Pyridazine-derived systems-from novel complexes to functional molecular switches

Abstract

Chapter 1: The chapter begins with a general introduction to tetrazine-derived ligands, alongside the photophysical properties of metal complexes, particularly Ir III, Rh III and Re I species. The coordination chemistry of a series of tetra-aryl pyridazine ligands is then described. The ligands, first synthesised by Dr.Gareth Cooke, were exploited in the synthesis of novel [Ir(ppy)2(L)][PF6], [Rh(ppy)2(L)][PF6], [Re(CO)3(L)Cl] and [RhCp*(L)][PF6] complexes. Each was characterised to an extremely high degree using NMR techniques, complemented by X-ray crystallography. The [Ir(ppy)2(L)][PF6], [Rh(ppy)2(L)][PF6] and [Re(CO)3(L)Cl] complexes proved to be phosphorescent, and their emission properties are described and compared with prominent examples from the literature. Electrochemical studies were also carried out, with evidence for an interesting ECE’ mechanism being observed for the [RhCp*(L)][PF6] systems.