This article is about the negative anion. For other compounds with the formula NH2 but different charges, see amino radical and nitrenium ion.

Azanide is the IUPAC-sanctioned name for the anion NH−2. The term is obscure; derivatives of NH−2 are almost invariably referred to as amides,[1][2][3] despite the fact that amide also refers to the organic functional group –C(=O)−NR2. The anion NH−2 is the conjugate base of ammonia, so it is formed by the self-ionization of ammonia. It is produced by deprotonation of ammonia, usually with strong bases or an alkali metal. Azanide has a H–N–H bond angle of 104.5°.

Alkali metal derivatives

The alkali metal derivatives are best known, although usually referred to as alkali metal amides. Examples include lithium amide, sodium amide, and potassium amide. These salt-like solids are produced by treating liquid ammonia with strong bases or directly with the alkali metals (blue liquid ammonia solutions due to the solvated electron):[1][2][4]

2 M + 2 NH3 → 2 MNH2 + H2, where M = Li, Na, K

Silver(I) amide (AgNH2) is prepared similarly.[3]

Transition metal complexes of the amido ligand are often produced by salt metathesis reaction or by deprotonation of metal ammine complexes.

References

  1. ^ a b Bergstrom, F. W. (1940). "Sodium Amide". Organic Syntheses. 20: 86. doi:10.15227/orgsyn.020.0086.
  2. ^ a b P. W. Schenk (1963). "Lithium amide". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 1. New York, NY: Academic Press. p. 454.
  3. ^ a b O. Glemser, H. Sauer (1963). "Silver Amide". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry. Vol. 1 (2nd ed.). New York, NY: Academic Press. p. 1043.
  4. ^ Greenlee, K. W.; Henne, A. L. (1946). "Sodium Amide". Inorganic Syntheses. Inorganic Syntheses. Vol. 2. pp. 128–135. doi:10.1002/9780470132333.ch38. ISBN 9780470132333.