Vibrational relaxation of OH by oxygen atoms

The collisional removal of OH(v = 1) by O(3P) atoms is investigated. OH is generated by 193 nm photolysis of H2O2, and O(3P) atoms are generated by a microwave discharge in O2 diluted in Ar. OH(v = 0 and 1) concentrations are monitored by laser-induced fluorescence vs. the time after the photolysis laser pulse. From comparison of these concentrations with kinetic simulations, the room-temperature total removal rate constant for OH(v = 1) in collisions with O(3P) is determined to be (3.9 ± 0.6) × 10−11 cm3 molecule−1 s−1. This value is slightly larger than the OH(v = 0)–O(3P) reaction rate constant, but the difference is within the experimental uncertainty.