of BBL. The influence imposed by lanthanides of different ionic radii and initiating groups of different structures on the activity, controllability, and stereoselectivity of polymerization were systematically studied and compared. Highly heterotactic PLA (P r up to 0.99) and syndiotactic PHB (P r ≈ 0.81) with high molecular weight and narrow polydispersity formed and were automatically capped with
一系列中性双
金属
镧系芳氧化物p -C 6 H 4 [OLnL(THF)n ] 2 [Ln = Y(1),Yb(2),Sm(3)(n = 1)和
LA(4)(n = 2),L = Me 2 NCH 2 CH 2 N CH 2-(2-OC 6 H 2 - t Bu 2 -3,5)} 2 ]和醇盐p -C 6 H 4 CH 2 [OLnL(THF) )] 2 通过Ln(C 5 H 5)3(THF),LH 2与p-的一锅反应合成了由胺桥联的双
酚盐
配体支撑的[Ln = Y(5),Yb(6)] 。苯二醇和1,4-苯二
甲醇。所有络合物已被充分表征通过元素分析,单晶X射线衍射分析和IR和多核NMR光谱(在的情况下1,4和5)。对它们的催化行为的研究表明,通常,所有配合物都是外消旋
丙交酯(
LA)和外消旋-
β-丁内酯(BBL),但BBL除外3和4。系统地研究和比较了不同离子半径的
镧系元素和不同结构的引发基团对