Aluminum and zinc complexes supported by functionalized phenolate ligands: Synthesis, characterization and catalysis in the ring-opening polymerization of ε-caprolactone and rac-lactide
作者:Cheng Zhang、Zhong-Xia Wang
DOI:10.1016/j.jorganchem.2008.07.002
日期:2008.9
ε-caprolactone was studied. The zinc complexes (4a–4d) exhibited higher catalytic activity than the aluminum complexes (3a–3e). The diphenolato zinc complex 5 showed lower catalytic activity than the ethylzinc complexes 4a–4d. The aluminum complex (3b) is inactive to initiate the ROP of rac-lactide, while the zinc complex (4d) is active initiator for the ROP of rac-lactide, giving atactic polylactide.
合成并表征了一系列由官能化酚盐配体支撑的铝和锌配合物。2-(3,5-R 2 C 3 N 2)C 6 H 4 NH 2(R = Me,Ph)与水杨醛或3,5-二叔丁基水杨醛反应制得2--((2-(1H -吡唑-1-基)苯基亚氨基)甲基)苯酚衍生物2a - 2d。用当量治疗2a - 2d。AlR 2 3(R 2 = Me,Et)的摩尔数给出了相应的芳基铝氧化物3a - 3e,同时与当量反应。ZnEt2得到芳基氧化锌4a - 4d。用0.5当量处理2c。ZnEt 2形成双酚锌复合物5。所有新化合物均通过1 H和13 C NMR光谱及元素分析进行了表征。配合物3a,4a和5的结构通过单晶X射线衍射技术进一步表征。配合物的催化活性的3 - 5朝向ε己内酯的开环聚合进行了研究。锌络合物(4a - 4d)比铝配合物(3a - 3e)表现出更高的催化活性。双酚锌复合物5的催化活性低于乙基锌复合物4a -