Salts of HCN‐Cyanide Aggregates: [CN(HCN) 2 ] − and [CN(HCN) 3 ] −

Although pure hydrogen cyanide can spontaneously polymerize or even explode, which is initiated by small amounts of bases (e.g. CN - ), the reaction of liquid HCN with [WCC]CN (WCC = weakly coordinating cation = Ph 4 P, Ph 3 PNPPh 3 = PNP) was investi-gated. Depending on the cation, it was possible to extract salts from liquid HCN, containing the formal dihydrogen tricyanide [CN(HCN) 2 ] - and trihydrogen tetracyanide ions [CN(HCN) 3 ] - , when the crystal-lization was carried out fast and at low temperatures. X-ray structure elucidation revealed hydrogen-bridged linear [CN(HCN) 2 ] - and Y-shaped [CN(HCN) 3 ] - molecular ions in the crystal. Both anions can be considered members of highly labile cyanide HCN-solvates of the type [CN(HCN) n ] - ( n = 1, 2, 3 ...) as well as formal polypseudohalide ions.