Lewis Acid Catalyzed Synthesis of Cyanidophosphates.

Salts containing new cyanido(fluorido)phosphate anions of the general formula [PF6-n(CN)n](-) (n=1-4) were synthesized by a very mild Lewis-acid-catalyzed synthetic protocol and fully characterized. All [PF6-n(CN)n](-) (n=1-4) salts could be isolated on a preparative scale. It was also possible to detect the [PF(CN)5](-) but not the [P(CN)6](-) anion. The best results with respect to purity, yield, and low cost were obtained when the F(-)/CN(-) substitution reactions were carried out in ionic liquids.