O2(b1Σg +) Quenching by O2, CO2, H2O, and N2 at Temperatures of 300–800 K

Rate constants for the removal of O2(b1Σg +) by collisions with O2, N2, CO2, and H2O have been determined over the temperature range from 297 to 800 K. O2(b1Σg +) was excited by pulses from a tunable dye laser, and the deactivation kinetics were followed by observing the temporal behavior of the b1Σg +–X3Σg – fluorescence. The removal rate constants for CO2, N2, and H2O were not strongly dependent on temperature and could be represented by the expressions k CO2 = (1.18 ± 0.05) × 10–17 × T 1.5 × exp ( 595 ± 25 T ) , k N2 = (8 ± 0.3) × 10–20 × T 1.5 × exp ( 503 ± 21 T ) , and k H2O = (1.27 ± 0.08) × 10–16 × T 1.5 × exp ( 675 ± 27 T ) cm3 molecule–1 s–1. Rate constants for O2(b1Σg +) removal by O2(X), being orders of magnitude lower, demonstrated a sharp increase with temperature, represented by the fitted expression k O2 = (7.4 ± 0.8) × 10–17 × T 0.5 × exp ( − 1104.7 ± 53.3 T ) cm3 molecule–1 s–1. All of the rate constants measured at room temperature were found to be in good agreement with previously reported values.