为了研究乙酰丙酮铁(Fe(acac)3)与双亚胺基吡啶类配体组成催化体系的乙烯齐聚行为,合成由乙酰丙酮铁和3种不同结构双亚胺基吡啶配体组成的催化体系.通过比较研究3种含不同取代基配体的催化体系的乙烯齐聚性能,发现配体取代基结构与齐聚活性和齐聚产物分布有很大的关系,合适的取代基位阻及电子效应是决定催化体系活性和产物分布的重要因素.反应温度对催化体系活性和产物分布具有较大影响,随着反应温度的升高,齐聚活性降低,齐聚产物分布向低碳数方向移动;随着n(A1):72(Fe)从500增加到3000,齐聚活性先迅速增加,在”(A1):n(Fe)-2000左右时达到最大,然后呈现下降的趋势,n(A1):n(Fe)对齐聚产物的分布基本没有影响.
Three iron acetylacetonate complexes ligated with different bis (imino)pyridyl ligands were synthesized in order to analyze the oligomerization behavior of iron acetylacetonate and bis(imino)pyridyl ligands catalyst system. In comparison on the oligomerization behavior of three different substituented catalysts, catalytic activities and distribution of oligomers for bis (imino) pyridyl iron acetylacetonate complexes were greatly influenced by the structures of the ligands. The proper steric and electronic effect of the substituents were the main factors responsible for the catalytic behavior. Meanwhile, the reaction temperature significantly affected catalytic activities and oligomer distribution. The activities rapidly decreased with the increase of reaction temperature, and more low-molecular-weight products were produced. With the A1/Fe molar ratio increasing from 500 to 3 000, catalytic activities rapidly increased at first, and reached the highest activities at n(A1)/n(Fe)=2 000, then decreased slowly. The distribution of the obtained oligomers was almost invariant with the A1/Fe molar ratio.