Trihydrido trimethylamine aluminum

Lithium tetrahydridoaluminate(l —) may be used as obtained commercially. Trimethylammonium chloride is dried under vacuum at 100° for 1 hr. The benzene solvent should be dried by heating at the reflux temperature for a period in excess of 1 hr over lithium tetrahydrido-aluminate(l —) followed by distillation under a nitrogen atmosphere. In a nitrogen-filled dry box, 47.8 g (0.50 mol) of trimethylammonium chloride is transferred to a Schlenk tube. To a 1000-mL three-necked flask containing a large, egg-shaped stirring bar, 22.8 g (0.60 mol) of lithium tetrahydrido-aluminate(l —) is added. A 20% excess of lithium tetrahydrido-aluminate(l —) is used in order to eliminate the possibility of obtaining 

Analysis is accomplished by standard vacuum-line techniques. A 1.00-mL aliquot of (CH3)3N-A1H3 in benzene solution is placed in an ampul and attached to a multipurpose vacuum line equipped with gas-separation traps and a Toepler pump and is hydrolyzed by using a mixture composed of equal amounts of water and concentrated hydrochloric acid. 

The number of moles of hydrogen gas evolved is measured from standard PVT relationships. The aluminum trichloride remaining in solution is analyzed for aluminum by using standard EDTA+ solution and dithizone indicator. The active hydride/aluminum ratio was found to be 3.0 1.0 in all preparations. 

The H/Al ratio, as well as percent composition of active hydride and aluminum are determined by analysis of a weighed portion of a solid sample using techniques described in the analysis of (CH3)3 N A1H3. The H/Al ratio is found to be 2.00 1.00. Anal. Calcd. for wt % of active hydride and aluminum H, 1.99 Al, 26.7. Found H, 2.00 Al, 26.6. 

The compound can be stored indefinitely at room temperature in a water-and oxygen-free environment. 

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TRIHYDRIDO(TRIMETHYLAMINE)ALUMINUM AND (DIETHYLAMINO)HYDRIDOALUMINUM COMPLEXES... 

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