Perfluoromethylphosphine-nickel compounds, including a new volatile heterocycle

Article abstract of DOI:10.1021/ic50043a014

The displacement of 3CO from Ni(CO)₄ by (CF₃)₂PF occurs as readily as the displacement of 2CO by CF₃PF₂, but this method arrives at pure (CF₃PF₂)₄Ni (mp -84°, bp estd 160°) far more easily than pure [(CF₃)₂PF]₄Ni (air-stable, mp 57.8°, bp estd 218°), for steric reasons such as prevent third-stage action by (CF₃)₃P. The infrared spectra suggest a slight increase of C-O bond strength as CF₃ replaces F in PF₃-Ni-CO compounds, and the effect is ascribed to minor differences in π bonding. The action of PF₃ upon (CF₃PF₂)₄Ni relates to the hypothesis that compounds of the type Li₂NiL′₂ often will be more stable than others having different proportions of the same ligands. The new chelate compound (CF₃)₂PC₂F₄P(CF₃) ₂-Ni(CO)₂ (mp 30°, bp estd 179°) is more volatile but less stable than the similar C₂H₄-connected compound: complete displacement of the ligand (CF₃)₂PC₂F₄P(CF₃) ₂ and one CO leads to the product [(CF₃)₂PC₂H₄P(CF₃) ₂]₂NiCO with one bisphosphine unit acting unifunctionally.