Lithium amide

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Lithium amide

__ Li+
      __ N3−
      __ H+
Names
IUPAC name
Lithium amide
Other names
Lithium azanide
Lithamide
Identifiers
3D model (
JSmol
)
ChemSpider
ECHA InfoCard
 100.029.062 Edit this at Wikidata
UNII
  • InChI=1S/Li.H2N/h;1H2/q+1;-1 checkY
    Key: AFRJJFRNGGLMDW-UHFFFAOYSA-N checkY
  • InChI=1/Li.H2N/h;1H2/q+1;-1
    Key: AFRJJFRNGGLMDW-UHFFFAOYAO
  • [Li+].[NH2-]
Properties
LiNH2
Molar mass 22.96 g·mol−1
Appearance white solid
Density 1.178 g/cm3
Melting point 375 °C (707 °F; 648 K)
Boiling point 430 °C (806 °F; 703 K) decomposes
reacts
Solubility slightly soluble in ethanol
insoluble in ammonia
Thermochemistry
Std enthalpy of
formation
(ΔfH⦵298)
 -182 kJ/mol
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorusSpecial hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid
3
1
2
W
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Lithium amide or lithium azanide is an inorganic compound with the chemical formula LiNH2. It is a white solid with a tetragonal crystal structure.[1] Lithium amide can be made by treating lithium metal with liquid ammonia:[2]

2 Li + 2 NH3 → 2 LiNH2 + H2

Other lithium amides

The conjugate bases of amines are known as amides. Thus, a lithium amide may also refer to any compound in the class of the lithium salt of an

lithium hexamethyldisilazide
(LiHMDS). They are produced by the reaction of Li metal with the appropriate amine:

2 Li + 2 R2NH → 2 LiNR2 + H2

Lithium amides are very reactive compounds. Specifically, they are strong bases.

Examples

Lithium tetramethylpiperidide has been crystallised as a tetramer.[3] On the other hand, the lithium derivative of bis(1-phenylethyl)amine crystallises as a trimer:[4]

Tetrameric lithium tetramethylpiperidide
Trimeric lithium bis(1-phenylethyl)amide

It is also possible to make mixed oligomers of metal

superbases, which are mixtures of metal alkoxides and alkyls. The cyclic oligomers form when the nitrogen of the amide forms a sigma bond to a lithium, while the nitrogen lone pair
binds to another metal centre.

Other organolithium compounds (such as

BuLi
) are generally considered to exist in and function via high-order, aggregated species.

See also

References

  1. PMID 17243680
    .
  2. ^ P. W. Schenk (1963). "Lithium amide". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 1. NY, NY: Academic Press. p. 454.
  3. doi:10.1021/ja00340a031
    .
  4. doi:10.1039/A904725E
    .
  5. doi:10.1021/ja00138a030
    .

External links

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