Zinc cyanide is the inorganic chemical compound with the formula Zn(CN)2. It adopts a polymeric structure consisting of tetrahedral zinc centers linked by bridging cyanide ligands. The structure can also be described as being two interpenetrating adamantain structures. The cyanide group shows head to tail disorder with any zinc atom having between 1 and 4 carbon neighbours and the remaining being nitrogen atoms. It shows one of the largest negative coefficents of thermal expansion, beating the previous largest zerconium tungstate.
Zn(CN)2 is employed as a catalyst for the cyanosilylation of aldehydes and ketones.
Zinc cyanide is also a byproduct of gold extraction were zinc metal is added to the gold cyanide solution to precipitate the gold.