Chloramines

{{Short description|Class of chemical compounds}} '''Chloramines''' refer to derivatives of ammonia and organic amines wherein one or more N−H bonds have been replaced by N−Cl bonds.<ref name="Berliner 1931">{{cite journal |last1=Berliner |first1=J. F. T. |title=The Chemistry of Chloramines |journal=American Water Works Association |date=1931 |volume=23 |issue=9 |pages=1320−1333 |doi=10.1002/j.1551-8833.1931.tb17955.x |jstor=41228138 |archive-date=2 October 2025 |archive-url=https://ia600601.us.archive.org/32/items/the-chemistry-of-chloramines-1931/THE_CHEMISTRY_OF_CHLORAMINES_%281931%29.pdf |url=https://www.jstor.org/stable/41228138 |access-date=4 October 2023|url-access=subscription }}</ref><ref name="Kovavic 1970">{{cite journal |last1=Kovacic |first1=Peter |last2=Lowery |first2=Michael K. |last3=Field |first3=Kurt W. |title=Chemistry of N-bromamines and N-chloramines |journal=Chemical Reviews |date=1970 |volume=70 |issue=6 |pages=639−665 |doi=10.1021/cr60268a002 |url=https://pubs.acs.org/doi/pdf/10.1021/cr60268a002 |access-date=4 October 2023|url-access=subscription }}</ref> Two classes of compounds are considered: inorganic chloramines and organic chloramines. Chloramines are the most widely used members of the '''halamines'''.<ref>{{cite journal |doi=10.1021/acs.chemrev.6b00687 |title=Chemical Insights into Antibacterial ''N'' -Halamines |date=2017 |last1=Dong |first1=Alideertu |last2=Wang |first2=Yan-Jie |last3=Gao |first3=Yangyang |last4=Gao |first4=Tianyi |last5=Gao |first5=Ge |journal=Chemical Reviews |volume=117 |issue=6 |pages=4806–4862 |pmid=28252944 }}</ref>

==Inorganic chloramines== Inorganic chloramines comprise three compounds: monochloramine (NH₂Cl), dichloramine (NHCl₂), and nitrogen trichloride (NCl₃). Monochloramine is of broad significance as a disinfectant for water.<ref>{{cite book|last1=Lawrence|first1=Stephen A.|title=Amines: Synthesis, Properties and Applications|date=2004|publisher=Cambridge University Press|isbn=9780521782845|page=172|url=https://books.google.com/books?id=35xwBwjhe2MC&pg=PA172|language=en}}</ref>

Inorganic chloramines are produced by the reaction of ammonia and hypochlorous acid or chlorine. An urban legend claims that mixing household bleach (aqueous sodium hypochlorite) with ammonia-based cleaners releases chlorine gas or mustard gas; in reality, the gas produced by the reaction is a mixture of inorganic chloramines.

==Organic chloramines== [[image:N-chloropiperidine.png|thumb|144px|''N''-Chloropiperidine is a rare example of an organic chloramine.<ref>{{OrgSynth | first1= George P.|last1= Claxton |first2=Lloyd|last2= Allen|first3= J. Martin |last3=Grisar | title = 2,3,4,5-Tetrahydropyridine Trimer| volume = 56 | pages = 118| year = 1977| doi= 10.15227/orgsyn.056.0118}}</ref>]] [[image:Chloramine T.svg|thumb|144px|Chloramine-T is often referred to as a chloramine, but it is really a salt (CH₃C₆H₄SO₂NClNa) derived from a chloramine.<ref name=CR>{{cite journal|doi=10.1021/cr60311a005|title=Chloramine T and Related N-halogeno-N-metallo Reagents|journal=Chemical Reviews|volume=78|pages=65–79|year=1978|last1=Campbell|first1=Malcolm M.|last2=Johnson|first2=Graham.}}</ref>]]

