WebElements Periodic Table of the Elements | Phosphorus

Phosphorus compounds: phosphorus pentachloride

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

Phosphorus pentachloride

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

Synonyms

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

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Element analysis

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

Synthesis

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

References

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.