Nomenclature
CAS number: 16853-85-3
(
T-4)-Tetrahydroaluminate(1) lithium (1:1); lithium tetrahydroaluminate; lithium aluminum hydride; lithium aluminohydride; lithium alanate.
AlH
4Li; mol wt 37.95.
Al 71.10%, H 10.62%, Li 18.29%.
LiAlH
4.
Description and references
Prepd by treating lithium hydride with an ether
soln of AlCl3: Finholt, et al., J. Am. Chem. Soc. 69, 1199 (1947). Crystal structure: Sklar, Post, Inorg. Chem. 6, 669 (1967). Review of chemistry: J.
S. Pizey, Synthetic Reagents Vol. 1 (John Wiley, New York, 1974) pp 101-294.
Properties
Microcrystalline white powder when pure; gray
when aluminum impurity present. Monoclinic crystals. d 0.92. Stable in dry air at room
temperature, decomp above 125°, slowly loses hydrogen at 120°, decomp
in moist air, may ignite on grinding in air. Soly (parts/100 parts
solvent): 30 (ether); 13 (tetrahydrofuran); 10 (dimethylcellosolve);
2 (dibutyl ether); 0.1 (dioxane). Reacts rapidly with water and alcohols;
reduces aldehydes, ketones, acid chlorides and esters to alcohols;
nitriles to amines; aromatic nitro compounds to azo compounds. Does
not attack olefinic double bonds unless they are conjugated with a
phenyl group and a carbonyl or nitrile group.Use
Reducing agent; in preparation of other hydrides.