Nitramide or nitroamine is a chemical compound with the molecular formula H2N−NO2. Substituted derivatives R1R2N−NO2 are termed nitramides or nitroamines as well. Organyl derivatives of nitramide, R−NH−NO2 and R2N−NO2, are widely used as explosives: examples include RDX and HMX. It is an isomer of hyponitrous acid. Nitramide can be viewed as a nitrogen analog of nitric acid (HO−NO2), in which the hydroxyl group −OH is replaced with the amino group −NH2.

Nitramide
  Nitrogen, N
  Hydrogen, H
  Oxygen, O
Names
IUPAC name
Nitramide
Systematic IUPAC name
Nitric amide
Other names
  • Nitroamide
  • Nitramine[1]
  • Nitroamine[1]
  • Nitroammonia
  • Nitroazane
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
UNII
  • InChI=1S/H2N2O2/c1-2(3)4/h1H2 checkY
    Key: SFDJOSRHYKHMOK-UHFFFAOYSA-N checkY
  • InChI=1/H2N2O2/c1-2(3)4/h1H2
    Key: SFDJOSRHYKHMOK-UHFFFAOYAT
  • N[N+](=O)[O-]
Properties
H2N−NO2
Molar mass 62.028 g·mol−1
Appearance Colorless solid[2]
Density 1.378 g/cm3
Melting point 72 to 75 °C (162 to 167 °F; 345 to 348 K)[2]
Acidity (pKa) 6.5[3]
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Structure

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The nitramide molecule is essentially an amine group (−NH2) bonded to a nitro group (−NO2). It is reported to be non-planar in the gas phase,[4] but planar in the crystal phase.[2]

Synthesis

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Thiele and Lachman's original synthesis of nitramide involved the hydrolysis of potassium nitrocarbamate:[2]

(K+)2(O2N−N−CO2) + 2 H2SO4 → H2N−NO2 + CO2 + 2 KHSO4

Other routes to nitramide include hydrolysis of nitrocarbamic acid,

O2N−NH−CO2H → H2N−NO2 + CO2

reaction of sodium sulfamate with nitric acid,

Na(SO3NH2) + HNO3 → H2N−NO2 + NaHSO4

and reaction of dinitrogen pentoxide with two equivalents of ammonia.

N2O5 + 2 NH3 → H2N−NO2 + [NH4]+NO3

Organic nitramides

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Also called nitramines, organic nitramides are important explosives. They are prepared by nitrolysis of hexamethylenetetramine.

 
The organic nitramide RDX is a widely used explosive.

References

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  1. ^ a b "Nitramide".
  2. ^ a b c d Häußler, A.; Klapötke, T. M.; Piotrowski, H. (2002). "Experimental and Theoretical Study on the Structure of Nitramide H2NNO2" (PDF). Zeitschrift für Naturforschung. 57 b (2): 151–156. doi:10.1515/znb-2002-0204.
  3. ^ 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 154. ISBN 0-08-029214-3. LCCN 82-16524.
  4. ^ Tyler, J. K. (1963). "Microwave Spectrum of Nitramide". Journal of Molecular Spectroscopy. 11 (1–6): 39–46. Bibcode:1963JMoSp..11...39T. doi:10.1016/0022-2852(63)90004-3.