Quasi-Living trans-1,4-Polymerization of Isoprene by Cationic Rare Earth Metal Alkyl Species Bearing a Chiral (S,S)-Bis(oxazolinylphenyl)amido Ligand

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• 作者：Hui Liu ; Jianyun He ; Zhanxiong Liu ; Zhengguo Lin ; Gaixia Du ; Shaowen Zhang ; Xiaofang Li
• 刊名：Macromolecules
• 出版年：2013
• 出版时间：May 14, 2013
• 年：2013
• 卷：46
• 期：9
• 页码：3257-3265
• 全文大小：384K
• 年卷期：v.46,no.9(May 14, 2013)
• ISSN：1520-5835

文摘

A series of chiral mononuclear dialkyl complexes [(S,S)-BOPA]Ln(CH₂SiMe₃)₂ (1, 2) (BOPA = (S,S)-bis(oxazolinylphenyl)amido; Ln = Sc (1); Ln = Lu (2)) and binuclear alkyl complexes [慰-(S)-OPA鈥揅₆H₄鈥?CH₂SiMe₃)C鈺怤鈥揅H(ⁱPr)CH₂鈥揙]Ln(CH₂SiMe₃)}₂ (3,4) (OPA = (oxazolinylphenyl)amine; Ln = Y (3); Ln = Tm (4)) have been synthesized in moderate yields via one-pot acid鈥揵ase reactions by use of the tris(trimethylsilylmethyl) rare earth metal complexes with the chiral tridentate (S,S)-bis(oxazolinylphenyl)amine ligand. In the presence of activator with or without a small amount of AlⁱBu₃, the dialkyl complexes 1 and 2 exhibit very high activities (up to 6.8 脳 10⁵ g mol_Ln^鈥? h^鈥?) and trans-1,4-selectivity (up to 100%) in the quasi-living polymerization of isoprene, yielding the trans-1,4-PIPs with moderate molecular weights (M_n = (0.2鈥?.0) 脳 10⁵ g/mol) and narrow molecular weight distributions (M_w/M_n = 1.02鈥?.66).