Phosphorus pentafluoride Molecular structure

As indicated in Table 10-4, the four pentafluorides are all well known. Phosphorus pentafluoride, which may be prepared by fiuorinating PC15 with AsF3 or CaF2 is molecular, with a tbp structure in the solid state13 and under all other conditions. It is a colorless gas (bp -102°C), which reacts readily with Lewis bases such as amines and ethers, as well as F , to form six-coordinate complexes. The fluxional character of the molecule, whereby the axial and equatorial F atoms change places rapidly on the nmr time scale is generally explained as a Berry pseudorotation. 

The gas phase molecular structures of phosphorus pentafluoride and pentachloride... 

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