氫氟烴

氫氟烴 (HFCs) 是一類由氟原子替代烷烴里的一部分氫原子而成。它們是最常見的有機氟化合物。在常溫常壓下，大多數的氫氟烴是氣體。它們可以用來作為冷凍劑。1,1,1,2-四氟乙烷是目前最常用的 HFC 冷凍劑，也可替代老牌的氯氟烴如：R-12和氫氟氯碳化物如：R-21。^[1] 雖然氫氟烴不會破壞臭氧層，不過它的全球暖化潛勢卻是二氧化碳的上千倍。^[2]

醫學用處

C–F 化學鍵較少的氫氟烴的行為與母體碳氫化合物相似，但它們的反應性可以顯著改變。例如，尿嘧啶和5-氟尿嘧啶都是無色的高熔點晶體固體，但是後者是有效的抗癌藥。C-F鍵在藥物中的使用取決於這種改變的反應性。^[3] 多種藥物和農藥僅包含一個氟中心或一個三氟甲基基團。

淘汰

與巴黎協定中的其他溫室氣體不同，氫氟碳化合物在其他國際正在談判中。^[4]

2016年9月，紐約森林宣言敦促全球減少氫氟烴的使用。^[5] 2016年10月15日，由於這些化學品對氣候變化的貢獻，來自197個國家的談判人員在盧安達基加利舉行的聯合國環境規劃署首腦會議上達成了具有法律約束力的協定在蒙特婁議定書的修正案中逐步淘汰氫氟烴（HFC）。^[6]^[7]^[8] 美國尚未批准《基加利協定》。^[9] 截至2020年2月，美國有16個州禁止或正在逐步淘汰HFC。^[10]

參考資料

^ Milman, Oliver. 100 countries push to phase out potentially disastrous greenhouse gas. The Guardian (London, UK). 22 September 2016 [22 September 2016]. （原始內容存檔於2019-04-21）.
^ US EPA, OAR. Understanding Global Warming Potentials. US EPA. 2016-01-12 [2019-09-06]. （原始內容存檔於2019-09-04）（英語）.
^ 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
^ Davenport, Carol. A Sequel to the Paris Climate Accord Takes Shape in Vienna. New York Times. 23 July 2016 [17 August 2016]. （原始內容存檔於2019-05-03）.
^ The New York Declaration of the Coalition to Secure an Ambitious HFC Amendment. Washington, DC: US Department of State. 22 September 2016 [22 September 2016]. （原始內容存檔於2020-05-09）.
^ Johnston, Chris; Milman, Oliver; Vidal, John. Climate change: global deal reached to limit use of hydrofluorocarbons. The Guardian. 15 October 2016 [15 October 2016]. （原始內容存檔於2019-04-28）.
^ Climate change: 'Monumental' deal to cut HFCs, fastest growing greenhouse gases. BBC News. 15 October 2016 [15 October 2016]. （原始內容存檔於2019-06-03）.
^ Nations, Fighting Powerful Refrigerant That Warms Planet, Reach Landmark Deal. New York Times. 15 October 2016 [15 October 2016]. （原始內容存檔於2019-06-13）.
^ Drew Kann, CNN Video by Lacey Russell and Alex King. Trump's rollback of climate change regulations will be felt far beyond his presidency. CNN. [2019-09-06]. （原始內容存檔於2019-09-06）.
^ Baker Administration Planning Rule To Ban Hydrofluorocarbons. [2020-06-21]. （原始內容存檔於2020-07-29）.

參見

[milman-2016-1] Milman, Oliver. 100 countries push to phase out potentially disastrous greenhouse gas. The Guardian (London, UK). 22 September 2016 [22 September 2016]. （原始內容存檔於2019-04-21）.

[2] US EPA, OAR. Understanding Global Warming Potentials. US EPA. 2016-01-12 [2019-09-06]. （原始內容存檔於2019-09-04）（英語）.

[Ullmann-3] 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

[4] Davenport, Carol. A Sequel to the Paris Climate Accord Takes Shape in Vienna. New York Times. 23 July 2016 [17 August 2016]. （原始內容存檔於2019-05-03）.

[ny-declaration-on-hfcs-2016-5] The New York Declaration of the Coalition to Secure an Ambitious HFC Amendment. Washington, DC: US Department of State. 22 September 2016 [22 September 2016]. （原始內容存檔於2020-05-09）.

[6] Johnston, Chris; Milman, Oliver; Vidal, John. Climate change: global deal reached to limit use of hydrofluorocarbons. The Guardian. 15 October 2016 [15 October 2016]. （原始內容存檔於2019-04-28）.

[7] Climate change: 'Monumental' deal to cut HFCs, fastest growing greenhouse gases. BBC News. 15 October 2016 [15 October 2016]. （原始內容存檔於2019-06-03）.

[8] Nations, Fighting Powerful Refrigerant That Warms Planet, Reach Landmark Deal. New York Times. 15 October 2016 [15 October 2016]. （原始內容存檔於2019-06-13）.

[9] Drew Kann, CNN Video by Lacey Russell and Alex King. Trump's rollback of climate change regulations will be felt far beyond his presidency. CNN. [2019-09-06]. （原始內容存檔於2019-09-06）.

[10] Baker Administration Planning Rule To Ban Hydrofluorocarbons. [2020-06-21]. （原始內容存檔於2020-07-29）.

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