M = Fe: 3d, M = Co: 4d) has been synthesized, characterized, and investigated as precatalysts for the polymerization of ethylene in the presence of modified methylaluminoxane (MMAO). The substituents of pyridinebisimine ligands and their positions located significantly influence catalyst activity and polymer property. It is found that the catalytic activities of the iron complexes/MMAO systems are mainly
一系列2,6-双(亚
氨基)
吡啶铁(II)和
钴(II)配合物[2,6-(ArNCMe)2 C 5 H 3 N] MCl 2(Ar = 2,6- i -Pr 2 C 6 H 3,M = Fe:3a,M = Co:4a; Ar =2,4,6 - i- Pr 3 C 6 H 2,M = Fe:3b,M = Co:4b; Ar = 2, 6-我-Pr 2 -4-BRC 6 ħ 2,M = Fe为图3c中,M = CO:4C ; Ar为2,4-我-Pr已经合成,表征和研究了2 -6-BrC 6 H 2,M = Fe:3d,M = Co:4d作为改性甲基铝氧烷(
MMAO)存在下
乙烯聚合的预催化剂。
吡啶双
亚胺配体的取代基及其位置显着影响催化剂活性和聚合物性能。发现
铁络合物/
MMAO体系的催化活性主要由电子效应决定,而
钴络合物/
MMAO体系的催化活性主要由阻碍效应控制。