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RESEARCH PRODUCT

Titanium Complexes of Chelating, Dianionic O,S,O‐Bisphenolato Ligands: Syntheses, Characterisation, and Catalytic Activity

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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 )(NH 2 tBu)] (6). Reaction of 2 with an excess of NHiPr 2 provides a mixture of compounds: ionic [NH 2 iPr 2 ][Ti(tbop-κ 3 O,S,O)Cl 3 ] (7).CH 2 Cl 2 and molecular [Ti 2 (μ-tbop-κ 3 O,S,O) 2 -Cl 2 (NiPr 2 ) 2 ] (8). The structures of 1-8 were confirmed by NMR spectroscopy; complexes 1, 5, 6 and 7 were further investigated by X-ray crystallography. Compounds 1, 2, 4 and 5, when supported on MgCl 2 and activated with alkylaluminiums, effectively polymerise ethene.