The Molecular Control and Design for Chemical Reaction Mechanisms of Metal Compounds.

本文主要研究了以下三个方面的问题：（1）单重态卡宾类似物与不饱和烃的加成反应机理：用从头算分子轨道方法研究了单重态卡宾类似物XR_2（X=C，Si，Ge，Sn ; R=H，F）与乙烯的加成反应。反应机理为两步反应。CiLC-IRC分析表明过渡态具有重要的单重激发特征。(2)对顺式丁二烯和二甲硅基丁二烯的电环化反应机理进行了理论研究，用从头算分子轨道方法计算了丁二烯和1，4二甲硅基丁二烯的两种反应途径（顺旋和反旋）的过渡态。采用CiLC-IRC方法对这些反应机理进行了分析。从末端碳（或硅）原子的双自由基性质解释了顺旋和反旋机理的区别。(3)Ziegler-Natta聚合反应机理及助催化作用作为烯烃聚合的模型，本文用从头算分子轨道方法研究了乙烯和丙烯的插入机理。

We treated three subjects as shown in following ;(1) The reaction mechanisms of singlet carbene analogs into unsaturated hydrocarbon.The addition of singlet carbene analogs XR_2 (X=C, Si, Ge, and Sn ; R=H and F) into ethylene have been investigated by ab initio molecular orbital methods. The reaction mechanisms are twi-step processes. The CiLC-IRC analysis showed important singlet excitation character for the transition state.(2) Theoretical studies on the electrocyclic reaction mechanisms for s-cis butadiene and disilylbutadiene.The transition states of two reaction pathways (conrotatory and disrotatory) for butadiene and 1,4-disilylbutadiene were obtained by ab initio molecular orbital methods. These mechanisms aking the reaction pathways were analyzed by CiLC-IRC method. The difference between the conrotatory and the disrotatory mechanisms was explained from the biradical character of the terminal carbon (or silicon) atoms.(3) The Reaction Mechanisms and cocatalysis of Ziegler-Natta polymerization.As a model of olefin polymerization for a heterogeneous Ziegler-Natta catalyst, the mechanisms of the insertion of ethylene and propylene are studied by ab initio molecular orbital methods.