{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:63097"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:63097","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Group 4 metal and vanadium bis(phenolato) complexes : synthesis, structure and olefin polymerisation activity","abstract":"The first objectives of this work were to obtain a enantiomerically pure [Ti{OSSO}X2] polymerisation catalyst and to use it to determine at what degree of polymerisation a polystyrene chain becomes cryptochiral. The resolution of the Delta and Lambda enantiomers of a [Ti{2,2’-(OC6H2-6-tBu-4-Me)2SC2H4S}X2] was attempted via chiral template synthesis. Complexation of the achiral bis(phenol) to a (R)-1,1’-bi-2-naphthoxy titanium species was not diastereoselective and reaction with 3,3’-substituted templates did not proceed at all. Surprisingly, the partial hydrolysis of [Ti{(R)-C20H12O2}{2,2’-(OC6H2-6-tBu-4-Me)2SC2H4S}] in acetone solution did proceed diastereoselectively to give a homochiral dinuclear species, bridged by a binaphtoxy moiety and by an oxygen atom. A chiral template can be abandoned if an [OSSO]-type ligand is developed with a chiral source that predetermines the configuration with which the ligand coordinated to the metal centre. Therefore, trans-1,2-dithiacyclohexanediyl-bridged bis(phenols) were synthesised in three steps. Nucleophilic attack of an hydroxyarenethiolate on cyclohexene oxide, followed by chlorination, and substitution by a second equivalent of the thiolate gave exclusively 1,2-trans bis(phenols) via anchimeric assistance. The chiral bis(phenols) could be resolved either by classical resolution with (1S)-camphorsulfonyl chloride or by preparative (chiral) HPLC of the diastereomers and enantiomers respectively. Reaction of trans-1,2-dithiacyclohexanediyl-bridged [OSSO]-type ligands with TiX4 proceeds diastereoselectively, thus giving access to enantiomerically pure precatalysts. In contrast to 1,4-dithiabutanediyl-bridged [OSSO] ligands, [2,2’-(HOC6H2-6-R1-4-R2)2SC6H10S] are so efficient in directing and maintaining the configuration of their respective titanium complexes that large ortho-substituents are not required. To investigate cryptochiality, low molecular weight oligostyrenes were produced by optically active titanium catalysts. The molecular weight during polymerisation could be controlled by addition of 1-hexene as a chain-transfer agent. Depending on the substitution of the ligand, 1-hexene-terminated oligostyrenes with a minimum molecular weight of 800-1300 g mol-1 could be obtained. Oligomers with a polymerisation degree of up to ca. 45 show optical activity. Reaction of racemic [2,2’-(HOC6H2-6-tBu-4-Me)2SC6H10S] with VOCl3 afforded a C1-symmetrical bis(phenolato) vanadium(V) complex, which spontaneously resolves upon crystallisation. iastereoselectivity is the same as for titanium complexes. When activated with MAO, [V{2,2’-(OC6H2-6-tBu-4-Me)2SC6H10S}OCl] did not polymerise propene or styrene, but was highly active for the polymerisation of ethene. Using similar nucleophilic ring-opening methodology as for the cyclohexanediyl-bridged [OSSO]-type ligands, a family of trans-1,2-azathiacyclohexanediyl-bridged [OSNO]-type bis(phenols) was synthesised. In this fashion [2,2’-(HOC6H2-6-tBu-4-R1)2SC6H10NR2] (R1 = tBu, Me; R2 = H, Me), [2,2’-(HOC6H2-4,6-tBu2)2SC6H10N=CH] and [2,2’-(HOC6H2-4,6-tBu2)2SC6H10NHCH2] were obtained. Although for such asymmetrical ligands many isomers are possible, formation of titanium complexes of the first ligands proceeded with perfect diastereoselectively; the half-salen and half-salan hybrids gave a mixture of two isomers (Scheme S.4). All titanium complexes were configurationally stable in solution up to 100°C. For [Ti{2,2’-(HOC6H2-6-tBu-4-R1)2SC6H10NR2}X2] (X = Cl, OiPr), cis-alpha and cis-beta2 coordination modes of the ligand were observed, depending on the nitrogen substituent and on the auxiliary ligand. In [Ti{2,2’-(HOC6H2-4,6-tBu2)2SC6H10N=CH}Cl2] and [Ti{2,2’-(HOC6H2-4,6-tBu2)2SC6H10NHCH2}Cl2] both configurations