RÖNTGEN- UND PHOTOELEKTRONENSPEKTROSKOPISCHE UNTERSUCHUNGEN VON CHEMISCHEN VERBINDUNGEN

Abstract

The molecular structure is correlated to chemical shifts of N1s and S2p binding energies and the intensity distribution curves of S KB emission bands in various organic compounds and ligands in complexes mainly with transition metals. Conjugative effects are shown to influence the N1s binding energies in compounds containing amino groups, and the charge distribution in neutral and mesoionic N-heterocycles and betaines. The correlation between chemical bond and S KB intensity distribution in compounds containing thioether (-S-) and thione (>C=S) functions is reviewed and some new examples of S3p delocalisation due to sulfur lone pair -Π interaction with aromatic systems are reported. The coordination in neutral bis- and tris-complexes of 1,3-dichalcogen and aza-isosteric systems with numerous metal ions is characterized by means of the measured low-energy shift of the N1s binding energy due to deprotonation of the ligand and a positive shift of the S2p binding energy due to sulfur-metal donor bond. An additional structure on the high-energy side and a broadening of the S KB band confirm the interaction between the sulfur lone pair and the metal d electrons.