| This thesis describes the exploration of new catalysts for the insertion polymerization and oligomerization of ethylene, as well as the mechanistic study of a key step in the polymerization catalyzed by palladium alkyl complexes that contain ortho-phosphino-arenesulfonate ligands ([PO] -).;Chapter One provides an introduction to the synthesis of functionalized polyethylene.;Chapter Two describes the synthesis and characterization of the base-free [2-PR2-4-Me-benzenesulfonate]Ni(benzyl) complexes (R = 2-OMe-Ph (4a), Cy (4b)), and the homopolymerization of ethylene using these catalysts.;Chapter Three describes the chemistry of palladium alkyl complexes that incorporate the NHC-sulfonate ligand N-(2,6-diisopropylphenyl)- N'-2-benzenesulfonate-NHC ([C-O]-, NHC = cyclo-CNCH2CH2N).;Chapter Four focuses on the mechanism of cis/trans isomerization of [PO]PdMe(2,6-lutidine) ([PO]- = 2-P(2-OMe-Ph)2-4-Me-benzenesulfonate) complex. Three possible mechanisms for this isomerization are proposed, including those via a tetrahedral transition state, a 5-coordinate transition state, and a 3-coordinate zwitterionic intermediate. Kinetics, structure activity correlations and solvent effects show that this isomerization occurs via competing lutidine-catalyzed and unimolecular mechanisms, and that the latter involves sulfonate dissociation to produce a configurationally labile 3-coordinate intermediate. |
