四氯化硅氢化关键反应的密度泛函理论模拟研究

The research of key reaction of SiCl_(4) hydrogenation with density functional theory simulation

本文利用Gaussian软件对四氯化硅氢化过程中的关键反应进行了理论研究,相关计算均通过密度泛函理论并采用B3LYP/6-311+G(2d,p)基组和方法进行。模拟结果表明该过程所涉及的反应遵循自由基链式机理;对各基元反应能量变化以及活化能进行比较,发现该过程的链引发为热致SiCl_(4)分子均相分解为SiCl_(3)自由基和Cl原子。SiCl_(3)自由基引导并维持后续的链式扩展过程,随后经历自由基和原子间的终止反应,生成SiHCl_(3)、SiH_(2)Cl_(2)、SiH_(3)Cl和SiH_(4)等目标产物。

The key reactions that involved in hydrogenation of SiCl_(4) were theoretically studied with Gaussian software.All calculations were performed by using Density Functional Theory at the B3LYP/6-311+G(2d,p)level.Simulationresults showed that the reactions proceeded through a radical chain mechanism.The heats and activation energies of the elementary reactions were calculated.In the initiation step,heat caused SiCl_(4) molecule to undergo homolysis to SiCl_(3) radical and Cl atom.The SiCl_(3) radical induced and maintained a radical chain sequence consisting of many propagation steps and the chain was terminated by various combinations of radicals and free atoms to produce SiHCl_(3),SiH2Cl_(2),SiH_(3)Cl and SiH_(4).