Bimetallic group 4 complexes as olefin polymerisation catalysts

• Main Author: Collins, Richard
• Other Authors: Mountford, Philip
• Published: University of Oxford 2016
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.730346

This Thesis describes the synthesis and characterisation of half-sandwich bimetallic complexes supported by &kappa;¹-amidinate ligands with different bridging moieties. <b>Chapter 1</b> introduces homogeneous polyolefin catalysis with a focus on Group 4 metals. The mechanism, catalyst development and the activation chemistry of metallocene and post-metallocene catalysts are discussed. The beneficial properties generated by bimetallic catalysts through cooperative interactions are introduced. <b>Chapter 2</b> describes the synthesis, structures and copolymerisation capabilities of cyclopentadienyl-amidinate phenylene bridged bimetallic titanium complexes. A series of monometallic cyclopentadienyl-amidinate dimethyl and dichloride titanium complexes are presented for comparison. A detailed description of their activation to form well-defined cationic species is presented. <b>Chapter 3</b> describes the synthesis, structures and copolymerisation capabilities of cyclopentadienyl-amidinate titanium bimetallic complexes with conformationally constrained and ferrocenyl covalent tethers. Alongside the ferrocenyl complexes introduced in Chapter one, an electrochemical analysis of all ferrocene based complexes will be discussed. <b>Chapter 4</b> details two different binuclear cocatalysts and their performances in a high temperature EPDM copolymerisation study. The form of the catalytic species is investigated through abstraction reactions with monometallic and bimetallic complexes previously introduced. <b>Chapter 5</b> describes the synthesis of a bimetallic zirconium complex and attempted synthesis of a Group 4 heterobimetallic complex. A parallel polymerisation reactor (PPR) experiment on in situ generated precatalysts is discussed, which is supported by synthetic and polymerisation experiments. <b>Chapter 6</b> presents full experimental procedures and characterising data for the new complexes reported in this Thesis.