The synthesis, structure and ethene polymerisation catalysis of mono(salicylaldiminato) titanium and zirconium complexes
Pennington, Dale A.; Clegg, William; Coles, Simon J.; Harrington, Ross W.; Hursthouse, Michael B.; Hughes, David L.; Light, Mark E.; Schormann, Mark; Bochmann, Manfred; Lancaster, Simon J.; Pennington Dale A.; Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy; Clegg William; School of Natural Sciences (Chemistry); Coles Simon J.; School of Chemistry, University of Southampton; Harrington Ross W.; School of Natural Sciences (Chemistry); Hursthouse Michael B.; School of Chemistry, University of Southampton; Hughes David L.; Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy; Light Mark E.; School of Chemistry, University of Southampton; Schormann Mark; Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy; Bochmann Manfred; Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy; Lancaster Simon J.; Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy
Журнал:
Dalton Transactions
Дата:
2005
Аннотация:
The silyl ethers 3-Bu<sup>t</sup>-2-(OSiMe3)C6H3CH.dbd;NR (2aâ e) have been prepared by deprotonation of the known iminophenols (1aâ e) and treatment with SiClMe3 (a, R = C6H5; b, R = 2,6-Pr<sup>i</sup>2C6H3; c, R = 2,4,6-Me3C6H2; d, R = 2-C6H5C6H4; e, R = C6F5). 2aâ c react with TiCl4 in hydrocarbon solvents to give the binuclear complexes [Ti{3-Bu<sup>t</sup>-2-(O)C6H3CH.dbd;N(R)}Cl(µ-Cl3)TiCl3] (3aâ c). The pentafluorophenyl species 2e reacts with TiCl4 to give the known complex Ti{3-Bu<sup>t</sup>-2-(O)C6H3CH.dbd;N(R)}2Cl2. The mononuclear five-coordinate complex, Ti{3-Bu<sup>t</sup>-2-(O)C6H3CH.dbd;N(2,4,6-Me3C6H2)}Cl3 (4c), was isolated after repeated recrystallisation of 3c. Performing the dehalosilylation reaction in the presence of tetrahydrofuran yields the octahedral, mononuclear complexes Ti{3-Bu<sup>t</sup>-2-(O)C6H3CH.dbd;N(R)}Cl3(THF) (5aâ e). The reaction with ZrCl4(THF)2 proceeds similarly to give complexes Zr{3-Bu<sup>t</sup>-2-(O)C6H3CH.dbd;N(R)}Cl3(THF) (6bâ e). The crystal structures of 3b, 4c, 5a, 5c, 5e, 6b, 6d, 6e and the salicylaldehyde titanium complex Ti{3-Bu<sup>t</sup>-2-(O)C6H3CH.dbd;O}Cl3(THF) (7) have been determined. Activation of complexes 5aâ e and 6bâ e with MAO in an ethene saturated toluene solution gives polyethylene with at best high activity depending on the imine substituent.
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