VIBRATIONAL-RELAXATION OF NO(NU=2,3) BY ATOMIC OXYGEN

A two-laser, pump-probe arrangement has been used to measure room-temp erature rate constants for the collision-induced relaxation of NO(nu = 2, 3) by O atoms. The rate constants k(O)(nu) are equal to (2.2 +/- 0 .2) x 10(-11) and (2.5 +/- 0.3) x 10(-11) cm(3) s(-1) for nu = 2 and 3 , respectively. These values are significantly lower than previously m easured values for nu = 1, but are in accord with model predictions as suming the role of a metastable NO2 intermediate. The NO self-relaxat ion rate constants k(NO)(nu) have been measured to be (3.2 +/- 0.3) x 10(-12) and (4.0 +/- 0.4) x 10(-12) cm(3) s(-1) for nu = 2 and 3, resp ectively, in reasonable agreement with published results.