- Synthesis and styrene polymerization behavior of new titanium complexes Cp*TiCl(OCHRCH2NAr)
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A series of titanium complexes Cp*TiCl(OCHRCH2NAr) (Cp* = C5Me5, R = H, Ar = phenyl (2a); R = H, Ar = 2,6-dimethylphenyl (2b); R = Me, Ar = phenyl (2c); R = Me, Ar = 2,6-dimethylphenyl (2d)) was prepared by the reaction of corresponding 2-phenylamino-ethanol derivatives with Cp*TiCl3 in the presence of excessive triethylamine. All the titanium complexes display higher catalytic activity towards the syndiospecific polymerization of styrene in the presence of modified methylaluminoxane (MMAO) as a cocatalyst, yielding higher molecular weight polystyrenes with higher syndiotacticities and melting temperatures (Tm) than their mother complex Cp*TiCl3. When 2-(2,6-diisopropyl-phenylamino)-ethanol was reacted with Cp*TiCl 3, an unexpected monodentate complex Cp*TiCl 2(OCH2CH2NHC6H3 iPr2-2,6) 3 was obtained. The complex 3 displays relative low catalytic activity towards styrene polymerization, but produces higher molecular weight polystyrene with higher syndiotacticities.
- Chen, Jie,Li, Yue-Sheng,Wu, Ji-Qian,Hu, Ning-Hai
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