Bimetallic Aluminum Complexes Supported by Bis(salicylaldimine) Ligand: Synthesis, Characterization and Ring-opening Polymerization of Lactide  

作　　者：Tong Shi Quan-De Zheng Wei-Wei Zuo Shao-Feng Liu Zhi-Bo Li 

机构地区：[1]Key Laboratory of Biobased Polymer Materials, Shandong Provincial Education Department [2]School of Polymer Science and Engineering, Qingdao University of Science and Technology [3]State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University

出　　处：《Chinese Journal of Polymer Science》2018年第2期149-156,共8页高分子科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No. B040102);State Key Laboratory for Modification of Chemical Fibers and Polymer Materials (Donghua University) (No. LK1501);Department of Science and Technology of Qingdao and Shandong Province (Nos. 159181jch and 2015GGX107015)

摘　　要：Two types of bifunctional bis（salicylaldimine） ligands（syn-L and anti-L） were designed and synthesized to support bimetallic aluminum complexes. Owing to the rigid anthracene skeleton, syn-L and anti-L successfully locked two Al centers in close proximity（syn-Al2） and far apart（anti-Al2）, respectively. The distance between two Al centers in syn-Al2 was defined by X-ray diffraction as 6.665 ？, which is far shorter than that in anti-Al2. In the presence of stoichiometrical Bn OH, syn-Al2 and anti-Al2 were both efficient for ring-opening polymerization（ROP） of rac-LA with the former being more active. In the presence of excess Bn OH, syn-Al2 showed an efficient and immortal feature, consistent with high conversions, matched Mns, narrow molecular weight distributions and end group fidelity, while anti-Al2 had a much lower activity or even became entirely inactive due to rapid decomposition, indicated by in situ ～1H-NMR experiments of Al complexes with Bn OH.Two types of bifunctional bis（salicylaldimine） ligands（syn-L and anti-L） were designed and synthesized to support bimetallic aluminum complexes. Owing to the rigid anthracene skeleton, syn-L and anti-L successfully locked two Al centers in close proximity（syn-Al2） and far apart（anti-Al2）, respectively. The distance between two Al centers in syn-Al2 was defined by X-ray diffraction as 6.665 ？, which is far shorter than that in anti-Al2. In the presence of stoichiometrical Bn OH, syn-Al2 and anti-Al2 were both efficient for ring-opening polymerization（ROP） of rac-LA with the former being more active. In the presence of excess Bn OH, syn-Al2 showed an efficient and immortal feature, consistent with high conversions, matched Mns, narrow molecular weight distributions and end group fidelity, while anti-Al2 had a much lower activity or even became entirely inactive due to rapid decomposition, indicated by in situ ～1H-NMR experiments of Al complexes with Bn OH.

关 键 词：Bimetallic catalyst Aluminum complex Ring-opening polymerization Immortal polymerization POLYESTER 

分 类 号：O641.4[理学—物理化学]