the oligomeric products displayed Schulz–Flory distributions with high selectivities for α-olefins (>99%). On the other hand, the highly linear polymers displayed narrow dispersities and comprised both fully saturated and unsaturated chain ends with the vinyl content (–CHCH2) found to rise with the reaction temperature. By modulating the steric hindrance exerted by the ortho-R1 substituents in the precatalyst
双核双(亚
氨基)
吡啶-
钴(II)配合物的六个实例,[1,5- 2-(CMe N)-6-(CMe N(2,6-R 1 2 -4-R 2 -C 6 H 2))C 5 H 3 N} 2(C 10 H 6)] Co 2 Cl 4(R 1 = Me,R 2 = H Co1 ; R 1 = Et,R 2 = H Co2 ; R 1 = i Pr ,R 2 = H Co3 ; R 1 = Me,R2 =我Co4 ; R 1 = Et,R 2 = Me Co5 ; R 1 = CHPh 2,R 2 = Me Co6),是由相应的双(三齿)区室
配体( L1-L6)以合理的产率制备的。Co3和Co5的分子结构显示两个N, N, N-二
氯化钴单元在1,5-
萘基连接单元周围采用反位,每个
钴中心均显示出扭曲的三角锥型几何形状。在使用MAO或
MMAO激活后,研究表明,Co1-Co6可以促进
乙烯的聚合和低聚,并具有较高的总体活性(在70°C时,Co1