AlCl_3催化1,1-二甲基-1,2,2,2-四氯二硅烷裂解机理的计算

Mechanism calculation on the decomposition of 1,1-dimethyl-1,2,2,2-tetrachlorosilane catalized by AlCl_3

采用密度泛函(B3LYP)及二级微扰(MP2)方法对AlCl3催化1,1-二甲基-1,2,2,2-四氯二硅烷裂解反应的机理进行了计算.结果表明,该二硅烷在三氯化铝催化剂作用下可以同时按2种通道进行裂解.裂解反应分3步进行,通道1的速控步为第3步,其活化能为241.656kJ.mol-1.通道2的速控步为第1步,其活化能为250.227kJ.mol-1.从速控步的活化能可知,2种反应通道进行的难易程度相差不大.裂解反应为放热反应,反应的理论产率较高.

The mechanism of the decomposition of 1,1-dimethyl-1,2,2,2-tetrachlorosilane vis the catalysis of AlCl3 was investigated by DFT and MP2 methods.The calculation results had shown that the reaction could be proceed in two channels.The reaction decomposed by three steps,the third step of the first channel was the rate determining step,and its activation energy was 241.656 kJ·mol-1.The first step of the second channel was the rate determining step,and its activation energy was 250.227 kJ·mol-1.From the activation energy of the rate determining step,we could see that the two reaction channels were both easier to proceed.The decomposition reaction was exothermic reaction and the theoretical-yield was higher.