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

► A new method for measuring the deactivation rate constants of O2(a1Δ) in gas phase. ► It suits fairly high O2(a1Δ) concentration without measuring its absolute value. ► Its operation is very simple and accurate owing to high signal/noise ratio. ► The deactivation rates of O2(a1Δ) by gaseous D2O is for the first time measured.