Title: Aluminum Lithium Hydride
CAS Registry Number: 16853-85-3
CAS Name: Lithium tetrahydroaluminate
Additional Names: lithium aluminum hydride; lithium aluminohydride; lithium alanate
Molecular Formula: AlH4Li
Molecular Weight: 37.95
Percent Composition: Al 71.10%, H 10.62%, Li 18.29%
Line Formula: LiAlH4
Literature 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.
Density: d 0.92
Use: Reducing agent; in preparation of other hydrides.