Photon stimulated ion desorption of condensed acetonitrile molecules induced by core excitation

Abstract

Photon stimulated ion desorption (PSID) of condensed acetonitrile molecules induced by carbon and nitrogen core excitation has been examined to elucidate the Auger process following resonant core excitation and the ion desorption mechanism related to this Auger process using total electron yield, total ion yield, resonant Auger electron spectra. Resonant Auger electron spectra show a strong dependence on the character of excitation. In particular, these Auger spectra are drastically changed between the carbon 1s to theπ * CN excitation and that of the C H * excitation. The spectrum of the total ion yield divided by the total electron yield shows that the desorption efficiency is largely increased at the resonant excitation of carbon 1s electron in the CH 3 group to C H * orbital. The results of the resonant Auger spectra and the Auger electron-photoion coincidence (AEPICO) measurements at various resonant excitations are discussed in relation to the bonding/anti-bonding character and localized character of the excited state and the Auger final state.