Preparation of copper hydride
Preparation of copper hydride from lithium aluminium hydride and copper iodide
A solution of lithium aluminium hydride in ether-pyridine is prepared by mixing concentrated ether solution of LiAlH4 with absolute pyridine. Copper iodide is dissolved in pyridine and both solutions were mixed yielding a blood-red pyridine solution of copper hydride. The reaction mixture is left for additional 4-6 hours to stand at room temperature. The purification of copper hydride carry out by dissolving residual aluminium iodide and lithium iodide in at least equal volume of ether to the pyridine solution. Copper hydride forms which is separated by centrifugation, washed with ethyl ether. Copper hydride is dissolved again in pyridine, and precipitated with ether. For the finally pure copper hydride this procedure is repeated few times. Finally CuH is separated from ether by evaporated in a high vacuum.
Copper hydride preparation reaction may also be carried out by treating a solution of Copper iodide in pyridine-tetrahydrofuran-ether with an ether solution of LiAlH4. In this case, CuH precipitates as soon as the two solutions are mixed, while both aluminium iodide and lithium iodide remain in solution. The copper hydride precipitate is purified by washing with ethyl ether, redissolving in pyridine and reprecipitating with ether.
Handbook of preparative inorganic chemistry. Vol. 2. 1963, 1004.
Preparation of copper hydride from copper sulfate and hypophosphorous acid
16 g of copper sulfate 5-hydrate are dissolved in 60 ml of water and this solution is mixed with 20 g of 50% hypophosphorous acid (or 30 g of 30% concentration) in 400 ml of water, and allowed to stand in a bath maintained at 30-35° C for at least six hours. The red-brown product is filtered by suction (some material clings tenaciously to the reaction vessel as a shiny film), washed with water, and dried in vacuo.
Yield = 3.5-4g
The hypophosphorous acid may also be prepared by dissolving 15 g of barium hypophosphite monohydrate in 400 ml water, adding three milliliters of concentrated sulfuric acid and filtering off the barium sulfate to give a clear liquid. Twelve grams of sodium hypophosphite monohydrate in 400 ml water and one milliliter of acid form an alternative solution suitable for use.
The copper hydride decomposes to metallic copper and hydrogen on gentle heating.
Inorganic laboratory preparations, by G. G. Schlessinger, 22-23, 1962
Copper Monohydride, Copper hydride (CuH), AC1MNYC0, CTK4B9693, 13517-00-5