{"id":{"repo_id":"ubc","oai_identifier":"oai:circle.library.ubc.ca:2429/679"},"canonical_url":"https://search.dev.ndltd.org/etd/ubc/oai:circle.library.ubc.ca:2429/679","repository":{"repo_id":"ubc","name":"University of British Columbia","base_url":"http://circle.library.ubc.ca/oai/request"},"display":{"title":"Indium complexes and their role in the ring-opening polymerization of lactide","abstract":"The synthesis and characterization of a series of chiral indium complexes bearing a tridentate NNO ligand are reported. The ligand 2-[[[(dimethylamino)cyclohexyl]amino]methyl]- 4,6-bis(tert-butyl) phenol (H₂NNO) was synthesized via a previously published procedure and bound to indium by both a protonolysis and salt metathesis route. A dimethylated indium complex (NNO)InMe₂ (1) was isolated by reaction of InMe₃ with H₂NNO. A one-pot saltmetathesis route was used to produce a unique mixed-bridge dinuclear indium complex [(NNO)InCl] ₂(μ-OEt)(μ-Cl) (3) from a mixture of indium trichloride, potassium ethoxide and the monopotassiated salt of the ligand, KH(NNO). Direct reaction of KH(NNO) and indium trichloride resulted in the formation of (NNO)InCl₂ (4) which was carried forward to 3 by reaction with sodium ethoxide. The complex 3 is active for the ROP of β-butyrolactone ε-caprolactone and lactide and is the first reported indium-based catalyst for lactide or β-butyrolactone ROP. Kinetic studies of 3 for ROP of LA revealed that catalyst was well-behaved, and that the rate was first order with regard to lactide and catalyst. The enthalpy and entropy of activation for the ROP were experimentally determined. Polymer produced by ROP by 3 has narrow molecular weight distribution and a good correlation is seen between the observed moleular weight and monomer loading. A mechanism was proposed for 3 acting as a catalyst for the ROP of lactide; however further experiments are required to confirm this mechanism. Polymer samples isolated from the ROP of rac-lactide by rac-3 show isotactic enrichment. It is postulated that the chiral catalyst 3 is exerting stereocontrol via an enantiomorphic site control mechanism.","abstract_html":"The synthesis and characterization of a series of chiral indium complexes bearing a tridentate NNO ligand are reported. The ligand 2-[[[(dimethylamino)cyclohexyl]amino]methyl]- 4,6-bis(tert-butyl) phenol (H₂NNO) was synthesized via a previously published procedure and bound to indium by both a protonolysis and salt metathesis route. A dimethylated indium complex (NNO)InMe₂ (1) was isolated by reaction of InMe₃ with H₂NNO. A one-pot saltmetathesis route was used to produce a unique mixed-bridge dinuclear indium complex [(NNO)InCl] ₂(μ-OEt)(μ-Cl) (3) from a mixture of indium trichloride, potassium ethoxide and the monopotassiated salt of the ligand, KH(NNO). Direct reaction of KH(NNO) and indium trichloride resulted in the formation of (NNO)InCl₂ (4) which was carried forward to 3 by reaction with sodium ethoxide. The complex 3 is active for the ROP of β-butyrolactone ε-caprolactone and lactide and is the first reported indium-based catalyst for lactide or β-butyrolactone ROP. Kinetic studies of 3 for ROP of LA revealed that catalyst was well-behaved, and that the rate was first order with regard to lactide and catalyst. The enthalpy and entropy of activation for the ROP were experimentally determined. Polymer produced by ROP by 3 has narrow molecular weight distribution and a good correlation is seen between the observed moleular weight and monomer loading. A mechanism was proposed for 3 acting as a catalyst for the ROP of lactide; however further experiments are required to confirm this mechanism. Polymer samples isolated from the ROP of rac-lactide by rac-3 show isotactic enrichment. It is postulated that the chiral catalyst 3 is exerting stereocontrol via an enantiomorphic site control mechanism.","abstract_has_math":false,"creators":["Douglas, Amy Frances"],"institution":"University of British Columbia","degree_name":"Master of Science - MSc","degree_level":"master's","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2008,"date_issued":"2008","date_published":"2008","updated_at":"2026-07-24T05:07:11Z","subjects":[],"languages":["eng"],"rights":["Attribution-NonCommercial-NoDerivatives 4.0 International"],"rights_urls":["http://creativecommons.org/licenses/by-nc-nd/4.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2429/679","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Douglas, Amy Frances"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2008"]},{"key":"dc:publisher","label":"Institution","values":["University of British Columbia"]},{"key":"dc:type","label":"Dc Type","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["master's"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science - MSc"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of British Columbia"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["http://creativecommons.org/licenses/by-nc-nd/4.0/","Attribution-NonCommercial-NoDerivatives 4.0 International"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2429/679","http://circle.library.ubc.ca/bitstream/2429/679/1/ubc_2008_spring_douglas_amy.