文献类型：期刊文献

英文题名：Ring-opening polymerization of rac-lactide, copolymerization of rac-lactide and ε-caprolactone by zinc complexes bearing pyridyl-based tridentate amino-phenolate ligands

作者：Fang, Chaoli[1,2];Ma, Haiyan[1]

机构：[1]East China Univ Sci & Technol, Sch Chem & Mol Engn, Shanghai Key Lab Funct Mat Chem, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem & Mol Engn, Lab Organometall Chem, 130 Meilong Rd, Shanghai 200237, Peoples R China

年份：2019

卷号：119

起止页码：289

外文期刊名：EUROPEAN POLYMER JOURNAL

收录：;EI(收录号：20193207284243);WOS:【SCI-EXPANDED(收录号:WOS:000489191900033)】；

基金：This work is subsidized by the National Natural Science Foundation of China (NNSFC, 21474028 and 21871082). All the financial supports are grate fully acknowledged. H. Ma also thanks the very kind donation of a Braun glove-box by AvH foundation.

语种：英文

外文关键词：Ring-opening polymerization; Zinc complex; Cyclic ester; Copolymerization

摘要：A series of zinc complexes supported by tridentate aminophenolate ligands bearing a substituted pyridyl ring, LZn[N(SiMe3)(2)] = {2-[(6-R-3-pyrid-2-yl)CH2N(R-4)CH2]-4-R-2-6-R-1-C6H2O}, 1: R-1 = Trityl, R-2 = Me, R-3 = Me, R-4 = Bn; 2: R-1 = Trityl, R-2 = Me, R-3 = Me, R-4 = (n)Hex; 3: R-1 = Trityl, R-2 = Me, R-3 = Me, R-4 = Cy; 4: R-1 = Trityl, R-2 = Me, R-3 = Ph, R-4 = Cy; 5: R-l = Trityl, R-2 = Me, R-3 = Bu-t, R-4 = Cy; 6: R-1= R-2 = Bu-t, R-3 = Ph, R-4 = Cy), were synthesized via the reactions of Zn[N(SiMe3)(2)](2) and the corresponding aminophenols. The X-ray diffraction analysis of typical complex 2 confirmed its monomeric nature, where the metal centre is tetra-coordinated by three donors of the aminophenolate ligand and one silylamido group in a distorted tetrahedral geometry. All these zinc complexes were moderately to highly active initiators toward the ring-opening polymerization (ROP) of rac-lactide (rac-LA). The substituents on the ortho-positions of the phenolate and pyridyl rings as well as on the skeleton nitrogen atom of the ligand show significant influences on the catalytic activities and the stereoselectivities of the corresponding complexes toward the polymerization of rac-LA, leading to the production of atactic polylactides (PLAs) via complex 5 (P-m = 0.53) and moderate isotatic bias PLAs via complexes 1-4, 6 (P-m = 0.63-0.66). In addition, complexes 2 and 4 could efficiently initiate the copolymerization of rac-LA and epsilon-CL at 70 degrees C to afford random copolymers with high molecular weights and moderate polydispersities.