From mono- to poly-nuclear late-transition metal catalysts for the polymerisation of ethylene

In Chapter One, an introduction to the field of metal-mediated olefin polymerisation catalysis is undertaken. The area of non-metallocene monometallic systems and, in particular, imino-based chelated (NN-, NNN-) late transition metal systems is briefly documented with a view to introducing the emerging field of olefin polymerisation mediated by multi-component catalysts Concurrent Tandem Catalysis (CTC) and Encapsulated Bimetallic (EB). The Chapter concludes with a description of the objectives set for the thesis. Chapters Two to Five discuss the synthesis and characterisation of mono- and bi metallic complexes (cobalt, iron and nickel) containing mono- and bi-nucleating ligands that incorporate bi- and tri-dentate binding domains (viz., iminophenanthroline, iminobipyridine, iminopyridine, a-diimine). Each Chapter is dedicated to the preparation of a specific type of precatalysts monometallic (Chapter Two), fused EB (Chapter Three), remote EB (Chapter Four) and functionalised remote EB (Chapter Five). In Chapter Two, the syntheses of monometallic complexes are described. Chapter Three reports the preparation of fused EB precatalysts, in which the two catalytic sites share a central aryl moiety. In Chapter Four, remote EB precatalysts have been developed, each possessing two discrete binding domains tethered by a methylene linker. Chapter Five is concerned with the functionalisation of the linker in remote EB iminopyridine-based nickel precatalysts/catalysts All complexes incorporate electronically active groups on the ligand manifold. Chapter Six compares the performances of the complexes from all four chapters by our complexes for the polymerisation of ethylene. Both the oligomer and the polymer portions were analysed through a range of techniques (e.g., GC, GPC, DSC, *H and C NMR). Regardless of the metal employed, encapsulated bimetallic catalysts produced higher molecular weights PE compared to their monometallic counterparts. In Chapter Seven, the details of the experimental procedures are disclosed.