Investigations of Ruthenium Charge-Transfer Complexes and Extended Materials

Abstract

The Creutz-Taube ion, synthesised in 1969 by Carol Creutz and Henry Taube, initiated decades of research into intramolecular electron transfer between dinuclear metal centres. In particular, significant efforts have been devoted to ruthenium and osmium dinuclear complexes with pyridyl and polypyridyl bridges. Such systems are significant by virtue of their easily accessible redox couples and high electron densities, resulting in pronounced charge transfer behaviour. The electronic properties of such complexes are not straightforward, owing to competing effects from π-donor and π-acceptor ligands. While these systems have been used to develop 1D polymers, 2D and 3D materials are relatively unexplored. A family of coordination complexes trans-[Ru(acac)2(X)2] (X = N-donor ligands) have been developed. These complexes have been used to produce coordination polymers with closely related behaviours. This work aims to elucidate electronic trends and relationships within this family of ruthenium complexes and coordination polymers by leveraging several analytical techniques, including electrochemistry, spectroscopy, crystallography, and density functional theory. By applying these analytical techniques to discrete, polymer and host-guest systems that incorporate similar Ru motifs, we can describe the competing effects inherent to these systems, demonstrate their similarities and differences, and identify trends that could lead to functionalised systems in the future.