Exploring uncharted regions of atmospheric reaction pathways*

Alkene ozonolysis is a primary oxidation pathway for alkenes, the most abundant organic compounds in the Earth’s troposphere after methane, and also an important source of atmospheric hydroxyl radicals (OH).  Alkene ozonolysis takes place through a complicated reaction pathway with multiple intermediates and barriers along the way to OH products.  A carbonyl oxide species, known as the Criegee intermediate (RR'COO), represents a critical branching point on the pathway that controls the products formed in this important class of reactions.  Recent studies have focused on characterizing Criegee intermediates utilizing infrared and ultraviolet spectroscopic methods, and examining their unimolecular and bimolecular reactions under laboratory and atmospheric conditions.