Tetrahydroaluminate

Although the lUPAC has recommended the names tetrahydroborate, tetrahydroaluminate, etc, this nomenclature is not yet ia general use. Borohydrides. The alkaU metal borohydrides are the most important complex hydrides. They are ionic, white, crystalline, high melting soHds that are sensitive to moisture but not to oxygen. Group 13 (IIIA) and transition-metal borohydrides, on the other hand, are covalendy bonded and are either Hquids or sublimable soHds. The alkaline-earth borohydrides are iatermediate between these two extremes, and display some covalent character. 

See Dibenzoyl peroxide Lithium tetrahydroaluminate Hydrazine Oxidants REDOX REACTIONS ROCKET PROPELLANTS... 

Presence of carbon dioxide in solutions of the hydride in dimethyl or bis(2-methoxy-ethyl) ether can cause a violent decomposition on warming the residue from evaporation. Presence of aluminium chloride tends to increase the vigour of decomposition to explosion. Lithium tetrahydroaluminate may behave similarly, but is generally more stable. 

Tetrahydro-l-naphthyl hydroperoxide See 1,2,3,4-Tetrahydro-l-naphthyl hydroperoxide Lithium tetrahydroaluminate... 

A 20 g sample, prepared and stored in a dry box for several months, developed a thin crust of oxidation/hydrolysis products. When the crust was disturbed, a violent explosion occurred, later estimated as equivalent to 230 g TNT. A weaker explosion was observed with potassium tetrahydroaluminate. The effect was attributed to superoxidation of traces of metallic potassium, and subsequent interaction of the hexahydroaluminate and superoxide after frictional initiation. Precautions advised include use of freshly prepared material, minimal storage in a dry diluent under an inert atmosphere and destruction of solid residues. Potassium hydrides and caesium hexahydroaluminate may behave similarly, as caesium also superoxidises in air. 

Addition of nitromethane to ethereal lithium tetrahydroaluminate solution at ambient temperature gave an explosively violent rection [1], and this was confirmed when addition of 0.5 ml of dry nitromethane to 10 ml of reducant solution led, after 30 s, to a violent explosion which pulverised the flask [2]. The violence of the explosion suggests that lithium ad-nitromethanide (or possibly lithium fulminate) may have been involved. 

Lithium tetrahydroaluminate See Lithium tetrahydroaluminate Ethyl acetate... 

Of a series of lithium hydrocuprates Li CuH +i (n = 1-5), only the title compound (when solvated with THF) appeared a more powerful reducant than lithium tetrahydroaluminate. Safety precautions similar to those adopted for the complex aluminium hydride seem appropriate. 

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