查看“︁卤代甲烷”︁的源代码

'''卤代甲烷'''化合物是[[甲烷]]（CH<sub>4</sub>）当中一个或多个[[氢]]被[[卤素]][[官能团|取代基]]（主要是[[氟]]（F）、[[氯]]（Cl）、[[溴]]（Br）、[[碘]]（I））所取代的化合物。卤代甲烷可以在海洋环境的自然界存在，也可以由人工制成，最受注意的是作为[[制冷剂]]、[[溶剂]]与及[[推进剂]]等。很多卤代甲烷由于曝露在高空的[[紫外光]]中会破坏保护地球的[[臭氧层]]而受到广泛注视。

==合成==
===工業合成===
各種鹵代甲烷可以通[[自由基取代反應]]合成。有能量(熱或紫外線)的輸入下，鹵素[[均裂]]成兩個[[自由基]]<ref>{{cite book|author = Robert Neuman |title=Organic Chemistry|chapter=Chapter 11 Free Radical Substitution and Addition Reactions}}</ref>。甲烷和自由基發生{{tsl|en|chain propagation|鏈增長}}，產生[[甲基自由基]](<chem>CH3.</chem>)。生成的<chem>CH3.</chem>不穩定，與鹵素生成鹵代甲烷。<br>
:<math> \mathrm{X}-\;\mathrm{X}\; \xrightarrow{UV/heat} \; {\mathrm{X} \cdot} + {\mathrm{X} \cdot}</math><br>
:<chem> CH4 +  X. -> CH3. +  H-X</chem><br>
:<chem> CH3. + X-X -> CH3X + X.</chem><br>
其中X表示鹵素<br>
此反應還可生成[[二卤甲烷|二鹵甲烷]]。<br>
:<chem> CH3X + X. -> CH2X. + H-X </chem> <br>
:<chem> CH2X. + X-X -> CH2X2 + X. </chem> <br>
[[三卤甲烷|三鹵甲烷]]及[[四卤甲烷|四鹵甲烷]]亦然。


===自然界合成===
[[陆生植物|陸生植物]]、[[真菌]]、[[光合微生物]]等可自行合成鹵代甲烷，<ref>{{cite journal|journal=Angewandte Chemie International Edition|volume=49|issue=21|language=en|date=2010-05-10|pages=3646–3648|doi=10.1002/anie.201000119|url=https://onlinelibrary.wiley.com/doi/10.1002/anie.201000119|title=Halomethane Biosynthesis: Structure of a SAM-Dependent Halide Methyltransferase from Arabidopsis thaliana|accessdate=2022-07-16|author=Jason W. Schmidberger, Agata B. James, Robert Edwards, James H. Naismith, David O'Hagan|pmid=20376845|pmc=3386781|archive-date=2022-07-16|archive-url=https://web.archive.org/web/20220716093643/https://onlinelibrary.wiley.com/doi/10.1002/anie.201000119|dead-url=no}}</ref>這些植物都擁有{{tsl|en|methyl halide transferase|卤代甲烷转移酶}}。
小部分熱帶植物可合成氯甲烷<ref>{{cite journal|journal=Geophysical Research Letters|volume=35|issue=19|language=en|issn=0094-8276|date=2008-10-07|doi=10.1029/2008GL035241|url=http://doi.wiley.com/10.1029/2008GL035241|title=Methyl chloride and isoprene emissions from tropical rain forest in Southeast Asia|accessdate=2022-07-16|author=Takuya Saito, Yoko Yokouchi, Yoshiko Kosugi, Makoto Tani, Elizabeth Philip, Toshinori Okuda}}</ref>，如藜木科植物有[[氯甲烷轉移酶]]。<ref> Nagatoshi Y, Y., Nakamura T. Plant Biotechnol. 2007;24:503–506.</ref>
==危害==
卤代甲烷大多含有毒性，其中[[氯甲烷]]和[[溴甲烷]]破壞[[臭氧層]]，而[[碘甲烷]]則影響[[氣膠]]和[[臭氧]]的生成。<ref>{{cite journal|journal=Current Biology|volume=13|issue=20|language=en|date=2003-10|pages=1809–1813|doi=10.1016/j.cub.2003.09.055|url=https://linkinghub.elsevier.com/retrieve/pii/S0960982203007395|title=Genetic Control of Methyl Halide Production in Arabidopsis|accessdate=2022-07-27|author=Robert C. Rhew, Lars Østergaard, Eric S. Saltzman, Martin F. Yanofsky|archive-date=2022-06-20|archive-url=https://web.archive.org/web/20220620130224/https://linkinghub.elsevier.com/retrieve/pii/S0960982203007395|dead-url=no}}</ref>
==用途==
鹵代甲烷可用作{{tsl|en|fumigant|熏蒸劑}}以驅蟲。此外，鹵代甲烷還是無數化學反應的[[前体|前體]]<ref>{{cite journal|journal=Journal of the American Chemical Society|volume=131|issue=18|language=en|issn=0002-7863|date=2009-05-13|pages=6508–6515|doi=10.1021/ja809461u|url=https://pubs.acs.org/doi/10.1021/ja809461u|title=Synthesis of Methyl Halides from Biomass Using Engineered Microbes|accessdate=2022-07-16|author=Travis S. Bayer, Daniel M. Widmaier, Karsten Temme, Ethan A. Mirsky, Daniel V. Santi, Christopher A. Voigt|archive-date=2022-07-16|archive-url=https://web.archive.org/web/20220716093643/https://pubs.acs.org/doi/10.1021/ja809461u|dead-url=no}}</ref>
== 參見 ==
*[[氯氟烃]]
*[[卤代烷]]
*[[卤化]]

== 外部链接 ==
*[http://www.mksinst.com/techinfo/GasConversionTable.aspx Gas conversion table] {{Wayback|url=http://www.mksinst.com/techinfo/GasConversionTable.aspx |date=20160702115202 }}
*[http://www.faqs.org/faqs/sci/chem-faq/part3/section-1.html Nomenclature FAQ] {{Wayback|url=http://www.faqs.org/faqs/sci/chem-faq/part3/section-1.html |date=20210211235216 }}
*[http://books.nap.edu/books/0309057825/html/63.html History of Halon use by the US Navy]{{Wayback|url=http://books.nap.edu/books/0309057825/html/63.html |date=20000819163823 }}
*[http://books.nap.edu/openbook.php?record_id=9042&page=5 Ozone Loss: The Chemical Culprits]{{Wayback|url=http://books.nap.edu/openbook.php?record_id=9042&page=5 |date=20110927183754 }}
==參考文獻==
{{reflist}}

{{stub|有机化合物}}
{{卤代甲烷}}

[[Category:气溶胶喷射剂]]
[[Category:杜邦]]
[[Category:温室气体]]
[[Category:卤代烃类溶剂]]
[[Category:卤代甲烷| ]]
[[Category:HVAC]]
[[Category:制冷剂]]
[[Category:灭火剂]]