A quasi-static method for measuring the deactivation rate constants of O2(a1Δg) in gas phase by IR radiation decay

Abstract A quasi-static method is developed for measuring the deactivation rate constants of O 2 (a 1 Δ g ) in gas phase by monitoring its IR radiation decay via a flow-stop technique. This method has taken into account the energy-pooling reaction of O 2 (a 1 Δ) and thus suits fairly high O 2 (a 1 Δ) concentration without identifying its absolute value, leading to simpler operation and higher signal/noise ratio. Utilizing this method, the O 2 (a 1 Δ) deactivation rate by D 2 O is for the first time measured to be 2.10 ± 0.18 × 10 −18  cm 3  s −1 , while those for O 2 ( X 3 Σ g - ), H 2 O, H 2 and D 2 are found to agree well with the data in literature.