coexist and did not interconvert at elevated temperatures, but HCl catalysed the isomerization from cis-alpha to cis-beta2. Upon activation with methylaluminoxane, [Ti{OSNO}X2] complexes were moderately active in the polymerization of styrene and gave trace activity in the polymerization of 1-hexene, thus combining the worst polymerisation properties of their parent ligands, rather than the best. A different way to influence polymerisation properties is to investigate the effect of the linkage between the arene groups. For group 4 [ONNO]-type catalysts, only salen- and salan-type complexes are known; 1,4-diazabutanediyl-bridged bis(phenolato) species were not examined. These ligands were synthesised by reaction of the 3,5-tBu2-catechol with ethylene diamine and optional methylation of the nitrogen atoms. With the appropriate metal precursors MX4 (M = Ti, Zr, Hf) a series of group 4 metal dichloro and di(isopropoxy) complexes [M{2,2’-(OC6H2-4,6-tBu2)2NRC2H4NR}X2] (Ti: R = H, Me; X = Cl, OiPr; Zr, Hf: X = Cl; R = Me) was obtained. Whilst [ONNO] zirconium and hafnium dichlorides gave configurationally stable cis-alpha species up to 100°C, titanium [ONNO] complexes gave both cis-alpha and cis-beta isomers (Scheme S.5). The configuration of [Ti{2,2’-(OC6H2-4,6-tBu2)2MeNC2H4NMe}Cl2] and [Ti{2,2’-(OC6H2-4,6-tBu2)2HNC2H4NH}Cl2] changed from cis-beta to cis-alpha at elevated temperatures. Upon activation with methylaluminoxane, all precatalysts polymerised styrene with modest activity. Good (M = Ti) to excellent (M = Zr, Hf) activity in the atactic polymerization of 1-hexene was observed.","abstract_html":"The first objectives of this work were to obtain a enantiomerically pure [Ti{OSSO}X2] polymerisation catalyst and to use it to determine at what degree of polymerisation a polystyrene chain becomes cryptochiral. The resolution of the Delta and Lambda enantiomers of a [Ti{2,2’-(OC6H2-6-tBu-4-Me)2SC2H4S}X2] was attempted via chiral template synthesis. Complexation of the achiral bis(phenol) to a (R)-1,1’-bi-2-naphthoxy titanium species was not diastereoselective and reaction with 3,3’-substituted templates did not proceed at all. Surprisingly, the partial hydrolysis of [Ti{(R)-C20H12O2}{2,2’-(OC6H2-6-tBu-4-Me)2SC2H4S}] in acetone solution did proceed diastereoselectively to give a homochiral dinuclear species, bridged by a binaphtoxy moiety and by an oxygen atom. A chiral template can be abandoned if an [OSSO]-type ligand is developed with a chiral source that predetermines the configuration with which the ligand coordinated to the metal centre. Therefore, trans-1,2-dithiacyclohexanediyl-bridged bis(phenols) were synthesised in three steps. Nucleophilic attack of an hydroxyarenethiolate on cyclohexene oxide, followed by chlorination, and substitution by a second equivalent of the thiolate gave exclusively 1,2-trans bis(phenols) via anchimeric assistance. The chiral bis(phenols) could be resolved either by classical resolution with (1S)-camphorsulfonyl chloride or by preparative (chiral) HPLC of the diastereomers and enantiomers respectively. Reaction of trans-1,2-dithiacyclohexanediyl-bridged [OSSO]-type ligands with TiX4 proceeds diastereoselectively, thus giving access to enantiomerically pure precatalysts. In contrast to 1,4-dithiabutanediyl-bridged [OSSO] ligands, [2,2’-(HOC6H2-6-R1-4-R2)2SC6H10S] are so efficient in directing and maintaining the configuration of their respective titanium complexes that large ortho-substituents are not required. To investigate cryptochiality, low molecular weight oligostyrenes were produced by optically active titanium catalysts. The molecular weight during polymerisation could be controlled by addition of 1-hexene as a chain-transfer agent. Depending on the substitution of the ligand, 1-hexene-terminated oligostyrenes with a minimum molecular weight of 800-1300 g mol-1 could be obtained. Oligomers with a polymerisation degree of up to ca. 45 show optical activity. Reaction of racemic [2,2’-(HOC6H2-6-tBu-4-Me)2SC6H10S] with VOCl3 afforded a C1-symmetrical