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本文用微扰分子轨道(PMO),Hackel分子轨道(HMO)和自洽场分子轨道(PPP)方法研究了芳香酮、芳香胺、酚和含氮杂环等化合物的解离常数(pK_α)和π-电子分布的关系。结果表明对交替烃,PMO,HMO和PPP在某些情况下,有类似的平行结果。pK_α与活性原子上的电荷密度q_w有着良好的线性关系。但对芳香甲酸和含氮杂环,pK_α与q_x有反比关系。对芳香甲酸pK_α主要由偶极矩决定。而含氮杂环主要由氮原子中的孤对电子与最高充满轨道中的电子间的排斥积分所控制。
In this paper, the dissociation constants (pK_α) of aromatic ketones, aromatic amines, phenols and nitrogen-containing heterocycles were studied by means of perturbation molecular orbital (PMO), Hackel molecular orbital (HMO) π-electron distribution of the relationship. The results show that for alternative hydrocarbons, PMO, HMO and PPP have similar parallel results in some cases. pK_α has a good linear relationship with the charge density q_w on the active atom. However, there is an inverse relationship between pK_α and q_x for aromatic formic acid and nitrogenous heterocycles. The pK_α for aromatic formic acid is mainly determined by the dipole moment. The nitrogen-containing heterocycles are mainly controlled by the exclusion integral between the lone pair of electrons in the nitrogen atom and the electron in the highest filled-up orbit.