9,9-Dimethylxanthene-based binuclear phenoxy-imine neutral nickel(II) catalysts for ethylene homo- and copolymerization
作者:Wei-Wei Li、Hong-Liang Mu、Jing-Yu Liu、Yue-Sheng Li
DOI:10.1016/j.jorganchem.2017.03.006
日期:2017.5
Mononuclear neutral nickel catalyst Ni1 and binuclear complexes Ni2 and Ni3 based on rigid 9,9-dimethylxanthene frameworks featuring short Ni−Ni distances were synthesized, characterized and applied in ethylene (co)polymerization. Binuclear catalyst Ni2 exhibited higher activity in ethylene polymerization than corresponding mononuclear Ni1, and produce higher molecular weight polymer with a bimodal
合成了具有短Ni-Ni距离的基于刚性9,9-二甲基framework吨骨架的单核中性镍催化剂Ni 1和双核配合物Ni 2和Ni 3,并将其应用于乙烯(共)聚合中。双核催化剂Ni 2在乙烯聚合中表现出比相应的单核Ni 1更高的活性,并且产生具有双峰分子量分布的更高分子量的聚合物。催化剂Ni 2具有非常强的热稳定性,并且在93°C时仍显示出良好的活性。Ni 1产生的聚合物微观结构揭示具有多种支链类型的超支化结构,而Ni 2产物主要具有甲基支链。在共聚单体1,5-己二烯,1,7-辛二烯和10-十一碳烯酸甲酯的存在下,单核Ni 1催化活性低或掺入效率低,而双核催化剂Ni 2有效地将这些共聚单体束缚在聚合物链中,得到具有独特微结构的共聚物。