Nitrogen trichloride

Nitrogen trichloride
	; Nitrogen, N Chlorine, Cl
Names
	Other names Trichloramine; Agene; Nitrogen(III) chloride; Trichloroazane; Trichlorine nitride
Identifiers
CAS Number	10025-85-1 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:37382 ;
ChemSpider	55361 ;
ECHA InfoCard	100.030.029
EC Number	233-045-1;
Gmelin Reference	1840
PubChem CID	61437;
RTECS number	QW974000;
UNII	VA681HRW8W ;
CompTox Dashboard (EPA)	DTXSID4074938 ;
	InChI InChI=1S/Cl3N/c1-4(2)3 Key: QEHKBHWEUPXBCW-UHFFFAOYSA-N ; InChI=1/Cl3N/c1-4(2)3 Key: QEHKBHWEUPXBCW-UHFFFAOYAZ;
	SMILES ClN(Cl)Cl;
Properties
Chemical formula	NCl3
Molar mass	120.36 g·mol−1
Appearance	yellow oily liquid
Odor	chlorine-like
Density	1.653 g/mL
Melting point	−40 °C (−40 °F; 233 K)
Boiling point	71 °C (160 °F; 344 K)
Solubility in water	immiscible; slowly decomposes
Solubility	soluble in benzene, chloroform, CCl4, CS2, PCl3
Structure
Crystal structure	orthorhombic (below −40 °C)
Molecular shape	trigonal pyramidal
Dipole moment	0.6 D
Thermochemistry
Std enthalpy of; formation (ΔfH⦵298)	232 kJ/mol
Hazards
NFPA 704 (fire diamond)	2 0 3 OX
Autoignition; temperature	93 °C (199 °F; 366 K)
Related compounds
Other anions	Nitrogen trifluoride; Nitrogen tribromide; Nitrogen triiodide
Other cations	Phosphorus trichloride; Arsenic trichloride
Related chloramines	Monochloramine; Dichloramine
Related compounds	Nitrosyl chloride
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Nitrogen trichloride, also known as trichloramine, is the chemical compound with the formula NCl₃. 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 occurrence

The compound is generated by treatment of ammonium chloride with calcium hypochlorite. When prepared in an aqueous-dichloromethane mixture, the trichloramine is extracted into the nonaqueous phase.^[2] Intermediates in this conversion include monochloramine and dichloramine, NH₂Cl and NHCl₂, respectively.

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.

Structure and properties

Like ammonia, NCl₃ is a pyramidal molecule. The N-Cl distances are 1.76 Å, and the Cl-N-Cl angles are 107°.^[4]

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.

Reactions and uses

The chemistry of NCl₃ has been well explored.^[5] 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 HOCl

Concentrated samples of NCl₃ can explode to give N₂ and chlorine gas.

2 NCl₃ → N₂ + 3 Cl₂

NCl₃ can react with certain organic compounds to produce amines.^[2]

Safety

Nitrogen trichloride can irritate mucous membranes — it is a lachrymatory agent, but has never been used as such.^[6]^[7] The compound (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.^[8] In 1813, an NCl₃ explosion blinded Sir Humphry Davy temporarily, inducing him to hire Michael Faraday as a co-worker. They were both injured in another NCl₃ explosion shortly thereafter.^[9]

References

^ "Chlorine Chemistry - Chlorine Compound of the Month: Chloramines: Understanding "Pool Smell"". American Chemistry Council. Retrieved 17 December 2019.
^ ^a ^b Kovacic, Peter; Chaudhary, Sohan S. (1968). "1-Amino-1-Methylcyclohexane". Organic Syntheses. 48: 4. doi:10.15227/orgsyn.048.0004.
^ Hawthorn, J.; Todd, J. P. (1955). "Some effects of oxygen on the mixing of bread doughs". Journal of the Science of Food and Agriculture. 6 (9): 501–511. Bibcode:1955JSFA....6..501H. doi:10.1002/jsfa.2740060906.
^ Holleman, A. F.; Wiberg, E. (2001). Inorganic Chemistry. San Diego: Academic Press. ISBN 978-0-12-352651-9.
^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
^ White, G. C. (1999). The Handbook of Chlorination and Alternative Disinfectants (4th ed.). Wiley. p. 322. ISBN 978-0-471-29207-4.
^ "Health Hazard Evaluation Report: Investigation of Employee Symptoms at an Indoor Water Park" (PDF). NIOSH ENews. 6 (4). August 2008. HETA 2007-0163-3062.
^ Thénard J. L.; Berthollet C. L. (1813). "Report on the work of Pierre Louis Dulong". Annales de Chimie et de Physique. 86 (6): 37–43.
^ Thomas, J.M. (1991). Michael Faraday and The Royal Institution: The Genius of Man and Place (PBK). CRC Press. p. 17. ISBN 978-0-7503-0145-9.

External links

[1] "Chlorine Chemistry - Chlorine Compound of the Month: Chloramines: Understanding "Pool Smell"". American Chemistry Council. Retrieved 17 December 2019.

[OS-2] Kovacic, Peter; Chaudhary, Sohan S. (1968). "1-Amino-1-Methylcyclohexane". Organic Syntheses. 48: 4. doi:10.15227/orgsyn.048.0004.

[3] Hawthorn, J.; Todd, J. P. (1955). "Some effects of oxygen on the mixing of bread doughs". Journal of the Science of Food and Agriculture. 6 (9): 501–511. Bibcode:1955JSFA....6..501H. doi:10.1002/jsfa.2740060906.

[4] Holleman, A. F.; Wiberg, E. (2001). Inorganic Chemistry. San Diego: Academic Press. ISBN 978-0-12-352651-9.

[5] Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.

[6] White, G. C. (1999). The Handbook of Chlorination and Alternative Disinfectants (4th ed.). Wiley. p. 322. ISBN 978-0-471-29207-4.

[7] "Health Hazard Evaluation Report: Investigation of Employee Symptoms at an Indoor Water Park" (PDF). NIOSH ENews. 6 (4). August 2008. HETA 2007-0163-3062.

[8] Thénard J. L.; Berthollet C. L. (1813). "Report on the work of Pierre Louis Dulong". Annales de Chimie et de Physique. 86 (6): 37–43.

[Thomas1991-9] Thomas, J.M. (1991). Michael Faraday and The Royal Institution: The Genius of Man and Place (PBK). CRC Press. p. 17. ISBN 978-0-7503-0145-9.

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