Criegee intermediate

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Criegee zwitterion

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.[1][2]

The formation of this sort of structure was first postulated in the 1950s by Rudolf Criegee,[3] 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.[4]

See also[edit]


  1. ^ Welz, Oliver; Savee, John D.; Osborn, David L.; Vasu, Subith S.; Percival, Carl J.; Shallcross, Dudley E.; Taatjes, Craig A. (13 January 2012). "Direct Kinetic Measurements of Criegee Intermediate (CH2OO) Formed by Reaction of C2I with O2". Science. 335 (6065): 204–207. Bibcode:2012Sci...335..204W. doi:10.1126/science.1213229. 
  2. ^ Castro, Joseph (January 12, 2012). "How mysterious molecules may help cool Earth". MSNBC. Retrieved 2012-01-12. 
  3. ^ "Offsetting Global Warming: Molecule in Earth's Atmosphere Could 'Cool the Planet'". Science Daily. January 12, 2012. Retrieved 2012-01-14. 
  4. ^ 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.