Rahul Sharma (Editor)

Phosphorus pentafluoride

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Related compounds
  
Molar mass
  
125.966 g/mol

Density
  
5.53 g/cm³

Formula
  
PF5

Boiling point
  
-84.55 °C

Appearance
  
colourless gas

Phosphorus pentafluoride Phosphorus pentafluoride Wikipedia

Phosphorus pentafluoride, PF5, is a phosphorus halide. It is a colourless gas at room temperature and pressure.

Contents

Fluxionality in phosphorus pentafluoride


Preparation

Phosphorus pentafluoride was first prepared in 1876 by the fluorination of phosphorus pentachloride using arsenic trifluoride.

Structure

Phosphorus pentafluoride FilePhosphoruspentafluoride2Dpng Wikimedia Commons

Single-crystal X-ray studies indicate that the PF5 molecule has two distinct types of P−F bonds (axial and equatorial): the length of an axial P−F bond is distinct from the equatorial P-F bond in the solid phase, but not the liquid or gas phases due to Pseudo Berry Rotation.

Phosphorus pentafluoride Pentafluoride bond More information

Fluorine-19 NMR spectroscopy, even at temperatures as low as −100 °C, fails to distinguish the axial from the equatorial fluorine environments. The apparent equivalency arises from the low barrier for pseudorotation via the Berry mechanism, by which the axial and equatorial fluorine atoms rapidly exchange positions. The apparent equivalency of the F centers in PF5 was first noted by Gutowsky. The explanation was first described by R. Stephen Berry, after whom the Berry mechanism is named. Berry pseudorotation influences the 19F NMR spectrum of PF5 since NMR spectroscopy operates on a millisecond timescale. Electron diffraction and X-ray crystallography do not detect this effect as the solid state structures are, relative to a molecule in solution, static and can not undergo the necessary changes in atomic position.

Phosphorus pentafluoride PF5 Lewis Structure How to Draw the Lewis Structure for PF5

Phosphorus pentafluoride wwwchemeddlorgalfrescoddworkspaceSpacesSto

Phosphorus pentafluoride FilePhosphorus pentafluoridePNG Wikimedia Commons

Phosphorus pentafluoride Phosphorusphosphorus pentafluoride WebElements Periodic Table

References

Phosphorus pentafluoride Wikipedia