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

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

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

Chemical compound

1,1,2-Trichloro-1,2,2-trifluoroethane, also called trichlorotrifluoroethane (often abbreviated as TCTFE) or CFC-113, is a chlorofluorocarbon. It has the formula Cl2FC−CClF2. This colorless, volatile liquid is a versatile solvent.[5]

Quick Facts Names, Identifiers ...

Production

CFC-113 can be prepared from hexachloroethane and hydrofluoric acid:[6]

This reaction may require catalysts such as antimony, chromium, iron and alumina at high temperatures.[7]

Another synthesis method uses HF on tetrachloroethylene instead.[8]

Atmospheric reactions

CFC-113 measured by the Advanced Global Atmospheric Gases Experiment (AGAGE) in the lower atmosphere (troposphere) at stations around the world. Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion.
Atmospheric concentration of CFC-113 since year 1992.

CFC-113 is a very unreactive chlorofluorocarbon. It remains in the atmosphere about 90 years,[9] 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:[10][11]

CClF2CCl2F → C2F3Cl2 + Cl•
Cl• + O3 → ClO• + O2

This reaction is followed by:

ClO• + O → Cl• + O2

The process regenerates Cl• to destroy more O3. The Cl• will destroy an average of 100,000 O3 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 most heavily produced CFCs. In 1989, an estimated 250,000 tons were produced.[5] It has been used as a cleaning agent for electrical and electronic components.[12] CFC-113’s low flammability and low toxicity made it ideal for use as a cleaner for delicate electrical equipment, fabrics, and metals. It would not harm the product it was cleaning, ignite with a spark or react with other chemicals.[13] It was used as a dry-cleaning solvent, introduced by Du Pont in March 1961 as "Valclene"[14] and was also marketed as the "solvent of the future" by Imperial Chemical Industries in the 1970s under the tradename Arklone. Others from this series were Perklone (Tetrachloroethylene), Triklone (Trichloroethylene), Methoklone (Dichloromethane) and Genklene (1,1,1-Trichloroethane).[15][16]

CFC-113 is one of the three most popular CFCs, along with CFC-11 and CFC-12.[17]

CFC-113 in laboratory analytics has been replaced by other solvents.[18]

Reduction of CFC-113 with zinc gives chlorotrifluoroethylene:[5]

CFCl2−CClF2 + Zn → CClF=CF2 + ZnCl2

Dangers

Aside from its immense environmental impacts, Freon 113, like most chlorofluoroalkanes, forms phosgene gas when exposed to a naked flame.[19]

See also

References

  1. [1]
    NIOSH Pocket Guide to Chemical Hazards. "#0632". National Institute for Occupational Safety and Health (NIOSH).
  2. [2]
    Touloukian, Y.S., Liley, P.E., and Saxena, S.C. Thermophysical properties of matter - the TPRC data series. Volume 3. Thermal conductivity - nonmetallic liquids and gases. Data book. 1970.
  3. [3]
    "1,1,2-Trichloro-1,2,2-trifluoroethane". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  4. [4]
    Safety Data Sheet fishersci.com
  5. [5]
    Siegemund, Günter; Schwertfeger, Werner; Feiring, Andrew; Smart, Bruce; Behr, Fred; Vogel, Herward; McKusick, Blaine (2002). "Fluorine Compounds, Organic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a11_349. ISBN 978-3527306732.
  6. [6]
    Social and Economic Implications of Controlling the Use of Chlorofluorocarbons in the EEC pitt.edu
  7. [7]
    Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present., p. V11 507 (1994)
  8. [8]
    Robert D. Ashford: Ashford's Dictionary of Industrial Chemicals, p. 1131. 2nd Edition. Wavelength Publications, 2001
  9. [9]
    "Global Change 2: Climate Change". University of Michigan. January 4, 2006. Archived from the original on 2008-04-20. Retrieved 2008-05-28.
  10. [10]
    Molina, Mario J. (1996). "Role of chlorine in the stratospheric chemistry". Pure and Applied Chemistry. 68 (9): 1749–1756. doi:10.1351/pac199668091749. S2CID 22107229.
  11. [11]
    "Guides | SEDAC".
  12. [12]
    "Chlorofluorocarbons". Columbia Encyclopedia. 2008. Retrieved 2008-05-28.
  13. [13]
    "Guides | SEDAC". sedac.ciesin.columbia.edu.
  14. [14]
    Coin-Op 1961-04: Vol 2 Iss 4 P. 61
  15. [15]
    Industrial Finishing and Surface Coatings. (1973). UK: Wheatland journals, Limited.
  16. [16]
    Morrison, R. D., Murphy, B. L. (2013). Chlorinated Solvents: A Forensic Evaluation. Royal Society of Chemistry
  17. [17]
    Zumdahl, Steven (1995). Chemical Principles. Lexington: D. C. Heath. ISBN 978-0-669-39321-7.
  18. [18]
    "Use of Ozone Depleting Substances in Laboratories. TemaNord 516/2003" (PDF). Archived from the original (PDF) on 2008-02-27. Retrieved 2008-05-06.
  19. [19]
    "False Alarms: The Legacy of Phosgene Gas". HVAC School. Retrieved 9 May 2022.
Share this article:

This article uses material from the Wikipedia article 1,1,2-Trichloro-1,2,2-trifluoroethane, and is written by contributors. Text is available under a CC BY-SA 4.0 International License; additional terms may apply. Images, videos and audio are available under their respective licenses.