State-to-state rotational energy transfer in OH (χ2Πi) by N2 and Ar

Abstract

Rotational energy transfer in ground state OH has been studied by using a pump-probe method. A tunable infrared laser prepares OH in a specific N, J, e/f state in v = 2 in a discharge flow, and a time-delayed ultraviolet laser measures the population of that level or others populated by collisional RET by using LIF. For neither heavy collider is there conservation of total parity, a propensity seen in He collisions.1 For both Ar and N2, the rate of transfer between spin-orbit components is similar to that within each component, and the rate falls exponentially with increasing rotational energy of the final state.