Aluminum Complexes Bearing Bidentate Amido–Phosphine Ligands for Ring-Opening Polymerization of ε-Caprolactone: Steric Effect on Coordination Chemistry and Reactivity
作者:Chuanzhi Wei、Binghao Han、Dejuan Zheng、Quande Zheng、Shaofeng Liu、Zhibo Li
DOI:10.1021/acs.organomet.9b00502
日期:2019.10.14
structures suggested that different substituents on the ligands could lead to unignorable changed coordination environments around the Al center, thus affecting their catalytic properties. In the presence of BnOH, complexes Al1–Al5 efficiently catalyzed the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) with high conversions in a controlled manner, and high molecular weights (Mn up to 118.6
的铝配合物大号阿尔梅2(AL1 - AL5:LH = 2,6-(R 1)2 -4-R 2 -C 6 H ^ 2 NHCH 2 C ^ 6 ħ 4 -2-PPH 2 ; AL1,R 1 = H ,R 2= H;Al 2,R 1= Me,R 2= H;Al 3,R 1=i Pr,R 2= H;Al 4,R 1= Ph2 CH,R 2=i Pr;Al5,R 1 = Cl,R 2 = H)已经合成并通过元素分析和1 H,13 C和31 P NMR表征。溶液中的NMR分析揭示了软P供体的有趣的半不稳定配位。Al2 – Al4的分子结构X射线衍射研究确定了这些元素,显示了所有结构中铝中心周围的扭曲的四面体几何形状。对这些晶体结构的仔细比较表明,配体上的不同取代基可能会导致Al中心周围配位环境的变化不明显,从而影响其催化性能。在BnOH的存在下,复合物AL1 - AL5有效地以受控的方式高转化率和高的分