Positional Electronic Effects in Iminopyridine-N-oxide Nickel Catalyzed Ethylene Polymerization  

作　　者：Mingjun Chi Ao Chen Wenmin Pang Chen Tan Changle Chen 

机构地区：[1]CAS Key Laboratory of Soft Matter Chemistry,Hefei National Laboratory for Physical Sciences at the Microscale,Department of Polymer Science and Engineering,University of Science and Technology of China,Hefei,Anhui 230026,China [2]Institutes of Physical Science and Information Technology,Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education,Anhui University,Hefei,Anhui 230026,China

出　　处：《Chinese Journal of Chemistry》2021年第6期1683-1689,共7页中国化学（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.52025031,21690071,22001004,U19B6001 and U1904212);K.C.Wong Education Foundation。

摘　　要：A series of dibenzhydryl-based iminopyridine-N-oxide ligands bearing a range of electron-donating or-withdrawing substituents(OMe,H;and NO_(2))and corresponding nickel pre-catalysts are prepared and characterized.The substituents are installed at different positions on the ligand structure,including 4-position of the pyridine-N-oxide moiety(position X)and 4-position of the aniline moiety(position Y).These nickel pre-catalysts are highly active in ethylene polymerization with the addition of very little amount of aluminum cocatalysts,leading to the formation of polyethylenes with molecular weights of well above one million.Electron-donating substituents make the catalysts sensitive to polymerization temperature.In contrast,the catalysts bearing electron-withdrawing NO_(2) substituents show relatively steady performances at different temperatures.Most importantly,we demonstrate that different substituents and different positions both play important roles in determining the properties of nickel catalysts.This provides an alternative strategy for the future design of high-performance polymerization catalyst.

关 键 词：ETHYLENE POLYMERIZATION NICKEL lminopyridine-N-oxide Substituent effects 

分 类 号：O62[理学—有机化学]