过渡金属络合物催化乙烯齐聚

摘要

综述了乙烯齐聚的最新成果，重点阐述了用于乙烯齐聚的新型催化剂．讨论了烯烃高聚与齐聚催化剂的关系．烯烃高聚与齐聚的反应机理相同，差别主要在于烯烃插入与β-H消除反应的速率．第Ⅳ副族金属络合物主要催化乙烯齐聚，第Ⅲ副族金属主要催化乙烯高聚；改变茂金属催化体系的助催化剂和反应条件可得到齐聚产物．选择体积较小配体的第Ⅷ族金属络合物，有利于β-H消除得到齐聚产物．%Recent achievements in ethylene oligomerization by using transition metal complexes as cat-alysts are reviewed with emphases on the description of novel catalyst systems. The relationship be-tween the behavior of catalysts in oligomerization and polymerization has been discussed. Theoligomerization and polymerization of ethylene have readily identifiable mechanistic feature, differenceis the rate of insertion and β-H elimination. M4+ (M=Ti,Zr) complexes mainly catalyze ethyleneoligomerization, and M3+ (M = Ti, Zr) complexes catalyze polymerization. Altering the cocatalystcomposition of group Ⅳ B metallocene catalyst systems and reaction conditions leads to oligomerizationof ethylene. Group Ⅷ complexes with small volume of ligands favor the β-H elimination and oligomer-ization.