Knowledge Bank

A sequential optical double resonance technique with sensitive LIF-detection has been employed for the assignment and the investigation of single states of $NO2$ in the energy range between 17000 and $25000cm-1$. Assignments for selected states and information about perturbations, "good quantum numbers", and IVR could be obtained from the double resonance spectra in the frequency domain. Subsequently, we were able to measure state-to-state rotational and vibrational energy transfer in $NO2-NO2$ and $NO2$-Ar collisions, and the competition between bimolecular reaction and collisional energy transfer using a time resolved double resonance technique. From these data we obtained direct information about propensity rules and intermolecular interactions for collisional energy transfer of $NO2$ at high vibrational excitation