Hydrofluorocarbon

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Hydrofluorocarbons (HFCs) are organic compounds that contain fluorine and hydrogen atoms, and are the most common type of organofluorine compounds. They are frequently used in air conditioning and as refrigerants in place of the older chlorofluorocarbons such as R-12 and hydrochlorofluorocarbons such as R-21.[1] They do not harm the ozone layer as much as the compounds they replace, but they do contribute to global warming. Their atmospheric concentrations and contribution to anthropogenic greenhouse gas emissions are rapidly increasing, causing international concern about their radiative forcing.

Fluorocarbons with few C–F bonds behave similarly to the parent hydrocarbons, but their reactivity can be altered significantly. For example, both uracil and 5-fluorouracil are colourless, high-melting crystalline solids, but the latter is a potent anti-cancer drug. The use of the C-F bond in pharmaceuticals is predicated on this altered reactivity.[2] Several drugs and agrochemicals contain only one fluorine center or one trifluoromethyl group.

Unlike other greenhouse gases in the Paris Agreement, hydrofluorocarbons have other international negotiations.[3]

In September 2016, the New York Declaration on Forests urged a global reduction in the use of HFCs.[4] On 15 October 2016, due to these chemicals' contribution to climate change, negotiators from 197 nations meeting at the summit of the United Nations Environment Programme in Kigali, Rwanda reached a legally-binding accord to phase out hydrofluorocarbons (HFCs) in an amendment to the Montreal Protocol.[5][6][7]

References[edit]

  1. ^ Milman, Oliver (22 September 2016). "100 countries push to phase out potentially disastrous greenhouse gas". The Guardian. London, UK. Retrieved 22 September 2016. 
  2. ^ G. Siegemund, W. Schwertfeger, A. Feiring, B. Smart, F. Behr, H. Vogel, B. McKusick "Fluorine Compounds, Organic" in "Ullmann's Encyclopedia of Industrial Chemistry" 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a11_349
  3. ^ Davenport, Carol (23 July 2016). "A Sequel to the Paris Climate Accord Takes Shape in Vienna". New York Times. Retrieved 17 August 2016. 
  4. ^ "The New York Declaration of the Coalition to Secure an Ambitious HFC Amendment". Washington, DC: US Department of State. 22 September 2016. Retrieved 22 September 2016. 
  5. ^ Johnston, Chris; Milman, Oliver; Vidal, John (15 October 2016). "Climate change: global deal reached to limit use of hydrofluorocarbons". The Guardian. Retrieved 15 October 2016. 
  6. ^ "Climate change: 'Monumental' deal to cut HFCs, fastest growing greenhouse gases". BBC News. 15 October 2016. Retrieved 15 October 2016. 
  7. ^ "Nations, Fighting Powerful Refrigerant That Warms Planet, Reach Landmark Deal". New York Times. 15 October 2016. Retrieved 15 October 2016.