Structures and Aggregation Behavior of Ion Pair Catalysts

This thesis delves into the complex aggregation behavior in ion pairs catalysis, aiming to elevate our understanding to a new level. On the one hand, ion pair aggregation driven by purely electrostatic interactions is investigated using pyridinamide ion pair catalysts. Here, diffusion-ordered spectroscopy (DOSY) NMR measurements are conducted and combined with conductivity and nucleophilicity studies from a collaboration. This joint investigation seeks to elucidate the underlying aggregation behavior, which is responsible for the remarkable reactivity observed within this catalyst class. On the other hand, aggregation trends of a combination of electrostatic and intermolecular interactions are investigated thoroughly for the CPA-catalyzed transfer hydrogenation of imines. Here, the primary focus lies on the study of late reaction intermediates as well as higher aggregates of both the binary and the ternary complex of CPAs. Therefore, special 1D and 2D multinuclear NMR experiments were used as central tool to identify such new species. These studies should elevate our understanding of ion pair aggregation in catalysis and change our view on the significance of potential side-species.