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词条 1,1,2-Trichloro-1,2,2-trifluoroethane
释义

  1. Atmospheric reactions

  2. Uses

  3. See also

  4. References

{{chembox
| Watchedfields = changed
| verifiedrevid = 477201671
| ImageFileL1=1,1,2-Trichloro-1,2,2-trifluoroethane skeletal.svg
| ImageFileR1=1,1,2-Trichloro-1,2,2-trifluoroethane 3D.png
| IUPACName=1,1,2-Trichloro-1,2,2-trifluoroethane
| OtherNames=CFC-113
Freon 113
Frigen 113 TR
Freon TF
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 6188
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 0739N04X3A
| InChI = 1/C2Cl3F3/c3-1(4,6)2(5,7)8
| InChIKey = AJDIZQLSFPQPEY-UHFFFAOYAE
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 478511
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C2Cl3F3/c3-1(4,6)2(5,7)8
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = AJDIZQLSFPQPEY-UHFFFAOYSA-N
| CASNo=76-13-1
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem=6428
| SMILES = ClC(F)(F)C(Cl)(Cl)F
}}
|Section2={{Chembox Properties
| Formula=C{{sub|2}}Cl{{sub|3}}F{{sub|3}}
| MolarMass=187.376
| Appearance=Colorless to water-white liquid[1]
| Odor = like carbon tetrachloride[1]
| Density=1.56 g/mL
| MeltingPtC=-35
| BoilingPtC=47.7
| Solubility=170mg/L
| VaporPressure = 285 mmHg (20°C)[1]
|Section3={{Chembox Hazards
| MainHazards=
| FlashPt=
| AutoignitionPt =
| PEL = TWA 1000 ppm (7600 mg/m{{sup|3}})[1]
| IDLH = 2000 ppm[1]
| REL = TWA 1000 ppm (7600 mg/m{{sup|3}}) ST 1250 ppm (9500 mg/m{{sup|3}})[1]
| LCLo = 250,000 ppm (mouse, 1.5 hr)
87,000 (rat, 6 hr)[2]
}}

Trichlorotrifluoroethane, also called 1,1,2-Trichloro-1,2,2-trifluoroethane or CFC-113 is a chlorofluorocarbon. It has the formula Cl{{sub|2}}FC-CClF{{sub|2}}. This colorless, volatile liquid is a versatile solvent. It has attracted much attention for its role in the depletion of stratospheric ozone.[3] The amount of CFC-113 in the atmosphere has remained at about 80 parts per trillion, since the early 1990s. It is isomeric with 1,1,1-Trichloro-2,2,2-trifluoroethane, known as CFC-113a, which has the structural formula CF{{sub|3}}-CCl{{sub|3}}. The Montreal Protocol in 1987 called for the phase out of all CFCs, including CFC-113, by 2010.

Atmospheric reactions

CFC-113 is a very unreactive chlorofluorocarbon. It remains in the atmosphere about 90 years,[4] sufficiently long that it will cycle out of the troposphere and into the stratosphere. In the stratosphere, CFC-113 can be broken up by ultraviolet radiation (where sunlight in the 190-225 nm (UV) range), generating chlorine radicals (Cl•), which initiate degradation of ozone requiring only a few minutes:[5][6]

C{{sub|2}}F{{sub|3}}Cl{{sub|3}} → C{{sub|2}}F{{sub|3}}Cl{{sub|2}} + Cl•

Cl• + O{{sub|3}} → ClO• + O{{sub|2}}

This will occur in only half a second. It is followed by:

ClO• + O → Cl• + O{{sub|2}}

The process regenerates Cl• to destroy more O{{sub|3}}. The Cl• thus is a catalyst, which destroy an average of 100,000 O{{sub|3}} molecules during its atmospheric lifetime of 1–2 years. In some parts of the world, these reactions have significantly thinned the Earth's natural stratospheric ozone layer that shields the biosphere against solar UV radiation; increased UV levels at the surface can cause skin cancer or even blindness.[12]

Uses

CFC-113 was one of the many CFCs that were produced to eliminate toxic and flammable substances in the areas that they were used. It has been used as a cooling agent in refrigerants and air conditioners, aerosol propellant, and a cleansing agent for electrical and electronic components.[7] CFC-113 is one of the three most popular CFCs, along with CFC-11 and CFC-12 and saw much use in its time. CFC-113 is a refrigerant used in cooling systems. When it is in a gas form and compressed, it heats up, when it is expanded, it cools.[8]

CFC-113 also is a very volatile and apolar molecule so it was used as a foaming agent in the production of packaging material, insulation, foams for cushioning, and things like shoe soles.

CFC-113 has such a low flammability and low toxicity that it was also used as a cleaner for delicate electrical equipment, fabrics, and even metals. It would not harm the product it was cleaning, ignite with a spark or react with other chemicals. 

CFC-113 in laboratory analytics has been replaced by other solvents.[9]

See also

  • 1,1,1-Trichloro-2,2,2-trifluoroethane

References

1. ^{{PGCH|0632}}
2. ^{{IDLH|76131|1,1,2-Trichloro-1,2,2-trifluoroethane}}
3. ^Günter Siegemund, Werner Schwertfeger, Andrew Feiring, Bruce Smart, Fred Behr, Herward Vogel, Blaine McKusick “Fluorine Compounds, Organic” Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. {{DOI|10.1002/14356007.a11_349}}
4. ^{{cite web |url=http://www.globalchange.umich.edu/globalchange2/current/lectures/climate_change/the_science.htm |title=Global Change 2: Climate Change |publisher=University of Michigan |date=January 4, 2006 |accessdate=2008-05-28 |archive-url=https://web.archive.org/web/20080420150554/http://www.globalchange.umich.edu/globalchange2/current/lectures/climate_change/the_science.htm |archive-date=2008-04-20 |dead-url=yes |df= }}
5. ^{{cite journal | author = Molina, Mario J. | title = Role of chlorine in the stratospheric chemistry | journal = Pure and Applied Chemistry | volume = 68 | issue = 9 | pages = 1749–1756 | year = 1996 | doi=10.1351/pac199668091749}}
6. ^{{Cite web | url=http://www.ciesin.org/TG?OZ/prodcfcs.html | title=Guides | SEDAC}}
7. ^{{cite encyclopedia | year = 2008 | title = Chlorofluorocarbons | encyclopedia = Columbia Encyclopedia | url = http://www.encyclopedia.com/doc/1E1-chlorofl.html | accessdate = 2008-05-28 }}
8. ^{{cite book | last = Zumdahl | first = Steven | title = Chemical Principles | publisher = D. C. Heath | location = Lexington | year = 1995 | isbn = 978-0-669-39321-7 }}
9. ^{{Cite web |url=http://www.norden.org/pub/ebook/2003-516.pdf |title=Use of Ozone Depleting Substances in Laboratories. TemaNord 516/2003 |access-date=2008-05-06 |archive-url=https://web.archive.org/web/20080227052412/http://www.norden.org/pub/ebook/2003-516.pdf |archive-date=2008-02-27 |dead-url=yes |df= }}
{{Fluorine compounds}}{{DEFAULTSORT:Trichloro-1, 2, 2-Trifluoroethane, 1, 1, 2-}}

4 : Organofluorides|Chlorofluorocarbons|Greenhouse gases|Refrigerants

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