bis(phenolato) vanadium(V) complex, which spontaneously resolves upon crystallisation. iastereoselectivity is the same as for titanium complexes. When activated with MAO, [V{2,2’-(OC6H2-6-tBu-4-Me)2SC6H10S}OCl] did not polymerise propene or styrene, but was highly active for the polymerisation of ethene. Using similar nucleophilic ring-opening methodology as for the cyclohexanediyl-bridged [OSSO]-type ligands, a family of trans-1,2-azathiacyclohexanediyl-bridged [OSNO]-type bis(phenols) was synthesised. In this fashion [2,2’-(HOC6H2-6-tBu-4-R1)2SC6H10NR2] (R1 = tBu, Me; R2 = H, Me), [2,2’-(HOC6H2-4,6-tBu2)2SC6H10N=CH] and [2,2’-(HOC6H2-4,6-tBu2)2SC6H10NHCH2] were obtained. Although for such asymmetrical ligands many isomers are possible, formation of titanium complexes of the first ligands proceeded with perfect diastereoselectively; the half-salen and half-salan hybrids gave a mixture of two isomers (Scheme S.4). All titanium complexes were configurationally stable in solution up to 100°C. For [Ti{2,2’-(HOC6H2-6-tBu-4-R1)2SC6H10NR2}X2] (X = Cl, OiPr), cis-alpha and cis-beta2 coordination modes of the ligand were observed, depending on the nitrogen substituent and on the auxiliary ligand. In [Ti{2,2’-(HOC6H2-4,6-tBu2)2SC6H10N=CH}Cl2] and [Ti{2,2’-(HOC6H2-4,6-tBu2)2SC6H10NHCH2}Cl2] both configurations coexist and did not interconvert at elevated temperatures, but HCl catalysed the isomerization from cis-alpha to cis-beta2. Upon activation with methylaluminoxane, [Ti{OSNO}X2] complexes were moderately active in the polymerization of styrene and gave trace activity in the polymerization of 1-hexene, thus combining the worst polymerisation properties of their parent ligands, rather than the best. A different way to influence polymerisation properties is to investigate the effect of the linkage between the arene groups. For group 4 [ONNO]-type catalysts, only salen- and salan-type complexes are known; 1,4-diazabutanediyl-bridged bis(phenolato) species were not examined. These ligands were synthesised by reaction of the 3,5-tBu2-catechol with ethylene diamine and optional methylation of the nitrogen atoms. With the appropriate metal precursors MX4 (M = Ti, Zr, Hf) a series of group 4 metal dichloro and di(isopropoxy) complexes [M{2,2’-(OC6H2-4,6-tBu2)2NRC2H4NR}X2] (Ti: R = H, Me; X = Cl, OiPr; Zr, Hf: X = Cl; R = Me) was obtained. Whilst [ONNO] zirconium and hafnium dichlorides gave configurationally stable cis-alpha species up to 100°C, titanium [ONNO] complexes gave both cis-alpha and cis-beta isomers (Scheme S.5). The configuration of [Ti{2,2’-(OC6H2-4,6-tBu2)2MeNC2H4NMe}Cl2] and [Ti{2,2’-(OC6H2-4,6-tBu2)2HNC2H4NH}Cl2] changed from cis-beta to cis-alpha at elevated temperatures. Upon activation with methylaluminoxane, all precatalysts polymerised styrene with modest activity. Good (M = Ti) to excellent (M = Zr, Hf) activity in the atactic polymerization of 1-hexene was observed.","abstract_has_math":false,"creators":["Meppelder, Geert Johannes Marinus"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Okuda, Jun"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2009,"date_issued":"2009","date_published":"2009","updated_at":"2026-07-30T19:43:35Z","subjects":["info:eu-repo/classification/ddc/540","Metallorganische Chemie","Polymerisation","Styrol","Chemie","organometallic chemistry","chirality","olefin polymerisation","styrene"],"languages":["eng"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-124555%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-124555%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-124555%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/63097","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Okuda, Jun"]},{"key":"dc:creator","label":"Author","values":["Meppelder, Geert Johannes Marinus"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2009"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-33115"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/540","Metallorganische Chemie","Polymerisation","Styrol","Chemie","organometallic