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Revision as of 12:45, 30 November 2010 editBeetstra (talk | contribs)Edit filter managers, Administrators172,031 edits Script assisted update of identifiers from ChemSpider, CommonChemistry and FDA for the Chem/Drugbox validation project - Updated: {{cascite}} StdInChI StdInChIKey.← Previous edit		Latest revision as of 00:24, 4 October 2023 edit undoMadeOfAtoms (talk | contribs)Extended confirmed users2,653 edits Redirect to Monochloramine (since it is often called "chloramine") instead of to Chloramines.Tag: Redirect target changed
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	{{expert-subject|Chemicals|date=January 2010}}
			{{Rcatshell|
	{{chembox
			{{R with history}}
	| verifiedrevid = 329009156
	| Name = Chloramine
	| ImageFile = Chloramine-2D.png
	| ImageSize = 140px
	| ImageName = Chloramine
	| ImageFile1 = Chloramine-3D-vdW.png
	| ImageSize1 = 140px
	| ImageName1 = Chloramine
	| OtherNames = Monochloramine<br />Chloramide<br />Chloroazane
	| Section1 = {{Chembox Identifiers
	| PubChem = 25423
	| InChI = 1/ClH2N/c1-2/h2H2
	| SMILES = ClN
	| InChIKey = QDHHCQZDFGDHMP-UHFFFAOYAS
	| StdInChI = 1S/ClH2N/c1-2/h2H2
	| StdInChIKey = QDHHCQZDFGDHMP-UHFFFAOYSA-N
	| CASNo = 10599-90-3
	| CASNo_Ref = {{cascite|correct|CAS}}
	| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
	| ChemSpiderID = 23735
	}}
	| Section2 = {{Chembox Properties
	| Formula = NH<sub>2</sub>Cl
	| MolarMass = 51.48 g/mol
	| Appearance = colorless
	| Solvent = other solvents
	| SolubleOther = Soluble
	| MeltingPt = −66 °C
	| BoilingPt =
	}}
	| Section8 = {{Chembox Related
	| OtherCpds = ]<br/>]}}
	}}		}}
	'''Chloramine''' (monochloramine) is an ] with the ] NH<sub>2</sub>Cl. It is a colourless liquid at room temperature, but it is usually handled as a dilute solution where it is used as a ]. The term chloramine also refers to a family of ]s with the formulas R<sub>2</sub>NCl and RNCl<sub>2</sub> (R is an organic group). ], NHCl<sub>2</sub>, and ], NCl<sub>3</sub>, are also well known.
	==Synthesis and chemical reactions==
	NH<sub>2</sub>Cl is a highly unstable compound in concentrated form. Pure NH<sub>2</sub>Cl decomposes violently above &minus;40 °C.<ref>Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.</ref> NH<sub>2</sub>Cl is, however, quite stable in dilute solution, and this considerable stability is the basis of its applications.
	NH<sub>2</sub>Cl is prepared by the ] between ] and ]<ref name=ref29>Fair, G. M., J. C. Morris, S. L. Chang, I. Weil, and R. P. Burden. 1948. The behavior of chlorine as a water disinfectant. J. Am. Water Works Assoc. 40:1051-1061.</ref> under mildly alkaline conditions:
	:NH<sub>3</sub> + HOCl &rarr; NH<sub>2</sub>Cl + H<sub>2</sub>O
	The synthesis is conducted in dilute solution. In this reaction HOCl undergoes attack by the ] NH<sub>3</sub>. At a lower pH, further chlorination occurs.
	===Laboratory methods===
	The above syntheses are useful but do not deliver NH<sub>2</sub>Cl in pure form. For research purposes, the pure compound can be prepared by contacting ] with ]:
	:NH<sub>2</sub>F + CaCl<sub>2</sub> &rarr; NH<sub>2</sub>Cl + CaClF
	==Uses and chemical reactions==
	NH<sub>2</sub>Cl is a key intermediate in the traditional synthesis of ].
	Monochloramine oxidizes sulfhydryls and disulfides in the same manner as HClO,<ref name=ref46>Jacangelo, J. G., V. P. Olivieri, and K. Kawata. 1987. Oxidation of sulfhydryl groups by monochloramine. Water Res. 21:1339-1344.</ref> but only possesses 0.4% of the biocidal effect of HClO.<ref name=ref64>Morris, J. C. 1966. Future of chlorination. J. Am. Water Works Assoc. 58:1475-1482.</ref>
	==Reduction of organic chloramines==
	Chloramines are often an unwanted side product of oxidation reactions of organic compounds (with amino groups) with ]. The reduction of chloramines back into amines can be carried out through a mild hydride donor. ] will reduce chloramines, but this reaction is greatly sped up with acid catalysis.
