借助于G03W程序的B3LYP方法,对Pd催化三甲基硅乙炔与溴乙烯生成4-三甲基硅-1-丁烯-3-炔历程中的反应物、中间体、过渡态以及产物的分子几何构型、能量等进行了优化,获得了反应势能面上各反应驻点的几何构型及其活化能,并确定了过渡态的结构,同时利用过渡态理论研究了其反应速率,探讨了反应机理。计算结果表明,Sonogashira反应历程中的最大吉布斯自由能出现在炔基加成阶段,△G298为150.72kJ/mol,即炔基加成为整个反应的决速步。
The density functional theory based hybrid-method B3LYP has been used to investigate the sonogashira reaction mechanism of trimethylsilylacetylene reacting with vinyl bromide. The optimized geometrical structures and energies for all stationary points and the structures of transition states were obtained through the vibration analysis. The transition state theory was used to study the rate of reac- tion. It is shown that the largest Gibbs free energy lies at the step of yne-addition, which maybe the rate determining step of the whole Sonogashira cross-coupling reaction, with the value of △G298 150.72 k J/tool.