Gas phase FT ICR investigation of the production of phosphoranides and ion chemistry of tris(trifluoromethyl)phosphine

In a long cylindrical ion cyclotron resonance (ICR) cell the ion chemistry of tris(trifluoromethyl)phosphine has been investigated. The only major negative primary ion, produced by dissociative electron attachment is the phosphide ion (CF3)2P−, which reacts at elevated kinetic energy with the neutral molecules at 2 × 10−7 mbar to produce three phosphoranides: CF3PF3−, (CF3)2PF2−, and (CF3)3PF−. Simultaneously, three minor ions CF3−, F−, and C2F3− are formed by self-collision-induced dissociation. Ion-molecule reactions between CF3− and (CF3)3P have also been investigated. Positive ions form phosphonium ions and a diphosphonium product ion, (CF3)2P-P(CF3)3+, whereas no P-P bond is observed with negative ions. All the structures and reaction pathways have been investigated theoretically with the aid of DFT calculations. The results are in excellent agreement with the experiments. The electron affinity of tris(trifluoromethyl)phosphine as EA((CF3)3P) = 22.6 kcal/mol has been calculated.