The design, synthesis and characterisation of a range of surfactant-based ligand architectures is presented. The amphiphilic ligands have been shown to form metallosurfactants with a wide range of s-, d- and f-block metals as well as being able to form stable micellar systems either through self-assembly or via doping into a carrier microemulsion. The overall aim of this work was to produce surfactant ligands capable of sequestering metal ions and localising them on the surface of micellar droplets within an oil-in-water microemulsion. Chapter Two investigates the formulation and characterisation of a 1-alkyl-3-methyl imidazolium based micellar system capable of forming stable microemulsions with extremely high oil loadings as well as acting as a carrier for more complex surfactants. This chapter also describes the synthesis and characterisation two novel macrocyclic ligand architectures designed to coordinate a range of s-, d- and f-block metals to form a series of metallosurfactants capable of aggregation in aqueous media. Chapter Three explores an array of acyclic surfactant ligands synthesised from ethylene diamine and diethylene triamine precursors and functionalised with poly-alcohol arms. These amphiphilic ligands were coordinated to Ni(II) and Cu(II) in order to gain insight into their coordination geometries via photophysical studies. Tensiometric investigations of the free ligands and their Sr(II) and Y(III) metallosurfactants assessed their microemulsion compatibility as alternatives to macrocyclic architectures. Chapter Four presents a series of cationic bis-cyclometallated Ir(IIII) complexes where the diimine ligand is a bipyridine species functionalised with a lipophilic alkyl chain and the cyclometallating ligands contain ethyl ester moieties which, upon deprotection, afford water soluble complexes. Combined tensiometric and photophysical studies found these species to be dual emissive as free complexes in solution, with emission arising from both ligand-centred and metal-to-ligand charge transfer mechanisms. Upon aggregation into micelles however, either a quenching of the ligand-centred emission or an enhancement of the metal-to-ligand charge transfer rendered the complexes mono-emissive. Chapter Five reports the synthesis and characterisation of three novel DO3A-based surfactant ligands incorporating pendent chromophores as antennae for near-IR sensitised emission from a range of Ln(II) ions. Luminescent lifetime studies determined that the ligands form 8-coordinate complexes with hydration states suggesting the presence of 0-1 inner sphere water molecules. Combined tensiometric and photophysical studies proved the metallosurfactants to be capable of self-assembly into micelles in aqueous media and found aggregation to have a notable effect on the local environment of the Ln(III) ions.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:732224 |
| Date | January 2017 |
| Creators | Stokes, Emily C. |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/106671/ |
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