Fan Huijun, Chang Guanru, Bi Huiqin, Gui Xu, Wang Hui, Xu Guoyong, Dai Shengyu
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 230601, China.
School of Chemistry and Chemical Engineering, Key Laboratory of Inorganic Functional Material, Huangshan University, Huangshan, Anhui 245041, China.
ACS Polym Au. 2021 Nov 22;2(2):88-96. doi: 10.1021/acspolymersau.1c00039. eCollection 2022 Apr 13.
Low-molecular-weight (MW) ethylene oligomers with hyperbranched microstructures are often difficult to be synthesized by traditional catalytic processes. In this study, a series of -terphenyl iminopyridyl ligands and the corresponding Pd(II) and Ni(II) complexes bearing remote conjugated substituents with different electronic effects (H, Me, F, Cl, and Bu) were synthesized in a simple and efficient way. These Pd(II) and Ni(II) complexes were highly effective in the ethylene oligomerization and co-oligomerization with methyl acrylate (MA). Low-MW ethylene oligomers with hyperbranched microstructures were generated using the iminopyridyl Pd(II) and Ni(II) complexes in ethylene oligomerization. More importantly, polar functionalized ethylene-MA co-oligomers with low MWs and varying incorporation ratios were generated via ethylene and MA co-oligomerization using the Pd(II) complexes. Most notably, these ethylene oligomers obtained by different metal species showed a significant difference in microscopic chain architectures. The remote conjugated electron effect showed little effect on the polymerization parameters of the iminopyridyl system, which is very different from those of the salicylaldiminato system.
具有超支化微观结构的低分子量（MW）乙烯低聚物通常难以通过传统催化方法合成。在本研究中，以简单高效的方式合成了一系列带有具有不同电子效应（H、Me、F、Cl和Bu）的远程共轭取代基的三联苯亚氨基吡啶配体以及相应的Pd（II）和Ni（II）配合物。这些Pd（II）和Ni（II）配合物在乙烯齐聚以及与丙烯酸甲酯（MA）的共齐聚反应中表现出高效性。在乙烯齐聚反应中，使用亚氨基吡啶基Pd（II）和Ni（II）配合物生成了具有超支化微观结构的低MW乙烯低聚物。更重要的是，通过使用Pd（II）配合物进行乙烯与MA的共齐聚反应，生成了具有低MW且不同掺入比例的极性官能化乙烯-MA共低聚物。最值得注意的是，通过不同金属物种获得的这些乙烯低聚物在微观链结构上表现出显著差异。远程共轭电子效应在亚氨基吡啶体系的聚合参数上几乎没有影响，这与水杨醛亚胺体系非常不同。
