Activation of Acetonitrile with (C F ) PF and Amines.

Acetonitrile is deprotonated by a combination of the strong Lewis acid (C F ) PF and triethylamine. The resulting cyanomethyl function is bound to the phosphorus moiety, affording the highly stable salt [HNEt ][P(C F ) F (CH CN)]. Salt metathesis reactions furnished the corresponding [Cu(MeCN) ] and [Ag(MeCN)] derivatives in which the CH CN substituent of the anion [P(C F ) F (CH CN)] coordinates to the metal. An investigation of the gas separation capability of the silver salt [Ag(MeCN)][P(C F ) F (CH CN)] shows an uptake of 1.7 equivalents of isobutene from a propane/isobutene mixture. The reaction of (C F ) PF with acetonitrile and diethylamine furnishes [P(C F ) F {NHC(CH )NEt }]-a phosphate featuring an amidine ligand which formally results from hydroamination of acetonitrile by HNEt . Exchange of HNEt with the primary amines H NPh and H NBu leads to comparable amidine salts that exhibit a solvent-dependent conformational isomerism.