7351. Phosphorus Pentachloride

Nomenclature

CAS number: 10026-13-8
Phosphoric chloride; phosphorus perchloride.
Cl5P; mol wt 208.24.
Cl 85.13%, P 14.87%.
PCl5.

Description and references

Prepn: Maxson, Inorg. Synth. 1, 99 (1939). Review: Payne, “The Chemistry of Phosphorus Halides” in Topics in Phosphorus Chemistry Vol. 4, M. Grayson, E. J. Griffith, Eds. (Interscience, New York, 1967) pp 85-155.

Properties

White to pale yellow, fuming, deliquesc, cryst mass; pungent, unpleasant odor; attacks the eyes and mucous membranes. mp 148° under pressure; sublimes at about 100° without melting. bp 160°. Hydrolyzed by water to form phosphoric acid and hydrogen chloride. Reacts with alcohols (ROH) to form the corresponding chloride (RCl). Sol in carbon disulfide or tetrachloride. Keep in tightly closed containers and handle with caution. Corrosive.

Caution

Potential symptoms of overexposure are irritation of eyes, skin and respiratory system; bronchitis; dermatitis. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 256.

Use

As catalyst in manuf acetylcellulose; for replacing hydroxyl groups by Cl, particularly for converting acids into acid chlorides.