In
chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...
, hyponitrite may refer to the
anion (
N=NOsup>2−), or to any
ionic compound
In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions (Cation, cations) and negatively charged ions (Anion, anions), which results in a compound with no net electric charge (electrica ...
that contains it. In
organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain ...
, it may also refer to the
group −O−N=N−O−, or any
organic compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...
with the generic formula R
1−O−N=N−O−R
2, where R
1 and R
2 are organic groups.
Such compounds can be viewed as
salts and
ester
In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...
s of
hyponitrous acid.
An acid hyponitrite is an ionic compound with the anion (
ON=NOsup>−).
Hyponitrite ion
Hyponitrite exhibits
cis–trans isomerism.
[Egon Wiberg, Arnold Frederick Holleman (2001) ''Inorganic Chemistry'', Elsevier ]
The ''trans'' (''E'') form is generally found in hyponitrite salts such as
sodium hyponitrite () and
silver(I) hyponitrite ().
The ''cis'' (''Z'') form of sodium hyponitrite can be obtained too, but it is more reactive than the ''trans'' form.
The ''cis'' hyponitrite anion is nearly planar and almost symmetric, with lengths of about 140
pm for N−O bond and 120 pm for the N−N bond, and O−N−N angles of about 119°.
Reactions
The hyponitrite ions can act as a bidentate
ligand
In coordination chemistry, a ligand is an ion or molecule with a functional group that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's el ...
in either bridging or chelating mode. There is a bridging ''cis''-hyponitrite group in the red dinuclear form of nitrosyl pentammine cobalt(III) chloride,
o(NH3)5NOl
2.
Hyponitrite can reduce elemental
iodine to
hydroiodic acid:
: + 3 + 3 → + + 6 HI
Hyponitrite esters
Organic ''trans''-hyponitrites R
1−O−N=N−O−R
2 can be obtained by reacting ''trans''
silver(I) hyponitrite with various
alkyl halides. For example, reaction with
''tert''-butyl chloride yields ''trans'' di-''tert''-butyl hyponitrite.
Other alkyl radicals reported in the literature include
ethyl,
and
benzyl.
These compounds can be a source of alkoxyl
radicals.
See also
Other
nitrogen
Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...
oxyanions include
*
nitrate
Nitrate is a polyatomic ion with the chemical formula . salt (chemistry), Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are solubility, soluble in wa ...
,
*
nitrite,
*
peroxonitrite, (peroxynitrite), OONO
−
*
peroxonitrate,
*
trioxodinitrate, (hyponitrate),
N=NO2sup>2−
*
nitroxylate,
2N−NO2sup>4−
*
orthonitrate,
References
{{Nitrogen compounds
Nitrogen oxyanions
Nitrogen–oxygen compounds
Hyponitrites