Efficient initiators for the ring‐opening polymerization of L‐lactide: Synthesis and characterization of NNO‐tridentate Schiff‐base zinc complexes
Efficient initiators for the ring‐opening polymerization of L‐lactide: Synthesis and characterization of NNO‐tridentate Schiff‐base zinc complexes
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L-丙交酯开环聚合的有效引发剂：NNO-三齿希夫碱锌配合物的合成和表征
DOI：
10.1002/pola.22956
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Chu‐Chieh Lin
中科院分区：
文献类型：
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作者：
Wen;Yong Huang;Chu‐Chieh Lin
制备了一系列以锌烷氧化物与nno -三齿希夫碱配体（L1H-L6H）为配体的l -丙交酯开环聚合催化剂。二乙基锌（ZnEt2）与L1H-L6H反应分别生成[(μ-L)ZnEt]2 （1a-6a）。化合物1a-6a与苯甲醇（BnOH）进一步反应，分别生成相应的化合物[LZn(μ-OBn)]2 （1b-6b）。x射线晶体结构研究表明，所有这些化合物1a-6a都是通过希夫碱配体的酚氧原子二聚体桥接的。然而，1b-6b的分子结构表现为二聚体特征，桥接苯烷氧基氧原子。由1b-6b引发的l -丙交酯开环聚合反应进行迅速，分子量控制良好，所得聚合物分子量分布非常窄。实验结果表明，nno配体亚胺碳上的取代基对锌配合物的反应性有显著影响。©2008 Wiley期刊公司[J] .化学工程学报，2008,31 (4):559 - 567
A series of efficient catalysts, based on zinc alkoxides coordinated with NNO-tridentate Schiff-base ligands (L1H-L6H), for ring opening polymerization of L-lactide have been prepared. The reactions of diethyl zinc (ZnEt2) with L1H-L6H yielded [(μ-L)ZnEt]2 (1a–6a), respectively. Further reaction of compounds 1a–6a with benzyl alcohol (BnOH) produced the corresponding compounds of [LZn(μ-OBn)]2 (1b–6b), respectively. X-ray crystal structural studies reveal that all of these compounds 1a–6a are dimeric bridging through the phenolato oxygen atoms of the Schiff-base ligand. However, the molecular structures of 1b–6b show a dimeric character bridging through the benzylalkoxy oxygen atoms. Ring-opening polymerization of L-lactide, initiated by 1b–6b, proceeds rapidly with good molecular weight control and yields polymer with a very narrow molecular weight distribution. Experimental results show that the substituents on the imine carbon of the NNO-ligand affect the reactivity of zinc complexes dramatically. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6466–6476, 2008