Ring Opening Polymerization ofω-Pentadecalactone by Weakly Oxophilic Fe(II)-based Catalytic Systems Bearing Bulkyα-Diimine Ligands  

作　　者：Li-Jia Liu Wen-Peng Zhao Li-Shuang Ma Chun-Yu Zhang Feng Wang Xue-Quan Zhang Heng Liu 

机构地区：[1]Shandong ProvincialCollege Laboratoryof Rubber Materialand Engineering/Key Laboratory of Rubber-Plastics,MinistryofEducation,Schoolof Polymer Science and Engineering,Qingdao University of Science&Technology,Qingdao 266042,China [2]College of Chemistry and Chemical Engineering,China University of Petroleum(East China),Qingdao 266580,China

出　　处：《Chinese Journal of Polymer Science》2025年第4期640-654,共15页高分子科学(英文版)

基　　金：financially supported by the National Natural Science Foundation of China(Nos.21901020 and 22003076);China Postdoctoral Science Foundation(No.2021M701818);Shandong Provincial Natural Science Foundation(No.ZR2022QE237);the Qingdao Postdoctoral Applied Research Project.H.Liu sincerely acknowledges financial support from the Taishan Scholars Program(No.tsqn202211165)。

摘　　要：High catalytic efficiencies in ring opening polymerization(ROP)of a large ring-sized macrolactone,ω-pentadecalactone(PDL),by using transition metal Fe(II)-based catalysts were achieved for the first time in this study.Benefited from the bulky nature of the ligatedα-diimine ligands,as evidenced from single-crystal structures,as well as the weakly oxophilic nature of the metal centers,chain transesterification reactions could be partially suppressed,allowing the polymerization proceed in a living-like and semi-controllable manner,i.e.good linear dependence of propagation rates on catalyst concentration and PDL concentration as observed in the detailed kinetics studies.The whole polymerization proceeds via a“coordination-insertion”mechanism,and with the aid of density functional theory(DFT)calculation studies,a“slow insertion→fast elimination”manner was demonstrated for the monomer propagation step,suggesting the insertion of Fe-OR into the carbonyl group C=O as the rate-determining step.The present catalytic system also showed fast chain transfer reactions to alcohol compounds,affording quasi-immortal characteristics.DFT calculations showed that such a transfer reaction only required an energy barrier of 6.4 kcal/mol,performing a good consistency with the fast chain transfer rates.

关 键 词：ω-Pentadecalactone Ring opening polymerization Polyester Ferrous catalysts 

分 类 号：O631.5[理学—高分子化学]