E. Muetterties, T. A. Bither, M. W. Farlow
Nov 1, 1960
Citations
0
Influential Citations
42
Citations
Journal
Journal of Inorganic and Nuclear Chemistry
Abstract
Abstract Phosphorus tri- and pentafluorides were prepared in high yield and conversion by reaction of the respective chlorides and CaF 2 at 300–400°. The pentafluoride is a very strong acceptor molecule and forms complexes with amines, ethers, nitriles, sulphoxides and other organic bases. The 19 F spectra of the complexes are fully consistent with an octahedral model, and the PF coupling constants, similar to that in PF 6 − , suggest a relative insensitivity of hybridization to the type of donor molecule. In accord with the strong acceptor properties, the pentafluoride is an excellent catalyst for ionic polymerizations. Especially noteworthy is the PF 5 -catalysed polymerization of tetrahydrofuran to a very high ( M n − = 280,000) molecular weight elastomer. Phosphorus trifluoride, unlike the pentafluoride, exhibits no significant acceptor properties. However, the trifluoride does undergo a curious disproportionation, 3MF + 5PF 3 → 3MPF 6 + 2P, that may involve an MPF 4 intermediate.