Nitrogen trichloride explained

Nitrogen trichloride, also known as trichloramine, is the chemical compound with the formula . This yellow, oily, and explosive liquid is most commonly encountered as a product of chemical reactions between ammonia-derivatives and chlorine (for example, in swimming pools). 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 ammonia and other nitrogenous substances in the water, such as urea from urine.^[1]

Preparation and structure

The compound is prepared by treatment of ammonium salts, such as sal ammoniac with a chlorine source.

Intermediates in this conversion include monochloramine and dichloramine, and, respectively.

Like ammonia, is a pyramidal molecule. The N-Cl distances are 1.76 Å, and the Cl-N-Cl angles are 107°.^[2]

Reactions and uses

The chemistry of 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 ammonia and hypochlorous acid.

NCl3 + 3 H2O -> NH3 + 3 HOClNCl3 explodes to give N2 and chlorine gas.

2 NCl3 -> N2 + 3 Cl2This 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,^[3] 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.^{[4] [5]} 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 several fingers and an eye in two explosions.^[6] In 1813, an explosion blinded Sir Humphry Davy temporarily, inducing him to hire Michael Faraday as a co-worker. They were both injured in another explosion shortly thereafter.^[7]

See also

• List of food contamination incidents

Further reading

• Book: Jander, J. . Recent Chemistry and Structure Investigation of Nitrogen Triiodide, Tribromide, Trichloride, and Related Compounds . Advances in Inorganic Chemistry . 1976 . 19 . 1–63 . 10.1016/S0065-2792(08)60070-9 . Advances in Inorganic Chemistry and Radiochemistry . 9780120236190.
• Kovacic, P. . Lowery, M. K. . Field, K. W. . Chemistry of N-Bromamines and N-Chloramines . Chemical Reviews . 1970 . 70 . 6 . 639–665 . 10.1021/cr60268a002.
• Hartl, H. . Schöner, J. . Jander, J. . Schulz, H. . Die Struktur des Festen Stickstofftrichlorids (−125 °C) . Zeitschrift für Anorganische und Allgemeine Chemie . 1975 . 413 . 1 . 61–71 . 10.1002/zaac.19754130108.
• Cazzoli, G. . Favero, P. G. . Dal Borgo, A. . Molecular Structure, Nuclear Quadrupole Coupling Constant and Dipole Moment of Nitrogen Trichloride from Microwave Spectroscopy . Journal of Molecular Spectroscopy . 1974 . 50 . 1–3 . 82–89 . 10.1016/0022-2852(74)90219-7 . 1974JMoSp..50...82C.
• Bayersdorfer, L. . Engelhardt, U. . Fischer, J. . Höhne, K. . Jander, J. . Untersuchungen an Stickstoff–Chlor-Verbindungen. V. Infrarot- und RAMAN-Spektren von Stickstofftrichlorid . Zeitschrift für Anorganische und Allgemeine Chemie . 1969 . 366 . 3–4 . 169–179 . 10.1002/zaac.19693660308.

External links

• OSHA - Nitrogen trichloride
• Nitrogen Trichloride - Health References

Notes and References

1. Web site: Chlorine Chemistry - Chlorine Compound of the Month: Chloramines: Understanding "Pool Smell" . . 17 December 2019.
2. Book: Holleman, A. F. . Wiberg, E. . Inorganic Chemistry . Academic Press . San Diego . 2001 . 978-0-12-352651-9.
3. 10.1002/jsfa.2740060906. Some effects of oxygen on the mixing of bread doughs. Journal of the Science of Food and Agriculture. 6. 9. 501–511. 1955. Hawthorn. J.. Todd. J. P.. 1955JSFA....6..501H.
4. Book: White, G. C. . The Handbook of Chlorination and Alternative Disinfectants . 4th . Wiley . 1999 . 978-0-471-29207-4 . 322.
5. HETA 2007-0163-3062 . Health Hazard Evaluation Report: Investigation of Employee Symptoms at an Indoor Water Park . August 2008 . NIOSH ENews . 6 . 4 .
6. Thénard J. L. . Berthollet C. L. . Claude Louis Berthollet . Report on the work of Pierre Louis Dulong . . 1813 . 86 . 6 . 37 - 43 . Louis Jacques Thénard.
7. Book: Thomas, J.M.. Michael Faraday and The Royal Institution: The Genius of Man and Place (PBK). 1991. CRC Press. 978-0-7503-0145-9. 17.