Aluminum Complexes of Monopyrrolidine Ligands for the Controlled Ring-Opening Polymerization of Lactide
Aluminum Complexes of Monopyrrolidine Ligands for the Controlled Ring-Opening Polymerization of Lactide
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DOI：
10.1021/acs.organomet.8b00161
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发表时间：
2018-06-11
期刊：
影响因子：
2.8
通讯作者：
Jones, Matthew D.
中科院分区：
文献类型：
--
作者：
Beament, James;Mahon, Mary F.;Jones, Matthew D.
在本文中，我们报告了一系列 Al(III) 半萨兰配合物的完整表征（溶液态核磁共振波谱和固态结构）及其在外消旋丙交酯开环聚合中的应用。根据所使用的配体和络合的化学计量，分离出Al(X)(2)Me或Al(X)Me-2形式的结构。有趣的是，Al(2)(2)Me 和 Al(2)Me-2 产生具有强全同立构偏差的 PLA（P-m 高达 0.80），而所有其他配合物产生无规立构 PLA。这与最近对类似萨兰配体系统的研究形成鲜明对比。获得了具有可预测分子量和窄分布的 PLA。从配体的空间和电子性质方面讨论了结果。
In this paper we report the full characterization (solution-state NMR spectroscopy and solid-state structures) of a series of Al(III) half-salan complexes and their exploitation for the ring-opening polymerization of rac-lactide. Depending on the ligand employed and stoichiometry of the complexation, structures of the form Al(X)(2)Me or Al(X)Me-2 were isolated. Interestingly Al(2)(2)Me and Al(2)Me-2 produce PLA with a strong isotactic bias (P-m up to 0.80), whereas all other complexes produced atactic PLA. This is in contrast to recent studies on similar salan ligand systems. PLAs with predictable molecular weights and narrow distributions were achieved. The results are discussed in terms of steric and electronic properties of the ligands.