Neutral Mono(5-aryl-2-iminopyrrolyl)nickel(II) Complexes as Precatalysts for the Synthesis of Highly Branched Ethylene Oligomers: Preparation, Molecular Characterization, and Catalytic Studies
作者:Cláudia A. Figueira、Patrícia S. Lopes、Clara S. B. Gomes、Joselaine C. S. Gomes、Luis F. Veiros、Francisco Lemos、Pedro T. Gomes
DOI:10.1021/acs.organomet.8b00669
日期:2019.2.11
New substituted 5-aryl-2-(N-2,6-diisopropylphenylformimino)-1H-pyrrole ligand precursors reacted with the complex trans-[Ni(o-C6H4Cl)(PPh3)2Cl] to give rise to new mono(2-iminopyrrolyl) nickel(II) complexes with general formula [Niκ2N,N′-5-aryl-NC4H2-2-C(H)═N-2,6-iPr2C6H3}(o-C6H4Cl)(PPh3)]. The pyrrole 5-aryl substituent is a phenyl or a bulky anthracen-9-yl ring, the first being also modified by
新的取代的5-芳基-2-(N -2,6-二异丙基苯基甲亚氨基)-1 H-吡咯配体前体与反式-[Ni(o -C 6 H 4 Cl)(PPh 3)2 Cl]络合物反应,得到上升到新的单(2- iminopyrrolyl)镍(II)与通式[镍κ络合物2 ñ,ñ '-5-芳基- NC 4 H ^ 2 -2-C(H)= N-2,6-我Pr 2 C 6 H 3 }(o -C 6 H 4 Cl)(PPh 3)]。吡咯5-芳基取代基是苯基或大的蒽-9-基环,第一个也被具有释放电子(甲氧基)或吸收电子(氟)特性的对位取代基修饰。这些新化合物通过NMR光谱,元素分析得到了充分表征,其中两个通过单晶X射线衍射得以表征。在不同的反应条件下,将络合物作为无铝催化剂用于乙烯的低聚/聚合反应,即使在作为单组分催化剂进行测试时,也显示出催化活性。添加膦清除剂,例如[Ni(COD)2 ],可显着提高催化活性。所得的聚乙烯产物是具有M