Kinetic studies of the reactions of O2(b1Σg+) with several atmospheric molecules

Thermal rate coefficients for the removal (reaction + quenching) of O-2((1)Sigma(+)(g)) by collision with several atmospheric molecules were determined to be as follows: O-3, k(3)(210-370 K) = (3.63 +/- 0.86) x 10(-11) exp((-115 +/- 66)/T); H2O, k(4)(250-370 K) = (4.52 +/- 2.14) x 10(-12) exp((89 +/- 210)/T); N-2, k(5)(210-370 K) = (2.03 +/- 0.30) x 10(-15) exp((37 +/- 40)IT); CO2, k(6)(298 K) = (3.39 +/- 0.36) x 10(-11); CH4, k(7)(298 K) = (1.08 +/- 0.11) x 10(-13); CO, k(8)(298 K) = (3.74 +/- 0.87) x 10(-15); all units in cm(3) molecule(-1) s(-1). O-2((1)Sigma(+)(g)) was produced by directly exciting ground-state O-2((3)Sigma(-)(g)) with a 762 nm pulsed dye laser. The reaction of O-2((1)Sigma(+)(g)) with O-3 was used to produce O(P-3), and temporal profiles of O((3)p) were measured using VUV atomic resonance fluorescence in the presence of the reactant to determine the rate coefficients for removal of O-2((1)Sigma(+)(g)). Our results are compared with previous values, where available, and the overall trend in the O-2((1)Sigma(+)(g)) removal rate coefficients and the atmospheric implications of these rate coefficients are discussed. Additionally, an upper limit for the branching ratio of O-2((1)Sigma(+)(g)) + CO to give O(P-3) + CO, was determined to be <= 0.2 % and this reaction channel is shown to be of negligible importance in the atmosphere.