平行苯环和夹心小基团体系间电荷转移的研究

Theoretical study of electron transfer in the system of some small group-benzene sandwich compounds

利用密度泛函理论(DFT)对两苯环和夹心小基团NO、H2O和NH+4的体系进行了电荷转移研究.通过改变两苯环间距获得不同体系的能量和平衡几何构型.在模型A和模型C中当两苯环间距分别为0.60和0.58nm时有最大稳定化能,电荷转移显著.模型B中两苯环间距为0.53nm时有最大稳定化能,但电荷转移不显著.电子转移矩阵元Vrp在B3LYP 6-31G 水平用Koopmans理论计算.在模型A中随着两苯环间距增大,Vrp随之增大.Vrp在模型C的变化趋势与模型A的正好相反.在模型B中随着两苯环间距增大,Vrp先增大后减小.

Charge transfer in some small group-benzene sandwich compounds was studied by density-functional method. Charge transfer was discussed at the equilibrium geometry. The maximum stabilization energies in model A and model C were obtained at the distance 0.60 and 0.58nm between two benzenes respectively. Besides, at these distances, there are sharp changes of charge transfer. The maximum stabilization energy was obtained at 0.53nm between two benzenes for model B. However, the change of charge transfer is hardly obvious. V_(rp) (electron transfer matrix element) was calculated by the Koopmans' theorem at the DFT/B3LYP level of theory. It was found that V_(rp) improves with the distances increase in model A and decreases in model C. In model B, V_(rp) increases firstly and then decreases.