difference: The introduction of an additional CH2 group into the bridge of ligands with two P/N units leads to a different selectivity of the corresponding chromium‐based catalysts. Whereas 1 produces an ethylene trimerization system, 2 provides an unprecedented ethylene tetramerization system that produces 1‐octene with high purity and little or no polymer side products (see scheme; DMAO=Me3Al‐depleted
                                    变化很小,差异很大:将额外的CH 2基团引入具有两个P / N单元的
配体桥会导致相应的
铬基催化剂具有不同的选择性。而1产生
乙烯三聚系统,2提供了产生1-
辛烯以高纯度和极少或没有聚合物副产物前所未有的
乙烯四聚系统(参见方案; 
DMAO =我3的Al-耗尽甲基铝氧烷)。