Lithium aluminium hydride is an inorganic compound that is majorly used as the reducing agent. The chemical formula for the molecule is LAH or LiAlH4 with a molecular weight of 37.95 g/mol. The chemical structure of the molecule is also given below that is made up of one lithium cation, one aluminium hydride anion where aluminium is connected four hydrogen atoms ahead.
It is prepared by the reaction of lithium hydride with aluminium chloride together for small industry scales as given below –
4 LiH + AlCl3 → LiAlH4 + 3 LiCl
For the industrial preparation of molecule, you should follow two steps majorly. One, the reaction of sodium and Al atoms with hydrogen atoms under high temperature or pressure conditions. During the second step, allow the product to exchange the metal ions (cations and anions) to release the final product.
This is an odourless molecule with white or grey color. The hydride is a white crystalline solid with a density of 0.97 g/mL and a melting point of 150 degree Celsius approximately. This is also available commercially as a dispersion for mineral oil and helps to prevent the violent reaction of molecule with the atmospheric moisture.
This molecule is not stable and hard to find in pure state. It decomposes quickly to lithium and aluminium products that were used as the reactants earlier. This is true that LAH is a srong base and a wonderful reducing agent too. This is soluble in ether and organic solvent as per the requirements.