This Thesis describes the synthesis and characterisation of a series ofbisphenolate supported samarium borohydride, amide and zwitterionic rare earth complexes and their ability to effect the ring opening polymerisation (ROP) of cyclic esters and methylmethacrylate (MMA). Chapter 1 introduces ROP from both an industrial and an academic perspective and describes in detail the research in this area, with emphasis on rare earth initiators. The lanthanide elements and the bisphenolate ligand are also introduced. Chapter 2 describes the synthesis and characterisation ofbisphenolate supported samarium borohydride and silylamide complexes. Chapter 3 describes the ability of a selection of samarium borohydride and amide complexes to effect the ROP of the cyclic esters s-caprolactone (f-CL) and rac- lactide (rac-LA). Emphasis is placed on the effect that the nature of the bisphenolate pendant arm and the initiating moiety has on the polymerisation process. Chapter 4 describes the synthesis and characterisation of rare earth zwitterionic complexes and the ability ofa range of these complexes to effect the ROP of s-Cl. and rac-lactide. Mechanistic aspects ofthe ROP process will be discussed, as will the ability of these complexes to yield amide functionalised poly(rac-LA). Chapter 5 describes the ability ofbisphenolate samarium borohydride complexes to initiate the polymerisation of MMA. The experimental work conducted as part of this study is further supported computationally by calculations at the DFT level, both aspects will be described. Aspects concerning the synthesis and characterisation of the related borohydride derivative [Sm(N2siMe3NNPY)(BH4)2Li]oo will also be emphasised. Chapter 6 contains full experimental and characterising data for all 0 f the new compounds reported in this Thesis. Appendices A- T contain tables of selected crystallographic data for all new crystallographically characterised complexes described in this Thesis (partially on CD).
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:560913 |
| Date | January 2009 |
| Creators | Dyer, Hellen Elizabeth |
| Contributors | Mountford, Philip |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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