Product channels of the reactions of O2(b1[formula omitted

Abstract

Laser-induced fluorescence (LIF) experiments have been employed to evaluate the branching fractions for the product channels for O2(b1Σg+) reactions with M = CO2, N2, H2, C2H4, N2O, H2O CH4 and I2 molecules. O2(b1Σg+) was formed by exciting ground-state oxygen molecules with pulses from a tunable dye laser, and the kinetics were followed by observing the temporal profiles of the O2 b1Σg+ − X3Σg-, O2a1Δg − X3Σg-, and I2 A′3Π2u, A3Π1u − X1Σg+ fluorescence signals. It has been found that O2(b1Σg+) is quenched to O2(a1Δg) with a branching fraction 1.00 ± 0.05 for all tested molecules except iodine. The reaction of O2(b1Σg+) with I2 has been found to have two dominant product channels, O2(X3Σg-) + I2(A′3Π2u or A3Π1u) and O2(X3Σg-) + 2 I(2P3/2) with branching fractions of 33 ± 7% and 67 ± 7%, respectively. Emission from I2(A′3Π2u or A3Π1u) molecules formed in recombination of iodine atoms in the gas phase was detected in the near IR.