不饱和类卡宾H2C=CLiF的密度泛函研究

采用量子化学中的密度泛函方法,在B3LYP/6 311G水平上全优化得到了不饱和类卡宾H2C=CLiF的平衡构型.结果表明,不饱和类卡宾H2C=CLiF只有2种平衡构型.对这2种平衡构型之间相互转化的过渡态进行计算,求得了转化势垒.根据计算得到的微观性质,采用统计热力学及过渡态理论,研究了2种平衡构型之间相互转化的热力学及动力学性质,进而讨论了2种平衡构型在不同温度下的稳定性问题.

DEF Studies on the Unsaturated-Carbenoid H2C=CLiF

Configurations and properties of unsaturated carbenoid H2C=CLiF have been obtained by using DFT method at B3LYP/6 311G level.The results show that H2C=CLiF has two equilibrium configurations 1 and 2(Fig.3).The transition state of isomerization of 1 to 2 has also been obtained (Fig.3).Thermodynamic and kinetic properties of isomerization of 1 to 2 have been calculated according to statistical mechanics and transition state theory.Thermodynamic properties show that 1 is more stable than 2 in the temperature range of 100～1000 K,and the kinetic properties show that the rate of transformation from 2 to 1 is very fast.So 1 is the only “stable equilibrium species” existed in unsaturated carbenoid H2C=CLiF.Vibrational frequencies and infrared intensities of stable equilibrium 1 at B3LYP/6 311G level have been given.