Lithium amide

Crystal structure
__ Li +      __ N 3−      __ H +
Crystal system	tetragonal
Space group	I 4 (No. 82)
Lattice parameters	a = 504.309 pm c = 1022.62 pm
General
Surname	Lithium amide
Ratio formula	LiNH 2
Brief description	colorless and odorless solid
External identifiers / databases
CAS number 7782-89-0 EC number 231-968-4 ECHA InfoCard 100,029,062 PubChem 24532 Wikidata Q2565173
properties
Molar mass	22.96 g mol −1
Physical state	firmly
density	1.178 g cm −3 (20 ° C)
Melting point	373 ° C
boiling point	430 ° C
solubility	Decomposes in water insoluble in ethanol and benzene
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 261-314 EUH: 014 P: 280-301 + 330 + 331-305 + 351 + 338-309 + 310-402 + 404
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Lithium amide is a chemical compound of the lithium from the group of amides .

Extraction and presentation

Lithium amide is produced industrially by heating lithium or lithium hydride in a stream of ammonia . It also forms slowly when lithium is dissolved in liquid ammonia. As with other alkali and alkaline earth amides, this reaction is considerably accelerated by the presence of iron (II) chloride .

${\displaystyle \mathrm {2\ Li+2\ NH_{3}\longrightarrow 2\ LiNH_{2}+H_{2}} }$

${\displaystyle \mathrm {LiH+NH_{3}\ {\xrightarrow {350\;^{\circ }C}}\ LiNH_{2}+H_{2}} }$

properties

Lithium amide is a colorless and odorless solid that decomposes in water.

${\displaystyle \mathrm {LiNH_{2}+H_{2}O\longrightarrow LiOH+NH_{3}} }$

The compound is generally very sensitive to hydrolysis, crystallizes tetragonally with space group I 4 (No. 82) and attacks glass weakly. When heated in a vacuum, it gives off ammonia above 300 ° C. However, quantitative degradation to lithium imide only takes place at 400 ° C and only above 750-800 ° C does it decompose with the release of nitrogen, hydrogen and ammonia.

${\displaystyle \mathrm {2\ LiNH_{2}\ {\xrightarrow {400\;^{\circ }C}}\ Li_{2}NH+NH_{3}} }$

use

Lithium amide is used in organic chemistry in Claisen condensations , in the alkylation of nitriles and ketones, and in the synthesis of ethynyl compounds and carbinols . It is still used as a reagent for the cross-coupling of aryl chlorides and amines .

Individual evidence

1. ^ WIF David, MO Jones, DH Gregory, CM Jewell, SR Johnson, A. Walton, PP Edwards: A mechanism for non-stoichiometry in the lithium amide / lithium imide hydrogen storage reaction . In: Journal of the American Chemical Society , 2007 , 129 (6) , pp. 1594-1601 doi : 10.1021 / ja066016s
2. ↑ ^{a b c d e f g h} Lithium amide data sheet (PDF) from Merck , accessed on March 27, 2013.
3. ↑ ^{a b} Roger Blachnik (Ed.): Pocket book for chemists and physicists . Volume III: Elements, Inorganic Compounds and Materials, Minerals . founded by Jean d'Ans, Ellen Lax. 4th, revised and revised edition. Springer, Berlin 1998, ISBN 3-540-60035-3 , pp. 536 ( limited preview in Google Book search).
4. ↑ ^{a b} Entry on lithium amide in the Hazardous Substances Data Bank , accessed on March 28, 2013.
5. ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , p. 666.
6. ↑ ^{a b} Georg Brauer (Ed.), With the collaboration of Marianne Baudler u a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 448.
7. ↑ Data sheet Lithium amide, powder, 95% from Sigma-Aldrich , accessed on March 28, 2013 ( PDF ).