygen chain molecules or hydrogen polyoxides exist and that even infinite oxygen chains can exist in a low temperature gas. With this spectroscopic evidence a search for these type of molecules can start in interstellar space.

See also

• Molozonide