Cannabaceae

Hyponitrous acid
Tautomer wireframe models of hyponitrous acid
Names
Preferred IUPAC name
Diazenediol
Systematic IUPAC name
N-(Hydroxyimino)hydroxylamine
Other names
Hyponitrous acid dimer
Identifiers
3D model (JSmol)
3DMet
ChEBI
ChemSpider
141300
KEGG
  • InChI=1S/H2N2O/c3-1-2-4/h(H,1,4)(H,2,3)
    Key: NFMHSPWHNQRFNR-UHFFFAOYSA-N
  • ON=NO
Properties
H2N2O2
Molar mass 62.0282 g/mol
Appearance white crystals
Conjugate base Hyponitrite
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
explosive when dry
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Hyponitrous acid is a chemical compound with formula H
2
N
2
O
2
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 [ON=NO]2− anion, and the "acid hyponitrites" containing the [HON=NO] anion.[1]

Structure and properties[edit]

There are two possible structures of hyponitrous acid, trans and cis. trans-Hyponitrous acid forms white crystals that are explosive when dry. In aqueous solution, it is a weak acid (pKa1 = 7.21, pKa2 = 11.54),[2] and decomposes to nitrous oxide and water with a half life of 16 days at 25 °C at pH 1–3:

Since this reaction is not reversible, N
2
O
should not be considered as the anhydride of H
2
N
2
O
2
.[1]

The cis acid is not known,[1] but its sodium salt can be obtained.[3]

Preparation[edit]

Hyponitrous acid (trans) can be prepared from silver(I) hyponitrite and anhydrous HCl in ether:

Spectroscopic data indicate a trans configuration for the resulting acid.[3]
It can also be synthesized from hydroxylamine and nitrous acid:

Biological aspects[edit]

In enzymology, a hyponitrite reductase is an enzyme that catalyzes the chemical reaction[4]

References[edit]

  1. ^ a b c Wiberg, Egon; Holleman, Arnold Frederick (2001). Inorganic Chemistry. Elsevier. ISBN 0-12-352651-5.
  2. ^ Perrin, D. D., ed. (1982) [1969]. Ionisation Constants of Inorganic Acids and Bases in Aqueous Solution. IUPAC Chemical Data (2nd ed.). Oxford: Pergamon (published 1984). Entry 120. ISBN 0-08-029214-3. LCCN 82-16524.
  3. ^ a b Catherine E. Housecroft; Alan G. Sharpe (2008). "Chapter 15: The group 15 elements". Inorganic Chemistry (3rd ed.). Pearson. p. 468. ISBN 978-0-13-175553-6.
  4. ^ "ENZYME - 1.7.1.5 Hyponitrite reductase".

One thought on “Cannabaceae

  1. Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
    View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction

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