锗烯与异氰酸多通道反应的理论计算  

Theoretical study of the multi-channel reaction mechanism for the Germylene with isocyanic acid

作　　者：韩彦霞[1] 孔超[1] 陈东平[1] 侯丽杰[1] 耿志远[2] 

机构地区：[1]陇东学院化学化工学院,庆阳745000 [2]西北师范大学化学化工学院,兰州730070

出　　处：《原子与分子物理学报》2012年第5期797-806,共10页Journal of Atomic and Molecular Physics

基　　金：陇东学院青年科技创新基金资助项目(XYZK1104)

摘　　要：采用密度泛函理论B3LYP方法研究了单重态GeH_2与HNCO的反应机理.在B3LYP/6-311++G**水平上对反应物、中间体、过渡态进行了全几何参数优化,通过频率分析和内禀反应坐标(IRC)确定中间体和过渡态,用QCISD(T)/6-311++G**方法计算了各个驻点的单点能.计算表明单重态的锗烯与异氰酸的反应有抽提氧、插入N-H键、抽提亚氨基的反应路径.采用经Winger校正的Eyring过渡态理论分别计算了1个大气压、不同温度下反应势垒较低通道的热力学及动力学性质,结果表明插入N-H键反应(GeH_2+HNCO→IM7→TS6→P2)通道在温度400 K～1400 K内,有较高的平衡常数和反应速率常数,为主反应通道,主产物为GeH_3NCO.The reaction mechanism of Germylene with isocyanic acid has been investigated by B3LYP method of density function theory ,while the geometries and harmonic of reactants, intermediates, transition states and products have been calculated at the B3LYP/6-311＋＋G＊＊ level. To obtain more precise energy result, stationary point energies were calculated at QCISD（T）/6-311＋＋G＊＊// B3LYP /6-311 ＋＋G＊＊ level. Intermediates and transition states were confirmed by the results of vibration analysis and the IRC calculation. The results indicate that the reaction of singlet state Germylene with isocyanic acid have O-atom abstraction channel, insert N-H channel, NH abstraction channel. In temperature range of from 100 to 2300 K, the statistical thermodynamics and Eyring transition state theory with Winger correction are used to study the thermodynamic and kinetic characters of the channel with low energy barrier at 1.0 Atm. The reaction GeH2＋HNCO→IM7→TS6→P2 was the main pathway with larger equilibrium constant and higher rate constant in temperature range from 400 to 1400 K, GeH3NCO was the main products.

关 键 词：锗烯 异氰酸 反应机理 活化能 过渡态 

分 类 号：O64[理学—物理化学]