Kinetic studies of the deactivation of O 2 ( 1 Σ g + ) and O( 1 D)

Abstract

The kinetics of the deactivation of O 2 ( 1 Σ g + ) is studied in real time. O 2 ( 1 Σ g + ) is generated in this system by the O( 1 D) + O 2 reaction following O 3 laser flash photolysis in the presence of excess O 2 , and it is monitored by its characteristic emission band at 762 nm. Quenching rate constants were obtained for O 2 , O 3 , N 2 , CO 2 , H 2 O, CF 4 and the rare gases. Since O( 1 D) is the precursor for the formation of O 2 ( 1 Σ g + ), the addition of an O( 1 D) quencher effectively lowers the initial concentration of O 2 ( 1 Σ g + ). By measuring the initial intensity of the 762 nm fluorescence signal, the relative quenching efficiencies were determined for O( 1 D) quenching by N 2 , CO 2 , Xe, and Kr with respect to O 2 ; the results are in good agreement with literature values.