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含氮氧配位原子的镍催化剂是一类新型催化剂.文章以配体为犤NH=CH-CH=CH-O犦的镍催化剂为模型,用密度泛函方法(DFT)在B3LYP/LANL2MB水平上研究了该类乙烯聚合催化的反应机理.计算结果表明,催化的反应过程中,中心原子镍最先形成带空位的四边形阳离子配合物,乙烯以垂直于催化剂平面的方式占据空位,然后旋转到催化剂平面内以利于插入反应的进行;插入反应发生后,在催化剂中Ni和β-C之间形成一种氢桥键,协助新空位的形成,实现链的增长.
Nickel catalyst containing nitrogen and oxygen atoms is a new type of catalyst.In this paper, a nickel catalyst with a ligand of 犤 NH = CH-CH = CH-O 犦 was used as a model and the density functional theory (DFT) was used at B3LYP / LANL2MB level The catalytic mechanism of this kind of ethylene polymerization was studied.The results showed that the central atom of nickel formed the tetragonal cation complex with vacancy firstly in the catalytic reaction and occupied the vacancy by ethylene perpendicular to the catalyst plane and then rotated In the catalyst plane, the insertion reaction is facilitated. After the insertion reaction occurs, a hydrogen bridge is formed between Ni and β-C in the catalyst to assist the formation of new vacancies and achieve the growth of the chain.