Nickel (II) complexes bearing 2-ethylcarboxylate-6-iminopyridyl ligands: synthesis, structures and their catalytic behavior for ethylene oligomerization and polymerization
作者:Xiubo Tang、Wen-Hua Sun、Tielong Gao、Junxian Hou、Jiutong Chen、Wei Chen
DOI:10.1016/j.jorganchem.2004.12.027
日期:2005.3
diffraction. In the cases of 7, 8 and 10, the ligands chelate with the nickel centers in tridentate fashion in which the carbonyl oxygen atoms coordinate with the metal centers, while the carbonyl oxygen atoms are free from coordinating with the nickel centers in 11 and 12. Upon activation with methylaluminoxane (MAO), these complexes are active for ethylene oligomerization (up to 7.97 × 105 g mol−1 (Ni) h−1
一系列的镍(II)络合物(L)的NiCl 2(7 - 9)和(L)NIBR 2(10 - 12)通过相应的2-羧酸-6-亚氨基吡啶的反应制备的配位体1 - 6与氯化镍2 ·6H 2 O或(DME)NiBr 2(DME = 1,2-二甲氧基乙烷)。所有配合物均通过红外光谱和元素分析进行表征。的固态结构7,8,10,11和12是由X射线衍射测定。在这种情况下7,8和10,配体螯合,在三齿方式的镍中心,其中所述羰基的氧原子与金属中心坐标,而羰基的氧原子是来自用在镍中心协调免费11和12。当用甲基铝氧烷(MAO)活化,这些复合物是用于乙烯低聚(高达7.97×10活性5克摩尔-1(镍)H -1为11与2个当量的PPH 3作为辅助配体)和/或聚合(1.37 ×10 4 g摩尔-1(Ni)h -1(9))。的乙烯低聚活动7 - 12在PPH的存在显着改善3作为辅助配体。讨论了配位环境和反应条件对乙烯催化行为的影响。