Nitrogen trichloride, also known as trichloramine, is the

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one ele ...

with the formula NCl₃. This yellow, oily, pungent-smelling and explosive liquid is most commonly encountered as a byproduct of

chemical reaction A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and break ...

s between

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogeno ...

-derivatives and

chlorine Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is ...

(for example, in

swimming pool A swimming pool, swimming bath, wading pool, paddling pool, or simply pool, is a structure designed to hold water to enable Human swimming, swimming or other leisure activities. Pools can be built into the ground (in-ground pools) or built ...

s). Alongside monochloramine and dichloramine, trichloramine is responsible for the distinctive 'chlorine smell' associated with swimming pools, where the compound is readily formed as a product from hypochlorous acid reacting with

and other nitrogenous substances in the water, such as urea from

urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellular ...

Preparation and structure

The compound is prepared by treatment of ammonium salts, such as

ammonium nitrate Ammonium nitrate is a chemical compound with the chemical formula . It is a white crystalline salt consisting of ions of ammonium and nitrate. It is highly soluble in water and hygroscopic as a solid, although it does not form hydrates. It ...

with chlorine. Intermediates in this conversion include monochloramine and dichloramine, NH₂Cl and NHCl₂, respectively. Like ammonia, NCl₃ is a pyramidal molecule. The N-Cl distances are 1.76 Å, and the Cl-N-Cl angles are 107°.

Reactions and uses

The chemistry of NCl₃ has been well explored. It is moderately polar with a dipole moment of 0.6 D. The nitrogen center is basic but much less so than ammonia. It is hydrolyzed by hot water to release

and hypochlorous acid. :NCl₃ + 3 H₂O → NH₃ + 3 HOCl NCl₃ explodes to give N₂ and chlorine gas. This reaction is inhibited for dilute gases. Nitrogen trichloride can form in small amounts when public water supplies are disinfected with monochloramine, and in swimming pools by disinfecting chlorine reacting with urea in urine and sweat from bathers. Nitrogen trichloride, trademarked as Agene, was at one time used to bleach

flour Flour is a powder made by grinding raw grains, roots, beans, nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredient of bread, which is a staple food for many c ...

, but this practice was banned in the United States in 1949 due to safety concerns.

Safety

Nitrogen trichloride can irritate mucous membranes—it is a lachrymatory agent, but has never been used as such. The pure substance (rarely encountered) is a dangerous explosive, being sensitive to light, heat, even moderate shock, and organic compounds. Pierre Louis Dulong first prepared it in 1812, and lost two fingers and an eye in two explosions. In 1813, an NCl₃ explosion blinded Sir

Humphry Davy Sir Humphry Davy, 1st Baronet, (17 December 177829 May 1829) was a British chemist and inventor who invented the Davy lamp and a very early form of arc lamp. He is also remembered for isolating, by using electricity, several elements for the ...

temporarily, inducing him to hire

Michael Faraday Michael Faraday (; 22 September 1791 – 25 August 1867) was an English scientist who contributed to the study of electromagnetism and electrochemistry. His main discoveries include the principles underlying electromagnetic inductio ...

as a co-worker. They were both injured in another NCl₃ explosion shortly thereafter.

References

External links

OSHA - Nitrogen trichloride

Nitrogen Trichloride - Health References
{{Chlorides Inorganic amines Chlorides Nitrogen halides Inorganic chlorine compounds Inorganic nitrogen compounds Explosive chemicals Nitrogen(III) compounds Liquid explosives

Preparation and structure

Reactions and uses

Safety

See also

References

Further reading

External links