Strontium Cyanide, Sr(CN)₂

Strontium Cyanide, Sr(CN)₂, may be formed by the absorption of nitrogen by strontium carbide, or, in very small quantity, by the action of carbon monoxide on the nitride at red heat. By passing anhydrous hydrocyanic acid over crystallised strontium hydroxide, a solution of strontium cyanide in the water of crystallisation of the hydroxide is obtained. It is unstable in the presence of excess of hydrocyanic acid. On evaporation in vacuo deliquescent orthorhombic crystals of the tetrahydrate, Sr(CN)₂.4H₂O, separate out. If dehydration of the crystals in vacuo is attempted they lose hydrocyanic acid as well as water. A solution can also be prepared by fusing strontium ferro-cyanide and extracting with water.

Several double cyanides are known, some of them no doubt containing complex ions. There is the strontium mercury compound, SrHg(CN)₄.5H₂O, and also the compound Sr(CN)₂.Hg(CN)₂.HgI₂.7H₂O. Strontium manganocyanide, Sr₂Mn(CN)₆, has been obtained, and strontium manganese manganocyanide, SrMn,Mn(CN)₆. There are also a cobaltocyanide and an unstable chromocyanide.