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

Although pure hydrogen cyanide can spontaneously polymerize or even explode, when 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 investigated. Depending on the cation, it was possible to extract salts containing the formal dihydrogen tricyanide [CN(HCN) 2 ] − and trihydrogen tetracyanide ions [CN(HCN) 3 ] − from liquid HCN when a fast crystallization was carried out 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.