the Y3+ ion in a κ3-fashion. Compounds 1–3 initiate ring-opening polymerization (ROP) of ɛ-caprolactone (ɛ-CL) and racemic lactide (rac-LA) in toluene at 25 °C. The obtained polylactides are characterized by atactic structures Pr = 0.54–0.58, and rather narrow polydispersities (Mw/Mn = 1.1–1.5). For ɛ-caprolactone polymerization, the resulting polymers have moderate polydispersities (Mw/Mn = 1.4–2.4)
摘要由单阴离子四齿
酚盐
配体[[C5H4NCH2)2NCH2(3,5-tBu2C6H2O)] Ln(
BH4)2 [Ln = Y(1),Nd(2),Sm(3)]配位的新型
镧系元素双(
硼氢化物)配合物通过Ln( )3(THF)3与等摩尔量的
苯酚锂[(C5H4NCH2)2NCH2(3,5-tBu2C6H2O)Li]在THF中于60°C的反应合成。从
甲苯重结晶后,分别以75%,64%和69%的收率分离出复合物。X射线分析表明,
苯酚的
配体在1中是四齿的,而两个
硼氢化物基团则以κ3的方式与Y3 +离子配位。化合物1-3在25°C的
甲苯中引发
ε-己内酯(ɛ-CL)和消旋
丙交酯(rac-
LA)的开环聚合(ROP)。所获得的聚
丙交酯的特征在于无规结构Pr = 0.54-0.58,并且具有较窄的多分散性(Mw / Mn = 1.1-1.5)。