chemistry","chirality","olefin polymerisation","styrene"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/63097","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-124555%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The first objectives of this work were to obtain a enantiomerically pure [Ti{OSSO}X2] polymerisation catalyst and to use it to determine at what degree of polymerisation a polystyrene chain becomes cryptochiral. The resolution of the Delta and Lambda enantiomers of a [Ti{2,2’-(OC6H2-6-tBu-4-Me)2SC2H4S}X2] was attempted via chiral template synthesis. Complexation of the achiral bis(phenol) to a (R)-1,1’-bi-2-naphthoxy titanium species was not diastereoselective and reaction with 3,3’-substituted templates did not proceed at all. Surprisingly, the partial hydrolysis of [Ti{(R)-C20H12O2}{2,2’-(OC6H2-6-tBu-4-Me)2SC2H4S}] in acetone solution did proceed diastereoselectively to give a homochiral dinuclear species, bridged by a binaphtoxy moiety and by an oxygen atom. A chiral template can be abandoned if an [OSSO]-type ligand is developed with a chiral source that predetermines the configuration with which the ligand coordinated to the metal centre. Therefore, trans-1,2-dithiacyclohexanediyl-bridged bis(phenols) were synthesised in three steps. Nucleophilic attack of an hydroxyarenethiolate on cyclohexene oxide, followed by chlorination, and substitution by a second equivalent of the thiolate gave exclusively 1,2-trans bis(phenols) via anchimeric assistance. The chiral bis(phenols) could be resolved either by classical resolution with (1S)-camphorsulfonyl chloride or by preparative (chiral) HPLC of the diastereomers and enantiomers respectively. Reaction of trans-1,2-dithiacyclohexanediyl-bridged [OSSO]-type ligands with TiX4 proceeds diastereoselectively, thus giving access to enantiomerically pure precatalysts. In contrast to 1,4-dithiabutanediyl-bridged [OSSO] ligands, [2,2’-(HOC6H2-6-R1-4-R2)2SC6H10S] are so efficient in directing and maintaining the configuration of their respective titanium complexes that large ortho-substituents are not required. To investigate cryptochiality, low molecular weight oligostyrenes were produced by optically active titanium catalysts. The molecular weight during polymerisation could be controlled by addition of 1-hexene as a chain-transfer agent. Depending on the substitution of the ligand, 1-hexene-terminated oligostyrenes with a minimum molecular weight of 800-1300 g mol-1 could be obtained. Oligomers with a polymerisation degree of up to ca. 45 show optical activity. Reaction of racemic [2,2’-(HOC6H2-6-tBu-4-Me)2SC6H10S] with VOCl3 afforded a C1-symmetrical bis(phenolato) vanadium(V) complex, which spontaneously resolves upon crystallisation. iastereoselectivity is the same as for titanium complexes. When activated with MAO, [V{2,2’-(OC6H2-6-tBu-4-Me)2SC6H10S}OCl] did not polymerise propene or styrene, but was highly active for the polymerisation of ethene. Using similar nucleophilic ring-opening methodology as for the cyclohexanediyl-bridged [OSSO]-type ligands, a family of trans-1,2-azathiacyclohexanediyl-bridged [OSNO]-type bis(phenols) was synthesised. In this fashion [2,2’-(HOC6H2-6-tBu-4-R1)2SC6H10NR2] (R1 = tBu, Me; R2 = H, Me), [2,2’-(HOC6H2-4,6-tBu2)2SC6H10N=CH] and [2,2’-(HOC6H2-4,6-tBu2)2SC6H10NHCH2] were obtained. Although for such asymmetrical ligands many isomers are possible, formation of titanium complexes of the first ligands proceeded with perfect diastereoselectively; the half-salen and half-salan hybrids gave a mixture of two isomers (Scheme S.4). All titanium complexes were configurationally stable in solution up to 100°C. For [Ti{2,2’-(HOC6H2-6-tBu-4-R1)2SC6H10NR2}X2] (X = Cl, OiPr), cis-alpha and cis-beta2 coordination modes of the ligand were observed, depending on the nitrogen substituent and on the auxiliary ligand. In [Ti{2,2’-(HOC6H2-4,6-tBu2)2SC6H10N=CH}Cl2] and [Ti{2,2’-(HOC6H2-4,6-tBu2)2SC6H10NHCH2}Cl2] both configurations coexist and did not interconvert at elevated temperatures, but