dilithium acetylide

Chemical properties

crystal(s) white powder(s); decomposes in water, evolves acetylene when dissolved in acid [HAW93]

Preparation

Lithium carbide, Li2C2, may be prepared by the direct combination of lithium and carbon at about 1000°C or by the reaction of lithium metal with acetylene in liquid ammonia. The latter process first yields lithium acetylide, LiC=CH, which decomposes to lithium carbide. The conversion to the carbide is incomplete, however . A convenient laboratory preparation of lithium carbide may be carried out by bubbling acetylene into a solution of n-butyllithium in hexane. The precipitated carbide may be filtered from the reaction mixture, washed, and dried. Lithium carbide is ionic and yields acetylene on hydrolysis.