In
chemistry
Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...
, hyponitrite may refer to the
anion
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 convent ...
(
N=NOsup>2−), or to any
ionic compound
In chemistry, an ionic compound is a chemical compound composed of ions held together by electrostatic forces termed ionic bonding. The compound is neutral overall, but consists of positively charged ions called cations and negatively charged i ...
that contains it. In
organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; ...
, it may also refer to the
group
A group is a number of persons or things that are located, gathered, or classed together.
Groups of people
* Cultural group, a group whose members share the same cultural identity
* Ethnic group, a group whose members share the same ethnic ide ...
−O−N=N−O−, or any
organic compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...
with the generic formula R
1−O−N=N−O−R
2, where R
1 and R
2 are organic groups.
[M. N. Hughes (1968), "Hyponitrites". Quarterly Reviews of the Chemical Society, volume 22, issue 1, pages 1–13. .] Such compounds can be viewed as
salts
In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively cha ...
and
ester
In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...
s of respectively
hyponitrous acid
Hyponitrous acid is a chemical compound with formula or HON=NOH. It is an isomer of nitramide, H2N−NO2; and a formal dimer of azanone, HNO.
Hyponitrous acid forms two series of salts, the hyponitrites containing the N=NOsup>2− anion, and t ...
or HON=NOH.
An acid hyponitrite is an ionic compound with the anion (
ON=NOsup>−).
Hyponitrite ion
Hyponitrite exhibits
cis–trans isomerism
''Cis''–''trans'' isomerism, also known as geometric isomerism or configurational isomerism, is a term used in chemistry that concerns the spatial arrangement of atoms within molecules. The prefixes "''cis''" and "''trans''" are from Latin: " ...
.
[Egon Wiberg, Arnold Frederick Holleman (2001) ''Inorganic Chemistry'', Elsevier ]
The ''trans'' (''E'') form is generally found in hyponitrite salts such as
sodium hyponitrite
Sodium hyponitrite is a solid ionic compound with formula or ()2 N=NO−.Egon Wiberg, Arnold Frederick Holleman (2001) ''Inorganic Chemistry'', Elsevier
There are ''cis'' and ''trans'' forms of the hyponitrite ion . The ''trans'' form is mo ...
() and
silver(I) hyponitrite ().
The ''cis'' (''Z'') form of sodium hyponitrite can be obtained too, and 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°.
[Claus Feldmann, Martin Jansen (1996), "''cis''-Sodium Hyponitrite – A New Preparative Route and a Crystal Structure Analysis". Angewandte Chemie International Edition in English, volume 35, issue 15, pages 1728–1730. .]
Reactions
The hyponitrite ions can act as a bidentate
ligand
In coordination chemistry, a ligand is an ion or molecule (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 electr ...
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 act as a reducing agent for example reducing
iodine
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a vi ...
:
: + 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 halide
The haloalkanes (also known as halogenoalkanes or alkyl halides) are alkanes containing one or more halogen substituents. They are a subset of the general class of halocarbons, although the distinction is not often made. Haloalkanes are widely ...
s. For example, reaction with
''t''-butyl chloride yields ''trans'' di-''tert''-butyl hyponitrite.
[H. Kiefer and T. G. Traylor (1966), Tetrahedron Lett., page 6163.][R. L. Huang, T. W. Lee, and S. H. Ong (1969), J. Chem. Soc. C, page 40.][R. C. Neuman and R. J. Bussey (1970), J. Am. Chem. Soc., volume 92, page 2440.]
Other alkyl radicals reported in the literature include
ethyl
Ethyl may refer to:
Arts and entertainment
* Cold Ethyl, a Swedish rock band
*Ethyl Sinclair, a character in the ''Dinosaurs'' television show
Science and technology
* Ethyl group, an organic chemistry moiety
* Ethyl alcohol (or ethanol)
* E ...
,
[J. R. Partington and C. C. Shah (1932), J. Chem. Soc., page 2589.] and
benzyl
In organic chemistry, benzyl is the substituent or molecular fragment possessing the structure . Benzyl features a benzene ring () attached to a methylene group () group.
Nomenclature
In IUPAC nomenclature, the prefix benzyl refers to a substi ...
.
[J. B. Sousa and S. K. Ho (1961), J. Chem. Soc., page 1788.][J. B. Sousa and S. K. Ho (1960), Nature, volume 186, page 776.][N. H. Ray (1960), J. Chem. Soc., page 4023.] These compounds can be a source of alkoxyl
radicals.
See also
Other
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
oxoanion An oxyanion, or oxoanion, is an ion with the generic formula (where A represents a chemical element and O represents an oxygen atom). Oxyanions are formed by a large majority of the chemical elements. The formulae of simple oxyanions are determine ...
s include
*
nitrate
Nitrate is a polyatomic ion
A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zer ...
,
*
nitrite
The nitrite polyatomic ion, ion has the chemical formula . Nitrite (mostly sodium nitrite) is widely used throughout chemical and pharmaceutical industries. The nitrite anion is a pervasive intermediate in the nitrogen cycle in nature. The name ...
,
*
peroxonitrite, (peroxynitrite), OONO
−
*
peroxonitrate,
*
trioxodinitrate
Angeli's salt, sodium trioxodinitrate, is the inorganic compound with the formula Na2 2O3 It contains nitrogen in an unusual reduced state. It is a colorless, water-soluble solid, a salt. In research, this salt is used as a source of the metastab ...
, (hyponitrate),
N=NO2sup>2−
*
nitroxylate Nitroxylic acid or hydronitrous acid is an unstable reduced oxonitrogen acid. It has formula H4N2O4 containing nitrogen in the +2 oxidation state. The corresponding anion called nitroxylate is or .
The first clue that nitroxylic acid exists was wh ...
,
2N−NO2sup>4−
*
orthonitrate
Orthonitrate is a tetrahedral oxoanion of nitrogen with the formula . It was first identified in 1977 and is currently known in only two compounds, sodium orthonitrate (Na3NO4) and potassium orthonitrate (K3NO4). The corresponding oxoacid, orthon ...
,
*
dinitramide,
2N−N−NO2sup>−
*
nitrosyl hyponitrite,
NNONOsup>−
References
{{Nitrogen compounds
Oxyanions
Nitrogen–oxygen compounds