含过渡金属和柔性配体催化体系的构象搜索  

Conformational Screening of the Catalyst System Containing Transition Metal and Flexible Ligand

作　　者：钟绪琴 刘振 Zhong Xuqin;Liu Zhen(School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237)

机构地区：[1]华东理工大学化工学院,上海200237

出　　处：《有机化学》2023年第2期734-741,共8页Chinese Journal of Organic Chemistry

基　　金：国家自然科学基金(No.22171084)资助项目。

摘　　要：采用密度泛函理论对含有过渡金属和柔性配体的分子进行优化时,通常只能将初始结构优化到势能面上的局部最小点,而确定反应势能面上各中间体和过渡态的最低能量构象是准确描述一个催化反应最优路径的关键.使用Cr/PCCP体系催化乙烯选择性三聚/四聚反应路径中的关键过渡态(TS1,TS2,TS3)作为分子模型,对基于Tinker软件包和CREST软件包的两种构象搜索方法进行了对比测试.使用两种构象搜索方法均成功找到了三个分子模型的最低能量构象,并且两种方法获得的构象数量总数相差不大.与基于Tinker软件包的构象搜索方法相比,使用CREST软件包进行构象搜索的计算流程更加简单,并且大大减少了计算时间.A geometry optimization on a molecular system containing a transition metal center and a flexible ligand will certainly yield a minimum on the potential energy surface(PES).However,there is no guarantee that the optimized structure is a global minimum on the PES,but a local minimum in most cases.The searching for the global minimum of each intermediate and the transition state is of crucial importance for mechanistic understanding on a specific reaction.In this work,three transition states(TS1,TS2,TS3)for the Cr/PCCP catalyzed ethylene tri-/tetramerization were selected as the molecular models,which were subjected to a sophisticated conformational search using Tinker program and CREST program,respectively.With a careful analysis,the global minimum for each of these three transition states was successfully located using either Tinker program or CREST program,and both methods generated a similar number of conformers in this study.Compared with Tinker program,the conformational screening using CREST program is more straightforward and easier to use.

关 键 词：过渡金属配合物 柔性配体 构象搜索 密度泛函理论(DFT) 

分 类 号：O641.4[理学—物理化学] O621.251[理学—化学]