HCl catalysed the isomerization from cis-alpha to cis-beta2. Upon activation with methylaluminoxane, [Ti{OSNO}X2] complexes were moderately active in the polymerization of styrene and gave trace activity in the polymerization of 1-hexene, thus combining the worst polymerisation properties of their parent ligands, rather than the best. A different way to influence polymerisation properties is to investigate the effect of the linkage between the arene groups. For group 4 [ONNO]-type catalysts, only salen- and salan-type complexes are known; 1,4-diazabutanediyl-bridged bis(phenolato) species were not examined. These ligands were synthesised by reaction of the 3,5-tBu2-catechol with ethylene diamine and optional methylation of the nitrogen atoms. With the appropriate metal precursors MX4 (M = Ti, Zr, Hf) a series of group 4 metal dichloro and di(isopropoxy) complexes [M{2,2’-(OC6H2-4,6-tBu2)2NRC2H4NR}X2] (Ti: R = H, Me; X = Cl, OiPr; Zr, Hf: X = Cl; R = Me) was obtained. Whilst [ONNO] zirconium and hafnium dichlorides gave configurationally stable cis-alpha species up to 100°C, titanium [ONNO] complexes gave both cis-alpha and cis-beta isomers (Scheme S.5). The configuration of [Ti{2,2’-(OC6H2-4,6-tBu2)2MeNC2H4NMe}Cl2] and [Ti{2,2’-(OC6H2-4,6-tBu2)2HNC2H4NH}Cl2] changed from cis-beta to cis-alpha at elevated temperatures. Upon activation with methylaluminoxane, all precatalysts polymerised styrene with modest activity. Good (M = Ti) to excellent (M = Zr, Hf) activity in the atactic polymerization of 1-hexene was observed."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University 161 S. : graph. Darst. (2009). = Aachen, Techn. Hochsch., Diss., 2009"]},{"key":"dc:title","label":"Title","values":["Group 4 metal and vanadium bis(phenolato) complexes : synthesis, structure and olefin polymerisation activity"]}]}],"canonical_facts":{"dc:contributor":["Okuda, Jun"],"dc:coverage":["DE"],"dc:creator":["Meppelder, Geert Johannes Marinus"],"dc:date":["2009"],"dc:description":["The first objectives of this work were to obtain a enantiomerically pure [Ti{OSSO}X2] polymerisation catalyst and to use it to determine at what degree of polymerisation a polystyrene chain becomes cryptochiral. The resolution of the Delta and Lambda enantiomers of a [Ti{2,2’-(OC6H2-6-tBu-4-Me)2SC2H4S}X2] was attempted via chiral template synthesis. Complexation of the achiral bis(phenol) to a (R)-1,1’-bi-2-naphthoxy titanium species was not diastereoselective and reaction with 3,3’-substituted templates did not proceed at all. Surprisingly, the partial hydrolysis of [Ti{(R)-C20H12O2}{2,2’-(OC6H2-6-tBu-4-Me)2SC2H4S}] in acetone solution did proceed diastereoselectively to give a homochiral dinuclear species, bridged by a binaphtoxy moiety and by an oxygen atom. A chiral template can be abandoned if an [OSSO]-type ligand is developed with a chiral source that predetermines the configuration with which the ligand coordinated to the metal centre. Therefore, trans-1,2-dithiacyclohexanediyl-bridged bis(phenols) were synthesised in three steps. Nucleophilic attack of an hydroxyarenethiolate on cyclohexene oxide, followed by chlorination, and substitution by a second equivalent of the thiolate gave exclusively 1,2-trans bis(phenols) via anchimeric assistance. The chiral bis(phenols) could be resolved either by classical resolution with (1S)-camphorsulfonyl chloride or by preparative (chiral) HPLC of the diastereomers and enantiomers respectively. Reaction of trans-1,2-dithiacyclohexanediyl-bridged [OSSO]-type ligands with TiX4 proceeds diastereoselectively, thus giving access to enantiomerically pure precatalysts. In contrast to 1,4-dithiabutanediyl-bridged [OSSO] ligands, [2,2’-(HOC6H2-6-R1-4-R2)2SC6H10S] are so efficient in directing and maintaining the configuration of their respective titanium complexes that large ortho-substituents are not required. To investigate cryptochiality, low molecular weight oligostyrenes were produced by optically active titanium catalysts. The molecular weight during polymerisation could be