Internal energy of photofragments studied by dispersed fluorescence spectroscopy

Abstract

Abstract The fluorescence emission following inner-shell excitation of molecules has been analyzed in the wavelength region 300 nm≤ λ fluo ≤1000 nm. The main contributions to the experimental spectrum are due to transitions of the parent molecules ionized in the outer valence shells as well as to the radiative decay of excited photofragments, mainly neutral and singly charged atoms. As an example, the dispersed fluorescence spectra of N 2 O after photoexcitation and photoionization of the nitrogen 1s electron are presented. For the molecular ion the vibrational resolved spectrum of the N 2 O + A 2 Σ→X 2 Π transitions has been observed. Upon resonant excitation to the (N 1s −1 π*) and (N 1s −1 σ*) states strong emission lines are found which have been attributed to transitions of nitrogen and oxygen atoms produced mainly in the 3p, 3d, 4d and 4f excited state of the neutral and of the singly charged ion. The relative intensities of these atomic transitions vary strongly with the character of the resonance and contain information about the intermediate dissociative molecular states produced after electronic relaxation.