查看“︁七氧化二氯”︁的源代码

{{Chembox
| ImageFile =  Dichlorine-heptoxide-3D-balls.png
| ImageSize = 
| IUPACName = 七氧化二氯
| OtherNames = 氧化氯(VII)<br />高氯酸酐
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 109884
| InChI = 1/Cl2O7/c3-1(4,5)9-2(6,7)8
| InChIKey = SCDFUIZLRPEIIH-UHFFFAOYAG
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/Cl2O7/c3-1(4,5)9-2(6,7)8
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = SCDFUIZLRPEIIH-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 10294-48-1
| PubChem = 123272
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 52356
| SMILES = O=Cl(=O)(=O)OCl(=O)(=O)=O
  }}
|Section2 = {{Chembox Properties
|   Formula = Cl<sub>2</sub>O<sub>7</sub>
|   MolarMass = 182.901
|   Appearance = 无色油状液体
|   Density = 1.9 g/cm<sup>3</sup>
|   MeltingPt = −91.5 °C
|   BoilingPt = 82 °C
|   Solubility = 
  }}
| Section3 = {{Chembox Hazards
|   MainHazards = 氧化性
|   FlashPt = 
|   Autoignition = 
  }}
}}

'''七氧化二氯'''是一种[[氯]]的[[氧化物]]，化学式为Cl<sub>2</sub>O<sub>7</sub>，是[[高氯酸]]的[[酸酐]]。可由高氯酸与[[五氧化二磷]]反应製得。<ref name=Holl>Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.</ref>
:<chem>2HClO4 + P4O10 -> Cl2O7 + H2P4O11</chem>

它也可以由氯气和[[臭氧]]反应而成。<ref>{{Cite journal| first1 = A. C.| title = The Formation of Chlorine Heptoxide on Illumination of Mixtures of Chlorine and Ozone| first2 = G. K.| last1 = Byrns| journal = Journal of the American Chemical Society| volume = 56| issue = 5| pages = 1250–1251| year = 1934| doi = 10.1021/ja01320a506| last2 = Rollefson}}</ref>七氧化二氯会慢慢[[水解]]成[[高氯酸]], 不在水溶液里的高氯酸也是很危险的。

==结构==
Cl<sub>2</sub>O<sub>7</sub>是吸热化合物，意味着它本质上不稳定，会分解为其组成元素，并释放能量：<ref>{{Cite journal|last=Martin|first=Jan M. L|date=2006-10-12|title=Heats of formation of perchloric acid, HClO<sub>4</sub>, and perchloric anhydride, Cl<sub>2</sub>O<sub>7</sub>. Probing the limits of W1 and W2 theory|journal=Journal of Molecular Structure: THEOCHEM|series=Modelling Structure and Reactivity: the 7th triennial conference of the World Association of Theoritical and Computational Chemists (WATOC 2005)|volume=771|issue=1|pages=19–26|doi=10.1016/j.theochem.2006.03.035|issn=0166-1280|arxiv=physics/0508076}}</ref>

:<chem>2Cl2O7 -> 2Cl2 + 7O2</chem> <math>\left( \Delta H^\circ = -132 \mathrm{kcal}/\mathrm{mol} \right)</math>

Cl<sub>2</sub>O<sub>7</sub>的Cl&minus;O&minus;Cl键角为 118.6°，中间Cl&minus;O键的键长为1.709&nbsp;Å，Cl=O键长则为1.405&nbsp;Å。<ref name=Holl/>七氧化二氯中的氯达到了最高的[[氧化态]]+7，但它其实是共价化合物。

==反应==
七氧化二氯在[[四氯化碳]]里和一级/二级[[胺]]反应，产生高氯酰胺：<ref>{{Cite journal| first1 = C. D.| first2 = K.| title = Reactions of dichlorine heptoxide with amines| last1 = Beard| journal = Journal of the American Chemical Society| volume = 96| issue = 10| pages = 3237–3239| year = 1974| doi = 10.1021/ja00817a034| last2 =  Baum}}</ref>

:<chem>2RNH2 + Cl2O7 -> 2RNHClO3 + H2O</chem>
:<chem>2R2NH + Cl2O7 -> 2R2NClO3 + H2O</chem>

它还与[[烯烃]]反应，生成高氯酸烷基酯。举个例子，它会和[[丙烯]]四氯化碳溶液反应，生成高氯酰异丙基和1-氯-2-丙基高氯酸酯。<ref>{{Cite journal| first1 = K. .| title = Reactions of dichlorine heptoxide with olefins| journal = The Journal of Organic Chemistry| last1 = Baum| volume = 41| issue = 9| pages = 1663–1665| year = 1976| doi = 10.1021/jo00871a048}}</ref>

七氧化二氯和[[醇]]的反应会生成高氯酸酯。<ref>{{cite journal|journal=Journal of the American Chemical Society|volume=96|issue=10|language=en|issn=0002-7863|date=1974-05|pages=3233–3237|doi=10.1021/ja00817a033|url=https://pubs.acs.org/doi/abs/10.1021/ja00817a033|title=Reactions of dichlorine heptoxide with alcohols|accessdate=2022-02-02|author=Kurt Baum, Charles D. Beard|archive-date=2022-04-25|archive-url=https://web.archive.org/web/20220425201608/https://pubs.acs.org/doi/abs/10.1021/ja00817a033}}</ref>

七氧化二氯是一种强酸性氧化物，在溶液中与高氯酸形成平衡。

==安全性==
虽然Cl<sub>2</sub>O<sub>7</sub>是最稳定的氯的氧化物，但它仍是强氧化剂，可通过火焰、机械冲击、与[[碘]]接触而引爆。<ref>{{cite book
| title = Lewis' dictionary of toxicology
| first1 = Robert Alan
| last1 = Lewis
| publisher = CRC Press
| year = 1998
| isbn = 1-56670-223-2
| page = [https://archive.org/details/lewisdictionaryo0000lewi/page/260 260]
| url-access = registration
| url = https://archive.org/details/lewisdictionaryo0000lewi/page/260
}}</ref>不过，它的氧化性不如其它氯的氧化物强，并且在低温时不会侵蚀[[硫]]、[[磷]]、[[纸]]。<ref name="Holl" />它对人体的影响与[[氯气]]相似，需要与它相同的预防措施。<ref>{{cite encyclopedia
| editor = Jeanne Mager Stellman
| title = Halogens and their compounds
| encyclopedia = Encyclopaedia of occupational health and safety
| edition = 4th
| isbn = 92-2-109817-6
| year = 1998
| publisher = International Labour Organization
| page = [https://archive.org/details/encyclopaediaofo0003unse/page/104 104.210]
| url = https://archive.org/details/encyclopaediaofo0003unse/page/104
}}</ref>

== 参考文献 ==
<references/>
{{无机氯化合物}}
{{氧化物}}
[[Category:氯的氧化物]]
[[Category:七价氯化合物]]
[[Category:酸性氧化物]]