title: The synthesis, structure and ethene polymerisation catalysis of mono(salicylaldiminato) titanium and zirconium complexes.
abstract: The silyl ethers 3-But-2-(OSiMe3)C6H3CH=NR (2a-e) have been prepared by deprotonation of the known iminophenols (1a-e) and treatment with SiClMe3 (a, R = C6H5; b, R = 2,6-Pri2C6H3; c, R = 2,4,6-Me3C6H2; d, R = 2-C6H5C6H4; e, R = C6F5). 2a-c react with TiCl4 in hydrocarbon solvents to give the binuclear complexes [Ti{3-But-2-(O)C6H3CH=N(R)}Cl(mu-Cl3)TiCl3] (3a-c). The pentafluorophenyl species 2e reacts with TiCl4 to give the known complex Ti{3-But-2-(O)C6H3CH=N(R)}2Cl2. The mononuclear five-coordinate complex, Ti{3-But-2-(O)C6H3CH=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-But-2-(O)C6H3CH=N(R)}Cl3(THF) (5a-e). The reaction with ZrCl4(THF)2 proceeds similarly to give complexes Zr{3-But-2-(O)C6H3CH=N(R)}Cl3(THF) (6b-e). The crystal structures of 3b, 4c, 5a, 5c, 5e, 6b, 6d, 6e and the salicylaldehyde titanium complex Ti{3-But-2-(O)C6H3CH=O}Cl3(THF) (7) have been determined. Activation of complexes 5a-e and 6b-e with MAO in an ethene saturated toluene solution gives polyethylene with at best high activity depending on the imine substituent.
authors.affiliation: Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich, UK NR4 7TJ.
authors.forename: Dale A
authors.initials: DA
authors.lastname: Pennington
authors.forename: William
authors.initials: W
authors.lastname: Clegg
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Coles
authors.forename: Ross W
authors.initials: RW
authors.lastname: Harrington
authors.forename: Michael B
authors.initials: MB
authors.lastname: Hursthouse
authors.forename: David L
authors.initials: DL
authors.lastname: Hughes
authors.forename: Mark E
authors.initials: ME
authors.lastname: Light
authors.forename: Mark
authors.initials: M
authors.lastname: Schormann
authors.forename: Manfred
authors.initials: M
authors.lastname: Bochmann
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Lancaster