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

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 . This colorless, volatile liquid is a versatile solvent.

Production

CFC-113 can be prepared from hexachloroethane and hydrofluoric acid:^[1]

C2Cl6 + 3HF -> CF2Cl-CFCl2 + 3HCl This reaction may require catalysts such as antimony, chromium, iron and alumina at high temperatures.^[2]

Another synthesis method uses HF on tetrachloroethylene instead.^[3]

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 (UV, sunlight in the 190-225 nm range), generating chlorine radicals (Cl•), which initiate degradation of ozone requiring only a few minutes:^{[5] [6]}

This reaction is followed by:

The process regenerates Cl• to destroy more . The Cl• will destroy an average of 100,000 molecules during its atmospheric lifetime of 1–2 years.

Uses

CFC-113 was one of the most heavily produced CFCs. In 1989, an estimated 250,000 tons were produced. It has been used as a cleaning agent for electrical and electronic components.^[7] 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.^[8] It was used as a dry-cleaning solvent, introduced by Du Pont in March 1961 as "Valclene"^[9] 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).^{[10] [11]}

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

CFC-113 in laboratory analytics has been replaced by other solvents.^[13]

Reduction of CFC-113 with zinc gives chlorotrifluoroethylene:

Dangers

Aside from its immense environmental impacts, Freon 113, like most chlorofluoroalkanes, forms phosgene gas when exposed to a naked flame.^[14]

See also

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

Notes and References

1. http://aei.pitt.edu/38825/1/A3821.pdf Social and Economic Implications of Controlling the Use of Chlorofluorocarbons in the EEC
2. Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present., p. V11 507 (1994)
3. Robert D. Ashford: Ashford's Dictionary of Industrial Chemicals, p. 1131. 2nd Edition. Wavelength Publications, 2001
4. Web site: Global Change 2: Climate Change . . January 4, 2006 . 2008-05-28 . https://web.archive.org/web/20080420150554/http://www.globalchange.umich.edu/globalchange2/current/lectures/climate_change/the_science.htm . 2008-04-20 . dead .
5. Molina, Mario J. . Role of chlorine in the stratospheric chemistry . Pure and Applied Chemistry . 68 . 9 . 1749–1756 . 1996 . 10.1351/pac199668091749. 22107229 . free .
6. Web site: Guides | SEDAC.
7. Encyclopedia: 2008 . Chlorofluorocarbons . . 2008-05-28 .
8. Web site: Guides | SEDAC. sedac.ciesin.columbia.edu.
9. Coin-Op 1961-04: Vol 2 Iss 4 P. 61
10. Industrial Finishing and Surface Coatings. (1973). UK: Wheatland journals, Limited.
11. Morrison, R. D., Murphy, B. L. (2013). Chlorinated Solvents: A Forensic Evaluation. Royal Society of Chemistry
12. Book: Zumdahl, Steven . Chemical Principles . . . 1995 . 978-0-669-39321-7 . registration .
13. Web site: Use of Ozone Depleting Substances in Laboratories. TemaNord 516/2003 . 2008-05-06 . https://web.archive.org/web/20080227052412/http://www.norden.org/pub/ebook/2003-516.pdf . 2008-02-27 . dead .
14. Web site: False Alarms: The Legacy of Phosgene Gas . HVAC School . 9 May 2022.