Vibrational relaxation of OH(X 2Πi, v=1–3) by O2

Rate constants for OH(X 2Πi, v=1–3) vibrational relaxation induced by nonreactive collision with O2 have been measured. OH(v) is created by the H+O3 →OH(v≤9)+O2 reaction in an electron-irradiated O3, H2, Ar mixture. OH(v) fundamental and first overtone IR emission is observed using time-resolved Fourier spectroscopy. Spectral fitting followed by kinetic fitting of the resultant populations using a single-quantum relaxation model yields rate constants of kv=1 =(1.3±0.4)×10−13, kv=2=(2.1±0.3)×10−13, kv=3=(2.9±0.8) ×10−13 (all units are in cm3 /s). Our measurements are consistent with and extend published results on the same system, as well as predictions made by Schwartz–Slawsky–Herzfeld theory.