Collisional vibrational energy transfer of OH (A 2Σ+, v′=1)

Vibrational energy transfer (VET) and quenching of the v′=1 level of A 2Σ+ OH have been studied using laser-induced fluorescence in a discharge flow cell at room temperature. VET cross sections (Å2) are N2, 30.1±2.8; O2, 2.8±0.3; Ar, 0.56±0.05; H2O, 8.6±0.6. The rotational energy distribution in v′=0 following the VET event was determined for nine colliders. It is nonthermal, generally populating high rotational levels. There are three broad categories of colliders that cause varying degrees of vibrational to rotational energy transfer; H2, D2, and CH4 show the least; N2, CO2, CF4, and N2O more; and O2 and Ar the most, with about one-third of the vibrational energy appearing as OH rotation.