chemistry Chemistry is the scientific study of the properties and behavior of matter. It is a natural science that covers the elements that make up matter to the compounds made of atoms, molecules and ions: their composition, structure, proper ...

, 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 conve ...

( 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 ...

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. Th ...

with the generic formula R¹−O−N=N−O−R², where R¹ and R² 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 c ...

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 ...

s of respectively hyponitrous acid 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=NOsup>2−.Egon Wiberg, Arnold Frederick Holleman (2001) ''Inorganic Chemistry'', Elsevier There are ''cis'' and ''trans'' forms of the hyponitrite ion . The ''trans'' form is ...

() and

silver(I) hyponitrite Silver hyponitrite is an ionic compound with formula Ag2N2O2 or ()2 N=NOsup>2−, containing monovalent silver cations and hyponitrite anions. It is a bright canary yellow solid practically insoluble in water and most organic solvents, including ...

(). 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 elect ...

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)₅NOl₂. Hyponitrite can act as a reducing agent for example reducing

iodine Iodine is a chemical element with the Symbol (chemistry), 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 , ...

: : + 3 + 3 → + + 6 HI

Hyponitrite esters

Organic ''trans''-hyponitrites R¹−O−N=N−O−R² can be obtained by reacting ''trans''

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 us ...

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,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 Radical may refer to: Politics and ideology Politics *Radical politics, the political intent of fundamental societal change *Radicalism (historical), the Radical Movement that began in late 18th century Britain and spread to continental Europe and ...

References

{{Nitrogen compounds Oxyanions Nitrogen–oxygen compounds

Hyponitrite ion

Reactions

Hyponitrite esters

See also

References