OD + CO → D + CO 2 branching kinetics probed with time-resolved frequency comb spectroscopy

Abstract Time-resolved direct frequency comb spectroscopy was used to study the kinetics of the OD + CO → D + CO 2 reaction, which is important for atmospheric and combustion chemistry. Complementing our recent work on quantifying the formation rate of the trans -DOCO radical, we report measurements of the kinetics of the chemically activated product channel, D + CO 2 , at room temperature. Simultaneous measurements of the time-dependence of OD and CO 2 concentrations directly yield the products’ formation rate and its dependence on pressure and bath gas. Together with the trans -DOCO formation rate, these new measurements provide absolute yields of branching channels for both products of OD + CO in the low-pressure limit.