Ithaca College

Dr. Shizuka Hsieh presents: Making radicals from vibrationally-excited organic hydroperoxides.

Abstract: The OH radical is an active and important oxidant in the atmosphere, often called the vacuum cleaner of the troposphere. An unusual source of these OH radicals is visible-light photodissociation via highly vibrationally-excited molecules. We investigate the vibrational states of organic hydroperoxides, CH3OOH and CH3CH2OOH, that are secondary pollutants formed from hydrocarbon emissions. A combination of laser photoacoustic spectroscopy and quantum mechanical calculations indicates that excitation involves both O-H stretch and torsional motion about the peroxide O-O bond. Laser-induced fluorescence reveals which of these vibrationally-excited states preferentially dissociate to form OH radicals.

Dr. Hsieh is a Associate Professor of Chemistry and the Assistant Provost for Sciences at Trinity Washington University. She earned her PhD in Physical Chemistry from the University of Oxford.

Come join us in 333 Center for Natural Sciences at 4:00 PM this Thursday, March 3rd. Pizza and soda will be served!