顺式卤代硅烯异构化为卤代甲硅烷基硅烯的热力学与动力学分析  

Dynamical and Thermodynamic Studies on the Isomerization Reaction of cis-Halogeno Silylene to Halogeno Silyl(silylene)

作　　者：贝逸翎[1] 主沉浮[1] 

机构地区：[1]山东大学化学与化工学院,济南250100

出　　处：《化学学报》2008年第7期810-816,共7页Acta Chimica Sinica

基　　金：山东省自然科学基金(No.Y2001B06)资助项目

摘　　要：利用密度泛函理论(DFT)中的B3LYP方法,全参数优化了顺式卤代硅烯HXSi=SiXH(X=F,Cl,Br,I)异构化反应的反应物、产物及过渡态的几何构型,计算出了它们的振动频率、零点振动能(ZPVE)和总能量,并对它们进行了振动分析,以确定过渡态的真实性.又计算了反应的热力学函数变化、平衡常数及速率常数,比较了不同卤素对反应的影响.热力学与动力学计算结果表明,该异构化反应过程是一个放热的、且在低温下可自发进行的反应,但对于溴代硅烯和碘代硅烯而言,当温度达到1000K时,反应开始转化为非自发反应.The isomerization reactions of cis-halogeno silylene （HXSi = SiXH, X= F, Cl, Br, I） to halogeno silyl（silylene） have been studied by using the B3LYP method of density functional theory. All of the structures of the reactants, transition states and products have been optimized. The energies of the reactants, products, and transition states, zero-point vibration energies, their harmonic vibrational frequencies, and bartier energies have been calculated, and analyzed to determine the reality of the reactants, products and transition states. Then, the changes in thermodynamic functions, equilibrium constants, and rate constants for the isomerization reaction have been computed and the effects of the different halogen elements on the reactions have been compared. The result shows that the isomerization reaction processes are exothermic and have spontaneous tendency at low temperature. When the temperature increased and arrived at 1000 K, the isomerization reaction processes of bromo and iodo silico ethylenes changed to nonspontaneous process.

关 键 词：顺式卤代硅烯 异构化反应 密度泛函 自然键轨道 热力学 动力学 

分 类 号：O621.25[理学—有机化学]