Alkaline earth and rare earth complexes for the ring opening polymerisation of cyclic esters
<p>This Thesis describes the use of alkaline earth and rare earth complexes bearing phenolate ligands as catalysts in the amine-initiated, immortal ring opening polymerisation (ROP) of cyclic esters. Mechanistic elucidation was performed and two propagation pathways are presented.</p><...
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| Format: | Thèse |
| Langue: | English |
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2012
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| _version_ | 1826296134174244864 |
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| author | Clark, L |
| author2 | Mountford, P |
| author_facet | Mountford, P Clark, L |
| author_sort | Clark, L |
| collection | OXFORD |
| description | <p>This Thesis describes the use of alkaline earth and rare earth complexes bearing phenolate ligands as catalysts in the amine-initiated, immortal ring opening polymerisation (ROP) of cyclic esters. Mechanistic elucidation was performed and two propagation pathways are presented.</p><p>Chapter One introduces cyclic esters and catalytic routes to polyesters by ROP. Common techniques for polymer characterisation are described and an overview of relevant phenolate-supported ROP catalysts is given. Reversible chain transfer in ROP is also discussed.</p><p>Chapter Two describes the synthesis and characterisation of zwitterionic Group 3 complexes bearing bis(phenolate)-amino ligands and the development of the amine-initiated, immortal ROP methodology using this class of catalyst. Detailed studies into the ROP of <em>rac</em>-lactide using amines and a zwitterionic yttrium complex are presented and the mechanism of amine-initiated, immortal ROP was derived.</p><p>Chapter Three documents further amine-initiated, immortal ROP studies using a zwitterionic yttrium complex as the catalyst. The preparation of multiarm polymers is described and further investigations using the cyclic esters, ε-caprolactone and <em>rac</em>-β-butyrolactone are presented.</p><p>Chapter Four describes the use of Group 2 and lanthanide phenolate complexes in the amine-initiated ROP of <em>rac</em>-lactide. Bulk polymerisation studies revealed the generality of the amine-initiated, immortal ROP methodology and an alternative propagation pathway was derived from mechanistic studies.</p><p>Chapter Five details the synthesis and characterisation of Group 3 amide complexes supported by phenolate-amino ligands. Each complex was screened for ROP capability and amine co-initiators were employed.</p><p>Chapter Six contains experimental details and characterisation data for the new complexes and polymer products described in this Thesis.</p><p>CD Appendix contains crystallography .cif files, supporting information for each Chapter and spreadsheets containing polymerisation data.</p> |
| first_indexed | 2024-03-07T04:11:40Z |
| format | Thesis |
| id | oxford-uuid:c80769ca-27f6-4067-bfc2-6a8632cd4269 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T04:11:40Z |
| publishDate | 2012 |
| record_format | dspace |
| spelling | oxford-uuid:c80769ca-27f6-4067-bfc2-6a8632cd42692022-03-27T06:49:25ZAlkaline earth and rare earth complexes for the ring opening polymerisation of cyclic estersThesishttp://purl.org/coar/resource_type/c_db06uuid:c80769ca-27f6-4067-bfc2-6a8632cd4269Inorganic chemistryCatalysisOrganometallic ChemistryEnglishOxford University Research Archive - Valet2012Clark, LMountford, P<p>This Thesis describes the use of alkaline earth and rare earth complexes bearing phenolate ligands as catalysts in the amine-initiated, immortal ring opening polymerisation (ROP) of cyclic esters. Mechanistic elucidation was performed and two propagation pathways are presented.</p><p>Chapter One introduces cyclic esters and catalytic routes to polyesters by ROP. Common techniques for polymer characterisation are described and an overview of relevant phenolate-supported ROP catalysts is given. Reversible chain transfer in ROP is also discussed.</p><p>Chapter Two describes the synthesis and characterisation of zwitterionic Group 3 complexes bearing bis(phenolate)-amino ligands and the development of the amine-initiated, immortal ROP methodology using this class of catalyst. Detailed studies into the ROP of <em>rac</em>-lactide using amines and a zwitterionic yttrium complex are presented and the mechanism of amine-initiated, immortal ROP was derived.</p><p>Chapter Three documents further amine-initiated, immortal ROP studies using a zwitterionic yttrium complex as the catalyst. The preparation of multiarm polymers is described and further investigations using the cyclic esters, ε-caprolactone and <em>rac</em>-β-butyrolactone are presented.</p><p>Chapter Four describes the use of Group 2 and lanthanide phenolate complexes in the amine-initiated ROP of <em>rac</em>-lactide. Bulk polymerisation studies revealed the generality of the amine-initiated, immortal ROP methodology and an alternative propagation pathway was derived from mechanistic studies.</p><p>Chapter Five details the synthesis and characterisation of Group 3 amide complexes supported by phenolate-amino ligands. Each complex was screened for ROP capability and amine co-initiators were employed.</p><p>Chapter Six contains experimental details and characterisation data for the new complexes and polymer products described in this Thesis.</p><p>CD Appendix contains crystallography .cif files, supporting information for each Chapter and spreadsheets containing polymerisation data.</p> |
| spellingShingle | Inorganic chemistry Catalysis Organometallic Chemistry Clark, L Alkaline earth and rare earth complexes for the ring opening polymerisation of cyclic esters |
| title | Alkaline earth and rare earth complexes for the ring opening polymerisation of cyclic esters |
| title_full | Alkaline earth and rare earth complexes for the ring opening polymerisation of cyclic esters |
| title_fullStr | Alkaline earth and rare earth complexes for the ring opening polymerisation of cyclic esters |
| title_full_unstemmed | Alkaline earth and rare earth complexes for the ring opening polymerisation of cyclic esters |
| title_short | Alkaline earth and rare earth complexes for the ring opening polymerisation of cyclic esters |
| title_sort | alkaline earth and rare earth complexes for the ring opening polymerisation of cyclic esters |
| topic | Inorganic chemistry Catalysis Organometallic Chemistry |
| work_keys_str_mv | AT clarkl alkalineearthandrareearthcomplexesfortheringopeningpolymerisationofcyclicesters |