Stereospecific Styrene Polymerization by Methylalumoxane-Activated Ti (IV) N-Trimethylsilylamido Complexes Bearing the N-Biphenyl or N-(6-(2-(Diethylboryl)phenyl)-Pyrid-2-yl) Motif

作者：Narayana Gurram Venkata; Xu Guangjuan; Wang Dongren; Speiser Maria; Frey Wolfgang; Buchmeiser Michael R^*

来源：Macromolecular Chemistry and Physics, 2014, 215(20): 2007-2013.

DOI：10.1002/macp.201300764

• catalysts
• polymerization
• styrene
• syndiotactic polymers

Cp%26apos;TiCl2(N-(6-(2-(diethylboryl)phenyl)pyrid-2-yl)SiMe3), [Cp%26apos; = C5H5 (3), C-5(CH3)(5) (4)], and the aminoborane-free half-titanocene analogs with the general formula: Cp%26apos;TiCl2(N-(biphenyl-3-yl)SiMe3); [Cp%26apos; = C5H5 (7), C-5(CH3)(5) (8)] are synthesized and used in the polymerization of styrene. All the pre-catalysts are active in styrene polymerization, %26gt;90% syndiotactic poly(styrene) (st-PS) is produced, exceeding that of their ansa-homologues (C-5(CH3)(5))TiCl2(6-(2-(diethylboryl)phenyl)pyrid-2-ylamido)(dimethylsilyl) (9) and (C-5(CH3)(5))TiCl2(3-biphen-3-ylamido)(dimethylsilyl) (10) both in activity and molecular weight. Pre-catalyst 8 allows for the synthesis of high-molecular-weight st-PS with activities up to 5000 kg(st-PS) mol(cat)(-1) h(-1). Implications of the 2-(diethylboryl)phenyl)pyrid-2-yl group on polymerization activity and molecular weight are discussed.

• 出版日期2014-10