Lithium nitride

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Lithium nitride
Unit cell ball and stick model of lithium nitride
Identifiers
CAS number26134-62-3 YesY
EC number247-475-2
ChEBICHEBI:30525 N
Jmol-3D imagesImage 1
Properties
Molecular formulaLi3N
Molar mass34.83 g/mol
Appearancered, purple solid
Density1.270 g/cm3
Melting point813 °C; 1,495 °F; 1,086 K
Solubility in waterreacts
log P3.24
Hazards
EU IndexNot listed
Main hazardsreacts with water to release ammonia
Related compounds
Other anionsLithium oxide
Other cationsSodium nitride
Related compoundsLithium amide

Lithium imide

 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references
 
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Lithium nitride
Unit cell ball and stick model of lithium nitride
Identifiers
CAS number26134-62-3 YesY
EC number247-475-2
ChEBICHEBI:30525 N
Jmol-3D imagesImage 1
Properties
Molecular formulaLi3N
Molar mass34.83 g/mol
Appearancered, purple solid
Density1.270 g/cm3
Melting point813 °C; 1,495 °F; 1,086 K
Solubility in waterreacts
log P3.24
Hazards
EU IndexNot listed
Main hazardsreacts with water to release ammonia
Related compounds
Other anionsLithium oxide
Other cationsSodium nitride
Related compoundsLithium amide

Lithium imide

 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Lithium nitride is a compound with the formula Li3N. It is the only stable alkali metal nitride. The solid is a red or purple color and has a high melting point.[1]

Preparation and handling[edit]

Lithium nitride is prepared by direct combination of elemental lithium with nitrogen gas:[2]

6 Li + N2 → 2 Li3N

Instead of burning lithium metal in an atmosphere of nitrogen, a solution of lithium in liquid sodium metal can be treated with N2. Lithium nitride reacts violently with water to produce ammonia:

Li3N + 3 H2O → 3 LiOH + NH3

Structure[edit]

Li3N has an unusual crystal structure that consists of two types of layers, one sheet has the composition Li2N contains 6-coordinate Li centers and the other sheet consists only of lithium cations.[3]

The hypothetical nitride ion, N3−, would be an extremely strong Brønsted base, easily qualifying as a superbase. It is, in fact, a stronger base than the hydride ion, and so deprotonates hydrogen:

Li3N + 2 H2 → LiNH2 + 2 LiH

Lithium nitride has been investigated as a storage medium for hydrogen gas, as the reaction is reversible at 270 °C. Up to 11.5% by weight absorption of hydrogen has been achieved.[4]

References[edit]

  1. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0080379419. 
  2. ^ E. Döneges "Lithium Nitride" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 984.
  3. ^ Barker M.G., Blake A.J, Edwards P.P., Gregory D.H., Hamor T. A., Siddons D. J., Smith S. E. (1999). "Novel layered lithium nitridonickelates; effect of Li vacancy concentration on N co-ordination geometry and Ni oxidation state". Chem. Commun. (13): 1187–1188. doi:10.1039/a902962a. 
  4. ^ Ping Chen, Zhitao Xiong, Jizhong Luo, Jianyi Lin and Kuang Lee Tan (2002). "Interaction of hydrogen with metal nitrides and amides". Nature 420 (6913): 302–304. doi:10.1038/nature01210. PMID 12447436. 

See also[edit]