An experimental and computational study of the unimolecular-decay reaction of diethyl-substituted Criegee intermediate (CH)COO.

We have performed direct kinetic measurements to determine the thermal unimolecular-decay rate coefficient of (CH)COO as a function of temperature (223-296 K) and pressure (4-100 torr) using time-resolved UV-absorption spectroscopy. The stabilised (CH)COO Criegee intermediate was produced by photolysing 3-bromo-3-iodopentane ((CH)CIBr) with 213 nm radiation in the presence of O. We performed quantum-chemistry calculations and master-equation simulations to complement the experimental work.