【摘要】 在正确认识卟吩结构的基础上,选用考虑电子相关的MP2和B3LYP方法,从理论上得到质子化卟吩的S4轴,与晶体衍射实验的结果一致.进一步分析表明:分子呈更高的D2d对称性;同时证实,实验预测的动态平均的D4h构型是质子化卟吩势能面上的一个多级鞍点,其最大虚频的虚振动指向D2d构型,其他虚振动指向的均为能量较高的亚稳结构.更多还原

【Abstract】 On the basis of the correct understanding of porphine structure,the S₄ axis of protonated porphine is obtained first in theory by MP2 and B3LYP methods considering electron correlation energy,which is in agreement with crystal analysis experiments.The further analysis shows that the protonated porphine also has two C₂ axes and two σ_d planes,the total molecular symmetry is D_2d point group.Meanwhile,it is proved that the dynamically averaged D_4h configuration,which is prognosticated on the basis of experiments,is a multi-order saddle point with the largest imaginary frequency whose eigenvector corresponds to D_2d configuration,and the eigenvectors of other imaginary frequencies correspond to high-energy metastable structure.更多还原