In chemistry, dioxirane is a compound with formula , whose molecule consists of a ring with one
carbon and two
oxygen atoms, and two
hydrogen atoms attached to the carbon. It is a
heterocyclic compound
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and ...
, the smallest cyclic organic
peroxide.
The compound itself is highly unstable and has never been observed at room temperature. Derivatives in which the hydrogens are replaced by other
functional groups are called dioxiranes, and may be more stable. Some of them, such as
dimethyldioxirane (DMDO) and the more reactive
methyl(trifluoromethyl)dioxirane
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs ...
, are used in organic synthesis as oxidizing reagents, most notably as the key catalytic intermediate in the
Shi epoxidation reaction.
Difluorodioxirane, which boils at about –80 to –90 °C, is one of the very few dioxirane derivatives that is stable in pure form at room temperature.
Synthesis
Dioxirane is highly unstable and the majority of studies of it have been
computational; it has been detected during the low temperature (-196 °C) reaction of
ethylene
Ethylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon-carbon double bonds).
Ethylene i ...
and
ozone,
although even at these temperatures such a mixture can be explosive.
Its formation is thought to be radical in nature, preceding via a
Criegee intermediate. Microwave analysis has indicated C-H, C-O and O-O
bond lengths of 1.090, 1.388 and 1.516 Å respectively.
The very long and weak O-O bond (c.f.
hydrogen peroxide O-O = 1.47 Å) is the origin of its instability.
See also
*
Oxaziridine
*
Ethylene oxide
*
1,2-Dioxetane
*
1,3-Dioxetane
1,3-Dioxetane (1,3-dioxacyclobutane) is a heterocyclic organic compound with formula C2O2H4, whose backbone is a four-member ring of alternating oxygen and carbon atoms. It can be viewed as a dimer of formaldehyde
Formaldehyde ( , ) (systema ...
References
{{Functional group
Functional groups
Organic peroxides