A Criegee intermediate (also called a Criegee zwitterion or Criegee biradical) is a carbonyl oxide with two charge centers. These molecules help to break down sulfur dioxide and nitrogen dioxide in the atmosphere, and may help offset global warming.
The formation of this sort of structure was first postulated in the 1950s by Rudolf Criegee, for whom it is named, but it wasn't until 2013 that direct detection of such chemicals was reported. Infrared spectroscopy suggests the electronic structure is a zwitterion rather than a biradical as some had proposed.
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- Castro, Joseph (January 12, 2012). "How mysterious molecules may help cool Earth". MSNBC. Retrieved 2012-01-12.
- "Offsetting Global Warming: Molecule in Earth's Atmosphere Could 'Cool the Planet'". Science Daily. January 12, 2012. Retrieved 2012-01-14.
- Su, Yu-Te; Huang, Yu-Hsuan; Henryk A., Witek; Lee, Yuan-Pern (12 April 2013). "Infrared Absorption Spectrum of the Simplest Criegee Intermediate CH2OO". Science. 340 (6129): 174–176. Bibcode:2013Sci...340..174S. doi:10.1126/science.1234369.