Phosphorus compounds: phosphorus pentachloride

phosphorus symbol icon

The phosphorus in phosphorus pentachloride formally is in the oxidation state 5.

Crystal structure of phosphorus pentachloride

Phosphorus pentachloride

  • Formula as often written: PCl5
  • Hill system formula: Cl5P1
  • CAS registry number: [10026-13-8]
  • Formula weight: 208.237
  • Class: chloride


  • phosphorus pentachloride
  • phosphorus(V) chloride
  • phosphoric chloride
  • phosphorus chloride

Physical properties

  • Colour: off-white
  • Appearance: crystalline solid
  • Melting point: 167°C
  • Boiling point: 160°C
  • Density: 2100 kg m-3


Coming soon...

Element analysis

Element percentages for the elements in phosphorus pentachloride
Element %
Cl 85.13
P 14.87


PCl3 + Cl2 → PCl5

Careful chlorination of phosphorus(III) trichloride results in phosphorus(V) pentachloride. The tyield is about 85%. Phosphorus(V) pentachloride is a white solid whose density is about 1600 kg m-3 and whose melting point is about 148°C under pressure. It sublimes at about 160°C.

Solid state structure

  • Geometry of phosphorus: mixed 4-, 6-coordinate: tetrahedral and octahedral
  • Prototypical structure:

Crystal structure of phosphorus pentachloride

Isotope pattern

What follows is the calculated isotope pattern for the PCl5 unit with the most intense ion set to 100%.

Formula: P1Cl5

mass  %
206  62.5 _______________________________
207 0.0
208 100.0 __________________________________________________
209 0.0
210 64.0 ________________________________
211 0.0
212 20.4 __________
213 0.0
214 3.3 __
215 0.0
216 0.2


The data on these compounds pages are assembled and adapted from the primary literature and several other sources including the following.

  • R.T. Sanderson in Chemical Periodicity, Reinhold, New York, USA, 1960.
  • N.N. Greenwood and A. Earnshaw in Chemistry of the Elements, 2nd edition, Butterworth, UK, 1997.
  • F.A. Cotton, G. Wilkinson, C.A. Murillo, and M. Bochmann, in Advanced Inorganic Chemistry, John Wiley & Sons, 1999.
  • A.F. Trotman-Dickenson, (ed.) in Comprehensive Inorganic Chemistry, Pergamon, Oxford, UK, 1973.
  • R.W.G. Wyckoff, in Crystal Structures, volume 1, Interscience, John Wiley & Sons, 1963.
  • A.R.West in Basic solid state chemistry Chemistry, John Wiley & Sons, 1999.
  • A.F. Wells in Structural inorganic chemistry, 4th edition, Oxford, UK, 1975.
  • J.D.H. Donnay, (ed.) in Crystal data determinative tables, ACA monograph number 5, American Crystallographic Association, USA, 1963.
  • D.R. Lide, (ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 77th edition, 1996.
  • J.W. Mellor in A comprehensive treatise on inorganic and theoretical chemistry, volumes 1-16, Longmans, London, UK, 1922-1937.
  • J.E. Macintyre (ed.) in Dictionary of inorganic compounds, volumes 1-3, Chapman & Hall, London, UK, 1992.

WebElements Shop

WebElements now has a WebElements shop at which you can buy periodic table posters, mugs, T-shirts, games, fridge magnets, molecular models, and more.

Periodic Table fridge magnets Periodic Table fridge magnets
Buy our periodic table fridge magnets here

WebElements poster Periodic table t-shirts Periodic table mouse mats Molymod molecular model kits Chemistry educational resources

phosphorus atomic number