Zur Beziehung zwischen dem Reaktionsverhalten und der elektronischen Struktur von Zweikernverbindungen der späten 3d-Metalle

01/07/2019 to 30/06/2022

This research project aims at studying the relation between the electronic structure and the chemical properties of coordination compounds of nickel and iron from a novel type of adaptive dithiolate ligands. The chemical bond between sulphur and a late transition metal features a variety of intriguing properties, one of which is a comparatively high covalent character. A higher covalent character is beneficial for electronic coupling of metal sites across metal-sulphur linkages, which explains the properties and function of a variety of metal-sulfur structures in Nature. Different from natural structures, the electronic coupling between metal sites in synthetic structures typically is very strong and its variation is essentially not possible. To overcome this limitation, this research project addresses parameters that allow for varying the strength of electronic coupling in bimetallic metal-sulphur structures in a systematic fashion. Preliminary work on bimetallic structures of nickel showed that attenuating electronic coupling strength provides suitable means to increase the performance of these compounds in oxidative hydrogen splitting. The same bimetallic compounds of nickel also provided high-fidelity models for quantitative studies of the mechanism of (dis)assembly of sulfur bridged bimetallic structures that feature so prominently in Nature. All precedent and future work of this research project relies on the properties of a novel type of ligand framework, which combines the adaptive and dynamic coordination properties of aromatic π-systems and thiophenol groups. This has allowed these ligands to bind a single and multiple metal atoms and adopt flexibly to changes in metal oxidation states, which renders these compounds clearly suitable for the quantitative mechanistic work that is the objective of this research project. On the long run, this research project aims for developing reactive 3d-metal structures that catalyze the interconversion of electrical and chemical bond energies in an efficient manner.