A STUDY OF VIBRATIONAL SELECTIVITY OF ELECTRONIC AUTOIONIZATION PROCESSES IN N2O USING 2-DIMENSIONAL PHOTOELECTRON-SPECTROSCOPY

Two-dimensional photoelectron spectroscopy has been used to investigat e vibrational selectivity accompanying electronic autoionizing decays of Rydberg states between the X (2) Pi and A (2) Sigma(+) ionization t hresholds in N2O. Measurements of electron yield as a function of both electron and photon energy have been carried out using tuneable synch rotron radiation. This study, which is the most comprehensive to date, has enabled the vast majority of the accessible vibrational levels of the X (2) Pi ion to be investigated. The experimental resolution was good enough to observe individual vibrational levels and complex vibra tional selectivity was evident throughout the two-dimensional spectrum . A significant number of the features in the spectrum could be ascrib ed to vibrational progressions in the symmetric stretch mode.