Hyponitrite

Hyponitrite ion

Hyponitrite exhibits cis–trans isomerism.

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 either bridging or chelating mode. There is a bridging cis-hyponitrite group in the red dinuclear form of nitrosyl pentammine cobalt(III) chloride, [Co(NH3)5NO]Cl2.

Hyponitrite can reduce elemental iodine to hydroiodic acid: : + 3 + 3 → + + 6 HI

Hyponitrite esters

Organic trans-hyponitrites R1−O−N=N−O−R2 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.

References

References

1. (1968). "Hyponitrites". Quarterly Reviews, Chemical Society.
2. Egon Wiberg, Arnold Frederick Holleman (2001) ''Inorganic Chemistry'', Elsevier {{ISBN. 0-12-352651-5
3. (1996). "Cis-Sodium Hyponitrite—A New Preparative Route and a Crystal Structure Analysis". Angewandte Chemie International Edition in English.
4. {{Greenwood&Earnshaw
5. (2000). "Correlation of the Product ''E''/''Z'' Framework Geometry and O/O vs O/N Regioselectivity in the Dialkylation of Hyponitrite". [[J. Am. Chem. Soc.]].
6. (1966). "Di-t-butyl hyponitrite. A convenient source of t-butoxy radicals". Tetrahedron Letters.
7. (1969). "Reactions of the α-methoxybenzyl radical in carbon tetrachloride and in other solvents. Carbon tetrachloride as a chlorinating agent". J. Chem. Soc. C.
8. (1970). "High pressure studies. V. Activation volumes for combination and diffusion of geminate tert-butoxy radicals". Journal of the American Chemical Society.
9. (1932). "384. Hyponitrites. Part II : metallic salts. Part III : esters". Journal of the Chemical Society.
10. (1961). "347. Alkoxy-radicals. Part I. The kinetics of thermal decomposition of dibenzyl hyponitrite in solution". Journal of the Chemical Society.
11. (1960). "Disproportionation and Dimerization of the Benzyloxyl Free Radical in Solution". Nature.
12. Ray, N. H.. (1960). "794. The rates of decomposition of free-radical polymerisation-catalysts: measurements of short half-lives by a thermal method". Journal of the Chemical Society.
13. (1983). "Decomposition rates, synthesis, and spectral properties of a series of alkyl hyponitrites". [[J. Org. Chem.]].