	==Uses in water treatment==
	NH<sub>2</sub>Cl is commonly used in low ]s as a secondary ] in ]s as an alternative to free chlorine ]. This application is increasing. ] (sometimes referred to as '''free chlorine''') is being displaced by chloramine, which is much more stable and does not dissipate from the ] before it reaches consumers. NH<sub>2</sub>Cl also has a very much lower, however still present, tendency than free chlorine to convert organic materials into ]s such as ] and ]. Such compounds have been identified as ]s and in 1979 the ] began regulating their levels in U.S. drinking water. Furthermore, water treated with chloramine lacks the distinct chlorine odour of the gaseous treatment and so has improved taste. In swimming pools, chloramines are formed by the reaction of free chlorine with organic substances. Chloramines, compared to free chlorine, are both less effective as a sanitizer and more irritating to the eyes of swimmers. When swimmers complain of eye irritation from "too much chlorine" in a pool, the problem is typically a high level of chloramines.{{fact|date=April 2009}} Pool test kits designed for use by homeowners are sensitive to both free chlorine and chloramines, which can be misleading.{{fact|date=April 2009}}
	] Chloramine-treated water has a greenish cast, the source of the colour is uncertain. Pure water by contrast normally is bluish. This greenish color may be observed by filling a white polyethylene bucket with chloraminated tap water and comparing it to chloramine-free water such as distilled water or a sample from a swimming pool.
	===Health risks===
	Adding chloramine to the water supply can increase exposure to lead in drinking water, especially in areas with older housing; this exposure can result in increased lead levels in the bloodstream and can pose a significant health risk.<ref></ref>
	There is also evidence that exposure to chloramine can contribute to respiratory problems, including ], among ].<ref></ref> Respiratory problems related to chloramine exposure are common and prevalent among competitive swimmers.<ref></ref>
	Chloramine use, together with ], ], and ], has been described as a public health concern and an example of the outcome of poorly implemented environmental regulation. These methods of disinfection decrease the formation of regulated byproducts, which has led to their widespread use. However, they can increase the formation of a number of unregulated cytotoxic and genotoxic byproducts, some of which pose greater health risks than the regulated chemicals,<ref></ref> causing such diseases as cancer, kidney disease, thyroid damage,<ref></ref>and birth defects.<ref></ref>.
	===Removing chloramine from water===
	Chloramine can be removed from tap water by treatment with superchlorination (10 ppm or more of free chlorine, such as from a dose of sodium hypochlorite bleach or pool sanitizer) while maintaining a pH of about 7 (such as from a dose of hydrochloric acid). Hypochlorous acid from the free chlorine strips the ammonia from the chloramine, and the ammonia outgasses from the surface of the bulk water. This process takes about 24 hours for normal tap water concentrations of a few ppm of chloramine. Residual free chlorine can then be removed by exposure to bright sunlight for about 4 hours.
	==Situations where NH<sub>2</sub>Cl is removed from water supplies==
	Many animals are sensitive to chloramine and it must be removed from water given to many animals in zoos. ] owners remove the chloramine from their ] because it is ] to ]. Aging the ] for a few days removes ] but not the more stable chloramine, which can be neutralised using products available at pet stores.
	Chloramine must also be removed from the water prior to use in ] machines, as it would come in contact with the bloodstream across a permeable membrane. However, since chloramine is neutralized by the digestive process, kidney dialysis patients can still safely drink chloramine-treated water.
	] use reducing agents such as ] or ] to remove chloramine from brewing liquor as it, like ], it can be removed by boiling, however boil time to reduce chloramine to a terminal measurement is longer<ref></ref>. Residual sodium can cause off flavors in beer (See Brewing, Michael Lewis) so potassium metabisulfite is preferred.
	Chloramine can be removed from bathwater and birthing tubs by adding 1000 mg of vitamin C (as the ascorbic acid form) to a medium size bathtub (about 40 gallons of water).<ref></ref>
	==Organic chloramines==
	A variety of organic chloramines are known and proven useful in ]. One example is ''N''-chloromorpholine ClN(CH<sub>2</sub>CH<sub>2</sub>)<sub>2</sub>O, ''N''-chloro], and ''N''-chloro] chloride.<ref>Lindsay Smith, J. R.; McKeer, L. C.; Taylor, J. M. "4-Chlorination of Electron-Rich Benzenoid Compounds: 2,4-Dichloromethoxybenzene" Organic Syntheses, CollectedVolume 8, p.167 (1993)..http://www.orgsyn.org/orgsyn/pdfs/CV8P0167.pdf describes several N-chloramines</ref>
	==Safety==
	NH<sub>2</sub>Cl is toxic in concentrated form.<ref></ref> US EPA regulations limit chloramine concentration to 4 ] (ppm). A typical target level in US public water supplies is 3 ppm. In order to meet EPA regulated limits on halogenated ], many utilities are switching from chlorination to chloramination. While chloramination produces fewer total halogenated ], it produces greater concentrations of unregulated iodinated ] and ].<ref>Occurrence of a New Generation of Disinfection Byproducts† Stuart W. Krasner,,, Howard S. Weinberg,, Susan D. Richardson,, Salvador J. Pastor,, Russell Chinn,, Michael J. Sclimenti,, Gretchen D. Onstad, and, Alfred D. Thruston, Jr. Environmental Science & Technology 2006 40 (23), 7175-7185 http://dx.doi.org/10.1021/es060353j </ref><ref>{{cite pmid|17980649}}</ref>. Both iodinated ] and ] have been shown to be genotoxic.<ref>{{cite pmid|17980649}}</ref>
	==References==
	{{reflist}}
	==External links==
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