Multiresonant Spectroscopy and Dynamics of Molecular Extravalent States: State-Resolved Intramolecular Relaxation of NO2 Above 9 eV

摘要

Multiresonant methods are described for the optical selection of individual vibrational states at energies near and above the first ionization threshold of NO2. These techniques are applied to resolve distinct Rydberg series converging to respective vertical ionization potentials by optical absorption from assigned vibration-rotation levels of the low-living sharp 3rho sigma2 state. Spectra of levels lying between adiabatic and vertical thresholds show evidence for vibrational autoionization. This process is found to be comparatively slow (T>30ps) for all levels but those for which autoionization via a delta v = -1 transition in the symmetric stretch, 1, is accessible. Such rates are fastest for levels just above this nv = -1 threshold, exhibiting characteristic Fano lineshapes as broad as 11/cm. (MJM)