Organic chloramines feature the NCl functional group attached to an organic substituent. The simplest organic chloramine is ''N''-chloromethylamine, {{chem2|CH3NHCl}};<ref>{{cite journal|doi=10.1016/j.watres.2016.11.065 |title=Formation and reactivity of inorganic and organic chloramines and bromamines during oxidative water treatment |date=2017 |last1=Heeb |first1=Michèle B. |last2=Kristiana |first2=Ina |last3=Trogolo |first3=Daniela |last4=Arey |first4=J. Samuel |last5=von Gunten |first5=Urs |journal=Water Research |volume=110 |pages=91–101 |pmid=27998787 }}</ref> notable examples include ''N''-chloromorpholine (ClN(CH₂CH₂)₂O), ''N''-chloropiperidine, and ''N''-chloroquinuclidinium chloride.<ref>{{OrgSynth|last1=Lindsay Smith |first1=J. R. |last2=McKeer |first2=L. C. |last3=Taylor |first3=J. M. |title=4-Chlorination of Electron-Rich Benzenoid Compounds: 2,4-Dichloromethoxybenzene |date=1989 |volume=67 |page=222 |doi=10.15227/orgsyn.067.0222}}</ref>

Chloramines are commonly produced by the action of sodium hypochlorite on secondary amines: :R₂NH + NaOCl → R₂NCl + NaOH ''Tert''-butyl hypochlorite can be used instead of bleach:<ref>{{cite journal|title=Osmium-catalyzed Vicinal Oxyamination of Olefins by N-chloro-N-Argentocarbamates: Ethyl ''Threo''-[1-(2-hydroxy-1,2-diphenylethyl)]carbamate|first1=Eugenio|last1=Herranz|first2=K. Barry|last2=Sharpless|journal=Org. Synth.|year=1983|volume=61|page=93|doi =10.15227/orgsyn.061.0093}}</ref> :R₂NH + ''t''-BuOCl → R₂NCl + ''t''-BuOH

Very few chloramines are stable, and they easily decompose. In acid, they homolyze in the Hofmann–Löffler reaction; in base, they eliminate to the corresponding imines.

==Swimming pools== Chloramines are formed by reaction of chlorine used to disinfect swimming pools with ammonia and urea introduced into the pools by human perspiration, saliva, mucus, urine, and other biologic substances, and by insects and other pests.<ref>{{cite web|title=Controlling Chloramines in Indoor Swimming Pools|url=http://www.health.nsw.gov.au/environment/factsheets/Pages/chloramines.aspx|work=NSW Government Health|accessdate=20 February 2013|date=3 December 2012}}</ref> Chloramines, especially trichloramine, are responsible for most of the "chlorine smell" of pools,<ref>{{cite web |date=July 2006 |title=Chloramines: Understanding "Pool Smell" |url=https://chlorine.americanchemistry.com/Science-Center/Chlorine-Compound-of-the-Month-Library/Chloramines-Understanding-Pool-Smell/ |website=American Chemistry Council |url-status=dead |archive-url=https://web.archive.org/web/20191217170314/https://chlorine.americanchemistry.com/Science-Center/Chlorine-Compound-of-the-Month-Library/Chloramines-Understanding-Pool-Smell/ |archive-date=17 December 2019 |access-date=17 December 2019}}</ref> as well as for skin, eye, and respiratory irritation.<ref name="Bessonneau 2011">{{cite journal | last1=Bessonneau | first1=Vincent | last2=Derbez | first2=Mickaël | last3=Clément | first3=Michel | last4=Thomas | first4=Olivier | title=Determinants of chlorination by-products in indoor swimming pools | journal=International Journal of Hygiene and Environmental Health | year=2011 | volume=215 | issue=1 | pages=76–85 | issn=1438-4639 | doi=10.1016/j.ijheh.2011.07.009 | pmid=21862402 }}</ref>

==References== {{Reflist|2}}

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Category:Nitrogen–halogen compounds Category:Swimming pools