Titanium Complexes Having Chelating Diaryloxo Ligands Bridged by Tellurium and Their Catalytic Behavior in the Polymerization of Ethylene

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• 作者：Yuushou Nakayama ; Kouji Watanabe ; Norikazu Ueyama ; Akira Nakamura ; Akira Harada ; and Jun Okuda
• 刊名：Organometallics
• 出版年：2000
• 出版时间：June 26, 2000
• 年：2000
• 卷：19
• 期：13
• 页码：2498 - 2503
• 全文大小：119K
• 年卷期：v.19,no.13(June 26, 2000)
• ISSN：1520-6041

文摘

A series of titanium complexes having tellurium-bridged chelating bis(aryloxo) ligands,[TiX₂{2,2'-Te(4-R-6-R'-C₆H₂O)₂}]₂ (5b, X = Cl, R = Me, R' = ^tBu; 6a, X = OⁱPr, R = R' = H;6b, X = OⁱPr, R = Me, R' = ^tBu), were prepared. 5b and 6b were determined by X-raycrystallography to have chloro- and isopropoxo-bridged dimeric structures. The structuraldata for these complexes indicated that the Ti-Te coordination bonds were stronger thanthe similar Ti-S coordination bonds in the corresponding sulfur-bridged complexes. Thereaction of (C₅R₅)TiCl₃ (R = H, Me) with 2,2'-Te(4-R-6-R'-C₆H₂OLi)₂ gave monocyclopentadienyl derivatives, (C₅R₅)TiCl{2,2'-Te(4-Me-6-^tBu-C₆H₂O)₂} (7, R = H; 8, R = Me). Themonomeric four-legged piano-stool geometry of 8 was revealed by X-ray analysis. Uponaddition of methylaluminoxane (MAO), these complexes catalyzed the polymerization ofethylene. The activities of the tellurium-bridged complexes were found to be significantlyhigher than those of the corresponding methylene-bridged complex.