Photochemical processes after primary core excitations of condensed H2O and NH3, and of N2 and CO chemisorbed on different substrates have been investigated by means of special developed detectors and synchrotron radiation. In this study it was possible for the first time to measure the desorption of neutral particles with a highly sensitive apparatus and under high photon energy resolution. As charge transfer processes can take place in strongly coupled systems very efficiently, neutral dissociation products constitute the majority for chemisorbates. For the chemisorbed system N2/Ru(001) atom-selective bond breaking was found at the neutral [1h]1e-LUMO-resonance depending on the site of the primary excitation in the diatomic molecule. Further data of N2 and CO on Ni(111), Cu(111), and Ru(001) clearly show that this site selectivity is strongly influenced by surface effects. Compared with free molecules in the gas phase, primary dissociative core-excited states of both, chemisorbed and condensed molecules can lead to significantly different excitation decay processes and photochemical reactions.    «

Photochemical processes after primary core excitations of condensed H2O and NH3, and of N2 and CO chemisorbed on different substrates have been investigated by means of special developed detectors and synchrotron radiation. In this study it was possible for the first time to measure the desorption of neutral particles with a highly sensitive apparatus and under high photon energy resolution. As charge transfer processes can take place in strongly coupled systems very efficiently, neutral dissoci...    »