Reaction dynamics of H+O2 at 1.6 eV collision energy

The hot H atom reaction, H+O2→OH+O, has been studied at a center-of-mass collision energy of 1.6 eV. H atoms were generated by 266 nm photolysis of HI in a mixture of HI and O2 at 293 K. The OH product was probed by laser-induced fluorescence and the nascent OH vibrational, rotational, and fine structure distributions were determined. The OH (ν=0)/OH (ν=1) vibrational branching ratio was measured to be 1.72±0.09. Our data suggest that the H+O2 reaction at this collision energy proceeds via two competing mechanisms: reaction involving a long-lived complex and direct reaction.