0000000000136525
AUTHOR
Katarzyna R. Przybylak
Titanium Complexes Stabilized by a Sulfur‐Bridged Chelating Bis(aryloxo) Ligand as Active Catalysts for Olefin Polymerization
The mixed-ligand complexes [Ti2(μ-OR)2(OR)2(κ3-tbop)2] (1a) for R = Me and (1b) R = Et were prepared by the reaction of Ti(OR)4 and H2tbop {H2tbop = 2,2′-thiobis[4-(1,1,3,3-tetramethylbutyl)phenol]} in methanol. Treatment of 1a and 1b with AlMe3 led to the substitution of terminal alkoxy groups to create the organometallic compounds [Ti2(μ-OR)2(κ3-tbop)2(Me)2] (2a) for R = Me and (2b) for R = Et. Controlled hydrolysis of 2b causes the evolution of methane and the formation of the titanoxane compounds [{Ti2(μ-OEt)2(κ3-tbop)2}2(μ-O)2]·2CH2Cl2 (3). Structures of 1a, 1b, 2a, 2b, and 3 were confirmed by NMR spectroscopy; 1b and 3 were further investigated with X-ray crystallography. Compounds 1a…
Syntheses, Structure, and Reactivity of Chiral Titanium Compounds: Procatalysts for Olefin Polymerization
Titanium complexes with chelating alkoxo ligands have been synthesised with the aim to investigate titanium active centres in catalytic ethylene polymerisation. The titanium complexes cis-[TiCl2(η2-maltolato)2] (1, 89 %), and cis-[TiCl2(η2-guaiacolato)2] (2, 80 %) were prepared by direct reaction of TiCl4 with maltol and guaiacol in toluene. The addition of maltol to [Ti(OiPr)4] in THF results in the formation of species [Ti(OiPr)2(maltolato)2] (3, 82 %). The titanium compound cis-[Ti(OEt)2(η2-maltolato)2] (4, 74 %) was obtained by the transesterification reaction of species 3 with CH3CO2Et. When compound 4 is dissolved in THF a dinuclear species [Ti2(μ-OEt)2(OEt)4(η2-maltolato)2] (5, 45 %)…
Titanium Complexes of Chelating, Dianionic O,S,O‐Bisphenolato Ligands: Syntheses, Characterisation, and Catalytic Activity
Titanium complexes based on 2,2'-thiobis[4-(1,1,3,3-tetramethylbutyl)phenolato] (tbop) are prepared by reaction of TiCl 4 or Ti(NMe 2 ) 4 with the parent biphenol. Three new complexes are reported: [Ti 2 (μ-tbop-κ 3 O,S,O)(μ-tbop-κ 2 O,O)-(tbop-κ 3 O,S,O)Cl 2 ] (1).2CH 3 CN, [Ti 2 (μ-tbop-κ 3 O,S,O) 2 Cl 4 ] (2) and [Ti(tbop-κ 3 O,S,O) 2 ] (3). Substitution of the chlorides in 1 and 2 by 2,6-diisopropylphenolato and imido (NtBu) ligands generates the new compounds [Ti 2 (μ-tbop-κ 3 O,S,O) 2 -Cl 2 (dipp) 2 ] (4).Et 2 O and [Ti 2 (μ-tbop-κ 3 O,S,O) 2 (NtBu) 2 -(NH 2 tBu) 2 ] (5), respectively. Treatment of 5 with crude Me 3 -SiCl, containing Me 3 SiOH, produces [Ti(tbop-κ 3 O,S,O)Cl(O-SiMe 3 …