Re(I), Ir(III) and Au(I) luminescent complexes for imaging, sensing and therapy

This thesis further developed several fluorescent ligand systems and their coordination to transition metals. Their synthesis and coordination chemistry to Re(I), Ir(III)or Au(I) is described, with detailed discussions on the photophysical properties and their potential towards imaging, sensing and therapeutic applications. In Chapters 2–3, N–substituted–1,8–naphthalimide fluorophores were synthesised and their coordination to Re(I) was investigated. Chapter 2 describes a series of fac– [Re(CO)3(N^N)(LX)]BF4 complexes, axially substituted with naphthalimide fluorophores. Chapter 3 builds on work in Chapter 2 by investigating dipicolylamine–appended naphthalimide ligands and corresponding fac–[Re(CO)3(L)]BF4 complexes. The core investigations of both chapters centre on the photophysical properties where subtle changes of the substituents were observed to have profound effects on both the photophysical and physical properties. The feasibility of these compounds as cellular imaging agents, and also for photodynamic therapy in Chapter 2, was assessed. Chapter 4 expands Au(I)! coordination chemistry of alkynyl–derived 1,8–naphthalimide fluorophores. Seven new fluorophores, together with their Au(I) phosphine complexes, are described. These compounds were evaluated for imaging capabilities, via the fluorescent ligand and the inherent toxicity from the Au(I) core was assessed. Selected examples showed outstanding characteristics as potentialoptical/therapeutic agents. Chapter 5 involved the further conjugated anthracene–1,9–dicarboximide core, possessing an additional ringcompared to naphthalimide species in Chapters 2–4. The synthesis and characterisation of two novel anthracene based fluorophores, together with their Re(I) complexes, is described. These new compounds were again assessed as cellular probes and the results gave insight into the possible localisation of structurally related anticancer drugs. Chapter 6 describes the synthesis of three novel cyclometalated Ir(III) complexes of the general form [Ir(C^N)2(N^N)]BF4, where N^N represents a novel, fluorescent! phenylimidazo–phenanthroline ligand, capable of binding to NO. All precursors, ligands and complexes were extensively characterised and the response to NO was determined. The complexes in particular show great promise as effective NO probes