Potassium amide is an inorganic compound with the chemical formula KNH2. Like other alkali metal amides, it is a white solid that hydrolyzes readily. It is a strong base.[1]

Potassium amide
Structural formula of potassium amide
Names
IUPAC name
Potassium amide
Other names
Potassamide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.037.508 Edit this at Wikidata
EC Number
  • 241-275-9
  • InChI=1S/K.H2N/h;1H2/q+1;-1 ☒N
    Key: FEMRXDWBWXQOGV-UHFFFAOYSA-N ☒N
  • InChI=1/K.H2N/h;1H2/q+1;-1
    Key: FEMRXDWBWXQOGV-UHFFFAOYAQ
  • [NH2-].[K+]
Properties
KNH2
Molar mass 55.121 g·mol−1
Appearance white solid
Odor ammonia-like
Density 1.57 g/cm 3
Melting point 338 °C (640 °F; 611 K)
reacts
Solubility ammonia: 3.6 g/(100 mL)
Thermochemistry
-128.9 kJ/mol
Related compounds
Other cations
Lithium amide
Sodium amide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Production edit

Potassium amide is produced by the reaction of ammonia with potassium. The reaction typically requires a catalyst.[2]

Structure edit

Traditionally KNH2 is viewed as a simple salt, but it has significant covalent character and is highly aggregated in ammonia solution.[citation needed] The compound has been characterized by X-ray crystallography as the solvent-free form[3] as well as the mono- and diammonia solvates. In KNH2·2NH3, the potassium centers are each bonded to two amido ligands and four ammonia ligands, all six of which bridge to adjacent potassium centers. The result is a chain of hexacoordinate potassium ions. The K–NH2 distances are 2.7652(11) whereas the K–NH3 distances are respectively 2.9234(11) and 3.0698(11) Å.[4]

References edit

  1. ^ Takaki, Katherine S. (2001). "Potassium Amide". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rp193. ISBN 0471936235.
  2. ^ O. Glemser, H. Sauer (1963). "Silver Amide". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 1. NY, NY: Academic Press. p. 1043.
  3. ^ Juza, R.; Jacobs, H.; Klose, W. (1965). "Die Kristallstrukturen der Tieftemperaturmodifikationen von Kalium- und Rubidiumamid". Zeitschrift für Anorganische und Allgemeine Chemie. 338 (3–4): 171–178. doi:10.1002/zaac.19653380309.
  4. ^ Kraus, Florian; Korber, Nikolaus (2005). "Hydrogen Bonds in Potassium Amide-Ammonia(1/2), KNH2.2NH3". Zeitschrift für Anorganische und Allgemeine Chemie. 631 (6–7): 1032–1034. doi:10.1002/zaac.200400467.