Dioxidanylium, which is protonated molecular oxygen, or just protonated oxygen, is an
ion
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...
with formula .
It is formed when hydrogen containing substances
combust Combust can refer to:
* Combust (astrological aspect), the obscuring of the unassisted viewing of a planet by the Sun's light
* Combustion
Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the r ...
, and exists in the
ionosphere
The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an ...
, and in
plasmas that contain
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...
and
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...
.
Oxidation by O
2 in
superacid
In chemistry, a superacid (according to the classical definition) is an acid with an acidity greater than that of 100% pure sulfuric acid (), which has a Hammett acidity function (''H''0) of −12. According to the modern definition, a superacid ...
s could be by way of the production of protonated molecular oxygen.
It is the
conjugate acid
A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a ...
of
dioxygen
There are several known allotropes of oxygen. The most familiar is molecular oxygen (O2), present at significant levels in Earth's atmosphere and also known as dioxygen or triplet oxygen. Another is the highly reactive ozone (O3). Others are:
*A ...
. The
proton affinity
The proton affinity (PA, ''E''pa) of an anion or of a neutral atom or molecule is the negative of the enthalpy change in the reaction between the chemical species concerned and a proton in the gas phase:
::: A- + H+ -> HA
::: B + H+ -> BH+
...
of dioxygen (O
2) is 4.4 eV.
Significance
Protonated molecular oxygen is of interest in trying to detect dioxygen in space. Because Earth's atmosphere is full of O
2, its spectrum from a space object is impossible to observe from the ground. However should be much more detectable.
Formation
Reaction of
dioxygenyl with hydrogen:
: + H
2 → + H
•
The reaction of the
trihydrogen cation
The trihydrogen cation or protonated molecular hydrogen is a cation (positive ion) with formula , consisting of three hydrogen nuclei ( protons) sharing two electrons.
The trihydrogen cation is one of the most abundant ions in the universe. It ...
with dioxygen is approximately thermoneutral:
:O
2 + → + H
2
When atomic hydrogen, created in an electric discharge is rapidly cooled with oxygen and condensed in solid neon, several reactive ions and molecules are produced. These include HO
2 (
hydroperoxyl
The hydroperoxyl radical, also known as the hydrogen superoxide, is the protonated form of superoxide with the chemical formula HO2. This species plays an important role in the atmosphere and as a reactive oxygen species in cell biology.
Struc ...
), HOHOH
−, H
2O(HO), HOHO
− as well as . This reaction also forms
hydrogen peroxide
Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%†...
(H
2O
2) and
hydrogen tetroxide (H
2O
4).
Properties
In the infrared spectrum the ''v''
1 band due to vibrating O–H has a
band head In spectroscopy a band head is the abrupt edge of a spectroscopic band. When a band is described as degrading to the Violet (color), violet, it means that for wavelengths above the band head wavelength, the spectrum is dark as the band comes to a su ...
at 3016.73 cm
−1.
Reactions
A helium complex (He–O
2H
+) also is known.
[
appears to react rapidly with hydrogen:][
: + H2O → O2 + H3O+
]
Related
The protonated molecular oxygen dimer has a lower energy than that of protonated molecular oxygen.
References
{{Reflist
Reactive oxygen species
Cations
Hydrogen compounds