5:30pm - 6:30pm
The Miller Room 328 Havemeyer
New York, NY 10027
Abstract: Alkene ozonolysis is a primary oxidation pathway for alkenes emitted into the troposphere and an important mechanism for generation of atmospheric OH radicals, particularly in low light conditions, urban environments, and heavily forested areas. Alkene ozonolysis proceeds through Criegee intermediates, R1R2COO, which eluded detection until very recently. The simplest Criegee intermediate, CH2OO, and methyl-substituted Criegee intermediates, CH3CHOO and (CH3)2COO, have now been generated by an alternative synthetic route and detected by VUV photoionization. UV excitation of the Criegee intermediates is found on a strong π*←π transition that induces dissociation. IR excitation of methyl-substituted Criegee intermediates in the CH stretch overtone and combination band region initiates unimolecular decay. The latter enables direct examination of the hydrogen transfer reaction leading to OH products, which is a key non-photolytic source of OH radicals in the atmosphere.
Pizza will be provided!
Tuesday, February 21, 2017 at 5:30pm
Room 328 Havemeyer (Miller Seminar Room)
Department of Chemistry, Columbia University, Havemeyer Hall, 3000 Broadway, New York, NY 10027, USA | 212-854-2202 | http://chem.columbia.edu/