For selected examples of diatomic molecules chemisorbed on transition and noble metals [ N 2 on Ru(001) and Ni(111), CO on Ru(001) and Cu(111)], we survey core-induced bond breaking by N1s and O1s excitation. We demonstrate that supplementary information on the primarily excited electronic states and on the mechanism of bond dissociation is supplied by ions, neutral molecules and atoms, and decay electrons emitted upon electronic evolution. By comparing yields of neutrals and ions, and their translational energies as a function of excitation energy for the different systems, we discriminate between molecular and surface-induced aspects of bond dissociation. In particular we analyze the potential of the substrate–adsorbate interaction to enhance atom selectivity in core-excitation-induced bond breaking.
