Homogeneous catalysts for the synthesis of oxygenated polymers
<p>This thesis describes the synthesis and characterisation of novel mono and dinuclear homogenous [Zn(II)] and [In(III)] metal complexes. Their applications as catalysts for CO<sub>2</sub>/epoxide or epoxide/anhydride ring opening copolymerisation and lactide ring opening polymeri...
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| Format: | Thèse |
| Langue: | English |
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2017
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| _version_ | 1826315954183733248 |
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| author | Thevenon, A |
| author2 | Williams, C |
| author_facet | Williams, C Thevenon, A |
| author_sort | Thevenon, A |
| collection | OXFORD |
| description | <p>This thesis describes the synthesis and characterisation of novel mono and dinuclear homogenous [Zn(II)] and [In(III)] metal complexes. Their applications as catalysts for CO<sub>2</sub>/epoxide or epoxide/anhydride ring opening copolymerisation and lactide ring opening polymerisation to generate polycarbonates and polyesters, respectively, are also reported.</p> <p>Chapter 3 reports the first indium phosphasalen catalysts for CO<sub>2</sub>/cyclohexene oxide ring opening copolymerization. The catalysts are active at 1 bar pressure of CO<sub>2</sub> and are most effective without any co-catalyst. It is also possible to use the complexes to isolate and characterise the key intermediates in the catalytic cycle. Kinetic and spectroscopic analyses show that polymerisation proceeds via a rare <em>cis</em>-mononuclear coordination- insertion mechanism.</p> <p>Chapter 4 describes a series of mono and dinuclear zinc macrocycle catalysts with very high activities for the <em>racemic</em> lactide ring opening polymerisation. In most cases, the dinuclear zinc catalysts significantly out-perform the mono-zinc homologue. In addition, kinetic and spectroscopic investigations suggest a role for the ligand conformation in mediating rate. The catalysts perform very well under immortal conditions and operate at low catalyst loading, whilst conserving high activities.</p> <p>Chapter 5 presents four dinuclear zinc acetate salen catalysts for the ring opening copolymerisation of CO<sub>2</sub>/cyclohexene oxide and phthalic anhydride/cyclohexene oxide. The catalysts show moderate activities for CO<sub>2</sub>/epoxide copolymerisation but are highly active for epoxide/anhydride copolymerisation. Structure/activity relationship studies reveal that the more flexible and electron donating ligand displays the highest activity. Poly(ester-<em>b</em>-carbonate)s are also afforded using the most active catalyst in terpolymerisations of anhydride/epoxide/CO<sub>2</sub>.</p> |
| first_indexed | 2024-03-06T19:56:27Z |
| format | Thesis |
| id | oxford-uuid:25c312d1-11c9-4180-a62d-b87a41f521c0 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:35:29Z |
| publishDate | 2017 |
| record_format | dspace |
| spelling | oxford-uuid:25c312d1-11c9-4180-a62d-b87a41f521c02024-12-01T19:03:22ZHomogeneous catalysts for the synthesis of oxygenated polymersThesishttp://purl.org/coar/resource_type/c_db06uuid:25c312d1-11c9-4180-a62d-b87a41f521c0Inorganic ChemistryGreen ChemistryChemistryEnglishORA Deposit2017Thevenon, AWilliams, C<p>This thesis describes the synthesis and characterisation of novel mono and dinuclear homogenous [Zn(II)] and [In(III)] metal complexes. Their applications as catalysts for CO<sub>2</sub>/epoxide or epoxide/anhydride ring opening copolymerisation and lactide ring opening polymerisation to generate polycarbonates and polyesters, respectively, are also reported.</p> <p>Chapter 3 reports the first indium phosphasalen catalysts for CO<sub>2</sub>/cyclohexene oxide ring opening copolymerization. The catalysts are active at 1 bar pressure of CO<sub>2</sub> and are most effective without any co-catalyst. It is also possible to use the complexes to isolate and characterise the key intermediates in the catalytic cycle. Kinetic and spectroscopic analyses show that polymerisation proceeds via a rare <em>cis</em>-mononuclear coordination- insertion mechanism.</p> <p>Chapter 4 describes a series of mono and dinuclear zinc macrocycle catalysts with very high activities for the <em>racemic</em> lactide ring opening polymerisation. In most cases, the dinuclear zinc catalysts significantly out-perform the mono-zinc homologue. In addition, kinetic and spectroscopic investigations suggest a role for the ligand conformation in mediating rate. The catalysts perform very well under immortal conditions and operate at low catalyst loading, whilst conserving high activities.</p> <p>Chapter 5 presents four dinuclear zinc acetate salen catalysts for the ring opening copolymerisation of CO<sub>2</sub>/cyclohexene oxide and phthalic anhydride/cyclohexene oxide. The catalysts show moderate activities for CO<sub>2</sub>/epoxide copolymerisation but are highly active for epoxide/anhydride copolymerisation. Structure/activity relationship studies reveal that the more flexible and electron donating ligand displays the highest activity. Poly(ester-<em>b</em>-carbonate)s are also afforded using the most active catalyst in terpolymerisations of anhydride/epoxide/CO<sub>2</sub>.</p> |
| spellingShingle | Inorganic Chemistry Green Chemistry Chemistry Thevenon, A Homogeneous catalysts for the synthesis of oxygenated polymers |
| title | Homogeneous catalysts for the synthesis of oxygenated polymers |
| title_full | Homogeneous catalysts for the synthesis of oxygenated polymers |
| title_fullStr | Homogeneous catalysts for the synthesis of oxygenated polymers |
| title_full_unstemmed | Homogeneous catalysts for the synthesis of oxygenated polymers |
| title_short | Homogeneous catalysts for the synthesis of oxygenated polymers |
| title_sort | homogeneous catalysts for the synthesis of oxygenated polymers |
| topic | Inorganic Chemistry Green Chemistry Chemistry |
| work_keys_str_mv | AT thevenona homogeneouscatalystsforthesynthesisofoxygenatedpolymers |