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The synthesis and characterization of a series of chiral indium complexes bearing a tridentate NNO ligand are reported. The ligand 2-[[[(dimethylamino)cyclohexyl]amino]methyl]- 4,6-bis(tert-butyl) phenol (H₂NNO) was synthesized via a previously published procedure and bound to indium by both a protonolysis and salt metathesis route. A dimethylated indium complex (NNO)InMe₂ (1) was isolated by reaction of InMe₃ with H₂NNO. A one-pot saltmetathesis route was used to produce a unique mixed-bridge dinuclear indium complex [(NNO)InCl] ₂(μ-OEt)(μ-Cl) (3) from a mixture of indium trichloride, potassium ethoxide and the monopotassiated salt of the ligand, KH(NNO). Direct reaction of KH(NNO) and indium trichloride resulted in the formation of (NNO)InCl₂ (4) which was carried forward to 3 by reaction with sodium ethoxide. The complex 3 is active for the ROP of β-butyrolactone ε-caprolactone and lactide and is the first reported indium-based catalyst for lactide or β-butyrolactone ROP. Kinetic studies of 3 for ROP of LA revealed that catalyst was well-behaved, and that the rate was first order with regard to lactide and catalyst. The enthalpy and entropy of activation for the ROP were experimentally determined. Polymer produced by ROP by 3 has narrow molecular weight distribution and a good correlation is seen between the observed moleular weight and monomer loading. A mechanism was proposed for 3 acting as a catalyst for the ROP of lactide; however further experiments are required to confirm this mechanism. Polymer samples isolated from the ROP of rac-lactide by rac-3 show isotactic enrichment. It is postulated that the chiral catalyst 3 is exerting stereocontrol via an enantiomorphic site control mechanism."]},{"key":"dc:format","label":"Dc Format","values":["2028265","application/pdf"]},{"key":"dc:title","label":"Title","values":["Indium complexes and their role in the ring-opening polymerization of lactide"]}]}],"canonical_facts":{"dc:creator":["Douglas, Amy Frances"],"dc:date":["2008"],"dc:description":["The synthesis and characterization of a series of chiral indium complexes bearing a tridentate NNO ligand are reported. The ligand 2-[[[(dimethylamino)cyclohexyl]amino]methyl]- 4,6-bis(tert-butyl) phenol (H₂NNO) was synthesized via a previously published procedure and bound to indium by both a protonolysis and salt metathesis route. A dimethylated indium complex (NNO)InMe₂ (1) was isolated by reaction of InMe₃ with H₂NNO. A one-pot saltmetathesis route was used to produce a unique mixed-bridge dinuclear indium complex [(NNO)InCl] ₂(μ-OEt)(μ-Cl) (3) from a mixture of indium trichloride, potassium ethoxide and the monopotassiated salt of the ligand, KH(NNO). Direct reaction of KH(NNO) and indium trichloride resulted in the formation of (NNO)InCl₂ (4) which was carried forward to 3 by reaction with sodium ethoxide. The complex 3 is active for the ROP of β-butyrolactone ε-caprolactone and lactide and is the first reported indium-based catalyst for lactide or β-butyrolactone ROP. Kinetic studies of 3 for ROP of LA revealed that catalyst was well-behaved, and that the rate was first order with regard to lactide and catalyst. The enthalpy and entropy of activation for the ROP were experimentally determined. Polymer produced by ROP by 3 has narrow molecular weight distribution and a good correlation is seen between the observed moleular weight and monomer loading. A mechanism was proposed for 3 acting as a catalyst for the ROP of lactide; however further experiments are required to confirm this mechanism. Polymer samples isolated from the ROP of rac-lactide by rac-3 show isotactic enrichment. It is postulated that the chiral catalyst 3 is exerting stereocontrol via an enantiomorphic site control mechanism."],"dc:format":["2028265","application/pdf"],"dc:identifier":["http://hdl.handle.net/2429/679","http://circle.library.ubc.ca/bitstream/2429/679/1/ubc_2008_spring_douglas_amy.pdf"],"dc:language":["eng"],"dc:publisher":["University of British Columbia"],"dc:rights":["http://creativecommons.org/licenses/by-nc-nd/4.0/","Attribution-NonCommercial-NoDerivatives 4.0 International"],"dc:title":["Indium complexes and their role in the ring-opening polymerization of lactide"],"dc:type":["Text"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["master's"],"thesis:degree_name":["Master of Science - MSc"],"thesis:institution_name":["University of British Columbia"]},"updated_at":"2026-07-24T05:07:11Z"}