Ligand Steric and Electronic Effects on β-Ketiminato Neutral Nickel(II) Olefin Polymerization Catalysts
作者:Dong-Po Song、Xin-Cui Shi、Yong-Xia Wang、Ji-Xing Yang、Yue-Sheng Li
DOI:10.1021/om2010194
日期:2012.2.13
A series of novel neutral nickel complexes 3a–g and 4a–d bearing the β-ketiminato ligands [(2,6-iPr2C6H3)N═CHCHC(R)O]Ni(R′)(L) (for 3a–g, R′ = Me, L = Py, and R = tBu (3a), Ph (3b), 1-naphthyl (3c), 9-anthryl (3d), PhNMe2(p) (3e), PhOMe(p) (3f), PhCF3(p) (3g); for 4a–d, R′ = Ph, L = PPh3, and tBu (4a), Ph (4b), 1-naphthyl (4c), 9-anthryl (4d)) have been synthesized and characterized. The molecular
一系列新颖的中性镍配合物3a – g和4a – d带有β-酮亚胺基配体[(2,6- i Pr 2 C 6 H 3)N═CHCHC(R)O] Ni(R')(L) (对于3a – g,R'= Me,L = Py,并且R = t Bu(3a),Ph(3b),1-萘基(3c),9-蒽(3d),PhNMe 2(p)(3e),PhOMe(p)(3f),PhCF 3(p)(3g); 对于4a – d,R'= Ph,L = PPh 3,并且t Bu(4a),Ph(4b),1-萘基(4c),9-蒽(4d))已经合成并表征。3b – d,f,g和4a,c的分子结构X射线晶体学分析进一步证实了这一点。这些配合物用于乙烯聚合反应,系统地研究了配体的空间和电子对催化性能的影响,包括活性,分子量(MW)和所得聚乙烯的支化数。带有更大体积的配体的配合物显示出更高的活性并产生更多的支链聚乙烯。发现缺乏电子的配体增加了催化