controlled by addition of 1-hexene as a chain-transfer agent. Depending on the substitution of the ligand, 1-hexene-terminated oligostyrenes with a minimum molecular weight of 800-1300 g mol-1 could be obtained. Oligomers with a polymerisation degree of up to ca. 45 show optical activity. Reaction of racemic [2,2’-(HOC6H2-6-tBu-4-Me)2SC6H10S] with VOCl3 afforded a C1-symmetrical bis(phenolato) vanadium(V) complex, which spontaneously resolves upon crystallisation. iastereoselectivity is the same as for titanium complexes. When activated with MAO, [V{2,2’-(OC6H2-6-tBu-4-Me)2SC6H10S}OCl] did not polymerise propene or styrene, but was highly active for the polymerisation of ethene. Using similar nucleophilic ring-opening methodology as for the cyclohexanediyl-bridged [OSSO]-type ligands, a family of trans-1,2-azathiacyclohexanediyl-bridged [OSNO]-type bis(phenols) was synthesised. In this fashion [2,2’-(HOC6H2-6-tBu-4-R1)2SC6H10NR2] (R1 = tBu, Me; R2 = H, Me), [2,2’-(HOC6H2-4,6-tBu2)2SC6H10N=CH] and [2,2’-(HOC6H2-4,6-tBu2)2SC6H10NHCH2] were obtained. Although for such asymmetrical ligands many isomers are possible, formation of titanium complexes of the first ligands proceeded with perfect diastereoselectively; the half-salen and half-salan hybrids gave a mixture of two isomers (Scheme S.4). All titanium complexes were configurationally stable in solution up to 100°C. For [Ti{2,2’-(HOC6H2-6-tBu-4-R1)2SC6H10NR2}X2] (X = Cl, OiPr), cis-alpha and cis-beta2 coordination modes of the ligand were observed, depending on the nitrogen substituent and on the auxiliary ligand. In [Ti{2,2’-(HOC6H2-4,6-tBu2)2SC6H10N=CH}Cl2] and [Ti{2,2’-(HOC6H2-4,6-tBu2)2SC6H10NHCH2}Cl2] both configurations coexist and did not interconvert at elevated temperatures, but HCl catalysed the isomerization from cis-alpha to cis-beta2. Upon activation with methylaluminoxane, [Ti{OSNO}X2] complexes were moderately active in the polymerization of styrene and gave trace activity in the polymerization of 1-hexene, thus combining the worst polymerisation properties of their parent ligands, rather than the best. A different way to influence polymerisation properties is to investigate the effect of the linkage between the arene groups. For group 4 [ONNO]-type catalysts, only salen- and salan-type complexes are known; 1,4-diazabutanediyl-bridged bis(phenolato) species were not examined. These ligands were synthesised by reaction of the 3,5-tBu2-catechol with ethylene diamine and optional methylation of the nitrogen atoms. With the appropriate metal precursors MX4 (M = Ti, Zr, Hf) a series of group 4 metal dichloro and di(isopropoxy) complexes [M{2,2’-(OC6H2-4,6-tBu2)2NRC2H4NR}X2] (Ti: R = H, Me; X = Cl, OiPr; Zr, Hf: X = Cl; R = Me) was obtained. Whilst [ONNO] zirconium and hafnium dichlorides gave configurationally stable cis-alpha species up to 100°C, titanium [ONNO] complexes gave both cis-alpha and cis-beta isomers (Scheme S.5). The configuration of [Ti{2,2’-(OC6H2-4,6-tBu2)2MeNC2H4NMe}Cl2] and [Ti{2,2’-(OC6H2-4,6-tBu2)2HNC2H4NH}Cl2] changed from cis-beta to cis-alpha at elevated temperatures. Upon activation with methylaluminoxane, all precatalysts polymerised styrene with modest activity. Good (M = Ti) to excellent (M = Zr, Hf) activity in the atactic polymerization of 1-hexene was observed."],"dc:identifier":["https://publications.rwth-aachen.de/record/63097","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-124555%22"],"dc:language":["eng"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-33115"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University 161 S. : graph. Darst. (2009). = Aachen, Techn. Hochsch., Diss., 2009"],"dc:subject":["info:eu-repo/classification/ddc/540","Metallorganische Chemie","Polymerisation","Styrol","Chemie","organometallic chemistry","chirality","olefin polymerisation","styrene"],"dc:title":["Group 4 metal and vanadium bis(phenolato) complexes : synthesis, structure and olefin polymerisation activity"],"dc:type":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-30T19:43:35Z"}