Chemists have identified a cascade of reactions for how mysterious molecules known as Criegee intermediates generate hydroxyl radicals – an oxidant that helps remove pollutants from the lower atmosphere.
“We’ve solved another piece of the puzzle in the formation of hydroxyl radicals, by zooming in to see all the steps of the reaction in much finer detail than ever before,” says co-author Joel Bowman, a theoretical chemist at Emory. “This kind of detailed data is important to atmospheric chemists trying to make predictive models for how the atmosphere will respond to climate change.”
The Bowman group collaborated with the lab of experimental chemist Marsha Lester at the University of Pennsylvania.
The theoretical work revealed that a Criegee intermediate first produces highly energized vinyl hydroperoxide, or VHP, then rapidly decomposes to hydroxyl radicals, along with vinoxy byproducts.