Vibrational relaxation of NO(ν = 2, 3) by atomic oxygen

A two-laser, pump-probe arrangement has been used to measure room-temperature rate constants for the collision-induced relaxation of NO(ν = 2, 3) by O atoms. The rate constants kO(ν) are equal to (2.2 ± 0.2) × 10−11 and (2.5 ± 0.3) × 10−11 cm3 s−1 for ν = 2 and 3, respectively. These values are significantly lower than previously measured values for ν = 1, but are in accord with model predictions assuming the role of a metastable NO2∗ intermediate. The NO self-relaxation rate constants kNO(ν) have been measured to be (3.2 ± 0.3) × 10−12 and (4.0 ± 0.4) × 10−12 cm3 s−1 for ν = 2 and 3, respectively, in reasonable agreement with published results.